batterydata/paper-abstracts huggingface dataset:
A selenium/carbon (Se/C) composite has been suggested as an excellent substitute cathode material due to its high theoretical volumetric capacity. However, it exhibits severe capacity decay, which is caused by the dissolution of active materials as well as shuttle effect. One effective strategy to alleviate this dissolution is to confine the Se within porous carbon frameworks. Here, we report the effects of carbon structure and dopant on the electrochemical performances of Se infiltrated carbon composites with three types carbons; (i) nitrogen-doped ordered mesoporous carbon (NOMC), (ii) sulfur-doped ordered mesoporous carbon (SOMC), and (iii) macroporous spherical carbon, which have different porosities and dopants. The Se/C cathodes are prepared by meting selenium-sulfur compound and then evaporating sulfur from the compound, providing nanoscale space for efficient electrolyte access to the reaction site. Among the three composite cathodes, the Se/NOMC exhibits the highest rate-capability and cyclic stability due to an abundance of cylindrical mesopores (4–5 nm pore diameter) that can provide enough electrolyte diffusion path and effectively impede the dissolution of selenium. As a result, the Se/NOMC has a high volumetric capacity of 1605 mAh cm−3 and excellent capacity retention of 100% during 500 cycles at 0.648 A h cm−3 (C-rate of C/2.5).
Energy storage devices, such as batteries and flywheels, are promising options for providing operating reserves due to their fast response and low emissions during operation. However, because of the complex nature of power systems, adding energy storage-based reserves to the power system may not necessarily benefit the environment. In this paper, we analyze these impacts in a test system and identify important drivers that affect the environmental outcomes. Dispatch results are obtained by solving an optimal power flow (OPF) problem and are used to determine emissions. We find that the impacts of adding energy storage are highly case-dependent. In systems with high renewable penetration levels and significant renewable curtailment, adding energy storage reduces emissions; in other systems, the impacts on emissions could be positive, neutral, or negative. The analyses presented in this paper show that policies to procure energy storage as a means to reduce emissions may actually lead to increased system-wide emissions if current dispatch algorithms are used. We also explore the impacts of modifying the dispatch algorithm to ensure system emissions with energy storage are no worse than system emissions without energy storage.
The purpose of this study was to compare teachers’ ratings of academic performance over 24 months between children with new-onset seizures (N =121) and those with new-onset asthma (N =54) aged 4 to 14. At each data collection point (baseline, 12 months, 24 months), children with seizures were placed into two groups according to their recurrent seizure status (yes/no) during that period. Longitudinal linear mixed models were used to explore differences between the asthma group and the two seizure groups and to determine if differences in teachers’ ratings of performance in children with seizures were associated with age, gender, or use of medication. In the seizure sample, scores for children in both groups (with and without recurrent seizures) initially declined at 12 months; however, at 24 months, children who did not have recurrent seizures improved, whereas children who continued to have recurrent seizures declined. There was a trend for younger children to decline more than older children.
Reduced amplitude of the P300 event-related potential has been consistently associated with a variety of externalising problems, including conduct disorder. The few available genetically-informative studies of these relationships, however, were conducted among adolescents/adults (i.e., at an age when conduct disorder has typically already become manifest). Among 200 general population twins with a mean age of 9 years (range 6–14 years), we studied the relationship between the P300 waveform elicited by an auditory oddball task and the DSM-oriented conduct problems scale of the Child Behavior Checklist 6–18. Conduct problems scores were negatively and significantly correlated (r = −0.19, p = 0.01) with P300 amplitude; correlations between P300 amplitude and the other DSM-oriented Child Behavior Checklist scales were non-significant, except for oppositional defiant problems (p = 0.01). We found moderate heritability estimates for both P300 amplitude (0.58, CI:0.37;0.73) and conduct problems (0.52, CI:0.25;0.70). Bivariate twin analyses indicated that the covariation between these two phenotypes can be explained by additive genetic factors only, with a genetic correlation of −0.33. An association between reduced P300 amplitude and conduct problems can be substantiated already in childhood, at an age that precedes the most typical onset of conduct disorder. This relationship appears to be genetic in nature. Reduced P300 amplitude can represent a valuable marker for conduct problems, and can contribute to the early identification of children at high-risk for conduct disorder.
A facile two-step annealing process is applied to synthesize nanocage Co3O4, using cobalt-based metal-organic framework as precursor and template. The as-obtained nanocages are composed of numerous Co3O4 nanoparticles. N2 adsorption–desorption isotherms show that the as-obtained Co3O4 has a porous structure with a favorable surface area of 110.6 m2 g−1. Electrochemical tests show that nanocage Co3O4 is a potential candidate as anode for lithium-ion batteries. A reversible specific capacity of 810 mAh g−1 was obtained after 100 cycles at a high specific current of 500 mA g−1. The material also displays good rate capability, with a reversible capacity of 1069, 1063, 850, and 720 mAh g−1 at specific current of 100, 200, 800, and 1000 mA g−1, respectively. The good electrochemical performance of nanocage Co3O4 can be attributed to its unique hierarchical hollow structure, which is maintained during electrochemical cycling.
We optimized synthesis condition of LiFePO4-C composites by solid-state reaction of LiH2PO4 and FeC2O4·2H2O in the presence of carbon powder. The preparation was conducted under a N2 flow through two heating steps. First, the starting materials were thoroughly mixed in a stoichiometric ratio and decomposed at 350–380°C to form the precursor. Second, the resulting precursor was heated at a high temperature to form the crystalline phase LiFePO4. For formation of the precursor, the optimized temperature was 350°C for LiFePO4 and 380°C for LiFePO4-C composites, respectively. For formation of crystalline phase composites, the optimized condition was to heat the precursor in a pelletized form at 800°C for 5h, and the optimized content of carbon was 3–10wt.%. In composites, the carbon not only increases the rate capability, but also enhances capacity stability. We found that capacity of the composites increases with specific surface area of carbon. The best result was observed from a composite made of 8.7wt.% of black pearls BP 2000 having a specific surface area of 1500m2 g−1. At room temperature and low current rate (0.02C), such a composite shows a specific capacity of 159mAhg−1. Electrochemical properties and cycling performance of the optimized composite also were evaluated.
Large yet infrequent disruptions of electrical power can impact tens of millions of people in a single event, triggering significant economic damages, portions of which are insured. Small and frequent events are also significant in the aggregate. This article explores the role that insurance claims data can play in better defining the broader economic impacts of grid disruptions in the U.S. context. We developed four case studies, using previously unpublished data for specific actual grid disruptions. The cases include the 1977 New York City blackout, the 2003 Northeast blackout, multi-year national annual lightning-related electrical damage and multi-year national line-disturbance events. Insured losses represent between 3 and 64 per cent of total loss costs across the case studies. The household sector emerges as a larger locus of costs than indicated in previous studies, and short-lived events emerge as important sources of loss costs.
Two technologies developed by US firm DuPont – one based on nanofibre science and the other which involves a ‘bio-based’ polymer – have received ‘IDEA Achievement Awards’, which were presented to the company at the International Engineered Fabrics Conference and Expo (IDEA07) that was held recently in Florida.
Physical properties and electrochemical behavior of LiNi1−x Co x O2 (0.1≤x≤0.9) were investigated for use as positive electrode material in lithium secondary batteries with long cycle life. LiNi1−x Co x O2 are characterized by an α-NaFeO2 type structure. In a three-electrode test cell, LiNi0.7Co0.3O2 showed a large discharge capacity of 159Ahkg−1, and good cycle performance, with a discharge capacity deterioration ratio of 0.73% per cycle. In a 2Wh-class cell, LiNi0.7Co0.3O2 exhibited a discharge capacity of 520mAh, and good cyclability, with a discharge capacity deterioration ratio of 0.026% per cycle. LiNi0.7Co0.3O2 is a promising positive electrode material, having the largest discharge capacity and the best cycle performance in the series of LiNi1−x Co x O2 compounds.
Vanadium Oxide (V2O5) nanobelts were synthesized, intercalating with a conducting polymer polyethylene glycol (PEG), by simple hydrothermal process. Investigations were conducted by X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC) and Scanning electron microscopy (SEM) and Cyclic voltammetry (CV). The results show that the H atoms in PEG are hydrogen bonded with the O atoms of the VO bonds of the V2O5, which effectively shielded against electrostatic interaction between the V2O5 interlayer and Li+ ions when the V2O5 is modified by the intercalation of PEG. The broad endothermic peak temperature increases with increasing concentration of PEG content in V2O5 nanobelts. Cathodic performance of PEGxV2O5 (x =0, 0.5 and 1) nanobelts for Li ion rechargeable battery was investigated. The V2O5 nanobelts exhibit a high specific discharge capacity of 397.61mAhg−1 for Li ion electrochemical intercalation.
It remains a challenge to render aqueous batteries operating at subzero temperatures properly, not even to mention the maintenance of their flexibility and mechanical robustness. This fundamentally arises from the freezing of hydrogel electrolytes under such low temperature, resulting in performance deterioration and elasticity loss. Here we propose an intrinsically freeze-resistant flexible zinc manganese-dioxide battery (Zn-MnO2-B) comprising a designed anti-freezing hydrogel electrolyte which can preclude the ice crystallization of the hydrogel component and maintain a high ion conductivity even at −20 °C. Benefiting from exceptional freeze resistance, the fabricated anti-freezing Zn-MnO2-B (AF-battery) exhibits excellent electrochemical stability and mechanical durability at subzero temperatures. Even at −20 °C, the specific capacity of the AF-battery can retain over 80% with Coulombic efficiencies approaching ∼100%, compared to the thorough performance failure of the Zn-MnO2-B with traditional polyacrylamide (PAM) hydrogel electrolyte. More impressively, the flexibility of batteries can also be well maintained even under severe mechanical stresses at subzero temperatures, such as being bent, compressed, hammered or washed in an ice bath. Furthermore, the AF-battery sealed in an ice cube can be integrated in series to power a wristband of an electronic watch, LED lights and a 72 cm2 electroluminescent panel. It is believed that this work opens new perspectives to develop anti-freezing batteries and would play the role of a model system for developing new hydrogel aqueous electrolytes for flexible batteries in extremely cold environments.
l-Ascorbic acid (AA) has been shown to undergo oxidation on polyaniline (PANI) without a platinum-group catalyst. A direct ascorbic acid fuel cell (DAAFC) has been assembled by employing an anode coated with PANI catalyst. From the experimental studies using cyclic voltammetry, amperometry and IR spectroscopy, it has been concluded that PANI facilitates the oxidation of AA. It has been possible to achieve a maximum power density of 4.3mWcm−2 at a load current density of 15mAcm−2 at 70°C. As both AA and PANI are inexpensive and environmental-friendly, the present findings are expected to be useful for the development of cost-effective DAAFCs for several low power applications.
Cardiac electrical activity is mainly evaluated by monitoring the electrical biosignals. This requires a long-lasting power supply to make implantable devices cost-effective and efficient. Since the current trend is to implant catheter-free stand-alone electrodes (implantable cardiac monitors), the need for smaller devices is at odds with the need for long-life batteries. To avoid these problems, we propose a passive endocardial sensor able to monitor the movement of the considered chamber based on a permanent magnet shaped for implantation in the internal chamber of the heart (i.e. the right atrium) and an external gauss meter unit to measure sensor-induced magnetic field variations. Since the magnet is permanent, no replacement is needed after the first implant, thereby reducing the risks linked to invasive procedures, and the battery in the external device can be substituted more easily. To test our idea we used a permanent magnet mounted on the tip of a commercial catheter for heart mapping together with a dedicated gauss meter built in our laboratory. The device was tested in vitro and the magnetic field variations were acquired and measured in different conditions of movement and distances. The results demonstrate the feasibility of our approach and open an interesting new scenario where permanent magnets can be used to monitor the mechanical behaviour of the heart.
Are the linguistic forms that are memorized in the mental lexicon and those that are specified by the rules of grammar subserved by distinct neurocognitive systems or by a single computational system with relatively broad anatomic distribution? On a dual-system view, the productive –ed-suffixation of English regular past tense forms (e.g., look–looked) depends upon the mental grammar, whereas irregular forms (e.g., dig–dug) are retrieved from lexical memory. On a single-mechanism view, the computation of both past tense types depends on associative memory. Neurological double dissociations between regulars and irregulars strengthen the dual-system view. The computation of real and novel, regular and irregular past tense forms was investigated in 20 aphasic subjects. Aphasics with non-fluent agrammatic speech and left frontal lesions were consistently more impaired at the production, reading, and judgment of regular than irregular past tenses. Aphasics with fluent speech and word-finding difficulties, and with left temporal/temporo-parietal lesions, showed the opposite pattern. These patterns held even when measures of frequency, phonological complexity, articulatory difficulty, and other factors were held constant. The data support the view that the memorized words of the mental lexicon are subserved by a brain system involving left temporal/temporo-parietal structures, whereas aspects of the mental grammar, in particular the computation of regular morphological forms, are subserved by a distinct system involving left frontal structures.
Studies of established schizophrenia have consistently found that cognitive function predicts social and clinical outcomes. The findings from first-episode studies have been more variable, with only some studies reporting predictive relationships. We tested the possibility that an index of general cognitive ability, IQ, may be a more sensitive and reliable predictor of outcome in first-episode schizophrenia than specific measures of memory and executive function. Fifty-four patients with first-episode schizophrenia or schizoaffective disorder were assessed for cognitive and social function as well as symptoms at three time points over the four years following first presentation of their psychotic illness. Regression analyses were performed to determine whether IQ and specific neuropsychological measures at first episode and one-year follow-up predicted four-year social function and residual symptoms. The effects of premorbid and concurrent IQ on outcome were also assessed. Premorbid IQ and IQ at each assessment significantly predicted social function at four-year follow-up. This relationship remained significant after the social function or symptom scores at first presentation were accounted for in the regression. Specific measures predicted certain domains of social function, but these were weaker and less consistent than IQ. The predictive values of cognition on residual symptoms were less strong; the most consistent finding was a relationship between IQ and the negative syndrome. This study suggests that early in the course of schizophrenia, general cognitive ability, as measured by IQ, is a more sensitive and reliable predictor of functional outcome than measures of specific ability.
Lithium-sulfur batteries show fascinating potential for advanced energy system due to their high specific capacity, low-cost, and environmental benignity. However, their wide applications have been plagued by low coulombic efficiency, fast capacity fading and poor rate performance. Herein, a facile method for preparation of S@PDA (PDA = polydopamine) composites with core–shell structure and good electrochemical performance as well as the First-Principles calculations on the interactions of PDA and polysulfides are reported. Taking the advantages of the core–shell structure with porous sulfur core, the high mechanical flexibility of PDA for accommodating the volumetric variation during the discharge/charge processes, the good lithium ion conductivity and the strong chemical interactions between the nitrogen/oxygen atoms with lone electron pair and lithium polysulfides for alleviating their dissolution, the S@PDA composites exhibit high discharge capacities at different current densities (1048 and 869 mAh g−1 at 0.2 and 0.8 A g−1, respectively) and excellent capacity retention capability. A capacity decay as low as 0.021% per cycle and an average coulombic efficiency of 98.5% is observed over a long-term cycling of 890 cycles at 0.8 A g−1. The S@PDA electrode has great potential as a low-cost cathode in high energy Li–S batteries.
The synthesis aspects and electrochemical behaviors of Li–Mn–O compounds prepared at high temperatures of 950–1100°C were investigated. Heating temperature, oxygen content in reaction atmosphere, and cooling rate affect on the product structure and composition. High heating temperatures favor the expansion of unit cell volume and shrinkage of surface area, and slow cooling rate can diminish only oxygen vacancies and the oxygen absorptions are not enough to affect the lattice parameter and surface area severely. The greatly oxygen-deficient LiMn2O4 spinels were prepared by following a slow cooling for 10h to room temperature. In both room and high temperature CV studies, a new oxidation peak at ca. 3.97V was observed for oxygen-deficient spinel, which was considered coming from an oxidation process related with the 3.2V discharge plateau. Meanwhile, splits phenomenon of all the two pairs of redox peaks relative to normal LiMn2O4 spinel was found during high temperature CV measurements at 85°C. dQ/dV–V plot confirmed the splits. Analysis of the increased capacity at 3.2V plateau during room and high temperature discharges coupled with surface area revealed that dissolution reaction of Li–Mn–O spinel in electrolyte, which intensified by elevated temperature, caused the growth of oxygen vacancy in spinel structure.
Nanotechnology has revolutionized various industries and has become a notable catalyst for economic growth. The emerging issues of human health and safety associated with nanotechnology development have raised regulatory concerns worldwide. In occupational settings, the same novel characteristics of nanomaterials that are utilized for innovation may also be the source of toxins with adverse health effects for workers. The existing regulatory framework may function effectively to regulate chemical substances in their conventional forms but may not be adequate with regard to the specific issues of nanoform substances. A foundation of knowledge concerning properties of nanomaterials, and risk management approaches for these materials have been established, but conclusive results remain elusive. It is difficult for lawmakers to regulate nanotechnology-related activities effectively if conventional regulatory mechanisms are applied. The present article analyses in a country study the adequacy of existing Malaysian occupational safety and health law with regard to the specific issues presented by nanotechnology. The applicable regulatory approaches are examined to justify the adoption of soft law instruments as regulatory mechanisms for nanotechnology. A number of soft law best practices are briefly discussed as a basis to recommend practical solutions to close the existing regulatory gap.
The paper presents a conceptual design of an underwater star wars’ system, which will be more difficult to detect by the enemy than a recently proposed ‘surface’ star wars’ system. The paper suggests that for the proposed structures needed for the underwater star wars’ system, the material of construction should be a composite and not a metal, as use of the latter for large deep diving underwater vessels will result in such structures sinking to the bottom of the ocean like stones, due to the fact that they will have no reserve buoyancy. The paper also shows that composites have better sound absorption characteristics, thereby making the underwater structures difficult to detect through sonar equipment. It is proposed that these underwater structures should operate up to a depth of 7.16 miles (11.52km), as at this depth, all of the oceans’ bottoms can be reached. The author shows that current technology can be used to construct and operate such vessels, but more progress needs to be made with metal matrix and ceramic composites, so that the hulls of underwater missiles and torpedoes can be constructed in these materials.
Minocycline is a tetracycline antibiotic that has been shown to attenuate central nervous system (CNS) lentivirus infection, immune activation, and brain injury in model systems. To initiate assessment of minocycline as an adjuvant therapy in human CNS HIV infection, we conducted an open-labelled pilot study of its effects on cerebrospinal fluid (CSF) and blood biomarkers of infection and immune responses in 7 viremic subjects not taking antiretroviral therapy.