batterydata/paper-abstracts huggingface dataset:
To critically assess the value of material-specific memory deficits in lateralizing temporal lobe dysfunction preoperatively, we compared the neuropsychological data of 50 consecutive patients with unilateral mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS; right: 31, left: 19) with those of 50 age- and education-matched healthy control subjects. On case-control comparison, both the subcohorts with left and right MTLE-HS performed poorly on intelligence tests, in addition to individual memory tests. However, comparison of the verbal and visual memory functions between subcohorts with right and left MTLE-HS revealed that learning trials and delayed word list recall were the only tests that hypothesized left temporal lobe dysfunction. We conclude that material-specific memory deficits are largely test driven, but there is a lateralizing role for task-specific deficits in left MTLE-HS. Although neuropsychological data help to define baseline neuropsychological impairment, caution should be exercised in interpreting the lateralizing value of material-specific memory deficits prior to surgery.
The cycling and storage performances of LiCoO2 (LCO)-LiNi0.5Co0.2Mn0.3O2 (NCM)/pitch-coated silicon alloy-graphite (Si-C) full cells with ethylene carbonate (EC)–based and fluoroethylene carbonate (FEC)–based electrolytes are investigated at elevated temperatures. Excess FEC (used as a co-solvent in LiPF6-based electrolytes), which is not completely consumed during the formation of the solid electrolyte interphase (SEI) layer on the electrodes, is prone to defluorination in the presence of Lewis acids such as PF5; this reaction can generate unwanted HF and various acids (H3OPF6, HPO2F2, H2PO3F, H3PO4) at elevated temperatures. Our investigation reveals that the HF and acid compounds that are formed by FEC decomposition causes significant dissolution of transition metal ions (from the LCO-NCM cathode) into the electrolyte at elevated temperatures; as a result, the reversible capacity of the full cells reduces because of the deposition of the dissolved metal ions onto the anode. Moreover, we demonstrate possible mechanisms that account for the thermal instability of FEC in LiPF6-based electrolytes at elevated temperatures using model experiments.
With respect to carbon steel, corrosion examinations are performed in boiling water under the conditions of with and without exposure to γ-rays. Simulating a radiation-induced concentration cell, one set of samples is connected to the anode of external battery, while the other to the cathode. The corrosion current monitored during the corrosion and weight loss measurement after a prescribed corrosion period have revealed that corrosion rate under γ-rays is six times larger as that under a non-irradiated condition. An interesting feature observed by XRD analysis is that γ-ray exposure remarkably enhances the preferential dissolution of a specific (110) plane, which potentially triggers an occurrence of the pitting corrosion and an incipient crack; tensile stress being superposed, cracks like IASCC are implied to readily initiate and propagate through materials. Several measures against IASCC often found in the existing nuclear plants are envisaged in the light of controlling a radiation-induced concentration cell formation reported before.
Natural hazard-triggered technological accidents (Natechs) refer to accidents involving releases of hazardous materials (hazmat) triggered by natural hazards. Huge economic losses, as well as human health and environmental problems are caused by Natechs. In this regard, learning from previous Natechs is critical for risk management. However, due to data scarcity and high uncertainty concerning such hazards, it becomes a serious challenge for risk managers to detect Natechs from large databases, such as the National Response Center (NRC) database. As the largest database of hazmat release incidents, the NRC database receives hazmat release reports from citizens in the United States. However, callers often have incomplete details about the incidents they are reporting. This results in many records having incomplete information. Consequently, it is quite difficult to identify and extract Natechs accurately and efficiently. In this study, we introduce machine learning theory into the Natech retrieving research, and a Semi-Intelligent Natech Identification Framework (SINIF) is proposed in order to solve the problem. We tested the suitability of two supervised machine learning algorithms, namely the Long Short-Term Memory (LSTM) and the Convolutional Neural Network (CNN), and selected the former for the development of the SINIF. According to the results, the SINIF is efficient (a total number of 826,078 records were analyzed) and accurate (the accuracy is over 0.90), while 32,841 Natech reports between 1990 and 2017 were extracted from the NRC database. Furthermore, the majority of those Natech reports (97.85%) were related to meteorological phenomena, with hurricanes (24.41%), heavy rains (19.27%), and storms (18.29%) as the main causes of these reported Natechs. Overall, this study suggests that risk managers can benefit immensely from SINIF in analyzing Natech data from large databases efficiently.
In electrochemical synthesis of manganese oxide, current density has a substantial influence on redox behavior, but less effect on the film morphology. Here we report that a small amount (even not detectable by electron microscopy) of carbon nanotubes can significantly affect the film growth pathway. Although, the galvanostatic syntheses of manganese oxide were similar in the absence and presence of carbon nanotubes, the morphological structures are totally different. This difference is also valid for electrochemical behavior in favor of the formation of a single redox couple. The influence of carbon nanotubes on potentiodynamic electrodeposition of manganese oxide was also similar, leading to the appearance of a strong redox couple without any noticeable capacitive behavior. It should be emphasized that this influence is only valid for the experimental condition under consideration (i.e., low current densities), and electrodeposition at higher current densities in the presence of carbon nanotubes may strengthen the capacitive behavior in favor of supercapacitors (as discussed in the second part). The interesting point is that this tiny additive can predominantly control the electrochemical properties of the system under consideration: supercapacitor or battery.
Polyimide (PI) film is usually considered as a valuable pyrolysis precursor of graphitized films applied in various electrodes and batteries. In this work, reduced graphene oxide (RGO) sheets were chosen as the catalysts to improve the graphitization properties of PI film. To analyze the structural evaluations, the crystalline growth process with RGO increasing was carefully investigated by transmission electron microscope (TEM) and the crystalline sizes were calculated by X-ray diffraction (XRD) and Raman spectra. The obvious induced effects were confirmed in graphitization of RGO/PI composites at 2300 °C. Finally, the electrical properties of as-prepared RGO/graphite composites were also improved with RGO increasing.
The mechanical degradation upon cycling of sulfur-based electrodes is investigated by operando acoustic emission (AE). The AE response of S-based electrodes using two different binders, polyvinylidene difluoride (PVdF) and carboxymethylcellulose (CMC), as well as two different current collectors, usual aluminum foil and porous non-woven carbon paper (CP), are compared. In all cases, AE signals are mainly detected during the 1st plateau of the 1st discharge, related to the initial dissolution of elemental sulfur into the electrolyte, causing a collapse of the electrode network. At the end of charge, the formation of micrometric sulfur on the surface of the electrode can be acoustically detected, in particular in the case of the CMC/Al formulation, where signals are also detected during subsequent cycles. This is believed to be a result of the good adhesion of CMC-based electrode to the current collector, which allows acoustic waves to propagate through the electrode to the AE sensor more easily. However, with CP current collector, no AE activity is detected upon charge, reflecting a lower mechanical stress attributed to a more homogeneous growth of the S particles in the electrode. It is also noted that inefficient electrode formulation/elaboration can be detected via AE, as AE signals are emitted at the end of the discharge when the cell polarizes more than usually observed. The use of CP as a current collector greatly improves the electrochemical performance of the cells, especially when combined with the better adhesion/cohesion strengths of CMC binder, reaching an initial capacity of 1180 mAh g−1 (∼4.5 mAh cm−2) stabilizing around 860 mAh g−1 after 50 cycles.
A Ni-rich material (LiNi0.88Co0.09Mn0.03O2) was used as a cathode for Li-ion full cells to investigate the capacity fading behavior when the Ni content in the layered oxide cathode is very high. The morphology and compressive strength of the cathodes were analyzed after 1, 100, 200, and 300 full-cell cycles. A comparison of the results with those obtained for the LiNi0.8Co0.1Mn0.1O2 cathode revealed that the increased Ni content leads to further mechanical deterioration of the material upon cycling. The lattice parameter variation of the LiNi0.88Co0.09Mn0.03O2 electrode during cycling was measured using in situ X-ray diffraction analysis; the results showed that the variation of the lattice parameter of the LiNi0.88Co0.09Mn0.03O2 electrode was higher than that of the LiNi0.8Co0.1Mn0.1O2 electrode. The LiNi0.88Co0.09Mn0.03O2 electrode has a high specific capacity, indicating that more Li can be extracted from the electrode, which leads to the increased changes in the lattice parameter. Consequently, the high-Ni-containing electrode exhibits degraded mechanical and surface stabilities, as evidenced by observation of microcracks, a decrease in compressive strength of secondary particles, and increased internal pressure of the cells. Therefore, the mechanical and surface stability issues should be carefully considered when Ni-rich layered oxide cathode materials are used in Li-ion full cells.
Brain damaged patients suffering from representational neglect (RN) fail to report, orient to, or verbally describe contra-lesional elements of imagined environments or objects. So far this disorder has only been reported after right brain damage, leading to the idea that only the right hemisphere is involved in this deficit. A widely accepted account attributes RN to a lateralized impairment in the visuospatial component of working memory. So far, however, this hypothesis has not been tested in detail. In the present paper, we describe, for the first time, the case of a left brain damaged patient suffering from right-sided RN while imagining both known and new environments and objects. An in-depth evaluation of her visuospatial working memory abilities, with special focus on the presence of a lateralized deficit, did not reveal any abnormality. In sharp contrast, her ability to memorize visual information was severely compromised. The implications of these results are discussed in the light of recent insights in the neglect syndrome.
Extreme fast charging, with a goal of 15 minutes recharge time, is poised to accelerate mass market adoption of electric vehicles, curb greenhouse gas emissions and, in turn, provide nations with greater energy security. However, the realization of such a goal requires research and development across multiple levels, with battery technology being a key technical barrier. The present-day high-energy lithium-ion batteries with graphite anodes and transition metal oxide cathodes in liquid electrolytes are unable to achieve the fast-charging goal without negatively affecting electrochemical performance and safety. Here we discuss the challenges and future research directions towards fast charging at the level of battery materials from mass transport, charge transfer and thermal management perspectives. Moreover, we highlight advanced characterization techniques to fundamentally understand the failure mechanisms of batteries during fast charging, which in turn would inform more rational battery designs.
We will only deal with electrical circuits with direct currents, and not alternating current. Negatively charged electrons, which have a very small charge but can have appreciable potential energy, will flow from the negative terminal of an electrical circuit to the positive (Ben Franklin assumed that current flowed in the opposite direction). Resistance is expressed in units of ohms (Greek capital omega Ω) and is the ratio of volts/current. Electrical circuits may be broken into series and into parallel. We also use a “Power Law” to describe the electrical power dissipated in a circuit. Current flow obeys Ohm's Law and Kirchoff's Voltage and Current Laws. The “efficiency” of an electrical circuit means having good conductors in the leads compared to the main device in the circuit – a fact exploited by Edison making possible his electric lightbulb. The simple electric switch turns out to be the core technology in modern electronic computers. Key Words: electrical circuit, direct current, alternating current, electrons, Ben Franklin, resistance, ohms (Greek capital omega Ω), series circuit, parallel circuit, Ohm's Law, Kirchoff's Laws, current divider, voltage divider.
Vanadium pentoxide (V2O5) films were prepared by electrochemical and thermal decomposition of vanadyl sulphate on titanium dioxide covered titanium plates and glassy carbon discs. The prepared material by thermal decomposition showed high surface area and good physical stability; while the electrodeposited films, although being homogeneous, showed poor adhesion. The V2O5 electrodes were chemically and electrochemically stable in aqueous (1M H2SO4 + 1M NaOH, pH 3) and organic (0.1M But4NPF6 + CH3CN) solutions. In both cases, a well defined electrochemical response was observed. At the experimental conditions, the prepared materials were not active for the electrooxidation of toluene. The theoretical modeling suggests that the lack of activity is due to the weak interaction between toluene and the V2O5 surface.
Nano-sized carboxylates Na2C7H3NO4 and Na2C6H3N2O4 were prepared and investigated as anode materials for lithium-ion batteries. Both carboxylates exhibit high reversible capacities around 190 mAh/g above a cut-off voltage of 0.8 V vs. Li+/Li, potentially improving the safety of the batteries. In addition, good rate performance and long cycle life of these carboxylates make them promising candidates as anode materials for lithium-ion batteries.
Photovoltaic energy has experienced tremendous growth in terms of implementation at facilities for power supply in rural areas and for energy dispatch to grid. The relative position of the fixed panels can present the problem of varying amounts of shadowing among them, which can reduce the overall energy produced from the array of photovoltaic panels on specific dates and times, in addition to the problems in each of the panels themselves. The existing methods calculate the distances between the rows of PV panels using a fixed height of the sun, such that the rays always strike perpendicular to the panels, thereby limiting the duration of solar gain to 4h. This paper proposes a method that optimises the minimisation of the distance between the rows of fixed photovoltaic panels. The proposed method is based on the exact calculation of the shadows of the panels for the different positions of the sun, which depends on the latitude of the facility, throughout the course of the day and for all of the planned hours of solar gain. To illustrate the proposed method, it has been applied to a case study for which the solutions obtained using the traditional methods are compared, indicating that the distance can be reduced by up to 40% when the tilt angle of the panel is 60°. In conclusion, the proposed general method for optimally minimising the distance between the PV panels in solar arrays, which is of particular interest for standalone photovoltaic (PV) systems in remote areas that act as isolated small power producing units for the supply of electricity.
Low temperature fuel cells consuming ethanol without reformation would be a major step toward the use of renewable energy sources from biomass. However, the necessary electrodes and electrocatalysts still are far from being perfect and suffer from various poisoning and deactivation processes. This work describes investigations on systems using carbon/ZnS-based electrocatalysts for ethanol oxidation in complete membrane electrode assemblies (MEAs). MEAs were built on Nafion membranes with active masses prepared from ZnS nanoparticles and Vulcan carbon support. Under operation, acetic acid and acetaldehyde were identified and quantified as soluble oxidation products, whereas the amount of CO2 generated could not be quantified directly. Overall conversion efficiencies of up to 25% were estimated from cells operated over prolonged time. From polarization curves, interrupt experiments and analysis of reaction products, mass transport problems (concentration polarization) and breakthrough losses were found to be the main deficiencies of the ethanol oxidation electrodes fabricated so far.
Nowadays, it becomes the head of concern for many modern power girds and energy management systems to derive an optimal operational planning with regard to energy costs minimization, pollutant emissions reduction and better utilization of renewable resources of energy such as wind and solar. Considering all the above objectives in a unified problem provides the desired optimal solution. In this paper, a Fuzzy Self Adaptive Particle Swarm Optimization (FSAPSO) algorithm is proposed and implemented to dispatch the generations in a typical micro-grid considering economy and emission as competitive objectives. The problem is formulated as a nonlinear constraint multi-objective optimization problem with different equality and inequality constraints to minimize the total operating cost of the micro-grid considering environmental issues at the same time. The superior performance of the proposed algorithm is shown in comparison with those of other evolutionary optimization methods such as conventional PSO and genetic algorithm (GA) and its efficiency is verified over the test cases consequently.
In this study, we report the preparation of carbon nanotubes (CNTs) anchor layer on a Cu substrate (CNTs/Cu) by using electrophoretic deposition technique. The CNTs anchor layer increases adhesion strength between Si-O-C composites and Cu substrate, as a result, it is possible to improve deposited Si amounts and areal capacity. The electrodeposited Si-O-C composites on CNTs/Cu (Si-O-C/CNTs/Cu) show homogenously coated surface morphology without cracks even large passing charge for electrodeposition of 15 C cm−2, resulting in 0.21 mg cm−2 of deposited Si amounts. On the other hand, Si-O-C composites deposited on as-received Cu substrate (Si-O-C/Cu) begin to peel off from substrate at 8 C cm−2 of passing charge, resulting in 0.13 mg cm−2 of deposited Si amounts, and decrease down to 0.10 mg cm−2 at 15 C cm−2 of passing charge. As a results, the improved Si amounts deposited on CNTs/Cu substrate achieve higher areal capacity, delivering 0.24 mA h cm−2, which attains increase in 84.6% in comparison to Si-O-C/Cu, which has areal capacity of 0.13 mA g cm−2 at 8 C cm−2 of passing charge. Moreover, the Si-O-C/CNTs/Cu shows improved anode performances including discharge capacity and C-rate performance of the Si-O-C composites than Si-O-C/Cu without CNTs anchor layer.
The intercalation and diffusion of lithium ions in a bundle of carbon nanotubes (CNTs) are investigated via an ab initio molecular dynamics simulation method based on the density functional theory. We found that lithium ions quickly penetrate into the CNTs and the space between neighboring CNTs. With a low Li ion density, the Li ions tend to stay close to the nanotube ends. Interestingly, Li ions are able to penetrate through the carbon nanotube and move from one end to the other. We also discovered that Li ions may remain between two neighboring CNTs, which presents a new approach for Li ion intercalation and storage. Importantly, Li ions located among three neighboring CNTs have very strong adsorption potentials that are a factor of four larger than those of Li ions located along the central axis of a single-walled nanotube (SWNT). This indicates that Li ions located among three neighboring CNTs would be very difficult to remove from a nanotube bundle, which suggests that Li storage capacity in this case is possibly irreversible, and that keeping the nanotubes apart with an appropriate distance would hinder or promote the formation of irreversible intercalation. Our findings contribute to the understanding of lithium intercalation and diffusion in CNTs, which has implications for the experimental development and application of rechargeable Li ion batteries.
Several Mediterranean islands are not connected to the main electricity grid yet meaning that independent local grids cater for their power requirements, mainly using imported fossil fuels whose resources scarcity, especially during the high-demand summer months, is a significant challenge. Seasonal variability in power demand, fuel price volatility, as well as a growing tourism development, impose some additional complexity. The present study analyses specific island grids of the Aegean Sea. Selected islands are analysed as case studies over a 20-year period (2016–2036). The developed energy modelling exercise uses a Harmony Search Algorithm in its core. It investigates whether the deployment of renewable energy sources could lead to a sustainable system, decrease the current burden from the government budget, and support local resources. In doing so we examine whether an increased share of RES, battery storage, and their combination could reduce islands’ reliance on imports and potentially eliminate the current heavily subsidised status quo. The results show that a 30% increase of the consumption will require increases in installed power capacities by 40–70%, in the best case scenario. The latter involves significantly lower per-kWh cost, between 17% and 36% of the current values, due to the large share of RES.
Within a battery pack of electric vehicles, a constant and homogeneous temperature distribution is an ideal case. However, what is in fact frequently observed is an unbalanced cycle life performance between series/parallel connected cells. While previous studies have proposed models that simulate the capacity fade of a single lithium-ion battery (LIB) in cycle life tests, most of them do not consider the accompanying effects when batteries are connected, and these models could only investigate cycling under a constant cell temperature. To analyze the temperature difference effect on a battery pack, we develop a cycle life model that allows for temperature variation of LIBs during cycling, and we apply the model to the simulation of series connected LIBs based on the porous electrode theory. We assign different hypothetical temperatures to each of the cells in series. Such a design generates a state of performance imbalance. Our result shows that the capacity degradation of the battery pack increases with the increase of temperature difference and of the average temperature. We then conduct an experiment to verify this adverse effect. The experimental data agree well with the simulation result.
This paper derives simple algorithms for determining parameters of two circuit models for charging/discharging batteries. The problems of identifying parameters for the circuit models are converted into algebraic problems of solving systems of polynomial equations of special structures. A recent algebraic tool is applied to obtain analytical solutions to these polynomial equations and simple algorithms for extracting model parameters from experimental responses. Computational results are obtained for 3 types of batteries: Li-polymer, lead-acid and NiMH.