batterydata/paper-abstracts huggingface dataset:
3D porous and self-supported carbon hybrids are promising electrode materials for supercapacitor application attributed to their prominent properties such as binder-free electrode fabrication process, excellent electric conductivity and high power density etc. We present here a facile chemical vapor deposition method to fabricate a novel 3D flexible carbon hybrid nanostructure by growing a monolayer of nitrogen-doped carbon nanotubes on the skeleton of carbon foam (N-CNTs/CF) with Fe nanoparticle as catalyst. With such 3D porous, flexible and ultralight carbon nanostructure as binder-free electrode material, large surface area is available and fast ionic transport is facilitated. Moreover, the carbon-based network can provide excellent electronic conductivity. The electrochemical studies demonstrate that the supercapacitor constructed from the N-CNTs/CF hybrid exhibit high power density of 69.3 kW kg−1 and good stability with capacitance retention ration above 95% after cycled at 50 A g−1 for 5000 cycles. Therefore, the prepared porous N-CNTs/CF nanostructure is expected to be a type of excellent electrode material for electrical double layer capacitors.
Publisher Summary Constant-current charging is suitable when the discharged ampere hours taken out in the previous discharge cycle are known. It is necessary to monitor battery voltage or manually cut off the current at the end of charge to ensure a good service life for the battery. This type of charging requires regulation by means of an automatic timer. A normal recharge time of 20 h is recommended, whereby the constant-current charging rate is established to give an input of 110% of the previous output. There are many constant-current methods that permit satisfactory charging of sealed nickel-cadmium batteries. These methods differ in the length of time required to charge, the complexity of the circuits used and the various techniques for charging with maximum safety and reliability. Numerous charging systems mentioned are: normal rate charge, accelerated charge, and permanent or floating charge. In addition, two-step constant-current charging and constant-current charger designs for normal-rate charging is explained.
This research is purposed to compare cognitive functions between normal, ADHD and RD children. We selected three groups of 30 primary school students (normal, ADHD and RD) by available sampling. These groups were matched in age (8-9), IQ (96-116) and gender (Female and Male). We evaluated their brain cognitive functions by CAS (cognitive assessment system). The results showed that normal group's performances (Full Scale) were meaningfully better than ADHD and RD groups but, there were no meaningful differences between ADHD and RD subject groups. Also Normal children's performance in all four scales of PASS was meaningfully better than ADHD and RD children, but there was no meaningful difference between the average scores of four scales between ADHD and RD children.
This report focuses on the relatively new salt, lithium 4,5-dicyano-2-(trifluoromethyl)imidazolide (LiTDI), and its functionality together with a silicon based composite electrode in a half-cell lithium ion battery context. LiTDI is a promising alternative to the commonly used LiPF6 salt because it does not form HF which can decompose the oxide layer on Si. The formation of a solid electrolyte interphase (SEI) as well as the development of the active Si-particles are investigated during the first electrochemical lithiation and de-lithiation. Characterizations are carried out at different state of charge with scanning electron microscopy (SEM) as well as hard x-ray photoelectron spectroscopy (HAXPES) at two different photon energies. This enables a depth resolved picture of the reaction processes and gives an idea of the chemical buildup of the SEI. The SEI is formed by solvent and LiTDI decomposition products and its composition is similar to SEI formed by other carbonate based electrolytes. The LiTDI salt or its decomposition products are not in itself reactive towards the active Si-material and no unwanted side reactions occurs with the active Si-particles. Despite some decomposition of the LiTDI salt, it is a promising alternative for electrolytes aimed towards Si-based electrodes.
In this paper, we report a hierarchical structure Ni(OH)2 nanosheet array electrode by a directed liquid-phase approach, which consists of amorphous Ni(OH)2 interface layer and crystalline ultra-thin porous Ni(OH)2 nanosheets top layer. The testing results present that the maximum discharge capacity of 404.8mAhg−1 at lower rate of 1.4Ag−1 and the ultra-high capacity of 1714Fg−1 at super-high rate of 50Ag−1 without decay after 3000 cycles was obtained, respectively. This unique design provides excellent flexibility, long and stable cycle lifetimes, high energy and power densities simultaneously.
School climate is a broad, multi-dimensional construct that represents the quality and character of school life. Although many student-reported measures of school climate are available, less is known about the specific dimensions assessed by various measures. Using three comprehensive models of school climate as a guide, a systematic literature review of school climate measurement tools was conducted with two main questions. First, which dimensions are identified and measured in published studies of student-reported school climate? Second, what overlap in studies of student-reported school climate measures exist with the model dimensions? Results from the review of 18 school climate measures largely supported five dimensions (safety, relationships, teaching and learning, institutional environment, and school improvement processes) with at least three dimensions present within all reviewed measures. The discussion elaborates on the dimensions and sub-dimensions assessed in these tools, implications for failing to measure the sub-dimension of respect for diversity, and a new sub-dimension titled academic orientation that emerged from overlap in measurement tools.
We examined the dependence of stomatal conductance on physiological properties and meteorological variables using a Jarvis-type stomatal conductance model that included a function representing leaf chlorophyll concentration as a physiological property. We sampled the leaves of 5- and 10-year-old Quercus serrata trees. A low leaf chlorophyll concentration imposed a restriction on the opening capacity of the stomata. The stomatal conductance variability depended markedly on chlorophyll function; the degree of dependence was almost equal to that on solar radiation or vapour pressure deficit. The characteristics of stomatal conductance response to meteorological or physiological changes exhibited little seasonal variation (except relative to temperature). Stomatal conductance variability depended on the following meteorological parameters in decreasing order: radiation, vapour pressure deficit, leaf temperature, and soil moisture; this order did not vary seasonally. The dependence of stomatal conductance variability on the seasonal change in chlorophyll concentration was larger in spring and autumn than in summer. These results indicate that the consideration of seasonal changes in plant physiological properties is important in evaluating the water, energy, and CO2 cycles between plants and the atmosphere.
The electrochemical behavior, chemical composition and the topography of the solid electrolyte interphase (SEI) on lithium electrodes cycling in ether-based electrolytes are investigated using X-ray photoelectron spectroscopy (XPS), scanning probe microscopy (SPM) and electrochemical impedance spectroscopy (EIS). Electrolytes with ethers (1,2-Dimethoxyethane (DME), Diethylene glycol dimethyl ether (DG) and Triethylene glycol dimethyl ether (TEGDME)) are employed to understand the effect of ether/alkyl moieties ratio on the formation of the SEI films. The cycling behavior and impedance spectra of the symmetrical cells show that the stability and property of those SEI films depend on the selection of the solvent. The results indicate that DG and TEGDME based electrolytes lead to a higher resistance for lithium ion migration through the SEI film. Combined with XPS spectra and depth profile, different chemical composition and depth profile distribution for those SEI films are observed. This difference could be attributed to the decomposition of the electrolytes with different ethers. The height images and phase images obtained from SPM show that the decomposition of the three solvents on lithium metal is active after the immersion of the lithium electrodes in electrolytes. In contrast, the decomposition of TFSI− from lithium salt is more active during the cycling of the cells.
The cycle life of LiCoO2-based all solid-state thin-film cells has been studied at room temperature, and at elevated temperatures of 50, 100, and 150°C. X-ray diffraction, as well as Raman analysis, has been used to complement the electrochemical data in examining structural and chemical changes. XRD and Raman spectroscopy data indicate that elevated temperature soaks of the thin-film batteries in the quiescent state causes no discernable changes in the LiCoO2 cathode layer. However, when the thin-film batteries are cycled at elevated temperatures, decreases in average grain size of the LiCoO2 film occur with dramatic concomitant charge and discharge capacity loss.
Flower-like Ni0·85Se nanosheets (Ni0·85Se-16 h) are synthesized by a two-step hydrothermal method. The electrochemistry performance and phase transformation of nickel selenides which obtained from different reaction times are examined. All the nickel selenides experience the phase transformation process. However, the opened flower-like Ni0·85Se-16 h sample takes the phase change process more slowly than others. In addition, the electrochemical properties differences between flower-like Ni0·85Se-16 h and NiO are also studied. Ni0.85Se-16 h exhibits a areal capacitance of 3.35 F cm−2 at 4 mA cm−2 which is approximately 3.6-fold higher than that of NiO. Then, the hybrid supercapacitor is assembled by using Ni0·85Se-16 h as a positive electrode and activated carbon as a negative electrode. The hybrid configuration could acquire a high energy density of 44.2 Wh kg−1 at a power density of 888.9 W kg−1, and 28.5 Wh kg−1 at 12825 W kg−1. The above results emphasize the fact that the opened flower-like construction could effectively promote the electron/ion transportation in the interface between the electrolyte and the active materials which delay the phase transition process and prove the fact that selenization process could enhance the areal capacitance more effectively than oxidation process. Thus, make it a potential candidate as battery-like electrode materials for hybrid supercapacitors.
Artificial intelligence coupled with wireless home sensors can monitor the use of insulin pens and inhalers by patients and alert of errors in self-medication in an unobtrusive manner.
A non-aqueous vanadium acetylacetonate redox flow battery with different organic solvents and tetrabutylammonium hexafluorophosphate has been investigated. Cyclic voltammograms show three redox couples in 1,3-dioxolane, tetrahydrofuran, acetylacetone and two redox couples in dimethyl sulfoxide. Cell potentials between 2.21 and 2.61V are measured, depending on the solvent used. Impedance Spectroscopy has been used to determine rate limiting step in the non-aqueous redox flow battery. Experiments in a charge–discharge test cell yielded coulombic and energy efficiencies of 85.9–98.5% and 26.6–43.6%, respectively.
This work explores a qualitative appraisal of lead acid battery electrodes by Electrochemical Impedance Spectroscopy. Lead acid cells behavior has been examined by gathering data of impedance modifications in distinct electrolyte volumes, from a full one to a battery filled at about 20% of the total volume of acid. Since the current between electrodes is inhomogeneous around the collector by varying the quantity of the electrolyte, we have associated numerical values of the elements in the battery equivalent circuit, to the homogeneity of the current in the electrodes. Theoretical considerations dealing with modeling, equivalent circuits and corresponding equations are provided. As a function of the electrolyte quantity, we investigated the dependence of the values for components of the Randle circuit. A particular attention has been devoted to constant phase element (CPE) peculiarities, as this parameter was found essential for a good quality fit over an extended range of batteries. The stability depending on current homogeneity at a certain battery state of charge was analysed in order to assess the effect of electrolyte volumes, and thereby to provide new quality requirements for improvement of lead-acid battery performance.
A ternary composite of polypyrrole (PPy), Prussian blue (PB), and graphene oxide (GO), PPy⿿PB⿿GO, was successfully prepared through spontaneous polymerization of pyrrole and formation of PB nanocubes on GO. The obtained nanocomposite was characterized by transmission electron microscopy, scanning electron microscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy. The results indicate that the PPy-protected PB nanocubes were well dispersed on the GO. Electrochemical testing showed a specific capacitance of 525.4Fg⿿1 at a current density of 5Ag⿿1 in the potential range from ⿿0.2 to 0.6V, obtained in an electrolyte of 1molL⿿1 KNO3 during the galvanostatic charge⿿discharge cycles, which is superior to the performance of binary cathode materials, including PPy⿿PB and PPy⿿GO nanocomposites. The as-prepared supercapacitor could retain a specific capacitance of 96% after 2000 cycles. It was confirmed that the three components⿿PPy, PB, and GO⿿led to the display of integrated electrochemical behavior and a resulting capacitor with enhanced performance. The significant enhancement in electrochemical performance of the ternary nanocomposite can be attributed to the synergistic effect of PPy-protected PB nanocubes dispersed on GO sheets with the pseudocapacitance from PB and PPy on the double-layer capacitance from GO.
Energy production and storage are both critical research domains where increasing demands for the improved performance of energy devices and the requirement for greener energy resources constitute immense research interest. Graphene has incurred intense interest since its freestanding form was isolated in 2004, and with the vast array of unique and highly desirable electrochemical properties it offers, comes the most promising prospects when implementation within areas of energy research is sought. We present a review of the current literature concerning the electrochemical application of graphene in energy storage/generation devices, starting with its use as a super-capacitor through to applications in batteries and fuel cells, depicting graphene's utilisation in this technologically important field.
Insects express a battery of potent antimicrobial proteins in response to injury and infection. Recent work from several laboratories has demonstrated that this response is neither stereotypic nor completely nonspecific, and that different pathways are responsible for inducing the expression of antifungal and antibacterial peptides. Here we report the cloning of two closely linked attacin genes from Drosophila melanogaster. We compare their protein coding sequences and find the amino acid sequences to be more highly conserved than the nucleotide sequences, suggesting that both genes are expressed. Like other antimicrobial peptides, attacin expression is strongly induced in infected and injured flies. Unlike others, attacin transcription is uniquely sensitive to mutations in the 18-Wheeler receptor protein, and thus may be regulated by a distinct signaling pathway. The number and organization of binding sites for κB and other transcription factors in the promoter regions of both attacin genes are consistent with strong and rapid immune induction. We demonstrate that these promoter regions are sufficient to direct beta-galactosidase expression in transformed Drosophila third-instar larval fat body in a bacterially inducible manner. We present a comparison of the promoter regions of the two attacin genes to those cloned from other antimicrobial peptide genes to assist a better understanding of how antimicrobial genes are differentially regulated.
Through homogeneous precipitation method, uniform spherical α-Ni(OH)2 particles were obtained at appreciate aging time in urea solution without any help of templates or dispersants. From SEM images, aging time exhibited great effects on the morphology of as-synthesized α-Ni(OH)2. Also, long aging time helped to improve the electrochemical performances of α-Ni(OH)2. It was found that the proper aging time was 12h. However, α-Ni(OH)2 showed low charge/discharge capacities at high temperatures. Therefore, yttrium was added to improve the high-temperature electrochemical performances of α-Ni(OH)2. The influences of doping ratios of Y on the morphologic and high-temperature electrochemical characteristics were investigated through XRD, SEM, TEM, constant current charge/discharge, and cyclic voltammetric measurements. The α-Ni(OH)2 samples with the addition of about 5.8mol% Y showed a discharge capacity of 250mAh/g at 0.2C rate and 60°C, much higher than that of α-Ni(OH)2 without Y dopants (157mAh/g).
The progress met in the world market of photovoltaics underlines the maturity of investments realized, guarantees the reliability of the technology utilized and designates the variety of applications in covering the energy demands of both stand-alone and grid connected consumers. Concerning stand-alone systems, the incorporation of photovoltaic systems in water pumping applications is thought to be one of the most popular and ideal uses of solar energy exploitation, especially under the common allegation of coincidence between insolation and water demand. In this study, an attempt to investigate the opportunities of a PV powered water pumping system able to meet additional – apart from the water pump – electricity loads, results in the development of an optimum sizing methodology which is accordingly validated by experimental measurements. From the results obtained, it becomes clear that a properly designed PV-pumping configuration of 610Wp is capable of covering both the electricity (max 2kWh/day) and the water (max 400L/h) management demands of a large variety of remote consumers.
This article presents some of the earliest evidence of visuospatial and numerical cognitive deficits in children with the chromosome 22q11.2 deletion syndrome; a common but ill-understood genetic disorder resulting in medical complications, cognitive impairment, and brain morphologic changes. Relative to a group of typically developing controls, deleted children performed more poorly on tests of visual attentional orienting, visual enumeration and relative numerical magnitude judgment. Results showed that performance deficits in children with the deletion could not be explained by a global deficit in psychomotor speed. Instead, our findings are supportive of the hypothesis that visuospatial and numerical deficits in children with the chromosome 22q11.2 deletion are due, at least in part, to posterior parietal dysfunction.
It is reported lithium superoxide as the discharge product can largely decrease the charge voltage and enable a high round-trip efficiency of lithium-oxygen (Li-O2) batteries. Here, we conduct a numerical investigation of the discharge behaviors of such batteries with LiO2 as the discharge product. A mathematical model considering the mass transport and electrochemical reaction processes is first developed, which gives good agreement of the simulated discharge voltage with the experimental data. Then, with this model, the effects of electrode and electrolyte properties on the discharge performance are detailedly investigated. It is found that a thin cathode with a large porosity is favorable for a high specific capacity, and a high catalytic activity can lead to a high discharge voltage. For the cathode with different geometrical properties, it is found that the oxygen solubility and diffusivity have similar impacts on discharge capacities, but the oxygen solubility has a larger impact on energy densities. Besides, the limitations and further developments of the present model are also discussed. The results obtained from this work may give useful guidance for the discharge performance improvements of non-aqueous Li-O2 batteries, and provide implications for other energy storage systems with solid product formation such as Na-O2 batteries and Li-S batteries.
The primary objective of the proposed paper is to conduct a techno-economic study of an off-grid PV/Biomass hybrid system. We employed various optimization techniques. This included the Flower Pollination Algorithm (FPA), the Harmony Search (HS) algorithm, the Artificial Bee Colony (ABC) Algorithm and the Firefly Algorithm (FA). The ultimate objective was to determine an optimal solution for the sizing problem. In this context, the proposed procedure optimally selects the capacity of three types of generators, namely solar PV, biomass, and battery banks. The data for this study was collected from Monshaet Taher village, located in Egypt. To improve the performance, we restrained the selection between these generators to be based on minimizing the Net Present Cost (NPC) for a specified Loss of Power Supply Probability (LPSP) and Percentage of the excess energy (EXC). Three different battery technologies, including Flooded lead-acid (FLA), Lithium Ferro Phosphate (LFP) and Nickel Iron (Ni-Fe) have been considered in this study. The simulation results show that the Firefly Algorithm has the minimum execution time and best performance among the other algorithms, it also shows that the optimal configuration is obtained for a system comprising of 24 PV panels, 4 biomass power systems, and 298 Ni-Fe batteries.
Resistance to endocrine therapies remains a major clinical problem for the treatment of estrogen receptor-α (ERα)-positive breast cancer. On-target side effects limit therapeutic compliance and use for chemoprevention, highlighting an unmet need for new therapies. Here we present a full-antagonist ligand series lacking the prototypical ligand side chain that has been universally used to engender antagonism of ERα through poorly understood structural mechanisms. A series of crystal structures and phenotypic assays reveal a structure-based design strategy with separate design elements for antagonism and degradation of the receptor, and access to a structurally distinct space for further improvements in ligand design. Understanding structural rules that guide ligands to produce diverse ERα-mediated phenotypes has broad implications for the treatment of breast cancer and other estrogen-sensitive aspects of human health including bone homeostasis, energy metabolism, and autoimmunity.