batterydata/paper-abstracts huggingface dataset:
Unlike fossil-fueled generation, solar energy resources are geographically distributed and highly intermittent, which makes their direct control extremely difficult and requires storage units as an additional concern. The goal of this research is to design and develop a flexible tool, which will allow us to obtain (1) an optimal capacity of an integrated photovoltaic (PV) system and storage units and (2) an optimal operational decision policy considering the current and future market prices of the electricity. The proposed tool is based on hybrid (system dynamics model and agent-based model) simulation and meta-heuristic optimization. In particular, this tool has been developed for three different scenarios (involving different geographical scales), where PV-based solar generators, storage units (compressed-air-energy-storage (CAES) and super-capacitors), and grid are used in an integrated manner to supply energy demands. Required data has been gathered from various sources, including NASA and TEP (utility company), US Energy Information Administration, National Renewable Energy Laboratory, commercial PV panel manufacturers, and publicly available reports. The constructed tool has been demonstrated to (1) test impacts of several factors (e.g. demand growth, efficiencies in PV panel and CAES system) on the total cost of the integrated generation and storage system and an optimal mixture of PV generation and storage capacity, and to (2) demonstrate an optimal operational policy.
Microgrids are LV or MV electric networks which utilize various distributed generators (DG) to serve local loads. In this paper, dynamic models of the main distributed generators including photovoltaic (PV) cell, wind turbine, hydro turbine as well as the equivalent power electronic interfaces, battery unit of PV and excitation system of hydro turbine have been made in ElectroMagnetic Transient Program/Alternative Transient Program (EMTP/ATP) software package. Control strategies based on active power/frequency and reactive power/voltage droops for the power control of the inverters have been also developed. Case studies have been carried out in a distribution network to investigate the dynamic behavior of the micro-sources in both steady state and fault scenarios. Simulation results verify the feasibility of the proposed models.
In this review, a convenient hydrogen generation technology based on sodium borohydride and water as hydrogen carriers has been summarized. The recent progresses in the development of the hydrogen generation from sodium borohydride hydrolysis are reviewed. The NaBH4 hydrolysis behavior is discussed in detail. From reported results, it is considered that hydrogen generation from sodium borohydride hydrolysis is a feasible technology to supply hydrogen for the PEMFC. It has been found that the reported results are encouraging although there are some engineering problems that lie ahead. The critical issues of this hydrogen generation technology have been highlighted and discussed.
A poly(o-anisidine-co-metanilic acid)/activated carbon composite is evaluated as an active material for electrochemical supercapacitors. Poly(o-anisidine-co-metanilic acid) (PASM) is potentiodynamically deposited on an activated carbon (AC)-coated stainless-steel substrate, in a supporting electrolyte of 1.0M H2SO4 containing dissolved o-anisidine and metanilic acid, at a sweep rate of 50mVs−1. Scanning electron micrographs show a uniformly deposited, thick PASM film on the activated carbon. Electrochemical techniques, such as impedance analysis, cyclic voltammetry and galvanostatic experiments, are carried out to investigate the suitability of the PASM/AC electrode for supercapacitor applications. A maximum specific capacitance of 576Fg−1 is obtained for PASM/AC at a 5mAcm−2 current density.
Objective This study adopted an inner ear test battery comprising audiometry, caloric test, ocular vestibular-evoked myogenic potential (oVEMP) test and cervical VEMP (cVEMP) test to find the factors related to the occurrence of vertigo in patients with otosclerosis. Methods Fifty otosclerosis patients comprising 27 patients with vertigo (Group A) and 23 patients without vertigo/dizziness (Group B) were enrolled. Each patient underwent otoscopy, image study, audiometry, caloric test, and oVEMP and cVEMP tests via bone vibration stimuli. Results The sequence of inner ear deficits in Group A was in the order from oVEMP test (84%), cVEMP test (51%), caloric test (38%) and mean bone-conducted (BC) hearing threshold (14%), exhibiting a significantly declining trend (p <0.001). The rate of inner ear dysfunction in Group B also declined significantly but in a different order – cVEMP test (55%), oVEMP test (52%), mean BC hearing threshold (33%), and caloric test (18%). Comparison between the two groups revealed a significant difference in the oVEMP test results (p <0.01), but not in the results of the BC hearing threshold, caloric test or cVEMP test (p >0.05). Further, no significant differences existed between the BC hearing threshold and vestibular function test results. Conclusion Otosclerosis patients with vertigo have more frequent abnormalities of oVEMPs to impulsive stimulation than do those without, consistent with more frequent abnormalities of the utricle. Abnormalities of oVEMPs and cVEMPs are more frequent than for caloric testing and BC hearing thresholds. Significance The relative frequency of abnormalities may reflect the degree of pathological involvement of the utricle, saccule, semicircular canals and cochlea in otosclerosis patients with vertigo.
Prader–Willi syndrome (PWS) is an imprinting disorder caused by a deficiency of paternally expressed gene(s) in the 15q11–q13 chromosomal region. The regulation of imprinted gene expression in this region is coordinated by an imprinting center (PWS-IC). In individuals with PWS, genes responsible for PWS on the maternal chromosome are present, but repressed epigenetically, which provides an opportunity for the use of epigenetic therapy to restore expression from the maternal copies of PWS-associated genes. Through a high-content screen (HCS) of >9,000 small molecules, we discovered that UNC0638 and UNC0642—two selective inhibitors of euchromatic histone lysine N-methyltransferase-2 (EHMT2, also known as G9a)—activated the maternal (m) copy of candidate genes underlying PWS, including the SnoRNA cluster SNORD116, in cells from humans with PWS and also from a mouse model of PWS carrying a paternal (p) deletion from small nuclear ribonucleoprotein N (Snrpn (S)) to ubiquitin protein ligase E3A (Ube3a (U)) (mouse model referred to hereafter as m+/pΔS−U). Both UNC0642 and UNC0638 caused a selective reduction of the dimethylation of histone H3 lysine 9 (H3K9me2) at PWS-IC, without changing DNA methylation, when analyzed by bisulfite genomic sequencing. This indicates that histone modification is essential for the imprinting of candidate genes underlying PWS. UNC0642 displayed therapeutic effects in the PWS mouse model by improving the survival and the growth of m+/pΔS−U newborn pups. This study provides the first proof of principle for an epigenetics-based therapy for PWS.
A combinatorial screening method, combined with scanning electrochemical microscopy (SECM) in a tip-generation–substrate-collection (TG–SC) mode, was applied to systematically and rapidly identify potential bimetallic catalysts (Pt–M, M=Pd, Ru, Ir) for the hydrogen oxidation reaction (HOR). The catalytic oxidation of hydrogen on the candidate catalysts was further examined during cyclic voltammetric scans of the substrate with a tip close to the substrate. The quantitative rate of hydrogen oxidation on the candidate substrates was determined for different substrate potentials from SECM approach curves by fitting to a theoretical model. SECM screening results revealed that Pt4Pd6, Pt9Ru1 and Pt3Ir7 were the optimum composition of the catalysts from the Pt–Pd, Pt–Ru and Pt–Ir bimetallic systems for hydrogen sensors. The catalytic activity of the candidate catalysts in HOR was highly dependent on the substrate potential. The kinetic parameters for HOR were obtained on Pt4Pd6 (Tafel slope=124mV, k°=0.19cm/s, α =0.52), Pt9Ru1 (Tafel slope=140mV, k°=0.08cm/s, α =0.58) and Pt3Ir7 (Tafel slope=114mV, k°=0.11cm/s, α =0.48) and compared with Pt (Tafel slope=118mV, k°=0.17cm/s, α =0.5). Among the bimetallic catalysts studied, Pt4Pd6 exhibited the highest activity toward HOR with a high standard rate constant value in a wide range of applied potentials.
The synergistic effect on the physical and electrochemical properties derived from mixing bis(trifluoromethanesulfonyl)imide-based, TFSI−, and (trifluoromethanesulfonyl)(nonafluorobutanesulfonyl)imide-based, IM14 −, ionic liquids (ILs) with a common N-butyl-N-methylpyrrolidinium, PYR14 +, cation has been examined. The incorporation of even small mole fractions (x ≤0.3) of PYR14IM14 into PYR14TFSI is capable of strongly hindering the ability of the mixtures to crystallize. The lowering of the melting point caused by PYR14IM14 addition, in conjunction with the relatively high conductivity of PYR14TFSI, results in an ionic conductivity for all of the mixtures approaching 10−4 and 10−3 Scm−1 at −20°C and 20°C, respectively. The PYR14TFSI/PYR14IM14 binary mixtures may therefore be appealing for electrolyte applications in electrochemical devices operating at low temperatures.
The present study investigates the effects that concreteness fading has on learning and transfer across three grade levels (4–6) in elementary school science education in comparison to learning with constantly concrete representations. 127 9- to 12-years-old elementary school students studied electric circuits in a computer-based simulation environment, where circuits remained concrete (bulbs) throughout the learning or faded from concrete to abstract (bulbs to resistors). The most important finding was that the outcomes seemed to be influenced by a developmental factor: the study found a significant interaction between condition and grade level in relation to learning outcomes, suggesting that the outcomes generally improved as a function of grade level, but that there were notable differences between the conditions regarding the improvement of outcomes across the three grades. According the results, learning with constantly concrete representations either took less time or resulted in better learning compared to concreteness fading. Because transfer is one of the central arguments for concreteness fading, a somewhat surprising finding was that the concrete condition succeeded at least as well as the fading condition on transfer tasks. The study also discusses why the results and issues related to the conceptualisation and operationalisation of central concepts in the study call for caution towards generalization and for more research with young learners across different grades.
Pain in the hand affects an estimated 12–21% of the population, and at older ages the hand is one of the most common sites of pain and osteoarthritis. The association between symptomatic hand osteoarthritis and disability in everyday life has not been studied in detail, although there is evidence that older people with hand problems suffer significant pain and disability. Despite the high prevalence of hand problems and the limitations they cause in older adults, little attention has been paid to the hand by health planners and policy makers. We plan to conduct a prospective, population-based, observational cohort study designed in parallel with our previously reported cohort study of knee pain, to describe the course of musculoskeletal hand problems in older adults and investigate the relative merits of different approaches to classification and defining prognosis.
In order to enhance electronic/ionic conductivity and stabilize the crystal structure of the layered V2O5 material, carbon-encapsulated Mn-doped V2O5nanorods (Mn0.1V2O5@C) were prepared through hydrothermal treatment and followed by annealing at a high temperature. The as-prepared sample appears as quasi spheres with a diameter range of 2–5μm, in which the Mn0.1V2O5 nanorods (20nm in diameter and 200nm in length) are embedded within the porous carbon matrix. These quasi spheres have a hierarchically porous structure and possess a specific surface area of 26.48m2 g−1. They can deliver the specific capacities of 265, 247, 236, 219, 186 and 164mAhg−1 at the rates of 0.1, 0.5, 2, 5, 10 and 20C over the potential range of 4.0–2.0V (vs. Li+/Li), respectively. After cycled at 5C rate for 500 times at room temperature, they can retain 94% of the initial capacity due to both carbon encapsulation and Mn doping. The results indicate that the Mn0.1V2O5@C quasi spheres possess excellent rate capability and long span life, which are promising to be applied in high-power rechargeable lithium batteries.
Abstract Nanomaterials are of interest in many biomedical applications for potential enhancements in structural strength of bone implants, controlled drug release, improved chemical interactions, and scaffolding for cell in-growth and tissue replacement. Unfortunately, the key changes in material properties that enhance performance seem to lead in some cases to increased toxicity. By shifting the distribution of wear particle sizes to smaller individual particles, adverse effects may be created, either directly from the nanoparticle interactions or through intermediary species, such as reactive oxygen. Either way, biological activity often seems to be dependent on particle size, and deleterious side effects and workplace hazards must be evaluated and avoided.
Rechargeable aqueous zinc-ion batteries (ZIBs) are very promising energy storage systems owing to their low cost, high reliability, and high volumetric energy density; however, the stiff challenge for the progress of ZIBs is the lack of suitable materials that permit divalent ion-intercalation/deintercalation with fast kinetics, long cycling durations, and high rate capabilities. Herein, we demonstrate V10O24·12H2O dendrites with a large interlayer spacing of 1.4 nm, fabricated through a simple hydrothermal method. The unique, open, and stable structure complemented by a mixed valence enables a satisfactory battery performance: a specific capacity of 164.5 mAh g−1, long-term cycling stability of 80.1% capacity retention after 3000 cycles, and high power density of 12247.8 W kg−1 at a high energy density of 88.5 Wh kg−1. This study provides a viable and attractive cathode material for practical ZIBs.
Connexin43 (Cx43) gap junctions expressed in astrocytes can significantly impact neuronal survival in stroke. However, little is known regarding Cx43 spatial and temporal expression during the initial stages of brain ischemia. Using immunohistochemistry and Western blot analysis, we examined Cx43 spatial and temporal expression as a function of neuronal injury within the first 24 h after permanent middle cerebral artery occlusion (pMCAO). Western blot analysis showed a significant increase in Cx43 protein expression in the core ischemic area at 2 and 3 h after pMCAO. However, after 6 h of pMCAO Cx43 levels were significantly reduced. This reduction was due to cell death and concomitant Cx43 degradation in the expanding focal ischemic region, while the peri-infarct zone revealed intense Cx43 staining. The neuronal cell-death marker Fluoro-Jade C labeled injured neurons faintly at 1 h post-pMCAO with a time-dependent increase in both intensity and size of punctate staining. In addition, decreased microtubule-associated protein 2 (MAP2) immunoreactivity and thionin staining similarly indicated cell damage beginning at 1 h after pMCAO. Taken together, Cx43 expression is sensitive to neuronal injury and can be detected as early as 2 h post-pMCAO. These findings underscore Cx43 gap junction as a potential early target for therapeutic intervention in ischemic stroke.
The accurate estimation of state of health (SOH) and a reliable prediction of the remaining useful life (RUL) of Lithium-ion (Li-ion) batteries in hybrid and electrical vehicles are indispensable for safe and lifetime-optimized operation. The SOH is indicated by internal battery parameters like the actual capacity value. Furthermore, this value changes within the battery lifetime, so it has to be monitored on-board the vehicle. In this contribution, a new data-driven approach for embedding diagnosis and prognostics of battery health in alternative power trains is proposed. For the estimation of SOH and RUL, the support vector machine (SVM) as a well-known machine learning method is used. As the estimation of SOH and RUL is highly influenced by environmental and load conditions, the SVM is combined with a new method for training and testing data processing based on load collectives. For this approach, an intensive measurement investigation was carried out on Li-ion power-cells aged to different degrees ensuring a large amount of data.
The active particle cracking and electrode pulverization of iron oxide anode material as a result of volume expansion during charge/discharge process cause poor reversibility and significant capacity fading in rechargeable lithium-ion batteries. Here, we demonstrate a facile solvothermal route to immobilize the Fe3O4 particles on the porous active carbon. The present method enables us to obtain nano-porous and mosaic structured Fe3O4@C spheres with an average size of ca. 100 nm. The porous active carbon plays an important role in the improvement of electrochemical properties of Fe3O4. It not only acts as a host for the deposition of Fe3O4 particles, but also provides void spaces for active Fe3O4 to buffer the volume expansion. The good contact between Fe3O4 and active carbon ensures the fast electron/Li-ion transport. As a result, the porous Fe3O4@C shows a high reversible specific capacity of ∼1000 mAh g−1, good cycle stability and excellent rate capability. Therefore, we believe that this composite is a potential candidate for anode material of high-energy lithium-ion battery.
Publisher Summary This chapter explains analog and digital signals and their interconversion. Bridging the gap between the analog and the digital at some point is important if one wants to market the latest gadget. The chapter discusses how to make the analog-to-digital leap. Analog means a continuously variable signal. It means that the item being measured can be chopped up into infinite little pieces over time. The simplest form of digital is two states: It's either there or not. Digital signals could be used to represent Boolean statements, one level indicating true and the other indicating false. Boolean logic is based on a digital representation of the world. Digital processing speeds eventually increased enough to take over almost all applications. An analog signal is converted to digital by chopping it up into chunks at predetermined time intervals. (This chopping is called the sample rate. The faster the sample rate, the higher the frequency that can be digitized.) Then the signal is measured at that point in time and assigned a digital value, which is called sampling the signal. Digital signals (typically represented as 1 or 0) can be crammed together to indicate different levels of analog. A single digit can indicate two levels. To convert a digital signal back to analog, the circuit has to simulate the analog signal it represents. This always requires some kind of filtering. There are many ways to convert digital to analog. One is by pulse width modulation (PWM). The digital PWM is fed into a low-pass filter that removes the switching frequency of the signal, essentially leaving an analog signal.
Two copper-ion conducting solid-polymer electrolyte systems based on polyacrylonitrile (PAN) have been synthesized and characterized using DC polarization tests and impedance measurements. The system with 21 mol% PAN: 30 mol% EC: 45 mol% PC: 04 mol% CuCNS has a room temperature conductivity of 3.30×10−5 S cm−1 and an activation energy of 0.25 eV. The conductivity versus temperature plot obeys an Arrhenius type variation. It is predominantly an ionic conductor with negligible electronic conductivity. It has a high anionic transference number (t −=0.80) due to CNS− ions and a low cationic transference number (t +=0.20) due to Cu+ ions. The system with 20 mol% PAN: 41 mol% EC: 34 mol% PC: 5 mol% CuTf has a room temperature conductivity of 4.10×10−3 S cm−1 and an activation energy of 0.14 eV. It obeys the VTF equation. The system appears to be a mixed conductor with a cationic (Cu2+/Cu+) transference number of t +=0.50 and an electronic transference number of t e=0.50 with negligible anionic conductivity. Both systems yielded free standing stable polymer electrolyte films.
The performance and failure mode of Ni/MH batteries made from a series of Mn-modified A2B7 superlattice and a commercially available AB5 metal hydride alloys were studied and reported. Cells with the Mn-free A2B7 alloy generally show improved low-temperature, higher peak power, and similar charge-retention behavior over those with a conventional AB5 alloy. As Mn-additive amount increased, cell voltage and high-rate capacity improved, low temperature, charge retention, and cycle life first improved, but then deteriorated, and peak power and high temperature voltage stand deteriorated. Analysis of battery performance test results show the use of a superlattice alloy containing 2.3% Mn as the best overall alloy composition. Failure analysis of the highly cycled AB5 alloy containing cells indicate a balanced degradation in negative, positive, separator, and a moderate loss of electrolyte. Same analysis on cells containing the various superlattice alloys suffered from a high degree of pulverization and oxidation of its negative electrode (with the 9.3% Mn content experiencing the worst amount of pulverization/oxidation) and a high degree of electrolyte loss.
Energy harvesting from renewable ambient energy sources has recently gained attention for newly developed generators and applications. Although considerable amount of energy is available in surrounding environment in various shapes, scavenging ambient energy has many challenges, which include operating with low input voltage, supplying high output voltage, and coldstart without auxiliary assistance. In this paper, a voltage boost energy harvester with autonomous startup capability that can operate in sub-1-V input voltage is proposed. The proposed circuit has a simple integrative configuration with positive feedback oscillator, energy harvesting flyback converter, and voltage regulating DC/DC converter. Comprehensive mathematical analysis and experimental validation is presented in this paper. The proposed circuitry is readily implementable using commercial-off-the-shelf components.