batterydata/paper-abstracts huggingface dataset:
The effect of temperature on surface film formation on nickel electrode was studied in 1moldm−3 bis(perfluoroethylsulfonyl)imide dissolved in propylene carbonate by atomic force microscopy (AFM) and ac impedance spectroscopy. Cyclic voltammetry measurements revealed that electrolyte decomposition reactions are accelerated at elevated temperatures, especially at 60 and 80°C. In situ AFM measurements showed that the film formation is fast and the resulting surface film is thicker at 80°C than at room temperature. Furthermore, it was confirmed by ac impedance measurements that the resistance of surface film was very low at elevated temperatures. These results were discussed in relation to superior cycling characteristics of lithium deposition and dissolution at the elevated temperatures.
TiNb24O62 with large theoretical capacity and safe working potential is regarded as a candidate for lithium ion batteries. However, poor electronic conductivity of TiNb24O62 restricts its widely application. Herein, we propose a novel methodology concerned about nitrogen-doped carbon coating to improve the electrochemical performance of TiNb24O62 nanowires. According to a series of analyses, it is found that nitrogen-doped carbon coating plays a key role on improving the electronic conductivity and electrochemical activity of TiNb24O62 nanowires. Meanwhile, both first principles calculations and in-situ XRD technique are applied to realize the structural evolution of nitrogen-doped carbon coated TiNb24O62 nanowires. The obtained results show a high diffusion channel for lithium ions in the lattice of TiNb24O62 and the good electrochemical reversibility of nitrogen-doped carbon coated TiNb24O62 nanowires. In addition, a full lithium ion battery is assembled by using nitrogen-doped carbon coated TiNb24O62 nanowires as anode and LiFePO4 as cathode. Such a cell can deliver a high capacity, indicative of a great potential for practical applications. Therefore, nitrogen-doped carbon coated TiNb24O62 nanowires can be a promising anode for high-rate lithium ion batteries.
ABSTRACT Background Numerous studies have linked dementia to the subsequent deterioration of oral health. Few investigators, however, have examined oral disease as a potential risk factor in the development of dementia. The authors conducted a study to investigate a potential association between a history of oral disease and the development of dementia. Methods Longitudinal dental records supplemented data collected from 10 annual cognitive assessments of 144 Milwaukee participants in the Nun Study, a longitudinal study of aging and Alzheimer disease, who were 75 to 98 years old. Neuropathologic findings at autopsy were available for 118 participants who died. Results A low number of teeth increased the risk of higher prevalence and incidence of dementia. Conclusion Participants with the fewest teeth had the highest risk of prevalence and incidence of dementia. Clinical Implications Edentulism or very few (one to nine) teeth may be predictors of dementia late in life.
An enduring tendency towards negative thinking is thought to increase vulnerability for future depression. However, it has not been possible to assess this tendency in non-depressed mood states. We examined if response latency to endorse dysfunctional attitudes is associated with depressive outcomes in a longitudinal study. A sample of young people at familial risk of depression (N = 252, aged 10–19, 56.3 % female) completed a computer-administered dysfunctional attitude scale. The main outcome measure was the difference in reaction time to agree versus disagree with dysfunctional attitudes. Cross-sectional differences between current and previous depression and no psychiatric disorder groups as well as longitudinal associations with depressive symptoms were examined. Young people with current and previous depression were quicker to agree with dysfunctional attitudes than those without disorder. In young people free from depressive disorder, faster agreements with dysfunctional attitudes were specifically associated with increased depressive symptoms over time. Self-reported dysfunctional attitudes did not differentiate the formerly depressed and no disorder groups and showed a longitudinal association with depressive symptoms for older adolescents only. Reaction time to endorse dysfunctional attitudes may indicate changes in affective processing that represent an early risk for future depression that is not indexed by self-report measures of negative thought.
The design of a campus mail delivery vehicle powered by 350bar hydrogen feeding a 1.2kW PEM fuel cell to charge a lead acid battery pack is described. Five vehicles supplied to the campus at the University of Birmingham to measure the performance and to evaluate relevance to fleet operations are discussed. It is shown that the performance is better than that of a standard diesel van in two drive cycles, one following an academic circuit around the campus, the other doing multiple mail delivery stops. The acceleration and drive cycle compliance are found to be adequate on campus and the efficiency is significantly better than the diesel. The need for extension of range and increase in power and acceleration to meet standard urban drive cycles is clearly demonstrated.
Nanotechnology is developing far faster than our understanding of its effects. This lapping of our understanding by speedy development is typical of new technologies, and in the United States we let development occur, introducing new artifacts into the world, without any serious attempt to understand beforehand their effects, long-term or short-term. We have been willing to pay the price of pushing the technological envelope, but pushing the nanotechnological envelope has some special risks, requiring more caution.
Chitosan oligosaccharides (COS) as a new, environmentally and water-based organic compound, is firstly applied as the electrode binder for Li2ZnTi3O8 electrode in lithium-ion batteries. Compared with conventional polyvinylidene fluoride (PVDF) binder, the COS binder is used for Li2ZnTi3O8 electrode significantly improves the electrochemical performances in terms of the first Columbic efficiency, cycling behavior, rate capability and long life cycle. At 0.1Ag−1, the initial discharge capacity of 215.6mAhg−1 can be obtained for Li2ZnTi3O8 with COS binder system and the Columbic efficiency is as high as 93.6%, which are apparently better than PVDF binder system. Moreover, 66.1mAhg−1 can be remained after 1000 cycles and the retention is 33.6% for COS binder system, while the PVDF binder system has only 37.9mAhg−1 (22.8%). In addition, the cycling stability of Li2ZnTi3O8 electrode has been improved after using COS as binder. The elevated electrochemical performances of Li2ZnTi3O8 electrode with COS binder system can be ascribed to the characters of COS binder, which not only provide numerous hydroxyl groups formed strong hydrogen binds with both active materials and copper current collector, but also suppress swelling of electrode with electrolyte solution.
Abstract The integration of several sources, microgrids, distributed generation, and various load types are supported owing to efficient control and management capabilities of smart grid. On the other hand, Internet of Things (IoT) is experiencing marvelous advances in terms of architecture, network types, and device compliance in a wide variety. The software related improvements of IoT are also extremely remarkable since many novel protocols, standards, connectivity methods, and security precautions are implemented. In this chapter, a comprehensive introduction on IoT-based smart grid infrastructures is presented. The technological developments are achieved in communication and security issues that enable the integration of smart grid and IoT systems. The smart grid applications and driving factors of IoT for smart grid systems are examined in depth that all stages of the smart grid system starting from generation to consumption levels are systematically analyzed. The IoT applications enabled in smart grid system in terms of application areas such as smart cities, smart home applications, home energy management systems, energy harvesting issues, smart sensor networks, distributed generation, and microgrid have been discussed. Finally, the open issues, future research directions, and report several important research areas are presented.
A new approach is presented to characterize the variable leakage resistance, a parameter in the variable leakage resistance model we developed to model supercapacitors used in environmentally powered wireless sensor network applications. Based on an analysis of the supercapacitor terminal behavior during the self-discharge, the variable leakage resistance is modeled as a function of the supercapacitor terminal voltage instead of the self-discharge time, which is more practical for an environmentally powered wireless sensor node. The new characterization approach is implemented and validated using MATLAB Simulink with a 10F supercapacitor as an example. In addition, effects of initial voltages and temperatures on the supercapacitor self-discharge rate and the variable leakage resistance value are explored.
The small intestine is a part of the gastrointestinal tract in which digestion and absorption of nutrients takes place. The small bowel follows the stomach and is followed by the large intestine, reaching from the pylorus to the valve of Bauhin and is separated into the duodenum, the jejunum, and the ileum. Capsule endoscopy (CE) has the potential to offer a perfect overview of the small-bowel mucosa and complete visualization of the entire small bowel is achieved in most cases. In this video, there is an overview offered on normal findings in small-bowel CE and typical anatomical landmarks are indicated. This article is part of an expert video encyclopedia.
The development of physically representative models that allow reliable simulation of the processes under realistic conditions is essential to the development and optimization of fuel cells, the introduction of cheaper materials and fabrication techniques, and the design and development of novel architectures. Full three-dimensional, multiphase, non-isothermal computational fluid dynamics models of planar air-breathing and airflow-channel PEM fuel cell have been developed. These comprehensive models account for the major transport phenomena in both these types: convective and diffusive heat and mass transfer, electrode kinetics, transport and phase-change mechanism of water, and potential fields. The models are shown to understand the many interacting, complex electrochemical, and transport phenomena that cannot be studied experimentally. Fully three-dimensional results of the species profiles, temperature distribution, potential distribution, and local current density distribution are presented and analyzed with a focus on the physical insight and fundamental understanding for the air-breathing and airflow-channel PEM fuel cells.
Electricity generation using renewable energy generation technologies is one of the most practical alternatives for network planners in order to achieve national and international Greenhouse Gas (GHG) emission reduction targets. Renewable Distributed Generation (DG) based Hybrid Energy System (HES) is a sustainable solution for serving electricity demand with reduced GHG emissions. A multi-objective optimisation technique for minimising cost, GHG emissions and generation uncertainty has been proposed in this paper to design HES for sustainable power generation and distribution system planning while considering economic and environmental issues and uncertainty in power availability of renewable resources. Life cycle assessment has been carried out to estimate the global warming potential of the embodied GHG emissions from the electricity generation technologies. The uncertainty in the availability of renewable resources is modelled using the method of moments. A design procedure for building sustainable HES has been presented and the sensitivity analysis is conducted for determining the optimal solution set.
With the development of computer software and hardware in the past few years, it has been possible to produce effective training virtual environments on everyday personal computers with little expert training required for users or designers. However, the development of the equipment that enables this has brought little coinciding research on what features to include when designing these environments. Despite these increased advances in PC capabilities for desktop virtual environments (VEs), there are still limitations on the number of objects that can be programmed to be interactive, usually due to restrictions on programming time and cost. As a result, it is often left to the programmer to decide which of the objects included to increase the realism of the environment will be interactive and which aesthetic. The work presented in this paper is an experiment that aims to establish a guide for environment designers to aid effective environment interaction development by identifying key elements in a VE design.
Polyethylene oxide (PEO) based-solid polymer electrolytes were prepared with low weight polymers bearing carboxylic acid groups added onto the polymer backbone, and the variation of the conductivity and performance of the resulting Li ion battery system was examined. The composite solid polymer electrolytes (CSPEs) were composed of PEO, LiClO4, PAA (polyacrylic acid), PMAA (polymethacrylic acid), and Al2O3. The addition of additives to the PEO matrix enhanced the ionic conductivities of the electrolyte. The composite electrolyte composed of PEO:LiClO4:PAA/PMAA/Li0.3 exhibited a low polarization resistance of 881.5 ohms in its impedance spectra, while the PEO:LiClO4 film showed a high value of 4,592 ohms. The highest ionic conductivity of 9.87 × 10−4 S cm−1 was attained for the electrolyte composed of PEO:LiClO4:PAA/PMAA/Li0.3 at 20 °C. The cyclic voltammogram of Li+ recorded for the cell consisting of the PEO:LiClO4:PAA/PMAA/Li0.3:Al2O3 composite electrolyte exhibited the same diffusion process as that obtained with an ultra-microelectrode. Based on this electrolyte, the applicability of the solid polymer electrolytes to lithium batteries was examined for an Li/SPE/LiNi0.5Co0.5O2 cell.
Since the electric grid does not store electrical energy, the demand for electric power must be matched by the production almost instantaneously. The supply-demand balance imposes a severe constraint on the penetration of renewable energy sources – especially wind and solar – in the power production markets of all nations, because solar irradiance and wind energy are not available at all hours of the day and exhibit daily and seasonal variabilities. Using the hourly data of the electric power demand in the Electric Reliability Council of Texas, we calculate the implications of this constraint on the substitution of fossil fuel power plants with renewable energy sources. When the market penetration of renewables increases and the utilization of solar and wind energy sources expands to approximately 25%–30% of the annual electricity production, significant energy storage capacity is needed. Simulations of the entire electric grid are performed to determine the power ratings of the renewable sources and the necessary storage capacity to substitute part or all of the fossil fuel power capacity in Texas with renewable energy sources.
Modification of exfoliated graphite (EG) electrode with generation 2 poly(propylene imine) dendrimer by electrodeposition resulted in an electrochemical sensor which was used to detect lead ions in water to a limit of 1 ppb and a linear response between 2.5 and 40 ppb using square wave anodic stripping voltammetry (SW-ASV). Pb(II) was also removed from spiked water sample using a 40-mm diameter unmodified EG electrode with an applied potential of −1,000 mV for 180 min. A removal efficiency of 99% was calculated from a 150 mL sample. The results obtained in both cases using SW-ASV, correlated with atomic absorption spectroscopy.
Endocrine therapy in the setting of breast cancer has undoubtedly advanced clinical outcomes in this disease, but treatment with endocrine therapy is accompanied by a wide spectrum of side effects. It is of prime importance to understand and characterize these toxicities to facilitate clinical decision-making. Somewhat surprisingly, there is a relative paucity of data pertaining to cognitive changes associated with endocrine therapy. In this article we review cognitive associated with two classes of endocrine therapy: (1) selective estrogen receptor modulators (SERMs; tamoxifen and raloxifene) and (2) aromatase inhibitors (AIs; anastrozole, letrozole, and exemestane). Companion studies to the Multiple Outcome of Raloxifene Evaluation (MORE), the Study of Tamoxifen and Raloxifene (STAR) and National Surgical Adjuvant Breast and Bowel Project (NSABP) P-1 trials provide relevant data to understand the effect of SERMs on cognition. In contrast, substudies of the Arimidex, Tamoxifen Alone or in Combination (ATAC), Tamoxifen and Exemestane Adjuvant Multinational (TEAM) and Breast International Group (BIG) 1-98 trials juxtapose cognitive effects of AIs against those of tamoxifen. These and other studies are examined herein to provide a comprehensive overview of the effect of endocrine therapy on cognition.
High-capacity lithium-storage materials in metal composite form are being extensively researched, which can replace the carbon-based lithium intercalation materials currently commercialized as the negative electrode of lithium rechargeable batteries. Herein, Sn nanocrystals and Sn nanocrystal/carbon composites with various particle sizes are prepared by the chemical reduction method where surfactant can control the resultant particle size because the particle size of metal-based materials is the main underlying factor for their electrochemical enhancement. The chemical reduction approach using surfactants is very effective for varying the particle size of Sn nanocrystals. Sn nanocrystals with the optimized particle size in terms of anodic properties are made into a composite with carbon acting as an agglomeration preventer as well as an electronic conductor. The controlled size of the Sn nanocrystal in the carbon is associated with their drastically improved electrochemical performance retaining above 65% of the initial capacity after 30 cycles.
Electrochemical monitoring of electrical and structural changes of both PPy and PPy–PEG films electrochemical deposited, in order to highlight if the structural stability offered by PEG has an influence on electrical properties and stability in aqueous solution over immersion time was investigated. Electrochemical analysis suggests that PPy–PEG film inserts cations easier than PPy film for a short immersion time probably due to ability of PEG to form complexes with metal cations. The FTIR spectra showed that the PEG incorporation decreases the rate of PPy overoxidation probably by restraining the electron release and by rendering O2 inaccessible to PPy. Mott–Schottky analysis based on capacitance measurement reveal p-type conductance for both films. The in situ AFM analysis sustains electrochemical behaviour and has permitted elaboration of a model of PPy and PPy–PEG films behaviour during immersion in testing solution.
The research of the operation of low-power photovoltaic generation plants used for self-contained electric power supply in Siberian climatic conditions is performed in this paper. It provides an analysis of the operation of individual units of an automated control system, and gives recommendations for the selection of hardware components. The article describes the operational principles, developed based on functional modules of the programmable logic controller, ensuring maximum possible use of solar energy in this continuous power supply system. The results of plant operation have been obtained, in the form of a power counter log, as well as data on the volume of solar energy produced in both overcast and in sunny weather, throughout the observation period. The article provides visual illustration of generated energy, which could be used to assess the efficiency and economic viability of the low-power photovoltaic plant. Authors would like to point out that examples of the proposed methodology for the construction of self-contained power supply systems can be found in existing industrial facilities, on which further scientific research can be based.
This article looks at the phenomenon of ‘communicative” language testing as it emerged in the late 1970s and early 1980s as a reaction against tests constructed of multiple choice items and the perceived over-emphasis of reliability. Lado in particular became a target for communicative testers. It is argued that many of the concerns of the communicative movement had already been addressed outside the United Kingdom, and that Lado was done an injustice. Nevertheless, the jargon of the communicative testing movement, however imprecise it may have been, has impacted upon the ways in which language testers approach problems today. The legacy of the communicative movement is traced from its first formulation, through present conundrums, to tomorrow's research questions.
Renewable energy technologies do not always employ sustainable resources. The scarcity of cobalt supply must be addressed in transportation electrification.
Substituted LiR x Mn2− x O4 (R=La3+, Ce3+ , Pr3+ and x =0.00−0.20) nanoparticles are prepared by the sol–gel method and the consequent changes in their lattice structure, dielectric and electrical parameters are determined by XRD, ED-XRF, SEM, LCR meter bridge and dc electrical resistivity measurements. Diffraction data show that the samples are single-phase spinel materials with crystallites sizes between 21 and 38nm. The lattice parameter, cell volume and X-ray density are found to be affected by doping the Li-manganate with the rare-earth elements. The ED-XRF analysis confirms the stoichiometric composition of the synthesized samples and SEM reveals their morphology. Calculated values of the dielectric constant (έ) and the dielectric loss (tan δ) decrease with the frequency of the applied field. This is attributed to Maxwell–Wagner polarization. Replacement of manganese by the rare-earth elements results in an improvement in the structural stability of the material, which is considered to be useful for enhancement of the cycleability of the compounds when used in lithium rechargeable batteries, and increases significantly the values of έ and tan δ (except for Ce). Lithium manganate nanomaterials with high έ and low tan δ may be attractive for application in memory storage devices.