batterydata/paper-abstracts huggingface dataset:
Several hydrophilic ionic liquids dissolved in water with different molalities are studied as “water-in-ionic liquid” supporting electrolytes. They exhibit wide electrochemical stability window from 3 to 4.4 V, high ionic conductivities and good flowability, making them promising supporting electrolytes for aqueous high-voltage rechargeable batteries. In such supporting electrolytes, enhanced redox activities of lithium insertion/extraction in anodic TiO2 film at low negative potential and Fe3+/Fe2+ couple at moderate positive potential were observed. Cyclability of an aqueous TiO2/Fe2+ hybrid battery is demonstrated with a voltage of 1.7 V.
Achieving fast and accurate collective decisions with a large number of simple agents without relying on a central planning unit or on global communication is essential for developing complex collective behaviors. In this paper, we investigate the speed versus accuracy trade-off in collective decision-making in the context of a binary discrimination problem—i.e., how a swarm can collectively determine the best of two options. We describe a novel, fully distributed collective decision-making strategy that only requires agents with minimal capabilities and is faster than previous approaches. We evaluate our strategy experimentally, using a swarm of 100 Kilobots, and we study it theoretically, using both continuum and finite-size models. We find that the main factor affecting the speed versus accuracy trade-off of our strategy is the agents’ neighborhood size—i.e., the number of agents with whom the current opinion of each agent is shared. The proposed strategy and the associated theoretical framework can be used to design swarms that take collective decisions at a given level of speed and/or accuracy.
With an indisputable complexity of communication for hearing and speaking impaired people, most sign language recognition systems utilize virtual reality or onscreen robots. This paper presents the design and development of a special and low-cost humanoid robot that can perform as a sign language interpreter. To the best of our knowledge, this is the first endeavor to fabricate a humanoid robot for Bangla sign language (BdSL) and Medical signs interpretation.
Metal-organic frameworks (MOFs) derived porous carbons are promising electrode materials in electrochemical energy conversion and storage systems. However, the typical synthetic route of MOFs involving high temperature, organic solvent, massive energy consuming, and laboratory-scale production, hinders the realistic applications of MOFs serving as sacrificial templates for porous carbon. Herein, we demonstrate that highly crystalline MIL-100 (Fe) nanoparticles (MIL: Materials of Institute Lavoisier) can be synthesized in large scale with low cost under mild and green conditions. High-temperature pyrolysis of MIL-100(Fe) under argon atmosphere results in hollow carbon polyhedra (HCPs) featuring high degree of graphitization and hierarchical pore structures. The obtained HCPs are excellent electrode materials for electric double-layer capacitors (EDLCs), and show a specific capacitance of 214 F g−1 at current density 50 mA g−1. Moreover, the HCP-based supercapacitors can endure more than 5000 cycles without significant degradation of capacitance. The unique structure of HCPs, including hollow polyhedral shape, hierarchical micro/mesopore structures, and ultrathin layer of highly graphitized carbon shells, endows the superior performance of HCPs based EDLCs with specific capacitance and high rate capability.
Owing to the high abundance of sodium and its low cost compared to lithium, sodium ion batteries have recently attracted a renewed interest as possible candidates for stationary and mobile energy storage devices. Herein, we present a new sodium ion intercalation material, Na x Co2/3Mn2/9Ni1/9O2, which has been synthesized by a sol–gel route in air followed by a heat treatment at 800 °C for 12 h. Its structure has been studied by X-ray diffraction showing that the material crystallized in a P2-type structure (space group P63/mmc). As far as the electrochemical properties of Na x Co2/3Mn2/9Ni1/9O2 as positive electrode are concerned, this compound offers a specific capacity of 110 mAh g−1 when cycled between 2.0 and 4.2 V vs. Na+/Na. The electrodes exhibited a good capacity retention and a coulombic efficiency exceeding 99.4%, as well as a reversible discharge capacity of 140 mAh g−1 when cycled between 2.0 and 4.5 V. These results represent a further step towards the realization of efficient sodium ion batteries, especially considering that the synthesis method proposed here is simple and cost effective and that all the electrochemical measurements were carried out without any use of additives or any optimization for both the materials and the cell components.
Diffusion tensor imaging (DTI) technique is important for exploring more sensitive imaging-based biomarkers in prevention and early treatment of cognitive dysfunction induced by type 2 diabetes mellitus (DM).
Novel nanostructured silicon composites, Si/Poly(3,4-ethylenedioxythiophene) nanowire network (Si/PNW) and Si/(S-doped-carbon nanowire network) (Si/S-CNW), are prepared by a soft-template polymerization of 3,4-ethylenedioxythiophene (EDOT) using sodium dodecyl sulfate (SDS) as surfactant with the presence of Si nanoparticles and a subsequent carbonization of Si/PNW, respectively. The presence of Si nanoparticles in the soft-template polymerization of EDOT plays a critical role in the formation of PEDOT nanowire network instead of 1D nanowire. After the carbonization of PEDOT, the S-doped-carbon nanowire network matrix shows higher electrical conductivity than PNW counterpart, which facilitates to construct robust conductive bridges between Si nanoparticles and provide large electrode/electrolyte interfaces for rapid charge transfer reactions. Thus, Si/S-CNW composite exhibits excellent cycling stability and rate capability as anode material, retaining a specific capacity of 820 mAh g−1 after 400 cycles with a very small capacity fade of 0.09% per cycle.
Unknown Note: ‘Page numbers followed by “f” indicate figures and “t” indicate tables’.
This paper presents a performance analysis of plug-in hybrid electric vehicles (PHEVs) considering battery preheating economy under low temperature conditions. In subzero temperature environments, PHEVs suffer a dramatic loss of all-electric driving range due to the energy and power reduction of LiFePO4 batteries, as well as severe battery degradation due to lithium ion plating. This decreases the battery life time and thus increases the operating cost of the PHEV. A quasi-static model is adopted for the simulated bus, and a battery dynamic degradation model is established based on the Arrhenius degradation theory. The PHEV performance under low-temperature conditions is evaluated considering three factors: fuel cost, electricity cost, and battery degradation cost. In addition, the economics of battery preheating powered by the engine or grid is first investigated in this paper. The charge depleting-charge sustaining energy management strategy and convective heating method are adopted. Simulation results show that the preheating strategy can reduce the PHEV operating cost by up to 22.3% in 40 Harbin driving cycles. The heating process becomes increasingly necessary as the battery price, heating efficiency, and daily recharging time of the PHEV increase as well as the environment temperature decreases.
Core–shell Fe@Fe3C/C nanocomposites were prepared by adopting α-FeOOH nanorods as the Fe precursor though a simple and green route. The obtained core–shell nanospheres consisted of single crystalline Fe cores (20–50nm) coated with well-proportioned Fe3C shell (∼8nm) in amorphous carbon. The composites delivered a reversible capacity of ∼500mAh g−1 after 30 cycles. However, no obvious changes were observed in the XRD patterns of Fe@Fe3C/C electrodes before and after the discharge process, indicating that Fe and Fe3C are inactive for lithium storage. Many characterizations were performed to propose a reasonable explanation about the Li storage capacity.
A Si–carbon core–shell powder was prepared via resorcinol-formaldehyde (RF) microemulsion polymerization in the presence of hydrophobized Si nano-particles and subsequent carbonization. The Si nano-particles were completely encapsulated by amorphous carbon shell. With this core–shell approach, the anodic performance of Si electrode for lithium cells has been improved on aspects of Si utilization and cycle retention, which seems to be indebted to the formation of stable electronic conductive network by an intimate contact between Si core and carbon shell. The capacity delivered by this electrode is, however, smaller than that of bare Si due to the presence of RF-derived carbon and electrochemically inactive silicon oxide that was generated during the carbonization process by a reaction between Si and oxygen from the RF gel. The evolution of cracks in the carbon shell after cycling is additional problem to be solved.
Hierarchical porous nickel cobaltite (NiCo2O4) nanomaterials were synthesized via a hard-templating route. The obtained materials consist of nanostructured cubic NiCo2O4 spinels and a spot of cubic NiO nanoparticles, and the materials display a typical hierarchical porous structure. The NiCo2O4 electrode displays quasireversible dynamics characteristics, mainly Faradaic capacitance behavior and capacitance relaxation feature. The NiCo2O4 electrode exhibits an excellent long cycling behavior with no capacitance decays during 5,000 cycles at a current density of 2 A g−1 in 1 M KOH electrolytes, and the NiCo2O4 electrode exhibits both high power and energy performances even after 5,000 cycles with respective value of 1,758 W kg−1 and 8.3 W h kg−1 in 1 M KOH electrolytes, indicating that the NiCo2O4 nanomaterials are promising candidates for electrochemical capacitors.
Novel rose rock-shaped cuprous oxide anchored graphene nanocomposite (Cu2O-GN) is successfully synthesized by a simple and efficient one-step solvothermal method. Notably, the reduction of graphene oxide (GO) and deposition of nano-Cu2O on GN occur simultaneously during the polyol reaction process. The nanocomposite is systematically characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). We also explore the formation mechanism of Cu2O-GN including the concentration effect of the precursor, precipitation agent, GO, and heating rate on the morphology of the resulting nanocomposite. It is noteworthy that Cu2O is gradually decorated on the large sheets of GN to form ordered three-dimensional nanostructure with the optimized concentration of GO, which is crucial to the growth of the final nanoarchitectures. In addition, the electrochemical properties of the Cu2O-GN nanocomposite are investigated by cyclic voltammetry and galvanostatic charge-discharge measurements. The composite shows a favorable electrochemical capacitance (416 F g−1 at 1 A g−1), rate performance and cycling stability. Also, a high specific capacitance and good retention point to its promising applications as electrode materials in supercapacitors.
Both Ni doping and carbon coating are adopted to synthesize a nano-sized LiFePO4 cathode material through a simple solid-state reaction. It is found that the Ni2+ has been successfully doped into LiFePO4 without affecting the phospho-olivine structure from the XRD result. The images of SEM and TEM show that the size of particles is distributed in the range of 20–60nm, and all the particles are coated with carbon completely. The results of XPS show the valence state of Fe and Ni in the LiFePO4. The electronic conductivity of the material is as high as 2.1×10−1 Scm−1, which should be ascribed to the coefficient of the conductive carbon network and Ni doping. As a cathode material for lithium-ion batteries, the Ni doped LiFePO4/C nanocomposite delivers a discharge capacity of 170mAhg−1 at 0.2C, approaching the theoretical value. Moreover, the material shows excellent high-rate charge and discharge capability and long-term cyclability. At the high rates of 10 and 15C, this material exhibits high capacities of 150 and 130mAhg−1, retaining 95% after 5500 cycles and 93% after 7200 cycles, respectively. Therefore, the as-prepared material is capable of such large-scale applications as electric vehicles and plug-in hybrid electric vehicles.
Thin films of Sn were deposited on Pt/Si substrates by sputtering technique and subjected to electrochemical lithiation studies. Electrochemical lithiation of Sn resulted in the formation of Sn–Li alloys of different compositions. Charging of Sn-coated Pt/Si electrodes was terminated at different potentials and the electrodes were examined for physicochemical properties. The scanning electron microscopy and atomic force microscopy images suggested that the Sn films expanded on lithiation. Roughness of the film increased with an increase in the quantity of Li present in Sn–Li alloy. Electrochemical impedance data suggested that the kinetics of charging became sluggish with an increase in the quantity of Li in Sn–Li alloy.
This chapter draws attention to case studies of scientific discovery as an important source of information about visualisation as a real-time cognitive process. These show that visual modes of representation are essential to the generation, communication and dissemination of new knowledge. I survey a number of strategies of visualisation and develop a process model based on the ways that scientists in a wide range of fields manipulate the dimensionality of images in order to move between representations that are local, situated and often personal and images that are widely understood and have an objective status as depictions of facts or laws. This shows that the cognitive status of visual images changes as scientists integrate novel representations into their arguments.
Cognitive impairment has been identified in the early phase of schizophrenia spectrum disorders, and is a major contributor to disease-related disability. While screening tools assessing cognitive impairment have been validated for adult schizophrenic populations, there is a need for brief, easily administered, standardized instruments that provide clinically relevant information for adolescents. This study examines the utility of the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) in identifying and quantifying neurocognitive impairment in adolescents with schizophrenia spectrum disorders and other serious psychiatric illnesses. 112 adolescents, including 32 healthy subjects and 80 patients, were administered the RBANS. Patients with psychotic disorders demonstrated significant impairment on the RBANS total score compared to patients with other disorders and healthy controls, but this impairment appeared somewhat less severe than is typically reported for in adult patients with schizophrenia on this measure. The RBANS appears to be sensitive in the detection of neurocognitive impairment in a psychiatric population of adolescents with psychotic symptomatology, and may therefore have utility as a clinical screening instrument and/or neurocognitive outcome measure in this population.
This work presents the main features of the new power plant that comprises the modified reversible hydroelectric (HE) power plant operating together with the photovoltaic (PV) power plant. Such Solar Hydroelectric Power Plant (SHE) uses solar energy as the only input for production of solar and hydro energy. Thereat, water reservoir serves for daily and seasonal energy storage, thus basically solving the problem of energy storage, which is the biggest problem of wider use of solar energy. The most expensive part of SHE is the PV generator, whose optimal sizing is essential for providing energetic independence of a settlement or isolated consumer. A systematic approach that includes all relevant elements of this system has been implemented for optimal sizing of the PV power plant. The developed model was used in analysis of certain parameters of the SHE system. The results of the analysis show the system characteristics and that the proposed model describes the operation of the power plant very well. The feasibility and characteristics of the power plant were tested on electric energy supply of the island of Vis in Croatia. It has been established that the system is real, feasible and can be very successfully applied on different locations, for different consumers and can vary in size. The prerequisite for realization of such system is the construction of a modified reversible HE power plant. The presented SHE represents a permanently sustainable energy source that can continuously provide power supply to a consumer, using exclusively natural and renewable energy sources, without causing harmful effects on the environment.
ABSTRACT This paper offers an overview of population-based perspectives and strategies related to the role of physical activity in the management of diabetes. Topics include the importance of physical activity promotion, need for theoretically driven approaches, individual-level population-based strategies and resistance training. Studies undertaken in the Physical Activity and Population Health Research Laboratory at the University of Alberta are presented as illustrative examples throughout. Recommendations and implications for research and practice are discussed, with a call for ecological approaches that recognize the inter-relationships between individuals and the multiple levels of their environments.
Flexible piezoelectric generators (PEGs) have recently attracted significant interest, as they are able to harvest mechanical energy and convert it to electricity, decreasing reliance on conventional energy sources. These devices enable innovative applications including smart clothing, wearable electronics, on-skin and implantable sensors, as well as harvesting energy from the movement of vehicles, water and wind. Poly(vinylidene fluoride) and related fluoropolymers are the most common flexible piezoelectric materials, widely utilized for their high electromechanical conversion efficiencies, optimal mechanical flexibility, processability and biocompatibility. This critical review covers the processing of fluoropolymers towards the maximization of piezoelectric conversion parameters. Particular emphasis is placed on the correlation between synthetic routes, inclusion of further co-monomers, addition of additives and nanomaterials, as well as processing techniques and the optimized electricity generation in the resultant PEGs, providing an important analysis to complement existing literature. The importance of novel polymer deposition techniques, which reduce reliance on the conventional, highly energetic post-processing steps, is highlighted. Recent advances in fluoropolymer-based flexible PEGs open an array of exciting applications, which rapidly progress towards commercialization. This review provides a timely analysis of this increasingly important field to the cross-disciplinary community of polymer chemists, materials scientists, nanotechnologists, engineers, and industry practitioners.
Layered LiNi0.2Mn0.2Co0.6O2 phase, belonging to a solid solution between LiNi1/2Mn1/2O2 and LiCoO2 most commercialized cathodes, was prepared via the combustion method at 900°C for a short time (1h). Structural, electrochemical and magnetic properties of this material were investigated. Rietveld analysis of the XRD pattern shows this compound as having the α-NaFeO2 type structure (S.G. R-3m; a =2.8399(2)Ǻ; c =14.165(1)Ǻ) with almost none of the well-known Li/Ni cation disorder. SQUID measurements clearly indicate that the studied compound consists of Ni2+, Co3+ and Mn4+ ions in the crystal structure. X-ray analysis of the chemically delithiated Li x Ni0.2Mn0.2Co0.6O2 phases reveals that the rhombohedral symmetry was maintained during Li-extraction, confirmed by the monotonous variation of the potential–composition curve of the Li//Li x Ni0.2Mn0.2Co0.6O2 cell. LiNi0.2Mn0.2Co0.6O2 cathode has a discharge capacity of ∼160mAhg−1 in the voltage range 2.7–4.3V corresponding to the extraction/insertion of 0.6 lithium ion with very low polarization. It exhibits a stable capacity on cycling and good rate capability in the rate range 0.2–2C. The almost 2D structure of this cathode material, its good electrochemical performances and its relatively low cost comparing to LiCoO2, make this material very promising for applications.
Photoelectrochemical water splitting to produce H2 is dependent on the electrochemical potentials between photoelectrodes and the electrolyte, which are difficult to measure. Here the authors use an electrochemical atomic force microscope technique to sense the potential of catalyst-coated electrode surfaces in operando.
Advice to remain active and normalisation of activity are commonly prescribed in the management of low back pain (LBP). However, no research has assessed whether objective measurements of physical activity predict outcome and recovery in acute low back pain.
This study compares the performance of two PVmodules, one fixed and the other fitted with a two-axis tracking system which enables the PVcollector to move and be controlled to follow the Sun’s radiation. A computer unit was employed to monitor the solar radiation exposure of both systems and to control the movement of the solar tracking PVmodule. Throughout the day, the results obtained from the fixed and tracked systems were collected on a DAQ card installed on an online computer. The two motors of the tracking system were connected to output from the computer that was used to follow the sun. The movement of the two-axis tracking PVmodule was compared to mathematical calculations of the sun’s position from sunrise to sunset. The amount of solar radiation received on the surface of the module and hence its output power varied according to the time and the place where the experimental system was mounted. Overall, it was found that the daily output power of the tracking module was 13–15% higher than the fixed module.
Electrochemical impedance spectroscopy (EIS) is an indispensable technique for the investigation of polarization processes in Lithium-ion Batteries. These cause performance limitation or degradation. A physically meaningful impedance model is key when drawing conclusions on further cell improvement. This study introduces an in-depth impedance analysis of a commercial high-power graphite anode. The impedance spectra measured between 0 °C and 30 °C and 0%–100% SOC were analyzed by the distribution of relaxation times (DRT-method), enabling a separation of loss processes by their individual time constants. Using this method, we separated charge transfer resistance and solid electrolyte interface resistance at medium frequencies (10 Hz–200 Hz) and the contact resistance anode/current collector in the at high frequency range (5 kHz–100 kHz). Two fundamentally different model structures were set up, either (i) two modifications of a serial model connecting RQ-elements and a Warburg element for solid state diffusion, or (ii) three modifications of a transmission line model with one-path or two-path design. The suitability of all serial and TLM model structures was tested, and the fitting procedure was supported using microstructure parameters gained from x-ray tomography. The favored one-path transmission line model reveals that the lithium-ion transport in the electrolyte contributes more to polarization than expected. Impediment of lithium-ion transport is caused by the pore structure and the tortuosity of the high-power graphite anode, and has to be considered for meaningful interpretation of impedance spectra.