batterydata/paper-abstracts huggingface dataset:
Nonflammable organic electrolyte solutions containing fluorinated alkylphosphates (FAP) have been examined as safer electrolytes for lithium-ion batteries (LIB). Although the ionic conductivity of LiPF6 in neat tris(2,2,2-trifluoroethyl)phosphate (TFEP) solvent is very low, it increases upon the addition of alkyl carbonates such as ethylene carbonate (EC) and fluoroethylene carbonate (4-fluoro-2-oxo-1,3-dioxolane, FEC). A specific conductivity of 1 mS cm−1 or higher was obtained at room temperature for the system containing proper amounts of the carbonates and 0.5 M (mol dm−3) LiPF6. A conventional mixed alkylcarbonate-based solution containing LiPF6 showed a sign of considerable exothermic reactions on the differential scanning calorimetry (DSC) response below 300 °C. However, the LiPF6/TFEP solution showed no significant exothermic response up to 400 °C, even in the presence of charged LiCoO2 (LCO) positive electrode. The addition of an alkylcarbonate to the LiPF6/TFEP solution produced an exothermic response as a result of the thermal decomposition of the carbonate over the charged LCO. However, the temperature at which the exothermic reaction starts was significantly higher in the system containing FEC than that containing EC. The thermal analysis results suggested that the LiPF6/FEC + TFEP combination could work as a safer electrolyte system in LIB under severe conditions.
In this paper, a power flow management algorithm for photovoltaic system feeding DC and AC loads is presented. PV being a major energy source enables the DC loads to be connected directly to the DC bus. A grid connected PV system involves one power source (PV array), one power sink (load) and two power sources/sink (utility and battery), and hence a power flow management system is required to balance the power flow among these sources. A unique control algorithm is developed for selecting the operating mode of the bidirectional converter by sensing the battery voltage. The bidirectional converter has three modes of operation namely, the rectifier mode, inverter mode and the voltage control mode. In both the rectifier and inverter modes of operation, the converter current is controlled by employing a hysteresis current controller and unity power factor is achieved in both the cases. In voltage control mode, the converter regulates the inverter voltage and supplies the reactive power to the grid. Detailed simulation studies are carried out on a single phase bidirectional converter in MATLAB/Simulink environment. The viability of the scheme has been ascertained by performing experimental studies on a laboratory prototype. The control strategy is digitally implemented on an Altera Cyclone II FPGA board and the algorithm is verified for different modes of operation by varying the load and the relevant results are presented.
Under optimized synthesis conditions, very large area uniform SnO2 nanofibers consisting of orderly bonded nanoparticles have been obtained for the first time by thermal pyrolysis and oxidization of electrospun tin(II)2-ethylhexanoate/polyacrylonitrile (PAN) polymer nanofibers in air. The structure and morphology were elaborated by X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The SnO2 nanofibers delivered a reversible capacity of 446mAhg−1 after 50 cycles at the 100mAg−1 rate and excellent rate capability of 477.7mAhg−1 at 10.0C. Owing to the improved electrochemical performance, this electrospun SnO2 nanofiber could be one of the most promising candidate anode materials for the lithium-ion battery.
The development of a flow cytometry-based micronucleus (FCMMN) assay for measuring the micronucleus (MN) frequency in cells following exposure to test chemicals has potential for improving reproducibility and reducing turn-around time when compared with the traditional microscopy-based micronucleus method. A major drawback of the FCMMN assay is that a false-positive interpretation could result from the presence of large numbers of apoptotic or necrotic bodies in the measured sample. Although several studies have reported ways in which the FCMMN assay could be improved using different staining techniques or electronic gating strategies, to date none of these protocols are suitable for use as a screening assay. To reduce the interference from apoptosis, performing the FCMMN assay with an apoptosis-resistant cell line may be an alternative approach. This study reports the use of p53-mutated cell lines to minimise the interference found in the FCMMN assay. Two commonly used cell lines (WIL2-NS and L5178Y) were investigated by comparison of (1) cytotoxicity and micronucleus induction in the FCMMN assay following treatment with model genotoxicants and (2) apoptotic responses after exposure to inducers of apoptosis. Both cell lines were responsive to all genotoxicants, producing concentration-dependent results with respect to genotoxicity. WIL2-NS cells were found to be more tolerant to apoptosis induction than L5178Y cells. This characteristic could be beneficial to minimise the interference from apoptotic nuclei in the FCMMN genotoxicity-screening assay.
Lithium-insertion during the arc discharge growth process is investigated by using resonance Raman spectroscopy combined with ab initio calculations. The measurements were performed using two pairs of single-wall carbon nanotubes, one of the members being prepared employing a lithium-contained catalyst and the other its lacking lithium counterpart. The lowest wave number lines were observed as selective resonances for the first pair for which a line occurs at 142.3cm−1 from the Li-catalyst prepared sample and at 162.2cm−1 for the non-lithium case. The remaining lines are seen in both samples. For the second pair the first two lower-lying lines are selectively seen for the non-lithium sample while for the lithium-contained catalyst case the two highest wave number lines are selectively observed. These different resonance conditions lead us to perform electronic property calculations. The results show that this effect can be tracked to the charge transfer occurring from lithium atoms inserted into the bundles. Calculation shows that the transfer is limited to a Li-insertion rate of Li6C68.
Interfacial structures of electrode–current collector and electrode–electrolyte have been designed to be stabilized for improved cycling performance of amorphous silicon (Si) that is considered as an alternative anode material to graphite for lithium-ion batteries. Interfacial structural stabilization involves the interdigitation of Si electrode–Cu current collector substrate by anodic Cu etching with thiol-induced self-assembly, and the formation of self-assembled siloxane on the surface of Si electrode using silane. The novel interfacial architecture possesses promoted interfacial contact area between Si and Cu, and a surface protective layer of siloxane that suppresses interfacial reactions with the electrolyte of 1M LiPF6/ethylene carbonate (EC):diethylene carbondate (DEC). FTIR spectroscopic analyses revealed that a stable solid electrolyte interphase (SEI) layer composed of lithium carbonate, organic compounds with carboxylate metal salt and ester functionalities, and PF-containing species formed when having siloxane on Si electrode. Interfacially stabilized Si electrode exhibited a high capacity retention 80% of the maximum discharge capacity after 200 cycles between 0.1 and 1.5V vs. Li/Li+. The data contribute to a basic understanding of interfacial structural causes responsible for the cycling performance of Si-based alloy anodes in lithium-ion batteries.
Electrodeposition of Zn was conducted in a new electrolyte system composed of an alkaline solution (9 M KOH + 5 wt% ZnO) modified with a small amount (0.5 wt%) of room temperature ionic liquid 1-ethyl-3-methylimidazolium dicyanamide (EMI-DCA). At a high deposition current density of 80 mA cm−2, a porous, dendrite-free Zn film characterized by clusters of small Zn particles was obtained. The mechanism for the modified Zn morphology in the EMI-DCA containing electrolyte was studied by cyclic voltammetry, chronoamperometry, electrochemical impedance spectroscopy (EIS) and scanning electron microscopy. It was found that the addition of EMI-DCA changed the Zn nucleation process and reduced the potential variation during electrodeposition, which suppressed the uneven growth of Zn deposits and the formation of Zn dendrites. EIS results indicated that there was adsorption of EMI+ cations at the Zn film/electrolyte interface, which may have contributed to suppressed dendritic Zn growth.
Nonaqueous Li-O2 batteries are of great interest because of their high theoretical energy density, and a stable porous cathode plays a vital role in electrochemical performance of Li-O2 batteries. Herein, catalyst nanoarchitecturing via functionally implanted cobalt nanoparticles in N-doped carbon host is fabricated by an ultrasonic method combined with controlled calcination process and served as an effective electrocatalyst for Li-O2 batteries. The synthesized catalyst holds a three-dimensional porous network structure, which could offer numerous active sites and provide the channels for mass transfer. When employed as an oxygen electrode, the Li-O2 battery shows improved discharge capacity of 3862 mA h g−1 at a current density of 0.1 mA cm−2 and superior cycling stability up to 40 cycles with a limited capacity of 500 mA h g−1, owing to the porous carbon substrate with highly graphitic and better catalytic activity of implanted Co nanoparticles. The N-doped carbon with a high degree of graphitization is obtained by a catalytic pyrolysis method and Co as main catalyst also give a good reference for future design of efficient catalysts for electrochemical application.
Battery charge efficiency across a range of input powers is an important performance parameter in variable charging systems. Here we use equivalent circuit theory to model the inherent trade-off between battery charging power and energy stored and compare our model to the existing Ragone model for discharge power and energy. An additional parameter is included to account for undercharge and underdischarge of the battery due to premature arrival at the battery's voltage limits. At a given power, energy efficiency is predicted to be higher for charging than discharging when only accounting for energy dissipated by internal resistance. We experimentally determine charge and discharge energy–power curves for lithium-ion batteries and find they exhibit a reduction in energy stored or withdrawn as power increases. We isolate the effects of undercharge and underdischarge from energy lost to internal resistance, and find the former outweighs the latter effect. Furthermore, the shallow shape of the voltage curve near the charge voltage cutoff results in a more limited range of charging powers than discharging powers. The model is expected to help inform operational parameters for battery charging for variable power sources.
This paper examines long-term recovery outcomes of businesses impacted by major natural disasters. Data were collected via two large-scale mail surveys—one administered to Santa Cruz County, California businesses 8 years after the Loma Prieta earthquake and the other administered to businesses in South Dade County, Florida, 6 years after Hurricane Andrew. Based on the results of OLS regression models, we argue that long-term recovery experiences of businesses are affected by various factors, including the economic sector in which a business operates, its age and financial condition, and the scope of its primary market; direct and indirect disaster impacts, including physical damage, forced closure, and disruption of operations; and owner perceptions of the broader economic climate. Previous disaster experience, level of disaster preparedness, and use of external sources of aid were not found to significantly affect the long-term economic viability of businesses in the two study communities.
Two prominent low-carbon energy resources, wind and sunlight, depend on weather. As the percentage of electricity supply from these sources increases, grid operators will need to employ strategies and technologies, including energy storage, to balance supply with demand. We quantify energy and material resource requirements for currently available energy storage technologies: lithium ion (Li-ion), sodium sulfur (NaS) and lead-acid (PbA) batteries; vanadium redox (VRB) and zinc-bromine (ZnBr) flow batteries; and geologic pumped hydroelectric storage (PHS) and compressed air energy storage (CAES). By introducing new concepts, including energy stored on invested (ESOI), we map research avenues that could expedite the development and deployment of grid-scale energy storage. ESOI incorporates several storage attributes instead of isolated properties, like efficiency or energy density. Calculations indicate that electrochemical storage technologies will impinge on global energy supplies for scale up — PHS and CAES are less energy intensive by 100 fold. Using ESOI we show that an increase in electrochemical storage cycle life by tenfold would greatly relax energetic constraints for grid-storage and improve cost competitiveness. We find that annual material resource production places tight limits on Li-ion, VRB and PHS development and loose limits on NaS and CAES. This analysis indicates that energy storage could provide some grid flexibility but its build up will require decades. Reducing financial cost is not sufficient for creating a scalable energy storage infrastructure. Most importantly, for grid integrated storage, cycle life must be improved to improve the scalability of battery technologies. As a result of the constraints on energy storage described here, increasing grid flexibility as the penetration of renewable power generation increases will require employing several additional techniques including demand-side management, flexible generation from base-load facilities and natural gas firming.
Anthraquinone-2, 6-disulfonic acid (AQDS) was added to the electrolyte of a vanadium redox flow battery (VRFB) with the goal of enhancing its performance. This study utilized carbon paper electrodes and a Nafion 117 ion exchange membrane for the membrane-electrode assembly. The cycling performance was investigated over multiple charge and discharge cycles. The addition of AQDS was found to increase capacity efficiency by an average of 7.6% over the control VRFB containing no AQDS, while decreasing the overall cycle duration by ~18%. It is thus reported that the addition of AQDS to a VRFB electrolyte has the potential to inexpensively increase the activity and capacity.
Carbon electrode materials have been extensively studied due to their diverse structure and chemistry which has enabled diverse applications. The thermal synthesis of graphite felt (GF) from polymeric precursors and the physical and electrochemical properties of flexible graphite felts are summarised. In electrochemical flow cells, the three-dimensional structure of GF as an electrode material counteracts the limitations of the low conversion and space–time yield possible with two-dimensional electrodes. The high volumetric area of GF facilitates the treatment of dilute solutions. The physical structure of GF enables it to act as a turbulence promoter, enhancing the hydrodynamics and mass transport rates in electrochemical systems. The electrochemical applications of GF in electroanalysis, electrosynthesis, electrochemical advanced oxidation processes, redox flow batteries, fuel cells, and metal ion removal are illustrated by examples. The characterisation of reaction environment, including non-ideal electrolyte flow, mass transport rates, fluid pressure drop, current and potential distributions of GF in electrochemical reactors are also considered.
This paper proposes a fully distributed self-configuration media access control (MAC) protocol for IEEE 802.11-based multi-hop mobile ad hoc networks. The proposed MAC protocol targets to determine proper stations to become supervisors to support network management. This study first formulates the supervisor determination problem as the virtual backbone construction problem. Because determining the optimal number of supervisors falls into the NP-complete problem, this study uses many rules to determine enough supervisors to support network management. The determined supervisors are divided into multiple sets, and the supervisors in a set need to transmit beacon frames in the specific beacon interval. Using the proposed rules, not all the stations need to transmit beacon frames in each beacon interval. Moreover, the neighboring supervisors do not transmit beacon frames in the same beacon interval, thereby avoiding network partitioning, saving battery power, and achieving reliable broadcast. Simulation results confirm that the proposed MAC protocol actually determines enough and minimum number of supervisors. Results also show that the proposed MAC protocol leads to less packet collisions and reduces energy consumption, compared with the IEEE 802.11 standard.
Intracoelomic implantation of transmitters into fish requires making a surgical incision, incision closure, and other surgery related techniques; however, the tools and techniques used in the surgical process vary widely. We review the available literature and focus on tools and techniques used for conducting surgery on juvenile salmonids because of the large amount of research that is conducted on them. The use of sterilized surgical instruments properly selected for a given size of fish will minimize tissue damage and infection rates, and speed the wound healing of fish implanted with transmitters. For the implantation of transmitters into small fish, the optimal surgical methods include making an incision on the ventral midline along the linea alba (for studies under 1 month), protecting the viscera (by lifting the skin with forceps while creating the incision), and using absorbable monofilament suture with a small-swaged-on swaged-on tapered or reverse-cutting needle. Standardizing the implantation techniques to be used in a study involving particular species and age classes of fish will improve survival and transmitter retention while allowing for comparisons to be made among studies and across multiple years. This review should be useful for researchers working on juvenile salmonids and other sizes and species of fish.
In this paper, the substitution of different amounts of Cr for Ni in the hydrogen storage electrode alloy of Mg1.75Al0.25Ni has been carried out to form quaternary Mg1.75Al0.25Ni1−x Cr x (0≤ x ≤0.3) alloys by means of solid diffusion method (DM). The XRD profiles exhibited that the quaternary alloys still kept the same main phase of Mg3AlNi2 (S.G. Fd3m) as that of ternary Mg1.75Al0.25Ni alloy. The electrochemical studies found that Cr substituted quaternary alloy reached its maximum discharge capacity (165mAhg−1) after 2 cycles, which was larger than that of the Mg1.75Al0.25Ni alloy (154mAhg−1). Among these quaternary alloys, the Mg1.75Al0.25Ni0.9Cr0.1 electrode alloy was found possessing the highest cycling capacity retention rate. Cyclic voltammetry (CV) results and anodic polarization curves demonstrated that appropriate content (x lower than 0.1) of Cr effectively improved the reaction activity of electrode and inhibited the cycling capacity degradation to some degree. Electrochemical impedance spectroscopy (EIS) analyses indicated that the increase of Cr content would raise the polarization resistance R p on the particle surface of these quaternary alloys.
This work focuses on a new technique called active thermal scanning for in-line monitoring of porosity and areal loading of Li-ion battery electrodes. In this technique a moving battery electrode is subjected to thermal excitation and the induced temperature rise is monitored using an infra-red camera. Static and dynamic experiments with speeds up to 1.5 m min−1 are performed on both cathodes and anodes and a combined micro- and macro-scale finite element thermal model of the system is developed. It is shown experimentally and through simulations that during thermal scanning the temperature profile generated in an electrode depends on both coating porosity (or area loading) and thickness. It is concluded that by inverting this relation the porosity (or areal loading) can be determined, if thermal response and thickness are simultaneously measured.
Sulfur is a promising cathode material for lithium batteries as it has high theoretical specific capacity and low cost. However, practical electrochemical performance of lithium-sulfur batteries needs to be improved. In this work, a new method is described to prepare carbon matrix for sulfur to improve electrochemical properties of sulfur electrodes. The carbon matrix is prepared by deoxidizing carbon precursor synthesized by carbonizing sucrose with concentrated sulfuric acid. Carbon matrix-sulfur composite has been characterized by scanning electron microscopy, transmission electron microscopy and Fourier transform infrared. Results indicate that carbon matrix-sulfur composite is composed of lamellas. The lamella contains a layer of carbon coating on the outside and chemical bonds of C-S. The formation of C-S bonds is promoted by deoxidizing carbon precursor. The carbon matrix-sulfur electrode exhibits improved discharge properties, which results from the appropriate structure. Carbon coating and C-S bonds confine sulfur and maintain contact between sulfur species and conductive carbon matrix.
The description of childhood absence epilepsy (CAE) a benign self-limited generalized epilepsy has become a matter of debate. The objectives of this work were to evaluate the existence of psychiatric and cognitive impairments among patients with typical CAE and to correlate their possible relation to seizure frequency, duration of epilepsy, IISL, and valproate therapy.
Theory of mind (ToM) refers to an individual's ability to attribute mental states to predict and explain another person's behavior. It has been shown that patients with cervical dystonia (CD) present impaired ToM ability supporting the idea that CD is a network disorder. An emerging hypothesis is that different phenotypes of CD reflect distinct key nodes in the malfunctioning cerebral network. The aim of the present study was to investigate whether the presence of tremor as additional phenotypic feature of CD influences the ability to attribute a cognitive or emotional state to another person. We enrolled 35 patients with CD, 21 with tremor (CD-T) and 14 without tremor (CD-NT) and 47 age-matched healthy subjects (HS). The Emotion Attribution Task (EAT) was adopted to assess the affective ToM ability while the Advanced Test (AT) was used to investigate the cognitive ToM ability. Results showed that CD patients’ performance was worse than HS in recognizing the emotional feelings expressed in the EAT situations, with no difference between CD-T and CD-NT. Regarding cognitive ToM, both CD-T and CD-NT performed worse than HS in the AT task. However, it also emerged that CD-T were more impaired in AT task than CD-NT. Our results indicate that both affective and cognitive aspects of ToM are impaired in CD and that cognitive ToM is more impaired in patients presenting tremor respect to those without. These findings support the hypothesis that the cerebral network responsible of motor and non-motor impairments is more widespread in CD-T than CD-NT.
In this study, the side effects of contingent shock (CS) treatment were addressed with a group of nine individuals, who showed severe forms of self-injurious behavior (SIB) and aggressive behavior. Side effects were assigned to one of the following four behavior categories; (a) positive verbal and nonverbal utterances, (b) negative verbal and nonverbal utterances, (c) socially appropriate behaviors, and (d) time off work. When treatment was compared to baseline measures, results showed that with all behavior categories, individuals either significantly improved, or did not show any change. Negative side effects failed to be found in this study.