batterydata/paper-abstracts huggingface dataset:
In recent years, the electrochemical reduction of carbon dioxide (CO2RR) and the reduction of nitrogen (NRR) have attracted increasing attention due to their potential to transform energy from renewable and clean sources to chemical energy stored in value-added chemicals, such as hydrocarbons, alcohols and ammonia (NH3). Meanwhile, CO2RR can also reduce the global carbon footprint and address global climate change, while NRR may significantly improve the energy efficiency of NH3 production. However, because CO2 and N2 molecules are inert, electrocatalysts with low overpotentials, high selectivities and superior faradaic efficiencies (FE) are required to enhance these two kinetically slow reactions. For the first time, this review discusses the similarities and differences between CO2RR and NRR in the following aspects: (1) fundamental theory of the reaction mechanisms and the corresponding catalyst design principles; (2) reaction systems and product analysis methods; (3) recent advances in heterogeneous electrocatalysts synthesized from different metals with various compositions, structures and morphologies. Much progress has been achieved to improve catalytic performance towards CO2RR and NRR. Finally, an outlook of future developments for CO2RR and NRR is proposed.
We present a simulation and multi-objective optimization framework for the integration of renewable generators and storage devices into an electrical distribution network. The framework searches for the optimal size and location of the distributed renewable generation units (DG). Uncertainties in renewable resources availability, components failure and repair events, loads and grid power supply are incorporated. A Monte Carlo simulation—optimal power flow (MCS-OPF) computational model is used to generate scenarios of the uncertain variables and evaluate the network electric performance. As a response to the need of monitoring and controlling the risk associated to the performance of the optimal DG-integrated network, we introduce the conditional value-at-risk (CVaR) measure into the framework. Multi-objective optimization (MOO) is done with respect to the minimization of the expectations of the global cost (C g ) and energy not supplied (ENS) combined with their respective CVaR values. The multi-objective optimization is performed by the fast non-dominated sorting genetic algorithm NSGA-II. For exemplification, the framework is applied to a distribution network derived from the IEEE 13 nodes test feeder. The results show that the MOO MCS-OPF framework is effective in finding an optimal DG-integrated network considering multiple sources of uncertainties. In addition, from the perspective of decision making, introducing the CVaR as a measure of risk enables the evaluation of trade-offs between optimal expected performances and risks.
Symmetric EDLCs made using high purity carbon electrodes derived from coconut char were tested using 1 M Tetraethylammonium hexafluorophosphate dissolved in two different solvents namely acetonitrile and propylene carbonate. The cell voltage of the capacitor made using propylene carbonate can be extended to 3.5 V and it exhibited good cycling and thermal stability upto 70 °C while the voltage was limited to below 3.0 V in acetonitrile. XPS analysis of the positive and negative electrodes of EDLCs post cycling showed that the primary degradation products were related to ring opening reactions in propylene carbonate based electrolytes while water played a key role in degradation of acetonitrile based EDLCs.
Morphology control of metal sulfides has always been of great significance in the application as anode for sodium ion batteries (SIBs). In this paper, the microstructure of WS2 nanosheets were controlled by tailoring different sulfur sources, obtaining a small size and few-layered product by thioacetamide (TAA) finally. Results show that the size of WS2 nanosheets plays a significant role in the Na-ion storage. Small size and few layered WS2 nanosheets prepared with TAA exhibit the capacity of 261mA h g−1 at the current densities of 100mAg−1 and 226mA h g−1 at 700mAg−1, which is obviously higher than that of other WS2 samples. This difference of Na-ion storage performance mainly depends on the insertion reaction mechanisms of Na-ion during the charge/discharge process in diverse layered structures. It can be found that the small size and few layered structure can significantly improve the Na-ion storage with inserted into WS2 interlayers. We believe that this work will inspire the fabrication of layered structure transition metal dichalcogenides as anode materials for SIBs.
Through their dense range of empirical sortings, Kaufman and Kaliner, in this issue of Theory and Society, are effective in showing mechanisms through which places replicate themselves over time, but also in how their cultural and economic profiles can shift. Their work points to the utility of matched comparisons of historical interaction, both symbolic and material, as tool for understanding trajectories of stability and change.
Silicon has the highest known theoretical capacity (∼4140 mAhg−1) to store lithium. Among different forms of Si, Si nanowires (SiNWs) are the most promising candidates for the next-generation lithium-ion batteries. Lithiation of SiNWs is a complex process, which is not very well understood. Here, we present density functional theory calculations on Li incorporation in SiNWs using surface and interface geometries. Our results show that, initially, Li intercalation proceeds through Si(110) facets, leading to the formation of an amorphous Li2Si shell. For interfaces between the lithiated (amorphous Li2Si) shell and unlithiated (pristine c-Si) core region we find that the Li intercalation barriers are independent of the actual interface orientation, while interface energies show an orientation dependence similar to surface energies. In particular, a-Li2Si/c-Si(111) is most favorable while a-Li2Si/c-Si(110) is least favorable. Since high-energy interfaces typically show a higher mobility than low-energy interfaces, the experimentally observed anisotropic swelling of SiNWs can be understood on the basis of interface energetics.
The well-designed MWCNTs/MnO2/PPy composites, used as an anode in an asymmetric supercapacitor (ASC), were successfully synthesized via three steps. The scanning electron microscopy (SEM) exhibits that the composites have a special structure which is composed of nanotubes and many particles. To enhance the electrochemical performance of the composites, the redox additive (I-/I2) with 1 mol L−1 Na2SO4 solution is employed as electrolyte. As expected, cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) tests verify that, in three-electrode system, the specific capacitance can reach 806 F g−1 at the current density of 1 A g−1 with 1 mmol of I2. At the same time, after assembling an asymmetric supercapacitor with active carbon (AC), the maximum energy density and power density of the device is 92.4 Wh kg−1 and 761.9 W kg−1, respectively. The most important thing is that the practical application of MWCNTs/MnO2/PPy composites can be strongly demonstrated by successfully lighting a light-emitting diode.
Li4Ti5O12/C composites have been synthesized via a solid state reaction with TiO2-anatase, Li2CO3 and different carbon sources, such as conductive graphite KS-6 and sucrose, as the starting materials. It was found that the carbon layer from sucrose was homogeneously coated on the Li4Ti5O12 surface and the KS-6 was embedded among the Li4Ti5O12 particles as a conductive bridge without affecting the spinel structure of Li4Ti5O12. Moreover, it was demonstrated that the sucrose and KS-6 played different roles in improving the electrochemical properties of Li4Ti5O12/C composite. Compared with samples prepared by solely KS-6 or sucrose as the carbon source, the Li4Ti5O12/C composite (LTO-1) with KS-6 and sucrose as carbon sources together revealed the optimal electrochemical performance. It showed a high initial specific capacity of 152.5mAhg−1 at 0.2C and an excellent cycling performance with 96.8% capacity retention after 1000 cycles at 25°C at 1C. Furthermore, the (LTO-1)/LiMn2O4 full battery demonstrated a good cycling performance at 55°C and could pass the 5C–20V overcharge test, external short-circuit and nail-puncture test. Therefore, it is believed that the Li4Ti5O12/C might be a promising anode material for large-scale lithium ion batteries of electric vehicle (EV), hybrid electric vehicle (HEV) and energy storage devices for solar or wind energy.
Experiments are made with negative electrode of 2 V cell and 12 V lead-acid battery doped with typical activated carbon additives. It turns out that the negative electrode containing tens-of-micron-sized carbon particles in NAM exhibits markedly increased HRPSoC cycle life than the one containing carbon particles with much smaller size of several microns or the one containing no activated carbon. The improved performance is mainly attributed to the optimized NAM microstructure and the enhanced electrode reaction kinetics by introducing appropriate activated carbon. The beneficial effects can be briefly summarized from three aspects. First, activated carbon acts as new porous-skeleton builder to increase the porosity and active surface of NAM, and thus facilitates the electrolyte diffusion from surface to inner and provides more sites for crystallization/dissolution of lead sulfate; second, activated carbon plays the role of electrolyte supplier to provide sufficient H2SO4 in the inner of plate when the diffusion of H2SO4 from plate surface cannot keep pace of the electrode reaction; Third, activated carbon acts as capacitive buffer to absorb excess charge current which would otherwise lead to insufficient NAM conversion and hydrogen evolution.
The H2-Ce redox flow cell is optimized using commercially-available cell materials. Cell performance is found to be sensitive to the upper charge cutoff voltage, membrane boiling pretreatment, methanesulfonic-acid concentration, (+) electrode surface area and flow pattern, and operating temperature. Performance is relatively insensitive to membrane thickness, Cerium concentration, and all features of the (−) electrode including hydrogen flow. Cell performance appears to be limited by mass transport and kinetics in the cerium (+) electrode. Maximum discharge power of 895 mW cm−2 was observed at 60 °C; an energy efficiency of 90% was achieved at 50 °C. The H2-Ce cell is promising for energy storage assuming one can optimize Ce reaction kinetics and electrolyte.
A water based solid state synthesis of LiFePO4 has been conducted by utilizing freeze granulation. Various processing conditions were tested and achieved powder properties were characterized by density, XRD, specific surface area, carbon content, conductivity and SEM. Freeze granulation, a novel method for precursor preparation was shown to be an effective method to provide high degree of homogeneity prior to calcination and high ultimate yield of pure LiFePO4. Cathodes were manufactured by water based as well as NMP system based tape casting. A commercial LiFePO4/C powder was also characterized and used to manufacture cathodes as comparison in this study. Charge cycling tests showed promising results with high capacity and long term stability, well in the range of what the commercial powder provided. Post-milling of calcined powder prior to paste preparation for tape casting tended, however, to retard the capacity owing to disturbed carbon distribution and loss of conductivity of the LiFePO4/C. In comparison with the solvent system for cathode manufacturing, the water based system gave similar cell performance, illustrating the possibility to apply a more environmentally sustainable processing of Li-battery cells.
The results of using an original procedure for estimating albedo from the photogrammetric data and exposure parameters by an unmanned aerial vehicle (UAV) in Antarctica are discussed. The difficulties of photogrammetric observations performed under extreme conditions are considered. Conclusions are drawn on the ways to improve the recording equipment and on the course of refining the procedure for calculating albedo values based on photogrammetric materials and metadata.
This communication demonstrates the success in the anodic deposition of hydrous ruthenium oxide (denoted as RuO2·xH2O) from RuCl3·xH2O in aqueous media with/without adding acetate ions (CH3COO−, AcO−) as the complex agent. The benefits of as-deposited RuO2·xH2O include the low electron-hopping resistance and the low contact resistance at the Ti-RuO2·xH2O interface which are clarified in electrochemical impedance spectroscopic (EIS) studies. The cycling stability, specific capacitance, and power performance of as-deposited RuO2·xH2O are further improved by annealing in air at 150°C for 2h. The morphologies of as-deposited and annealed RuO2·xH2O films, examined by scanning electron microscopy (SEM), are very similar to that of thermally decomposed RuO2. The high onset frequencies of 660 and 1650Hz obtained from EIS spectra for the as-deposited and annealed RuO2·xH2O films, respectively, definitely illustrate the high-power merits of both oxide films prepared by means of the anodic deposition without considering the advantages of its simplicity, one-step, reliability, low cost, and versatility for electrode preparation.
Room temperature ionic liquids are nowadays the most appealing research target in the field of liquid electrolytes for lithium batteries, due to their high thermal stability, ionic conductivity and wide electrochemical windows. The cation structure of such solvents strictly influences their physical and chemical properties, in particular the viscosity and conductivity. In this paper we report on the preparation and characterization of a complete series of solutions between lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and the promising N-methoxyethyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)-imide (PY1,2O1) ionic liquid. A wide molality range has been explored in order to identify the optimal compositions in terms of conductivity and electrochemical stability. Our thermal results show that the solutions are amorphous independently on the LiTFSI content. Up to salt concentration of 0.4molkg−1 the solutions have a very low viscosity (η ∼36cP), a high ionic conductivity, even at temperatures below 0°C, and a good electrochemical stability. Cations transport numbers ranging between 0.05 and 0.39 have been determined as a function of LiTFSI content. The combination of these properties makes the PY1,2O1-based solutions potentially attractive liquid electrolytes for lithium batteries.
The current research examines a potentially new strategy to increase attitude certainty: framing messages as two sided. That is, we explore the consequences of articulating that others have considered both the positives and negatives of a message position, in the absence of any real differences in substantive content presented. Although classic research and theory appear to assume no clear benefit for simply framing a message as two sided, we develop and apply a meta-cognitive approach that predicts advantages for such messages with respect to attitude certainty and attitude-behavior correspondence.
Many forms of epilepsy manifest and/or are diagnosed months or even years after an epileptogenic insult or identification of a genetic defect.Epilepsies that result from an insult or genetic defect could be amenable to secondary prevention but preventive treatments are not available.Development of preventive therapies is complicated by the fact that only a subset of at-risk individuals develop clinical epilepsy.Biomarkers are needed to clearly identify individuals who have the highest risk of developing epilepsy after an epileptogenic insult.We propose a strategic roadmap designed to facilitate the identification, characterization and clinical validation of biomarkers for epileptogenesis.
Background: Many individuals living with arthritis in the UK are not able to access NHS podiatry services to manage their foot problems. We have previously reported perceived confusion over the definition of podiatry, a podiatrist’s skill set and where podiatrists can be of most benefit within the UK NHS organisation. Uncertainty was also reported with regards to decision making around 'patient access criteria' for UK NHS health care in relation to the lower limb. The aim of this study was to explore the views of stakeholders in podiatry services, patients, commissioners and general practitioners (GP), to further understand experiences of referral, access and provision of treatment in the NHS for foot problems for patients living with arthritis.
Highly ordered N-doped mesoporous carbon/graphene frameworks (N-MCF/N-MGF) were prepared using superlattice of self-assembled Fe3O4 nanoparticles as template. The prepared N-MCF catalyst shows enhanced oxygen reduction reaction (ORR) activity compared with commercial Pt/C catalyst. The N-MGF catalyst demonstrates lower oxygen evolution reaction (OER) overpotential (324mV at 10mAcm−2) than most of the previously reported carbon based materials, non-noble metal oxides and their hybrids, and comparable with noble metal oxides (ruthenium/iridium oxide, RuO2 and IrO2) catalysts. The prepared N-MGF catalysts also exhibit negligible mass transfer resistance, good durability and bifunctionality in ORR and OER. The significantly improved electrocatalytic performance results from their large surface area, ordered pores, excellent internal diffusion property, and superior intrinsic conductivity. The materials show great potential for various applications in energy conversion and storage, including fuel cells, electrolyzers and metal-air batteries.
Objective The present study examines the possibility that a chronic pain condition, such as fibromyalgia, was associated with deficits in decision making and associative learning. Methods Fifteen patients with fibromyalgia (aged 42–59 years) and 15 healthy controls (aged 39–61 years) participated in the experiment. Subjects completed anxiety (STAI) and depression (BDI) questionnaires, as well as standardized neuropsychological tests (Stroop and WAIS subscales). In addition, an emotional decision-making task (Iowa Gambling Task) and a conditional associative learning task (CALT) were administered to all participants. Results Results indicated that fibromyalgia had a poorer performance than healthy controls in both tasks, showing more perseveration errors in the learning task, and more disadvantageous decisions, as well as a more random behavior in the gambling task. Moreover, we observed that poor performance on the associative learning task was mediated by depression, whereas performance on the gambling task was not influenced by depression. No group differences were found on the standardized neuropsychological tests. Conclusion These findings indicate that pain and depressive symptoms in fibromyalgia might lead to significant deficits in emotionally charged cognitive tasks. Furthermore, it suggests that chronic pain might impose a high cost on executive control, undermining mainly affective processes involved in learning, memory, attention, and decision-making.
Nanomaterials have shown enormous potentials in electronics and energy technology innovations. However, processing of nanoscale materials is challenging and often has extremely limited scalability. We designed and synthesized a Si–carbon nanotube (CNT) yarn which is mechanically as strong and flexible as widely used yarns in the textile industry but simultaneously possesses high electrical conductivity. This composite yarn is readily weavable and the process is highly scalable. As an illustration of potential applications, coin-cell lithium ion batteries were fabricated using the yarns as the anode. Because of the high electrical conductivity, the yarn electrode performs without the need of a copper current collector. A Li-storage capacity of 2200mAh/g was demonstrated, which is five times higher than graphite electrodes and higher compared with previously demonstrated energy yarns based on pseudo capacitor or ultracapacitor materials.
Mesoporous TiO2 microspheres, synthesized by a facile template-free solvothermal method and subsequent heat treatment, are exploited as the electrode for hybrid supercapacitors. The effects of the calcination temperature on the phase composition, particulate microstructure and morphology are characterized by XRD, Raman, FE-SEM and N2 adsorption/desorption measurements. Hybrid supercapacitors utilizing the as-prepared TiO2 mesoporous microspheres as the negative electrode and activated carbon (AC) as the positive electrode in a non-aqueous electrolyte are fabricated. The electrochemical performance of these hybrid supercapacitors is studied by galvanostatic charge–discharge and cyclic voltammetry (CV). The hybrid supercapacitor built from TiO2 microspheres calcined at 400 °C shows the best performance, delivering an energy density of 79.3 Wh kg−1 at a power density of 178.1 W kg−1. Even at a power density of 9.45 kW kg−1, an energy density of 31.5 Wh kg−1 is reached. These values are much higher than the AC–AC symmetric supercapacitor. In addition, the hybrid supercapacitor exhibits excellent cycling performance, retaining 98% of the initial energy density after 1000 cycles. Such outstanding electrochemical performance of the hybrid supercapacitor is attributed to the matched reaction kinetics between the two electrodes with different energy storage mechanisms.
Publisher Summary This chapter provides an overview of the embedded system. An embedded system can be defined as “a system whose principal function is not computational but which is controlled by a computer embedded within it.” In embedded systems the computer is hidden from view, such that the user often doesn't know it's even there. Some example embedded systems discussed in the chapter are domestic refrigerator, a car door mechanism, and the Derbot autonomous guided vehicle. The chapter also describes microprocessors and microcontrollers and illustrates differences between the two. The embedded computer is usually a microcontroller: a microprocessor adapted for embedded control applications. Microcontrollers are designed according to accepted electronic and computer principles and are fundamentally made up of microprocessor core, memory, and peripherals. In addition, microchip offers a wide range of microcontrollers, divided into a number of different families. Each family has similar central architecture and instruction set. The Microchip 12F508 is a good microcontroller to introduce a range of features of microcontrollers in general and of peripheral interface controller (PIC) microcontrollers in particular.
There are two important steps necessary for the optimization of electrochemical double-layer capacitors (EDLC): maximizing the volumetric capacitance and minimizing the ohmic resistance. The application of force during the assembly of an EDLC cell is one way to achieve this optimization. The effect of the application of force on the performance characteristics of EDLC cells, assembled using porous activated carbon electrodes, was determined. It was shown that applying force to the body of the cell during assembly only provides a significant increase in the performance of the EDLC with the initial application. The results showed that any increase in the applied force beyond that initial stage does not result in a subsequent increase in performance and can result in a substantial decrease in the performance characteristics of the EDLC cell. Furthermore, it was concluded that the substantial decrease shown was attributed to an alteration of the physical structure of the porous material, which produced significant decreases in the accessible surface area and the material resistance of the activated carbon electrodes.