batterydata/paper-abstracts huggingface dataset:
The objective of this research is to clarify the mechanical properties and self-healing ability of the Excavation Damaged Zone (EDZ) around rock caverns in clastic-rock. Observations of nearly one hundred closed roadways up to fifty years old, which can be regarded as very severe EDZs with no initial sealability and are up to 300m deep in clastic-rock, were made at the Kushiro Coal Mine, Japan, to accomplish the objective. Most old roadways were closed, though a few remain open. Closure of old roadways was mainly due to roof deflection and/or floor heave. Large plastic deformations dominated; however, severe fractures were seldom observed in closed old roadways. Rayleigh wave velocity and hydraulic conductivity in the closed old roadways were in the range of 0.3–1.2km/s and 5×10−7–1×10−7 m/s, respectively, and those in EDZ and EdZ (Excavation disturbed Zone) around recently excavated roadways were 1.1–1.8km/s and 1×10−8–5×10−8 m/s, respectively. The extent of EDZ around the present tailgate was in the range of 1–5m. Mechanical excavation and prevention from water are suggested as the key points for long-term maintenance of rock repositories. Pressurization from inside the cavern to decrease the permeability of EDZ is proposed for maintenance of rock repositories in medium-hard clastic-rock masses at similar depths for long periods.
The mixture of graphite, vapor grown carbon fibers (VGCFs), and carbon nanohorns (CNHs) was heat-treated in Ar atmosphere and carbon-coated by using a chemical vapor deposition (CVD) method (C-graphite/VGCF/CNH). Scanning electron microscopy observation showed that graphite, VGCF, and CNHs were covered by carbon film. Thermogravimetric analysis also indicated that carbon film formed by the CVD method combusted at 550 °C and the quantity of carbon film was about 4 wt%. The C-rate properties of half-cell for C-graphite/VGCF/CNH were superior to those for the mixture of graphite, VGCF, and CNHs (C-graphite/VGCF/CNH (discharge) : 3C/0.1C, 85%, graphite/VGCF/CNH (discharge) : 3C/0.1C, 50%), accelerating a promising application for quick charge–discharge of Li-ion batteries.
Nanoparticle loaded quasi solid electrolytes are important from the view point of developing electrolytes for dye sensitized solar cells (DSSCs) having long term stability. The present work shows the influence of isoelectric point of nanopowders in electrolyte on the photoelectrochemical characteristics of DSSCs. Electrolytes with nanopowders of silica, alumina and magnesia which have widely differing isoelectric points are used in the study. Adsorption of ions from the electrolyte on the nanopowder surface, characterized by zeta potential measurement, show that cations get adsorbed on silica, alumina surface while anions get adsorbed on magnesia surface. The electrochemical characteristics of nanoparticulate loaded electrolytes are examined through cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). DSSCs fabricated using liquid, silica or alumina loaded electrolytes exhibit almost similar performance. But interestingly, the magnesia loaded electrolyte-based cell show lower short circuit current density (J SC) and much higher open circuit voltage (V OC), which is attributed to adsorption of anions. Such anionic adsorption prevents the dark reaction in magnesia loaded electrolyte-based cell and thus, enhances the V OC by almost 100 mV as compared to liquid electrolyte based cell. Also, higher electron life time at the titania/electrolyte interface is observed in magnesia loaded electrolyte-based cell as compared to others.
A Li–Te rechargeable cell with exceptionally high specific capacity and cycling stability at high charge/discharge rates is presented. The cell was composed of a Te/mesoporous carbon CMK-3 composite positive electrode and a Li metal negative electrode. The Te/CMK-3 electrode was prepared using a melt diffusion process and characterized using scanning electron microscope, X-ray diffraction, and Brunauer–Emmett–Teller surface area analysis. Cyclic voltammograms of the Te/CMK-3 electrode suggested reversible (de)lithiation of Te at 1.63/1.88 VLi+/Li combined with irreversible formation processes. Initial cell cycling for formation process revealed voltage plateaus consistent with the cyclic voltammograms until a stationary capacity of about 400 mA h g−1 at 1C with 100 % coulombic efficiency was reached. Discharge capacities retained 96 % (0.5C), 86 % (1C), 78 % (2C), and 69 % (5C) of the theoretical specific capacity. Long-term cyclability tests involving 1000 charge/discharge cycles at 10C rate delivered an unprecedented specific capacity of 286 mA h g−1 at essentially 100 % coulombic efficiency (85 % capacity retention). The study bears testimony to the favorable high-rate stability of the Li–Te/CMK-3 cell design outperforming previously reported chalcogen-based electrode systems.
MnO is a promising anode material for lithium ion batteries (LIBs), but a big challenge remains in impeding its structural and kinetic deterioration in the lithiation/delithiation process. In this study, we report that the structural integrity and electrochemical kinetics of MnO electrodes can be significantly enhanced by homogenously embedding MnO nanoparticles in robust carbon microsheets. The MnO/C microsheets were synthesized by sintering polyurethane (PU) sponge grafted with manganese polyacrylate at 800 °C. At a current density of 100 mA g−1, the resulting microsheets delivered a high reversible capacity of 797.6 mAh g−1 after 50 cycles. They also exhibited good cycling stability and rate capability of 323.2 mAh g−1 at 2000 mA g−1, showing one of the best lithium storage properties among the reported MnO anodes. The excellent electrochemical performance is attributed to the buffering, confining and conducting effects of robust carbon microsheets on MnO nanoparticles. These synergistic effects allow the hybrid microsheets to keep good structural integrity, high electronic conduction, and fast electrochemical kinetics in the cycling process. Our findings offer an alternative strategy to address the structural and kinetic issues of a MnO anode in the lithiation/delithiation process, which might be extendable to other electrode materials of LIBs.
The aim of this review is to illustrate the role of working memory and executive functions for scholastic achievement as an introduction to the question of whether and how working memory and executive control training may improve academic abilities. The review of current research showed limited but converging evidence for positive effects of process-based complex working-memory training on academic abilities, particularly in the domain of reading. These benefits occurred in children suffering from cognitive and academic deficits as well as in healthy students. Transfer of training to mathematical abilities seemed to be very limited and to depend on the training regime and the characteristics of the study sample. A core issue in training research is whether high- or low-achieving children benefit more from cognitive training. Individual differences in terms of training-related benefits suggested that process-based working memory and executive control training often induced compensation effects with larger benefits in low performing individuals. Finally, we discuss the effects of process-based training in relation to other types of interventions aimed at improving academic achievement.
HIV-infected women may be particularly vulnerable to certain types of neurocognitive impairments which may be exacerbated by aging and other predictors. Within the context of cognitive reserve, this article examines issues surrounding women as they age with HIV. For this, a review of 12 recent studies (2013–2016) using data from the Women’s Interagency HIV Study (WIHS), the largest cohort study comparing HIV-infected and demographically matched uninfected women, is presented that specifically examines neurocognition. In general, HIV-infected women are more vulnerable to developing neurocognitive impairments than uninfected women; other factors that may contribute to these neurocognitive impairments include recent illicit drug use, reading level (educational quality/cognitive reserve), stress, PTSD, insulin resistance, liver fibrosis, and age. Surprisingly, when examined in some analyses, age × HIV interactions were not observed to impact neurocognitive performance, findings largely consistent in the literature; however, longitudinal analyses of these data have yet to be performed which may yield future insights of how cognitive reserve may be compromised over time. Yet, with insulin resistance, liver fibrosis, stress, and other known predictors of poorer neurocognition also occurring more with advanced age, in time, the synergistic effect of age and HIV may be more robust and observable as this population ages.
The purpose of Directive 2012/19/EU which is related to WEEE (Waste Electrical and Electronic Equipment), also known as “e-waste”, is to contribute to their sustainable production and consumption that would most possibly be achieved by their recovery, recycling and reuse. Under this perspective, the present study focused on the recovery of valuable materials, metals and metalloids from LCDs (Liquid Crystal Displays). Indium (In), arsenic (As) and stibium (Sb) were selected to be examined for their Leaching Capacity (R) from waste LCDs. Indium was selected mainly due to its rarity and preciousness, As due to its high toxicity and wide use in LCDs and Sb due to its recent application as arsenic’s replacement to improve the optimal clarity of a LCD screen. The experimental procedure included disassembly of screens along with removal and recovery of polarizers via thermal shock, cutting, pulverization and digestion of the shredded material and finally leaching evaluation of the aforementioned elements. Leaching tests were conducted under various temperatures, using various solid:liquid (S/L) ratios and solvents (acid mixtures), to determine the optimal conditions for obtaining the maximum leaching capacities. The examined elements exhibited different leaching behaviors, mainly due to the considerable diversity in their inherent characteristic properties. Indium demonstrated the highest recovery percentages (approximately 60%), while the recovery of As and Sb was unsuccessful, obtaining poor leaching percentages (0.16% and 0.5%, respectively).
Potassium ion batteries (KIBs) are gaining attention as attractive, low-cost alternatives to lithium ion batteries (LIBs). Emerging KIB materials are not yet fully understood, so in situ characterization techniques are being developed to address the similarities and differences to the operation of LIB materials, including aspects of interfacial ion transfer and solid electrolyte interphase (SEI) formation. Here, we introduce the use of Hg disc-well microelectrodes as probes in scanning electrochemical microscopy (SECM) for the detection of K+ gradients on an operating graphitic material. Electrochemically controlled amalgamation and stripping reactions on these probes permit their accurate positioning near a conductive surface, and the detection of local concentration changes once the substrate is biased to intercalate K+. K+ reduction into the Hg phase follows a behavior similar to that of Li+ and Na+ and yields an electrochemical response that is used to evaluate local substrate reactivity. Using these probes in situ, we demonstrate the reversible intercalation of K+ on a surface site of patterned highly oriented pyrolytic graphite (HOPG), a model interface for carbonaceous KIB materials. Our method affords a direct measurement of localized K+ fluxes, which are not resolvable through bulk electroanalytical techniques, thus making our approach potentially informative about reaction mechanisms for nascent KIB-based energy storage technologies.
Whereas studies of the past 10years have shown the executive functions (EFs) in adults to be differentiated into at least three principal components (working memory, inhibition, and flexibility), EF structure in children is far less well understood despite a large body of research on the subject. A study was undertaken to test different structural models of EFs through confirmatory factor analysis (CFA) on a large sample of typically developing kindergarteners (N =272). The method employed sought to remedy the shortcomings of past research in this field such as absence of CFA, insufficient number of EF components tested, insufficient number of indicators per latent variable, and absence of control on processing speed. Children were assessed using a battery of EF tasks developed by the researchers to measure working memory (WM), flexibility, and inhibition (backward word span, backward block span, fruit Stroop, day–night test, hand Stroop, Trails-P, card sort, face sort, and verbal fluency shift). CFA results show the best-fitting model to comprise two factors, namely, an inhibition factor and a WM–flexibility factor. Invariance analyses suggest that this structure is the same for girls and boys and that latent variable means do not differ by sex. These results support the hypothesis of EF differentiation during development. The researchers formulate other hypotheses regarding neurophysiological development.
Submersed aquatic vegetation is an important modulator of sediment delivery from the Susquehanna River through the Susquehanna Flats into the Chesapeake Bay. However, the dynamic interactions between vegetation and the physical drivers of sediment transport through the region are not well understood. This study used a new vegetation component in a coupled flow-wave-sediment transport modeling system (COAWST) to simulate summer through fall 2011, when the region experienced a sequence of events including Hurricane Irene and Tropical Storm Lee. Fine sediment was exported under normal flows and high-wind forcing but accumulated under high flows, with accumulation doubling in the presence of vegetation. The relative effects of vegetation under normal flows and high-wind forcing depended on previous sediment dynamics. The presence of vegetation facilitated deposition of fine sediments within the patch under normal flows and subsequent resuspension during a wind-driven event. However, during significant discharge events, the system was completely dominated by riverine dynamics with vegetation enhancing net deposition as well as channeling the flow. While further refinement of the bed model may be needed to capture some nuances, the COAWST modeling system provides new insights into detailed sediment dynamics in complex vegetated deltaic systems.
In this study, exclusive affect of microwave mediated synthesis on the physicochemical and electrochemical properties of α-MnO2 have been differentiated from that of α-MnO2 synthesized in conventional-reflux method. The TG, XRD, BET and SEM analyses show improved physicochemical properties like additional lattice K+ ions, better crystallinity, high surface area (155 m2 g−1) as well as pore volume (0.67 cm3 g−1) and hierarchical porous ball-like morphology of the microwave-synthesized α-MnO2. The CV studies show lower polarization resistance and higher rate pseudocapacitance (258 Fg−1 at 100 mVs−1) of microwave-synthesized α-MnO2 as compared to its reflux-synthesized counterpart (168 Fg−1 at 100 mVs−1). The CP studies show better high rate charge-discharge performance (146 Fg−1 at 16 Ag−1), longer cyclic stability (91.4% capacitance retention after 400 charge-discharge cycles at 16 Ag−1) and higher Coulombic efficiency (∼100%) of microwave-synthesized α-MnO2 as compared to the reflux-synthesized sample (80 Fg−1 at 16 Ag−1; 74.1% capacitance retention after 400 charge-discharge cycles at 16 Ag−1; 85% Coulombic efficiency). Further, due to facile mass transfer in the perfectly porous matrix, the microwave-synthesized α-MnO2 shows lower equivalent series resistance and better frequency response (higher specific capacitance at elevated operating frequency) as revealed from the impedance studies.
Many battery energy-storage applications are currently undergoing a progressive change away from the traditional flooded lead–acid battery to a valve-regulated design which offers convenience both in operation (spill-proof, able to be rapidly recharged) and in reduced maintenance. At the same time, there are large changes in prospect in the applications themselves. In the transport sector, it appears that at least part of the largest of all present markets, the 12/14V starting, lighting and ignition (SLI) battery, will be replaced by a 36/42V system. Also, there may be some substitution of electric and/or hybrid electric vehicles for vehicles that employ internal combustion engines alone. There is also, currently, rapid growth in the use of valve-regulated lead–acid batteries for telecommunications and there is enormous potential for future growth in remote-area power supplies (RAPSs). The present paper reviews some of the salient aspects of the research and development programs that are being carried out in order to meet these challenges.
The effects of 28 h of sleep deprivation were compared with varying doses of alcohol up to 0.1% blood alcohol concentration (BAC) in the same subjects. The study was conducted in the laboratory. Twenty long-haul truck drivers and 19 people not employed as professional drivers acted as subjects. Tests were selected that were likely to be affected by fatigue, including simple reaction time, unstable tracking, dual task, Mackworth clock vigilance test, symbol digit coding, visual search, sequential spatial memory and logical reasoning. While performance effects were seen due to alcohol for all tests, sleep deprivation affected performance on most tests, but had no effect on performance on the visual search and logical reasoning tests. Some tests showed evidence of a circadian rhythm effect on performance, in particular, simple reaction time, dual task, Mackworth clock vigilance, and symbol digit coding, but only for response speed and not response accuracy. Drivers were slower but more accurate than controls on the symbol digit test, suggesting that they took a more conservative approach to performance of this test. This study demonstrated which tests are most sensitive to sleep deprivation and fatigue. The study therefore has established a set of tests that can be used in evaluations of fatigue and fatigue countermeasures.
To improve the rate capability and cyclability of carbon anode for Li-ion batteries, graphite was modified by forming a graphite–metal oxide (G–MO) composite. Structure analyses and electrochemical characteristics were performed. An insertion mechanism is proposed.
Lithium ion batteries are among the most promising electrochemical storage systems currently available. However, even though their high values of specific energy and energy density make them suitable for the development of new research approaches to counteract the global energy consumption, its diffusion is still limited in several sectors because of the high costs and safety problems. Five different Lithium ion cells of similar energy size but different chemical composition have been studied here, with the aim of pinpointing the fundamental characteristics of each battery. A comprehensive knowledge of these technologies can help finding out the critical parameters indicating dangerous situations. An automated test system based on the synchronous measurement of battery voltage, current and temperature has been employed in this comparative study. The system allows for testing the cells with a huge variety of protocols, from the standard charge cycle to the more complex power control test. Experimental results highlight that, for example, the LiNiCoO2 and the Lithium Polymer batteries outperform for their energy density and specific energy while the LiFePO4 show the highest versatility, efficiency and safety.
The performance of the anode materials is critical to further development of Li-ion batteries. However, the cycling stability and safety performance of anode materials are still far from satisfying. Here we propose a new strategy, i.e., the disorder/order engineering, by which the anode performance of the Li-ion battery can be improved. First, the disordered materials were prepared by vitrifying V2O5-TeO2 (VT) liquids, and then the VT glass powder was mixed with acetylene black and binder to form anode for a lithium ion battery. Second, by subjecting the battery to discharging/charging cycles, the VT glass was partially transformed into ordered phases at the nanoscale, i.e., the disorder-order transition occurred. Even the first cycle of discharging/charging induced the disorder-order transition. The ordered nano-domains and the disordered matrix exert a synergetic effect to facilitate the ionic and electronic transport and to maintain structure stable against discharging/charging. As a consequence, both the capacity and the cycling stability were greatly enhanced, and the structural origin of such enhancement was explored. This study has opened a new way for developing high performance anodes for Li-ion batteries.
Abstract This chapter begins with a general introduction to the Lagrangian methods, which provide a quantitative description of both track and speed of water current flow, employed to obtain an overall picture of oceanic subsurface currents and gyres over large areas. This is followed by a description of different kinds of freely drifting subsurface floats used for such measurements. These consist of surface-trackable subsurface drifters, satellite-recovered pop-up drifters, Swallow floats tracked by ship-borne hydrophones, subsurface floats transmitting to moored acoustic receivers, subsurface floats listening to moored acoustic sources, horizontally displaced and vertically cycling subsurface float (ALACE), and drifting profiling floats (ARGO floats) that allow estimation of geostrophic currents at various depths from repeat profiles of water temperature, salinity, and depth data (density data). A brief account of profiling observations from polar regions is also provided.
Rational robust hierarchical-porous Graphene/C/SiO2 hollow microspheres (G/C/SiO2) were designed as scaffold to load sulfur. The sulfur was impregnated into the microspheres to generate sulfur-Graphene/C/SiO2 composites (S-G/C/SiO2) for Li-S batteries. The 3D porous microspheres consist of SiO2 nanoparticles connected by interconnected graphene and carbon layer, which could leave enough room for volume changes of sulfur during the charge-discharge process, and imprison the polysulfide via physical adsorption and chemical binding, thus effectively improving the cycle stability. As a result, the S-G/C/SiO2 with 20.1wt. % SiO2 exhibits high discharge capacities up to 1118.4mA h g−1 at 0.1C, an excellent rate capability of 551.7mA h g−1 at 5C, and an exciting cycle performance of 626.3mA h g−1 after 400 cycles at 0.5C (ultralow capacity decay of only 0.062% per cycle), represented to be a promising cathode material for Li-S batteries.
Hybrid energy system is an excellent solution for electrification of remote rural areas where the grid extension is difficult and not economical. Such system incorporates a combination of one or several renewable energy sources such as solar photovoltaic, wind energy, micro-hydro and may be conventional generators for backup. This paper discusses different system components of hybrid energy system and develops a general model to find an optimal combination of energy components for a typical rural community minimizing the life cycle cost. The developed model will help in sizing hybrid energy system hardware and in selecting the operating options. Micro-hydro-wind systems are found to be the optimal combination for the electrification of the rural villages in Western Ghats (Kerala) India, based on the case study. The optimal operation shows a unit cost of Rs. 6.5/kWh with the selected hybrid energy system with 100% renewable energy contribution eliminating the need for conventional diesel generator.