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Glucose oxidase (GOx) from Penicillium funiculosum 46.1 was purified using step-by-step ultrafiltration and it was characterized by spectrophotometric and spectrofluorometric methods. It was shown that spectra of GOx produced by P. funiculosum are typical for flavoproteins. Absorption spectrum has distinct peaks at 380 and 457 nm, excitation spectrum at 373 and 447 nm, and emission spectrum at 530 and 562 nm. The pH correlation of enzyme activity and catalytic characteristics in various buffer systems (phosphate (pH 5.0–9.0), citrate (pH 3.0–5.0), citrate-phosphate (pH 3.0–9.0), and universal (pH 3.0–9.0)) were registered. It was determined that the GOx is the most efficiently interacting with substrate (glucose) in phosphate buffer at pH 7.0 with kcat/Km = 21,825 M−1 s−1. Interaction of several different redox mediators (9,10-phenantroline-5,6-dione, 9,10-phenanthrenequinone, N-methylphenazonium methyl sulfate, ferrocene, ferrocenecarboxylic acid, α-methylferrocenemethanol, ferrocenecarboxaldehyde) with GOx from P. funiculosum was investigated by evaluation of the difference in fluorescence emission intensity of FAD(oxidized) and FADH2(reduced) forms. It was found that 9,10-phenantroline-5,6-dione and 9,10-phenanthrenequinone are the best redox mediators for this type of GOx. | non-battery |
Despite being currently under-represented in IPCC reports, PV generation represents a growing share of power generation. This Perspective argues that underestimating PV potential led to suboptimal integration measures and that specific deployment strategies for emerging economies should be developed.
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A gel polymer electrolyte based on the blend of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and fully cyanoethylated cellulose derivative (DH-4-CN) was prepared and characterized. Thermal, mechanical, swelling, liquid electrolyte retention and electrochemical properties, as well as microstructures of the prepared polymer electrolytes, were investigated using thermogravimetric analysis, electrochemical impedance spectroscopy, linear sweep voltammetry, and scanning electron microscopy. The results showed that the addition of DH-4-CN could obviously improve the conductivity of PVDF-HFP based electrolyte. The maximum ionic conductivity of 4.36mScm−1 at 20°C can be obtained for PVDF-HFP/DH-4-CN 14:1 in the presence of 1M LiPF6 in EC and DMC (1:1, w/w). The dry blend membranes exhibit excellent thermal behavior. All the blend electrolytes are electrochemically stable up to about 4.8V vs. Li/Li+ for all compositions. The results reveal that the composite polymer electrolyte qualifies as a potential application in lithium-ion battery. | battery |
Hollingsworth & Vose Co has formed a joint venture with India's Nath Group with plans to build a new mill near Aurangabad in Maharashtra. | non-battery |
The pumping loss of redox flow batteries increases dramatically when scaling up to large-area cells, and becomes a key limiting factor for engineering high-performance cell stacks. This work proposes a hierarchical interdigitated flow field design that has independently regulated distribution/collection channels to lower pumping loss and enhance mass transport: a small quantity of primary branch channels with larger section area is engineered to transport the electrolyte across the length of the entire electrode with a relatively low pressure drop, while a large number of secondary branch channels with smaller section area serve to inject the electrolyte into the adjacent porous electrode with a relatively high velocity to ensure good mass transport. The analytical and experimental methods are combined to understand the mass transport phenomena in the presented flow field. It is shown that the hierarchical interdigitated flow field can significantly reduce the pumping loss by 65.9% and increase the pump-based voltage efficiency from 73.8% to 79.1% at 240 mA cm−2 and 3.0 mL min−1 cm−2 compared with the conventional interdigitated flow field, which demonstrates that the hierarchical interdigitated flow field presents a promising solution for scaling up the high-performance redox flow batteries. | battery |
Solutions of novel fluorinated lithium dodecaborate (Li2B12F x H12−x ) salts have been evaluated as electrolytes in nonaqueous asymmetric supercapacitors with Li4Ti5O12 as negative electrode, and activated carbon (AC) as positive electrode. The results obtained with these new electrolytes were compared with those obtained with cells built using standard 1M LiPF6 dissolved in ethylene carbonate and dimethyl carbonate (EC:DMC; 1:1, v/v) as electrolyte. The specific energy, rate capability, and cycling performances of nonaqueous asymmetric cells based on these new electrolyte salts were studied. Cells assembled using the new fluoroborate salts show excellent reversibility, coulombic efficiency, rate capability and improved cyclability when compared with the standard electrolyte. These features confirm the suitability of lithium-fluoro-borate based salts to be used in nonaqueous asymmetric supercapacitors. | battery |
A coherent polyaniline (PANI)/graphene oxides (GOs)/multi-walled carbon nanotubes (MWCNTs) composite was prepared by in-situ solution polymerization as a positive electrode of supercapacitors. The orderly growth of PANI nano-dots on GOs led to the formation of the nano-ravines that can enhance ions diffusion efficiency. MWCNTs surrounded by PANI connected all components, and thus the conductivity with the increasing electron transfer rate was improved. The results showed that the electrode exhibited the outstanding electrochemical performances with the specific capacitance up to 696Fg−1 at 20mVs−1. The KOH-activated GOs/MWCNTs were used as a negative electrode to assemble an asymmetric supercapacitor (ASC). The ASC possessed an extended working potential (1.6V), a good rate capability (58% capacitance retention even after the current density being increased by 10 times), an excellent cycling stability (89% capacitance retention after 3000 cycles), and a decent average energy and power density (69Wh/kg and 6.4kW/kg). | battery |
In this paper the characteristics and performance of composite polymer electrolytes formed by dispersing selected ceramic (e.g. γ-LiAlO2, Al2O3, SiO2) powders in poly(ethylene oxide)–lithium salt (e.g. PEO–LiCF3SO3) matrices, are reported and discussed. Particular emphasis is devoted to the role of these composite electrolytes in providing the conditions for stabilizing the interface with the lithium metal electrode, as well as for enhancing the electrolyte’s overall transport properties. Finally, results based on tests of practical prototypes demonstrate that these unique properties allow the development of new types of high performance, rechargeable lithium polymer batteries. | battery |
A simplified model of mass-transport phenomena on the anodic side of direct methanol fuel cells (DMFCs) is presented, with the objective of estimating the cross-over flux in order to enable feedforward (sensorless) control of anodic concentration in DMFC systems. The effect of parameter uncertainty on the tracking error of the control system is analysed and several models for temperature dependence are proposed. Experimental data on methanol cross-over was gathered in a DMFC system, and the models were discriminated by means of nonlinear regression. The regression results and an initial test run indicate that feedforward control of anodic methanol concentration in DMFC systems is feasible.
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TNF promotes a regulated form of necrosis, called necroptosis, upon inhibition of caspase activity in cells expressing RIPK3. Because necrosis is generally more pro-inflammatory than apoptosis, it is widely presumed that TNF-induced necroptosis may be detrimental in vivo due to excessive inflammation. However, because TNF is intrinsically highly pro-inflammatory, due to its ability to trigger the production of multiple cytokines and chemokines, rapid cell death via necroptosis may blunt rather than enhance TNF-induced inflammation. Here we show that TNF-induced necroptosis potently suppressed the production of multiple TNF-induced pro-inflammatory factors due to RIPK3-dependent cell death. Similarly, necroptosis also suppressed LPS-induced pro-inflammatory cytokine production. Consistent with these observations, supernatants from TNF-stimulated cells were more pro-inflammatory than those from TNF-induced necroptotic cells in vivo. Thus necroptosis attenuates TNF- and LPS-driven inflammation, which may benefit intracellular pathogens that evoke this mode of cell death by suppressing host immune responses. | non-battery |
Recruitment of extra neural resources may allow people to maintain normal cognition despite amyloid-β (Aβ) plaques. Previous fMRI studies have reported such hyperactivation, but it is unclear whether increases represent compensation or aberrant overexcitation. We found that older adults with Aβ deposition had reduced deactivations in task-negative regions, but increased activation in task-positive regions related to more detailed memory encoding. The association between higher activity and more detailed memories suggests that Aβ-related hyperactivation is compensatory.
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New hydrophobic ionic liquids based on (fluorosulfonyl)(pentafluoroethanesulfonyl)imide ([(FSO2)(C2F5SO2)N]−, FPFSI−) anion with various oniums, including imidazolium, tetraalkyl ammonium, pyrrolidinium, and piperidinium, were prepared and characterized. Their physicochemical and electrochemical properties, including phase transitions, thermal stability, viscosity, density, specific conductivity and electrochemical windows, were extensively characterized, and were comparatively studied with the corresponding ionic liquids containing the isomeric but symmetric TFSI− ([(CF3SO2)2N]−) anion. These new FPFSI−-based ionic liquids display low melting points, low viscosities, good thermal stability, and wide electrochemical windows allowing Li deposition/dissolution. All these desired properties suggest they are potential electrolyte materials for Li (or Li-ion) batteries. | battery |
LiFePO4 has been extensively studied in recent years because of superior thermal stability for the next generation of lithium-ion batteries. Nevertheless, LiFePO4 still undergo iron dissolution at high temperature or moisture-contaminated electrolyte, and the detailed mechanism is still not clear. Few efforts have been devoted to the correlations between surface chemistry and aging mechanisms. Here, we present a direct visual observation of surface corrosion process at olivine LiFePO4, and found the direct relationship between impurity phases and LiFePO4 corrosion. By using the LiFePO4 ingot sample with a flat surface as model materials, two types of impurity phase (iron-rich and phosphorus-rich) can be clearly observed and their influences on LiFePO4 corrosion were investigated in detail by SEM, Tof-SIMS, and electrochemical Tafel analysis. Similar to the electrochemical cell mechanism in a common metal corrosion process, an oxidation–reduction mechanism was suggested at the impurity phases-relevant corrosion behavior. Iron-rich impurity phases are seriously corroded due to the lower corrosion potentials, which inhibit the corrosion of the adjacent LiFePO4 bulk. On the contrary, phosphorus-rich impurity phase is stable due to higher corrosion potentials, which evokes the serious corrosion occurring at the adjacent LiFePO4 bulk. These findings provide the deep understanding the underlying mechanism in the LiFePO4 aging. | battery |
Several methods have been investigated to enhance the cycle life of amorphous MgNi used as the negative electrode for Ni-MH batteries. The first approach involves modifying its surface composition in different ways, including the electroless deposition of a chromate conversion coating, the addition of chromate salt or NaF into the electrolyte and the mechanical coating of the particles with various compounds (e.g. TiO2). Another approach consists of developing (MgNi+AB5) composite materials. However, the cycle life of these modified MgNi electrodes remains unsatisfactory. On the other hand, the modification of the bulk composition of the MgNi alloy with elements such as Ti and Al appears to be more effective. For instance, a Mg0.9Ti0.1NiAl0.05 electrode retains 67% of its initial discharge capacity (404mAhg−1) after 15 cycles compared to 29% for MgNi. The charging conditions also have a great influence on the electrode cycle life as demonstrated by the existence of a charge input threshold below which minor capacity decay occurs. In addition, the particle size has a major influence on the electrode performance. We have developed an optimized electrode constituted of Mg0.9Ti0.1NiAl0.05 particles with the appropriate size (>150μm) showing a capacity decay rate as low as ∼0.2% per cycle when charged at 300mAhg−1. | battery |
This essay examines the public debate about the agricultural biotechnologies known as genetically modified organisms, as that debate is being carried out in its most dichotomizing forms in the United States. It attempts to reveal the power of sharply dichotomous thinking, as well as its limits. The essay draws on the work of Michel Serres, who uses the concept of the parasite to reconstruct or reframe fundamental dichotomies in western philosophy; it attempts a similar reframing of the public debates about GMOs. The purpose of such a reframing is to create possibilities for dialogue among participants that will move beyond the polarization that characterizes much of the current debate in the U.S.
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A detailed investigation of the effect of the thermal stabilizing additive, propane sultone (PS), on the reactions of the electrolyte with the surface of the electrodes in lithium-ion cells has been conducted. Cells were constructed with meso-carbon micro-bead (MCMB) anode, LiNi0.8Co0.2O2 cathode and 1.0M LiPF6 in 1:1:1 EC/DEC/DMC electrolyte with and without PS. After formation cycling, cells were stored at 75°C for 15 days. Cells containing 2% PS had better capacity retention than cells without added PS after storage at 75°C. The surfaces of the electrodes from cycled cells were analyzed via a combination of TGA, XPS and SEM. The addition of 2% PS results in the initial formation of S containing species on the anode consistent with the selective reduction of PS. However, modifications of the cathode surface in cells with added PS appear to be the source of capacity resilience after storage at 75°C. | battery |
The use of inexpensive and biodegradable deep-eutectic ionic mixtures as solvents for the electrochemical synthesis of conducting polymers could potentially improve the sustainability of these processes and reduce their economic cost. Such an unexplored approach was investigated in this communication by growing a model polymer such as polyaniline from a 1:2 mixture of choline chloride and 1,2-ethanediol (the so-called Propeline) using potentiodynamic and potentiostatic electrochemical procedures. Beyond a preparation method, cyclic voltammetry was also used to characterize the growth of the polymers. The morphology of the films, and their optical properties, were assessed ex-situ by means of scanning electron microscopy and spectroscopic measurements in the UV–vis. The polyanilines thus prepared exhibited nanoparticulated morphology and high reversibility to doping/dedoping which evidences fast charge transport across the films. Excellent conductivities higher than 50 S cm−1 were found under this approach.
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In this study, it was the first report that Bacillus sp. CCZU11-1 was used for the biotransformation of 1,3-propanediol cyclic sulfate (1,3-PDS) and its derivatives. The catalytic performance of Bacillus sp. sulfatase in the biotransformation of 1,3-PDS was significantly improved by biocatalyst permeabilization and immobilization. Using cell permeabilization, the hydrolytic activity of the whole-cell biocatalyst was increased by 3.5-fold after 1.5 h of pretreatment with 10 % (v/v) toluene at 30 °C and pH 7.0. Biotransformation of 20 mM 1,3-PDS for 24 h, 1,3-propanediol (1,3-PD) could be obtained in the yield of 97.4 % under the optimized reaction condition. Additionally, the immobilized biocatalysts, permeabilized cells entrapped in calcium alginate, and cross-linked enzyme aggregates were further employed to biotansform 1,3-PDS. Moreover, the total operational time of the immobilized biocatalysts could reach above 240 h with high conversion rate (>90 %).
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Four new functionalized ILs based on piperidinium and pyrrolidinium cations with two ether groups and TFSI− anion are synthesized and characterized. Physical and electrochemical properties of these ILs, including melting point, thermal stability, viscosity, conductivity and electrochemical stability, are investigated. All the ILs are liquids at room temperature, and the viscosities of P(2o1)2-TFSI and P(2o1)(2o2)-TFSI are 55 and 53mPas at 25°C, respectively. Behavior of lithium redox, chemical stability against lithium metal and charge–discharge characteristics of lithium batteries, are also investigated for these IL electrolytes with 0.6molkg−1 LiTFSI. Though the cathodic limiting potentials of these ILs are 0.4V versus Li/Li+, the lithium plating and striping on Ni electrode can be observed for these IL electrolytes, and these IL electrolytes show good chemical stability against lithium metal. Li/LiFePO4 cells using these IL electrolytes without additives have good capacity and cycle property at the current rate of 0.1C, and the cell using the P(2o1)(2o2)-TFSI electrolyte owns good rate property. | battery |
We replicated and extended previous research on microswitch facilitated choice making by individuals with profound multiple disabilities. Following an assessment of stimulus preferences, we taught 6 adults with profound multiple disabilities to emit 2 different responses to activate highly preferred stimuli. All participants learnt to activate both microswitches. Five participants showed a higher overall level of responding when both switches activating preferred stimuli were available concurrently. After completion of microswitch training, a choice assessment was conducted in which participants had access to 2 microswitches concurrently, with 1 connected to the most highly preferred stimulus and the other to a least preferred stimulus. Choice making behavior was shown in 3 participants and provided support for the preference assessment results. The results of the 3 remaining participants showed that both the most highly preferred and the least preferred stimuli may serve as reinforcers for microswitch activation responses. | non-battery |
The anodic deposition rate of cobalt oxide from CoCl2·6H2O is strongly affected by the type of complex agents (acetate ion (AcO−), citrate ion, EDTA) added into the deposition solutions. The oxidation potential of CoCl2·6H2O, examined by linear sweep voltammetry (LSV), is negatively shifted from ca. 1.1V to about 0.8, 0.5, and 0.2V by adding AcO−, citrate ion, and EDTA, respectively. The deposition rate of cobalt oxide is found to depend not only on the coordinating strength between Co and ligands but also on the conversion rate of the Co–L complexes (L: ligand) into the oxy-hydroxyl-Co species after electron transfer. The textural and electrochemical characteristics of resultant Co oxides, examined by X-ray photoelectron spectroscopic (XPS), scanning electron microscopic (SEM), open-circuit potential versus time, and cyclic voltammetric analyses, are also influenced by varying the complex agents. The deposition rate is the highest when the Co oxide is deposited from the precursor solution containing AcO−, which also exhibits the highest specific capacitance of ca. 230Fg−1 among all Co oxide deposits (as the oxide loading ≥0.05mgcm−2), demonstrating its most promising applicability in the electrochemical supercapacitors. | battery |
A three-dimensionally interconnected carbon nanotube/layered MoS2 nanohybrid network is reported with best-so-far rate capability and outstanding long cycle life as lithium ion battery anode. The monolayer and bilayer MoS2 ultrathin nanosheets with large surface to volume ratio facilitate fast Li ion transport further boosting high power capability, while incorporating high conductive CNT enhances the electronic conductivity and retains the structural integrity. The nanohybrid delivers discharge capacity as high as 512mAhg−1 at 100Ag−1 and 1679mAhg−1 over 425 cycles at 1Ag−1 with 96% discharge capacity retention of the initial cycle. | battery |
The salt lithium difluoromono(oxalato)borate (LiDFOB) showed some promising results for lithium-ion-cells. It was synthesized via a new synthetic route that avoids chloride impurities. Here we report the properties of its solutions (solvent blend ethylene carbonate/diethyl carbonate (3:7, mass ratio), including its conductivity, cationic transference number, hydrolysis, Al-current collector corrosion-protection ability and its cycling performance with some electrode materials. Some Al-corrosion studies were also performed with the help of our recently developed computer controlled impedance scanning electrochemical quartz crystal microbalance (EQCM) that proofed to be a useful tool for battery material investigations. | battery |
Two- and four-electrode electrochemical cells were designed for characterization studies of highly resistive non-aqueous automotive lubricant using electrochemical impedance spectroscopy (EIS). The influence of internal configuration of the impedance analyzer, the media’s temperature and properties, shielding of the cables, and the electrochemical cell geometry and arrangement on the impedance results were investigated. The most accurate EIS measurements can be made in the two-electrode configuration with active shields where a single arc at high frequencies and a complicated low frequency impedance feature were observed in complex impedance plots. When four-electrode cells were employed, the impedance load, geometry and positioning of voltage electrodes; finite resistance of the impedance analyzer; and capacitive coupling between the signal lines introduced two types of impedance measurement artifacts. A capacitive-resistive low frequency load was interpreted as a measurement artifact originating from geometry and positioning of voltage electrodes. The appearance of additional medium frequency load combining resistive, capacitive and inductive features is intrinsic to the measurement setup and is due to a combination of several instrumental and experimental factors resulting in a voltage divider effect. | battery |
A miniaturized and low-cost algal growth-inhibition assay, with Pseudokirchneriella subcapitata, based on the standard ISO 8692 and using 96-well microplates, was tested and optimized in this work, to be used as a useful tool for pollutant phytotoxicity screening. For validation, the performance of the microplate algal growth-inhibition assay was first compared with the standard flask assay for the toxicity testing of five reference toxicants (copper(II) sulfate, zinc sulfate, potassium permanganate, potassium dichromate and 3,5-Dichlorophenol) and six wastewater samples. Statistical evaluation of EC50 results from both methods demonstrated a good agreement between microplate and flask assays either in testing chemicals (r2 = 0.975, p < 0.0017) or environmental samples toxicity (r2 = 0.984, p < 0.0001). In addition, the performance of this algal microplate bioassay was also evaluated in comparison with Lemna test, ISO 20079, for phytotoxicity assessment of 27 wastewater samples from industries and treatment plants. The results showed that the algal test was more sensitive for most of the samples, but a significant agreement between both tests was observed (r2 = 0.644, p < 0.0001). In conclusion, this miniaturized test can be a good tool to include in a battery of tests for phytotoxicity screening of a wide range of chemicals and environmental samples, with the advantage of requiring low sample volumes for the test, allowing large numbers of samples to be tested, and generating low volumes of waste. | non-battery |
Publisher Summary This chapter explains the operation of the sensors and actuators used throughout a modern car. Special emphasis is placed on sensors and actuators used for power train (i.e., engine and transmission) applications since these systems normally employ the largest number of such devices. The chapter also discusses sensors found in other subsystems on modern cars. Automotive electronics have many examples of electronic control in virtually every subsystem. Modern automotive electronic control systems use microcontrollers based on microprocessors to implement almost all control functions. Each of these subsystems requires one or more sensors and actuators in order to operate. Fundamentally, an electronic control system uses measurements of the plant variable being regulated for feedback control. Temperature is an important parameter throughout the automotive system. In operation of an electronic fuel control system, it is vital to know the temperature of the coolant, the temperature of the inlet air, and the temperature of the exhaust gas oxygen sensor. | non-battery |
The increasing amount of solid waste arising from municipalities and other sources and its consequent disposal has been one of the major environmental problems in Turkey. Istanbul is a metropolitan city with a current population of around 14 million, and produces about 9000ton of solid waste every day. The waste composition for Istanbul has changed markedly from 1981 to 1996 with large decreases in waste density, much of which is related to decreased amounts of ash collected in winter. In recent years, the Istanbul region has implemented a new solid waste management system with transfer stations, sanitary landfills, and methane recovery, which has led to major improvements. In the Black Sea region of Turkey, most of the municipal and industrial solid wastes, mixed with hospital and hazardous wastes, are dumped on the nearest lowlands and river valleys or into the sea. The impact of riverside and seashore dumping of solid wastes adds significantly to problems arising from sewage and industry on the Black Sea coast. Appropriate integrated solid waste management systems are needed here as well; however, they have been more difficult to implement than in Istanbul because of more difficult topography, weaker administrative structures, and the lower incomes of the inhabitants. | non-battery |
Although human alcoholics exhibit lasting cognitive deficits, it can be difficult to definitively rule out pre-alcohol performance differences. For example, individuals with a family history of alcoholism are at increased risk for alcoholism and are also behaviorally impaired. Animal models of controlled alcohol exposure permit balanced group assignment, thereby ruling out the effects of pre-existing differences. Periadolescent male rhesus macaques (N = 5) consumed alcohol during 200 drinking sessions (M–F) across a 10-month period (mean daily alcohol consumption: 1.38 g/kg/day). A control group (N = 5) consumed a fruit-flavored vehicle during the same period. Spatial working memory, visual discrimination learning and retention and response time behavioral domains were assessed with subtests of the Monkey CANTAB (CAmbridge Neuropsychological Test Automated Battery). Spatial working memory performance was impaired in the alcohol group after 120 drinking sessions (6 mo) in a manner that depended on retention interval. The chronic alcohol animals were also impaired in retaining a visual discrimination over 24 hrs when assessed 6–8 weeks after cessation of alcohol drinking. Finally, the presentation of distractors in the response time task impaired the response time and accuracy of the chronic alcohol group more than controls after 6 months of alcohol cessation. Chronic alcohol consumption over as little as 6 months produces cognitive deficits, with some domains still affected after acute (6–8 wks) and lasting (6 mo) discontinuation from drinking. Animals were matched on alcohol preference and behavioral performance prior to exposure, thus providing strong evidence for the causal role of chronic alcohol in these deficits. | non-battery |
Esters of acrylic acid and methacrylic acid, more commonly known as acrylates and methacrylates, respectively, are key raw materials in the coatings and printing industry, with several of its chemical class used in food packaging. The results of over 200 short-term in vitro and in vivo mutagenicity studies available in the open literature have been evaluated. Despite differences in acrylate or methacrylate functionality or in the number of functional groups, a consistent pattern of test response was seen in a typical regulatory battery of mutagenicity tests. No evidence of point mutations was observed when acrylic acid or over 60 acrylates and methacrylates were investigated in Salmonella bacterial tests or in hprt mutation tests mammalian cells, and no evidence of a mutagenic effect was seen when tested in whole animal clastogenicity and/or aneuploidy (chromosomal aberration/micronucleus) studies. Consistent with the in vivo testing results, acrylic acid exhibited no evidence of carcinogenicity in chronic rodent cancer bioassays. In contrast, acrylic acid and the entire acrylate and methacrylate chemical class produced a consistently positive response when tested in the mouse lymphoma assay and/or other in vitro mammalian cell assays designed to detect clastogenicity. The biological relevance of this in vitro response is questioned based on the non-concordance of in vitro results with those of in vivo studies addressing the same mutagenic endpoint (clastogenicity). Thus, in short-term mutagenicity tests, the acrylates and methacrylates behave as a single chemical category, and genotoxicity behavior of a similar chemical can be predicted with confidence by inclusion within this chemical class, thus avoiding unnecessary testing. | non-battery |
The in situ strategy of cathode protection opportunistically uses PF6 − anions in electrolyte as chemical reagents to convert inactive precursor molecules to active electrolyte additives. With our approach, a bifunctional x(SiMe3)2 precursor replaces fluoride in the hexafluorophosphate, forming either a bidentate monoanion P(x)F4 − or a linear x(PF5 −)2 dianion, depending on the bridge x (e.g., oxalato, malonato, succinato, and catecholato). While the efficiency of these species as cathode protective agents has been demonstrated, the mechanism for their beneficial action remains unknown. In this study, several molecular precursors have been synthesized, and the topology and energetics of secondary anions were correlated with their cycling performance. Regardless of their structural motif, all such additives demonstrated improved electrochemical performance by reducing initial cathode impedance and lowering the rate of capacity fade compared to the baseline electrolyte. However, bidentate monoanions with a malonato bridge showed significant advantage over other molecular designs for mitigating the impedance rise, suggesting that structural strain in the anion is important for easing surface modification of the cathode. | battery |
Road transportation, as an important requirement of modern society, is presently hindered by restrictions in emission legislations as well as the availability of petroleum fuels, and as a consequence, the fuel cost. For nearly 270 years, we burned our fossil cache and have come to within a generation of exhausting the liquid part of it. Besides, to reduce the greenhouse gases, and to obey the environmental laws of most countries, it would be necessary to replace a significant number of the petroleum-fueled internal-combustion-engine vehicles (ICEVs) with electric cars in the near future. In this article, we briefly describe the merits and demerits of various proposed electrochemical systems for electric cars, namely the storage batteries, fuel cells and electrochemical supercapacitors, and determine the power and energy requirements of a modern car. We conclude that a viable electric car could be operated with a 50 kW polymer-electrolyte fuel cell stack to provide power for cruising and climbing, coupled in parallel with a 30 kW supercapacitor and/or battery bank to deliver additional short-term burst-power during acceleration. | battery |
Anode material Li4Ti5O12 for lithium-ion batteries has been prepared by a novel sol–gel method with oxalic acid as a chelating agent and Li2CO3 and tetrabutyl titanate [Ti(OC4H9)4] as starting materials. Various initial conditions were studied in order to find the optimal conditions for the synthesis of Li4Ti5O12. Oxalic acid used in this method functioned as a fuel, decomposed the metal complexes at low temperature and yielded the free impurity Li4Ti5O12 compounds. Thermal analyses (TG–DTA) and XRD data show that powders grown with a spinel structure (Fd3m space group) have been obtained at 800°C for 16h. SEM analyses indicated that the prepared Li4Ti5O12 powders had a uniform cubic morphology with average particle size of 200nm. The influence of synthesis conditions on the electrochemical properties was investigated and discussed. The discharge capacity of Li4Ti5O12 synthesized with an oxalic acid to titanium ratio R =1.0 was 171mAhg−1 in the first cycle and 150mAhg−1 after 35 cycles under an optimal synthesis condition at 800°C for 20h. The very flat discharge and charge curves indicated that the electrochemical reaction based on Ti4+/Ti3+redox couple was a typical two-phase reaction. | battery |
A hybrid of multi-walled carbon nanotubes (MWCNTs) anchored with SnS nanosheets is synthesized through a simple solvothermal method for the first time. Interestingly, SnS can be controllably deposited onto the MWCNTs backbone in the shape of nanosheets or nanoparticles to form two types of SnS/MWCNTs hybrids, SnS NSs/MWCNTs and SnS NPs/MWCNTs. When evaluated as an anode material for lithium-ion batteries, the hybrids exhibit higher lithium storage capacities and better cycling performance compared to pure SnS. It is found that the SnS NSs/MWCNTs hybrid exhibits a large reversible capacity of 620mAhg−1 at a current of 100mAg−1 as an anode material for lithium-ion batteries, which is better than SnS NPs/MWCNTs. The improved performance may be attributed to the ultrathin nanosheet subunits possess short distance for Li+ ions diffusion and large electrode-electrolyte contact area for high Li+ ions flux across the interface. It is believed that the structural design of electrodes demonstrated in this work will have important implications on the fabrication of high-performance electrode materials for lithium-ion batteries. | battery |
This study describes the assembly of a rechargeable seawater battery using hard carbon as the anode, seawater as the cathode, and a fast Na ion-conducting ceramic as the solid electrolyte. Two different Na ion-conducting ceramics, β″-Al2O3 and Na3Zr2Si2PO12 (NASICON), are used as the solid electrolytes in this study. The discharge capacity of the seawater battery with the NASICON solid electrolyte is 120mAhg−1 after the first cycle and over 91% coulombic efficiency after twenty cycles. However, under the same experimental conditions, the discharge capacity of the seawater battery with a β"-Al2O3 electrolyte significantly drops to 10mAhg−1 after one cycle. It is observed that the stability of NASICON in seawater is superior to that of β"-Al2O3 and impedance results of NASICON are not changed significantly compared to that of β"-Al2O3 after cycling tests. The stability of Na ion-conducting ceramics in seawater and their effects on the electrochemical performance of seawater batteries are presented and discussed. | battery |
Funding is essential to support the early stages of an academic career but isn’t the sole determinant of success. Huilin Pan discusses how personal development and supportive teams have been crucial to her development as an independent researcher.
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This study presents a brief review of Hybrid Power Sources (HPSs) for space applications to compare the results obtained for a HPS under unknown load containing pulses. The reliable technologies for energy sources and Energy Storage Systems (ESS) that can operate safety in extreme environments (very low temperature, intense radiation environments etc.) and under dynamic load demand (including load pulses) are compared based on the targets for power and energy density, efficiency, and lifetime. The pros and cons for HPS architectures and ESS topologies proposed in the literature are discussed in frame of optimization of the whole system. Two new optimization strategies were proposed to optimally operate the Fuel Cell (FC) system based on two control loops implemented based on the global optimization control of the boost DC-DC converter and the load-following control of the fuel flow rate or of the air flow rate. The comparative study performed (under constant load, dynamic load, and variable PV power) points out the advantages of one of the proposed optimization strategy in all performance indicators. For example, the gaps compared with the reference strategy are of 1.88%, 13.61 W/lpm, and 293 lpm for FC system efficiency, fuel consumption efficiency, and fuel economy, if the maximum load is considered. Also, different control methods are proposed at the ESS side to mitigate the load pulses (protecting the FC system) and regulate the DC voltage. The results obtained in this paper are discussed related to other ESS hybridizations and control solutions reported in the literature. | battery |
The enhancement of the surface alignment by magnetic field had a great theoretical and practical significance in the improvement of electrochemical capacitor. In the present study, the NiO nanowires were synthesized by liquid-phase reduction method, and the electrode was prepared within external magnetic field. The effects of magnetic field on the electrode surface and the electrochemical behavior were investigated. X-ray diffraction and scanning electron microscope studies showed that the applied magnetic field results in an orderly surface structure of the electrode, which induced an effective transfer path for the electrons and ions. Meanwhile, the orderly electrode surface improved the electrochemical capacitance, as well as decreased the internal resistance. It was found on the cyclic voltammetry and galvanostatic charge/discharge measurements that the electrode prepared with the magnetic field displays an increased capacitance (506 F g−1), high power density (135.8 W kg−1) and energy density (17.6 Wh kg−1), and improved cycle stability compared to the electrode without magnetic field. Electrochemical impedance spectroscopy results demonstrated enhanced electrochemical properties for the addition of magnetic field.
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The energy density of lithium-ion batteries can be raised by increasing the redox potential of the positive electrode. This can be done in principle by substituting oxygen in commonly used lithium transition metal oxides with the more electronegative fluorine. To synthesize the quaternary lithium transition metal fluoride LiMgFeF6 with triturile structure a sol–gel process without toxic chemicals was used. The as-synthesized LiMgFeF6 was ball milled with carbon and binder to characterize the electrochemical properties of the LiMgFeF6/carbon/binder nanocomposite against lithium metal. After 20 cycles of galvanostatic cycling a reversible specific capacity of 107 mAh g−1, which is 80% of the theoretical capacity (1 eq. Li = 133 mAh g−1), was retained. In a rate performance test up to a discharge rate of 1C the LiMgFeF6/carbon/binder nanocomposite provided a specific capacity of 64 mAh g−1. Moessbauer spectroscopy and cyclic voltammetry confirmed the electrochemically active redox couple Fe3+/Fe2+ during cycling against lithium metal. Structural changes of the trirutile structure after lithium insertion have been investigated by X-ray powder diffraction. | battery |
Understanding inter- and intraspecific variation in parental care has been an important focus in studies of avian behaviour and evolution. Unfortunately, typical methods for quantifying parental care, such as field observation and video recordings, can be extremely time-consuming. Here, we demonstrate that utilizing behavioural analysis software, such as EthoVision XT, can reduce time required for video data extraction by 37−69 %. This method is highly accurate; results and error rates did not differ from those of manual observation. We suggest this method could be beneficial and time-saving for studies analyzing large amounts of video recordings.
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The goal of this study is to evaluate the effect of crime and discipline on graduation rates in higher education. Using national data on more than 1250 public and private non-profit institutions that were drawn from the Integrated Postsecondary Education Data System, the results reveal that more violence on and around campus is associated with lower 4-year graduation rates, whereas higher rates of disciplinary actions regarding alcohol, drugs, and weapons are associated with higher graduation rates. Furthermore, the findings suggest that utilizing the student conduct system rather than the criminal justice system to address minor offenses is more likely to lead to student success. This study contributes to the growing literature on college effectiveness and the influence of institutional structures and organizational policies on student achievement. The results of this study suggest that violent crime, institutional conduct systems, and campus police departments warrant further investigation.
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Numerical simulation of sediment transport is a coupled problem based on computation of profiles of water velocity and suspended sediment concentration. Effects of the water velocity profile and turbulent pulsation on vertical motion of suspended particles are emphasized in this study. Explanation of amplified sediment deposit in zones of separated flow near both natural and manmade bottom irregularities (like walls of shipping channels) is given. A semi-empirical approach to determination of long-term sediment deposit/erosion is suggested. | non-battery |
Since dependency on fossil fuels and nuclear energy has become a main global concern, the South Korean government has made significant efforts for the diffusion and vitalization of renewable energy generation facilities. One of the notable efforts for renewable energy is the government's and research institutes’ provision of natural resource maps. Although these maps are useful for the diffusion of renewable energy generation systems, the economic feasibility of these systems can be affected by various factors (e.g., cost of the components in the systems or the characteristics of national electricity demand). Therefore, the current study investigates the economic feasibility of renewable energy generation systems in 17 selected cities in South Korea using information on the currently considered components and the hybrid optimization of multiple energy resources (HOMER) software. Based on the simulation results, the optimal configurations for the cities are introduced, the potentiality of utilizing renewable energy resources in the cities evaluated, and the renewable energy resources ranked for each city. Among the suggested cities, Jeju and Incheon are nominated as two promising locations for utilizing renewable energy resources. Moreover, this study presents the general economic feasibility maps for South Korean cities, as well as discusses both implications and limitations. | battery |
There is mounting evidence supporting the effectiveness of task-shifted mental health interventions in low- and middle-income countries (LMIC). However, there has been limited systematic scale-up or sustainability of these programs, indicating a need to study implementation. One barrier to progress is a lack of locally relevant and valid implementation measures. We adapted an existing brief dissemination and implementation (D&I) measure which includes scales for acceptability, appropriateness, feasibility and accessibility for local use and studied its validity and reliability among a sample of consumers in Ukraine. | non-battery |
The spread of severe acute respiratory syndrome coronavirus 2, taking on pandemic proportions, is placing extraordinary and unprecedented demands on healthcare systems worldwide. The increasing number of critical patients who, experiencing respiratory failure from acute respiratory distress syndrome, need respiratory support, has been leading countries to race against time in arranging new Intensive Care Units (ICUs) and in finding affordable and practical solutions to manage patients in each stage of the disease. The simultaneous worldwide emergency caused serious problems for mechanical ventilators supply. This chaotic scenario generated, indeed, a frenetic race to buy life-saving ventilators. However, the variety of mechanical ventilators designs, together with the limitations in time and resources, make the decision-making processes on ventilators procurement crucial and not counterbalanced by the evaluation of devices quality. This paper aimed at offering an overview of how evidence-based approach for health technologies evaluation, might provide support during Corona Virus Disease 2019 (COVID-19) pandemic in ICUs management and critical equipment supply. We compared and combined all the publicly available indications on the essential requirements that ICU ventilators might meet to be considered acceptable for treating COVID-19 patients in severe to critical illnesses. We hope that the critical analysis of these data might help readers to understand how structured decision-making processes based on evidence, evaluating the safety and effectiveness of a given medical device and the effects of its introduction in a healthcare setting, are able to optimize time and resources allocation that should be considered essential, especially during pandemic period.
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Introduction: REM sleep behavior disorder (RBD) is strongly associated with synucleinopathy and is caused by REM sleep without atonia (RSWA), the loss of normal muscle atonia during REM sleep. We aimed to determine whether RSWA severity was associated with cognitive functioning in RBD. Materials and methods: Both idiopathic (iRBD) and symptomatic RBD (sRBD) patients completed two cognitive batteries: CNS Vitals Signs (CNS-VS) and Useful Field of View (UFOV). All subjects underwent PSG and their muscle (SM: submentalis; AT: anterior tibialis) tone during REM sleep was visually and automatically scored. Group differences between sRBD and iRBD were then compared, and regression models fit to determine the relationship of RSWA and dependent cognitive measures. Results: Twenty iRBD and 10 sRBD participated. Demographics were similar between groups. Deficits on cognitive testing were observed on CNS-VS in processing speed (p = 0.014) and psychomotor speed (sRDB < iRBD, p = 0.019) and on Total UFOV and subtests 2 and 3 (sRBD > iRBD, all p < 0.002). sRBD patients had greater combined phasic and tonic RSWA in SM (p = 0.026) and longer mean phasic burst duration (p = 0.03). Regression analyses demonstrated that SM RSWA independently predicted overall CNS-VS Neurocognitive Index (NCI) (F = 4.5, p = 0.006), adjusting for age, gender, depressive symptoms (Zung score), and sleep disturbances (PSQI), and this relationship also remained significant in the iRBD group after excluding sRBD patients (F = 3.5, p = 0.03). Conclusion: SWA is predictive of lower overall cognitive performance in patients with RBD. Acknowledgements: The project described was supported by the National Institute on Aging (P50 AG016574), and through Grant Number 1 UL1 RR024150-01. The content is solely the responsibility of the authors. | non-battery |
Herein, we present a new strategy for the mass production of high-quality reduced graphene oxide (RGO) with a surface area of 354 m2 g−1 using high pressure hydrogen as a reducing agent under hydrothermal conditions. The high pressure used is solely generated from the packing of the gas cylinder itself and a pressure meter could simply fulfil the role of monitoring pressure. The reduction process is green without chemical wastes produced. Comparing to other reported methods, the significant advancements of our strategy lie not only in the high-quality RGO with high C/O ratio, conductivity and surface area, but also in the most environment-friendliness and cost-effectiveness, which make the large scale fabrication feasible. Moreover, clean noble metal nanocrystals such as Pt could be easily in situ deposited onto the surface of RGO nanosheets when noble metal salts are introduced into the system. In particular, the prepared RGO and Pt/RGO show exceptional electrochemical performances in supercapacitors and lithium oxygen batteries because of their clean electrochemical surface, good conductivity and large surface area. Our results reveal that the obtained RGO have a specific capacitance of 884.4 F g−1 at a current density of 0.5 A g−1, and the Pt/RGO electrode can deliver discharge–charge capacities of 1000 mAh g−1 for 40 cycles with a high round-trip efficiencies of 74.9% at 50 mA g−1 when used as Li–O2 battery electrodes. | battery |
MgTi, Mg0.5Ni0.5Ti and MgTi0.5Ni0.5 alloys doped with 10wt.% Pd were prepared by high energy ball milling and evaluated as hydrogen storage electrodes for Ni–MH batteries. X-ray diffraction analyses indicated that the Mg0.5Ni0.5Ti and MgTi0.5Ni0.5 alloys could be monophased or composed of a nanoscale mixture of MgTi+NiTi and MgTi+MgNi phases, respectively. Their hydrogen storage characteristics were investigated electrochemically in KOH electrolyte. No activation step was observed during the cycling of the Mg–Ti–Ni electrodes in contrast to that observed with the MgTi electrode. The highest hydrogen discharge capacity was obtained with the MgTi0.5Ni0.5 electrode (536mAhg−1) compared to 401 and 475mAhg−1 for the Mg0.5Ni0.5Ti and MgTi electrodes, respectively. The ternary Mg–Ti–Ni alloys showed a better cycle life with an average capacity decay rate per cycle lower than 1.5% compared to ∼7% for the binary MgTi electrode. The Mg–Ni–Ti electrodes also displayed a much higher discharge rate capability than the binary MgTi electrode, especially with the Mg0.5Ni0.5Ti electrode. The origin of this was established on the basis of the anodic polarization curves, where a substantial decrease of the concentration overpotential (reflecting a higher hydrogen diffusivity) was observed for the Mg0.5Ni0.5Ti electrode. | battery |
Objectives The purpose of this review is to critically evaluate the available evidence from the published scientific literature on dementia care and service provision in rural and remote settings from the perspective of formal/paid caregiving, in order to assess the current state of knowledge, identify policy and practice implications, and make recommendations for future research. Methods A systematic review of the literature indexed in ISI Web of Knowledge, PsychInfo, Medline, Healthstar, CINAHL, EMBASE, and Sociological Abstracts was conducted. Data were extracted from papers meeting inclusion criteria: peer-reviewed papers that focused on dementia or Alzheimer's disease (AD), examined care or service provision in relation to persons with AD or dementia, and relevant to rural or remote care or services. Results The search identified 872 articles for review, reduced to 72 after removing duplicates and articles not meeting criteria. Of the 72 remaining, 46 are included in this current review focusing on formal or paid care. A future review will focus on the 26 studies on informal/unpaid care. Six themes that correspond to the current state of knowledge in rural dementia care in the 46 included studies were: diagnostic processes, service provision, service models and programs, staff education and support needs, use of technology, and long-term care. Conclusions Despite the growing body of evidence over the 20 years covered by this review, much of the research is descriptive and/or based on small sample sizes, and distributed across the care continuum. Hence the body of evidence on which to base policy and program decisions remains limited. More research is needed that would support the development of comprehensive rural dementia care models. | non-battery |
Nowadays nickel-rich LiNixCoyMn1-x-yO2 (0.5 < x < 1) cathode materials attract great research interests due to their high specific capacity in lithium ion batteries. However, poor cycling performance and serious safety concerns trade off their benefits. Here, we present an effective etching-induced coating strategy for surface modification of LiNi0.8Co0.1Mn0.1O2 cathode materials by LiAlO2. Hydrolysis of AlCl3 creates H+ to etch the hydroxide precursor of LiNi0.8Co0.1Mn0.1O2 and to induce oriented deposition of Al(OH)3 layer on surface of the hydroxide precursor, which is transformed into uniform γ-LiAlO2 coating on the LiNi0.8Co0.1Mn0.1O2 particles after the subsequent lithium impregnating and annealing. The 2.2 wt% LiAlO2-coated LiNi0.8Co0.1Mn0.1O2 cathode delivers a high rate capacity of 135.2 mAh g−1 at 10 C and long cyclability with capacity retention of 85.8% after 200 cycles at 0.5 C. In addition, the thermal stability of LiAlO2-coated LiNi0.8Co0.1Mn0.1O2 is significantly improved. The enhanced battery performances are due to partial Al3+ doping and Li+ conductive LiAlO2 coating layer that provides well-connected networks for Li+ transport, improves the structural stability and prevents core materials from the attack by side products. | battery |
Summary The purpose of this study was to examine the physiological correlates of the Yo–Yo intermittent recovery test level 1 (Yo–Yo IR1) in basketball players. Twenty-two male basketball players (means±S.D., body mass 72.4±11.4kg, height 181.7±6.9cm, age 16.8±2.0 years) were tested for maximal oxygen uptake (VO2max), ventilatory threshold (VT) and running economy (RE) on a motorized treadmill. Lower limb explosive strength and anaerobic-capacity was assessed using vertical jumps (CMJ), 15m shuttle running sprint (15mSR) and line drill (LD), respectively. The same test battery was replicated after an experimental basketball game in order to assess selective effect of fatigue on physical performance. Pre to post-game CMJ (40.3±5.7 versus 39.9±5.9cm) and 15mSR (5.80±0.25 versus 5.77±0.22s) performances were not significantly different (p >0.05). LD performance decreased significantly post-game (from 26.7±1.3 to 27.7±2.7s, p <0.001). Yo–Yo IR1 performances (m) were significantly related to VO2max (r =0.77, p =0.0001), speed at VO2max (r =0.71, p =0.0001) and %VO2max at VT (r =−0.60, p =0.04). Yo–Yo IR1 performance was significantly correlated to post-game LD decrements (r =−0.52, p =0.02). These findings show that Yo–Yo IR1 may be considered as a valid basketball-specific test for the assessment of aerobic fitness and game-related endurance. | non-battery |
Renewable energy technologies do not always employ sustainable resources. The scarcity of cobalt supply must be addressed in transportation electrification.
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The effect of bismuth (Bi) for both VO2 +/VO2+ and V3+/V2+ redox couples in vanadium flow batteries (VFBs) has been investigated by directly introducing Bi on the surface of carbon felt (CF). The results show that Bi has no catalytic effect for VO2 +/VO2+ redox couple. During the first charge process, Bi is oxidized to Bi3+ (never return back to Bi metal in the subsequent cycles) due to the low standard redox potential of 0.308V (vs. SHE) for Bi3+/Bi redox couple compared with VO2 +/VO2+ redox couple and Bi3+ exhibit no (or neglectable) electro-catalytic activity. Additionally, the relationship between Bi loading and electrochemical activity for V3+/V2+ redox couple was studied in detail. 2wt% Bi-modified carbon felt (2%-BiCF) exhibits the highest electrochemical activity. Using it as negative electrode, a high energy efficiency (EE) of 79.0% can be achieved at a high current density of 160mA/cm2, which is 5.5% higher than the pristine one. Moreover, the electrolyte utilization ratio is also increased by more than 30%. Even the cell operated at 140mA/cm2 for over 300 cycles, the EE can reach 80.9% without obvious fluctuation and attenuation, suggesting excellent catalytic activity and electrochemical stability in VFBs. | battery |
Many enterprises have been devoting a significant portion of their budget to product development in order to distinguish their products from those of their competitors and to make them better fit the needs and wants of customers. Hence, businesses should develop product designing that could satisfy the customers’ requirements since this will increase the enterprise’s competitiveness and it is an essential criterion to earning higher loyalties and profits. This paper investigates the following research issues in the development of new digital camera products: (1) What exactly are the customers’ “needs” and “wants” for digital camera products? (2) What features is more importance than others? (3) Can product design and planning for product lines/product collection be integrated with the knowledge of customers? (4) How can the rules help us to make a strategy during we design new digital camera? To investigate these research issues, the Apriori and C5.0 algorithms are methodologies of association rules and decision trees for data mining, which is implemented to mine customer’s needs. Knowledge extracted from data mining results is illustrated as knowledge patterns and rules on a product map in order to propose possible suggestions and solutions for product design and marketing. | non-battery |
Much work has focused on the effects of metal-contaminated sediment on benthic community structure, but effects on ecosystem functions have received far less attention. Decomposition has been widely used as an integrating metric of ecosystem function in lotic systems, but not for lentic ones. We assessed the relationship between low-level sediment lead (Pb) contamination and leaf-litter decomposition in a lentic system. We measured 30-day weight loss in 30 litter-bags that were deployed along a Pb-contamination gradient in a cypress-forested lake. At each deployment site we also quantified macrobenthos abundance, dissolved oxygen, water depth, sediment organic content, sediment silt/clay content, and both total sediment and porewater concentrations of Cd, Cu, Ni, Pb and Zn. Principal components (PC) analysis revealed a negative relationship between Pb concentration and benthic macroinvertebrate abundance, and this covariation dominated the first PC axis (PC1). Subsequent correlation analyses revealed a negative relationship between PC1 and percent leaf-litter loss. Our results indicate that leaf-litter decomposition was related to sediment Pb and benthic macroinvertebrate abundance. They also showed that ecosystem function may be affected even where sediment Pb concentrations are mostly below threshold-effects sediment quality guidelines—a finding with potential implications for sediment risk assessment. Additionally, the litter-bag technique used in this study showed promise as a tool in risk assessments of metal-contaminated sediments in lentic systems. | non-battery |
Lithium-sulfur battery is one of the most promising alternative power sources, but the polysulfide shuttle between the anode and cathode induces low Coulombic efficiency, low utilization of the sulfur cathode, and severe degradation of cycle life. Herein, the polysulfide shuttle was tuned by the loading of sulfur and electrolyte in a Li-S cell. A lithium-sulfur cell with a high initial discharge capacity of 1053 mAh g−1 at a high rate of 1 C and an ultralow decay rate of 0.049%/per cycle during 1000 cycles was obtained by using carbon nanotube@sulfur cathode and suppressing polysulfide shuttle to a shuttle factor of 0.02 by matching the sulfur/electrolyte loading. The use of matching the sulfur/electrolyte loading is a facile way to tune the shuttle of polysulfide, which provides not only new insights to the energy chemistry of Li/S batteries, but also important principle to assemble a Li/S cell with recommend loading for their commercialization application in portable mobile devices and electric vehicles. | battery |
One of the most critical factors for lifetime and operability of ad-hoc and sensor networks is the limited amount of available energy. To this respect, minimizing the interference in the network (i.e., the overlapping of signals at network nodes) has certainly a positive effect, because it induces a reduction of the number of conflicting transmissions, and then results in an overall saving of energy consumption. Along this direction, in this paper we study the computational hardness of several interference minimization problems which arise while supporting some classic network communication patterns such as broadcasting (one-to-all), gossiping (all-to-all), and symmetric gossiping (symmetric all-to-all). In particular, concerning the non-approximability results, we prove that for any of the above communication patterns, the prominent problem of minimizing the maximum interference experienced by any node in the network is hard to approximate within better than a logarithmic factor, unless NP admits slightly superpolynomial time algorithms. On a positive side, we show that any approximation algorithm for the problem of minimizing the total transmission power assigned to the nodes in order to guarantee any of the above communication patterns, can be transformed, by maintaining the same performance ratio, into an approximation algorithm for the problem of minimizing the total interference experienced by all the nodes in the network. | non-battery |
In this paper, a series of sulfonated poly(ether ether ketone) (SPEEK) hybrid membrane doped by the different amount of sulfonated graphene oxide (SGO) nanosheets are prepared by solution-casting method. The membrane structure, physicochemical property and cell performance of vanadium redox flow battery (VRB) have been characterized through FT-IR, SEM, XPS, and single-cell test system, etc. The incorporation of SGO in SPEEK improves the water uptake, ion exchange capacity and proton conductivity of the hybrid membrane, and effectively reduces the swelling degree and the vanadium ion permeability. In the single cell performance test, the energy efficiency of the SPEEK/SGO-3 hybrid membrane is 81.1%, which is higher than that of SPEEK (76.0%) and Nafion 117 membrane (73.8%). And, a longer self-discharge time (56.6 h) against Nafion 117 (23.5 h) and SPEEK (32.8 h) membrane is shown. In addition, the incorporated SGO nanofillers don't improve the chemical stability of SPEEK membrane soaked by 1.5 M V5+ solution although they block the vanadium ion permeation. Then, the durability for SPEEK/SGO hybrid membranes should be further explored for VRB system. | battery |
In order to achieve a profound understanding of the production process of electrodes for lithium-ion batteries, methods to determine the (intermediate) product quality are a necessity. Therefore, a new, fast and easy to use two point method to determine the relative resistivity of dry electrodes has been established. The method is used to determine process-induced changes in the electrode’s structure. A materials testing machine is used to ensure a homogeneous and constant mechanical stress during the analysis. By applying a direct current and measuring the voltage drop the electron transport characteristic along the whole electrode cross-section, taking all battery relevant resistances into account, can be determined. The result is an easy to compare relative resistivity value including coating resistance, contact resistance between coating and adhering current collector as well as the contact resistances between sample and probe. Process-induced changes are clearly visible in the results. The influence of the main testing parameters – contact stress and applied current – is determined. To cross-check the results, an established ‘powder probe’ method is used to confirm the relative resistivity changes caused by calendering. Slight calendering of LiNiMnCoO2 cathodes leads to an increase in electrode resistivity as conductive pathways are broken by the applied shear forces. However, increasing the cathode density to 2.95g/cm3 decreases resistivity by one third compared to uncalendered electrodes by re-establishing and shortening electrical pathways. Furthermore, a relative resistivity of anodes produced with a high energy powder mixing step is measured and shows that applying too much stress to the carbon black leads to a loss in long range conductivity, resulting in electrodes with an increased resistivity of up to 50%. | battery |
Flexible Li-ion batteries have shown great promise in powering wearable electronic devices due to their high energy/power densities and long cycling time. However, coordinating the promising electrochemical performance and flexibility for different applications is still a big challenge. Herein, we report a highly conductive graphene-modified mesoporous anatase TiO2 (M-TiO2-GS) hierarchical film electrode for flexible Li-ion battery anode via a two-step vacuum filtration method. In such a hierarchical film electrode, the down-layer composed of bare graphene component provides ideal mechanical flexibility and electronic conductivity, and the hybrid top-layer composed of both graphene and active M-TiO2 guarantees effective Li+ and electrons transport pathways and acts as the active layer for energy storage. The designed M-TiO2-GS film electrode delivers a reversible capacity of 205 and 76 mAh g−1 at rates of 0.5C and 20C, respectively, and high capacity retention of ∼70.5% after 3500 cycles at 5C. When packed in flexible cells, the M-TiO2-GS electrode can also maintain a highly reversible capacity and outstanding cycling stability in both flating and benting conditions. This work may provide a promising anode candidate for the next-generation flexible LIBs and the developed two-step filtration method can be readily applied to other flexible electrodes. | battery |
Municipal waste landfills contain numerous sources of mercury which could be emitted to the atmosphere. Their generation of methane by anaerobic bacteria suggests that landfills may act as bioreactors for methylated mercury compounds. Since our previous study at a single Florida landfill, gaseous inorganic and methylated mercury species have now been identified and quantified in landfill gas at nine additional municipal landfills in several regions of the US. Total gaseous mercury occurs at concentrations in the μgm−3 range, while methylated compounds occur at concentrations in the ngm−3 range at all but one of the landfill sites. Dimethylmercury is the predominant methylated species, at concentrations up to 100ngm−3, while monomethyl mercury was generally lower. Limited measurements near sites where waste is exposed for processing (e.g. working face, transfer areas) suggest that dimethylmercury is released during these activities as well. Although increasing amounts of landfill gas generated in the US are flared (which should thermally decompose the organic mercury to inorganic mercury), unflared landfill gas is a potentially important anthropogenic source of methylated mercury emissions to the atmosphere. | non-battery |
With the limited but ongoing usage of perfluorooctane sulfonate (PFOS), the health effects of both PFOS and its alternatives are far from being understood. Long-term potentiation (LTP) was evaluated in rats after exposure to PFOS and its alternatives, aiming to provide some evidence about their potential to affect cognitive ability. Different dosages of PFOS and alternative chemicals, including perfluorohexane sulfonate (PFHxS), perfluorobutane sulfonate (PFBS) and chlorinated polyfluorinated ether sulfonate (Cl-PFAES), were given to rats via acute intracerebroventricular injection. The field excitatory postsynaptic potential (fEPSP) amplitude of the input/output functions, paired-pulse facilitations, and LTP in vivo were recorded. PFOS and its alternatives inhibited LTP in varying degrees, without significant effects on the normal synaptic transmission. In addition, PFHxS and Cl-PFAES exhibited comparable potential to PFOS in disturbing LTP. The results suggested that acute exposure to PFOS and its alternatives impaired the synaptic plasticity by a postsynaptic rather than a presynaptic mechanism. Besides, the fEPSP amplitude of the baseline was reduced by Cl-PFAES but not by other compounds, indicating that Cl-PFAES might act in a different mode. Providing some electrophysiological evidence and the potential mechanism of the neurotoxicity induced by PFOS and its alternatives, the present study addresses further evaluation of their safety and health risks.
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Invasive crayfish are spreading rapidly across Europe, where they are replacing the native crayfish species and impacting negatively on some other biota. Freshwater crayfish and many benthic fishes share similar habitat and food requirements and hence potentially compete for resources. In this study, we investigated impacts of the introduced signal crayfish (Pacifastacus leniusculus) on fish in stony littoral habitats of two large boreal lakes. We compared the littoral fish community composition and the densities of two common benthic fish species between sites with and without crayfish. To evaluate whether signal crayfish share the same food resources as benthic littoral fish or change their feeding habits, we used mixing models and trophic niche estimates based on analyses of stable isotopes of carbon and nitrogen. Both the community composition of littoral fish and the densities of benthic fish species were similar at sites with and without signal crayfish. Even though stable isotope signatures indicated strong dietary overlap between crayfish and benthic fish, the use of food sources and trophic niche widths of fish were not noticeably different between crayfish sites and non-crayfish sites. Our results suggest that, at current densities, the non-native signal crayfish does not have significant impacts on benthic fish in the stony littoral habitats of large boreal lakes.
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A fluorinated electrolyte mixture, containing 1 M LiPF6/fluoroethylene carbonate:bis (2,2,2-trifluoroethyl) carbonate (1:1 w:w) with prop-1-ene-1,3-sultone as an electrolyte additive exhibited promising cycling and storage performance in Li(Ni0.4Mn0.4Co0.2)O2/graphite pouch type Li-ion cells tested to 4.5 V. The prop-1-ene-1,3-sultone additive was added to help control gas evolution in the fluorinated electrolyte cells, which was improved but still problematic even with the additive. Cells with the fluorinated electrolyte demonstrated higher impedance in early cycles compared to cells with carbonate solvents and state of the art additives. Symmetric cells were used to show this high impedance originated at the negative electrode/electrolyte interface. Nevertheless, in charge–discharge cycling tests to 4.5 V, cells with the fluorinated electrolyte and 1, 2 or 3% prop-1-ene-1,3-sultone additive, outperformed all non-fluorinated electrolytes with all additives tested. With further work, these, or other fluorinated carbonates, coupled with appropriate additives, may represent a viable path to NMC/graphite cells that can operate to 4.5 V and above. | battery |
Redox flow batteries (RFBs) are enjoying a renaissance due to their ability to store large amounts of electrical energy relatively cheaply and efficiently. In this review, we examine the components of RFBs with a focus on understanding the underlying physical processes. The various transport and kinetic phenomena are discussed along with the most common redox couples. | battery |
Publisher Summary Welding in the context of this chapter is the joining of two or more pieces of metal so that the parts to be joined merge with one another forming a homogeneous whole across the connection. Welding a metal requires the introduction of energy that can be as heat directly or in a form that will convert to heat where it is required. The chapter describes the principal features of the welding processes applied to the materials that are most commonly used in structural, mechanical, and process plant engineering—namely, steels and aluminum alloys. It reviews manual metal arc welding, submerged arc welding, and gas shielded welding. In manual metal arc welding, the welder holds in a clamp or holder, a length of steel wire, coated with a flux consisting of minerals, called a welding electrode or rod; the holder is connected to one pole of an electricity supply. The metal part to be welded is connected to the other pole of the supply and as the welder brings the tip of the rod close to it, an arc starts between them. Submerged arc welding uses a continuous bare wire electrode and a separate flux added over the joint separately in the form of granules or powder. The arc is completely enclosed by the flux so that a high current can be used without the risk of air entrainment or severe spatter but otherwise the flux performs the same functions as the flux in manual metal arc welding. | non-battery |
The self-discharge of Zn anode material is identified as a main factor that can limit the energy density of alkaline Zn–air batteries. Al2O3 has most positive effect on controlling the hydrogen evolution reaction accompanied by corroding Zn anode among various additives. The overpotential for hydrogen evolution is measured by potentio-dynamic polarization analysis. Al-oxide with high overpotential for hydrogen evolution reaction is uniformly coated on the surface of Zn powders via chemical solution process. The morphology and composition of the surface-treated and pristine Zn powders are characterized by SEM, EDS, XRD and XPS analyses. Aluminum is distributed homogeneously over the surface of modified Zn powders, indicating uniform coating of Al-oxide, and O1s and Al2p spectra further identified surface coating layer to be the Al-oxide. The Al-oxide coating layer can prevent Zn from exposing to the KOH electrolyte, resulting in minimizing the side reactions within batteries. The 0.25 wt.% aluminum oxide coated Zn anode material provides discharging time of more than 10 h, while the pristine Zn anode delivers only 7 h at 25 mA cm−2. Consequently, a surface-treated Zn electrode can reduce self-discharge which is induced by side reaction such as H2 evolution, resulting in increasing discharge capacity. | battery |
Hydrolysis of organic titanate was used to modify γ-MnO2 to produce a TiO2/MnOx composite as a new anode material with enhanced electrochemical properties for lithium ion battery. The composition, structure, valence state as well as the lithium storage mechanism of the composite have been carefully studied with inductively coupled plasma (ICP) elemental analysis, X-ray diffraction(XRD), electron microscopy, X-ray photoelectron spectroscopy (XPS) and solid-state nuclear magnetic resonance (NMR) spectroscopy. The electrochemical measurement shows that the specific capacity of the composite stays above 972mAh/g for 100 cycles at a current rate of 100mA/g, which is much better than γ-MnO2. The significant improvement can be ascribed to the involvement of both insertion and conversion lithium storage mechanisms owing to the incorporation of a small amount of TiO2 (∼5%) to MnO2, as well as the presence of Mn2O3 in the composite. This new strategy is expected to be extended to improve the electrochemical properties of other metal oxides for lithium ion battery applications. | battery |
All-solid-state sodium batteries are attractive due to the abundance of sodium and advantageous for safe battery operation by avoiding flammable organics and liquids and suppressed dendrite formation. Currently, the lack of a chemically stable sodium solid electrolyte with high ion conductivity at room temperature is one of the challenges for future development of sodium batteries. Herein, we present a NaxCoO2/Nasicon/Na thin-film model sodium solid-state battery using a Sc-substituted Nasicon solid electrolyte with a high ionic conductivity of 4 × 10−3 S cm−1. The battery shows a high specific capacity of 150 mAh g−1 at room-temperature and discharge rates of up to 6C. Excellent chemical stability of this solid electrolyte at high voltages of up to 4.2 V increases the accessible sodium (de)intercalation range and battery capacity. Direct extraction of the interface resistances between the electrode materials of the thin-film model cell using electrochemical impedance spectroscopy gives a unique opportunity of correlation the electrochemical performance with properties of electrode materials and their interfaces. | battery |
The synthesis of solid electrolytes with high ionic conductivity and the design of electrode interface with preferable compatibility are critical to realize the bulk-type application of all-solid-state batteries. In order to realize the superior electrochemical performance, argyrodite Li6PS5Cl is a promising solid electrolyte in all-solid-state batteries due to high ionic conductivity and electrochemical stability. Meanwhile, the solution reprecipitation is a valid process providing intimate ionic contact between electrodes and electrolytes to mitigate the interface incompatibility. Here, a wet-slurry process by dispersing active material (LiNi0.8Co0.1Mn0.1O2), solid electrolyte (Li6PS5Cl), binder (ethyl cellulose) and conductive additives (carbon black) in anhydrous ethanol is developed to fabricate cathode. The effect of different contents of the binder in the composite cathodes on the electrochemical performance is investigated. The all-solid-state battery with a composite cathode containing 1 wt% of ethyl cellulose shows a reversible discharge capacity of 111.7 mAh g−1 at 30 °C and its capacity retention is approximately 89.7% after 100 cycles. This work demonstrates that the fast ion migration and stable interface between active particles and solid electrolyte enabled by optimum content of chemically compatible binder are critical to the electrochemical performance of all-solid-state lithium-ion batteries. | battery |
Patient participation is important for improving outcomes, respect for self-determination and legal aspects in care. However, how patients with heart failure view participation and which factors may be associated with participation is not known. The aim of this study was therefore to describe the influence of structured home care on patient participation over time in patients diagnosed with heart failure, and to explore factors associated with participation in care. | non-battery |
The main aims in the care of individuals with amyotrophic lateral sclerosis (ALS) are to minimize morbidity and maximize quality of life. Although no cure exists for ALS, supportive and symptomatic care provided by a specialist multidisciplinary team can improve survival. The basis for supportive management is shifting from expert consensus guidelines towards an evidence-based approach, which encourages the use of effective treatments and could reduce the risk of harm caused by ineffective or unsafe interventions. For example, respiratory support using noninvasive ventilation has been demonstrated to improve survival and quality of life, whereas evidence supporting other respiratory interventions is insufficient. Increasing evidence implicates a causal role for metabolic dysfunction in ALS, suggesting that optimizing nutrition could improve quality of life and survival. The high incidence of cognitive dysfunction and its impact on prognosis is increasingly recognized, although evidence for effective treatments is lacking. A variety of strategies are used to manage the other physical and psychological symptoms, the majority of which have yet to be thoroughly evaluated. The need for specialist palliative care throughout the disease is increasingly recognized. This Review describes the current approaches to symptomatic and supportive care in ALS and outlines the current guidance and evidence for these strategies.
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Seizure-prone EL/Suz mice have been studied as a model of multifactorial epilepsy for five decades. In prior behavioral studies, EL/Suz mice were shown to exhibit heightened locomotor activity, which implies a state of underlying hyperexcitability. The aim of the present study was to establish the premorbid behavioral development of basic motor skills and activity levels of EL/Suz mice, as compared with DDY mice, the control strain that is not seizure-prone. EL/Suz and DDY pups were monitored from Postnatal Day (PND) 3 to assess body weight, surface righting, negative geotaxis, forelimb grip strength, eye opening, habituation to a novel environment, and exploratory behavior in a two-compartment task. EL/Suz mice weighed less from PNDs 3 to 21 and exhibited delayed surface righting (PNDs 3, 5, 7) and negative geotaxis (PNDs 5, 7, 9) responses. EL/Suz and DDY mice differed in their habituation to a novel environment, with EL/Suz mice exhibiting higher activity, both within a single 10-minute session and across the 3 days of testing. EL/Suz and DDY mice also differed in the two-compartment task, with EL/Suz mice exhibiting increased locomotor activity and spending a greater amount of time in the light compartment. Thus, the present findings reveal that EL/Suz mice exhibit some developmental delays, altered habituation to a novel environment, and increased exploratory activity. Overall, the present results demonstrate that the behavioral and physiological phenotype of seizure-prone EL/Suz mice is deviant more than 2 months before the onset of seizure susceptibility. | non-battery |
Twenty four waste cellular phones, manufactured between 2002 and 2011, were selected in order to determine the total heavy metal content in each of their parts (printed circuit boards (PCBs), plastic housing (PH) and liquid crystal display monitors (LCDs)) and compare the results with the permissible limits set by the 2003 Directive on Restriction of Hazardous Substances (RoHS). All the selected samples were pulverized and digested with strong acids. Inductively coupled plasma-mass spectrometry was used to measure the heavy metal content in each sample. The results revealed that concentration levels of the examined heavy metals were higher in PCBs, followed by PH and LCD in that particular order (PCB>PH>LCD). With the exception of Pb and Cr present in PCBs of mobile phones released before the year 2006, all the other metal concentrations were according to the Directive. Concentration levels of Cd, Hg were lower than the permissible limits set by the EU, either before or after the validity of the 2003 RoHS Directive. Considering their significant heavy metal content, coupled with their large quantities produced worldwide in an annual rate, waste cellular phones need to be treated under an environmentally sound management scheme, prioritizing recycling and at the same time eliminating the possibility of any harm. | non-battery |
VO2 as one of the most prospective cathode materials applied for lithium-ion batteries, has appealed increasing attentions owing to its high theoretical specific capacity, unique tunnel structure, as well as low cost. Among multiple methods to optimize the electrochemical performances of VO2(B), heteroatom-doping has attracted increasing interests owing to its efficiently adjusting the microstructure and interplanar distances of VO2(B). Here, W-doped VO2(B) nanosheets-built 3D networks are obtained readily via a hydrothermal route by oxalic acid reduction of vanadium pentoxide. The resultant 3D networks possess ultrathin nanowalls, interconnected structure and enlarged tunnels, which are advantageous for the easy access of electrolyte and fast diffusion of lithium ions. As a consequence, high reversible specific capacity of 304 mAh g−1, ultrahigh rate capability (200 mAh g−1 at 2 A g−1), and high-temperature electrochemical performances are achieved as the 3D networks are applied for lithium storage. | battery |
A solid polymer electrolyte (SPE) for calcium-ion conduction was produced and characterized. Poly(ethylene glycol) diacrylate was photocrosslinked under blue light in the presence of calcium salt to form a stable network with high thermal stability and promising conductivity. An ionic conductivity of 3.4 × 10−4 S/cm at 110 °C and 3.0 × 10−6 S/cm at room temperature was achieved, which is similar to early-stage lithium SPEs. The electrolytes evaluated under thermogravimetric analysis (TGA) remained stable up to temperatures of approximately 140 °C. XRD confirmed no salt precipitation within the polymer matrix, and Raman analysis indicated the complexation of the calcium ions to the PEGDA network. This study is a contribution towards suitable polymer electrolytes for solid-state calcium-ion batteries. | battery |
Improving the electron conductivity and lithiated structure stability for Si anodes can result in high stable capacity in cells. A Silicon/Wolfram Carbide@Graphene (SW@G) composite anode is designed and produced by a simple two-step ball milling the mixture of coarse-grained Si with good conductive wolfram carbide (WC) and graphite. The SW@G composite consists of multiple-scale WC particles, which are uniformly distributed in amorphous Si matrices, and wrapped by graphene nanosheets (GNs) on the outside. Owing to the unique concrete-like core-shell structure, the wrapping of GNs on the Si improves the conductivity and structural stability of the composite. The inner WC particles which tightly connect the Si and graphene act as the cornerstone to resist large volumetric expansion of Si during charge/discharge, and in particular serve as the high-speed channels of electrons as well as provide more interface paths for Li+ to accelerate their transfer inside the Si. These contribute to the excellent electrochemical properties of SW@G composite anode, including high volumetric capacity (three times higher than that of graphite), superior rate capability, and long-life stable cycleability. The synthetic method developed in this work paves the way for large-scale manufacturing of high performance Li storage anodes using commercially available materials and technologies. | battery |
A facile, green and highly efficient method for the decoration of carbon nanotubes with ZnO was developed for the fabrication of binder-free composite electrode for supercapacitor applications. The nano composite was prepared by using reactive magnetron sputtering in Ar/O2 environment. This approach leads to more uniform coating with tuneable thickness, which alters the electrochemical performance of the nano composite electrodes. The structure and surface morphology of the composite film have been studied by means of X-ray diffraction (XRD) analysis, scanning electron microscopy and field emission scanning electron microscopy (FESEM). The XRD study reveals the formation of Wurtzite ZnO structure. The electrochemical performance of nano composite electrode was investigated using cyclic voltammetry, chronopotentiometry and electrochemical impedance measurements in non-aqueous electrolyte. The nano composite electrode shows significant increase in the specific capacitance up to 48Fg−1 with an energy density 13.1Whkg−1 in the potential range −2V to 1V. | battery |
Studies of polymer electrolyte solutions for lithium-polymer batteries are described. Two different salts, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and lithium trifluoromethanesulfonate (LiTf), were dissolved in a variety of polymers. The structures were all based upon the ethylene oxide unit for lithium ion solvation, and both linear and comb-branch polymer architectures have been examined. Conductivity, salt diffusion coefficient and transference number measurements demonstrate the superior transport properties of the LiTFSI salt over LiTf. Data obtained on all of these polymers combined with LiTFSI salts suggest that there is a limit to the conductivity achievable at room temperature, at least for hosts containing ethylene oxide units. The apparent conductivity limit is 5×10−5 S/cm at 25°C. Providing that the polymer chain segment containing the ethylene oxide units is at least 5–6 units long, there appears to be little influence of the polymer framework to which the solvating groups are attached. To provide adequate separator function, the mechanical properties may be disconnected from the transport properties by selection of an appropriate architecture combined with an adequately long ethylene oxide chain. For both bulk and interfacial transport of the lithium ions, conductivity data alone is insufficient to understand the processes that occur. Lithium ion transference numbers and salt diffusion coefficients also play a major role in the observed behavior and the transport properties of these polymer electrolyte solutions appear to be quite inadequate for ambient temperature performance. At present, this restricts the use of such systems to high temperature applications. Several suggestions are given to overcome these obstacles. | battery |
A highly transparent electrochromic capacitive (ECC) window was explored by combining a high contrast electrochromic polymer (ECP) and a transparent capacitive polymer. A blue and a red color ECP, poly(3,3-bis(bromomethyl)-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepine) (PR-Br) and poly(3,4-di(2-ethylhexyloxy)thiophene-co-3,4-di(methoxy)thiophene) (Th-OR), respectively, were introduced into an ECC window having a thin polyaniline (PANI) film as a capacitive layer. The as prepared ECC window showed high transparency (>72% for PR-Br), large color contrast, and long capacitive stability over 10000 cycles, by combining non-aqueous acidic electrolyte and precise control of each electrode's working potential using in situ potential matching. Upon introducing a dielectric poly(methylmethacrylate) (PMMA) layer, the blue ECC window made of PR-Br and PANI showed bistable ECC properties, along with a high energy density of 9.7 and 13.5 W h kg−1 with a power density of 75.3 and 58.8 kW kg−1, respectively, for bleaching and coloring. The red ECC window made of Th-OR and PANI also showed a high energy density (10.5 W h kg−1). The energy stored in an ECC window could be transferred to another device, like a battery, to switch the color or to light a LED when the ECC window is connected in series. Thus the ECC window in this study functions as a color switching smart window and a rechargeable battery, to provide a new path to achieve energy saving EC windows with multi-color tunability. The working principle of these ECC windows can be widely applied in various electrochemical devices for multiple functions in one device.
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Future scenarios and assessment studies used to prepare for long-term energy transitions and develop robust strategies to address climate change are highly dependent on the assessment of technology characteristics and availability. The electric power sector in the United States recently experienced a significant cost escalation: e.g., construction costs for large plants such as nuclear and coal-fired power plants doubled between 2003 and 2007. We assess the main drivers of this escalation. While many factors have affected costs, some of the most significant include cost of materials, particularly the price of metals and to a lesser extent cement, possible increases in labor quantity requirements, the aggressive worldwide competition for power plant design and construction resources, driven by high demand in Asia, market and regulatory changes, and general uncertainty about future regulations and climate policies. We recalibrate power sector technology costs in the Global Change Assessment Model (GCAM) based on an extensive literature review of recent (post-2010) studies and in the process develop a coherent and updated set of current cost and performance assumptions for all major electricity-generating technologies. While current cost and performance assumptions of electricity-generating technologies are key drivers of short-term technology deployment and technology mix in the electricity sector, medium- and long-term deployment pathways are significantly affected by assumed efficiency improvement rates and cost reductions. We develop and demonstrate a method to project efficiency and construction cost of power plants and report a sensitivity analysis to explore the importance of such assumptions in future scenarios generated by GCAM. | battery |
The vanadium redox flow battery (VRFB) has emerged as a viable grid-scale energy storage technology that offers cost-effective energy storage solutions for renewable energy applications. In this paper, a novel methodology is introduced for modeling of the transport mechanisms of electrolyte flow, species and charge in the VRFB at the pore scale of the electrodes; that is, at the level where individual carbon fiber geometry and electrolyte flow are directly resolved. The detailed geometry of the electrode is obtained using X-ray computed tomography (XCT) and calibrated against experimentally determined pore-scale characteristics (e.g., pore and fiber diameter, porosity, and surface area). The processed XCT data is then used as geometry input for modeling of the electrochemical processes in the VRFB. The flow of electrolyte through the pore space is modeled using the lattice Boltzmann method (LBM) while the finite volume method (FVM) is used to solve the coupled species and charge transport and predict the performance of the VRFB under various conditions. An electrochemical model using the Butler–Volmer equations is used to provide species and charge coupling at the surfaces of the carbon fibers. Results are obtained for the cell potential distribution, as well as local concentration, overpotential and current density profiles under galvanostatic discharge conditions. The cell performance is investigated as a function of the electrolyte flow rate and external drawing current. The model developed here provides a useful tool for building the structure–property–performance relationship of VRFB electrodes. | battery |
TiO2 nanotube arrays (NTAs) decorated with controllable Ag particles were prepared by pulse reverse current deposition in AgNO3/NaNO3 aqueous solution, aiming to improve the photoelectrochemical properties of TiO2 NTA electrode in visible-light region. By tuning the pulse current density and deposited charge density, a controllable synthesis of Ag structures was achieved. Excellent photocurrent responses of TiO2 NTAs in UV and visible light regions were achieved by depositing Ag nanorods and nanoparticles, which was attributed to highly efficient charge separation by the Schottky junction at the Ag/TiO2 interface and localized surface plasmon resonance effect of Ag nanostructures. | battery |
We have prepared NiO particles on Ni sheet and Ni foam substrates by chemical bath deposition and the following heat-treatment, and assembled a hybrid capacitor (HC) cell with the NiO-loaded Ni sheet or Ni foam positive electrode and activated carbon negative electrode. The deposited NiO particles had flower-like porous morphology which was composed of aggregated nanosheets. The maximum operating voltage of both HC cells was 1.5V, which was much higher than theoretical decomposition voltage of water (1.23V). The HC cell with NiO/Ni foam (HCfoam) had higher discharge capacitance and high-rate dischargeability and lower IR drop than the HC cell with NiO/Ni sheet (HCsheet) because of the increase in the utilization of NiO active material. Both energy and power densities per mass of active materials, were much higher than those for the HCsheet. Both HCfoam and HCsheet showed excellent cycle stability for 2000 cycles. | battery |
In 2017, Puerto Rico sustained extensive damage from Hurricane Maria, increasing the risk of fires and carbon monoxide (CO) poisonings. Using a population-based, in-person survey of households with children less than 6 years old in Puerto Rico, we collected data in 2010 concerning the presence of smoke alarms and CO alarms in these households. We generated national estimates by extrapolating the number of households in each stratum using data from the 2010 Census. We determined which household characteristics predicted the presence of these alarms. Of 355 households analyzed, 31% had functional smoke alarms, or an estimated 109,773 households territory wide. The presence of smoke alarms was associated with living in multifamily housing and no child in the household receiving government medical insurance. Public housing or publicly subsidized housing, as compared to owner-occupied housing and unsubsidized rental housing, was associated with having a functional smoke alarm in households with children aged less than 6 years. Based on only six houses having CO alarms, we estimated only 7685 (2%) households had CO alarms. The low prevalence of functional smoke or CO alarms 7 years before Hurricane Maria is unfortunate and should be remedied by ensuring that such alarms are widely installed in current rebuilding activities. | non-battery |
Electrochemical and physical measurements elucidate several thermodynamic properties and chemical factors that affect the performance of a non-aqueous all-vanadium flow battery. An H-type test cell was constructed that demonstrates stable coulombic efficiencies of 70% without flow after several weeks of slow cycling, with a steady plateau voltage near 1.7V during most of the discharge step. Environmental oxygen and water are associated with side reactions that affect long-term charge/discharge response of the battery. Oxygen passivates the electrode and may react with the solvent or supporting electrolyte, while water can cause the formation of oxovanadium complexes. Reversible cycling of the vanadyl acetylacetonate complex appears possible. | battery |
It is an effective method by synthesizing one-dimensional nanostructure to improve the rate performances of cathode materials for Li-ion batteries. In this paper, Li3V2(PO4)3 nanorods were successfully prepared by hydrothermal reaction method. The structure, composition and shape of the prepared were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scan electron microscope (SEM) and transmission electron microscope (TEM), respectively. The data indicate the as-synthesis powders are defect-rich nanorods and the sizes are the length of several hundreds of nanometers to 1μm and the diameter of about 60nm. The preferential growth direction of the prepared material was the [120]. The electrodes consisting of the Li3V2(PO4)3 nanorods show the better discharge capacities at high rates over a potential range of 3.0–4.6V. These results can be attributed to the shorter distance of electron transport and the fact that ion diffusion in the electrode material is limited by the nanorod radius. All these results indicate that the resulting Li3V2(PO4)3 nanorods are promising cathode materials in lithium-ion batteries. | battery |
Various screening tools have been proposed to identify HIV-Associated Neurocognitive Disorder (HAND). However, there has been no systematic review of their strengths and weaknesses in detecting HAND when compared to gold standard neuropsychological testing. Thirty-five studies assessing HAND screens that were conducted in the era of combination antiretroviral therapy were retrieved using standard search procedures. Of those, 19 (54 %) compared their screen to standard neuropsychological testing. Studies were characterised by a wide variation in criterion validity primarily due to non-standard definition of neurocognitive impairment, and to the demographic and clinical heterogeneity of samples. Assessment of construct validity was lacking, and longitudinal useability was not established. To address these limitations, the current review proposed a summary of the most sensitive and specific studies (>70 %), as well as providing explicit caution regarding their weaknesses, and recommendations for their use in HIV primary care settings.
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Fibroin nanofibrils were synthesized by a pH-controlled heat denaturation method. The nanofibrils were then applied to the surface of a carbon paste electrode to prepare a novel and biocompatible electrode for electrical double-layer supercapacitor applications. The capacity per surface area at a charge/discharge current of 1.0 A was obtained as 4.68 mF cm−2. The electrode showed improved capability and charge/discharge behavior.
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Spray drying method has been successfully applied to the field of lead-acid batteries. Lead powder/carbon black composite can be obtained by spray drying and subsequent calcination process. Glucose is added to increase the adhesion of carbon black and lead powder. The morphology changes before and after calcination are examined by FE-SEM. The composite negative material can enable the sum of discharge capacity increased by 8.27% from 4374.855 Ah to 4736.706 Ah at a discharge current of 25 A after 66 cycles. And the charge acceptance of the test cell also can be obviously enhanced. | battery |
A new phase of energy transition makes auxiliary technologies such as energy storage and other flexibility options more important. Economic policy that aims to steer this transition needs to grasp the complex system dynamics underlying energy and society. This conceptual article gives an overview of energy technology innovation theories that exemplify the growing importance of flexibility for electricity usage. First, the article presents different conceptualizations of technology innovation and diffusion. Second, how energy systems are embedded in physical infrastructures and social power relations is shown with a brief history of electricity in contemporary industrialized societies. Third, energy innovation is discussed in context of challenges of the upcoming energy transition. Fourth, energy technology innovations are further contextualized in light of insights from political economy and energy social sciences. Finally, the discussed approaches are synthesized to amend the holistic technology innovation system approach for studying energy technology innovations such as energy storage. | non-battery |
This work reports a detailed characterization of the reduction of oxygen in pyrrolidinium-based ionic liquids for application to lithium-oxygen batteries. It is found that, in the absence of Li+, all electron transfer kinetics are fast, and therefore, the reactions are limited by the mass transport rate. Reversible reduction of O2 to O2 •− and O2 •− to O2 2− take place at E 0 =2.1V and 0.8V vs. Li+/Li, respectively. In the presence of Li+, O2 is reduced to LiO2 first and then to Li2O2. The solubility product constant of Li2O2 is found to be around 10−51, corroborating the hypothesis that electrode passivation by Li2O2 deposition is an important issue that limits the capacity delivered by lithium-oxygen batteries. Enhancing the rate of Li2O2 formation by using different electrode materials would probably lead to faster electrode passivation and hence smaller charge due to oxygen reduction (smaller capacity of the battery). On the contrary, soluble redox catalysts can not only increase the reaction rate of Li2O2 formation but also avoid electrode passivation since the fast diffusion of the soluble redox catalyst would displace the formation of Li2O2 at a sufficient distance from the electrode surface. | battery |
Coal-based coke powder is a by-product when coke is smashed for metallurgy and chemical industry. There is a vast output of coke powder every year around world, most of which is combusted as cheap fuel or abandoned directly. In this work, the electrochemical performance of graphitized boron-doped coal-based coke powder as anode for lithium ion batteries was investigated. The effects of boron content and graphitization temperature on the anode performance of boron-doped coal-based coke powder were also investigated in this paper. Results showed that a reversible capacity of 360.3mAh/g of boron-doped coal-based coke powder can be obtained, while that of unboron-doped was 292.9mAh/g. X-ray diffraction (XRD) analysis for the boron-doped coal-based coke powder showed that the distance between carbon layers was lowered by a proper amount of doped boron and higher graphitization temperature. X-ray photoelectron spectrometer (XPS) analysis was carried out to explain the effect of boron doping on the electrochemical performances of coal-based coke anodes. | battery |
Low energy density and limited cyclability are preventing the commercialization of aqueous Zn–MnO2 batteries. Here, the authors combine the merits of operating Zn anodes in alkaline conditions and MnO2 cathodes in acidic conditions, via an electrolyte-decoupling strategy, to realize high-performance batteries.
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Hollow Sn nanostructures were obtained by simply controlling PVP addition in a solution-based reduction process. These nanostructures are assembled by many Sn nanoparticles with an inner void structure in the center. As an anode in Na-ion battery, the hollow Sn nanoparticles present improved cycling stability and capability in comparison with solid Sn nanoparticles, clearly indicating enhanced electrochemical properties for pure Sn anode in Na-ion battery. Moreover, their electrochemical impedance spectroscopy and charge/discharge profiles reveal the hollow structure not only maintains much higher capacity at large volumetric shrinkage process, but also provides structural stability and facilitated charge transfer in Sn anodes during the electrochemical reaction. Therefore, this hollow Sn nanostructure could provide new insight towards the exploration and design of alloy anode materials in Na-ion battery. | battery |
Despite increasing interest in the attentional biases of pain patients towards pain-related stimuli, there have been no investigations of whether the main caregivers of chronic pain patients also selectively attend to pain-related information. We compared the attentional biases to painful or happy faces of 120 chronic pain patients, 118 caregivers, and 50 controls. Analyses found that both patients and caregivers demonstrated biases towards painful faces that were not observed in control participants or to happy faces. Those patients and caregivers who were high in fear of pain demonstrated greater biases than those low in fear of pain, and the biases of the high-in-fear-of-pain group differed significantly from zero. When sub-groups of caregivers were compared, it was found that biases towards painful faces were not observed for those caregivers who accurately identified the level of pain the patient currently reported. In contrast, those caregivers who overestimated or underestimated the patients’ pain demonstrated biases that were significantly greater than zero. These results add to the growing weight of evidence suggesting that biases towards pain-related stimuli are observed in chronic pain patients, but that the nature of the stimuli is important. In addition, the results suggest that caregivers, particularly those who either under- or overestimate the level of pain that the patient reports, also demonstrate similar biases. Future research should investigate the links between caregivers’ biases and the way in which caregivers respond to pain. | non-battery |
We characterized high-power lithium-ion cells in terms of performance and cycle and calendar life at 45°C. Among other parameters, we measured the C/25 capacity every 4 weeks during the test. Differentiation of the C/25 voltage versus capacity data with respect to capacity (dV/dQ) has been used to elucidate another type of side reaction at the anode. In cycle-life cells, with their higher capacity throughput, the analysis showed that one phase transition (a peak in the profile) was disappearing with time. In contrast, this effect was not seen in calendar-life cells. | battery |
Slow-scan rate cyclic voltammetry (SSCV), potentiostatic intermittent titration (PITT) and electrochemical impedance spectroscopy (EIS) have been applied simultaneously to study Li ion intercalation into V2O5 films prepared by evaporative vacuum-deposition on Pt foils. Two different films, 1600 and 3600 Å thick, were used to study the influence of the film's thickness on the major electroanalytical characteristics of these intercalation electrodes. Modeling of the impedance spectrum related to the thin V2O5 film was performed using an equivalent circuit analog including the following elements: three R ∣∣ C semicircles (covering the high-frequency domain) and finite-length Warburg in sequence with the intercalation capacity (a straight line of unit slope at intermediate frequencies, and a sloping capacitive line at the very low frequencies). Sharp minima on D versus E plots, which are observed in the vicinity of the cyclic voltammetric peaks, present further evidence of very high, attractive electron–ion interactions during Li ion intercalation into the V2O5 electrode, as was already described for similar processes in graphite and some transition metal oxides: Li x CoO2, Li x NiO2, Li x Co y Ni1−y O2 and Li x Mn2O4. The diffusion length in these electrodes related to the V2O5 film's thickness. | battery |
The microstructure of nanometer-scale tin powder synthesized by the wire electric explosion (WEE) method is examined by transmission electron microscopy (TEM) at different Li insertion states, and then electrochemical properties of the tin power electrode are characterized by galvanostatic charge–discharge experiments. It is found that several Li/Sn inter-metalic compounds are formed during lithium insertion, namely Li1−x Sn, L13Sn5 and Li7Sn2. The passivation layer (or solid electrolyte interface, SEI) on the surface of particles cycled in an organic electrolyte electrochemical cell is characterized as Li2CO3 and ROCO2Li by FT-IR spectroscopy. A great part of the passivation layer is amorphous, but a small is poorly crystallized. | battery |
With the aim of developing lithium ion batteries with a long life and high efficiency for power storage, we experimentally evaluated combinations of cathode and anode active materials, in which batteries are able to obtain over 4000 cycles or 10 years of life. An acceleration method was evaluated using coin cells. We found that changing the current density was effective for evaluating battery life, since the logarithm of the cycle life showed a linear relationship to current density. Based on the current density increasing method, various combinations of cathode and anode active materials were tested. The cell system of LiCoO2/Li4/3Ti5/3O4 clearly showed a long life of about 4000 cycles. The energy density of the cell using the Li4/3Ti5/3O4 anode is obviously smaller than that using a graphite anode, the cell with Li4/3Ti5/3O4 anode was thought to have some merit especially in the large-scale-layer-built type battery by the applicability of the Al anode collector and a light weight battery case. | battery |
We show that anodes made by depositing thin films of polymer-derived silicon oxycarbide (SiCO) on copper have properties that are comparable to, or better than that of powder-based SiCO anodes. The great advantage of the thin film architecture is its simplicity, both in manufacturing and in application. The films are produced by spraying a film of the liquid polymer-precursor on copper, and then converting it into SiCO by heating at ∼1000°C; at this point they are ready for constructing electrochemical cells. They show a capacity of ∼1000mAhg−1, 100% coulombic efficiency, good capacity at very high C-rates, and minimal fading at ∼60 cycles. However, if the films are thick they delaminate due to the volume change as lithium is cycled in and out. The transition from thin-film to thick-film behavior occurs when the SiCO films are approximately 1μm thick. An analytical method for estimating this transition is presented. | battery |