batterydata/paper-abstracts huggingface dataset:
With declining prices on the German primary control reserve (PCR) market and simultaneously decreasing battery cell and system prices, it is unclear whether an investment in a battery energy storage system (BESS) providing PCR will be profitable. In order to address this issue, we outline different bidding strategies for PCR auctions and analyze their impact on revenues and battery aging. Furthermore, following a net present value (NPV) approach, we investigate how the development of PCR prices and battery system prices affects the attractiveness of BESS providing PCR. The results show that the bidding strategies developed in this paper allow for reasonable revenues from PCR provision. A higher willingness of the bidder to take risks is not rewarded with higher revenues in the scenario presented in this paper. Furthermore, the impact of the choice of the bidding strategy on battery aging seems negligible. However, the development of PCR market prices and battery system prices is crucial for the attractiveness of BESS providing PCR. Investments come with a high risk due to the volatility of PCR market prices and the uncertainty of future battery system prices. A strong drop in PCR prices would make investments unattractive, even in the case of an optimistic estimate of the BESS price development. However, if PCR prices decrease moderately, an investment in a BESS providing PCR lead to a positive NPV over the system lifetime under the assumptions made in this study.
Layered high manganese cathode materials Li1+n [Ni m Co m Mn1−2m ]O2 (n =0.46 and 0.36; m =0.15, 0.20 and 0.25) are prepared by coprecipitation method. The manganese (m <0.25) and lithium (n >0.3) content in the system are controlled at a high level. Structural and electrochemical feature changes of the resulted cathode materials have been studied thoroughly. The results indicate that the excess lithium in the cathode materials system tends to stabilize the high-Mn layered structure and improve electrochemical performance. The results reveal that samples of m =0.15 with a high manganese content exhibit the highest capacity and best cycling efficiency. The improved electrochemical performance is considered to be owing to the slow activation of Li2MnO3, which is good for stabilizing the structure.
Many researches highlight the relationship between fatigue and performance. Sleep deprivation consists in keeping the participant awake for minimum sixteen hours. The study is focused to on highlighting the influence of 24hours of sleep deprivation on short term memory and attention to details tasks. The participants were 74 young students, aged between 19 and 24 years old (m= 21.2; S.D.=1.63). The instrument: tachistoscope test (TAVTMB) (Schuhfried, 2006). By applying Man Whitney nonparametric test for independent groups, the research hypothesis has been confirmed (p<0.05). The findings provide psychological evidence-based data confirming the assumed hypothesis.
The development of novel manganese vanadate electrode materials with high capacity and good rate capability is a great challenge. In this work, a novel manganese vanadate grown on reduced graphene oxide is successfully prepared by a fast and facile approach. Small Mn2.1V0.9O4 particles (20–50 nm) are anchored on reduced graphene oxide, which significantly alleviates volume changes and improves electrical conductivity and lithium ion transfer. In addition, the strong chemical interactions between Mn2.1V0.9O4 and reduced graphene oxide are conducive to accelerate charge transfer. These features are favorable for achieving high reversible capacity and excellent rate performance. As an anode for lithium-ion batteries, a high discharge capacity of 981 mA h g−1 is retained after 80 cycles at 100 mA g−1. Even at 2000 mA g−1, a high capacity of 748 mA h g−1 is achieved. New prospects are brought by this work for the synthesis and the potential application of manganese vanadate materials.
For three decades, scholars have focused on generalized interpersonal trust as the key component of social capital and there is a wide consensus that trust in strangers is the prime indicator of people’s general trust in others. However, little work with a specific focus on trust in strangers has been conducted in a comparative multilevel framework. The few existing studies are inconclusive because of deficiencies in both conceptualization and test strategy. Filling this gap, this article examines the determinants of trust in strangers on the broadest country base ever used in the study of trust, drawing on global cross-cultural evidence from the fifth and sixth rounds of the World Values Surveys—the first international surveys to include a direct question on trust in strangers. Reaching beyond conventional wisdom about the sources of generalized trust, we demonstrate that human empowerment at the country level is a powerful moderator of well-known individual-level determinants of trust. Specifically, in countries with lagging human empowerment, institutional trust, trust in known people, and material satisfaction are the only individual-level characteristics that enhance trust in strangers. We also detect an unexpected negative effect of education where human empowerment is lagging. In sharp contrast, in countries with advanced human empowerment, a much broader set of individual-level characteristics increases trust in strangers. This set includes ethnic tolerance, membership in voluntary associations, social movement activity, emancipative values, subjective well-being, age, and education. These insights inform a multilevel theory of trust, showing that human empowerment operates as a contextual activator of individual trust promoters.
A solid-state secondary cell with Prussian blue, i.e., iron (III) hexacyanoferrate (II), as the active material of both the anode and cathode was constructed. The Prussian blue was mixed with graphite powder, potassium chloride and diluted hydrochloric acid to form a thick paste. A Nafion membrane was used as separator. The charge–discharge performance of the cell was studied in galvanostatic mode. For a stabilized cell, the cell voltage was invariably 1.0 V at half-discharge, whereas it varied from 2.0 to 1.0 V at half-charge depending on the charging rate. Double-step chronopotentiometric experiments were also carried out to understand the charge–discharge behaviour. The practical capacity was estimated to be 20 A h/kg from the maximum deliverable current on discharge. The cell was stable up to 60 cycles of charge–discharge and did not show any significant deterioration.
Molybdenum disulfide (MoS2) is a promising candidate for high-performance electrodes of lithium ion batteries (LIBs) and sodium ion batteries (SIBs). In this work, we propose an integrated towel-like structure comprising edge-rich, interlayer-expanded, and oxygen-incorporated MoS2 nanosheets oriented anchored on curly N-doped graphene (MS@N-G). The heterogeneous interfaces are connected via chemical bonds, which provide high-speed electronic transport and improve the structural stability of the hybrid materials. The designed structure delivers excellent rate capability of 461 mAh g−1 at 2000 mA g−1 for LIBs and 350 mAh g−1 at 1000 mA g−1 for SIBs, and long lifespan performance with 675 mAh g−1 at 500 mA g−1 after 450 cycles for LIBs and 396 mAh g−1 at 500 mA g−1 after 140 cycles for SIBs. This study reveals that the fundamental approach to improve the electrochemical performance of MoS2 on the electrode level is building a robust connection between the MoS2 and conductive matrix and optimizing the electron conduction across the interfaces. The materials design approach and synthesize procedure could be applied more broadly to high-performance energy storage electrode materials.
Backpack is commonly carried either posteriorly or anteriorly. Although load carriage has been shown to have significant effects on postural alignment and spinal muscle activity, its effect on spinal loading was not studied. The objective of this study is to investigate the effect of different load carriage methods on spinal loading over time via the measurement of spinal compression. Eight male adults participated in this study. They were asked to carry a load equivalent to 15% of their body weight either anteriorly or posteriorly for 20 min followed by 10 min of unloading. Their statures were measured before load carriage and every 2 min after carrying the load. The sequence of loading conditions was randomized and the participants took a 20-min rest with Fowler’s posture for spinal length recovery prior to each testing condition. The amount of spinal compression was found to be associated with carrying duration. Spinal compression during anterior carriage was larger than that of posterior carriage. There was a mild recovery of spinal compression after the removal of the carried load for both the anterior and posterior carriage conditions. Relevance to industry Short-term putting a backpack anteriorly might be useful for temporarily relieving postural changes induced by posterior carriage. However, prolonged anterior carriage is not recommended. The effects of load carriage on spinal compression should be considered in the design of a load carriage system with load partially or completely positioned in the front
In this study the synergistic and catalytic properties of a novel nano-composite cathode material of nominal composition Li(M)xMn2-xO4 (M=Pt-Au; x # 0.2) has been explored. Li(PtAu)xMn2-xO4 nanomaterial for use in lithium-ion batteries (LIB) was synthesized by incorporation of the Pt-Au (1:1) nanoparticles onto the spinel phase LiMn2O4. Ultra-low scan rate (0.01mV s−1) cyclic voltammetry of the cathode material in 1M LiPF6 (in 1:1 EC:DMC), showed four sets of redox peaks, which reflect the typical redox process of the active material in the spinel structure due to lithium intercalation and deintercalation. The Li/Li(PtAu)0.02Mn1.98O4 cell had less polarization as it effectively accommodates the structural transformation during Li+ ion charge and discharge. The Li(PtAu)0.02Mn1.98O4 cathode showed an increase in discharge currents densities with an exchange current density, i 0, value of 2.8×10−4 A cm−2, which suggests increase in the rate of electron transfer compared to LiMn2O4 (1.8×10−4 A cm−2). Li(PtAu)0.02Mn1.98O4 exhibited excellent capacity retention upon extended cycling and can release 90 mAh g−1 at 10C with a capacity retention of 99% after 50 cycles. Faster charge transportation at high current rates proved to prevent the pronounced pile-up of Li+ ions and undesired Mn3+ ions on the surfaces. The electrochemical impedance spectroscopy (EIS) results showed a decrease in charge transfer resistance for LiMn2O4 after surface coverage with conductive PtAu NP's. For the lithium diffusion coefficient in Li(PtAu)0.02Mn1.98O4 thin film, its magnitude order is 10−11 cm2·s−1.
Lithium bis(oxalato)borate (LiBOB) is a promising salt for lithium ion batteries. However, to achieve better electrochemical performance of LiBOB, the development of appropriate electrolytes is essential. In this work, the electrochemical behaviors of sulfolane (SL) with LiBOB were studied by employment of dimethyl sulfite (DMS) and diethyl sulfite (DES) as mixed solvents, respectively. Both of the LiBOB-based electrolytes show high oxidation potentials (>5.5V), and good conductivities. When used in Li/MCMB (mesophase carbon microbeads) cells, these two kinds of novel electrolytes exhibit not only excellent film-forming characteristics, but also low impedances of the interface films. Besides, when used in LiFePO4/Li cells, compared to the cell with the electrolyte system of 1M LiPF6-EC/DMC (1:1, v/v), both of the LiBOB-based electrolytes exhibit several advantages, such as more stable cycle performance even at elevated temperature, and higher mean voltage.
Conventionally neglected mechanism of reversible redox reactions by oxygen ions in lithium-nickel oxide materials (LNO; Li2x Ni2-2x O2, 0 < x < 1) is proposed as a primary cause of unexpectedly high energy density of Li-ion battery. Using first-principles density functional theory calculations, cluster expansion theory, and Monte Carlo simulations, we unveil the underlying mechanism that is ascribed to the phase transition between layered and rocksalt structures initiated by cation disordering of Li and Ni at certain Li composition. At x = 0.5, the oxygen ions are put under specific chemical bondings of straight-linear type LiOLi configuration. They enable an active oxygen redox reaction involving peroxo (O2 2−) and superoxo (O2 −) ions, shown to dramatically increase the energy density of the LNO cathode. Using Monte Carlo simulations, we identify the proportional information to find the LiOLi configurations around the synthetic temperature of LNO materials. Our results indicate that the cation-disorder is a driving force for the oxygen redox via formation of the specific bondings. On the basis of our study, it is expected to provide useful guidelines for the design of Li-ion batteries with high energy densities beyond conventional ones.
The feasibility of using energy dispersive X-ray diffraction to characterize full size battery cells is demonstrated by unprecedented in situ measurements of the electrochemical processes taking place inside high temperature sodium metal halide (Na/MCl2, M=Ni and/or Fe) cells during charge/discharge cycling. Diffraction data provide phase information either via line scans across the 5cm wide cells or via fixed location scans as a function of time. The data confirm the propagation of a well-defined chemical reaction front, as a function of charge/discharge time, beginning at the ceramic separator and proceeding inward. Measurement of the temporal evolution of the phase abundances yields mechanistic understanding and reaction rates as a function of charge/discharge state. In the case where M includes Fe, the data also clearly show the appearance of an intermediate phase, Na6FeCl8, during charging, thereby underscoring the power of this technique to reveal subtle mechanistic information. A number of additional detailed electrochemical kinetic effects are also discussed. This study shows that in situ high energy X-ray diffraction characterization of advanced battery cells in space and time is eminently feasible on a routine basis, and has great potential to advance the understanding of “buried” chemical processes.
Carbon/vanadium dioxide (C/VO2(B)) core–shell microspheres were prepared by a one-step hydrothermal process and characterized by X-ray diffraction and scanning electron microscopy. The electric cycling performance of C/VO2(B) in organic and LiCl aqueous electrolytes was evaluated by the galvanostatic method and by cyclic voltammetry, respectively. The results showed that the product had very stable cycling performance in both types of electrolytes compared to pure VO2(B).
Li-rich layered materials are one of promising candidates of cathode materials for energy storage in electric vehicles (EVs) due to their high energy density. The practical application of these materials relies on the in-depth understanding of the crystal structures and reaction mechanisms during the electrochemical processes to overcome the potential decay issue. In this work, in-situ electrochemical Raman spectroscopy has been developed and used to investigate the structural evolution of the Li-rich layered material (0.5LiNi0.5Mn0.5O2·0.5Li2MnO3). An electrochemical Raman spectroscopic cell with an excellent air-tightness and optical signal collection efficiency has been designed and used for in-situ investigation of the NM Li-rich material during the very first two electrochemical cycles. We found that the reactions of Ni2+ to Ni3+ and Ni3+ to Ni4+ appearing in the potential range of from 3.70 V to 4.45 V show a good reversibility. The in-situ Raman spectra after the first two electrochemical cycles also indicate the activation of Li2MnO3 changes the ionic local coordination structure and increases the ionic disorder of the pristine NM Li-rich layered material. This structural change has a great impact on the subsequent electrochemical cycles. The in-situ Raman spectroscopy results can help to improve the performance of NM Li-rich layered materials.
Mesoporous nickel cobaltite (NiCo2O4) nanoneedles grown on three dimensional graphene networks have been successfully prepared by a facile solvothermal reaction with subsequent annealing treatment. The NiCo2O4/3DGN hybrid is then used as binder-free electrode for high-performance lithium-ion batteries and supercapacitors. The three dimensional graphene based binder-free electrode is considered more desirable than powder nanostructures in terms of shorter Li+ ion diffusion and electron transportation paths, good strain accommodation, better interfacial/chemical distributions and high electrical conductivity. As a result, when used as an anode material for lithium-ion batteries (LIBs), it exhibits high specific discharge capacity as well as superior cycling stability up to 2000 cycles. When it is used for supercapacitor application, this hybrid delivers a high specific capacitance of 970Fg−1 at a high current density of 20Ag−1 with excellent capacitance retention of ∼96.5% after 3000 cycles. Moreover, this synthesis strategy is simple and effective, which could be extended to the construction of other three dimensional graphene based metal oxides hybrid for energy applications.
Bond graphs are a promising possibility for modeling complex physical systems. This paper explores its potential by undertaking the analysis, modeling and design of a water pumping photovoltaic system. The effectiveness of photovoltaic water pumping systems depends on the sufficiency between the generated energy and the volume of pumped water. Another point developed in this paper presents the optimization of a photovoltaic (PV) water pumping system using maximum power point tracking technique (MPPT). The optimization is based on the detection of the optimal power. This optimization technique is developed to optimize the usage of power. The presented MPPT technique is used in photovoltaic water pumping system in order to increasing its efficiency. A buck–boost chopper allows an adaptation interface between the panel and the battery checked by a tracking mechanism known as the MPPT (Maximum Power Point Tracking). A new algorithm is presented to control a maximum power point tracker MPPT through a bond graph. From the chemical reactions in the batteries to the control laws of the power electronics structures, a bond graph model is proposed for every single part of the system. The model is used in simulations and the results compared to actual measurements. The model is used in simulations and the results compared to actual measurements, showing an accuracy of nearly 99%.
Background Inconsistent results on neuropsychological outcome in patients treated for acyanotic congenital heart disease (aCHD) questioned the clinical relevance of possible neurobehavioral sequelae in this group. This study was designed to objectify the neuropsychological profile and evaluate associations with medical data. Methods Patients with a corrected atrial or ventricular septal defect, ASD-II or VSD, (n =46; mean age 9 years, 2 months) and a matched control group were submitted to an intelligence test (Wechsler Intelligence Scale for Children, third edition, Dutch version) and evaluated with a neuropsychological test battery (Developmental Neuropsychological Assessment, second edition, Dutch version). Hospitalization variables were retrieved to evaluate associations with cognitive outcome. Parents completed a behavioral checklist (Achenbach Child Behavior Checklist for Children aged 6–18). Results ASD-II patients showed lower scores in domains of visuospatial processing, language, attention, and social perception. VSD patients displayed subtle problems in attention and visuospatial information processing. Only few perioperative medical factors, but also socioeconomic variables were associated with cognitive outcomes. Parents of ASD-II patients reported more school problems when compared to controls. Conclusions After treatment for aCHD, subtle cognitive difficulties can present in domains of visuospatial information processing, language, attention, and social perception. These shortcomings might hamper school performances, as is suggested by lower school competence ratings. Ongoing follow-up and cognitive screening is warranted to promote developmental progress, in which both parents and clinicians share responsibility.
Addicted individuals pursue substances of abuse even in the clear presence of positive outcomes that may be foregone and negative outcomes that may occur. Computational models of addiction depict the addicted state as a feature of a valuation disease, where drug-induced reward prediction error signals steer decisions toward continued drug use. Related models admit the possibility that valuation and choice are also directed by 'fictive' outcomes (outcomes that have not been experienced) that possess their own detectable error signals. We hypothesize that, in addiction, anomalies in these fictive error signals contribute to the diminished influence of potential consequences. Using a simple investment game and functional magnetic resonance imaging in chronic cigarette smokers, we measured neural and behavioral responses to error signals derived from actual experience and from fictive outcomes. In nonsmokers, both fictive and experiential error signals predicted subjects' choices and possessed distinct neural correlates. In chronic smokers, choices were not guided by error signals derived from what might have happened, despite ongoing and robust neural correlates of these fictive errors. These data provide human neuroimaging support for computational models of addiction and suggest the addition of fictive learning signals to reinforcement learning accounts of drug dependence.
Resilience is the maintenance and/or quick recovery of mental health during and after periods of adversity. It is conceptualized to result from a dynamic process of successful adaptation to stressors. Up to now, a large number of resilience factors have been proposed, but the mechanisms underlying resilience are not yet understood. To shed light on the complex and time-varying processes of resilience that lead to a positive long-term outcome in the face of adversity, the Longitudinal Resilience Assessment (LORA) study has been established. In this study, 1191 healthy participants are followed up at 3- and 18-month intervals over a course of 4.5 years at two study centers in Germany. Baseline and 18-month visits entail multimodal phenotyping, including the assessment of mental health status, sociodemographic and lifestyle variables, resilience factors, life history, neuropsychological assessments (of proposed resilience mechanisms), and biomaterials (blood for genetic and epigenetic, stool for microbiome, and hair for cortisol analysis). At 3-monthly online assessments, subjects are monitored for subsequent exposure to stressors as well as mental health measures, which allows for a quantitative assessment of stressor-dependent changes in mental health as the main outcome. Descriptive analyses of mental health, number of stressors including major life events, daily hassles, perceived stress, and the ability to recover from stress are here presented for the baseline sample. The LORA study is unique in its design and will pave the way for a better understanding of resilience mechanisms in humans and for further development of interventions to successfully prevent stress-related disorder.