batterydata/paper-abstracts huggingface dataset:
Lithium sulfur battery is considered one of the most promising rechargeable energy storage devices due to its ultrahigh theoretical energy density and specific capacity. It still cannot be applied because of some key problems. In particular, the shuttle effect of soluble polysulfide compounds leads to the rapid attenuation of battery capacity, short cycle life and serious self-discharge effect. TiO2 quantum dots and polysulfide compounds have strong interactions and can capture soluble polysulfide compounds, thus inhibiting the shuttle effect. Herein, we introduce a battery separator based on TiO2 quantum dots modified multi walled carbon nanotubes to solve the shuttle effect and adapt to the expansion of electrodes during charging and discharging. The interlayer has abundant spacing and excellent conductivity. This strategy can significantly improve the stability of lithium sulfur batteries. As a result, Li-S cells with MWCNTs@TiO2 quantum dots modified separator deliver an initial capacity of 1083 mAh g−1 and keep a cycle capacity of 610 mAh g−1 after 600 cycles at the rate of 838 mA g−1, which maintains an average capacity decay of only 0.072% per cycle. This simple and effective method can greatly improve the application capacity of lithium sulfur batteries.
In this work, the electrochemistry of the tris(2,2‘-bipyridine) complex of iron(II) was investigated, in order to develop a better understanding of the behaviour of this complex. Two ionic liquids (ILs), based on the 1-ethyl-3-methylimidazolium cation and two ILs based on the 1-butyl-1-methylpyrrolidinium cation, as well as three conventional aprotic solvents were used. The semi-integral electroanalysis was used to aid the interpretation of the results. The iron(II) complex presented a reversible oxidation reaction and three reduction reactions, which are normally considered to be reversible, however our results demonstrate that this is not always the case, with the reversibility of the reactions being highly dependent on the solvent used. A novel method for synthesising iron(III) tris(2,2‘-bipyridine) is reported, and mixtures of the iron(II) and iron(III) complexes were used to determine the standard rate constants of the oxidation reaction. The long term stability of solutions of the iron(III) complex is also studied in this work, which is very important for possible electrochemical applications of this complex, such as in battery electrolytes.
Over 3 million stillbirths occur annually in sub Saharan Africa; most occur intrapartum and are largely preventable. The standard of care for fetal heart rate (FHR) assessment in most sub-Saharan African settings is a Pinard Stethoscope, limiting observation to one person, at one point in time. We aimed to test the functionality and acceptability of a wireless FHR monitor that could allow for expanded monitoring capacity in rural Southwestern Uganda.
LiFePO4/polyacenes (PAS) composite is synthesized by iron oxyhydroxide as a new raw material and phenol–formaldehyde resin as both reducing agent and carbon source. The mechanism of the reaction is outlined by the analysis of XRD, FTIR as well as TG/DSC. The results show that the formation of LiFePO4 is started at 300°C, and above 550°C, the product can be mainly ascribed to olivine LiFePO4. The electrochemical properties of the synthesized composites are investigated by charge–discharge tests. It is found that the prepared sample at 750°C (S750) has a better electrochemical performance than samples prepared at other temperatures. A discharge capacity of 158mAhg−1 is delivered at 0.2C. Under high discharge rate of 10C, a discharge capacity of 145mAhg−1 and good capacity retention of 93% after 800 cycles are achieved. The morphology of S750 and PAS distribution in it are investigated by SEM and TEM.
Electrochemically prepared poly(methyl)thiophene is characterized by cyclic voltammetry and galvanometry with an activated carbon counter-electrode. It is then used as a cathode in a laminated plastic asymmetric hybrid electrochemical device with a nano-structured Li4Ti5O12 anode. This device displays the specific power of a supercapacitor, with a higher specific energy of 10Wh/kg, and better cycle-life than a Li-ion battery. The matching ratio of the active materials was found to strongly influence cycle-life.
Composites with conducting polymers (ICPs) as a matrix were electrodeposited on anodes of platinum or carbon black filled polypropylene from a stirred electrolyte with dispersed particulate materials (concentration c E) such as copper phthalocyanine or carbon black (CB). The solvent (H2O or CH3CN) contained the monomer (pyrrole or bithiophene) and the supporting electrolyte, 0.1 M LiClO4. The concentration c C in the composite increases in proportion to log c E, starting from a threshold value c E,O. c C-Values of 2–60% are found, depending on the nature of the dispersed material; c E,0 varies widely, from 1 mg dm−3 to 1 g dm−3. A codeposition mechanism could be derived, consisting of two steps: I. Temkin type strong adsorption of the particle and II. charge transfer. II was treated as an activated, potential dependent process. In case of the polypyrrole/CB-composite c C decreases with increasing BET-surface. This is rationalized in terms of a synchronous charge of the electrochemical double layer capacitance of the CB particles. PPy as a matrix is superior over polybithiophene, were oligomers are dissolving. High insertion rates (c C) are obtained in comparison to other systems.
The local heat generation in a single stack lithium ion battery cell was investigated as a function of the C-rate and state of charge (SoC). For that purpose, a custom build electrochemical cell design developed for local in-operando temperature measurements is used. The local temperature evolution in both electrodes and the separator is compared with local heat generation rates calculated from galvanostatic intermittent titration technique (GITT) measurements. The impact of reversible and irreversible heats is evaluated as a function of the C-rate and the SoC. The results reveal substantial differences in the local heat generation rates of the individual components of the battery cell related to their kinetic and thermodynamic properties. Significant SoC dependencies of the local reversible and irreversible heat generation are reflected by both the local temperature measurements and the heat generation rates calculated from GITT. A distinct asymmetry between charging and discharging is revealed which results from the intrinsic asymmetry of the reversible heat as well as differences in the kinetic limitations of the lithiation and delithiation of active materials. This study indicates, that the heat generation rates of the individual cell components should be considered accurately in order to build up basics for targeted material-, design- and thermal management optimization to handle thermal issues in large battery packs.
The thermodynamic and kinetic properties of Pd-coated Mg y Sc(1− y) thin film electrodes are investigated. These thin film electrodes can be described as a two-layer structure, in which the Pd and Mg y Sc(1− y) layer contribute to the overall electrochemical response. In order to identify the response of the Pd layer in the two-layer system, thin films consisting of solely Pd, with identical thickness and orientation, were measured. Based on the fact that the chemical potentials of the individual layers of the Pd-coated Mg y Sc(1− y) thin films are equal at equilibrium, the exact hydrogen concentration in each layer could be determined. It is shown that during the major part of the hydrogen extraction process of the Mg y Sc(1− y) thin films, the composition of the Pd topcoat is close to PdH0.001. The kinetics of the surface reactions was investigated using electrochemical impedance spectroscopy and showed that, when cross-correlating the results of Mg y Sc(1− y) thin films (y =0.65−0.85) and pure Pd films, the surface kinetics are completely dominated by the Pd topcoat. Additionally, it was shown that the charge transfer reaction, and not the absorption reaction is the rate-determining step. The impedance response, dominating the overall kinetic impedance at the hydrogen-depleted state, could be linked to the transfer of hydrogen across the Pd/Mg y Sc(1− y) interface in the two-layer thin film electrode.
Abstract A closed-loop system for autonomous management of disease symptoms can provide better care for patients who have chronic illnesses, and improve the healthcare system with personalized medicine and lower costs. Wireless electronics play a key role in forming a closed-loop network between body and computer. Computers can continuously utilize detected physiological signals from body, analyze conditions by adaptive algorithms, and directly deliver therapeutic stimulation to the tissues. Two examples are introduced in this chapter, including neural and gastric electrical stimulation applications targeting management of neurological and gastric disorders. System designs and experimental results illustrate the feasibility of the feedback-based stimulation to alleviate symptoms. Wireless signal transduction and wireless power transfer mechanisms across tissues make it possible to eliminate battery in the implants for long-term use and reduce implant size for endoscopic implementation. Practical considerations for efficient wireless power transfer with small antennas are discussed.
Bifacial photovoltaics are widely investigated with the aim of reducing the amount of silicon used and increasing conversion efficiencies. The output power of bifacial photovoltaics depends on the quantity of solar radiation incident on the reverse face. Furthermore, controlling the orientation can distribute the times of peak power output in the morning and afternoon to better match the demand. In this study, the demand patterns of individual houses or the whole Hokkaido region were analyzed assuming the substitution of a conventional large-scale electric power system with one using bifacial photovoltaics. The supply–demand balances and electrical storage capacities were investigated. When comparing a large scale solar power plant (mega-solar power plant) using monofacial photovoltaics or vertical bifacial photovoltaics (in which the orientation could be adjusted), the supply–demand could be better balanced for individual houses in the latter case, thereby allowing the storage capacity to be reduced. A bifacial solar module was modeled by 3D-CAD (three dimensional computer aided design) and thermal fluid analysis. The module temperature distribution of bifacial photovoltaics was calculated with respect to the environmental conditions (wind flow, direct and diffuse solar radiation, etc.) and internal heat generation, as well as the orientation of the solar panels. Furthermore, the output power of bifacial photovoltaics can be easily obtained from the analysis result of modular temperature distribution and the relation between temperature and output power.
The threshold and direction of excitability changes induced by low- and high-frequency repetitive transcranial magnetic stimulation (rTMS) in the primary motor cortex can be effectively reverted by a preceding session of transcranial direct current stimulation (tDCS), a phenomenon referred to as “metaplasticity”. Here, we used a combined tDCS–rTMS protocol and visual evoked potentials (VEPs) in healthy subjects to provide direct electrophysiological evidence for metaplasticity in the human visual cortex. Specifically, we evaluated changes in VEPs at two different contrasts (90 and 20 %) before and at different time points after the application of anodal or cathodal tDCS to occipital cortex (i.e., priming), followed by an additional conditioning with low- or high-frequency rTMS. Anodal tDCS increased the amplitude of VEPs and this effect was paradoxically reverted by applying high-frequency (5 Hz), conventionally excitatory rTMS (p < 0.0001). Similarly, cathodal tDCS led to a decrease in VEPs amplitude, which was reverted by a subsequent application of conventionally inhibitory, 1 Hz rTMS (p < 0.0001). Similar changes were observed for both the N1 and P1 component of the VEP. There were no significant changes in resting motor threshold values (p > 0.5), confirming the spatial selectivity of our conditioning protocol. Our findings show that preconditioning primary visual area excitability with tDCS can modulate the direction and strength of plasticity induced by subsequent application of 1 or 5 Hz rTMS. These data indicate the presence of mechanisms of metaplasticity that keep synaptic strengths within a functional dynamic range in the human visual cortex.
Binary nickel–cobalt oxy-hydroxides (denoted as NCOH) with tunable crystal phases are prepared from an atomic mixture of Ni(OH)2 + Co(OH)2 in the 1:2 ratio (denoted as (Ni/2Co)(OH)2) through a microwave-assisted hydrothermal annealing (MAHA) method. The (Ni/2Co)(OH)2 powders are synthesized through a sol–gel process from an aqueous solution containing NiCl2·6H2O and CoCl2·6H2O. The MAHA process is demonstrated to be a novel and promising method for transforming/tuning the crystal phase and size of NCOH at relatively low annealing temperatures in short time. The MAHA temperature and time are varied to transform the crystalline phases from a hydroxide mixture to NiCo2O4 nanocrystals, which can be quantified by a crystalline index (denoted as CI) value obtained from X-ray diffraction (XRD) patterns. The higher content and larger size of NiCo2O4 nanocrystals are, the longer electrochemical activation time is needed. The rate of phase transformation can be enhanced by adding microwave adsorbents, graphene oxide (GO), to obtain a NiCo2O4/RGO composite with reduced crystal size (RGO: reduced GO). The variation in the crystalline index and the effect of the potential window on the specific capacitance of NCOH powders are systematically compared and discussed in this work.
A facile method for preparing mesoporous perforated Co3O4 nanoparticles with hollow channels and a thin carbon layer was newly designed and achieved with sacrificial carbon nanotube (CNT) templates. The threaded Co3O4 nanoparticles on the CNTs were fabricated through a hybridization process, and a subsequent calcination process produced mesoporous perforated Co3O4 nanoparticles. With a finely tuned calcination, CNTs were sacrificed to generate hollow channels in the Co3O4 nanoparticles and to provide a carbon source for the formation of a few nm-thick carbon layer on the surface of the Co3O4 nanoparticles simultaneously. The prepared mesoporous perforated Co3O4 nanoparticles with a robust electronic conductive layer enabled not only an enhanced electrochemical reactivity from the greatly increased contact area between the electrolyte and electrode but also a high electronic conductivity of the overall electrode so that excellent electrochemical performances (1115.1 mA h g−1 after 100 cycles; 595.9 mA h g−1 @ 5 C rate) were successfully achieved in the anode application of a lithium-ion battery.
Publisher Summary Energy is no less crucial to the environmental dimensions of human well-being than to the economic ones. Energy use and environmental problems are strongly interrelated. Energy systems are critical to the economy of nations and are slow to change. At the same time, environmental issues are critical to energy planning because environmental constraints and the costs of coping with them are as important as resource scarcity or the monetary costs of energy technology. Investments in energy efficiency are the most cost-effective way to simultaneously reduce the risks of climate change, oil import interruption, and local air pollution, and to improve the productivity of the economy. Energy and economics interact directly through supply and demand, prices, and capital investments.
Serotonin is a monoamine neurotransmitter produced from tryptophan and abnormal levels of these molecules have been associated with several disorders, notably depression, migraine, bipolar disorder, anxiety and schizophrenia. In the present work, we have developed a novel electrochemical sensor using SnO2-SnS2 nanocomposite for selective and simultaneous determination of depression biomarkers serotonin (SE) and tryptophan (Trp) in the presence of ascorbic acid (AA). The SnO2-SnS2 composite prepared by hydrothermal method was characterized by powder XRD, FE-SEM, FITR, UV–Visible, CV, EIS and SWV techniques. The SnO2-SnS2 modified glassy carbon electrode (SnO2-SnS2/GCE) exhibited two well defined oxidation peaks at 0.43 and 0.83V corresponding to SE and Trp respectively in phosphate buffer saline at pH7. Under optimum conditions, linear relationships between the peak currents and concentrations were obtained in the range of 0.1–700μM for SE and 0.1–800μM for Trp with the lowest detection limits (3s/m) of 45 and 59nM respectively. Significant peak to peak separations and higher peak currents make this electrode suitable for simultaneous detection of the two important neurochemicals SE and Trp. The sensor was successfully applied for the detection of SE in human blood samples and Trp in spirulina with high recovery percentage.
Time-of-use electricity tariffs are gradually being introduced around the world to expose consumers to the time-dependency of demand, however their effects on peak flows in distribution networks, particularly in areas with domestic energy storage, are little understood. This paper presents investigations into the impact of time-of-use and time-of-export tariffs in residential areas with various penetrations of battery storage, rooftop solar PV, and heat pumps. By simulating battery operation in response to high resolution household-level electrical and thermal demand data, it is found that home batteries operating to maximise cost savings in houses signed up to time-dependent tariffs cause little reduction in import and export peaks at the low voltage level, largely because domestic import and export peaks are spread out over time. When operating to maximise savings from the first three-tier time-of-use tariff introduced in the UK, batteries could even cause increases in peak demand at low voltage substations, if many batteries in the area commence charging at the start of the overnight off-peak price band. Home batteries operating according to time-dependent electricity tariffs significantly miss out on the potential peak shaving that could otherwise be achieved through dedicated peak shaving incentives schemes and smarter storage control strategies.
ABSTRACT Investigations on several B, C and D-segment vehicles were done to evaluate the impact of an engine encapsulation on the cooling down behaviour of the engine. Approximately 7K higher temperatures measured in the powertrain after 12 hours cooling down can be expected of such a concept. Main target of heat storage in the powertrain is to reduce CO2 emissions during engine restart due to elevated oil and coolant starting temperatures. Estimations based on measurements and calculations done on a C-segment diesel car resulted in a CO2 reduction of about 1.5 percent in the NEDC cycle after 9 hours cooling down. Two different encapsulation approaches where tested and compared to each other. Assets and drawbacks of both approaches in terms of heat storage capability, thermal safety and weight balance were investigated.
In this study, BaFeO4 was prepared from K2FeO4 and characterized by SEM, XRD, IR, and TG. BaFeO4 is insoluble in pure water and its solubility increases with the increase in the concentration of KOH solution. The measured solubility of BaFeO4 is higher than that of K2FeO4 in saturated KOH solution at 25°C, and may be due to the presence of a higher concentration of carbonate in the concentrated KOH solution. BaFeO4 has been found to decompose both in dry environment and in KOH solution. The instability of BaFeO4 is studied in detail by means of constant current discharge, XPS, XRD, and IR spectra. The reason why BaFeO4 is not stable is discussed in this paper.
Cognitive remediation (CR) has shown significant promise in addressing the cognitive deficits that accompany serious mental illness. However, this intervention does not appear to completely ameliorate the cognitive deficits that accompany these illnesses. D-cycloserine (DCS), an NMDA receptor partial agonist, has been shown to enhance the therapeutic benefits of learning-based psychosocial interventions for psychiatric disorders. Thus, the goal of this study is to examine the utility of combining cognitive remediation and d-cycloserine in the treatment of cognitive deficits among individuals with bipolar disorder.
Solution processed perovskite semiconductors have developed rapidly over the past decade to yield excellent performance in both solar cell and light emitting diode devices. Both of these device types are prepared using similar materials and architectures, raising the possibility of perovskite based light emitting solar cells. Recent reports have indicated that some low band gap perovskite solar cells are able to emit infrared light efficiently, however, intermediate band gap perovskite solar cells which emit visible light have not, to the best of our knowledge been deliberately designed or extensively characterized. In this work, we have investigated the use of different electron transport layers in order to minimize energetic barriers to electron injection and extraction in methylammonium lead bromide (MAPbBr3) films. We demonstrate that through appropriate band structure engineering, MAPbBr3 can be used to make such “peroptronic” light-emitting solar cells, which simultaneously exhibit efficient solar cell power conversion efficiencies over 1% and 0.43 lm W−1 green light emission.
In ecotoxicology, critical effect concentrations are the most common indicators to quantitatively assess risks for species exposed to contaminants. Three types of critical effect concentrations are classically used: lowest/ no observed effect concentration (LOEC/NOEC), LCx (x% lethal concentration) and NEC (no effect concentration). In this article, for each of these three types of critical effect concentration, we compared methods or models used for their estimation and proposed one as the most appropriate. We then compared these critical effect concentrations to each other. For that, we used nine survival data sets corresponding to D. magna exposition to nine different contaminants, for which the time-course of the response was monitored. Our results showed that: (i) LOEC/NOEC values at day 21 were method-dependent, and that the Cochran–Armitage test with a step-down procedure appeared to be the most protective for the environment; (ii) all tested concentration–response models we compared gave close values of LC50 at day 21, nevertheless the Weibull model had the lowest global mean deviance; (iii) a simple threshold NEC-model both concentration and time dependent more completely described whole data (i.e. all timepoints) and enabled a precise estimation of the NEC. We then compared the three critical effect concentrations and argued that the use of the NEC might be a good option for environmental risk assessment.