batterydata/paper-abstracts huggingface dataset:
MESSENGER Neutron Spectrometer (NS) observations of cosmic-ray-generated thermal neutrons provide the first direct measurements of Mercury’s surface elemental composition. Specifically, we show that Mercury’s surface is enriched in neutron-absorbing elements and has a measured macroscopic neutron-absorption cross section of 45–81×10−4 cm2/g, a range similar to the neutron absorption of lunar basalts from Mare Crisium. The expected neutron-absorbing elements are Fe and Ti, with possible trace amounts of Gd and Sm. Fe and Ti, in particular, are important for understanding Mercury’s formation and how its surface may have changed over time through magmatic processes. With neutron Doppler filtering – a neutron energy separation technique based on spacecraft velocity – we demonstrate that Mercury’s surface composition cannot be matched by prior models, which have characteristically low abundances of Fe, Ti, Gd, and Sm. While neutron spectroscopy alone cannot separate the relative contributions of individual neutron-absorbing elements, these results provide strong new constraints on the nature of Mercury’s surface materials. For example, if all the measured neutron absorption were due to the presence of an Fe–Ti oxide and that oxide were ilmenite, then Mercury’s surface would have an ilmenite content of 7–18wt.%. This result is in general agreement with the inference from color imaging and visible-near-infrared spectroscopy that Mercury’s overall low reflectance is consistent with a surface composition that is enriched in Fe–Ti oxides. The incorporation of substantial Fe and Ti in oxides would imply that the oxygen fugacity of basalts on Mercury is at the upper range of oxygen fugacities inferred for basalts on the Moon.
As mobile wireless networks increase in popularity and pervasiveness, using internet ubiquitously is not a dream. The integration of Worldwide Interoperability for Microwave Access (WiMAX) and Wireless fidelity (WiFi) technologies seems to be a feasible option for better and cheaper wireless coverage extension. WiFi is already widely deployed in highly developed cities. Its weakness is short coverage, and no guarantee of quality of service (QoS). WiMAX multi-hop relay networks that employ relay stations are expected to extend coverage and reduce the cost of deployment in the near future. This hybrid network can take advantage of the benefits of both technologies to provide ubiquitous services with high QoS. In order to improve the bandwidth utilization and reduce the interference in heterogeneous wireless networks, this work applies genetic algorithm-based resource management techniques to manage the precious bandwidth resource in the heterogeneous wireless networks with minimal human intervention. The simulation results show that our scheme is effective in terms of performance metrics, including dropping probability of handoff calls, new call blocking probability, and bandwidth utilization.
Ordered, supramolecular structures which aim at tailoring the surface properties of materials have been greatly influenced by the advent of the layer-by-layer (LBL) self-assembly techniques. Any material with bonding abilities (ionic or hydrogen bonds) and which is accessible by a solvent can be transformed by assembly into a multilayer by the LBL approach. Here we propose a nanostructured sulfur cathode with a truffle-like architecture which comprises a sulfur particle embedded with hollow carbon nanospheres and encapsulated with an ion-selective, flexible LBL nanomembrane decorated with conductive carbon. As a result of this hierarchical arrangement cathodes with a final loading of 65% sulfur can operate at a high rate of 2C (a 1C rate corresponds to a complete charge or discharge in 1 hour) for over 500 cycles with nearly 100% coulombic efficiency. These results indicate that this type of nanointerfacial engineering could also be a promising solution for the low electrical conductivity of other battery cathodes.
Electrochemical impedance spectroscopy (EIS) was performed during the first charge of a graphite/lithium metal test cell to determine the effect of an additive to a polysiloxane-based (PS-B) electrolyte on passive film formation on graphite surface. The graphite electrode was separated from the lithium metal electrode by a porous polyethylene membrane immersed in the PS-B electrolyte containing dissolved vinyl ethylene carbonate (VEC) and lithium bis(oxalato) borate (LiBOB). The presence of the VEC additive suppressed the formation of a gel-like passive film on the graphite electrode, and increased the discharge capacity [H. Nakahara, A. Masias, S.Y. Yoon, T. Koike, K. Takeya, Proceedings of the 41st Power Sources Conference, Philadelphia, 14–17 June, 2004, p. 165]. EIS analysis of the charged graphite electrode revealed that the addition of VEC decreased the passive film resistance, the film capacitance, and the charge transfer resistance. The dependence of film resistance on cell voltage corresponded only to island-like film formation, as opposed to gel-like film formation. This finding was supported by SEM observations that revealed no gel-like film formation [H. Nakahara, A. Masias, S.Y. Yoon, T. Koike, K. Takeya, Proceedings of the 41st Power Sources Conference, Philadelphia, 14–17 June, 2004, p. 165]. The VEC addition decreased the film resistance and the charge transfer resistance, which increased the discharge capacity of the graphite electrode.
New concepts have arisen in recent years concerning configurations of the so-called hybrid charge-storage devices in which a faradaic, rechargeable battery-type electrode is combined with a non-faradaic, electrochemical, double-layer type of electrochemical capacitor electrode, the combination now being referred to as an “asymmetric” device. Other hybrid systems combine a double-layer electrochemical capacitor device with a fuel-cell or a separate rechargeable battery. Following a discussion of dependence of cell voltage of regular, two-electrode, non-faradaic electrochemical capacitors on state-of-charge (SOC), comparisons are made with recently conceived hybrid combinations of a battery-type rechargeable electrode with a double-layer capacitor-type electrode. Advantages, disadvantages and requirements of such hybrid systems over regular electrochemical supercapacitors or batteries are discussed and critically examined in regard to available energy- and power-densities, energy and coulombic efficiency, cycle-life, voltage profiles on discharge, and self-discharge behaviour. Emphasis is given to importance of using a third electrode, as reference, especially in evaluations of discharge/recharge behaviour of each electrode of an hybrid pair having very different electrochemical characteristics, one faradaic, the other non-faradaic. Use of a reference electrode also provides the opportunity of following self-discharge behaviour of the individual electrodes independently.
Since 1990, a special macrocell system, the so-called anode-ladder-system, has been used world-wide to monitor the corrosion risk of new concrete structures, besides other systems. This sensor-system indicates the depth of the critical chloride content initiating corrosion, i.e. the critical depth of the reinforcement with respect to corrosion. Subsequently, the time-to-corrosion can be determined, enabling the owners of buildings to initiate preventive protection measures before cracks and spalling occur. By measurement of the potentials and the electrical resistance of the concrete around the sensors, an estimation of the humidity, the availability of oxygen and the corrosion behaviour after depassivation is possible. To be able to monitor the corrosion risk for existing structures as well, a new sensor-system has been developed called expansion-ring-system. It consists of six measuring rings (‘anodes’) separated by sealing rings as parts of the main sensor and a ‘cathode-bar’, which are installed in small holes, to be drilled into the concrete.
Tropical inland waters are increasingly recognized for their role in the global carbon cycle, but uncertainty about the effects of such systems on the transported organic matter remains. The seasonal interactions between river, floodplain, and vegetation result in highly dynamic systems, which can exhibit markedly different biogeochemical patterns throughout a flood cycle. In this study, we determined rates and governing processes of organic matter turnover. Multi-probes in the Barotse Plains, a pristine floodplain in the Upper Zambezi River (Zambia), provided a high-resolution data set over the course of a hydrological cycle. The concentrations of oxygen, carbon dioxide, dissolved organic carbon, and suspended particulate matter in the main channel showed clear hysteresis trends with expanding and receding water on the floodplain. Lower oxygen and suspended matter concentrations prevailed at longer travel times of water in the floodplain, while carbon dioxide and dissolved organic carbon concentrations were higher when the water spent more time on the floodplain. Maxima of particulate loads occurred before highest water levels, whereas the maximum in dissolved organic carbon load occurred during the transition of flooding and flood recession. Degradation of terrestrial organic matter occurred mainly on the floodplain at increased floodplain residence times. Our data suggest that floodplains become more intense hotspots at prolonged travel time of the flood pulse over the floodplain.
Gelatin is alternatively adopted as the binder to modify Si anode coupling with its carbonization treatment. The binder can provide good bonding and uniform dispersion of the particles besides its environmental benignancy. Importantly, the carbonized binder containing nitrogen will be advantageous to the electrical conductivity of the electrode. In addition, some spaces are formed in the electrode due to the decomposition and shrinkage of the gelatin binder during heat-treatment, which may facilitate electrolyte penetration and accommodate volume change during cycling. All these merits make contribution to the good electrochemical performance of the modified Si electrode. It exhibits a reversible capacity of 990.3 mA h g−1 after 70 cycles at a current density of 100 mA g−1 and 904 mA h g−1 after 100 cycles at 400 mA g−1.
Delayed neurocognitive recovery (DNCR) is a common and serious complication after radical prostatectomy. We hypothesized that patients with DNCR in the early postoperative period would report reduced health-related quality of life (HRQoL) and more cognitive failures 12 months after surgery, compared with patients without DNCR.
A uniformly microdisc-shaped LiFePO4/C (MD-LFP/C) material with preferentially exposed (010) planes is synthesized by heating the mixture of a microdisc-shaped precursor (MD-precursor) and polyvinylpyrrolidone(PVP) in N2 atmosphere. In particular, the MD-precursor of LiFePO4 is prepared through a simple one-pot two-step precipitation method by using ascorbic acid (AA) and PVP as morphology controlling agents. The results reveal that MD-precursor can only be obtained from the solution containing both AA and PVP. The subsequent calcination transforms the precursor into the LiFePO4/C while retaining the microdisc shape. The initial discharge capacities of the MD-LFP/C are 127, 101, 71.3 and 55.9mAhg−1 at 0.25, 2.5, 10 and 25C, respectively, in a 1.0moldm−3 Li2SO4 aqueous solution. The capacity retentions are 98% after 80 charge-discharge cycles and 80% after 200 cycles, respectively. The current work demonstrates that the MD-LFP/C composite can be prepared by an aqueous precipitation route and it has good electrochemical performance and stability for aqueous lithium-ion batteries.
Although the psychomotor vigilance task (PVT) is commonly used in sleep and other research settings, normative data for PVT performance in children have not been published. This report presents normal PVT performance measures among children without a sleep disorder participating in the Tucson Children’s Assessment of Sleep Apnea (TuCASA) study. TuCASA is a community-based, prospective study of sleep-disordered breathing in Caucasian and Hispanic children ages 6 to 11 years. A standard 10-min PVT trial was completed by 360 participants—48% female and 36% Hispanic; mean age 8.9 years. Detailed analyses were performed for 162 children with respiratory disturbance indices <1 and no parent-reported sleep problems. Mean and median reaction times (RT) decreased with increasing age (p trend < 0.001). Children ages 6 and 11 had median RTs of 544.24 and 325.70 ms, respectively. Standard deviations in RTs also decreased with increasing age (p trend = 0.001), as did lapses (p trend < 0.001), but no trend was apparent in total errors. There were statistically significant (p = 0.006) differences in the performance of boys and girls. Gender differences were greatest at age 6, where boys had shorter RTs, and decreased with age until performance was approximately equal by age 11. No ethnic differences were detected. Children’s PVT performance improves with age and differs by gender. These differences should be considered when the PVT is utilized in pediatric populations.
Nanosized carbon-coated lithium iron phosphate (LiFePO4/C) particles were synthesized using a novel low-cost colloidal process with LiH2PO4, FeCl2 and anhydrous N-methylimidazole (NMI) as starting materials, following by a short annealing step at 600 °C. The ∼3–5 nm thick carbon coating comes from the carbonization of molten salt NMIH+Cl− derived from NMI; the resulting carbon contents of the LiFePO4/C powder is 2.53 wt.%. The materials were characterized by thermogravimetric and differential thermal analysis, differential scanning calorimetry, powder X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, atomic absorption spectroscopy, Raman spectroscopy, four-point probe method, cyclic voltammetry and galvanostatic cycling experiments in coin cells. The LiFePO4 phase reveals agglomeration of semi-spherically particles with an average individual size of 35 ± 4 nm. Carbon-coated LiFePO4 posseses electronic conductivity of 1.4 × 10−3 S cm−1 at room temperature causing a markable increase in rate capability. Cycling the cells between 2.2 and 4.2 V vs. Li+/Li resulted in a discharge capacity of 164 mAh g−1 at the first cycle of C/20 and 162 mA hg−1 after 35 cycles, which corresponds to over 95% of the theoretical capacity of olivine LiFePO4.
This paper presents a harmonised framework of sediment quality assessment and dredging material characterisation for estuaries and port zones of North and South Atlantic. This framework, based on the weight-of-evidence approach, provides a structure and a process for conducting sediment/dredging material assessment that leads to a decision. The main structure consists of “step 1” (examination of available data); “step 2” (chemical characterisation and toxicity assessment); “decision 1” (any chemical level higher than reference values? are sediments toxic?); “step 3” (assessment of benthic community structure); “step 4” (integration of the results); “decision 2” (are sediments toxic or benthic community impaired?); “step 5” (construction of the decision matrix) and “decision 3” (is there environmental risk?). The sequence of assessments may be interrupted when the information obtained is judged to be sufficient for a correct characterisation of the risk posed by the sediments/dredging material. This framework brought novel features compared to other sediment/dredging material risk assessment frameworks: data integration through multivariate analysis allows the identification of which samples are toxic and/or related to impaired benthic communities; it also discriminates the chemicals responsible for negative biological effects; and the framework dispenses the use of a reference area. We demonstrated the successful application of this framework in different port and estuarine zones of the North (Gulf of Cádiz) and South Atlantic (Santos and Paranaguá Estuarine Systems).
The new electrode materials with large specific capacitance, cycling stability and high rate capability are important to advance the development of supercapacitors. A nanocomposite of mesoporous MnO2 nanospheres anchered reduced graphene oxide (MG) was synthesized by a simple and inexpensive reflux reaction. KMnO4 refluxed with oxalic acid as reducing agent was used to the growth of mesoporous MnO2 nanospheres on graphene oxide (GO). The MG as an electrode exhibits a specific capacitance of 466.7Fg−1 at a current density of 1Ag−1, which is 3.33 times larger than that of pure MnO2 (140Fg−1) and 3.19 times of graphene (146Fg−1). The rate capability arrives at 10Ag−1 with specific capacitance of 454.8Fg−1. The capacitance retention is 92% over 2000 cycles at 1Ag−1. The electrochemical impedance spectroscopy (EIS) demonstrates roles of mesopores and RGO in facilitating electronic transport and ionic diffusion across the pores and interfaces.
In this study, manganese oxide (MnOx)-decorated carbonized porous silicon nanowire arrays (MnOx/C/PSiNWs) are synthesized through eco-friendly and cost-effective processes. This electrode material system exhibits excellent electrochemical behavior with a specific capacitance reaching 635 F g−1, as well as the highest areal power (100 mWcm−2) and energy (0.46 mW h cm−2) ever reported in a silicon nanowire-based pseudocapacitor electrode. Furthermore, an asymmetric hybrid supercapacitor (AHS) is designed using MnOx/C/PSiNWs as the positive electrode, carbonized porous silicon nanowires (C/PSiNWs) as the negative electrode and 1-ethyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)imide (EMIM-TFSI)/acetonitrile as the electrolyte. The supercapacitor shows an excellent power density of 25 kW kg−1 and an energy density of 261 W h kg−1 at a current density of 0.2 mA cm−2 with a large operational potential window (3.6 V) and a good capacitance retention (82% after 10000 CV cycles). The results show that the MnOx/C/PSiNW electrodes are promising materials for the future generation of high performance supercapacitors.
The main vector for transmission of malaria in India is the Anopheles culicifacies mosquito species, a naturally selected subgroup of which is completely refractory (R) to transmission of the malaria parasite, Plasmodium vivax;
A three-electrode Li-ion cell with metallic lithium as the reference electrode was designed to study the charging process of Li-ion cells. The cell was connected to three independent testing channels, of which two channels shared the same lithium reference to measure the potentials of anode and cathode, respectively. A graphite/LiCoO2 cell with a C/A ratio, i.e., the reversible capacity ratio of the cathode to anode, of 0.985 was assembled and cycled using a normal constant-current/constant-voltage (CC/CV) charging procedure, during which the potentials of the anode and cathode were recorded. The results showed that lithium plating occurred under most of the charging conditions, especially at high currents and at low temperatures. Even in the region of CC charging, the potential of the graphite might drop below 0V versus Li+/Li. As a result, lithium plating and re-intercalating of the plated lithium into the graphite coexist, which resulted in a low charging capacity. When the current exceeded a certain level (0.4C in the present case), increasing the current could not shorten the charging time significantly, instead it aggravated lithium plating and prolonged the CV charging time. In addition, we found that lowering the battery temperature significantly aggravated lithium plating. At −20°C, for example, the CC charging became impossible and lithium plating accompanied the entire charging process. For an improved charging performance, an optimized C/A ratio of 0.85–0.90 is proposed for the graphite/LiCoO2 Li-ion cell. A high C/A ratio results in lithium plating onto the anode, while a low ratio results in overcharge of the cathode.
Hydropower reservoirs (of conventional and pumped storage plants) provide dispatchable power and large-scale energy storage. They are a suitable technology in autonomous power systems with high levels of renewable generation, because of their capacity to buffer intermittencies and high variability of renewable energies such as wind and solar power. This paper presents results of a study comparing the operation of a wind hydro hybrid system including a conventional hydropower with a reservoir and including a pumped storage hydropower plant. This comparative study was carried out based on the adaptation of software Homer (The Micropower Optimization Model) to simulate hydropower plants with water storage capacity and to simulate pumped storage hydroelectric plants. The case study of this paper arose from data related to Rio Grande do Sul, in southern Brazil. The case study is based on a river basin in southern Brazil for which two sites were identified; one below where can be installed the engine room and where there is a reasonable area to implement a water reservoir; other above where a reservoir may also be implemented for the case of pumped storage hydropower plant. The results show that the system with pumped storage plant naturally has the highest initial costs, but the optimal solution of the hybrid system with pumped storage plant require a smaller flooded area than the system with conventional reservoir, thus representing a lower environmental impact.
In the near future, the portable power market will demand greater specific energy and power from lithium battery technology. These requirements cannot be met by conventional batteries or through extrapolation of the capabilities of conventional systems. New materials and systems must be developed to meet these stringent future requirements. Nanomaterials offer a new exciting alternative to the standard materials traditionally used for fabrication of batteries. The work described herein, deals with a novel approach to the use of nanomaterials in the electrodes of lithium-ion batteries. We have synthesized and chemically modified carbon nanotubes and subsequently tested these modified nanotubes as electrodes in small lithium batteries. This paper describes electrochemical characterization of the novel electrodes as well as determination of the specific energy of simple one-cell batteries containing these novel electrodes. We have been able to demonstrate a laboratory cell with a specific exceeding 600Wh/kg and pulse power exceeding 3kW/kg.
ABSTRACT The OCV (open circuit voltage)-based method for SOC (state of charge) estimation by using the dual neural network fusion battery model is proposed in this paper. The weights of the constructed dual neural network fusion battery model can be used to describe the characteristics of the corresponding parameters of electrochemical model for the battery. The constructed dual neural network fusion battery model consists of two neural network models connected in series. The first part is a linear neural network battery model which can be used to identify parameters of the first-order electrochemical model or second-order electrochemical model for the battery, the second part is a BP (Back of Prorogation) neural network used for capturing the relationship between OCV and SOC. The DST (Dynamic Stress Test) data is adopted for training the dual neural network fusion battery model, by which the relationship between OCV and SOC is offline obtained. Under FUDS (Federal Urban Driving Schedule) condition, the experimental results show that the dual neural network fusion battery model can effectively estimate SOC based on the first-order electrochemical model or second-order electrochemical model.