batterydata/paper-abstracts huggingface dataset:
The conductivity of LiBOB based electrolyte, which we formed in our lab, has been compared with commercialized LiPF6 based electrolyte firstly. The charge and discharge capacity of the LiFePO4/Li half-cell with two kind of electrolyte has compared both at room temperature and elevated temperature. LiBOB cell presented better charge/discharge stability at elevated temperature than the counterpart. ICP method was adopted to analyze the reaction of electrolytes with cathode material at high temperature. Cyclic voltammogram was conducted to analyze the charge/discharge process of the cell in both LiBOB based electrolyte and LiPF6 based electrolyte at different temperature.
Cognitive deficits represent a significant characteristic of schizophrenia. However, a majority of the clinical studies have been conducted in antipsychotic drug treated patients. Thus, it remains unclear if significant cognitive impairments exist in the absence of medication. This is the first meta-analysis of cognitive findings in drug-naïve patients with schizophrenia. Cognitive data from 23 studies encompassing 1106 patients and 1385 controls published from 1992 to 2013 were included. Tests were to a large extent ordered in cognitive domains according to the Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) battery. Analysis was performed with STATA using the random-effects model and heterogeneity as well as Egger's publication bias was assessed. Overall the results show that patients performed worse than healthy controls in all cognitive domains with medium to large effect sizes. Verbal memory, speed of processing and working memory were three of the domains with the greatest impairments. The pattern of results is in line with previous meta-analytic findings in antipsychotic treated patients. The present meta-analysis confirms the existence of significant cognitive impairments at the early stage of the illness in the absence of antipsychotic medication.
The traditional electrolyte for lithium-ion batteries is a combination of 1 M LiPF6 with a cyclic carbonate-based solvent (for example, ethylene carbonate). The lack of a suitable alternative solvent has hindered further exploration of new functional electrolytes. Here we design and synthesize a fluorinated cyclic phosphate solvent, 2-(2,2,2-trifluoroethoxy)-1,3,2-dioxaphospholane 2-oxide (TFEP), for use in lithium-ion batteries. Our design rationale is that this solvent molecule has a fused chemical structure of cyclic carbonates that can form a stable solid electrolyte interphase and organic phosphates that can trap hydrogen radicals and prevent combustion. An electrolyte formula composed of 0.95 M LiN(SO2F)2 in TFEP/2,2,2-trifluoroethyl methyl carbonate shows excellent non-flammability with zero self-extinguishing time and enables the highly stable operation of graphite anodes (~0.1 V versus lithium) and high-voltage LiNi0.5Mn1.5O4 cathodes (~4.7 V versus lithium), and thereby outperforms traditional electrolytes. This work opens up new frontiers in electrolyte developments towards safe lithium-ion batteries with higher energy densities.
A series of Pb–Na alloys were synthesized by adding sodium to lead. Linear sweep voltammetry (LSV), cyclic voltammograms (CV), electrochemical impedance spectroscopy (EIS), open circuit potential (OCP), and other analytical methods were used to investigate the electrochemical performances of the Pb–Na alloys in 1.28gcm−3 H2SO4 solution. The results indicate that the addition of sodium reduces the generation of PbO and PbSO4 greatly during anodic process, inhibits the oxygen evolution reaction and accelerates the evolution of hydrogen, and the Pb–Na alloys have good cycle performance and corrosion resistance properties. The alloys retain the merits, whilst removing the flaws, of the pure grid, thereby providing a promising positive grid alloy for spirally wound lead acid batteries.
Weblogs, or blogs, have rapidly gained in popularity over the past few years. In particular, the growth of business blogs that are written by or provide commentary on businesses and companies opens up new opportunities for developing blog-specific search and mining techniques. In this paper, we propose probabilistic models for blog search and mining using two machine learning techniques, latent semantic analysis (LSA) and probabilistic latent semantic analysis (PLSA). We implement the models in our database of business blogs, BizBlogs07, with the aim of achieving higher precision and recall. The probabilistic model is able to segment the business blogs into separate topic areas, which is useful for keywords detection on the blogosphere. Various term-weighting schemes and factor values were also studied in detail, which reveal interesting patterns in our database of business blogs. Our multi-functional business blog system is indeed found to be very different from existing blog search engines, as it aims to provide better relevance and precision of the search.
The increasing penetration of intermittent renewable energy sources has renewed interest in energy storage methods and technologies. This paper describes a gravitational potential energy storage method. A review of current storage methods that make use of the principle of gravitational potential energy is done, with a comparison given in terms of power, energy rating and round trip efficiency. One of these gravitational energy storage methods, involving moving a solid mass vertically up and down, is further analysed in terms of energy storage capacity, energy and power density and the levelised cost of storage. Two different hoisting methods are discussed, the first of which is the traditional drum winder hoist and the second is a proposed, multi-piston hoist based on the use of linear electric machines. The two hoist methods produce storage systems with distinctly different properties and storage applications.
Thermal gravimetric analysis (TGA) and differential thermal analysis (DTA) involving air oxidation of fluid coke, coal-tar pitch delayed coke and needle coke suggested that active sites are present which can be correlated to the crystallographic parameters, L a and L c , and the d(002) spacing. This finding was extended to determine the relationship between active sites on carbon and their role in catalyzing electrolyte decomposition leading to irreversible capacity loss (ICL) in Li-ion batteries. Electrochemical data from this study with graphitizable carbons and from published literature were analyzed to determine the relationship between the physical properties of carbon and the ICL during the first charge/discharge cycle. Based on this analysis, we conclude that the active surface area, and not the total BET surface area, has an influence on the ICL of carbons for Li-ion batteries. This conclusion suggests that the carbon surface structure plays a significant role in catalyzing electrolyte decomposition.
PEDOT-PSS coated nanostructured Ge anodes were prepared for lithium-ion batteries. The obtained binder-free electrodes show excellent electrochemical performance. The representative anode exhibits a reversible capacity of 640mAhg−1 after 1000 cycles at a current density of 2Ag−1, which is much better than the nanostructured Ge anodes without PEDOT–PSS coating. The significantly enhanced cycle performance can be attributed to that the PEDOT-PSS coating highly facilitates the structural integrity of the electrode.
In the present study, are reported investigations obtained with the room temperature molten salt (RTMS) ethyl-methyl-imidazolium bis-(trifluoromethanesulfonyl)-imide (EMI-TFSI) in order to use it as solvent in lithium battery. The thermal stability, viscosity, conductivity and electrochemical properties are presented. A solution of 1m lithium bis-(trifluoromethanesulfonyl)-imide (LiTFSI) in EMI-TFSI has been used to test the electrolyte in a battery with LiCoO2 and Li4Ti5O12 as respectively cathode and anode materials. Cycling and power measurements have been obtained. The results have been compared with those obtained with a molten salt formulated with a different anion, BF4 − and with a conventional liquid organic solvent EC/DMC containing LiTFSI. The 1m LiTFSI/EMI-TFSI electrolyte provides the best cycling performance: a capacity up to 106mAhg−1 is still delivered after 200 cycles, with 1C rate at 25°C.
Knowing and highlighting a link between gender and motivational and cognitive aspects that shape attitude towards work may be useful in streamlining the process of recruitment and selection in the corporate environments. This research aims to study gender differences on attitudes towards work among young students. The overall objective of this research is to highlight the link between gender and attitude towards work. In the research a number 90 subjects aged 18 to 24 years (45 female students and 45 male students) have participated. After statistical processing of data, the results do not confirm statistically significant differences between genders in the measured values of subtests of the AHA battery.
Traditional solid electrolyte interphase (SEI) forming additives of vinylene carbonate (VC), fluoroethylene carbonate (FEC) and ethylene sulfite (ES) are studied with respect to their impact on the formation and growth of the cathode electrolyte interphase (CEI) layer. T-half cells are assembled and undergo three different electrochemical investigation plans: after formation (0.1C, 5 cycles) and long term cycling (0.1C, 5 constant current cycles + 1C, 100/150 constant current/voltage cycles), scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and gas chromatography-mass spectrometry (GC-MS) are combined to investigate morphology, CEI composition, CEI thickness and aging products for cells with different electrolyte systems. The obtained results reveal a significant influence of these additives on the CEI composition and CEI growth. With the help of SEM, it is found that large areas of electrolyte decomposition products are formed at the aged electrode surfaces (=after cycling), with the exception when 2 vol% of FEC is added into the reference electrolyte. From XPS measurements, CEI thicknesses are calculated. The reference electrolyte with 2 vol% of FEC shows the thinnest layer after long time aging (0.8 ± 0.2 nm). For the addition of 2 vol% of VC, an incremental growth of the CEI thickness occurs from the 100th to 150th cycle (from 1.0 ± 0.1 nm to 2.9 ± 0.4 nm). By correlating the CEI thickness values with the electrochemical performance, it can be observed that for lithium metal based half cells, the existence of a thinner CEI layer corresponds to a better cycling behavior, with 2 vol% of FEC showing the highest discharge capacity of 114.4 ± 0.2 mAh/g after 150 cycles at 1C. GC-MS shows that both VC and FEC help to prevent fast electrolyte aging.
Publisher Summary The actual density of a solid substance, even of a relatively small individual crystal, may be measured by determining the density of an inert liquid mixture in which the crystal remains just suspended. A crystal of sodium nitrate (2260 kgm-3) could be floated in about 50 mL of bromoform in a suitable flask—taking care that no air bubbles are attached—and then made to achieve the “just suspended” state by slowly adding chloroform from a burette. At this point, the crystal density may be assumed to be equal to that of the liquid mixture, which can readily be estimated. Solid densities have very small temperature dependence, but this can be ignored for industrial crystallization purposes.
Detection of human immunodeficiency virus (HIV) infections has been enhanced by incorporating p24 antigen detection with current HIV antibody detection using enzyme immunoassays (EIAs). However, screening for HIV antibodies has increased through the use of rapid, lateral-flow HIV antibody detection assays that currently do not have the capability to detect HIV p24 antigen. In this report, a lateral-flow based assay using super-paramagnetic particles as the detection marker was developed for the detection of HIV-1 p24 antigen. This magnetic immuno-chromatographic test (MICT) uses an inexpensive, low-maintenance instrument that detects the magnetic moment of the super-paramagnetic particles in a magnetic field. MICT is simple to perform, provides a numerical output for easier determination of reactive results and can be completed in 40min. The lower limit of detection for HIV-1 p24 spiked into assay sample buffer and 50% plasma was 30pg/ml for both. Detection of HIV-1 p24 antigen at 50pg/ml was reproducible in both inter-run and intra-run assays with coefficients of variation of <13%. Furthermore, the MICT p24 assay was able to detect intact virus spiked into 50% plasma (lower detection limit of ∼250,000 viral RNA copies/ml). MICT detection of increasing HIV-1 p24 levels in commercially available seroconversion panels by MICT was only slightly later than that detected by much more complex EIAs. MICT could provide a simple, low-cost, and portable method for rapid HIV-1 p24 detection in a variety of testing environments.
The reasons for the rapid and widespread successes of continuous titration solution calorimetry, isothermal power-compensation flow calorimetry, high-precision heat-conduction calorimetry, and temperature-scanning heat-conduction calorimetry are examined. The characteristics of these successes are used to make general predictions about the future of calorimetry.
We present a novel fabrication route yielding Raney-platinum film electrodes intended as glucose oxidation anodes for potentially implantable fuel cells. Fabrication roots on thermal alloying of an extractable metal with bulk platinum at 200°C for 48h. In contrast to earlier works using carcinogenic nickel, we employ zinc as potentially biocompatible alloying partner. Microstructure analysis indicates that after removal of extractable zinc the porous Raney-platinum film (roughness factor ∼2700) consists predominantly of the Pt3Zn phase. Release of zinc during electrode operation can be expected to have no significant effect on physiological normal levels in blood and serum, which promises good biocompatibility. In contrast to previous anodes based on hydrogel-bound catalyst particles the novel anodes exhibit excellent resistance against hydrolytic and oxidative attack. Furthermore, they exhibit significantly lower polarization with up to approximately 100mV more negative electrode potentials in the current density range relevant for fuel cell operation. The anodes’ amenability to surface modification with protective polymers is demonstrated by the exemplary application of an approximately 300nm thin Nafion coating. This had only a marginal effect on the anode long-term stability and amino acid tolerance. While in physiological glucose solution after approximately 100h of operation gradually increasing performance degradation occurs, rapid electrode polarization within 24h is observed in artificial tissue fluid. Optimization approaches may include catalyst enhancement by adatom surface modification and the application of specifically designed protective polymers with controlled charge and mesh size.
Solid polymer electrolytes (SPEs) are currently attracting extensive interest as Li-ion conducting materials for building safe and high energy density rechargeable lithium metal batteries due to their low flammability and ease in process. The structural design of polymer matrices could effectively regulate the physicochemical and electrochemical properties of SPEs, thereby enhancing the performance of rechargeable all solid-state lithium metal batteries (ASSLMBs). Herein, we report a new type of flowable polymer electrolyte (FPE), containing a liquid-like polymer with highly conductive polyether side chains and sulfonimide lithium salts [i.e., lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and lithium bis(fluorosulfonyl)imide (LiFSI)]. The high amorphicity and segmental mobility of the liquid-like polymer matrices facilitate fast ionic transport, thus leading to the highest ionic conductivity reported (6.6 × 10−4 S cm−1 at 70 °C and 1.4 × 10−4 S cm−1 at 30 °C). The introduction of FPE as a buffer layer between Li metal (Li°) electrode and poly(ethylene oxide)-based SPE decreases the interfacial resistivity of Li°/electrolyte and improves remarkably cyclability and coulombic efficiency of the Li° || LiFePO4 cell. These results suggest that the FPEs are promising candidates for lithium metal protection in ASSLMBs.
Writing is a complex task that requires the integration of multiple cognitive, linguistic, and motor abilities. Until now, only a few studies investigated writing abilities in individuals with Intellectual Disability (ID). The aim of the present exploratory study was to provide knowledge on the organization of writing in two populations with ID, Down syndrome (DS) and Williams syndrome (WS), trying to disentangle different components of the process. A battery tapping diverse writing demands as low-level transcription skills as well as high-level writing skills was proposed to 13 individuals with WS, 12 individuals with DS and 11 mental-age-matched typically developing (TD) children. Results showed that the two groups with genetic syndromes did not differ from TD in writing a list of objects placed in bedroom, in the number of errors in the text composition, in a text copying task and in kind of errors made. However, in a word dictation task, individuals with DS made more errors than individuals with WS and TD children. In a pseudoword dictation task, both individuals with DS and WS showed more errors than TD children. Our results showed good abilities in individuals with ID in different aspects of writing, involving not only low-level transcription skills but also high-level composition skills. Contrary to the pessimistic view, considering individuals with ID vulnerable for failure, our results indicate that the presence of ID does not prevent the achievement of writing skills.
In this paper we compare the behavior of non-spherical and spherical β-Ni(OH)2 as cathode materials for Ni–MH batteries in an attempt to explore the effect of microstructure and surface properties of β-Ni(OH)2 on their electrochemical performances. Non-spherical β-Ni(OH)2 powders with a high-density are synthesized using a simple polyacrylamide (PAM) assisted two-step drying method. X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM), thermogravimetric/differential thermal analysis (TG–DTA), Brunauer–Emmett–Teller (BET) testing, laser particle size analysis, and tap-density testing are used to characterize the physical properties of the synthesized products. Electrochemical characterization, including cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and a charge/discharge test, is also performed. The results show that the non-spherical β-Ni(OH)2 materials exhibit an irregular tabular shape and a dense solid structure, which contains many overlapped sheet nano crystalline grains, and have a high density of structural disorder and a large specific surface area. Compared with the spherical β-Ni(OH)2, the non-spherical β-Ni(OH)2 materials have an enhanced discharge capacity, higher discharge potential plateau and superior cycle stability. This performance improvement can be attributable to a higher proton diffusion coefficient (4.26×10−9 cm2 s−1), better reaction reversibility, and lower electrochemical impedance of the synthesized material.
Cadmium is a toxic agent that it is also an environmental contaminant. Cadmium exposure may be implicated in some humans disorders related to hyperactivity and increased aggressiveness. This study presents data indicating that cadmium induces cellular death in cortical neurons in culture. This death could be mediated by an apoptotic and a necrotic mechanism. The apoptotic death may be mediated by oxidative stress with reactive oxygen species (ROS) formation which could be induced by mitochondrial membrane dysfunction since this cation produces: (a) depletion of mitochondrial membrane potential and (b) diminution of ATP levels with ATP release. Necrotic death could be mediated by lipid peroxidation induced by cadmium through an indirect mechanism (ROS formation). On the other hand, 40% of the cells survive cadmium action. This survival seems to be mediated by the ability of these cells to activate antioxidant defense systems, since cadmium reduced the intracellular glutathione levels and induced catalase and SOD activation in these cells.
The effect of low molecular weight borate ester on the ionic conductivity of polyacrylonitrile (PAN) was systematically investigated by means of measuring conductivity using the impedance technique. Gel polymer electrolyte (SPE) films consisting of PAN as host polymer, LiCF3SO3 and LiBF4 as ionic salts, and poly (ethylene glycol) borate ester (PEGB), ethylene carbonate/propylene carbonate (EC/PC) as plasticizers were prepared by physical blending method. All measurements were performed on electrolyte samples with various contents. Fourier transform infrared spectroscopy (FT-IR) gave evidence of the interactions among PAN, plasticizers and lithium salt. The surface morphology of the electrolytes was investigated by scanning electron microscopy (SEM). Thermal properties of these materials were searched with thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Conductivity studies of these blend polymer electrolytes were carried out in the temperature range 20–100°C. The maximum ionic conductivity values of 1.8×10−3 and 1.4×10−4 Scm−1 were measured for the film containing 4PAN-10EC/PC-4LiBF4 and 4PAN-10PEGB-4LiCF3SO3, respectively, at room temperature. These films have a good conductivity, better dimensional stability and wide electrochemical stability window. These unique properties make the composite gel membranes suitable for application as electrolyte in rechargeable Li-ion batteries.
In this paper a MATLAB/Simulink based generalised electrical equivalent model of Vanadium Redox Flow Battery (VRFB) has been proposed with an objective of interfacing VRFB with renewable energy sources. The impact of practical parameters like flow rate, self discharge, pump power loss and charge-discharge current profile has been considered for analysing VRFB performance. The model involves online estimation of VRFB stack terminal voltage and state of charge (SOC) under different constant current charge-discharge profiles. The accurate estimation of electrical characteristics of VRFB leads to a benchmark for selection of the design parameters of an efficient charge controller taking into account the variability of renewable energy sources. An optimal range of variable electrolyte flow rates for dynamic SOC has been estimated to design suitable flow rate controller. This ensures minimum VRFB system power consumption during charging and maximum power output during discharging which leads to maximum overall VRFB system efficiency. A generic MATLAB library has also been created for optimal design of any generalised VRFB system. A practical 20 Cell 1kW 6h VRFB system has been used for experimental validation of simulation results of the proposed model which shows a very good agreement having maximum error within 0.5% and 0.21% for VRFB cell terminal voltage estimation during charging and discharging respectively. The proposed model of the VRFB system is then applied for interfacing and investigating the performance of a 1kW 6h VRFB with a microgrid system comprising of 10kW Solar PV, local loads and distribution grid.