batterydata/paper-abstracts huggingface dataset:
Artificial graphite (AG) and natural graphite (NG) have different physical properties, which should have significant effects on their unique electrochemical characteristics: NG is known to have superior specific capacity and low cost, whereas AG shows superior cyclability and low-swelling characteristics. Herein, we present a straightforward strategy using triphenylphosphine to improve NG, enabling its physical properties to resemble those of AG and thereby improving its cyclability and swelling characteristics. The volume of a-few-nanometer-sized pores of NG is significantly reduced by triphenylphosphine treatment, which is similar to that of the AG. As a result, triphenylphosphine-treated NG (TPP) anode shows improved cyclability (83.6% after 300 cycles) compared to that of NG, confirming the correlation between nanopore volume and cyclability. Furthermore, the expansion of single-layer pouch cell prepared with TPP, as monitored by in situ thickness measurement, is suppressed to 9% after 55 cycles, which is superior to the pristine NG showing 14% expansion after the same number of cycles. Electrochemical impedance analyses of symmetric cells reveal that the changes of ionic and solid-electrolyte interface (SEI) resistance are accompanied by the reduction of nanopores, confirming that the formation of decreased SEI layer is a crucial factor for realizing less-swelling and highly durable anodes based on the cost-effective NG materials.
Results of a numerical and experimental study into buckling performance of multi-segment pressure hull subjected to uniform hydrostatic pressure are discussed. Constituents of multi-segment configurations are bowed-out cylindrical shells with, and without flanges. Details about five collapse tests of laboratory scale mild steel, CNC machined models are given. Segments were about 200mm diameter, 100mm long and had uniform wall thickness of 3mm. Experimental collapse pressures were in the range from 12 to 20MPa. Numerical collapse pressures agreed well with those obtained during experiments.
Either side of organic photovoltaics incorporates a transparent conducting electrode for light entry, which becomes particularly crucial under indoor light conditions with low light intensity. However, since electrical resistivity and optical transparency with respect to film thickness are mutually contradictory, sufficiently thick (>150 nm) electrodes are inevitably required to ensure the appropriate electrical conductivity, at the sacrifice of transmittance. This paper introduces an electric field induced filament doping method to realize ultra-thin indium tin oxide with high conductivity. The proposed method allows for injecting metal dopants (i.e., Ni) into ultra-thin indium tin oxide under an electric field, enabling substantial resistance reduction while retaining high transmittance and low surface roughness. Optimum light absorption and effective carrier transport via filament doping provides improved performance for indoor organic photovoltaics. As a proof-of-principle demonstration, we fabricate poly(3-hexylthiophene):indene-C60 bisadduct based inverted organic photovoltaics with 10 nm Ni-doped indium tin oxide as a transparent cathode, leading to a power conversion efficiency of 14.6 ± 1.8% under the 1000-lux light-emitting diode. This efficiency is 40% higher than that achieved from the device using commercially available 150 nm indium tin oxide.
A prototype of oxide thermoelectric (TE) module by p–n coupled oxide elements has been fabricated for the first time, for the application of power generation at high-temperatures in air. For the single couple, the π-shaped joints of sintered bodies of Li-doped NiO (p-type) and (Ba, Sr)PbO3 (n-type) were used. TE performance of both single couple and the module were investigated in the temperature range from 440 to 1060K. The maximum output power from a single couple was 7.91mW with the operating temperature difference of 552K. The assembled module with four elements showing almost four times larger power, 34.4mW, than that of a single element. The reliability of this oxide couple at high-temperature in air, and an application of module for the power generation using the waste heat from a stove are also reported.
Micro-supercapacitors are promising energy storage devices that can complement batteries in miniaturized portable electronics and microelectromechanical systems. Here, we develop a facile method to fabricate a hierarchically structured film as electrode material of micro-supercapacitor. A poly (3,4-ethylenedioxythiophene):poly (styrenesulfonate)/manganese dioxide/poly (3,4-ethylenedioxythiophene) (PEDOT:PSS/MnO2/PEDOT) ternary film is prepared via a two-step process. Firstly, MnO2 nanoparticles are directly synthesized in the PEDOT:PSS matrix and the PEDOT:PSS/MnO2 mixed solution is spin-coated on the substrate. Then a porous PEDOT film is synthesized by the vapor phase polymerization (VPP) on the PEDOT:PSS/MnO2 precursor film. Electrochemical tests reveal that the ternary film exhibits a high specific capacitance of 391.36F/cm3 at current density of 3.75A/cm3, as well as excellent cycle stability with capacitance retention of 92% after 5500 cycles. The volumetric capacitance of PEDOT:PSS/MnO2/PEDOT-microsupercapacitor achieves 13.64F/cm3. The excellent electrochemical performances indicate that each component in the hybrid film provides unique and crucial function to achieve optimized electrochemical properties. As a result, this ternary composite film shows promising future as electrode material for electrochemical energy storage devices.
There is a growing consensus that bariatric surgery is currently the most efficacious and long-term treatment for clinically severe obesity. However, it remains to be determined whether poor physical fitness, an important characteristic of these patients, improves as well. The purpose of this pilot study is to investigate the effect of gastric bypass surgery on physical fitness and to determine if an exercise program in the first 4 months is beneficial.
Introduction Chronic maltreatment and disorganized attachment in children predict the development of dissociation, which can negatively impact functioning. Few measures of child dissociation currently exist and amongst these, limitations exist when they are applied to populations of maltreated children. Objective This paper details the development of the Child Dissociation Assessment System (CDAS), consisting of the Child Dissociation Code (CDC) and Child Dissociation Tool (CDT). The CDC allows clinicians to screen for dissociative symptoms while the CDT examines how these symptoms impact different domains of functioning. Method Both measures score verbal and non-verbal material, which emerges during the MacArthur Story Stem Battery (MSSB), a child-friendly narrative story stem task whose non-threatening nature is suited for use with maltreated children. Using the CDAS, the MSSB protocols of 20 children between 6 and 12 years old (10 from a clinical sample and 10 from a non-clinical sample) were scored. Results The CDAS possesses adequate to excellent inter-rater reliability, and the CDC discriminates between maltreated and non-maltreated children. Conclusion The CDAS may be of interest for researchers and clinicians working with populations of maltreated children. Preliminary findings are promising and a larger-scale validation would be indicated.
This paper presents an optimal online power management strategy applied to a vehicular power system that contains multiple power sources and deals with largely fluctuated load requests. The optimal online power management strategy is developed using machine learning and fuzzy logic. A machine learning algorithm has been developed to learn the knowledge about minimizing power loss in a Multiple Power Sources and Loads (M_PS&LD) system. The algorithm exploits the fact that different power sources used to deliver a load request have different power losses under different vehicle states. The machine learning algorithm is developed to train an intelligent power controller, an online fuzzy power controller, FPC_MPS, that has the capability of finding combinations of power sources that minimize power losses while satisfying a given set of system and component constraints during a drive cycle. The FPC_MPS was implemented in two simulated systems, a power system of four power sources, and a vehicle system of three power sources. Experimental results show that the proposed machine learning approach combined with fuzzy control is a promising technology for intelligent vehicle power management in a M_PS&LD power system.
This work presents the current waste management system at the pulp and paper mill complex of Stora Enso Oyj Veitsiluoto Mills at Kemi, Northern Finland. This paper covers examples of case studies carried out at the mill and describes how the wastes and by-products are utilized as a neutralizing agent for acidic wastewaters (i.e., green liquor dregs from the causticizing process), as a hardener in filling mine cavities (i.e., ash from the fluidized bed boiler), as a landscaping agent (i.e., ash as well as the fibre clay from chemical wastewater treatment plant), as a hydraulic barrier material for landfills (i.e., fibre clay), and as a soil enrichment agent (i.e., calcium carbonate from the precipitated calcium carbonate plant). In addition, the wood waste from the wood-handling plant, sawmill, packaging pallet plant and from the groundwood mill, as well as the biosludge from the biological wastewater treatment plant, are all incinerated in the fluidized bed boiler for energy production. Due to effective utilization of the solid wastes generated at the mills, the annual amount of waste to be disposed of in the landfill has decreased between 1994 and 2004 from 42,990 to 6083tonn (expressed as wet weight). The paper also gives an overview of the relevant European Union legislation on the forest industry and on waste management, as well as of the pulping process and of the generation of major solid wastes in the pulp and paper mills.
Graphene/multiwall carbon nanotubes/MnO2 (GR/MCNTs/MnO2) hybrid material with a specific capacitance of 126Fg−1 within a potential window of 0–1.1V vs. saturated calomel electrode has been synthesized by a simple redox reaction between graphene/multiwall carbon nanotubes (GR/MCNTs) and KMnO4 at room temperature. The morphology and structure of the obtained material are examined by XRD, SEM and TEM. The electrochemical properties are characterized by cyclic voltammetry, galvanostatic charge–discharge and electrochemical impedance spectroscopy. The mass percentage of MnO2 with layered structure is 37% in the hybrid material. An asymmetrical electrochemical capacitor (EC) is assembled using GR/MCNT/MnO2 hybrid material as positive electrode and GR/MCNT material as negative electrode, respectively. The electrochemical properties of the two electrodes and the asymmetrical EC are investigated in 1molL−1 Na2SO4 aqueous electrolyte. The asymmetrical EC can cycle reversibly in a cell potential of 0–2.0V and gives a high energy density of 28.33Whkg−1, which is much higher than those of symmetrical ECs based on GR/MCNT/MnO2 (6.20Whkg−1) and GR/MCNT (3.92Whkg−1). Moreover, the asymmetrical EC presents a high power density (5kWkg−1 at 13.33Whkg−1) and excellent cycling performance of 83% retention after 2500 cycles.
A challenge in animal behavior studies using Global Positioning System (GPS) collars is selecting a sampling frequency to accomplish desired goals. High data resolution (i.e., frequent sampling) is appealing, because it maximizes behavioral information garnered. Extended sampling might be needed, however, to describe long term behaviors or seasonal dynamics. Because tradeoffs exist between high data resolution and sampling duration, we evaluated the effects of variable GPS sampling intervals on proportions of pastures used by cattle and distance traveled per day. This was accomplished with GPS collars configured to record cattle positions every 5min for 15 d in three 829–864-ha pastures. Data were iteratively reduced to simulate increasingly longer GPS recording intervals from once every 10min up to once daily. Two techniques were used to measure the percentage of pastures accessed by cattle. The first counted only pixels containing GPS coordinates. The second counted pixels containing coordinates and/or traversed by lines between vertices. Expansion of GPS recording intervals decreased (P < 0.01) estimates of the proportion of pastures visited by cattle with rates of decline best fit by exponential decay functions for both line and point techniques (R2 = 0.93 and 0.97, respectively). Spatial errors accompanying less frequent sampling intervals, however, were extremely large with the line technique and misrepresented areas visited by cattle. Expansion of GPS sampling intervals decreased (P < 0.001) distance traveled per day by cattle about 10% with each iteration. If travel corridors or accurate assessments of resources accessed are of critical concern, then longer GPS integration intervals should be avoided because they propagate flawed spatial interpretations. Similarly, if accurate measures of travel distances are critical, we suggest using a relatively frequent GPS recording interval.
This paper deals with the synthesis of poly(ethylene glycol) (PEG) grafted poly(acrylo nitrile) (PAN) copolymers as novel solid-solid phase change materials via two step free radical polymerization reaction. The structural and thermal characterizations of the synthesized copolymers, namely PEG1500-g-PAN, PEG2000-g-PAN, PEG4000-g-PAN, PEG10000-g-PAN and PEG35000-g-PAN, were performed by Fourier transform infrared spectroscopy, Nuclear magnetic resonance spectrometry, differential scanning calorimetry and thermogravimetry. They were thermally stable and had the capability of absorbing and releasing great amount of heat ranging between 70 and 126Jg−1 at the temperature interval of 40–65°C during heating and successive cooling cycles. To transform the PEG-g-PAN copolymers into the assemblies appropriate for thermal energy storage (TES) systems, thermo-regulating PEG-g-PAN nanowebs were also produced by means of coaxial electrospinning. The SEM images of PEG-g-PAN nanowebs displayed that they were all composed of hollow cylindrical ultrafine fibers with the average diameters ranging in 175–277nm. During the differential scanning calorimetry measurements, those nanowebs demonstrated repeatable solid-solid phase change with the heat storage capacities varying between 35 and 75Jg−1 at the same temperature interval with the corresponding PEG-g-PAN copolymers. The PEG-g-PAN copolymers and their electrospun nanowebs can be promising TES materials and can have convenient industrial applications.
Excessive accumulation of amyloid-β (Aβ) caused by cleavage of amyloid precursor protein (APP) is thought to be the primary cause of Alzheimer’s disease (AD). Two key enzymes ADAM10 and BACE1 are involved in the initial cleavage of APP, resulting in the onset of two pathways, the amyloidogenic pathway and the non-amyloidogenic pathway, respectively. Altering APP metabolism towards the non-amyloidogenic pathway is thought to reduce Aβ production. It has been reported that, in vivo, exogenous neurotrophic factors make APP apt to entering the non-amyloidogenic pathway. Since astrocytes secrete a battery of neurotrophic factors, we investigated the role of astrocyte-derived factors in the dynamics of Aβ generation in neural cells. Results show that C6 glioma cell-conditioned medium (GCM), obtained from cultured astrocyte-derived C6 glioma cells, inhibit Aβ1-42 production and shift APP processing towards the non-amyloidogenic pathway in APPswe-HEK293 cells. Such effect is attributed to two key APP cleavage enzymes, ADAM10 and BACE1. Two neurotrophic factors in the GCM, nerve growth factor and fibroblast growth factor 2, are responsible for the up-regulation of ADAM10 and down-regulation of BACE1, respectively. Our findings enhance our understanding of the relationship between astrocytes and Aβ generation, indicating that stimulation of astrocytic neurotrophic factors could slow AD progression.
In our recent work, we demonstrated that the use of bio-derived rosin as a binder additive could improve the electrochemical performance of lithium titanium oxide (LTO) anodes. As a sequential study, four representative modified rosin-derivatives are used as additives for polyvinylidene difluoride (PVdF) binders in order to further improve the cell performance of LTO electrodes. The rosin derivative modified via simple hydrogenation retains carboxylic acids and is favorable to lithium ion transport when compared to the modified rosins, which loose these functional groups via esterification. The hydrogenated rosin additive increases cyclic capacities, initially by 10mAhg−1 and more so at high current charge/discharge rates.
Microbial fuel cells (MFCs) are emerging as a promising alternative renewable energy source, especially for remote monitoring applications. Due to its low voltage and power output, MFCs are unable to directly drive most commercial electronic devices. A power management system (PMS) is needed to accumulate MFC energy first and then drive the load intermittently. In this study, a transformer-based PMS is proposed, which is able to function under a lower voltage input than other available MFC PMS designs. Two super-capacitors are included in the proposed PMS. The first is analytically optimized to maximize the average harvested power, while the second is selected based on the energy required to drive a given load. A continuous-mode MFC was built and used to successfully drive an IEEE 802.15.4 wireless sensor system using the proposed PMS. Experimental results showed that the proposed PMS worked well under a very low input voltage (0.18V). The configuration of two super-capacitors and a transformer in this transformer-based PMS provides more flexibility in harvesting power from MFCs.
In the study described in this article, the role of lignosulfonate dopant (LS) in promoting redox activity of electrosynthesized conducting films based on polypyrrole (PPy), polyaniline (PANI) and poly(3,4-ethylenedioxythiophene) (PEDOT) is demonstrated. The enhanced pseudocapacitive characteristics of the renewable dopant in composite electrodes was achieved by combining the reversible redox charge transfer of surface-confined quinones and their interaction with an electron–conducting polymer backbone. Because of the different oxidation potentials of the three monomers and the parent lignosulfonate, it was found that methoxyphenol functional groups present in the biomacromolecule are converted to quinones during the electropolimeryzation of aniline and 3,4-ethylenedioxythiophene. In contrast, in the case of pyrrole, lignosulfonate is incorporated into growing PPy in its reduced form and therefore the formed PPy/LS composite film needs a post-polymerization oxidation to induce the redox activity of LS. The observed redox activity of the PPy/LS, PANI/LS and PEDOT/LS composite films was strongly dependant on the preparation conditions including: density of the polymerization current, monomer-to-dopant mass ratio and the electropolymerization charge. The effect of these variables on redox activity of the three types of polymeric films was studied in detail and optimal preparation conditions were found. Cyclic voltammetry and galvanostatic charge–discharge measurements in 0.1M HClO4 solution reveal that combining conducting polymers with LS dopant results in improved charge storage properties. Thus LS-containing conducting polymers are expected to work effectively as cathodes in energy storing devices such as batteries and supercapacitors.
We investigated an environmentally friendly leaching process for the recovery of cobalt and lithium from the cathode active materials of spent lithium-ion batteries. The easily degradable organic acid DL-malic acid (C4H5O6) was used as a leaching reagent. The structural, morphology of the cathode materials before and after leaching were characterized by X-ray diffraction (XRD) and scanning electronic microscopy (SEM). The amount of Co and Li present in the leachate was determined by atomic absorption spectrophotometry (AAS). Conditions for achieving a recovery of more than 90 wt.% Co and nearly 100 wt.% Li were determined experimentally by varying the concentrations of leachant, time and temperature of the reaction as well as the initial solid-to-liquid ratio. We found that hydrogen peroxide in a DL-malic acid solution is an effective reducing agent because it enhances the leaching efficiency. Leaching with 1.5M DL-malic acid, 2.0 vol.% hydrogen peroxide and a S:L of 20gL−1 in a batch extractor results in a highly efficient recovery of the metals within 40min at 90°C.
Maik Gude has held the Chair of Lightweight Design and Structural Assessment at TU Dresden's Institute of Lightweight Engineering and Polymer Technology (ILK) since 2014. He advocates the simulation-based, end-to-end development of materials, structures and technologies in multi-material lightweight design. He has also coordinated the national open Forel research platform subsidized by the Federal Ministry of Education and Research (BMBF) since 2013. After study- ing engineering mathematics at TU Clausthal, he completed his doctorate at TU Dresden in 2000, where he gained habilitation in 2008 before being appointed Associate Professor.© Diana Wolfrum | TU Dresden
Over the last 30 years, a large amount of research on PV-Thermal (PVT) collectors has been carried out. An overview of this research is presented, both in terms of an historic overview of research projects and in the form of a thematic overview, addressing the different research issues for PVT.
The application of Na3·32Fe2·34(P2O7)2 sodium cathodes with abundant resources and robust structure is severely hindered by the poor electronic conductivity. A multiple-dimensional carbon matrix could provide a satisfactory electronic conductivity as well as facilitate structural stability via wrapping and bridging of the active material. With an analysis of the raw materials and their respective reactions, Na3·32Fe2·34(P2O7)2@C (NFPCs) composites with a hybrid carbon matrix have been synthesized. The reactions in the system result in versatile N-doped carbon structures, including thin carbon layers, carbon rods, carbon nanosheets and carbon scaffolds. This integrated carbon architecture wraps and bridges the Na3·32Fe2·34(P2O7)2 particles, not only promoting electronic conductivity, but also serving as a buffer to minimize volume changes and stabilize the structural integrity of the composite. Furthermore, the nitrogen doping could generate more defects and active sites, which provide improved conductivity and better redox activity. Finally, the synthesized composite material has demonstrated impressive rate capabilities (100 mAh g−1 at 0.1 C and 66 mAh g−1 at 20 C), and outstanding cycling stability (90.5% at 1 C after 1000 cycles, 89.9% at 5 C after 2000 cycles). This study takes the utmost advantage of the synthesis, which is also easily scaled-up for mass production.
To enhance the thermal stability of LiCoO2 in lithium ion batteries, 4-isopropyl phenyl diphenyl phosphate (IPPP) was investigated as an additive in 1.0M LiPF6/EC+DEC (1:1wt.%) electrolyte. The thermodynamics and kinetics parameters of the single LiCoO2 and Li x CoO2–IPPP-electrolyte are detected and calculated based on the C80 microcalorimeter data. The results indicated that IPPP can enhance the thermal stability of LiCoO2 electrode in lithium ion battery more or less corresponding to the IPPP content in electrolyte. Furthermore, the electrochemical performances of LiCoO2/IPPP-electrolyte/Li cells become slightly worse after using IPPP additive in the electrolyte. This alleviated trade-off between thermal stability and cell performance provides a possibility to formulate an electrolyte containing 5–10% of IPPP and enhance the LiCoO2 electrode thermal stability with minimum sacrifice in performance.
This study explored the influence of social position and competition on tree transpiration using spatial structure parameters and competition indices.