batterydata/paper-abstracts huggingface dataset:
SnO2 nanooctahedron with {221} high-index facet (HIF) was synthesized by a simple hydrothermal method, and was firstly employed to sensitive electrochemical sensing of a typical organic pollutant, 1-naphthol (1-NAP). The constructed HIF SnO2 modified glassy carbon electrode (HIF SnO2/GCE) possessed advantages of large effective electrode area, high electron transfer rate, and low charge transfer resistance. These improved electrochemical properties allowed the high electrocatalytic performance, high effective active sites and high adsorption capacity of 1-NAP on HIF SnO2/GCE. Cyclic voltammetry (CV) results showed that the electrochemical oxidation of 1-NAP obeyed a two-electron transfer process and the electrode reaction was under diffusion control on HIF SnO2/GCE. By adopting differential pulse voltammetry (DPV), electrochemical detection of 1-NAP was conducted on HIF SnO2/GCE with a limit of detection as low as 5nM, which was relatively low compared to the literatures. The electrode also illustrated good stability in comparison with those reported value. Satisfactory results were obtained with average recoveries in the range of 99.7–103.6% in the real water sample detection. A promising device for the electrochemical detection of 1-NAP with high sensitivity has therefore been provided.
Highly crumpled graphene nanosheets (GS) with a BET surface area as high as 722.1 m2 g−1 is prepared by a thermal exfoliation method. A systematical investigation is performed on the electrochemical performances of porous Ni2P/GS nanocomposite synthesized by the low temperature solid state reaction method. It is shown that Ni2P nanoparticles anchor on graphene sheets producing a porous structure and GS have beneficial effects on the electrochemical properties of Ni2P nanoparticles when investigated as pseudocapacitor materials. The novel Ni2P/GS composite electrode exhibits a superior specific capacitance of 1912 F g−1 and 888 F g−1 at current densities of 5 and 50mAcm−2, respectively. The specific capacitance decreases to 1473 F g−1 after 2500 cycles, suggesting its excellent cycling stability. It is confirmed that the GS with good electrical conductivity serve as a conducting network for fast electron transfer between the active materials and charge collector, as well as buffered spaces to accommodate the volume expansion/contraction during cycling, thus, leading to enhancement of the electrochemical properties of the Ni2P electrode.
LiCo1−y M y O2 (M=Ni or Fe) oxides with large specific areas and nanoscale grain sizes were prepared by an improved amorphous citric precursor method (IACP) at low temperature. Their electrocatalytic performances were characterized by the polarization curves of gas diffusion electrodes employing the oxides. The measurements of polarization curves indicate that most of the samples, especially LiCo0.6Ni0.4O2 and LiCo0.8Fe0.2O2, showed excellent bifunctional electrocatalytic activities. The activities of the oxides for oxygen evolution could be improved by acid-delithiation.
A hyperbranched poly[bis(hexaethylene glycol)benzoate] with terminal acetyl groups was prepared, and ionic conductivity, thermal property, and electrochemical stability of the polymer electrolyte with LiN(CF3SO2)2 were investigated. Ionic conductivity of the polymer electrolyte exhibited a maximum value of 9×10−5 S/cm at a [LiN(CF3SO2)2]/[repeat unit] ratio of 0.6 (corresponding to a Li/O ratio of 0.04) and 80°C. The effect of a hyperbranched polymer, a poly[bis(triethylene glycol)benzoate] with terminal acetyl groups (poly-Ac1b), as an additive on ionic conductivity of a linear poly(ethylene oxide) (PEO)/LiN(CF3SO2)2 electrolyte was also investigated. Addition of 10wt.% poly-Ac1b improved ionic conductivity and also ion transference number in the polymer electrolyte.
While lithium bis(fluorosulfonyl) imide (LiFSI) is widely used in current Li-ion batteries (LIBs), the role of LiFSI in the LIB performance remains elusive. We herein elucidate the effects of LiFSI on the electrochemical performance of graphite anodes in comparison with those of lithium hexafluorophosphate (LiPF6). An in-depth electrochemical analysis using graphite/Li half cells and graphite/graphite symmetric cells confirms that LiFSI provides little improvement to the cyclability of the graphite anode at 25 °C, but enables far better performance in cycle and storage tests at 60 °C. The superior thermal stability of the graphite anode in LiFSI electrolyte is attributed to the formation of a thin, inorganic-rich solid electrolyte interphase (SEI) layer as indicated by differential scanning calorimetry (DSC) and X-ray photoelectron spectroscopy (XPS) measurements.
Objectives: Gamma (‘40 Hz’) rhythms may play a role in the integration of sensory processing activity. Impaired temporal integration may be a key feature of the associated disturbances in schizophrenia. This is the first study to examine the time course of Gamma activity induced in response to stimuli in this disorder. Methods: Gamma activity induced in response to task-relevant and irrelevant auditory oddball stimuli was examined in 35 medicated schizophrenics and 35 age- and gender-matched normal controls. We employed a moving Welch window with short time FFT to examine the time course of Gamma amplitude. The amplitude spectrum for each time point was de-trended to eliminate any contribution of broad spectrum activity (EEG or EMG) to Gamma amplitude. Results: For targets, schizophrenics showed a significant decrease in post-stimulus Gamma response amplitude in left hemisphere and frontal sites and an increase in right hemisphere and parieto-occipital sites (P<0.0009). The abnormalities correlated with PANSS general symptom scores. In the non-targets (at a different latency), schizophrenics showed a widespread Gamma decrease (P<0.0005). Conclusions: The Gamma findings in non-targets may reflect an abnormality in appropriately processing irrelevant stimuli. This could result in defective processing of the context (integration) of relevant target information.
Previous vanadium redox flow battery models (VRFB) use the ion mobility deduced from the ion diffusivity measured at low ion concentrations, resulting in an overestimation of the ionic conductivity in VRFBs that virtually operate at much higher ion concentrations. To address this issue, we propose to use the Stokes–Einstein relationship to determine an ion concentration-dependent ion mobility. A two-dimensional, transient model that incorporates the effect of ion concentrations on ion mobility is developed for VRFBs. It is shown that the present model results in: (i) a more accurate estimation of ionic conductivity, (ii) a more accurate prediction of cell voltage particularly at high current densities, and (iii) a more realistic simulation of the concentration distributions and local current density distributions in the electrodes. Finally, the model is applied to the study of the effects of important electrode design parameters and operating conditions on cell performance. It is found that the local current density, being distributed across the electrode in a manner opposite to that predicted by previous models, is much lower at the current collector side than that at the membrane side. This fact suggests that the region away from the membrane is not well utilized in conventional electrodes, thus a thinner electrode is preferred.
Titanium dioxide/reduced graphene oxide (TiO2-rGO) composites were synthesized at different loadings of carbonaceous phase, characterized and used as anode materials in Lithium-ion cells, focusing not only on the high rate capability but also on the simplicity and low cost of the electrode production. It was therefore chosen to use commercial TiO2, GO was synthesized from graphite, adsorbed onto TiO2 and reduced to rGO following a chemical, a photocatalytic and an in situ photocatalytic procedure. The synthesized materials were in-depth characterized with a multi-technique approach and the electrochemical performances were correlated i) to an effective reduction of the GO oxidized moieties and ii) to the maintenance of the 2D geometry of the final graphenic structure observed. TiO2-rGO obtained with the first two procedures showed good cycle stability, high capacity and impressive rate capability particularly at 10% GO loading. The photocatalytic reduction applied in situ on preassembled electrodes showed similarly good results reaching the goal of a further simplification of the anode production.
Porous polymer electrolytes (PPEs) are attractive for developing lithium-ion batteries because of the combined advantages of liquid and solid polymer electrolytes. In the present study, a new porous polymer membrane doped with phytic acid (PA) is prepared, which is used as a crosslinker in polymer electrolyte matrix and can also plasticize porous polymer electrolyte membranes, changing them into soft tough flexible materials. A PEO–PMMA–LiClO4–x wt.% PA (x = weight of PA/weight of polymer, PEO: poly(ethylene oxide); PMMA: poly(methyl methacrylate)) polymer membrane is prepared by a simple evaporation method. The effects of the ratio of PA to PEO–PMMA on the properties of the porous membrane, including morphology, porous structure, and mechanical property, are systematically studied. PA improves the porous structure and mechanical properties of polymer membrane. The maximum tensile strength and elongation of the porous polymer membranes are 20.71 MPa and 45.7% at 15 wt.% PA, respectively. Moreover, the PPEs with 15 wt.% PA has a conductivity of 1.59 × 10−5 S/cm at 20 °C, a good electrochemical window (>5 V), and a low interfacial resistance. The results demonstrate the compatibility of the mechanical properties and conductivity of the PPEs, indicating that PPEs have good application prospects for lithium-ion batteries.
The transport properties of gel-type ionic conducting membranes consisting of poly(methylmethacrylate) (PMMA), polyethylene oxide (PEO), LiX (X=ClO4, BF4, CF3SO3) and dimethyl phthalate (DMP) are studied. The polymer films are characterized by FTIR and impedance spectroscopic studies. At room temperature, the highest conductivity, viz., 0.64×10−4 Scm −1 , is obtained for a film of PMMA, PEO, LiBF4 and DMP. Hybrid polymer electrolytes based on PMMA–PEO appear very promising for lithium battery applications.
Effect of poly(ethylene oxide) on the electrochemical properties of polymer electrolyte based on electrospun, non-woven membrane of PVdF is demonstrated. Electrospinning process parameters are controlled to get a fibrous membrane consisting of bead-free, uniformly dispersed thin fibers with diameter in the range of 1.5–1.9 μm. The membrane with good mechanical strength and porosity exhibits high uptake when activated with the liquid electrolyte of lithium salt in a mixture of organic solvents. The polymer gel electrolyte shows ionic conductivity of 4.9 × 10−3 S cm−1 at room temperature. Electrochemical performance of the polymer gel electrolyte is evaluated in Li/polymer electrolyte/LiFePO4 coin cell. Good performance with low capacity fading on charge–discharge cycling is demonstrated.
A chitinase-secreting strain CH2 was one of 353 strains isolated from rhizosphere of eggplant. Based on 16S rDNA sequence alignment and several biochemical and physiological characteristics, the strain was identified to be of Bacillus cereus. On chitin–Ayers (CA) medium, the strain secreted chitinase. Evaluation of its activity, combined with sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), showed it to be a 15.0-KD chitinase. On glass slides, germination of the fungal spores was effectively suppressed by the bacterial suspension, supernatant from the suspension, and 0.005% solution of chitinase extracted from the strain CH2. The optimum pH for chitinase was 7.1 and optimum temperature was 40°C. At that temperature, high-level chitinolytic activity was retained for 10 days. In greenhouse experiments, suspension of the cells of the CH2 strain reduced the severity of Verticillium wilt on eggplant by 69.69%, its supernatant by 54.04%, and the enzyme diluted to 0.01% strength by 53.13% in 14 days. Strain CH2 and its chitinase have good commercial potential in controlling Verticillium wilt.
Objective This double-blind, sham-controlled trial investigated the effects of two daily tDCS sessions over a 5-day period in treatment-resistant depression. Method Twenty-four treatment-resistant depressed patients received two daily sessions of active or sham anodal tDCS to the left prefrontal cortex (2mA, 10 sessions over 1week). Depression severity, psychomotor retardation and cognitive function were assessed. Results Active tDCS was not significantly superior to sham tDCS on the HDRS at week 4, as well as on the MADRS and SRRS scales, and on neuropsychological tests. Response rates were not significantly higher with active tDCS. tDCS was well tolerated, with mild adverse events limited to transient scalp discomfort. Conclusion tDCS did not induce clinically relevant antidepressant effect in active and sham stimulation groups. There was no impact on psychomotor and neuropsychological functioning. Significance tDCS efficacy on specific symptom profiles in pharmacotherapy-resistant depression is limited. The use of optimized stimulation protocol and longer period of follow up may valuably contribute to specify the place of tDCS in treatment-resistant depression.
Herein, polycrystalline Nb2O5 nanoparticles including pseudo-hexagonal (TT-), orthorhombic (T-), tetragonal (M-) and monoclinic (H-) phases are uniformly anchored onto graphene sheets through a polyol-mediated solvothermal reaction and post heat-treatment, enabling us to discuss the effect of Nb2O5 crystalline phases on Li+ intercalation process. Electrochemical results show that Li+ intercalation into M- and H-Nb2O5 are also capacitive behavior, exhibiting higher capacity of 650 C g−1 and 615 C g−1 than T- and TT-phases of 585 C g−1 and 530 C g−1 at 0.5 A g−1. The higher capacity-retention is also obtained for M- and H-phases (509 and 452 C g−1) compared to T- and TT-phases (305 and 207 C g−1) at 20 A g−1. The high rate performance of H-phase can be explained by higher Li+ diffusion coefficients (D Li) of 1.6 × 10−12 cm2 s−1, which is almost two order of magnitude higher than TT-phase of 4.7 × 10−14 cm2 s−1. This results indicate that Nb2O5 with various crystal structures shows similar Li+ capacitive intercalation behavior, but more ordered arrangement of unit cell may provide more vacancy for Li+ with the lower diffusion barriers, thus leading to higher rate performance.
This article examines consumer perception of transactions whose benefits of consumption and cost of purchase unfold over time. Specifically, the article employs the notion of narrow framing to suggest that, when consumers confront a series of decisions, they tend to make evaluations one at a time, rather than take into consideration the entire portfolio. Consistent with this argument, the authors test the pattern alignment hypothesis, which states that consumers prefer payment schemes that match the pattern of benefits and payments in each period, rather than a scheme that encompasses an entire financing period. In two experiments, the authors find general support for the pattern alignment hypothesis and for the underlying process by which this hypothesis occurs. Specifically, Experiment 2 highlights the mediating role of consumers' perceived fairness in determining the effectiveness of a financing program. The paper concludes with a discussion of the theoretical and practical implications of developing financing and pricing strategies that promote the perception of fairness.
A simple energy harvesting strategy has been developed to selectively catalyze glucose in the presence of oxygen in a glucose/O2 fuel cell. The anode consists of an abiotic catalyst Al/Au/ZnO, in which ZnO seed layer was deposited on the surface of Al/Au substrate using hydrothermal method. The cathode is constructed from a single rod of platinum with an outer diameter of 500 μm. The abiotic glucose fuel cell was studied in phosphate buffer solution (pH 7.4) containing 5 mM glucose at a temperature of 22 °C. The cell is characterized according to its open-circuit voltage, polarization profile, and power density plot. Under these conditions, the abiotic glucose fuel cell possesses an open-circuit voltage of 840 mV and delivered a maximum power density of 16.2 μW cm−2 at a cell voltage of 495 mV. These characteristics are comparable to biofuel cell utilizing a much more complex system design. Such low-cost lightweight abiotic catalyzed glucose fuel cells have a great promise to be optimized, miniaturized to power bio-implantable devices.
Photovoltaic (PV) pumping offers the possibility of supplying water to remote and desert regions for their daily needs. The sizing of the PV pumping systems is a very significant step in order to optimize the power peak of the PV array and to ensure the best choice of the motor, the pump and the inverter. Two mathematical models were proposed in this article to contribute in the studies of PV pumping sizing. These models link directly the operating electrical power to the water flow rate of the pump versus total head. These models are based essentially on the experimentation of pumps on CDER PV pumping test facility. Two pumping systems are tested: the first uses a centrifugal pump and the second uses a positive displacement pump. The results obtained by the models are very satisfactory. Also, the models enabled us to simulate the electrical and hydraulic performances of two tested pumps. The performances are calculated using the measured meteorological data of different sites located in Sahara and coastline regions of Algeria.
A complete capacity fade analysis was carried out for Sony 18650 cells cycled at elevated temperatures. The major causes of capacity loss were identified and a complete capacity fade balance was carried out to account for the total capacity loss of Li-ion battery as a function of cycle number and temperature. The three most significant parameters that cause capacity loss were loss of secondary active material (LiCoO2/carbon) and primary active material (Li+) and the rate capability losses. Intrinsic capacity measurements for both positive and negative electrode has been used to estimate the capacity loss due to secondary active material and a charge balance gives the capacity lost due to primary active material (Li+). Capacity fade has been quantified with secondary active material loss dominating the other losses.
Despite a continuous reduction in battery prices, investment in storage systems carries a high risk. Indeed, many applications lack an adequate test protocol and method to predict the performance of batteries in operations. In this paper, we focus on lithium-ion battery energy storage systems (BESS), for which we introduce a novel method. With this method, predicting the efficiency of lithium-ion BESS becomes possible for any application from a single set of measurements. We show that evaluating the battery resistance as a function of the C-rate provides general “capability charts” based on which the efficiency can be evaluated under arbitrary operation profiles. Application-specific test procedures therefore become unnecessary. We have applied the novel procedure on three different lithium-ion cell technologies and illustrate its accuracy in the example of grid-connected BESS used for primary control reserve.
An extensive research effort is being made to develop the next generation of anode materials for lithium ion batteries. A large part of this effort has been related to silicon, primarily due to its considerable theoretical capacity; however, very limited cycling stability has prevented widespread commercial adoption. A potential solution for this is to use convertible sub-stoichiometric silicon nitride (a-SiNx), which goes through an irreversible conversion reaction during the initial lithiation cycle, producing active silicon domains in an inactive, lithium conducting matrix. Relative to pure silicon, the resulting composite material has gained cycle life at the cost of reduced specific capacity. The specifics of the conversion reaction, however, have not yet been determined; hence, the impact of varying nitrogen content remains uncertain. In this work we develop a model reaction which relates the reversible and irreversible capacities of an electrode to the composition of the conversion products. By fitting this model to experimental data from a large number of a-SiNx thin film electrodes with different thickness and composition, we determine with a high probability that the matrix composition is Li2SiN2. From this, the reversible and irreversible capacities of the material can be predicted for a nitride of a given composition.
Since long-term survivorship is now a reality for an increasing number of people with cancer, understanding their mood states (i.e., transient subjective emotional states) can inform health-care policy as well as help support individual patients. This study described the mood states of Italian long-term cancer survivors, compared them with normative data, and tested their association with the main clinical and socio-demographic sample’s characteristics.
Anaphylaxis is an acute systemic reaction with symptoms of an immediate-type allergic reaction which can involve the whole organism and is potentially life-threatening [1–3].
Within the past decade there has been a fair amount of interest in utilizing the high energy densities of hydrocarbon fuels at the small scale. The motivation for this is primarily twofold. The first application involves the generation of electricity via the heat released by combustion, in the second application chemical micro-thrusters would provide milli-Newton and micro-Newton levels of thrust for Divert and Attitude Control on the next generation of micro-satellites and micro-aerial vehicles. With this in mind many schemes addressing the fundamental thermal challenges associated with small-scale combustion have been proposed, analyzed, and tested. This review will focus on experimental work that has been conducted on heat-recirculating “Swiss-Roll” combustors and the impact of geometry, materials, catalysts, and scale on the thermal performance, extinction criteria/extinction regimes, and flame dynamics. Additionally, an overview of meso-scale power systems is provided covering both propulsion and electric power generation.
Rechargeable metal-air batteries possess high energy density and are projected to be excellent alternates to the state of the art current storage devices such as Li-ion batteries. The performance of metal-air batteries is guided by the kinetics of electrochemical reactions involving oxygen reduction and oxygen evolution. The present study explores the use of a gel- based electrolyte in combination with a ceramic catalyst based on titanium carbonitride for Li-O2 battery. Stable and highly ionically conducting gel electrolyte combined with active bi-functional electrocatalyst results in flexible and thin cell design. The high bi-functional activity of the electrode for oxygen reduction and oxygen evolution reactions in non-aqueous dimethyl acetamide medium lends itself to be a very good electrode material for Li-O2 chemistry. The Li-O2 cell with the gel electrolyte delivers high energy density of 1040 Wh/kg for 120 continuous cycles at high drain currents of 625mA/g.