batterydata/paper-abstracts huggingface dataset:
The ever-increasing number of mobile device users has also raised the users’ expectation of mobile services accordingly. This phenomenon has given pressures to the mobile service providers to improve their services in order to stay competitive in the market. The service oriented approach is seen to be a promising scheme for mobile services. This paper presents mobile service oriented architectures for Nearest-Neighbor (NN) queries that are classified into five categories, namely (i) intermittent query mobile services, (ii) continuous query mobile services, (iii) context-aware mobile services, (iv) continuous moving object query mobile services, and (v) data broadcast mobile services. These services incorporate query, location and context-aware services, ontological context model, and broadcast. The proposed architectures are concerned with mobile services for clients on the move requesting services based on their current location, which is arguably the most important feature in a wireless environment. Furthermore, we also discuss the Quality-of-Service (QoS) requirement for mobile services in which request latency time is one of the most important parameters to consider. Some analytical models for query latency measurement are presented and the results are compared with the simulation experiments.
A polythiophene (PTh) film was successfully electrochemically polymerized onto a carbon paper substrate by a galvanostatic method in an oil-in-ionic liquids (ILs) microemulsions electrolyte. The morphology of the as-prepared PTh film was investigated by using a scanning electron microscope, and the result demonstrates that the PTh particle size is to be between 2–3μm. The FT-IR spectrum of PTh film shows that the polymerization has occurred at the 2, 5-substituted position of the thiophene ring to form α-α PTh film. Further work has also been done to investigate the potential application of the PTh film as a supercapacitor electrode material in 1mol/L Na2SO4 solution. The highest specific capacitance of 103 Fg−1 can be reached at the lowest current density of 0.3 Ag−1, and the coulombic efficiency is 91.63% when the current density is 1 Ag−1. The cycle stability based on the PTh film electrode was investigated, and the result disclose that it has a good cycle stability after 500 cycles. The work demonstrates that the feasibility of electrochemically assembling of PTh film in O/ILs micromulsions.
Conventional diesel engines with ethanol as fuel are associated with problems due to high self-ignition temperature of the fuel. The hot surface ignition method, wherein a part of the injected fuel is made to touch an electrically heated hot surface (glowplug) for ignition, is an effective way of utilizing ethanol in conventional diesel engines. The purpose of the present study is to investigate the effect of thermal insulation on ethanol fueled compression ignition engine. One of the important ethanol properties to be considered in the high compression ratio engine is the long ignition delay of the fuel, normally characterized by lower cetane number. In the present study, the ignition delay was controlled by partial insulation of the combustion chamber (low heat rejection engine) by plasma spray coating of yttria stabilized zirconia for a thickness of 300μm. Experiments were carried out on the glowplug assisted engine with and without insulation in order to find out the possible benefits of combustion chamber insulation in ethanol and diesel operation. Highest brake thermal efficiency of 32% was obtained with ethanol fuel by insulating the combustion chamber. Emissions of the unburnt hydrocarbons, oxides of nitrogen and carbon monoxides were higher than that of diesel. But the smoke intensity and was less than that of diesel engine. Volumetric efficiency of the engine was reduced by a maximum of 9% in LHR mode of operation.
We propose bubble-sensing, a new sensor network abstraction that allows mobile phone users to create a binding between sensing tasks and the physical world at locations of interest, that remains active for a duration set by the user. We envision mobile phones being able to affix sensing task bubbles at places of interest and then receive sensed data as it becomes available in a delay-tolerant fashion, in essence, creating a living documentary of places of interest in the physical world. The system relies on other mobile phones that opportunistically pass through bubble-sensing locations to acquire tasks and do the sensing on behalf of the initiator, and deliver the data to the bubble-sensing server for retrieval by the user who initiated the task. We describe an implementation of the bubble-sensing system using sensor-enabled mobile phones, specifically, Nokia’s N80 and N95 (with GPS, accelerometers, microphone, camera). Task bubbles are maintained at locations through the interaction of “bubble carriers”, which carry the sensing task into the area of interest, and “bubble anchors”, which maintain the task bubble in the area when the bubble carrier is no longer present. In our implementation, bubble carriers and bubble anchors implement a number of simple mobile phone based protocols that refresh the task bubble state as new mobile phones move through the area. Phones communicate using the local Ad-Hoc 802.11g radio to transfer task state and maintain the task in the region of interest. This task bubble state is ephemeral and times out when no bubble carriers or bubble anchors are in the area. Our design is resilient to periods when no mobiles pass through the bubble area and is capable of “reloading” the task into the bubble region. In this paper, we describe the bubble-sensing system and a simple proof-of-concept experiment.
In the recent past, wireless sensor networks (WSN) have been used in a wide variety of applications which have special properties and requirements. In this study, a novel version of quantum-inspired gravitational search algorithm is presented as a new optimization methodology which is well suitable for quadrivalent encoded problems. The proposed method is adapted in a wireless sensor network in precise agriculture application to find an optimal and adaptive design of wireless sensor network to improve the energy consumption and extend the life span of the network, taking into consideration the communication limitations and application-specific requirements. The performance of the proposed method which is called QQIGSA is compared with the binary genetic algorithm (BGA) and binary particle optimization (BPSO). The experimental results indicate that the WSN designed by QQIGSA has the most performance in fulfilling the requirements and prolonging the lifetime of the network.
In this paper, we report on the orientations of Turkish college students to interpersonal arguing and compare them with American students’ predispositions for arguing. In measuring the argument orientations, a group of instruments was utilized: argument motivations, argument frames, and taking conflict personally. Turkish data come from 300 college students who were asked to complete self-report surveys. Analyses contrast the mean scores of the Turkish and American respondents, offer gender-based comparisons in the Turkish data, and show whether religiosity has an effect on Turkish students’ arguing orientations. In order to give an explanatory account of the argument motivations of Turkish college students, the relevant socio-cultural and political facts about Turkey were also considered. Our investigation has revealed that Turkish students have more advanced and positive understandings of interpersonal arguing compared to American ones. We have also found clear sex-typing between Turkish male and female students, and have discovered some limited evidence for religiosity’s relevance to interpersonal arguing.
Continuing technological development decreases the useful lifetime of electronic equipment, resulting in the generation of waste and the need for new and more efficient recycling processes. The objective of this work is to study the effectiveness of supercritical fluids for the leaching of cobalt contained in lithium-ion batteries (LIBs). For comparative purposes, leaching tests are performed with supercritical CO2 and co-solvents, as well as under conventional conditions. In both cases, sulfuric acid and H2O2 are used as reagents. The solution obtained from the supercritical leaching is processed using electrowinning in order to recover the cobalt. The results show that at atmospheric pressure, cobalt leaching is favored by increasing the amount of H2O2 (from 0 to 8% v/v). The use of supercritical conditions enable extraction of more than 95wt% of the cobalt, with reduction of the reaction time from 60min (the time employed in leaching at atmospheric pressure) to 5min, and a reduction in the concentration of H2O2 required from 8 to 4% (v/v). Electrowinning using a leach solution achieve a current efficiency of 96% and a deposit with cobalt concentration of 99.5wt%.
LiFePO4/C composite fibers were synthesized by using a combination of electrospinning and sol–gel techniques. Polyacrylonitrile (PAN) was used as an electrospinning media and a carbon source. LiFePO4 precursor materials and PAN were dissolved in N,N-dimethylformamide separately and they were mixed before electrospinning. LiFePO4 precursor/PAN fibers were heat treated, during which LiFePO4 precursor transformed to energy-storage LiFePO4 material and PAN was converted to carbon. The surface morphology and microstructure of the obtained LiFePO4/C composite fibers were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and elemental dispersive spectroscopy (EDS). XRD measurements were also carried out in order to determine the structure of LiFePO4/C composite fibers. Electrochemical performance of LiFePO4/carbon composite fibers was evaluated in coin-type cells. Carbon content and heat treatment conditions (such as stabilization temperature, calcination/carbonization temperature, calcination/carbonization time, etc.) were optimized in terms of electrochemical performance.
This paper describes a project for the integration of mini-hydro renewable energy in the trolleybus traction lines and in the electric battery operated mini-buses. Given the nearby hydropower resource of the Mondego river, a study was carried out in order to assess the technical and economical feasibility of hydropower production at an already existing multi-purpose mobile dam-bridge, located in Coimbra, Portugal, where a very low head run-of-river small-hydropower plant can be installed. As the main civil works have already been done, the hydropower installation costs are significantly reduced because the investment mainly resumes to hydro-mechanical, hydro-electrical and electrical equipment, with expected low hydraulic structure impact, as well as minimum environmental and visual impacts. The optimization of the hydroelectric production takes into account the seasonal water supply demands for agricultural, municipal and industrial use, the water discharges from the upstream reservoir system of Aguieira–Raiva–Fronhas, the very low head turbines state of the art technology, the physical constraints of the structure and the special feed-in tariff for renewable power plants. The small-hydropower plant, coupled with the electric public urban transportation fleet, will contribute to a sustainable clean mobility concept, reducing electric grid transportation losses by decentralized production and reducing greenhouse gases emissions, contributing to urban air quality improvement and to the Kyoto Protocol fulfillment.
A low-cost and high-performance energy storage device is a key component for sustainable energy utilization. Recently, sodium (Na) ion batteries have been highlighted as a possible competitor to lithium (Li) ion batteries due to their potential merit in the cost effectiveness. Na resources are earth-abundant, and Na electrochemistry shares many similarities with Li. However, their relatively low energy/power densities and unreliable cycle stability need to be addressed. Herein, we propose a novel high-performance cathode for Na rechargeable batteries based on mass-scalable functionalized graphite nanoplatelets. This new class cathode material can deliver a high energy of ~500Whkg−1 without noticeable capacity decay after 300 cycles. Furthermore, it can retain an energy of ~100Whkg−1 at a power of ~55kWkg−1 (less than 10-s charge/discharge), which is the highest among cathodes for Na ion batteries. This transition-metal-free high-performance cathode is expected to lead to the development of low-cost and high-performance Na rechargeable batteries.
Summary In the context of globalization and policies to promote free trade on an international scale, this paper discusses what has happened to artisans in Quito, Ecuador, over the past 30 years. The trends of conservation and decline have not been uniform over time and they have not affected all micro-firms in the same way. There has been a long-term process of restructuring and decline of these producers and they have clearly suffered from national and international free trade policies. This has resulted in levels of alienation, xenophobia and racism that are likely to have negative political consequences.
A differential scanning calorimeter (DSC) was used to perform a thermal stability study of the LiPF6–EC:EMC electrolyte. The effect of different variables on its thermal stability was evaluated: salt (LiPF6) concentration effect, solvents, EC:EMC ratios, and heating rates. Hermetically sealed and crimped DSC pans were used during the experiments. The results indicate that the salt concentration, solvent concentration, and heating rates play an important role in the thermal stability of the LiPF6–EC:EMC electrolyte.
We describe herein approaches for R&D of improved solutions for Li-ion batteries, new concepts for measuring aging processes of Li-ion battery electrodes and approaches for the synthesis of novel electrode materials for Li-ion batteries. We demonstrate the possibility of successfully using standard LiPF6 solutions for Li-ion batteries at elevated temperatures by the use of organosilicon additives. We also show how these solutions are compatible for 5V systems. We show how measurements of the self-discharge current of lithiated graphite electrodes during cycling, reflect the complicated aging of the electrodes, and we map the various processes that influence the overall aging trends observed. Several novel approaches for the synthesis of nanomaterials for Li-ion batteries, including carbonaceous materials, tin-based compounds and transition metal oxides, are described. These include soft reactions in the liquid phase, high temperature reactions under autogenic pressure and the use of microwave radiation and sonochemistry.
The two human pronapsin genes which are located immediately adjacent to one another on chromosome 19 were shown, using quantitative RT-PCR, to have distinctly different expression patterns. Transcription of the pronapsin A gene in normal human lung tissue was not appreciably altered in lung carcinomas and comparable pronapsin A mRNA levels were also quantified in lung epithelial cell lines and in tumour cell lines originating from human lung epithelium. Pronapsin A may thus have considerable diagnostic value as a marker for primary lung cancer. In contrast, the pronapsin B gene, which lacks an in-frame stop codon and so may be a transcribed pseudogene, is expressed at comparable levels in normal human spleen, thymus, cytotoxic and helper T-lymphocytes, natural killer (NK) cells and B-lymphocytes. The mRNA levels quantified in B-cells from adults with chronic lymphoblastic leukaemia were not significantly different from those measured in B-cells from healthy individuals. Similarly, comparable levels of expression were quantified in monocytes from healthy individuals and from a patient with acute myeloid leukaemia, whereas in alveolar macrophages, which are terminally differentiated myeloid cells, transcription of the pronapsin B gene was down-regulated by approximately one order of magnitude. Reciprocally, an ∼20-fold up-regulation in expression of the procathepsin D gene in the macrophages relative to the circulating monocytes was revealed by quantitative measurements made in parallel throughout all of this study for the respective mRNAs encoding the intracellular aspartic proteinases, procathepsin D and procathepsin E. Thus, while there appears to be little difference in expression of the pronapsin A and B genes between healthy and malignant human cells and tissues, the reciprocal alterations in the levels of transcription of the pronapsin B and procathepsin D genes may have significance in the developmental processes associated with myeloid cell differentiation into macrophages.
The oxygen reduction reaction (orr) was studied on composite electrodes GC/PPy/PPy(Ni x Co3−x O4)/PPy with x=0.3 and 1, in 2.5×10−3 M KOH+0.8 M KCl at room temperature. The orr takes place on the oxide particles with formation of hydrogen peroxide (H2O2), which diffuses through the polymer layers to reach the bulk of electrolyte solution. The amount of H2O2 produced, determined indirectly by iodine spectrometry, depended strongly on the oxide stoichiometry. The effects of the orr and of the generation of H2O2 on the conductivity of PPy and on the behaviour of the embedded oxide particles are discussed.
High surface area and a three dimensional NiCrAl alloy foam current collector was used for two kinds of thick lithium iron phosphate electrodes. One kind of electrodes were compressed after the slurry of active material in the metal foam was dried and then annealed at 140°C for half a day whereas the other kind of electrodes were prepared without pressing. When the addition of carbon black was 4wt% for the two kinds of electrodes, a charge-discharge test revealed that the capacity of the cell using the pressed electrode faded much more although the voltage-drop was much smaller at the plateau region. For example, the capacity of the pressed electrode exhibited 85mAhg−1, while it was 135mAhg−1 for the unpressed electrode although the voltage-drop at the plateau region was 250mV higher at 0.5C-rate for the unpressed electrode. The AC impedance analysis showed that the charge transfer resistance of the pressed electrode was only 15Ω whereas it was 4 times higher for the unpressed electrode. The results illustrated that the effective redox area was much larger for the unpressed electrode since the cell using the unpressed electrode exhibited much higher capacity even at the condition of poor electronic conductivity. To solve the low electronic conductivity issue for the unpressed electrode, the addition of carbon black was further increased to 14 wt% and as a result, there was almost no difference in voltage drop at plateau region or charge transfer resistance between the two kinds of electrodes. Obviously, the capacity of unpressed electrode exhibited much higher at higher current rate due to the larger effective redox area.
Ce-doped Li1+x Ce y V3−y O8 (0≤ y ≤0.015) cathode materials have been prepared through a citrate sol–gel route followed by heating at 550°C in air. Demonstrated by XRD and elemental mapping, single-phase and homogeneous Li1+x Ce y V3−y O8 solid solutions are obtained at y ≤0.01, while CeVO4 impurity presents with increasing of y up to 0.015. The Li1+x Ce y V3−y O8 at y =0.01 delivers initial capacity of 262.33mAhg−1 and capacity retention of 98.9% within the first 50 cycles, much better than the pristine Li1+x V3O8 cathode (261.86mAhg−1 and 87.7% accordingly). Electrochemical analyses show that an appropriate dosage of Ce can significantly suppress the capacity fading arose from lithiation phenomena around 2.55 and 2.3V upon cycling. These interesting phenomena are mainly attributed to the stabilization of the microstructure of the material and the modification of their crystallinity and grain morphology, which lead to suppression of structural damage from the two-phase transformation around 2.55V upon cycling and the dissolution of active material in the electrolyte on the 2.3V phenomena.
SEM images of round-shaped natural graphite, currently widely used as the anode active material of Li-ion batteries, show that the surface mainly consists of the basal plane, which suggests that the Li insertion/extraction reaction rate is quite limited. In contrast to this suggestion, however, the anode of commercial Li-ion batteries is capable of high rate charging/discharging. In order to explain this inconsistency, we propose that there are nano-holes in the graphene layers of the graphite allowing Li to be very easily inserted and extracted via the holes. Prior to the measurements a quantum chemical investigation was performed on the energy required for Li to pass through the hole in a graphene layer (E act). The results showed that the E act value is too high when the size is smaller than pyrene, but is fairly low for holes of the size of coronene, implying that Li can pass through the basal plane layer if there is a hole larger than coronene. Characterization of the rounded graphite sample and flaky natural graphite was conducted by constant-current charge/discharge cycle tests, X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM). XRD revealed no appreciable difference between the rounded graphite and flaky natural graphite, in agreement with Raman data. A detailed analysis of the HRTEM results revealed the presence of a number of variously sized circular images. We believe that these are holes in the graphene layer through which Li can pass. The mechanism of formation of the holes is discussed.
Organic ionic plastic crystals (OIPCs) have been studied as solid-state electrolytes because of their desirable properties such as non-flammability, plasticity, and ionic conductivity. However, the temperature range of their conductive plastic crystal phase is narrow. We previously reported that N-ethyl-N-methylpyrrolidinium bis(fluorosulfonyl)amide ([C2mpyr][FSA]) exhibited a wide temperature range of plastic crystal behavior and high ionic conductivity at room temperature. In this study, the relationship between the side chain structure of pyrrolidinium and the physicochemical properties of their compounds with FSA was investigated. With two introduced ethyl groups, N,N-diethylpyrrolidinium bis(fluorosulfonyl)amide ([C2epyr][FSA]) showed higher ionic conductivity than [C2mpyr][FSA], while maintaining a sufficient temperature range of plastic crystal phase. The ionic conductivity of [C2epyr][FSA] was further improved by the addition of 5 mol% LiFSA. For the [C2epyr][FSA] composited with 5 mol% LiFSA, the lithium transference number was determined to be 0.27 at 60 °C. Reversible lithium plating/stripping reaction was observed on a Ni electrode in the CV measurement. Symmetric pyrrolidinium cation with a longer alkyl chain (up to two carbons) showed conductive plastic solid phase in a wide temperature range and a higher lithium transference number.