batterydata/paper-abstracts huggingface dataset:
John Alexander McClelland (1870–1920) was educated at Queen’s College Galway and the Cavendish Laboratory in Cambridge. He was Professor of Experimental Physics at University College Dublin from 1900 to 1920. He was best known for his pioneering work on the scattering of β rays and on the conductivity of gases and the mobility of ions. He established a research school on atmospheric aerosols that was continued by his successor, John James Nolan (1887–1952), which strongly influenced physics research in Ireland up to the present. A recently discovered manuscript of a commemorative address by Nolan in 1920, which is reproduced in Appendix I, is a unique contemporary summary of McClelland’s research and character, and is an important contribution to the history of experimental physics in Ireland.
In situ chemical oxidation polymerization of pyrrole on the surface of sulfur particles was carried out to synthesize a sulfur/polypyrrole (S/PPy) nanocomposite with core-shell structure. The composite was characterized by elemental analysis, X-ray diffraction, scanning/transmission electron microscopy, and electrochemical measurements. XRD and FTIR results showed that sulfur well dispersed in the core-shell structure and PPy structure was successfully obtained via in situ oxidative polymerization of pyrrole on the surface of sulfur particles. TEM observation revealed that PPy was formed and fixed to the surface of sulfur nanoparticle after polymerization, developing a well-defined core-shell structure and the thickness of PPy coating layer was in the range of 20–30 nm. In the composite, PPy worked as a conducting matrix as well as a coating agent, which confined the active materials within the electrode. Consequently, the as prepared S/PPy composite cathode exhibited good cycling and rate performances for rechargeable lithium/sulfur batteries. The resulting cell containing S/PPy composite cathode yields a discharge capacity of 1039 mAh·g−1 at the initial cycle and retains 59% of this value over 50 cycles at 0.1 C rate. At 1 C rate, the S/PPy composite showed good cycle stability, and the discharge capacity was 475 mAh·g−1 after 50 cycles.
In this study, the microstructure of mangrove-charcoal-derived carbon (MC) was studied using XRD, STM and TEM. MC was found to consist of aligned quasi-spherical structural units with diameters of around 5–20nm. It shows typical hard carbon characteristics, including a strongly disoriented single graphene layer and BSU, formed by two or three graphene layers stacked nearly parallel. Some curved and faceted graphene layers, especially closed carbon nanoparticles with fullerene-like, were observed in the as-prepared samples. MC was also evaluated as an anodic material for Li-ion batteries. MC carbonized at 1000°C possessed the highest available discharge capacity (below 0.5V) of 335mAhg−1, the high first-cycle coulombic efficiency of 73.7%, good rate and cyclic capability and PC-based electrolyte compatibility. 7Li nuclear magnetic resonance (NMR) spectra of fully lithiated mangrove charcoal-derived carbons indicated the co-existence of three Li species.
Here, we report the skin temperature rise due to the absorption of radio frequency (RF) energy from three handheld mobile phones using infrared thermography technique. Experiments are performed under two different conditions, viz. when the mobile phones are placed in soft touch with the skin surface and away from the skin surface. Additionally, the temperature rise of mobile phones during charging, operation and simultaneous charging and talking are monitored under different exposure conditions. It is observed that the temperature of the cheek and ear regions monotonically increased with time during the usage of mobile phones and the magnitude of the temperature rise is higher for the mobile phone with higher specific absorption rate. The increase in skin temperature is higher when the mobile phones are in contact with the skin surface due to the combined effect of absorption of RF electromagnetic power and conductive heat transfer. The increase in the skin temperature in non-contact mode is found to be within the safety limit of 1°C. The measured temperature rise is in good agreement with theoretical predictions. The empirical equation obtained from the temperature rise on the cheek region of the subjects correlates well with the specific absorption rate of the mobile phones. Our study suggests that the use of mobile phones in non-contact mode can significantly lower the skin temperature rise during its use and hence, is safer compared to the contact mode.
We examine the relationship between CEO tenure and audit fees. After controlling for client and auditor attributes in the analyses, we find that audit fees are higher in the initial 3 years of CEOs’ service, suggesting that CEOs in their early career are more likely to show high risk-taking behavior and manage earnings that increases the probability of financial misreporting. Auditors incorporate this risk in their audit pricing decisions resulting in higher audit fees. We also find that audit fees are higher in the final year of CEOs’ service, supporting the argument for departing CEOs’ horizon problem that CEOs in their final year are more likely to manage earnings, and auditors perceive this action as increasing reporting risk in their audit pricing decisions, resulting in higher audit fees. However, the firms with more effective audit committees pay relatively lower audit fees in initial years of CEOs’ service indicating that effective audit committees reduce auditors’ assessed risk during this time-period resulting in lower audit fees. We do not find any evidence on the effect of firms’ CFO power and corporate social responsibility performance on audit fees in these two time-periods of CEOs’ service. The main results hold in a battery of supplemental tests that include the effect of several CEO characteristics, client bargaining power and the effect of SOX. Our study extends CEO characteristics and audit fee literature, and have implications for auditors in their client acceptance and audit pricing decisions, and for regulators to identify the filers with higher financial reporting and audit engagement risk.
Objective To examine health, psychological, and autonomic impairment differences between individuals with fibromyalgia and those with other chronic benign pain in these conditions. The possible role of the autonomic nervous system in the maintenance of chronic benign pain can be examined using heart rate variability (HRV), which measures the interplay between the excitatory sympathetic and the inhibitory parasympathetic nervous system. Predictors of HRV will also be examined. Methods This study examined resting HRV in a sample of 84 patients with chronic benign pain, a subgroup of whom had fibromyalgia. Participants completed a battery of self-report measures and underwent measurements of resting HRV. Results Individuals with fibromyalgia experienced higher levels of depression (t (82)=−2.27, p <.05) and significantly greater difficulty with physical functioning (t (75.8)=2.65, p <.01) than did those with other chronic benign pain, there were no significant differences in any of the HRV indices. Across all pain conditions, we found that age, gender, physical health functioning, pain anxiety, and pain sensations were all significant predictors of HRV, suggesting that each are involved in the relationship between chronic benign pain and autonomic function. Conclusions These findings emphasize the importance of addressing psychological distress and physical functioning in chronic pain populations and specifically fibromyalgia. Future research can further examine the role of physical health functioning, psychological distress, and pain severity in the relationship between chronic pain and autonomic abnormalities.
One-dimensional (1D) nanorods of LiV3O8 single crystals have been fabricated by using well-defined home-made VO2 (B) nanorods as the vanadium resource, combined with a convenient solid-state reaction. The as-obtained LiV3O8 nanorods were characterized by XRD, TEM and SEM, indicating this material was highly crystalline and a single phase. The electrochemical performance of LiV3O8 nanorods as the positive electrode material for rechargeable lithium batteries was investigated, which demonstrated that as-prepared LiV3O8 nanorods exhibited as high as 348mAhg−1 discharge capacity in first cycle at 20mAg−1 current density, and still remained at 303mAhg−1 at 50mAg−1 afterwards; moreover, until 50 cycles, they kept 315mAhg−1, recorded at 50mAg−1. All these results imply that single-crystalline 1D nanorods of LiV3O8 are promising cathode material for rechargeable lithium batteries.
Herein we report a simple approach for the preparation of graphene oxide-carbon nanotube-sulfur composites. The self-standing composites can be easily prepared by freeze drying a frozen graphene oxide-carbon nanotube suspension, and then impregnated with sulfur by melt diffusion. Composites obtained in this way are physicochemically characterized by elemental analysis, X-ray diffractometry (XRD), electron microscopy and gas adsorption, showing a three dimensional macroporous graphene-based architecture in which sulfur is homogeneously distributed. The performance of self-standing composites with sulfur loadings over 4.0 mg cm−2 is evaluated as binder-free positive electrodes for Lithium-Sulfur (Li-S) batteries. Results show that the incorporation of just 2 wt.% of CNTs significantly improves both the specific capacity and capacity retention compared to the results shown by the CNT-free samples, and slightly improves the performance of thermally reduced samples. More importantly, reversible specific capacity values over 500 mAh g−1 at a rate of 0.1C after 100 charge/discharge cycles are obtained for either thermally reduced and CNT containing samples, which in terms of areal capacity correspond to values over 2.0 mAh cm−2.
The exploration of highly active and stable noble-metal-free electrocatalysts for hydrogen and oxygen evolution reaction is a challenging task to achieve sustainable production of H2 through water splitting. Herein, we present the design and synthesis of a novel three-dimensional(3D)-networked heterogeneous nickel phosphide/sulfide electrocatalyst consisting of Ni2P strongly coupled with Ni3S2 in situ grown on Ni foam. Benefiting from the strong interfacial coupling effects between Ni2P and Ni3S2, large surface area, highly conductive Ni foam support, and the unique 3D open configuration, the optimal 3D-networked hybrid electrode exhibits superior electrocatalytic activity with extremely low overpotentials of 80 and 210 mV to deliver a current density of 10 mA cm−2 for HER and OER in 1.0 M KOH, respectively. Assembled as an electrolyzer for overall water splitting, this electrode delivers an impressive low onset potential of only 1.45 V and gives a current density of 10 mA cm−2 at a very low cell voltage of 1.50 V, which is dramatically superior to the current state-of-the-art electrocatalysts. In combination with density functional theory (DFT) calculations, this study demonstrates that the strong coupling interactions between Ni2P and Ni3S2 synergistically optimize the electronic structure and tune the hydrogen (or water) adsorption energy, thus significantly enhancing the overall electrochemical water-splitting activity. Our work might shed some new lights on the design and fabrication of efficient and robust three-dimensional hybrid electrode materials for a variety of electrochemical applications.
Abstract New biomaterials will be required to undergo certain toxicity tests for biocompatibility and safety assessment. This chapter provides a broad overview of the in vitro toxicity tests, specifically on cytotoxicity and genotoxicity. The chapter further describes apoptosis as the mode of cytotoxicity and the relevant techniques to understand the effects of biomaterials on apoptosis.
In this study, the charge efficiency, nucleation growth, and morphology of electrodeposited copper from spent Li-batteries were studied. The charge efficiency for these deposits shows a maximum value of 99.41%, under a charge density of 5.0 C cm−2. Studies with the SEM technique at pH 2.0 show well-formed nuclei. At pH 4.5, the deposits take the form of dendrites. XRD analysis shows that, in both cases, a Cu2O structure is present, but with a large amount at pH 4.5, evidenced by peaks of [002] and [110] directions.
New polymer/ligand complexes could be easily obtained due to the molecular self-assembly of carboxylic acid and hydrogen acceptor fragments through the intermolecular hydrogen-bonding. The polymer/ligand complexes consisting of poly(ethyleneglycol)bis(carboxymethyl)ether (PEOCA), operating as a hydrogen-bonding donor, and pyrazine, 4,4′-bipyridine, or 1,3,5-triazine, serving as a hydrogen-bonding acceptor, exhibited a gel-like structure at room temperature. The high ion conductivity of the order of 10−4–10−6 S cm−1 was achieved for the PEOCA/ligand complexes with LiClO4. The decrease in their conductivity corresponded to the increase in the viscosity and glass transition temperatures of the polymer complexes, but their electrical properties were similar to those of conventional cross-linked PEO polymer electrolytes.
The increasing market demand for electric vehicles requires a continuous development and improvement of battery systems. A crucial aspect is the application of analytical methods to characterize the battery systems in the most exact way. At the same time these methods should remain as simple as possible. The current analysis procedures use essentially the battery system- and battery cell-characteristic of the voltage curve in relaxation- and operation-time. These approaches alone are not conclusive enough due to the influences of relaxation time and varying load currents. In recent years, methods based on electrochemical impedance spectroscopy (EIS) have found application for accurate analysis of occurring electrochemical processes and diagnosis of lithium ion batteries. This publication aims to show how the state of charge can be predicted with the use of EIS and a simplified equivalent circuit for redundant supplementing the OCV-method (open circuit voltage) and the current- counting method. Therefore film batteries with a graphite anode and a Ni1/3 Mn1/3 Co1/3 cathode are charged and discharged according to a specified procedure. The battery is (dis)charged with steps of 10% followed by an EIS measurement. The measured data is used to determine the elements of the simplified equivalent circuit. These elements are analyzed for their different values at various states of charge. From these measurements can be concluded that EIS can be applied for the estimation of state of charge (in the middle range) as redundant method to other estimation methods. It therefore provides an additionally methods by which statements about the battery conditions can be made.
Phase structure and electrochemical properties of the Ml1−x Mg x Ni2.80Co0.50Mn0.10Al0.10 (x =0.08, 0.12, 0.20, 0.24, 0.28) (Ml=La-rich mixed lanthanide) alloys were studied. X-ray diffraction (XRD) analysis and Rietveld refinement show that the alloys consist mainly of LaNi5 and (La,Mg)Ni3 phase. Due to variation in phases of the alloys, the maximum discharge capacity, the high rate dischargeability (HRD), and the low temperature dischargeability increase first and then decrease. The maximum discharge capacity increases from 322mAhg−1 (x =0.08) to 375mAhg−1 (x =0.12), and then decreases to 351mAhg−1 (x =0.28) with increasing x. As the case of x =0.20, HRD at 1200mAg−1 and discharge capacity at 233K reaches 41.7% and 256mAhg−1, respectively. The cycling stability is improved by substituting La with Ml and B-site multi-alloying, and the capacity retention of Ml0.72Mg0.28Ni2.80Co0.50Mn0.10Al0.10 at the 200th cycle is 71%.
Biofuel cells are devices for generating electrical energy directly from chemical energy of renewable biomass using biocatalysts such as enzymes. Efficient electrical communication between redox enzymes and electrodes is essential for enzymatic biofuel cells. Carbon nanotubes (CNTs) have been recognized as ideal electrode materials because of their high electrical conductivity, large surface area, and inertness. Electrodes consisting entirely of CNTs, which are known as CNT paper, have high surface areas but are typically weak in mechanical strength. In this study, cellulose (CL)–CNT composite paper was fabricated as electrodes for enzymatic biofuel cells. This composite electrode was prepared by vacuum filtration of CNTs followed by reconstitution of cellulose dissolved in ionic liquid, 1-ethyl-3-methylimidazolium acetate. Glucose oxidase (GOx), which is a redox enzyme capable of oxidizing glucose as a renewable fuel using oxygen, was immobilized on the CL–CNT composite paper. Cyclic voltammograms revealed that the GOx/CL–CNT paper electrode showed a pair of well-defined peaks, which agreed well with that of FAD/FADH2, the redox center of GOx. This result clearly shows that the direct electron transfer (DET) between the GOx and the composite electrode was achieved. However, this DET was dependent on the type of CNTs. It was also found that the GOx immobilized on the composite electrode retained catalytic activity for the oxidation of glucose.
A new type of nano-sized cobalt oxide compounded with mesoporous carbon spheres (MCS) as negative electrode material for lithium-ion batteries was synthesized. The composite containing about 20wt.% cobalt oxide exhibits a reversible capacity of 703mAh/g at a constant current density of 70mA/g between 0.01 and 3.0V (vs. Li+/Li), and remains a capacity retention of 77% after the 30th cycle. The improvement could be attributed to that the MCS had a good electronic conductivity and severed as dispersing medium to prevent cobalt oxide nanoparticles from aggregating, and the mesopores (cobalt oxide not fully occupied) can provide the enough space to buffer the volume change during the Li-ion insertion and extraction reactions in cobalt oxide nanoparticles.
With technological advances there are many physical objects that are designed in digital format, some examples are: books, agendas, tickets, etc. One of the characteristics of digital objects is that each type of object has its own format, in most cases each object type can only be interpreted by a particular application, so will have problems to be interpreted. Internet of things (IoT) promotes the integration and communication between physical objects, including digital objects on the IoT can automate and streamline many tasks. The absence of common format for digital objects also causes problems of interaction and communication. There is no standardized way to obtain the actions or services associated with the digital object, which makes it difficult for these digital objects to interact and integrate in a generic way with other applications, devices or embedded systems. Based on the problems identified in this document a proposal is detailed in search for a single structure and for the construction of any digital object. The validity of the approach has been verified through a prototype system working with real appliances.
The capacitive mixing procedure for energy extraction based on Double Layer Expansion (CDLE) belongs to the group of so-called CAPMIX techniques, which aim at obtaining energy from the salinity difference between fresh and sea waters. Specifically, the CDLE technique takes advantage of the voltage rise that occurs when sea water is exchanged for river water in a pair of porous electrodes which jointly behave as an electrical double layer supercapacitor. In this article, we deal with some experimental aspects that appear essential for optimizing the extracted energy, and have not yet been analyzed with sufficient detail. This investigation will help in evaluating those parameters which need to be fixed in a future CDLE device. These include the charging potential, the durations of the different cycle steps, the load resistance used, and the porosity and hydrophilicity of the carbon.
The surface of as-prepared LiMn2O4 was modified with Al2O3 by a melting impregnation method. X-ray diffraction, field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) studies indicated that Al2O3 nano-particles are distributed around the spinel. X ray absorption fine structure analysis (XAFS) further demonstrated that Al atoms were also doped to the surface of LiMn2O4 particles. The nano-Al2O3 particle coating improves the capacity retention of spinel LiMn2O4 efficiently at both room temperature and 55°C. The mechanism of improvement for surface modified LiMn2O4 can be attributed to the inhibition of a surface Jahn-Teller distortion and the decrease of manganese dissolution, leading to good electric contact among particles.
Graphene is an excellent material for energy storage devices such as supercapacitors. Graphene electrodes have been fabricated using a variety of methods. Many of these methods are based on using graphene oxide and then reducing it using one of the various possible methods, resulting in reduced graphene oxide. This report focuses on thermal reduction along with thermally assisted ionic liquid (IL) electrolyte wetting of the electrodes. The thermal processing of graphene electrodes with IL shown here results in superior supercapacitor performance through improved IL wetting of the electrodes, due to reduced IL viscosity at elevated temperatures.
A soluble lead battery benefiting from the incorporation of an ion exchange membrane to separate the positive and negative electrolyte compartments has been described. A static cell, using an electrolyte volume of 7.5 ml, was configured with and without a membrane. The use of a membrane enables the selection of electrode specific additives. In this paper, a proof of concept cell is shown with the use of Bi3+, which when added to the positive electrolyte compartment leads to a twenty-fold increase in cycle life of the cell. The bismuth ions cause a shift in the reaction mechanism and kinetics of lead dioxide dissolution during the discharge reaction.
Redox flow batteries (RFBs) have emerged as prime candidates for energy storage on the medium and large scales, particularly at the grid scale. The demand for versatile energy storage continues to increase as more electrical energy is generated from intermittent renewable sources. A major barrier in the way of broad deployment and deep market penetration is the use of expensive metals as the active species in the electrolytes. The use of organic redox couples in aqueous or non-aqueous electrolytes is a promising approach to reducing the overall cost in long-term, since these materials can be low-cost and abundant. The performance of such redox couples can be tuned by modifying their chemical structure. In recent years, significant developments in organic redox flow batteries has taken place, with the introduction of new groups of highly soluble organic molecules, capable of providing a cell voltage and charge capacity comparable to conventional metal-based systems. This review summarises the fundamental developments and characterization of organic redox flow batteries from both the chemistry and materials perspectives. The latest advances, future challenges and opportunities for further development are discussed.