batterydata/paper-abstracts huggingface dataset:
The surface of spinel LiMn2O4 was modified with TiO2 by a simple sol–gel method to improve its electrochemical performance at elevated temperatures and higher working potentials. Compared with pristine LiMn2O4, surface-modification improved the cycling stability of the material. The capacity retention of TiO2-modified LiMn2O4 was more than 85% after 60 cycles at high potential cycles between 3.0 and 4.8V at room temperature and near to 90% after 30 cycles at elevated temperature of 55°C at 1C charge–discharge rate. SEM studies shows that the surface morphology of TiO2-modified LiMn2O4 was different from that of pristine LiMn2O4. Powder X-ray diffraction indicated that spinel was the only detected phase in TiO2-modified LiMn2O4. Introduction of Ti into LiMn2O4 changed the electronic structures of the particle surface. Therefore a surface solid compound of LiTi x Mn2−x O4 may be formed on LiMn2O4. The improved electrochemical performance of surface-modified LiMn2O4 was attributed to the improved stability of crystalline structure and the higher Li+ conductivity.
The roosting habits of many temperate zone bats are well documented at microhabitat scales, but fewer studies have included multi-scale assessments of landscape patterns in bat roost site selection.
A recombinant amylomaltase, MQ-01, obtained by cultivation of Bacillus subtilis expressing the amylomaltase gene from Thermus aquaticus is to be used in the production of enzymatically-synthesized glycogen; which is intended for use as a food ingredient. In order to establish the safety of MQ-01, the enzyme was subjected to standard toxicological testing. In a battery of standard Salmonella typhimurium strains (TA98, TA100, TA1535, and TA1537) and in Escherichia coli WP2 uvrA, both with and without metabolic activation, MQ-01 failed to exhibit mutagenic activity. Similarly, MQ-01 did not display clastogenic properties in Chinese hamster lung fibroblast cells (CHL/IU), in an in vitro chromosomal aberration assay. In a 13-week subchronic toxicity study in rats, oral administration of MQ-01 at doses of up to 15mL/kg body weight/day (corresponding to approximately 1230mg/kg body weight/day) did not produce compound-related clinical signs or toxicity, changes in body weight gain, food consumption, hematology, clinical chemistry, urinalysis, organ weights, or in any gross and microscopic findings. The results of this study support the safety of MQ-01 in food production.
The plasma modification of the polypropylene (PP) membrane as a separator in lithium-ion battery (LIB) has been reported in this paper. Specifically, a commercial PP separator was modified by an atmospheric pressure glow discharge plasma jet (APGD-PJ) with the acrylic acid (AA) monomer. The morphology, electrolyte uptake and retention, the pore size distribution, and the electrochemical properties of the modified PP separator were analyzed. The experimental results indicate that the AA polymer (PAA) was uniformly coated on the surface of the PP membrane, and the contact angle of modified PP was reduced from 112° to 39° using He/O2/AA plasma and the electrolyte uptake of the modified PP separator increased to above 300% of the value of the unmodified one. Compared with the original PP, the cells assembled with the PP separator modified with Ar/O2/AA or He/O2/AA plasma showed higher capacities and better C-rate capacity. The excellent performances of assembled LIB endow the APDG-PJ as a promising protocol for modifying polyolefin separators for LIB applications.
A cognitive-stimulation tool was created to regulate functional connectivity within the brain Default-Mode Network (DMN). Computerized exercises were designed based on the hypothesis that repeated task-dependent coactivation of multiple DMN regions would translate into regulation of resting-state network connectivity. Forty seniors (mean age: 65.90 years; SD: 8.53) were recruited and assigned either to an experimental group (n =21) who received one month of intensive cognitive stimulation, or to a control group (n =19) who maintained a regime of daily-life activities explicitly focused on social interactions. An MRI protocol and a battery of neuropsychological tests were administered at baseline and at the end of the study. Changes in the DMN (measured via functional connectivity of posterior-cingulate seeds), in brain volumes, and in cognitive performance were measured with mixed models assessing group-by-timepoint interactions. Moreover, regression models were run to test gray-matter correlates of the various stimulation tasks. Significant associations were found between task performance and gray-matter volume of multiple DMN core regions. Training-dependent up-regulation of functional connectivity was found in the posterior DMN component. This interaction was driven by a pattern of increased connectivity in the training group, while little or no up-regulation was seen in the control group. Minimal changes in brain volumes were found, but there was no change in cognitive performance. The training-dependent regulation of functional connectivity within the posterior DMN component suggests that this stimulation program might exert a beneficial impact in the prevention and treatment of early AD neurodegeneration, in which this neurofunctional pathway is progressively affected by the disease.
In previous studies a novel amphiphilic co-polymer was developed for use in lithium-ion batteries. In order to evaluate the electrochemical stability of that electrolyte and compare it with others, a voltammetric method was applied on a set of electrolytes with different salts, solvents and polymers. However, initially the voltammetric methodology was studied. Platinum was found to be the most suited electrode material, experiencing no significant interfering reactions and a proper diffusion-controlled kinetic behaviour when sweep rate was varied. Furthermore, the influence on the voltammograms of adding water traces to the electrolytes was studied. It could be established that the oxidation peak around 3.8V versus Li was related to water reactions. It was concluded that quantitative voltage values of the stability limits were difficult to assess using voltammetry. On the other hand, the method seemed well suited for comparison of electrolytes and to investigate the influences of electrolyte components on the stability. The voltammetric results varied little between the different electrolytes evaluated and the anodic and cathodic limits, as defined here, were in the range of 1 and 4.5V vs. Li, respectively. Although the novel polymer did not affect the stability limit significantly it seemed to promote the breakdown reaction rate in all electrolytes tested. Furthermore, the use of LiTFSI salt reduced the stability window.
Due to good biocompatibility and mechanical properties, magnesium (Mg) and its alloys are considered promising degradable materials for orthopedic applications. In this work, a Mg metal matrix composite (MMC) was fabricated using Mg-2.9Zn-0.7Zr alloy as the matrix and 1 wt% nano-hydroxyapatite (n-HA) particles as reinforcements. In vitro corrosion behavior and cytocompatibility of a Mg–Zn–Zr/n-HA composite and a Mg–Zn–Zr alloy were investigated. In contrast with the Mg–Zn–Zr alloy, the MMC has better properties. The average corrosion rate of MMC is 0.75 mm/yr after immersion in simulated body fluid (SBF) for 20 days, and the surface of MMC is covered with white Ca–P precipitates. The electrochemical test results show that the corrosion potential (Ecorr) of MMC increases to −1.615 V and its polarization resistance (Rp) is 2.56 KΩ with the addition of n-HA particles. The co-cultivation of MMC with osteoblasts results in the adhesion and proliferation of cells on the surface of the composite. The maximum cell density is calculated to be (1.85±0.15) × 104/l after 5 days of co-culture with osteoblasts. The average cell numbers for two groups after culturing for 3 and 5 days (P<0.05) are significantly different. All the results demonstrate that the Mg–Zn–Zr/n-HA composite can be potentially used as biodegradable bone fixation material.
9LiFePO4·Li3V2(PO4)3/C is synthesized via a carbon thermal reaction using petroleum coke as both reduction agent and carbon source. The as-prepared material is not a simple mixture of LiFePO4 (LFP) and Li3V2(PO4)3 (LVP), but a composite possessing two phases: one is V-doped LFP and the other is Fe-doped LVP. The typical structure enhances the electrical conductivity of the composite and improves the electrochemical performances. The first discharge capacity of 9LFP·LVP/C in 18650 type cells is 168mAhg−1 at 1C (1C9LFP·LVP/C =166mAg−1), and exhibits high reversible discharge capacity of 125mAhg−1 at 10C even after 150 cycles. At the temperature of −20°C, the reversible capacity of 9LFP·LVP/C can maintain 75% of that at room temperature.
Atomic force microscopy was used to monitor the macroscopic deformation in a delaminated Ti3C2 paper electrode in situ, during charge/discharge in a variety of aqueous electrolytes to examine the effect of the cation intercalation on the electrochemical behavior and mechanical response. The results show a strong dependence of the electrode deformation on cation size and charge. The electrode undergoes a large contraction during Li+, Na+ or Mg2+ intercalation, differentiating the Ti3C2 paper from conventional electrodes where redox intercalation of ions (e.g. Li+) into the bulk phase (e.g. graphite, silicon) results in volumetric expansion. This feature may explain the excellent rate performance and cyclability reported for MXenes. We also demonstrated that the variation of the electromechanical contraction can be easily adjusted by electrolyte exchange, and shows interesting characteristics for the design of actuators based on 2D metal carbides.
Pua YH, Wrigley TW, Cowan SM, Bennell KL. Intrarater test-retest reliability of hip range of motion and hip muscle strength measurements in persons with hip osteoarthritis. Objective To examine the relative and absolute intrarater test-retest reliability of muscle strength and range of motion (ROM) measurements of the hip performed in people with hip osteoarthritis. Design Repeated measures. Setting Human movement laboratory of a university. Participants Participants (N=22; 10 men, 12 women; age range, 50-84y) with hip osteoarthritis. Interventions On 2 separate occasions, at least 1 week apart, isometric torque measurements were obtained from the hip rotators, flexors, abductors, and extensors. Passive ROMs in hip rotation, flexion, abduction, and extension were also determined. Main Outcome Measures Relative reliability was estimated using the intraclass correlation coefficient, model 2,2 (ICC2,2). Absolute reliability was estimated using the coefficient of variation (CV) and the standard error (SE) of measurement. Results For measurements of muscle strength, ICC2,2 ranged from .84 to .97, and the CV ranged from 8% to 15.7%. Hip extensors and internal and external rotators showed high ICC2,2 (>.96) and low CV (<9.8%); hip abductors showed the lowest ICC2,2 (.84) and the highest CV (15.7%). For ROM measurements, ICC2,2 ranged from .86 to .97 and SE ranged from 3.1° to 4.7°. Hip flexion ROM showed the highest ICC2,2 (.97) and an SE of 3.5°; hip extension ROM showed the lowest ICC2,2 (.86) and the highest SE (4.7°). Conclusions Strength and ROM testing of the hip in people with hip osteoarthritis can be performed with good to excellent reliability.
The creation of a sustainable energy generation, storage, and distribution infrastructure represents a global grand challenge that requires massive transnational investments in the research and development of energy technologies that will provide the amount of energy needed on a sufficient scale and timeframe with minimal impact on the environment and have limited economic and societal disruption during implementation. In this opinion paper, we focus on an important set of solar, thermal, and electrochemical energy conversion, storage, and conservation technologies specifically related to recent and prospective advances in nanoscale science and technology that offer high potential in addressing the energy challenge. We approach this task from a two-fold perspective: analyzing the fundamental physicochemical principles and engineering aspects of these energy technologies and identifying unique opportunities enabled by nanoscale design of materials, processes, and systems in order to improve performance and reduce costs. Our principal goal is to establish a roadmap for research and development activities in nanoscale science and technology that would significantly advance and accelerate the implementation of renewable energy technologies. In all cases we make specific recommendations for research needs in the near-term (2–5 years), mid-term (5–10 years) and long-term (>10 years), as well as projecting a timeline for maturation of each technological solution. We also identify a number of priority themes in basic energy science that cut across the entire spectrum of energy conversion, storage, and conservation technologies. We anticipate that the conclusions and recommendations herein will be of use not only to the technical community, but also to policy makers and the broader public, occasionally with an admitted emphasis on the US perspective.
High capacity cathode materials Li[Li0.2Mn0.54Ni0.13Co0.13]O2−x F x (x =0, 0.05 and 0.10) have been synthesized by a sol–gel method using NH4F as F source. The effects of fluorine content on the structure, morphology and electrochemical performance of the Li[Li0.2Mn0.54Ni0.13Co0.13]O2−x F x have been extensively studied. With fluorine doping, cycling stability of Li[Li0.2Mn0.54Ni0.13Co0.13]O2−x F x is significantly improved because of the stabilization of the host structure. Li[Li0.2Mn0.54Ni0.13Co0.13]O1.95F0.05 shows a capacity retention of 88.1% after 50 cycles at 0.2C at room temperature, much higher than that of 72.4% for pristine one. The improvement mechanism of fluorine doping has been investigated by electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS). The results demonstrate that fluorine incorporation stabilizes the electrode/electrolyte interface by suppressing the formation of poorly conducting LiF in the SEI layer and thus maintains stable interfacial resistances. As compared to the enhanced material structure, the stabilized electrode/electrolyte interface is the primary factor contributing to the improved electrochemical performance. In addition, the thermal stability of fully delithiated electrode is also greatly improved by fluorine doping.
In this research work organic/inorganic nano composites were synthesized from poly-2-hydroxyethylmethacrylate and properly modified silica nanoparticles by in situ polymerization. In particular, fumed nanosilica was functionalized with methacryloylpropyltrimetoxy silane (MPTMS) in order to obtain a more homogeneous, reliable and mechanically performing nano composite. For comparison, nano composites with non functionalised silica were also prepared. Scanning electron microscopy was performed in order to visualize the effects of functionalization on the mode and state of dispersion. This analysis demonstrated that MPTMS grafted onto silica surface acts as an effective coupling agent and assures a good dispersion and distribution of nanoparticles as well as a strong nano particle/matrix interfacial adhesion. As a result of strong interactions occurring between phases, a pronounced increase of the glass transition temperature and mechanical parameters were recorded. Finally, these novel nano composites were seeded with murine fibroblast and human mesenchymal stem cells, and observed in time-lapse experiments proving an effective biological response.
(Mg1−x Zr x )2Ni (x=0.0, 0.1, 0.2, 0.3 and 0.4) hydrogen-storage alloy electrodes are synthesized by means of a mechanical alloying process using a planetary ball mill. After milling for 160 h, (Mg1−x Zr x )2Ni alloy with x=0.0 remained the nanocrystalline phase. By contrast, Zr addition to this alloy enhances the structural disorder and amorphization. The discharge capacity of a (Mg1−x Zr x )2Ni electrode increases with Zr content and reaches the highest capacity of 530 mAh g−1 at x=0.3, then decreases to 230 mAh g−1 at x=0.4, i.e., lower than that of pure Mg2Ni. Cyclic stability and rate capability vary with Zr addition.
As a sulfur-containing cathode material, sulfide polyacrylonitrile (SPAN) is expected to be used for long-life lithium–sulfur battery because there is no shuttle effect occurred in its charge process. However, its specific capacity and discharge potential need to be further improved to satisfy the urgent demands for high-performance batteries. In this paper, Te0.045S0.955PAN composite was synthesized by co-heating Te x S1- x and PAN, and the superior electrochemical performance to that of SPAN was obtained because of doping Te with high conductivity. The as-prepared Te0.045S0.955PAN composite possessed the specific capacity of 675 mAh g−1 after 100 cycles at the current density of 0.1 A g−1 with high capacity retention of 96.6% compared to the second cycle. Especially, during cycling, Te0.045S0.955PAN showed average discharge voltages of 1.88–1.91 V, which were higher than 1.85–1.88 V for SPAN at the same current density. Thus doping Te provides a new strategy for increasing the energy density of SPAN.
This study describes the application of a novel technique for obtaining vertical profiles (0– 400 m above ground level) of PM size distributions in a highly polluted setting dominated by domestic burning of wood and coal. At night, smoke from domestic fires is emitted into a highly stable and shallow katabatic flow layer. This layer is only ∼ 20– 40 m in depth and gives rise to very high concentrations that may persist late into the night. The mass size distribution of wood/coal smoke in Christchurch is overwhelmingly dominated by fine particles ( < 1 μ m in aerodynamic diameter). The vertical profiles reveal that layers of pollutants (with distinct PM signatures) may be found in such wintertime nocturnal settings. In Christchurch (population ∼ 400,000) a dominant mechanism appears to be undercutting by shallow drainage flows. This creates elevated layers with a daytime surface PM signature (predominately coarse material with modes at 2.5 and 6.25 μ m ). These results confirm the usefulness of the deployment of miniature optical PM instruments on tethered balloons in cool, humid, polluted conditions. Such measurements allow the proper evaluation of the current generation of air pollution dispersion models.
A silicon membrane developed by researchers in the USA at the University of Rochester is set to help in the development of diagnostic devices the size of a credit card by enabling an electro-osmotic pump, incorporated into a “lab-on-a-chip”, to run on a low-voltage power source.
We demonstrate the synthesis of nano Ge/C composite using a facile and cost-effective electrochemical deposition method, and its application as an anode material in Li-ion batteries. Nano Ge/C composite is electrodeposited directly on Cu foil in ethylene glycol containing GeCl4 and carbon black. The Ge particles with an average size of ∼20nm are uniformly covered with carbon. Compared with the pure Ge electrode, the Ge/C electrode exhibits a higher first reversible capacity of 1224mAg−1, and maintains a capacity of 1095mAhg−1 at 0.1C over 50 cycles. Even at the high rate of 2C, the capacity of the Ge/C electrode is still high at 972mAhg−1. The presence of carbon black and pores in the Ge/C electrode improves the conductivity of the electrode, and mitigates the stress inside the electrode by supplying buffer volume, leading to the enhanced electrochemical characteristics of the electrode. Further, the full Li-ion cell composed of Ge/C anode and LiCoO2 cathode exhibits good cyclability, rate capability, and coulombic efficiency.
Electrospinning is an useful technique to produce nanofiber webs. Since electrospun nanofiber webs have a nanoporous structure, they have a potential application for a polymer electrolyte or a separator. Poly(vinylidene fluoride) (PVDF) is used as one of polymer electrolyte binders. We studied application of eletrospun PVDF nanofiber webs as an electrolyte binder or a separator for a battery. Diameters of the electrospun PVDF nanofibers were 100–800nm. The electrospun PVDF nanofiber web was thermally treated at 150–160°C to improve the physical property and dimensional stability. The tensile strength and elongation at break as well as the tensile modulus were notably improved by the thermal treatment. Level of cryatallinity of the electrospun PVDF nanofiber was increased by the thermal treatment. The ion conductivity of the polymer electrolyte formed from the electrospun PVDF nanofiber web and 1M LiN(CF3SO2)2 electrolyte solution was 1.6–2.0 × 10−3 S/cm. The electrospun PVDF nanofiber mat was treated with ethylene plasma to use as a separator. The ethylene plasma-treated mat showed a role of shutter by melting the polyethylene (PE) layer grafted on the PVDF nanofibers.
Hydrothermally synthesized LiFePO4 has been prepared with different synthesis times in order to study defects in the crystal structure and their evolution. The Mössbauer spectra can be interpreted as due to three components, Fe2+ in LiFePO4, Fe2+ in unreacted precursor material which resembles the Mössbauer spectrum of Fe2+ in vivianite (Fe3(PO4)2·8H2O) and Fe3+. The Fe3+ contribution differs from room temperature oxidation of the precursor material, and can partly be due to charge compensating defects in the LiFePO4 structure. With increasing synthesis time, the latter two contributions virtually disappear from the spectra.
The present work focuses on the design and development of highly oriented well aligned nano shrubs of polyaniline decorated Co3O4 (COP) and demonstration as an efficient electrode for the fabrication of supercapacitors. Morphological results suggest that COPs are composed of PANI nano shrubs grown from the pores of Co3O4 to form a three-dimensional nanostructure. Further, supercapacitor with the configurations of [(indium tin oxide)ITO-COP/1 M Na2SO4/COP-ITO] was fabricated and its performance evaluated leading to high specific capacitance value (1151 F g−1 @ 3 A g−1), high rate performance of 70% at the current density ranging from 3 to 20 A g−1, and excellent cycling stability (92% after 5000 cycles @ 10 A g−1). The excellent performance of this hybrid nanocomposite is attributed to well aligned self-assembled structural advantage of COP and the synergistic effects of cobalt oxide and polyaniline which is responsible for the substantial reduction in the charge transfer resistance as revealed by electrochemical impedance spectroscopy. All these results suggest that the developed strategy can be used for the development of efficient hybrid conductive nanocomposite based electrode material for other combinations of transition metal oxide-conductive polymer based supercapacitors.