batterydata/paper-abstracts huggingface dataset:
Metallic (1T) molybdenum disulphide (MoS2) is a promising electrode material in the electrochemical energy storage application due to its excellent electrical conductivity and ionic intercalation property. Here, we report the metallic MoS2 modified with porous graphitic carbon nitride (g-C3N4) as a novel nanocomposite for efficient supercapattery electrode. The 1T-MoS2 is grown on the surface of porous g-C3N4, and thus it facilitates easier ion intercalation between these two materials. The prepared electrode of g-C3N4/MoS2 composite attained a maximum specific capacity of 515 C g−1 at 1 A g−1 current density and obtained 66% capacitive retention even at a high current density of 20 A g−1 in three electrode cell. A symmetric cell is fabricated using g-C3N4/MoS2 composite as both positive and negative electrodes to study the practical applicability of the electrode material. The cell exhibits an excellent performance with a maximum specific capacity of 198 C g−1 at a current density of 1 A g−1 and specific energy of 147 Wh kg−1 at a power density of 2691 W kg−1. This symmetric cell still delivers an energy density of 46 Wh kg−1 at a power density as high as 26.74 kW kg−1. Moreover, the cell exhibits extended cyclic stability with capacitive retention of 89% after 8000 cycles. This outstanding electrochemical performance suggests the future scope of g-C3N4/MoS2 nanocomposite as an efficient electrode material for energy storage devices.
Health disparities are a persistent problem in many high-income countries. Health policymakers recognize the need to develop systematic methods for documenting and tracking these disparities in order to reduce them. The experience of the U.S., which has a well-established health disparities monitoring infrastructure, provides useful insights for other countries.
The perception of temporal intervals changes during the life-span, and especially older adults demonstrate specific impairments of timing abilities. Recently, we demonstrated that timing performance and cognitive status are correlated in older adults, suggesting that timing tasks can serve as a behavioral marker for the development of dementia. Easy-to-administer and retest-capable timing tasks therefore have potential as diagnostic tools for tracking cognitive decline. However, before being tested in a clinical cohort study, a further validation and specification of the original findings is warranted. Here we introduce several modifications of the original task and investigated the effects of temporal context on time perception in older adults (> 65 years) with low versus high scores in the Montreal Cognitive Assessment survey (MoCA) and a test of memory functioning. In line with our previous work, we found that temporal context effects were more pronounced with increasing memory deficits, but also that these effects are stronger for realistic compared to abstract visual stimuli. Furthermore, we show that two distinct temporal contexts influence timing behavior in separate experimental blocks, as well as in a mixed block in which both contexts are presented together. These results replicate and extend our previous findings. They demonstrate the stability of the effect for different stimulus material and show that timing tasks can reveal valuable information about the cognitive status of older adults. In the future, these findings could serve as a basis for the development of a diagnostic tool for pathological cognitive decline at an early, pre-clinical stage.
Synchrotron based in situ X-ray diffraction technique has been used to study the mechanism of capacity fading of LiCoO2 cycled to a higher voltage above the normal 4.2V limit and to investigate the mechanism of capacity retention improvement by ZrO2 surface coating on LiCoO2. It was found that the capacity fading of LiCoO2 cycled at higher voltage limit is closely related to the increased polarization rather than the bulk crystal structure damage. The capacity of uncoated LiCoO2 sample dropped to less than 70mAhg−1 when charged to 4.8V after high voltage cycling. However, when the voltage limit was further increased to 8.35V, the capacity was partially restored and the corresponding structural changes were recovered to the similar level as seen in fresh sample. This indicates that the integrity of the bulk crystal structure of LiCoO2 was not seriously damaged during cycling to 4.8V. The increased polarization seems to be responsible for the fading capacity and the uncompleted phase transformation of LiCoO2. The polarization-induced capacity fading can be significantly improved by ZrO2 surface coating. It was proposed that the effect of ZrO2-coating layer on the capacity retention during high voltage cycling is through the formation of protection layer on the surface of LiCoO2 particles, which can reduce the decomposition of the electrolyte at higher voltages.
New glyme–Li salt complexes were prepared by mixing equimolar amounts of a novel cyclic imide lithium salt LiN(C2F4S2O4) (LiCTFSI) and a glyme (triglyme (G3) or tetraglyme (G4)). The glyme–Li salt complexes, [Li(G3)][CTFSI] and [Li(G4)][CTFSI], are solid and liquid, respectively, at room temperature. The thermal stability of [Li(G4)][CTFSI] is much higher than that of pure G4, and the vapor pressure of [Li(G4)][CTFSI] is negligible at temperatures lower than 100°C. Although the viscosity of [Li(G4)][CTFSI] is high (132.0mPas at 30°C), because of its high molar concentration (ca. 3moldm−3), its ionic conductivity at 30°C is relatively high, i.e., 0.8mScm−1, which is slightly lower than that of a conventional organic electrolyte solution (1moldm−3 LiTFSI dissolved in propylene carbonate). The self-diffusion coefficients of a Li+ cation, a CTFSI− anion, and a glyme molecule were measured by the pulsed gradient spin-echo NMR method (PGSE-NMR). The ionicity (dissociativity) of [Li(G4)][CTFSI] at 30°C is ca. 0.5, as estimated from the PGSE-NMR diffusivity measurements and the ionic conductivity measurements. Results of linear sweep voltammetry revealed that [Li(G4)][CTFSI] is electrochemically stable in an electrode potential range of 0–4.5V vs. Li/Li+. The reversible deposition-stripping behavior of lithium was observed by cyclic voltammetry. The [LiCoO2|[Li(G4)][CTFSI]|Li metal] cell showed a stable charge–discharge cycling behavior during 50 cycles, indicating that the [Li(G4)][CTFSI] complex is applicable to a 4V class lithium secondary battery.
The current studies test the hypothesis that the financial burden of college can initiate a psychological process that has a negative influence on academic performance for students at selective colleges and universities. Prior studies linking high college costs and student loans to academic outcomes have not been grounded within relevant social psychological theory regarding how and when the financial burden of college can influence students’ psychological and cognitive processes. We test the hypothesis that the salient financial burden of college impairs students’ cognitive functioning, especially when it creates an identity conflict or perceived barrier to reaching a student’s desired financially successful future. First, we use longitudinal data from 28 selective colleges and universities to establish that students who accumulate student loan debt within these contexts are less likely to graduate from college because student loan debt predicts a decline in grades over time, even when controlling for factors related to socioeconomic status and prior achievement. Then, in an experiment, we advance research in this area with a direct, causal test of the proposed psychological process. An experimental manipulation that brings high college costs to mind impairs students’ cognitive functioning, but only when those thoughts create an identity conflict or a perceived barrier to reaching a student’s desired financially successful future.
The aim of this study was to examine the effects of amygdalohippocampal deep brain stimulation (AH-DBS) on cognitive functioning in patients with refractory temporal lobe epilepsy. The population consisted of 10 patients (7 men) who underwent ipsilateral (n =8) or bilateral (n =2) AH-DBS. Intellectual and neuropsychological evaluation was performed before and 6months after initiation of AH-DBS. Group analyses revealed no overall pattern of change in cognitive measures, but improvement was seen in emotional well-being. Individual results varied over a broad spectrum ranging from no cognitive effects to negative effects on intelligence capacities, divided attention, and concept formation, to positive effects on speed of information processing and speed of finger movements. AH-DBS is a valuable treatment alternative for patients with refractory epilepsy that appears to have no major adverse neuropsychological consequences and enhances emotional well-being on the group level. Individual results are too diverse at this moment to allow viable interpretation. Additional studies are needed to confirm these preliminary results.
Background Neuropsychological (NP) performance is a consistent correlate of everyday functioning in schizophrenia, but it is unclear whether relationships between individual NP ability areas and domains of everyday functioning are general or specific. Assessments of real-world everyday functioning may be influenced by environmental and social factors (e.g., social security, disability status, opportunities and restrictions in living situations). This study examined the specificity of the relationships between different NP abilities and performance-based measures of social and living skills. Methods 181 ambulatory older (age>50) patients with schizophrenia were examined with NP tests measuring episodic and working memory, executive functioning, verbal fluency, and processing speed. All subjects performed tasks examining social (Social Skills Performance Assessment: SSPA) and everyday living (UCSD Performance Based Skills Assessment: UPSA) skills. Results Using canonical analysis, the NP variables were used to predict the functional capacity measures. The analysis found that 37% of the variance in the functional capacity and NP measures was shared, X 2 (54)=106.29, p <.001. Two canonical roots described the cognitive variables and the roots were differentially associated with everyday living and social skills. The root loading on processing speed, episodic memory, and executive functions were associated with UPSA scores, while the root loading on working and episodic memory and verbal fluency were associated most strongly with social competence. Implications Social and everyday living skills deficits in patients with schizophrenia may reflect generally independent domains of functional outcome, linked through cognitive performance. The data suggest that somewhat different cognitive processes are associated with these two domains of functional capacity, although there appears to be some overlap, which may be due to the nature of the NP tests employed.
In this paper we present a comprehensive structural, chemical and electrochemical characterization of monoclinic Li0.33MnO2 as a positive electrode material for aqueous high-voltage hybrid supercapacitors. The monoclinic Li0.33MnO2, which is traditionally used as cathode material for lithium ion batteries, was synthesized through a simple thermal solid-state synthesis. The monoclinic Li0.33MnO2 electrode exhibits a wide operational potential window ranging between −1.25 and 1.25V vs SCE, which enables it to serve as either a negative or a positive electrode. In addition, this electrode material exhibits a high specific capacity of 140mAhg−1 at a low current density of 0.1Ag−1, and 76mAhg−1 at high current density of 1Ag−1 in this range of potentials. Hybrid supercapacitors composed of Li0.33MnO2 positive electrode and activated carbon (AC) negative electrode were fabricated. They exhibit outstanding electrochemical performance in terms of operational potential window, cycleability, and energy and power density. The Li0.33MnO2/AC hybrid capacitor has an energy density of 13.5 Wh kg−1 at power density of 100Wkg−1, which is twice than that of MnO2/AC and AC/AC supercapacitors, and an energy density of 7 Wh kg−1 at 1000Wkg−1, which is seven times higher than that of AC/AC capacitors at this power density. Furthermore, this hybrid capacitor presents an excellent cycle life with 80% specific capacitance retention after 12,000 cycles to 2V. The electrochemical charge storage mechanism of the monoclinic Li0.33MnO2 was investigated by cyclic voltammetry and X-ray diffraction.
Tin oxide (SnO2) is an attractive anode in lithium ion batteries (LIBs), but its applications have been significantly hampered by the huge volume change during the electrochemical cycling. In this work we demonstrate a rational design of crystalline SnO2 @ amorphous TiO2 core-shell nanostructures, where the crystalline SnO2 core was synthesized by a hydrothermal method and the amorphous TiO2 shell was deposited by atomic layer deposition. The SnO2@TiO2 nanostructures deliver excellent performances during the electrochemical process, having a high reversible capacity of 1259 mAh g−1 at cycling rate of 80 mA g−1, which is still up to 703 mAh g−1 after 50 cycles. The acceptable rate capacity is also revealed with 412 mAh g−1 at 400 mA g−1. The coulombic efficiency is stable at around 100% regardless of cycling rates and numbers. The electrochemical performances of the SnO2@TiO2 batteries are better than those of the SnO2 ones without TiO2 coating. In the SnO2@TiO2 nanostructures, the amorphous TiO2 shell layer can experience an isotropic stress, having the ability to evidently reduce the volume change, lattice stress and so the risk of fracture during the cycling process, which is responsible for their outstanding behaviors. The strategy provided in our study is expected to be a precious guideline for designing an ideal electrode for energy storage devices.
An ionic complex of anionic and cationic monomers was obtained by protonation of (N,N-diethylamino)ethylmethacrylate (DEA) with acrylic acid (AAc). Free radical copolymerization of the ionic complex and acrylamide (AAm), yielded the ionically crosslinked polyampholytic gel electrolytes [poly(AAc–DEA–AAm), designated as PADA] using two types of organic solvents containing a lithium salt. The PADA gel electrolyte exhibited good thermal stability shown by the DSC thermogram. The impedance analysis at temperatures ranging from −30 to 75°C indicated that the ionic conductivities of the PADA gel electrolytes were rather close to those of liquid electrolytes. The temperature dependence of the ionic conductivities was found to be in accord with the Arrhenius equation. Moreover, the ionic conductivities of PADA gel electrolytes increased with an increase of the molar ratios of cationic/anionic monomers. The ionic conductivities of PADA gels prepared in solvent mixtures of propylene carbonate, ethyl methyl ether and dioxolane (3:1:1, v/v) were higher than those of PADA gels prepared in propylene carbonate only. Significantly, the ionic conductivities of two kinds of PADA gel electrolytes were in the range of 10−3 and 10−4 Scm−1 even at −30°C. The electrochemical windows of PADA gel electrolytes measured by cyclic voltammetry were in the range from −1V to 4.5V.
Effective waste reduction and recycling is predicated upon credible data on refuse generation and disposal. Despite improvements in the quality of data for municipal solid wastes (MSW) disposal, dependable generation and recycling statistics to support planning, regulation and administration are lacking. The available aggregates on national waste production from two sources do not conform to each other and fail to serve the requirements of local solid waste planning. As recycling estimates will be difficult to discern, the collection of generation data based on weighing waste samples at generator sites has been portrayed as the key for developing sustainable local databases. The coefficients developed from the databases for the various categories of residential, commercial, industrial and institutional wastes can be used as variables for waste generation models.
We have examined the effects of different types of slurry on CH4 and N2O emissions, Zn and Cu contents of rice, and nitrate content of the drainage water. The experiment included four treatments: (1) anaerobically digested cattle slurry (ADCS), (2) ADCS filtered to remove the coarse organic matter fraction, (3) anaerobically digested pig slurry (ADPS), and (4) chemical fertilizer (CF). The application rate was 30 g NH4–N m−2. Different amounts of C were incorporated with fertilization: 725 g C m−2 in ADCS, 352 g m−2 in filtered ADCS, and 75 g m−2 in ADPS. The average CH4 emissions during a growing period were 304, 359, 452, and 579 mg m−2 day−1 in the CF, ADPS, filtered ADCS, and ADCS treatments, respectively. The CH4 emission was significantly higher in ADCS than in CF and ADPS. Negligible N2O emissions were observed during the growing period. Comparable concentrations of Zn and Cu were observed in the rice grain among the treatments. In contrast, their concentrations in the stems and leaves were significantly higher in ADPS than in CF treated rice, although the values were lower than the upper limit of feed additives. Nitrate concentrations in the drainage water were consistently low (0.5 mg N L−1). The present study suggested that ADPS, containing a lower amount of C than ADCS, might be an organic fertilizer in paddy field with comparable environmental impacts to chemical fertilizers (CF), but long-term field studies are needed to better understand the effects of these organic fertilizers.
Surface wave methods gained in the past decades a primary role in many seismic projects. Specifically, they are often used to retrieve a 1D shear wave velocity model or to estimate the VS,30 at a site. The complexity of the interpretation process and the variety of possible approaches to surface wave analysis make it very hard to set a fixed standard to assure quality and reliability of the results. The present guidelines provide practical information on the acquisition and analysis of surface wave data by giving some basic principles and specific suggestions related to the most common situations. They are primarily targeted to non-expert users approaching surface wave testing, but can be useful to specialists in the field as a general reference. The guidelines are based on the experience gained within the InterPACIFIC project and on the expertise of the participants in acquisition and analysis of surface wave data.
The importance of MnOOH dispersion and interfacial contact between MnOOH nanowires and carbon black for the cathode of metal-air batteries has been clearly demonstrated from the textural, voltammetric, and electrochemical impedance spectroscopic (EIS) analyses. In comparing with the physically mixed composite, the MnOOH nanowires/XC-72 composite co-precipitated by hydrothermal synthesis shows much better performances of oxygen reduction in 1M KOH, which is attributed to the higher active surface area resulting from the better dispersion of MnOOH and the smooth electron pathways resulting from the higher interfacial contact surface area between oxide and carbon nanoparticles within the hydrothermally co-precipitated MnOOH/XC-72 nanocomposites. The absence of diffusion responses in the low-frequency range of EIS spectra reveals no/minor oxygen-diffusion effect at low overpotentials (E ≥−0.3V vs. Ag/AgCl).
The ever increasing penetration of renewable energy systems (RESs) in today deregulated intelligent power grids, necessitates the use of electrical storage systems. Energy storage systems (ESSs) are helpful to make balance between generation and demand improving the performance of whole power grid. In collaboration with RESs, energy storage devices can be integrated into the power networks to bring ancillary service for the power system and hence enable an increased penetration of distributed generation (DG) units. This paper presents different applications of electrical energy storage technologies in power systems emphasizing on the collaboration of such entities with RESs. The role of ESSs in intelligent micropower grids is also discussed where the stochastic nature of renewable energy sources may affect the power quality. Particular attention is paid to flywheel storage, electrochemical storage, pumped hydroelectric storage, and compressed air storage and their operating principle are discussed as well. The application of each type in the area of power system is investigated and compared to others.
The spinel LiMn2O4 was modified with TiO2-B nanobelts to improve its specific capacity and cycling performance. TiO2-B/LiMn2O4 composites were fabricated by a facile liquid phase mixing method. The morphology and structure of the samples were characterized by means of X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The results show that TiO2-B nanobelts are uniformly distributed in LiMn2O4 particle. Compared with bare LiMn2O4, TiO2-B/LiMn2O4 composite cathode material shows enhanced specific capacity of 129mAhg−1 and improved cycling stability. After 50 cycles, the 0, 0.5, 1.0, 2.0 and 3.0wt.% TiO2-B nanobelts modified LiMn2O4 exhibited the capacity retention of 86.1, 92.6, 93.7, 94.5 and 92.8%, respectively. The improvement of the electrochemical performance is attributed to suppression of Mn2+ dissolution, higher structural stability of the composite and rapid Li+ diffusion resulting from the open lattice channels and unique one-dimensional structure of TiO2-B nanobelts.
A battery separator is a porous membrane that separates the positive and negative electrodes while maintaining a good ionic flow. A method of making separators made of polyetherimide through a phase-inversion process is described. The membranes prepared by this process showed uniform porous structures as indicated by the scanning electron microscope (SEM) images. The membranes also exhibited satisfactory tensile properties and enabled high ionic conductance when saturated with a liquid electrolyte for lithium-ion batteries. Coin cells with this type of separators were prepared. Stable cycling performance and improved rate capabilities were observed when tested at room temperature.
The current doctrine of informed consent for clinical care has been developed in cultures characterized by low-context communication and monitoring-style coping. There are scarce empirical data on patients’ norm perception of information disclosure in other cultures.
A nonlinear equivalent circuit model is developed for lithium ion cells using variable resistors that are functions of the cell temperature. The voltage and thermal characteristics of a commercial cell with a LiFePO4 positive and graphite negative electrode are modeled using a lumped energy balance coupled with the equivalent circuit representation. The cell voltage and temperature during full depth charge–discharge operations can be represented accurately by a one pair RC model. The model is able to represent cell voltage and temperature over a wide range of powers with a global set of parameters. The parameters established, model predictions of the heat generation rates under various conditions are examined. Due to the unique discharge behavior of LiFePO4 positive electrode, the rate of heat generation is constant over most of the state of charge (SOC) window and steeply rises near the end of discharge. A higher heat transfer coefficient of the cooling medium, in addition to lowering the operating voltage, results in higher heat generation. Thus battery cooling systems should be designed to operate at an optimal rate of heat removal considering the operating efficiency, in addition to battery life.