batterydata/paper-abstracts huggingface dataset:
Background Acute CNS inflammatory demyelination in childhood may induce permanent cognitive impairment. However, there has been no epidemiological assessment of prognostic factors for school performance in a cohort of children with such a disease. Methods The cohort consisted of 344 children from the French “KIDSEP” neuropediatric cohort with at least one clinically defined attack of CNS inflammatory demyelination occurring before the age of 16 years, and with at least two years of follow-up (inclusion from 1990 to 2003, follow-up until June 2007). We used multivariate survival analysis (Cox model) to evaluate the prognostic value for grade retention between the start of elementary school (∼6 years of age) and the end of high school (∼17–18 years of age), of variables related to both the socioeconomic status of the parents and the characteristics of the disease at onset. Results The cohort was monitored for a mean of 8.0±3.4 years. Grade retention after disease onset was recorded for 151 patients (43.9%). The risk of grade retention was significantly higher for boys, children from families with lower social status and poorer housing conditions, children over the age of 11 years at disease onset and children suffering optic neuritis or brainstem dysfunction at the first attack or irreversible disability, even if only moderate, following the first attack. Conclusions The risk factors for poor school performance are related to low socioeconomic status and to factors predictive of a relapsing severe course of the disease, leading to the diagnosis of multiple sclerosis.
This paper aims at emphasizing the level of some fitness components and subjects’ deficient areas requiring a specific training, as well as identifying the results trend between the 2006 and 2009 assessments, in athletes with intellectual disabilities (ID). The Fun Fitness battery test used in this study is acknowledged by kinetotherapists and by specialists in adapted physical activities. As more training periods and competitions are available for the athletes, we should have expected a significant improvement in 2009 as compared to 2006 in all the tested components, but except for the strength, results don’t emphasize a unitary progress trend.
Harvesting energy from ambient mechanical motions addresses limitations of traditional power supplies by providing a sustained electric power source. Here, a high-performance rotary triboelectric nanogenerator (r-TENG) is applied in a variety of circumstances to specifically harvest mechanical energy from human body motions. When rotating at 500rmin−1, it can produce an ac electric output that has a current amplitude of 0.75mA and a voltage amplitude of 200V at a frequency of 750Hz. Integrated with structural components that transfer mechanical motions and electric components that achieve power management, the r-TENG is demonstrated as a power source by harvesting energy from foot pedaling, arm swinging and foot pressure. The generated electricity can effectively charge consumer electronics such as a cellphone, which shows the promise of the r-TENG as a power source for portable, wearable and even implantable electronics.
Stainless-steel mesh electrodes coated with polybithiophene, obtained by electrochemical polymerization (constant potential and constant current), have been investigated as cathode materials in a lithium–polybithiophene rechargeable battery by cyclic voltammetry, electrochemical impedance spectroscopy and long-term charge–discharge cycling process. The effects of different growth methods on the surface morphology of the films and the charge–discharge capacity are discussed in detail. The results show that polybithiophene-hexafluorophosphate is a very promising cathode material for manufacturing lithium–polymer rechargeable batteries with a highly stable discharge capacity of 81.67mAhg−1 after 50 cycles.
The electrochemical performance of lithium ion battery (LIB) is strongly affected by the micro-structure of its electrode laminate. A comprehensive understanding of the micro-structure evolution in LIB electrode laminate fabrication process can help to further improve its property. Here, recent progress involving slurry making, coating and drying process in electrode fabrication process is reviewed. The interaction mechanism among particles of active material and conducting additive and polymer molecular in different solvent environment is discussed in detail. And ways to control and improve the electrode micro-structure are proposed. Not only LIB, this review will also provide hints and instructions to other kinds of electrochemical energy storage devices such as supercapacitor, Li-S and Li-air battery.
The PR China has been very fast developing its energy sector in order to sustain its impressive economic growth. China's installed hydropower capacity is not only the highest in the world; it also shows a globally unique dimension in growth and dynamic. The southwestern province of Yunnan has one of the highest hydropower potentials within China. Its development makes the province one of the key suppliers of electric energy in China, supplying the economic and energy hungry load centers of coastal China but also Southeast Asia. In a decade Yunnan will have an installed hydropower capacity that exceeds that of Canada or the United States. The province is therefore often referred to as China's forthcoming (hydro-) powerhouse or as Asia's battery. Yunnan's rapid development is mainly based on large and prestigious hydropower projects along major rivers, often forming large reservoirs. Secondly it rests on centers of small hydropower development. They are based on small (sub-)catchments where SHP stations mostly form cascades of diversion type projects affecting entire watersheds. Both developments are creating hydroscapes. While Yunnan's large scale hydropower development is relatively well studied, there is an obvious research gap on Yunnan's small hydropower sector. But the latter has not only a huge relevance it also causes serious tangible cumulative implications. This rapid expansion of Yunnan's hydropower sector takes place in one of the most biologically, geographically and ethnically diverse regions in China. This creates a large need for careful management in order to avoid potentially significant environmental and social conflicts. Therefore the article shows the current status of Yunnan's ambitious hydropower development program including its political frame. It critically analyses the environmental and socio-economic consequences of both large and small hydropower projects. It further describes the transboundary implications and the relevance of the power grid.
Graphitic carbon nitrides (g-C3N4) are becoming increasingly significant due to the theoretical prediction of their unusual properties and promising applications ranging from photocatalysis, heterogeneous catalysis, to fuel cells. Recently, a variety of nanostructured and nanoporous g-C3N4 materials have been developed for a wide range of new applications. This feature article gives, at first, an overview on the synthesis of g-C3N4 nanomaterials with controllable structure and morphology, and secondly, presents and categorizes applications of g-C3N4 as multifunctional metal-free catalysts for environmental protection, energy conversion and storage. A special emphasis is placed on the potential applications of nanostructured g-C3N4 in the areas of artificial photocatalysis for hydrogen production, oxygen reduction reaction (ORR) for fuel cells, and metal-free heterogeneous catalysis. Finally, this perspective highlights crucial issues that should be addressed in the future in the aforementioned exciting research areas.
Microstructures and electrochemical characteristics of La0.7Ce0.3Ni3.75−x Cu0.75Mn0.35Al0.15(Fe0.43B0.57) x hydrogen storage alloys have been investigated. X-ray diffraction results indicate that the alloys consist of a single phase with CaCu5-type structure, and lattice parameters c, cell volume V and c/a ratio increase with increasing x value. Maximum discharge capacity of the alloy electrodes first increases from 311.0mAh/g (x =0) to 316.0mAh/g (x =0.15), and then decreases to 311.0mAh/g (x =0.20). High-rate dischargeability at the discharge current density of 1200mA/g first increases from 51.3% (x =0) to 60.7% (x =0.15), and then decreases to 53.6% (x =0.20). Cycling stability first increases with increasing x from 0 to 0.10 and then decreases when x increases to 0.20, which should be ascribed to the improvement of the pulverization resistance and the deterioration of corrosion resistance.
Mesoporous TiO2 was prepared via a sol–gel method from an ethylene glycol-based titanium-precursor in the presence of a non-ionic surfactant at pH 2. Only the anatase structure was detected after annealing, while the BET specific surface area was measured as being 90m2 g−1 with a rather monomodal pore diameter close to 5nm. Electrochemical performances were investigated by cyclic voltammetry and galvanostatic techniques. Mesoporous TiO2 exhibits excellent rate capability (184mAhg−1 at C/5, 158mAhg−1 at 2C, 127mAhg−1 at 6C, and 95mAhg−1 at 30C) and good cycling stability.
Amorphous Mg–Ni–La alloys for hydrogen storage are prepared by rapid solidification. Ag nanoparticles have been deposited onto graphene sheets to form graphene/Ag (G/A) nanocomposite through solvothermal method using ethylene glycol as solvent and reducing agent. The effects of surface modification of amorphous Mg–Ni–La alloy by introduction of different contents of G/A are systematically investigated by XRD, FT-IR, SEM, TEM and conventional electrochemical tests. The results show that the discharge capacity, cycle life, discharge potential characteristics and electrochemical kinetics of the electrodes are all improved. The surface modification enhances the electrocatalytic activity of the alloy and reduces the contact resistance of the electrodes. The Mg65Ni27La8 with 20 wt.% G/A electrode has the largest discharge capacity of 814.8 mAh g−1, which is 1.33 times that of the electrode without G/A, and the best electrochemical kinetics. Further increasing of G/A content will lead to the increase of contact resistance of the electrode, resulting in the degradation of electrode performance.
Porous carbon materials have initiated a fast evolution in recent years because of their broad applications in various fields. However, the major challenge remains is control porosity, foaming agents, processing materials and good thermal and mechanical properties. In the present investigation, graphite foams with varying porosities (50–70%) were prepared using coal tar pitch derived semi coke as a carbon matrix and ammonium bicarbonate as a space holder, followed by carbonization and graphitization. The graphite foams were characterized in terms of structural, morphological, mechanical and thermal properties. The results reveal that graphite foams prepared trough space holder technique having excellent mechanical and thermal properties. The graphite foam is found to possess a thermal conductivity of 27.5 W/(m.K), compressive strength of 7.5 MPa, with a relative density (ρrd) of 0.41. The graphite foam is also found to be thermally stable and outperforming those metals, conductive polymers, and their composites. The newly developed graphite foams are promising for specific applications in aerospace electronic devices with excellent mechanical and heat dissipation characteristics, especially regarding extreme high temperatures.
The recently released U.S. Environmental Protection Agency (U.S. EPA) Supplemental Guidance for Assessing Risk from Early Life Exposure to Carcinogens (SGAC) provides guidance to account for potential increased early life susceptibility to carcinogens that are acting via a mutagenic mode of action. While determination of the mode of carcinogenic action is central to the SGAC procedures and other regulatory risk assessments, little guidance is given as to the approaches, criteria, and nature of the evidence required to define a mutagenic mode of action. The purpose of this paper is to provide a framework along with practical guidance for the process of assigning a mode of action. Strengths, weaknesses, reliability, and choice of a test battery are discussed for select bacterial, cell culture, whole animal and human cell assays. Common confounding factors of induced pathology, cytolethality, and regenerative cell proliferation in rodent cancer bioassays are discussed along with approaches to account for these effects in assigning a mode of action and in risk assessments. Specific examples are given to illustrate the complexity in generating a data set sufficient to move from the default regulatory position of assuming a genotoxic mode of action to actually assigning a nongenotoxic mode of action. A two-part framework is proposed for assigning a mode of action. First, a weight of evidence approach is used to assess mutagenic potential based on results of genetic toxicology test systems. Second, a descriptor is assigned to classify the degree to which mutagenic activity likely played a role in the mode of action of tumor formation. This option provides a more realistic way of describing the mode of action instead of being bound by the strict genotoxic vs. nongenotoxic choices.
In this paper, 3D hollow framework of GeOx is synthesized using a bubble-template hydrothermal procedure. The as-obtained hollow structure exhibits excellent cycling performance and rate capability in comparison with GeOx nanoparticles when used as an anode material in lithium ion batteries. The GeOx 3D hollow framework shows a high capacity of up to 1480 mAh·g−1 and 1109 mAh·g−1 at 80 mA·g−1 and 1600 mA·g−1 current density, respectively. The excellent lithium storage performance can be attributed to the unique 3D hollow framework. The framework not only acts as the buffer layer to alleviate the strain during lithiation, but also facilitates the electron transfer during the charge/discharge processes.
Flexible electrodes attract significant attention to meet increasing demands for flexible power sources but are held back from practical applications owing to its their heavy weight and poor electrochemical performance. Herein, a robust three-dimensional (3D) flexible and light reduced graphene oxide modified N-doped carbon foam-TiO2 (NCF@rGO-TiO2) electrode is constructed by using a flexible and light (2.2 mg cm−2) NCF@rGO matrix to support TiO2. The electrode has a 3D high conductivity network, large specific surface area, abundant pore structure, and nano-sized active material, which is are highly conductive to improve electrochemical kinetics of the TiO2. Hence, the flexible electrode shows high rate performances (lithium ion batteries (LIBs): 334 and 134 mAh g−1 at 0.1 and 20 C; sodium ion batteries (SIBs): 305 and 120 mAh g−1 at 0.5 and 10 C). Uniting the robust structure of the NCF@rGO skeleton and the small volume change of the TiO2 in electrochemical reaction, the flexible electrode also exhibits good cycling performances for LIBs (82.7% capacity retention after 3000 cycles at 10 C) and SIBs (nearly 100% capacity retention after 70 cycles at 5 C). And, a soft-packaged battery can run well in any bend states, thus offering an attractive vista toward flexible power sources.
Cobalt-free Li and Mn-rich layered cathode materials are promising for next generation lithium ion batteries due to their high specific capacity and low cost. However, these materials are facing serious issues, such as structural collapse due to volume shrinkage during Ni2+ oxidation to Ni4+ and oxygen vacancy generation over 4.5V. In this work, we report a strategy to address the issue of volume shrinkage caused by structural deformation via constructing a large-size rigid frame by simultaneously doping inactive and large radius atoms of Cd and S. This strategy significantly reduces the volume shrinkage when fully delithiated relative to the pristine material. The Cd- and S-doped cathode materials present a highly reversible structure, which were determined by using HAADF-STEM and in-situ XRD characterization. The doped Cd and S atoms act as supporting atoms and synergistically enlarge the layer spacing of crystalline from 0.455 to 0.483 nm. The in-situ XRD monitors the structural changes in real time during charging and discharging processes, further verifying structural stability during cycling. Due to the unique structural properites, an initial capacity of 268.5 mAh g−1 at 0.1 C along with a good rate capacity of 153.8 mAh g−1 at 5 C were achieved. Also, a capacity of 243.4 mAh g-1 at 0.1 C over 80 cycles indicate good cyclic stability of the co-doped Li- and Mn-rich layered cathode.
Fe3O4–pyrolytic graphite oxide (Fe3O4–PGO) composite has been prepared by solvothermal reaction at 200°C. The as-prepared Fe3O4–PGO composite displays excellent cycle stability and rate capability with the initial discharge capacity of 1275mAhg−1 and capacity retention of 81% after 50 cycles compared with pure Fe3O4. The reasons are as follows: (i) in situ synthesized Fe3O4 firmly anchors onto the exfoliated PGO sheets, and the PGO acts as a conductive agent to provide a fast path for electron transportation; and (ii) the interstitial cluster structure of microsphere-type Fe3O4 in Fe3O4–PGO composite facilitates more better percolation of the electrolyte, more efficient accommodation with the strain and stress of volume change upon cycling and faster Li-ion transfer.
Three-dimensional (3D) nanoarchitectures can improve the performance of electrical energy storage systems. In this paper, combining an improved solvothermal method with calcination treatment, thin layer carbon-coated MoO2 nanoparticles with the size of 20-50nm were uniformly dispersed in 3D graphene aerogel (abbreviated as MoO2@C-Gas). The hybrid materials were subsequently used as a new-structured anode for lithium-ion batteries (LIBs), yielding high reversible capacity with excellent stable cyclability. We found that the battery with MoO2@C-Gas electrode could deliver a discharge capacity of 1515mAhg−1 at a current density of 80mAg−1 in the first cycle, and remain at 1113mAhg−1 over 60 cycles. Furthermore, with the increase of current density, it also exhibited a high rate of capability and good cycling performance. The outstanding performance of the hybrid electrode were attributed to the unique 3D aerogel morphology and the close combination between C@MoO2 and graphene layers, which could significantly improve the anode's electronic conductivity.
We studied the effect of salt concentration and solvent ratio on the cycling performance of LiMn2O4 cathode and graphite anode in LiPF6–ethylene carbonate (EC)–ethyl methyl carbonate (EMC) electrolytes. The results show that solvent ratio has negligible impact on the performance of both electrodes but does affect the issues of thermal compatibility and ionic conductivity. Salt concentration affects the performance in two reverse ways: LiMn2O4 cathode requires low concentration, while graphite anode requires high concentration. It is observed that, during the first cycle, both electrodes produce irreversible capacity and form a solid electrolyte interface (SEI) film on their surface. From the view point of operation at low temperatures, 1M LiPF6 3:7 EC–EMC is recommended for Li-ion cells.
Electrochemical and structural characteristics of amorphous Mg0.9Ti0.1Ni, Mg0.9V0.1Ni and Mg0.9Ti0.06V0.04Ni alloys prepared by mechanical alloying (MA) were investigated. In charge–discharge cycle tests, the decay of discharge capacity with increasing cycle number was suppressed by partial substitution with either Ti or V, and the alloy partially substituted with both Ti and V, Mg0.9Ti0.06V0.04Ni, exhibited further improved cycle performance. Results of X-ray diffractometry (XRD) indicated that the oxidation of Mg on the alloy surface during the charge–discharge cycles could be fairly suppressed by the partial substitution with both Ti and V. Moreover, it was found from Auger electron spectroscopy (AES) that thickness of oxidized surface layer of the MgNi alloy particle was decreased by the introduction of both Ti and V. It was suggested that composite oxide layer in which both Ti and V species existed might be very effective in suppressing the oxidation of the alloy surface, leading to the synergistic effect on charge–discharge cycle performance.
Given the diversity of multiple sclerosis (MS) symptoms including cognitive impairment in certain domains, the need to develop a rapid and at the same time thorough tool for cognitive assessment is mandatory and represents an unmet need in the clinical and research fields of MS. The Brief International Cognitive Assessment for MS (BICAMS) is a good and practical tool to achieve this mission but is not present in the Arabic language for Arabic speaking countries yet.
In organic electrosynthesis C–C bond formation and functional group interconversion proceed via reactive intermediates that are generated by electron transfer at the anode and cathode. Electron transfer combined with a chemical reaction provides conversions that are not available in non-electrochemical reactions. These are potential selectivity, redox-umpolung, and the substitution of a hydrogen atom for a nucleophile or the addition of two nucleophiles to a double bond in one-pot reactions. Furthermore electrolysis is well suited for oxidation and reduction of functional groups. Electrochemical syntheses need mostly fewer steps, produce less waste, provide a cheaper reagent, require less auxiliaries and allow often an easier scale-up than non-electrochemical syntheses. In addition, they can be conducted at ambient temperature and pressure. All these qualities agree well with the rules of green chemistry. This statement is substantiated with examples of C–C bond formation and functional group interconversion at the anode and cathode.
Electrolyte imbalance in vanadium redox flow batteries is an important problem for its long-term operation as it leads to loss of energy. To address this problem, a modified open circuit voltage (OCV) cell is developed by adding a middle half cell between the negative and positive half cells of a conventional OCV cell and used to predict the oxidation state of vanadium in the electrolyte solution from the measured voltage in each side of the electrolyte (positive and negative). The correlation between the oxidation state of vanadium and cell voltage is explained by a basic electrochemical principle and the Nernst equation. The experimental results show that at different oxidation states of vanadium, the predicted OCV agrees reasonably with the experimental data. In addition, the effect of the state of charge (SOC) and electrolyte imbalance on the energy capacity of a cell is discussed.
The highly concentrated lithium bis(fluorosulfonyl)imide/1,2–dimethoxyethane electrolyte is in the good graces of researchers due to its excellent electrochemical performance in lithium-metal batteries. However, our study reveals that the more concentrated electrolyte incurred more drastic lithium-dendrite growth. Minimum onset time (tsc) of lithium-dendrite formation of only 7.4 and 18.6 h are observed in 4 M lithium bis(fluorosulfonyl)imide/1,2-dimethoxyethane electrolyte galvanostatically polarized at current densities of 1.0 and 0.5 mA cm−2, respectively. In contrast, tsc are as long as around 56 and > 190 h in 1 M electrolyte at 1.0 and 0.5 mA cm−2, respectively. We found that 1 M electrolyte has comprehensive advantages in many respects, including Li+ transference number (0.61), salt diffusion coefficient (1.47 × 10−5 cm2 s−1), ionic conductivity (1.52 × 10−2 S cm−1), low polarization potential and solid electrolyte interphase protection, which collectively make contributions to outstanding lithium-dendrite suppression.