batterydata/paper-abstracts huggingface dataset:
Co(OH)2 nanocone arrays are prepared by a facile hydrothermal synthesis method. The Co(OH)2 nanocones are single crystalline in nature and have an average diameter of about 200 nm. The pseudocapacitive behavior of the Co(OH)2 nanocone arrays is investigated by cyclic voltammograms (CV) and galvanostatic charge–discharge tests in 2 M KOH. As cathode for supercapacitor, the Co(OH)2 nanocone arrays exhibit a capacitance of 562 F g−1 at 2 A g−1 as well as rather good cycling stability. The enhanced supercapacitor performances are due to the porous array architecture providing fast ion and electron transfer, large reaction surface area and good strain accommodation.
Random data generators play an important role in computer science and engineering since they aim at simulating reality in IT systems. Software random data generators cannot be reliable enough for critical applications due to their intrinsic determinism, while hardware random data generators are difficult to integrate within applications and are not always affordable in all circumstances. We present an approach that makes use of entropic data sources to compute the random data generation task. In particular, our approach exploits the chaotic phenomena happening in the crowd. We extract these phenomena from social networks since they reflect the behavior of the crowd. We have implemented the approach in a database system, RandomDB, to show its efficiency and its flexibility over the competitor approaches. We used RandomDB by taking data from Twitter, Facebook and Flickr. The experiments show that these social networks are sources to generate reliable randomness and RandomDB a system that can be used for the task. Hopefully, our experience will drive the development of a series of applications that reuse the same data in several and different scenarios.
Anatase TiO2 nanowires containing minor TiO2(B) phase were prepared by a hydrothermal chemical reaction followed by the post-heat treatment at 400°C. The phase structure and morphology were analyzed by X-ray diffraction, Raman scattering, transmission electron microscope, and field-emission scanning electron microscopy. The electrochemical properties were investigated by employing constant current discharge–charge test, cyclic voltammetry, and electrochemical impedance techniques. These nanowires exhibited high rate capacity of 280mAhg−1 even after 40 cycles, and the coulombic efficiency was approximately 98%, indicating excellent cycling stability and reversibility. The electrochemical impedance spectra showed a stable kinetic process of the electrode reaction. These results indicated that the TiO2 nanowires have promising application for high energy density lithium-ion batteries.
Disordered hard carbon/graphene (C@G) hybrid is successfully designed and prepared for the first time through a facile route. SEM and TEM analyses show the uniform distribution of carbon microspheres and carbon layers on the surface of graphene. As an anode material of sodium-ion batteries, such a construction could ensure an effective contact area with the electrolyte and offer massive active sites. It displays a stable sodium storage capacity of ∼300 mAh g−1 after 100 cycles at a current density of 50 mA g−1 and exhibits an excellent rate performance. The unique structure and advantageous synergistic effect between disordered hard carbon and graphene make a significant contribution to the good Na+ insertion/extraction property.
Aqueous sodium-ion battery is attractive, because of the low cost and the high safety. However, since the electrochemical window of the aqueous electrolyte is narrow, there have been few reports concerning the optimum cathode materials for use in aqueous sodium-ion batteries up to now. This work focused on Na2FeP2O7 as a cathode material for a novel aqueous sodium-ion battery, and investigated the electrolyte dependence of the performances of a Na2FeP2O7//NaTi2(PO4)3 full-cell. The battery performances such as the rate capability and cyclability of Na2FeP2O7//NaTi2(PO4)3 full-cell with 2 M Na2SO4 or 4 M NaClO4 aqueous electrolyte were better than that with the non-aqueous electrolyte. However, a Na2FeP2O7//NaTi2(PO4)3 full-cell with 4 M NaNO3 aqueous electrolyte exhibited a large irreversible capacity due to the corrosive side reaction.
Two important properties of absorptive glass mat (AGM) separators are examined in order to design optimum separators for advanced valve-regulated lead–acid (VRLA) batteries. Acid stratification in the separator depends on its micro-glass-fibre diameter, and it is found that the extent of stratification can be estimated based on hydrodynamics theory. Decreasing the plate-group pressure of the separator in the wetted state is also investigated, and it is considered that the phenomenon is caused by the balance between the fibre strength and the surface tension of acid solution. Given these results, the way to design AGM separators according to purpose has been identified. Accordingly, a new AGM separator has been developed and this functions both to suppress stratification and to maintain plate-group pressure.
Fuel cell vehicles, as a substitute for internal-combustion-engine vehicles, have become a research hotspot for most automobile manufacturers all over the world. Fuel cell systems have disadvantages, such as high cost, slow response and no regenerative energy recovery during braking; hybridization can be a solution to these drawbacks. This paper presents a fuel cell hybrid bus which is equipped with a fuel cell system and two energy storage devices, i.e., a battery and an ultracapacitor. An energy management strategy based on fuzzy logic, which is employed to control the power flow of the vehicular power train, is described. This strategy is capable of determining the desired output power of the fuel cell system, battery and ultracapacitor according to the propulsion power and recuperated braking power. Some tests to verify the strategy were developed, and the results of the tests show the effectiveness of the proposed energy management strategy and the good performance of the fuel cell hybrid bus.
Wind has come to be considered as an attractive energy source due to its abundance, ubiquity, and sustainability in nature. When an energy harvester driven by wind is miniaturized with high-power and robustness, it can be useful for self-powered systems of mobile electronic devices. In this work, a vertically stacked triboelectric nanogenerator (VS-TENG) is investigated. When wind is introduced into the air gap of the VS-TENG, a thin and flexible polymer membrane repeatedly comes in contact with and separates from upper and lower electrodes. This thin device structure makes the VS-TENG suitable for vertical stacking without bulky volume. Vertical stacking not only provides multiplied output power via parallel stacking but also enables utilization of bi-directional wind by a cross stack.
The capacity degradation of the lithium ion battery should be well predicted during battery system design. Therefore, high-fidelity capacity degradation models that are suitable for the task of capacity prediction are required. This paper proposes a novel capacity degradation model that can simulate the degradation dynamics under varying working conditions for large-format lithium ion batteries. The degradation model is built based on a mechanistic and prognostic model (MPM) whose parameters are closely linked with the degradation mechanisms of lithium ion batteries. Chemical kinetics was set to drive the parameters of the MPM to change as capacity degradation continues. With the dynamic parameters of the MPM, the capacity predicted by the degradation model decreases as the cycle continues. Accelerated aging tests were conducted on three types of commercial lithium ion batteries to calibrate the capacity degradation model. The good fit with the experimental data indicates that the model can capture the degradation mechanisms well for different types of commercial lithium ion batteries. Furthermore, the calibrated model can be used to (1) evaluate the longevity of a battery system under a specific working load and (2) predict the evolution of cell variations within a battery pack when different cell works at different conditions. Correlated applications are discussed using the calibrated degradation model.
Cognitive impairment is a core feature of schizophrenia. Previous studies have indicated that exposure to neurotropic infectious agents such as Herpes Simplex Virus type 1 may contribute to cognitive deficits and neuroanatomical abnormalities in individuals with schizophrenia. We examined the association between exposure to neurotropic infectious agents and cognitive function in 1308 participants in the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) trial. This sample included all of the individuals in the CATIE trial for whom baseline blood samples were available. Cognition was evaluated at baseline by a test battery which yielded composite scores in the domains of processing speed, verbal memory, vigilance, reasoning, and working memory as well as a summary neurocognitive score. Solid phase immunoassay techniques were used to measure IgG class antibodies to Herpes Simplex Virus type 1 (HSV-1), Herpes Simplex Virus type 2 (HSV-2), Cytomegalovirus (CMV), and to Toxoplasma gondii (T gondii) in the sera of the study individuals. We found a significant association between the neurocognitive summary score and antibodies to HSV-1 but not to HSV-2, CMV, or T. gondii. There was also a significant association between HSV-1 exposure and the Verbal Memory, Vigilance, and Processing Speed composite scores. HSV-1 may modulate the neurocognitive function of individuals with schizophrenia through its ability to establish latency in the central nervous system and undergo periodic reactivation. A better understanding of the role of HSV-1 may lead to better methods of treatment for the cognitive impairments associated with schizophrenia.
Inhibiting properties of two kinds of surfactant, cationic cetyl trimethyl ammonium bromide (CTAB) and anionic sodium dodecyl benzene sulfonate (SDBS) with three different concentrations, in relation to zinc passivation have been explained in the primary Zn/MnO2 alkaline batteries. Discharge performance of alkaline cell affected by utilization of surfactant in anodic gel. Therefore, electrochemical properties of anodic zinc have been investigated by cyclic voltammetry, X-ray diffraction, scanning electron microscopy (SEM) and ac impedance techniques. The results show that alkaline cell with 0.01gl−1 of anionic SDBS surfactant decreased effectively the rate of zinc-passivation reaction. Also, it exhibited ZnO morphology with smaller grain size, causing longer service life gradually, step by step. By contrast, 0.01gl−1 of cationic CTAB surfactant remarkably increased the rate of charge transfer and mass transfer in the alkaline cell, on impedance data. Consequently, more volumetric energy density obtained in first discharge step due to more activated zinc surface area. Furthermore, scanning electron microscopy (SEM) has shown non-homogenous morphology with coarse ZnO growth. This was confirmed by X-ray diffractograms showing the highest intensity of ZnO peak. When the concentration of these surfactants (CTAB and SDBS) increased, more inhibiting properties were observed. This property was stronger in the cells with anionic SDBS surfactant. Our study is mainly focused on the understanding the mechanism of zinc passivation in the presence of the surfactants.
Persistent luminescence is a singular property of some materials which are able to store the excitation or light irradiation energy at intrinsic traps or defects before slowly emitting lower energy photons within several hours. When such compounds are prepared as nanoparticles (NPs), when functionalization is realized to get colloidal materials well dispersed in aqueous medium, such nanoprobes open the use of the persistent luminescence for bioimaging applications. Recently, the numbers of in vivo applications increased with new modalities and new expectations. In this review, we focused our attention on the ZnGa2O4:Cr (ZGO:Cr) nanoparticles. When ZnGa2O4 (ZGO), a normal spinel is doped with Cr3+ ions, a high brightness persistent luminescence material with an emission spectrum perfectly matching the transparency window of living tissues is obtained. It allows in vivo mouse imaging with an excellent target-to-background ratio. One interesting characteristic of ZGO:Cr lies in the fact that its persistent luminescence can be excited with orange/red light, well below its band gap energy and in the transparency window of living tissues. This important property allows multiple re-excitations to perform long term bioimaging. Antisite defects of the direct spinel structure are assumed to provide shallow traps which store the excitation light. Charge release by room temperature thermal excitation and recombination center, here trivalent chromium, are responsible for the persistent luminescence. Following a primary excitation (UV or visible), one also observed that trapped charges can be released under 977nm light stimulation for several spinel gallate materials, therefore increasing the modalities and the materials envisioned for in vivo excitation of these NPs.
The reduction mechanism of ethylene sulfite (ES) in propylene carbonate (PC) based electrolyte is investigated using density functional theory in gas phase. Based on the electron affinity energy and lowest unoccupied molecular orbital (LUMO) energy, it can be known that free ES is reduced most easily compared with ES-Li+ and ES-Li+-PC, generating SO2 and propanal. However, the binding energy of ES-Li+ and ES-Li+-PC is quite negative, indicating that both of them are more possible in electrolyte solution than the free ES. The reductive decomposition products of ES-Li+ and ES-Li+-PC are OSO2Li, OSO2Li-R and ethylene. OSO2Li and OSO2Li-R are the main compositions of the solid electrolyte interphase film on the anode of lithium ion battery, which inhibits the reductive decomposition of PC. These calculations provide a detailed explanation on the experimental phenomena.
This study uses rotating ring-disk electrode (RRDE) and linear sweep voltammetry (LSV) to characterize oxygen reduction kinetics in alkaline solution on platinum electrodes with various thickness of hydrous oxide (oxyhydroxy) film. Oxyhydroxy films are created on Pt electrodes by pretreatment in 1.0moldm−3 KOH at a constant voltage. The pretreatment voltage ranges from −1.2 to 1.0V and is increased stepwise before each new experimental run to produce seven discreet films. LSV plots show oxyhydroxy film thickness strongly inhibits oxygen reduction and is inversely proportional to RRDE oxygen reduction current I D for LSV voltages E D from −0.1 to −0.46V, but this trend reverses at E D more negative than −0.46V so that the worst-performing electrode becomes the best. However, this improvement disappears at around −0.8V, suggesting this change involves a negatively charged ion, possibly embedded into the metal in the top few atomic layers either interstitially or substitutionally. The 1.0V-pretreated electrode in the E D range from −0.46 to −0.9V of highest oxygen reduction current also exhibits the lowest hydrogen peroxide production, with zero H2O2 produced at −0.6V, indicating the brief presence of the oxyhydroxy film on the Pt surface has strong lingering effects. The post-oxyhydroxy Pt surface is very different than the native Pt for oxygen reduction pathway and efficiency. Reaction order with respect to oxygen is close to 1. The rate constants of the direct O2 to H2O electroreduction reaction are increased with decreasing the potential from −0.2 to −0.6V, but the O2 to H2O2 electroreduction is contrary to this expectation. The rate constants of H2O2 decomposition on the oxyhydroxy film-covered Pt electrode are near constant around 1×10−4 cms−1 at E D >−0.5V.
Ethnopharmacological relevance Gumiganghwal-tang (GGT, known as Kumi-Kyokatsu-to in Japanese) is a traditional herbal prescription made from nine different herbs that is used for the treatment of the common cold, pain, and inflammatory diseases. Aim of the study This study evaluated the potential genotoxicity of an aqueous GGT extract using three standard battery of tests as part of a safety evaluation. Materials and methods We prepared GGT using a water extraction method and subsequently extracted six compounds from GGT by high performance liquid chromatography. GGT extract genotoxicity was assayed using three standard tests including the in vitro bacterial reverse mutation test, the in vitro chromosomal aberration test with Chinese hamster lung cells, and the in vivo micronucleus test using ICR mouse bone marrow recommended by the Korean Food and Drug Administration. Results The bacterial reverse mutation assay showed that GGT extract doses ranging from 333.3 up to 5000mg/plate induced a greater than 2-fold increase in the number of revertant TA1537 strain colonies exhibiting metabolic activation (with S-9 mix), when compared with the vehicle control. The chromosomal aberration test showed that GGT extract induced an increase in the number of chromosomal aberrations after treatment for 6h with the S-9 mix and 22h without the S-9 mix, when compared with vehicle control. In contrast, the micronucleus test showed that GGT extract did not significantly increase the number of micronucleated polychromatic erythrocytes (MNPCEs) in ICR mouse bone marrow. Conclusions Based on these results, it was concluded that GGT extract acted as a genotoxic material in our experimental conditions. We did not identify the compounds responsible for the induction of genotoxic effects, but it was significant that we provided a basic genotoxicity profile for GGT.
This paper presents an experimental investigation of CuO–oleic acid nanofluids as a new phase change material for the thermal energy storage of cooling systems. This paper also presents the preparation of nanofluids, which is solid–liquid composite material consisting of CuO nanoparticles with sizes ranging from 1 to 80nm dispersed in oleic acid. CuO nanoparticles were synthesized by precipitation method. Sedimentation photograph and particle size distribution of nanofluids prepared by two step method, illustrate the stability and evenness of dispersion. Thermophysical properties of CuO–oleic acid nanofluids such as phase change temperatures and latent heats were analysed by DSC measurements. Using thermal diffusivity analyser, enhancement of thermal conductivity of nanofluids with different mass fraction of CuO nanoparticles was found to be higher than oleic acid. Based on the test results, complete solidification times of nanofluids with 0.5, 1.0, 1.5 and 2wt% of CuO nanoparticles could be saved by 10.71, 16.07, 19.64 and 27.67% respectively, than the base fluid. Similarly, complete melting times of nanofluids with 0.5, 1.0, 1.5 and 2wt% of CuO nanoparticles could be saved by 7.14, 14.28, 25 and 28.57% respectively, than the base fluid. Thus, CuO–oleic acid nanofluids can be recommended as better PCM for cooling thermal energy storage applications.
The potential for supercapacitors to expand the safe operating window of a wind-powered reverse osmosis membrane (wind-membrane) system by buffering short term wind fluctuations and intermittency was investigated. Experiments were carried out using synthetic brackish water (5500 mg/L NaCl) with three sizes of supercapacitor bank to determine the effect of increasing the short term energy storage capacity. The wind speed ranged from 4 to 14 m/s for both intermittency and fluctuation experiments, with periods of no-power of 0.5–5 min and 15 s–20 min cycles, respectively. When the wind-membrane system was powered by the supercapacitors, wind speeds of >7 m/s were required for the supercapacitor bank state of charge (SOC) to increase, otherwise they discharged gradually to a threshold value dictated by the control electronics. While the SOC of the supercapacitors was above this threshold value, the operation of the wind-membrane system was as under steady-state conditions, thereby achieving independence of the wind speed fluctuations or intermittency. This resulted in an 85% increase in the average flux and 40% increase in permeate quality under fluctuations when compared to the system performance without supercapacitors. It is concluded that supercapacitors are an effective method of buffering short term wind speed fluctuations to provide steady-state performance and improve the productivity of renewable energy membrane systems.
The chemical preparation of high purity potassium and barium ferrates for alkaline electrochemical storage are presented. The synthesized salts are used to demonstrate a variety of high capacity super-iron (Zn anode) alkaline AAA cell configurations which utilize these Fe(V) salts. Results of 500 days, full stability, of the synthesized K2FeO4 are presented. Synthetic pathways yielding 80–100g of 96.5–99.5% pure K2FeO4 and BaFeO4 are presented, and the products of these syntheses are demonstrated to provide a high energy electrochemical discharge in a variety of AAA alkaline cells. BaFeO4 super-iron alkaline AAA cells provide over 0.8Wh during 2.8Ω discharge, yielding over 200% higher capacity than conventional alkaline batteries. The barium super-iron cell configurations studied provide higher capacity than the potassium super-iron alkaline cell configurations studied.
There is a great interest in developing efficient electrode materials for sodium-ion batteries, which are currently being projected as a promising alternative to lithium-ion batteries. Here we report the synthesis of a sodium-ion battery cathode material, Na0.5Ni0.25Mn0.75O2, through a sol-gel method. The as-synthesized layered Na0.5Ni0.25Mn0.75O2 material exhibits a layered P2-type structure, and shows excellent electrochemical properties when studied as a cathode for sodium-ion batteries, with a specific discharge capacity of 210mAhg−1 and a good capacity retention of 80% at 50th cycle in the voltage range from 1.5 to 4.4V at 0.1C. The layered Na0.5Ni0.25Mn0.75O2 material also exhibits good cycling stability with remarkably smooth and flat charge-discharge profiles at a high voltage of 4.1V vs Na. The overall electrochemical performance of layered Na0.5Ni0.25Mn0.75O2 is quite promising, and hence the present study will greatly contribute to the on-going search for advanced and efficient electrodes for sodium-ion batteries.
Herein, pomegranate-like Silicon/Nitrogen-doped graphene microspheres (PSNGM) constructed by individual Si nanoparticle core wrapped by flexible nitrogen-doped reduced graphene oxide nanosheets (NG) have been synthesized through a facile and industrially large-scale spray drying approach. The PSNGM anode delivers excellent electrochemical performance: the reversible specific capacity at 100mAg−1 remains as large as 1141.6mAhg−1 after 150 cycles, with a high capacity retention of 96.1% from 2nd to 150th cycle; the capacity at 100mAg−1 can recover back to ∼1340mAhg−1 even after suffering a high current density of 5000mAg−1. The excellent performance is attributed to the unique pomegranate-like structure, nanoparticlization of Si and nitrogen doping of graphene: the pomegranate-like skeleton forms a highly conductive network, in which each Si nanoparticle is homogenously wrapped by flexible and conductive N-doped graphene nanosheets; flexible porous pomegranate-like structure can effectively accommodate the large volume variation during cycling; the N-doped graphene matrix guarantees its high conductivity for better electron and ion kinetics. The presented spray drying strategy is facile, low-cost and effective for large-scale industrial production of Si/graphene composite anode, and it can also be extended to fabricating other high-capacity electrode materials with low conductivities and large volume expansion.