batterydata/paper-abstracts huggingface dataset:
Temperature dependent Co K-edge extended X-ray absorption fine structure is used to investigate local disorder in LiCoO2 nanoparticles. We find that the nanostructuring has direct influence on the bondlength characteristics. The results reveal a substantial decrease in the force constant of Co–O bonds (the Co–O bonds becoming more flexible), while that for the Co–Co bonds showing hardly any change (or increases slightly) in LiCoO2 nanoparticles with respect to the bulk. Therefore, both random disorder and Co–O bondlength flexibility should be the factors to limit the battery characteristics of the LiCoO2 nanoparticles.
Large-scale lithium-ion batteries operating at higher temperature may provide additional advantageous aspects such as higher power and use of new materials which are inactive at ambient temperatures. As a first step for this direction, we applied LiFePO4 cathode to middle-temperature region of 60 °C–115 °C and investigated temperature-dependent charge–discharge properties. By selecting suitable electrolyte and battery components tolerant to the elevated temperature, stable operation was attained for no less than 50 cycles below 115 °C. High-rate performance was significantly improved as operating temperature increased up to 100 °C, but suffered from abrupt increase in polarization above 100 °C, where the corresponding impedance signal emerged, which might be assigned to some side reactions occurring at the surface of LiFePO4 particles. At 100 °C, the discharge capacity over 100 mAh g−1 was achieved at 200C rate, even with 10wt% of carbon in the electrode composite of LiFePO4. Shrinkage of miscibility gap was not confirmed for samples larger than 40 nm at < 115 °C.
It is recognized that information on both quantity and composition of residential waste is important for the effective planning of household waste handling infrastructure. In this paper, we present the results of a survey on household waste generation and composition in Beijing, China. Sample communities were selected by the integration of five indices including family population, income, age, and education. Wastes were sampled on a daily basis from 113 households in six different districts of Beijing City for ten days. The results showed that the generation rate of household wastes was 0.23kg/pers/day. The bulk density was approximately 221kg/m3, and the moisture content was approximately 50%. Household waste consisted of kitchen waste, paper/cardboard, plastics, textiles, metals, glass and other wastes, the proportion of each waste was approximately 69.3%, 10.3%, 9.8%, 1.3%, 0.8%, 0.6% and 2.7%, respectively. An evaluation of the relationship between daily per capita generation of household waste and socio-economic factors indicated that household size and income both showed a negative relationship with household waste generation (kg/pers/day). As for the effect of education, families with a secondary educational level produced fewer household wastes (kg/pers/day) than those with a primary or advanced educational level.
There are tools and criteria in the literature aimed at distinguishing between appropriate and inappropriate medicines use. However, many have not been externally validated with regard to patient-related outcomes, potentially limiting their use in clinical practice.
The melt-spinning technique is applied to the preparation of the nanocrystalline and amorphous Mg2Ni-type alloys with nominal compositions of Mg2Ni1−x Mn x (x =0, 0.1, 0.2, 0.3, 0.4). The as-spun alloy ribbons possessing a continuous length, a thickness of about 30μm and a width of about 25mm were prepared. The structures of the as-spun alloy ribbons are characterized by XRD and TEM. The electrochemical performances of the as-spun alloy ribbons are measured by an automatic galvanostatic system. The results show that no amorphous structure is detected in the as-spun Mg2Ni alloy, whereas the as-spun Mg2Ni0.6Mn0.4 alloy displays a nanocrystalline and amorphous structure, confirming that the substitution of Mn for Ni notably intensifies the amorphous forming ability of the Mg2Ni-type alloy. The amorphization degree of the as-spun alloys containing Mn increases with increasing spinning rate. The melt spinning also significantly enhances the electrochemical performances such as the discharge capacity and the electrochemical cycle stability of the Mn-containing alloys. Furthermore, the high rate dischargeability (HRD) of the (x ≤0.1) alloys increases with an increase in the spinning rate, while for the (x ≥0.2) alloys, the HRD exhibits a maximum value at a particular spinning rate, and it varies with the change in Mn contents of the alloys.
A significant proportion of people report cognitive impairments, in particular memory problems, and express concern that these impairments will worsen with the passage of time. Unfortunately, the lack of well-designed studies has meant that disentangling the relative influences of factors likely important in the development and course of neuropsychological impairment has proved problematic. In addition to experiencing neuropsychological difficulties, people with epilepsy have to manage the psychosocial sequalae often associated with epilepsy. A diagnosis of epilepsy can have negative implications for quality of life and be associated with an increased risk of psychosocial problems; and individuals with epilepsy do not all experience its impact equally. The impacts of neuropsychological functioning on quality of life have only been rarely investigated, but there is some evidence to suggest that quality of life may correlate better with self-perceived cognitive difficulties than with scores on formal tests of cognitive functioning.
Objective Chronic fatigue syndrome (CFS) describes a condition that is primarily characterized by fatigue and flu-like symptoms that are not alleviated by rest. This study investigated the relationship among metacognitions, negative emotions, and symptom severity in CFS. Methods A total of 96 patients who had received a diagnosis of CFS according to the Oxford Criteria completed a battery of self-report measures that consisted of the Depression Anxiety Stress Scales, the 30-Item Metacognitions Questionnaire, the Chalder Fatigue Questionnaire (CFQ), and the RAND 36-Item Short-Form Health Survey-Physical Functioning. Results Correlation analyses showed that negative emotions and metacognitions were positively correlated with measures of symptom severity and that metacognitions were a better predictor of symptom severity than anxiety and depression. Hierarchical regression analyses indicated that (1) lack of cognitive confidence predicted both mental and physical factors of the CFQ and physical functioning independently of negative emotions and (2) beliefs about the need to control thoughts predicted the mental factor of the CFQ independently of negative emotions and lack of cognitive confidence. Conclusion The data support the potential application of the metacognitive model of psychological disorder to understanding CFS.
70Li2S·(30-x)P2S5·xLi3PO4 (mol%) amorphous powders are prepared by a high-energy ball milling technique, and the glass-ceramics are obtained by the crystallization of as-prepared amorphous samples. The XRD patterns show that a crystalline phase with a Li7P3S11 structure is obtained for x ≤ 3, while a structure change is observed for x = 5. The Li+-ion conductivity is enhanced by the substitution of Li3PO4 for P2S5, and the 70Li2S·29P2S5·1Li3PO4 glass-ceramics exhibit the highest total conductivity of 1.87 × 10−3 S cm−1 at 25 °C and the lowest activation energy of 18 kJ mol−1. The LiCoO2 in the all-solid-state cell of In-Li/70Li2S·29P2S5·1Li3PO4/LiCoO2 exhibits a discharge capacity of 108 mAh g−1, which is 20% higher than that in the In-Li/70Li2S·30P2S5/LiCoO2 cell. The higher discharge capacity of the LiCoO2 electrode is attributed to the higher Li+-ion conductivity of the solid electrolyte and lower interface resistance of electrode–electrolyte.
Li4Ti5O12 (LTO) is inherently a poor ionic and electronic conductor, and the modification methods available could solely meliorate either ionic or electronic conductivity. In order to simultaneously improve both the ionic and electronic conductivities, LTO was composited with Li2ZrO3 accompanying with superficial Zr4+ doping by the simple reaction between Zr(NO3)4·5H2O and LiNO3 on the LTO surface. From the comparative experiments, the as-modified LTO with a Li2ZrO3/LTO mass ratio of 0.009 and sintered at 750 °C exhibits the most excellent rate performance (achieving capacities of 155.3, 149.6, 145.4, 139.6, 130.2 and 153.2 mAh g−1 at 100, 200, 400, 800, 1600 and 100 mA g−1, respectively) and long-term cyclability (retaining a capacity of 102 mAh g−1 after the 2000th cycle at 500 mA g−1). By the detailed structural characterization and electrochemical impedance spectra analysis, the formation of the tetragonal Li2ZrO3 with good ionic conductivity and the superficial Zr4+ doping with improved electronic conductivity is responsible for the markedly enhanced cycling and rate performance of LTO.
Scientific journals play a critical role in research validation and dissemination and are increasingly vocal about the identification of research priorities and the targeting of research results to key audiences. No new journals specialising in health policy and systems research (HPSR) and focusing in the developing world or in a specific developing world region have been established since the early 1980s. This paper compares the growth of publications on HPSR across Latin America and the world and explores the potential, feasibility and challenges of innovative publication strategies.
Aim of the study A knowledge attitude and practice study centred on leishmaniasis and its treatment was performed among the Chayahuita, an Amazonian Peruvian ethnic group living in an endemic area. This study documents traditional Chayahuita plant's use and disease concepts. Also, activty of some medicinal plants used by the Chayahuita is highlighted and discussed. Materials and methods Ninety-three Chayahuita people were interviewed, following a semi-structured questionnaire focussed on disease knowledge and perception, personal attitude and healing practices. Simultaneously, a collection of plants was performed in different ecotopes, in order to make an extensive inventory of the pharmacopoeia. Results For the Chayahuita, cutaneous (CL) and muco-cutaneous leishmaniasis (MCL) are considered as diseases of their own, with specific names, aetiologies, mode of transmission. Regarding CL, Chayahuita people consider that the humid characteristic of the skin ulcer is a discriminative fact orienting the diagnostic forTa’ta’ (leishmaniasis). Forty-six different species were designated useful against LC and /or MCL (29 species by means of the questionnaire and 27 species when collecting in different ecotopes). Thirty-seven extracts corresponding to 31 species used medicinally were screened in vitro against Leishmania amazonensis axenic amastigotes, assessing their viability by the reduction of tetrazolium salt (MTT). Six species displayed a good activity (10μg/ml<IC50<20μg/ml): an undetermined hemi-epiphytic Clusiaceae, Cybianthus anthuriophyllus Pipoly (Myrsinaceae), two Piper, Piper sanguineispicum Trel., and Piper loretoanum Trel. (Piperaceae), Desmodium axillare Sw. DC. (Fabaceae), and Clibadium sylvestre (Aubl.) Baill. (Asteraceae). Conclusion Perception of leishmaniasis, attitude, treatments and diet prohibitions still largely reflects traditional Chayahuita cosmovision, even if some tentative of bio-medical re-interpretation is arising.
The paper presents the model of two variants of a’fortiori reasoning applicable in the case of statutory law as well the example of the genuine law case, which has been modeled with use of established methodology. The model of reasoning assumes the existence of “less–more” relation between the analyzed actions, which has been expressed by means of strict partial order and some additional assumptions. The paper also contains the implementation of the analyzed example.
High surface area metal electrodes are desirable for applications in energy storage and energy conversion. Here, the formation and electrochemical characterization of a hybrid material made by electroless deposition of gold onto a scaffolding of vertically aligned carbon nanofibers is described. Vertically aligned carbon nanofibers, ∼80nm in diameter, provided mechanical support and electrical contact to the highly textured nanoscale gold coatings. By chemically functionalizing the nanofiber surfaces and then using electroless deposition methods, a highly textured metal coating was formed. The electrochemical response of these “nano-on-nano” hybrid electrodes was characterized using electrochemical methods. The results show that using the metallic coatings can increase the electrochemically active surface area by up to a factor of 10 compared with the starting carbon nanofiber scaffolds. The electrochemical response of the electrodes was modulated by varying the deposition time of the gold.
Nanocrystalline Mn-substituted lithium ferrites were synthesized by sol–gel method. The structural data show that, the cubic phase was converted into tetragonal phase observed by XRD analysis. X-ray photoelectron spectroscopy has been used to characterize valence state of materials and the composition of the products. The electrical property study was carried out by using two probe methods and it is revealed that the all Mn substituted ferrites are semiconducting in nature. Thermoelectric power measurement also confirms 1.5⩽ x ⩾0.0 N-type and 2.5⩽ x ⩾2.0 shows the P-type semiconducting nature of Mn-substituted lithium ferrites. The effect of manganese substitution in lithium ferrites has a crucial role on the structural and electrical properties of the system.
Solid anion-exchange membranes that display interpenetrating polymer network (IPN) architecture were developed to be assembled on air electrode surface to improve its electrochemical stability in alkaline environment. The IPN membranes associate an anionic conducting polyepichlorohydrin network entangled within a cross-linked poly(2-hydroxyethyl methacrylate) in different mass proportions. The membranes possess suitable mechanical and thermal properties, an ionic conductivity of about 1×10−3 Scm−1 and suitable cation selectivity. The electrochemical behaviour of the air electrode/IPN membrane assemblies (AEMA) were then evaluated in LiOH 5M. The polarization curves indicate that a good electrochemical interface was established between the electrode and the IPN membranes. Moreover, the AEMA exhibits a discharge stability in LiOH 5M ten times higher compared to a bare electrode under the same conditions.
We report synthesis of lithium poly (4-vinylphenol) phenolate borate (LiPVPPB) single-ion conductor comprised of boron atoms with sp3 electronic configuration covalently bonded to a polystyrene backbone with high thermal and electrochemical stability. The highly delocalized anionic charges surrounding the boron atoms in the polymer give rise to weak association with lithium ions in the polymer matrix, resulting in an ion transference number close to unity and remarkably high ionic conductivity. A composite membrane blended with LiPVPPB and poly(vinylidene-fluoride-co-hexafluoropropene) (PVDF-HFP) was fabricated. The battery of the electrolyte displays excellent cyclability with nearly 100% coulombic efficiency over a wide temperature range. The superior membrane performance suggests that single ion polymer electrolyte materials are highly promising for safe and high power applications of lithium ion batteries.
This study is related to results gained from “Primary School Students’ Science Summer” project which was supported by TÜBİTAK as part of Science and Society projects. Primary purpose of this study is to generalize such projects and sharing with scientists for shedding a light on further studies by determining how science and art activities were being evaluated from students’ point of view. The second purpose of the research is to state if getting involved in such projects generates a positive change on attitudes of students towards science. It was found that students’ views were generally positive about the activities done during five days of summer science school.
We show that employing single wall carbon nanotubes (CNTs) as the conducting agent significantly increases the capacity of silicon oxycarbide anodes at high C-rates. In these anodes 515mAhg−1 can be extracted in just over 3min. The capacity decreases to 300mAhg−1 at the same extraction rate when carbon black is used as the conducting agent. The CNT anodes have good cyclic stability, retaining 89.2% of initial capacity after 40 cycles. The coulombic efficiency ranges from 95% to 100%.
As the cost of renewable energy falls below fossil fuels, the key barrier to widespread sustainable electricity has become availability on demand. Energy storage can enable renewables to provide this availability, but there is no clear technology that can meet the low cost needed. Thus, we introduce a concept termed thermal energy grid storage, which in this embodiment uses multi-junction photovoltaics as a heat engine. We report promising initial experimental results that suggest it is feasible and could meet the low cost required to reach full penetration of renewables. The approach exploits an important tradeoff between the realization of an extremely low cost per unit energy stored, by storing heat instead of electricity directly, and paying the penalty of a lower round trip efficiency. To understand why this tradeoff is advantageous, we first introduce a general framework for evaluating storage technologies that treats round trip efficiency, as well as cost per unit energy and power, as variables.
The effects of three types of straight chain polyols (propanetriol, butantetraol, and pentitol) and one branched chain polyols pentaerythritol as electrolyte additives on the electrochemical properties of gelled electrolyte valve-regulated lead-acid (GEL-VRLA) batteries were systematically studied. Our result shows that a moderate mechanical dispersion of fumed silica in H2SO4 solution is beneficial to improve the electrochemical properties of the gelled electrolyte. Adding of straight chain polyols (propanetriol, butantetraol, and pentitol) can decrease not only the optimum dispersion time, but also the electrolyte resistance of the gel. The optimum dispersion time needed is pure (90minutes)>adding pentitol (80minutes)>adding butantetraol (70minutes)>adding propanetriol (60minutes). Furthermore, the optimum agitation time can be reduced by 88% with adding of branch chain polyols pentaerythritol. Also, the charge-transfer resistance (Rct) of gel can be reduced by more than one order of magnitude. More important, the peak current (capacity) of the lead electrode is stable with agitation time, which is significant for practical application. The adding of pentaerythritol makes the gel more uniform and porous, demonstrating that it is a promising gel electrolyte for VRLA batteries.
The parallel hybrid-vehicle system discussed here features two mechanisms: an internal-combustion-engine energy-distribution mechanism and dual energy-integration mechanism. The former comprises a first pulley set and a second pulley set, whereby it is possible to adjust its radius ratio and change the road surface oriented output load, output speed and required load, to maintain an optimal operating state for the internal-combustion engine at a given generator rotational speed. In this way, the engine can be maintained in an optimal state. For the dual energy-integration mechanism, any power source can be individually actuated by an electric motor and the power transmitted from the internal-combustion engine energy-distribution mechanism. Moreover, a one-way clutch can prevent the actuated power source from reversion, so any output power source will not be affected by another inactive power source. Also, the two input power-sources can be integrated into a bigger power source via a dual energy-integration mechanism, thus resulting in twice the output energy and obtaining the necessary tractive power to reach the road surface. A dynamic equation is therefore derived for this system to obtain the flow direction of the power source. Furthermore, dynamic equations of various system components can be established by modularized software Matlab/simulink and fuzzy logic are used to control and develop this system’s dual energy-integration mechanism as a control strategy. After the engine’s energy is distributed by the controller of the dual energy-integration mechanism, decelerated by the reduction ratio of the first pulley set of internal combustion engine distribution mechanism and added to the generator torque energy transmitted from second pulley set, the engine can maintain an optimum state under various operating conditions.
In this study, we report the effect of the crystallographic orientation of silicon nanowires (SiNWs) on electrochemical performance as a negative electrode material. We synthesize vertically aligned SiNWs from differently oriented Si substrates with axial orientations of Si <100>, <110>, and <111> by the metal-assisted chemical etching method. To investigate the influence of a carbon matrix on SiNWs, various ratios of carbon/SiNWs are incorporated into negative electrode materials. The electrochemical performance of the <110>-SiNWs is greatly improved by increasing the carbon/SiNWs ratio from 0.5 to 2 compared to <100> and <111>-SiNWs. The electrochemical results reveal that a reversible capacity of more than 3200 mAh g−1 at a current rate of 0.1 C was obtained by using <110>-SiNWs with a carbon/SiNWs ratio of 2. The enhanced electrochemical performance is attributed to the relatively large interspacing between atoms along the <110> direction, which is much larger than those along the <100> and <111> directions. We also suggest that a large amount of carbon accommodates the volume expansion that occurs during the Li alloying/dealloying processes with Si and increases the electronic conductivity.
Inverse spinel LiNiVO4 thin films were prepared by rf-sputtering, fallowed by films annealed at 300, 450 and 600°C for 2h to induce the crystallization of the films. The films were characterized by X-ray diffraction, Rutherford backscattering spectroscopy, nuclear reaction analysis, Auger electron spectroscopy, atomic force microscopy and scanning electron microscope techniques. The Anodic electrochemical performance films have been cycled in the range of 0.02–3.0V, at room temperature, at a current density 75μAcm−2. Galvanostatic cycling and cyclic voltammetry results shows characteristic cycling curves with respect to annealing temperature. The films annealed at 450°C showed best electrochemical performance and excellent capacity retention during cycling was observed due to its nanosized morphology.
Abstract A solid oxide fuel cell (SOFC) is a device in totally solid state that can convert chemical energy of various fossil fuels into electric energy directly via electrochemical reaction, at a low pollution level and it possesses high efficiency. In this chapter, the basic characteristics of SOFCs are introduced. The working principle and properties requirements of SOFC components such as electrolyte, anode, cathode, interconnect, and sealant were demonstrated, subsequently the commonly used materials for SOFC components were reviewed. Most of these materials are ceramics or composites that contain ceramics. To meet the property requirements for the operation of SOFCs, the performance of the typical materials was optimized via composition adjustment and preparation procedure control. Sometimes it needs to combine different types of materials to obtain their advantages. This shows us some methods and experiences to improve the performance of ceramic materials. This chapter also provides the readers with the basic knowledge on SOFCs.