batterydata/paper-abstracts huggingface dataset:
Background At our institution, the total artificial heart (TAH) Jarvik-7 (CardioWest) has been used since 1986 as a bridge to transplantation for the most severely ill patients with terminal congestive heart failure. Methods: Between 1986 and 2001, 127 patients (108 males, mean age 38 ± 13) were bridged to transplantation with the Jarvik-7 TAH. All were in terminal biventricular failure despite high-dose inotropic support. Nine patients had a body surface area (BSA) of <1.6 m2. In Group I patients (78%), the etiology of cardiac failure was dilated cardiomyopathy, either idiopathic (n = 60) or ischemic (n = 38). The other 29 patients (Group II) had disease of miscellaneous origin. We analyzed our experience with regard to 3 time periods: 1986 to 1992 (n = 63); 1993 to 1997 (n = 36); and 1998 to 2001 (n = 33). Results Although Group II patients represented 30% of indications before 1992, they comprised only 15% during the 2 subsequent periods. Duration of support for transplant patients increased dramatically after 1997, reaching 2 months for the most recent period (5 to 271 days). In Group I, the percentage of transplanted patients increased from 43% before 1993 to 55% between 1993 and 1997, and reached 74% thereafter. The major cause of death was multiorgan failure (67%). The clinical thromboembolic event rate was particularly low with no instance of cerebrovascular accident and 2 transient ischemic attacks. Total bleeding complication rate was 26%, including 2 deaths related to intractable hemorrhage and 2 others related to atrial tamponade. The cumulative experience was 3,606 total implant days with only 1 instance of mechanical dysfunction. Conclusions TAH is a safe and efficient bridge for patients with terminal congestive heart failure awaiting cardiac transplantation.
In the present study, α-NaCuPO4 compound was prepared by solid-state reaction method and characterized by X-ray powder diffraction and infrared spectroscopy. The AC electrical conductivity and dielectric relaxation properties of this compound have been investigated by means of impedance spectroscopy measurements over a wide range of frequencies and temperatures 209 Hz–1 MHz and 598–708 K, respectively. Both impedance and modulus analysis exhibit the grain and grain boundary contribution in the electrical response of the sample. It was found that the data of the AC measurements follow the overlapping large polaron tunneling model and the model’s parameters were determined.
The secondary lithium battery using lithium metal as a negative electrode has attracted more attention due to its extremely high theoretical specific energy. During the charge and discharge cycle, lithium ions are reduced and nonuniformly deposit on the surface of the lithium electrode, which leads to the formation and growth of lithium dendrites. The growth of lithium dendrites can pierce through the separator and causes internal short circuit of the battery as well as battery catastrophes like thermal runaway. The lithium dendrite growth process is complicated and can be affected by various factors. In this paper, a phase field model is developed to simulate the growth process of lithium dendrites, and the effects of anisotropic strength, applied voltage and microstructure of solid electrolyte interphase (SEI) on the growth of lithium dendrites are considered and investigated. The geometric model of solid electrolyte interphase (SEI) is established by numerical reconstruction method. Then, the growth process of lithium dendrites in solid electrolyte interphase (SEI) is investigated, which provides insight on revealing the growth mechanism of lithium dendrites.
Human activity recognition (HAR) has become a vibrant research field over the last decade, especially because of the spread of electronic devices like mobile phones, smart cell phones and video cameras in our daily lives. In addition, the progress of deep learning and other algorithms has made it possible for researchers to use HAR in many fields including sports, health and well being. HAR is, for example, one of the most promising resources for helping older people with the support of their cognitive and physical function through day-to-day activities. This study focuses on the key role machine learning plays in the development of HAR applications. While numerous HAR surveys and review articles have previously been carried out, the main/overall HAR issue was not taken into account, and these studies concentrate only on specific HAR topics. A detailed review paper covering major HAR topics is therefore essential. This study analyses the most up-to-date studies on HAR in recent years and provides a classification of HAR methodology and demonstrates advantages and disadvantages for each group of methods. This paper finally addresses many problems in the current HAR subject and provides recommendations for potential study.
Energy storage now a days is becoming an imperative part of renewable energy. With the massive growth of renewable energy sources, energy storage can play a substantial role in renewable energy integration in India. It is beneficial for entire supply chain mainly due to enhanced electric power quality, dependability and better grid stability. Thus, lowering renewable energy intermittency, with increased user-friendliness and accessibility of electrical energy in remote places and reduction in harmful emissions. This paper Part-I of two papers primarily presents an overview of the selected energy storage technologies like Pumped hydro energy storage, Compressed air energy storage, Battery energy storage, Flywheel, Supercapacitors, Hydrogen energy storage, Superconducting magnetic energy storage, and Thermal energy storage. It highlights driving factors for growing energy storage in India. A comprehensive comparison of various technical characteristics and features of these technologies is also discussed.
We study the effects of external magnetic fields on the precision of parameter estimation with thermal entanglement of two spins in XX model, in the presence of Dzyaloshinskii–Moriya (DM) interaction. Although DM interaction excites but external magnetic fields usually decrease quantum mechanical properties of spin systems such as entanglement, we show by calculating the quantum Fisher information that not only DM interaction D but also homogeneous magnetic field B can increase the precision of parameter estimation, overwhelming the destructive effects of thermalization. We also show that inhomogeneous magnetic field b increases (decreases) the precision of parameter estimation if it is less (greater) than D.
Electrodes comprising thermally deposited Pt, PtRu and PtRuW on titanium mesh were evaluated for the oxidation of ethylene glycol in acidic electrolyte. The electrodes were characterised using cyclic voltammetry, scanning electron microscopy and X-ray diffraction and the effect of reactant concentration and temperature were examined. Single fuel cell tests employing the titanium mesh anode with the PtRuW catalyst showed better performance than that of the PtRu catalyst. A peak power density of 15 mW cm−2 was obtained at a temperature of 90 °C with 1.0 M ethylene glycol solution. The performance of the catalysed PtRu mesh electrode was comparable to that of a commercial, alcohol oxidation, PtRu carbon supported catalyst.
Microbundles of carbon nanostructures (CNS) have been used to fabricate binder-free LiFePO4 electrodes. The inherent ability of CNS to form a nano-porous structure after the reassembly of CNS dispersion from solution to film-forming state is used to encapsulate the LiFePO4 particles. The LiFePO4/CNS electrode shows high electrical conductivity of 9.1 S cm−1 compared to 0.4 S cm −1 for conventional LiFePO4/carbon electrodes. LiFePO4/CNS flexible electrodes shows specific discharge capacity of 56 mAh g−1, 41 mAh g−1 and 37 mAh g−1 at 1C, 3C and 5C rates respectively. These specific discharge capacities are higher than that of conventional LiFePO4/carbon electrodes i.e. 40 mAh g−1, 13 mAh g−1 and 0.01 mAh g−1 at 1C, 3C and 5C rates respectively. Improvements in the specific discharge capacity at high C-rate is attributed to highly conductive pathways between the CNS and LiFePO4 particles, which assist fast transport of electrons at the electrode/CNS interfaces and between the electrode particles for rapid electrochemical reactions.
Low-temperature performance of LiBF4 and LiPF6-based electrolytes in LiFePO4/Li and graphite/Li half cells was investigated. In the temperature range from 0°C to −40°C, electrochemical impedance spectroscopy (EIS) results show that the charge-transfer resistance (R ct) of graphite/Li cell decreases, the R ct of LiFePO4/Li cell increases, and sum resistance of LiFePO4/Li and graphite/Li cell decreases when replacing LiPF6 with LiBF4. In the temperature range from 25°C to −40°C, energy barrier (W) for Li-ion jump at the solid electrolyte interface (SEI) alters slightly from 16.04kJ/mol to 13.60kJ/mol in LiFePO4/Li cells, but declines greatly from 46.47kJ/mol to 19.81kJ/mol in graphite/Li cells when using LiBF4 instead of LiPF6, meanwhile, activation energy (ΔG) of electrode reaction is approximately the same (∼60kJ/mol). The above results indicate that the ionic conductivity is the main limiting factor for low-temperature performance of electrolytes in LiFePO4/Li cell, while factors related with electrolyte-interface are more crucial in graphite/Li cell than in LiFePO4/Li cell.
An optimal design of a three-component hybrid fuel cell electric vehicle comprised of fuel cells, battery, and supercapacitors is presented. First, the benefits of using this hybrid combination are analyzed, and then the article describes an active power-flow control strategy from each energy source based on optimal control theory to meet the demand of different vehicle loads while optimizing total energy cost, battery life and other possible objectives at the same time. A cost function that minimizes the square error between the desired variable settings and the current sensed values is developed. A gain sequence developed compels the choice of power drawn from all devices to follow an optimal path, which makes trade-offs among different targets and minimizes the total energy spent. A new method is introduced to make the global optimization into a real-time based control. A model is also presented to simulate the individual energy storage systems and compare this invention to existing control strategies, the simulation results show that the total energy spent is well saved over the long driving cycles, also the fuel cell and batteries are kept operating in a healthy way.
Porous flower-like α-Fe2O3 nanostructures have been synthesized by ethylene glycol mediated iron alkoxide as an intermediate and studied as an anode material of Li-ion battery. The iron alkoxide precursor is heated at different temperatures from 300 to 700°C. The α-Fe2O3 samples possess porosity and high surface area. There is a decrease in pore volume as well as surface area by increasing the preparation temperature. The reversible cycling properties of the α-Fe2O3 nanostructures have been evaluated by cyclic voltammetry, galvanostatic charge discharge cycling, and galvanostatic intermittent titration measurements at ambient temperature. The initial discharge capacity values of 1063, 1168, 1183, 1152 and 968mAhg−1 at a specific current of 50mAg−1 are obtained for the samples prepared at 300, 400, 500, 600 and 700°C, respectively. The samples prepared at 500 and 600°C exhibit good cycling performance with high rate capability. The high rate capacity is attributed to porous nature of the materials. As the iron oxides are inexpensive and environmental friendly, the α-Fe2O3 has potential application as anode material for rechargeable Li batteries.
Nano SiO2–P(VDF-HFP) composite porous membranes were prepared as the matrix of porous polymer electrolytes through in situ composite method based on hydrolysis of tetraethoxysilane and phase inversion. SEM, TEM, DSC and AC impedance analysis were carried out. It is found that the in situ prepared nano silica was homogeneously dispersed in the polymeric matrix, enhanced conductivity and electrochemical stability of porous polymer electrolytes, and improved the stability of the electrolytes against lithium metal electrodes. The in situ composite method was found to be much better than the direct composite method in lowering the interfacial resistance between electrolyte and lithium metal electrode. Moreover, cycle test of lithium batteries using lithium metal as anode and sulfur composite material as cathode showed that the electrolyte based on in situ composite of silica presented stable charge–discharge behavior and little capacity loss of battery.
The fabrication process of Li-ion battery electrodes plays a prominent role in the microstructure and corresponding cell performance. Here, a mesoscale particle dynamics simulation is developed to relate the manufacturing process of a cathode containing Toda NCM-523 active material to physical and structural properties of the dried film. Particle interactions are simulated with shifted-force Lennard-Jones and granular Hertzian functions. LAMMPS, a freely available particle simulator, is used to generate particle trajectories and resulting predicted properties. To make simulations of the full film thickness feasible, the carbon binder domain (CBD) is approximated with μm-scale particles, each representing about 1000 carbon black particles and associated binder. Metrics for model parameterization and validation are measured experimentally and include the following: slurry viscosity, elasticity of the dried film, shrinkage ratio during drying, volume fraction of phases, slurry and dried film densities, and microstructure cross sections. Simulation results are in substantial agreement with experiment, showing that the simulations reasonably reproduce the relevant physics of particle arrangement during fabrication.
A detailed investigation of the effects on the microstructure and electrochemical properties of lead–calcium–tin–aluminum alloys of adding tin and calcium was undertaken. Cyclic voltammetry (CV), linear sweep voltammetry (LSV), and electrochemical impedance spectroscopy (EIS) were used to study the anode electrochemical behavior (such as the growth of lead dioxide, a passive film and the evolution of oxygen) of the lead grid alloy in sulfuric acid solution. The structure and corrosion morphology of the lead alloy were observed and analyzed using a polarizing microscope, scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). The experimental results show that the grains gradually became smaller as the content of calcium increased, and the content of tin decreased, in the alloy. The size and shape of grains were related to the ratio of tin to calcium content in the alloys. The linear sweep voltammetry and AC impedance measurements suggested that the preferred ratio of tin to calcium content, r, is between 9 and 15, and the optimum range of tin content in the alloys is 0.8–1.1%.
Objective: To find out whether 14–16-year-old pupils with visual perception disabilities have atypical EEG activation patterns during visual discrimination. Methods: EEG correlation indices (EEGCIs), based on the waveform characteristics of two EEG signals, were used as measures of slow joint activation of cortical regions during visual discrimination in pupils with visual perception disabilities. Results: During visual discrimination low EEGCIs were seen between the left temporal and both parieto-occipital EEG channels in pupils with visual perception disabilities and in pupils with a poor occupational outcome. The pupils with low performance intelligence and those with difficulties in the visual discrimination task had low EEGCIs within the left hemisphere. The left hemispheric dominance of the findings is suggested to reflect the psychophysiology of the task since visual discrimination demands attention to details (local processing) and is thus supposed to be more strongly represented in the left hemisphere. Conclusions: During visual discrimination, low EEGCIs were seen in the posterior and left hemispheric regions of pupils with disabilities in visual perception and visual discrimination and with a poor occupational outcome. Significance: Low EEGCIs in posterior and left hemispheric regions during visual discrimination can to some extent be seen as neurophysiological markers for visual perception disabilities and a poor occupational outcome and imply an increased need for adjustment of the educational curriculum and a need for occupational guidance.
The surface-modified ZnO by Sn6O4(OH)4 was prepared by a simple hydrolyzation process and the influence of Sn6O4(OH)4 on electrochemical performance of ZnO was investigated by charge/discharge cycling test, slow rate cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Compared with the unmodified ZnO, the Sn6O4(OH)4-modified ZnO showed improved electrochemical properties, such as superior electrochemical cycle stability, higher discharge capacity and utilization ratio. The surface modification could suppress the dissolution of ZnO in the alkaline electrolyte and maintain the electrochemical activity of ZnO. When the Sn6O4(OH)4 content reached 27wt.%, the discharge capacity of the modified ZnO hardly declined over 80 cycling test, the average utilization ratio could reach 98.5%, and the modified ZnO electrodes had no obvious weight loss after the cycling tests. However, the charge/discharge plateau voltage with the Sn6O4(OH)4-modified ZnO slightly decreased. For the modified ZnO electrodes, two anodic peaks occurred in the CV curves, and the charge transfer resistance increased from the EIS results, both of which were ascribed to the suppressive effect of surface modification on the electrochemical reactions.
In this Review, we discuss the state-of-the-art understanding of non-precious transition metal oxides that catalyze the oxygen reduction and evolution reactions. Understanding and mastering the kinetics of oxygen electrocatalysis is instrumental to making use of photosynthesis, advancing solar fuels, fuel cells, electrolyzers, and metal–air batteries. We first present key insights, assumptions and limitations of well-known activity descriptors and reaction mechanisms in the past four decades. The turnover frequency of crystalline oxides as promising catalysts is also put into perspective with amorphous oxides and photosystem II. Particular attention is paid to electronic structure parameters that can potentially govern the adsorbate binding strength and thus provide simple rationales and design principles to predict new catalyst chemistries with enhanced activity. We share new perspective synthesizing mechanism and electronic descriptors developed from both molecular orbital and solid state band structure principles. We conclude with an outlook on the opportunities in future research within this rapidly developing field.
The co-existence of two mechanisms, the surface chemisorption mechanism (SCM) and the tunnel storage mechanism (TSM), for the charge storage of MnO2 is investigated. Sample α-MnO2 whose tunnels (2×2) are almost vacant is synthesized by chemical co-precipitation technique. To verify whether the charge storage of as-prepared α-MnO2 involves the charges based on the SCM besides the TSM, Ba2+ and K+ are intercalated into the tunnels of α-MnO2 by refluxing and samples Ba-MnO2 and K-MnO2 are obtained, respectively. By powder X-ray diffraction, ICP and the extraction test, it is confirmed that Ba2+ and K+ occupy the tunnels and are difficult to remove. By electrochemical analyses, we have found that the charge storage of Ba-MnO2 and K-MnO2 basically depends on the SCM, as Ba2+ and K+ stabilized in the tunnels in advance block the intercalation/deintercalation of cations from the electrolyte. Thus, it can be inferred that for α-MnO2 two mechanisms contribute to the charge storage. The contributions of α-MnO2's mechanisms are estimated. The charges based on the TSM predominantly account for 81.2–89.9% of the total charges. The charges on the SCM may contribute to 7.9–16.8% and are not negligible. The charges from double-layer capacitance may be negligible, since it is only 1.1–4.1%.
Tupinambismerianae, is a large, omnivorous tegu lizard native to South America. Two populations of tegus are established in the state of Florida, USA, but impacts to native species are poorly documented. During summer 2013, we placed automated cameras overlooking one American alligator (Alligator mississippiensis) nest, which also contained a clutch of Florida red-bellied cooter (Pseudemys nelsoni) eggs, and one American crocodile (Crocodylus acutus) nest at a site in southeastern Florida where tegus are established. We documented tegu activity and predation on alligator and turtle eggs at the alligator nest, and tegu activity at the crocodile nest. Our finding that one of the first two crocodilian nests to be monitored was depredated by tegus suggests that tegus should be further evaluated as a threat to nesting reptiles in Florida.
A facile and scalable method is proposed to prepare microscale Li2S–C composite from Li2SO4 through carbon-thermal reduction, followed by a carbon coating process. Multi-solvent recrystallization was utilized to reduce the particle size of Li2SO4 to 2μm. This fine-grain Li2SO4 helps to shorten the particle size of reduction product from 10μm to 3μm. Using fine Li2SO4 also brings the benefit of greatly reducing the over potential during the initial charge process and increasing the kinetics for Li2S materials. Finally, the microscale Li2S–C composite prepared from fine Li2SO4 enables a stable capacity of 350 mAh g-1 at 0.2C, higher than that obtained using a cathode prepared from commercial Li2SO4.
Two kinds of cyano-containing imidazolium-based ionic liquid, 1-cyanopropyl-3-methylimidazolium-bis(trifluoromethanesulfonyl)imide (CpMI-TFSI) and 1-cyanomethyl-3-methylimidazolium-bis(trifluoromethanesulfonyl)imide (CmMI-TFSI), each of which contained 20wt% dissolved LiTFSI, were used as electrolytes for lithium secondary batteries. Compared with 1-ethyl-3-methylimidazolium-bis(trifluoromethane-sulfonyl)imide (EMI-TFSI) electrolyte, a reversible lithium deposition/dissolution on a stainless-steel working electrode was observed during CV measurements in these cyano-containing electrolytes, which indicated that a passivation layer (solid electrolyte interphase, SEI) was formed during potential scanning. The morphology of the working electrode with each electrolyte system was studied by SEM. Different dentrite forms were found on the electrodes with each electrolyte. The SEI that formed in CpMI-TFSI electrolyte showed the best passivating effect, while the deposited film formed in EMI-TFSI electrolyte showed no passivating effect. The chemical characteristics of the deposited films on the working electrodes were compared by XPS measurements. A component with a cyano group was found in SEIs in CpMI-TFSI and CmMI-TFSI electrolytes. The introduction of a cyano functional group suppressed the decomposition of electrolyte and improved the cathodic stability of the imidazolium-based ionic liquid. The reduction reaction route of imidazolium-based ionic liquid was considered to be different depending on whether or not the molecular structure contained a cyano functional group.