batterydata/paper-abstracts huggingface dataset:
Objective The primary objective of this study was to assess central auditory functions in a group of primary school children with dyslexia mainly phonological awareness problems and to compare their performance with children with good phonological awareness ability. Design A group of 52 students with phonological awareness problems (according to their performance in phonological awareness subtest of Arabic Reading Test (ART)) and 31 age- and sex matched students without phonological awareness problems participated in the study. All children were free from any neurological problems, had normal distant visual acuity, normal peripheral hearing sensitivity in both ears and IQ equal or above 90. The children from both groups were subjected to central auditory tests (CAT). Comparison between both groups in their performance in CAT was done and the correlations between CAT and items of phonological awareness subtest were examined. Results The students with phonological awareness problems as a group performed significantly poorer than controls on all central auditory tests. Also, there was a significant correlation between the speech perception in noise test (SPIN) and phonological awareness in the left ear mainly for (Recognition of the middle sound of the word, Deletion of the middle sound of the word and Addition of a sound to the word). Conclusions The group of children with phonological awareness problem showed clinically significant diminished performance compared to the group without phonological awareness problem, reflecting difficulties in the processing of auditory information.
This study describes a series of air monitoring measurements of particle number (PN), black carbon (BC) and PM2.5 mass concentrations in the vicinity of the Los Angeles International Airport (LAX) (roughly 150 m downwind of the LAX's south runways) as well as on-road measurements of the aforementioned pollutants using a mobile platform on three major freeways (i.e., I-110, I-105, and I-405) during May–July 2016. All measurements were performed in the “impact zone” of LAX with the predominant westerly winds from coast to inland. The overall impact of aircraft emissions from the LAX airport and its facilities in comparison to vehicular emissions from freeways on air quality was evaluated on a local scale (i.e. areas in the vicinity of the airport). PN concentration was, on average, 4.1 ± 1.2 times greater at the LAX site than on the studied freeways. Particle number emission factors for takeoffs and landings were comparable, with average values of 8.69 × 10 15 particles/kg fuel and 8.16 × 10 15 particles/kg fuel, respectively, and indicated a nearly 4-fold statistically significant reduction in PN emission factors for takeoffs during the past decade. BC emission factors were 0.12 ± 0.02 and 0.11 ± 0.01 g/kg fuel during takeoffs and landings, respectively. Additionally, the mean PM2.5 emission factor values for takeoffs and landings were also comparable, with values of 0.38 ± 0.04 and 0.40 ± 0.05 g/kg fuel, respectively. Within the impact zone of the airport, an area of roughly 100 km2 downwind of the LAX, measurements indicated that the LAX daily contributions to PN, BC, and PM2.5 were approximately 11, 2.5, and 1.4 times greater than those from the three surrounding freeways. These results underscore the significance of the LAX airport as a major source of pollution within its zone of impact comparing to freeway emissions.
The nail penetration of lithium-ion batteries (LIBs) has become a standard battery safety evaluation method to mimic the potential penetration of a foreign object into LIB, which can lead to internal short circuit with catastrophic consequences, such as thermal runaway, fire, and explosion. To provide a safe, time-efficient, and cost-effective method for studying the nail penetration problem, an integrated computational method that considers the mechanical, electrochemical, and thermal behaviors of the jellyroll was developed using a coupled 3D mechanical model, a 1D battery model, and a short circuit model. The integrated model, along with the sub-models, was validated to agree reasonably well with experimental test data. In addition, a comprehensive quantitative analysis of governing factors, e.g., shapes, sizes, and displacements of nails, states of charge, and penetration speeds, was conducted. The proposed computational framework for LIB nail penetration was first introduced. This framework can provide an accurate prediction of the time history profile of battery voltage, temperature, and mechanical behavior. The factors that affected the behavior of the jellyroll under nail penetration were discussed systematically. Results provide a solid foundation for future in-depth studies on LIB nail penetration mechanisms and safety design.
In this work, we have reported the application of electropolymerised polypyrrole–reduced graphene oxide (Ppy–RGO) nanocomposite films as an effective tool for entrapping and liberating the model dye Acid Red 1, and thereby proposed this as an ecofriendly treatment for dye-containing textile effluents. Initially, a polypyrrole–graphene oxide (Ppy–GO) nanocomposite film was anodically synthesised by an in situ electropolymerisation of pyrrole and GO. The Ppy–GO film was then electrochemically reduced to form a Ppy–RGO nanocomposite film. The synthesised nanocomposite films were characterised by spectroscopy, microscopy, surface analysis and thermogravimetry. Brunauer, Emmett and Teller surface area analysis showed a 7.4-fold increase in surface area of Ppy–RGO films compared to that of NO3-
Ethnopharmacological relevance In traditional medicine, Astragalus mongholicus (AM) has been used for the treatment of general weakness, chronic illness, and to increase overall vitality. Aim of the study The present study investigated possible effects of the saponin fraction of AM on the central nervous system. Moreover, its effects on locomotor activity, anxiety, and hippocampal morphology were studied. Material and methods AM extract was tested for its effects on locomotor activity using the Moti-Test, for situational anxiety in the elevated plus maze, and for anticonvulsant activity against acute pentylenetetrazole (PTZ)-induced seizures and in the PTZ kindling model. Results It was shown that AM (50, 100, 200mg/kg) did not interfere with locomotor activity and situational anxiety as measured in the elevated plus maze. In these doses, AM significantly suppressed pentylenetetrazole (PTZ)-induced seizures (p <0.05). Its anticonvulsant efficacy was also evident against repeated PTZ seizures (p <0.05). This suggests potential therapeutic usefulness. After subchronic application, the number of cells in hippocampal CA1 was reduced, whilst the cell number in CA3 and hilus remained unaffected. Conclusions Doses of AM extract which did not interfere with locomotor acticity and situational anxiety appear to be useful in the treatment of convulsive disorders. The mechanisms underlying this effect on hippocampal morphology are not yet understood.
Metal-organic-frameworks (MOF) derivation has been demonstrated to be an effective strategy to obtain porous metal oxides with controlled morphologies and improved electrochemical properties for lithium-ion batteries. One-dimensional mesoporous NiO nanorod is synthesized for the first time in this work from a rod-like Ni-MOF precursor, which is formed by a fast and facile room-temperature reaction. The mesoporous NiO nanorod delivers a larger-than-theoretical reversible capacity of 1019mAhg−1 after 100 cycles at 100mAg−1 and good high-rate capabilities when used as an anode material for rechargeable lithium ion batteries. The mesoporous structure derived from the MOF precursor along with 1D nanoparticle-integrated nanorod morphology can facilitate lithium diffusion, resist volume change and maintain structural stability of the electrode during repetitive cycling, thus resulting in enhanced reversible Li-storage capacities and excellent cyclability.
Electrochemical impedance spectroscopy (EIS) is one of the most important analytical tools for characterization of electrochemical double-layer capacitors (EDLC). As an example, we have characterized a commercial capacitor (BCAP0350 Maxwell Technologies) by EIS, and we will discuss the typical performance of an EDLC compared to an ideal capacitor. EIS was used to determine internal resistance and capacitance of the same capacitor as a function of temperature and as a function of time during constant voltage tests. In addition, the effect of the electrolyte on the temperature behavior was investigated. While the capacitance is a very weak function of temperature, the ESR increases significantly with reduced temperature. Temperature effects are much more pronounced for propylene carbonate (PC) than for acetonitrile (AN)-based electrolytes. From the data obtained at various temperatures and voltages, we could determine acceleration factors for the degradation. On the basis of an Arrhenius plot of the leakage current measured during load life tests at capacitor voltages between 2.5V and 3.0V and temperatures between −40°C and +70°C, we determined acceleration factors for capacitor degradation of about 2 for a temperature increase of 10°C and also a factor of about 2 for a potential increase of 0.1V.
LiNi0.5Co0.5O2 layered material could be a possible cathode material for advanced lithium-ion batteries in applications such as medical devices. The material was prepared by the co-precipitation method, which leads to a highly stoichiometric and homogeneous powder with a desirable particle size. It has shown reasonable cycling stability at a C/2 rate up to 100cycles, and is expected to be much more stable at lower rates and capable of providing the needed capacity. We also showed that the use of lithium fluoroalkyl-phosphate Li[PF3(C2F5)3] salt-based electrolyte significantly improves the calendar life of the battery. Aging tests have been performed under severe conditions (storage at 50°C and 4.1V) clearly show a huge capacity loss for the conventional cathode LiNi0.8Co0.2O2 while LiNi0.5Co0.5O2 electrode exhibits a limited capacity fading. Finally, because it has less nickel content, differential scanning calorimetry (DSC) measurements confirm that LiNi0.5Co0.5O2 is much safe than the LiNi0.8Co0.2O2 cathode.
In this work, mesoporous NiCo2O4 has been successfully synthesized by in situ removal of template method. The NiCo2O4 composite was precipitated by hydrolysis method using ethylene glycol as a high boiling point solvent at 140°C under atmospheric environment. Zinc hydroxide is used as the sacrificial template to construct the mesoporous structure with high specific surface area. The structure and morphology characteristics were carried out by X–ray diffraction, scanning electron microscopy, high resolution transmission electron microscopy, and N2 adsorption experiments. The electrochemical properties were investigated through AC impedance spectroscopy, cycling voltammetry and charge/discharge test in 7M KOH. The results exhibit that the as–prepared mesoporous NiCo2O4 shows a large specific surface area of 219.2m2 g−1, a high specific capacity of 660.53Cg−1 at current density of 1Ag−1. The mesoporous NiCo2O4 electrodes still remain 90% specific capacity retention compared with the first cycle over 32,000cycles, which exhibits the as–prepared electrode possess long–term stability.
All-solid-state lithium-ion batteries (ASLBs) are receiving considerable attention due to their safety superiority and high energy density (achieved by bipolar configuration). Inorganic solid electrolytes are explored as a key-enabling material of the ASLBs. However, their critical challenges, including grain boundary resistance, interfacial instability with electrode materials and complicated processability, remain yet unresolved. Here, we demonstrate a new class of gel electrolyte with reversible thixotropic transformation and abuse tolerance as an effective and scalable approach to address the aforementioned longstanding issues. The gel electrolyte consists of (fluoropolymer/cellulose derivative) matrix and liquid electrolyte. The reversible thixotropic transformation is realized via sol-gel transition based on Coulombic interaction of the polymer matrix with liquid electrolyte. This unusual rheological feature allows the gel electrolyte to be printed in various forms. In addition, the gel electrolyte shows low crystallinity, thus playing a viable role in delivering high ionic conductivity. Based on understanding of rheological/electrochemical characteristics of the gel electrolyte, we fabricate a form factor-free pouch-type cell assembled with the gel electrolyte using sequential screen-printing process. The resultant cell shows exceptional safety upon exposure to various harsh abuse conditions, along with decent electrochemical performance.
The high flash point solvent adiponitrile (ADN) was investigated as co-solvent with ethylene carbonate (EC) for use as lithium-ion battery electrolyte. The flash point of this solvent mixture was more than 110°C higher than that of conventional electrolyte solutions involving volatile linear carbonate components, such as diethyl carbonate (DEC) or dimethyl carbonate (DMC). The electrolyte based on EC:ADN (1:1wt) with lithium tetrafluoroborate (LiBF4) displayed a conductivity of 2.6mScm−1 and no aluminum corrosion. In addition, it showed higher anodic stability on a Pt electrode than the standard electrolyte 1M lithium hexafluorophosphate (LiPF6) in EC:DEC (3:7wt). Graphite/Li half cells using this electrolyte showed excellent rate capability up to 5C and good cycling stability (more than 98% capacity retention after 50 cycles at 1C). Additionally, the electrolyte was investigated in NCM/Li half cells. The cells were able to reach a capacity of 104mAhg−1 at 5C and capacity retention of more than 97% after 50 cycles. These results show that an electrolyte with a considerably increased flash point with respect to common electrolyte systems comprising linear carbonates, could be realized without any negative effects on the electrochemical performance in Li-half cells.
Temporal lobe epilepsy (TLE) with hippocampal sclerosis is the most common type of drug-resistant epilepsy. Non-human primates are attractive models for studying the pathogenic mechanisms of TLE, with the goal of developing new drugs and interventions. In this study, we developed and tested a Cynomolgus monkey (Macaca fascicularis) model of TLE. A total of 5 Cynomolgus monkeys received3–4 weekly unilateral hippocampal injections of kainic acid (KA) to induce repetitive acute seizures. Animals were monitored via video and electroencephalography (EEG) to assess KA-induced acute seizures and subsequent spontaneous recurrent epileptiform discharges (SREDs). During acute seizures, EEG recording showed bursts of generalized spike discharges arising from the temporal lobe ipsilateral to the KA injection. Three months later, we detected abundant interictal epileptiform discharges (IEDs) during pentobarbital induced anesthesia. Furthermore, two monkeys exhibited synchronized epileptiform discharges accompanied by symptoms mimicking absence seizures. No obvious convulsive symptoms were observed in any monkeys. Overall, our data indicate successful development of a Cynomolgus monkey model of TLE via unilateral hippocampal injection of KA.
Sn–Zr and Ag-doped Sn–Zr thin films were prepared by an electron-beam evaporation method using pure separate metal sources. Electrochemical cycling performance was obtained as a function of film composition. The cycling stability of Sn–Zr film electrodes increased with Zr content. An Ag-doped Sn–Zr thin film such as Sn57Zr33Ag10 showed excellent cycling stability and capacity retention. The composition dependence on electrochemical behavior is related to the microstructural changes in the films.
A novel Li[Ni0.67Co0.15Mn0.18]O2 cathode material encapsulated completely within a concentration-gradient shell was successfully synthesized via co-precipitation. The Li[Ni0.67Co0.15Mn0.18]O2 has a core of Li[Ni0.8Co0.15Mn0.05]O2 that is rich in Ni, a concentration-gradient shell having decreasing Ni concentration and increasing Mn concentration toward the particle surface, and a stable outer-layer of Li[Ni0.57Co0.15Mn0.28]O2. The electrochemical and thermal properties of the material were investigated and compared to those of the core Li[Ni0.8Co0.15Mn0.05]O2 material alone. The discharge capacity of the concentration-gradient Li[Ni0.67Co0.15Mn0.18]O2 electrode increased with increasing upper cutoff voltage to 4.5V, and cells with this cathode material delivered a very high capacity, 213mAh/g, with excellent cycling stability even at 55°C. The enhanced thermal and lithium intercalation stability of the Li[Ni0.67Co0.15Mn0.18]O2 was attributed to the gradual increase in tetravalent Mn concentration and decrease in Ni concentration in the concentration-gradient shell layer.
With a global market share of about 90%, crystalline silicon is by far the most important photovoltaic technology today. This article reviews the dynamic field of crystalline silicon photovoltaics from a device-engineering perspective. First, it discusses key factors responsible for the success of the classic dopant-diffused silicon homojunction solar cell. Next it analyzes two archetypal high-efficiency device architectures – the interdigitated back-contact silicon cell and the silicon heterojunction cell – both of which have demonstrated power conversion efficiencies greater than 25%. Last, it gives an up-to-date summary of promising recent pathways for further efficiency improvements and cost reduction employing novel carrier-selective passivating contact schemes, as well as tandem multi-junction architectures, in particular those that combine silicon absorbers with organic–inorganic perovskite materials.
Abstract This is the first chapter in the second part of this book, titled “Science and Technology Policy in the Modern Age.” The chapter is a sequence of thoughtful and sometimes anecdotal analyses of various aspects of science policy during the Clinton era. It begins with a discussion of the implications of Clinton initially placing his vice-president, Al Gore, in charge of all things to do with technology. This raised concerns among scientists about reductions in funding for basic research and led to an increase in lobbying for scientific issues (the author was hired by the American Physical Society in 1994 to lobby for research). The chapter goes on to make the case that by the end of the 1990s the science and technology policy landscape in Washington had changed dramatically in the following ways: economic growth had become a prime rationale for research funding; dramatic medical advances had provided a strong argument for more investment in medical research; advocacy groups had proliferated; the boundaries between scientific disciplines had begun to blur; Europe and Asia were nipping at the heels of America’s science and technology supremacy; and, responding in part to changes in the tax code and in part to the revolution in information technology, industry had virtually abandoned its support of long-term research. The chapter’s extensive coverage of biomedical and genomics research during this period demonstrates how political maneuverings and personalities affected policy.
The Glasgow Outcome Scale (GOS) was first published in 1975 by Bryan Jennett and Michael Bond. With over 4,000 citations to the original paper, it is the most highly cited outcome measure in studies of brain injury and the second most-cited paper in clinical neurosurgery. The original GOS and the subsequently developed extended GOS (GOSE) are recommended by several national bodies as the outcome measure for major trauma and for head injury. The enduring appeal of the GOS is linked to its simplicity, short administration time, reliability and validity, stability, flexibility of administration (face-to-face, over the telephone and by post), cost-free availability and ease of access. These benefits apply to other derivatives of the scale, including the Glasgow Outcome at Discharge Scale (GODS) and the GOS paediatric revision. The GOS was devised to provide an overview of outcome and to focus on social recovery. Since the initial development of the GOS, there has been an increasing focus on the multidimensional nature of outcome after head injury. This Review charts the development of the GOS, its refinement and usage over the past 40 years, and considers its current and future roles in developing an understanding of brain injury.
The phase and microstructure stabilities of LiAlO2 for improving the matrix reliability of molten carbonate fuel cells are investigated. The phase transformation and particle growth of LiAlO2 are examined via immersion tests of pure γ-LiAlO2,an α-/γ-LiAlO2 mixture and pure α-LiAlO2 in molten carbonate at 650°C in an air atmosphere. Dissolution of Li+ ions occurs mainly from γ-LiAlO2 over an 18000h period, and the dissolved Li+ ions precipitate as LiNaCO3 and α-LiAlO2. Particle growth takes place continuously from an early stage of heat-treatment and quickly progresses by the accelerated dissolution and precipitation of Li+ ions after 10000h. By contrast, the particle size and the crystalline phase of α-LiAlO2 do not change during 3000h of immersion. These results show that α-LiAlO2 is less soluble than γ-LiAlO2 and is more stable in molten carbonate.
Nanostructured and nanosized materials are widely applied to tackle the pressing challenges associated with energy conversion. In this conceptual review, rather than highlighting separate examples, we aim to give a general overview about where and how nanostructure design can be beneficial in the three major research fields (photo)thermal chemical energy conversion, electrochemical energy conversion, and solar energy conversion. It will be shown that in many cases the design of catalytically active nanostructures is the main task and that especially for catalysts nanostructure and activity are inseparably linked to each other. Moreover, electrochemical and photochemical processes are complicated by the overlap of multiple processes that all need to be optimized, including in particular light absorption, charge migration, recombination and trapping events and surface processes. It will also be shown how the development of materials for new challenges can often be based on our knowledge on existing materials for related applications.
Three dimensionally ordered macroporous membrane of a Li-ion conductive ceramic, Li–La–Ti–O (LLT), for all solid-state rechargeable lithium battery was prepared using colloidal templating process combined with sol–gel method. An opal structure consisting of mono-dispersed polystyrene beads (470nm in diameter) was used as a template. The preparation conditions of LLT membrane were optimized to obtain a relatively large size porous membrane. The LLT calcinated at 600°C was amorphous, and its Li-ion conductivity was 10−5 Scm−1 at room temperature. The composite electrodes of LLT–Li4Ti5O12 and LLT–LiMn2O4 were successfully prepared by sol–gel process.
Nanomaterials design may offer a solution to tackle many fundamental problems in conventional batteries. Cui et al. review both the promises and challenges of using nanomaterials in lithium-based rechargeable batteries.
Plasma-fluorination of petroleum coke and those heat-treated at 1860, 2300 and 2800°C (abbreviated to PC, PC1860, PC2300 and PC2800) was conducted for 15, 30 and 60min using CF4 gas at 90°C. Fluorine contents obtained by elemental analysis were negligible except PC fluorinated for 60min (0.7at.%). Fluorine concentration on the surface decreased with increasing heat-treatment temperature of petroleum coke, i.e. from PC to PC2800 when plasma-fluorination was made for 30 and 60min. Transmission electron microscopic observation revealed that the closed edges of PC2800 were destroyed and opened by plasma-treatment. Plasma-fluorination increased surface disorder of heat-treated petroleum cokes, however, slightly reduced surface areas. These surface structure changes increased first coulombic efficiencies of PC2300 and PC2800 by 6–8 and 8–10% at both 60 and 150mAg−1, respectively.