batterydata/paper-abstracts huggingface dataset:
Thanks to the independent sizing of power and energy, hydrogen-based energy storage is one of the very few technologies capable of providing long operational times in addition to the other advantages offered by electrochemical energy storage, for example scalability, site versatility, and mobile service. The typical design consists of an electrolyzer in charge mode and a separate fuel cell in discharge mode. Instead, a unitized regenerative fuel cell (URFC) is a single device performing both energy conversions, achieving a higher compactness and power-to-weight ratio. This paper presents a performance model of a URFC based on a proton exchange membrane (PEM) electrolyte and working on hydrogen and oxygen, which can provide high energy and power densities (>0.7 W cm−2). It provides voltage, power, and efficiency at varying load conditions as functions of the controlling physical quantities: temperature, pressure, concentration, and humidification. The model constitutes a tool for designing the interface and control sub-system as well as for exploring optimized cell/stack designs and operational conditions. To date, only a few of such analyses have been carried out and more research is needed in order to explore the true potential of URFCs.
The present study investigated the temperature dependence of the local structure of 0.4Li2MnO3-0.6LiMn1/3Ni1/3Co1/3O2 electrodes during the first discharge cycle, using neutron and synchrotron X-ray diffraction. It was found that at 60 °C, a capacity of more than 280 mAh/g could be achieved at a voltage of 2.5–4.8 V vs. Li/Li+, which was larger than the capacity at room temperature. To clarify the reason for this, an analysis was carried out based on the pair distribution function for electrodes following their first charge and discharge cycles. The results indicated a unique distortion of Ni-O6 octahedra at higher temperature. In addition, an analysis using X-ray absorption near edge structure spectroscopy indicated a change in valence during charging and discharging based on a shift in the position of peaks associated with Mn, Ni, and Co. At 60 °C, the shift was particularly large for the Ni peak. Thus, the operating temperature can have a large effect on the behavior of especially Ni, which can influence the battery characteristics.
Metallic carbon has been extensively studied for its potential novel applications in catalysis, superconductivity, and electronic devices. Currently, the design of metallic carbon is mainly by educated intuition which could miss some more stable allotropes. Here we carry out a global structure search on the potential energy surface, and identify a new three-dimensional (3D) metallic carbon phase, termed Hex-C18, which is energetically more favorable than most of the previously identified 3D metallic carbon allotropes. Using state-of-the-art theoretical calculations, we show that Hex-C18 not only possesses a high thermodynamic stability, large heat capacity, high Debye stiffness, anisotropic elasticity, and super hardness, but also is a promising anode material for lithium ion batteries (LIBs). As compared to graphite commercially used in LIBs, Hex-C18 exhibits a lower Li diffusion energy barrier and a higher Li capacity because of its intrinsic metallicity and regular porosity. In addition, the simulated x-ray diffraction of Hex-C18 matches well with a previously unidentified low-angle diffraction peak in experimental XRD spectra of detonation soot, implying the possibility of its existence in the specimen. This study expands the family of metallic carbon, and may open a new frontier in design of high performance anode materials for LIBs as well.
Gasoline compression ignition combustion has been regarded as a potential technology for future vehicle power source. Understanding the relationship between gasoline properties and its auto-ignition behaviors is critical to the development of this new combustion technology. Aiming at this goal, a comprehensive parametric study was conducted to investigate the influence mechanism of gasoline octane number, fuel sensitivity and equivalence ratio on the combustion behaviors of an advanced compression engine. A hybrid analysis method was proposed in the study; a reaction kinetics model coupled with a new-developed gasoline surrogate mechanism was used to trace the engine’s combustion characteristics, while a density-based global sensitivity analysis method was applied to decode the composite effect of each factor. Results demonstrate two distinct combustion modes in low temperature conditions and give separation functions in the input space of three factors (R-Squares are above 97%). The reaction kinetics analysis points out the shift of dominant reaction groups is the main reason for incomplete combustion phenomenon. Then the global sensitivity result shows octane number is the dominant factor controlling the rate of the combustion heat release under all conditions (the averaged sensitivity index exceeds 0.7); fuel sensitivity only makes a considerable effect on combustion performances under low temperature regions, with sensitivity indices of 0.2–0.3. Besides, the local sensitivity of each factor on combustion behaviors at specific points is also given to understand the influence mechanism resulted from the variations of fuel properties. This study provides a useful method for getting deeper insights into the combustion dynamics and kinetic reaction in gasoline compression ignition engines.
Exploring conceptual frontiers between batteries, supercapacitors, redox flow batteries (RFBs) and fuel cells (FCs), we have used a battery material (i.e. LiFePO4) and a supercapacitor material (i.e. graphene) in the form of nanoparticles dispersed in an aqueous electrolyte to characterize the electrochemical activity of the resulting electroactive nanofluids. X-ray diffraction, TEM, Raman, XPS and AFM analyses were carried out to characterize the solid LiFePO4 and RGO components. The corresponding electroactive nanofluids were prepared by dispersion in an aqueous Li2SO4 electrolyte and stabilized with Diaminobenzoic Acid (DABA). Cyclic voltammetry measurements were used to analyze their electrochemical behavior in three-electrode cells. Charge-discharge tests of the LiFePO4/RGO (positive) vs. RGO (negative) nanofluids were also performed. Effective utilization of dispersed electroactive particles (ca. 100 mAh/g(LFP) at 1C) was demonstrated, which turned out to be superior to the same LFP material used as solid electrode. A charge-transfer percolation effect provided by the RGO dispersion is proposed as the mechanism for the good performance of LiFePO4 (not coated with carbon!) and RGO Nanofluids. Our results constitute a first step and proof of concept of the possible application of electroactive nanofluid electrodes in alternative flow batteries.
The relationship among working memory, mathematic ability, and the cognitive impairment of children with difficulties in mathematics was examined. A group of children with difficulties in mathematics (MD) was compared with a group of children with a normal level of achievement matched for vocabulary, age, and gender (N=49). The children were required to perform a variety of working memory and short-term memory tasks that had been administered 1 year previously. Moreover, the children were asked to perform tasks designed to provide information about speed of articulation. The results suggest a general working memory deficit in children with MD, specifically in the central executive component of Baddeley's model and primarily in the ability to inhibit irrelevant information. However, the MD children were not impaired in speech rate and counting speed tasks, which mainly involve the role of the articulatory loop.
Interpenetrating organic polymer composites consisting of two conducting polymers have been successfully prepared by sequential electropolymerization of the parent monomers: aniline and 3,4-ethylenedioxythiophene. The electropolymerization of poly(3,4-ethylenedioxythiophene) (PEDOT) and polyaniline (PANI) was carried out in acetonitrile solution. In the first step, a potentiostatic electrodeposition of PEDOT was performed. Then in the second step, a potentiostatic electrodeposition of PANI was carried out, in acetonitrile solution without addition of protic acid, in the potential range where PEDOT was in its oxidized and conducting states. We observed that the oxidized PEDOT film exhibited a Lewis acid behavior that allowed the polymerization of polyaniline on PEDOT modified electrode in the absence of protic acid. A mechanism of the polymerization of PANI onto PEDOT was proposed. The electrochemical properties of the composite films have been analyzed by means of cyclic voltammetry and in situ resistometry. In the case of the interpenetrating composite based on PEDOT/PANI, the variation of the electronic resistance as a function of potential displayed a drastic change comparing to that of PEDOT or PANI alone. These results indicated that the obtained electroactive material was not a bilayer or sandwhich structure but an interpenetrating composite in which the two conducting polymers interacted each other to give new electrical properties. Also, we observed an increase of the stability of PANI in the PEDOT/PANI composite when the measurements were carried out in acidic aqueous solution. An important advantage of these organic conductive polymer composites is the simplicity of their preparation.
A long-term (2002–2011), spatially robust, ichthyoplankton sampling program conducted in the New York/New Jersey Harbor produced 3,033 epibenthic samples from which the relationships between winter flounder egg and larval distributions and environmental parameters were examined. Variations in water temperature, sediment characteristics, and tidal phase were all significantly associated with egg distributions. Inferences about spawning habitats were based on the presence of early-stage eggs (ES1 and ES2). In the Lower Bay (LB), these habitats were primarily non-channel and characterized by more sandy substrates, averaging 96.5 % sand, 2.3 % silt/clay, 0.2 % total organic carbon (TOC), and shallower water (average depths of 5.3 m) compared to LB non-channel stations without ES1 and ES2 eggs (50.2 % sand, 42.0 % silt/clay, 2.1 % TOC, and 7.9 m depths). Occurrences of all stages of eggs in channels were associated with strong tides and severe cold winter water temperatures. These conditions increase the probability of egg transport from shallow spawning sites through increased vertical mixing (strong tides) and delayed development that prolongs the risk of displacement (cold temperatures). Yolk-sac (YS) and Stage-2 larvae were smaller in 2010 when spring water temperatures were highest. Overall, YS larval size decreased with warmer winters (cumulative degree-days for the month preceding peak YS larval collections, r2 = 0.82, p < 0.05). In all years, YS larvae collected in LB were smaller and Stage-3 larvae collected in channels were larger and possibly older than those from non-channel habitat. Because estuarine winter flounder populations are highly localized, adverse effects experienced during egg and larval stages are likely to propagate resulting in detrimental consequences for the year class in the natal estuary.
Today’s batteries are commercially developed technologies and are commonly used for energy storage in active distribution grids. In spite of their numerous advantages, batteries are expensive; consequentially, they should be installed and managed in an optimal manner. Furthermore, every battery technology has particular technical and economic characteristics that may be particularly well- or poorly-suited to certain applications. This paper represents a comparison based optimal planning of several battery technologies to find the best choice in distribution grid applications. The proposed planning methodology is a novel four-layer procedure that considers the uncertainty of battery characteristics as well as load and wind power. The long-term planning layer optimizes the location, capacity and power rating of batteries. The short-term scheduling layer includes the probabilistic optimal power flow with respect to technical constraints. In the uncertainty modeling layer, the technical and economic characteristics of battery technologies and load demands are modeled using fuzzy values. Moreover, in order to consider the correlations and independencies of the wind power profiles, they are classified to several categories using factor analysis technique in the classifying layer. The numerical results show that Zn-Br technology is the most suitable option in deterministic studies, however, the Na-S technology can be an alternative in uncertain conditions. Several sensitivity analyses are carried out to generalize and extend the results. Finally, it is found that more storage capacity is required in realistic conditions thanks to using factor analysis technique.
A rational strategy for the synthesis of ternary cubic phase Zn2Ti3O8 solid spheres has been developed for application in lithium ion batteries. In this process, titanium glycolate solid spheres are used as nanostructure template and titanium source, whose functional groups are replaced by zinc ions through a solvothermal ion exchange method in accordance with the Zn/Ti atomic ratio of 2:3. When adjusting the Zn/Ti atomic ratios to 0:3, 1:3, the anatase TiO2 solid spheres and multiphase complex of TiO2/ZnTiO3 solid spheres can be obtained. However, with the increasing of Zn/Ti atomic ratio to 3:3, in addition of cubic phase Zn2Ti3O8 solid spheres, a lot of hexagonal ZnO nanoparticles are synthesized. As anodes for lithium ion batteries, the delivered capacities of Zn2Ti3O8 solid spheres are higher than those of TiO2 and TiO2/ZnTiO3 solid spheres at 300 mA g−1. Notably, the high purity cubic phase Zn2Ti3O8 solid spheres can still release a reversible capacity of 146.7 mAh g−1 even at 2000 mA g−1 over 1000 cycles. Also, the Zn2Ti3O8 solid spheres show a good electrochemical performance in the full cells. The superior electrochemical properties are ascribed to the favorable crystal structure and highly developed porous structure of Zn2Ti3O8 solid spheres.
In recent years, many researchers have proposed new DC/DC converters in order to meet the fuel cell requirements. The reliability of these DC/DC converters is crucial in order to guarantee the availability of fuel cell systems. In these converters, power switches ranked the most fragile components. In order to enhance the reliability of DC/DC converters, fuel cell systems have to include fault-tolerant topologies. Usually, dynamic redundancy is employed to make a fault-tolerant converter. Despite this kind of converter allows ensuring a continuity of service in case of faults, the use of dynamic redundancy gets back to increase the complexity of the converter. In order to cope with reliability expectations in DC/DC converters, floating interleaved boost converters seem to be the best solution. Indeed, they have much to offer for fuel cells and DC renewable energy sources (i.e. photovoltaic system), including reduced input current ripple and reliability in case of faults. Despite the offered benefits of this topology, operating degraded modes lead up to undesirable effects such as electrical overstress on components and input current ripple increasing. The aim of this paper is to carry out a thorough analysis of these undesirable effects and to propose remedial strategies to minimize them.
In this article, a novel method, namely full modified nonlocal (FMNL) theory, for bending and buckling analysis of simply supported rectangular nano plates has been proposed. In this theory, a complete representation of strong-form of governing equation and boundary conditions are derived based on the infinite series of modified nonlocal constitutive equations by applying the variational principle. It is shown that by rearranging and then computing the sum of the infinite series which appears in the maximum bending deflection and critical buckling load, the truncation errors will be eliminated. A radius of convergence for the computed series is calculated to make sure the analyses are valid and reliable. In addition, the results of the presented method are compared with MD simulations to confirm the validity of FMNL theory. One of the advantages of the FMNL theory is that the defect of nonlocal theory in vanishing of small scale effect for some problems can be resolved. Furthermore, the FMNL theory will be a criterion for accuracy of the primary modified nonlocal theory that considers only two terms of the series of the modified nonlocal constitutive equation in predicting critical buckling loads and maximum bending deflections.
“Green Growth” and “Sustainability” are now keywords for industrial growth engines. This research examines the economic, environmental, and technological feasibility of hybrid systems by simulating a system composed of renewable energy, an existing grid system, and a diesel generator on Jeju Island in South Korea. Korea depends heavily on oil imports. Thus, in Korea, efficient energy management is imperative. For this reason, the current Korean administration is striving to improve its energy infrastructure with the construction of stable energy supplies and reliable systems the implementation of energy policies, such as smart grids, and the diffusion of renewable energy generation sources. This study finds that the most economically feasible hybrid system is a grid-connected wind turbine–photovoltaic–battery–converter hybrid system. Given the economic feasibility of this hybrid system, implementing it would decrease the price of electricity in Jeju. Both the implications and limitations of this study will be discussed in the last section of this paper.
A liquid silicone was used as a binder to make composite solid electrolytes from lithium-ion conductive inorganic solid electrolytes (ISEs): an oxysulfide glass, 0.01Li3PO4–0.63Li2S–0.36SiS2 and/or a lithium germanium thio-phosphate, Li3.25Ge0.25P0.75S4. Ionic conductivities of the composites were of the order of 10−4 Scm−1, even when the silicone was enriched to 10% (v/v). On the other hand, the composite with styrene–butadiene block co-polymer (SBR) or polypropylene oxide–polyethylene oxide (PO–EO) co-polymer as binder showed much lower conductivity. In the composite electrolyte, the silicone rubber must partly cover the surface of the ISE particles because the composite electrolyte is molded before the vulcanization of the fluid liquid silicone; and thus, it must rarely interfere with the conduction between the ISE particles. Hydrocarbons were found to be suitable in the preparation process of the composite solid electrolyte (CSE).
The carbon nanotubes (CNTs), the as-prepared FeB nanoparticles and the CNTs decorated with FeB nanoparticles (denoted as FeB/CNTs) are introduced respectively into MgH2 system by wet milling with cyclohexane (CYH), and results show that wet milling with CYH and adding dopants (CNTs, FeB or FeB/CNTs) both improve the hydrogen storage properties of MgH2. The MgH2−10 wt% FeB/CNTs (CYH) composite shows the best properties. Its onset dehydrogenation temperature is 196 °C, which is 114 °C lower than that of the MgH2 (without CYH). Furthermore, the hydrogen desorption activation energy of MgH2−10 wt% FeB/CNTs (CYH) is reduced to 89.7 kJ/mol. The composite starts to absorb hydrogen at temperature as low as 39 °C, and can take up 6.2 wt% of H2 at 150 °C and 5 MPa H2 within 10 min. The hydrogen sorption cycling measurements indicate that the kinetics of the MgH2−10 wt% FeB/CNTs (CYH) composite keeps almost stable within 20 cycles, and the hydrogen storage capacity remains at 6.02 wt% (93% of the initial capacity) after 20 cycles. It is believed that the in-situ formed Fe and B as the active species and the good thermal conductivity of CNTs help enhance the hydrogen storage properties of the MgH2.
Currently, there is a disparity in the availability of doctors between urban and rural areas of developing countries. Most experienced doctors and specialists, as well as advanced diagnostic technologies, are available in urban areas. People living in rural areas have less or sometimes even no access to affordable healthcare facilities. Increasing the number of doctors and charitable medical hospitals or deploying advanced medical technologies in these areas might not be economically feasible, especially in developing countries. We need to mobilize science and technology to master this complex, large scale problem in an objective, logical, and professional way. This can only be achieved with a collaborative effort where a team of experts works on both technical and non-technical aspects of this health care divide. In this paper we use a systems engineering framework to discuss hospital networks which might be solution for the problem. We argue that with the advancement in communication and networking technologies, economically middle class people and even some rural poor have access to internet and mobile communication systems. Thus, Hospital Digital Networking Technologies (HDNT), such as telemedicine, can be developed to utilize internet, mobile and satellite communication systems to connect primitive rural healthcare centers to well advanced modern urban setups and thereby provide better consultation and diagnostic care to the needy people. This paper describes requirements and limitations of the HDNTs. It also presents the features of telemedicine, the implementation issues and the application of wireless technologies in the field of medical networking.
Sensorless online temperature measurement of lithium-ion cells based on electrochemical impedance spectroscopy (EIS) measurements is introduced and applied to a commercial 2 Ah pouch cell. The method's sensitivity on temperature and state of charge (SOC) is investigated, taking a closer look to the selection of measurement frequency. The internal temperature is determined as precise as ±0.17 K with SOC status known and ±2.5 K with SOC status unknown at isothermal conditions. Furthermore, the influence of a temperature gradient, as it will develop during cell operation, is studied in detail and the simulation results are validated experimentally. Finally, the method's ability to monitor the temperature is demonstrated during a thermal cool down.
We have synthesized a new inorganic/organic hybrid material, which comprises vanadium pentoxide (V2O5) and the binary polymers poly(2,5-dimercapto-1,3,4-thiadiazole) (PDMcT) and polyaniline (PANI), and have investigated its electrochemical property. Fourier transform infrared spectra (FT-IR) confirms that both 2,5-dimercapto-1,3,4-thiadiazole (DMcT) and aniline molecules are oxidatively intercalated into the interlayer of V2O5 xerogel, and result in a binary polymers/V2O5 hybrid material. X-ray diffraction (XRD) shows that intercalation of polymers expands the V2O5 interlayer distance by 4.8Å. V K-edge X-ray absorption near-edge structure spectroscopic analysis shows no significant change in VO6 octahedral symmetry, but a slight reduction of the V(5+) state. Electrochemical investigations in the 4–2V range versus Li/Li+ using non-aqueous electrolyte cells show that as-synthesized binary polymers/V2O5 material exhibits an initial discharge capacity of ∼190mAhg−1 while an oxygen-treated sample exhibits an initial capacity of about 220mAhg−1 and a better reversibility for lithium insertion/de-insertion.