Flight deck interval management and delegated separation for equivalent visual operations
An emerging Next Generation Air Transportation System concept — Equivalent Visual Operations (EVO) — can be achieved using an electronic means to provide sufficient visibility of the external world and other required flight references on flight deck displays that enable the safety, operational tempos, and visual flight rules (VFR)-like procedures for all weather conditions. Synthetic and enhanced flight vision system technologies are critical enabling technologies to EVO. Current research evaluated concepts for flight deck-based interval management (FIM) operations, integrated with Synthetic Vision and Enhanced Vision flight-deck displays and technologies. One concept involves delegated flight deck-based separation, in which the flight crews were paired with another aircraft and responsible for spacing and maintaining separation from the paired aircraft, termed, “equivalent visual separation.” The operation required the flight crews to acquire and maintain an “equivalent visual contact” as well as to conduct manual landings in low-visibility conditions. The paper describes results that evaluated the concept of EVO delegated separation, including an off-nominal scenario in which the lead aircraft was not able to conform to the assigned spacing resulting in a loss of separation.
Performance Comparison of Interval Management Concepts Using an Optimization-Based Scheduler in Terminal Airspace
A rapid increment in the amount of air traffic flows in aviation markets causes severe problems of flight delays. As part of an effort to resolve the problems, advanced Interval Management (IM) concept for Air Traffic Management (ATM) has drawn attentions. It focuses on reducing aircraft separation amount by fully taking advantages of modern avionics of flight management system and ADS-B (Automatic Dependent SurveillanceBroadcasting) capabilities. The main purpose of this paper is to understand the multidirectional performance metrics including the efficiency of airspace usage and aircraft scheduling performance, which should be balanced when the advanced IM concepts are applied to the practical demand set of flights which composed of different classes. To impove the scheduling performance, the optimization-based scheduling planner is utilized and predicts the optimum Scheduled Times of Arrival (STAs) at the pre-defined scheduling points in a given route structure. The scheduling planner is integrated in a dynamic planner (DP) by interacting with the real-time simulation algorithm to emulate the flight time advancement in a series of update cycles until all aircraft arrive at the runways. The realtime simulation produces the Actual Times of Arrival (ATAs) in consideration of the uncertainties during flight, and the computed ATAs become the initial conditions of the scheduling planner for the next cycle. Combined with the various IM concepts, the DP computes the relative efficiency of the flight scenarios that have different IM strategies corresponding to the level of equipage of the aircraft.
Parboiled rice effluent: A wastewater niche for microalgae and cyanobacteria with growth coupled to comprehensive remediation and phosphorus biofertilization
Abstract The potential of microalgae and cyanobacteria for bioremediation of wastewater by nutrient uptake combined with simultaneous biomass production is a well recognized perception of today's world. The present study illustrates the treatment of a highly polluted wastewater generated during parboiling of paddy in rice mill industries, widely operational in developing countries where rice is the staple food crop, with the help of microalgal and cyanobacterial isolates capable of growing at high rates in parboiled rice mill effluent (RME). This endeavor leads to comprehensive bioremediation of the said effluent and subsequent use of the harvested biomass as slow release phosphorus biofertilizers and the treated effluent for crop irrigation. The RME-acclimatized algal consortium demonstrated highest growth in terms of fresh weight and greatest remediation efficiency at the end of 36 days' treatment of RME, with 93.9% phosphorus and 100% ammonia-nitrogen removal, 98.7%, 91.6% and 93.5% reduction in biological oxygen demand, chemical oxygen demand and total dissolved solid, respectively, and an increment of 186 ± 0.3 mg L − 1 dissolved oxygen, bringing down the pollutants level well below the discharge limits suggested by Central Pollution Control Board, India. Additionally, microalgae in the consortium aggregated in clumps spontaneously in presence of the filaments of Phormidium sp. facilitating easy harvest. The RME-acclimatized algal consortium demonstrated highest accumulation of polyphosphate (poly-P) (0.76 ± 0.01% of dry weight) as well as highest release of phosphorus in non-sterile soil emphasizing the essential role of soil phosphorus solubilizing organisms to leach soluble phosphorus from the insoluble poly-P present in the biomass. The rice seedlings watered with treated RME also showed improved growth effect on shoot height and leaf width. The study results establish the suitability of RME as an excellent growth media for microalgae and cyanobacteria.