batterydata/paper-abstracts huggingface dataset:
In this paper we present a flexible single layer triboelectric generator (S-TEG). The device consists of two fixed intedigital electrodes on the top and bottom surfaces of a polyimide substrate. In operation, the S-TEG is a fixed surface. Electricity is generated by sliding friction with external objects. In comparison to traditional TEGs with movable electrodes, the fixed electrodes on S-TEG simplify packaging process. Charges of hundreds nC can be generated by a rod sliding on the S-TEG. Due to the interdigitated shape of the electrodes energy harvesting is still possible regardless of the material of the scratching rod. Various materials can be utilized to generate electricity free of the limitation of triboelectric properties, which greatly broadens the S-TEG׳s application field. In addition, the output voltage can be greatly enhanced by using the slippage of two S-TEGs. When one S-TEG slides on another, the maximum peak output voltage can reach 342.8V and more than 1000nC charges are transferred in each sliding cycle. Owing to the simple fabrication process, S-TEG devices using this structure are suitable for mass production. A demonstration was conducted to illustrate the potential of this S-TEG device to harvest energy from sliding surfaces encountered in daily life. An S-TEG integrated in a computer mouse pad can sufficiently drive 20 LEDs and a LCD screen.
The development of cost-effectiveness and efficient bifunctional electrocatalysts is essential for the commercialization of rechargeable metal-air batteries. Herein, a controlled one-step alginate biomass carbonization strategy is presented to prepare the FeCox alloy nanoparticles encapsulated in N-doped porous carbon/multiwalled carbon nanotubes composites (FCx-NC/CNTs). Benefiting from the particular core-shell structure, high dispersion of active sites (FeCox alloy nanoparticles) and fine conductive network (CNTs and N-doped porous carbon), the optimized FCx-NC/CNTs-10 (containing 10 wt% CNTs in FCx-NC/CNTs) hybrid displays a remarkable bifunctional activity and long-term stability for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Notably, the corresponding bifunctional activity parameter (ΔE) is as low as 0.80 V, outperforming most state-of-the-art reported bifunctional electrocatalysts. Moreover, the FCx-NC/CNTs-10 based rechargeable Zn-air battery exhibits a fast dynamic response and an excellent rechargeability with a high peak power density of 156 mW cm−2 and a narrow voltage loss after continuous operating 430 cycles (∼144 h). This kind of FCx-NC/CNTs hybrid with excellent electrochemical catalytic activity provides a great potential in metal-air batteries.
Remembering meaningful information is an important component of verbal memory. However, findings from existing story memory tests have been mixed in patients with temporal lobe epilepsy (TLE). We developed a test, the Story Learning and Memory (SLAM) test, in which a story is presented repeatedly until a performance criterion is reached, and verbatim recall is obtained only once, after a delay. In Study 1 we demonstrated a significant learning deficit in patients with left, but not right, TLE, and they were further impaired in retention of the story despite having learned it to the same criterion as subjects with right TLE and healthy subjects. These deficits remained confined to patients with left TLE after surgery. For clinical use we developed the SLAM in three versions in two languages; in studies 2 and 3 we tested and proved their equivalence.
Aims of this study Centella asiatica has a reputation to restore decline cognitive function in traditional medicine and in animal model. However, little evidence regarding the efficacy of Centella asiatica from systematized trials is available. Therefore, the present randomized, placebo-controlled, double-blind study investigated the effect of Centella asiatica on cognitive function of healthy elderly volunteer. Materials and methods Twenty-eight healthy elderly participants received the plant extract at various doses ranging 250, 500 and 750mg once daily for 2 months. Cognitive performance was assessed using the computerized test battery and event-related potential whereas mood was assessed using Bond–Lader visual analogue scales prior to the trial and after single, 1 and 2 months after treatment. Results The results showed that the high dose of the plant extract enhanced working memory and increased N100 component amplitude of event-related potential. Improvements of self-rated mood were also found following the Centella asiatica treatment. Conclusion Therefore, the present findings suggest the potential of Centella asiatica to attenuate the age-related decline in cognitive function and mood disorder in the healthy elderly. However, the precise mechanism(s) underlying these effects still require further investigation.
ABsTRACT In lithium ion batteries, high-capacity anodes that undergo very large volume change during charge/discharge cycles are needed to apply a strongly adhesive polymer binder due to the severe mechanical stress developed during the cycles. Although bio-derived alginate is known to be a potential candidate for the binder owing to its strong mechanical property, it can be improved using a number of modifications such as physical crosslinking. Here, we propose a significantly better method of improving the electrochemical performance of the binder by introducing dual-crosslinked alginate with polyacrylamide. The polyacrylamide provides strong adhesion in the electrode with resistance to the penetration of the organic electrolyte. Both ionic and covalent crosslinkings in the binder maintain their intrinsic good binding properties and additionally enhance lithium ion diffusion. More interestingly, an in-situ electrochemical dilatometer study indicates that the dual-crosslinked binder is considerably helpful to prevent volume expansion beyond the inevitable value caused by active materials in electrodes during the cycle. Consequently, the Si/C (1/3) electrode retains nearly 840 mAh g−1 high capacity even after one hundred cycles with excellent cycleability.
In this paper, we have prepared the carbon-coated Li9V3(P2O7)3(PO4)2 (LVPP/C) composite via a simple carbon thermal reduction and its lithium inserted-extracted mechanism are systematically investigated. LVPP/C cathode can keep a reversible capacity of 100.6mAhg−1, 98.7% of the initial discharge capacity, after 50 cycles within 2.5V–4.6V, while an obviously capacity-fading is observed within 2.5V–4.8V. Meanwhile, the LVPP/C anode delivers a well rate capability and, a reversible capacity of 94.5mAhg−1 (1.0–2.5V) can still be retained after 60 cycles, ranging from 0.1C to 2C and finally in 0.1C succession. A good preservation of the LVPP structure is observed during the discharge-charge process by in-situ XRD and an intercalation reaction mechanism is also confirmed for LVPP/C anode here for the first time. At last, a novel symmetrical full battery by using LVPP/C as both cathode and anode simultaneously has been successfully assembled. The investigation shows that this symmetrical cell, with an average voltage of 2.5V, can deliver a reversible capacity of 59.8mAhg−1 after 30 cycles at 0.1C.
Publisher Summary This chapter helps learn the basic theory of electricity. It begins with the description of Ohm's law, which states that voltage equals current multiplied by resistance. This law is one of the best taught principles in school for the budding engineer or technician. All other rules are based on this foundation. Its fundamental fact is that resistance impedes current flow. This impedance creates a voltage drop across the resistor that is proportional to the amount of current flowing through it. The chapter considers two other types of impedance that can be found in a circuit: inductive reactance and capacitive reactance. Every wire, trace, component, or material in the circuit has these three components in it: resistance, inductance, and capacitance. There are two ways for components to be configured in a circuit: series and parallel. Series components line up one after another; parallel components are hooked up next to each other. The chapter also describes Thevenin's Theorem, which is based on the idea of using superposition to analyze a circuit. When one has two different variables affecting an equation, making it difficult to analyze, one can use the technique of superposition to solve the equation, if one is dealing with linear equations. Using Thevenin's Theorem allows one to reduce any circuit into a voltage divider. Finally, the chapter discusses two different types of current that are alternating current and direct current. These terms came into being to describe a couple of different modes of electricity. A firm understanding of these two modes helps one in all aspects of engineering.
At the Plymouth Third International Workshop on Genotoxicity Testing in June 2002, a new expert group started a working process to provide guidance on a common strategy for genotoxicity testing beyond the current standard battery. The group identified amongst others “Follow-up testing of tumorigenic agents not positive in the standard genotoxicity test battery” as one subject for further consideration [L. Müller, D. Blakey, K.L. Dearfield, S. Galloway, P. Guzzie, M. Hayashi, P. Kasper, D. Kirkland, J.T. MacGregor, J.M. Parry, L. Schechtman, A. Smith, N. Tanaka, D. Tweats, H. Yamasaki, Strategy for genotoxicity testing and stratification of genotoxicity test results—report on initial activities of the IWGT Expert Group, Mutat. Res. 540 (2003) 177–181]. A workgroup devoted to this topic was formed and met on September 9–10, 2005, in San Francisco. This workgroup was devoted to the discussion of when it would be appropriate to conduct additional genetic toxicology studies, as well as what type of studies, if the initial standard battery of tests was negative, but tumor formation was observed in the rodent carcinogenicity assessment. The important role of the standard genetic toxicology testing to determine the mode of action (MOA) for carcinogenesis (genotoxic versus non-genotoxic) was discussed, but the limitations of the standard testing were also reviewed. The workgroup also acknowledged that the entire toxicological profile (e.g. structure–activity relationships, the nature of the tumor finding and metabolic profiles) of a compound needed to be taken into consideration before the conduct of any additional testing. As part of the meeting, case studies were discussed to understand the practical application of additional testing as well as to form a decision tree. Finally, suitable additional genetic toxicology assays to help determine the carcinogenic MOA or establish a weight of evidence (WOE) argument were discussed and formulated into a decision tree.
The Movement Assessment Battery for Children (M-ABC) is one of the most accepted tools, both in clinical practice and in research, for the diagnosis of Developmental Coordination Disorders (DCDs) in children. The present study aimed to: (1) establish the construct validity of M-ABC in Israel by comparing the motor performance of typically developed children in four age groups (ranging from 6 to 12 years) and (2) examine the impact of socio-demographic parameters on children's motor performance. Participants were 249 typical children, between 4.1 and 12.08 years old, whose motor performance was evaluated by the M-ABC. The results showed that age, gender, mother's education level, and socioeconomic status had an impact on children's motor performance. Thus, the M-ABC may serve as a suitable tool for examining the motor performance of children in Israel. This examination should also refer to socio-demographic factors in order to shed light on the contribution of environmental disadvantages to children's motor performance.
Silver with a high theoretical capacity for lithium storage is an attractive alloy based anode for Li-ion batteries, but large volume changes associated with AgLix alloy formation leads to electrode cracking, pulverization and rapid capacity fading. A buffer matrix, like the electrospun hollow carbon nanofibers, can reduce this problem to a great extent. Herein, we demonstrate the facile synthesis of a free-standing, binder free Ag-C hybrid electrode through co-axial electrospinning, where well dispersed Ag nanoparticles are embedded in hollow carbon nanofibers. Using this approach, the long cycle life of carbon is complemented with the high lithium storage capacity of Ag, resulting in a high performance anode. The Ag-C composite electrode delivers a capacity of 739mAhg−1 (>conventional graphite anodes) at 50mAg−1, with ∼85% capacity retention after 100 cycles. In addition, the Ag-C composite nanofibers are highly porous and exhibit a large accessible surface area (∼726.9m2 g−1) with an average pore diameter of ∼6.07nm. The encapsulation of Ag in the hollow interiors not only provides additional lithium storage sites but also enhances the electronic conductivity, which combined with the reduced lithium diffusion path lengths in the nanofibers result in faster charge-discharge kinetics and hence a high rate performance.
The thermal, transport, rheological and flammability properties of electrolyte mixtures, proposed for safer lithium-ion battery systems, were investigated as a function of the mole composition. The blends were composed of a lithium salt (LiTFSI), organic solvents (namely EC, DEC) and an ionic liquid (PYR13TFSI). The main goal is to combine the fast ion transport properties of the organic compounds with the safe issues of the non-flammable and non-volatile ionic liquids. Preliminary tests in batteries have evidenced cycling performance approaching that observed in commercial organic electrolytes.
The purpose of this study was to devise quantitative methods for the assessment of praxic skills of the upper limbs by developing a computerised task which permits each component of a sequence of actions to be timed precisely. Furthermore, two versions of such a quantitative measure were developed to investigate the relationship between meaningful and meaningless movements. The praxic skills of 35 patients with Alzheimer's disease (AD) and 75 healthy controls were assessed on two 3-item sequential movement tasks involving either meaningful or meaningless actions. A qualitative rating scale assessment of gesture imitation and pantomime was also administered. AD patients were significantly slower than controls on both the sequential movement tasks. Indeed, the correlation between AD patients' abilities on the novel and traditional tasks provided evidence that the sequential movement tasks constitute valid measures of praxis. Within the AD population, disease severity was also found to have a minimal and inconsistent influence upon praxis. The apraxia assessment results are considered in relation to the debate over whether apraxia constitutes an early or late feature of AD, and also to theoretical claims about the cognitive neuropsychological deficit underlying ideational apraxia.
Nanosized α-Fe2O3 (ca. 50nm) and Li–Fe composite oxides (ca. 29nm) powders were synthesized via gel polymer route. The gels were obtained with thermal polymerization of acrylic acid solutions of iron and lithium nitrates. The calcination of these gels at temperatures from 300°C to 500°C results in α-Fe2O3 from Fe(NO3)3 precursor and Li–Fe composite oxides Li2O–Fe3O4–LiFeO2 from a mixed precursors of Fe(NO3)3 and LiNO3. Thermal gravimetric analysis, X-ray diffraction and transmission electron microscopy were used to investigate the precursors and products. The electrochemical performance of the Fe-based oxides was also evaluated. After 200 cycles, their capacity can be as high as 1300mAh/g for α-Fe2O3 and 1400mAh/g for Li–Fe oxide while the initial capacity loss is as low as 21.8%. The Li–Fe oxide electrodes exhibit better capacity retention than the α-Fe2O3 electrodes. They are interesting negative electrodes for high energy density lithium-ion batteries.
This paper proposes a novel topology of multimode hybrid energy storage system (HESS) and its energy management strategy for electric vehicles (EVs). Compared to the conventional HESS, the proposed multimode HESS has more operating modes and thus it could in further enhance the efficiency of the system. The rule-based control strategy and the power-balancing strategy are developed for the energy management strategy to realize mode selection and power distribution. Generally, the DC–DC converter will operate at peak efficiency to convey the energy from the batteries to the UCs. Otherwise, the pure battery mode or the pure ultracapacitors (UCs) mode will be utilized without the DC–DC converter. To extend the battery life, the UCs have the highest priority to recycle the energy and the batteries are isolated from being recharged directly during regenerative braking. Simulations and experiments are established to validate the proposed multimode HESS and its energy management strategy. The results reveal that the energy losses in the DC–DC converter, the total energy consumption and the overall system efficiency of the proposed multimode HESS are improved compared to the conventional HESS.
A novel and relatively simple electrochemical method is described to determine the hydrogen diffusion coefficient (D) and the surface area (A) of hydrogen-absorbing alloy particles. In this method, which is called ‘potential step chronoamperometry (PSCA)’, hydrogen is dissolved into the alloy until the hydrogen concentration is uniform, and then the dissolved hydrogen is extracted electrochemically at a sufficiently high potential step (larger than +0.2 V vs. Hg∣HgO) with an anodic hydrogen ionization current that changes with time. From an electrochemical kinetic analysis and Fick's law for diffusion to a spherical particle, the variation of j (current density, A g−1) as a function of t −1/2 (t is time, s) is found to be linear over a small time range, i.e. t<a 2/D (a is the particle radius) (less than about 7∼500 s) and the diffusivity and surface area can be determined from the intercept and slope of this line. The value of the diffusion coefficient of hydrogen in a LaNi4.7Al0.3 alloy is found to be in the range 3.1×10−14–8.6×10−13 m2 s−1. In the hydrogen concentration region that was examined, i.e. H/M>0.06, the value of the diffusion coefficient declines sharply with increasing hydrogen concentration in the alloy particles. This dependence of the diffusion coefficient of hydrogen on its concentration is discussed in terms of the nature of both the diffusing species and the diffusion medium. It is also found that the hydrogen transport is governed solely by solid-state diffusion in the alloy particles only after a certain period of time (approximately 40–70 s).
Si/C composites have been synthesized by spray drying technique and investigated as a potential anode material for lithium-ion batteries. Polyvinyl alcohol (PVA) has been used as carbon precursor because it is soluble in water and consequently the spray drying step can be done in an environmental friendly media. This technique favours the coating of silicon particles with a polymer layer which is then carbonized to get a homogeneous carbon coating. Although the galvanostatic cycling stability of Si/C composite is slightly improved compared to that of pure nano-silicon, a significant enhancement of cycleability was observed by adding a PVA cross-linking step before pyrolysis.
Undoped and 2 wt% vanadium (V5+) doped TiO2 samples are prepared in polyol medium by low-temperature solvothermal method. The as-prepared samples are annealed at 400 °C for 5 h in an air atmosphere to increase the crystallinity. The XRD pattern shows that pure anatase TiO2 is formed in both the doped and undoped samples. The maximum sizes of nanoparticles are found to be 300 nm and 15 nm with spherical shaped morphology for undoped TiO2 and V5+ doped TiO2 samples respectively. In addition, 2 wt% V5+ doped sample exhibits excellent electrochemical performance with high reversible specific capacity and excellent rate capability compared to the undoped case. This improvement can be attributed to the substitution of the Ti4+ ions by V5+ ions in the TiO2 lattice and create more Ti4+ vacancies in the lattice. This action may lead to the generation of apparently more number of free holes in the doped p-type semiconductor. Therefore, the increased hole concentration in the valence band can contribute to the electrical conductivity of the doped sample. Vanadium doping also influences the sample crystallinity and reduces the particle size, which provides a larger active surface area than that of undoped TiO2.
Three types of inorganic–organic hybrid polymers containing the ate complex structure (e.g. aluminate, borate) were prepared as lithium ion conducting polymer electrolytes. The relationship between polymer structure and ionic conductivity was discussed from which it was shown that the concepts of molecular design used were very important. Ionic conductivity was enhanced by the introduction of Lewis acid groups, which reduced the charge density on the ate complex and weakened ion pairing between the lithium ion and the immobilized anion. Ionic conductivity was found to be dependent on the length and structure of the oligoether chain. In addition, introduction of bulky groups onto the polymer backbone in the region of the oligoether chain restricted the mobility of the latter.
Dendritic growth on Li bulk metal and powder electrode surfaces was observed during a charge–discharge cycle. Cell cycling was performed with high current density (1mAcm−2). Using the ‘optical cell’, it is observed that Li powder electrodes suppress the growth of dendrite at the electrode surface. The potential profile for dendritic growth also well correlates with the optical observations. The use of powder electrodes having an LiF and Li2CO3 surface layer seem to cause a further reduction in dendritic growth during charge/discharge cycles. The increased surface area of the powders, as well as the artificially controlled SEI film, which uniformly covered the electrode surface, may reduce the dendritic growth.
A population group that is often overlooked in the recent revolution of self-tracking is the group of older people. This growing proportion of the general population is often faced with increasing health issues and discomfort. In order to come up with lifestyle advice towards the elderly, we need the ability to quantify their lifestyle, before and after an intervention. This research focuses on the task of activity recognition (AR) from accelerometer data. With that aim, we collect a substantial labelled dataset of older individuals wearing multiple devices simultaneously and performing a strict protocol of 16 activities (the GOTOV dataset,
Correction for ‘Encapsulating V2O5 into carbon nanotubes enables the synthesis of flexible high-performance lithium ion batteries’ by Debin Kong et al., Energy Environ. Sci., 2016, 9, 906–911.
During the lithiation and delithiation of a thin film electrode, stress in the electrode is deduced from the curvature change of the film using the Stoney equation. The accuracy of such a measurement is conditioned on the assumptions that (a) the mechanical properties of the electrode remain unchanged during lithiation and (b) small deformation holds. Here, we demonstrate that the change in elastic properties can influence the measurement of the stress in thin film electrodes. We consider the coupling between diffusion and deformation during lithiation and delithiation of thin film electrodes and implement the constitutive behavior in a finite-deformation finite element procedure. We demonstrate that both the variation in elastic properties in thin film electrodes and finite-deformation during lithiation and delithiation would challenge the applicability of the Stoney-equation for in-situ stress measurements of thin film electrodes.