batterydata/paper-abstracts huggingface dataset:
Objective Previous studies have been inconclusive whether dominant resting state alpha rhythms differ in amplitude in dyslexic subjects when compared to control subjects, being these rhythms considered as a reflection of effective cortical neural synchronization and cognition. Here we used a validated EEG source estimation to test the hypothesis that resting state alpha rhythms are abnormal in dyslexic subjects and are related to reading deficits. Methods Eyes-closed resting state electroencephalographic (EEG) data were recorded in 26 dyslexics (12 males, mean age of 11years±0.5standard error of mean, SEM) and 11 age-matched normal control subjects (8 males, mean age of 11years±0.7SEM). EEG rhythms of interest, based on individual alpha frequency peak, were the following: about 2–4Hz (delta), 4–6Hz (theta), 6–8Hz (alpha 1), 8–10Hz (alpha 2), and 10–12Hz (alpha 3). For the higher frequencies, we selected beta 1 (13–20Hz), beta 2 (20–30Hz), and gamma (30–40Hz). Cortical EEG sources were estimated by low resolution electromagnetic tomography (LORETA). LORETA solutions were normalized across all voxels and frequencies. Results Compared to the control children, the dyslexics showed lower amplitude of parietal, occipital, and temporal alpha 2 and alpha 3 sources. In the dyslexics, some of these sources were correlated to reading time of pseudo-words (parietal alpha 2, r =−0.56, p =0.02; parietal alpha 3, r =−0.58, p =0.02; temporal alpha 3, r =−0.57, p =0.02); the higher the alpha power, the shorter the reading time. Conclusions Dyslexic children are characterized by limited abnormalities of resting state EEG rhythms as to topography (posterior regions) and frequency (alpha), which were related to phonological encoding (pseudo-words reading). Significance Dyslexia may be associated to some functional impairment of cortical neuronal synchronization mechanisms involved in the resting state condition.
The role of working memory in vocabulary acquisition has been well established in the literature. In this study, we proposed and empirically tested the multicomponent view of vocabulary acquisition, which states that multiple language and cognitive skills are involved to facilitate phonological and semantic representations needed for vocabulary acquisition. Working memory and attention were hypothesized to be directly and indirectly related to vocabulary, whereas inference and morphosyntactic knowledge were hypothesized to be directly related to vocabulary (measured by the Picture Vocabulary Test of the Woodcock–Johnson III battery). Results from 262 kindergartners using path analysis revealed that all the multiple cognitive and language skills were directly related to vocabulary after controlling for age, gender, racial/ethnic backgrounds, socioeconomic status (as measured by free or reduced-price lunch eligibility), and each other. Furthermore, working memory and attention also made indirect contributions via inference and morphosyntactic knowledge. Total effects (beta weights), accounting for direct and indirect effects, were .33 for working memory, .23 for attention, .18 for inference, and .18 for morphosyntactic knowledge. These results indicate that although working memory is important, contributions of other language and cognitive skills should be considered in vocabulary acquisition. Theoretical and practical implications are discussed.
Performance results obtained from a 6200ton demonstration-scale anaerobic bioreactor, constructed on the Pacara Pintada Landfill in Tucumán, Argentina, are described. The operational aspects over a 30-month period for the Tucumán bioreactor demonstrate the ability to maintain the bioreactor in the mesophilic range, with the result that the generation and collection of the biogas has been maintained at accelerated rates with a rate constant of approximately 0.5year−1. Field measurements of metal concentrations in leachate indicated significant attenuation over time. Refuse subsidence, measured over a 28-month period, ranged from 4% to 19%, with an average of 11% subsidence across the Tucumán cell.
In order to develop novel membranes for vanadium redox flow battery (VRB) with low self-discharge rate and low cost, sulfonated poly(fluorenyl ether ketone) (SPFEK) was synthesized directly via aromatic nucleophilic polycondensation of bisphenol fluorene with 60% sulfonated difluorobenzophenone and 40% difluorobenzophenone. The SPFEK membrane shows the lower permeability of vanadium ions. The open circuit voltage evaluation demonstrates that the SPFEK membrane is superior to Nafion 117 membrane in self-discharge test. Both energy efficiencies (EE) and power densities of the VRB single cell based on the SPFEK membrane are higher than those of the VRB with Nafion 117 membrane at the same current densities. The highest coulombic efficiency (CE) of VRB with SPFEK membrane is 80.3% while the highest CE of the VRB with Nafion 117 membrane is 77.0%. The SPFEK membrane shows the comparative stability to Nafion 117 membrane in VO2 + electrolyte. The experimental results suggest that SPFEK membrane is a promising ion exchange membrane for VRB.
We prepared slurries by dispersing LiMn2O4 and LiCoO2 into toluene or NaPO3 aqueous solution. The slurries were then milled with a high-pressure wet-type jet mill to form fine particles. In estimating the performance of Li cells containing the materials, we found that the cell capacity improved with a decrease in the materials’ particle size. Maximum cell capacity was obtained using materials produced by milling NaPO3 slurry to reduce the particle diameter to 2–3μm. Such the maximum value was disappeared by treating the materials with toluene. The treatment, however, did not provide remarkable increase in the cell capacity. We found that the cell cycle life tended to increase with a decrease in the mean diameter of the material particles.
Sodium-ion batteries (SIBs) have shown promising prospects for complementarity to lithium-ion batteries (LIBs) in the field of grid-scale energy storage. After a decade of continuous fundamental research on SIBs, it's becoming increasingly urgent to advance the commercialization. For SIB anode materials, hard carbon is the most mature and currently the only material likely to be commercialized, but it is still far away from large-scale industrialization. Herein, we carry out a comprehensive overview of the current state of the art in terms of three main aspects. Firstly, a fundamental understanding of the microstructure and sodium storage mechanism of hard carbon is introduced, which can be categorized into three different processes: capacitive adsorption, nanopore filling, and intercalation in carbon interlayers. Then, based on an in-depth understanding of the sodium storage mechanism, optimization methods in terms of increasing the specific capacity, rate performance, initial coulombic efficiency (ICE), and long-cycling stability are comprehensively summarized and analyzed. Finally, potential methods and associated benefits for the design of carbon structures and the solid electrolyte interface (SEI) are discussed, hoping to provide useful guidelines for future research and commercialization.
The graphene nanopowder for electro-catalytic oxidation of dopamine and uric acid in the presence of ascorbic acid has been investigated by cyclic voltammetry, linear polarization and chronoamperometry. The graphene nanopowder modified electrode was prepared using the drop coating method, which displayed excellent electrocatalytic activity towards the oxidation of dopamine and uric acid compared with the bare glassy carbon electrode in phosphate buffer solution at pH = 7.0. Linear responses for dopamine and uric acid were obtained in the ranges of 3.3 μmol/L to 249.1 μmol/L and 6.7 μmol/L to 386.3 μmol/L with detection limits of 1.5 μmol/L and 2.7 μmol/L (S/N = 3), respectively. The response time was less than 2 s in case of dopamine and 3 s in case of uric acid, respectively. The results demonstrated that the graphene nanopowder had potential for detecting dopamine and uric acid.
In this study, the effect of the binder (PVdF and CMC/NBR) and the preparation process of sulfur electrode ink/slurry on electrochemical performance and cycling behaviour of Li/S cells was investigated. Well-dispersed and homogeneous slurries obtained using high-energy mechanical dispersion (Dispermat®) permit to decrease the impedance response of the electrodes and thus to improve the cycling performances at high C-rates. The main effect of CMC/NBR binder was mostly related to electrode adhesion properties, resulting in better cycle life. A detailed analysis of EIS data gives us an insight into electrode impedance response and their variation depending on the electrode fabrication process and nature/type of a binder.
Bulk and surface reconstructed Li[Li0.2Mn0.54Ni0.13Co0.13]O2 cathode materials induced by spinel embedment and γ-MnO2 modification were synthesized by a one-step hydrothermal method. The results of XRD, XPS and SEM confirmed the introduction of γ-MnO2. The analysis of XPS, TEM images, dQ/dV curves and CV curves demonstrated that a spinel phase is embedded synchronously in the bulk of layered structure during the process of γ-MnO2 modification. The results of charge-discharge profiles and dQ/dV curves demonstrated the irreversible discharge capacity loss in the initial cycle is reduced with the introduction and collaboration of spinel and γ-MnO2. Namely, the initial coulombic efficiency is improved up to approximately 100%. Furthermore, the specific discharge capacity and rate performances are enhanced by a structure breakthrough for Li+ transport through blending with electrochemical active spinel-phase and γ-MnO2. In addition, the capacity retention of the material is enhanced from 64% up to 85% after 200 cycles. The main reasons are that the surface of Li[Li0.2Mn0.54Ni0.13Co0.13]O2 is stabilized and the phase transformation from surface to bulk is mitigated under the protection of γ-MnO2 coating layer.
As an alternative to conventional inorganic intercalation electrode materials, organic electrode materials are promising candidates for the next generation of sustainable and versatile energy storage devices. In this paper we provide an overview of organic electrode materials, including their fundamental knowledge, development history and perspective applications. Based on different organics including n-type, p-type and bipolar, we firstly analyzed their working principles, reaction mechanisms, electrochemical performances, advantages and challenges. To understand the development history and trends in organic electrode materials, we elaborate in detail various organics with different structures, including conducting polymers, organodisulfides, thioethers, nitroxyl radical polymers and conjugated carbonyl compounds. The high electrochemical performance, in addition with the unique features of organics such as flexibility, processability and structure diversity, provide them great perspective in various energy storage devices, including rechargeable Li/Na batteries, supercapacitors, thin film batteries, aqueous rechargeable batteries, redox flow batteries and even all-organic batteries. It is expected that organic electrode materials will show their talents in the “post Li-ion battery” era, towards cheap, green, sustainable and versatile energy storage devices.
Analysis of ictal semiology is essential to presurgical evaluation of patients with epilepsy. To assess the localizing value of behavioral arrest in temporal lobe epilepsy (TLE), we analyzed 107 video/EEG monitoring-documented seizures of 107 adult patients with TLE for a set of defined seizure phenomena with respect to frequency and sequence of occurrence in relation to epileptogenic (mesial vs extramesial, left vs right) origin. Behavioral arrest was observed more frequently in left-sided temporal seizures: 25.7% of left-sided mesial seizures and 25.0% of left-sided extramesial seizures exhibited behavioral arrest, whereas only 3.4% of right-sided mesial seizures and 10.5% of right-sided extramesial seizures were associated with behavioral arrest. In addition, occurence of behavioral arrest within the sequence of seizure phenomena was remarkably consistent, being observed mainly as the first apparent feature of seizure onset. Thus, behavioral arrest is a valuable early indicator of a left-sided temporal epileptogenic focus in adult patients with TLE.
Hydrogen from direct splitting of water molecules using photons is reckoned to be a sustainable and renewable energy solution for the post fossil-fuel era. Efficient photocatalysts, including metal-free photocatalysts, are key determinants of cost-effective hydrogen generation at a large-scale. The search for new materials that are metal-free is therefore ongoing. Recently, 2D phosphorene, a phosphorus analogue of graphene, has been added as a new semiconductor to the family of monolayer-flatland materials. In this review, we focus on analysing the fundamental electronic, optical and chemical properties of 2D phosphorene and assess its suitability as a metal-free water splitting photocatalyst. We also critically analyse its stability against claims from environmental antagonists and attempt to predict its future as a photocatalyst. This review provides timely information for researchers, scientists and professionals devoted to materials research for photocatalysis.
This paper represents the evaluation of ageing parameters in lithium iron phosphate based batteries, through investigating different current rates, working temperatures and depths of discharge. From these analyses, one can derive the impact of the working temperature on the battery performances over its lifetime. At elevated temperature (40°C), the performances are less compared to at 25°C. The obtained mathematical expression of the cycle life as function of the operating temperature reveals that the well-known Arrhenius law cannot be applied to derive the battery lifetime from one temperature to another. Moreover, a number of cycle life tests have been performed to illustrate the long-term capabilities of the proposed battery cells at different discharge constant current rates. The results reveal the harmful impact of high current rates on battery characteristics. On the other hand, the cycle life test at different depth of discharge levels indicates that the battery is able to perform 3221 cycles (till 80% DoD) compared to 34,957 shallow cycles (till 20% DoD). To investigate the cycle life capabilities of lithium iron phosphate based battery cells during fast charging, cycle life tests have been carried out at different constant charge current rates. The experimental analysis indicates that the cycle life of the battery degrades the more the charge current rate increases. From this analysis, one can conclude that the studied lithium iron based battery cells are not recommended to be charged at high current rates. This phenomenon affects the viability of ultra-fast charging systems. Finally, a cycle life model has been developed, which is able to predict the battery cycleability accurately.
Ni-rich layered oxides are promising cathode candidates for Li-ion batteries because of their high discharge capacity, high energy density, and low cost. However, poor cycling stability and thermal instability during cycling limit their commercial application in electric vehicles. To overcome these drawbacks, Ni-rich transition metal hydroxide precursors comprising a Ni-rich core and Ni-less surface region are successfully prepared in this study by a simple treatment process with dilute sulfuric acid. The final cathode materials have a compositional core-shell design, taking advantage of the stable cyclability and high thermal stability of the Ni-less surface layer as well as the high capacity of the Ni-rich core. The cycling stability of this Ni-rich cathode significantly improves after leaching, showing a capacity retention of 82.3% after 150 cycles at a rate of 0.5C and elevated temperature of 60 °C, much higher than that of a pristine Ni-rich cathode (65.4%). Furthermore, the thermal stability of the prepared Ni-rich cathode improves remarkably after leaching. These results suggest that the prepared cathode meets the energy storage demands of electric vehicles in terms of energy density, power, and cycling life; therefore, it is a promising cathode material for electric vehicle applications.
In this study, Li4Ti5O12/C (LTO/C) composites were successfully synthesized via a facile one-pot sol-gel method using citric acid as carbon source. The physical and electrochemical properties of the as-prepared composites were extensively investigated. These analyses signify that the uniformly coated carbon layer from citric acid on the surface of the LTO particles was found, and also resulting in the partial reduction of Ti4+ to Ti3+ after the sintering in an inert atmosphere. Owing to the synergistic effect of highly conductive carbon coating layer and the mixed valence of Ti4+/Ti3+, the synthesized LTO/C composite electrode showed the significantly improved high-rate capability and stability, which delivered initial discharge capacity of 165.7, 161.7, 153.9 and 147.9 mAh g−1 at the charge/discharge current density of 1, 5, 10, and 20C, respectively, and the discharge capacity even retained up to 98% of that of the first cycle after the consecutive 50 cycles at 20C. This one-pot sol-gel process may present a facile pathway for large-scale preparation of LTO/C as high-performance anode materials for lithium-ion batteries.
The Dualfoil model is used to simulate the electrochemical behavior and temperature rise for MCMB/LiCoO2 Li-ion cells under a small constant-resistance load, approaching a short-circuit condition. Radial mass transport of lithium from the center of the pore to the pore wall has been added to the model to describe better current limitations at very high discharge currents. Electrolyte and solid-surface-concentration profiles of lithium ions across the cell at various times are developed and analyzed to explain the lithium-ion transport limitations. Sensitivity tests are conducted by changing solution and solid-state diffusion coefficients, and the heat-transfer coefficient. Because diffusion coefficients increase at high temperature, calculated discharge curves can show currents dropping initially but then rising to a second peak, with most of the available capacity being consumed in the second peak. Conditions which lead to such a second peak are explored.
Surface engineering is an effective strategy to restrain the generation of rocksalt NiO phase on surface of layered LiNi0.815Co0.15Al0.035O2 (NCA) primary nanoparticles, a representative Ni-rich layered oxides cathode materials. Herein, we demonstrate the kilogram-scale synthesis of few-layer reduced graphene oxide (rGO) conformably coated NCA primary nanoparticles cathode materials by a mechanical wet ball-milling strategy. The lightening rGO coating layer effectively avoids the direct contact of electrolyte and NCA with rapid electrons transfer. As a result, the as-obtained NCA@rGO hybrids with only 1.0 wt% rGO content can deliver a high specific capacity (196 mAh g−1 at 0.2 C) and fast charge/discharge capability (127 mAh g−1 at 5 C), which is much higher than the corresponding NCA nanoparticles (95 mAh g−1 at 5 C). Even after 100 cycles at 1 C, 91.7% of initial reversible capacity is still maintained. Furthermore, a prismatic pouch cell (240 mAh) is also successfully assembled with the commercial graphite anode.
This study examines the feasibility of powering a range of portable devices with a direct methanol fuel cell (DMFC). The analysis includes a comparison between a Li-ion battery and DMFC to supply the power for a laptop, camcorder and a cell phone. A parametric study of the systems for an operational period of 4 years is performed. Under the assumptions made for both the Li-ion battery and DMFC system, the battery cost is lower than the DMFC during the first year of operation. However, by the end of 4 years of operational time, the DMFC system would cost less. The weight and cost comparisons show that the fuel cell system occupies less space than the battery to store a higher amount of energy. The weight of both systems is almost identical. Finally, the CO2 emissions can be decreased by a higher exergetic efficiency of the DMFC, which leads to improved sustainability.
In this paper we report the strategy followed in our laboratories for the progress of lithium ion batteries. The results show that nanotechnology is a very promising tool for achieving breakthrough in electrode and electrolyte materials. The concept is demonstrated for the cases of metal storage and metal oxide anodes, phospho olivine lithium iron phosphate cathodes and solvent-free, poly(ethylene oxide)-based polymer electrolytes.
The energy storage system (ESS) in a conventional stand-alone renewable energy power system (REPS) usually has a short lifespan mainly due to irregular output of renewable energy sources. In certain systems, the ESS is oversized to reduce the stress level and to meet the intermittent peak power demand. A hybrid energy storage system (HESS) is a better solution in terms of durability, practicality and cost-effectiveness for the overall system implementation. The structure and the common issues of stand-alone REPS with ESS are discussed in this paper. This paper presents different structures of stand-alone REPS with HESS such as passive, semi-active, and active HESS. As there are a variety of energy storage technologies available in the market, decision matrixes are introduced in this paper to evaluate the technical and economic characteristics of the energy storage technologies based on the requirements of stand-alone REPS. A detailed review of the state-of-the-art control strategies such as classical control strategies and intelligent control strategies for REPS with HESS are highlighted. The future trends for REPS with HESS combination and control strategies are also discussed.
When developing new products it is important for design teams to understand customer perceptions of consumer products because the success of such products is heavily dependent upon the associated customer satisfaction level. The chance of a new product’s success in a marketplace is higher if users are satisfied with it. In this study, a new methodology of generating customer satisfaction models using a neuro-fuzzy approach is proposed. In contrast to previous research, non-linear and explicit customer satisfaction models can be developed with the use of the proposed methodology. An example of notebook computer design is used to illustrate the methodology. The proposed methodology was measured against the benchmark of statistical regression to determine its effectiveness. Experimental results suggested that the proposed approach outperformed the statistical regression method in terms of mean absolute errors and variance of errors.