batterydata/paper-abstracts huggingface dataset:
The 5V spinel LiNi0.5Mn1.5O4 cathodes have been surface-modified with ZnAl2O4 by a sol–gel method and characterized by X-ray diffraction, high-resolution transmission electron microscopy, and electrochemical measurements. Although the pristine electrode experienced the prominent degradation after the storage test at 60°C in the intervals of cycling test at room temperature, the ZnAl2O4-coated LiNi0.5Mn1.5O4 cathode exhibited the significant capacity retention even after storing at elevated temperatures. The X-ray photoelectron spectroscopy data reveals that the improved electrochemical performances of surface-coated cathode are mostly due to the suppressed side reaction between the cathode and the electrolyte especially at the high-temperature environment. Differential scanning calorimetry showed that the decreased heat evolution could be found with the surface-modified cathode. Our experimental findings suggest a direction to the further development of cathode materials which are endurable to the highly oxidized state and high-temperature environment.
We report for the first time the enhanced capacitance of multi-walled carbon nanotubes (MWCNTs) after exfoliation. Transmission electron microscopy studies confirmed that the MWCNTs were partially exfoliated with improved effective surface area. Carbon cloth electrode deposited with partially exfoliated carbon nanotubes (Ex-CNTs) yielded specific capacitances in a range of 130–165Fg−1 at charging/discharging current densities from 5 to 0.5Ag−1, with coulombic efficiencies of ∼98%. The specific capacitance of Ex-CNTs was an order of magnitude higher than untreated MWCNTs, and comparable to graphene at all charging/discharging current densities we studied. The enhanced capacitance can be attributed to improved effective surface area and increased defect density of the exfoliated tubular structure. The results declared that Ex-CNTs are promising electrode materials for high-capacitance supercapacitors.
ABSTRACT Herein, we report an effective, fast and controllable electrochemical synthesis of layered structure LiNbO2 by electrolysis of solid Nb2O5 in molten LiF-LiCl salt. For the first time, the electrochemical performance of LiNbO2 as an anode for lithium ion battery is investigated. Such a material shows a high reversible capacity of ∼190mAhg−1 at 0.25C (1C=200mAg−1), superior rate capability (52mAhg−1 at 80C) and excellent long-term cycle stability (75mAhg−1 after 1000 cycles at 50C), due to the favorable kinetics benefiting from the high electronic conductivity and fast lithium diffusion in layered crystal structure of LiNbO2. It indicates that LiNbO2 is a promising anode candidate. Moreover, this work may provide a facile and controllable way to synthesize electrode materials for lithium ion batteries and other electrochemical energy storage applications.
Nitrogen-doped graphene as a metal-free catalyst for oxygen reduction was synthesized by heat-treatment of graphene using ammonia. It was found that the optimum temperature was 900 °C. The resulting catalyst had a very high oxygen reduction reaction (ORR) activity through a four-electron transfer process in oxygen-saturated 0.1 M KOH. Most importantly, the electrocatalytic activity and durability of this material are comparable or better than the commercial Pt/C (loading: 4.85 µgPt cm−2). XPS characterization of these catalysts was tested to identify the active N species for ORR.
Résumé Introduction La batterie RAPID regroupe des tests neuropsychologiques étalonnés de façon isolée sur des populations différentes. L’objectif de cette étude est d’établir des normes comparatives pour la batterie RAPID à partir d’un même échantillon de sujets. Population et méthodes La batterie RAPID comprend neuf tests : score de mémoire avec indiçage, Set Test d’Isaacs, Mini-Mental State Examination, test de rappel Libre/rappel Indicé à 16 items, Trail-Making Test, Crossing-Off Test, copie des trois triangles de la BEC 96, test de dénomination orale de 30 images, test d’appariement catégoriel. Des sujets âgés de 50 ans à 89 ans ont été sélectionnés par tirage au sort dans 11 cabinets de médecine générale. Résultats Les normes ont été établies sur 476 sujets répartis selon quatre classes d’âge (50–59 ans, 60–69 ans, 70–79 ans et 80–89 ans) et trois niveaux scolaires. Le premier niveau scolaire est constitué des sujets sans diplôme et/ ou ayant le Certificat d’Etudes Primaires. Le deuxième niveau est constitué des sujets ayant le brevet et/ ou le certificat d’aptitudes professionnelles. Le dernier niveau est constitué des sujets ayant le baccalauréat et/ ou ayant fait des études supérieures. La plupart des tests ne suivant pas une loi normale, le 10e, le 25e, le 75e, le 90e percentile et la médiane ont été calculés pour chaque score de test. Les résultats indiquent un taux de participation élevé (75 %). Les scores augmentent avec le niveau scolaire et diminuent avec l’âge. Ces résultats sont donc similaires à ceux obtenus dans d’autres études, cependant on constate une variabilité des valeurs, notamment pour le percentile 10. Conclusion Ces normes, issues d’un même échantillon, facilitent la comparaison des résultats entre les tests de la batterie RAPID et permettent l’interprétation des résultats en termes de profil cognitif.
We report on a novel method for in situ lithiation of lithium free TiS2 using Li3N in an all-solid-state battery configuration. This method was tested using a Li3N–TiS2–80Li2S:20P2S5 composite positive electrode and an indium metal negative electrode. It is shown that approximately 37% of Li3N spontaneously decomposes during composite preparation regardless of the composition. Solid-state battery cells built with a 3:1 stoichiometric ratio of Li:Ti demonstrated a high 1st cycle charge capacity of 287mAhg−1, 20% greater than the theoretical capacity of TiS2 at 239mAhg−1. The difference provides an excess capacity in the indium metal negative electrode.
Crops are constantly faced with the challenges of different abiotic stresses on the field. Development of sustainable approach for stress amelioration on crop is pertinent. This study investigated the ameliorative roles of biochar and compost on maize crop simultaneously subjected to drought and heavy metal (Pb) stresses. Metal stress was imposed by growing maize on Pb-contaminated soil while drought stress was imposed by reducing the soil field capacity to 25 and 50%. Four levels (0, 5, 10 and 15 t/ha) of biochar and compost replicated three times as well as their combinations were used. Pb uptake, translocation factors, photosynthetic pigments, osmolytes (proline and cysteine), biomass accumulation in stressed maize crop, and post-cropping soil Pb concentration were determined. Combination of stresses reduced biomass accumulation in maize. Biochar in combination with compost, however, enhanced biomass production in stressed maize crop by 50–75% compared to unamended soil (control). Proline accumulation was more under the single stress of heavy metal (100% FC) compared to combined stresses. Unlike proline, combined stresses of Pb and 50% FC enhanced chlorophyll and cysteine accumulation more than single stress. Their concentrations were further increased with amendments compared to control. Pb accumulation in maize crop was more under combined stresses than single stress (100% FC). Compared to other soil amendments, application of biochar alone at 10 t/ha, generally reduced Pb uptake by maize and post-cropping soil Pb concentration. Biochar and compost reduced Pb uptake, and enhanced biomass and osmolyte production in stressed maize crop.
This study demonstrates the first example of a stretchable and wearable textile-based hybrid supercapacitor–biofuel cell (SC–BFC) system. The hybrid device, screen-printed on both sides of the fabric, is designed to scavenge biochemical energy from the wearer's sweat using the BFC module and to store it in the SC module for subsequent use. The BFC relies on lactate, which is oxidized enzymatically to generate electricity. The generated bioenergy is stored directly and rapidly in the printed in-plane SCs. The SC energy-storage module employs MnO2/carbon nanotube composites that offer high areal capacitance and cycling electrochemical stability. Both printed SC and BFC devices rely on optimal elastomer-containing ink formulations and serpentine structure patterns that impart a stable electrochemical performance after a variety of mechanical deformations. Such a fabrication route ensures that the energy-harvesting and storage properties of the two integrated devices are not compromised. The SC–BFC hybrid system can thus deliver stable output over long charging periods, boost the voltage output of the BFC, and exhibit favorable cycling ability. Such attractive performance, demonstrated in successful on-body testing, along with the unique architecture and low-cost scalable fabrication, make the new garment-ased hybrid energy device useful for meeting the power and mechanical resiliency requirements of wearable electronics and smart textiles.
Political participation is a mainstay of political behavior research. One of the main dilemmas many researchers face pertains to the number of dimensions of political participation, i.e. whether we should model political participation as a unidimensional or multidimensional latent construct. Over the years, scholars usually have favored the solution with more than one dimension of political participation and they have backed the claim of multiple dimensions with a number of empirical tests. In this paper, I argue that the results from the frequently used testing procedures which rely on the model fit inspection and the Kaiser criterion can be very misleading and may yield in extracting too many dimensions. By employing bi-factor modeling to a European Social Survey dataset, I show that in a majority of countries political participation can be considered an essentially unidimensional latent quantity. I demonstrate that additional dimensions of political participation are very weak and unreliable and that we cannot regress them on external variables nor build composite scores based on them. These findings cast doubt on the conclusions of numerous previous studies where researchers modeled more than one dimension of political participation.
The number of women in the workforce is continuing to increase and surveys suggest that one-fourth of employed women with a child less than 1 year of age will be concurrently breastfeeding and working for at least 1 month. Combining breastfeeding and employment is a complex process in American society. Women will be seeking practical, sound advice on how to be successful in this combination. This article offers suggestions for promoting its success, describes the pre-planning that needs to occur, and provides current lactation recommendations and resources. It also offers information about working with employers, the importance of a support network, decisions that each family must make, the use of breast pumps, milk storage, lactation enhancement including the use of herbs, and practical tips for the mother’s working day.
This paper proposes a refocusing of consent for clinical genetic testing, moving away from an emphasis on autonomy and information provision, towards an emphasis on the virtues of healthcare professionals seeking consent, and the relationships they construct with their patients.
The oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) of air electrodes consisting of La0.5Sr0.5CoO3 and/or carbon in the electrocatalyst layer are studied by using two types of gas diffusion electrodes. Cyclic voltammetry and square wave voltammetry studies reveal very low ORR activity of carbon-free perovskite and remarkably enhanced ORR of perovskite-carbon composites. The ORR current density at −0.5 V vs. Hg/HgO is higher than 200 mA cm−2 in a wide range of perovskite-carbon composition, suggesting good peroxide reducing capability of the perovskite. The ORR mechanisms of perovskite-carbon composites are consistent with the 2+2-electron mechanisms. The ORR and OER properties of perovskite-carbon composite electrodes are significantly influenced by the carbon species. The electrode exhibits a higher ORR current density, but inferior cycling performances when a carbon material with a higher specific surface area is used, and vice versa. Under a current density of 20 mA cm−2 and ORR and OER durations of 30 min, a gas diffusion type electrode consists of La0.5Sr0.5CoO3 and a low surface area carbon are capable of more than 150 cycles.
A large proportion of university students are now part of the millennial generation. Mobile technology is now an integral part of their everyday life. We studied the students’ viewpoints about the educational use of mobile technology to support their learning process. Among 2140 students of Psychology and Educational Science in Islamic Azad university of South Tehran Branch, 289 students were selected by using cluster random sampling method. Researcher-made Likert-type questionnaire developed (reliability based on Cronbach's alpha = 0.87). We used U Mann-Whitney test to evaluate the impact of gender and educational course on the rate of the educational use of mobile, kruskal-Wallis test to assess the impact of academic major on the rate of educational use of mobile, and one- sample t- test to assess the effective factors on the rate of the educational use of mobile. The most educational use of mobiles by university students are calculator usage, text messaging, and English dictionary. Having a mobile with multiple capabilities, long battery life and good network coverage are the most influential factors in the educational use of mobiles. Gender has a significant effect on the educational use of mobile, but the academic major and course doesn’t have any significant effect on educational use of mobile by the university students. The findings of current research could help authorities in Iran and possibly other developing countries to lay practically the ground for mobile-based learning in universities.
Despite the recent progress in Zn-air battery fabrication, the development of highly electroactive, non-precious-metal-based, and durable electrocatalysts for such batteries remains challenging. To address this issue, spinel-type MnCo2O4.5 nanoparticles (NPs) prepared by a solvothermal method followed by calcination were characterized by a range of instrumental techniques and employed in rechargeable Zn-air batteries to promote the oxygen reduction and oxygen evolution reactions. The bifunctional activity of the MnCo2O4.5 NPs was further evaluated by linear sweep voltammetry, which showed that both the reduction and oxidation current densities obtained in the presence of this catalyst exceed those observed with catalyst-free carbon. Moreover, the incorporation of the MnCo2O4.5 NPs into an air-breathing cathode resulted in a decreased charge–discharge voltage gap and improved round-trip efficiency. Therefore, these MnCo2O4.5 NPs are a highly beneficial and novel kind of bifunctional electrocatalyst for rechargeable Zn-air batteries.
The effects of changing the dipping and curing times of tubular positive electrodes on the discharge capacity were investigated. The comparative study showed that longer dipping and curing times do not necessarily result in electrodes with better first capacity performance. Acid adsorption studies of tubular plates filled with lead oxide showed that about one-third of the acid, that would have been adsorbed after 15h, was already adsorbed after 5s of dipping. The optimum surface area and porosity of the cured active material was obtained after 15–60min of dipping. This is equivalent to the rest period used in the formation process where the plates are kept in the acid just before charging. Curing times should be kept around 24h in order to reduce the free lead in the oxide. The study showed that the pore size distribution of the formed active material influenced the high current discharge ability more than the available surface area of the positive electrode. However, the surface area and pore size distribution changed dramatically during capacity cycling and the continuous capacity performance of the tubular electrode was partially influenced by the initial characteristics of the cured active material.
A history of the term and concept of learning disabilities precedes a discussion of why the term best captures the common thread of all developmental disorders of learning. To give the reader a picture of the field today, current knowledge of the phenomenology, epidemiology, etiology, mechanisms, diagnosis, and treatment options for learning disabilities is presented.
Harsh operating conditions, such as high temperatures, hinder the grid-scale application of liquid metal batteries (LMBs). Now, their operating temperature is shown to be substantially lowered thanks to a lithium-ion-conducting solid-state electrolyte.
Three Li3-xNaxV2(PO4)3 (x=0.5, 1.5 and 2.0) samples are synthesized by a traditional solid-state reaction method in this work. Their phase composition, surface morphology and electrochemical property are described and compared by using various physical/chemical methods. Phase analysis results reveal that Li2.5Na0.5V2(PO4)3 consists of monoclinic Li3V2(PO4)3, rhombohedral Li3V2(PO4)3 and rhombohedral Na3V2(PO4)3. While, both Li1.5Na1.5V2(PO4)3 and LiNa2V2(PO4)3 are the two-phase mixture consisted of rhombohedral Li3V2(PO4)3 and rhombohedral Na3V2(PO4)3. Electrochemical testing results reveal that LiNa2V2(PO4)3 and Li1.5Na1.5V2(PO4)3 can deliver the initial discharge capacities of 101.4mAhg−1 and 108.6mAhg−1 with a long potential plateau at 3.69V, respectively. In contrast, Li2.5Na0.5V2(PO4)3 presents an initial discharge capacity of 111.7mAhg−1 with four potential plateaus. High lithium ion diffusion coefficient in Li2.5Na0.5V2(PO4)3 indicates that the existence of monoclinic Li3V2(PO4)3 phase can improve the ionic conductivity and then be responsible for good electrochemical performance. Besides, in-situ X-ray diffraction observation of LiNa2V2(PO4)3 demonstrates that the phase transition is not fully reversible but quasi-reversible during the lithiation-delithiation process. The partial irreversibility of structural evolution for LiNa2V2(PO4)3 induces the capacity loss upon repeated cycles.
Our research group has previously demonstrated that the peripheral motion contrast threshold (PMCT) test predicts older drivers’ self-report accident risk, as well as simulated driving performance. However, the PMCT is too lengthy to be a part of a battery of tests to assess fitness to drive. Therefore, we have developed a new version of this test, which takes under two minutes to administer. We assessed the motion contrast thresholds of 24 younger drivers (19–32) and 25 older drivers (65–83) with both the PMCT-10min and the PMCT-2min test and investigated if thresholds were associated with measures of simulated driving performance. Younger participants had significantly lower motion contrast thresholds than older participants and there were no significant correlations between younger participants’ thresholds and any measures of driving performance. The PMCT-10min and the PMCT-2min thresholds of older drivers’ predicted simulated crash risk, as well as the minimum distance of approach to all hazards. This suggests that our tests of motion processing can help predict the risk of collision or near collision in older drivers. Thresholds were also correlated with the total lane deviation time, suggesting a deficiency in processing of peripheral flow and delayed detection of adjacent cars. The PMCT-2min is an improved version of a previously validated test, and it has the potential to help assess older drivers’ fitness to drive.
Na2Li2Ti6O14 was successfully prepared by a solvothermal method. The XRD patterns show that the as-prepared samples have good purity and crystallinity. Further Rietveld refinement and theoretical calculation suggested that lithium should occupy 16n and 8e sites of the lattice during the intercalation process, and nearly six lithiums can be inserted reversibly into the lattice. The amount of ammonium hydrogen carbonate added during the reactions have significant impacts on the structures and morphologies of the materials, and well-defined hierarchical and porous spheres can be obtained at a suitable condition. The electrochemical tests showed that the charge/discharge specific capacities of the four samples under a current density of 50 mA g−1 after 50 cycles are 103.9/104.3, 175.1/177.1, 191.9/194.1, and 138.4/140.4 mA h g−1, suggesting that the performance of the NLTO-L-3 is much better than other samples. Furthermore, NLTO-L-3 also exhibits good cycling stability and rate capability, and its revisable capacity is about 93 mA h g−1 at 2.8 A g−1 after 500 cycles. The excellent performance can be attributed to the hierarchical structures and porous characteristics. These features are helpful for reducing the impedance and for improving the diffusion dynamics of materials, as further confirmed by EIS measurement.
The growing awareness of public procurement as an innovation policy tool has recently sparked the interest of both policy makers and researchers. While an increasing number of studies is being published every year, an overview of the field is missing. Researchers, practitioners, and policy makers are often using ambiguous wording and have not yet reached consensus on the terminology and concepts involved. This state of affairs leads to research fragmentation and lack of knowledge convergence. For the purpose of contributing to knowledge synthesis and consolidation, this article provides a structured review of the literature on innovation in public procurement. From categorizing publications based on innovation drivers, concepts, and research approaches, the emerging structure of the field is described and synthesized into a framework of innovation in public procurement. The proposed framework differentiates between literature streams on (1) innovations in the public procurement process, (2) innovation of public services by means of procurement, and (3) the use of public procurement as a tool for demand-side innovation policy-making. For each of these streams of literature, different focus areas as well as research gaps and opportunities for future research are identified. Based on analysis of existing research, the proposed framework provides an overview of state-of-the-art knowledge, a unified terminology, and a holistic understanding of innovation in public procurement. The framework is both a point of departure for future research and a source of knowledge for practitioners.
Early detection of a high-risk patient following hip fracture surgery is of paramount clinical importance. American Society of Anesthesiologists (ASA) grading is an easy and efficient index in predicting a worse outcome. The red cell distribution width (RDW) and handgrip strength, are gaining interest as a prediction tool as well. Accordingly, the objective of this study was to investigate the potential association between ASA, RDW and grip strength and detect the effects of combining RDW and grip strength for predicting early complication after hip fracture surgery in the elderly.