batterydata/paper-abstracts huggingface dataset:
Resumen Introducción Las descripciones de apraxia en la variante frontal de la demencia frontotemporal (DFT-vf) son a menudo aisladas y contradictorias (Blass & Rabins, 2009; Donoso & Salinas, 2009). Aún no han sido reportadas correlaciones entre apraxia y severidad de la demencia en la DFT-vf. Objetivo Estudiar la relación entre la severidad de la demencia y el déficit práxico en pacientes con DFT-vf. Comparar las pruebas de praxias con tareas de cognición social y funciones ejecutivas, en su capacidad de funcionar como indicadores de la severidad de la demencia en pacientes con DFT-vf. Pacientes y métodos Se evaluaron 24 pacientes con DFT-vf (Lund & Manchester, 1994; Neary et al., 1998). Se utilizó la Batería de Evaluación Cognitiva de Apraxias (Politis, 2003) para valorar el rendimiento práxico; y el Mini-Mental State Examination (Folstein et al., 1975), el Test del Reloj (Freedman et al., 1994) y la escala de Valoración Clínica de Demencia (CDR) (Hughes et al., 1982) para cuantificar el grado de deterioro cognitivo de cada paciente. Se utilizaron tareas de cognición social y función ejecutiva para evaluar dichos dominios. Resultados El desempeño en la batería de praxias correlacionó con las medidas de severidad de la demencia. Asimismo, los pacientes con mayor deterioro cognitivo rindieron significativamente peor en la batería de praxias. Conclusiones Estos resultados sugieren una relación entre praxias y severidad de la demencia en DFT-vf no descripta previamente en la bibliografía. Asimismo, la apraxia se presenta como un marcador cognitivo precoz de la DFT-vf, reforzando el hallazgo de alteraciones práxicas sistemáticas en este tipo de demencia (Rubinstein y Politis, 2007).
A thorough X-ray photoelectron spectroscopy (XPS) is carried out on the Sb/Na electrochemical cell to rationalize the different electrochemical performances in terms of irreversible capacity on first cycle, cumulated capacity losses, reversible capacity and capacity retention. Surface analysis of Sb electrode cycled versus sodium using three different electrolyte formulations by changing the nature of the salt (NaClO4 or NaPF6) and the nature of the solvents (PC or EC/DMC mixture) was performed by a combined XPS core peaks and quantification data analysis to establish the main components of the solid electrolyte interphase film (SEI) and its evolution on cycling. The passivation layer formed during cycling is mainly constituted of carbonates, Na2CO3 and alkylcarbonates, that appear during the discharge after the preferential deposition of NaF from the degradation of FEC. The solvent appears to have a key role, and the NaClO4/PC electrolyte, despite the high viscosity of its solvent gives the best compromise in terms of performances by forming a stable and thick SEI at the surface of all components of the composite electrode.
Mercury contained in buried landfill waste may be released via upward emission to the atmosphere or downward leaching to groundwater. Data from the US Geological Survey’s Amargosa Desert Research Site (ADRS) in arid southwestern Nevada reveal another potential pathway of Hg release: long-distance (102 m) lateral migration of elemental Hg (Hg0) through the unsaturated zone. Gas collected from multiple depths from two instrumented boreholes that sample the entire 110-m unsaturated zone thickness and are located 100 and 160m away from the closest waste burial trench exhibit gaseous Hg concentrations of up to 33 and 11ngm−3, respectively. The vertical distribution of gaseous Hg in the borehole closest to the disposal site shows distinct subsurface peaks in concentration at depths of 1.5 and 24m that cannot be explained by radial diffusive transport through a heterogeneous layered unsaturated zone. The inability of current models to explain gaseous Hg distribution at the ADRS highlights the need to advance the understanding of gas-phase contaminant transport in unsaturated zones to attain a comprehensive model of landfill Hg release.
A series of composites of Li4Ti5O12 particles well dispersed among graphene oxide (GO) nanosheets as binder-free anode materials for high capacity and rate lithium-ion batteries are prepared and investigated. The morphology, microstructure and elemental compositions of the as-prepared composites are characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. Electrochemical tests reveal that the electrode with GO content 10% presents a reversible Li-ion storage specific capacity of 201 mAh g−1 at 0.5C (1C = 175 mA g−1), and the specific capacity still maintain in 162 mAh g−1 even at 30C. Moreover, this composite exhibits an excellent cycling stability, with a first charge capacity of 162 mAh g−1 at 30C and less than 3% loss after 300 cycles. The addition of GO provides the additional capacity via oxygen-containing functional group and nano-cavity, additionally, replacing the CMC by GO, which makes the composite with CMC binder-free, speeds up the lithium ion diffusion in anode materials.
A stable and eco-friendly anion-exchange membrane (AEM) was prepared and applied in a non-aqueous all-copper redox flow battery (RFB). The AEM was prepared via a simple procedure, leading to a cross-linked structure containing quaternary ammonium groups without involvement of harmful trimethylamine. A network was thus constructed which ensured both ion transport and solvent resistance. The ion exchange capacity (IEC) of the membrane was tuned from 0.49 to 1.03 meq g−1 by varying the content of the 4, 4′-bipyridine crosslinking agent. The membrane showed a good anion conductivity and retention of copper ions. As a proof of principle, a RFB single cell with this crosslinked membrane yielded a coulombic efficiency of 89%, a voltage efficiency of 61% and an energy efficiency of 54% at 7.5 mA cm−2.
The stack shunt current of VRB (vanadium redox flow battery) was investigated with experiments and 3D (three-dimensional) simulations. In the proposed model, cell voltages and electrolyte conductivities were calculated based on electrochemical reaction distributions and SOC (state of charge) values, respectively, while coulombic loss was estimated according to shunt current and vanadium ionic crossover through membrane. Shunt current distributions and coulombic efficiency are analyzed in terms of electrolyte conductivities and stack cell numbers. The distributions of cell voltages and shunt currents calculated with proposed model are validated with single cell and short stack tests. The model can be used to optimize VRB stack manifold and channel designs to improve VRB system efficiency.
Spherical porous tin oxide was fabricated via a spray pyrolysis technique. TEM revealed that the primary SnO2 crystals had an average size of about 5nm. The electrochemical measurements showed that the spherical porous SnO2 samples have excellent cyclability, which can deliver a reversible capacity of 410mAhg−1 up to 50 cycles as a negative electrode for lithium batteries. The second step of the study was to thermal treat the initial tin oxide for 3h at 600, 800, 1000 and 1200°C, respectively, in order to identify the particle size effect on the electrochemical performance toward lithium. It was found that the morphologies of these spherical clusters could be maintained even after thermal treatment at 1200°C. It was also proved that finer the size of the tin oxide particles the better the electrochemical performance.
Cube-like and plate-like Li[Li0.2Mn0.54Ni0.13Co0.13]O2 particles are obtained after treated in LiCl and KCl molten salts at 800 °C, respectively, comparing to the ball-like original particles calcined in air. The oxide treated in KCl molten salt with large specific area of 17.05 m2 g−1 delivers high discharge capacities of 254.1 mAh g−1 and 168.5 mAh g−1 at current densities of 200 mA g−1 and 2000 mA g−1, respectively. In addition, enhanced cycle stability with capacity retention of 94.9% after 80 cycles at charge–discharge current densities of 200 mA g−1 is obtained for the oxide treated in LiCl molten salt with sacrifice of a little capacity. Such electrochemical performance change is proved to be independent of Li+ diffusion coefficient. It appears that the treatment in molten salts can effectively reform the electrochemical performances of Li[Li0.2Mn0.54Ni0.13Co0.13]O2 cathode materials for various applications.
A study was undertaken to explore whether the isotopic compositions of Pb and Sr are useful to distinguish mixtures of uncontaminated groundwater, seawater, and landfill leachate at the Fresh Kills landfill, Staten Island, New York. Ratios of 87Sr/86Sr ranged from 0.7088 to 0.7137 and could be used to distinguish Sr that was derived from seawater from that in uncontaminated groundwater. Lead isotopic abundances did not vary systematically among the different water sources. Plots of 87Sr/86Sr versus dissolved organic C, B, and NH4 + defined perpendicular trends, documenting where leachate or sea water mixed with uncontaminated groundwater, and demonstrating that leachate has not contaminated groundwater in aquifers beneath the landfill.
The development of high voltage electrolytes is one of the key aspects for increasing both energy and power density of electrochemical double layer capacitors (EDLCs). The usage of blends of ionic liquids and organic solvents has been considered as a feasible strategy since these electrolytes combine high usable voltages and good transport properties at the same time. In this work, the ionic liquid 1-butyl-1-methylpyrrolidinium bis{(trifluoromethyl)sulfonyl}imide ([Pyrr14][TFSI]) was mixed with two nitrile-based organic solvents, namely butyronitrile and adiponitrile, and the resulting blends were investigated regarding their usage in electrochemical double layer capacitors. Both blends have a high electrochemical stability, which was confirmed by prolonged float tests at 3.2V, as well as, good transport properties. In fact, the butyronitrile blend reaches a conductivity of 17.14mS·cm−1 and a viscosity of 2.46mPa·s at 20°C, which is better than the state-of-the-art electrolyte (1mol·dm−3 of tetraethylammonium tetrafluoroborate in propylene carbonate).
Recent research has highlighted the relationships between impairments in cognitive functioning and poorer functional outcomes among people with schizophrenia (PWS). The purpose of this study was to replicate and extend this work by testing the relationships between cognition and functional outcome among deaf adults with schizophrenia. Empirical findings from deafness-oriented research reveals enhanced abilities in certain aspects of visual–spatial processing compared to hearing people. Sixty-five PWS (34 deaf, 31 hearing) were assessed using measures of verbal and visual memory, attention, and visual processing. The first hypothesis tested whether cognition predicted functional outcome in a similar fashion for both deaf and hearing subjects (n =63). For all subjects, higher levels of cognitive ability were associated with higher levels of functional outcome, and the strongest predictors of outcome were verbal memory and visual–spatial memory (recall condition) (VSM recall). However, the deaf and hearing groups did show different patterns of relationships between cognition and functioning when all cognitive variables were examined. The second hypothesis was that deaf subjects would display superior performance in early visual processing, visual–spatial memory (copy condition) (VSM copy), and VSM recall. Deaf subjects displayed superior performance on each task; however, no significant differences emerged. Deaf subjects outperformed hearing subjects in an unexpected domain (word memory/recognition). This study extends prior work in the area of cognition and schizophrenia and indicates that deaf and hearing subjects may benefit from interventions that address different domains of cognition.
Direct borohydride fuel cells (DBFCs) exhibit the potential for a wide range of applications due to their high energy and power density; however, the hydrolysis of BH4 − significantly limits the use of DBFCs. In this paper, PdNix-B/carbon nanotubes (PdNix-B/CNTs) (x = 0, 0.3, 0.6, 0.9) composites have been prepared by a chemical reduction method in which PdNix-B nanoparticles of approximately 3.5 nm are grown on the surface of carbon nanotubes. A cell was assembled with PdNix-B/CNTs as the anode catalyst, a polymer fibre membrane (PFM) as a substitute for the Nafion membrane and LaNiO3 as the cathode catalyst. The results show that the Ni element displays an ability to balance the competition between the hydrolysis and oxidation of BH4 −. A peak power density of 105 mW cm−2 (x = 0.9) was achieved at 25 °C. However, the highest fuel efficiency of 69% was achieved at x = 0.3, and the corresponding power density was 87 mW cm−2, which represents the best comprehensive performance of these DBFCs.
Quantitative information on the molybdenum containing species produced by the reaction of aqueous cyanide with the amorphous molybdenum sulfide MoS3 has been obtained from extended X-ray absorption fine structure (EXAFS) studies. The results of this chemical excision study, in which Mo–Mo bonded triangular clusters are extracted from the solid, suggest that 70% of the molybdenum present in MoS3 is found in Mo3 clusters. This result is consistent with earlier diffraction and EXAFS experiments, but rules out the simplistic models proposed in those studies.
Due to rich redox sites and high electronic conductivity, multi-metal sulfides are considered as a competitive candidate for energy storage and conversion. Recently, nanostructure engineering and composition control are usually employed to enhance the electrochemical performance of metal sulfides. Herein, Fe3Ni6S8 solid solution anchored on N-doped carbon matrix (denoted as Fe3Ni6S8/N–C) with hierarchical structure is constructed through a facile freeze-drying/carbonization method using NaCl template. Fe3Ni6S8/N–C hybrid consists of interconnected porous carbon networks and nanoflakes can act as robust anode for sodium ion batteries (SIBs) and considerable electrocatalysts for hydrogen evolution reaction (HER). It delivers high capacity of 450.1 mAh g−1 at 10 A g−1, giving high capacity retention of 68.7% compared to that at 0.1 A g−1. And stable capacities of 596.6 mAh g−1 can be maintained for 180 cycles at 1.0 A g−1 as SIBs anode. When used as a HER catalyst, it exhibits a smaller Tafel slope of 55 mV dec−1 and superior long-term stability. The Fe3Ni6S8/N–C hierarchical structure can provide enhanced conductivity, rich active sites and rapid electron/ion transport channels, leading to impressive electrochemical performance.
The hydrogen absorption properties of LaNi4.8T0.2 (T=Mg, Bi and Sb) alloys are reported. The effects of the substitution of Ni in the LaNi5 compound with Mg, Bi and Sb are investigated. The ability of alloys to absorb hydrogen is characterized by the pressure–composition (p–c) isotherms. The p–c isotherms allow the determining thermodynamic parameters enthalpy (ΔH des ) and entropy (ΔS des ) of the dehydrogenation processes. The calculated ΔH des and ΔS des data helps to explain the decrease of hydrogen equilibrium pressure in alloys doped with Al, Mg and Bi and its increase in the Sb-doped LaNi5 compound. Generally, partial substitution of Ni in LaNi5 compound with Mg, Bi and Sb cause insignificant changes of hydrogen storage capacity compared to the hydrogen content in the initial LaNi5H6 hydride phase. However, it is worth to stress that, in the case of LaNi4.8Bi0.2, a small increase of H/f.u. up to 6.8 is observed. The obtained results in these investigations indicate that the LaNi4.8T0.2 (T=Al, Mg and Bi) alloys can be very attractive materials dedicated for negative electrodes in Ni/MH batteries.
Li4Ti5O12 has been considered as a promising electrode material for lithium secondary batteries. In this work a spray drying process was developed to prepare porous and spherical Li4Ti5O12 powders with Li2CO3 and rutile type TiO2 as precursors and PVB as forming agent of pores. The experimental results showed that porous and spherical morphology of the spray-dried powders was maintained during the sintering and the subsequent heat treatment. The oxygen atmosphere was demonstrated important to the electrochemical performance of the Li4Ti5O12 powders. However, overtime heat treatment would result in superfluous loss of lithium content and therefore led to obvious decrease of charge and discharge capacities.
An advanced cathode composite Na2.5Fe1.75(SO4)3/Ketjen/rGO for sodium ion batteries has been prepared, joining together the excellent electrochemical properties of the three components: off stoichiometric iron sulfate alluaudite, Ketjen Black carbon and reduced graphene oxide (rGO). This electrode material has been exhaustively characterized by XRD, thermogravimetric analysis, Raman spectroscopy and SEM and TEM microscopy. The study has demonstrated that a high quality electrode material has been designed containing a porous sulfate core properly coated by interweaved rGO fibers and Ketjen Black nanoparticles. The electrochemical study has revealed an excellent performance providing specific capacities close to the theoretical one at 1C. Additionally, this composite has shown a very good rate capability and a great cycling stability for at least 200 cycles maintaining a coulombic efficiency of 96%. The post mortem analysis, which includes EPR and XPS measurements, has demonstrated that the carbonaceous coating on the composite generates a stable and protective SEI layer over the active material guaranteeing a successful performance during a long cycle life.
This work reports the electrochemical characterization of a micro-scale FeSn2 electrode in a lithium battery. The electrode is proposed as anode material for advanced lithium ion batteries due to its characteristics of high capacity (500mAhg−1) and low working voltage (0.6V vs. Li). The electrochemical alloying process is studied by cyclic voltammetry and galvanostatic cycling while the interfacial properties are investigated by electrochemical impedance spectroscopy. The impedance measurements in combination with the galvanostatic cycling tests reveal relatively low overall impedance values and good electrochemical performance for the electrode, both in terms of delivered capacity and cycling stability, even at the higher C-rate regimes.
We synthesize Li(Li1/6Mn1/2Ni1/6Co1/6)O2 with a coprecipitation method, and study the electrochemical properties and the atomic configuration by means of galvanostatic charge–discharge test, neutron total scatterings, and the density functional theory calculation. From the average-structure analysis using the Bragg profile, that is, the Rietveld analysis, it is found that the sample has the Li2MnO3-type layered structure (space group; C2/m) and Ni and Co exist at both the two sites (4g and 2b sites) in the transition-metal layer. The DFT calculation indicates that there is a local atomic ordering denoted as LiMn6 in the transition-metal layer in the same way as Li2MnO3. Moreover, such a local structure can explain a reduced pair distribution function, G(r), derived from neutron total scatterings. Detailed investigation on the G(r) also suggests a local distortion along the c axis perpendicular to the layer.
A new process to obtain hydrogen from water using aluminum in sodium aluminate solutions is described and compared with results obtained in aqueous sodium hydroxide. This process consumes only water and aluminum, which are raw materials much cheaper than other compounds used for in situ hydrogen generation, such as hydrocarbons and chemical hydrides, respectively. As a consequence, our process could be an economically feasible alternative for hydrogen to supply fuel cells. Results showed an improvement of the maximum rates and yields of hydrogen production when NaAlO2 was used instead of NaOH in aqueous solutions. Yields of 100% have been reached using NaAlO2 concentrations higher than 0.65M and first order kinetics at concentrations below 0.75M has been confirmed. Two different heterogeneous kinetic models are verified for NaAlO2 aqueous solutions. The activation energy (E a) of the process with NaAlO2 is 71kJmol−1, confirming a control by a chemical step. A mechanism unifying the behavior of Al corrosion in NaOH and NaAlO2 solutions is presented. The application of this process could reduce costs in power sources based on fuel cells that nowadays use hydrides as raw material for hydrogen production.
With the aim of improving the electrochemical properties of this candidate cathodic material for lithium ion batteries, a vanadium oxide (V2O5) and polypyrrole (Ppy) hybrid was prepared using pyridinesulfonic acid (PSA) as additive. The hybrid synthesis has been carried out in the literature by chemical polymerization of pyrrole in the host inorganic matrix, using the V2O5 dispersed in an acidic solution as an oxidizing agent. In this work the hybrid has been synthesised with PSA giving good results compared to other samples of the pristine V2O5 and to the Ppy/V2O5 hybrid without additive. An improvement of about 20% in the charge storage capacity has been achieved. The reasons for this improvement are discussed and analyzed using different experimental techniques. The hybrid material has the added advantage of an improved performance without the addition of any binder or conducting element as a cathode in a lithium ion battery.
With the increasing demand for large-scale battery systems in electric vehicles (EVs) and smart renewable energy grids, organic materials including small molecules and polymers utilized as electrodes in rechargeable batteries have received increasing attraction. In recent years, two-dimensional (2D) organic materials possessing planar layered architecture exhibit optional chemical modification, high specific surface area as well as unique electrical/magnetic properties, which have been emerging as the promising functional materials for wide applications in optoelectronics, catalysis, sensing, etc. Integrating with high-density redox-active sites and hierarchical porous structure, significant achievements in 2D organic materials as cathode materials for alkali-metal-ion batteries have been witnessed. In this review, the recent progress in synthetic approaches, structure analyses, electrochemical characterizations of 2D organic materials as well as their application in alkali-metal-ion batteries containing lithium ion battery (LIB), lithium sulfur battery (LSB), lithium air battery (LAB) and sodium ion battery (SIB) are summarized systematically, and their current challenges including cycling stability and electron conductivity for cathode materials in battery fields are also discussed.
The feasibility of scaling-up the electrolytic production of carbon nanotubes in molten salts has been investigated with the aid of electron microscopy (TEM and SEM). Using molten LiCl as the electrolyte and commercial graphite as both cathode and anode materials, carbon nanomaterials, including nanotubes, were prepared by constant voltage electrolysis. The cell was more than 20 times as large as that used in previous work. The nanotube concentration in the final product increased with cell voltage (including iR drop) from 1 vol.% at 4.0 V to 35 vol.% at 8.4 V. Under desired conditions, the charge and energy consumption for the cathode erosion was 0.28 Ah/g and 4.1 Wh/g, of which 60–70 wt.% were for producing nanomaterials (nanotubes: >30 vol.%). When adding 1 wt.% SnCl2 to the electrolyte, partial and fully filled nanotubes were obtained with the nanomaterials containing up to 20 wt.% Sn. Preliminary results from applying the product as the electrode in lithium ion batteries are reported.