batterydata/paper-abstracts huggingface dataset:
Nano-electromechanical systems (NEMS) developed using piezoelectric nanowires (NWs) have gained immense interest in energy harvesting applications as they are able to convert several different forms of mechanical energy sources into electric power and thereby function as reliable power sources for ultra-low power wireless electronics. In this work, a piezoelectric NEMS vibrational energy harvester is fabricated through the development of a synthesis process for vertically aligned barium titanate (BaTiO3) nanowire (NW) arrays directly on a conductive substrate. These poled ferroelectric NW arrays are characterized through direct vibration excitation and demonstrated to provide efficient harvesting of mechanical vibrational energy producing an average power density of ∼6.27 μW cm−3 from 1g acceleration. In order to substantiate the superior energy harvesting performance of the newly developed BaTiO3 NW arrays, a direct comparison is made with conventional ZnO NW arrays. Here, we clearly report that the ferroelectric BaTiO3 NW NEMS energy harvester has ∼16 times greater power density than the ZnO NW NEMS energy harvester from the same acceleration input.
The electroencephalogram (EEG) is a widely used non-invasive method for monitoring the brain. It is based upon placing conductive electrodes on the scalp which measure the small electrical potentials that arise outside of the head due to neuronal action within the brain. Historically this has been a large and bulky technology, restricted to the monitoring of subjects in a lab or clinic while they are stationary. Over the last decade much research effort has been put into the creation of “wearable EEG” which overcomes these limitations and allows the long term non-invasive recording of brain signals while people are out of the lab and moving about. This paper reviews the recent progress in this field, with particular emphasis on the electrodes used to make connections to the head and the physical EEG hardware. The emergence of conformal “tattoo” type EEG electrodes is highlighted as a key next step for giving very small and socially discrete units. In addition, new recommendations for the performance validation of novel electrode technologies are given, with standards in this area seen as the current main bottleneck to the wider take up of wearable EEG. The paper concludes by considering the next steps in the creation of next generation wearable EEG units, showing that a wide range of research avenues are present.
The deterioration mechanism of nickel metal-hybrid batteries for hybrid electric vehicles (HEVs) has been investigated. For HEV use, the deterioration of the batteries is caused by the degradation of the positive electrode which is influenced by the migration of the constituent elements of the negative electrode alloy as well as by the oxidation of the negative electrode. Based on the elucidated deterioration mechanism, the degradation of the positive electrode has been suppressed by employing a hydrogen-absorbing alloy with higher oxidation resistibility for the negative electrode, prolonging the cycle life of nickel metal-hydride batteries for HEVs.
A novel single flow zinc–bromine battery is designed and fabricated to improve the energy density of currently used zinc–bromine flow battery. In the assembled battery, liquid storage tank and pump of positive side are avoided and semi solid positive electrode is used for improving energy efficiency and inhibiting bromine diffusion into environment. The single flow battery with this design shows columbic efficiency (CE) of 92% and energy efficiency (EE) of 82% over 70 cycles at the current density of 20 mA cm−2, which is comparable with the performance of the traditional zinc–bromine flow battery; furthermore, it has much lower weight and bromine emission.
We present a novel concept of an implantable active microport based on micro technology that incorporates a high-resolution volumetric dosing unit and a drug reservoir into the space of a conventional subcutaneous port. The controlled release of small drug volumes from such an “active microport” is crucial e.g. for innovative methods in cancer treatment or pain therapy. Our microport system delivers a flow rate in the range of 10–1,000 μl/h and enables a patient-specific release profile. The core of our device is a two-stage piezoelectric micropump. It features a backpressure-independent volumetric dosing capability i.e. a stable flow rate is ensured up to a backpressure of 30 kPa. The stroke volume and hence the resolution of the mircopump is voltage controlled and can be preset between 10 and 200 nl. A miniaturized high-performance electronic control unit enables freely programmable dosing profiles. This electronic circuit is optimized for both energy consumption and weight which are both essential for a portable device. The data of an implemented pressure sensor are used to permanently monitor the dosing process and to detect a potential catheter occlusion. A polyurethane soft lithography process is introduced for the fabrication of the prototype. Therewith, a compact multilayer system has been developed which measures only 50 × 35 × 25 mm3.
Cell-based therapies are emerging as new promising treatments in stroke. However, their functional mechanism and therapeutic potential during early infarct maturation has so far received little attention. Here, we asked if cell-based delivery of the interleukin-1 receptor antagonist (IL-1Ra), a known neuroprotectant in stroke, can promote neuroprotection, by modulating the detrimental inflammatory response in the tissue at risk. We show by the use of IL-1Ra-overexpressing and IL-1Ra-deficient mice that IL-1Ra is neuroprotective in stroke. Characterization of the cellular and spatiotemporal production of IL-1Ra and IL-1α/β identifies microglia, not infiltrating leukocytes, as the major sources of IL-1Ra after experimental stroke, and shows IL-1Ra and IL-1β to be produced by segregated subsets of microglia with a small proportion of these cells co-expressing IL-1α. Reconstitution of whole body irradiated mice with IL-1Ra-producing bone marrow cells is associated with neuroprotection and recruitment of IL-1Ra-producing leukocytes after stroke. Neuroprotection is also achieved by therapeutic injection of IL-1Ra-producing bone marrow cells 30 min after stroke onset, additionally improving the functional outcome in two different stroke models. The IL-1Ra-producing bone marrow cells increase the number of IL-1Ra-producing microglia, reduce the availability of IL-1β, and modulate mitogen-activated protein kinase (MAPK) signaling in the ischemic cortex. The importance of these results is underlined by demonstration of IL-1Ra-producing cells in the human cortex early after ischemic stroke. Taken together, our results attribute distinct neuroprotective or neurotoxic functions to segregated subsets of microglia and suggest that treatment strategies increasing the production of IL-1Ra by infiltrating leukocytes or microglia may also be neuroprotective if applied early after stroke onset in patients.
A bidirectional (Bi) DC/DC converter is one of the key components in a hybrid energy storage system for electric vehicles and plug-in electric vehicles. Based on the detailed analysis of the losses in the converter, this paper firstly develops a model to theoretically calculate the efficiency of the converter. Then, the influences of temperature, switching frequency, duty cycle and material of switching device on the converter’s efficiency are experimentally investigated. The analysis of the experimental results has shown that (1) The efficiency at the switching frequency of 15kHz is about 2% higher than that of 25kHz. (2) The efficiency at 25°C is similar to that at 85°C for the MOSFET SiC while the efficiency at 25°C is 2% higher than that at 85°C for the IGBT Si for both buck and boost modes. (3) In buck mode, when the duty cycles are decreasing from 66.7%, 50% to 33.33%, the peak efficiencies are also decreasing from 97.6%, 94.5% to 90.3%, respectively. In boost mode, when the duty cycle is increasing from 33.33%, 50% to 75%, the peak efficiency is decreasing from 96.9%, 96.5% to 92.4%, respectively. (4) The developed model can calculate the converter’s efficiency accurately
SnO2 nanoparticles (SNPs) entrapped in a graphene framework are synthesized for use as an anode material in Li ion batteries. A framework is prepared by covalently linking SNPs-anchored graphene oxide layers with diboronic acids. The framework provides the SNPs with more effective buffering than thermally reduced graphene oxide. SNPs in a graphene framework maintain the initial particle size and morphology after repeated charge-discharge cycles, with no inter-particle aggregation. The volume increase of the composite, accompanied by Li+ insertion into SNPs, is also significantly suppressed. The isolation of an individual nanoparticle and the firmness of a framework, which are ascribed to densely cross-linked graphene layers, results in better cyclability and rate performance by comparison with thermally reduced SNPs-anchored graphene oxide.
Phenolic Resin-based hard carbon microspheres (PF-HCSs) were successfully synthesized by a simple hydrothermal route in a stainless steel autoclave and followed carbonization at different temperatures. The materials possess perfect spherule shape and interlayer spacing above that of equilibrium graphite, facilitating Na intercalation and favoring efficient ion storage. A high reversible capacity of 311mAhg−1 and good long-term electrochemical stability are achieved in the PF-HCS-1250 anode obtained at 1250°C. Carbonizing the samples at higher carbonization temperature than 1250°C results in such a decrease of the reversible capacity down to 270mAhg−1. That can be related to the appearing closed pore structure and the decreasing interlayer space which exceeds the limited value sodium ion can insert. Hence the most suitable hard carbon anode material for sodium ion batteries should possess a large interlayer space and a suitable pore structure.
Nanocrystalline tin oxide (SnO2) materials are synthesized by a chemical precipitation method. The nanoparticles are of 5–20nm in size, as calculated by using Scherrer’s formula, and as observed by transmission electron microscopy (TEM). The electrical properties of the consolidated nano-structured SnO2 are studied using an impedance spectroscopic technique. The SnO2 particles are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), TEM and impedance spectroscopy. Electrochemical tests are performed using nanocrystalline SnO2 as the negative electrode for a lithium cell. The results show that nanocrystalline SnO2 materials can be used as an anode material for battery application.
Surface modifications of electrode materials can improve the electrochemical and thermal properties of cathodes for use in lithium batteries. In this study, AlF3-coated LiCoO2 and AlF3-coated Li[Ni1/3Co1/3Mn1/3]O2 cathode materials are blended, as both have the same crystal structure and exhibit similar electrochemical properties. The composite electrodes exhibit high discharge capacities of 180–188mAhg−1 in a voltage range of 3.0–4.5V at room temperature. The capacity retention of the composite electrode is greater than 95% of the initial capacity after 50 cycles. The thermal stability of these composite electrodes is greatly improved because of the superior thermal stability of AlF3-coated Li[Ni1/3Co1/3Mn1/3]O2. The blended AlF3-coated LiCoO2 and AlF3-coated Li[Ni1/3Co1/3Mn1/3]O2 electrode shows two exothermic peaks, one at 227°C from AlF3-coated LiCoO2 and another at 277°C from AlF3-coated Li[Ni1/3Co1/3Mn1/3]O2, accompanied by significantly reduced exothermic heat generation.
In this study, F-doped tree-like nanofiber structural poly-m-phenyleneisophthalamide (PMIA) membranes are prepared via one-step electrospinning approach and their application performance as separators for lithium-sulfur batteries are discussed. The F-doped PMIA membrane can be regarded as matrix to form gel polymer electrolyte. The F doping endows the PMIA membranes with extraordinary high electrolyte uptake, excellent ability of preserving the liquid electrolyte and forceful chemisorption to polysulfides. And the tree-like structure effectively blocks polysulfides by the physical confinement. The lithium-sulfur cell with the F-doped PMIA separator exhibits high first-cycle discharge capacity of 1222.5 mAh g−1 and excellent cycling stability with good capacity retention of 745.7 mAh g−1 and coulombic efficiency of 97.97% after 800 cycles. The remarkable performance can be ascribed to the suppressed shuttle effects through both the physical trapping of polysulfides by the gel polymer electrolyte based on matrix with F-doped PMIA membrane and the tree-like structure in a working cell.
Objective To examine cognitive function in individuals with traumatic brain injury (TBI) prior to and after participation in an aerobic exercise training program. Design Pre-post intervention study. Setting Medical research center. Participants Volunteer sample of individuals (N=7) (age, 33.3±7.9y) with chronic nonpenetrating TBI (injury severity: 3=mild, 4=moderate; time since most current injury: 4.0±5.5y) who were ambulatory. Intervention Twelve weeks of supervised vigorous aerobic exercise training performed 3 times a week for 30 minutes on a treadmill. Main Outcome Measures Cognitive function was assessed using the Trail Making Test Part A (TMT-A), Trail Making Test Part B (TMT-B), and Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Sleep quality and depression were measured with the Pittsburgh Sleep Quality Index (PSQI) and Beck Depression Inventory, version 2 (BDI-II). Indices of cardiorespiratory fitness were used to examine the relation between improvements in cognitive function and cardiorespiratory fitness. Results After training, improvements in cognitive function were observed with greater scores on the TMT-A (10.3±6.8; P=.007), TMT-B (9.6±7.0; P=.011), and RBANS total scale (13.3±9.3; P=.009). No changes were observed in measures of the PSQI and BDI-II. The magnitude of cognitive improvements was also strongly related to the gains in cardiorespiratory fitness. Conclusions These findings suggest that vigorous aerobic exercise training may improve specific aspects of cognitive function in individuals with TBI and cardiorespiratory fitness gains may be a determinant of these improvements.
Children born to mothers with lupus have a higher rate of learning disorders. Now, in mouse studies, Betty Diamond and her colleagues show that neurotoxic antibodies found in mothers with lupus are transferred to the brains of their offspring. This leads to abnormalities in cortical formation during development and in cognitive function when the pups become adults.
Dye tracing is a classic technique in hydrogeology to investigate surface-water or groundwater flow characteristics, and it is useful for many applications including natural or industrial issues. The Fluo-Green field fluorometer has been successfully tested in a karst environment and is specifically suitable for in-cave karst water monitoring. Karst research often uses dyes to obtain information about groundwater flow in unexplored cave passages. The compact device, alternatively named Fluo-G, meets the requirements of cave media: small (10 × 16 × 21 cm), lightweight (0.75 kg without ballast) and simple in conception. It is easy for cavers to set up and handle compared to other sampling methods. The fluorometer records uranine, turbidity and temperature with a user-defined time-step (1 min – 1 day). Very low energy consumption allows 9,000 measurements with six AA batteries. The device was calibrated and tested in the laboratory and in field conditions in Belgian karst systems. Results are in good fit with other sampling methods: in-situ fluorometers and automatic water sampling plus laboratory analysis. Recording high quality data (breakthrough curves) in karst with in-cave monitoring is valuable to improve knowledge of karst systems. Many hydrological and hydrogeological applications can benefit from such a low-cost and compact device, and finding the best compromise between resources and quality data is essential. Several improvements are possible but preliminary field tests are very promising.
Osteoporosis affects over 220 million people worldwide, and currently there is no ‘cure’ for the disease. Thus, there is a need to develop evidence-based, safe and acceptable prevention strategies at the population level that target multiple risk factors for fragility fractures to reduce the health and economic burden of the condition.
Environmental reward (ER) is an established mechanism contributing to depression. Given the high prevalence of depression in China and Taiwan, it is important to develop measures that facilitate the examination of cultural similarities and differences in ER. The reward probability index (RPI) assesses ER through items measuring individual access to rewarding (Reward Probability) and aversive (Environmental Suppressor) events. The purpose of the current study is to translate the RPI into Chinese (C-RPI) and to study cultural difference in ER by examining structural- and item-level differences in RPI functioning. A total of 930 college students were recruited from China (n = 300), Taiwan (n = 300), and the United States (n = 330). Confirmatory factor analysis was used to study the configural invariance of the RPI and C-RPI. Item response theory-based differential item functioning (DIF) testing was used to study item level differences in functioning between the RPI and C-RPI. Results overall support the established RPI structure in all three regions. Most Reward Probability items exhibit no DIF across cultures, while most Environmental Suppressor items exhibit DIF across cultures. Findings highlight cultural difference in ER constructs and cultural factors contributing to the observed DIF. The assessment and clinical implications of the findings are also discussed.
Carbon nanotube-embedding LiFePO4 is synthesized via a solution-based two-step method. The embedded carbon nanotubes are found to improve electron and ion transfer, resulting in excellent high rate capability. An electrode of the nanocomposite, prepared without additional conducting agent, delivers a discharge capacity of 165 mAh g−1 at 0.1 C, 120 mAh g−1 at 30 C, and 78 mAh g−1 at 120 C, based on the weight of LiFePO4. Furthermore, the discharge curve at a discharge rate of 60 C retains the potential plateau above 3.0 V.
Evidence suggests that brain infiltration of lymphocytes contributes to acute neural injury after cerebral ischemia. However, the spatio-temporal dynamics of brain-infiltrating lymphocytes during the late stage after cerebral ischemia remains unclear.
A series of iron-doped nickel cobalt oxide/activated carbon (Fe0.1Ni0.9Co2O4/AC) composites with various ratios of activated carbon were synthesised via a microwave-assisted hydrothermal method. The introduction of activated carbon significantly promotes the catalytic activity of Fe0.1Ni0.9Co2O4 for the oxygen evolution reaction (OER); meanwhile the complete coverage of nanoparticulate Fe0.1Ni0.9Co2O4 onto activated carbon particles prevents the carbon oxidation, leading to improved cycling durability of a zinc-air cell. Scanning electron microscopy images shows a good protective coverage of the nanoparticulate Fe0.1Ni0.9Co2O4 onto the activated carbon particles. Rotating disk electrode voltammetry and electrochemical impedance spectroscopic results reveal that the OER overpotential and charge-transfer resistance of the Fe0.1Ni0.9Co2O4 electrocatalyst are substantially lowered by the introduction of activated carbon. With respect to the cycling stability, Fe0.1Ni0.9Co2O4/1.0 wt%AC and Fe0.1Ni0.9Co2O4/1.5 wt%AC composites maintain excellent activity for 80 h in a rechargeable zinc-air battery, due to the uniformly protective coverage of metal oxide on activated carbon. Furthermore, the Fe0.1Ni0.9Co2O4/3.7 wt%AC composite was examined in a prolonged rechargeable zinc-air battery test for 120 h and the charge-discharge voltage gap was negligibly enlarged (0.02 V increment after 120 h), which showed their potential as electrocatalysts for long-term energy storage systems.
Corticobasal syndrome (CBS) is a progressive neurodegenerative disorder with asymmetric presentation and course characterized by degeneration of basal ganglia and cortical structures. Limb apraxia is a commonly observed deficit in CBS. Few studies have examined comprehensively the nature of deficits in limb apraxia. The goal of our study was to investigate the severity of deficits in various conceptual and gesture production task modalities. CBS patients were divided in two groups based on the side of brain that was initially affected by the disease. Ten patients with right hemisphere presentation (RHP) and seven with left hemisphere presentation (LHP) were included. The results showed that while selective conceptual tasks deficits were present in both groups, the overall picture suggests preserved conceptual representations of tools and actions in CBS patients with either LHP or RHP. Both groups were impaired relative to controls on gesture production tasks. Performance on transitive gestures was more severely affected in both groups than intransitive gestures. Imitation was more severely affected than pantomime, suggesting deficits in visuomotor transformations. The addition of verbal cuing during concurrent imitation affected only the LHP patients, rendering them more impaired relative to controls in their imitation with verbal cuing as opposed to their imitation only performance. Imitation of non-representational gestures was least accurate and intransitive gestures were most accurate. Patients were more severely impaired relative to controls when holding the object and when they were shown pictures of tools to pantomime.
A simple chemical oxidative polymerization of pyrrole (Py) directly onto the surface of LiFePO4 particles was applied to the synthesis of polypyrrole-LiFePO4 (PPy-LiFePO4) powder. The LiFePO4 sample without carbon coating was synthesized by a solvothermal method. The polyethylene glycol (PEG) was used as additive during Py polymerization for increasing the PPy-LiFePO4 conductivity. Properties of resulting LiFePO4, PPy-LiFePO4 and PPy/PEG-LiFePO4 samples were characterized by XRD, SEM, TGA and galvanostatic charge–discharge measurements. These methods confirmed the presence of polypyrrole on LiFePO4 particles and its homogeneous distribution in the resulting powder material. The PPy/PEG-LiFePO4 composites show higher discharge capacity than pure LiFePO4, as PPy/PEG network improves the electron conductivity. It presents specific discharge capacity of 153mAh/g at C/5 rate.