batterydata/paper-abstracts huggingface dataset:
As a promising candidate for conventional micro-power sources, the micro-direct methanol fuel cell (μDMFC) is currently attracting increased attention due to its various advantages and prospective suitability for portable applications. This paper reports the design, fabrication and analysis of a high-performance μDMFC with two metal current collectors. Employing micro-stamping technology, the current collectors are fabricated on 300-μm-thick stainless steel plates. The flow fields for both cathode and anode are uniform in shape and size. Two sheets of stainless steel mesh are added between the membrane electrode assembly (MEA) and current collectors in order to improve cell performance. To avoid electrochemical corrosion, titanium nitride (TiN) layers with thickness of 500nm are deposited onto the surface of current collectors and stainless steel mesh. The performance of this metallic μDMFC is thoroughly studied by both simulation and experimental methods. The results show that all the parameters investigated, including current collector material, stainless steel mesh, anode feeding mode, methanol concentration, anode flow rate, and operating temperature have significant effects on cell performance. Moreover, the results show that under optimal operating conditions, the metallic μDMFC exhibits promising performance, yielding a maximum power density of 65.66mWcm−2 at 40°C and 115.0mWcm−2 at 80°C.
Recent advances in the understanding of structural and electronic effects in heterogeneous electrocatalysis are summarized. Typical examples are given illustrating how the knowledge obtained from a detailed theoretical analysis of structural and electronic effects supported by model experiments can be used for the rational design of new electrocatalytic materials. Recent successes and future challenges in designing active, stable, and selective electrocatalysts are discussed.
The publisher regrets that this article was published with errors to the author details. The correct information for this article is reprinted below: M. Ghaemia,*, A. Gholamib, R.B. Moghaddamc aDepartment of Chemistry, Science Faculty, Golestan University, 49138-15739, Gorgan, Iran bDepartment of Chemistry, Science Faculty, Tarbiat Modares University, 14115-175, Tehran, Iran cDepartment of Chemistry, K. N. Toosi University of Technology, 15875-4416, Tehran, Iran(* Corresponding author. Tel.: +98 171 4427173; fax: +98 171 4427040, e-mail:ghaemi_m@gmx.de)
A novel free-standing composite film electrode for Li-S battery is investigated. This novel electrode consists of polyvinylpyrrolidone-coated hollow sulfur microspheres (PVPS) that are homogeneously confined within the conductive composite matrix of graphene and poly(3,4-ethylene-dioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS). The characteristic large surface area and wrinkled surface of graphene sheets allow the formation of a conductive layer on the surface of PVPS to suppress the polysulfide dissolution and accommodate the volumetric expansion of sulfur. The addition of PEDOT-PSS also enhances the adhesion between the PVPS and the graphene surface, the overall conductivity of the electrode, and the charge transportation during the charging and discharging processes. The best electrode performances are achieved for a composite film cathode with a sulfur content of about 63.9%, which delivers an initial specific capacity of around 1060 mAh g−1 at 0.1 C. This electrode also displays an excellent capacity retention of 75% after 500 cycles at 1C, corresponding to a capacity decay of only 0.05% per cycle.
This paper explores the inverse problem approach for finding the current distribution within an electrochemical cell from magnetic field measurements. Current distribution is shown to be a useful measurement for diagnosis of cells and development of cell design. Existing current distribution measurement methods are discussed to provide context and motivation for the work. Magnetic field measurements can be obtained non-invasively and contain information about the current distribution, which is extracted using an appropriate solver. Experimental results are presented which test the effectiveness of a particular inverse problem solver, using both simulated and real magnetic field measurements. The solver presented is based upon one found in literature, but with novel problem-specific modifications. Errors in conductance values in the forward model definition are simulated in order to quantify their effect on solution quality. A modification to the solver is proposed to improve robustness against these model errors. This results in improved solution quality when using real measured data from a resistor-wire model of a cell, and simulated data from a model which more accurately represents the conductance of the cell plate grid and active mass.
Background Filtered-exhaust helmet systems are commonplace during total joint arthroplasty, but their ability to limit intraoperative contamination has been questioned. We hypothesized that activation of the airflow system after complete gowning would lead to decreased contamination of the surgical environment. Methods Using a fluorescent particle model, the maximal particle spread from a filtered-exhaust helmet and contamination of the surgical environment based on timing of airflow activation through simulated surgical gowning procedures were evaluated. Results Helmet airflow analysis revealed particle spread greater than 5 feet in all trials. Activation before gowning resulted in a significantly greater contamination in the control group compared with the experimental group (P = .014). Conclusions We recommend complete surgical gowning before activation of the airflow system.
Paper-based electronics have been considered as one of the most exciting technologies in the near future due to sustainability, low cost, mechanical flexibility, etc. Even though there have been numerous studies regarding this technology, there is not any available quantitative study on how paper electronics would minimize the impact on the environment. This work aims to give the first detailed analysis regarding this important question. To this end, we for the first time designed and prototyped paper-based multilayer printed circuit boards (P-PCBs), which show comparable functions to the currently available organic printed circuit boards (O-PCBs); yet the P-PCBs adopt a “green” preparation process. A life cycle assessment study was performed to quantify the P-PCBs' environmental impacts, e.g. acidification potential, global warming potential, human toxic potential, ozone layer depletion potential, etc. Our current research reveals that the P-PCBs have about two magnitude lower impact on the environment than O-PCBs based on the results of the life cycle assessment, which suggests that the P-PCB technique is beneficial for the environment at the regional or global production level. The current study gives useful information and sheds light on the future technological directions for various paper based electronics studies.
In the nickel hydroxide synthesis, the β-Ni(OH)2 phase grows after total α-Ni(OH)2 aging. A mixture of α-Ni(OH)2 and β-Ni(OH)2 phases is formed when a part of α-Ni(OH)2 suffers aging. Galvanostatic oxidation of the α/β-Ni(OH)2 produced by chemical synthesis formed a new type of active material. On discharge, it presented higher capacity than active material produced from β-Ni(OH)2. Therefore, α/β-Ni(OH)2 is a promising material for β-Ni(OH)2 substitution, as a alternative precursor material used in the positive electrodes of alkaline batteries. Anions of the solution and water molecules are present in the nickel hydroxide powder. This is result of the synthesis method developed here. The characterization of the precursor material is determined with help of: X-ray diffraction, thermal analyses, Fourier transformation infrared spectroscopy, specific superficial area and electron scanning microscopy.
Intercalation current of Li+ to a graphite electrode varied sharply with [Li+] from the proportionality to a constant, exhibiting critical behavior at [Li+]=10mM. The voltammetrically cathodic peak current, which is caused by the intercalation, was proportional to the square-root of the scan rate, irrespective of the concentrations. The current for [Li+]<10mM is controlled both by diffusion and electric migration of Li+ in solution, whereas that for [Li+]>10mM is controlled by diffusion of Li in the graphite. In order to validate the critical behavior, the time-dependent mass transport theory was developed by use of the Nernst–Planck equation for the solution phase and the diffusion equation for the graphite one. Both equations were combined at the interface through a kind of the Nernst equation which contained a maximum concentration of Li in the graphite predicted from the structure of LiC6. The theory supported the critical behavior in the potential domain of the limiting current. From the critical concentration, the diffusion coefficient of Li in the graphite was estimated to be 0.79×10−11 cm2 s−1, independent of the concentrations.
The Mobile Ad Hoc Network (MANET) is wireless network which provides communication among wireless mobile hosts without the need of any standing network infrastructure. In such networks, and to facilitate communication between participating nodes, every node has to offer routing services. Routing in MANET is responsible for selecting and forwarding packets along optimal paths. Finding an optimal route is a crucial task in MANET where routes tend to be multi-hop. Many routing protocols have been proposed in literature. However, few of them are efficient when the network is sparse and highly dynamic. Position-based routing and forwarding provides the opportunity for improving the efficiency and performance of the existing MANET routing strategies. This research work presents an extensive overview of geographic forwarding techniques in MANET. In particular, it focuses on the presentation of the basic operation mode of geographic forwarding, which is greedy forwarding. Meanwhile, this research work presents a qualitative evaluation of the most current and popular greedy forwarding strategies used with position based routing protocols. Furthermore, the findings have been used to conclude the most appropriate unicast forwarding policy for future research efforts.
Si–Ge–Mo composites are prepared using an RF/DC magnetron sputtering method, and their potential use as anode materials for rechargeable lithium-ion batteries is investigated. The Si–Ge–Mo composite films present an amorphous structure. The reaction mechanism of the Si–Ge–Mo with Li is investigated by various analytical techniques. The fabricated Si0.41Ge0.34Mo0.25 composite film shows excellent electrochemical properties, including a high energy density (1st charge: 1193mAhg−1), long cycleability (ca. 870mAhg−1 over 100 cycles), and good initial Coulombic efficiency (ca. 96%). Additionally, when coupled with a LiCoO2 cathode, the Si0.55Ge0.22Mo0.23 composite electrode used as an anode shows excellent cycleability with a high energy density. The excellent electrochemical properties demonstrated by the Si–Ge–Mo composite film electrode confirm its potential as an alternative anode material for lithium-ion batteries.
Assessing the biomass and productivity of fin- and shellfish supported by coastal ecosystems is important to develop plans for the conservation and restoration of these ecosystems, but such assessments are not easy to obtain. We developed a protocol that, from density data, quantifies biomass at recruitment for species where information exists to derive life history tables, and productivity where such information does not exist. Our protocol also assesses the variability (i.e., variance) for the calculated biomass and productivity values. For relatively well-reported species, inferences regarding differences among habitats or species can be suggested. For instance, application of our protocol to juvenile pinfish confirms its well-known preference for structured habitats. Mud crabs also seem to reach higher productivity levels in structured than open bottom habitats. For poorly reported species, only a general idea can be gleaned. However, larger data sets of fin- and shellfish density in shallow coastal systems are needed to increase the accuracy, precision, and comprehensiveness of the estimates of biomass at recruitment and productivity generated with our protocol. With such larger data sets and the use of statistical tools such as Bayesian methods, the protocol can significantly help improve our understanding and management of fisheries productivity in coastal systems.
Negawatt trading or trade in wattage of energy saved from consumption has been a much debated idea that has evaded wide-scale practical application. Tushar et al. look at the challenges to wide-scale negawatt trading and explain how recent technological developments can help address those challenges.
When lithium-ion batteries age with cycling, the battery capacity decreases and the resistance increases. The aging mechanism of different types of lithium-ion batteries differs. The loss of lithium inventory, loss of active material, and the increase in resistance may result in battery aging. Generally, analysis of the battery aging mechanism requires dismantling of batteries and using methods such as X-ray diffraction and scanning electron microscopy. These methods may permanently damage the battery. Therefore, the methods are inappropriate for the battery management system (BMS) in an electric vehicle. The constant current charging curves while charging the battery could be used to get the incremental capacity and differential voltage curves for identifying the aging mechanism; the battery state-of-health can then be estimated. This method can be potentially used in the BMS for online diagnostic and prognostic services. The genetic algorithm could be used to quantitatively analyze the battery aging offline. And the membership function could be used for onboard aging mechanism identification.
Heat generation plays an important role for energy storage systems like batteries in electric and hybrid vehicles. In order to investigate the thermal and electrical behaviour the batteries were exposed to cycling programs including various methods of battery cooling by flowing air. Two different experimental methods were presented to study the establishing of the heat balance. The second part of the paper describes the simulation of the temperature distribution by using finite element methods (FEM). The electric and thermal battery model was compared with results obtained from temperature measurements at four selected points during battery cycling.
Systemic hypertension is a prominent feature in humans with metabolic syndrome (MS) and this is partly caused by an enhanced endothelin-1 (ET-1) mediated vasoconstriction. There are indications that systemic hypertension might be a feature in equine metabolic syndrome (EMS) but if ET-1 is involved in the development of hypertension in horses is not known. Increased levels of cortisol have also been found in humans with MS but there are no reports of this in horses. Before blood pressure, plasma ET-1 and serum cortisol can be evaluated in horses with EMS, it is necessary to investigate the interday variation of these parameters on clinically healthy horses. The aims of the present study were therefore to evaluate the interday variation and influence of transportation on systemic blood pressure, plasma ET-1 and serum cortisol in healthy Standardbred and Icelandic horses, and to detect potential breed differences.
Identifying suitable layered materials as electrodes with desirable electrochemical properties remains a key challenge for rechargeable Na-ion batteries (NIBs). Using first principles methods, here we examine the efficacy of layered molybdenum disulphide (MoS2) as a host electrode material for NIBs. We identify various low energy Na adsorption sites and evaluate the stability of the hexagonal and tetragonal polytypes of MoS2 upon Na intercalation. Our results illustrate a moderately strong binding between Na and MoS2 that is thermodynamically favorable against the cluster formation and phase separation of Na. We find that while Na intercalation in MoS2 results in a phase transformation from the hexagonal phase to the tetragonal phase, it gives rise to a maximum theoretical capacity of 146 mAh g−1 and a low average electrode potential in the range of 0.75–1.25 V. Our calculations of Na diffusion kinetics indicates a moderately fast mobility of Na in the van der Waals interlayer spaces of MoS2. These results highlight the promise of MoS2 as an appealing negative electrode (anode) for rechargeable NIBs.
In electrochemical catalysis, parameters such as current, resistance, or capacitance must be referred to the electrochemically exposed area, otherwise they lack physical sense. For this reason it is necessary to know this exposed area as accurately as possible. Although there are several experimental methods to estimate the electrochemically exposed area, these are usually not suitable for different metals and present large errors in measurements, for example when two or more metals are mixed. Moreover, the technical difficulties of carrying out this type of measure mean that it is often necessary to resort to approximations with great error, such as the spherical approach, with the aim of having an approximate value of the area. In this work, Molecular Dynamics simulations were performed to study the morphology of graphene-supported nanoparticles. A method for the calculation of the electrochemically active surface area is proposed and tested for Pt, Au, and Pt/Au nanoalloys. These results are compared with existent experimental data and a model is proposed for the calculation of the electrochemically active area for supported nanoparticles of different sizes.
This study aims to develop a correlation equation between a porous electrode structure and the effective conductivity so as to design an optimal structure for a thick electrode layer of a high-capacity battery. We carried out a three-dimensional reconstruction of a lithium cobalt oxide and graphite electrode based on the cross-sectional images obtained via focused ion beam-scanning electron microscopy (FIB-SEM). The Li ion and electron conductivities are evaluated based on the effective conductive path determined from simulation and these values are compared with the experimental results obtained by electrochemical impedance spectroscopy carries out with a symmetric cell and the direct conductivity measurement under compression. Moreover, the amount of binder and the diameter of the active material particles are increased and decreased numerically using an actual reconstructed electrode structure, and the effect of those structures on the effective conductivity is examined. The most dominant factors that degrade ionic conductivity are the binder distribution and the particle morphology, respectively, in the cathode and anode, and a correlation equation with the function of porosity is obtained. These values are compared with those obtained by theoretical model equations, and the difference between the current effective ionic conductivity and the physical limiting value is determined.
Objective: To examine the relationship between severity of injury and objective and subjective posttraumatic brain injury (TBI) symptomatology many years postinjury. Design: Observational, cross-sectional. Setting: Research center at an urban medical facility. Participants: 496 community dwelling adults with TBI ranging in severity from mild to severe. Participants ranged from 15–47 years postinjury. Interventions: Not applicable. Main Outcome Measures: Measures included severity of injury as measured by duration of loss of consciousness, the Brain Injury Screening Questionnaire, a 100-item self-report measure of cognitive, emotional, and physical symptoms and the Cambridge Neuropsychological Test and Automated Battery, a computerized assessment of neuropsychological functioning. Results: Results of a multivariate analysis of variance revealed no differences across levels of injury severity in self-reported memory/attention symptoms, mood symptoms, or impulsivity/dysexecutive symptoms. Differences in physical symptoms were found across severity groups such that individuals who had lost consciousness for 20 minutes to 1 day reported more physical symptoms than all other severity levels (P<.05), and the severity-physical symptom relationship reveals a curvilinear trend. These findings were maintained when time since injury was controlled for. Similarly, in a sample of 89 individuals with TBI, no differences were found in objective neuropsychological performance (on measures of processing speed, accuracy, or executive functioning) across levels of injury severity. Conclusions: The patterns of subjective and objective symptomatology observed in our cohort of individuals 15–47 years post-TBI contradict the conventional assumption that individuals with more severe injuries (as measured by loss of consciousness) experience more symptoms. This calls into question the usefulness of duration of loss of consciousness as a means of classifying TBI severity, given its inability to predict the long-term course of TBI.
This paper presents, for the first time, the recycling and use of spent Li-ion battery cathode tape as a catalyst in the degradation of an organic dye. In our proposal, two major environmental problems can be solved: the secure disposal of cell phone batteries and the treatment of effluents with potentially toxic organic dyes. The spent Li-ion battery cathode investigated in this paper corresponds to 29% of the mass of Li-ion batteries and is made up of 83% LiCoO2, 14.5% C and less than 2.5% Al, Al2O3 and Co3O4. The use of spent Li-ion battery cathode tape increased the degradation velocity constant of methylene blue in the absence of light by about 200 times in relation to pure H2O2. This increase can be explained by a reduction in the activation energy from 83kJmol−1 to 26kJmol−1. The mechanism of degradation promoted by LiCoO2 is probably related to the generation of superoxide radical (O2 − ). The rupture of the aromatic rings of methylene blue was analyzed by ESI-MS.
High-performance, low-cost, safe and environmentally friendly batteries are important for portable electronics and electric vehicles. Here, we synthesized NiAlCo-layered double hydroxide (LDH) nanoplates attached to few-walled carbon nanotubes (NiAlCo LDH/CNT) as the cathode material of a rechargeable NiZn battery in aqueous alkaline electrolytes. The α-phase nickel hydroxide with ultrathin morphology and strong coupling to nanotubes afforded a cathode with a high capacity of ∼354 mA h g−1 and ∼278 mA h g−1 at current densities of 6.7 A g−1 and 66.7 A g−1, respectively. Al and Co co-doping is unique for stabilizing α-phase nickel hydroxide with only a small capacity loss of ∼6% over 2000 charge and discharge cycles at 66.7 A g−1. Rechargeable ultrafast NiZn batteries with NiAlCo LDH/CNT cathode and a zinc anode can deliver a cell voltage of ∼1.75 V, energy density of ∼274 W h kg−1 and power density of ∼16 kW kg−1 (based on active materials) with a charging time of <1 minute. The results open the possibility of ultrafast and safe batteries with high energy density.
Election campaigns are not only party campaigns, but depend to a significant degree on the efforts and activities of individual candidates. While some country-specific analyses of candidate campaigning have been done, large-N comparative studies are missing. The 2009 European Election Candidate Study, conducted in all 27 EU countries, does allow for such a comparative analysis. On the basis of this data, the article takes a closer look at three core components of individual campaigns and their respective determinants: duration, intensity, and the use of different campaign tools. Our findings show that only a combination of factors on the individual, party, and country level is able to explain significant amounts of the observed variance in each of the core components.