batterydata/paper-abstracts huggingface dataset:
Swelling of a commercial 5 Ah lithium-ion cell with a nickel/manganese/cobalt-oxide cathode is investigated as a function of the charge state and the charge/discharge rate. In combination with sensitive displacement measurements, knowledge of the electrode configuration within this prismatic cell's interior allows macroscopic deformations of the casing to be correlated to electrochemical and mechanical transformations in individual anode/separator/cathode layers. Thermal expansion and interior charge state are both found to cause significant swelling. At low rates, where thermal expansion is negligible, the electrode sandwich dilates by as much as 1.5% as the charge state swings from 0% to 100% because of lithium-ion intercalation. At high rates a comparably large residual swelling was observed at the end of discharge. Thermal expansion caused by joule heating at high discharge rate results in battery swelling. The changes in displacement with respect to capacity at low rate correlate well with the potential changes known to accompany phase transitions in the electrode materials. Although the potential response changes minimally with the C-rate, the extent of swelling varies significantly, suggesting that measurements of swelling may provide a sensitive gauge for characterizing dynamic operating states.
Electrolytic manganese dioxide (EMD) recovered from a simulated leaching solution of spent alkaline batteries using a modified cyclone cell is tested as a cathode material for Li secondary batteries. An EMD/C(Super P) composite heat-treated at 400°C after high-energy mechanical milling shows better electrochemical performance than that of pure EMD in terms of cycleability and capacity fading. The electrochemical characteristics of the EMD/C(Super P) composite are investigated by various analytical techniques. The irreversible capacity during the first cycle is mainly due to the formation of a Li2MnO3 phase. The carbon composite also retards the dissolution of Mn during cycling.
Two-dimensional morphological (2DM) metal oxides are highly desirable for the improvement of electrochemical performance of lithium-ion batteries (LIBs). Herein, a facile and scalable strategy to fabricate porous 2DM zinc-cobalt oxide (ZCO) plates is reported, with the help of a morphology-maintained annealing treatment of metal organic frameworks (MOFs). Through change the proportion of metal nitrates in the precursors, a series of porous ZCO plates are synthesized. Thanks to the porous structure, 2DM morphological features and nanosized building block of Co3O4 plates, the Co3O4 plates electrode as anode materials for LIBs display the high reversible capacity (1027 mA h g-1 at 100 mA g−1 after 100 cycles), remarkable rate capability (541 mA h g-1 even at 1000 mA g−1). Furthermore, this strategy of synthesizing the ZCO plates with MOFs provides a new approach to design bimetallic transition metal oxides that the ratio of transition metal is continuously adjusted and has great lithium storage properties.
Objective Emotional adjustment to cancer survivorship may be influenced by how patients interpret treatment side effects and other cancer-related experiences. The current study examined cognitive representations of illness, as conceptualized by the Self-Regulatory Model (SRM), in men treated for localized prostate cancer (PC). More severe PC perceptions were hypothesized to predict poorer emotional well being, particularly among men experiencing greater post-treatment sexual dysfunction or general life stress. Methods The Perceived Stress Scale, Expanded Prostate Cancer Index Composite, Illness Perception Questionnaire-Revised, and Functional Assessment of Cancer Therapy were administered to 214 men within 18 months of completing treatment for early stage PC. Results Perceptions that PC was less comprehensible, was less likely to be controlled by treatment, and was more likely caused by one's own personality and behaviors remained associated with poorer emotional well being after adjusting for relevant medical and demographic factors. Life stress moderated the relationship between perceived consequences of PC and emotional well-being, such that more severe perceptions of negative consequences predicted poorer emotional well-being only for men experiencing higher life stress. Degree of sexual dysfunction did not moderate any relationships between cancer perceptions and emotional well-being. Conclusion Within 18 months of completing treatment for localized PC, more severe perceived consequences of PC were associated with poorer emotional well-being, particularly among men experiencing greater life stress. Interventions that target distortions in illness perceptions may enhance emotional adjustment among the most distressed PC survivors.
The reaction of TiX4(X=Cl or Br) with the tripodal ligands MeC(CH2SMe)3 or MeC(CH2SeMe)3, (L3) in anhydrous n-hexane or CH2Cl2 produced the extremely moisture sensitive complexes [TiX4(L3)]. These were characterised by microanalysis, IR, UV–Vis and variable temperature 1H,13C{1H} and 77Se NMR spectroscopy. The NMR studies showed that in solution in CH2Cl2 the complexes contain L3 bound as bidentates, and that pyramidal inversion and exchange between the free and coordinated chalcogen donors is rapid at room temperature. Ligand dissociation/exchange increases TiCl4<TiBr4 and MeC(CH2SMe)3<MeC(CH2SeMe)3 and attempts to isolate TiI4 analogues were unsuccessful. The reactions of [MCl4(Me2S)2] (M=Zr or Hf) with (L3) in anhydrous CH2Cl2 produces white or cream 7-coordinate [MCl4(L3)], which are insoluble in chlorocarbon solvents. The reactions of TiX4 (X=Cl, Br or I) with the trithia-macrocycles [9]aneS3 and [10]aneS3 produced [TiX3([n]aneS3)]X, whilst reaction of TiCl4, SbCl5 and [9]aneS3 in anhydrous CH2Cl2 gave [TiCl3([9]aneS3)]SbCl6. Spectroscopic studies suggest these macrocyclic compounds contain 6-coordinate cations, [TiX3([n]aneS3)]+ (n=9 or 10) but with Zr and Hf the complexes [MCl4([n]aneS3)] are 7-coordinate and neutral.
Due to their cycling stability and high power density, the supercapacitors bridge the power/energy gap between traditional dielectric capacitors and batteries/fuel cells. Electrode materials are key components for making high performance supercapacitors. An activated carbon nanowhiskers (ACNWs) wrapped-on graphitized electrospun nanofiber (GENF) network (ACNWs/GENFN) with 3D porous structure is prepared as a new type of binder-free electrode material for supercapacitors. The supercapacitor based on the ACNWs/GENFN composite material displays an excellent performance with a specific capacitance of 176.5 F g−1 at current density of 0.5 A g−1, an ultrahigh power density of 252.8 kW kg−1 at current density of 800 A g−1 and an outstanding cycling stability of no capacitance loss after 10,000 charge/discharge cycles.
The cycle life of lead-carbon battery is greatly restricted by the hydrogen evolution reaction (HER) of lead-carbon electrode. Lead carbon composite, rather than the pure carbon additive, inhibits the HER effectively, and may also strengthen the connection between lead and carbon components of lead-carbon electrode, which contributes to the performance enhancement of lead-carbon battery. In this paper, a novel lead carbon (C/Pb) composite is prepared by electroless plating lead on the rice-husk-based hierarchical porous carbon. The as-prepared C/Pb composite significantly suppresses the HER, and enlarges the electrochemically active surface area of the lead-carbon electrode. As expected, the cycle life of lead carbon battery with the optimized C/Pb composite in negative electrode is >11 times of the blank one under high-rate partial state-of-charge (HRPSoC) operation. This performance improvement is attributed to the enhanced interface between lead and carbon, and the inhibition effect on HER of C/Pb composite.
Polymer electrolytes composed of an acrylonitrile and butyl acrylate copolymer poly(AN-co-BuA) with addition of LiN(CF3SO2)2 (LiTFSI) or LiI and LiTFSI salt mixture are studied by impedance spectroscopy, DSC, Raman spectroscopy, X-ray diffraction, SEM and TEM. Impedance study shows that the ionic conductivity of the electrolytes containing LiTFSI is strongly dependent on the salt content and transition from “salt-in-polymer” to “polymer-in-salt” regime is observed at high salt content. Gradual changes of physical properties of the studied polymer electrolytes are observed in the course of their prolonged storage under argon atmosphere. These include the increase of glass transition temperature and decrease of ionic conductivity. In order to study the effects of this ageing process, measurements on samples of electrolyte films were repeated after several months. Precipitation of salt, which occurred at the nanometer length scale is observed with the aid of electron microscopy in electrolytes containing more than 84wt.% of salt. Crystalline salt is not observed in electrolytes with lower amount of salt – however, the results indicate the structural changes of salt aggregates, which strongly influence transport of ions through the electrolyte. For preparation of electrolytes with mixed LiTFSI and LiI salts, a mixture of salts (16wt.% LiI, 84wt.% LiTFSI) is used, which exhibits the lowest melting temperature. The electrolyte comprising poly(AN-co-BuA) and 65wt.% of the salt mixture exhibits high ionic conductivity and turns out to be more stable than electrolytes comprising only LiTFSI salt.
A 5V lithium secondary cell was fabricated using LiFe0.5Mn1.5O4 cathode material with all-solid-state design. As an additional approach to improve the battery performance of the all-solid-state secondary cell, a metal oxide-retaining layer was placed between the cathode material and solid electrolyte. The cathode material has an excellent cyclability in this cell design, since it just loses 5 and 18% of its initial capacity after 100 and 500 charge–discharge cycles, respectively.
Understanding what underpins the activity and stability of oxygen evolution catalysts is an ongoing issue in the field of water splitting. Now, researchers show that balancing the rate of Fe dissolution and deposition over a metal hydr(oxy)oxide host yields dynamically stable Fe active sites, with the Fe–host interaction key to the performance.
Background Herbal remedies are increasingly popular for the treatment of functional dyspepsia. Chios mastic gum is a resinous exudate from the stem of Pistacia lentiscus var. chia. It is a traditional natural remedy used throughout the eastern Mediterranean. The aim of this study was to assess the efficacy of Chios mastic gum in patients with functional dyspepsia. Methods One hundred and forty eight patients fulfilling Rome II criteria for functional dyspepsia were randomly assigned to receive either Chios mastic gum 350mg three times daily or placebo. After 3 weeks of treatment the change from baseline in the severity of symptoms of functional dyspepsia was assessed using the Hong Kong index of dyspepsia. Patients’ global assessment of efficacy was also evaluated. Results The symptom score after treatment was significantly lower in the Chios mastic gum than in the placebo group ((14.78±1.78) vs (19.96±1.83)) (p <0.05). There was a marked improvement of symptoms in 40% of patients receiving placebo and in 77% of patients receiving Chios mastic gum (p <0.02). Individual symptoms that showed significant improvement with Chios mastic gum were: stomach pain in general, stomach pain when anxious, dull ache in the upper abdomen and heartburn (<0.05 for all four symptoms). Conclusion Chios mastic gum significantly improves symptoms in patients with functional dyspepsia compared to placebo.
The effect of discharge rate of direct methanol fuel cell (DMFC) on fuel efficiency was comparatively investigated using a DMFC single cell and a DMFC system. The results obtained from the single cell were used to model the DMFC system. Several semi-empirical equations were derived that relate discharge current, voltage, power output, energy density and fuel consumption for a nominal 25W DMFC system. The decrease in fuel efficiency with decreased power output that is observed for the DMFC system is attributable to the increase of methanol crossover that can be observed for an individual cell. A DMFC system can achieve maximum energy density and fuel efficiency at an appropriately high level of power output.
False colour infrared (IR) thermography was performed on a sunny summer day in the Berlin Botanic Garden. The main interest focused on blossoms of different size, colours and shapes: disk-, bowl- and funnel-like anatomy demonstrating various modes of light absorption and heating-up during the day. Some of the flowers were phototropic or even solar tracking. Blossom temperatures ranged from 18.0 to 33.3°C (mean 26.3±2.5°C, S.D., n =37) at 21°C air temperature. Several thermograms showed honey- and bumblebees also. In some cases the results are compared with those of a contact-free IR thermometry. One winter- and one late-spring-flowering plant are included in the overview.
Potassium barium hexacyanoferrate (K2BaFe(CN)6) was investigated as a cathode material for reversible Ca2+ ion insertion/extraction type rechargeable battery using non-aqueous electrolytes. The electrochemical performance of K2BaFe(CN)6was evaluated using cyclic voltammetry and galvanic cycling at ambient temperature. It is shown that addition of water led to significant enhancement in intercalation and de-intercalation of Ca2+ ions, leading to improved charge/discharge capacity. The enhancement in performance is attributed to formation of solvation spheres around the intercalating Ca2+ ions which provide screening from the electrostatic charges of the BaFe(CN)6 lattice. A reversible capacity of 55.8 mA hr g−1 and a coulombic efficiency of 93.8% was demonstrated at the end of 30 charge/discharge cycles.
By using electrospinning and carbonization, tin nanoparticles enwrapped in carbon nano-fibers (Sn/C) present high capacity and well cyclic performance. The precursor compositions of SnCl2 and polyacrylonitrile (SnCl2/PAN) have a significant effect on the crystal structure, morphology of Sn/C composites, and the electrochemical performance. Along with the increased concentration of tin in the precursors of SnCl2/PAN, the diameters of the carbonized Sn/C nanofibers are decreased. The samples of SnCl2/PAN with starting weight ratio 3:2 (Sn3Pan2), 1:1 (Sn1Pan1) and 2:3 (Sn2Pan3) present the initial discharge capacity 977.8, 1329.8, and 1137.0mAhg−1, respectively. In the following cycles, the Sn/C nanofibers present high capacity and well cyclic performance. The sample Sn1Pan1 retains a charge capacity of 741.1mAhg−1 (92% of the initial charge capacity) after 40 cycles. Because the nanoparticles of tin metal are enwrapped in carbon nanofibers, the volume change and aggregation of metal anode are decreased during charging and discharging processes.
A simple aqueous-processable alkaline ionomer (amenable to scale-up) has been developed for enhancing electrode/electrolyte interfaces in clean energy devices (e.g. alkaline polymer electrolyte membrane fuel cells). The water uptake of the alkaline ionomer is tuneable allowing its use as a tool for fundamental studies into these interfaces.
Episodic memory impairment is a well-recognized feature of mesial temporal lobe epilepsy. Semantic memory has received much less attention in this patient population. In this study, semantic memory aspects (word–picture matching, word definition, confrontation and responsive naming, and word list generation) in 19 patients with left and right temporal lobe epilepsy secondary to mesial temporal sclerosis (MTS) were compared with those of normal controls. Patients with LMTS showed impaired performance in word definition (compared to controls and RMTS) and in responsive naming (compared to controls). RMTS and LMTS patients performed worse than controls in word-picture matching. Both patients with left and right mesial temporal lobe epilepsy performed worse than controls in word list generation and in confrontation naming tests. Attentional-executive dysfunction may have contributed to these deficits. We conclude that patients with left and right MTS display impaired aspects of semantic knowledge. A better understanding of semantic processing difficulties in these patients will provide better insight into the difficulties with activities of daily living in this patient population.
The battery state of energy and state of power are two important parameters in battery usage. The state of energy represents the residual energy storage in battery and the state of power represents the ability of battery discharge/charge. To estimate the two states with high accuracy, the characteristics of battery maximum available capacity and open-circuit voltage are analyzed under different working temperatures. Meanwhile, the equivalent circuit model of the battery is employed to embody the battery dynamic performance. To improve the accuracy of the battery states estimation, the multi-time-scale filter is applied in battery model parameters identification and battery states prediction. Besides, the state of power is analyzed by multi-constrained conditions to ensure battery work with safety. The proposed approach is verified by experiments operated on lithium-ion battery under new European driving cycle profiles and dynamic test profiles. The experimental results indicate the proposed method can estimate the battery states with high accuracy for actual application. In addition, the factors affecting the change of battery states are analyzed.
Differential scanning calorimetry (DSC) has been used to measure the thermal interactions between several binder materials and representative anode carbons both in the presence of cell electrolyte (EC:DEC/1M LiPF 6+2 wt.% vinylene carbonate) and after washing/drying. Binders consisting of homo- or copolymers of vinylidene fluoride (VDF) were examined as well as other fluorinated and non-fluorinated binder materials. The heat evolved by the reactions of these materials was compared to that arising from other exothermic phenomena occurring in charged anodes at elevated temperatures. A matrix of anode material combinations was designed to investigate the role of carbon structure, carbon surface area, state of charge, binder level and presence of electrolyte. The temperature and magnitude of the exothermic reactions were measured up to 375°C and average enthalpy values were obtained over several duplicate samples to allow good quantitative comparison of the material reactions. The exothermic anode reactions were sensitive to the state of charge and presence of electrolyte. The magnitude of the reactions increased with increasing surface area of the carbon particles. However, similar reaction enthalpies were seen for all binder materials and binder levels.
This work studied the thermal management of lithium ion batteries both numerically and experimentally. Numerically, a two dimensional CFD (computational fluid dynamics) model has been developed to perform detailed simulations of the thermal management issues within a battery pack cooled by air. Experimentally, systematic tests were performed to provide datasets to validate the CFD model. The main components in the experimental facility included a multi-cell battery pack and a wind tunnel. The wind tunnel facility generated well-controlled cooling air flow with velocity up to 30 m s−1 (∼67 miles per hour). So that the study can be performed under flow conditions directly relevant to practice. The major contributions from this combined numerical-experimental study are threefold. First, the CFD model has been shown to capture the dynamics of the cooling of battery modules consisting of multiple battery cells, including temperature non-uniformity among cells. Second, the CFD simulations have been compared directly against experimental data to quantify the accuracy and validity of the CFD models. Third, based on the validated CFD models, a reduced-order model is developed to predict the maximum cell temperature in the battery module. The accuracy and simplicity of the reduced-order model makes it promising for in situ monitoring and control purposes.
ABSTRACT Background Endodontics as a discipline has offered patients the opportunity to maintain their natural teeth. As the population expands and ages, the demand for endodontic therapy can be expected to increase as patients seek dental options to keep their teeth for a lifetime. Clinical Implications New materials, techniques and instruments are entering the marketplace to assist dentists in providing patients with more predictable and reliable endodontic treatment. In addition, these new systems make the delivery of endodontic services more efficient. This article describes these advances in endodontic treatment for dentists interested in incorporating these advances into their clinical practice.
A new type composite nonwoven separator has been developed by combining a polyacrylonitrile (PAN) nano-fiber nonwoven and ceramic containing polyolefin nonwoven. The physical, electrochemical and thermal properties of the separator were investigated. The separator has mean pore size of about 0.8μm as well as narrow pore-size distribution. Besides, the separator possesses higher porosity and air permeability than a conventional microporous membrane separator. The separator showed tensile strength of 46N5cm−1 at 10% elongation. Any internal short circuit was not observed for cells with the separator during charge–discharge test, and the cells showed stable cycling performance. Moreover, the cells showed better rate capabilities than cells with the conventional one. On a hot oven test at 150°C, the composite nonwoven separator showed better thermal stability than the conventional one. In addition, internal short circuit by thermal shrinkage of separator was not observed for a cell with the separator at 150°C for 1h.
Self reports of everyday functioning on the part of people with schizophrenia have been found to be poorly correlated with the reports of other informants and with their own performance of tests of cognition and functional abilities. However, it is not clear which informants are best for providing accurate reports of everyday functioning. This study examined the convergence between self-reports on the part of people with schizophrenia (n=193), whose real-world functioning was rated by a friend or relative (n=154), or a high contact clinician (n=39) across 6 functional status rating scales. In addition, correlations between these reports and patient's performance on neuropsychological tests and a performance-based measure of functional capacity were also calculated. For convergence between raters, friend or relative informants and patient reports were significantly correlated for 4/6 rating scales. For the smaller sample of clinician informants, the correlations were significant on 2/6 scales. In the analyses of convergence between patient performance scores and functioning ratings, only 1/12 correlations between patient report and performance were significant, while friend or relative reports also were only correlated with performance on one rating scale. In contrast, clinician reports of functioning were correlated with patients' functional capacity performance on 4/6 rating scales and with neuropsychological test performance on 2/6. High contact clinicians appear to generate ratings of everyday functioning that are more closely linked to patients' ability scores than friend or relative informants. Later analyses will determine if there are differences between friend or relative informants.