batterydata/paper-abstracts huggingface dataset:
We report spectroscopic results from investigations of a novel solid polymeric fast-ion-conductor based on poly(acrylonitrile), (PAN, of repeat unit [CH2CH(CN)] n ), and the salt LiCF3SO 3 . From NMR studies of the temperature and concentration dependencies of 7Li- and lH-NMR linewidths, we conclude that significant ionic motion occurs at temperatures close to the glass transition temperature of these polymer-in-salt electrolytes, in accordance with a recent report on the ionic conductivity. In the dilute salt-in-polymer regime, however, ionic motion appears mainly to be confined to local salt-rich domains, as determined from the dramatic composition dependence of the ionic conductivity. FT-Raman spectroscopy is used to directly probe the local chemical anionic environment, as well as the Li+–PAN interaction. The characteristic δ s(CF3) mode of the CF3SO3 − anion at ∼750–780 cm−l shows that the ionic substructure is highly complex. Notably, no spectroscopic evidence of free anions is found even at relatively salt-depleted compositions (e.g. N:Li∼60–10:1). A strong Li+–PAN interaction is manifested as a pronounced shift of the characteristic polymer CN stretching mode, found at ∼2244 cm−l in pure PAN, to ∼2275 cm−l for Li+-coordinated CN moieties. Our proton-NMR data suggest that upon complexation of PAN with LiCF 3 SO3, the glass transition occurs at progressively lower temperatures.
Objective: Executive dysfunction in Alzheimer’s disease (AD) is associated with delusions, agitation and disinhibition, rapid progression and care dependency. We correlated resting cerebral glucose metabolism in Alzheimer’s disease (AD) and mild cognitive impairment (MCI) with scores on the Trail Making Test (TMT) as a measure of executive function. Methods: Ten patients with AD, 10 patients with mild cognitive impairment (MCI) and 14 controls were included. We compared resting cerebral glucose metabolism in patients with that in controls and correlated TMT scores with cerebral glucose metabolism. Neuropsychological correlates of the TMT were also investigated. Results: Patients had reduced frontotemporoparietal and posterior cingulate metabolism compared to controls. TMT-A correlated with left middle frontal, TMT-B and TMT-Q with right middle frontal and TMT-B with right precentral glucose metabolism. TMT-A and TMT-B scores correlated (p<0.05) with word fluency and recall subtests of the CERAD (Consortium for the Establishment of a Registry for Alzheimer’s Disease) neuropsychological test battery, TMT-Q with delayed constructional praxis scores (p<0.05). Conclusions: PET and neuropsychological correlates indicate that executive function measured by TMT is frontal lobe mediated and demands working memory. The neuropsychological correlates of the tasks confirm the complexity of the task.
Carbon felt, which is a textile material that consists of randomly oriented short carbon fibers, has been used as an electrode material of vanadium redox flow batteries owing to its high electrical conductivity, large specific surface area, and chemical stability. Despite these advantages, the inert surface of the carbon felt has been a critical drawback, leading to low electrode performance. The heat-treatment method has been principally proposed as one of the methods for activating the carbon felt surface. However, the heat-treatment method causes local damage on the carbon felt surface. In this study, glucose is selected as a coating material to protect the carbon felt during the heat treatment and provide abundant functional groups as active sites in the redox reaction. We confirm that the glucose-based carbon-coating layer on the carbon felt exhibits a higher crystalline graphitic structure than heat-treated carbon felt and promotes electrochemical properties such as electron-transfer kinetics and reversibility of the redox reaction. The carbon felt with a glucose-based carbon-coating layer exhibits an energy efficiency of 82.79% at 100 mA cm−2, which is 2.0% higher than that of a neat carbon felt.
A novel nanocomposite of polyaniline/urchin-like mesoporous TiO2 spheres (PANI/UMTS) has been synthesized as electrode material for supercapacitors. In the composite, UMTS are used as support material and modified by γ-aminopropyltriethoxysilane (APTES), PANI is assembled onto the surface of it via grafting polymerization. Characterization of structure and morphology of the composite indicates that the UMTS with good mechanical strength and high specific surface area can improve the morphology of PANI and increase its stability. Consequently, PANI/UMTS exhibits excellent electrochemical performance. A high specific capacitance of 422Fg−1 is reached at a current density of 0.7Ag−1, and a high capacitance retention ratio of 73% as the current density is increased by 20 times can be achieved. In addition, almost 100% of its initial specific capacitance can be retained after charge/discharge for 500 cycles. All results suggest that the PANI/UMTS is a promising electrode material for high-performance supercapacitors.
An open-up network structure assembled by interconnected 3D heterostructure Fe3O4/Ni/C nanoplate arrays on Ni foam is successfully synthesized via a facile hydrothermal method with subsequent CVD heat treatment. When used as a binder free anode material for lithium-ion battery (LIBs), it shows quite a favorable electrochemical performance with high reversible capacity and good rate capability. A high capacity of 832.5mAhg−1 is achieved at 0.3C and a specific capacity of 279mAhg−1 can still be delivered at current density of 4.5C, corresponding to 34% of the capacity at 0.3C. The self-supporting nanoplates are intercrossed and interconnected with robust adhesion on Ni foam, preventing the active material from peeling off during the electrochemical reactions. Ni foam substrate, uniform carbon layer on the nanoplate surface and in-situ formed Ni nanocrystals together play important roles in effectively building a fast 3D electron transport network for electrode reactions. The excellent electrochemical performance makes this composite a promising candidate as anode material for high energy density LIBs.
Spinel LiCrTiO4 is synthesized via sol-gel pretreatment and subsequent solid state reaction at different calcining temperatures. Structural observation and electrochemical evaluation show that 800°C is a suitable calcining temperature for LiCrTiO4 preparation. Compared with samples prepared at other temperatures, LiCrTiO4 formed at 800°C exhibits better electrochemical performance with the capacity retention of 92.2% at 100mAg−1 after 80 cycles. Even cycled at a higher current density of 500mAg−1 in 0.0-3.0V, LiCrTiO4 prepared at 800°C still shows excellent cycling performance with a reversible capacity of 226.7mAhg−1 after 80 cycles. Ex-situ valence analysis reveals that the high lithium storage capacity in LiCrTiO4 between 0.0 and 3.0V is attributed to the reversible redox process of Ti4+/Ti3+ and Cr3+/Cr2+ couples. In addition, quasi zero-strain characteristic of LiCrTiO4 during lithiation is also demonstrated by in-situ and ex-situ structural observations. Therefore, LiCrTiO4 exhibits high structural stability and electrochemical reversibility as anode material for rechargeable lithium-ion batteries.
A reversible dual-graphite intercalation chemistry with simultaneous accommodation of Li+ and PF6− in graphitic structures is enabled for the first time by a high voltage electrolyte based on a fluorinated solvent and additive, which is capable of supporting the chemistry at 5.2 V with high efficiency. This all-graphite battery promises an energy storage device of low cost, high safety and high environmental friendliness that are critical for large scale energy harvesting/storage needs.
Based on the exposure potential to humans and environment, pronamide was one of 52 chemicals on the first list evaluated under US EPA’s Endocrine Disruptor Screening Program (EDSP). The purpose of EDSP is to screen chemicals for their potential to interact with estrogen-, androgen-, or thyroid-signaling pathways. A battery of 11 Tier 1 assays was completed for pronamide in accordance with EDSP test guidelines. In addition, Other Scientifically Relevant Information, which included existing data from regulatory guideline studies and published literature, was used in a weight-of-evidence (WoE) evaluation of potential endocrine activity. The WoE conclusion is that pronamide does not interact directly with estrogen, androgen, or thyroid receptors or post-receptor events. Across in vivo studies, the liver is consistently and reproducibly the target organ for pronamide’s effects. Pronamide activates hepatocytic nuclear receptors (including constitutive androstane receptor), induces hepatic enzymes, produces hepatocellular hypertrophy and increases liver weights. These changes are coupled with increased metabolic activity and a subsequent increased metabolism and/or clearance of both steroid and thyroid hormones. Thus, while pronamide alters some endocrine-sensitive endpoints in EDSP Tier 1 assays, effects on liver metabolism likely explain altered hormone levels and indirect endocrine changes.
Background The MATRICS Consensus Cognitive Battery (MCCB) and proposed co-primary measures are gaining momentum as outcome measures in clinical trials, highlighting the need to evaluate their psychometric properties. The MCCB composite score has been proposed to be the optimal primary outcome measure, though its validity is unknown. This study aimed to evaluate the factor structure of the MCCB in a schizophrenia sample and determine whether its cognitive domains are separable. Methods 183 outpatients with schizophrenia or schizoaffective disorder completed a comprehensive test battery. Confirmatory factor analysis was used to test the factor structure of the MCCB; hierarchical regression then examined the relative contribution of individual cognitive variables to predict the MCCB factor scores. Finally, the relationships between the resulting factors and two performance-based measures of functional capacity were explored. Results A three-factor MCCB model representing processing speed, attention/working memory, and learning fits the data well and was an improvement over a unifactorial model. Symbol coding, spatial span, and visual learning were the most robust predictors for each of the three factors; symbol coding proved to be the best single predictor of overall cognitive performance. The three factors were also significantly related to a performance-based measure of everyday functioning but not a performance-based measure of social skills. Conclusions These analyses suggest that the six MCCB “domains” as constructed can be collapsed into fewer domains composed of multiple item scores; they also support the notion that impaired processing speed is a fundamental cognitive deficit in schizophrenia and that MCCB performance is related to functional capacity. Cognition and functional capacity measures require more research to determine if they differ.
High power electrolytic manganese dioxide (HPEMD), offers distinct performance advantages in alkaline-MnO2 cells compared to the best conventional alkaline EMD materials previously available. Advantages are seen mainly on heavy continuous and heavy pulse drains. No comprehensive model to explain the chemical and structural basis for the improved performance of HPEMD has yet emerged. Hydrothermal electrolytic plating of EMD at 120–125°C has given rise to several exceptional materials including two samples with excellent high power discharge performance. A systematic study of physico-chemical properties of all of the hydrothermally produced materials as well as commercial EMD samples, including HPEMD, has shown that superior high power performance is linked to porosimetry. By employing the needed plating conditions, one can produce a superior HPEMD material having BET area in the range 20–31m2 g−1 and simultaneously a micropore area (deBoer “t” method) greater than 8.0m2 g−1, all within the context of a typical pore volume of 0.035–0.050cm3 g−1 and a calculated meso–macropore radius greater than 32Å (cylindrical pore model). A qualitative model explaining the need for a balance between BET area and micropore area is proposed. A possible explanation regarding the physico-chemical nature of the micropores and their relation to cation vacancies, as supported by stepped potential electrochemical spectroscopy (SPECS) investigations of heat treated EMDs, is given.
Background Self-report questionnaires are widely used to assess physical function in older adults. However, they often lack a clear frame of reference and hence interpreting and rating task difficulty levels can be problematic for the responder. Consequently, the usefulness of traditional self-report questionnaires for assessing higher-level functioning is limited. Video-based questionnaires can overcome some of these limitations by offering a clear and objective visual reference for the performance level against which the subject is to compare his or her perceived capacity. Hence the purpose of the study was to develop and validate a novel, video-based questionnaire to assess physical function in older adults independently living in the community. Methods A total of 61 community-living adults, 60years or older, were recruited. To examine validity, 35 of the subjects completed the video questionnaire, two types of physical performance tests: a test of instrumental activity of daily living (IADL) included in the Short Physical Functional Performance battery (PFP-10), and a composite of 3 performance tests (30s chair stand, single-leg balance and usual gait speed). To ascertain reliability, two-week test-retest reliability was assessed in the remaining 26 subjects who did not participate in validity testing. Results The video questionnaire showed a moderate correlation with the IADLs (Spearman rho=0.64, p <0.001; 95% CI (0.4, 0.8)), and a lower correlation with the composite score of physical performance tests (Spearman rho=0.49, p <0.01; 95% CI (0.18, 0.7)). The test-retest assessment yielded an intra-class correlation (ICC) of 0.87 (p <0.001; 95% CI (0.70, 0.94)) and a Cronbach's alpha of 0.89 demonstrating good reliability and internal consistency. Conclusions Our results show that the video questionnaire developed to evaluate physical function in community-living older adults is a valid and reliable assessment tool; however, further validation is needed for definitive conclusions.
Rapid development of miniature, portable and highly integrated electronics increases the demand for micro-sized power sources and on-chip energy storage units; micro-supercapacitors with in-plane electrode finger arrays are developed for this purpose. This study fabricates flexible, solid-state, interdigital micro-supercapacitors with MoO3-x nanorods as cathode fingers and glucose-derived activated carbon nanospheres as anode fingers via a facile and economic screen-printing technique. A highly concentrated sodium alginate bio-hydrogel is used as the non-toxic and biocompatible electrolyte, which provides wider electrochemical stability window (∼2.8 V) than that of conventional aqueous electrolytes (1.23 V). The fabricated asymmetric micro-supercapacitors present outstanding electrochemical performances, for example, high areal capacitance of 47.20 mF cm−2, superior energy density of 21.20 μWh cm−2 (47.11 mWh cm−3) at a power density of 0.18 mW cm−2 (0.40 W cm−3), and excellent capacitance retention of 95% after 10,000 cycles. The device also exhibits good mechanical stability and can be integrated into any printed circuits, demonstrating its potential application for highly customized power systems in the Internet of Things and wearable/implantable on-chip electronics with high safety requirement.
Forming an effective solid electrolyte interphase (SEI) is a significant issue in lithium ion batteries that utilize graphite as a negative electrode material, because the SEI determines the reversibility of the intercalation and de-intercalation of lithium ions into graphite for secondary batteries. In propylene carbonate (PC)-based electrolyte solutions, ceaseless co-intercalation of solvated lithium ions takes place because no effective SEI is formed. It is indisputable that this continuous co-intercalation leads to graphite exfoliation; however, the reason for this is currently not well understood. In this study, we investigate interfacial reactions that contribute to SEI formation on highly oriented pyrolytic graphite (HOPG) in ethylene carbonate (EC) and PC-based electrolyte solutions by in situ atomic force microscopy. The blisters formed on HOPG after the decomposition of solvated lithium ions within the graphite layers do not change over the course of ten electrochemical cycles in an EC-based electrolyte solution. In contrast, when cycling in PC-based electrolytes, the blisters continually change, and the height at the vicinity of the graphite edge plane increases. These morphological changes are attributed to the continuous co-intercalation of solvated lithium ions in PC-based electrolyte solutions.
A zinc–air battery using zinc regeneration electrolysis with propanol oxidation as a counter electrode reaction is reported in this paper. It possesses functions of both zincate reduction and electrochemical preparation, showing the potential for increasing the electronic energy utilization. Charge/discharge tests and scanning electron microscopy (SEM) micrographs reveal that when a nickel sheet plated with the high-H2-overpotential metal, cadmium, was used as the negative substrate electrode, the dendritic formation and hydrogen evolution are suppressed effectively, and granular zinc deposits become larger but relatively dense with the increase of charge time. The performance of batteries is favorable even if the charge time is as long as 5h at the current density of 20mAcm−2. Better discharge performance is achieved using a ‘cavity-opening’ configuration for the discharge cell rather than a ‘gas-introducing’ configuration. The highest energy efficiency is up to 59.2%. That is, the energy consumed by organic electro-synthesis can be recovered by 59.2%. Cyclic voltammograms show that the sintered nickel electrode exhibits a good electro-catalysis activity for the propanol oxidation. The increase of propanol concentration conduces to an enhancement in the organic electro-synthesis efficiency. The organic electro-synthesis current efficiency of 82% can be obtained.
The chemically cross-linked gel polymer electrolytes supported by the microporous polyethylene membrane were prepared for application in lithium-ion polymer cells. The chemical cross-linking by star-shaped siloxane acrylate allowed to encapsulate an electrolyte solution in the porous membrane and also promote strong interfacial adhesion between the electrodes and the membrane. Lithium-ion polymer cells composed of a mesocarbon microbead anode and a lithium–cobalt oxide cathode were assembled by using in situ chemical cross-linking method, and their charge/discharge cycling performances were evaluated. Effect of the cross-linking agent content on cycling performances of the cells has been investigated.
A symmetrical graphene-based supercapacitor is constructed for studying the charge-transfer mechanism within the graphene-based electrodes using both experiment measurements and molecular simulation. The in-house synthesized graphene is characterized by XRD, SEM and BET measurements for morphology and surface area. It is observed that the electric capacity of graphene electrode can be reduced by both high internal resistance and limited mass transfer. Computer modeling is conducted at the molecular level to characterize the diffusion behavior of electrolyte ions to the interior of electrode with emphasis on the unique 2D confinement imposed by graphene layers. Although graphene powder poses a moderate internal surface of 400 m2 g−1, the capacitance performance of graphene electrode can be as good as that of commercial activated carbon which has an overwhelming surface area of 1700 m2 g−1. An explanation to this abnormal correlation is that graphene material has an intrinsic capability of adaptively reorganizing its microporous structure in response to intercalation of ions and immergence of electrolyte solvent. The accessible surface of graphene is believed to be dramatically enlarged for ion adsorption during the charging process of capacitor.
The preparation of a sulfur/dehydrogenated polyacrylonitrile (S/DPAN) composite by manual mixing followed by heat treatment at 300 °C in argon atmosphere is described. Electron microscopy analysis reveals very different morphology before and after heat treatment of the composites. Manually mixed S/DPAN cathode composites containing 48 wt% of sulfur exhibit a stable discharge capacity of 1050 mAh g−1 after 80 galvanostatic discharge–charge cycles at 0.2C, and good C-rate performance with up to 770 mAh g−1 at 1C. Results indicate that the long chains of polyacrylonitrile are retained during synthesis and may contribute to the enhanced electronic conductivity of the composite.
An efficient and economical oil expression system that can operate on solar power in rural areas of underdeveloped and developing countries is needed. Recent improvements in both oil extraction and solar energy technologies have indicated the possibilities for fabricating oil extraction equipment. Thus, the objective of our study was to develop a simple oil expression unit capable of producing high quality oil based on solar energy in remote rural areas. A photovoltaic (PV), batch operated, low-pressure oil press, using a 190W, 12V dc motor, was designed, fabricated, and tested using coconut and groundnut as the raw material. Samples used in the study were ground to particle size between 500μm and 2mm and were pressed at 12±1% moisture content. The press was evaluated based on the oil extraction efficiency (OEE), power consumption, and oil quality. The press had an average OEE of 73% for coconuts and 70% for groundnuts after 12min of pressing. The oil expression efficiency was characterized by three main stages namely delayed, rapid, and retarded. The power consumption was affected greatly by the pressing time, with power consumption increasing with an increase in the pressing time. The specific energy consumption was found to increase significantly after 8min of pressing and correlated with the compaction of the cake, which resulted in more power being required to express the entrapped oil. The expressed oil was fresh, free from foots, and of high quality with an average moisture content of 0.015% for coconut oil and 0.019% for groundnut. Analyses showed that the viscosities were 42.1MPas (coconut oil) and 59.1MPas (groundnut oil), at 25°C. Overall, the press performed well and was comparable in performance to other types of presses.
Li-S batteries have been considered promising candidates for the next-generation energy storage devices because of their extremely high energy densities and low cost. However, Li dendrite formation/dissolution and shuttle of high-order polysulfides prevent their practical applications. Herein, we demonstrate a highly concentrated electrolyte, 12 M lithium bis(fluorosulfonyl)imide (LiFSI) salt in DME solvent (12 M LiFSI/DME), that can effectively suppress both the Li dendritic growth on the anode and the polysulfide shuttle reactions on the cathode side. The highly concentrated electrolyte along with the robust solid electrolyte interphase (SEI) formed therein play the key role in achieving high coulombic efficiencies for both Li stripping/plating (> 99.2%) and S cathode (> 99.7%). Based on the in-depth understanding of the interactions between electrodes and highly concentrated electrolyte, we designed a novel dilute electrolyte (1 M LiFSI/HFE + DME), which achieves similar electrochemical performances in Li-S batteries as the concentrated electrolytes. These Li-S batteries with the highest CE for Li anode and sulfur cathode maintains a high reversible capacity of 786 mA h/g at 0.1 A/g after 300 cycles, or 644 mA h/g at 300th cycle even at 1 A/g without any detectable shuttle reactions.