batterydata/paper-abstracts huggingface dataset:
This work presents the quantitative analysis of different mechanistic contribution to charge storage process of Fe3O4 in Li2SO4 aqueous electrolyte using nanorod film electrode as the ideal platform. “Capacity (stored charge)-charging time” relationship and “current-sweep rate” power law relationship, etc. are investigated. In addition to capacitive charge storage process, diffusion-controlled process is also found to occur in Fe3O4 nanorod film. This diffusion-controlled contribution dominates at low rates (78.4% at 0.5mVs−1) and cannot be ignored even at relatively high rates (22.8% at 100mVs−1). Our finding clearly uncovers that nanostructured Fe3O4 stores charges not merely on the surface/near-surface like typical pseudocapacitive materials, but rather through the intercalation of Li+ in the bulk.
In this paper we propose a unified theory describing the rules governing the formation of various oxide and metal nanostructures via electrochemical anodization. Nanoporous metal oxides of various morphologies have been of keen interest owing to their potential for various functional applications in chemical and biomedical sensing, chemical and photocatalysis, energy conversion in batteries and supercapacitors. This unified theory, based on thermodynamic and electrochemical principles, explains that the formation of porous or compact metal oxide and porous metal structures is dictated by the reaction free energy balance between the electrochemical anodic formation of the metal oxide and the chemical dissolution of the metal oxide in the electrolyte. Based on this theory, a range of key experimental observations reported in the literature are explained, including (1) the selection of the formation of compact oxide, porous oxide or porous metal during anodization, (2) voltage dependence of thickness of compact oxides, and (3) in situ pore perforation by step-wise reduction of anodization voltage.
All-organic rechargeable batteries may have low cost, materials sustainability and environmental friendliness, particularly suitable for large scale electric energy storage applications. However, development of such a new generation of batteries is now hindered by the lack of appropriate organic anode materials. In this paper, we report a novel polythiophene/carbon composite, where n-dopable poly (3,4-dihexylthiophene) is in situ chemically polymerized on carbon nanofibers. This organic-carbon composite exhibits an exceptionally high reversible electrochemical capacity of ∼300mAhg−1 (or ∼ 200AhL−1) through n-type redox reactions and superior capacity retention of ⩾95% after a hundred cycles. Based on this n-type redox-active material, an all-organic Li-ion cell using polytriphenylamine as cathode-active material was constructed and found to operate successfully, demonstrating possible applications of this composite as a high capacity anode material for all-organic storage batteries.
Thermal reactions of a lithiated graphite anode in 1M LiPF6-ethylene carbonate (EC)/dimethyl carbonate (DMC) (50:50 vol.%) in the temperature range 40–320°C were investigated by TG–MS analysis. Studies by TG–MS during thermal reactions detected a small exothermic peak around 140°C due to CO2 (m/z =44) evolution, which suggests partial destruction of the SEI formed on the graphite and/or decomposition of the electrolyte through the SEI. In addition, the main exothermic reaction above 280°C, which is associated with simultaneous evolution of C2H4O (m/z =44), is caused by direct reaction of the lithiated graphite with solvent.
The construction and performance of a small-scale fuel cell using traditional catalysts and membrane separators is discussed. Cell active area was 1cm×1cm, with a total unit cell volume of 0.3cm3 each. Under well-hydrated conditions running under hydrogen and oxygen, these cells demonstrated over 600mWcm−2 at 80°C. Design of flow fields and the requirements for water management showed that flow channels that were too small may have resulted in early channel blockage on the cathode, leading to lower power. Miniature cells suffered from higher than expected interfacial resistance which increased with time and this may be due either to more difficult hydration control in the membrane at smaller dimensions, or less compression in the smaller scale size leading to higher flow field/diffusion layer interfacial resistances. Running single cells in methanol to alleviate hydration issues still showed much higher interfacial resistances, but cell performance was roughly 75mWcm−2 at 80°C in 1M MeOH with 20sccm of ambient pressure air, and 140mWcm−2 in 1M MeOH with 20sccm ambient pressure O2. Lower performance in MeOH may be attributed to swelling of the sealing gaskets in methanol, leading to increased interfacial resistances over time.
We examined the latent structure of four commonly used goal orientation instruments as well as the nomological network surrounding goal orientation, including possible antecedents and outcomes. Based on a sample of college undergraduates (n=384), confirmatory factor analysis supported the construct validity of the instruments by showing that responses to these different instruments reflected the same three latent factors—learning, performance-approach, and performance-avoid orientations. Structural equation modeling showed that the three goal orientation factors were differentially related to extraversion, neuroticism, openness to experience, adaptive learning strategies, enjoyment with schoolwork, grades, and response distortion. Finally, although stemming from the same latent structure, regression analyses suggested that certain scales yielded stronger criterion-related validities than others with respect to enjoyment and grades.
Clothing provides a means of controlling heat exchange with the environment, particularly important in cold climates as changing weather and activity require a continuous conscious adjustment of clothing to maintain thermal comfort. The most important property of cold weather clothing is its thermal insulation, which can be measured according to ISO 15831. The insulation value of a cold weather ensemble can be used for prediction of its performance in terms of providing thermal comfort using ISO 11079. Cold weather clothing builds on the layering principle: the inner layer or underwear controls moisture and air motion over the skin; the second layer is mainly insulative; and the outer layer protects against ambient factors such as wind, rain and snow. Modern materials and functional design allow clothing to be developed for quite extreme exposures.
Q-Cells AG of Thalheim, Germany completed its equipment installation for its manufacturing plant at the end of December allowing automated production of solar cells. The new plant will have a capacity of 12 MWp and is the first solar cell factory of this kind in Eastern Germany.
Aim To compare the long-term predictive power of heart rate variability (HRV) based on 24 h ECG recordings with a battery of simple autonomic function tests with regard to all-cause mortality in diabetic individuals. Methods 240 diabetic persons were randomly selected from the diabetic population. A 24-h ECG was obtained and analysed on the Pathfinder 700. In the RR Tools Program time domain and frequency domain parameters were computed. Five function tests were conducted: Valsalva ratio, heart rate response to standing (30:15 ratio), expiration/inspiration ratio (E/I ratio), orthostatic blood pressure response (Ortho BP), and increase in diastolic blood pressure during sustained handgrip. Results 178 patients agreed to participate and 136 patients who completed all 5 function tests and had an acceptable ECG recording were included in the analyses. 64 individuals (47%) died during the 15½ year follow-up. Using Cox proportional hazard analyses correcting for age and gender we found that among the HRV parameters only the power in the low frequency band (LF) had an independent predictive value on all-cause mortality (p=0.0002). Multivariate analysis of the five function tests showed that Valsalva (p=0.002), 30:15 ratio (p=0.037), and handgrip (p=0.037) were independent predictors of death. When finally the independent predictors among the function tests and the HRV parameters were assessed in the same model, no significant value could be shown for LF power (p=0.44). Conclusion The study indicates that simple autonomic function tests are superior to HRV based on 24-h ECG recordings in predicting all-cause mortality in the diabetic population.
Biologically templated electrodes for Li-ion batteries are proposed. However, many questions regarding their practicality and their use on a large scale remain. Herein we revisit the phage-assisted synthesis of Co3O4 nanoparticles so as to identify the bio-chemistry/chemistry involved beyond this engineering phage synthetic approach and weigh its overall benefit. Various synthesis approaches to mimic the role of the phage which consist of using (i) wild or genetically modified phages made by insertions of specific peptides in the capsid protein, (ii) free peptides, and (iii) MWCNTs as the template were tried, and the resulting Co3O4 nanoparticles were checked for their morphology, size, organization, and electrochemical performances. We spotted the importance of a tetra-peptide motif in the Co3O4 nucleation/texturation process, whether this motif is part of the phage capsid or not, suggesting that the structure of the whole phage is not necessary for the production of the nanoparticles. In light of such findings the use of self-organized peptides or engineered bacteria for the templated synthesis of materials on a larger scale is proposed.
The effect of Ni by Cu substitution on the structural, solid–gas and electrochemical hydrogenation properties of TiNi has been investigated. Pseudo-binary TiNi1−x Cu x (x ≤ 0.5) compounds have been synthesized by induction melting. They crystallize in B2 structure above 350 K and either in B19′ (x < 0.1) or B19 (0.2 ≤ x ≤ 0.5) at room temperature (RT). For all compounds, Pressure-Composition Isotherms at 423 K exhibit a single slopping plateau pressure within the range 10−3–1 MPa of hydrogen pressure revealing a metal to hydride transformation. Both the hydrogenation capacity and the hydride stability decrease with Cu-content. The hydrided pseudobinary compounds crystallize in the tetragonal S.G. I4/mmm structure as for TiNi hydride. The electrochemical discharge capacity increases with Cu content from 150 mAh g−1 for TiNi up to 300 mAh g−1 for TiNi0.8Cu0.2 and then decreases again for larger Cu amounts. Electrochemical isotherms and in-situ neutron diffraction measurements at RT demonstrate that such a capacity increase results from a metal to hydride phase transformation in which the hydride phase is destabilized by Cu substitution. The TiNi0.8Cu0.2 compound exhibits interesting cycling stability for 30 cycles and good high-rate capability at D/2 rate. This compound has promising electrochemical properties as compared to commercial LaNi5-type alloys with the advantage of being rare-earth metal free.
New methodologies that aim to collect data in innovative ways (e.g. big data) are putting pressure on the traditional surveys based on questionnaires. In order to obtain from respondents the necessary effort to provide high quality data, we propose to help respondents focusing on the tasks one at the time by using a dynamic presentation of web questionnaires combined with a timing control. This work explores a development strategy for such questionnaires. The results show an overall good survey experience, and some significant improvement of data quality. In particular, a much larger proportion of respondents followed properly specific instructions added to check that they were reading carefully. Therefore, it seems that these dynamic questionnaires could be considered for future data-collection.
Submicrometre particles of multiferroic BiMn2O5 are prepared by a hydrothermal method. We demonstrate for the first time that BiMn2O5-multiwalled carbon nanotube (MWCNT) composite can be used as a new active material for positive electrodes of electrochemical supercapacitors (ES). The possibility of fabrication of BiMn2O5–MWCNT composites from colloidal suspensions using Celestine blue dye as a co-dispersant for BiMn2O5 and MWCNT is demonstrated. The composite BiMn2O5–MWCNT electrodes with high mass loading and high active material to current collector mass ratio show a capacitance of 6.0 F cm−2 (540 F cm−3) at a scan rate of 2 mV s−1 and capacitance retention of 75 and 58% at scan rates of 100 and 200 mV s−1, respectively. The new findings pave the way to the fabrication of efficient asymmetric devices, containing BiMn2O5–MWCNT positive electrodes and activated carbon–carbon black (AC–CB) negative electrodes. The asymmetric device shows good capacitive behavior and good cyclic stability in a voltage window of 1.8 V. The analysis of power-energy characteristics indicates that maximum energy density of 13.0 W h L−1 (9.0 W h kg−1) and maximum power density of 3.6 kW L−1 (2.5 kW kg−1) can be achieved.
A longitudinal study traced the development of the understanding of false belief and various measures of spontaneous language production and comprehension over the course of one year. The subjects were 28 normally developing preschoolers who averaged 3–5 years when the study began. The children were given a battery of tasks to assess false-belief-understanding and language mastery during four testing periods, with the contents of the materials varying and counterbalanced. The results of regression analyses strongly suggest that the mastery of a specific aspect of syntax, namely tensed complements, is a precursor and possible prerequisite of successful false-belief performance.
Troubleshooting in a practice situation requires two types of information, namely for reasoning about the problem-cause and for finding an adequate solution (declarative information) and for manipulating the environment (procedural information). It is hypothesized that presenting this information piece-by-piece during practice (i.e., presentation of declarative and procedural information separately) frees up working memory and facilitates learning. Moreover, this effect is augmented when both information types are presented just-in-time (i.e., declarative information before practice and procedural information during practice). This should yield highest test performance and instructional efficiency, which is defined as higher test performance combined with lower mental effort during practice. Eighty-five students (49 male, 36 female; M =15.2 years, SD =.59) participated in a 2×2 factorial experiment with the factors timing of declarative information and timing of procedural information, both before or during practice. Transfer test scores and transfer efficiency scores support the first hypothesis; the second hypothesis was not supported.
Polymer electrolytes based on mixtures of lithium trifluoromethylsulfonylimide, LiTFSI and lithium oligoether sulfates dissolved in poly(oxyethylene) were studied. The properties of these mixed electrolytes i.e. thermal stability, ionic conductivities, transference numbers, diffusion coefficients and electrochemical stabilities were established in a wide range of compositions. A satisfactory compromise was found between high cationic transference numbers and high conductivities, while markedly decreasing the total amount of LiTFSI used. Since lithium oligoether sulfates should be considerably less expensive than LiTFSI and easy to recycle, these mixed polymer electrolytes seem to be promising.
This study examined the relationship between neuropsychological performance and three different indices of cannabis use in schizophrenia. These indices were DSM-IV lifetime abuse/dependence, frequency of use, and recency of use. Sixty males with schizophrenia/schizoaffective disorder and 17 healthy males were recruited. The two groups were matched for age, years of education, and premorbid IQ. Medical history, substance use, and psychiatric symptoms were assessed. A neuropsychological battery was also administered to assess attention/processing speed, executive functions, memory, and perceptual organisation. Substance use within 24 hours of cognitive assessment was screened by urine analysis, and a range of confounds were controlled. In the schizophrenia group, 44 participants met DSM-IV criteria for lifetime cannabis abuse/dependence. In addition, there were three mutually exclusive frequency-of-cannabis-use subgroups comprising “high” frequency users (n =11), “medium” frequency users (n =7), and “low” frequency users (n =34) over the preceding year. There were also four mutually exclusive recency-of-cannabis-use categories comprising “cannabis abuse/dependence in the past week” (n =11 users), “non-dependent cannabis use in the past week” (n =7 users), “non-dependent cannabis use in the past month, but prior to the past week” (n =7 users), and “non-dependent cannabis use prior to the past month” (n =9 users). The control group performed better than the schizophrenia group in all cognitive domains. Within the schizophrenia group, a larger proportion of participants with lifetime cannabis abuse/dependence demonstrated better performance than those without lifetime abuse/dependence on a component of psychomotor speed. Frequency and recency of cannabis use were also associated with better neuropsychological performance, predominantly in the domains of attention/processing speed and executive functions. In conclusion, cannabis use is associated with enhanced cognitive functioning in schizophrenia. Implications of the results, limitations of the study, and directions for future research are discussed.
A novel nanostructured Sn–Fe2O3–C anode material, prepared by high-energy ball milling, is here originally presented. The anode benefits from a unique morphology consisting in Fe2O3 and Sn active nanoparticles embedded in a conductive buffer carbon matrix of micrometric size. Furthermore, the Sn metal particles, revealed as amorphous according to X-ray diffraction measurement, show a size lower than 10 nm by transmission electron microscopy. The optimal combination of nano-scale active materials and micrometric electrode configuration of the Sn–Fe2O3–C anode reflects into remarkable electrochemical performances in lithium cell, with specific capacity content higher than 900 mAh g−1 at 1C rate (810 mA g−1) and coulombic efficiency approaching 100% for 100 cycles. The anode, based on a combination of lithium conversion, alloying and intercalation reactions, exhibits exceptional rate-capability, stably delivering more than 400 mAh g−1 at the very high current density of 4 A g−1. In order to fully confirm the suitability of the developed Sn–Fe2O3–C material as anode for lithium ion battery, the electrode is preliminarily studied in combination with a high voltage LiNi0.5Mn1.5O4 cathode in a full cell stably and efficiently operating with a 3.7 V working voltage and a capacity exceeding 100 mAh g−1.
Following anodic polarisation of lead anodes with different silver contents (0.5–0.7%) during Zn electrowinning, the discharge and corrosion of lead anode during the decay period at open circuit potential in sulphuric acid bath have been studied by electrochemical noise analysis (ENA) method. Potential and current decay behaviour over 16h shows 4 and 2 main characteristic regions, respectively. The wavelet transform has been employed to analyse the ENA data. The results of wavelets have demonstrated that energy distribution plot “EDP” was a powerful tool to provide useful information about the dominant process for different discharge and corrosion stages and mechanisms. The discharge is predominant than corrosion for all anodes for the regions I, II and III, and ENA feature of events changes from large timescale to low timescale, diffusion control or exfoliation to metastable pitting and pit growth, respectively. Region IV, only observed for 0.6% and 0.7%Ag, corresponds to general and metastable pitting corrosion under diffusion control. It has been found that anode containing lower silver content have more corrosion products even after 16h of decay (discharge and attack dominated by pitting corrosion type with the highest corrosion due to the longest period of pitting during the 16h).
In this study, manganese orthophosphate (Mn3(PO4)2) is investigated as a new coating material for the Ni-rich LiNi0.6Co0.2Mn0.2O2 cathode with the aim of improving its thermal properties. A sol–gel process is employed to achieve a uniform coating of nano–sized crystalline Mn3(PO4)2. The coated electrode is found to exhibit an improved rate capability at high current drain, and cycle performance is enhanced at a high temperature of 60°C. The effect of the Mn3(PO4)2 coating thus formed is further investigated by AC impedance spectroscopy, the results of which confirm that interfacial impedance is significantly decreased even in the initial cycles, and the growth of impedance is successfully suppressed during progressive cycles. The thermal stability of LiNi0.6Co0.2Mn0.2O2 is also improved by the Mn3(PO4)2 coating, because of the high structural stability attributed to strong PO4 covalent bonds. On the basis of these results, the Mn3(PO4)2 coating is proposed as a viable surface modification method for the enhancement of the electrochemical and thermal properties of LiNi0.6Co0.2Mn0.2O2.
In vanadium redox flow batteries (VFB), the power of the battery is determined by the number of cells in the stack. Serial and parallel layouts are commonly adopted interactively to suit the designed power demand. The bipolar stack design inevitably introduces shunt currents bypassing into the common manifolds in the stack and thereby resulting in a parasitic loss of power and energy. During standby, shunt current and its associated internal discharge reactions can generate heat and increase stack temperature, potentially leading to thermal precipitation in the positive half-cell. This study aims to investigate the effect of shunt current on stack efficiency and temperature variation during standby periods for a 40-cell stack. Dynamic models based on mass balance, energy balance and electrical circuit are developed for simulations and the results provide an insight into stack performance that will aid in optimising stack design and suitable cooling strategies for the VFB.
Widespread use of biofuels is inhibited by the significant energy burden of recovering fuel products from aqueous fermentation systems. Here, we describe a membrane-based extraction (perstraction) system for the recovery of fuel-grade biobutanol from fermentation broths which can extract n-butanol with high purity (>99.5%) while using less than 25% of the energy of current technology options. This is achieved by combining a spray-coated thin-film composite membrane with 2-ethyl-1-hexanol as an extractant. The membrane successfully protects the micro-organisms from the extractant, which, although ideal in other respects, is a metabolic inhibitor. In contrast to water, the extractant does not form a heterogeneous azeotrope with n-butanol, and the overall energy consumption of for n-butanol production is 3.9 MJ kg−1, substantially less than other recovery processes (17.0–29.4 MJ kg−1). By (a) extracting n-butanol from the fermentation broth without a phase change, (b) breaking the heterogeneous azeotrope relationship (less energy consumption for distillation), and (c) utilizing a small volume ratio of extractant:fermentation broth (1:100, v/v), the need for high energy intensity processes such as pervaporation, gas stripping or liquid–liquid extraction is avoided. The application of this perstraction system to continuous production of a range of higher alcohols is explored and shown to be highly favourable.