batterydata/paper-abstracts huggingface dataset:
This paper deals with the behaviour of battery-supported residential photovoltaic (PV) systems connected to smart grids, with a special focus on the interface with electricity distributors. In particular, this paper is aimed at the assessment of the benefits resulting from two predictive control strategies managing the charge of the electrochemical storage unit, in comparison with the conventional control strategy and applied to various combinations of photovoltaic system and battery pack sizes in a parametric analysis. The proposed control strategies dispatch electricity to the battery pack or national grid depending on the state of charge and differ in the shape of the profile of exported electricity, hence adapting to different interface profiles required at the electricity distributor’s side. In particular, the research shows that, by the proposed control strategies, the frequencies of occurrence of high values of exported electricity may be decreased by almost 100%, whereas medium-high values of exported electricity by 50%. Moreover, both of the control strategies are shown to be able to lower the yearly quadratic effective imbalance coefficient by around 15% in case of PV systems sized for Zero Energy Buildings (ZEBs), thus showing opportunities in the mitigation of electricity grid stresses from PV systems.
Fe K-edge X-ray absorption near edge spectroscopy (XANES) and extended X-ray absorption fine structure (EXAFS) have been performed on electrodes containing LiFePO4 to determine the local atomic and electronic structure and their stability with electrochemical cycling. A versatile electrochemical in situ cell has been constructed for long-term soft and hard X-ray experiments for the structural investigation on battery electrodes during the lithium-insertion/extraction processes. The device is used here for an X-ray absorption spectroscopic study of lithium insertion/extraction in a LiFePO4 electrode, where the electrode contained about 7.7mg of LiFePO4 on a 20μm thick Al-foil. Fe K-edge X-ray absorption near edge spectroscopy (XANES) and extended X-ray absorption fine structure (EXAFS) have been performed on this electrode to determine the local atomic and electronic structure and their stability with electrochemical cycling. The initial state (LiFePO4) showed iron to be in the Fe2+ state corresponding to the initial state (0.0mAh) of the cell, whereas in the delithiated state (FePO4) iron was found to be in the Fe3+ state corresponding to the final charged state (3mAh). XANES region of the XAS spectra revealed a high spin configuration for the two states (Fe (II), d6 and Fe (III), d5). The results confirm that the olivine structure of the LiFePO4 and FePO4 is retained by the electrodes in agreement with the XRD observations reported previously. These results confirm that LiFePO4 cathode material retains good structural short-range order leading to superior cycling capability.
The SA government has said that rural households using solar energy would be granted a limited operation and a maintenance subsidy of up to R40 a household. Any amount above R40 a month would be paid by the end user. This is part of the Government initiative to provide free basic energy services. The objective is to provide social relief to those who earn less than the minimum national income level, affecting paraffin, electricity and solar home systems.
The electropolymerization of diphenylamine (DPA) dissolved in 2 mol dm−3 H2SO4 has been studied on a gold electrode by cyclic electrochemical quartz crystal microbalance measurements. Similar experiments have been accomplished with DPA microcrystals attached to a gold electrode, in the presence of aqueous acidic media. In both cases the redox transformations of the poly(diphenylamine) films formed on Au have been investigated in solutions of different pHs. The cyclic voltammograms and the mass changes refer to two closely spaced redox reactions resulting in the formation of cation radicals and dications, respectively. The irregular, broad shape of the voltammetric waves may be explained by presence of other electrochemically active sites beside the linear diphenylbenzidine structure. The results indicate a pH and potential-dependent relative contribution of anions and hydrogen ions to the overall ion exchange process. The expulsion of protons is the predominant ion transport process at the beginning of the oxidation and the incorporation of anions occurs at a later stage of oxidation. The sorption/desorption of solvent molecules also contributes to the mass change observed during the redox transformations of the polymer.
Lithium titanate spinel (Li4Ti5O12, or LTS) is receiving consideration as a nanopowder anode material for use in lithium-ion batteries. LTS has more positive working potential than traditional graphite anodes, and it does not react with electrolyte components. However, the main drawback of LTS powder is its poor interparticle electronic conductance that reduces the high-rate ability of the electrode. To improve this we have coated the surface of the LTS powder with a titanium nitride layer by atomic layer deposition (ALD). In situ infrared spectroscopy studies were conducted to confirm the attachment of the titanium precursor. The nitrogen content of films was measured by total nitrogen content testing. Transmission electron microscopy (TEM) micrographs confirmed the formation of a thin titanium nitride film around LTS particles by ALD. Finally, lithium cells with electrodes made of original and modified LTS nanopowders were assembled and tested.
Summary Market-based rural electrification with solar energy is increasingly common in developing countries. This article revolves around three main claims about solar electrification in Kenya’s unsubsidized market: (1) The benefits of solar electrification are captured primarily by the rural middle class. (2) Solar electricity plays a modest role in supporting economically productive and education-related activities, but “connective” applications such as television, radio, and cellular telephone charging often receive a higher priority. (3) Solar electrification is more closely tied to increased television use, the expansion of markets, more rural–urban communication, and other processes that increase rural–urban connectivity than to poverty alleviation, sustainable development, or the appropriate technology movement.
This paper presents an overview of the current solid waste management situation in Singapore and provides a brief discussion of the future challenges. Singapore is a small island city-state with a large population, warm climate and high humidity. Over the past two to three decades, rapid industrialization and economic development have caused a tremendous increase in solid waste generation. The yearly disposed solid waste increased from 0.74 million tonnes in 1972 to 2.80 million tonnes in 2000. Solid waste management in Singapore has traditionally been undertaken by the Ministry of Environment (ENV), with the participation of some private sectors in recent years. The hierarchy of solid waste management in Singapore is waste minimization (reduce, reuse and recycle or so-called 3 Rs), followed by incineration and landfill. As land is extremely scarce and only one newly constructed offshore landfill site is available, solid waste incineration has been identified as the most preferred disposal method. Waste minimization, the utilization of incineration ashes, industrial waste management are regarded to be the major challenges in the future.
Developing low-cost and highly effective doped carbon catalysts for the oxygen reduction reaction remains an urgent requirement for fuel cell applications. Herein, we design a facile and effective preparation strategy for the fabrication of a 3D porous carbon network catalyst comprised of an ultrathin nanosheet and anchored with Fe3C nanoparticles. The catalyst was prepared using an iron–tannin framework coated over g-C3N4 as precursor, and simultaneously with g-C3N4 as a nitriding agent and structural/morphological template. Optimum catalyst exhibits excellent ORR performance and durability in an alkaline medium; the half-wave potential (+0.86 V vs. RHE) is 40 mV more positive than that of commercial Pt/C, and its current density at +0.9 V (vs. RHE) reaches −1.153 mA cm−2, which is almost 2.42 times that of commercial Pt/C. Significantly, the catalyst also shows outstanding ORR performance in acidic conditions with a half-wave potential of +0.73 V (vs. RHE), comparable to that of Pt/C, and better long-term stability than Pt/C. Based on our characterization results, we ascribe the outstanding performance of catalyst to: the enhanced amount of Fe–Nx active sites and active nitrogen species, including pyridinic-N and graphitic-N; Fe3C nanoparticles covered with ultrathin doped carbon layer; and the high surface area and porous structure.
Children with epilepsy have known deficits on objective measures of learning and memory. Parents and children report that memory deficits have a negative impact on everyday functioning. In adults with epilepsy, self-report of memory is more strongly associated with depression than performance on memory tests. We investigated the cognitive and psychological predictors of everyday memory in 37 children with medically intractable epilepsy, using children's self-report and parent ratings of everyday memory performance and standard tests of attention, intelligence, visual and verbal memory, working memory, and mood/emotional state. Standard multiple regressions demonstrated that only a parent report measure of attention uniquely and significantly (P⩽0.05) predicted estimates of everyday memory performance, accounting for 33% of variance in children's own ratings and 27% of variance in parents' ratings. Findings suggest that everyday memory in children with intractable epilepsy differs from that of adults; attentional problems may underlie everyday memory problems in these children.
High-performance lithium ion battery (LIB) featured with excellent rate properties and cycling stability is highly required in various application fields. However, at this point in time, its practicality is very challenging due to the kinetic barrier related to ineffective electron and Li ion transfer in the batteries. Therefore, design of the electrode structure with higher storage and rate performances is very desirable. In this paper, we have developed a three-dimensional (3D) multilayered graphene-metal oxide hybrid nanostructure using a simple dip-coating method. A high porosity nickel foam is used both as a current collector and template for the fabrication of 3D structured electrodes. Graphene act both as buffer layers, preventing the aggregation of metal oxides, and provide electron pathways for fast electron transfer. Because of their unique features, the electrodes exhibit superior electrochemical performances as anodes for LIBs (graphene-Mn3O4@nickel foam, ∼ 1000mAhg−1 after 50 cycles; graphene-Fe3O4@nickel foam, ∼ 1200mAhg−1 at a current density of 200mAg−1). The enhancement of the electrochemical properties can be attributed to the fact that the 3D multilayered structure can accommodate the volume expansion of metal oxides and maintain the electrical and structural integrities.
Herein, we report a three-dimensionally (3D) ordered macro-/mesoporous carbon (3DOM-mC) as the ZnO nanoparticles support for the anode material in lithium-ion batteries (LIBs). The 3DOM-mC is synthesized by the typical dual-templating method that combines the hard-templating (silica opal as template) and soft-templating techniques using resol (phenol/formaldehyde) as the carbon source. The prepared 3DOM-mC material having ordered interconnected macropores and mesopores is then applied to support ZnO nanoparticles to form the ZnO/3DOM-mC composite via a simple in situ solution growth approach. In the ZnO/3DOM-mC composite, the ZnO nanoparticles (∼4.5 nm) are evenly dispersed on the macropore walls of the 3DOM-mC. The ZnO/3DOM-mC composite (40 wt% ZnO loading) anode shows an enhanced LIB performance delivering a specific capacity of 973.3 mAh g−1 after 100 cycles and 1396.6 mAh g−1 after 300 cycles at 0.1 C. This good electrochemical performance of the ZnO/3DOM-mC is ascribed to the ordered interconnected macropores of the 3DOM-mC that can provide the rapid diffusion of Li ions and electrolytes and the ordered mesopores that can buffer the volume expansion of ZnO during the cycling operation.
A templated freeze-drying method is developed to prepare the porous LiFePO4 materials with the controlled pore size and porosity, by conveniently adjusting the size and content of the template in the precursor solution. The morphology and structure of the porous LiFePO4 materials are characterized and the relavant electrochemical lithium-insertion performances are systematically studied. It’s found that the porous characteristics play a critical role in the lithium-ion intercalation processes and significantly affect the power capability of LiFePO4. The optimized porous LiFePO4 material presents remarkable specific capacity (167mAhg−1 at 0.1 C), rate capability (151mAhg−1 at 1 C and 110mAhg−1 at 10 C) and cycling stability (99.3% retention after 300 cycles at 1 C). These findings demonstrate that the electrochemical performance of the electrode material can be purposely tuned and remarkably improved by the rational design and introduction of the suitable pores, which open up new strategies for the synthesis of advanced porous materials for the lithium-ion power battery applications.
In this article,cobalt additives are introduced into nickel hydroxide electrodes by two incorporation methods—co-precipitated cobalt hydroxide during the nickel hydroxide synthesis or post-added CoO with nickel hydroxide. The results of X-ray diffraction, cyclic voltammetry, electrochemical impedance spectroscopy, and charge–discharge tests indicate that (i) the diffraction peaks show a decrease in intensity and increase in the half peak breadths for Ni(OH)2 with co-precipitated cobalt hydroxide; (ii) the electrochemical activity of nickel hydroxide can be improved by both incorporated cobalt and the effects of post-added CoO are more notable; (iii) CoOOH derived from post-added CoO is not stable in the KOH electrolyte when the potential of the Ni(OH)2 electrode is lowered and its reduction product may be inactive, thus results in an irreversible capacity loss of nickel-metal-hydride battery after over-discharge-state storage.
Size-controlled PtRu nanoparticles embedded in TiO2 were prepared by simultaneous multi-gun sputtering from pure targets of Pt, Ru, and TiO2. The mean diameter of the PtRu nanoparticles, as confirmed by their high-resolution transmission electron microscopic images, can be varied from ∼1.8 to ∼3.7nm by changing the RF power ratio of PtRu and TiO2. The transmission electron diffraction and grazing incidence wide angle X-ray scattering patterns of the PtRu nanoparticles embedded in TiO2 confirmed that the PtRu exists as a mixed alloy structure consisting of both fcc and hcp phases, whereas the TiO2 matrix is present as an amorphous phase. The size-controlled PtRu/TiO2 electrodes were found to exhibit unique electronic properties depending on their size, which affected the potential of zero total charge and methanol oxidation reaction. The mass activity of PtRu/TiO2 for methanol oxidation was determined by the interplay of the surface electronic factors at the metal–solution-interface and the value of the oxophilicity of the nanoparticles was increased by decreasing the particle size.
We report the growth of CuO nanowires from copper foils oxidized in air at temperatures between 400 and 800  ∘C
Nanostructure materials have many special physical and chemical properties compared to traditional micron scale materials. For instance, nanomaterials with quantum confined effect have unique electrical, optical, magnetic and thermal properties (Manmeet et al. 2006). Potential applications of nanomaterials have attracted extensive concern of scientific research. In recent years, human beings are extremely interested in one dimensional nanostructure materials such as nanowires, nanotubes and nanorods owing to their potential applications in fabrication of nanodevices (Xia et al. 2003; Liu et al. 2014a, b; Miao et al. 2014). Cupric oxide (CuO) is a p-type semiconductor with a narrow band gap of about 1.2 eV (Rakhshani 1986) and is expected to be used as high temperature superconductors (MacDonald 2001), giant magnetoresistance materials (Zheng et al. 2000), promising solar cells materials (Maruyama 1998), lithium ion battery material (Gao et al. 2004), gas sensor (Liao et al. 2009) and electron field emission source (Zhu et al. 2005).
The α-polymorph of Li3FeF6 has been obtained at room temperature by a precipitation reaction from aqueous solution. This easy procedure that does not require any further annealing at high temperature yields a white powder with particles sizes ranging from 250 to 400nm. After proper processing by mechanical milling, particle sizes clearly below 100nm are achieved and this fluoride reacts reversibly with lithium at an average voltage of 3.1V, which is expected for the Fe3+/Fe2+ redox couple. After 12h of ball milling observed average particle size is ca. 50nm and a reversible capacity of 100mAhg−1 is obtained. This corresponds to 70% of the theoretical capacity expected for the one electron reduction of Fe3+. The mentioned capacity is fairly kept upon cycling making the new material useful as the positive electrode in lithium batteries. This is the very first time that a material for cathode application in lithium batteries is prepared at room temperature and from aqueous solution, a procedure which is easily scalable and hence of high industrial interest.
Many national and international governments establish organizations for applied science research funding. For this, several organizations have defined procedures for identifying relevant projects that based on prioritized technologies. Even for applied science research projects, which combine several technologies it is difficult to identify all corresponding technologies of all research-funding organizations. In this paper, we present an approach to support researchers and to support research-funding planners by classifying applied science research projects according to corresponding technologies of research-funding organizations. In contrast to related work, this problem is solved by considering results from literature concerning the application based technological relationships and by creating a new approach that is based on latent semantic indexing (LSI) as semantic text classification algorithm. Technologies that occur together in the process of creating an application are grouped in classes, semantic textual patterns are identified as representative for each class, and projects are assigned to one of these classes. This enables the assignment of each project to all technologies semantically grouped by use of LSI. This approach is evaluated using the example of defense and security based technological research. This is because the growing importance of this application field leads to an increasing number of research projects and to the appearance of many new technologies.
Algal species Raphidocelis subcapitata and Chlorella vulgaris are commonly used to test the chemicals with an antibacterial mode of action during marketing authorization process. However, significant differences in the sensitivity toward antibiotic exposure have been reported. The selection of an inappropriate test species would thus underestimate the environmental hazard of target chemicals and pose a potential threat to the ecosystem. Since oxidative stress is a crucial factor determining the inhibition of algal growth, an investigation on oxidative stress and antioxidant defense mechanisms in these two species was performed to explore its roles in species sensitivity. Here, roxithromycin (ROX), a macrolide antibiotic extensively used to treat respiratory, urinary and soft tissue infections, was used for testing. After 7 days exposure to ROX at the low (0.01 mg L−1) and high (0.09 mg L−1) concentrations, R. subcapitata was inhibited while the growth of C. vulgaris was stimulated. We investigated the roles of oxidative stress in algae by measuring the oxidative stress biomarkers (MDA), non-enzymatic antioxidants (GSH), and antioxidant enzymes (SOD, CAT, GP, GST). The results suggested that when the growth of algae is inhibited, MDA content as well as activities of oxidative stress enzymes would increase, and thus, activating the antioxidant system. On the contrary, it was inferred that when the growth is stimulated, MDA content and oxidative stress enzymes activities would decrease.
In-situ formation of pure olivine NaFePO4 from chemically synthesized LiFePO4 nanoparticles via an electrochemical ion-exchange route in sodium salt containing aqueous electrolyte is reported. Both in-situ electrochemical quartz crystal microbalance (EQCM) and in-situ X-ray diffraction (XRD) measurements are performed to monitor the formation of NaFePO4. Subsequently, a rechargeable Na-ion aqueous polysulfide battery is demonstrated where NaFePO4 and dissolved Na2S5 solution are used as cathode and anolyte, respectively; and are separated from each other by an ion-exchange polymeric membrane. In order to prevent diffusion of Na2S5 polysulfide from the anode to the cathode side, salt concentration at both sides of the NaFePO4||Na2S5 full cell is finely tuned resulting a 45 mAh g−1 cycling capacity over 200 cycles.
In the present study, the effects of bulb type palatal lift prosthesis (bulb-PLP) therapy on nasality and velopharyngeal function (VPF) of patients with velopharyngeal incompetence (VPI) following palatoplasty were longitudinally assessed. The subjects included 18 patients (3 to 52 years of age) who had shown persistent VPI following palatoplasty and who had received bulb-PLP therapy. Nasality and VPF were assessed by perceptual voice analysis, nasometer test, blowing test, and cephalometric radiographic examination. Based on the outcomes of bulb-PLP therapy, the subjects were classified into two groups: the effective group and the ineffective group. Furthermore, the obturating and VPF-activating effects by bulb-PLP therapy were analyzed, and factors relating to different VPF activities were determined. All subjects achieved adequate VPF by wearing a bulb-PLP. After treatment, 10 patients (55.6%) achieved successful activation of VPF without bulb-PLP (the effective group), while persistent VPI remained in 8 patients (the ineffective group). The beginning-blowing ratio of the effective group was significantly greater than that of the ineffective group (P < 0.05) and the velopharyngeal distance (V-P distance) of the effective group tended to be smaller (P = 0.07). Regarding the shape of the bulb head, the angular type was dominant in the ineffective group, while the round type was dominant in the effective group. Bulb-PLP therapy was useful for providing adequate VPF activation. Possible signs of the subsequent effective activation of VPF are considered to be: 1) preexisting adequate VPF on blowing, 2) smaller V-P distance, and 3) synchronized palatopharyngeal movement.