batterydata/paper-abstracts huggingface dataset:
The lack of a polymer electrolyte membrane (PEM, e.g. Nafion) in membraneless, laminar flow-based micro fuel cells (LF-FCs) eliminates several PEM-related issues such as fuel crossover, cathode flooding, and anode dry-out, as we reported previously. This paper explores the media flexibility of LF-FCs by working in acidic and alkaline media, as well under “mixed-media” conditions in which the anode is in acidic media while the cathode is in alkali, or vice versa. Operating a fuel cell under alkaline conditions has positive effects on the reaction kinetics, both at the anode and cathode, while the cell performance under “mixed-media” conditions offers an opportunity to increase the maximum achievable open cell potential (OCP). The lack of media-related constraints and the simplicity of the LF-FC design allow for these experiments to be performed consecutively in a single LF-FC without changing the system, except for altering the composition/pH of the fuel and oxidant stream. The performance of LF-FCs operated with different media is described and compared.
This study compares the dispersion of submicron-silicon and nano-sized silicon powders and the electrochemistry of the prepared anodes using carboxymethyl cellulose or guar gum as the binder. Carboxymethyl cellulose is found to be a better binder than guar gum for the electrochemistry of the anodes when the electrode active powder is submicron-silicon because carboxymethyl cellulose helps the dispersion of submicron-silicon while guar gum gels submicron-silicon in the electrode slurry. In contrast, guar gum is a better binder than carboxymethyl cellulose for cell performance when the active anode material is nano-sized silicon, which is much more oxidized on its surface. Batteries prepared with nano-sized silicon present a capacity below 1500 mAh g−1 at a current of 420 mA g−1 and poor initial Coulombic efficiency below 85%. For anodes using submicron-silicon as the active material, the constructed cells exhibit a capacity above 2500 mAh g−1 and good initial Coulombic efficiency above 93%.
The paper deals with the synthesis and characterisation of proton-conducting ionic liquids (PCILs) and their polymer electrolytes obtained by blending modified Nafion membranes with different concentrations of PCILs. The PCILs are obtained by the neutralization of triethylamine with different organic acids. The first part of the paper studies the influence of acidity and acid structure on PCIL thermal and electrochemical performance, while the second part examines membrane conductivity and reveals it to depend more on PCIL structure than on its intrinsic conductivity. At 130°C, conductivities exceeding 10mScm−1 were obtained in fully anhydrous conditions.
The effect of operating temperature on the discharge potential and cycle stability of an Fe–air solid oxide rechargeable battery was studied. An Fe–air cell operated at 773 K exhibited the highest discharge potential (1.07 V) and high cycle stability with a current density of 5 mA cm−2. The high discharge potential at lower operating temperatures is due to aggregation of the anode and Fe powder being suppressed. The high redox cycle stability of the Ni–Fe-based anode at 773 K is explained by the small volume change with suppressed aggregation under low-temperature operation. Electrochemical charge–discharge measurements at 773 K revealed excellent cycle stability for 30 cycles with a high energy density (round trip efficiency >80%).
This study developed a functional cycling system for home use by paraplegics. It is a hybrid system with functional electrical stimulation (FES). In an earlier study, three tasks were completed: (1) determine user needs and potential problems in interface design, (2) interviews with therapists, and (3) questionnaires to the patients. These findings were converted to functional elements (for design of the FES cycling ergometer) and design criteria (for evaluation of the FES-cycling device). The FES device has both hardware and software features. Hardware includes: arm-crank, leg-cycling, guarded thigh holders, protective paddleboard, easy-access battery box and easy wheelchair height adjustment. The wheelchair can roll into a U-shaped track so the patient can exercise while in the wheelchair. A pocket PC-based controller was used for stimulation control of the patient and data acquisition. A better controller was used to adjust the stimulation based on a pre-defined stimulation pattern. The data recorded was wired to a clinic for evaluation of cycling smoothness as well as to redesign the training protocol. Relevance to industry FES has demonstrated many physiological and psychological benefits for patients with spinal cord injuries. This study offers an improved design of the FES-cycling system, including hybrid exercise modes, an improved controller and wireless transmission of data and training protocol, all of which can be used at home to better serve patients with paraplegia.
This experiment examined the item-level relationship between 7-year-olds’ ability to read words aloud and their knowledge of the same words in the oral domain. Two types of knowledge were contrasted: familiarity with the phonological form of the word (lexical phonology), measured by auditory lexical decision, and semantic knowledge, measured by a definitions task. Overall, there was a robust relationship between word knowledge and reading aloud success. The association was stronger when words contained irregular spelling–sound correspondences. There was no evidence that a deeper or more semantic knowledge of words was more closely related to reading aloud success beyond the association between reading success and familiarity with the phonological form of the same words. This finding is not compatible with models that see semantics as contributing directly to the reading aloud process, at least during the relatively early stages of reading development. More critical was whether or not a word was considered a lexical item, as indexed by auditory lexical decision performance.
Carbon-based materials are crucial conductive additive and non-metal electrocatalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). However, the high potential needed for driving OER usually leads to electrochemical oxidation of carbon-based materials, reducing their catalysis durability. Meanwhile, the weak interaction between carbon-based conductive additive and transition metal oxides, nitrides, sulfides and other compounds that possess electrocatalyst activity affects the performance of the electrocatalysts. Herein, a novel three-dimensional (3D) bifunctional electrocatalyst was prepared by embedding CoO nanoparticles into nitrogen and sulfur co-doped carbon framework (denoted as Co/N/S-CF) through morphology-controlled solid-state pyrolysis. The carbon framework was derived from a morphology-retaining pyrolysis of poly(aniline-co-2-aminothiophenol) precursor, retaining the 3D porous structure of the latter. The embedded CoO nanoparticles improve electrocatalysis durability of the 3D carbon-based framework as CoO has lower OER potential than the electrooxidation decomposition potential of doped carbon materials. Only 1.61 V can attain a current density of 10 mA cm−2. Meanwhile, the catalyst retains the highly efficient activity of N and S co-doped carbon framework towards ORR with an onset potential of about 0.92 V, suggesting that it is a qualified electrocatalyst for ORR. Long-term stability of the catalyst for ORR and OER is superior to the commercially available Pt/C and IrO2. Furthermore, the overpotential between ORR and OER (oxygen electrode activity parameter) of the catalyst is calculated to be 0.796 V, indicating that the catalyst could be a promising bifunctional electrocatalyst for both ORR and OER.
Research on language learning motivation has been augmented in the EFL context which reflects its significance as a socio-psychological factor in learning English as a foreign language. Due to the meager amount of work done on the issue in Iran, this study tries to investigate instrumental and integrative motivation (i.e., motivational orientations) among Iranian undergraduate students. It is also aimed to grasp their attitudes towards the target language and the community. Gardner's (1985) Attitude/Motivation Test Battery was given to 50 undergraduate students majoring in English Literature at Razi University of Kermanshah, Iran. Although it is mostly believed that instrumental motivation is more dominant in academic contexts, the results of the study indicate that Iranian EFL learners are both instrumentally and integratively motivated to learn English. The results of the study seem to be helpful for EFL teachers and curriculum developers to amend the common trends of ELT in Iran based on some realistic outlooks regarding the learners’ motivations.
The effect of lanthanum dopant on the structural and electrical properties of LiCoVO4 cathode materials was investigated by X-ray absorption spectroscopy (XAS). The conductivity of LiCoVO4 was increased from 8.44×10−9 to 7.17×10−8 S/cm by doping proper amounts of La2O3. The doping of La results in slightly decreasing the oxidation states of Co and V and the intensity of Fourier transform (FT) around absorbing atom Co and V. It may result from the distortion of the inverse spinel structure of LiCoVO4. It was suggested that La dopant located in interstitial site near vanadium atom to make the tetragonal distortion. This distortion is contributed to the generation of the defects in the doped LiCoO4 and the enhancement of its conductivity.
Biocatalysts are an attractive alternative to conventional noble metal catalysts for fuel cell cathodes. In principle, they combine the possibility of more efficient operation (lower intrinsic overpotential) with the benefits of renewability, selectivity and low temperature operation. In order for these benefits to be realized in a practical cathode design, however, both improved sources of suitable oxygen-reducing oxidoreductases, and improved electrode designs are required. In this paper, we discuss the preparation and performance of cathodes based on the “encapsulation” of a laccase enzyme with silica or organic polymer binders on porous carbon paper supports. We show that these electrodes are both electrochemically efficient and stable to leaching or degradation over millions of turnovers. We also show that these electrodes can be used with conventional Pt-based anodes in a direct methanol fuel cell structure.
The publisher regrets that the following code was displayed within the article: “[baseline=(char.base)] [shape = circle, draw, inner sep = 1.5 pt] (char) 1”, [baseline=(char.base)] [shape = circle, draw, inner sep = 1.5 pt] (char) 2, and [baseline=(char.base)] [shape = circle, draw, inner sep = 1.5 pt] (char) 3”. Instead the format should have been as follows: ‘1, 2 and 3’. The publisher would like to apologise for any inconvenience caused.
Cubic sodium Prussian White, Na2-xFe2(CN)6·yH2O, and potassium Prussian White, K2-xFe2(CN)6·yH2O, are prepared following a mild synthetic methodology. While cubic symmetry is confirmed by XRD and TEM, IR and XPS show characteristic features different from Prussian Blue compositions. When investigated as cathode materials in sodium ion batteries, both compounds exhibit reversible capacities above 140 mAh g−1 at 1C (ca. 80 mA g−1). While sodium Prussian White shows better high rate capability (10C/0.1C = 0.64), potassium Prussian White exhibits longer cycle stability, with up to 80% of capacity retention after 500 cycles. Interestingly, the potassium Prussian White phase also provides an increase of 0.35 V in the high voltage redox peak compared to the sodium Prussian White analogue ascribed to the preferential insertion of K+ ions instead of Na+, resulting in an increment of the gravimetric energy density. On the other hand, the insertion of Na+ seems to occur at the lower voltage plateau. This hybrid Na+ and K+ insertion in the framework of potassium Prussian White is most likely the responsible of the long cycle stability as a consequence of synergistic effects.
A strategy in the rational design of the aligned carbon nanotube @ polyaniline (ACNT@PANI), arrayed on metal foils as supercapacitors, has been demonstrated towards the upper bound of the specific capacitance, namely a high surface area and nanometre thickness of PANI, good accessibility of ions and a low contact resistance. The structure of ACNT@PANI nanoelectrode arrays was investigated and correlated to the surface redox reaction, electronic and ionic transport and thus to the energy and power density of the supercapacitors. The thickness of the PANI film on each ACNT was found the most important parameter, which was optimized to achieve the specific capacitance (∼1100 F g−1) of PANI close to the maximum theoretic value. A prototype supercapacitor was assembled, and a practical application was demonstrated. This device shows a higher specific capacitance, a higher specific power and a lower internal resistance but reduced cost and volume than conventional two-plate supercapacitors, which may provide opportunities for a smarter design of energy storage devices.
Cognitive dysfunction is a common comorbidity in adults with treatment-resistant epilepsy (TRE). Recently, cannabidiol (CBD) has demonstrated efficacy in epilepsy treatment. However, our understanding of CBD's cognitive effects in epilepsy is limited. We examined long-term cognitive effects of CBD in adults with TRE as part of an ongoing prospective, open-label safety study. Twenty-seven adults with TRE (mean age: 34[SD +14], female 52%) enrolled in the UAB CBD program completed standardized cognitive testing (NIH Toolbox Cognition Battery (NIHTB-CB)) at pre-CBD administration baseline and at one-year follow-up. Participants were receiving stable CBD dose at the time of one-year testing (mean=36.5mg/kg/day). The NIHTB-CB consisted of two global composite scales (Fluid and Crystallized) and seven individual tests measuring aspects of working memory, episodic memory, executive function, processing speed, and language. All participants had recorded Chalfont Seizure Severity Scale (CSSS) scores at each visit. Statistical analyses consisted of t-test, Pearson correlation coefficient, and linear regression. At baseline, cognitive test performance was below average for both global composite scales (Fluid: 71 [±18] range: 46–117) and Crystallized (76 [±15] range: 59–112)]. Longitudinal analysis revealed no significant group change across the two global composite scales. Of the seven individual cognitive tests, none changed significantly over time. No correlation was found between the cognitive change scores and CBD dose (all P's≥0.21). Change in cognitive test performance was not associated change in seizure severity rating. These findings are encouraging and indicate that long-term administration of pharmaceutical grade CBD is overall cognitively well-tolerated in adults with TRE.
Composite polymer electrolytes were prepared consisting of amorphous polyether, Li salt and mesoporous inorganic filler, and we investigated their ion-conductive properties. We synthesized three types of filler, mesoporous silica, alumina and titania (MP-Si, Al, Ti), and characterized their structural and physicochemical properties using SEM, TEM, SAXS and BET surface area measurements. From these measurements, we confirmed that MP fillers have well-defined arrays of mesoporous and hexagonal structures. Dependence on the MP filler content of the glass transition temperature (T g) revealed that the addition of filler to original polyether-salt electrolyte causes T g decrease, to due to the dissociation of aggregated ions such as triples or crystalline complex domains. The MP-Ti composites had the greatest ionic conductivity (1.4×10−5 S/cm, 7.5wt% at 30°C) of all samples, and the values were more than double that of the original. The addition of MP-Ti also increased the lithium transference number, because the electrolyte/filler interface provided active sites that increase mobile Li ions and conducting paths so as to enhance the mobility.
We investigated whether improved early visual processing on cognitive remediation (CR) exercises generalizes to visual and auditory learning and information manipulation in schizophrenia. Fourteen participants received neuropsychological testing before and after CR consisting of visual, auditory and cognitive control training. Achievement on visual training exercises was strongly and significantly correlated with improved visual learning, but not improved verbal learning or increased ability to manipulate visual information. Improvement in training, not training time, predicted cognitive gain. Implications for improving cognitive outcomes from CR include ensuring the trained task is learned and providing exercises of multiple modalities.
The purpose of this study was to determine if relatively short-term vitamin E supplementation could reverse age-associated impairments in cognitive or motor function and the accumulated oxidative damage in the brain of aged mice. Separate groups of 5- or 20-month-old C57BL6 mice were placed on either a control diet or the same diet supplemented with α-tocopheryl acetate (1.65 g/kg). After 4 weeks on the diets, mice were tested for cognitive and motor functions over the next 8 weeks, during which the supplementation was maintained. Vitamin E supplementation increased the concentration of α-tocopherol in the cerebral cortex of both the young and old mice, but did not significantly affect oxidative damage to proteins and lipids in the brain cortex. When compared with young controls, the old control mice showed slower learning of a swim maze, longer reaction times, diminished auditory and shock-startle responsiveness, and diminished motor performance on tests of coordinated running and bridge walking. The vitamin E-administered old mice failed to show improvement of function relative to age-matched controls on any of the tests, but did show altered retention performance on the swim maze task and impaired performance in the test of coordinated running. The latter effects were not evident in young mice on the supplemented diet. Results of this study suggest that, when implemented in relatively old mice, supplementation of vitamin E is ineffective in reversing preexisting age-related impairments of cognitive or motor function, and has little effect on common measures of protein or lipid oxidative damage in the mouse brain. Moreover, the current findings indicate that vitamin E could have detrimental effects on some brain functions when implemented in older animals.
Formal design optimization involves application of mathematical optimization techniques to models derived from engineering science, often presented as computer simulations. Industry use of design optimization tools is now widespread and sophisticated. As the size and complexity of design problems addressed with these formal methods increase, so do the challenges for successful implementations. Based on the author's experiences, after briefly reviewing the mathematical challenges involved, the article describes several problem areas where optimization technology is likely to have a major impact in the development of improved artifacts in the coming years. These include conceptual and topological design, large complex systems, smart products, and enterprise-wide product design.
Tin pest is the result of an allotropic transformation of tin from its β phase to its α phase at temperatures below 13 °C. This transformation is accompanied by a change in density from 7.31 to 5.77 g/cm3. The resulting expansion usually results in degradation of the affected part, as the α phase material is mechanically weak and over time becomes little more than a gray powder. The tin pest effect is cumulative unless the sample in question is exposed to temperatures above 70 °C or so, where some reversion back to white tin has been observed. However, by this point a tin sample’s physical integrity may have been destroyed by the partial β to α transformation. The transformation to α tin is inhibited strongly by soluble alloying elements such as bismuth and antimony at concentrations of about 0.5%, or lead at concentrations of about 5%. Hence, tin pest is generally observed only in quite pure tin. However, nearly pure tin alloys may become common. For example, the advent of the European Union’s RoHS law, which essentially eliminates lead from solder, has spawned lead-free alloys that can be almost pure tin and may be at risk of tin pest. This risk has caused some concern over the long-term stability of emergent, lead-free solders during low temperature service. This overview article is written in light of this concern.
The kinetics of lithium atoms in various Li–Si binary compounds are investigated using density functional theory calculations and kinetic Monte Carlo calculations. The values of the Li migration energy barriers are identified by NEB calculations with vacancy–mediated, interstitial and exchange migration mechanisms in crystalline LiSi, Li12Si7, Li13Si4, and Li15Si4. A comparison of these NEB results shows that the vacancy–mediated Li migration is identified as the dominant diffusion mechanisms in Li–Si compounds. The diffusion coefficients of Li in Li–Si compounds at room temperature are determined by KMC simulation. From the KMC results, the recalculated migration energy barriers in LiSi, Li12Si7, Li13Si4, and Li15Si4 correspond to 0.306, 0.301, 0.367 and 0.320 eV, respectively. Compared to the Li migration energy barrier of 0.6 eV in crystalline Si, the drastic reduction in the Li migration energy barriers in the lithiated silicon indicates that the initial lithiation of the Si anode is the rate-limiting step. Furthermore, it is also found that Si migration is possible in Li–rich configurations. On the basis of these findings, the underlying mechanisms of kinetics on the atomic scale details are elucidated.
Serious shuttle effect of polysulfides is the main obstacle preventing the practical application of lithium sulfur batteries. Herein, we report an ultrathin yet multifunctional polysulfide blocking layer (MPBL) coated on the cathode to effectively restrain the polysulfides shuttling. This MPBL, which was prepared by a simple, one-step electrostatic spray deposition (ESD) technique, was fully and compactly coated on the electrode with controllable thickness, realizing the full protection of the whole cathode. It is noted that the MPBL can be very thin that guarantees the fast ion diffusion but still keeps a high efficiency of blocking polysulfides due to a combination of physical (from carbon) and chemical confinement (from conductive polymer). In addition, the MPBL with good conductivity can act as the upper current collector to reuse the captured polysulfides, and thus improve the sulfur utilization during cycling. With such multifunctional design, the MPBL-coated carbon-sulfur cathode exhibits long cyclic stability and high rate capability, which has only 0.042% capacity decay per cycle at 1C for 1000 cycles and a capacity of 615mAhg−1 even at a high rate of 3C.