batterydata/paper-abstracts huggingface dataset:
Generally, routing algorithms for opportunistic networks rely on the fact that nodes are willing to accept data from other nodes under any circumstances, but this is not the case. Selfish nodes might not want to participate in the routing process for various reasons, such as low resources (e.g. battery, memory, CPU, and network bandwidth), fear of malicious data from unknown users, or even lack of interest in helping nodes from other communities. Therefore, these types of nodes should be detected and avoided in the routing process. Moreover, incentive mechanisms that reward nodes when they actively take part in the network and punish them when they do not, should be employed where possible. In this paper, we propose SENSE, a novel social-based collaborative content and context-based selfish node detection algorithm with an incentive mechanism, which aims to reduce the issues of having selfish nodes in an opportunistic network. Since local information may not be sufficient to reach an informed decision, nodes running SENSE collaborate through gossiping, for the final goal of detecting selfish nodes, punishing and avoiding them. We compare our approach to an existing algorithm (IRONMAN) and show that it behaves better in terms of network performance and detection accuracy. Moreover, we show that SENSE behaves well even when we simulate the existence of devices with batteries that get depleted, thus rendering them inactive for given time periods.
As a promising anode material alternative to the carbons, Li4Ti5O12 has drawn wide attention for its overwhelming advantages in meeting requirements of lithium ion batteries with high power density, long cycling life and safety for electric vehicles and electricity storage stations. Its stability issue during storage is interesting and of large importance. In this work, the stability of commercial spinel Li4Ti5O12 material in air has been characterized by a series of physical and electrochemical techniques. First-principles calculations indicate that Li4Ti5O12 is lithium-truncated at the surface. This explains why it tends to absorb H2O and CO2 to form Li2CO3 but the formation of Li2CO3 does not significantly impact its electrochemical performances.
There is a substantial amount of public concern about patient safety, as, according to estimates from major studies, hundreds of thousands die in hospitals each year all over the developed world as a result of medical errors that could have been prevented. Unprecedented research commissioned by the EU has found that almost one out of every four families has experienced a serious medical error. Greek citizens concerning about serious medical errors in the hospital environment, were at the top of the list. Greek Ombudsman's report on medical errors has raised the debate among health policy makers as to the appropriate response to the problem. Proposals range from the implementation of nationwide mandatory reporting with public release of performance data, to voluntary reporting and quality-assurance efforts that protect the confidentiality of error-related data. Any successful safety program will first require a national effort to make significant investments in information systems, along with providing an environment and education that enables to contribute to an active quality improvement process. In this paper we propose the development and implementation of Medical Error Reporting Information System (MERIS), in order to identify, collect, analyse and report medical errors and patient adverse events, as a tool for enhancing patient safety and health care quality. We also describe the necessary organisational structure and the infrastructure environment of the system and the barriers to its successful implementation.
The use of carbide-derived carbon (CDC) as the positive electrode material for lithium-ion capacitors (LICs) is investigated. CDC based LIC cells are studied utilizing two different negative electrode materials: graphite and lithium titanate Li4Ti5O12 (LTO). The graphite electrodes are prelithiated before assembling the LICs, and LTO containing cells are studied with and without prelithiation. The rate capability and cycle life stability during 1000 cycles are evaluated by galvanostatic cycling at current densities of 0.4–4 mA cm−2. The CDC shows a specific capacitance of 120 F g−1 in the organic lithium-containing electrolyte, and the LICs demonstrate a good stability over 1000 charge-discharge cycles. The choice of the negative electrode is found to have an effect on the utilization of the CDC positive electrode during cycling and on the specific energy of the device. The graphite/CDC cell delivers a maximum specific discharge energy of 90 Wh kg−1 based on the total mass of active material in the cell. Both the prelithiated and non-prelithiated LTO/CDC cells show a specific energy of around 30 Wh kg−1.
The rate-determining step in electrochemical oxidation reaction of Li metal at the interface between an Li negative electrode and xLi2S–(100−x)P2S5 (x = 75, 70 or 67) solid electrolyte was determined on the basis of the study on Ag+ ion conductive solid electrolytes. For this purpose, potential step technique using a microelectrode was applied. Two possible rate-determining steps, the diffusion of Li+ ion vacancies and the reaction between interstitial Li+ ions and Li+ ion vacancies, were assumed, and we found the diffusion of Li+ ion vacancies is the rate-determining step in the present study. We also evaluated the exchange current density (i 0) of the Li/Li+ couple reaction and ionic conductivity (κ) of each solid electrolyte. Both i 0 and κ were increased as the x value was increased, suggesting that the conductivity of Li+ ions or the rate of the diffusion of Li+ ion vacancies was closely related to the rate of the Li/Li+ couple reaction.
A combined modelling-experiments approach is presented with the aim of determining in-situ key characteristics of a RFB. The porous electrode impedance was calculated and measured without and with a faradaic reaction, by means of a symmetric cell. The technique was applied to the specific [Fe(CN)6]3-/[Fe(CN)6]4- couple whose interest for RFB application is substantial. The interpretation of Electrochemical Impedance Spectroscopy (EIS) data enabled the determination of the key membrane and electrode resistances and the investigation of their evolutions during the battery operation. The effects of the cation composition in the supporting electrolyte, the carbon material and the cycling were analysed. The results gave insights on degradation mechanisms that can hinder RFB performance, and delineated the phenomena occurring during electrolyte circulation or during battery operation.
Although prey capture by cnidarians is mediated through nematocysts, their influence on prey selection by cnidarians remains poorly documented. The difficulty in visualizing nematocyst–prey interactions remains the chief obstacle to understanding how the wide variety of nematocyst types influences the mechanics of prey capture. One solution to this limitation has been to assign functional roles to nematocysts based on morphological characters of discharged cnidae. Here we report results of an alternative approach based upon dynamic traits of nematocyst discharge. We examined tubule lengths, tubule discharge velocities and net-to-gross displacement ratios of tubules of discharging nematocysts possessed by the cosmopolitan scyphomedusa, Cyanea capillata. This nematocyst assemblage consisted of euryteles, birhopaloids and three different isorhizas — a-isorhizas, A-isorhizas and O-isorhizas. Dynamic traits varied little within each nematocyst type but there were significant differences between the different types. Most importantly, dynamic traits varied significantly within a broad category of nematocyst – the isorhizas – indicating that conventional classification schemes that infer function based on broad nematocyst categories may not appropriately describe the functional roles of these nematocysts. The dynamic properties of discharging nematocysts were consistent with physical results described in studies using scanning electron microscopy images of nematocyst–prey interactions. These data suggest that nematocysts vary significantly in their roles during predation, but that inferences relating prey selection with broad nematocyst categories merit careful examination.
Low Co AB5-type MmNi3.8Co0.4Mn0.6Al0.2B x (x=0, 0.1, 0.2, 0.3, 0.4) hydrogen storage alloys were prepared by cast and rapid quenching. The microstructures and electrochemical performances of the as-cast and quenched alloys were analysed and measured. The effects of boron additive and rapid quenching technique on the microstructures and electrochemical properties of as-cast and quenched alloys were investigated comprehensively. The experimental results showed that the microstructure of as-cast MmNi3.8Co0.4Mn0.6Al0.2B x (x=0, 0.1, 0.2, 0.3, 0.4) alloys was composed of CaCu5-type main phase and a small amount of CeCo4B-type secondary phase. The abundance of the secondary phase increases with the increase of boron context x. The rapid quenching techniques were used in the preparation of the alloys. The amount of secondary phase in the alloys decreased with the increase of quenching rate. Rapid quenching made lattice constants increase slightly. The effects of rapid quenching on the electrochemical performances of the alloys are very significant. The discharge capacity of the alloys decreased obviously and the cycle stability increased dramatically with the increase of quenching rate. Rapid quenching made the activation capability of the alloys lowered. However, the activate performance and high rate discharge capability as well as discharge voltage characteristic of the alloys were modified obviously with the increase of boron content x.
The advanced technology of computing system was followed by the rapid improvement of medical instrumentation and patient record management system. The typical examples are hospital information system (HIS) and picture archiving and communication system (PACS), which computerized the management procedure of medical records and images in hospital. Because these systems were built and used in hospitals, doctors out of hospital have problems to access them immediately on emergent cases. To solve these problems, this paper addressed the realization of system that could transmit the images acquired by medical imaging systems in hospital to the remote doctors’ handheld PDA’s using CDMA cellular phone network. The system consists of server and PDA. The server was developed to manage the accounts of doctors and patients and allocate the patient images to each doctor. The PDA was developed to display patient images through remote server connection. To authenticate the personal user, remote data access (RDA) method was used in PDA accessing the server database and file transfer protocol (FTP) was used to download patient images from the remove server. In laboratory experiments, it was calculated to take ninety seconds to transmit thirty images with 832 × 488 resolution and 24 bit depth and 0.37 Mb size. This result showed that the developed system has no problems for remote doctors to receive and review the patient images immediately on emergent cases.
Single-chamber solid oxide fuel cells (SC-SOFCs) incorporating thin-film Sm0.15Ce0.85O1.925 (SDC) as the electrolyte, thick Ni+SDC as the (supporting) anode and SDC+BSCF (Ba0.5Sr0.5Co0.8Fe0.2O3−δ ) as the cathode were operated in a mixture of methane, oxygen and helium at furnace temperatures of 500–650°C. Because of the exothermic nature of the oxidation reactions that occur at the anode, the cell temperature was as much as 150°C greater than the furnace temperature. Overall, the open circuit voltage was only slightly sensitive to temperature and gas composition, varying from ∼0.70 to ∼0.78V over the range of conditions explored. In contrast, the power density strongly increased with temperature and broadly peaked at a methane to oxygen ratio of ∼1:1. At a furnace temperature of 650°C (cell temperature ∼790°C), a peak power density of 760mWcm−2 was attained using a mixed gas with methane, oxygen and helium flow rates of 87, 80 and 320mLmin−1 [STP], respectively. This level of power output is the highest reported in the literature for single chamber fuel cells and reflects the exceptionally high activity of the BSCF cathode for oxygen electro-reduction and its low activity for methane oxidation.
A critical issue to boost the development of sodium ion batteries is the development of advanced active materials via meticulous understanding of the synthesis process. The practical application of sodium vanadium phosphate (Na3V2(PO4)3), which shows high energy density, stable structure and excellent thermal properties, is hindered by the intrinsic poor electronic conductivity. Carbon coating was proved to be an effective strategy to cover such pristine limitation and deserved systematic and intensive investigation. Herein, saccharides that widely distributed in nature with different molecular weights were selected to identify the function mechanism of carbon sources in preparing Na3V2(PO4)3@C composite via solid state reaction. Comprehensive and systematic results evidenced that the high polymer starch with glucose polymerization could construct three-dimensional interconnected carbon network, which would boost the electron conductivity and stabilize the structure upon repeated sodium ions insertion/extraction. As a consequence, the extraordinary high rate capability and long-time stability were obtained: a high rate capacity of 72 mA h g−1 could be delivered even at 40 C and the cell retained a capacity retention of 82.8% after 1000 cycles at 1 C. We believe that our work presents here would provide important insights into the carbon coating strategy, which will be favourable for accelerating the commercialization of SIBs.
A novel precious metal-free electrode catalyst SnO2/m-ZSM-5 nanocomposite has been successfully synthesized. This SnO2/m-ZSM-5 nanocomposite shows high and stable electrochemical catalytic activity for methanol oxidation, which is comparable to Pt/C. The high electrochemical performance has been attributed to the synergetic catalytic effects between the mesoporous ZSM-5 matrix and the loaded SnO2 nanocrystals.
Harvesting energy from ambient vibration sources with ultrathin flexible piezoelectric energy harvesters (PEHs) for battery-free electronics has received attention in recent years. However, the excitation modes in the environment and human body motion are more complicated than the ideal harmonic modes employed in previous theoretical analyses, and their influence on the efficiency of PEHs has received little attention. In this study, these environmental excitation modes are classified into three types, i.e., the triangular, sinusoidal, and square wave modes, with varied duty ratios. We derived theoretically the output power of flexible PEHs under these excitation modes and establish a simple scaling law, in which the normalized output power depends only on two combined normalized parameters, i.e., the intrinsic system parameter and the excitation mode. Results reveal that the output power of PEHs changes dramatically for different excitation modes with varied duty ratios even when all the other parameters including excitation amplitude, excitation frequency, electrical parameter, and geometrical and material parameters of the PEHs are identical. This paper may provide a systematic understanding in the effect of excitation modes on the output power of flexible PEHs and promote the realization of energy harvesting from the complex environmental and human body motions.
Traditional sodium-ion battery cathodes utilize the change in oxidation state of the transition metal(s) in the structure to accommodate the electron transfer during charge and discharge. Recent researches on sodium-rich compounds such as Na2RuO3 and Na2IrO3 suggest that anionic reaction with oxygen can be an additional source of electrons during electrochemical reactions. Here we demonstrate for the first time that stoichiometric NaVO3, despite the valence of vanadium of 5+, delivers a reversible capacity by activating it beyond 4.5 V. Elemental analysis confirms Na removal and insertion from/into NaVO3 during charge/discharge. X-ray photoelectron spectroscopy and X-ray absorption near-edge spectroscopy results show that the oxidation state of vanadium remains unchanged, while oxygen is likely to compensate for the charge transfer during charge/discharge. Theoretical calculation on spin density of electrons in the lattice also supports the involvement of oxygen during sodium removal. Our demonstration of the unique behaviors of NaVO3 provides a new exciting direction for research in sodium-ion battery cathodes.
Mathematical modeling and simulation methods are important tools in studying various processes in science and engineering. In the current review, we focus on the applications of hybrid models (HMs) in chemical processes, oil and gas processes, and applied energy systems. These processes suffer from complexities that demand advanced mathematical tools to be employed for various purposes such as process development, identification, simulation and modeling, optimization, control, classification, clustering, forecasting, and monitoring. Beside the lack of adequate knowledge about the processes related to the chemical and energy systems, there are other mathematical complexities such as non-linearity, large and multi-scale, long dynamics, uncertainties, and high dimensionality. The HMs can provide a practical solution to such complex processes. The arrangements of different black-box models with themselves or with white-box models are alternatively used to reduce the model complexities. The hybrid gray-box models are of significant importance as they combine the physical significance and generalization capabilities of the white-box models with the complexity reduction capability of the black-box models to facilitate/enhance the modeling strategy, while a desired precision is targeted. Such a hybridized model enables the physically-meaningful computation for the time-demanding applications. In this paper, we review different sub-models, hybridization strategies, structural designs, screening criteria, and new directions in hybrid modeling, with focus on the corresponding applications in chemical, petroleum, and energy systems.
Results of theoretical and experimental studies of corrosion processes of graphite in vanadium electrolytes and methods for corrosion prevention are presented. Electric contact of positive half-cell electrolyte in the inlet/outlet channels of vanadium redox flow batteries (VRFB) with graphite collectors generates parasitic electric currents, which cause electrochemical oxidation of carbon atoms on the surface of the collectors. This leads to damaging the collectors and flow battery failure. The parasitic currents in the electrolyte channels were calculated and measured. Methods to prevent the corrosion, caused by the parasitic currents, were investigated: the graphite planar collectors were electrically isolated from electrolyte in inlet/outlet channels by o-rings and in inlet/outlet area of half-cell by isolation films. A corrosion resistant battery with collectors, fabricated from pyrolytic graphite, was constructed.
Core–shell nanocatalysts have demonstrated potential as highly active low-Pt fuel cell cathodes for the oxygen reduction reaction (ORR); however, challenges remain in optimizing their surface and interfacial structures, which often exhibit undesirable structural degradation and poor durability. Here, we construct an unsupported nanoporous catalyst with a Pt–Pd shell of sub-nanometre thickness on Au, which demonstrates an initial ORR activity of 1.140 A mgPt−1 at 0.9 V. The activity increases to 1.471 A mgPt−1 after 30,000 potential cycles and is stable over a further 70,000 cycles. Using aberration-corrected scanning transmission electron microscopy and atomically resolved elemental mapping, the origin of the activity change is revealed to be an atomic-scale evolution of the shell from an initial Pt–Pd alloy into a bilayer structure with a Pt-rich trimetallic surface, and finally into a uniform and stable Pt–Pd–Au alloy. This Pt–Pd–Au alloy possesses a suitable configuration for ORR, giving a relatively low free energy change for the final water formation from adsorbed OH intermediate during the reaction.
Lead dioxide electrodes with three-dimensional porous titanium as substrate (3D-Ti/PbO2) were prepared by galvanostatic electrodeposition. The structure, morphology and electrochemical performances of 3D-Ti/PbO2 were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), cyclic voltammetry and galvanostatic charge-discharge techniques. The electrochemical performances of 3D-Ti/PbO2 were optimized by adjusting the applied deposition current density. Results reveal that the 3D-Ti/PbO2 prepared at 1mAcm−2 had nanoparticles on its surface with abundant crystal orientations. It had a high capacity of 132 mAh g−1 with an active material utilization of 57% at discharge current density of 0.9 A g−1. With the same condition, the lead dioxide electrode with planar titanium substrate (Ti/PbO2) only had a capacity of 20.8 mAh g−1. The high electrochemical active surface area and small charge transfer resistance resulted in the high capacity of 3D-Ti/PbO2. The possible factors, which affected the electrochemical performances of 3D-Ti/PbO2, were interpreted in detail with voltammetric charge analysis and electrochemical impedance spectroscopy.
We have developed an efficient method to generate highly active Pd nanoparticles supported on graphene (Pd/G) by microwave-assisted chemical reduction of the corresponding aqueous mixture of a palladium salt and dispersed graphite oxide (GO) sheets. The Pd/G demonstrated excellent catalytic activity for the carbon–carbon cross-coupling reactions (Suzuki, and Heck) with a broad range of utility under ligand-free ambient conditions in an environmentally friendly solvent system. It also offers a remarkable turnover frequency (108,000h−1) observed in the microwave-assisted Suzuki cross-coupling reactions with easy removal from the reaction mixture, recyclability with no loss of activity, and significantly better performance than the well-known commercial Pd/C catalyst. The catalyst was fully characterized by a variety of spectroscopic techniques including X-ray diffraction (XRD), Raman, TGA, electron microscopy (SEM, TEM), and X-ray photoelectron spectroscopy (XPS). The remarkable reactivity of the Pd/G catalyst toward Suzuki cross-coupling reactions is attributed to the high degree of the dispersion and concentration of Pd(0) nanoparticles supported on graphene sheets with small particle size of 7–9nm due to an efficient microwave-assisted reduction method.
We explore the operations, balancing requirements, and costs of the Western Electricity Coordinating Council power system under a stringent greenhouse gas emission reduction target. We include sensitivities for technology costs and availability, fuel prices and emissions, and demand profile. Meeting an emissions target of 85% below 1990 levels is feasible across a range of assumptions, but the cost of achieving the goal and the technology mix are uncertain. Deployment of solar photovoltaics is the main driver of storage deployment: the diurnal periodicity of solar energy availability results in opportunities for daily arbitrage that storage technologies with several hours of duration are well suited to provide. Wind output exhibits seasonal variations and requires storage with a large energy subcomponent to avoid curtailment. The combination of low-cost solar technology and advanced battery technology can provide substantial savings through 2050, greatly mitigating the cost of climate change mitigation. Policy goals for storage deployment should be based on the function storage will play on the grid and therefore incorporate both the power rating and duration of the storage system. These goals should be set as part of overall portfolio development, as system flexibility needs will vary with the grid mix.