batterydata/paper-abstracts huggingface dataset:
Cochlear implants (CIs) provide children with profound hearing loss access to sounds and speech. Research on the effects of CI on speech and language development in mainland China is scarce due to the lack of standardized tests. This study aims at developing a vocabulary measure, the Mandarin Expressive and Receptive Vocabulary Test (MERVT), for pre-school children with CIs. Using responses from 102 normal-hearing preschool children, the initial vocabulary set was subjected to analyses to identify items with appropriate levels of difficulty and discrimination. Norms on 245 normal-hearing children aged 1;6 to 3;11 were later collected based on the final set of the items. Evaluation of the test's psychometric properties revealed good internal consistency. Significant correlations between the total MERVT scores and the Gesell Developmental Scale scores, between the MERVT expressive and receptive subtest scores and the total scores, and the gradual increase in MERVT scores with age, provided evidence of construct validity. Results from 29 children with CIs were also examined for evidence of the MERVT's construct validity. There was a significant correlation between these children's MERVT scores and their scores from an intelligence test. The MERVT scores increased with an increase in the duration of CI use and in chronological age. With good reliability and strong validity, the test is recommended for use in the monitoring of language development in children with CI.
An enhanced one-dimensional (1-D) stationary model for the all-vanadium redox flow battery (VRFB) is developed based on an existing 1-D model proposed by Vynnycky [Energy, 36 (2011): 2242 – 2256]. The enhanced model incorporates species conservation equations along with an advection term to describe the concentration changes in the porous electrodes. In addition, a complete Nernst equation, which accounts for proton concentrations in the VRFB is also included to improve the cell voltage prediction without using any arbitrary fitting contact voltage. The enhanced 1-D model is validated against experimental data from the literature and the ability of the model to predict the cell performance is investigated. The cell voltage prediction shows significant improvement over Vynnycky's 1-D model and also compares surprisingly well with higher-dimensional models. This enhanced 1-D model is also capable of capturing the cell performance at different electrolyte flow rates, especially evidenced by the polarization curves. Using both the power based and round-trip efficiencies, the optimal electrolyte flow rate for the VRFB can be determined. This enhanced 1-D model is expected to serve as a useful design tool for the development and optimization of VRFB systems.
A methodology for optimum sizing of battery integrated biomass gasifier based distributed power generation systems is discussed. Typically, biomass gasifier systems are sized considering peak demand resulting into lower operational efficiency due to part load operation during low demand period. The proposed methodology using design space approach enables designer with multiple combinations of gasifier engine and battery systems for given load profile from which an appropriate combination may be identified considering specific objective or constraints if any. Two gasifier operational strategies are discussed and compared using cost of energy. The methodology is further extended for sizing of hybrid systems incorporating gasifier, solar PV and battery system. The proposed methodology is illustrated using a realistic load profile generated through a structured household survey of an un-electrified hamlet. For given load profile, battery integrated gasifier engine system in intermittent operation mode has the lowest cost of electricity followed by gasifier engine system alone, hybrid system and solar PV battery system. Sensitivity analysis is done to incorporate uncertainty related to variation in key input parameters. The proposed sizing methodology may be helpful in wider replication of gasification systems by providing cost effective sizing of such systems.
The structures and compositions of materials have important influences on their performance. Herein, hierarchically structured yolk-shell Co and N codoped porous carbon microspheres (YS-Co/N-PCMs) have been successfully synthesized by using low-cost melamine, formaldehyde and cobalt acetate as raw materials via a facile template-free hydrothermal method and a subsequent pyrolysis. The formation process of the yolk-shell precursor is systematically investigated, involving a morphological evolution process from solid microspheres, ultrathin and wrinkled shells wrap, to yolk-shell structure formation. More importantly, the unique structure combines the favorable features towards oxygen reduction reaction (ORR), such as high surface area, sufficient Co-Nx and graphitic N active sites and suitable pore structures. As a result, the YS-Co/N-PCMs catalyst shows high catalytic activity for ORR in alkaline media for fuel cells, which not only outperforms commercial Pt-based catalysts in terms of resistance to methanol crossover and long-time stability, but is also better than many non-precious metal doped carbon-based catalysts reported previously. In addition, the YS-Co/N-PCMs catalyst also has high catalytic activity toward oxygen evolution reaction (OER). Therefore, the YS-Co/N-PCMs catalyst may serve as a promising alternative to Pt/C catalyst for ORR and OER in alkaline media.
Even though lithium ion batteries are the state-of-the-art battery technology for numerous applications, there is extensive research on alternative battery technologies. Dual-ion batteries (DIBs) and in particular their all carbon/graphite versions, the dual-carbon (DCBs) and dual-graphite batteries (DGBs), have emerged as an upcoming and alternative approach for stationary energy storage systems. However, there are still fundamental electrochemical processes during charge and discharge operation of DIBs not fully understood so far. In this work, the kinetic processes during bis(trifluoromethanesulfonyl) imide (TFSI) anion intercalation into graphitic carbon, that proceeds by stage formation, are discussed in detail. The computational calculation of structural parameters of TFSI-graphite intercalation compounds (TFSI-GICs) indicates a possible maximum specific capacity of 140 mAh g−1 and a walking-like diffusion of the TFSI anion within the graphite lattice. Moreover, a particular focus is set on understanding the overpotential generation during the charge process and its correlation to different specific capacities for varying graphite particle sizes and operating temperatures. In this context, a mechanism, supported by electrochemical and computational experiments, is proposed explaining the overpotential evolution on the basis of (apparent) anion diffusion coefficients in graphite. Temporarily higher (apparent) diffusion activation energies close to filled stages seem to be responsible for temporarily lower (apparent) diffusion coefficients and, thus, for the evolution of additional overpotentials during intercalation.
Recent work has investigated children's developing understanding of the anatomical locus of identity. In two studies, we extend this work by exploring the role of the mind as opposed to the brain in children's conceptualization of identity. In Experiment 1, an analysis of natural language indicated that adults use the term mind more frequently than the term brain with reference to identity-related mental processes. Children's output displayed a similar bias. In Experiment 2, we compared the judgments of 5- and 7-year-old children to those displayed by adults. Participants heard stories in which a magical transformation resulted in either a creature with a mismatch between brain and body or a creature with a mismatch between mind and body. Children were more accurate in recognizing the enduring identity of this transformed creature when the transformation resulted in a mismatch between mind and body as compared to brain and body.
The objective of the study was the estimation of the effect of surfactants on the toxicity of ZnO, TiO2 and Ni nanoparticles (ENPs) towards Daphnia magna. The effect of hexadecyltrimethylammonium bromide (CTAB), triton X-100 (TX100) and 4-dodecylbenzenesulfonic acid (SDBS) was tested. The Daphtoxkit F™ test (conforming to OECD Guideline 202 and ISO 6341) was applied for the toxicity testing. Both the surfactants and the ENPs were toxic to D. magna. The addition of ENPs to a solution of the surfactants caused a significant reduction of toxicity of ENPs. The range of reduction of the toxicity of the ENPs depended on the kind of the ENPs and their concentration in the solution, and also on the kind of surfactant. For nano-ZnO the greatest reduction of toxicity was caused by CTAB, while for nano-TiO2 the largest drop of toxicity was observed after the addition of TX100. In the case of nano-Ni, the effect of the surfactants depended on its concentration. Most probably the reduction of toxicity of ENPs in the presence of the surfactants was related with the formation of ENPs aggregates that inhibited the availability of ENPs for D. magna.
Yam mosaic virus (YMV; genus Potyvirus) is considered to cause the most economically important viral disease of yams (Dioscorea spp.) in West Africa which is the dominant region for yam production globally. Yams are a vegetatively propagated crop and the use of virus-free planting material forms an essential component of disease control. Current serological and PCR-based diagnostic methods for YMV are time consuming involving a succession of target detection steps. In this study, a novel assay for specific YMV detection is described that is based on isothermal reverse transcription-recombinase polymerase amplification (RT-exoRPA). This test has been shown to be reproducible and able to detect as little as 14pg/μl of purified RNA obtained from an YMV-infected plant, a sensitivity equivalent to that obtained with the reverse transcription-polymerase chain reaction (RT-PCR) in current general use. The RT-exoRPA assay has, however, several advantages over the RT-PCR; positive samples can be detected in less than 30min, and amplification only requires a single incubation temperature (optimum 37°C). These features make the RT-exoRPA assay a promising candidate for adapting into a field test format to be used by yam breeding programmes or certification laboratories.
The co-evolution of society and potentially disruptive technologies makes decision guidance on such technologies difficult. Four basic principles are proposed for such decision guidance. None of the currently available methods satisfies these principles, but some of them contain useful methodological elements that should be integrated in a more satisfactory methodology. The outlines of such a methodology, multiple expertise interaction, are proposed. It combines elements from several previous methodologies, including (1) interdisciplinary groups of experts that assess the potential internal development of a particular technology; (2) external scenarios describing how the surrounding world can develop in ways that are relevant for the technology in question; and (3) a participatory process of convergence seminars, which is tailored to ensure that several alternative future developments are taken seriously into account. In particular, we suggest further development of a bottom-up scenario methodology to capture the co-evolutionary character of socio-technical development paths.
Layered lithium transition metal oxides (Li1+xM1-xO2, M = Ni, Mn, Co) are attractive cathode materials for lithium-ion batteries due to their high reversible capacity. However, they suffer from structural changes that lead to substantial voltage fade. In this study, we use stress as a novel way to track irreversible changes in Li1.2Mn0.55Ni0.125Co0.125O2 (LR-NMC) cathodes. A unique and unpredicted stress signature is observed during the first delithiation. Initially, a tensile stress is observed, consistent with volume contraction from lithium removal, however, the stress reverses and becomes compressive with continued charging beyond 4 V vs Li/Li+, indicating volume expansion; this phenomenon is present in the first cycle only. This irreversible stress during delithiation is likely to be at least partially due to oxygen loss and the resulting cation rearrangement. Raman spectroscopy provides evidence of the layered-to-spinel phase transition after cycling in the LR-NMC films, as well as recovery of the original spectra upon re-annealing in an oxygen environment.
Biofuel cells are a next-generation energy device because they use renewable fuels with high energy density and safety. We have developed passive-type biofuel cell units, which generate a power over 100 mW (80 cm3, 39.7 g). Our biofuel cell, in which two-electron oxidation of glucose and four-electron reduction of O2 occurs at pH 7 in mediated bioelectrochemical processes under quiescent conditions, accomplished the maximum power density of 1.45 ± 0.24 mW cm−2 at 0.3 V. This performance was achieved by introducing three technologies: (1) Enzymes and mediator are densely entrapped on carbon-fiber electrodes with the enzymatic activity retained, (2) the concentration of buffer in electrolyte solution was optimized for the immobilized enzymes, and (3) the cathode structure was designed to supply O2 efficiently. The cell units with a multi-stacked structure successfully operate a radio-controlled car (16.5 g), which demonstrates the potential of biofuel cells in practical applications.
A pseudo two-dimensional model (P2D) was presented to describe the electrochemical behaviour of a commercial 18650 cylindrical cell composed of graphite and LiFePO4 (LFP) electrodes. Simulations were conducted by COMSOL MULTIPHYSICS 5.2. The model validation was done with experimental data taken from Hydro-Québec for a full range of C-rates (currents). A mosaic model based on a C-rate dependent particle radius in positive and negative electrodes was assumed. The reaction kinetics and diffusion in a solid phase were recognized as cell performance limiting factors in the flat area and in the steep area at the end of discharge of the cell voltage–capacity curve, respectively. Since the diffusion polarization in a solid phase played an important role in the steep area at the end of discharge of the cell voltage–capacity curve, a concentration dependent diffusion coefficient in LFP positive electrode was considered. Based on the fact that activation overpotential was a major polarization in the flat area of the cell voltage–capacity curve in addition to decreasing the particle radius at higher C-rates, a contact resistance between the surface of the particles and the solid matrix was predicted. This contact resistance on the surface of active materials in the positive electrode described the feature of low electronic conductivity in LFP. There was a good agreement between the simulated results with experimental discharge data in a full range of C-rates.
Nitrogen-doped nanoporous carbon materials with large BET surface area (1322.5m2 g−1) and pore volume (0.87cm3 g−1) have been achieved by a synchronous carbonization/nitridation process, simply using potassium biphthalate and azodicarbonamide as carbon/nitrogen sources, respectively. The above carbon materials have been further impregnated with MnOx nanocrystallites that comes from the thermal decomposition of Mn(NO3)2. Taking the carbon-2:1-Mn sample as an excellent example, it also has large BET surface area (1160.1m2 g−1) and pore volume (0.77cm3 g−1) and exhibits high nitrogen/manganese contents of 4.13%, and 3.30%, respectively. The carbon-2:1-Mn sample delivers excellent capacitances of 564.5 and 496.8Fg−1 at the current density of 0.5 and 1.0Ag−1, respectively, as well as superior cycling stability of 96.10% even after charging/discharging for 5000 times. The present method of incorporating cheap MnOx substance into carbon matrix is efficient and also easy for large scale production of carbon nanocomposites, especially possessing large BET surface area and high pore volume.
Biomass-derived jet fuel is an alternative jet fuel (AJF) showing promise of reducing the dependence on fossil fuel and greenhouse gas emissions. Hydroprocessed esters and fatty acids (HEFA) concept is also known as one of the pathways for producing bio jet fuel. HEFA fuel was approved by the American Society for Testing and Materials in 2011, and can be blended up to 50% with conventional jet fuel. Since then, several HEFA economic and life-cycle assessments have been published in literature. However, there have been limited analyses on feedstock availability, composition, and their impact on hydrocarbon yield (particularly jet blendstock yield) and overall process economics.
A new concept lithium-ion conducting lithium lanthanum titanate solid electrolyte and Li4Ti5O12 composite is proposed as efficient anode of lithium-ion batteries with outstanding rate performance, which can be facilely prepared by one-pot combustion technique. The as-synthesized composites are in micrometer size with dense nature which effectively reduces the electrode-liquid electrolyte interface area, thus decreasing irreversible capacity during the first charge–discharge cycle and prolonging cycling stability. However, the composites are rich in lithium lanthanum titanate and Li4Ti5O12 dual phase boundaries due to intimate nanoscale mixing of the two phases. The apparent lithium-ion conductivity of the composite electrode gets significantly improved as compared to pristine Li4Ti5O12 due to the incorporation of lithium lanthanum titanate phase, a high lithium ionic conductor. As a result, the as-synthesized composites show a high capacity of 113.5 mA h g−1 even at a discharge rate of 40 C, more than 200% that of a pristine Li4Ti5O12. The concept is general, which may also be applicable to other electrode materials, and it thus introduces a new way for the development of high rate-performance electrodes for lithium-ion batteries.
Recently a pinch–torsion test is developed for safety testing of Li-ion batteries. It has been demonstrated that this test can generate small internal short-circuit spots in the separator in a controllable and repeatable manner. In the current research, the failure mechanism is examined by numerical simulations and comparisons to experimental observations. Finite element models are developed to evaluate the deformation of the separators under both pure pinch and pinch–torsion loading conditions. It is discovered that the addition of the torsion component significantly increased the maximum first principal strain, which is believed to induce the internal short circuit. In addition, the applied load in the pinch–torsion test is significantly less than in the pure pinch test, thus dramatically improving the applicability of this method to ultra-thick batteries which otherwise require heavy load in excess of machine capability. It is further found that the separator failure is achieved in the early stage of torsion (within a few degree of rotation). Effect of coefficient of friction on the maximum first principal strain is also examined.
As one of the bottleneck technologies of electric vehicles (EVs), the battery hosts complex and hardly observable internal chemical reactions. Therefore, a precise mathematical model is crucial for the battery management system (BMS) to ensure the secure and stable operation of the battery in a multi-variable environment. First, a Cloud-based BMS (C-BMS) is established based on a database containing complete battery status information. Next, a data cleaning method based on machine learning is applied to the big data of batteries. Meanwhile, to improve the model stability under dynamic conditions, an F-divergence-based data distribution quality assessment method and a sampling-based data preprocess method is designed. Then, a lithium-ion battery temperature-dependent model is built based on Stacked Denoising Autoencoders- Extreme Learning Machine (SDAE-ELM) algorithm, and a new training method combined with data preprocessing is also proposed to improve the model accuracy. Finally, to improve reliability, a conjunction working mode between the C-BMS and the BMS in vehicles (V-BMS) is also proposed, providing as an applied case of the model. Using the battery data extracted from electric buses, the effectiveness and accuracy of the model are validated. The error of the estimated battery terminal voltage is within 2%, and the error of the estimated State of Charge (SoC) is within 3%.
Soldering has a high potential for electrically connecting single battery cells even for multicellular battery assemblies. This work evaluates soldered connections for battery cells by assessing the electrical connection resistance with a special measuring and calculation method. Due to the solder layer in between the joint partners, the current paths differ from welded connections. A resistance network and a finite element model (FEM) simulation are applied to understand these current paths. For the chosen test scenario, simulation predicts a reduction of the total connection resistance by the solder layer. Measured connection resistances and tensile strength are compared to series of measurements with resistance spot welding, ultrasonic welding, laser beam welding and press connections. Not only the connection resistances are lower for soldered brass samples but also the tensile strength is higher. For iron soldering on lithium-ion battery cells, the solder’s liquidus temperature should be below ca. 150°C. Other heating techniques, such as laser soldering, seem more promising, because the heat input is rapid and extremely localized. As a conclusion, soldering is a good option for connecting battery cells. If the right heating technique is chosen and the parameters are optimally adjusted, soldering could overtrump other connection techniques in some aspects.
Polyimide materials with several kinds of mechanical properties have a great potential to use in aviation and space technology. One of these kinds of polyimide materials is poly(imide siloxane) copolymers. By this work, we also aimed to get flexible substrates in order to use as substrates in solar energy technology. Randomly segmented Poly(imide siloxane) and poly(urethane siloxane) block copolymers were produced based on benzofenon-3,3’,4,4’-tetracarboxylic dianhydride (BTDA), 4,4’-oxydianiline (ODA) and bis(3-aminopropyl) polydimethlysiloxane (APPS). The ODA and BTDA are the hard segments, APPS and BTDA are the soft segments in the structure. Many kinds of these copolymers could be produced by adjusting the soft and hard segment lengths. Poly(imide siloxane) block copolymers were insoluable in many organic solvents.
The results of road tests on valve-regulated lead-acid (VRLA) batteries in an idling-stop (stop and go) vehicle are reported. Idling-stop systems are simple systems to improve fuel economy of automobiles. They are expected to spread widely from an environmental perspective. Performances of a conventional flooded battery, a conventional VRLA battery, and an improved VRLA battery were compared in road tests with an idling-stop vehicle. It was found that the improved VRLA battery was suited to idling-stop applications because it had a smaller capacity loss than the conventional flooded battery during partial-state-of-charge (PSoC) operation. The positive grid was corroded in layers, unlike the usual grain boundary corrosion of SLI battery grid. It is because the corrosion proceeded mainly under PSoC conditions. The corrosion rate could be controlled by potential control of positive plates.