batterydata/paper-abstracts huggingface dataset:
A new concept of dual microcombustor based thermoelectric micropower generator with high power density (∼0.14 mW/mm3) and high conversion efficiency (4.66%) is reported in this work. A new configuration with a dual microcombustor system is experimentally investigated with two thermoelectric modules and operates with liquefied petroleum gas as fuel. The dual microcombustor is fabricated using a rectangular aluminium metal block and detailed investigations on flame stability limits and thermal characteristics were carried out. Dual microcombustor configuration helps to significantly improve the flame stability limits and thermal characteristics over the single combustor configuration due to increased flame-surface interaction and enhanced heat recirculation through solid walls. Maximum power point tracking (MPPT) algorithm is applied to achieve a maximum power output of 4.52 W with a maximum conversion efficiency of 4.66%. The application of porous media significantly helped improve the upper flame stability limits with a maximum conversion efficiency of 4.32%, and 4.66%, at ϕ = 1 and 0.9 respectively at 10 m/s mixture velocity. The system compactness and high output power with significantly improved conversion efficiency shows the possibility of its application in various portable micro-scale power generators for remote, stand-alone, military and aerospace applications.
A novel composite porous membrane is obtained by phase inversion using the prepared poly(acrylonitrile-N-vinylpyrrolidone) (P(AN-NVP)) as a polymer matrix, which absorbs liquid electrolyte to form the corresponding P(AN-NVP) based gel polymer electrolyte (GPE). A large number of test methods are used to characterize the overall performances of P(AN-NVP) membranes. These results show that when AN and NVP are copolymerized at a mass ratio of 6:1, the prepared P(AN-NVP) copolymer film possesses membrane structure that riching in three-dimensional interpenetrating micropores, and has lower crystallinity and satisfactory mechanical properties compared with that of pure PAN membrane, which greatly promotes the electrochemical performances of the corresponding GPE: the supreme liquid electrolyte uptake of 876.67 wt% and higher ion conductivity of 4.54 × 10−3 S cm−1 at room temperature, a significantly enhanced lithium ion transference number of 0.55, a broader electrochemical stability window of 5.11 V (vs. Li/Li+) and relatively stable interfacial compatibility. The higher charge-discharge capacity of 114.8 mAh g−1 at 0.2C, and the great capacity retention of 95.4% at 0.5C after 70 cycles with the coulomb efficiency of 98%. In addition, the GPE-6-1 based lithium ion battery exhibits excellent cycle performance and a weak voltage hysteresis of 5.8 mV over a 600 h Li plating/stripping process at current density of 0.5 mA cm−2 and capacity of 0.5 mAh cm−2.
Single ion conductors, such as solid electrolytes are promising alternatives to overcome drawbacks of lithium-ion batteries with binary electrolytes, e.g. thermal runaway and electrolyte decomposition. Within this research a pseudo-two-dimensional (P2D) battery model for cells with single ion conducting electrolytes is derived and compared to a state of the art P2D model for cells with binary electrolytes to elucidate the theoretical differences in cell performance when replacing binary with single ion conducting electrolytes, as well as the related advantages and bottlenecks. At high discharge rates, electrolyte potential losses are more distinct for binary electrolytes compared to single ion conducting electrolytes which results in a higher energy for the latter one. Further, sensitivity to variations in electrode and electrolyte are elucidated analyzing discharge curves, Electrochemical Impedance Spectroscopy (EIS) and maximal energy. Parameter variations indicate that single ion conducting electrolyte cells allow thick electrode designs. They can therefore be advantageous to classical binary electrolyte cells when building high energy cells, once the high conductivities of laboratory studies found their way into application.
Ascl1 and Sox2 convert human brain pericytes into the two major neuronal subclasses of GABA- and glutamatergic neurons. Unexpectedly, despite the lack of cell division, this conversion requires passage through a neural stem cell-like state.
Birds are continuously confronted by a large number of stressors, including pathogens. Despite their variety, all stressors induce an elevation in plasma corticosterone concentration, and consequently increase heterophil to leukocyte (H/L) ratio. In order to evaluate and differentiate effects of endocrine (non-bacterial) and bacterial stress on the proportions and ultrastructural characteristics of chicken leukocytes, a series of experiments were conducted with seven-week old chickens exposed either to dietary corticosterone or to intravenous (i.v.)-injected lipopolysaccharide (LPS). Samples were taken for haematological, endocrine, and electron microscopy examination. Administration of corticosterone and LPS significantly elevated plasma corticosterone concentrations and increased H/L ratios. Electron microscopy observations indicated changes in heterophil size, shape, and granulation, and lymphocyte cytoplasmic characteristics. Immature heterophils were observed in the peripheral blood, suggesting that corticosterone and LPS both stimulate an earlier release of heterophils from bone marrow and enhance their influx into blood circulation. The LPS induced a degenerative morphology and the destruction of lymphocytes, whereas corticosterone appeared to stimulate their redistribution rather than destruction. The results indicate that exposure to corticosterone or LPS similarly increase H/L ratios, but differentially alter the ultrastructure of heterophils and lymphocytes. Elucidation of the mechanisms that cause such changes may play an important role in distinguishing between a nonimmune and immune stress challenge at the molecular level.
In the context of developing renewable fuels for transportation based on Solar light (“Solar Fuels”), products derived from CO2 reduction and particularly methanol and methane appear as appealing renewable feedstocks. Two alternative photocatalytic routes to transform CO2 into methanol and methane which are based either on the use of artificial of solar light to effect the CO2 reduction are presented. It is shown that deep UV activation of CO2 can lead to the selective formation of CO or even to the reduction to methane by hydrogen or water. The latter process can be promoted by the presence of some solids with basic character such as hydrotalcites of alkali-exchanged zeolites. In spite of the high selectivity of these processes, the energy consumption is still too high and efficiency has to be increased. We discuss the limitations of the photocatalytic CO2 reduction arising from the limited choice of semiconductors, the lack of visible response of TiO2, the high reduction potential of CO2 activation, and the dilemma in the use of H2O as sacrificial reducing agent, since H2O can compete favorably for the electrons and produce the preferential generation of H2. The problems arising from the lack of selectivity toward a single product in the CO2 reduction have also been commented. Finally, we present our view on future developments and targets in this field.
Li-ion batteries offer great promise for the future of energy storage due to their superior gravimetric and volumetric energy density. One of the challenges in promoting their expanded use is to improve the cycle life of Li-ion batteries. This requires detailed understanding of the aging phenomenon. The aging mechanism of Li-ion batteries can have both chemical and mechanical origins. While the chemical degradation mechanisms have been studied extensively, mechanical degradation mechanisms have received little attention so far. In this study, we probe the changes in mechanical properties of a LiFePO4 cathode in a large format prismatic cell. Results indicate that mechanical degradation increases by aging; in addition, local degradation is observed in the composite cathode. Implications of the degradation in mechanical properties on binder degradation are discussed in detail.
Micro-hybrid vehicles with stop–start function and regenerative braking lead to higher requirements on flooded lead-acid batteries. A promising approach to improve the cycleability of flooded lead-acid batteries is the use of carbon additives in the negative active mass. In this study different carbons (carbon blacks and a lamp black) were studied by transmission electron microscopy and Raman spectroscopy. Furthermore, batteries containing carbon blacks and lamp black in the negative active material were cycled with 17.5% depth of discharge. Morphology, surface functionalisation, and the degree of order were correlated with the cycle life. In cycling tests, batteries with highly ordered carbon blacks increase the lifetime of the corresponding battery by up to a factor of two.
In the continuing search for new physical properties and combinations of properties in molecular materials, novel phenomena and structures are identified in three categories of TTF and BEDT–TTF (bis-ethylenedithiotetrathiafulvalene) charge-transfer salts with inorganic complex anions. When the anion is a 3d complex containing NCS– and an aromatic donor, long range π–d ferrimagnetic order is established by donor-anion π–π overlap; when the anion is a tris-oxalato-metallate(III) complex, both normal state and superconducting behaviour are dramatically influenced by changing guest molecules in the lattice, while incorporating columns of crown ether and H3O+/H2O leads to metallic conductors that simultaneously transport protons. To cite this article: P. Day, C. R. Chimie 6 (2003).
Nickel-rich Li[Ni0.6Co0.2Mn0.2]O2 is considered to be the next step forward towards the realization of high-energy lithium-ion batteries and has, thus, attracted intensive attention recently. However, achieving long-term cycling stability at elevated temperatures and voltages still remains a formidable challenge for practical applications. In this work, we successfully synthesized MnPO4-coated Li[Ni0.6Co0.2Mn0.2]O2 (MP-NCM) with an advantageously low coating content of only 1 wt% while providing substantially enhanced electrochemical performance and outstanding cycling stability. This improvement is ascribed to the MnPO4 coating, acting as an ideal protective layer to dramatically reduce the occurring side reactions with the electrolyte, especially at higher temperatures and cut-off voltages. By preventing the direct contact between the cathode active material and the electrolyte, the presence of the coating layer reduces the transition metal dissolution, thus, yielding good structural integrity upon cycling, while its amorphous nature allows for an enhanced apparent lithium ion diffusion, i.e., lithium de-/insertion kinetics. Additionally, the strong covalent bonding of the PO4-group contributes to an increased thermal stability and the high voltage performance of MP-NCM. On the basis of our work, the coating design strategy delivers valuable materials for the practical realization of lithium-ion batteries with superior long-term cycling stability at higher operation temperature and voltage.
The Japanese writing system employs two distinct categories of characters: Kana and Kanji. The difference between Kana and Kanji writing corresponds roughly to that between phonological and lexical systems in Western languages. When typing, most Japanese use alphabetical characters based purely on phonological rules. In particular, the Romaji system is used, in which a syllable consists of a single vowel, a consonant–vowel compound (e.g., ka, ki), or a sequence of consonant–y(semivowel)–vowel (e.g., kya, kyu). We describe a right-handed Japanese patient who developed pure agraphia that affected Romaji writing but preserved Kana and Kanji writing and who had a lesion in the left pars opercularis of the inferior frontal gyrus that extended to the anterior precentral gyrus. The patient demonstrated literal paragraphia in spelling Romaji across modalities. Our findings suggested that the patient’s agraphia in Romaji after a confined left frontal infarction was manifested by a selective impairment in syllable-to-grapheme conversion.
A stationary, isothermal, three-dimensional model for negative half cell of the vanadium redox flow battery is developed, which is based on the comprehensive conservation laws, such as charge, mass and momentum, together with a kinetic model for reaction involving vanadium species. The model is validated against the results calculated by the available two-dimensional model. With the given geometry of the negative half cell, the distributions of velocity, concentration, overpotential and transfer current density in the sections that are perpendicular and parallel to the applied current are studied. It is shown that the distribution of the electrolyte velocity in the electrode has significant impact on the distribution of concentration, overpotential and transfer current density. The lower velocity in the electrode will cause the higher overpotential, further result in the side reaction and corrosion of key materials locally. The development of the design of the vanadium redox flow battery is discussed, and the further research is proposed.
In this paper, an analytical model of a micro solid oxide fuel cell (SOFC) system fed by butane is introduced and analyzed in order to optimize its exergetic efficiency. The micro SOFC system is equipped with a partial oxidation (POX) reformer, a vaporizer, two pre-heaters, and a post-combustor. A one-dimensional (1D) polarization model of the SOFC is used to examine the effects of concentration overpotentials, activation overpotentials, and ohmic resistances on cell performance. This 1D polarization model is extended in this study to a two-dimensional (2D) fuel cell model considering convective mass and heat transport along the fuel cell channel and from the fuel cell to the environment. The influence of significant operational parameters on the exergetic efficiency of the micro SOFC system is discussed. The present study shows the importance of an exergy analysis of the fuel cell as part of an entire thermodynamic system (transportable micropowerplant) generating electric power.
A randomized, double-blind, placebo-controlled study (N01103, NCT00105040) evaluated behavioral and emotional effects of adjunctive levetiracetam (LEV) treatment in children and adolescents (4–16years old) with uncontrolled partial-onset seizures. Patients received adjunctive LEV 20–60mg/kg/day (n =64) or placebo (n =34) for 12weeks. The Achenbach Child Behavior Checklist (CBCL) and portions of the Child Health Questionnaire—Parent Form 50 (CHQ-PF50) were used to assess behavioral and emotional functioning at baseline and end of the treatment period. Worsening of the mean CBCL Aggressive Behavior score occurred for LEV but not placebo, leading to similar results for Externalizing Syndromes and Total Problems (all P <0.05 vs placebo). The change in the CBCL Activities Competence score favored LEV (P <0.05). These results are in line with the known safety profile of LEV.
The effects of PbZrO3 filler in polypropylene were studied by isothermal and nonisothermal chemiluminescence and FT-IR spectroscopy after γ(137Cs)-irradiation at 20, 50, 100 and 250kGy relative to neat material. For the two filler concentrations (2 and 5wt%) the improvement in radiation stability can be noticed. The increase in the filler concentration stabilizes polypropylene matrix, whose oxidation rate decreases sharply even at 250kGy. The interaction of polypropylene matrix with filler is discussed based on the adsorption of free radicals on zirconate particles and the electronic coupling of radiolysis intermediates and filler cations.
This paper proposes and validates a calendar and power cycling aging model for two different lithium battery technologies. The model development is based on previous SIMCAL and SIMSTOCK project data. In these previous projects, the effect of the battery state of charge, temperature and current magnitude on aging was studied on a large panel of different battery chemistries. In this work, data are analyzed using Dakin’s degradation approach. In fact, the logarithms of battery capacity fade and the increase in resistance evolves linearly over aging. The slopes identified from straight lines correspond to battery aging rates. Thus, a battery aging rate expression function of aging factors was deduced and found to be governed by Eyring’s law. The proposed model simulates the capacity fade and resistance increase as functions of the influencing aging factors. Its expansion using Taylor series was consistent with semi-empirical models based on the square root of time, which are widely studied in the literature. Finally, the influence of the current magnitude and temperature on aging was simulated. Interestingly, the aging rate highly increases with decreasing and increasing temperature for the ranges of −5 °C–25 °C and 25 °C–60 °C, respectively.
Objective: To find out whether 14–16 year old reading and writing impaired pupils have atypical EEG activation patterns during reading. Methods: EEG correlation indices (EEGCIs), based on the waveform characteristics of two EEG signals, were used as measurers of slow joint activation of cortical regions during reading in pupils with reading and writing impairment. Results: Reading was associated with high EEGCIs within the right hemisphere in reading and writing impaired pupils. The finding is analogous to the results of an earlier study [Byring, Electroencephalogr. Clin. Neurophysiol. 63 (1986) 1] in boys with spelling disabilities. The activation in the right hemisphere might represent a compensation for a left hemisphere dysfunction in pupils with reading and writing impairment during reading, as suggested by a number of functional neuroimaging studies. This interpretation was corroborated by high EEGCIs especially in those impaired pupils who had a good occupational outcome. Conclusions: EEGCIs during reading are high within the right hemisphere in pupils with reading and writing impairment. Significance: High EEGCIs within the right hemisphere during reading might be considered neurophysiological markers for reading and writing impairment.
Combined Heat and Power (CHP) is the sequential or simultaneous generation of multiple forms of useful energy, usually electrical and thermal, in a single and integrated system. Implementing CHP systems in the current energy sector may solve energy shortages, climate change and energy conservation issues. This review paper is divided into six sections: the first part defines and classifies the types of fuel cell used in CHP systems; the second part discusses the current status of fuel cell CHP (FC-CHP) around the world and highlights the benefits and drawbacks of CHP systems; the third part focuses on techniques for modelling CHP systems. The fourth section gives a thorough comparison and discussion of the two main fuel cell technologies used in FC-CHP (PEMFC and SOFC), characterising their technical performance and recent developments from the major manufacturers. The fifth section describes all the main components of FC-CHP systems and explains the issues connected with their practical application. The last part summarises the above, and reflects on micro FC-CHP system technology and its future prospects.
Numerous instruments are available to measure health-related quality of life (HRQoL) in patients with Chronic Obstructive Pulmonary Disease (COPD), covering a wide array of domains ranging from symptoms such as dyspnea, cough and wheezing, to social and emotional functioning. Currently no information or guide is available yet to aid the selection of domains for a particular study or disease population. The aim of this paper is to identify which domains of HRQoL are most important with respect to COPD, from the patient perspective.
This paper presents an electrochemical-thermal coupled overcharge-to-thermal-runaway (TR) model to predict the highly interactive electrochemical and thermal behaviors of lithium ion battery under the overcharge conditions. In this model, the battery voltage equals the difference between the cathode potential and the anode potential, whereas the temperature is predicted by modeling the combined heat generations, including joule heat, thermal runaway reactions and internal short circuit. The model can fit well with the adiabatic overcharge tests results at 0.33C, 0.5C and 1C, indicating a good capture of the overcharge-to-TR mechanism. The modeling analysis based on the validated model helps to quantify the heat generation rates of each heat sources during the overcharge-to-TR process. And the two thermal runaway reactions including the electrolyte oxidation reaction and the reaction between deposited lithium and electrolyte are found to contribute most to the heat generations during the overcharge process. Further modeling analysis on the critical parameters is performed to find possible solutions for the overcharge problem of lithium ion battery. The result shows that increasing the oxidation potential of the electrolyte, and increasing the onset temperature of thermal runaway are the two effective ways to improve the overcharge performance of lithium ion battery.
The Li pre-doping free cells using tin-phosphate glass (GSPO)-silicon composite anodes and lithium-rich layered oxide (LR-NMC) cathode were developed, in which the irreversible capacity of the cathode was utilized in order to compensate that of the anode. The irreversible capacity was equalized to that of the cathode at a Si/(GSPO + Si) mass ratio, r, of 0.8. The cell using the composite anode of r = 0.8 displayed a discharge capacity of 187 mAh g−1 as the cathode capacity at 30 °C and the 0.1C-rate. The long cycle performance of over 100 charge–discharge cycles was achieved. The cells also showed an excellent high- and low-temperature performance and a good rate performance. A stable performance was observed for over 50 cycles at 60 °C and the 0.5C-rate, and a high capacity of ca. 100 mAh g−1 as the cathode capacity even at −20 °C and the 0.2C-rate. The cell could discharge even at the 10C-rate. Furthermore, the Li pre-doping free cell showed an outstanding safety performance during the nail penetration test. When the 1500 mAh cell using the composite anode was penetrated by a nail, no thermal runaway was observed during the test.
The aim of this study is to evaluate the effects of segregation and of the presence of tertiary dendrite arms in the microstructural arrangement of a Pb–Sb alloy on its resultant corrosion behavior. In this context, a water-cooled unidirectional solidification system was used to obtain alloy samples having different dendritic patterns. Electrochemical impedance spectroscopy and potentiodynamic polarization curves were used to analyze the corrosion resistance in a 0.5M H2SO4 solution at 25°C. Three different dendritic arrays were investigated as a function of the cooling rate and antimony macrosegregation profile. It was found that the tertiary dendritic arms associated with the antimony segregation have an important role on the resulting corrosion response. It is shown that the sample with a well defined tertiary dendritic array provide a more homogeneously distributed interdendritic eutectic mixture exhibiting better corrosion protection.