batterydata/paper-abstracts huggingface dataset:
Adhesion of Li plating to electrode substrate and chemical stability of plated Li against electrolyte components are two essential factors affecting the cycling performance of Li metal in a rechargeable Li battery. Poor adhesion results in high contact resistance and further the formation of dead Li. Aiming to improve the adhesion of Li plating to Cu substrate, we plate a very thin tin layer as the primer for Li plating on the Cu substrate. By this way, Li metal is first reacted with tin to form a Li-Sn alloy, and then Li is cycled on resultant Li-Sn alloy so that the Li-Sn alloy functions as an “electric glue” to electrically connect the Li plating and Cu substrate. Attributed to the strong affinity between Li and Li-Sn alloy, the pre-plated tin layer is shown not only to enhance the adhesion of the plated Li to electrode substrate but also to improve the morphology of Li plating. Using a 1.0 m (molality) LiPF6 1:4 (wt.) fluoroethylene carbonate/ethylmethyl carbonate electrolyte, in this paper the effect of the tin primer layer on the Li cycling performance in a Li/Cu cell and a Cu/LiNi0.85Co0.10Al0.05O2 cell is demonstrated and discussed.
Deficits in everyday living skills and social skills are associated with the pervasive disability seen in schizophrenia. Cognitive impairments are determinants of these skills deficits and it is known that positive and negative symptoms add to the influence of cognitive impairments for prediction of real-world outcomes. This study examined the relative importance of cognitive impairments measured with a neuropsychological battery, performance-based measures of social and everyday living skills, and positive and negative symptoms for the prediction of real-world outcomes in social and residential domains. In contrast to most previous studies, we examined the importance of individual symptoms, as well as total subscale scores, for predicting clinician rated outcomes in 194 older outpatients with schizophrenia. Symptoms were rated with the Positive and Negative Syndrome Scale; everyday living skills were measured by the UCSD Performance-based Skills Assessment; and social skills were measured with the Social Skills Performance Assessment. For prediction of real-world social outcomes, blunted affect and passive-apathetic social withdrawal accounted for all of the predicted variance, while social competence and cognitive impairments did not enter the final equation. For residential functioning, everyday living skills were the most important predictor, followed by lack of spontaneity. The positive symptoms of hallucinatory behavior and suspiciousness also predicted real-world residential outcomes. These results suggest that real-world disability is the product of a complex array of ability deficits and symptoms, indicating interventions will need to be carefully targeted. For social and everyday living outcomes, variance accounted for by the entire array of predictive variables was less than 40%, suggesting that other factors, such as social and cultural influences, are involved as well.
Electrical energy storage (EES) such as lithium-ion (Li-ion) batteries can reduce curtailment of renewables, maximizing renewable utilization by storing surplus electricity. Several techno-economic analyses have been performed on EES, but few have investigated the financial performance. This paper presents a state-of-the-art financial model obtaining novel and significative financial and economics results when applied to Li-ion EES. This work is a significant step forward since traditional analysis on EES are based on oversimplified and unrealistic economic models. A discounted cash flow model for the Li-ion EES is introduced and applied to examine the financial performance of three EES operating scenarios. Real-life solar irradiance, load, and retail electricity price data from Kenya are used to develop a set of case studies. The EES is coupled with photovoltaics and an anaerobic digestion biogas power plant. The results show the impact of capital cost: the Li-ion project is unprofitable in Kenya with a capital cost of 1500 $/kWh, but is profitable at 200 $/kWh. The study shows that the EES will generate a higher profit if it is cycled more frequently (hence a higher lifetime electricity output) although the lifetime is reduced due to degradation.
The mobile computing paradigm has introduced new problems for application developers. Challenges include heterogeneity of hardware, software, and communication protocols, variability of resource limitations and varying wireless channel quality. In this scenario, security becomes a major concern for mobile users and applications. Security requirements for each application are different, as well as the hardware capabilities of each device. To make things worse, wireless medium conditions may change dramatically with time, incurring great impact on performance and QoS guarantees for the application. Currently, most of the security solutions for mobile devices use a static set of algorithms and protocols for services such as cryptography and hashes. In this work we propose a security service, which works as a middleware, with the ability to dynamically change the security protocols used between two peers. These changes can occur based on variations on wireless medium parameters and system resource usage, available hardware resources, application-defined QoS metrics, and desired data “security levels”. We compare our solution to some widespread static security protocols, demonstrate how our middleware is able to adapt itself over different conditions of medium and system, and how it can provide a performance gain in the execution of cryptographic primitives, through the use of data semantics.
Dimethyl methyl phosphonate (DMMP) was selected and tested as a non-flammable solvent for primary and secondary lithium batteries, because of its non-flammability, good solvency of lithium salts and appropriate liquidus properties. Experimental results demonstrated that DMMP can solvate considerable amount of commonly used lithium salts to form non-flammable and Li+-conducting electrolyte, which has very wide electrochemical window (>5V vs. Li) and excellent electrochemical compatibility with metallic lithium anode and oxide cathodes. Primary Li–MnO2 cells using DMMP-based electrolyte showed almost the same discharge performances as those using organic carbonate electrolytes, and also, Li–LiMn2O4 cells using DMMP electrolyte exhibited greatly improved cycleability and dischargeability, suggesting a feasible application of this new electrolyte for constructing high performance and non-flammable lithium batteries.
The vanadium redox flow battery (VFB) is one of the most promising stationary electrochemical storage systems. The reduction of system costs is a major challenge in the realization of its widespread application. The high complexity of this technology requires a close linking of technologic and economic aspects in system cost assessment. The present review provides an extensive literature analysis with a focus on techno-economic assessment of VFB. Considered materials, system designs and modelling approaches are assessed and compared in order to present and evaluate the current status of system cost assessment in a transparent way. Systems in a range of 2 kW–50 MW providing energy for up to 150 h are covered in literature resulting in an immense range of specific total system costs of 564–12931 € kW−1 or 89–1738 € (kWh)−1. Based on the data from the reviewed studies, guide values of 650 € (kWh)−1 and 550 € (kWh)−1 for installed VFB systems in a power range of 10–1000 kW providing energy for 4 h and 8 h respectively are derived from literature. Moreover, the relevance of precision in the definition of scope and components for meaningful results of techno-economic assessments of VFB systems is pointed out.
Partial exfoliation of graphene from graphite foil (GF) is achieved by a convenient one-step electrochemical exfoliation method to afford partially exfoliated graphene electrode (Ex-GF) with graphene sheets standing on GF matrix stably. Electropolymerization of pyrrole is carried out on Ex-GF with 1,5-naphthalene disulfonate (NDS) and 2-naphthalene sulfonate (NMS) as the ‘permanent’ doping anions to prepare Ex-GF/PPy-NDS and Ex-GF/PPy-NMS, respectively, in which the polymer is anchoring on the surfaces of graphene sheets. The PPy displays an opened structure due to the facilitated homogeneous nucleation on Ex-GF and so exhibits enhanced specific capacitance compared to the polymers deposited on pristine GF (to afford GF/PPy-NDS and GF/PPy-NMS). Specifically, Ex-GF/PPy-NDS film maintains 79% of its specific capacitance when the discharge current density increases from 1 to 20 A g−1. Moreover, discharge potential window of the polymer is enlarged to 1.3 V (from −0.8 to 0.5 V vs. SCE) due to the dual doping mode. Ex-GF/PPy-NDS film displays a high energy density of 82.4 Wh kg−1 at the power density of 650 W kg−1 and 65.1 Wh kg−1 at the power density of 13 kW kg−1. The cyclic charge/discharge stability of the polymer is also improved due to synergistic effect with partially exfoliated graphene.
We have previously indicated that the improvement of the interface degradation between a positive electrode and an ethylene oxide-based solid polymer electrolyte (SPE) is an important problem requiring a solution for all-solid-state lithium secondary batteries. Therefore, Li3PO4 thin-film on LiCoO2 powder was prepared by the spray coating technique. The observed Li3PO4 film was so thin (approximately 20nm thick) that its contribution to the increase in interfacial resistance was small. However, it played the role of an oxidation barrier for the SPE. A [Li3PO4-coated LiCoO2|SPE|Li] cell exhibited reversibility up to 4.6V with a 200mAhg−1 discharge capacity. The energy density of 760mWhg−1 is one of the highest values obtained for all-solid-state lithium secondary batteries.
We present an 8.9 year old girl diagnosed with autism and macrocrania. Because of macrocrania, hypertelorism and epidermal punctiform lesions in the palm of the hand, Gorlin syndrome was clinically suspected and molecularly confirmed by finding a deletion of 22 base pairs in the PTCH1 gene. The possibility of an association between autism and Gorlin syndrome is discussed.
The rising energy costs and carbon footprint of operating mobile telecommunication sites in the emerging world have increased research interests in green technology. The intermittent nature of most green energy sources creates the problem of designing the optimum configuration for a given location. This study presents the design analysis and control strategy for a cost effective and reliable operation of the hybrid green energy system (HGES) for GSM base transceiver station (BTS) sites in isolated regions. The design constrains the generation and distribution of power to reliably satisfy the energy demand while ensuring safe operation of the system. The overall process control applies the genetic algorithm-based technique for optimal techno-economic sizing of system's components. The process simulation utilized meteorological data for 3 locations (Abuja, Benin City and Sokoto) with varying climatic conditions in Nigeria. Simulation results presented for green GSM BTS sites are discussed and compared with existing approaches.
Single porous In2O3 nanosheets and In2O3/C nanosheet composite with double phases of c-In2O3 and rh-In2O3 were fabricated by a facile one-step solvothermal treatment of a mixture of d-fructose and In(NO3)3 using urea as a precipitating agent in water–ethanol mixed solution followed by calcination. The effect of solution on the fabrication of In2O3 nanosheets was investigated and a possible mechanism was proposed to explain the formation of nanosheets. In2O3/C nanosheet composite electrode exhibited a high lithium storage capacity of 869mAhg−1 after 100 cycles at 100mAg−1, excellent rate and long-term cycling performance. The superior electrochemical performance could be ascribed to the incorporation of carbon and the unique nanosheet architecture of the nanocomposite.
Carbonaceous materials derived from a variety of cheap and sustainable biomass have shown great potential as conductive substrates for the coating of pseudocapacitive materials. In this study, yeast-derived N-doped carbon microsphere/polyaniline (YC/PANI) composites are synthesized by an in situ polymerization approach, using yeasts as the carbon source and structural template. The self-templated hollow YC with good conductivity has many active sites for anchoring PANI, and alleviates the structure destruction caused by the redox reaction of PANI. Accordingly, the YC/polyaniline composite as a supercapacitor electrode exhibits a high specific capacitance (500 F g−1 at a current density of 1 A g−1) and good rate capability in a three-electrode system. Additionally, the symmetric supercapacitor of the YC/polyaniline composite delivers a high capacitance (100 F g−1 at 1 A g−1) and remarkable cycle life (95.4% of the initial capacitance maintenance after 5000 cycles). The uniform coating of PANI nanowires and robust structure stability of composites are responsible for excellent electrochemical properties.
Three-dimensional nanoporous nitrogen-doped graphene (3D-PNG) has been synthesized through a facial one-step synthesis method without additional silica template. The as-prepared 3D-PNGwas used as an electrocatalyst for the oxygen reduction reaction (ORR), which shows excellent electrochemistry performance, demonstrated by half-cell electrochemical evaluation in 0.1M KOH including prominent ORR activity, four electron-selectivity and remarkable methanol poisoning stability compared to commercial 20%Pt/C catalyst. The physical and surface properties of 3D-PNG catalyst were characterized by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and BET surface area analysis. The experiments show that 3D-PNG catalyst possesses super-large specific surface area reaching 920m2 g−1, which is superior to our most recently reported 3D-PNG synthesized by silica template (670m2 g−1) and other doped graphene catalysts in literature. When used for constructing a zinc–air battery cathode, such an 3D-PNG catalyst can give a discharge peak power density of 275mWcm−2. All the results announce a unique procedure to product high-efficiency graphene-based non-noble metal catalyst materials for electrochemical energy devices including both fuel cells and metal–air batteries.
Objective To express the views of a working party held to consider antibiotic resistance surveillance systems, their strengths and weaknesses, and their current and future applications. Methods The participants, all of whom were experienced in this field, discussed the development of surveillance systems in relation to the increasing prevalence of resistance to antibacterial agents and the current interest in surveillance systems shown by many official bodies, in both the human and veterinary fields. The problems inherent in surveillance systems were considered together with the applications of different systems. Results The properties of good antibiotic resistance surveillance systems were defined. Surveillance systems vary widely from those with a narrow base, focusing on few organisms in one disease area, to those covering many diseases, many organisms (including normal flora) and many compounds. Whatever their design, they should be able to detect significant differences and shifts in susceptibility to various antibacterial agents, and the information derived from them should reach as many interested parties as possible in a timely manner. In using this information to decide strategies, criteria for action need to be determined by pragmatic consensus. Funding remains a major problem, with few large studies being supported by official bodies in spite of their professed enthusiasm for surveillance. In consequence, many current systems are funded by the pharmaceutical industry and are of necessity restricted in their focus. Conclusions Antibiotic resistance surveillance studies should and can be well planned and well executed. Many current systems suffer from well-recognized but uncorrected biases. Consortium funding will be necessary for large schemes to be successful. There is no ‘ideal’ surveillance system.
Conjugated polyelectrolytes (CPEs) have been successfully applied in organic photovoltaics and organic light-emitting diodes, and recently those with inorganic cations became to serve as a hole-transporting layer (HTL) in inverted perovskite solar cells (iPSCs), whereas the CPE HTL materials with organic cations are really limited. In this work, we design a CPE whose side-chains are end-capped by CH3NH3 + cations, the same cations as that in the perovskite layer. The CPE is found to be more compatible to the perovskite material, and shows stronger abilities to reduce the traps both at the surface and in the bulk of the perovskite layer, compared with the typical poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS). The resulting iPSC presents much improved photovoltaic properties and a better long-term stability, with a power conversion efficiency of 19.76%, which is the highest value ever reported for iPSCs based on CPE HTLs.
Human activity recognition systems are currently implemented by hundreds of applications and, in recent years, several technology manufacturers have introduced new wearable devices for this purpose. Battery consumption constitutes a critical point in these systems since most are provided with a rechargeable battery. In this paper, by using discrete techniques based on the Ameva algorithm, an innovative approach for human activity recognition systems on mobile devices is presented. Furthermore, unlike other systems in current use, this proposal enables recognition of high granularity activities by using accelerometer sensors. Hence, the accuracy of activity recognition systems can be increased without sacrificing efficiency. A comparative is carried out between the proposed approach and an approach based on the well-known neural networks.
Mixing transition-metal phosphates Li3V2−x Fe x (PO4)3 (0≤x≤2) were first designed to be a type of intercalated and deintercalated cathodes to obtain high specific capacity for safe Li-ion batteries. Since the residual oxygen in the quartz tube furnace and pellet would oxidize the V3+ to V4+ in the Ar ambience during the sintering process, trace amounts of acetylene black inside and outside the pellet could play a role of deoxidizer to protect V3+ meanwhile ensure Fe3+ not reducing to Fe2+. With the concerted effort of inside and outside acetylene black, monoclinic structure Li3V2−x Fe x (PO4)3 (0≤x≤2) solid solutions had been successfully fabricated via a two-step synthesis method. X-ray diffractions with Rietveld refinement revealed that V1-sites were the preferred position when Fe3+ ions doped into Li3V2(PO4)3, which means, every V1-site was occupied with the same probability by V3+ and Fe3+ when 0<x<1, and then for V2-site when 1<x<2. X-ray photoelectron spectroscopy result showed the presence of trace amounts of acetylene black had realized the coexist of V3+ and Fe3+ in the Li3M2(PO4)3 framework. When evaluated as cathodes for Li-ion batteries, the pure Li3V2(PO4)3 electrode displayed the highest charge (137.2mAhg−1) and discharge (121.5mAhg−1) capacities in the first cycle, with the increase of Fe3+ content, all the charge and discharge capacities reduced drastically. Furthermore, the EIS results showed that the incorporation of the sluggish Fe3+ ions reduced the electronic conductivity and lithium conductivity, which in turn contributed to the poor electrochemical performance. Although our results did not show Fe3+/Fe2+ electrochemical activity contrary to our expectation, this preliminary study on Li3V2−x Fe x (PO4)3 (0≤x≤2) have provided a prerequisite for further improving the electrochemical properties by nanosizing and carbon-coating to better use these mixing transition-metal phosphate cathodes in the future.
Superstructure design of a single-layer MoS2/C/Ti3C2Tx@C composite electrode is reported. Application of the composite materials as high performance electrode for lithium ion batteries is investigated. The composite materials are comprised of the SL-MoS2/C superstructure and Ti3C2Tx@C core-shell structure. The SL-MoS2/C superstructure with a nanoscopic/atomic interface could efficiently prevent undesirable surface reactions between the active materials and electrolyte. The cycling performance of active MoS2 can be greatly improved due to the incorporation of superstructure. The SL-MoS2/C/Ti3C2Tx@C composite electrode shows an ultralong cycle life and delivers a discharge capacity of 962 mAh g−1 at the current density of 0.1 A g−1. A high reversible capacity of 875 mAh g−1 is retained even after 1500 cycles at the current density of 1.0 A g−1.
The relationship between verbal-auditory short-term memory (STM) and language is an open area of debate and contrasting hypotheses have been proposed, suggesting either that STM would strongly rely on language-related processes, or that it depends on a dedicated system related to language, but independent from it. In this study we examined 103 patients undergoing surgery for glioma resection in the left or right hemisphere, and we conducted a VLSM analysis on their behavioral performance on auditory-verbal STM, as well as on more general verbal and nonverbal tasks. The aim was to investigate whether the anatomical correlates of auditory-verbal STM were part of the language system or they were spatially segregated from it. VLSM results showed that digit span scores were linked to lesions in both the left supramarginal gyrus and superior-posterior temporal areas, as reported in the literature on patients with a selective deficit of auditory-verbal STM. Conversely, other verbal tasks involved areas only partly overlapping with those found for digit span, with repetition being affected by lesions in more anterior regions in the parietal, temporal, and frontal lobes, and word comprehension by lesions in a network including cortical and subcortical pathways in the temporal lobe. The present results, thus, show that auditory-verbal STM neural correlates are only partially overlapping with those supporting comprehension and production: while the left posterior–superior temporal cortex, involved in speech perception, takes part in both functions, the left supramarginal gyrus has a consistent and specific role only in STM, supporting the hypothesis of interacting but segregated networks.
Lithium-sulfur batteries have attracted a great interest in electrochemical energy conversion and storage, but their discharge mechanism remains not well understood up to now. Here, we report density functional theory (DFT) calculation study of the discharge mechanism for lithium-sulfur batteries which are based on the structure of S8 and Li2S x (1≤x≤8) clusters. The results show that for Li2S x (1≤x≤8) clusters, the most stable geometry is chainlike when x=1 and 6, while the minimal-energy structure is found to be cyclic when x = 2–5, 7, 8. The stability of Li2S x (1≤x≤8) clusters increases with the decreasing x value, indicating a favorable thermodynamic tendency of transition from S8 to Li2S. A three-step reaction route has been proposed during the discharge process, that is, S8→Li2S4 at about 2.30 V, Li2S4→Li2S2 at around 2.22 V, and Li2S2→Li2S at 2.18 V. Furthermore, the effect of the electrolyte on the potential platform has been also investigated. The discharge potential is found to increase with the decrease of dielectric constant of the electrolyte. The computational results could provide insights into further understanding the discharge mechanism of lithium-sulfur batteries.