batterydata/paper-abstracts huggingface dataset:
In this study, electrocatalytic effects of nitrogen (N) and oxygen (O) atomic co-doping on carbon electrode are studied for vanadium redox flow battery (VRFB). The N and O co-functionalized graphite felt (GF) electrodes are prepared by two different synthesis routes: (i) impregnation of urea or melamine on the pristine-GF followed by reactions at high temperatures (batch process), and (ii) chemical vapor deposition of the pristine-GF by ammoxidation reactions with NH3-O2 reactants (continuous process). The properties of the electrodes are characterized, and the effects of doping methods and the kinetic relevance of the N and O co-functionalization are investigated for the VO2+/VO2 + redox reactions. The ammoxidative surface reaction of the GF with NH3-O2 was highly effective for N and O co-doping with a significant formation of pyrrolic-N, pyridinic-N, quaternary-N, hydroxyl, and carbonyl functional groups with negligible degradation of the GF structure. The collective correlation analysis reveals that pyrrolic-N and hydroxyl are the most kinetically relevant molecular configurations of the N and O functional groups for facilitating VO2+/VO2 + redox kinetics. The N and O co-functionalized GF when utilized both for the cathode and anode electrodes for a VRFB afforded 3−4% greater initial voltage and energy efficiencies along with 1.6 times higher initial charge–discharge capacity than the conventional oxygen-doped GF electrode owing to the substantially lower reaction overpotential. The results elucidate the marked effects of N and O co-functionalization on the electrocatalytic activities of carbon electrodes for vanadium redox kinetics in VRFB.
The time dependence of the open-circuit voltage (OCV) and the capacity loss in Li/Li1−y CoO2 half-cells during high temperature aging were measured experimentally, and tentatively simulated with simple kinetics equations involving Li-ion diffusion and a phase transition, respectively. The respective activation energies were determined. The capacity loss was found to have a reversible and irreversible component. The latter is discussed in contest of recent observation of an irreversible hexagonal-to-spine phase transition.
Palladium membrane purification technology is a key unit operation to produce high purity hydrogen from a feedstock of hydrocarbon fuel. Palladium membrane technology has been investigated for many years, but designing affordable, leak free, and high flux membranes remains a challenge. Even more challenging are portable reforming applications where the membrane must integrate into fuel processing systems typically operating at much lower pressures than stationary industrial systems, in order to meet strict size, weight and rapid start-up requirements. In this work, a new supported palladium membrane composite structure is developed to meet the above challenges. Using microfabrication techniques, an ultra-thin palladium film supported on a microstructured nickel honeycomb is fabricated and characterized. The composite membrane is entirely metallic, highly selective and demonstrates flux rates of 0.47 mol of hydrogen per second per square meter of membrane area (140 standard cubic feet per hour per square) at 350 °C, using under 1 atm hydrogen partial pressure gradient driving force.
Polyvinylidene fluoride (PVDF) has great potential for its use as an energy harvesting material as it exhibits not only outstanding piezoelectric and electrostatic characteristics resulting from ferroelectric effects, but also remarkably robust stability against repeated mechanical stress compared to inorganic materials. We report enhanced performances of poly(vinylidenefluoride-co-trifluoroethylene) (P(VDF-TrFE)) based energy generators with wider range of selections of flexible substrates through a surface morphology engineering using solvent annealing method as the key technology for simple and cost-effective fabrication at room temperature. It is clearly revealed that a solvent annealed P(VDF-TrFE) film is crystallised at room temperature and that the surface morphology is changed from a rough surface into a smooth and flat surface with increasing annealing time. This surface morphology engineering results in 8 times enhanced output voltage and current of the energy generators because of well-aligned electrical dipoles. We also demonstrate a highly transparent and flexible energy generator by employing graphene electrodes with the solvent annealed P(VDF-TrFE) film, which can be effectively harvesting various mechanical energy sources.
The demand of microelectronic devices postulated high energetic flexible energy storage devices. Flexible solid state supercapacitor is flawless possible candidate to fulfill the requirement of microelectronic devices. This investigation provides practical evidence of the use of flexible solid state supercapacitors based on MnO2 electrodes with polyvinylpyrrolidone (PVP)-LiClO4 gel electrolyte. Initially, different acid mediated growths of MnO2 have been carried. Later, the electrochemical performances of MnO2 electrodes have been carried out. Impressively, the fabricated symmetric flexible solid state supercapacitor (FSS-SC) device demonstrates the highest operating potential window of 1.6V with extended cycling stability. Moreover, the cell exhibits high energy density of 23Wh/kg at power density of 1.9kW/kg. It is interesting to note that the device shows excellent flexibility upon bending at angle of 180° for number of times. These results clearly evidenced those symmetric FSS-SC devices based on MnO2 electrodes are promising energy storage devices for microelectronic applications.
Children with autism spectrum disorder (ASD) and those with Williams syndrome (WS) have difficulties with learning, though the nature of these remains unclear.
A number of studies have found that plug-in hybrid electric vehicles (PHEVs) will have relatively small grid impacts if charged with overnight off-peak electricity. However the greatest petroleum displacement will occur if vehicles are allowed to charge during the day, maximizing all-electric range. Charging during the day also allows for a smaller, lower cost battery. Mid-day charging will add to peak electricity demands and may occur in locations where it is difficult to construct new generation and transmission capacity. Solar photovoltaics (PV) provide an option to provide mid-day peaking capacity. Mid-day charging of PHEVs also may absorb low value or even curtailed PV generation during periods of low demand. This study identifies possible co-benefits of large scale PV and PHEV deployment by simulating the Texas grid and identifying changes in peak capacity requirements and PV curtailment. A modest deployment of PV is able to avoid most of the increase in capacity requirements associated with very large PHEV penetrations. PHEVs are also able to reduce curtailment at high PV penetration, especially if charging can be controlled to improve the coincidence of consumer charging demand with normal PV generation patterns.
A Ge/Cu3Ge/C composite, prepared by pyrolysis and a high energy mechanical milling process, was investigated as an anode material for Li-ion batteries. Electron probe micro-analyzer images showed that Ge and Cu3Ge were well dispersed in the carbon matrix. Various analytical techniques were carried out to clarify the reaction mechanism of the Cu3Ge single phase and the Ge/Cu3Ge/C composite ex situ XRD and ex situ HRTEM analyses for Ge/Cu3Ge/C composite electrode were carried out and the final phase formed was Li15Ge4. For the case of pure Cu3Ge electrode, it reacted with Li at very low rate and the final product was probably a Li–Ge compound. Electrochemical tests showed that the Ge/Cu3Ge/C composite exhibited better capacity retention than that of the Ge/C composite anode probably due to the presence of amorphous carbon which acted as a buffering matrix during volume expansion and Cu that formed during the first discharge increased the electrical conductivity locally.
Three leg inverters for photovoltaic systems have a lot of disadvantages, especially when the load is unbalanced. These disadvantages are for example, small utilization of the DC link voltage, the dependency of the modulation factor of the load current and the superposition of a DC component with the output AC voltage. A solution for these problems is the four-leg inverter. Consequently, generation of balanced voltage with sinusoidal waveform is necessary for these inverters. The power stage model of the 4-leg inverter in rotating coordinates dqo is highly coupled. Consequently, controller design procedure is very difficult and complex. On the other hand, adaptive control for 4-leg inverters has not yet been discussed in the literature. This paper proposes the state feedback approach to decouple the system and convert it to a second-order system which has two poles equal to zero. Then, it suggests a compensator to cancel poles of the closed-loop system and to convert the final system to a desired second-order system. Thanks to use of this strategy the transient performance of the system, such as overshoot and speed of response, becomes greatly adjustable. In addition, an STR (Self-Tuner Regulator) is introduced to tune the state feedback matrix and to guarantee the adaptive performance of the system. Simulation results validate that, by using proposed control strategy, the 4-leg inverter generates balanced voltage, with perfect sinusoidal waveform, in spite of the presence RL time-variant loads.
Surface coating has long been an important strategy to improve the electrochemical performances of electrode materials for Li-ion batteries. In this work, an amorphous Li3PO4 (LPO) layer, which is a poor electronic conductor but good ionic conductor, is coated directly on LiCoO2 composite electrodes by magnetron sputtering. The battery performances of the electrodes are studied at both room temperature (RT) and 50 °C. The LPO sputter-coating allows significant improvement of the electrode's cycling stability at both temperatures. With an optimum coating thickness of ∼60 nm, the electrode's capacity after 100 cycles at 1 C can reach 146 mAh g−1 (79.3% retention) and 140 mAh g−1 (78.2% retention) at RT and 50 °C, which are improved by 30% and 200%, respectively, compared to those of the bare LCO electrode. More impressively, the rate capability is also greatly enhanced by LPO-coating, and the observed high-temperature rate capability is even superior to the room-temperature one. The remarkable improvement of the LPO-coated electrodes is mainly attributed to the high chemical stability and temperature-enhanced electrochemical activity of the LPO coating layer, which synergistically serves as a physiochemical protection layer and an efficient pathway for Li+ transport.
Battery-supercapacitor hybrid devices (BSHDs) are promising for certain applications requiring both high energy and power densities, but restricted by the electrolyte-consuming mechanism and imbalance of charge-storage capacity and electrode kinetics between battery-type and capacitor-type electrodes. Herein, a new prototype of rocking-chair lithium-ion BSHD with high energy and power densities is developed by employing pseudocapacitive T-Nb2O5 with a porous nanoflower structure as the anode and battery-type LiNi0.815Co0.15Al0.035O2 complexed in a three-dimensional interconnected conductive network as the cathode. Benefiting from the rational selection and optimization of the active material and electrode architecture, the anode and cathode exhibit exceptionally matched faradaic capacity and kinetics. Consequently, the BSHD delivers superior performance (165 W h kg−1 at 105 W kg−1 and 9.1 kW kg−1 at 83 W h kg−1) to previously reported rocking-chair BSHDs and could surpass the state-of-the-art electrolyte-consuming BSHDs at the device level. Therefore, this work will open a new avenue towards high-performance BSHDs.
There has been considerable debate surrounding the benefits and drawbacks of the new approach to classifying the epilepsies released by the ILAE Commission on Classification and Terminology (2005–2009). This new approach has significant implications for the way we conceptualize and assess cognition and behavior in epilepsy; however, as yet, there has been limited discussion of these issues in the field. The purpose of this Targeted Review is to spark this discussion by encouraging researchers and clinicians to think about the changes that the new approach may bring. These may include (i) reframing the way we think about the comorbidities of epilepsy, (ii) more precisely characterizing the cognitive and behavioral phenotypes of electroclinical syndromes, (iii) more carefully mapping the longitudinal trajectory of cognitive and behavioral features relative to the timing of seizures, and (iv) considering the links between cognitive, behavioral, and neurological phenotypes in the new classification scheme. It is hoped that such changes will aid translation of the advances in cognitive and behavioral neuroscience into routine clinical practice by providing purer markers of disease and more targeted treatments. A Special Issue canvassing such issues will be forthcoming that will consider current knowledge of the cognitive and behavioral features of the epilepsies from the view of the new classification scheme.
This study proposes an intelligent PEV charging scheme that significantly reduces power system cost while maintaining reliability compared to the widely discussed valley-fill method of aggregated charging in the early morning. This study considers optimal PEV integration into the New York Independent System Operator's (NYISO) day-ahead and real-time wholesale energy markets for 21 days in June, July, and August of 2006, a record-setting summer for peak load. NYISO market and load data is used to develop a statistical Locational Marginal Price (LMP) and wholesale energy cost model. This model considers the high cost of ramping generators at peak-load and the traditional cost of steady-state operation, resulting in a framework with two competing cost objectives. Results show that intelligent charging assigns roughly 80% of PEV load to valley hours to take advantage of low steady-state cost, while placing the remaining 20% equally at shoulder and peak hours to reduce ramping cost. Compared to unregulated PEV charging, intelligent charging reduces system cost by 5–16%; a 4–9% improvement over the flat valley-fill approach. Moreover, a Charge Flexibility Constraint (CFC), independent of market modeling, is constructed from a vehicle-at-home profile and the mixture of Level 1 and Level 2 charging infrastructure. The CFC is found to severely restrict the ability to charge vehicles during the morning load valley. This study further shows that adding more Level 2 chargers without regulating PEV charging will significantly increase wholesale energy cost. Utilizing the proposed intelligent PEV charging method, there is a noticeable reduction in system cost if the penetration of Level 2 chargers is increased from 70/30 to 50/50 (Level 1/Level 2). However, the system benefit is drastically diminished for higher penetrations of Level 2 chargers.
Composition optimization of the ternary Pt–Ru–Cu system for the methanol electro-oxidation reaction (MOR) was performed by combinatorial synthesis and high-throughput screening methods. A thin film library of the Pt–Ru–Cu system was prepared by a sputtering system to generate 63 different compositions. The compositions were characterized in parallel by a multichannel multielectrode analyzer. The highest MOR activity was observed for the Pt66Ru17Cu17 composition. The Pt66Ru17Cu17/C composition was synthesized and characterized as a powder catalyst to verify the performance of this new composition. During cyclic voltammetry tests, the Pt66Ru17Cu17/C catalyst showed less dissolution and irreversible oxidation of Ru than a Pt50Ru50/C catalyst, with increasing number of cycles. In MOR activity measurement experiments, the Pt66Ru17Cu17/C catalyst exhibited 26 and 86% higher activities in cyclic and chronoamperometric tests, respectively, than those of the Pt50Ru50/C catalyst.
A flexible freestanding ternary NiO/RGO-Sn hybrid sandwiched between sulfur cathode and separator, shows chemically trapping effect for sulfur species and polysulfide intermediates for lithium-sulfur (Li-S) battery. In the extraordinary ternary system, the hierarchical NiO hollow structures are tightly wrapped with reduced graphene oxide (RGO), and Sn particles are homogeneously anchored on surface of NiO/RGO composite. This work demonstrated that NiO/RGO-Sn interlayer plays an important role on immobilizing polysulfides, realizing the reactivation of dissolved polysulfides in Li-S batteries. The hierarchical NiO with abundant pores which benefit for polysulfide storage and buffering volume change when acted as interlayers. Simultaneously, RGO with high conductivity serving as upper current collector can significantly improves the electrochemical performance. Besides, NiO and uniformly dispersed Sn particles on the surface of NiO/RGO can effectively prevent the polysulfides from diffusing to the lithium anode by physical and chemical absorption. Immobilizing effect of NiO and Sn for sulfur species and polysulfides is deeply investigated by XPS techniques. The excellent performance of the cell is dominated synergistically by several factors including high electron conductivity of RGO sheets, the abundant pores and the chemical reaction between Sn, NiO species and polysulfides.
Cognitive deficits have been found to be prevalent in early onset schizophrenia. Whether these deficits also characterise other early onset psychotic disorders to a similar degree is unclear, as very few comparative studies have been done. The primary purpose of this study was to compare the profile and severity of cognitive impairments in first-episode early onset psychotic patients who received the schizophrenia diagnosis to those diagnosed with other non-organic, non-affective psychotic disorders. The secondary purpose was to examine whether the profile of cognitive deficits, in terms of intelligence, executive functions, memory, attention and processing speed was global or specific. First-episode psychotic adolescents (N =39) between the ages 11 and 17 years were included, 18 of whom were diagnosed with schizophrenia, and 21 with other non-organic, non-affective psychoses, using ICD-10 criteria. A healthy control group (N =40) was included, matched on gender and age. Cognitive functions were assessed using WISC-III/R, the CANTAB battery, WCST, Trail Making B, fluency tasks, and Buschke's selective reminding task. A similar profile and level of impairment was found on measures of attention, executive functions, reaction time, and memory in the schizophrenic and psychotic adolescent groups. However, analyses of WISC-III factor profiles suggested that early onset schizophrenia patients may have more global IQ deficits than non-organic, non-affective psychoses when examined recently after illness onset. Compared to the deficits of adult schizophrenia described in the literature, the results suggest relatively spared simple reaction times in early onset patients.
The deficit in electricity and high diesel costs affects the pumping requirements of community water supplies and irrigation; so using solar energy for water pumping is a promising alternative to conventional electricity and diesel based pumping systems. Solar water pumping is based on photovoltaic (PV) technology that converts solar energy into electrical energy to run a DC or AC motor based water pump. The main objective of the study is to present a comprehensive literature review of solar pumping technology, evaluate the economic viability, identify research gaps and impediments in the widespread propagation of solar water pumping systems and technology. The study focuses on update on solar water pumping technology, performance analysis, optimum sizing, degradation of PV generator supplying power to pump, economic and environmental aspects and advances in PV materials and efficiency improvements. An update on the current state of research and utilization of solar water pumping technology is presented. Factors affecting performance of PV water pumping system, degradation of PV modules and efficiency improving techniques of PV water pumping systems are identified. Solar water pumping is found to be economically viable in comparison to electricity or diesel based systems for irrigation and water supplies in rural, urban and remote regions. The investment payback for some PV water pumping systems is found to be 4–6 years. The recent Indian incentives for PV pumping and policy initiatives for the promotion of solar water pumping in developing countries are also discussed. Potential follow-up research areas are also identified.
A technology was demonstrated for the production of hydrogen and other valuable products (nitrogen and clean water) through the electrochemical oxidation of urea in alkaline media. In addition, this process remediates toxic nitrates and prevents gaseous ammonia emissions. Improvements to urea electrolysis were made through replacement of aqueous KOH electrolyte with a poly(acrylic acid) gel electrolyte. A small volume of poly(acrylic acid) gel electrolyte was used to accomplish the electrochemical oxidation of urea improving on the previous requirement for large amounts of aqueous potassium hydroxide. The effect of gel composition was investigated by varying polymer content and KOH concentrations within the polymer matrix in order to determine which is the most advantageous for the electrochemical oxidation of urea and production of hydrogen.
Oxygen reduction and oxygen evolution reactions were studied on graphite electrodes with different crystal orientations. The kinetics for the redox couple O 2 / O 2 − are very fast, therefore no catalyst seems necessary to assist the charge transfer process. Apparently, the main source of the overpotential for the O2 reduction reaction is from mass diffusion. Li2O2 becomes soluble in non-aqueous electrolytes in the presence of the tetraethylammonium tetrafluoroborate additive. The soluble B - O 2 2 − ions can be oxidized electro-catalytically. The edge orientation of graphite demonstrates superior catalytic activity for the oxidation over basal orientation. The findings reveal an opportunity for recharging Li-air batteries efficiently and a new strategy of developing the catalyst for oxygen evolution reaction.
The parameters generated by a curve fitting method on the visual attentional blink (AB) of 14 dyslexic and 14 control children were compared. The two groups differed on AB minimum parameters, whereas both AB duration and AB amplitude parameters were the same. The results suggest that low AB minimum is associated with poor reading. Moreover, phonological awareness was found to correlate with visual AB parameters in the dyslexic group. Overall, the present study provides new methodological insights regarding the assessment of the AB and visual sequential processing in relation to reading disorders.
In battery management system (BMS), equivalent-circuit model (ECM) is commonly used to simulate battery dynamics. However, there always is a contradiction between model simplicity and accuracy. A simple model is usually unable to reflect all the dynamic effects of the battery, which may bring errors to parameter identification. A complex model, however, always has too many parameters to be identified and may have parameter divergence problem. This paper tries to solve this problem with a novel ECM by adding a moving average (MA) noise to the one resistor-capacity (RC) circuit model. It can accurately capture the battery dynamics and retain a simple topology. A recursive extended least squares (RELS) algorithm is applied to online identify the ECM parameters, which shows a high accuracy in the experiments. In addition, a battery state-of-power (SOP) prediction algorithm is derived based on the proposed ECM. It considers both the voltage and current limitations of the battery, and offers a two-level prediction of the battery peak power capabilities.