batterydata/paper-abstracts huggingface dataset:
Deep brain stimulation (DBS) is increasingly applied for the treatment of brain disorders, but its mechanism of action remains unknown. Here we evaluate the effect of basal ganglia DBS on cortical function using invasive cortical recordings in Parkinson's disease (PD) patients undergoing DBS implantation surgery. In the primary motor cortex of PD patients, neuronal population spiking is excessively synchronized to the phase of network oscillations. This manifests in brain surface recordings as exaggerated coupling between the phase of the beta rhythm and the amplitude of broadband activity. We show that acute therapeutic DBS reversibly reduces phase-amplitude interactions over a similar time course as that of the reduction in parkinsonian motor signs. We propose that DBS of the basal ganglia improves cortical function by alleviating excessive beta phase locking of motor cortex neurons.
Spinal cord injury (SCI) often results in significant dysfunction and disability. A series of treatments have been proposed to prevent and overcome the formation of the glial scar and inhibitory factors to axon regrowth. In the last decade, cell therapy has emerged as a new tool for several diseases of the nervous system. Stem cells act as minipumps providing trophic and immunomodulatory factors to enhance axonal growth, to modulate the environment, and to reduce neuroinflammation. This capability can be boosted by genetical manipulation to deliver trophic molecules. Different types of stem cells have been tested, according to their properties and the therapeutic aims. They differ from each other for origin, developmental stage, stage of differentiation, and fate lineage. Related to this, stem cells differentiating into neurons could be used for cell replacement, even though the feasibility that stem cells after transplantation in the adult lesioned spinal cord can differentiate into neurons, integrate within neural circuits, and emit axons reaching the muscle is quite remote. The timing of cell therapy has been variable, and may be summarized in the acute and chronic phases of disease, when stem cells interact with a completely different environment. Even though further experimental studies are needed to elucidate the mechanisms of action, the therapeutic, and the side effects of cell therapy, several clinical protocols have been tested or are under trial. Here, we report the state-of-the-art of cell therapy in SCI, in terms of feasibility, outcome, and side effects.
The membrane is a key component of the vanadium redox flow battery (VRFB) in terms of electrochemical performance as well as costs. The standard material Nafion® is cost intensive and therefore several alternative materials are in the focus of research. In this paper a substantial analytical approach is presented in order to quantify bottom price limits for different types of membranes. An in-depth analysis of material and production cost allows statements concerning cost potentials of different ion exchange membranes (IEM) and nano filtration membranes (NFM). The final result reveals that expected costs of IEM and NFM at high production volumes differ by one order of magnitude. Moreover, an analysis of the current market situation is made to provide a framework for economic considerations at present.
Battery state of health (SOH) monitoring has become a crucial challenge in hybrid electric vehicles (HEVs) and all electric vehicles (EVs) research, as SOH significantly affects the overall vehicle performance and life cycle. In this paper, we focus on the identification of Li-ion battery capacity fading, as the loss of capacity and therefore the driving range is a primary concern for EV and plug-in HEV (PHEV). While most studies on battery capacity fading are based on laboratory measurement such as open circuit voltage (OCV) curve, few publications have focused on capacity loss monitoring during on-board operations. We propose a battery SOH monitoring scheme based on partially charging data. Through analysis of battery aging cycle data, a robust signature associated with battery aging is identified through incremental capacity analysis (ICA). Several algorithms to extract this signature are developed and evaluated for on-board SOH monitoring. The use of support vector regression (SVR) is shown to provide the most consistent identification results with moderate computational load. For battery cells tested, we show that the SVR model built upon the data from one single cell is able to predict the capacity fading of 7 other cells within 1% error bound.
The effect of an oxidative treatment on the electrochemical performance of various low-temperature cokes as anodes in lithium ion batteries was examined in order to optimize their chemical composition and textural properties. Annealing in a stream of dry synthetic air over short time and temperature ranges was found to result in substantially increased cell capacity and improved capacity retention during cycling in coke oxidized at 350 °C for 1 h, which exhibited a capacity as high as 385 mAh g−1 after 20 cycles at C/50. However, raising the oxidation temperature to 500 °C resulted in undesirably increased irreversible capacity and polarization between the charge and discharge branches, the effect being confirmed by the high impedance values obtained after only a few cycles. 7Li MAS NMR spectroscopy was used to assess covalency in lithium bonds and its relationship to electrochemical performance in the studied batteries.
One big obstacle for a redox mediator (RM)-based Li–O2 system is the redox shuttling between the diffusible RM+ and Li anode, leading to the unexpected RM degradation and continuous deterioration of Li anode, which inevitably results in a low energy efficiency and a poor cycling stability for the Li–O2 battery. Here, InBr3 as a self-defensed RM is firstly introduced into Li–O2 batteries, which can lower the cell overpotential and thus improve the cycling performance. Moreover, due to the In3+ existence, an In-rich composite protective layer can be in situ generated on the Li anode, which contributes to suppressing the redox shuttling, improving the interface stability of Li and electrolyte, and inhibiting the dendrite formation. This work gives an insight into the development of self-defensed RM and the protection of the Li anode for Li–O2 batteries.
The prospect of increasing the energy density has promoted research on lithium metal batteries. Yet, avoiding the uncontrolled growth of lithium dendrites and the resulting interfacial instability to ensure the practical viability of the given battery technology remains a considerable challenge. Here, we report coating the separator with sulfated zirconia superacid to achieve a high lithium ion transference number of 0.85 and excellent cycle life when a full-cell paired with a LiNi0.82Co0.07Mn0.11O2 cathode was tested in a carbonate electrolyte under practical operating conditions. The exceptionally high transference number is attributed to strengthened binding of the PF6− anion of the lithium salt with the superacid. Furthermore, the presence of the superacid induces a mechanically stable solid–electrolyte-interphase (SEI) layer rich in LixPOyFz. This study demonstrates the beneficial effect of the superacid on emerging post-lithium-ion batteries by immobilizing the anion of the salt as well as modifying the SEI composition.
The authors regret to inform that they missed an author in the authorship line, who did significant contribution to this work by performing optical microscopy experiments. The corrected authorship is Jae-Hyun Shima, Changhoon Jungb, Sanghun Leec a Battery R&D Center, Samsung SDI Co. Ltd., Suwon, Gyunggido 16677, Republic of Korea b Analytical Engineering Group, Samsung Advanced Institute of Technology, Suwon, Gyunggido 16677, Republic of Korea c Department of BioNano Technology, Gachon University, Gyunggido 13120, Republic of Korea In addition, the authors have replaced the supporting videos which are movie clips obtained by in situ optical microscopy. This change does not have any effect on the conclusions of the original article. The authors would like to apologise for any inconvenience caused.
Oxygen-containing functional groups and pseudographic structure are key factors that affect the electrochemical properties of biomass derived carbon materials. In this work, the shaddock peel derived hard carbon with abundant carbon-oxygen double bond (CO) and highly ordered pseudographic structure is successfully synthesized by a H2SO4-assisted hydrothermal pretreatment and subsequent KOH-assisted low temperature (600 °C) pyrolysis procedure. The resulting unique structure is beneficial for the co-effective enhancement of Na+ storage sites and electrochemical reaction kinetics. The hard carbon exhibits excellent cycling and rate performances in sodium-ion batteries, delivering a high reversible capacity of 380 mAhg−1 at 50 mAg−1 after 500 cycles, and that of 274 and 199 mAhg−1 even at 500 and 1000 mAg−1, respectively. This performance is superior to the previously reported shaddock peel derived hard carbons. Besides, the surface-controlled redox mechanism of CO and Na+ occurring at the hard carbon is clearly revealed.
Glaucoma is a leading cause of blindness. Early detection is advocated but there is insufficient evidence from randomized controlled trials (RCTs) to inform health policy on population screening. Primarily, there is no agreed screening intervention. For a screening programme, agreement is required on the screening tests to be used, either individually or in combination, the person to deliver the test and the location where testing should take place. This study aimed to use ophthalmologists (who were experienced glaucoma subspecialists), optometrists, ophthalmic nurses and patients to develop a reduced set of potential screening tests and testing arrangements that could then be explored in depth in a further study of their feasibility for evaluation in a glaucoma screening RCT.
Capsule endoscopy (CE) has been widely used as a new technology to diagnose gastrointestinal tract diseases, especially for small intestine. However, the large number of images in each test is a great burden for physicians. As such, computer aided detection (CAD) scheme is needed to relieve the workload of clinicians. In this paper, automatic differentiation of tumor CE image and normal CE image is investigated through comparative textural feature analysis. Four different color textures are studied in this work, i.e., texture spectrum histogram, color wavelet covariance, rotation invariant uniform local binary pattern and curvelet based local binary pattern. With support vector machine being the classifier, the discrimination ability of these four different color textures for tumor detection in CE images is extensively compared in RGB, Lab and HSI color space through ten-fold cross-validation experiments on our CE image data. It is found that HSI color space is the most suitable color space for all these texture based CAD systems. Moreover, the best performance achieved is 83.50% in terms of average accuracy, which is obtained by the scheme based on rotation invariant uniform local binary pattern.
Oxygen evolution and reduction reactions (OER and ORR) are essential to the development of renewable energy conversion and storage technologies. For the first time, we investigate newly experimentally realized two-dimensional hexaaminobenzene-based coordination polymers (2D HAB-CPs) as OER and ORR catalysts through computational screening approach. We find that the interaction strength between intermediates and the transition metal complex (TM-N4) govern the catalytic activity of 2D HAB-CPs for OER and ORR. The interaction strength is strongly contingent on d-band centers, which can be modulated by changing TM atoms with different d-electron occupations. This modification of the interaction strength allows us to screen out the catalyst with the best catalytic performance. The best catalyst for OER is 2D Rh-HAB-CP with an over-potential ( η ) of 0.32V, followed by Co-HAB-CP (0.41V), while for ORR, Fe-HAB-CP has a smallest maximum free energy change ( Δ G max 1.23 ) of 0.52eV under equilibrium potential. Furthermore, these results inspire us to design a bifunctional OER/ORR catalyst by mixing Fe/Co precursors in 2D HAB-CP with the ORR/OER theoretical overpotentials even lower than that of the best ORR/OER catalysts (Pt/RuO2). In addition, all the 2D HAB-CPs are metallic due to the effects of d-p-π conjugation, which ensures fast electron transfer during the electrochemical reactions. Our findings highlight a new family of 2D materials as efficient non-precious-metal metal-air battery catalyst and offer a novel strategy in catalyst design.
The present article is an important addition to the nonperturbative formulation of QED with x-steps presented by Gavrilov and Gitman (Phys. Rev. D. 93:045002, 2016). Here we propose a new renormalization and volume regularization procedures which allow one to calculate and distinguish physical parts of different matrix elements of operators of the current and of the energy–momentum tensor, at the same time relating the latter quantities with characteristics of the vacuum instability. For this purpose, a modified inner product and a parameter
Vehicles emit non-methane hydrocarbons (NMHCs) from a number of sources, including missing, worn or improperly tightened fuel caps. Inspection and maintenance programs and the On-Board Diagnostic (OBD) system will detect some of these deficiencies, however, even properly tightened caps will emit NMHCs due to permeation, diffusion, cracks and gaps in seals, and failures of pressure-relief mechanisms. These emissions have not been previously quantified. In this study, in-use emissions from fuel caps were measured in 213 tests on vehicles of varying age and condition over several seasons, including cold and warm temperatures. Diffusion/permeation models are presented to complement the experimental work. NMHC emissions from fuel caps were detected from all vehicles, of which benzene constituted 2.5%. Emissions averaged 2.0mgh−1 (median=0.5mgh−1), and the distribution of emission rates was highly skewed by a small number of vehicles with much higher emissions, e.g., the 90th, 95th and maximum percentile values were 2.7, 5.0, and 62.7mgh−1, respectively. Emission rates increased substantially if the fuel cap was loose, in hot weather, and with vehicle age and mileage. Overall, emissions from properly functioning caps are small relative to running and refueling losses, though they may be significant if the gas cap is defective or loose. Further reductions in emissions may be achieved by using new low-torque cap designs, improved elastomers, properly tightening fuel caps, and replacing old caps.
This study comprehensively investigates tensile-compressive and shear effects of van der Waals (vdWs) interactions on free vibration of cantilever bilayer graphene nanoribbons (CBGNRs) to be answered to this question that how and how much the effects of each of these factors are in comparison with the other one when they are considered simultaneously. To this end, the CBGNRs are modeled based on sandwich beam theory in which each nanoribbon plays role of sandwich layer and vdWs interactions are equivalent to the sandwich core. At the first step a geometrical–analytical method is presented to calculate the equivalent tensile-compressive and shear moduli of vdWs interactions. After that, a set of coupled governing equations of motion and boundary conditions are derived and solved numerically by the harmonic differential quadrature method. This study shows that for designing multi-layer GNR based applications, such as resonators, the shear effect of vdWs interactions must be considered.
Li[Ni0.33Mn0.33Co0.33]O2/graphite and LiCoO2/graphite pouch cells filled with a combination of ethyl acetate (EA) and vinylene carbonate (VC), or methyl propanoate (MP) and VC with 1M LiPF6 function very well, even though these cells contain no ethylene carbonate, thought to be essential for the negative electrode solid electrolyte interphase (SEI). Cells filled with 1M LiPF6 in MP:VC (95:5 w:w) showed similar capacity retention and impedance after 1700h of cycling at 40°C as cells filled with 1M LiPF6 in EC:ethyl methyl carbonate (EMC)+2% VC. Cells filled with these ester containing electrolytes also showed better rate performance when cycled at -14°C, delivering 40% of the discharge energy at a current equivalent to 4C, while cells filled with EC:EMC+2% VC failed to deliver any capacity at a current of 3C. High precision coulometry measurements also showed that cells filled with 1M LiPF6 in MP:VC (95:5 w:w) had similar coulombic efficiency and charge endpoint capacity slippage as cells filled with 1M LiPF6 EC:EMC+2% VC which indicates ester based electrolytes can have long lifetime.
The economic impact of disasters is well known; however, the link between financial loss and behavioral health problems is unknown. Participants included 198 adults of ages 21 to 82, living within 10 miles of the Gulf Coast during the Deepwater Horizon Oil Spill and were involved in the fishing, harvesting, seafood processing, or service/tourism industries. The functional impact of financial resource loss at 2.5 years post spill was measured using the 26-item Financial Life Events Checklist (FLEC). Individuals responded to financial distress by reducing social events and utility bills and changing food-shopping habits. The FLEC significantly predicted higher drug use (Drug Abuse Screening Test), alcohol use (Alcohol Use Disorders Identification Test), mood problems (Profile of Mood States), and depressive symptoms (Beck Depression Inventory II) (p values ≤ 0.05) 4.5 years after the spill. This preliminary study supports the notion that the functional impact of financial loss has a long-term impact on behavioral health after an oil spill.
Co-substituted Ni(OH)2/carbon nanofiber (CNF) composite was synthesized by chemical coprecipitation method. X-ray powder diffraction (XRD) patterns evidenced that it was an intermediate phase with α-β structure. Transmission electron microscopy (TEM) images suggested crystalline α-β-NixCo1-x(OH)2 nanosheets growth on the surface of CNFs. The testing results of cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and charge-discharge showed that the composites had high specific capacitances, low electrochemical reaction impedance, and long cycle stability. Using the composite as a cathodic active material, a specific capacity of assembled NiZn pouch cells ranged from 160.25 mAh·g−1 at current density of 15 mA cm−2 to 91.35 mAh·g−1 at current density of 50 mA cm−2. In addition, those NiZn pouch cells have excellent rate performance and long cycle stability. After 1500 cycles, the energy capacity retained 215.24 Wh·kg−1, 98% of the initial value. The relationship between structure and the electrochemical performance was analyzed and discussed in detail. Intermediate phase α-β-Ni1-xCox(OH)2/CNF composites can be a promising cathodic active material for Ni-based batteries.
Realizing anode free lithium metal battery (AFLMB) is a promising approach to achieve higher energy density without complicated anode chemistry and processing cost. However, uneven lithium (Li) deposition on copper current collector results in dendrite growth and low reversibility. Herein, we report the effect of potassium nitrate (KNO3) additive to boost the cycling life and average coulombic efficiency (CE) of both full cell (Cu//LiNi1/3Mn1/3Co1/3O2 or Cu//NMC) and half cell (Cu–Li) configurations. The Cu//NMC cell possesses a capacity retention (CR) of ~40% after 50 cycles in the presence of KNO3 compared to ~40% after 15 cycles in the control electrolyte, 1 M LiPF6 in ethylene carbonate (EC) and diethyl carbonate (DEC) (1:1 v/v). The average CE of Cu//NMC cell with additive for 50 cycles increases to 96.50%, whereas it is 91.32% after 35 cycles without KNO3. The average efficiencies of Cu–Li cells are 96.20% and 85.74% after 60 cycles with and without KNO3 respectively. Morphological investigations by Scanning Electron Microscope (SEM) reveal a relatively smooth Li deposition with KNO3. These achievements originate mainly from (1) new solid electrolyte interphase components from the enhanced reductive decompositions of PF6 − and NO3 − and (2) electrostatic shielding effect of K+.
Safety is a key concern for high-power energy storage systems such as will be required for electric vehicles. Present lithium ion batteries, which use a flammable organic liquid electrolyte, lack inherent safety. Our approach in solving this problem is to replace the liquid electrolyte with a liquid-free polymer electrolyte. Data of the composition of the positive electrode, charge–discharge and cycle-life capability are presented. The cell using metallic lithium anode and crosslinked polymer electrolyte P(EO/MEEGE/AGE)-LiTFSI showed a discharge capacity of 134mAhg−1 of LiCoO2 at 60°C and 140mAhg−1 at 140°C.
Although the increased need for high-energy/power-density energy storage systems has revived the research on lithium metal batteries (LMBs), the influence of the separator on the performance of LMBs is still generally neglected. In the present study, a sandwich-structured separator (referred to as the CGC separator below) composed of two 2.5 µm thick cellulose nanofiber (CNF) surface layers and an intermediate 15 µm thick glass microfiber (GMF) and CNF composite layer is described. While the CNF surface layers of the CGC separator feature a homogeneous distribution of nano-sized pores favoring the attainment of a homogeneous current distribution at both electrodes, the intermediate GMF/CNF layer contains macropores facilitating the ionic transport through the separator. The CGC separator exhibited a much better electrolyte wettability and thermal stability compared to a Celgard separator, due to the use of the hydrophilic and thermally stable CNFs and GMFs. It is also shown that the combination of nano-sized and micro-sized fibers used in the CGC separator yields a higher ionic conductivity than that for the commercial separator (1.14 vs. 0.49 mS cm−1). Moreover, the influence of the separator pore structure (e.g. the porosity and pore distribution) on the performance of LMBs is studied for both Li anodes and LiFePO4 composite cathodes. The results demonstrate that the use of separators with high porosities and homogeneous surface pore distributions can improve the performances (e.g. capacities and stabilities) of LMBs considerably, and also highlights the importance of proper separator/electrode interactions. The present approach constitutes a practical engineering strategy for the production of separators with nano/micro fibers and a promising route for the development of LMBs with improved safety and enhanced electrochemical performances.
A two-dimensional quasi-steady-state model is applied to investigate charge/discharge behavior and performance of a VRFB. Emphasis is focused on exploring the influences of various strategies of soc-dependent operating current density on battery performance. For constant-current operation, with the increase of current density, although the system mean power density is significantly boosted, the system capacity and net discharge energy in a cycle are obviously decreased. It is quite difficult to give consideration to both the system capacity and system power simultaneously such that overall battery performance can be improved. Applying the strategy of soc-dependent operating current (i.e., low current at the end of charge/discharge process while high current for the rest time), the system capacity, power density and net discharge energy in a cycle can be simultaneously boosted while comparable efficiencies can be achieved. Optimally, at the mean operating current density of about 70 mA cm−2, the system capacity is maximally improved by 9.3% and the net discharge energy is maximally increased by 7.9% as compared with that under constant-current operation. As the same time, the energy-based system efficiency can be maintained over 78%, which is comparable with that for constant-current operation.