batterydata/paper-abstracts huggingface dataset:
Two different orientations of an enzymatic biofuel cell (EBFC) chip, involving highly dense and three-dimensional cylindrical micro-electrodes arrays, have been studied with the finite element method. Mass transport phenomenon around the micro-electrodes of an EBFC chip inside a blood artery has been simulated. The stability of the chip to its position and blood flow pattern surrounding it are also investigated. The comparison between horizontal position (HP) and vertical position (VP) reveals that the chip can be more stable in VP rather than in HP. In VP, the diffusive flux and convective flux values are bigger compared to HP, but both these fluxes are non-uniform around all electrodes in both the positions. In addition to that in case of HP, the electrodes located at different positions on a chip receive different amount of glucose. A novel designed chip with holes through the substrate has enhanced the diffusive and convective flux in the HP of a chip and also all micro-electrodes on a chip receives similar amount of glucose uniformly throughout from the top to the bottom.
For six decades the civil society and democracy thesis has generated great interest. How dependably can the relationship of associational membership to democracy be demonstrated empirically? Using a data set derived from 37 national surveys in eight countries, this article finds that the questions used commonly to measure civil society are unreliable or simply measure different things, thereby imperiling the assumed universal and robust relationship between civil society membership and democracy. By emphasizing problems related to question wording, this article intends to prompt the profession to improve and standardize measurement of membership in civil society organizations to determine whether this tantalizing hypothesis has the powerful predictive value ascribed to it by the field of comparative politics.
Integrated design of the structure topology and involved component layout is a challenging design issue when compared with traditional topology optimization. In this paper, we propose an implicit modeling approach that works completely on an Eulerian finite element mesh throughout the whole optimization process. To this aim, implicit level-set functions and R-functions are employed to describe geometrical shapes of movable components. In particular, a modified arctan function is adopted to depict the material discontinuity along the interface between the structure domain and each component domain. They are then used for material interpolations and analytical sensitivity analysis w.r.t. both pseudo-density design variables and location design variables related to the host structure and components, respectively. Based on a variety of numerical tests, it is demonstrated that considered design problems with movable components can easily be solved by extending the SIMP material model based topology optimization approach using an Eulerian mesh and the gradient-based optimization algorithm.
Clustered DNA damages—multiple oxidized bases, abasic sites, or strand breaks within a few helical turns—are potentially mutagenic and lethal alterations induced by ionizing radiation. Endogenous clusters are found at low frequencies in unirradiated normal human cells and tissues. Radiation-sensitive hematopoietic cells with low glycosylase levels (TK6 and WI-L2-NS) accumulate oxidized base clusters but not abasic clusters, indicating that cellular repair genotype affects endogenous cluster levels. We asked whether other factors, i.e., in the cellular microenvironment, affect endogenous cluster levels and composition in hematopoietic cells. TK6 and WI-L2-NS cells were grown in standard medium (RPMI 1640) alone or supplemented with folate and/or selenium; oxidized base cluster levels were highest in RPMI 1640 and reduced in selenium-supplemented medium. Abasic clusters were low under all conditions. In primary hematopoietic stem and progenitor cells from four non-tobacco-using donors, cluster levels were low. However, in cells from tobacco users, we observed high oxidized base clusters and also abasic clusters, previously observed only in irradiated cells. Protein levels and activity of the abasic endonuclease Ape1 were similar in the tobacco users and nonusers. These data suggest that in highly damaging environments, even normal DNA repair capacity can be overwhelmed, leaving highly repair-resistant clustered damages.
A need for environmentally acceptable alternative antifouling (AF) biocides has arisen through restrictions in the use of many common biocides in the European Union through the Biocidal Product Regulation (Regulation EU No. 528/2012). Three such alternatives are triphenylborane pyridine (TPBP), tralopyril and capsaicin. This study aims at extending the available information on the toxicity of these three emerging AF biocides to key marine invertebrates. Here we investigate the toxicity of tralopyril and capsaicin to the early life stages of the mussel Mytilus galloprovincialis and the sea urchin Paracentrotus lividus and also of tralopyril, capsaicin and TPBP to the early life stages of the copepod Tisbe battagliai. The EC50 that causes abnormal development of mussel’s D-veliger larvae and impairs the growth of sea urchin pluteus larvae are respectively 3.1 and 3.0 μg/L for tralopyril and 3,868 and 5,248 μg/L for capsaicin. Regarding the copepod T. battagliai, the LC50 was 0.9 μg/L for tralopyril, 1,252 μg/L for capsaicin and 14 μg/L for TPBP. The results obtained for the three substances are compared to a reference AF biocide, tributyltin (TBT), and their ecological risk evaluated. These compounds pose a lower environmental risk than TBT but still, our results suggest that tralopyril and TPBP may represent a considerable threat to the ecosystems.
This paper reports a modeling approach for the scale-up of a lithium-ion polymer battery (LIPB). A comparison of the experimental discharge curves with the modeling results confirmed that the parameters used to model a small-scale LIPB could be applied to a large-scale LIPB provided the materials and composition of the electrodes as well as the processes for manufacturing the batteries were the same. The potential and current-density distribution on the electrodes of a LIPB were predicted as a function of the discharge time using the finite element method. In addition, the temperature distributions of the LIPB were calculated based on the modeling results of the potential and current-density distributions. The temperature distributions from the model were in good agreement with the experimental measurements.
Children in third and fourth grades suffering from developmental dyscalculia (DD) and typically developing children were asked to compare numbers to a standard. In two separate blocks, they were asked to compare a number between 1 and 9 to 5, or a two-digit number between 10 and 99 to 55. In the single-digit comparisons, DD children were comparable to the control group in reaction time but showed a difference in error rates. In the two-digit number comparisons, DD children presented a larger distance effect than the controls. In addition, they were more influenced by the problem size than controls were. Assuming an analog representation of quantities, this suggests that quantities are less differentiated in those with DD than in typically developing children.
The efficient generation of spin current in superconductors is an open problem in superconducting spintronics. Here, the authors predict that the spin supercurrent generation efficiency in two-dimensional non centrosymmetric superconductors with Rashba spin-orbit interaction can be greatly enhanced by tuning the chemical potential.
A unique polyhedral-shaped hollow porous carbon with high specific capacity, high rate capability, and excellent cycling stability as both lithium-ion and sodium-ion battery anode material has been prepared from a Ni-ion exchanged resin at significantly low temperature (500 °C). Low temperature synthesis is achieved by room temperature exposure of Ni-ion exchanged resin to hydrazine hydrate, which reduces Ni2+ to active Ni metal catalyst prior to calcination. As an anode material for lithium-ion and sodium-ion batteries, the material delivers large reversible capacity and long-term cycle stability even at high current densities. As a lithium-ion battery anode material, it delivers 620 and 225 mAh g−1 at 1 and 20 A g−1, respectively, and 380 mAh g−1 after 3000 cycles at 5 A g−1. As a sodium-ion battery anode material, it delivers 227 and 133 mAh g−1 at 1 and 20 A g−1, respectively, and 144 mAh g−1 after 9000 cycles at 5 A g−1. The high rate capability and cycling stability arises from an appropriate balance of graphitization, nanoporosity, and thin-walled interconnected hollow structure. Overall, the performance of the material is exceptional for porous carbon, especially considering its low temperature bulk synthesis method.
This study systematically investigates the effects of structural aspects on the performance of a passive air-breathing direct methanol fuel cell (DMFC). Three factors are selected in this study: (1) two different open ratios of the current collector; (2) two different assembly methods of the diffusion layer; and (3) three membrane types with different thicknesses. The interrelations and interactions among these factors have been taken into account. The results demonstrate that these structural factors combine to significantly affect the cell performance of DMFCs. The higher open ratio not only provides a larger area for mass transfer passage and facilitates removal of the products, but also promotes higher methanol crossover. The hot-pressed diffusion layer (DL) can mitigate methanol permeation while the non-bonded variant is able to enhance product removal. The increase of membrane thickness helps obtain a lower methanol crossover rate and higher methanol utilisation efficiency, but also depresses cell performance under certain conditions. In this research, the maximum power density of 10.7mWcm−2 is obtained by selecting the current collector with a lower open ratio, the non-bonded DL, and the Nafion 117 membrane. The effect of methanol concentration on the performance of DMFCs is also explored.
The aim of this study was to evaluate the effect of obstructive sleep apnea syndrome on the cognitive performance of young and middle-aged patients. Patients were divided into two groups, one consisting of 30 patients less than 50 years of age and the other consisting of 28 patients 50 years and over. Normal subjects were similarly divided into two groups, composed of 17 younger and 24 older controls. Patients and controls were examined with all-night polysomnography and subsequently underwent cognitive testing via attention–alertness tests. Comparing young to middle-aged patients, there were statistically significant differences in cognitive performance, especially in attention tests. Younger patients’ cognitive performance was similar to their age-matched controls, while middle-aged patients showed cognitive decline in comparison with their age-matched controls. Although we studied only two age groups using 50 years of age as a cut-off, we could demonstrate that cognitive deterioration of untreated sleep apnea patients is age dependent, and several factors may contribute to this effect including brain hypoxia, sleep fragmentation, or comorbidities. Aging patients with sleep apnea demonstrate cognitive decline, while younger patients with the same disease severity are (somehow) able to compensate for this effect.
Stacked-cup type multiwall carbon nanotubes (MWCNTs) were synthesized by floating catalyst chemical vapor deposition methods. The materials were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). Electrochemical measurements showed that the stacked-cup-type MWCNTs as lithium-ion battery anode materials delivered a stable capacity of ~310 mAh g−1 at a rate of C/2 to 300 cycles. Furthermore, the materials were very stable and the coulombic efficiency exceeded 99.9 % over more than 300 cycles. Stable materials structure and the solid electrolyte interphase films were the main reasons for the durable cycling behavior, as confirmed by ex situ TEM and Raman spectroscopy, as well as electrochemical impedance spectroscopy (EIS). The results indicated that the stacked-cup-type MWCNTs produced in this work are candidate materials for lithium-ion battery anodes.
This paper presents a wireless and passive micro pressure system based on the LC mutual inductance detection mechanism for gastrointestinal (GI) pressure monitoring. The micro pressure system is composed of a sensor capsule (a pressure sensitive micro capacitive sensor in series with an induction coil to form an LC tank) and a detection unit (a detection coil connected with a network analyzer). The pressure variations under measurement lead to changes in the capacitance of the pressure sensor and therefore a shift in the LC tank resonant frequency, quantified by the impedance measurement of the detection coil. The pressure sensor was fabricated using microfabrication processes with key parameters optimized. The in vitro characterization of the micro pressure system recorded a sensitivity of 0.2491 kHz/kPa (−10 kPa to 30 kPa). One-month rabbit stomach pressure monitoring was conducted based on the developed micro pressure system as a confirmation of device long term in vivo stability. Furthermore, rabbit stomach pressure variations before and after food feeding was recorded and compared where three distinctive contraction patterns (random contraction with low amplitude, irregular strong contractions and regular contraction in a cyclic manner) following food feeding were located. Compared to previous reported GI pressure sensors, this LC tank is featured with simple device structure without batteries and electrical components for energy transfer. Both in vitro and in vivo characterization confirm the functionality of the system, which may enable the gastrointestinal motility study in the near future.
Adaptive computer games offer an attractive method for numeracy training in young children. However, the evidence for transfer of learning to standard measures of numerical and arithmetic skills is scarce. We carried out a randomized controlled trial on a sample of preschool children of middle socio-economic status to evaluate the effectiveness of the freeware videogame “The Number Race” (Wilson et al., 2006). Children were randomly assigned to the training group or to the control group performing an alternative computer-based activity matched for duration and setting. The groups were matched for age, gender, and IQ. Training yielded large improvements in mental calculation and spatial mapping of numbers, as well as smaller improvements in the semantic representation of numbers. Our findings complement previous studies that showed beneficial effects for disadvantaged children, thereby suggesting that “The Number Race” is a valuable tool for fostering mathematical learning in the general population of young children.
Guiding inquiry learning has been shown to increase knowledge gains. Yet, little is known about the effect of guidance on attitudes and behaviours, its interaction with student attributes, and transfer of impact once guidance is removed. We address these gaps in the context of an interactive Physics simulation on electric circuits (https://phet.colorado.edu/en/simulation/circuit-construction-kit-dc). 49 students in the Non-Directive condition received a set of goals to focus their inquiry, in addition to implicit support built into the simulation. 48 students in the Directive condition received, in addition to these, also detailed directions and prompts. Log-file analysis found that directive support led to more formal testing and less exploration. Clustering identified two groups of learners: one with higher incoming knowledge (Higher Knowledge), the other with higher incoming perceptions of competence and control (Higher PoCC). Working with the simulation improved knowledge and attitudes across cluster groups, so that prior differences all but disappeared. With regard to guidance, adding directive support improved knowledge gains for the Higher Knowledge group, yet suppressed their attitudinal growth. The same support had no effect on knowledge gains for the Higher PoCC group, yet it boosted their attitudinal growth. A transfer activity, where directive support was no longer available, found that impact on attitudes carried forward, yet impacts on behaviours and knowledge were short-lived. Overall, the study highlights the complex interaction between guidance and student attributes. For some, supporting short-term knowledge gains may inadvertenly lead to longer term negative impact on attitudes towards inquiry.
Native tree plantations have been proposed for the restoration of wildlife habitat in human-altered riparian corridors of western U.S. rivers. Evapotranspiration (ET) by riparian vegetation is an important, but poorly quantified, term in river water budgets. Native tree restoration plots will potentially increase ET. We used sap flow sensors and satellite imagery to estimate ET in a 8ha, cottonwood (Populus fremontii) restoration plot on the Lower Colorado River. Biometric methods were used to scale leaf area to whole trees and stands of trees. This technique was used to validate our estimates of ET obtained by scaling from branch level to stand (or plot) level measurements of ET. Cottonwood trees used 6–10mmday−1 of water during the peak of the growing season as determined by sap flow sensors, and annual rates scaled by time-series MODIS satellite imagery were approximately 1.2myear−1. Although irrigation was not quantified, the field had been flood irrigated at 2 week intervals during the 3 years prior to the study, receiving approximately 2myear−1 of water. A frequency-domain electromagnetic induction survey of soil moisture content showed that the field was saturated (26–28% gravimetric water content) at the 90–150cm soil depth under the field. Trees were apparently rooted into the saturated soil, and considerable saving of water could potentially be achieved by modifying the irrigation regime to take into account that cottonwoods are phreatophytes. The study showed that cottonwood ET can be monitored by remote sensing methods calibrated with ground measurements with an accuracy or uncertainty of 20–30% in western riparian corridors.
The effect of the electrolyte on the electrochemical utilization of manganese dioxide as active material for electrochemical capacitor was studied by cyclic voltammetry and electrochemical impedance spectroscopy. MnO2-based composite electrodes were characterized in salt-in-water (0.65 M K2SO4, 5 M LiNO3, 0.5 M LiNO3 and 0.5 M Ca(NO3)2) and water-in-salt (5 M LiTFSI (lithium bis-trifluoromethanesulfonimide)) electrolytes. Firstly, no effect of the cation valence on the specific capacitance was observed as similar values were measured in 0.5 M LiNO3 and 0.5 M Ca(NO3)2 aqueous solutions at both low and high scan rate, when a MnO2-based composite electrode was cycled in the pseudocapacitive potential region. Secondly, it was found that in 5 M LiTFSI, a MnO2 electrode is characterized by an extended potential stability window of about 1.4 V and exhibits a high specific capacitance of 239 F g−1 per active material mass at a scan rate of 2 mV s−1. However due to the low ionic conductivity of this solution, the rate capability is limited at high scan rate.
Electrospinning is attracting close interest as a versatile fabrication method for one dimensional mesostructured organic, inorganic and hybrid nanomaterials of controlled dimensions prepared as random or oriented continuous nanofibres with possibilities of ordered internal morphologies such as core–sheath, hollow or porous fibre, or even multichannelled microtube arrangements. The dimensionality, directionality and compositional flexibility of electrospun nanofibres and mats are increasingly being investigated for the targeted development of electrode and electrolyte materials, where the specific properties associated with nanoscale features such as high surface area and aspect ratios, low density and high pore volume allow performance improvements in energy conversion and storage devices. We present here a review on the application of electrospinning for the design and fabrication of architectured, nanofibrous materials for dye sensitised solar cells, fuel cells, lithium ion batteries and supercapacitors, with particular emphasis on improved energy and power density imparted by performance improvement to, inter alia, ionic conductivity, cyclability, reversibility, interfacial resistance and electrochemical stability, as well as mechanical strength, of electrospun electrode and electrolyte components.
All-metal self-supported cathodes, especially porous noble metals, are attractive alternatives for settling the issue of carbon- and binder-decomposition in Li–O2 batteries. However, the high cost of noble metals hinders their practical application. In the present study, nanoporous Ti foam is prepared using a molten Mg corrosion method for the first time. Electron microscope images demonstrate that, nanoporous Ti foam is obtained by treating Ti-Mo alloy plates in molten Mg at 650°C for 3hours. Then, the foam is coated with a layer of Au nanoparticles by cool-sputtering and used as self-supported Li–O2 battery cathodes. The nanoporous foam can decrease the consumption of gold markedly compared with traditional porous Au foam. Benefiting from the high stability, conductivity, and porosity of Ti foam, the Li–O2 batteries exhibit good durability (cycling 118 rounds at 1C rate within a 1000mAhg−1 capacity limitation).
The influence of the cell design of symmetric polypyrrole and cellulose-based electric energy storage devices on the cell resistance was investigated using chronopotentiometric and ac impedance measurements with different separator and electrode thicknesses. The cell resistance was found to be dominated by the electrolyte and current collector resistances while the contribution from the composite electrode material was negligible. Due to the electrolyte within the porous electrodes thin separators could be used in combination with thick composite electrodes without loss of performance. The paper separator contributed with a resistance of ∼1.5 Ω mm−1 in a 1.0 M NaNO3 electrolyte and the tortuosity value for the separator was about 2.5. The contribution from the graphite foil current collectors was about ∼0.4–1.1 Ω and this contribution could not be reduced by using platinum foil current collectors due to larger contact resistances. The introduction of chopped carbon fibres into the electrode material or the application of pressure across the cells, however, decreased the charge transfer resistance significantly. As the present results demonstrate that cells with higher charge storage capacities but with the same cell resistance can be obtained by increasing the electrode thickness, the development of paper based energy storage devices is facilitated.