batterydata/paper-abstracts huggingface dataset:
Fuel cells produce electricity without involving combustion processes. They generate no noise, vibration or air pollution and are therefore suitable for use in many vibration-free power-generating applications. In this study, a mini alkaline fuel cell signal detector system has been designed, constructed and tested. The initial results have shown the applicability of such system for used as an indicator of signal disturbance from cellular phones. A small disturbance even at 4mVcm−1, corresponding to an amplitude of 12–18mG in terms of electromagnetic field, can be well detected by such a device. Subsequently, a thermodynamics model has been developed to provide a parametric study by simulation to show the likely performance of the fuel cell alone in other environments. As such the model can provide many useful generic design data for alkaline fuel cells. Two general conclusions can be drawn from the present theoretical study: (i) fuel cell performance increases with temperature, pressure and correction factor, C f; (ii) the temperature factor (E/T) increases with increasing temperature and with increasing pressure factor.
In the last few years several indices and tools, aimed at identifying frail subjects in various care settings have been developed. However, to date none of them has been incorporated into usual practice in the primary care setting. The purposes of this study are: 1) to evaluate the predictive capacity of the Tilburg Frailty Indicator (TFI), the Gérontopôle Frailty Screening Tool (GFST) and the KoS model together with two biomarker levels (SOX2 and p16INK4a) for adverse events related to frailty; 2) to determine differences in the use of healthcare services according to frailty.
Gross DP, Knupp H, Esmail S. The utility of measuring sexual disability for predicting 1-year return to work. Objective To explore sexual disability in injured workers undergoing rehabilitation. Specifically, we investigated (1) factors associated with high ratings of sexual disability, (2) factors associated with noncompletion of the sexual disability questionnaire, and (3) the association between sexual disability and future recovery. Design Historical cohort study with 1-year follow-up. Setting Workers' compensation rehabilitation facility. Participants Workers' compensation claimants (N=1078) undergoing return-to-work assessment. Ratings of sexual disability were measured using the Sexual Behavior item of the Pain Disability Index. Other demographic, clinical, and occupational factors also were collected. Intervention Not applicable. Main Outcome Measures Outcomes included administrative indicators of timely and sustained recovery and return to work. Results Of subjects included in analysis, 18.5% did not complete the Sexual Behavior item. Claimants were less likely to complete if they were women, older, and single; had lower salaries, injury diagnoses other than sprain/strain, and fewer health visits before assessment; and reported lower recovery expectations. Higher levels of sexual disability were associated with higher levels of overall pain and disability, as well as being in a married/common law relationship. After adjusting for injury duration, the Sexual Behavior item was not associated significantly with any recovery measure or claims outcome. Conclusions A response bias exists in Canadian injured workers asked to complete a sexual disability rating. In those completing the questionnaire, higher sexual disability was associated most closely with higher pain severity and higher disability. Perceptions of sexual disability did not contribute to predicting recovery, which supports replacement of this item for use within this and related contexts.
Sputter-deposited amorphous silicon thin films on metallic copper current collectors are widely studied as lithium-ion anode systems. Electrochemical results indicate these electrodes exhibit near theoretical capacity for first few cycles; however delamination at the thin film–current collector interface causes rapid capacity fade leading to poor cycling performance. Primary reason for this interfacial delamination is the mechanical stress generated due to colossal volume expansion of silicon during lithiation. The focus of the current study is to present a mechanistic understanding of the role of mechanical properties of the current collector on this characteristic delamination behavior during electrochemical cycling. Toward this end, we have developed a computational framework that accounts for the coupled diffusion induced large deformation in silicon, elasto-plastic deformation of the current collector, as well as the nucleation and propagation of interfacial delamination. We have also performed a detailed parametric study to investigate the effect of mechanical properties of the current collector on the delamination of the thin film–current collector interface. We have accordingly determined that current collectors with low elastic modulus such as graphite can completely suppress interfacial delamination. Our analysis thus provides a sound mechanistic approach for designing next generation Si thin film anodes with improved capacity retention.
Access to electricity is limited in rural areas of Myanmar, where the majority of the population live. Myanmar׳s rich solar resource and the recent price drop in solar PV modules indicate initial suitability for rural solar electrification systems to meet the electricity demand. In many parts of Myanmar, women are responsible for supporting the family financially. The ability of rural women in Myanmar to take advantage of solar PV powered services to improve their lives depends on concurrent progress towards addressing the many dimensions of gender equality – empowerment, health, education, opportunity, voice, representation, and livelihood-in rural locations. This paper examines the barriers of solar PV applications and the potential for women led solar PV enterprise development in rural Myanmar. Although the entrepreneurial process is the same for men and women in theory, in practice different factors e.g. social/cultural, religion, economic and educational ultimately result in the disadvantaged status of women-led enterprises. Therefore, widespread and long-term eventuation of this potential in Myanmar depends on a government committed to renewable energy resources for rural electrification and to diligently and holistically addressing geographical, political, educational, financial, ethnic and technical barriers to the empowerment of a rural, female population.
Abstract Excess cadmium (Cd) exposure produces adverse health effects in human beings. Although Cd accumulates in the liver and kidneys, it can also accumulate in other organs and tissues, depending on its chemical form. Long-term exposure to inhaled Cd from cigarette smoke and ingested from foods are the human exposures of greatest concern. For populations living in proximity to hazardous waste sites, increased dietary consumption could occur from Cd-contaminated dust on food or hands, from garden vegetables or fruits grown in Cd-contaminated soil, and from Cd-contaminated water used for drinking or garden irrigation. This article addresses human exposure to Cd, the exposure pathways for Cd in the human body, and the potential health effects of such Cd exposures.
Few studies have specifically investigated the cognitive correlates of employment for persons with mental retardation. To evaluate the relationship of cognitive and adaptive functioning to work status, 56 competitively employed and 55 unemployed individuals with mental retardation underwent a comprehensive neuropsychological and adaptive behavioral evaluation. Results of multivariate analysis of covariance (MANCOVA) revealed significant group differences in cognitive and adaptive behavioral domains controlling for gender and severity of mental retardation. Follow-up ANCOVAs showed that the employed group performed significantly better than the unemployed group on measures of attention, memory, verbal comprehension, visual perception, and adaptive behavior. Using discriminant function analysis, 73.2 percent of the employed and 76.4 percent of the unemployed people were predicted correctly. These results suggest that adaptive behavior and specific aspects of cognitive functioning are significant predictors of successful employment for persons with mental retardation.
In the majority of cases, there is no difficulty in diagnosing Cystic Fibrosis (CF). However, there may be wide variation in signs and symptoms between individuals which encourage the scientific community to constantly improve the diagnostic tests available and develop better methods to come to a final diagnosis in patients with milder phenotypes. This paper is the result of discussions held at meetings of the European Cystic Fibrosis Society Diagnostic Network supported by EuroCareCF. CFTR bioassays in the nasal epithelium (nasal potential difference measurements) and the rectal mucosa (intestinal current measurements) are discussed in detail including efforts to standardize the techniques across Europe. New approaches to evaluate the sweat gland, future of genetic testing and methods on the horizon like CFTR expression in human leucocytes and erythrocytes are discussed briefly.
Key management is an important building block for all security operations in sensor networks. Most existing key management schemes try to establish shared keys for all pairs of neighbor sensors; hence, a large number of keys need to be preloaded on each sensor, which necessitates a large key space for the nodes in the network. The recent trend in research is to mainly consider homogeneous sensor networks, and to a lesser degree heterogeneous sensor networks, for key management. In this paper, we propose a novel key agreement protocol which is based on pairing-based cryptography over an elliptic curve. Using this protocol, any two nodes that need to communicate can independently compute the same secret key by using pairing and identity-based encryption properties. The proposed protocol significantly reduces the key space of a node. Additionally, the security analysis of the proposed protocol shows that it is robust against a number of attacks including wormhole attack, masquerade attacks, reply attacks, and message manipulation attacks.
Raman spectra of polymer electrolytes based on poly(ethylene glycol) dimethyl ether (PEGdME) with LiClO4, PEGdME/LiClO4, and the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate, PEGdME/[bmim]PF6, are compared. Raman spectroscopy suggests stronger interactions in PEGdME/LiClO4 than PEGdME/[bmim]PF6, thus corroborating previous results obtained by molecular dynamics simulations. Quantum Chemistry methods have been used to calculate vibrational frequencies and the equilibrium structure of segments of the polymer chain around the cation. A consistent picture has been obtained from Raman spectroscopy, density functional theory (DFT) calculations, and molecular dynamics simulations for these polymer electrolytes.
Saudi Arabia can transition to a 100% renewable energy system by 2040 including the integration of the power, desalination and non-energetic industrial gas sectors. Single-axis tracking PV and battery storage contribute the highest to the final LCOE of the system. By 2050, single-axis tracking PV accounts for 79% of the total electricity generation. Battery storage accounts for 30% of the total electricity demand. Battery storage and desalination plants provide additional flexibility to the energy system. Through sensitivity analysis, it is found that decreasing the capex of desalination plants results in lower full load hours (FLH) and a decrease in battery storage output. This results in lower energy system costs. However, the SWRO capex has to be reduced by 50% to achieve a reduction of 1% in SWRO FLH and a 2.1% in the annualised energy system costs. This is because it is preferable to run the expensive SWRO plants in baseload operation for total energy system cost reasons. Flexibility to the energy system can be provided at a lower cost by solar PV and battery storage than by SWRO plants and water storage. Decreasing battery capex reduces the flexibility of desalination plants further, increases single-axis tracking PV capacities, decreases wind and CCGT capacities, and ultimately results in lower LCOE. These insights enable to establish the least cost pathway for Saudi Arabia to achieve net zero emissions by mid-century.
A new facile approach to the surface modification of LiNi0.5Mn1.5O4 by lithium polyacrylate coating is demonstrated. This strategy is based on mild polymer electrolyte coating from aqueous lithium polyacrylate solution. The LiNi0.5Mn1.5O4 (LNM) and 1% PAALi coated LNM (LNM@1%PAALi) are characterized by XRD, SEM, TEM, ICP-OES, galvanostatic charge-discharge tests and electrochemical impedance spectra (EIS). XRD and SEM results indicate that there are no clear difference between LNM and LNM@1%PAALi. HRTEM results indicate PAALi is uniformly coated on LiNi0.5Mn1.5O4. ICP-OES results indicate that PAALi coating can effectively prevent the Ni ions and roughly prevent Mn ions dissolving from LiNi0.5Mn1.5O4 cathode materials. Galvanostatic charge-discharge tests show that the discharge capacity of LNM@1%PAALi reaches up to 131.5 mAh g−1 at 0.2C and the value is still as high as 101.5 mAh g−1 at 12C. In addition, LNM@1%PAALi shows high coulombic efficiency and retains 90.0% of its initial discharge capacity after 200 cycles. EIS proves that LNM@1%PAALi cells has distinct lower ohmic resistance of the electrolyte. SEM of the cycled electrodes implies that PAALi can promote the formation of valid SEI film, being favor of the compatibility between LNM and electrolyte.
Nanoscale Li4Ti5O12 (LTO) is considered a promising anode material for Li-ion batteries because of its outstanding safety. However, cointercalation-induced structural relaxation adversely affects its Li-ion storage properties. Therefore, there is a need to elucidate the connection between electrochemistry and LTO structural relaxation of nano-LTO. Herein, various LTO nanosheet crystals with designated degrees of residual strain were prepared by varying the annealing temperature. The cyclability and rate capability of the prepared 2D LTO nanocrystals were evaluated. During annealing, dehydration of layered lithium titanate hydrate precursors (LTH, (Li2−xHx)Ti2O5·yH2O), leads to topotactic transformation from a C-centered orthorhombic to a body-centered orthorhombic system. Dehydrated LTH is then converted into spinel LTO nanosheets. Residual strain induced during transformation causes LTO structure distortion rendering Li-O bonding more covalent. Strongly covalent Li-O bonds screen the Li-Li Coulomb repulsion when 8a−16c cointercalation occurs, leading to large irreversible capacity loss and deteriorated cyclability. Meanwhile, rich irreversible Li intercalation degrade the power capability of LTO nanocrystals despite their high surface area. In addition to mechanism elucidation, conditions are identified to eliminate residual strain-induced structural relaxation giving rise to nanosheet anodes with superior power and highly reversible cycling performance.
Lithium sulfur (Li-S) batteries are highly prospective for future generations of transportation and grid storage due to their high energy density and low cost. However, the Li dendrite growth from the anode and the “polysulfide shuttle” from the cathode may cause poor cycling performance and safety concerns, hindering the practicality of Li-S batteries. Herein, we demonstrate a novel separator design by coating three-dimensional (3D) carbon nanofiber (CNF) interlayers on both sides of the separator to achieve a high performance Li-S battery. The CNF interlayer can not only render a uniform Li deposition on the anode by eliminating the “tip effect”, but also restrain the polysulfide diffusion on the cathode with its porous and highly conductive 3D architecture, enhancing the utilization of S-related species significantly. So an average Coulombic efficiency of the Li metal anode protected by a CNF interlayer is up to 95% for 100 cycles at 0.5mAcm−2. Moreover, Li-S batteries with CNF interlayers can exhibit remarkable cycle performance, presenting an initial specific capacity of 1207.4mAhg−1 at 0.5C and retaining at 828.1mAhg−1 after 100 cycles. In addition, the low-cost raw materials and the simple preparation for CNF interlayers is suitable for industrial scale-up.
In this work, modified commercial cylindrical lithium-ion cells with multiple separate current tabs are used to analyze the influence of tab pattern, frequency and temperature on electrochemical impedance spectroscopy. In a first step, the effect of different current tab arrangements on the impedance spectra is analyzed and possible electrochemical causes are discussed. In a second step, one terminal is used to apply a sinusoidal current while the other terminals are used to monitor the local potential distribution at different positions along the electrodes of the cell. It is observed that the characteristic decay of the voltage amplitude along the electrode changes non-linearly with frequency, where high-frequent currents experience a stronger attenuation along the current collector than low-frequent currents. In further experiments, the decay characteristic is controlled by the cell temperature, driven by the increasing resistance of the current collector and the enhanced kinetic and transport properties of the active material and electrolyte. Measurements indicate that the ac current distribution depends strongly on the frequency and the temperature. In this context, the challenges for electrochemical impedance spectroscopy as cell diagnostic technique for commercial cells are discussed.
TiO2 nanotubes on Ti metal surface were prepared by the electrochemical anodization method. Then, nanosilver was deposited onto the nanotubes by the electroless dip coating and the anodization. The obtained TiO2 nanotubes were examined by using scanning electron microscopy, atomic force microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, cyclic voltammetry, and UV–Vis. The electrochemical band gap (EgCV) of the nanosilver-coated TiO2 nanotubes prepared by the anodization was found as 1.54 eV. Using the UV–Vis measurements, the optical band gap energy (Egop.) was calculated as 1.51 eV for the Ag/TiO2 nanotubes obtained by electroless dip coating. The electrical conductivity of the TiO2 nanotubes also increased from 3.0 × 10−4 to 34.7 S/cm after nano Ag deposition by the anodization method. These Ag/TiO2 nanotubes with low band gap and high electrical conductivity are desirable for the applications in electronics, Li-ion batteries, and solar cells.
LiAlO2 composited LiMnPO4/C cathode material has been synthesized by in-situ growth hydrothermal method. The coexistence of minor LiAlO2 in LiMnPO4 plays an important role in electrochemical properties. The composite is characterized by XRD, SEM, HRTEM, Raman microprobe spectroscopy and their electrochemical properties are also studied. It shows that the LiAlO2 is composed of pure α-LiAlO2 phase with flaky-shaped nanoplates. LiAlO2 nanoplates porous structure is inherited from anodic aluminum oxide (AAO) structure and serves as substrates to grow LiMnPO4 nanocrystals, which provide a high surface area with a porous structure. The structure of LiMnPO4 is not affected by LiAlO2 nanoplates compositing. Among the investigated samples, the one with 6wt.% LiAlO2 exhibits a higher specific discharge capacity of 142.8mAh/g at 0.05C rate with a high capacity retention of 94.8% after 50 cycles. Electrochemical impedance spectroscopy (EIS) results show that the lithium diffusion constant (DLi + ) for 6wt.% content LiAlO2-LiMnPO4/C electrode is 2.07×10−14 cm2/s which is higher than the values for other contents LiAlO2-LiMnPO4/C electrode. The LiAlO2 is effective in suppressing the increase of the interfacial resistance between the electrode/electrolyte interface during charge-discharge cycling.
In this study, the stress generation caused by phase transitions and lithium intercalation of nickel-manganese-cobalt (NMC) based half cell with realistic 3D microstructures has been studied using finite element method. The electrochemical properties and discharged curves under various C rates are studied. The potential drops significantly with the increase of C rates. During the discharge process, for particles isolated from the conductive channels, several particles with no lithium ion intercalation are observed. For particles in the electrochemical network, the lithium ion concentration increases during the discharge process. The stress generation inside NMC particles is calculated coupled with lithium diffusion and phase transitions. The results show the stresses near the concave and convex regions are the highest. The neck regions of the connected particles can break and form several isolated particles. If the isolated particles are not connected with the electrically conductive materials such as carbon and binder, the capacity loses in battery. For isolated particles in the conductive channel, cracks are more likely to form on the surface. Moreover, stresses inside the particles increase dramatically when considering phase transitions. The phase transitions introduce an abrupt volume change and generate the strain mismatch, causing the stresses increase.
To satisfy its high energetic demand1, the brain depends on the metabolic cooperation of various cell types2–4. For example, astrocytic-derived lactate sustains memory consolidation5 by serving both as an oxidizable energetic substrate for neurons6 and as a signalling molecule7,8. Astrocytes and neurons also differ in the regulation of glycolytic enzymes9 and in the organization of their mitochondrial respiratory chain10. Unlike neurons, astrocytes rely on glycolysis for energy generation9 and, as a consequence, have a loosely assembled mitochondrial respiratory chain that is associated with a higher generation of mitochondrial reactive oxygen species (ROS)10. However, whether this abundant natural source of mitochondrial ROS in astrocytes fulfils a specific physiological role is unknown. Here we show that astrocytic mitochondrial ROS are physiological regulators of brain metabolism and neuronal function. We generated mice that inducibly overexpress mitochondrial-tagged catalase in astrocytes and show that this overexpression decreases mitochondrial ROS production in these cells during adulthood. Transcriptomic, metabolomic, biochemical, immunohistochemical and behavioural analysis of these mice revealed alterations in brain redox, carbohydrate, lipid and amino acid metabolic pathways associated with altered neuronal function and mouse behaviour. We found that astrocytic mitochondrial ROS regulate glucose utilization via the pentose-phosphate pathway and glutathione metabolism, which modulates the redox status and potentially the survival of neurons. Our data provide further molecular insight into the metabolic cooperation between astrocytes and neurons and demonstrate that mitochondrial ROS are important regulators of organismal physiology in vivo.
This paper presents a description of par2Dhp—a 2D, parallel fully automatic hp-adaptive finite element code. The parallel implementation is an extension of the sequential code 2Dhp90, which generates fully automatic hp-approximations for solutions of various boundary value problems. The presented work addresses parallelization of each stage of the automatic hp-adaptive algorithm, including decomposition of the computational domain, load balancing and data re-distribution, a parallel frontal solver, and algorithms for parallel mesh refinement and mesh reconciliation. The application was written in Fortran 90 and MPI, and the load balancing is done through an interface with the Zoltan library. Numerical results are presented for the model L-shape domain problem, and a highly anisotropic heat conduction (battery) problem from Sandia National Laboratories.