batterydata/paper-abstracts huggingface dataset:
Symmetrical carbon/carbon double layer capacitors (EDLCs) were fabricated employing nanostructured mesoporous nongraphitized carbon black (NMCB) powders and their EDLC behavior was studied using electrochemical techniques viz., cyclic voltammetry, a.c.-impedance, and constant current cycling. Rectangular shape cyclic characteristics were observed indicating the double layer behavior of the NMCB carbon electrodes. The mechanism of double layer formation and frequency dependent capacitance were deduced from the ac-impedance analysis. Specific capacitance, power density and energy density were derived from constant current charge/discharge measurements. NMCB powders demonstrated a specific capacitance of about ∼39Fg−1 and the power density of 782Wkg−1 at a current density of 32mAcm−2. Nevertheless, at a low current density (3mAcm−2), the specific capacitance of ∼44Fg−1 was achieved, which corroborates with the values obtained by means of ac-impedance (40Fg−1) and cyclic voltammetry (41.5Fg−1). The test cells demonstrated the stable cycle performance over several hundreds of cycles.
For tin-based anode materials that suffer from poor cycling stability due to severe volume changes upon lithiation/delithiation processes, the morphology control method might provide a solution. Today, coaxial core-shell structure has attracted wide attention due to its ability to accommodate the volume changes of tin (core), which is well encapsulated in the carbon matrix (shell). Coaxial electrospinning is a simple and effective method to prepare this kind of material. In this work, tin was dispersed in the carbon core and then coated a carbon shell to form Sn@C/C nanofibers by coaxial electrospinning. Flow ratio and tin content were investigated as two main critical factors for controlling the core/shell structure, so as to improve the cycling preference of tin anodes. When tested as a lithium-ion battery anode, the material not only showed higher reversible specific capacity (626 mAh g−1) than pure carbon nanofibers, but also exhibited better cycling performance (50 cycles with 73% capacity retention), indicating that the volume change problem of tin anodes has been well resolved by this morphology control.
We report the durability of the optimized nickel–aluminum layered double hydroxide/carbon (Ni–Al LDH/C) composite prepared by liquid phase deposition (LPD) as cathode active materials in nickel metal hydride (Ni–MH) secondary battery. The positive electrode was used for charge–discharge measurements under two different current: 5 mA for 300 cycles in half-cell conditions, and 5.8 mA for 569 cycles in battery regime, respectively. The optimized Ni–Al LDH/C composite exhibits a good lifespan and stability with the capacity retention above 380 mA h gcomp −1 over 869 cycles. Cyclic voltammetry shows that the α-Ni(OH)2/γ-NiOOH redox reaction is maintained even after 869 cycles, and the higher current regime is beneficial in terms of materials utilization. X-ray diffraction (XRD) patterns of the cathode after charge and discharge confirms that the α-Ni(OH)2/γ-NiOOH redox reaction occurs without any intermediate phase.
Most of the commonly used light traps for plankton studies are often large, heavy and expensive, and cannot be easily used for pelagic sampling. Although many small, and simple light traps have been designed, most of them are fragile and have weak light sources, allowing only limited collection. In the present study, a new simplified light trap design was described, which is small, lightweight, robust, inexpensive ($70 USD) and easy to construct. The main body of the trap is constructed from a 6L commercial mineral water PET bottle, and the lighting component consists of four 3W white LED bulbs. Pelagic deployment of the new simplified trap and the commonly-used modified Doherty trap was conducted in the same location and compared the composition of the catches including larval fishes and invertebrates. The taxonomic composition of larval fishes collected between the two traps was similar, but it appears that the Doherty trap can collect larger sized larval fishes. Catch composition, wet weights and total number of marine invertebrates collected between the two types of traps are comparable. Ten taxa (copepods, amphipods, crab larvae and juveniles, Cumacea, Euphausiacea, molluscan larvae, isopods, mysids, ostracods and Polychaetes) accounted for over 98% of the total catch of individuals by both trap models. Copepods and crabs larvae were the two most abundant taxa, accounting for more than 55% of the catch. The new and simplified traps therefore represent a robust and comparable design that can be manufactured in large quantities (even in developing countries) and easier in transportation for spatial and temporal studies of plankton dynamics.
Wireless Sensor Networks typically consist of a large number of sensor nodes with constrained resources. Cluster-based routing algorithms for WSNs try to preserve battery power by grouping nodes into multiple clusters: a single node in each cluster, the Cluster Head (CH), communicates with a Base Station on behalf of the others. In an ideal collaborative setting, sensor nodes should alternate in the role of CH. However, the cooperation of nodes is not granted in WSNs with more than one governing authority, where sensor nodes can behave selfishly, in order to save their own resources. In this paper, we propose a novel evolutionary cluster-head determination algorithm called GREET, based on an Evolutionary Game Theory (EGT) approach. In the proposed algorithm, individual nodes adapt their strategies on the basis of the outcomes of the interactions with other nodes and converge to an Evolutionary Stable Strategy (ESS) equilibrium. We show that this ESS corresponds to one of the desired behavioral outcomes. This outcome is obtained without the support of external cooperation enforcement mechanisms. In the study, we use an analytic model of the population evolution, based on the so-called replicator dynamics, as a guide in the choice of the mechanisms, then we adapt the approach to realistic more scenarios. We show, by means of a systematic simulation study, that the algorithm extends the network lifetime and provides a better packet throughput, w.r.t other standard WSN algorithms, such as LEACH and CROSS.
Solid oxide fuel cells (SOFCs) based on a thin La0.8Sr0.2Ga0.8Mg0.2O3−δ (LSGM) electrolyte membrane supported by a nickel-based anode often suffers from undesirable reaction/diffusion between the Ni anode and the LSGM during high-temperature co-firing. In this study, a high performance intermediate-temperature SOFC is fabricated by depositing thin LSGM electrolyte membranes on a LSGM backbone of unique architecture coated with nano-sized Ni and Gd0.1Ce0.9O2−δ (GDC) particles via a combination of freeze-drying tape-casting, slurry drop-coating, and solution infiltration. The thickness of the dense LSGM electrolyte membranes is ∼30 μm while the undesirable reaction/diffusion between Ni and LSGM are effectively hindered because of the relatively low firing temperature, as confirmed by XRD analysis. Single cells show peak power densities of 1.61 W cm−2 at 700 °C and 0.52 W cm−2 at 600 °C using 3 vol% humidified H2 as fuel and ambient air as oxidant. The cell performance is very stable for 115 h at a constant current density of 0.303 A cm−2 at 600 °C.
A unique case from the Colombian cohort of autosomal dominant Alzheimer’s disease is reported in which disease progression is substantially delayed despite unusually high amyloid plaque pathology, possibly related to a rare mutation in APOE3.
Pt and Pt–Ru nanowire array electrodes were obtained by dc (direct current) electrodeposition of Pt and Ru into the pores of an anodic aluminum oxide (AAO) template on a Ti/Si substrate. Transmission electron microscope (TEM) examination showed all the nanowires had a uniform diameter of about 30nm. The brush shaped Pt and Pt–Ru nanowire array electrodes could be seen clearly by scanning electron microscope. Pt and Pt–Ru nanowire array electrodes gave the X-ray diffraction pattern of a face-centered cubic (fcc) crystal structure. The electro-oxidation of methanol on these electrodes was investigated at room temperature using cyclic voltammetry. The results demonstrated that the alloy nanowire array electrode was catalytically more active than a pure platinum nanowire array electrode and the Pt–Ru nanowire array electrode may have good potential for applications in portable fuel cell power sources.
Ultraviolet (UV) reduction campaigns since 1986 were based on the estimation that individuals get 80% of their cumulative lifetime UV dose by the age of 18. To investigate if this estimation is true, we compared annual UV doses received during life in 164 Danish volunteers: children, teenagers, indoor workers, and golfers (age range 4–67 y) who recorded sun exposure behavior in diaries and carried personal UV dosimeters, measuring time-stamped UV doses. The annual UV dose did not significantly correlate with age but the variation in annual UV dose was high (median 166 SED (standard erythema dose), 95% range: 37–551 SED). The annual UV dose did correlate with days with risk behavior (sunbathing/exposing upper body) (r=0.51, p<0.001) and in adults also with hours performing outdoor sports (r=0.39, p<0.001), gardening, and sun-bed sessions (r=0.26, p=0.02). Teenagers had significantly more days with risk behavior than adults (21 vs 13 d, p=0.006) but not than children (15 d). No differences in UV dose among the age groups were found on workdays. Only 25% of the lifetime UV dose was received before the age of 20 and the annual UV dose was thus independent of age. Reduction of cumulative lifetime UV dose could be obtained by minimizing risk behavior.
Whether there is a true increase in autism spectrum disorder (ASD) frequency or not remains unclear. Additionally, the rates of co-existing neurodevelopmental disorders (NDD) in a total population sample has not been fully examined before. Therefore, using a total population sample in Japan, we aimed to estimate the prevalence and cumulative incidence of autism spectrum disorder (ASD) annually, to determine whether there is a true increase in ASD prevalence by estimating the cumulative incidence of ASD annually, and to examine the rates of co-existing neurodevelopmental disorders (NDD).
A single graphene sheet represents a carbon material with the highest surface area available to accommodating molecules or ions for physical and chemical interactions. Here we demonstrate in an electric double layer capacitor the outstanding performance of graphite oxide for providing a platform for double layer formation. Graphite oxide is generally the intermediate compound for obtaining separated graphene sheets. Instead of reduction with hydrazine, we incorporate graphite oxide with a poly(ethylene oxide)-based polymer and anchor the graphene oxide sheets with poly(propylene oxide) diamines. This polymer/graphite oxide composite shows in a “dry” gel-electrolyte system a double layer capacitance as high as 130Fg−1. The polymer incorporation developed here can significantly diversify the application of graphene-based materials in energy storage devices.
Rechargeable Li–S batteries have suffered several technical obstacles, such as rapid capacity fading and low coulombic efficiency. To overcome these problems, we design new electrolytes containing N-methoxyethyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)-imide (Pyr1,2O1TFSI) and tri(ethylene glycol)dimethyl ether (TEGDME) in mass ratio of 7:3. Moreover, Lithium difluoro(oxalate)borate (LiODFB) is introduced for the modification. Although the addition of LiODFB as additive lead to extremely high viscosity of electrolyte and inferior performance of the cells, the electrolyte containing lithium bis(trifluoromethanesulfonyl)imide (LiTFSI, 0.84 nm) and LiODFB (0.60 nm) mixture with a total molar concentration of 0.4 mol kg−1 as binary lithium salt shows excellent electrochemical performance. The Pyr1,2O1TFSI/TEGDME electrolyte with LiTFSI/LiODFB binary lithium salts in mole ratio of 6:4 is obtained after optimizing ratio. The Li–S cells containing this electrolyte system show excellent capacity and cycle performance, whose initial discharge capacity is 1264.4 mAh g−1, and retains 911.4 mAh g−1 after 50 cycles with the coulombic efficiency more than 95%. It can be attributed the solid-electrolyte interphase (SEI)-forming ability of LiODFB which protect Li anode from suffering lithium dendrites and prevent the shuttle phenomenon. The novel electrolytes provide good cycling stability and high coulombic efficiency for the Li–S batteries, which is suggested as a promising electrolyte for Li–S batteries.
O1 A Nationwide Survey on Bariatric Surgery in France: Two Years Prospective Follow-Up and Predictive Factors of Outcome
The shunt current loss is one of main factors to affect the performance of the vanadium redox flow battery, which will shorten the cycle life and decrease the energy transfer efficiency. In this paper, a stack-level model based on the circuit analog method is proposed to research the shunt current loss of the vanadium redox flow battery, in which the SOC (state of charge) of electrolyte is introduced. The distribution of shunt current is described in detail. The sensitive analysis of shunt current is reported. The shunt current loss in charge/discharge cycle is predicted with the given experimental data. The effect of charge/discharge pattern on the shunt current loss is studied. The result shows that the reduction of the number of single cells in series, the decrease of the resistances of manifold and channel and the increase of the power of single cell will be the further development for the VRFB stack.
Objectives A “disconnectivity model” of schizophrenia has been proposed, but it is still unclear if white matter abnormalities are associated with gray matter changes and if they may be the anatomic substrate of cognitive impairment, which is a core symptom of the disorder. The first objective was to detect if white matter microstructure alterations in schizophrenia are associated with or independent of gray matter change, using an optimized method for white matter (Tract-Based Spatial Statistics) and gray matter analyses (whole-brain voxel-wise approach). The second objective was to identify the neuropsychological correlates of white matter abnormalities in the schizophrenic group, using a comprehensive neuropsychological battery. Methods In this case-control study 43 schizophrenic patients and 43 healthy volunteers were consecutively enrolled and matched for age and gender. Results Fractional anisotropy reduction was found in 6 fronto-temporal clusters (corrected p-values <0.05) in schizophrenic group in comparison with healthy volunteers, and 3 clusters showed fractional anisotropy increase (corrected p-values <0.05). Two of the clusters showing reduced fractional anisotropy were associated with reduced gray matter density in neuroanatomically-related regions in schizophrenic subjects (p-values ranging from 0.001 to 0.026). Executive, constructional-praxis, and working memory deficits were significant predictors of fractional anisotropy reduction in 4 clusters in the schizophrenic group (p-values ranging from <0.0001 to 0.0017). Conclusions Our data support the disconnectivity hypothesis in schizophrenia, enlightening a link between reduced fronto-temporal connectivity and “frontal” cognitive deficits. Reduced gray matter density may be involved primarily in the pathogenesis of some of these disconnected areas.
An efficient, convenient and flexible polyvinylidene fluoride/tetrabutylammonium hexafluorophosphate hierarchical nanofiber membrane (PVDF/TBAPF6 HNM) was successfully fabricated by one-step electrospinning and used as the separator of Li-ion capacitor (LIC). The PVDF/TBAPF6 HNMs displayed high ion conductivity of 4.28 × 10−3 S/cm, high mechanical strength, porosity, wettability and excellent thermal performance. Furthermore, the separator of PVDF/TBAPF6 HNM possessed lower interfacial resistance (134Ω) and better electrochemical stability, which exhibits better capacity retention and coulombic efficiency, compared with the commercial celgard 2340 separator. We believe that the gel polymer PVDF/TBAPF6 HNMs separator will have great potential in the field of the separator of LIC.
Synthesis of S-doped activated carbons (ACs) by carbonization and simultaneous activation of S-based polymers was found to be an efficient route to produce porous carbons for double layer capacitors (EDLCs) with high specific energy and power densities combined with low self-discharge. Here we investigate for the first time the processing-structure–property relationships related to the formation of polythiophene-derived ACs for EDLC applications. Sulfide bridges present in the polymer precursor were found to depress the shrinkage of the smallest micropores during the carbonization process and allow for the enhanced ion transport within the produced AC electrodes. The cyclic voltammetry (CV) measurements on S-doped ACs produced at 800 and 850 °C showed high specific capacitance (up to ∼200 F g−1) and no significant self-discharge in neutral aqueous electrolytes. More importantly, these capacitance values remained virtually identical for a sweep rate increasing from 1 to 50 mV s−1. The observed capacitance retention is quite remarkable for thick electrodes of ∼200 μm and a large AC particle size of 10–100 μm. It indicates great potential of the proposed synthesis technology for EDLCs operating at high frequencies and high currents. In the course of our systematic studies of AC performance in different electrolytes we found a strong correlation between the large pseudocapacitance and the significant self-discharge in ACs. We harness the difference between the characteristic times required to establish a double layer and that of the pseudocapacitive redox reactions and propose a simple method to estimate the fraction of pseudocapacitance. The proposed method is particularly valuable in cases when CV measurements do not show clear characteristic reduction–oxidation peaks.
Young children’s ability to learn something new from a third-party interaction may be related to the ability to imagine themselves in the third-party interaction. This imaginative ability presupposes an understanding of self–other equivalence, which is manifested in an objective understanding of the self and an understanding of others’ subjective perspectives. The current study measured imitative learning of a novel action seen only in a third-party interaction, mirror self-recognition, and perspective taking in a group of 48 18- to 20-month-olds. Patterns of performance suggest that understanding self–other equivalence is related to third-party learning.
Voltage based state of charge (SOC) estimation is challenging for lithium ion batteries that exhibit little open circuit voltage (OCV) change over a large SOC range. We demonstrate that by using a composite negative electrode composed of disordered carbon and graphite, we were able to introduce additional features to the OCV–SOC relationship that facilitate voltage-based SOC estimation. In contrast to graphite, the potential of disordered carbon is sensitive to the state of charge; this behavior, when manifested in a lithium ion battery, gives rise to additional beneficial features of the cell OCV–SOC relationship in terms of state estimation. We have demonstrated the effectiveness of the approach by comparing model simulations and corresponding experimental data of a cell composed of LiFePO4 positives and graphite+disordered carbon composite negative electrodes. Last, we find that although the graphite material has a higher coulombic capacity, very little (dynamic) performance loss is manifest with the mixed graphite+disordered carbon composite is employed.
Sodium ion batteries have attracted special research interests world widely for large-scale electrical stationary applications due to the abundant reserve and wide distribution of Na element. However, most cathodes suffer from limited capacity, poor rate capability or inferior cycling stability, which cannot meet the requirements of high-performance sodium ion batteries. Thus, developing cathode materials with improved capacity, rate and cycling performance is in urgent demand. Herein, we design a series of Na2Ru1-xMnxO3 using both cationic and anionic redox activities to achieve high capacity. Mn-doped Na2RuO3 has been found to be capable of enhancing the oxygen redox activity, raising the redox potential, preventing the generation of spinel phase and moisture-sensitive phase upon charge process, facilitating charge transfer kinetics and suppressing the O3→P3 phase transition in a long cycle. As a result, Na2Ru0.8Mn0.2O3 exhibits outstanding electrochemical performance by delivering a large capacity of over 90 mAh g−1 for long cycling of 1000 times at a high rate of 5 C. This study provides a prototype of high-performance ion-doped Na-rich cathode and could encourage scientists to explore more Na2MM’O3 materials for ultrafast sodium ion batteries with large capacity and superlong cycle life.
A nanoscaled Na3SbS3.75Se0.25 solid electrolyte with less grain-boundary resistance was synthesized using a liquid/solid fusion technology. The Na3SbS3.75Se0.25 solid electrolyte shows a high ionic conductivity of 4.03 × 10−3 S cm−1 at room temperature due to the significantly decreased amorphous phase in the electrolyte. Moreover, the small particle size of the solid electrolytes enhances the contact between solid electrolyte and electrode, reducing the interfacial contact resistance. As a result, FeS2/Na3SbS3.75Se0.25/Na all-solid-state sodium batteries achieve a high specific capacity of 140.6 mAh g−1 for 300 cycles at a high current of 500 mA g−1. In addition, FeS2/Na3SbS3.75Se0.25/Na cells also demonstrate a high rate-capacity of 365.3, 301.8, 210.1 and 96.0 mAh g−1 at current densities of 50, 300, 500 and 1000 mA g−1, respectively. The liquid/solid fusion technology is a unique synthesis strategy to develop superionic electrolytes for room temperature all-solid-state sodium secondary battery.
A high internal resistance and limited triple-phase boundaries are two critical issues that limit the performance of conventional solid-state Li–O2 batteries. In this work, we propose and fabricate a novel solid-state Li–O2 battery with an integrated electrolyte and cathode structure. This design allows a thin electrolyte layer (about 10% of that in conventional batteries) and a highly porous cathode (78% in porosity), both of which contribute to a significant reduction in the internal resistance, while increasing triple-phase boundaries. As a result, the battery outputs a discharge capacity as high as 14200 mA h gcarbon−1 at 0.15 mA cm−2, and can sustain 100 cycles at a fixed capacity of 1000 mA h gcarbon−1. The novel integrated electrolyte and cathode structure represents a significant step toward the advancement of Li–O2 batteries.
This report highlights some of the achievements in the chemistry of organophosphorus, -sulfur, -selenium, -tellurium and -silicon compounds from 2007. Of particular note were the developments in heterocyclic compound synthesis and the heteroatom-mediated control of stereochemistry. All publications cited were selected from readily accessible online journals.