batterydata/paper-abstracts huggingface dataset:
Remote patient monitoring (RPM) holds great promise for reducing the burden of congestive heart failure (CHF). Improved sensor technology and effective predictive algorithms can anticipate sudden decompensation events. Enhanced telemonitoring systems would promote patient independence and facilitate communication between patients and their physicians. We report the development of a novel hand-held device, called Blue Box, capable of collecting and wirelessly transmitting key cardiac parameters derived from three integrated biosensors: 2 lead electrocardiogram (ECG), photoplethysmography and bioelectrical impedance (bioimpedance). Blue Box measurements include time intervals between consecutive ECG R-waves (RR interval), time duration of the ECG complex formed by the Q, R and S waves (QRS duration), bioimpedance, heart rate and systolic time intervals. In this study, we recruited 24 healthy subjects to collect several parameters measured by Blue Box and assess their value in correlating with cardiac output measured with Echo-Doppler. Linear correlation between the heart rate measured with Blue Box and cardiac output from Echo-Doppler had a group average correlation coefficient of 0.80. We found that systolic time intervals did not improve the model significantly. However, STIs did inversely correlate with increasing workloads.
In 1960, over 60 % of bachelor degrees were awarded to men. However, the rate of women’s college completion has steadily risen and, by 2004, women received nearly 60 % of bachelor degrees. Drawing on the theoretical contributions of James Coleman, this paper examines the ability of social capital to explain observed differences in college enrollment. We use data from the 2002 Educational Longitudinal Study to examine social capital and quantify the strength of its relationship to college enrollment. We establish that men are currently disadvantaged with respect to key social capital variables, consistent with other published studies. We use logistic regression modeling to show that, after controlling for relevant variables, social capital is indeed related to college enrollment, and we provide an estimate of the degree to which the gender difference in enrollment can be explained by differences in social capital. In particular, we show that social capital reduces the odds ratio of women enrolling in college compared to men from 1.63 to 1.41. We show also that when grade point average is added to social capital, the odds ratio reduces from 1.41 to 1.23, showing that a substantial amount, but not all, of the gender disparity in college enrollment can be explained by these factors. In our final model, we test whether gender significantly interacts with social capital on college enrollment, a finding that would be consistent with women receiving differential returns to social capital. We find that women do not receive differential returns to social capital in comparison with men.
Selenium (Se) is an essential nutrient required for maintaining brain health across lifespan, and adequate nutritional Se status has been positively associated with sustained cognitive performance in older adults. However, critical physiological sex differences in Se metabolism have not been specifically assessed in human studies. Therefore, we aimed to investigate sex differences in the association between Se concentration in whole blood and cognitive performance in US older adults.
Fuel cells are devices that convert chemical energy in hydrogen enriched fuels into electricity electrochemically. Micro-tubular solid oxide fuel cells (MT-SOFCs), the type pioneered by K. Kendall in the early 1990s, are a variety of SOFCs that are on the scale of millimetres compared to their much larger SOFC relatives that are typically on the scale of tens of centimetres. The main advantage of the MT-SOFC, over its larger predecessor, is that it is smaller in size and is more suitable for rapid start up. This may allow the SOFC to be used in devices such as auxiliary power units, automotive power supplies, mobile electricity generators and battery re-chargers. The following paper is Part I of a two part series. Part I will introduce the reader to the MT-SOFC stack and its applications, indicating who is researching what in this field and also specifically investigate the design issues related to multi-cell reactor systems called stacks. Part II will review in detail the combinations of materials and methods used to produce the electrodes and electrolytes of MT-SOFC's. Also the role of modelling and validation techniques used in the design and improvement of the electrodes and electrolytes will be investigated. A broad range of scientific and engineering disciplines are involved in a stack design. Scientific and engineering content has been discussed in the areas of thermal-self-sustainability and efficiency, sealing technologies, manifold design, electrical connections and cell performance optimisation.
ABSTRACT The stability of 1-methyl-1-propylpyrrolidinium bis(trifluoromethanesulfonyl) imide (PYR13TFSI), 1-methyl-1-propylpyrrolidinium bis(fluorosulfonyl) imide (PYR13FSI), 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl) imide (PYR14TFSI) and 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl) imide (EMIM TFSI) ionic liquids (ILs) at different temperatures (room temperature and 95°C) was investigated by ion chromatography (IC) hyphenated to a mass spectrometer. The degradation of the cations can be summarized in the following way: The side chain of the main molecule cleaves and reacts subsequently with the main cation molecule to new decomposition products. In addition, the results show that at elevated temperatures more decomposition products are formed. The influence of Li+ cation based electrolyte salts, lithium hexafluorophosphate (LiPF6), lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) and lithium perchlorate (LiClO4), on the decomposition of the ionic liquids was analyzed over a long term stability study at room temperature and 60°C. It was found out that in the mixtures of ILs and electrolyte salt, the same decomposition products were formed like in the pure ILs at the same temperature. Accordingly, there is no influence of the electrolyte salts on the decomposition behavior of the IL cation. The influence of the counter anion on the decomposition of PYR13 + was analyzed as well. It was observed that different decomposition products were detected for PYR13TFSI and PYR13FSI.
Low-grade heat from sources below 100 ∘C offers a vast quantity of energy. The ability to extract this energy, however, is limited with existing technologies as they are not well-suited to harvest energy from sources with variable heat output or with a small temperature difference between the source and the environment. Here, we present a process for extracting energy from low-grade heat sources utilizing hydrophobic, nanoporous membranes that trap air within their pores when submerged in a liquid. By driving a thermo-osmotic vapour flux across the membrane from a hot reservoir to a pressurized cold reservoir, heat energy can be converted to mechanical work. We demonstrate operation of air-trapping membranes under hydraulic pressures up to 13 bar, show that power densities as high as 3.53 ± 0.29 W m−2 are achievable with a 60 ∘C heat source and a 20 ∘C heat sink, and estimate the efficiency of a full-scale system. The results demonstrate a promising process to harvest energy from low-temperature differences (<40 ∘C) and fluctuating heat sources.
Transition-metal sulfides have received increasing attention as electrode materials for high-performance Lithium-ion Batteries (LIBs). However, most of them are suffering from poor cycling stability and rate capability. Herein we report a new and facile strategy for synthesizing FeS2/nitrogen-doped graphene (FeS2/N-G) composite which shows improved electrochemical performance as an anode material for LIBs. The as-prepared FeS2/N-G (1:2, molar ratio) composite exhibits reversible discharge and charge capacities of 979 and 920mAh g−1, respectively, with good cycling performance and rate capability. SEM and TEM results show that the cubic FeS2 are uniformly distributed on the surface of the nitrogen-doped graphene nanosheets (N-GNS) in the composite. The superior electrochemical performance of FeS2/N-G composite as LIBs anode is attributed to their robust composite structure and the synergistic effects between cubic FeS2 and N-GNS. This synthesis approach could open up new opportunities in the design and fabrication of energy storage devices.
A layered Li–Ni–Ti oxide including divalent nickel and tetravalent titanium with a Ni2+/Ti4+ ratio of almost 1 was obtained by the ion exchange of a layered Na–Ni–Ti oxide precursor. By using various nickel and titanium sources, we obtained samples with different specific surface areas. Sample with larger specific surface areas had larger first charge capacities. However, a large irreversible capacity and poor cyclability were observed for all the samples when measured at room temperature. However, when we set the ambient temperature at 55°C, the cyclability improved. This suggests that the lithium diffusion rate strongly affects the electrode performance of layered Li–Ni–Ti oxide. We also employed a first-principles calculation of the LiNi0.5Ti0.5O2/Ni0.5Ti0.5O2 system to evaluate its structural and voltage characteristics.
Ageing water infrastructure is one of the major problems faced by water utilities around the world at present, and urgent solutions are required in order to maintain the integrity of the water supply network. In order to use pipe failure prediction models, accurate information about loads acting on these pipes is important. Water pressure (steady-state and transient) is one of the key loads that needs to be estimated accurately in order to improve the predictability of pipe failures. This paper reports the results of a pressure monitoring program, which was conducted to measure pressure fluctuations during events of pressure transients in three selected network sections in Australia. Pressure measurements were conducted in network sections which were considered as susceptible to pressure transients. Potential sources of pressure transients were identified, and high speed data loggers were installed in selected locations of each network to measure and monitor pressure transients. Pressure transients that were generated during normal operation were measured for a period of one month in each selected section. Further, some of the pressure transients were manually made to simulate the different pressures due to pump start-ups within the network. Pressure fluctuations that could potentially lead to pipe failures were measured at many locations during the monitoring program (several selected failures were reported in this article). Therefore, the effect of pressure transients must not be ignored in pipe failure prediction.
In this manuscript we report about the realization and testing of a high-voltage electrochemical double layer capacitor (EDLC) prototype (IES prototype), which has been assembled using innovative electrode and electrolyte components. The IES prototype displays a nominal capacitance of 4 F, a maximum voltage of 3.2 V and its maximal energy and power are in the order of 37 Wh kg−1 and 65 kW kg−1, respectively. Furthermore, it also displays good cycling stability, high capacitance retention after 80 h float test and acceptable self-discharge. Taking into account substantial improvements of the cell design and assembly procedure, the performance of the IES prototype indicates that the components utilized in this device might be suitable alternatives to the state-of-the-art materials used in high energy EDLCs.
Idiopathic intracranial hypertension (IIH) is a disorder of unidentified etiology characterized by raised intracranial pressure (ICP) without clinical, laboratory, or radiological evidence of intracranial pathology. The aim of this work was to determine the visual outcome in newly diagnosed IIH patients.
Fe2O3-filled carbon nanotube material was prepared by filling carbon nanotubes (CNTs) with iron nitrate and then heating in an argon flow. The morphology and structure of this material were investigated by transmission electron microscopy (TEM), scanning electron microscopy (SEM) coupled with X-ray energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) measurements. The morphology, particle size and amount of iron oxide that filled CNTs depended on the amount of iron nitrate precursor. When Fe:C=1:17wt%, almost all of the iron oxide particles resided inside CNTs and their particle size was smaller than that at Fe:C=1:8wt%. The electrochemical properties of this material were investigated using cyclic voltammetry (CV) and galvanostatic cycling.
Despite robust evidence of neurocognitive dysfunction in psychotic patients, the degree of similarity in cognitive architecture across psychotic disorders and among their respective first-degree relatives is not well delineated. The present study examined the latent factor structure of the Brief Assessment of Cognition in Schizophrenia (BACS) neuropsychological battery. Analyses were conducted on 783 psychosis spectrum probands (schizophrenia, schizoaffective, psychotic bipolar), 887 of their first-degree relatives, and 396 non-psychiatric controls from the Bipolar-Schizophrenia Network on Intermediate Phenotypes (B-SNIP) consortium. Exploratory factor analysis of BACS subtest scores indicated a single-factor solution that was similar across all groups and provided the best overall data fit in confirmatory analyses. Correlations between the standard BACS composite score and the sum of subscale scores weighted by their loadings on this unitary factor were very high in all groups (r≥.99). Thus, the BACS assesses a similar unitary cognitive construct in probands with different psychotic disorders, in their first-degree relatives, and in healthy controls, and this factor is well measured by the test's standard composite score.
The appearance of new alternative fuels for urban fleets has motivated the developing of a new methodology to plan the fuel supply infrastructure required to cover the new demand. The fuel cell hydrogen vehicle has been identified as the alternative with the greatest possibilities in the medium to long term to replace conventional vehicles. In order to make easier and cheaper the implantation of the new supply infrastructures, it is necessary to develop analyses which allow us to determine the design, size and so on. This research shows an analysis and a tool which allow us to approximate the design and size of a new hydrogen distribution infrastructure. To calculate the parameters needed to introduce in the infrastructure, the number of vehicles, the hydrogen consumption of these vehicles and the technology utilized to supply the hydrogen are taken into account. One of the most important considerations to determine these parameters is the hydrogen delivery system that is going to be used for the hydrogen fuelling stations. With the objective of validate this tool, a case study has been defined. This case is based on the implementation of a tram line powered by hydrogen. It is also defined, the requirement regarding to the necessities and the hydrogen supply infrastructure. The most important variables are the cost, demand, location of facilities and security of supply. Due to the big amount of parameters and variables this tool could be a good decision support system to help to delimit the size, cost, design…of this particular kind of infrastructure.
At the present time, trains in heavy haul operations are typically hauled by several diesel-electric locomotives coupled in a multiple unit. This paper studies the case of a typical consist of three Co–Co diesel-electric locomotives, and considers replacing one unit with an alternative version, with the same design parameters, except that the diesel-electric plant is replaced with flywheel energy storage equipment. The intelligent traction and energy control system installed in this unit is integrated into the multiple-unit control to allow redistribution of the power between all units. In order to verify the proposed design, a three-stage investigation has been performed as described in this paper. The initial stage studies a possible configuration of the flywheel energy storage system by detailed modelling of the proposed intelligent traction and energy control system. The second stage includes the investigation and estimation of possible energy flows using a longitudinal train dynamics simulation. The final stage compares the conventional and the proposed locomotive configurations considering two parameters: fuel efficiency and emissions reduction.
The energy transition has been alternatively characterized as a gradual transformation, a technological disruption or a systemic change. This Perspective argues that the transition is entering a new phase where it has unique characteristics, and research and policy can no longer treat it as a gradual transformation or mere disruption.
Poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP))-based gel polymer electrolyte (GPE) membranes are prepared by phase inversion method using urea as pore-forming agent and dimethylformamide as solvent, respectively, and the desired polymer electrolytes are obtained after being immersed the as-prepared polymer electrolyte membranes into liquid electrolytes for 1 h. Physicochemical properties of the GPEs are investigated by SEM, XRD, FT-IR, TG-DSC, EIS and LSV. When the weight ratio of urea to P(VDF-HFP) is up to 0.6:4, the results show that the polymer electrolyte membrane presents the most uniform surface with abundant interconnected micro-pores and excellent thermal stability, in which the ionic conductivity at room temperature can reach 2.671 mS cm−1 and the reciprocal temperature dependence of ionic conductivity follows Arrhenius relationship. The interfacial resistance of the Li/GPE/Li simulated cell with 0.6 g urea can rapidly increase to a steady value about 650 Ω cm−1 from the initial value about 475 Ω cm−1 during 15 days storage at 30 °C. The polymer electrolyte with 0.6 g urea can be stable at 5.3 V (vs Li/Li+) at room temperature and the assembled Li/GPE/LiCoO2 coin cell can also show good rate and cycle performance.
In order to show the best composition which gives water-resistance to Li-rich solid-solution layered oxide cathode materials for a water-based cathode preparation process, the water resistance of LLOs composed of xLi2MnO3―yLiNi1/2Mn1/2O2—(1-x-y)LiNi1/3Co1/3Mn1/3O2 was examined by comparing the charge/discharge cycle results obtained with the cathodes prepared with organic solvent-based and water-based binders. The composition area where the percentage content of Li2MnO3 is 70–75% was found to show both high charge/discharge capability and water resistance. In addition, by analyzing why this composition of Li2MnO3 exhibits high water resistance, it has become apparent that the oxidation states of Mn ions and existence of Co ions on the surface of LLOs are the key factors in inhibiting the dissolution of Mn and Ni ions from the LLO surfaces, and finally leading to their high water resistance.
FeS2 nanocrystals are successfully prepared in the carbon capsules of pre-prepared hierarchical porous carbon (HPC). The absorbed Fe ions in HPC are first calcined into Fe3O4 and then react with sulfur under vacuum conditions to synthesize FeS2. HPC, with micro-porous shells and inter-connected macro-porous carbon capsules, shows highly ionic/electrical conductivities and efficient buffer effect on the volume change of FeS2. FeS2@HPC exhibits a high specific capacity of 907 mAh·g−1 in the first cycle and remains 720 mAh·g−1 after 100 cycles at the rate of 1 C.
For redox flow batteries (RFBs), it is very important to flow electrolyte uniformly in the porous electrodes. Integrated segment methods have been studied to analyze in situ flow behavior in a cell of RFBs. However, the resolution of the contour plots obtained with these methods is very low at present since only several dozen segments can be used. Therefore, to visualize the flow patterns of electrolyte in the electrode, a model cell which consists of a single porous electrode and two clamping plates was constructed and tested. The experiments were performed by feeding hot working liquid to the cell after cooling the cell without discharging cooling water, and measuring the temperatures in the electrode by thermocouples and the temperature distribution of the outer surface of the clamping plate by infrared thermography (IRT). Time variations of temperatures of the outer surface of the clamping plate show similar trends with one in the electrode. Further, the temperature distributions measured by IRT were considerably changed when the inlet and outlet conditions were changed. This shows that the flow patterns of electrolyte in the electrode can be visualized by measuring the outer surface temperature distribution of the clamping plate by IRT.
A numerical simulation of an enzyme-catalyzed oxygen cathode is presented and applied to the analysis of transport limitations in operating electrodes, with the goal of predicting the limits of obtainable cathode current density. Based on macrohomogeneous and thin-film theories, and accounting for dual-substrate enzyme kinetics, the one-dimensional model predicts a maximum current density of about 9.2mAcm−2 at 0.6V (SHE) for a 300μm thick electrode operating oxygen-saturated pH 5 buffer at 37°C and relying on diffusion of dissolved oxygen alone. However, by introducing gas-phase diffusive transport, or alternatively a convective, flow-through approach, the model predicts that electrodes of identical thickness may provide current densities up to 60mAcm−2 in air and exceeding 100mAcm−2 in pure O2. Such performance would move enzyme electrodes closer to practical implementation in implantable power devices and other low-temperature fuel cells such as direct methanol fuel cells.
Phytoplankton deposition onto sediments affects trophic structures, sedimentary nutrient fluxes, and dissolved oxygen concentrations in coastal ecosystems. Deposition can occur as distinct events that are highly variable over space and time, necessitating detection methods that have similarly high resolution. We present an assessment of a novel rapid detection method that combines water-column and benthic fluorometry with surficial sediment sampling to identify phytoplankton deposition, as implemented in a 2-year study of a Florida estuary (24 monthly collections at 14 locations). Maximum water-column chlorophyll concentration, average benthic chlorophyll fluorescence, and the proportion of centric vs. pennate diatoms at the sediment–water interface were each fitted to sine functions to represent phytoplankton bloom cycles. The phase offsets among the three fitted sine functions were varied to maximize fit to the 336 observations. The fitted cycles were divided into four classes that separate dominance by benthic microalgae from early, late, and post-phytoplankton depositional states. Best-fitting cycles for the proportion of centric diatoms were consistently offset from water-column chlorophyll cycles, indicating peak deposition occurred after peak phytoplankton blooms. Phytoplankton deposition dominated the upstream region of the studied estuary and was associated with reduced dissolved oxygen concentrations. Benthic algae dominated in downstream regions, particularly during low freshwater flow conditions when light absorption by colored dissolved organic matter was low. This approach produced repeatable and consistent patterns that agreed with expected relationships and was practical for sampling with high spatial and temporal resolution.