In last decades significant investigation has been carried out in order to predict the bond strength of externally bonded reinforcement (EBR) systems with carbon fiber reinforced polymer (CFRP) materials in concrete and, as consequence of that, many analytical expressions can be found in the literature, including in standards. However, these expressions do not account for the influence of several parameters on bond behavior such as the type of surface preparation which is a mandatory and critical task in the strengthening application. The present work gives contributions to reduce this lack of knowledge. For this purpose, an experimental program composed of single-lap shear tests was carried out, the main parameters studied being: (i) the type of concrete surface preparation  and (ii) the bond length. Prior to the application of the EBR CFRP system, the roughness level provided by the different methods of surface preparation was characterized by a laser sensor. Test results revealed that sandblasting concrete surface preparation yielded higher values, in terms of maximum shear force and fracture energy. Finally, existing expressions in standards were upgraded in order to account for the concrete surface roughness level in the estimation of the bond strength. In last decades, fiber reinforced polymer (FRP) materials have been increasingly proposed to strengthen reinforced concrete (RC) structures ,2,3. ThiThe present work focuses on the bond behavior characterization between EBR CFRP system reinforcement and the concrete surface. As many researchers verified in their experimental works when this technique was applied, the bond strength depends on several factors, including mechanical and physical properties of concrete, composite material and epoxy adhesive which prevent the fully FRP tensile strength to be attained due to the premature debonding failure that typically occurs ,13,15. MIn terms of standard guidelines, the influence of the concrete surface roughness on the EBR system performance and bond strength has been recognized in a comprehensive manner ,2,30,31.Although the main guidelines recognize that concrete surface preparation prior the installation of the EBR FRP is an important task, the analytical formulations provided to predict the system bond strength still do not consider the influence of the use of different methodologies to do that. Possible reasons for this reside on the fact that different concrete preparation methods provide different roughness levels of the surface. Additionally, sometimes it is difficult to obtain a uniform surface roughness level, because this depends on human skills in the execution of the surface preparation method and it becomes a critical aspect when specimens under the same test conditions are produced. Therefore, a good scientific development would be to quantify the roughness level of the concrete surface before the reinforcement procedure and to understand how this influences the bond behavior of the EBR FRP system, when different methodologies of surface preparation are used. Then, the next step would be to introduce this influence on the bond strength prediction formulations. To measure the concrete surface roughness level after the application of different methods of surface preparation, several authors have used lasers profilometers ,32,33. TThe present paper aims at contributing to a better understanding the influence of the use of different concrete surface preparation methodologies on the bond behavior of CFRP EBR systems. For this purpose, an experimental program composed of single-lap shear tests was carried out. This was performed by adopting an experimental set-up developed by the authors and the main parameters studied were the type of concrete surface preparation (SB—sandblasting and GR—grinding) and the bond length between CFRP and concrete surface. Prior to the application of the EBR CFRP system, the roughness level provided by the different methods of surface preparation was characterized by a laser sensor, in order to make it possible to correlate these measurements with the results obtained in the bond tests which characterize the interface behavior between concrete and CFRP laminate. Then, the formulation proposed by the Italian National Research Council  was updab) were considered: (i) 150 mm, (ii) 200 mm and (iii) 250 mm. According to some provided analytical formulations ..Fl-sl prAs shown in During the loading process, inclined microcracks arose on the external concrete layer since the concrete tensile strength is lower than the corresponding adhesive’s strength. The emergence of these microcracks occurred from the loaded end to the free end section, accompanying the debonding process of the EBR CFRP system that starts when the bond strength is reached. Therefore, the bond strength is gradually lost in the successive loaded end sections during the loading process, and then other zones of bonded length are activated, providing its contribution to the stress transfer. While the debonding failure occurs, the stress distribution capacity in the successive loaded end sections become nil. The characteristics of the failure mechanism observed highlight the importance of the adhesive properties and the use of an effective surface preparation prior the installation of the EBR CFRP system that promotes a good adhesion between the concrete surface and the reinforcing material. These are crucial aspects in order to make it possible to increase the bond strength against debonding failure. Therefore, based on the analysis of the failure modes that occurred in the tests, important conclusions regarding the influence of the concrete surface preparation method used can be drawn.b value is higher than the theoretical effective bond length in stress transfer, promoting higher possibilities of having the influence of the existing heterogeneities in the concrete interfering with the bond conditions.Additionally, from a quantitative viewpoint, the amount of concrete attached to the CFRP after debonding failure was analyzed using a laser sensor SICK OD2-P50W10A0 with the same characteristics as the laser sensor used in the assessment of the concrete surface roughness see . The attThese results highlight that when SB was used, a thicker concrete layer attached to the CFRP was obtained, as had been verified in previous visual analyses of the fracture surfaces. On average, a concrete layer with a height of 1 and 1.8 mm appeared attached to the CFRP when GR and SB methods were used, respectively. As would be expected after the visual analysis of the fracture surfaces, a higher dispersion of the average concrete layer height was observed in the CFRP laminates of the SB specimens. In fact, this surface preparation method proved to be more effective to the bond behavior and made it possible to pull some coarse aggregates out of the concrete surface. In contrast, a weaker adhesion between the concrete and the reinforcing material was verified in GR specimens.lF-ls), (ii) maximum shear force  and (iii) total energy (Gf).In this section, a more detailed analysis of the influence of the study variables on the bond behavior between concrete and EBR CFRP system is carried out. Thus, the influence of concrete surface preparation methods used (GR and SB) and the bond length adopted  on the following key aspects is investigated: (i) response in terms of pull shear force vs. loaded end slip curves  were placed along the CFRP laminate centerline to measure longitudinal strains during the loading process in the specimens with Lε0) was analytically calculated by the following expression: ε0 = lF/(Ef × Af), where lF, Ef and Af represent the force applied, the CFRP Young’s modulus and the CFRP cross-section area, respectively. The interface behavior presented by the GR and SB specimens was very similar due to the same failure mode occurring. Before the start of debonding process, an exponential decrease of the longitudinal strain from the loaded end section to the strain gauge installed near to the free end section  is remarkable. As soon as the debonding process starts, the longitudinal strains recorded by the SG1 (strain gauge closer to the loaded end) approximate of the strain values analytically calculated at the loaded end section, which means that the shear stresses are no longer transmitted at the interface level in this section. At this phase, the typical S-shaped strain distribution is observed and remains until the failure. The transition between these two different behaviors can be identified as the instant when the bond strength has been reached. After the debonding process has started, the strain gauges placed along the bonded length registered progressively increasing values of longitudinal strains while the shear force increased. Thus, a translation of the zone capable of stress transfer along the bonded length is observed with increasing of shear force during the debonding process.In order to establish comparisons, Once the influence of the concrete surface roughness on the EBR system performance was recognized, in this section the formulation proposed by the Italian guideline CNR   for the lF,max) and the mean roughness coefficient obtained in the concrete surface roughness characterization (Rm) through a linear tendency line (R2 = 0.8) established as follows: lF,max = m × Rm + b, where m represents the effectiveness of increasing the roughness and b is the limit strength if a theoretical nil Rm value (perfectly smooth surface) could be obtained. In the formulation of the previous equation, only the results of the test series with bond length of 200 and 250 mm were included since these Lb values are not lower than the effective anchorage length (le) calculated according to CNR [le value from which the increase of Lb no longer means the increase of bond strength is 200 mm. It is also important to refer that the specimen SB_Lb200_3 was not included in the analytical approach presented in this section, taking into account the corresponding observed failure mode. The predicted bond strength proposed by the Italian guideline is established by Equation (5). Applying this equation for that case, the maximum shear force predicted (Fmax) is 27.1 kN, as represented by the red line in bf, tf and Ef are the width, thickness and Young’s modulus of the CFRP material, whereas ΓFm is the fracture energy. In turn, γRd is a corrective factor with a value of 1.25 and fb represents the mean bond strength obtained as a function of the parameter ΓFm. The fracture energy (ΓFm) is obtained by Equation (6) where kb is a geometrical corrective factor obtained as a function of the ratio between the width of the CFRP laminate (bf) and the width of concrete specimen (b) (Equation (7)) and kG is an additional experimental corrective factor which, according to CNR guideline [fcm and fctm represent the average compressive and tensile strength of concrete, respectively.g to CNR   using the values of ΓFm inside Equation (6) and all the other known parameters, the experimental values of kG were obtained. kG values and the mean roughness coefficient obtained in the concrete surface roughness characterization (Rm) through a linear tendency line (R2 = 0.8). In the same figure, the kG value proposed by the Italian guideline is represented by a red line. As concluded by the accuracy of the maximum shear force prediction, it is also verified that the kG mean value suggested by the CNR [kG value obtained proved to be higher than that suggested by the formulation included in the CNR guideline.Therefore, in order to improve the analytical formulation taking into account the influence of the concrete surface roughness prior to the EBR system installation and allow a better prediction of the bond strength when a more effective surface preparation method is used, the following procedure was adopted: (i) using the Equation (5) and considering the value  the CNR  can accuFmax prediction (Equation (5)) maintaining the kG value suggested by the guideline, a new parameter (kR—roughness corrective factor) was introduced in the calculation of the average interface fracture energy (ΓFm), which is defined as a function of the mean roughness coefficient (Rm), as demonstrated by Equations (8) and (9). From GR to SB, values of kR ranged between 0.8 and 1.7, respectively. According to the obtained results, the CNR guideline [kR = 1) a surface preparation method slightly more effective than the GR  and markedly less effective than the SB . In the absence of any information about the concrete surface roughness, it is recommended to use a value of kR equal to 1, as suggested in the CNR standard.To improve the kR) on existing CNR formulation for predicting the Fmax, the error values between the analytical formulation results and the experimental results were reduced from 11.8% to 4.4%.In order to assess the accuracy of the proposed analytical formulation, the average values of maximum shear force for each test series, obtained from the analytical model and from the experimental tests are compared with the prediction provided by the CNR guideline  in Figurm) and the root mean square (Rq), the SB method yielded to an average increase of 250% and 150%, respectively, in relation to the surface preparation with GR;Based on the measurements performed with the laser sensor, the results clearly showed that the SB method produced a higher level of concrete surface roughness than the GR. In terms of mean roughness coefficient  and total energy (Gf), allowing a better use of the tensile strength capacity of the CFRP laminate;The use of the SB method instead of GR provided an increase of maximum shear force  and total energy (Gf);The use of higher LkR) defined as a function of the mean roughness coefficient (Rm). The proposed analytical model proved to be able to accurately predict the bond strength of the EBR FRP system taking into account the roughness level of the concrete surface where the CFRP laminate is subsequently installed.Based on the obtained results from the experimental program, the influence of the surface roughness was included in the analytical formulation for predicting the maximum shear force proposed by CNR , throughThis paper presented and analyzed the obtained results from an experimental program composed of 24 single-lap shear tests in prismatic concrete specimens with CFRP laminates applied according to the EBR technique. The aim of this work was to study the influence of some important parameters on the bond behavior between concrete and the CFRP laminate, namely: (i) the type of concrete surface preparation method used before the application of EBR system that provides different levels of surface roughness (GR—grinding and SB—sandblasting) and (ii) the bond length . For this purpose, the roughness of the distinct concrete surfaces was assessed by using a laser sensor in order to allow the identification of its influence on the bond strength. Additionally, the formulation proposed by the Italian guideline CNR [


Price played an important role in most purchases. Buying behavior was strongly determined by consumers' price expectations. Emotion as a research hotspot was demonstrated to be ubiquitous in marketing and influenced purchase processing as well. This study addressed interests upon whether emotion arousal would influence consumers' price perceptions and their willingness to purchase. Compared to such emotion researches which normally adopted emotional pictures as priming stimuli, we creatively employed a two-player “Finger Play” (FP) game without monetary gains or losses to arouse subjects' emotion in the experiment. A 2 (FP Game Results: Continuous Win vs. Continuous Lose) by 2 (Price Conditions: High Price vs. Low Price) Event-Related Potentials (ERPs) experiment was designed to investigate whether game results would arouse different emotions and influence subjects' perception of product price. Both behavioral and ERP results indicated that subjects' price perception was deeply impacted by emotions induced from continuous win/lose experiences. Price played an important role in most purchases. Buying behavior was strongly determined by consumers' price expectations and the extent to which real prices violated those expectations , emotional arousal (low-to-high), and paradigms to evoke emotional process. Most affective ERP researches adopted stimuli from the International Affective Picture System (IAPS) which contains pictures rated with valence category (pleasant and unpleasant) and arousal level (low to high) on a nine-point scale , whether a competitive game could be adopted as the emotional priming paradigm instead of affective pictures to do the investigation. With our best knowledge and in order to strengthen subjects' sense of presence and authenticity, we creatively applied a two-player simple game—“Finger Play” (FP) known by nearly everyone involved no monetary gains or losses as the emotion priming stimuli, resulting a 2 (FP Game Results: Continuous Win vs. Continuous Lose) by 2 (Price Levels: High Price vs. Low Price) event-related potentials (ERPs) experiment designed to explore two research issues: (1) whether game results without monetary gain/loss would arouse subjects' different emotions; (2) If it would be, how the emotions impact subjects' perception of product price and their buying behavior. After the ERP experiment, participants were asked to rank a preference score of products chosen for this study to confirm that conditions of products attributes were controlled.Mean = 22.07 years, SD = 1.9 years). All subjects were native Chinese speakers, had normal or corrected-to-normal vision, and did not have any history of neurological disorders or mental diseases. This study was approved by the Neuromanagement Laboratory Ethics Committee at Zhejiang University. Informed consents were obtained from subjects prior to the formal experiments. Data from three subjects were discarded for excessive recording artifacts, resulting 23  valid subjects  were included in the final data analysis.Twenty-six healthy, right-handed students  recruited at Zhejiang University participated in this study, age from 19 to 27 years  and a low price set (from 200 to 400 RMB). Product pictures were equally and randomly divided into four groups, group 1 had 15 pictures corresponded with continuous win situation, group 2 also had 15 pictures corresponded with continuous lose situation, group 3 and group 4 had 30 pictures linked to other situations . Each product picture was paired with two prices (high price vs. low price), resulting doubled the number of total pictures. Every product picture with price presented twice and in a random sequence during the whole experiment. In preference rating experiment, same pictures used in ERP experiment were obtained, however, price information was erased in each picture. All the pictures were adjusted to a uniform size  and gray-processed by Photoshop software to ensure consistency in the background, brightness, contrast and color.Experiment instruction was shown to participants on paper handouts at the very beginning. Subjects were seated comfortably in a dimly lit, sound-attenuated and electrically shielded room. Experimental stimuli were presented centrally on a computer screen at a distance of 100 cm from each subjects' face. A keypad was provided to the participants to make their choices. Each subject had three practice trials to become familiar with the experimental procedure before the formal experiment.In order to construct subjects' sense of presence and authenticity, we referred to the experiment schematic diagram of Ma et al.  with somFigure There were two blocks in this experiment, every subject had 180 trials  in total . Participants took a rest about 3–5 min during the two blocks.When subjects finished the ERP experiment, they would have a 10 min rest. After the rest, all participants were asked to do the preference rating experiment  from a 64-channel electro-cap according to the 10/20 system and using a NeuroScan SynAmps 2 Amplifier . A cephalic (forehead) location was connected as the ground. EEGs were off-line re-referenced to the average of the left and the right mastoids. Horizontal Electrooculogram (EOG) was recorded at the left vs. right orbital rim while vertical EOG was recorded supra and infra-obitally at the left eye. The electrode impedance was maintained below 5 kΩ during the recording.T-test were used to analyze the ratio of adding to cart in the experiment. Further, a paired-samples T-test was adopted to analyze the preference degree ranking sores of hard-discs.For the behavioral data, descriptive statistics and EEG data were pre-processed through the software NeuroScan 4.5 before the statistic analysis. EOG artifacts were corrected firstly, followed by digital filtering through a zero phase shift . The EEGs were segmented for 1,000 ms in each epoch, beginning 200 ms before and continuing until 800 ms after the onset of both the game results and products presentations. The entire epoch was then baseline-corrected by the 200 ms interval prior to the stimulus onset. Trials that contained amplifier clipping, bursts of electromyography activity, or peak-to-peak deflection exceeding ±80 μV were excluded from the final average. Matlab R2015b was obtained to generate topographic maps for each condition.The statistic method repeated measures ANOVA was adopted to do the statistics analysis of ERP results. In our study, the dependent variables of ANOVA with the FP game results onset were the amplitudes of P300 and LPP, respectively, and the independent variables were the two levels of finger play results [Single Win vs. Single Lose (SW vs. SL)/Continuous Win vs. Continuous Lose (CW vs. CL)/Single Win vs. Continuous Win (SW vs. CW)/Single Lose vs. Continuous Lose (SL vs. CL)] and the electrodes with nine levels . The dependent variables of ANOVA with hard-disc onset were the amplitudes of P2 and LPP, respectively, and the independent variables were hard-disc with price in four groups [high price hard-discs paired to continuous win (CWHP) vs. low price hard-discs paired to continuous win (CWLP) vs. high price hard-discs paired to continuous lose (CLHP) vs. low price hard-discs paired to continuous lose (CLLP)] and the electrodes with six levels  for P2 and nine levels  for LPP.Based on the visual observation, the mean amplitudes from 290 to 400 ms of the central-parietal P300 and the mean amplitudes of LPP (from 500 to 800 ms) were mainly analyzed to examine the neural process when subjects knew the finger play results. Nine electrode sites from central parietal  were chosen for the analysis of P300 and LPP components. ANOVA factors were stimulus type (two levels: SW vs. SL or CW vs. CL or SW vs. CW or SL vs. CL) and electrodes .When a hard-disc picture was onset, the peak amplitude of early P2 component (in the range of 150–220 ms) was analyzed through six electrode sites  and the mean amplitude of late LPP component (from 500 to 800 ms) was analyzed through nine electrodes sites . ANOVA factors were price levels corresponding with FP results (four levels: CWHP vs. CWLP vs. CLHP vs. CLLP) and electrodes [six levels  for P2 and nine levels  for LPP]. The Greenhouse-Geisser correction was applied in all statistical analyses when necessary.According to our research purposes, we only analyzed the adding to cart ratio of hard-discs corresponded to continuous win or continuous lose results and the preference ranking scores of pictures linked to these two conditions.SD = 0.36), while the proportion of CLHP was 20.29% (SD = 0.24). Compared with CLLP , the adding to cart proportion of CWLP was much higher . The statistical results of paired-samples T-test also indicated that there were significant differences of adding to cart proportion among these four products groups .Descriptive statistics was adopted to analyze the behavioral data. Figure T-test was obtained to analyze the preference ranking scores of the hard-discs. Without the FP priming stimuli, subjects saw the products without price information directly and ranked nearly no differences in scores of preferences between products linked to CW results and CL results in the ERP experiment , and the T test result was not significant .A paired-samples We compared three situations' scalp waves which included SW vs. SL, CW vs. CL and SW/SL vs. CW/CL when FP result was onset. P300 and LPP components were observed in the situation . The amplitudes of SW and CW results were larger than SL and CL results. We also found larger P300 amplitudes of CW compared with SW, same as CL vs. SL .According to the statistical analysis, the main effect of FP results was significant . Larger LPP amplitudes were elicited in CW and CL results compared with SW and SL results . However, the main effects of neither SW vs. SL nor CW vs. CL conditions were significant .The main effect of FP results was significant when we compared the CW vs. SW conditions as well as CL vs. SL conditions  was mainly analyzed of the neural process. In addition, the early P2 was also observed when we compared the CWHP and CLHP conditions  and larger peak amplitude was elicited in CWHP condition . The latencies of these two conditions had no significant difference  .The main effect of Continuous Win compared with Continuous Lose in High Price condition was significant . Larger mean amplitudes from 500 to 800 ms of late positive potentials were observed of CWHP compared with CLHP . We did not find significant differences of LPP effects among CWLP vs. CLLP, CLHP vs. CLLP and CWHP vs. CWLP conditions . However, we examined the latency of peak amplitudes of LPP during the 500–800 ms time duration and found significant differences between CWLP and CLLP conditions  compared with losing (SL and CL) situation  was higher than CLHP . Meanwhile, the adding to cart proportion of CWLP  was much higher either compared with CLLP . It was easily to understand that higher adding ratio of low price hard-discs than high price ones. When we compared the adding proportion in same emotion situations (CW or CL), low price hard-discs were added to cart more than high price ones. However, the adding ratios of either high price or low price hard-discs were higher in CW situation than in CL situation  than CLLP  condition . This further illustrated that in the same emotion condition, subjects made decisions based on their common sense and had more dependence on their past experiences.The findings of this study indicated that emotions indeed played an important role in consumers' price perception and influenced their buying behavior. Additionally, the new experimental paradigm we creatively used could be applied in other marketing research issues. Win or lose feelings might impact not only customers' price perception, but also their other purchasing processes. However, the observation of brain-behavior relationship of our study was under well-controlled laboratory conditions and the ecological validity of the research might be limited. The customers' actual buying behavior might be dissimilar from our experimental settings. In the real marketing environment, the decision process of purchase might be more complicated and the information searching time might be much longer. There were some areas needed to improve in our future research. Firstly, the design of experiments needed to better reflect participants' real buying processes. Secondly, studies on how continuous win effect influenced consumer's buying behavior needed to be applied in other marketing issues, such as brand preference, product design, advertising etc. Moreover, mobile EEG equipment could be adopted to record customers' brain activities outside the laboratory but in more natural situations (Bleichner et al., To sum up, this study creatively integrated a competitive game without monetary gains or losses as an emotional priming paradigm into the investigation of how emotions influencing subjects' price perception. Both behavioral and ERP results indicated that subjects' price perception was deeply impacted by emotions. Emotions induced by winning include Single Win and Continuous Win were more positive than those evoked by losing include Single Lose and Continuous Lose situations. Continuous Win and Continuous Lose aroused more intensity emotions compared to Single Win and Single Lose. These emotion states lasted when hard-discs with price presented to subjects and evoked P2 and LPP components in CWHP and CLHP conditions as well as latency differences between CWLP and CLLP conditions. Thus, subjects added more hard-discs to cart when they experienced continuous win results compared to continuous lose situation. It was verified that emotion played an important role in consumer behavior and marketing from a new angle. Moreover, we firstly proposed this phenomenon as a new concept—“Continuous Win Effect” and planned to do more relative researches on this topic. Nevertheless, there still were some limitations in our research. First of all, the experimental setting might be very different from consumers' actual buying behavior. In the real marketing place, the decision process of purchase might be more complicated and the information searching time might be much longer. Secondly, we only tested the results of winning and losing without considering the situation of draw and others. Third, we only examined price perception of a well-known electronic product—mobile hard-disc without considering other products such as luxury goods, furniture, foods and beverages etc. The question might be whether emotions could impact price perceptions and consumers' behavior on these products as well or not. These deficiencies would be improved in future researches.As corresponding author, Qingguo MA confirmed that all experiments were performed in accordance with relevant guidelines and regulations. All experiments were approved by the Neuromanagement Laboratory Ethics Committee at Zhejiang University and reviewed by the ethics committee. The research design respects the personality of the subjects and will not cause psychological and physical damage to the subjects. The experiments are performed in accordance with APA Ethics Code and the principle of <International Ethical Guidelines for Biomedical Research Involving Human Subjects> by CIOMS. Further, written informed consent was obtained from all participants prior to the ERP experiments.QM designed the experiments. LZ and MW prepared the experiments and collected behavioral and ERP data. LZ processed and analyzed data. QM and LZ wrote the main manuscript text and prepared all the figures. All authors reviewed the manuscript.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


The bonding status between Carbon Fiber Reinforced Polymer (CFRP) and concrete is one of the key issues for the safety of CFPR-reinforced structures, thus it is of great importance to detect the debonding as early as possible. Instead of detecting the debonding which is artificially set at the very beginning, this paper investigates the feasibility of using low-cost piezoceramic sensors to detect and monitor the debonding of CFRP-reinforced concrete beams in situ. For existing debonding detection, a concrete beam reinforced with CFRP sheet was loaded through the three-point bending test till failure to induce debonding between CFRP sheet and the concrete substrate, and piezoceramic sensors were used to detect the existing debonding by analyzing the receiving ultrasonic waves. In addition, the debonding detection results were further compared with and verified by the vision-based strain testing results. For in-situ debonding monitoring, 10 piezoceramic sensors were used as an array to track the wave transmission changes during the loading process of a CFRP-reinforced concrete beam, and the debonding development process was successfully monitored. The test results show that the low-cost piezoceramic sensors are very effective to generate and receive ultrasonic waves, and are capable of detecting the existing debonding and monitoring of the in-situ debonding process as well. Over the years, a large number of concrete structures, such as buildings, bridges and tunnels need to be strengthened , due to It is known that the durability of CFRP-reinforced concrete structures is often controlled by the adhesive condition between the CFRP sheets and concrete substrate, since the stress shared by the CFRP is transferred from the structures to the CFRP through the interfacial bond. Debonding at the CFRP–concrete interface often results in premature failure of the strengthened structures . TherefoFor concrete-filled steel tubes, Xu et al.  used an The purpose of this study is to investigate the applicability of using low-cost piezoceramic sensors for CFRP-reinforced concrete debonding detection and monitoring. For debonding detection, a concrete beam reinforced with CFRP sheet was loaded till failure through the three-point bending test to induce debonding between CFRP sheet and the concrete substrate, and piezoceramic sensors were used to detect the existing debonding by analyzing the receiving ultrasonic waves. For comparison purposes, the debonding detection results were also compared with the vision-based strain testing results. For in-situ debonding monitoring, 10 piezoceramic sensors were used as an array to track the wave transmission changes during the loading process of a CFRP-reinforced concrete beam, the debonding developing trend was obtained and the debonding length was also evaluated.Two plain concrete beams from the standard test for flexural strength of concrete with dimension of 15.2 cm × 15.2 cm × 61.0 cm  were useAfter that, the two CFRP-reinforced beams were loaded to failure to generate debonding between CFRP and concrete, one of the beams (namely beam 1 afterwards) were tested after the failure to detect the debonding length, while on the other beam (namely beam 2 afterwards) piezoceramic sensors were pre-installed to monitor the debonding process in situ during loading.The loading test frame and setup is shown in After failure, the right half of the fractured beam was tested and 15 ultrasonic signal receiving points were equally spaced (1.9 cm) from the notch towards the end of the specimen see , with reIn the ultrasonic test, instead of using commercial ultrasonic transducers, low-cost piezoceramic disks (SMD07T02S412) were used to send and receive ultrasonic waves. The piezoceramic actuator was installed on the side surface, while the piezoceramic sensor scanned from receiving points 1 to 15 on the right half of the fractured beam. The actuating sensor was driven by a 100 V, 500 kHz square wave pulse generated from a pulser–receiver (Panametrics 5077PR), and the receiving sensor was connected to the pulser–receiver with a gain of 20 dB. The amplified receiving signals were then digitized by an NI-PXI 5133 digitizer at a sampling rate of 10 MHz, and 10,000 data points were recorded and transferred to a computer. In each measurement, 200 signals were averaged and saved to improve the signal-to-noise ratio.Ten receiving piezoceramic disks , with 2.The beam was loaded monotonically at 4.45 kN intervals. The beam was monitored till 57.85 kN of loading, after which the beam was loaded continuously till failure. Nondestructive testing (NDT) data was acquired at the loading intervals. The data acquisition procedure was mostly the same as used in Debonding between CFRP sheet and concrete substrate will significantly decrease the energy transmission between the sensors. For beam 1, time domain signals from receiving point 1 to 15 are shown in It is clearly seen that before receiving point 7 (12.7 cm from the notch), the amplitudes of the signals are considerably low, which implies that from receiving points 1 to 7, the CFRP was debonded. Note that the edge of the anchor patch was just in between receiving points 7 and 8 see . This reThough the signal amplitudes of receiving points 1 to 7 are considerably low, signals still could be obtained if a closer look was taken  were obtained at different loading levels, and signal amplitudes were used to describe the debonding process.For comparison, signals of sensor 2, which is 3.8 cm from the notch, obtained at 0 kN and 57.85 kN of loads are shown in In order to get a better understanding of the debonding process, normalized signal amplitudes obtained from sensor 1 (1.3 cm from the notch), 2, 9 and 10 were shown in The CFRP debonding length evaluation at 57.85 kN of loading was given a try in (1)In the debonding detection test, the signal amplitude obtained in the debonding area is less than 20% of the amplitude obtained from the sensor attached to the concrete surface, and a 12.7 cm debonding length was estimated. The results were compared and verified by the strain measurement results from the vision-based strain testing system. The ultrasonic pitch–catch method using piezoceramic sensors showed feasibilities for locating the existing debonding between CFRP sheet and concrete substrate.(2)In the debonding monitoring test, at 57.85 kN of load, the amplitudes of sensors 1 to 4 were 40% less than the amplitudes before loaded. Other than this amplitude drop, a first arrival delay phenomenon was also observed. The debonding process of CFRP-reinforced concrete beam during loading could be successfully monitored by piezoceramic sensors in situ.This study has investigated the feasibility of using low-cost piezoceramic sensors to detect and monitor the debonding of CFRP-reinforced concrete beams in situ. The following conclusions could be drawn:


The global outputs of annual publication in long non-coding RNAs (lncRNAs) and chemotherapeutic resistance research exponentially increased from 2 in 2008 to 176 in 2017. Using Java application CiteSpace V and VOSviewer, this study assessed the publication model of lncRNAs and chemoresistance by bibliometric analysis. Totally, 2883 authors contributed 528 publications of lncRNAs and chemoresistance in 215 academic journals in the recent decade (2008-2018). Oncotarget in the 215 academic journals published the highest number of publications (60). China had the highest number of publication outputs (358). The leading institute was Nanjing Medical University. Wang Y was the most influential author (13 counts). Gupta RA had the most cited documents (87 counts). “Gene expression” and “poor prognosis” were identified as the hotspots. “Cancer stem cell”, “HOTAIR” and “UCA1” were the frontiers of the fields in recent years. The increase of publications on lncRNAs and chemotherapeutic resistance will continue in the next years. HOTAIR and UCA1 with multiple roles in drug resistance may offer big opportunities for targeted chemoresistance in cancer therapy. These results may help us discover and explain the possible underlying laws of the subject. Chemotherapeutic agents, such as cisplatin, sunitinib, gemcitabine, paclitaxel and PARP inhibitors, have been widely applied in cancer treatment. While entirely eradicating the tumor and curing patients by chemotherapy alone are rare, in particular for advanced disease. The main obstacles are drug resistance that may be resulted from intrinsic and/or acquired factors. The factors of intrinsic resistance include drug breakdown, the aberrant expression and/or function of drug target, altered drug transport across membrane transporter, the ineffective interaction between drug and its molecular target . Inactiv2 = 0.9873), the model fitting curve revealed a significant correlation between the annual publications and publication year. Based on the equation of model fitting, it is estimated that the number of publications on lncRNAs and chemotherapeutic resistance would be about 268 in 2018. And 243 publications indexed in the WoSCC were retrievable on August 19, 2018.Excluding 14 non-official articles or reviews , 528 publications  indexed in the WoSCC of Thomson Reuters from 2008 to 2018 were extracted for further bibliometric analysis. 526 of the 528 articles (99.621%) were published in English, one in Chinese and one in German. The annual publications in WoSCC exponentially increased from 2 in 2008 to 176 in 2017 . With hiThe 528 publications of lncRNAs and chemoresistance were published in 215 academic journals. And the top 15 active journals published 206 of the 528 articles, accounting for 39.016% . With 60The distribution map of the country/institution can provide valuable information for researchers to better understand the community where they’re working. The distribution map indicated that the 528 publications came from 695 research institutes in 46 countries/territories . The topThe top 10 institutions published 174 of the 528 publications, accounting for 32.955% . NanjingThe 528 articles were written by 2883 authors working in the subject. The network map embodied the cooperation among authors . Among the top 10 authors with the largest number publications, WANG Y (13 publications) ranked the first, followed by LI J (11 publications) and Liu Y (11 publications)  developing at a slow pace ; the second stage with steady growth (2012–2015) ; the third stage with exponential growth (after 2015) . The preThe impact factor (IF) of a journal is an important factor to evaluate its influence of the published articles. Among the top 15 active journals that published these publications, 6 journals had an IF > 3.0, accounting for 30.583% (6/15). Four journals  had an IF > 5 . JournalEveryone in the top 10 prolific authors had at least six publications. While the comparison of the top 10 prolific authors with the top 10 co-cited authors showed that only Wang Y and Li J in the 10 prolific authors also appeared in the list of the top 10 co-cited authors  had the highest number of references (87), followed by Mercer TR (2009) with 50 references and Fan Y (2014) with 45 references . The timKeywords are the author’s generalization and refinement of the article core. Keywords with a high degree centrality were “gene expression”, “poor prognosis” and “cancer types”, indicating that research topics represented by these keywords are at the core of lncRNA and chemotherapeutic resistance research in the past decade . To date, about 20 lncRNAs were demonstrated to mediate chemotherapeutic resistance by various and often undefined mechanism in different cancer . ThroughThe burst words represent keywords that is often cited over a period of time, thereby indicating the frontier areas. The first 3 burst words after 2014 were “cancer stem cell”, “HOTAIR” and “UCA1” . Cancer in vitro and in vivo experiments confirmed that UCA1 induced cisplatin/gemcitabine resistance through the activation of CREB by p-AKT and the subsequent up-regulation of miR-196a-5p [The burst words of “HOTAIR” and “UCA1” reflected a wide study of their roles in chemoresistance from the scientific community. HOTAIR has been shown to mediate radiosensitivity, endocrine resistance and chemotherapeutic resistance in a variety of ways . The inc-196a-5p . The inc-196a-5p . UCA1 in-196a-5p . UCA1 in-196a-5p . Acting -196a-5p . The mul* OR chemotherapy drug resistance* OR chemotherapy-refractory drug* OR chemotherapeutic drug* OR drug resistance*)) AND (TS = (lnc RNA* OR long ncRNA* OR long non translated RNA* OR long non-coding RNA* OR long non protein coding RNA* OR long non-coding RNA* OR long untranslated RNA* OR long intergenic non protein coding RNA* OR large intergenic non coding RNA* OR large intergenic noncoding RNA* OR lincRNA* OR linc RNA*)) The wildcard character “*” captures any relevant variations of a term such as bibliometrics and bibliometric analysis. A bibliographic record was considered as relevant if any of the terms appear in its title, abstract, or keywords. The query returned 542 bibliographic records written in English between 2008 and 2018 on August 19, 2018. Excluding 14 non-official articles or reviews , 528 publications  were retained for further analyzed. The pipeline of the research procedure was displayed in Supplementary Figure 4.The publications were retrieved on Web of Science Core Collection (WoSCC) of Thomson Reuters on August 19, 2018. The search query consisted of seven terms as follows: (TS = (chemoresistance OR chemotherapy resistancef(x) = ax3 + bx2 + cx + d, x represents the publication year, f(x) represents the cumulative number of publications.The publication records, including author, title, abstract, organization, country, journal, keyword, and reference, were extracted and input into CiteSpace  in txt fThe strategies in the analysis of these publications included: (1) Clustering: Clustering is unsupervised learning that can uncover latent groups of entities sharing homogeneous characteristics. We captured thematically similar clusters on a document co-citation network by using a network clustering technique called smart local moving  to (2) B


Recently, Wi-Fi channel state information (CSI) motion detection systems have been widely researched for applications in human health care and security in flat floor environments. However, these systems disregard the indoor context, which is often complex and consists of unique features, such as staircases. Motion detection on a staircase is also meaningful and important for various applications, such as fall detection and intruder detection. In this paper, we present the difference in CSI motion detection in flat floor and staircase environments through analysing the radio propagation model and experiments in real settings. For comparison in the two environments, an indoor CSI motion detection system is proposed with several novel methods including correlation-based fusion, moving variance segmentation (MVS), Doppler spread spectrum to improve the system performance, and a correlation check to reduce the implementation cost. Compared with existing systems, our system is validated to have a better performance in both flat floor and staircase environments, and further utilized to verify the superior CSI motion detection performance in staircase environments versus flat floor environments. With the development of electronic and computer technologies, motion detection using various signals has been researched and efficiently utilized in health care ,2, enterWith the rapid commercialization of Wi-Fi devices, CSI-based systems have been generalized to various applications , includiCompared with a flat floor, when a human is moving on a staircase, he or she moves not only in the horizontal direction but also in the vertical direction, and the legs and arms bend with greater magnitude, as shown in In this work, we propose an indoor CSI motion detection system that can be used in both flat floor and staircase settings. The system architecture is illustrated in We present the difference in CSI motion detection in the two environments through a theoretical radio propagation model and experiments in real settings. The difference is analysed from the perspective of signal variance magnitude caused by the human movement direction.For comparison in the two environments, we propose a new system with several novel methods including the correlation-based fusion, MVS segmentation and Doppler spread spectrum to improve the system performance, and a correlation check to reduce the implementation cost. The proposed system is first validated to have a better performance compared to existing systems, and further utilized to verify the superior performance of CSI motion detection in staircase environments versus flat floor environments.Experiments in a real setting also validate the efficiency of the random forest (RF) algorithm for CSI motion detection in the two environments compared with that of the support vector machine (SVM) and K-nearest neighbour (KNN) algorithms.The main contributions of our work are as follows:The rest of the article is organized as follows. Related literature on motion detection systems will be investigated in Motion detection systems can be classified into four categories according to the technologies applied: sensor-, vision-, radar-, and CSI-based systems. Traditionally, sensors ,17,18,19Compared to traditional systems requiring specific hardware, a CSI-based system enables passive and non-invasive detection using existing commercial Wi-Fi devices without additional equipment requirements. WiFall  proposedd, Wireless signals can be leveraged to detect human motion mainly based on the signal variance caused by radio multi-path and shadow fading effects. According to the Friis free space Equation  31], th, th31], h is the maximum range of height variance, and When humans move in an indoor environment, the characteristics of wireless channels from multi-paths fluctuate over time and can be recorded as amplitude and phase variances. The multi-paths are categorized into line-of-sight (LOS) paths and reflected non-line-of-sight (NLOS) paths based on the surroundings, such as the ceiling, the floor, walls, furniture and moving humans. The total received power of receiver Equation  5]. d1 . d1 Pa iIn flat floor environments, a human moves only in the horizontal direction and the existing CSI motion detection systems mainly leverage j in stream i, respectively. In our work, a Wi-Fi router with two antennas served as the CSI transmitter, and a ThinkPad Laptop  with three antennas equipped with an Intel  Wi-Fi 5300 (Network Interface Card) NIC served as the CSI receiver. Therefore, we have a i and j are the numbers of CSI streams and subcarriers, respectively:Unlike common received signal strength indication (RSSI), CSI is a fine-grained signal containing streams and subcarrier information. CSI is based on orthogonal frequency-division multiplexing (OFDM) and multiple-input multiple-output (MIMO) technologies and records the wireless signal amplitude and phase information for each pair of transmit-receiver antennas in OFDM subcarriers. As in wireless protocol 802.11n, a 2.4-GHz band can be considered a narrowband flat-fading channel and can be modeled as shown byd as CSI , as show channel  6×30=180Similar motions such as walking and running are not easily discriminated based solely on time domain features because the corresponding scattered human body points are similar. However, the energy distribution of their frequency components is distinctive and can potentially improve classification performance. For example, walking and running involve similar body movements, but they correspond to distinctive body movement speeds and powers. We apply a short-term Fourier transformation to profile the spectrograms for walking and running motions performed on a staircase in The raw CSI stream collected by the Intel 5300 NIC for candidate walking motion is illustrated in riations , we safeAlthough denoised by the two-level filters, CSI is still redundant with six streams and thirty subcarriers in each stream. The multidimensional CSI data should first be fused to limit the redundancy without losing representative features before feature extraction. As shown in Unlike existing CSI systems that eliminate bad streams to avoid miss-detection because of “bad streams”  or even L across neighboring CSI packets, and the window is centered about the CSI packet in the current position. The high-level moving variance value denotes significant fluctuation of the CSI stream caused by dynamic human motion, whereas the low-level moving variance value denotes slight fluctuation of the CSI stream maintained by stable surroundings. Therefore, the CSI stream caused by motion can be segmented more accurately. For a CSI stream composed of n packets, the moving variance is defined as in Equation  becomes smaller. In particular, the start and end points of a significant CSI stream part caused by human motion are amplified by the start and end points of the fluctuation part of a moving variance stream. Therefore, the meaningful CSI stream part caused by human motion becomes more sensitive to segmentation to improve system performance.The CSI stream and corresponding moving variance stream of walking are shown in CSI represents fine-grained data, and both the time and frequency domain features have the potential to form concrete feature profiles of candidate motions. First, six features in the time domain are adopted: (1) The normalized standard deviation (STD) is calculated to reflect the scale of dynamic motion, and dramatic scale motion always results in a large STD. (2) The median absolute deviation (MAD) is used as a robust measurement of the variability of a univariate sample of quantitative data. The sum of the squared MAD can express the concentration of data. (3) The interquartile range (IR) is also extracted to indicate the dispersion of the CSI variance. (4) The signal Shannon entropy (SSE) is a generic measure of system disorganization and is used to reflect the disorganization of CSI variance. (5) Peak-to-peak (PtP) indicates the difference between the maximum and minimum amplitudes of the received signal. (6) The time duration (TD) of each type of motion is unique and essential for classification accuracy.Aside from time domain features, frequency domain features also benefit motion detection accuracy. The Doppler spread spectrum is adopted in  to analyThe Doppler spread spectrum is a symmetrical function with a zero mean and is always bounded by the maximum Doppler shift. An empirically selected threshold is adopted for each Doppler spectrum to obtain the final readings of the Doppler spread The expectation value Because highly correlated features have similar classification efficiencies, for all possible pair combinations of available features, we implemented a correlation check to limit the redundant features utilized in the classification. The correlation coefficient is used as the evaluation metric, and the formulation is given in Equation , where vThe calculated results are provided in We adopt the confusion matrix as shown in In addition, precision, recall and F1 score are used to analyze results of the confusion matrix. Precision is the positive predictive value, recall is the sensitivity, and F1 score or the F-measure is the weighted average of both the precision and the recall. These three mathematics rules are as the following:In our experiments, the Wi-Fi transmitter is a common commercial Wi-Fi router with two antennas, the receiver is a laptop equipped with an Intel 5300 NIC, and the Wi-Fi transmitter and receiver are always located at the same horizontal level. The CSI collection software is the open source CSI tool presented by Halperin et al., and the Intel 5300 NIC reports CSI for thirty subcarriers spread evenly among the 56 subcarriers of a 20-MHz channel or the 114 carriers in a 40-MHz channel . We condIn the training set, each specific motion lasts for approximately 3 s, and the sample number obtained for each type of motion is 50 (samples) * 8 (volunteers) = 400, where each sample is segmented from one CSI stream consisting of 1600 CSI packets. In addition, four types of motions are performed in two flat floor environments , with 400 (samples/each type of motion) * 4 (types of motions) * 2 (environments) = 3200 samples. Four types of motion are performed in only one staircase environment, and the sample number is 400 (samples/each type of motion) * 4 (types of motions) * 1 (environment) = 1600. Subsequently, empirical samples are forwarded into the shuffling phase, where the entire dataset of 4800 samples is randomly shuffled to avoid any possible sequential effects. The shuffling process is necessary because involving randomness helps mitigate the effect of human error, such as various subject body sizes and habitual differences in subject posture [For classification, machine learning RF is employed to achieve multiple candidate classifications. RF is a machine learning algorithm that integrates multiple trees via integrated learning. The multiple decision trees with an empirically selected amount of 150 are trained as the elementary elements and further integrated as RF in our work. In addition, because certain features are correlated with others, a stepwise correlation check is conducted based on the correlation check result introduced in To verify our proposed correlation-based CSI fusion method and explore the details of how different fusion methods affect classification, candidate motions are classified with different combinations of PCA and averaging fusion. As described in The classification results using different data fusion methods are shown in To limit the redundancy of features utilized in classification, we evaluate the combined effects of available features by removing one feature at one time based on the correlation check result in As expected, fewer features result in lower accuracy in general. However, two features, namely, MAD and Injuries caused by falls have been regarded as one of the major health threats among the elderly. Therefore, several recent studies have focused on CSI-based fall detection; however, they are mainly designed for flat floor environments and disregard complex indoor scenarios, such as a staircase. We implemented our system to detect falling and distinguished it from the most frequent indoor motions, including walking, running and sitting, in both flat floor and staircase environments, including rooms, corridors and staircases.We first present the confusion matrix of the experimental results in In conclusion, our system can detect falling in both flat floor and staircase indoor environments in complicated indoor scenarios, such as a hospital with elderly individuals or patients. Moreover, our experiments also verify the potential and better performance of CSI-based fall detection on a staircase versus a flat floor as in the previous analysis in Aside from human health care, CSI motion detection systems have also been applied to detect intruders by distinguishing human gaits for human security as individuals have unique motion characteristics, such as action habits and intensities. For example, young people always walk faster and more powerfully than the elderly, and the CSI variance generated by them is distinctive and can be applied to identify family members or detect intruders. In experiments to evaluate our system ability to detect intruders, we label one of the eight experimental volunteers as an intruder and distinguish the intruder from other volunteers using human walking and running gait CSI features in both flat floor and staircase environments.As shown in In this work, we proposed a novel indoor CSI motion detection system and validated the potential and better performance of CSI motion detection in staircase environments versus flat floor environments through experiments of fall detection and intruder detection. In addition, we presented several novel methods for CSI motion detection including correlation-based data fusion, MVS segmentation method, Doppler spread spectrum to improve the system performance, and a stepwise correlation check to reduce the implementation cost.


The structural performance of concrete structures subjected to fire is greatly influenced by the heating temperature. Therefore, an accurate estimation of the heating temperature is of vital importance for deriving a reasonable diagnosis and assessment of fire-damaged concrete structures. In current practice, various heating temperature estimation methods are used, however, each of these estimation methods has limitations in accuracy and faces disadvantages that depend on evaluators’ empirical judgments in the process of deriving diagnostic results from measured data. Therefore, in this study, a concrete heating test and a non-destructive test were carried out to estimate the heating temperatures of fire-damaged concrete, and a heating temperature estimation method using an adaptive neuro-fuzzy inference system (ANFIS) algorithm was proposed based on the results. A total of 73 datasets were randomly extracted from a total of 87 concrete heating test results and we used them in the data training process of the ANFIS algorithm; the remaining 14 datasets were used for verification. The proposed ANFIS algorithm model provided an accurate estimation of heating temperature. Inspection methods for the diagnosis and maintenance of buildings are very diverse. In recent years, methods for quantitatively measuring deformation of structures using camera equipment have been proposed ,2,3. HowThe heating temperature changes the thermal properties of concrete, which subsequently leads to a significant change in the behavior of the structural members . TherefoThe method of estimating heating temperature using statistical learning theory  with ultThis study proposed a heating temperature estimation method using an adaptive neuro-fuzzy inference system (ANFIS) to overcome the problems of existing heating temperature estimation methods. The ANFIS is a system that applies a training algorithm to the fuzzy theory and can solve complex problems, such as heating temperature estimation, which is hard to do using structural or numerical analysis. Furthermore, it has the advantage of providing a quantitative output by means of comprehensive considerations of the correlations between various input parameters . Thus, iAccording to previous research ,23,24,25In order to develop the ANFIS algorithm for estimating the heating temperature of concrete, factors which are closely related to the heating temperature should be configured as input parameters. Previous research ,16,17,18The ultrasonic pulse velocity test measures the rate at which ultrasonic waves are transmitted between electro-acoustic transducers after the transducers, composed of the receiver and the transmitter, come into contact with both sides of the concrete specimen, as shown in In general, when concrete is exposed to high temperatures, soot forms on the surface of the concrete at heating temperatures below 300 °C, the concrete surface turns pink, light gray, and light yellow at heating temperatures over 300 °C, and concrete melts at very high heating temperatures over 1200 °C ,27,28. IThe results of the ultrasonic pulse velocity test and colorimetric analysis on fire-damaged concrete showed that there are certain tendencies according to the heating temperature. Based on the results, the design compressive strength of concrete, ultrasonic pulse velocity, and reflectance of concrete surface were set as the ANFIS input parameters. It should be noted that in the actual fire-damaged structure, the ultrasonic pulse velocity and reflectance of concrete can be obtained by means of diagnosis, but it is impossible to identify the compressive strength of the concrete of the structural member before fire exposure. In such cases, the evaluator should do a diagnosis using information about the design compressive strength of concrete. Therefore, the design compressive strength of concrete rather than the actual compressive strength of concrete was set as the ANFIS input parameter in this study.The fuzzy theory, which serves as the basis of ANFIS, converts data that is difficult to digitize, such as linguistic variables, into a quantitative membership function to process data . For exaw) can be represented as below.In this study, a 5-step ANFIS algorithm for estimating heating temperatures was configured, as shown in In Step II, the number of possible cases for each fuzzified input parameter is taken into consideration to configure the fuzzy rules. In this study, because each of the three input parameters has five fuzzy sets, a total of fuzzy rules , the error increment (The fuzzy sets are then redefined using the updated conditional factors, and the fuzzy rules are reconfigured to recalculate the consequent parameters. That is, the calculation process from Step I to Step V in In this study, 73 datasets were randomly extracted from a total of 87 concrete heating test results and used them in the data training of the ANFIS algorithm; the remaining 14 datasets were used for verification. rocode 2 , the temIn this study, the heating test and non-destructive test on concrete specimens were conducted to identify the heating temperature of fire-damaged concrete. In addition, the ANFIS algorithm for estimating the heating temperature was configured based on the test results, and the accuracy of the proposed model was verified. The following conclusions can be drawn from the findings of this study.The concrete heating test found that spalling occurred at lower temperatures as the concrete compressive strength increased. It was also found that the ultrasonic pulse velocity tended to decrease because of micro-pores and cracks that occurred inside the concrete as the heating temperature rose.The colorimetric analysis revealed that the reflectance of the concrete surface increased as the heating temperature rose and the concrete compressive strength decreased.Based on the test results, this study proposed a heating temperature estimation method using the ANFIS algorithm, in which the ultrasonic pulse velocity, reflectance of the concrete surface, and design compressive strength of the concrete were set as the main input parameters.The heating temperatures of the specimens were evaluated using the proposed ANFIS algorithm. The results showed that the proposed model estimated the heating temperatures of the specimens, which were not used in training, with a high degree of accuracy.In this study, the data training was performed using only the test results of the specimens made of ordinary Portland cement without any admixture. Thus, it is difficult to discuss about the influence of different concrete mixes, for instance, with admixture. Once test data is available, however, the same procedure can be applied to derive the discoloration and heating temperature relationship through the data training process.


Wuchereria bancrofti and Onchocerca volvulus as prevalences of both infections move toward their respective elimination targets. The SD Bioline Onchocerciasis/LF IgG4 Rapid Test was used in 2 evaluation units (EU) to assess its performance as an integrated surveillance tool for elimination of lymphatic filariasis (LF) and onchocerciasis.Mali has become increasingly interested in the evaluation of transmission of both A cross sectional survey with SD Bioline Onchocerciasis/LF IgG4 Rapid Test was piggy-backed onto a transmission assessment survey (TAS) (using the immunochromatographic card test (ICT) Binax Filariasis Now test for filarial adult circulating antigen (CFA) detection) for LF in Mali among 6–7 year old children in 2016 as part of the TAS in two EUs namely Kadiolo-Kolondieba in the region of Sikasso and Bafoulabe -Kita-Oussoubidiagna-Yelimane in the region of Kayes.W. bancrofti CFA was 0.62%  [CI = 0.31–1.09]; while that of IgG4 to Wb123 was 0.19%  [CI = 0.04–0.50]. The number of positives tested with the two tests were statistically comparable (p = 0.09). In the EU of Bafoulabe-Kita-Oussoubidiagna-Yelimane, an overall prevalence of W. bancrofti CFA was 0%  and that of Wb123 IgG4 antibody was 0.06% , with no statistically significant difference between the two rates (p = 0.99).In the EU of Kadiolo- Kolondieba, of the 1,625 children tested, the overall prevalence of O. volvulus-hyperendemic district of Kolondieba. In the EU of Bafoulabe-Kita-Oussoubidiagna-Yelimane, an overall prevalence of Ov16-specific IgG4 was 0.18%  [CI = 0.04–0.47]. These 3 Ov16 IgG4 positives were from previously O.volvulus-mesoendemic district of Kita.In the EU of Kadiolo- Kolondieba, the prevalence of Ov16-specific IgG4 was 0.19%  [CI = 0.04–0.50]. All 3 positives were in the previously The SD Bioline Onchocerciasis/LF IgG4 Rapid test appears to be a good tool for integrated exposure measures of LF and onchocerciasis in co-endemic areas. After years of mass drug administration for lymphatic filariasis and onchocerciasis, many co-endemic countries need to demonstrate the interruption of transmission of these parasitic infections. This interruption of transmission is the key to stopping mass drug administration. One of the major challenges facing national programs is a reliable point of care diagnostic tool capable of detecting recent infection in children. To this end, the SD Bioline Onchocerciasis / LF IgG4 Rapid Test was used to evaluate the transmission interruption of lymphatic filariasis and onchocerciasis in previously endemic regions of Mali. This rapid diagnostic tool demonstrated good performance in 6 of districts in 2 “so-called’ evaluation units. There was very good overlap of the serological results obtained by the rapid diagnostic test (RDT) and previous endemicity profile of the different study districts for the two infections. We would argue that this RDT could be a single integrated approach for assessing transmission in areas where lymphatic filariasis and onchocerciasis are/were co-endemic. Approaches to onchocerciasis control and lymphatic filariasis (LF) elimination have proceeded along parallel but independent courses in Mali. For LF, annual mass drug administration (MDA) with albendazole and ivermectin began in 2004 and continued for 5 to 9 consecutive MDA campaigns. Onchocerciasis was originally highly endemic in five regions of Mali  as recommended by World Health Organization (WHO) were initiated in 2012 and are currently being performed in 22 evaluation units (EU). An EU includes one or several endemic districts based on geographic location, treatment coverage and population size .Loa loa infection, a filarial parasite that is absent in Mali . When assessed at the district level, the CFA prevalence was 0.69% [95% CI = 0.21–1.65] in Kadiolo and 0.57% [95% CI = 0.23–1.19] in Kolondieba. In the same EU, the overall prevalence of Wb123 IgG4 was 0.19% [95% CI = 0.04–0.50]; when assessed per district, the prevalence of IgG4 to Wb123 was 0.20% [95% CI = 0.0–0.97] in Kadiolo and 0.18% [95% CI = 0.03–0.60] in Kolondieba . For the Wb123 IgG4 antibody, only 1/1,700 (0.06% [95% CI = 0.0–0.28]) was found. This single positive was reported in the district of Bafoulabe; thus the local prevalence of Wb123 IgG4 was 0.21% [95% CI = 0.01–1.06]  were IgG4 positive to Ov16, but the upper 95% confidence level around this 0% prevalence was 0.59%.There was no statistical difference between the number positive (0/502) in Kadiolo, an O. volvulus-hypoendemic district and Kolondieba a previously O. volvulus-hyperendemic district  (p = 0.55). In the EU of Bafoulabe-Kita-Oussoubidiagna-Yelimane, an overall prevalence of Ov16-specific IgG4 of 0.18% [95% CI = 0.04–0.47] was recorded. These 3 individual Ov16 IgG4 positives were in the district of Kita among the 713 children tested, giving a prevalence of 0.42% for this district [95% CI = 0.10–1.14] , although there were no Ov16 positive children, the upper limit of the 95% CI exceeded 1%, suggesting that cut off point of antibody positivity for children should be raised above the 0.1% threshold. The comparison of positive cases of Ov16 between the previous O. volvulus-hypoendemic district (Yelimane) and the previous O. volvulus-mesoendemic district with 3 positives cases was similar (p = 0.99).Again it should be noted that in the CFA positive children were found primarily in the EU of Kadiolo-Kolondieba with 10 CFA positives detected using Binax Filariasis Now test in five different villages . No CFA Overall, single Ov16 or Wb123 IgG4-positive children were spread across 5 different villages of the 30 villages screened in Kadiolo–Kolondieba EU .O. volvulus and W. bancrofti as prevalences of both infections move toward their respective elimination targets. This reduction is due to the fact that the national lymphatic filariasis elimination program, since its creation, has distributed the required number of mass treatment campaigns with at least 5 consecutive rounds of albendazole and ivermectin treatment; thus TAS is ongoing in the different EUs  while the seroprevalence (antibodies) targeting the same parasite was 0.19% [95% CI = 0.04–0.50]. In the EU of Bafoulabe-Kita-Oussoubidiagna-Yelimane, the CFA prevalence was 0% [95% CI = 0.0–0.17] while the antibody seroprevalence was 0.06% [95% CI = 0.0–0.28]. The prevalences of LF infection measured using these two tests were comparable and with all the tests, the upper bounds did not reach the cutoff point of 2%  or antigen (CFA) testing, we suggest that the measurement of IgG4 to Wb123 might be preferable in decisions to stop MDA or in TAS following cessation of MDA as it allows the measurement of recent exposure. The challenge remains, however, to determine an acceptable prevalence threshold that would guarantee interruption of W. bancrofti transmission particularly since vector monitoring is not part of most LF elimination programs. In the Gambia, the recent use of the Wb123 IgG4 test suggests that this serological tool could be used to decide to stop MDA [Recent studies suggested that the Binax Filariasis Now test may overestimate the evalence ,17. Giveevalence , given tevalence  and givestop MDA . TherefoO. volvulus  assessment, the level of exposure to O. volvulus, as determined by the detection of the IgG4 antibodies to Ov16, the current prevalence estimates overlaid quite nicely with previous epidemiological profiles of the different study districts (Tables O. volvulus transmission level was above the current elimination threshold (0.1%) among the 6–7 year old, though the utility of this 0.1% target as a threshold is currently under debate [O. volvulus transmission  [Despite the application of the LF strategy for sampling of s Tables . All Ov1r debate ,21. The r debate . HoweverO. volvulus transmission potentials in subregions of countries such as Mali where many areas have undergone more than 24 years of CDTi with no or few epidemiological assessments [Within the context of onchocerciasis elimination, new data are needed to re-categorize essments . Moreoveessments . The seressments .Overall, the SD Bioline Onchocerciasis/LF IgG4 Rapid Test Wb123/Ov16 test, has 84% sensitivity and 98–99% specificity . As no aW. bancrofti and O. volvulus in children, with the potential to be used as a surrogate for interruption of transmission in a given focus as well as in post-MDA impact mesures in local populations in countries such as Mali. These data suggest that there is likely little or no transmission of either O. volvulus or W. bancrofti. Moreover, given the upper limits of the CI for Ov16 IgG4 in an O. volvulus-hypo-endemic region (and the fact that it does not differ from the hyper- and meso-endemic regions) a 0.1% threshold based on Ov-16-based IgG4 immunoassays may certainly be too conservative. Obviously, additional data underlying the utility of this POC test will be necessary if the elimination goals for both onchocerciasis and LF are to be achieved.Based on the present study using the SD Bioline Onchocerciasis/LF IgG4 Rapid Test in previously LF- and onchocerciasis co-endemic regions in Mali, this POC test appears to be a good tool for integrated measurement of exposure to


Although many theoretical and experimental studies are available on external confinement of columns using fiber-reinforced polymer (FRP) jackets, as well as numerous models proposed for the axial stress-axial strain relation of concrete confined with FRP jackets, they have not been validated with a sufficient amount and variety of experimental data obtained through full-scale tests of reinforced concrete (RC) columns with different geometrical and mechanical characteristics. Particularly, no systematical experimental data have been presented on full-scale rectangular substandard RC columns subjected to reversed cyclic lateral loads along either their strong or weak axes. In this study, firstly, test results of five full-scale rectangular substandard RC columns with a cross-sectional aspect ratio of two (300 mm × 600 mm) are briefly summarized. The columns were tested under constant axial load and reversed cyclic lateral loads along their strong or weak axes before and after retrofitting with external FRP jackets. In the second stage, inelastic lateral force-displacement relationships of the columns are obtained analytically, making use of the plastic hinge assumption and different FRP confinement models available in the literature. Finally, the analytical findings are compared with the test results for both strong and weak directions of the columns. Comparisons showed that use of different models for the stress-strain relationship of FRP-confined concrete can yield significantly non-conservative or too conservative retrofit designs, particularly in terms of deformation capacity. A significant amount of the existing RC buildings, particularly in developing countries, has typical deficiencies, like low quality of concrete, poor details of reinforcement, use of plain bars, lack of adequate transverse reinforcement for shear effects and inadequate confinement reinforcement at the potential plastic hinging regions. Thus, many existing substandard RC buildings are in urgent need of seismic retrofitting, particularly in terms of ductility, to achieve an acceptable performance during seismic actions. The fiber-reinforced polymer (FRP) composites have been widely used in reinforced concrete (RC) structures for repair and retrofit purposes in recent years. Many studies have demonstrated the efficiency of FRPs for the repair and retrofit of typical RC members ,15,16,17f’c) was 30 MPa and 16 MPa, respectively. The stress-strain relationships of concrete used for the construction of the columns are presented in fy) of 310 and 330 MPa, for longitudinal and transverse bars, respectively. The average mechanical characteristics of 14 mm-diameter longitudinal and 10 mm-diameter transverse plain bars are given in fy, fmax and fu are yield, maximum and ultimate tensile stresses and εy, εmax, and εu are the tensile strains corresponding to fy, fmax and fu, respectively. The stress-strain relationships for 14 mm-diameter longitudinal bars  are presented in Five substandard full-scale rectangular cantilever RC columns with a cross-sectional aspect ratio of two (600 mm × 300 mm) were tested under constant axial load and reversed cyclic lateral load. The substandard features of the tested columns were low quality of concrete, plain reinforcing bars and large spacing and low volumetric ratio of transverse reinforcement. The specimens were cast in two parts, foundations (1500 mm × 1000 mm × 600 mm) and columns, for which the average standard cylinder compressive strength of concrete at 180 days (Ash/sbk) were 0.0026 and 0.0013 for the R35 and RW35 series, respectively, where Ash is the total cross-sectional area of transverse reinforcement with spacing s and perpendicular to core dimension bk in the cross-section  was 0.0085. The clear cover was 25 mm over the transverse reinforcement. All specimens were constructed by using 90° hooked 10 mm-diameter stirrups with a spacing of 200 mm. The transverse steel reinforcement ratios (-section a.CFRP) were 0.00166 and 0.00332 for columns jacketed with one and two layers of CFRP sheets, respectively. For avoiding failure due to the loss of the bond of CFRP sheets, an overlap of a 200-mm length was formed at the end of the CFRP jackets.The columns REF-35 and REF-W-35 were the reference specimens in their series. These columns were designed to fail in flexure and exhibit low ductility due to premature crushing of concrete and buckling of longitudinal bars. The specimens RET-35-N1, RET-35-N2 and RET-W-35-N2 were retrofitted with external CFRP jackets with fibers aligned in the transverse direction. All corners of the rectangular cross-sections of these columns were rounded to a 30-mm radius before CFRP jacketing to satisfy the requirement of the Turkish Seismic Design Code (TSDC 2007) . The speThe specimens were subjected to combined action of axial load and reversed cyclic lateral load. As seen in Pcr and DRcr), yielding of the longitudinal bars (Py and DRy), peak load (Pmax and DRmax) and ultimate condition (Pu and DRu) are summarized in Although the lateral loading was continued until the development of significant damage and loss of strength, in this study, the ultimate condition is assumed to be at the displacement, which corresponds to 15% loss in lateral strength or sudden rupture of the FRP jacket before a 15% strength loss takes place. The 15% strength loss definition for ultimate condition is a widely-accepted assumption among other percentages, such as 20% or 25%. Since the behavior of sub-standard reinforced concrete members is rather brittle due to premature crushing of concrete or buckling of longitudinal bars, a percentage of 15% is selected here. The evolution of damage can be seen in The lateral force-drift ratio relationships of the specimens are presented in The lateral force-drift ratio relationships of the specimens are given in Many models have been proposed by different researchers for the stress-strain behavior of concrete externally confined uniformly with FRPs ,27,28,29kε) for FRPs. fcc) and ultimate strain values (εcc). Further details about the models can be found elsewhere [fco is the unconfined concrete compressive strength; εco is the axial strain corresponding to unconfined concrete strength; (h/b) is the cross-section aspect ratio (where h is the longer and b is the shorter side of the rectangular cross-section); fl is the lateral confinement pressure; f’l is the effective lateral confinement pressure; ks1 and ks2 are the shape factors for compressive strength and ultimate axial strain, respectively; εh,rup (kεεfu) is the actual hoop rupture strain, and εfu is the ultimate tensile strain of the FRP jacket; fju is the tensile strength, and Ej is the tensile modulus of the FRP jacket in the hoop direction, respectively; Ae is the effectively-confined cross-section area  and FRP-confined concrete strength and ultimate axial strain . Here, the unconfined concrete strength is assumed as the value obtained from standard cylinder tests (16 MPa) and the corresponding strain (εco) as 0.002. For each model, the FRP-confined concrete strength (fcc) and ultimate axial strain (εcc) values are obtained by using the equations provided in fco and εco are tabulated together with the effective confinement pressure (f’l) values, as seen in In order to compare the predictions of the above-mentioned models for the compressive behavior of the tested column cross-sections, axial stress-strain diagrams are plotted as seen in For obtaining the analytical load-displacement relationships of the tested FRP-jacketed columns, the moment-curvature relationships for the critical cross-sections  of the columns are required. In this study, the fiber analysis approach was used, for which the confined concrete behavior was considered by using the Lam and Teng , Ilki eth/2, where h is the depth of the column). These plastic hinge lengths are also in agreement with the requirements of the Turkish Seismic Design Code [e is the elastic top displacement; Δp is the plastic top displacement; φe is the elastic curvature at yielding; φ is the total average curvature in the plastic hinge zone; Lp is the plastic hinge length; and L is the height of the column from top of foundation to the actuator level at its center. Since the examined columns constitute an isostatic structural system, the loads at any point of the load-displacement relationships are obtained by making use of the resisted moments at the critical section (mid-height of assumed plastic hinge).The final stage of constructing inelastic load-displacement relationships of the columns was the nonlinear analysis of the columns making use of plastic hinge theory. In this stage, the assumption made for the plastic hinge length of the column is vitally important, since this affects the displacement capacity of the columns remarkably. While there are many suggestions made for the plastic hinge lengths of the columns e.g., ,38,39), ,39, 38,3ign Code . Furtherign Code ,35. Accoign Code ). In thiThe experimental lateral load-drift ratio relationships of the tested columns and the analytical predictions made by using the confined concrete strength and ultimate strain equations of different FRP-confined concrete models are presented in fcc) and the corresponding strain (εcc) can be calculated by using Equations (2) and (3). In these equations, κa and κb are the section shape factors, εf is the effective fracture strain of FRP and ψf is the safety factor. The effective fracture strain of FRP is proposed as 0.55εfu. A lower limit of 0.08fco is recommended for the maximum lateral confinement pressure provided by FRP confinement (fl = 2Eftfεfen/D), where Ef is the tensile modulus of elasticity of FRP, n is the number of plies of FRP reinforcement, tf is the nominal thickness of one ply of FRP reinforcement, εfe is the effective strain level in FRP reinforcement attained at failure and D is the diameter of the compression member of a circular cross-section. In addition, an upper limit of 0.01 is given for the ultimate axial strain of FRP-confined concrete. As seen in fcc/fco, εcc/εco and fl/fco ratios are provided, it can be noticed that, for the specimen retrofitted with one ply of CFRP confinement (RET-35-N1), the fl/fco ratio is slightly less than 0.08. In Another investigation is carried out using the approach given by ACI 440.2R . In thisb/h)2 < 1 for the lateral loading along the weak direction of the column, where b is the shorter and h is the longer dimension of the column cross-section. Accordingly, the equations given previously by Ilki et al. [Although the number of tested full-scale FRP-retrofitted columns and considered ranges of test parameters are not sufficient to propose a general model for extended rectangular columns, a slight modification is suggested here on the model based on the formulations given by Ilki et al.  to improi et al.  take theIn order to verify the predictions of the modified model with column test data of other researchers, four column tests were selected from the literature ,34,57. T(1)FRP retrofit of full-scale substandard rectangular RC columns with a cross-sectional aspect ratio of two successfully improved the ductility and energy dissipation capabilities.(2)Enhancement in ductility was remarkable for columns subjected to lateral loads along their strong or weak directions .(3)The use of different stress-strain models for FRP-confined concrete in compression led to significantly different analytical load-displacement curves for FRP-retrofitted columns. While use of the equations proposed by Ilki et al.  led to t(4)The model proposed by Ilki et al.  is modif(5)The use of equations provided by the ACI 440.2R  documentThe conclusions derived based on experimental and analytical studies conducted on the behavior of full-scale substandard rectangular FRP-retrofitted RC columns subjected to axial force and reversed cyclic lateral loads along their strong or weak axis are summarized below.