batterydata/paper-abstracts huggingface dataset:
Hybrid MOx–C (M = Sn, Ni) supports and Pt/MOx–C catalysts for direct alcohol fuel cells were prepared via the electrochemical oxidation and dispersion of a metal under the influence of a pulsed alternating current. We estimated conductivity and specific surface area of as-prepared SnO2, NiO and hybrid supports, as well as estimated their morphology and the morphology of Pt-based catalysts using X-ray diffraction, transmission and scanning electron microscopy analyses. Pt/MOx–C (M = Sn, Ni) catalytic systems with oxide contents of 30 and 60 % in hybrid supports and a Pt content of 25 % were used for the electrochemical oxidation of CO, methanol and ethanol in acidic and alkaline solutions. The presence of oxides in the hybrid supports for catalysts reduces the onset potential for the electrooxidation of CO and alcohols in an acidic solution. At Pt/SnO2–C, the onset potential of ethanol electrooxidation in an acidic solution decreases by 170 mV and increases the rate of the oxidation process by more than sevenfold at the low Tafel potential region. In alkaline solutions, the presence of metal oxides in the catalysts is not so effective, which is probably due to the high coverage of the platinum surface with oxygen-containing species. The Pt catalyst on the SnO2–C hybrid support exhibited superior electrochemical stability in an acidic solution and Pt/NiO–C—in an alkaline solution. The difference in the optimum oxide content (30 % for SnO2, 60 % for NiO) of the catalysts can be attributed to different morphologies of the oxides.
Pt/C catalyst degradation remains as one of the primary limitations for practical applications of proton exchange membrane (PEM) fuel cells. Pt catalyst degradation mechanisms with the typically observed Pt nanoparticle growth behaviors have not been completely understood and predicted. In this work, a physics-based Pt/C catalyst degradation model is proposed with a simplified bi-modal particle size distribution. The following catalyst degradation processes were considered: (1) dissolution of Pt and subsequent electrochemical deposition on Pt nanoparticles in cathode; (2) diffusion of Pt ions in the membrane electrode assembly (MEA); and (3) Pt ion chemical reduction in membrane by hydrogen permeating through the membrane from the negative electrode. Catalyst coarsening with Pt nanoparticle growth was clearly demonstrated by Pt mass exchange between small and large particles through Pt dissolution and Pt ion deposition. However, the model is not adequate to predict well the catalyst degradation rates including Pt nanoparticle growth, catalyst surface area loss and cathode Pt mass loss. Additional catalyst degradation processes such as new Pt cluster formation on carbon support and neighboring Pt clusters coarsening was proposed for further simulative investigation.
The phase constitution, microstructure, electrochemical properties, and lithiation mechanism of the melt-spun Al88−XSi12MnX (X = 1, 3, 5, 7, 10, 13, 15, mol%) ribbons were investigated as anode materials for lithium-ion batteries. When X = 1 and 3, the alloys were composed of coarse supersaturated α-Al grains and fine α-Si grains spread along the boundaries, and performed high initial capacities but fast capacity fade. As X was increased to 5 and 7, the constitution of alloys was characterized by nanoscaled α-Al and amorphous regions, and they exhibited capacities of 924 and 764 mAh g−1 initially, 733 and 578 mAh g−1 at the second cycle and then maintained 391 and 351 mAh g−1 after 50 cycles, respectively. When the Mn content was more than 10 %, an intermetallic compound Al4.01MnSi0.74 co-existed with α-Al and it evolved into the predominated constitution. The initial specific capacities were very high, but faded rapidly only experiencing few cycles. After lithiation, any compound with Li could not be detected in the Al85Si12Mn3 and Al83Si12Mn5 anodes, while the AlLi intermetallic compound could be detected when the Mn content was increased to 13 %. It could be considered that the appropriate phase constitution and microstructure in the Al83Si12Mn5 and Al81Si12Mn7 anodes were very beneficial to mitigating structure evolution, improving structure stability, and obtaining favorable electrochemical properties. The Al4.01MnSi0.74 compound was an active phase for Li storage in the present system, but it was responsible for serious structure evolution, poor cyclability, and pulverization.
Spinel LiNi0.5Mn1.5O4 (LNMO) is a promising high voltage cathode material for lithium ion batteries (LIBs). However, dissolution of Mn and unwanted side reactions between LNMO and the electrolyte raises several safety issues while also resulting in deteriorated electrochemical performance of LIBs at high working voltages. Here, we report the use of ultrathin atomic layer deposited (ALD) AlPO4 thin film as a coating material for LNMO electrodes to circumvent the stated issues. The as-prepared AlPO4 coated LNMO demonstrates excellent capacity retention with prolonged cycle life compared to the bare one. Synchrotron based X-ray spectroscopy was employed to understand how ultrathin coating layer improve the cycle life, and then develop a detailed mechanism for the effect of coating layer. Our studies revealed that using atomic scale coating layer with improved thermal stability effectively impede the side-reactions occurrence at high voltage, resulting in significantly improved safety and electrochemical performances.
Owing to the multiple redox couples of Nb5+/Nb4+ and Nb4+/Nb3+, Nb-based compounds have attracted great attention to be promising high-capacity anode materials for rechargeable batteries. Here, K6Nb10.8O30 groove nanobelts (GNB) are synthesized through heat-treating the adjustable electrospun potassium niobate nanofibers, thereupon the structural change in the lithiation and delithiation is evidently imaged via in situ transmission electron microscopy (TEM). From in situ observations, the K6Nb10.8O30 GNB, in virtue of its stability, is ascertained to be adopted as anode material in lithium-ion batteries (LIBs). Evaluated as lithium storage host, GNB outstrip nanowires (NW) in cyclicity and in reversible capacity. Even after 1000 cycles, the retention capacity of K6Nb10.8O30 GNB is as high as 69%. Furthermore, the lithium-storage mechanism is also investigated via in situ X-ray diffraction (XRD). It is proved that the phase transition takes place from Li-poor K6Nb10.8O30 phase to Li-rich Li22K6Nb10.8O30 phase via two steps. In addition, the results obtained from ex situ TEM and ex situ X-ray photoelectron spectroscopy (XPS) also prove that the behavior of lithiation and de-lithiation for K6Nb10.8O30 GNB is highly reversible, suggesting that it can be a possible anode material.
Methods for demonstrating the scalability of purification and separation procedures depend on the technology which is being used, and therefore it is necessary to establish the physical parameters which are important to the scaling processes. This article briefly looks at these factors for direct-flow, and tangential-flow filtration technologies.
Fe-substituted manganese dioxide (Mn1-xFexO2, x=0, 0.1, 0.3 and 0.4) nanoparticles were hydrothermally prepared. X-ray diffraction (XRD) analysis showed the γ-phase of MnO2 in all of samples. The presence of Fe was detected by elemental analysis with a X-ray fluorescence (XRF) spectrometer. Field-emission scanning electron microscopy (FE-SEM) images showed the size and morphology of Mn1-xFexO2 became small. The higher specific surface area of samples with increasing content of Fe was confirmed with Brunaure-Emmett-Teller (BET) method. In electrochemical tests, the Mn1-xFexO2-δ (x=0,0.1,0.3 and 0.4) electrode showed the smaller discharge capacity with increasing content of Fe (180 and 70 in x=0 and 0.4, respectively) in the 1st discharge. In addition, the Fe-substitution led to slightly improve the irreversible capacity, but the poor cycleability.
A longitudinal dynamic cohort study was conducted on patients with median nerve injuries to evaluate the relative responsiveness of five sensibility tests: touch threshold using the WEST (monofilaments), static two-point discrimination, locognosia, a pick-up test and an object recognition test. Repeated assessments were performed starting at 6 months after surgery. In order to compare the relative responsiveness of each test, effect size and the standard response mean were calculated for sensibility changes occurring between 6 and 18 months after repair. Large effect sizes (>0.8) and standard response means (>0.8) were obtained for the WEST, locognosia, pick-up and object recognition tests. Two-point discrimination was hardly measurable at any time point and exhibited strong flooring effects. Further analysis of all time points was undertaken to assess the strength of the monotonic relationship between test scores and time elapsed since surgery. Comparison of monotonicity between the five tests indicated that the WEST performed best, whereas two-point discrimination performed worst. These results suggest that the monofilament test (WEST), locognosia test, Moberg pick-up test and tactile gnosis test capture sensibility changes over time well and should be considered for inclusion in the outcome assessment of patients with median nerve injury.
Many women develop pelvic girdle pain (PGP) during pregnancy and about 10% have chronic pain several years after delivery. Self-administered pain provocation tests are one way to diagnose and evaluate this pain. Their validity in post-partum women is not yet studied.
An amorphous silicon thin-film deposited on a patterned wafer is prepared by radio-frequency (rf) magnetron sputtering and is characterized by X-ray diffraction, galvanostatic cycle testing and field emission scanning electron microscopy. The specimen is assembled in cell of configuration: silicon working electrode/1M LiPF6 in EC/DMC, electrolyte/lithium metal, counter electrode (EC=ethylenecarbonate; DMC=dimethyl carbonate). A patterned silicon (100) wafer prepared by photolithography and KOH etching is used as the electrode substrate. The size of the patterns, which are composed of arrays of the negative square pyramids, is 5μm/side. The patterned specimen (silicon film on patterned substrate) is compared with a normal specimen (silicon deposited on a flat substrate). The rate of capacity fade on cycling is monitored as a function of the voltage window and current density. The patterned specimen displays better cycle behaviour at a high current density (high C-rate). During the cycle tests at 200μAcm−2, the silicon electrodes yield an initial capacity of 327μAh (cm2 μm)−1. After 100 cycles, the capacity is 285μAh (cm2 μm)−1 and the capacity retention is 86%. Capacity retention is 76 and 61% at cycles 200 and 300, respectively.
Controlled psychoperceptual quality evaluation experiments are used to assess the excellence of produced audiovisual quality from fundamental signal processing algorithms to consumer services. When compromising produced quality for consumer services, used in dynamic and heterogeneous mobile contexts, the ecological validity of conventional quality evaluation methods can be questioned. The goal of this paper is to develop a method for evaluating the experienced multimedia quality in the context of use. We conducted three studies where the quality of mobile 2D and 3D television was assessed in three different field contexts, one simulated context and one controlled laboratory situation when audio-video compression and transmission parameters were varied. We propose a hybrid method for the design, data-collection and analysis of the experiments in the contexts of use. Its novelty is to complement conventional quantitative quality evaluation with concrete tools to identify factors that surround the assessment in the context. The methodological framework is part of our long-term aim to measure and understand the user-centered quality of experience.
This research aimed to explore the perceptions and experiences of cancer patients receiving osteopathic treatment as a complementary therapy when it is used in addition to conventional treatment for cancer pain.
Energy consumption continues to rise as society develops worldwide. Meanwhile, a lot of energy is wasted in the form of heat from various devices and systems. Here we report a new power generator, which works based on a difference in H+-ion concentration in a fuel cell structure and produces electricity by harvesting waste heat. The device works via the following three successive processes: H2 is oxidized at anode to H+ ions, the H+ ions then penetrate through a phosphoric acid-treated polybenzimidazole (PBI-PA) membrane and finally the H+ ions get reduced to H2 at cathode with electrons coming through external circuit from the anode. This system generates electricity at a current density of 21 mA cm−2 and a power density of 1.03 mW cm−2 at 170 °C. The cell's thermoelectric conversion efficiency at 170 °C is 13.72%, which is higher than typical values reported for many common thermoelectric materials in low temperature regimes. This innovative approach may allow for efficient generation of electricity from waste heat.
LiNi1/3Co1/3Mn1/3O2 was redesigned into new core-shelled Li{[NiyCo1-2yMny](1-x)}core{[Ni1/2Mn1/2]x}shellO2 (0≤x≤0.3, 6y+3x-6xy=2) to improve its performances. Those core-shelled materials were successfully synthesized at 800°C from core-shelled {[NiyCo1-2yMny](1-x)}core{[Ni1/2Mn1/2]x}shell(OH)2 precursors obtained via a co-precipitation route. Scanning Electron Microscope (SEM) shows that a morphology with good spherical secondary particles developed from needle-like primary particles was formed in the precursors and maintained well in the lithiated compounds even after the calcination at 800°C. Energy Disperse X-ray Spectrum (EDS) on the surface of precursors particles, in combination with evidence of size increase from core to shell during co-precipitation process, supports the formation of the core-shell structure as designed in the precursors. This is certified by subsequent EDS experiments on the cross-section of single particle of the lithiated compounds, showing that the lithiated compounds approximately had a targeted core-shell structure of Li{[NiyCo1-2yMny](1-x)}core{[Ni1/2Mn1/2]x}shellO2. Nevertheless, it is hard to detect differences in XRD for those lithiated compounds. Electrochemical tests and Differential Scanning Calorimetry (DSC) experiments demonstrate the gradually improved cyclability at a severe charge-discharge condition (55°C and charging to 4.5V) and thermal stability of materials with increasing x value (thickness of shell).
Coal gasification has already been extensively studied earlier under varying conditions of steam, CO2, O2, inert conditions. Belbaid coal and its e, N and NMP-DETA SCC products recovered through organo-refining under milder ambient pressure conditions were subjected to CO2-gasification in a fixed bed reactor under varying conditions. CO2 being an inert gas becomes the most challenging to be utilized during the gasification process. The SCCs showed better CO2-gasification reactivity than the raw Belbaid coal at 900 °C. The use of the catalyst K2CO3 tremendously increased the gasification reactivity for both raw coal and the SCCs. The use of sugarcane bagasse for CO2-gasification along with raw coal as well as with residual coal was also studied. Gasification under CO2 atmosphere conditions was used to structurally understand the coals as the coal structure gets loosened after extraction.
Schizochytrium sp. is a marine microalga with great potential as a promising sustainable source of lipids rich in docosahexaenoic acid (DHA). This organism’s lipid accumulation machinery can be induced by various stress conditions, but this stress induction usually comes at the expense of lower biomass in industrial fermentations. Moreover, oxidative damage induced by various environmental stresses can result in the peroxidation of lipids, and especially polyunsaturated fatty acids, which causes unstable DHA production, but is often ignored in fermentation processes. Therefore, it is urgent to develop new production strains that not only have a high DHA production capacity, but also possess strong antioxidant defenses.
Materials continue to play a dominant role in our society, as they have through the millennia. The developments in nanotechnology provide a unique opportunity to not only develop new classes of materials but also do so in harmony with a goal of sustainable development. There is, however, a large gap between the promise of nanotechnology and its integration into a new generation of nano-enabled products. The first half of this paper focuses on the promise of nanotechnology by exploring a novel, self-assembly based technique for the production of structural ceramics, which have the potential to dramatically affect a range of products such as power turbines and aircraft engines. In the second half of the paper examines some of the challenges in setting up a nano-engineered value chain, which is critical for a new generation of nano-enabled products.
Soil samples were taken under four tree species in various forest sites located in southern France. For each sampled A horizon of the soil profile, pH, organic matter content, C:N ratio and amounts of exchangeable cations (K, Ca, Mg) were measured, and collembolan fauna was extracted using Berlese-Tullgren funnels. A total of 78 species representing 11 families and 47 genera were identified. The relationships between Collembola and soil parameters were determined by co-inertia analysis which corresponds to the simultaneous Correspondence Analysis of the collembolan data table and the Multiple Correspondence Analysis of the environmental data table. The analysis revealed that the distribution of 10 species was related to pH, organic matter content via C and N and to base cations (K, Ca, Mg). Samples, linking these collembolan species and chemical parameters, were clustered according to humus forms. Collembola seem to be linked closer to the physical structure of humus than to its chemical parameters. Their specific contribution to pedogenetic processes as yet remains to be clarified.
Melt diffusion followed by vapor deposition is judiciously combined with atomic layer deposition (ALD) to construct Al2O3–coated (Se/porous N-doped carbon nanofibers)@Se composite (denoted SC@Se-Al2O3) materials for sodium-selenium (Na-Se) batteries. High mass loading, ultrastable and free-standing carbon-selenium cathode is conveniently achieved by tailoring both the Se content and the thickness of deposited Al2O3 layer. Importantly, in contrast to only 176 mAh g−1 of the electrode without Al2O3 deposition after 660 cycles, the composite with a Se content of 67wt% and a 3-nm Al2O3 thickness retains a reversible capacity of 503 mAh g−1 after 1000 cycles with no capacity fading at 0.5Ag−1. These findings clearly suggest that ALD strategy provides a viable, controllable and effective means of tuning the electrode performance towards high mass loading of active materials and long cycle life of the resulting battery for energy storage applications.
A three-dimensionally (3D) patterned Li4Ti5O12 electrode was fabricated by using a micro printing technology. Composite slurry including Li4Ti5O12, acetylene black, poly(vinylidene difluoride) and N-methyl pyrolidone was applied onto a current collector. The electrode has many lined patterns with high aspect ratio that stand in line on the current collector. The cyclic voltammograms of the half cell with 3D patterned electrode shows that the prepared electrode worked effectively as anode of a rechargeable lithium-ion battery. The cell with the 3D patterned electrode showed much better charge and discharge capacities than a conventional cell with a flat Li4Ti5O12 electrode at high rates. It was also confirmed that the cycle performance of the cell with 3D patterned electrode was equal or better than that with the conventional electrode.
Anodic hard carbon for lithium-ion batteries with high discharge capacity was successfully developed using mangrove green tree as a cheap raw material. To obtain commercial-level first-cycle Coulombic efficiency, the effects of heat pre-treatment in the low temperature range of 450–600°C at various pressures, to produce optimized char precursor before carbonization, were closely investigated, focusing on synthetic yield, structural and physical properties, first-cycle Coulombic efficiency, and discharge capacity of the resulting hard carbon. The hard carbon with heat pre-treatment involving optimum fabrication conditions of 500°C in inner gas at 0.7MPa for 39days exhibited higher synthetic yield of 30.0wt% and better first-cycle Coulombic efficiency of 81% and discharge capacity of 424mAh/g than that prepared through direct one-step carbonization, due to low H/C and Odiff/C ratios and a pore structure promoting lithium-ion insertion/desertion.
To determine the potential effectiveness of a six-session manualised self-esteem group using CBT approaches when given as an adjuvant to adolescent inpatients with Anorexia Nervosa (AN).
An amorphous V2O5 xerogel/graphite composite was synthesized and subjected to electrochemical characterization by cyclic voltammetry, chronopotentiometry and impedance measurements in aqueous LiNO3, NaNO3, KNO3 and Mg(NO3)2 solutions. The kinetics of cyclic intercalation/deintercalation reactions, and the dependence of coulombic capacity on cycle number were examined. The capacity retention depended on the type of inserted ions and decreased in the following order: Mg2+ >Li+ >Na+ >K+. By ultraviolet/visible (UV/VIS) spectroscopy the concentration of dissolved vanadium oxide was determined and correlated with the capacity fade in various electrolyte solutions. By means of Density Functional Theory calculation (DFT), the bond strength between vanadium and triple coordinated oxygen in V2O5 was found to be responsible for the differences in its solubility in various aqueous solutions.
A flexible self-charged power panel is integrally designed and fabricated to simultaneously harvest solar and mechanical energy and convert and store in electric energy. The flexible amorphous silicon solar cell, the transparent triboelectric nanogenerator (TENG), and lithium (Li)-ion batteries are coherently integrated into one thin panel with the encapsulating materials, ethylene-tetra-fluoro-ethylene (ETFE) for the solar modules. The flexible self-charged power panel exhibits good performance to directly convert solar and mechanical energy into electricity that was directly stored in Li-ion battery without excessive energy loss. The integrated device also greatly minimizes the usage of current collectors, substrates and packaging materials. Moreover, such a power panel can compensate for the absence of solar cells and prolongs the time of energy supply and improve the energy density of the whole device.