batterydata/paper-abstracts huggingface dataset:
Objective Organophosphate poisoning (OPP) is a significant cause of mortality in resource-poor countries, especially in economies such as that of South Africa where agricultural activity remains an important contributor to the economy. Long-term neurobehavioural sequelae of OPP have been reported in adults, but little is known about the neurodevelopmental outcomes of children who survive acute organophosphate pesticide poisoning, including that from domestic exposure. This study aimed to determine the performance of South African children surviving acute episodes of OPP on a standardized neurobehavioural battery compared to a control group of children previously admitted to hospital with paraffin poisoning. Methods Children were included who were 3–12 years with a previous admission for OPP to the Red Cross Children's Hospital, Cape Town. The control group comprised children admitted for paraffin poisoning and were matched to the index group for age, gender, home language, admission date and illness severity. All children were assessed for neurodevelopmental function. Caregivers were administered a questionnaire-based behavior rating scale, Achenbach System of Empirically Based Assessment. The neurodevelopmental performance and behaviour of OPP children was compared to that of the controls. Results A total of 91 children were tested, 46 OPP and 45 control children. No between group differences were found on any measures. Conclusion Although there were no significant differences between the children with OPP and those with acute paraffin exposure on preliminary analysis, possible explanations for this include sample size too small to detect subtle differences, exclusion from the study of children who had severe neurodisability or who had died due to OPP. Between group effects of these children may also have been masked by high prevalence risk factors in South Africa for poor development such as low socio-economic status, HIV exposure, maternal alcohol and smoking during pregnancy and poor maternal mental health.
The surfaces of LiCoO2 particles were modified to improve the charge-discharge cycling properties of Li-ion batteries containing LiCoO2 cathodes. The sol-gel technique was used to modify the surface of LiCoO2 particles with magnesium oxide. Capacity retention during cycling of the magnesium oxide-coated LiCoO2 cathode was superior to that of a cathode comprising pristine LiCoO2. Moreover, results obtained from TEM measurements indicate that the Li concentration was relatively homogeneous in the magnesium oxide-coated LiCoO2 particles after cycling tests. The crystallographic planes of the coating were found to be coherently oriented with those of the substrate, MgO(111)[1−10]//LiCoO2(003)[100]. Therefore, we believe that a thin cover of Mg on the surface of LiCoO2 stabilizes the surface, contributing to the homogeneity of charge and discharge reactions.
There was a small error in the program number of the acknowledgments and the correct version of the acknowledgments is shown below. This work was financially supported by the National Key R&D Program of China (No. 2016YFB0100400) and the National Natural Science Foundation of China (No. 51604032). The authors would like to apologize for any inconvenience caused.
This paper reports on a visual study of the CO2 bubble behavior in the anode flow field of an in-house fabricated transparent Direct Methanol Fuel Cell (DMFC), which consisted of a membrane electrode assembly (MEA) with an active area of 4.0 × 4.0cm2, two bipolar plates with a single serpentine channel, and a transparent enclosure. The study reveals that at low current densities, small discrete bubbles appeared in the anode flow field. At moderate current densities, a number of gas slugs formed, in addition to small discrete bubbles. And at high current densities, the flow field was predominated by rather long gas slugs. The experiments also indicate that the cell orientation had a significant effect on the cell performance, especially at low methanol flow rates; for the present flow field design the best cell performance could be achieved when the cell was orientated vertically. It has been shown that higher methanol solution flow rates reduced the average length and the number of gas slugs in the flow field, but led to an increased methanol crossover. In particular, the effect of methanol solution flow rates on the cell performance became more pronounced at low temperatures. The effect of temperature on the bubble behavior and the cell performance was also examined. Furthermore, for the present flow field consisting of a single serpentine channel, the channel-blocking phenomenon caused by CO2 gas slugs was never encountered under all the test conditions in this work.
Iron fluorides based on conversion chemistry are developed as alternative cathode materials for Li-ion batteries due to their high capacity, also suffering from some drawbacks, such as poor electrical conductivity and structural instability. In order to improve the electrochemical performance of iron fluoride, in this work, we focus on the enhancement of the lithium extraction capability of FeF3 by introducing extra C@LiF additive. FeF3/C@LiF composites are fabricated by high energy ball milling. Due to the compact connection between LiF and conductive carbon in FeF3/C@LiF composites, LiF can not only act as high-active reactant for lithium extraction process, but also provide active sites for subsequent charge/discharge reaction. Electrochemical study results suggest that a suitable content of LiF enables FeF3/C@LiF composite to deliver a satisfactory electrochemical performance, which retain a capacity of 229mAhg−1 at a current rate of 40mAg−1 after 50cycles (10% higher than that of FeF3/C composite).
Few tin (Sn)-oxide based anode materials have been found to have large reversible capacity for both sodium (Na)-ion and lithium (Li)-ion batteries. Herein, we report the synthesis and electrochemical properties of Sn oxide-based anodes for sodium-ion batteries: SnO, SnO2, and SnO2/C. Among them, SnO is the most suitable anode for Na-ion batteries with less first cycle irreversibility, better cycle life, and lower charge transfer resistance. The energy storage mechanism of the above-mentioned Sn oxides was studied, which suggested that the conversion reaction of the Sn oxide anodes is reversible in Na-ion batteries. The better anode performance of SnO is attributed by the better conductivity.
Neurocognitive impairment (NCI) remains prevalent in HIV-infected subjects despite effective combination antiretroviral therapy (CART). In subjects without evidence of hepatic decompensation, NCI is also a feature of chronic HCV infection. The present study aimed to examine cerebral function and establish differences between HIV-HCV co-infected (HCVco) and HIV mono-infected (HIVmo) individuals. Neurologically asymptomatic subjects with chronic HCVco were eligible and underwent computerized neurocognitive testing (CogState; CogState Ltd, Melbourne, Australia), a dementia assessment [International HIV Dementia Scale (IHDS)] and memory assessment [the Prospective and Retrospective Memory Questionnaire (PRMQ)]. Historic control data were available for 45 HIVmo individuals and differences between study groups were assessed. Twenty-seven HCVco subjects were recruited. Plasma HIV RNA was <50 copies/mL in 25/27 of HCVco subjects and all HIVmo subjects and nadir CD4+ cell count (mean ± SD) was 214 ± 166 cells/µL and 180 ± 130 cells/µL, in HCVco and HIVmo subjects, respectively. No statistically significant differences in neurocognitive parameters or PRMQ scores were observed between groups. However, a trend towards poorer executive function score was observed in HCVco subjects (p 0.106). IHDS score (mean ± SD) was poorer in HCVco subjects (10.48 ± 1.25) vs. HIVmo subjects (11.51 ±0.76), (p <0.001). In a multivariate model, increasing age and HCVco were the only factors significantly associated with poorer IHDS scores (p 0.039 and <0.001, respectively). In HIV-infected subjects stable on CART, statistically significantly poorer performance in the IHDS score was observed in subjects with HCVco, although no differences were observed after neurocognitive testing or memory assessment.
The subthalamic nucleus is targeted for the treatment of Parkinson’s disease. Unilateral lesions improve some aspects of parkinsonism but produce postural abnormalities in animal models but the exact pathways producing these effects remain to be defined. Using a battery of tests we evaluated the effects of lesioning one of the two major subthalamic targets, the substantia nigra pars reticulata in naı&#x0308;ve and 6-OHDA lesioned rats. Lesions targeting the mid-substantia nigra pars reticulata resulted in acute tonic–clonic seizures and intense contralateral rotational asymmetry. During the first month after substantia nigra pars reticulata lesions there was normalisation of the ipsilateral head position bias induced by unilateral 6-OHDA lesions, significant contralateral body axis bias but no significant alteration of apomorphine induced rotation and sensorimotor neglect in 6-OHDA lesioned rats. Combined with our previous data, this suggests that subthalamic projections via the substantia nigra pars reticulata are important in seizures and postural behaviours. Therefore unilateral subthalamotomy probably induces postural deficits in hemiparkinsonian animals via projections involving the substantia nigra pars reticulata. This has implications for patients undergoing subthalamotomy for treatment of Parkinson’s disease.
In the present work, effect of organically modified montmorillonite (MMT) clays on PMMA-based electrolytes has been investigated. The nanocomposites have been prepared by solution intercalation technique with varying clay loading from 0 to 5wt.%. The formation of partially exfoliated nanocomposites has been confirmed by XRD and TEM analyses. The obtained nanocomposites were soaked with 1M LiClO4 in 1:1 (v/v) solution of propylene carbonate (PC) and diethyl carbonate (DEC) to get the required gel electrolytes. Surface morphology and structural conformation of the nanocomposite electrolytes have been examined by SEM and FTIR analyses, respectively. It has been observed that the ionic conductivity of the nanocomposite gel polymer electrolytes increases with the increase in clay loading and attains a maximum value of 1.3×10−3 S/cm at room temperature as revealed by ac impedance spectroscopy. Improvement of electrochemical and interfacial stabilities has also been observed in the gel electrolytes containing MMT fillers.
Pure olivine LiFePO4 and LiFePO4/C composite powders are synthesized by using mechanical alloying (MA) and subsequent firing. The powder properties and the electrochemical characteristics of the prepared samples are investigated in comparison with those of a sample obtained by the conventional solid-state reaction. The olivine LiFePO4 prepared by MA shows a maximum discharge capacity of 135mAhg−1 at the C/20 rate (8.5mAg−1) when fired at a relatively low temperature of 600°C. A LiFePO4/C composite compound prepared by the MA process under optimum firing conditions has a high capacity of 156mAhg−1 at the C/20 rate, i.e. 92% of the theoretical capacity. The composite also displays a better rate capability, a higher charge–discharge capacity and a more stable cycle-life than when produced by the conventional solid-state method. The improved electrode performance of MA samples originates mainly from very fine particles of sub-micron size and with a rough surface morphology. These powder characteristics increases the surface area of LiFePO4 particles and maximizes the contact area with the conductor additive, which results in enhanced electronic conductivity. Consequently, the MA technique offers a promising synthetic process to overcome the disadvantages of olivine-type LiFePO4 and LiFePO4/C composite cathode materials for rechargeable lithium batteries.
A liquid carbon dioxide (l-CO2) based coating approach is developed for ultrathin, uniform, and conformal carbon coating of hierarchically mesoporous LiFePO4 (LFP) nano/microspheres for fabricating high-energy-density and high-power-density carbon coated LFP (C-LFP) with long-term cyclability. The unique properties of l-CO2 result in an ultrathin carbon layer (1.9nm) distributed all over the primary nano-sized LFP particles (20–140nm in diameter), forming a core (LFP)-shell (carbon) structure. This unique structure provides facile penetration of liquid electrolytes and rapid electron and Li-ion transport. C-LFP exhibits high reversible capacity, high energy and power density (168mAhg−1 at 0.1C, 109Whkg−1 and 3.3kWkg−1 at 30C, respectively) with excellent long-term cyclability (84% cycle retention at 10C after 1000 cycles). In addition, the ultrathin and uniform carbon layer of the mesoporous microspheres allows a high tap density (1.4gcm−3) resulting in a high volumetric energy density (458WhL−1 at a 30C rate). Furthermore, C-LFP presents a high capacity and stable cycling performance under low-temperature and high-temperature environment. Well-developed carbon coating approach in this study is simple, scalable, and environmentally benign, making it very promising for commercial-scale production of electrode materials for large-scale Li-ion battery applications.
Here the binder-free nickel foam supported nitrogen-doped carbon nanotubes (N-CNTs@Ni) are synthesized by a floating catalyst chemical vapor deposition (FCCVD) method. Without any additional treatment, it could be employed as the air electrode in the lithium-oxygen batteries and delivers 1814 mAh g−1 (normalized to the weight of the air electrode) at the current density of 0.05 mA cm−2. The loose packing 3-dimension network structure facilitates the O2 diffusion in the inner electrode and provides enough void volume for the products deposition during discharge process. The improved contact between N-CNTs and the current collector Ni is beneficial to suppress the volume expansion and leads to less polarization as well as good cycling performance.
Cubic spinel Co2SnO4 nanocrystals are successfully synthesized via a simple hydrothermal reaction in alkaline solution. The effect of alkaline concentration, hydrothermal temperature, and hydrothermal time on the structure and morphology of the resultant products were investigated based on X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It is demonstrated that pure Co2SnO4 nanocrystals with good crystallinity can be obtained in NaOH solution (2.0M) at 240°C for 48h. The galvanostatic charge/discharge and cyclic voltammetry were conducted to measure the electrochemical performance of the Co2SnO4 nanocrystals. It is shown that Co2SnO4 nanocrystals exhibit good electrochemical activity with high reversible capacity (charge capacity) of 1088.8mAhg−1 and good capacity retention as anode materials for Li-ion batteries, much better than that of bulk Co2SnO4 prepared by high temperature solid-state reaction.
We have studied a new electrolyte additive, 1,1-diphenylethane (DPE), to LiCoO2/graphite cells to reduce capacity loss during high temperature storage. It is demonstrated to be effective to reduce polarization after storage at 60 °C for one month in charged state. In half-cell tests, a LiCoO2/Li cell with DPE additive in electrolyte shows less capacity loss than that without DPE, while no significant difference is observed between DPE-added and DPE-free graphite/Li half cells. Scanning electron microscopy, X-ray diffraction, electrochemical impedance spectroscopy, time of flight-secondary ion mass spectroscopy, and hard X-ray photoelectron spectroscopy measurements are applied to elucidate the mechanism how DPE suppresses the increase in electrode resistance and polarization during the high temperature storage. All the results consistently show that less amount of surface layer is formed by electrolyte decomposition on LiCoO2 electrode surface in DPE-added electrolyte than the DPE-free one, leading to reduction of the electrode resistance and polarization.
Chitosan was applied as the electrode binder material for a spherical graphite anode in lithium-ion batteries. Compared to using poly (vinylidene ﬂuoride) (PVDF) binder, the graphite anode using chitosan exhibited enhanced electrochemical performances in terms of the first Columbic efficiency, rate capability and cycling behavior. With similar specific capacity, the first Columbic efficiency of the chitosan-based anode is 95.4% compared to 89.3% of the PVDF-based anode. After 200 charge–discharge cycles at 0.5C, the capacity retention of the chitosan-based electrode showed to be significantly higher than that of the PVDF-based electrode. Electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM) measurements were carried out to investigate the formation and evolution of the solid electrolyte interphase (SEI) formed on the graphite electrodes. The results show that a thin, homogenous and stable SEI layer is formed on the graphite electrode surface with chitosan binder compared with that using the conventional PVDF binder
The effect of poly(ethylene oxide) (PEO)-based surfactant in the gel polymer electrolyte on the cycling efficiency of lithium was investigated by means chronopotentiometry. The gel polymer electrolyte was prepared by thermal curing using bisphenol A ethoxylate diacrylate as a cross-linker. While an improvement in cycling efficiency of lithium was found for the electrolytes containing both of perfluorinated and star-shaped PEO-based surfactants, the better cycling efficiency was observed for the star-shaped surfactants than that for the perfluorinated surfactant. More than 90% of cycling efficiency of lithium was achieved for the polymer electrolyte using star-shaped PEO surfactants. The cycling efficiency of lithium in the gel polymer electrolyte containing star-shaped surfactant increased as increasing of the molecular weight of side chain. By using star-shaped PEO surfactant, the interface resistance was almost constant during the repeated cycles. The star-shaped PEO-based surfactants seem to be very effective to form stable SEI layer.
This study was an attempt to investigate the relationship between motivation/attitude and L2 writing. Participants were randomly selected from a total population of 30M.A. students of TEFL. Data were collected through using Gardner's Attitude/Motivation Test Battery Questionnaire and a Writing Proficiency Test (Arnold, 1991; Tompkins, 2004) to assess the participants’ English writing proficiency level, respectively. Although running Pearson-product correlation indicated no relationship between the participants with instrumental type of motivation and success in L2 academic writing, there was a relationship between the participants with integrative type of motivation and the writing skill. Moreover, there was no relationship between negative attitude and success in L2 writing, but there was a relationship between positive attitude and the writing skill. Pedagogical implications are presented throughout the paper.
This paper presents a new inorganic rechargeable battery system with LiCoO2 as the positive electrode of the battery whereas metallic lithium is plated onto the negative current collector. The electrolyte is based on LiAlCl4 and SO2. The inorganic character of the battery results in a new principle of operation which affords only a limited amount of metallic lithium in the cell. The positive intercalation electrode determines the amount of lithium in the cell in its charged state. Compared to other metallic lithium battery systems, no surplus of lithium is needed. This leads to a safe and reliable accumulator with excellent performing characteristics for electric vehicle and cordless tools applications.
Capacity loss due to electrolyte crossover through the membrane and pump losses due to pressure drop at the porous electrodes are widely known issues in vanadium redox flow batteries during operation. In commercial systems, these losses account for a significant reduction in the overall efficiency. Previous studies have been focused on the development of new membranes to solve the capacity loss, and design modification to reduce the pressure drop. In this work, we propose unique solutions to solve both problems and are demonstrated in a multi-cell stack for the first time. A 20-cell, 1 kW vanadium redox flow battery stack was assembled using thin bipolar plates and porous electrodes featuring interdigitated flow channels. Such a stack design is novel of its kind and can mitigate various problems associated with flow distribution and pump power in flow batteries. In addition, the electrolyte tanks were shunted together to rebalance the electrolyte automatically. The stack showed a very good and stable performance with an energy efficiency of 80.5% at a current density of 80 mA cm−2. The use of hydraulic shunt resulted in a constant capacity over 250 cycles while the use of flow channels on the porous electrodes resulted in ∼40% reduction in pressure drop, compared to a stack with standard felts. The reduction in pressure drop by employing flow channels reduced the pump power proportionally. Overall, capacity retention and utilization of active materials have been improved substantially. These methods are simple and applicable to any size of vanadium redox flow battery.
A new kind of modified electrode fabricated by mechanically attaching terbium hexacyanoferrate (TbHCF) samples to the surface of carbon ceramic electrodes (CCEs) derived from sol–gel technique was proposed. The resulting modified electrodes exhibit well-defined redox responses with the formal potential of +0.225V (vs. SCE) at a scan rate of 20mVs−1 in 0.5M KCl (pH 7) solution. The voltammetric characteristics of the TbHCF-modified CCEs in the presence of different alkali metal cations (Li+, Na+, K+, Rb+ and Cs+) were investigated by voltammetry. The TbHCF-modified CCEs presented a good electrocatalytic activity toward the ascorbic acid (AA) and was used for amperometric detection of AA. The diffusion coefficient (D) of AA in solution and the catalytic rate constant (k cat) were also calculated by chronoamperometry experiment. In addition, the TbHCF-modified CCEs exhibited a distinct advantage of the ability for amperometric detection of AA in the presence of uric acid (UA) by controlling the applied potential at low value (0.25V).
Inorganic ceramics- and organic polymer-based solid electrolytes (SE) could revolutionize battery technology because of their nontoxicity, stability during operation and enhanced safety. Of particular interest are electrolytes, which contain high concentrations of ion charge carriers with a minimum polymer concentration, and enable the major ion-conduction path through the inorganic material. In this article we compare ion-conduction mechanisms in two solid electrolytes composed of either an inert or active ceramic matrix with imbedded LiI:P(EO)n electrolytes. On the basis of AC-impedance and NMR data, we suggest that the high-ionic-conductivity (0.5 mS/cm) and low-activation-energy (2.3 kJ/mol) ion paths are brought about by the grain boundaries between the excess of LiI and inert LiAlO2 ceramic nanoparticles. Both confined-in-ceramic polymer electrolyte (PE) and ceramic LiAlO2 grains impede the total ion mobility. The fast ion transport in polymer-in-ceramic electrolytes composed of high-conductivity active Li10SnP2S12, goes through lithium-iodide-rich glass ceramics, and is restricted by slow ion transport via the imbedded polymer electrolyte. Unexpectedly, it was found that at 1:3 salt-to-polymer ratio, the contribution of grain-boundary conductivity in an inert-ceramic–based composite electrolyte is stronger than that of bulk conductivity via active ceramic matrix. One of the possible reasons of the reduced relative contribution of the active ceramics to the total conductivity of polymer-in-ceramic electrolyte is that the ceramic powder was not densified.