batterydata/paper-abstracts huggingface dataset:
During operation of redox flow batteries, differential transfer of ions and electrolyte across the membrane and gassing side reactions during charging, can lead to an imbalance between the two half-cells that results in loss of capacity. This capacity loss can be corrected by either simple remixing of the two solutions, or by chemical or electrochemical rebalancing. In order to develop automated electrolyte management systems therefore, the state-of-charge of each half-cell electrolyte needs to be known. In this study, two state-of-charge monitoring methods are investigated for use in the vanadium redox flow battery. The first method utilizes conductivity measurements to independently measure the state-of-charge of each half-cell electrolyte. The second method is based on spectrophotometric principles and uses the different colours of the charged and discharged anolyte and catholyte to monitor system balance and state-of charge of each half-cell of the VRB during operation.
A simplified one-dimensional transient computational model of a prismatic lithium-ion battery cell is developed using thermal circuit approach in conjunction with the thermal model of the heat pipe. The proposed model is compared to an analytical solution based on variable separation as well as three-dimensional (3D) computational fluid dynamics (CFD) simulations. The three approaches, i.e. the 1D computational model, analytical solution, and 3D CFD simulations, yielded nearly identical results for the thermal behaviours. Therefore the 1D model is considered to be sufficient to predict the temperature distribution of lithium-ion battery thermal management using heat pipes. Moreover, a maximum temperature of 27.6 °C was predicted for the design of the heat pipe setup in a distributed configuration, while a maximum temperature of 51.5 °C was predicted when forced convection was applied to the same configuration. The higher surface contact of the heat pipes allows a better cooling management compared to forced convection cooling. Accordingly, heat pipes can be used to achieve effective thermal management of a battery pack with confined surface areas.
Large, areal, brittle fracture of copper current collector foils has been observed by 3D x-ray computed tomography (XCT) of a spherically indented Li-ion cell. This fracture is hidden and non-catastrophic to a degree because the graphite layers deform plastically, and hold the materials together so that the cracks in the foils cannot be seen under optical and electron microscopy. The cracking of copper foils could not be immediately confirmed when the cell is opened for post-mortem examination. However, 3D XCT on the indented cell reveals “mud cracks” within the copper layer and an X-ray radiograph on a single foil of the Cu anode shows clearly that the copper foil has broken into multiple pieces. This failure mode of anodes in Li-ion cell has very important implications on the behavior of Li-ion cells under mechanical abuse conditions. The fragmentation of current collectors in the anode must be taken into consideration for the electrochemical responses which may lead to capacity loss and affect thermal runaway behavior of the cells.
Lithium-sulfur (Li-S) batteries are attractive and promising energy storage devices due to the large theoretical energy density (2600Whkg−1) and natural abundance of sulfur. However, several intrinsic drawbacks hamper broader application, for example, the poor conductivity, serious shuttle effect, as well as large volume expansion. In this work, hierarchical porous carbon materials (HPCMs) are prepared from natural bamboo leaves by carbonization and HF etching. The biogenetic SiO2 nanoparticles (NPs) with abundant mesopores in the carbonized bamboo leaves are etched by HF producing hierarchical meso-/microporous carbon that can be exploited to load sulfur on the nanoscale. The HPCMs/S composite loaded with 70.26wt. % sulfur shows a high initial discharge capacity of 1487mAhg−1 at a rate of 0.05C (1C=1675mAg−1) and the capacity of 707mAhg−1 is maintained at 1C for over 200 cycles with a capacity decay of only 0.014% per cycle. When the current density is increased from 0.2 to 4C, 62.3% of the capacity is retained, suggesting good rate capability and promising application to advanced Li-S batteries.
The aim of the study was to examine the learners’ interests about chemistry experiments based on their previous science experiences. Sample of the study consisted of 52 first year pre-service science teachers. The data gathered through chemistry experiments which preferred by the learners and an open ended survey. Results showed that participants prepared a chemistry experiment which they found easy to implement and understandable. It was also concluded that the experiments that have been chosen by most of the students have not been tried before for reasons such as lack of equipment or teachers not demonstrating experiments at the school.
Objective This study sought to determine if recognition/familiarity memory can be measured using event-related potentials (ERP) in response to a computer-adapted version of a commonly used non-verbal memory assessment instrument. If successful, resulting ERP would further our knowledge of the neurophysiology of recognition memory and could be used in a cognitive assessment battery for individuals whose capacity for verbal and/or non-verbal communication is impaired. Methods Behavioral and ERP responses were recorded during performance on a computer-adapted version of the Continuous Visual Memory Test (CVMT) [Trahan DE, Larrabee GJ. Continuous Visual Memory Test. Lutz, FL: Psychological Assessment Resources; 1988] and examined offline for recognition memory old/new effects. Behavioral performance was also compared with performance on an alternate form of the test under standard administration procedures. Results ERP to old (repeated) visual designs in the CVMT were more positive-going than those to new designs and reflected by both early frontal and late parietal old/new effects as commonly reported in the recognition memory literature. The behavioral results from the computer-adapted and standard administration versions of the CVMT showed a significant correlation. Conclusions The computer-adapted ERP version of the CVMT provides a way to directly assess, using neurophysiological responses, the cognitive processes associated with recognition memory as measured by the CVMT. Significance The results from this study contribute to linking the functional and neurophysiological profile of memory produced by experimental neuroimaging research with traditional clinical neuropsychological assessment.
Solid oxide fuel cells (SOFCs) have been considered as one of the most promising technologies for very high-efficiency electric energy generation from natural gas, both with simple fuel cell plants and with integrated gas turbine/steam turbine–fuel cell systems. The high temperature exhaust gas from SOFC can be utilized in other cycles i.e. Rankine, Brayton for additional power generation or for heating and cooling purpose (cogeneration/trigeneration). The analysis shows that the resulting maximum efficiency of this SOFC-combined system can be up to 90% depending upon the operating condition and configuration used. This paper reviews the application of SOFC technology in power generation sector. This paper also investigate the research work undertaken or going on in this field.
Epitaxial and highly textured Li(Ni x MnyCo1−x−y )O2 thin film cathodes are deposited by a one-step, high temperature pulsed laser deposition technique. Structural characterization using X-ray diffraction, transmission electron microscopy and selected area electron diffraction (SAED) reveals highly textured film along (003). The best film quality has been achieved at high temperature, with temperature as high as 750 °C. Different substrates and buffer layers have been investigated and Li(Ni0.5Mn0.3Co0.2)O2 (NMC) on stainless steel with a thin Au-buffer layer gives the best film quality. The NMC thin film cathodes give a high capacity of 167 mAh g−1 and 125 mAh g−1 at 0.1 C and 0.5 C, respectively. In addition, the cyclic voltammetry and charge discharge curves obtained after different cycles indicate good electrochemical stability with capacity retention of 89% after 100 cycles at 0.5 C. The electrochemical characteristics are correlated to the microstructure of the film and the effects of texture, grain size and density are discussed.
French-based consultancy Tecsol, which specializes in solar power, is developing an remote Internet system for establishing the viability of complex solar power installations.
Triazophos, O,O-diethyl-1-H-1,2,4-triazol-3-yl phosphorothioate, (TZ) is an organophosphate pesticide widely used as an insecticide in agriculture fields, however, its adverse effects on cognitive function remain unknown till date. The present study was designed to identify the effect of TZ on cognitive function in order to gain an insight into the molecular mechanism(s) probably involved in TZ induced toxicity. Wistar male albino rats were orally administered with TZ at 8.2 mg/kg bw daily for 30 days. Cognitive function was assessed by evaluating step down latency (SDL) in passive avoidance apparatus, transfer latency (TL) on elevated plus maze and escape latency (EL) using morris water maze. The biochemical changes, in terms of malondialdehyde (MDA), reduced glutathione (GSH) and brain derived neurotrophic factor (BDNF) levels were evaluated in hippocampi regions. Relative mRNA expression and protein expression of BDNF were also evaluated. The results demonstrated that rats treated with TZ showed significantly (p < 0.01) reduced SDL and prolonged TL and EL as compared to control group rats. Moreover, significantly low (p < 0.01) mRNA expression and protein levels (p < 0.001) of BDNF, increased MDA and reduced GSH levels were observed in TZ treated rats. The study concludes that chronic exposure to TZ significantly impairs the learning and memory which may be attributed to the significantly reduced mRNA and protein expression of BDNF in hippocampus. Moreover, BDNF is negatively correlated to MDA levels and positively correlated to GSH levels. Hence, it can be suggested that interplay between BDNF and oxidative stress plays an important role in mediating the toxic effects of TZ.
A silicon deposit of various forms was successfully coated on graphite by electrodeposition in molten CaCl2 containing nano-SiO2 as a silicon precursor. The morphologies of the deposited silicon can be tuned from Si nanowires to a dense film by controlling constant electrolysis cell voltage. In addition to controlling electrochemical polarizations, the substrate plays a key role in forming a dense silicon film. By analyzing the interface between the Si film and graphite substrate, a thin transition layer comprising of Si, SiC and C enables the good adhesion of the Si film with the carbon substrate and thereby helps the growth of a dense Si film. Besides the application for photovoltaics, the electrolytic p-type Si film was employed as a binder-free anode for lithium-ion batteries delivering a capacity of over 2500 mAh g−1 in the first 10 cycles and retaining 800 mAh g−1 after 40 cycles. Moreover, this method was applied for coating Si on carbon fibers, which could be a general way to prepare Si with controllable forms and silicon/carbon core-shell structures for functional materials.
Although evidence suggests that subjective memory complaints (SMCs) could be a risk factor for dementia, the relationship between SMCs and objective memory performance remains controversial. Old adults with or without mild cognitive impairment (MCI) may represent a highly heterogeneous group, based partly on the demonstrated variability in the level of executive function among those individuals. It is reasonable to speculate that the accuracy of the memory-monitoring ability could be affected by the level of executive function in old adults.
In Part 2 of this report, the hydrogen gas charging and electrochemical properties of a series of AB2-based metal alloys (Ti12.5Zr21V10Cr8.5Mn x Co1.5Ni46.5−x ) designed to have different fractions of Zr–Ni-type secondary phases by varying the Mn/Ni-content were studied to establish correlations of these properties with abundances of the secondary phases. In the gas charging, the general trend of pressure–concentration–temperature slope factor and hysteresis is to diminish with increase in the Zr7Ni10 phase abundance; the trend of reversible hydrogen storage capacity is to increase as the TiNi-derived AB phase abundance increases. As for the electrochemical properties, the number of activation cycles needed to achieve a given percentage of capacity and power decreases with increase in the total amount of secondary phases. Trends of changes in both the total and reversible capacities follow that in AB phase abundance; the evolution of high-rate dischargeability, bulk diffusion, and surface exchange current is similar to that of Zr7Ni10 phase abundance – increase in the beginning and decrease afterward as the Mn-content in the alloy increases. Other properties, such as metal–hydrogen bond strength and maximum gaseous phase storage capacity, are predominately dependent on the alloys’ composition, i.e. the Mn/Ni ratio.
Publisher Summary A small set of programming frameworks are indispensable in navigating through key challenges of multimedia processing including organizing input and output data buffer flows, partitioning memory intelligently, and using semaphores to control data movement. “Framework” is the term used to describe the complete code and data movement infrastructure within the embedded system. The application timeline is best characterized as the minimum time between data collection intervals. The timeline is critical to understand because it is the foremost benchmark that the processor must meet. Even when system bandwidth seems to meet initial estimates, the processor has to be able to handle the ebbs and flows of data transfers for finite intervals in any set of circumstances. There are two types of dual-core architectures available currently: asymmetric and symmetric. The main advantage of having two different architectures in the same physical package is that each core can optimize a specific portion of the processing task. This chapter discusses several types of multimedia frameworks that can ride on top of either a single or dual-core processor: asymmetric programming model, homogeneous programming model, and master-slave programming model. Regardless of the programming model, a framework is necessary in all but the simplest applications. The chapter describes the various strategies for architecting a framework: (1) a system where data is processed as it is collected, (2) a system where programming ease takes precedence over performance, and (3) a processor-intensive application where performance supersedes programming ease.
Anatase is an attractive supercapacitor material as it is widely available, non-toxic, stable over a wide potential window, and has a high theoretical value of specific capacitance, but the experimental value is still low. Here, we show that HF treatment leads to simultaneous nanostructuring and fluorine doping of anatase. Structural characterizations show a substantial reduction in the particle size and an order of magnitude increase in the surface area without any change in the distribution of the crystal facets of anatase. Material characterizations show that fluorine doping leads to the creation of oxygen vacancies as well as the Ti3+ states. Electrochemical characterizations show that these defects increase electronic charge carrier density ( 9 × 10 19 cm−3) and local conductivity of the doped anatase by an order of magnitude compared to the pristine anatase ( 7.68 × 10 18 cm−3). As a result of this, doped anatase shows three times (236 Fg−1) higher specific capacitance than the pristine one and its rate capability is also better. Doped anatase also has good cycling stability with a minimum decrease in the specific capacitance through 10000 charge/discharge cycles.
22q11.2 Deletion Syndrome (22q11DS) is a common microdeletion disorder associated with mild to moderate intellectual disability and specific neurocognitive deficits, particularly in visual-motor and attentional abilities. Currently there is evidence that the visual-motor profile of 22q11DS is not entirely mediated by intellectual disability and that these individuals have specific deficits in visual-motor integration. However, the extent to which attentional deficits, such as vigilance, influence impairments on visual motor tasks in 22q11DS is unclear. This study examines visual-motor abilities and reaction time using a range of standardised tests in 35 children with 22q11DS, 26 age-matched typically developing (TD) sibling controls and 17 low-IQ community controls. Statistically significant deficits were observed in the 22q11DS group compared to both low-IQ and TD control groups on a timed fine motor control and accuracy task. The 22q11DS group performed significantly better than the low-IQ control group on an untimed drawing task and were equivalent to the TD control group on point accuracy and simple reaction time tests. Results suggest that visual motor deficits in 22q11DS are primarily attributable to deficits in psychomotor speed which becomes apparent when tasks are timed versus untimed. Moreover, the integration of visual and motor information may be intact and, indeed, represent a relative strength in 22q11DS when there are no time constraints imposed. While this may have significant implications for cognitive remediation strategies for children with 22q11DS, the relationship between reaction time, visual reasoning, cognitive complexity, fine motor speed and accuracy, and graphomotor ability on visual-motor tasks is still unclear.
The mathematics-education community stresses the importance of real-world connections in teaching. The extant literature suggests that in actual classrooms this practice is infrequent and cursory, but few studies have specifically examined whether, how, and why teachers connect mathematics to the real world. In this study, I surveyed 62 secondary mathematics teachers about their understanding and use of real-world connections, their purposes for making connections in teaching, and factors that support and constrain this practice. I also observed 5 teachers making real-world connections in their classrooms and I conducted follow-up interviews; these qualitative data are used to illuminate findings from the survey data. The results offer an initial portrayal of the use of real-world connections in secondary mathematics classes and raise critical issues for more targeted research, particularly in the area of teacher beliefs about how to help different kinds of students learn mathematics.
The development of high-performance layered oxide cathodes for sodium ion batteries (SIBs) continues to facing be hindered by severe challenges to date. Herein, a single-phase P2-Na0.67Mn0.6Ni0.2Co0.1Cu0.1O2 (NMNCC) comprising multiple-layer-oriented stacked nanoflakes is designed and synthesized via a simple sol–gel method. The large lattice parameters ensure a large three-dimensional frame, which enables the diffusion of sodium ions. Owing to its optimal morphology structure modulation transition metal substitution strategy, the MNCC electrode delivers a reversible capacity of 131.3 mA h g−1 at 0.1 C with retention of 86.7% after 200 cycles. In addition, it provides an initial capacity of 86.7 mA h g−1, and a retention of 80.0% after 500 cycles even at a current density of up to 1 A g−1. The stable single-phase structure and slight volume shrinkage observed after Na+ extraction further delay structural degradation. High Na+ mobility and low Na+ diffusion resistance are also guarantee the excellent rate performance of the NMNCC electrode. Thus, we determine that the NMNCC cathode is significant in the advancement of promising novel layered oxide cathodes.
Improving energy density while maintaining power density and cycle stability is the most serious challenge for supercapacitors. The solid active electrode material might possess a higher redox species density compared with its traditional counterpart, however, its electrochemical reaction kinetics is several magnitude orders lower in solids than that in liquids, leading to a deterioration of power density. Thus, a new approach based on 3-TEMPO-1-methylylimidazolium bromide (MIm+-TEMPO• Br−) biredox electrolyte, and a PANI-gel network modified carbon paper (PNcp) electrode for supercapacitor were developed in this study. The biredox electrolyte possesses a high energy density comparable to solid redox materials and a fast kinetics of liquid redox reaction, while the cross-diffusion of ions leads to a serious voltage drop which presents an inherent self-discharge problem. Fortunately, the PNcp prepared by a millisecond photo-thermal process makes up for this shortcoming. On one hand, its unique PANI-gel network structure protects the biredox electrolyte from cross-diffusion phenomenon, on the other hand, the combination of doping/dedoping process of PANI and redox process of MIm+-TEMPO• Br− provides an extra effect to prevent the self-discharge and attain a synergetic electrochemical performance. This method explores an avenue to pursue for battery level energy density meanwhile maintains good power density.
LiMn2O4-coated LiCoO2 film was synthesized by the ESD technique. The bulk structure and its electrochemical property were studied by X-ray diffraction (XRD) and cyclic voltammetry (CV) and the surface structure were characterized using soft XAS at the O K-edge and the Mn L-edge. The bulk structure and the electrochemical property of the LiMn2O4-coated LiCoO2 film do not show substantial difference compared to the bare LiCoO2 film. The thermal stability of LiCoO2 film is improved by LiMn2O4 coating on the surface of the LiCoO2 film. The Mn L-edge and O K-edge results suggest that the structure at the surface of LiMn2O4-coated LiCoO2 film is a spinel LiCo x Mn2−x O4.
The development of rechargeable batteries that use metallic lithium anodes faces challenges such as dendrite formation. Here the authors review recent advances in preventing the proliferation of dendrite and discuss design principles for electrolytes and interfaces in lithium-metal batteries.
Some patients with organic amnesia show confabulation, the production of statements and actions unintentionally incongruous to the subject's history, present and future situation. It has been shown that confabulators tend to report as unique and specific personal memories, events or actions that belong to their habits and routines (Habits Confabulations). We consider that habits and routines can be characterized by multiplicity, as opposed to uniqueness. This paper examines this phenomenon whereby confabulators mistake multiplicity, i.e., repeated events, for uniqueness, i.e., events that occurred in a unique and specific temporo-spatial context. In order to measure the ability to discriminate unique from repeated events we used four runs of a recognition memory task, in which some items were seen only once at study, whereas others were seen four times. Confabulators, but not non-confabulating amnesiacs (NCA), considered repeated items as unique, thus mistaking multiplicity for uniqueness. This phenomenon has been observed clinically but our study is the first to demonstrate it experimentally. We suggest that a crucial mechanism involved in the production of confabulations is thus the confusion between unique and repeated events.