batterydata/paper-abstracts huggingface dataset:
The optimal design of multisource systems, hybrid systems in particular, requires an adequate choice of the energy management strategy. This latter usually impacts source sizing and lifetime. The present paper deals with an energy management approach based on a frequency sharing of the mission. Firstly, the limits of a symmetric frequency energy management are presented in the case of a hybrid system associating a fuel cell with a Li-Ion battery. Subsequently, an original energy “asymmetric” management strategy for the optimal sizing of this association is presented. This strategy is then tested on the “Hydrogen” platform at the LAPLACE research laboratory. Finally, the two energy management strategies are compared in the context of an integrated design by optimization; the asymmetric strategy offers significant gains in terms of system weight, which is important for embedded applications.
Visual memory is vulnerable to epilepsy surgery in adults, but studies in children suggest no change or small improvements. We investigated visual memory after epilepsy surgery, both group-wise and in individual children, using two techniques to assess change: 1) repeated measures analysis of variance (ANOVA) and 2) an empirically based technique for detecting cognitive change [standardized regression-based (SRB) analysis]. A prospective cohort consisting of 21 children completed comprehensive assessments of memory both before surgery (T0) and 6 (T1), 12 (T2), and 24months (T3) after surgery. For each patient, two age- and gender-matched controls were assessed with the same tests at the same intervals. Repeated measures ANOVA replicated the results of previous studies reporting no change or minor improvements after surgery. However, group analysis of SRB results eliminated virtually all improvements, indicating that the ANOVA results were confounded by practice effects. Standardized regression-based group results showed that in fact patients scored lower after surgery than would be predicted based on their presurgical performance. Analysis of individual SRB results showed that per visual memory measure, an average of 18% of patients obtained a significantly negative SRB score, whereas, on average, only 2% obtained a significantly positive SRB score. At T3, the number of significantly negative SRB scores outweighed the number of significantly positive SRB scores in 62% of patients. There were no clear associations of clinical variables (including side and site of surgery and postsurgical seizure freedom) with memory outcome. The present analysis revealed that given their individual presurgical functioning, many children obtained disappointing results on some visual memory tests after epilepsy surgery. Comparison of the SRB analysis with ANOVA results emphasizes the importance of empirically based techniques for detecting cognitive effects of epilepsy surgery in childhood.
The Intergovernmental Panel on Climate Change's fifth assessment report emphasizes the importance of bioenergy and carbon capture and storage for achieving climate goals, but it does not identify solar energy as a strategically important technology option. That is surprising given the strong growth, large resource, and low environmental footprint of photovoltaics (PV). Here we explore how models have consistently underestimated PV deployment and identify the reasons for underlying bias in models. Our analysis reveals that rapid technological learning and technology-specific policy support were crucial to PV deployment in the past, but that future success will depend on adequate financing instruments and the management of system integration. We propose that with coordinated advances in multiple components of the energy system, PV could supply 30–50% of electricity in competitive markets.
The Internet of Things (IoT) is an emerging paradigm that requires billions of wirelessly connected devices in a complex radio-frequency (RF) environment. With such a huge number of devices in this scenario, recharging or replacing batteries becomes impractical. Therefore, powering IoT devices by harvesting energy from ambient sources, such as that available in the RF spectrum, is an attractive solution. The antenna for the RF energy harvester must work on multiple bands to capture as much power as possible. This paper presents a fully printed 3D cube triple band Cantor fractal rectenna based on the system-on-package (SoP) concept; the antenna is realized on the package that houses a rectifier circuit and a multiband matching network. The combination of additive manufacturing and SoP ensures a lower cost and the efficient use of available space. The rectenna harvests RF power from GSM900, GSM1800, and 3 G 2.1 GHz frequency bands. Field tests of the RF energy harvester conducted in a real ambient environment confirm that up to 200 mV output voltage can be harvested. Also, 550 mV is harvested when the rectenna is near a smartphone during a live phone call. The promising results and lower cost make this design a suitable candidate to power IoT devices.
Stress occurring at the feet while wearing footwear is often determined using pressure measurement systems. However, other forms of stress, such as bending, torsional and shear loadings, cannot be detected in shoes during day-to-day activities. Nevertheless, the detection of these types of stresses would be helpful for understanding the mechanical aspects of various kinds of hard and soft tissue injuries. Therefore, we describe the development of a new measuring device that allows the reliable determination of bending and torsional load at the foot in shoes.
The high-resolution Fourier diffractometer (HRFD) was commissioned at the IBR-2 pulsed reactor at FLNP JINR in 1994. The specific feature of the HRFD design is the use of fast Fourier chopper for modulating the primary neutron beam intensity and the correlation method of diffraction data acquisition. This allowed to reach with HRFD extremely high resolution (Δd/d ≈ 0.001) over a wide range of inter-planar spacings at a relatively short flight path between chopper and sample (L = 20 m). Over time, a lot of diffraction experiments on crystalline materials, the main goal of which was to study their atomic and magnetic structures, were performed at HRFD. Successful implementation of the Fourier diffractometry technique at the IBR-2 reactor stimulated the construction of yet another Fourier diffractometer intended for internal mechanical stress studies in bulk materials (FSD, Fourier Stress Diffractometer). In this paper the experience of using this technique at the IBR-2, which is a long-pulse neutron source, is considered, the examples of HRFD studies are given, and possible solutions for existing technical problems of using correlation diffractometry and ways of increasing the intensity and resolution of HRFD are discussed.
“Making weight” behaviors are unhealthy weight control strategies intended to reduce weight in an effort to meet weight requirements. This study aimed to examine a brief measure of making weight and to investigate the relationship between making weight and weight, binge eating, and eating pathology later in life.
Objective To examine variables from social cognitive theory as correlates of physical activity in black and white individuals with multiple sclerosis (MS). Design Cross-sectional. Setting National survey. Participants Black (n=151) and white (n=185) individuals with MS were recruited through the North American Research Committee on Multiple Sclerosis Registry. Intervention Not applicable. Main Outcome Measures The battery of questionnaires included information on demographic and clinical characteristics, physical activity, exercise self-efficacy, function, social support, exercise outcome expectations, and exercise goal setting and planning. Results Black individuals with MS reported significantly lower levels of physical activity compared with white individuals with MS. Physical activity levels were significantly correlated with self-efficacy, outcome expectations, functional limitations as impediments, and goal setting in black participants with MS. The pattern and magnitude of correlations were comparable with those observed in white participants based on Fisher z tests. Conclusions Researchers should consider applying behavioral interventions that target social cognitive theory variables for increasing physical activity levels among black individuals with MS.
The fire extinguishment of a mixture of lithium-ion cathode and electrolyte is investigated based on the use of flame retardants. Four boehmite-based flame-retardants are embedded in the LiFePO4 cathode including 0.95μm AlOOH-L, 0.35μm AlOOH-S, and their individual microcapsules. The microcapsules are denoted as en-AlOOH-L and en-AlOOH-S. Here, the shell material is the chemically stable poly(urea-formaldehyde). The rheology of the cathode slurries improves as flame-retardants are added. This is especially significant for cases using microencapsulated boehmites, en-AlOOH-L and en-AlOOH-S. At 5–15wt%, the smaller AlOOH-S and en-AlOOH-S exhibit much better fire-extinguishing efficiency values—40-50% versus 30-40% for the larger AlOOH-L and en-AlOOH-L. This is because the smaller powder can be easier to form a dense barrier against further decomposition of the combustible materials. Among the four retardants, en-AlOOH-S is the best. It shows good fire retardancy in the cathode/electrolyte mixture without significant electrochemical sacrifice of the cathode.
The objective of this study was to investigate the effect of different glass ionomer cements on secondary caries inhibition in a fully automated in vitro biofilm model.
Base deficit (BD), anion gap (AG), and albumin corrected anion gap (ACAG) are used by clinicians to assess the presence or absence of hyperlactatemia (HL). We set out to determine if these tools can diagnose the presence of HL using cotemporaneous samples.
Man-made space debris is dominating the background meteorite environment with a growing debris population leading to increased collision risks for satellites, especially in the low Earth orbit and geostationary orbit protected environments. Here we present a computational model for estimating the effect of hypervelocity impact from debris particles on non-shielded propellant and pressurant tanks. Eulerian hydrocode simulation is utilised to model firstly penetration and shock wave formation in the propellant and secondly subsequent detonation wave propagation and interaction with the tank wall. Furthermore, reactive molecular dynamics is used to estimate the risk of detonation in a liquid hydrazine layer. We present simulations of a 3.5 mm aluminium spherical debris particle at a velocity of 14 km/s relative to a hydrazine tank. We find that the degree of damage is strongly dependent on tank temperature and hence on the satellite thermal configuration at its end of life.
Extensive efforts have recently been geared towards developing all-solid-state batteries largely because of their potential to enable high-energy-density Li anodes. Here, the authors report a high-performance lithium pouch cell with no excess lithium, enabled by just a dual-salt liquid electrolyte.
In the present work, nanostructured Cu2O films are directly grown from a Cu metal foil by means of a rapid thermal oxidation process. The structural characteristics of the films are investigated by field emission scanning electron microscopy, X-ray diffraction and attenuated total reflectance Fourier-transformed infrared spectroscopy. The electrochemical behaviour is investigated in both lithium (liquid electrolyte) and all-solid lithium polymer cells. At a discharge/charge rate of C/5, the films can provide a specific capacity greater than 220mAhg−1 in the all-solid configuration, with excellent cycling stability and capacity retention after prolonged cycling. High surface area, short diffusion path and good conduction of the Cu2O films are considered to be responsible for the good electrochemical performance, along with the use of the polymeric electrolyte which is directly formed in situ on the electrode film surface. The present findings can provide a new and easy approach to fabricate nanocomposite films with interesting performance as negative electrode particularly for the next generation of flexible all-solid-state Li-ion microbatteries.
The exploitation of electrode materials is extremely important for electrochemical energy storage systems with high energy and power densities as well as long lifespan. Herein, a facile halloysite nanotubes (HNTs) assisting deposition method is developed to prepare nickel disulfide interconnected nanosheet arrays on nickel manganese oxides (Ni-Mn-O) as electrodes for battery-type supercapacitors, resulting in exceptional energy storage performance. Taking advantage of the unique tubular architecture of hollow HNTs, gradient deposition of NiS2 and Ni-Mn-O nanosheets on HNTs are realized with two-step in-situ hydrothermal reaction and sulfidation. HNTs not only favor the formation of NiS2 during sulfidation but also offer good porosity for electrochemical energy storage. In solution state, the hybrid electrode exhibits a high capacity (1144.7C g−1 at 1 A g−1 and 597.5C g−1 at 20 A g−1) with excellent cyclic stability (92.6% after 2000 cycles). Solid-state symmetric supercapacitors fabricated with NiS2@Ni-Mn-O/HNT hybrid demonstrate outstanding electrochemical performance for portable energy storage application. Our symmetric supercapacitors show a highest energy density of 164.2 Wh kg−1 at a power density of 1.3 kW kg−1. The energy density remains as high as 28 Wh kg−1 even at the highest power density of 15.1 kW kg−1 with good long-term cycling stability (90.5% after 2000 cycles).
Novel hierarchical porous TiO2(B)/anatase microspheres have been prepared by a facile solvothermal approach and evaluated as anode materials for advanced lithium-ion battery applications. The obtained porous microspheres, with diameters ranging from 2.5 to 5.5μm, are assembled by porous TiO2 nanosheets with the lateral size of a few micrometers and thickness of ~13nm; whilst, the nanosheets are formed by aggregations of nanosized primary TiO2 crystallites (~5–7nm). The hierarchical porous structures are verified by BET test results with a typical type-IV isotherm curve, a high surface area (~186.2m2 g−1) and two kinds of pores (~4 and 8.3nm). The hierarchical porous TiO2 microspheres present excellent electrochemical performance with high Li storage capacity and excellent high-rate cycling capability (a specific capacity of 117mAhg−1 at the rate of 4000mAg−1 after 4500 cycles), which might be attributed to the enhanced Li+ diffusion and electronic conductivity induced by the hierarchical microstructures, the TiO2(B)/anatase heterojunction, and the pseudocapacitance of TiO2(B). Such hierarchical porous materials might be promising for applications in advanced power type lithium-ion batteries.
Power and spectrum efficiency have been the concerns for the customers in Long term evolution (LTE) uplink system. On one hand, due to the limited spectrum, it is difficult to provide a high quality of service (QoS) to the user equipment (UE) in a heavy traffic load. On the other hand, people have been paying more attention to the energy efficiency because of the battery constraint and the decreasing size of the mobile devices. Even though the issues mentioned above have been addressed in the literature, the study about tradeoff design of both two issues is sparse. The rationale for the tradeoff is that due to the fast changeable channel conditions and unpredictable data requests from UEs, adopting the unique resource allocation scheme, either power-saving (PS) or spectrum-saving (SS) scheme, is not flexible. Therefore, this paper proposes a tradeoff method to dynamically choose either PS or SS scheme according to the changeable UE's request and channel conditions. In the proposed system, multi-class UEs are considered. The performance of the PS-only scheme, SS-only scheme and the proposed hybrid scheme (H-PSSS) are analyzed and compared. Results show that the proposed hybrid scheme achieves the desired performance.
A simple mathematical model, based on the basic chemical reactions and mass transfer, was developed to predict some important characteristics of molten carbonate fuel cells (MCFC) with LiNaCO3 and LiKCO3 electrolytes for steady state operating conditions. The parallel and cross gas flow patterns were analyzed. Model simulates polarization characteristics, the effect of temperature, pressure and electrolyte type on the cell performance, various losses in the cell and gas flow rate changes through cell. The effect of fuel utilization on the cell potential and efficiency was also analyzed. Model predicts a better performance for the MCFC with LiNaCO3 electrolyte and the cross flow pattern, in general. Results show a strong influence of the operating temperature on the cell potential at temperatures below 625°C, where cell potential increases rapidly with increasing temperature. Above this temperature, however, the cell potential has almost a steady asymptotic profile. The model predicts cell efficiency steadily improving with increase in fuel utilization. The cell potential decreases almost linearly with increase in the fuel utilization percentage for both electrolytes. Models results show a stronger dependency of the cell potential on the operating pressure than that described by the Nerst equation which is in line with fact that the real variations in the cell potential can be higher due to decreased various losses.
Garnet Li7La3Zr2O12 (LLZO) solid electrolytes recently have attracted tremendous interest as they have the potential to enable all solid-state lithium batteries (ASSLBs) owing to high ionic conductivity (10−3 to 10−4 S cm−1), negligible electronic transport, wide potential window (up to 9 V), and good chemical stability. Here we present the key issues and challenges of LLZO in the aspects of ion conduction property, interfacial compatibility, and stability in air. First, different preparation methods of LLZO are reviewed. Then, recent progress about the improvement of ionic conductivity and interfacial property between LLZO and electrodes are presented. Finally, we list some emerging LLZO-based solid-state batteries and provide perspectives for further research. The aim of this review is to summarize the up-to-date developments of LLZO and lead the direction for future development which could enable LLZO-based ASSLBs.
Nanocrystalline, nanostructured, defective tin oxide particles and electrodes (supported on Ti) were prepared by a common synthetic path. The electrodes were characterized by cyclic voltammetry and impedance spectroscopy in a potential range, purportedly selected to exclude the hydrogen and oxygen evolution reactions as well as any other faradaic reaction involving the massive reduction of SnO2. Parallel particle characterization was performed by BET and electrophoretic mobility. A synergistic enhancement of the descriptive capability of each investigation technique is obtained. In particular, the semiconducting properties of the Ti/SnO2 electrodes are obtained and discussed in term of emptying/filling of the electronic traps within the band gap that is in terms of oxide resistance and electron trapping capacitance. In addition the voltammetric total, outer and inner charge quantities, Q tot, Q out and Q in, are determined and interpreted in terms of “electrochemical” porosity of the oxide layer. The outcomes are in total agreement with the BET investigations of the powder. The electric surface characteristics are parallelly investigated by the pH dependence of the oxide/solution capacitance of the electrodes and by the electrophoretic mobility of the particles. The results jointly point to a substantial reduction of charge accumulation capability at pH>5–6, where a net negative charge is observed on the surface.
In this paper, RuO2/TiO2 nanotubes composites were synthesized by loading various amounts of RuO2 on TiO2 nanotubes. The symmetric supercapacitors based on these nanocomposites were fabricated by using gel polymer PVA–H3PO4–H2O as electrolyte. The electrochemical capacitance performance of the nanocomposites in these supercapacitors was investigated by current–potential responses, galvanostatic charge–discharge tests and electrochemical impedance spectroscopy. The results show that the three dimensional nanotube network of TiO2 offers a solid support structure for active materials RuO2, allows the active material to be readily accessible (available) for electrochemical reactions, and improves the efficiency of the active materials. A maximum specific capacitance of 1263F/g was obtained for the RuO2 which was loading on TiO2 nanotubes.
A facile one-step solution-phase route to RGO/Ni3S2 on nickel foam (RGO/Ni3S2/NF) was presented. The RGO/Ni3S2/NF (RNS) nanocomposites were hydrothermal-assisted synthesized, in which nickel foam acted as an auxiliary reductant of GO and S, a Ni source of Ni3S2, and a substrate for composite film. RGO/Ni3S2/NF composites were characterized by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscope (FESEM), and transmission electron microscopy (TEM). The electrochemical performances of the supercapacitor with as-synthesized RGO/Ni3S2/NF (RNS) electrodes are evaluated using cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectrometry (EIS) in 2M KOH aqueous solution. It is found that the RGO/Ni3S2/NF electrode exhibits superior supercapacitor performance (7440 mF cm−2 at 10mAcm−2, i.e., 2188.8 F g−1 at 2.9 A g−1), compared with the Ni3S2/NF electrode (4360 mF cm−2 at 10mAcm−2) and the RGO/Ni(OH)2/NF electrode (3400 mF cm−2 at 10mAcm−2) prepared under identical conditions. Both the temperature and sulfur content play important roles in the controlled synthesis of RNS and its electrochemical performance.
The resurgence of interest in oxygen reduction in non-aqueous electrolytes makes it necessary to develop a fundamental understanding of the factors influencing its kinetics and reversibility. One of these key factors is the cation of the conducting salt. This study focuses on the influence of the cation by extending research to the field of the alkaline earth cations. At gold electrodes, the main formation of the peroxides is observed for all the different cations. However, the peroxides do not lead to a deactivation of the electrode as opposed to the observations in the presence of lithium ions. Interestingly, at platinum and glassy carbon the cation exerts a more complex influence on the product distribution: The number of electrons transferred per oxygen molecule (z) increases in the order z(Ca2+)<z(Sr2+)<z(Ba2+)≈z(Mg2+). This is in good agreement with the acceptor numbers of the cations, with high acceptor numbers fostering the formation of peroxides. These results add an important aspect in understanding the oxygen reduction in non-aqueous solvents.
Iron oxide nanowires are synthesized and characterized as negative electrode for lithium ion battery. The lithium-conversion reaction of the material is studied by electrochemical techniques as well as by XRD and SEM. Lithium cells based on the electrode material evidence a reversible capacity of about 800 mAh g−1 and a multiple-step electrochemical process leading to the formation of amorphous compound. Furthermore, SEM analysis of the compound formed by direct lithium atoms deposition on the iron oxide nanowires clearly evidences the change of the electrode morphology upon formation of a lithiated phase. We believe that the data here reported may shed light on the properties of the iron oxide nanowires as high capacity anode for lithium ion battery.