batterydata/paper-abstracts huggingface dataset:
Selenium (Se) is a prospective candidate of cathode material for high-energy batteries. However, the dissolution of high-order lithium selenides and the shuttle effect in electrolytes lead to low Se utilization, inferior capacity and poor cycling performance. Herein, a heteroatoms (N and O) dual-doped hierarchical porous carbon (HDHPC) with interconnected macro/meso/micropores is used to confine Se composite and developed as a cathode material for advanced Li/Na–Se batteries in low-cost carbonate electrolyte. For Li-Se batteries, Se/HDHPC cathode delivers an initial charge capacity of 613 mAh g−1 and maintains stable reversible capacity of 545 mAh g−1 with a capacity decay as low as 0.0074% per cycle after 1500 cycles at a current density of 0.5 C (1 C = 675 mA g−1). For Na-Se batteries, Se/HDHPC exhibits a high initial charge capacity of 619 mAh g−1 and retains as high as 402 mAh g−1 after 500 cycles at a current rate of 0.5 C. Moreover, Se/HDHPC composite also exhibits an excellent rate performance both in the Li-Se and Na-Se batteries even at a high rate up to 20 C (13.5 A g−1). Such excellent electrochemical properties of Se/HDHPC are mainly contributed from two aspects. One is the hierarchical porous structure of the HDHPC, which benefit the penetration of electrolyte and also act as micro reaction chambers to effectively suppress the volume change of the electrode. The other is the strong interaction between lithium/sodium selenide and carbon host induced by heteroatoms (N and O) dual-doping, which can strongly anchor the Se-contained species, thus preventing the side reaction of Se anions with electrolyte.
As a new generation of high quality graphene, electrochemically exfoliated graphene is an ideal platform for constructing integrated high-performance nanocomposites as advanced electrode materials for energy storage and conversion devices. To take on a challenge of direct growth of nanoparticles on electrochemically exfoliated graphene with limited oxygen-containing functional groups and its hydrophobic nature, a systematic study is carried out on growth of SnO2 nanocrystallites on the surface of electrochemically exfoliated graphene. The results indicate that these nanocrystals can efficiently grow on the functional group-free surface of electrochemically exfoliated graphene, if the precursor molecules can polymerize into larger molecules and aggregate on electrochemically exfoliated graphene followed by decomposition and phase transformation into the final metal oxide nanocrystallites. Some key factors affecting this non-classical crystal growth are investigated. Addition of a small amount of water in a polar aprotic solvent to stimulate polymerization of the precursor molecules and a solvothermal treatment to facilitate decomposition of the disordered aggregates of the polymerized precursors are crucial to the growth of nanocrystals on electrochemically exfoliated graphene. The improved electrical conductivity and structural stability of the hybrids may promote the performance of the materials in various applications, such as exceptional lithium storage capability.
A monomer; (3-cyanopropyl)methylsiloxane cyclics, is prepared by a hydrosiliylation reaction of 2,4,6,8-tetramethylcyclotetrasiloxane with allyl cyanide in toluene using a platinum(0)-1,3-divinyl-1,1,3,3-tetramethyl disiloxane complex as the catalyst. The cross-linkable polysiloxane is synthesised by ring-opening polymerisation with (3-cyanopropyl) methylsiloxane cyclics using fuming sulfuric acid. The polymers, abbreviated as D4D2-n indicates the number of cyanide groups in the side chain), are characterised by FT-IR and 1 H NMR. The solid polymer electrolyte is prepared by UV irradiation in an Indium–tin oxide cell. The cyanide pendants on the network backbones make the lithium salt easy to dissolve, accelerate the migration of free lithium ions, and can lower the glass transition temperature (T g) of the electrolyte. The maximum conductivity of the polymer with n=55 is 3.38×10−5 Scm−1 at room temperature. The temperature dependence of ionic conductivity (σ) obeys the Vogel–Tammann–Fulcher relationship which implies ionic conductivity (σ) obeys the Vogel–Tammann–Fulcher relationship which implies a free-volume cation transport mechanism.
Reduction of oxygen was investigated on porous electrodes made of La1−x Ca x CoO3 (with 0≤ x ≤0.6) perovskite-structured oxides, prepared by a sol–gel process. It was found that both the reaction rate and the electrode active surface area (determined by cyclic voltammetry in a narrow capacitive potential range and by impedance spectroscopy) depend on the partial substitution ratio x, both displaying a maximum value for x nearly equal to 0.4. However, in spite of the parallel trend exhibited by the reduction current and the electroactive surface area parameter, the current varies much more with x, that is, while the change in the surface area amounts to approximately 40% over the explored x range, the current increases fivefold. Subsequent investigation of the electrode surface composition revealed that surface cobalt concentration (estimated by XPS analysis) deviates significantly from the nominal bulk composition (determined by EDX analysis). It follows a similar dependence on x, showing equally a maximum for x near to 0.4. Such a behaviour seems to have a greater effect on the reaction rate, since Co cations are the surface active sites for oxygen electro-reduction.
Uneven pressure drops in a 75-cell 9.5-kWe proton exchange membrane fuel cell stack with a U-shaped flow configuration have been shown to cause localised flooding. Condensed water then leads to localised cell heating, resulting in reduced membrane durability. Upon purging of the anode manifold, the resulting mechanical strain on the membrane can lead to the formation of a pin-hole/membrane crack and a rapid decrease in open circuit voltage due to gas crossover. This failure has the potential to cascade to neighbouring cells due to the bipolar plate coupling and the current density heterogeneities arising from the pin-hole/membrane crack. Reintroduction of hydrogen after failure results in cell voltage loss propagating from the pin-hole/membrane crack location due to reactant crossover from the anode to the cathode, given that the anode pressure is higher than the cathode pressure. Through these observations, it is recommended that purging is avoided when the onset of flooding is observed to prevent irreparable damage to the stack.
The advent of mobile and ubiquitous systems has enabled the development of autonomous systems such as wireless-sensors for environmental data collection and teams of collaborating Unmanned Autonomous Vehicles (UAVs) used in missions unsuitable for humans. However, with these range of new application-domains comes a new challenge—enabling self-management in mobile autonomous systems. Autonomous systems have to be able to manage themselves individually as well as form self-managing teams which are able to adapt to failures, protect themselves from attacks and optimise performance. This paper proposes a novel distributed policy-based framework that enables autonomous systems of varying scale to perform self-management individually and as a team. The framework allows missions to be specified in terms of roles in an adaptable and reusable way, enables dynamic and secure team formation with a utility-based approach for optimal role assignment, caters for communication link maintenance amongst team-members and recovery from failure. Adaptive management is achieved by employing a policy-based architecture to enable dynamic modification of the management strategy relating to resources, role behaviour, communications and team management, without interrupting the basic software within the system. Evaluation of the framework shows that it is scalable with respect to the number of roles, and consequently the number of autonomous systems involved in the mission. It is also optimal with respect to role assignments, and robust to intermittent communication link and permanent team-member failures.
Dexterity impairments caused by carpal tunnel syndrome (CTS) make working and daily activities challenging. We aimed to investigate: i) the relationship between dexterity and nerve conduction studies (NCS) in workers with classic symptoms presentation; ii) the ability of the Functional Dexterity Test (FDT) to discriminate different levels of CTS severity as classified by NCS; iii) the diagnostic accuracy of a clinical battery composed of the FDT, Phalen’s test and Tinel’s sign.
Investment and policy decisions about low-carbon technologies have been affected by the promise of a ‘unicorn technology’ that may reduce emissions at low costs. Researchers show that such investment delays can have high implications on cost and emissions whether the unicorn technology materializes or not.
JUUL, an electronic nicotine delivery system (ENDS), which first appeared on the US market in 2015, controled more than 75% of the US ENDS sales in 2018. JUUL-type devices are currently the most commonly used form of ENDS among youth in the US. In contrast to free-base nicotine contained in cigarettes and other ENDS, JUUL contains high levels of nicotine salt (35 or 59 mg/mL), whose cellular and molecular effects on lung cells are largely unknown. In the present study, we evaluated the in vitro toxicity of JUUL crème brûlée-flavored aerosols on 2 types of human bronchial epithelial cell lines (BEAS-2B, H292) and a murine macrophage cell line (RAW 264.7).
This is the first report where crystalline carbon-coated Li4Ti5O12 nanowires are employed as an anode material for sodium-ion batteries. The Li4Ti5O12 nanowires are synthesized via a two-step ionic exchange process from Na2Ti3O7 nanowires to form hydrous lithium titanate nanowires, where excessive lithium oxide is adhered on the surface of the nanowires. The nanowire products are consequently heated to form Li4Ti5O12, and the resultant nanowires are subsequently coated by pitch as the carbon source. X-ray diffraction (XRD) and electron microscopic studies reveal that the carbon-coated Li4Ti5O12 nanowires are highly crystalline products and that their nanowire features have been modified with carbon nanolayers (<10nm in thickness). As a result, the electronic conductivity is approximately 3×10−1 Scm−1. The delivered capacities are about 168mAhg−1 at a rate of 0.2C (35mAg−1), 117mAhg−1 at a rate of 10C, 88mAhg−1 at a rate of 30C, 67mAhg−1 at a rate of 50C, and 38mAhg−1 at a rate of 100C; these conductivity values are superior to those achieved with bare Li4Ti5O12. Continuous cycling testing reveals outstanding cycling stability, showing 96.3% capacity retention after cycles. Ex-situ XRD and X-ray photoelectron spectroscopic studies indicate that the electrode reaction is followed by Na+ insertion and extraction, accompanied by the Ti4+/3+ redox couple. We believe that the excellent high rate capacity and rechargeability upon cycling result from the unique morphology of the highly crystalline Li4Ti5O12 nanowires assisted by conducting thin carbon layers.
In an effort to simultaneously improve upon existing power storage and generation devices while supplying America’s war fighters with state-of-the-art equipment, the US military has focused on fuel cell technology for several military applications. These applications include soldier and sensor power (0–100W) and auxiliary power units (500–3000W). Over the past few years, the fuel cell industry has realized remarkable decreases in the size and weight of proton exchange membrane (PEM) fuel cell systems. However, a safe and affordable means of storing and generating hydrogen does not yet exist to justify their transition into the field. In order to assess the hydrogen storage capacity and hydrogen generation rates of ammonia (NH3) based systems, the US Army Communications-Electronics Research, Development, and Engineering Center (CERDEC), tested several ammonia hydride hydrogen generator systems built by Hydrogen Components Inc. (HCI). Experimental results and analysis illustrate that while there are developments necessary at the sub-system level, the hydrogen generators are ideal energy storage devices for low power (5W) operations over wide temperature ranges. The results show that the hydrogen generators are capable of operating autonomously for over 50+ h of operation (at a 5W load) and producing hydrogen delivery system energy densities of 480Wh/kg.
This study provides a bibliographic review in the broad field of green composites seeking-out for materials with a potential to be applied in the near future on automotive body panels. Hereupon, materials deriving from renewable resources will be preferred as opposed to the exhaustible fossil products. With the technical information of bio-polymers and natural reinforcements a database was created with the mechanical performance of several possible components for the prospect green composite. Following the review, an assessment is performed where aspects of suitability for the candidate elements in terms of mechanical properties are analyzed. In that section, renewable materials for matrix and reinforcement are screened accordingly in order to identify which hold both adequate strength and stiffness performance along with affordable cost so as to be a promising proposal for a green composite.
Iron homeostasis is important for maintaining normal physiological brain functioning. In two independent samples, we investigate the link between iron concentration in the basal ganglia (BG) and implicit sequence learning (ISL). In Study 1, we used quantitative susceptibility mapping and task-related fMRI to examine associations among regional iron concentration measurements, brain activation, and ISL in younger and older adults. In Study 2, we examined the link between brain iron and ISL using a metric derived from fMRI in an age-homogenous sample of older adults. Three main findings were obtained. First, BG iron concentration was positively related to ISL in both studies. Second, ISL was robust for both younger and older adults, and performance-related activation was found in fronto-striatal regions across both age groups. Third, BG iron was positively linked to task-related BOLD signal in fronto-striatal regions. This is the first study investigating the relationship among brain iron accumulation, functional brain activation, and ISL, and the results suggest that higher brain iron concentration may be linked to better neurocognitive functioning in this particular task.
In this study, a full factorial experimental design was utilized to assess the effect of three factors on the adsorption of copper (II) and zinc (II) ions in an aqueous leachate of an industrial waste with illite as adsorbent. The chosen experimental factors at two levels were (A) pH at 2 and 7, (B) adsorbent content at 0.2 and 1.6gL−1, and (C) contact time at 10 and 120minB (adsorbent content), A (pH), and AB terms, with their high levels, positively influenced the adsorption process. Of the adsorption kinetics models, the second order model best described the data. Illite was a reasonably effective adsorbent for Cu2+ and Zn2+ from aqueous leachates of industrial waste.
The influence of substrate morphology and ageing on the charge–discharge performance of a Sn–Ni alloy anode electrodeposited on a Cu substrate are examined. The Sn–Ni alloy (Sn 82at.%–Ni 18at.% anode) shows a high capacity of around 480mAhg−1 up to 12 cycles, but its capacity rapidly fades with cycling. The initial capacity and the cyclic properties of the alloy electrode are significantly improved when the surface morphology of the Cu substrate is changed from smooth-type to nodule-type. Optimized ageing treatment leads to further enhancement in the charge–discharge performance of the anode. The increase in the capacity and better cyclic properties are attributed to stronger adhesion between the Si–Ni anode and the Cu substrate. This is induced by inter-locking of the nodule-type Cu substrate and a buffering effect of Cu–Sn intermetallic compounds formed during ageing.
Objective We investigated whether the relationship between cardio-respiratory fitness (CRF) and cognition in schizophrenia is general, or due to selective relationships between CRF and specific aspects of cognitive function. Method Eighty outpatients with schizophrenia spectrum disorders participated. Neurocognition was assessed with the Wechsler Adult Intelligence Scale version 4 General Ability Index (WAIS GAI), the MATRICS Consensus Cognitive Battery (MCCB) and the Emotion in Biological Motion (EBM) test. CRF was assessed with peak oxygen uptake measured directly during maximum exercise using a modified Balke protocol. Partial correlations, controlling for sex and age, were obtained for the perceptual and the verbal indices of WAIS GAI, six cognitive domains of MCCB, and the EBM total score. A factor analysis was conducted on all 15 subtests of the WAIS GAI and the MCCB, and the factors were subjected to separate regression analyses with CRF as predictor. Results Significant, moderately sized correlations were found between CRF and all cognitive domains except processing speed. The correlation appeared strongest for CRF and the Verbal Comprehension Index of WAIS GAI (r = 0.29, p = .005). The factor analysis identified three factors: one speed/attention/executive function factor, one verbal factor, and one perceptual factor. Regression analyses showed that VO2peak explained a significant amount of variance in the verbal factor only (R 2 = 0.06, β = 0.329, p = .03). Conclusion The results indicate that the relationship between CRF and cognition in schizophrenia is selectively tied to a modality-specific association with verbal cognitive abilities. These findings have implications for understanding the relation between cognitive factors and physical health in schizophrenia. ClinicalTrials.gov reg. number NCT02205684 (clinicaltrials.gov/ct2/show/NCT02205684).
Two independent assessments were performed of airborne asbestos concentrations generated during automotive repair work on vintage vehicles . The first involved removal of asbestos-containing seam sealant, and the second involved servicing of a drive clutch. Despite the relatively high concentrations (5.6–28%) of chrysotile fibers detected within bulk samples of seam sealant, the average asbestos concentration for personal breathing zone (PBZ) samples during seam sealant removal was 0.006f/cc (fibers/cubic centimeter of air). Many other air samples contained asbestos at or below the analytical limit of detection (LOD). Pneumatic chiseling of the sealant material during removal resulted in 69% of area air samples containing asbestos. Use of this impact tool liberated more asbestos than hand scraping. Asbestos fibers were only detected in air samples collected during the installation of a replacement clutch. The highest asbestos corrected airborne fiber concentration observed during clutch installation was 0.0028f/cc. This value is approximately 100 times lower than Occupational Safety and Health Administration’s (OSHA) permissible exposure limit (PEL) of 0.1f/cc. The airborne asbestos concentrations observed during the servicing of vintage vehicles with asbestos-containing seam sealant and clutches are comparable to levels reported for repair work involving brake components and gaskets.
A feasibility study and techno-economic analysis for a hybrid power system intended for vehicular traction applications has been performed. The hybrid consists of an intermediate temperature solid oxide fuel cell (IT-SOFC) operating at 500–800°C and a sodium–nickel chloride (ZEBRA) battery operating at 300°C. Such a hybrid system has the benefits of extended range and fuel flexibility (due to the IT-SOFC), high power output and rapid response time (due to the battery). The above hybrid has been compared to a fuel cell-only, a battery-only and an ICE vehicle. It is shown that the capital cost associated with a fuel cell-only vehicle is still much higher than that of any other power source option and that a battery-only option would potentially encounter weight and volume limitations, particularly for long drive times. It is concluded that increasing drive time per day decreases substantially the payback time in relation to an ICE vehicle running on gasoline and thus that the hybrid vehicle is an economically attractive option for commercial vehicles with long drive times. In the case where the battery has reached volume production prices at £70kWh−1 and current fuel duty values remain unchanged then a payback time <2 years is obtained. For a light delivery van operating with 6h drive time per day, a fuel cell system model predicted a gasoline equivalent fuel economy of 25.1kmL−1, almost twice that of a gasoline fuelled ICE vehicle of the same size, and CO2 emissions of 71.6gkm−1, well below any new technology target set so far. It is therefore recommended that a SOFC/ZEBRA demonstration be built to further explore its viability.
The aged dog brain accumulates β-amyloid in the form of diffuse senile plaques, which provides a potentially useful in vivo model system for studying the events surrounding the deposition of β-amyloid. We used postembedding immunocytochemistry at the electron microscopic level to determine the subcellular distribution of β-amyloid 1-40 and β-amyloid 1-42 peptides in the prefrontal and parietal cortex of behaviorally characterized dogs ranging in age from one to 17 years. Immunogold particles signaling β-amyloid 1-42 occurred over intracellular and extracellular fibrils that were approximately 8nm in width. Intracellular β-amyloid 1-42 fibrils were found in close proximity to glial fibrillary acidic protein fibers within astrocytes, but only in cells with signs of plasma membrane disruption. Neuronal labeling of β-amyloid 1-42 appears to be associated with the plasma membrane. Membrane-bound β-amyloid 1-42 occurs in the form of fine fibrils that are embedded in the dendritic membrane and appear to project into the extracellular space as determined by quantitative analysis of the immunogold particle distribution. Bundles of β-amyloid 1-42 were also closely associated and/or integrated with degenerating myelin sheaths of axons. In one dog that was impaired on several cognitive tasks, extensive β-amyloid 1-42 deposition was associated with microvacuolar changes and vascular pathology. The present findings suggest that β-amyloid 1-42 may be generated at the dendritic plasma membrane as well as in intracellular compartments. The close association between β-amyloid 1-42 and destroyed myelin suggests one possible new mechanism by which β-amyloid 1-42 induces neurodegeneration.
A hydrometallurgical leaching process has been developed for recovery of Co and Li from cathode material (LiCoO2) collected from spent LIBs using a mix solution of glucose and phosphoric acid. The spent LiCoO2 before and after leaching process are analyzed by scanning electron microscopy. A leaching rate of about 98% Co and nearly 100% Li is presented with 1.5mol/L phosphoric acid and 0.02mol/L glucose at 80°C in about 2h. During leaching process, glucose was oxidized into monocarboxylic acid with reduction of Co(III) to Co(II). Co in solution was recovered as Co-oxalate after leaching process. Using glucose as reductant to dissolve LiCoO2 with chelating agent of phosphoric acid is achieved here.