batterydata/paper-abstracts huggingface dataset:
Combining the oxidant and coolant flow in an air-cooled proton exchange membrane fuel cell can significantly simplify the fuel cell design. In this paper, an air-cooled PEM fuel cell stack with an open cathode flow field, which supplied the oxidant and removed the heat produced in the fuel cell, was fabricated and tested. The influence of different operating parameters on cell voltage performance and the overall cell ohmic resistance, such as cell temperature and airflow rate, was investigated. The cell temperature and the temperature difference between the cell and the hydrogen humidifier were shown to serve important roles in reducing the fuel cell ohmic resistance. The test results also showed a noteworthy temperature gradient between each cell of a 5-cell stack. A hydrophilic treatment of the cathode flow field channels was demonstrated to be an effective way to mitigate water management issues caused at elevated operating temperatures.
The coaxial MnO2/CNTs nanocomposite freestanding membrane is prepared via a simple two-step process, including that CNTs are grown on the surface of stainless steel mesh by chemical vapor deposition and then MnO2 is coated onto the surface of CNTs using electrodeposition. Scanning electron microscopy and transmission electron microscopy demonstrate that MnO2 nanoflakes are uniformly deposited on the surface of CNTs to form the coaxial MnO2/CNTs nanocomposites freestanding membrane. The thickness of MnO2 shell is in range of 25–50nm. Electrochemical characterizations shows that the initial discharge capacity of MnO2/CNTs nanocomposites freestanding membrane is as high as 2062mAhg−1 based on the total mass of MnO2/CNTs nanocomposites, and its capacity retention is 80% after 260cycles compared with the second cycle. The result suggests that the as-prepared coaxial MnO2/CNTs nanocomposite freestanding membrane anode indicates excellent cycle stability and good rate capability. Moreover, it can be prepared on a large scale and suitable for industrial production due to its simple and low-cost prepared process.
The most recent results obtained in our laboratory on the characterization of two classes of polymer electrolytes and of olivine-type lithium iron phosphate electrodes are reviewed and discussed, especially in view of their application in advanced lithium batteries.
Room temperature, magnesium ion-conducting molten electrolytes are prepared using a combination of acetamide, urea and magnesium triflate or magnesium perchlorate. The molten liquids show high ionic conductivity, of the order of mScm−1 at 298K. Vibrational spectroscopic studies based on triflate/perchlorate bands reveal that the free ion concentration is higher than that of ion-pairs and aggregates in the melt. Electrochemical reversibility of magnesium deposition and dissolution is demonstrated using cyclic voltammetry and impedance studies. The transport number of Mg2+ ion determined by means of a combination of d.c. and a.c. techniques is ∼0.40. Preliminary studies on the battery characteristics reveal good capacity for the magnesium rechargeable cell and open up the possibility of using this unique class of acetamide-based room temperature molten electrolytes in secondary magnesium batteries.
For electric vehicles, a supercapacitor can be coupled to the electrical system in order to increase and optimize the energy and power densities of the drive system during acceleration and regenerative breaking. This study looked at the charge acceptance and maximum discharge ability of a valve regulated lead acid (VRLA) and a Li-ion battery connected in parallel to supercapacitors. The test procedure evaluated the advantage of using a supercapacitor at a 2 F:1 Ah ratio with the battery types at various states of charge (SoC). The results showed that about 7% of extra charge was achieved over a 5-s test time for a Li-ion hybrid system at 20% SoC, whereas at the 80% SoC the additional capacity was approximately 16%. While for the VRLA battery hybrid system, an additional charge of up to 20% was achieved when the battery was at 80% SoC, with little or no benefit at the 20% SoC. The advantage of the supercapacitor in parallel with a VRLA battery was noticeable on its discharge ability, where significant extra capacity was achieved for short periods of time for a battery at the 60% and 40% SoC when compared to the Li-ion hybrid system. The study also made use of Electrochemical Impedance Spectroscopy (EIS) with a suitable equivalent circuit model to explain, in particular, the internal resistance and capacitance differences observed between the different battery chemistries with and without a supercapacitor.
This paper is concerned with the tank-to-wheel (TTW) analysis of a series plug-in hybrid electric bus operated in Gothenburg, Sweden. The bus line and the powertrain model are described. The definition and the calculation method of the recuperation and fuel-to-traction efficiencies are delineated for evaluating the TTW energy conversion. The two efficiencies are quantified and compared for two optimization-based energy management strategies, in which convex modeling and optimization are used. The impact of downsizing the battery on the two efficiencies is also investigated.
Voltammetric studies and galvanostatic oxidation results for the electrochemical oxidation of octyl. hexyl, butyl, isobutyl and benzyl alcohols on hydrated nickel-cobalt oxide electrode in alkaline media are reported. These compounds are oxidised to their corresponding acids with high efficiency. The electrodes are not contaminated and hence their repeated use for the oxidation of same or different compounds is possible. Oxidation of benzyl chloride leads to formation of benzyl alcohol, benzaldehyde along with benzoic acid.
Catalytic reformer furnaces (steam reformers) produce hydrogen-rich gas by cracking natural gas or naphtha in the presence of steam and a catalyst. This hydrogen-rich gas is a raw material in different petrochemical processes and is also used in the hydrotreating process in petroleum refineries. Unexpected operational failures of these reformers can cause major economic losses. These failures can happen when the feedstock flow, that cools the catalyst tubes located in the radiation chamber, is unintentionally restricted without also reducing the fuel burn rate. The thermal imbalance created in this situation can quickly produce a temperature surge large enough to cause the failure of the catalyst tubes through formation of large longitudinal cracks. This paper discusses a case of a temperature surge followed by the rupture of 13 catalyst tubes. The data show that the catalyst tubes that survived the event may retain sufficient structural integrity to return to normal operation.
Over the last several years bacteriophages have appeared as an interesting addition to electrochemical devices, both as recognition elements and as scaffolds and templates for novel electrode materials. Their natural ability for selective binding to specific analytes and the versatility offered by genetic modification and selection through phage display techniques in combination with chemical functionalization make them very attractive building blocks for modern cross-disciplinary electrochemical research. In this manuscript we review the latest development in the use of bacteriophages in electrochemical devices with a focus on sensors and phage-based materials.
In order to enhance cycling stability, Rb+ has been incorporated into Li-rich manganese based layered oxide cathode materials for lithium-ion batteries (LIBs) by a co-precipitation method and a subsequent solid-state reaction. The influence of the content of Rb+ in the cathodes on the performance was investigated and the optimal content was identified to be x =0.03. The inter-slab distance exhibited a slight increase after the Rb+ incorporation, which reduced the energy barrier for the intercalation/deintercalation process of Li+ in the cathode. Electrochemical characterization showed that the as-synthesized cathode materials have an improved cycleability and rate performance compared with the pristine Li-rich manganese layered oxide based cathodes for LIBs. In addition, it was confirmed that the Rb+ doping clearly suppresses the process of the simultaneous lithium extraction along with oxygen activation at the high voltage region which could alleviate the irreversible loss of oxygen in the form of Li2O. The improved diffusion coefficient of Li ions in the Rb+ incorporated cathodes was confirmed by electrochemical impedance spectroscopy measurements.
The Li3V2(PO4)3/C composite (LVP) including nanorods and irregular solids were successfully prepared by a sol–gel method. The influences of different precursors on the LVP cathode materials were investigated by using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), particle size distribution measurement and electrochemical methods. The LVP/C electrodes present good rate capability and excellent cyclic performance when they cycle in the range of 3.0–4.3V. The LVP1/C composite prepared by NH4H2PO4, LiOH, NH4VO4 and citric acid delivers the initial discharge capacity of 109.6mAhg−1 at 20C discharge rate and it still maintains 56.9mAhg−1 after 450 cycles, with the discharge capacity retention of 51.9%. For the LVP2/C composite synthesized by LiH2PO4, NH4VO4 and citric acid, however, the discharge capacities in the 1st and 450th cycles at 20C discharge rate are 107.1 and 96.2mAhg−1, respectively, with only 10.2% loss. The excellent rate capacity is attributed to the pure phases, nanorod structure, small particles and uniform carbon coating.
Potassium-ion batteries (PIBs) are considered as potential replacements to lithium-ion batteries for large scale energy storage applications due to abundant potassium resources and low cost. However, it is a rough road to find suitable materials with high capacity and cycling stability due to the large K ion radius. In this study, a simple method, electrodeposition, is used to anchor SnO2 nanoparticles on three dimensional carbon foam (SnO2@CF) as a freestanding anode for PIBs. The prepared freestanding SnO2@CF electrode features a three dimensional (3D) conductive carbon frame and SnO2 nanoparticles, which can enhance electron transfer, prevent SnO2 from losing electrical contact after large volume changes and facilitate electrolyte infiltration and K ion transfer. As expected, SnO2@CF delivers a high K storage specific capacity, and outstanding cycling stability (231.7 mA h g−1 after 400 cycles at 1 A g−1) and rate performance (371.4, 307.6, 247.3 and 143.5 mA h g−1 at 0.5, 1, 2 and 5 A g−1, respectively). Meanwhile, the phase transition of the SnO2@CF electrode is tracked during the charge and discharge processes in PIBs. This study provides a facile method to prepare freestanding electrode materials and a promising anode material for PIBs.
The objective of the study is about educational environment of young adult homeless. The study design combined qualitative and quantitative approaches and sample consisted of 90 homeless persons (60 were males) in age 18 to 26. Large majority of the young adult homeless grow up in an incomplete family (47%). Developmentally disadvantaged are especially those who lived in a state institution (34%). Over one third of the subjects reported serious physical punishment or abuse in the family. Dysfunctional family of origin, physical abuse and other forms of traumatic events in childhood are main causes of homelessness of young people in Prague.
Conversion of the abundant agricultural residual cotton stalk (CS) into useful chemicals or functional materials could alleviate the fossil fuels caused energy shortages and environmental crises. Although some advances have been achieved, less attention has been paid to the plant tissues effect. In this study, the plant tissue of CS was changed by part degradation of some components (hemicelluloses and lignin, for example) with the aid of acid/base (or both). The pretreated CS was transformed into hydrochar by hydrothermal carbonization (HTC) method. Morphological and chemical compositions of CS hydrochar were analyzed by various techniques, including elemental analysis, Fourier transform infrared (FTIR), BET analysis, X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). Methylene blue (MB) removal of prepared CS hydrochar was used to evaluate CS hydrochar pollutions adsorption capacity. Results reveal acid/base (or both) pretreatment is beneficial for CS raw material to prepare high-quality CS hydrochar. The effects of some parameters, such as initial MB concentration, temperature, pH value and recyclability on the adsorption of MB onto both acid and base-pretreated CS hydrochar (CS-H2SO4 + NaOH-HTC) were studied. The present work exhibits the importance of agricultural waste biomass material plant tissues on its derived materials, which will have a positive effect on the direct utilization of waste biomass.
Li-rich manganese-based layered electrode materials are expected to be superior performance cathode materials for next-generation lithium ion batteries due to high capacity, low cost and environmentally benignity. However, the commercialization of such cathode materials is impeded by severe capacity fading and poor rate performance. To overcome these problems, Al2O3 is coated on the Li1.256Ni0.198Co0.082Mn0.689O2.25, meanwhile, spinel-structure interface layer is formed between the Li1.256Ni0.198Co0.082Mn0.689O2.25 and Al2O3 coating. This modified cathode material has a significant improvement on rate performance with a discharge capacity of 189 mAhg−1 at current density of 1250 mAg−1. In addition, it reveals a discharge capacity of 240 mAhg−1 at current densities of 250 mAg−1 and a retention of 95.2% after 60 cycles. The improved rate performance and cycling stability are benefited from the formation of spinel-structure interface layer and Al2O3 coating.
The wide range of ability and disability in ASD creates a need for tools that parse the phenotypic heterogeneity into meaningful subtypes. Using eye tracking, our past studies revealed that when presented with social and geometric images, a subset of ASD toddlers preferred viewing geometric images, and these toddlers also had greater symptom severity than ASD toddlers with greater social attention. This study tests whether this “GeoPref test” effect would generalize across different social stimuli.
Introduction It has been asserted that damage to the cerebellum produces a specific pattern of cognitive deficits, but clinical studies have had ambiguous results. There remains particular uncertainty about the effects of focal cerebellar injuries on cognition in adults. Clinical reports and anatomical connectivity studies have suggested a possible functional convergence of frontal lobes and cerebellum. This investigation was designed to assess whether focal cerebellar injuries in adults would cause impairment on tasks previously demonstrated to be sensitive to prefrontal lesions. Method We investigated this question in 32 adults with either stroke or resection of benign tumours and 36 healthy control subjects. Patients underwent standard and experimental cognitive testing and an assessment of general health and well-being at least 3 months post onset. Results The group with right cerebellar lesions had lower performance on some tests of response control and verbal fluency than the controls and also the patients with left cerebellar lesions. On most tests, including most of the experimental tests sensitive to prefrontal lesions, the patients had no significant difference from the controls. The patient groups reported no health or functional decline. Conclusions These results and the bulk of the clinical literature suggest that damage to some cerebellar sites may have specific cognitive consequences, but the cognitive impairment after focal cerebellar injury in adults is mild or transient. After the acute epoch, demonstration of deficits may require more demanding probes of specific domains of cognition.
The New York Pine Plains are a unique ecosystem with normal statured and a dwarfed variety of pitch pines (Pinus rigida Mill.). Growing interspersed with the dwarf pines are trees of intermediate height and features. Several hypotheses have been put forward as to why some of the trees are dwarfed, but none have been substantiated. In this study, we tested whether dwarf or medium trees are hydraulically limited compared to normally growing trees. Granier style sap flux sensors were installed in three to six trees of each tree type and sap flux was measured in early August 2004. Sap flux measurements were scaled to crown stomatal conductance using leaf area to sapwood area ratios for each tree. Contrary to expectation, dwarf and medium stature trees had very low leaf area to sapwood area ratios, but high crown stomatal conductances compared to normal trees. Analyses of leaf area, ring widths, and crown stomatal conductance indicate that differences between normal, and dwarf and medium pines are not due to hydraulic limitation, but that stunted growth may be due to other causes.
Familial cases of frontotemporal dementia (FTD) provide an opportunity to study the pathophysiology of this clinically diverse condition. The C9ORF72 mutation is the most common cause of familial FTD, recent pathological descriptions challenge existing TDP-43 based hypotheses of sporadic FTD pathogenesis. Non-ATG dependent translation of the hexanucleotide expansion into aggregating dipeptide repeat (DPR) proteins may represent a novel pathomechanism. We report detection of the DPR aggregates very early in C9ORF72 FTD development and also describe childhood intellectual disability as a clinical feature preceding dementia. The index case presented with psychiatric symptoms, progressing into typical FTD. Autopsy revealed extensive neuronal DPR aggregates but only minimal TDP-43 pathology. Her intellectually disabled elder son, also carrying the C9ORF72 mutation, died aged 26 years and at autopsy only DPR aggregates without TDP-43 were found. A second son also has intellectual disability, his C9ORF72 status is unknown, but chromosomal microarray revealed no other cause of disability. These cases both extend the existing phenotype of C9ORF72 mutation and highlight the potential significance of DPR translation early in disease development.
We describe AnonySense, a privacy-aware system for realizing pervasive applications based on collaborative, opportunistic sensing by personal mobile devices. AnonySense allows applications to submit sensing tasks to be distributed across participating mobile devices, later receiving verified, yet anonymized, sensor data reports back from the field, thus providing the first secure implementation of this participatory sensing model. We describe our security goals, threat model, and the architecture and protocols of AnonySense. We also describe how AnonySense can support extended security features that can be useful for different applications. We evaluate the security and feasibility of AnonySense through security analysis and prototype implementation. We show the feasibility of our approach through two plausible applications: a Wi-Fi rogue access point detector and a lost-object finder.
Irreversible parasitic reactions and the resulting accumulation of insulating side products are main barriers for practical application of rechargeable lithium–oxygen (LiO2) batteries. Therefore, it is critical to develop multifunctional oxygen electrodes suitable for oxygen reduction reaction, oxygen evolution reaction, and decomposition of side reaction products. Here we report the application of ultrafine ruthenium on boron carbide (Ru/B4C) with highly efficient multifunctional activities as carbon-free oxygen electrodes for LiO2 batteries. Li2CO3 and LiOH can be completely decomposed by Ru/B4C at 4.0 V and 4.1 V, respectively, within the stability window of the electrolyte. A LiO2 battery using the Ru/B4C oxygen electrode achieves low overpotentials for LiO2 reactions, and excellent cycling performance under the capacities of 300 and 500 mAh g−1 Ru/B4C. In-situ gas chromatography analysis reveals that O2 is the major gas product during charging. Only a negligible amount of CO2 is observed in the first charging process. Therefore, Ru/B4C can be a very promising oxygen-electrode material for LiO2 batteries and Li–air batteries operated in ambient air.
Invasions of fouling organisms that colonize artificial structures are modifying coastal environments. Our goal was to assess harbor conditions including dissolved copper pollution, position in relation to open coast, temperature, and artificial structure density (substrate for fouling) as determinants of macroinvertebrate recruitment. Settlement panels were deployed over a gradient of human coastal modification (28 sites in California and 2 in southern Australia). Non-indigenous macroinvertebrates dominated panel cover (overall by six-fold compared to indigenous taxa). Marinas and sites of heavy shipping showed high macroinvertebrate diversity, contrasting with open-coast sites of lower human impact [Santa Catalina Island (SCI) and one mainland coastal site] where there was low macroinvertebrate fouling. At two SCI sites with low vessel traffic, invertebrates that were rare on exposed panels were more common in a protected space between plastic strips indicating larvae amount does not completely explain low invertebrate diversity, suggesting a contributing role of predators or larval recruitment pattern. While dissolved copper levels correlated strongly with artificial structure measured at the water surface, the pollution gradient was not supported as a driver of macroinvertebrate diversity in semi-partial analysis. Density of artificial structure was supported as a better predictor of macroinvertebrate diversity, including separately analyzed non-indigenous and indigenous groups, than dissolved copper, distance from open coast or temperature variation in semi-partial correlation analysis. An artificial structure density measure may therefore increase power in predicting abundance of fouling organisms and could be useful in moderating the influence of non-indigenous species.
A novel solid-state battery-supercapacitor hybrid device is fabricated for high-performance electrical energy storage using a Si anode and a TiO2 cathode in conjunction with a flexible, solid-like gel polymer electrolyte film as the electrolyte and separator. The electrodes were fabricated as three-dimensional nanostructured vertical arrays by sputtering active materials as conformal shells on vertically aligned carbon nanofibers (VACNFs) which serve as the current collector and structural template. Such nanostructured vertical core-shell array-electrodes enable short Li-ion diffusion path and large pseudocapacitive contribution by fast surface reactions, leading to the hybrid features of batteries and supercapacitors that can provide high specific energy over a wide range of power rates. Due to the improved mechanical stability of the infiltrated composite structure, the hybrid cell shows excellent cycling stability and is able to retain more than 95% of the original capacity after 3500 cycles. More importantly, this solid-state device can stably operate in a temperature range from −20 to 60 °C with a very low self-discharge rate and an excellent shelf life. This solid-state architecture is promising for the development of highly stable thin-film hybrid energy storage devices for unconventional applications requiring largely varied power, wider operation temperature, long shelf-life and higher safety standards.