batterydata/paper-abstracts huggingface dataset:
Redox-flow batteries (RFBs) can store large amounts of electrical energy from variable sources, such as solar and wind. Recently, redox-active organic molecules in aqueous RFBs have drawn substantial attention due to their rapid kinetics and low membrane crossover rates. Drawing inspiration from nature, here we report a high-performance aqueous RFB utilizing an organic redox compound, alloxazine, which is a tautomer of the isoalloxazine backbone of vitamin B2. It can be synthesized in high yield at room temperature by single-step coupling of inexpensive o-phenylenediamine derivatives and alloxan. The highly alkaline-soluble alloxazine 7/8-carboxylic acid produces a RFB exhibiting open-circuit voltage approaching 1.2 V and current efficiency and capacity retention exceeding 99.7% and 99.98% per cycle, respectively. Theoretical studies indicate that structural modification of alloxazine with electron-donating groups should allow further increases in battery voltage. As an aza-aromatic molecule that undergoes reversible redox cycling in aqueous electrolyte, alloxazine represents a class of radical-free redox-active organics for use in large-scale energy storage.
A novel tri-modal mesoporous carbon (TMC)/S composite as a high performance cathode for Li-S battery is reported. The TMC host, synthesized by a simple sol-gel templating method, possesses one of the highest surface area of 2371m2 g−1, pore volume of 2.85ccg−1 and a unique tri-modal mesopore structure (2.5nm/9nm/15nm). Electrochemical tests reveal that the TMC/S–50wt% nanocomposite cathode delivers an initial capacity up to 1029mAhg−1 at 3350mAg−1 (2C), and maintains a high reversible capacity of 843mAhg−1 after 100 cycles. And it retains a stable capacity of 708mAhg−1 after 100 cycles at 5025mAg−1 (charge/discharge in 20min, 3C). Even with a higher sulfur loading, the TMC/S–70wt% nanocomposite still reaches a reversible capacity of 700mAhg−1, and demonstrates a very low decay rate of only 0.088% per cycle over 300 cycles at 838mAg−1 (0.5C). We attribute such superior performance to the collective effect of tri-modal mesopore architecture, especially to the contribution of the exterior large mesopores (15nm), designed being not only large enough to accommodate rapid electrolyte transport, moreover, small enough to serve as additional buffer spaces for polysulfides entrapment.
The parameters characterizing lithiation processes in silicon anodes of lithium ion batteries (LIBs) are compared between μm- and nm-sized silicon particles. Galvanostatic electrochemical impedance spectroscopy (GS-EIS) is used to investigate the silicon-lithium alloying reaction in a practical charging operation (galvanostatic lithiation). Effective kinetic parameters depending on lithiation C-rates are obtained along lithiation progress from a large body of impedance data. Nanosizing benefits of nanoparticles over micro-particles are confirmed such as lower polarization resistance (Rp) and thinner solid-electrolyte interphase layer (SEI layer) over the whole lithiation range. Based on the kinetic information obtained from the non-stationary conditions, a lithiation strategy consisting of multiple galvanostatic steps is designed to lithiate silicon anodes in a faster way. 75% of full capacity is lithiated by a galvanostatic sequence of 4C–2C–1C–0.5C within 20 min. However, only 43% and 21% are achieved by a single-rate galvanostatic lithiation at 1 C and 0.5 C, respectively.
Visuo-spatial ability is associated with a quality of performance in a variety of surgical and medical skills. However, visuo-spatial ability is typically assessed using Visualization tests only, which led to an incomplete understanding of the involvement of visuo-spatial ability in these skills. To remedy this situation, the current study investigated the role of a broad range of visuo-spatial factors in colonoscopy simulator training. Fifteen medical trainees (no clinical experience in colonoscopy) participated in two psycho-metric test sessions to assess four visuo-spatial ability factors. Next, participants trained flexible endoscope manipulation, and navigation to the cecum on the GI Mentor II simulator, for four sessions within 1 week. Visualization, and to a lesser degree Spatial relations were the only visuo-spatial ability factors to correlate with colonoscopy simulator performance. Visualization additionally covaried with learning rate for time on task on both simulator tasks. High Visualization ability indicated faster exercise completion. Similar to other endoscopic procedures, performance in colonoscopy is positively associated with Visualization, a visuo-spatial ability factor characterized by the ability to mentally manipulate complex visuo-spatial stimuli. The complexity of the visuo-spatial mental transformations required to successfully perform colonoscopy is likely responsible for the challenging nature of this technique, and should inform training- and assessment design. Long term training studies, as well as studies investigating the nature of visuo-spatial complexity in this domain are needed to better understand the role of visuo-spatial ability in colonoscopy, and other endoscopic techniques.
Transition metal oxide-based anodes suffer from poor rate capability and cyclic stability owing to their low electronic conductivity and large volume change for lithium ion batteries (LIBs). Sandwich-type structure based on two-dimensional (2D) graphene (GS) and 2D transition-metal oxide nanosheets could offer many potential advantages in electrochemical energy storage field. In this study, we demonstrate a facile process to fabricate a layer-by-layer assembled 3D hierarchical sandwich-type architecture composed of 2D tungsten trioxide nanoplatelets and graphene (denoted as TTNPs-GS). When evaluated as anode materials, the sandwich-type architecture plays vital roles in endowing high electronic conductivity, accommodating large volume variation and achieving abundant ion transport paths, thus enabling superior lithium-ion storage performance. TTNPs-GS shows a good reversible capacity of 847mAhg−1 (theoretical capacity of 693mAhg−1 for tungsten trioxide), high-rate capability (292mAhg−1 at 3600mAg−1) and long cycle life (615mAhg−1 with 118.9% capacity retention at 1080mAg−1 after 1000 cycles).
Metal oxides (TiO2, Er2O3 and ZnO) were added to La–Mg–Ni-based hydrogen storage alloy electrodes and their effects on the structural and electrochemical properties were studied. The charge efficiency, especially at high charge current density was greatly ameliorated, and the high rate charge capability at 1440 mA g−1 increased from 85.1% (blank) to 94.1% (TiO2), 93.3% (Er2O3) and 90.5% (ZnO). The high temperature dischargeability was also improved in case of TiO2, Er2O3 and ZnO additives. These additives suppressed formation of Mg(OH)2 and La(OH)3 during charge/discharge process and therefore the cycling stability was improved. The discharge capacity retention at the 200th cycle increased from 72.9% (blank) to 79.6% (TiO2), 87.5% (Er2O3) and 77.9% (ZnO).
Nature has been a source of medicinal products for millennia, and during the past century many useful drugs have been developed from natural sources, particularly plants. This review briefly traces the evolution of natural products drug discovery, and outlines the impressive number of important drugs that have originated from natural sources, particularly those related to the treatment of cancer. It is clear that nature will continue to be a major source of new drug leads, and the vast untapped potential of microorganisms is emphasized. With the advent of genetic techniques that permit the isolation and expression of biosynthetic cassettes, microbes and their marine invertebrate hosts may well be the new frontier for natural products lead discovery, although plant endophytes also offer an exciting new resource. Effective drug development will depend on multidisciplinary collaboration embracing natural products lead discovery and optimization through the application of total and diversity-oriented synthesis and combinatorial chemistry and biochemistry, combined with good biology. These factors are illustrated by the impressive number of anticancer drugs, discussed in terms of their mechanisms of action, which are derived from natural sources.
V2ON thin film has been successfully fabricated by reactive dc sputtering method and annealing process and was investigated for its electrochemistry with lithium. The reversible discharge capacities of V2ON/Li cells cycled between 0.01 and 4.0V were found in the range of 803–915mAhg−1 during the first 50 cycles. By using ex situ scanning electron microscopy, transmission electron microscopy, selected-area electron diffraction and X-ray photoelectron spectroscopy measurements, the reversible transformation between nanocrystalline V2ON and well dispersed V, Li2O, Li3N nano-composites were revealed in the lithium electrochemical reaction. V2ON thin film exhibits high reversible capacity and good cycle performance with remarkable lower polarization than VN thin film.
Feedback of physiological responses have a great potential to support virtual training paradigms aimed to increase cognitive task performance under stressful threatening conditions. In the current study, we examined the sensitivity of a range of physiological indicators derived from electrodermal activity (EDA), blood pressure (BP) and heart rate (HR) to measure stress as induced by the threat of an electric shock (ES). In contrast to previous work that studied physiological stress responses compared to a rest condition, we compared conditions with high cognitive load combined with stress caused by threat of an ES, to conditions with high cognitive load without such stress. Twenty-five participants performed a cognitively demanding task in an experimental setup. At certain 10 s time intervals, indicated by a continuous tone, participants were either asked to do their best and increase cognitive task performance (non-threat condition), or they were told that they could receive an ES during this interval if cognitive task performance was not high enough (threat condition). Physiological measures, task performance and self-reported measures of stress and workload were analysed. Task performance and self-reported measures of stress and workload were roughly the same in both conditions. Especially EDA measures were affected by the threat of an ES. Threat and non-threat conditions could be distinguished with an across-participant classifier using EDA and BP features with an accuracy of 70%. These results suggest that EDA and BP can be used to evaluate stress coping training paradigms or to individually adapt the stress levels in virtual training environments.
High-capacity Si-embedded anodes and Li-rich cathodes are considered key compartments for post lithium-ion batteries with high energy densities. However, the significant volume changes of Si and the irreversible phase transformation of Li-rich cathodes prevent their practical application. Here we report lithium fluoromalonato(difluoro)borate (LiFMDFB) as an unusual dual-function additive to resolve these structural instability issues of the electrodes. This molecularly engineered borate additive protects the Li-rich cathode by generating a stable cathode electrolyte interphase (CEI) while simultaneously tuning the fluoroethylene carbonate (FEC)-oriented solid electrolyte interphase (SEI) on the Si–graphite composite (SGC) anode. The complementary electrolyte design utilizing both LiFMDFB and FEC exhibited an improved capacity retention of 85%, a high Coulombic efficiency of ∼99.5%, and an excellent energy density of ∼400 W h kg−1 in Li-rich/SGC full cells at a practical mass loading after 100 cycles. This dual-function additive approach offers a way to develop electrolyte additives to build a more favorable SEI for high-capacity electrodes.
Nanostructured Bi/C and Bi/Al2O3/C composites, prepared by high-energy mechanical milling (HEMM), are investigated as anode materials for Li-ion rechargeable batteries. X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) reveal that the Bi/C nanocomposite is composed of nano-sized Bi and amorphous C, while the Bi/Al2O3/C nanocomposite (obtained by the mechanochemical reduction of Bi2O3 and Al) is composed of nano-sized Bi, amorphous Al2O3, and amorphous C. The electrochemical reaction mechanism of the Bi/C nanocomposite electrode is identified by ex situ XRD analyses combined with a differential capacity plot. Electrochemical tests show that the Bi/C and Bi/Al2O3/C nanocomposites exhibit enhanced electrochemical performances compared with that of the pure Bi electrode.
Aqueous rechargeable lithium-ion batteries (ARLBs) use aqueous electrolytes, which create conditions where corrosion may occur when aluminum is used as the current collector. The electrochemical stability of AA1085 in 2 M Li2SO4 and 5 M LiNO3 aqueous electrolytes was evaluated over a range of pH conditions by cyclic voltammetry, linear sweep voltammetry, and chronoamperometry. Aluminum presented high corrosion resistance at pHs 5, 7, and 9 within the stability windows of both electrolytes. At the pH 11 condition, 2 M Li2SO4 is capable of inhibiting aluminum from pitting but the inhibiting effect is not sustainable and crystallographic pitting occurs under a continuously applied anodic potential. Aluminum was well passivated against pitting in 5 M LiNO3 electrolyte at pH 11 due to the formation of a thick corrosion product barrier layer. Raman spectra depicted the presence of sulfate and nitrate anions on aluminum surface after cyclic voltammetry at pH 11. Inductively coupled plasma results showed that the amount of dissolved aluminum in electrolyte after cyclic voltammetry increases when pH increases from 5 to 11. The chemical adsorption mechanisms of sulfate and nitrate anions on aluminum were proposed to explain the dependency of electrochemical stability of aluminum on pH, anodic potential, and type of anions. The applicability of aluminum as current collector in ARLB using the 2 M Li2SO4 and 5 M LiNO3 electrolytes is discussed.
Cathodic electrodeposition of Fe and Fe/CNTs composites from Fe2O3 suspensions in 10 M NaOH was reported for the first time. Triethanolamine (TEA) was used as an additive in the plating suspension and found to improve the morphology and adhesion of the deposits. TEA acted as an effective stabilizer for carbon nanotubes (CNTs) in strongly alkaline media and facilitated incorporation of CNTs into Fe matrix during the deposition, giving rise to Fe/CNTs composites. Current efficiency, microstructure, morphology of Fe deposits and Fe/CNTs composites as well as carbon content in Fe/CNTs revealed at different deposition conditions were determined.
The growth of managed health care in the United States has placed a high premium on the goal of efficiency in the treatment of psychopathology, but without sacrificing treatment efficacy in the process. A preliminary evaluation of a brief, 6-week version of cognitive behavioral group therapy (CBGT) for generalized social anxiety disorder was conducted. Various self-report and behavioral assessment measures were collected at pre- and posttreatment, and self-report assessments were again conducted at 6- and 12-week follow-ups. The results suggest improvement during the acute 6-week treatment phase, and further improvement during the 6 weeks following treatment termination. These gains were maintained at the 3-month follow-up assessment. Effect size comparisons with prior studies revealed that the present treatment produced comparable treatment gains at the 6-week follow-up assessment to those produced by prior studies using the standard 12-week CBGT protocol. Clinical and research implications are discussed.
Thermal shrinkage is a severe problem for the conventional polyolefin separators. In this work, we report the excellent performance of bacterial cellulose (BC) nanofibrous membranes as separators for lithium (Li) ion batteries. Properties of BC separator including morphology, ionic conductivity, electrochemical stability, thermal stability, mechanical strength and battery charge–discharge performance are characterized and compared to a commercial separator membrane (Celgard® 2325). Because of the unique fibrous and cross-linked three-dimensional network structure, BC separator shows excellent dimensional stability up to 180 °C, good ionic conductivity and competitive battery performance.
Water-insoluble PbSO4, PbO2, and PbO are fairly soluble in choline chloride/urea deep eutectic solvent (ChCl/urea DES) in 1:2 molar ratio. Very interestingly, solution prepared from PbO2 exhibits the almost identical electrochemical behavior as those from PbSO4 and PbO, indicating that Pb(II) is formed in the DES regardless of what Pb compound is introduced. The electrochemical reduction of the Pb(II) species is determined as an irreversible process, and involves the three-dimensional (3D) instantaneous nucleation with diffusion-controlled growth. From the dependence of the diffusion coefficient on temperature, the activation energy for diffusion of PbSO4 and PbO2 is determined to be 33.7 and 34.1kJmol−1, respectively. Electrodeposition of Pb was achieved potentiostatically and galvanostatically. The surface morphology of Pb deposits significantly depends on the applied potential and current. The coulombic efficiency of Pb electrodeposition is higher than 90%. Electrodeposition of Pb from a wet DES containing a mixture of three different Pb sources is also investigated. The XRD analysis confirmed that the electrodeposits consisted of metallic Pb.
Background Today's brain stimulation methods are commonly traced back historically to surgical brain operations. With this one-sided historical approach it is easy to overlook the fact that non-surgical electrical brain-stimulating applications preceded present-day therapies. Objective/Hypothesis The first study on transcranial electrical brain stimulation for the treatment of severe mental diseases in a larger group of patients was carried out in the 1870s. Methods Between 1870 and 1878 German psychiatrist Rudolph Gottfried Arndt published the results of his studies in three reports. These are contextualized with contemporary developments of the time, focusing in particular on the (neuro-) sciences. As was common practice at the time, Arndt basically reported individual cases in which electricity was applied to treat severe psychoses with depressive symptoms or even catatonia, hypochondriac delusion and melancholia. Despite their lengthiness, there is frequently a lack of precise physical data on the application of psychological-psychopathological details. Only his 1878 report includes general rules for electrical brain stimulation. Results Despite their methodological shortcomings and lack of precise treatment data impeding exact understanding, Arndt's studies are pioneering works in the field of electric brain stimulation with psychoses and its positive impacts. Today's transcranial direct current stimulation, and partly vagus nerve stimulation, can be compared with Arndt's methods. Although Arndt's only tangible results were indications for the application of faradic electricity (for inactivity, stupor, weakness and manic depressions) and galvanic current (for affective disorders and psychoses), a historiography of present-day brain stimulation therapies should no longer neglect studies on electrotherapy published in German and international psychiatric and neurological journals and monographs in the 1870s and 1880s.
High standards and urgent demands have been proposed for electrode materials because of the increasing market of rapid electrical power supply systems. Pseudocapacitance could provide an effective way for the development of electrode materials with both high energy and power densities. 3D graphene/α-Fe2O3 nanocrystal composites have been inspired by the combination of facet engineering and composite construction. The materials are evaluated as anode materials for secondary lithium ion batteries. Compared with the pristine α-Fe2O3 nanocrystal with oriented facet, the composites render evidently enhanced rate capability and long life span. Reversible capacities of 674 mA h g−1 (420th cycle) and 336 mA h g−1 (750th cycle) can be retained at relatively high rates of 1.0 A g−1, and 5.0 A g−1, respectively. Further investigations reveal that this outstanding performance is attributed to the enhanced pseudocapacitive contribution. The highly interconnected graphene matrix in the 3D composites provide fast electron transport pathways, and facilitate rapid ion diffusion, which eventually promote the pseudocapacitive lithium storage. The composite proves to be a promising candidate as a high-rate electrode material for lithium ion batteries.
An ad hoc grid is a heterogeneous computing and communication system that allows a group of mobile devices to accomplish a mission, often in a hostile environment. Energy management is a major concern in ad hoc grids. The problem studied here focuses on statically assigning resources in an ad hoc grid to an application composed of communicating subtasks. The goal of the allocation is to minimize the average percentage of energy consumed by the application to execute across the machines in the ad hoc grid, while meeting an application execution time constraint. This pre-computed allocation is then used when the application is deployed in a mission. Six different heuristic approaches of varying time complexities have been designed and compared via simulations to solve this ad hoc grid allocation problem. Also, a lower bound based on the performance metric has been designed to compare the performance of the heuristics developed.
This prospective investigation sought to discriminate children who were both aggressive towards and victimized by peers in the first grade, from those who were only aggressive, only victimized, or neither (i.e., socially adjusted), using early child and family risk factors. Two hundred thirty-eight children, their mothers, and teachers participated in a longitudinal study since birth. All three aggressor/victim subgroups showed greater temperamental dysregulation than the socially adjusted children, but only aggressive victims had significantly poorer social perception skills. Aggressive victims were distinguished from aggressors by greater exposure to maternal depression and from victims by lower levels of early inhibition, but they shared the experiences of negative family emotional expressiveness with aggressors and greater mother-child negativity with victims. The identification of early risk factors is crucial to prevention and early intervention efforts that have the potential to attenuate the long term emotional, social, and academic problems associated with aggressive victim status.
There is a rapidly increasing interest in new energy battery chemistries, particularly with respect to conducting polymers and especially with a focus on alternative systems to lithium and lithium ion. Herein we present a novel conducting polymer, poly(aniline-co-azure B) (PANAB), synthesized by introducing redox-active azure B into the polyaniline backbone through co-electropolymerization. The resultant PANAB possesses an electrochemical activity over a larger pH range as compared to polyaniline, and can thereby be used as a cathode-active material for a rechargeable aqueous Zn-polymer battery. This battery features large discharge specific capacities of 134.0 and 127.8mAhg−1 at 120 and 1000mAg−1, respectively, while maintaining good cycling performance. The co-electropolymerization strategy provides a route for the synthesis of more conducting polymers with organic redox-active groups for rechargeable batteries, supercapacitors and fuel cells.