batterydata/paper-abstracts huggingface dataset:
In this work, poly(ethylene oxide)-block-poly(acrylonitrile) (PEO-b-PAN) copolymer is used as a binder for LiFePO4 cathodes, where PEO-b-PAN not only conducts Li+ inside the cathode but also acts as a dispersant to disperse LiFePO4. This binder significantly increases the capacity under high discharge rate and overcome the limitation of LiFePO4 for high power density application. By XPS analysis, the incorporation of the PEO-b-PAN binder to the active materials of the LiFePO4 cathodes can be clearly observed from the binding energy of the nitrogen atom of the PEO-b-PAN. Due to the surface active properties of the PEO and PAN, PEO-b-PAN obviously increases the effective contact area and reduces electronical resistance. In addition to the surface active properties, this binder provides Li+ pathway; thus, it features low polarization, less interfacial resistance and good activity for electrochemical reaction. Consequently, these properties enable the PEO-b-PAN binder to have a higher discharge plateau potential at 3.10V, while it is only 2.86V for the PVDF binder at a 5C rate. Moreover, even at a 10C rate, the PEO-b-PAN binder still delivers extraordinary discharge capacities of 101mAhg−1, significantly higher than that of the PVDF binder (32mAhg−1). Overall, this ionic conducting and surface active binder exhibits good electrochemical properties and excellent high rate performance.
As tin based electrodes are of significant interest in the development of improved lithium-ion batteries it is important to understand the associated electrochemical reactions. In this work it is shown that the electrochemical behavior of SnO 2 coated tin electrodes can be described based on the SnO 2 and SnO conversion reactions, the lithium tin alloy formation and the oxidation of tin generating SnF 2. The CV, XPS and SEM data, obtained for electrodeposited tin crystals on gold substrates, demonstrates that the capacity loss often observed for SnO 2 is caused by the reformed SnO 2 layer serving as a passivating layer protecting the remaining tin. Capacities corresponding up to about 80 % of the initial SnO 2 capacity could, however, be obtained by cycling to 3.5V vs. Li +/Li. It is also shown that the oxidation of the lithium tin alloy is hindered by the rate of the diffusion of lithium through a layer of tin with increasing thickness and that the irreversible oxidation of tin to SnF 2 at potentials larger than 2.8V vs. Li +/Li is due to the fact that SnF 2 is formed below the SnO 2 layer. This improved electrochemical understanding of the SnO 2/Sn system should be valuable in the development of tin based electrodes for lithium-ion batteries.
We report the evaluation of a new automated protocol for the treatment of asyntactic comprehension. This is a follow-up study to the “Microworld for Aphasia” work of Crerar, Ellis, and Dean (1996). An efficacy study involving three patients is reported. All three patients achieved statistically significant improvements in written sentence comprehension as a result of eight hours of treatment focusing on active, passive, and object cleft sentence structures. Treatment effects generalized both to untreated Microworld sentences and to the more naturalistic sentences of the Philadelphia Comprehension Battery (Saffran, Schwartz, Linebarger, Martin, & Bochetto, 1988), with some further evidence of generalization to spoken sentence comprehension. Treatment effects were obtained with minimal input from a clinician.
A lumped (0-D) numerical model has been developed for simulating the thermal response of a lithium-ion battery pack with a phase-change composite (PCC™) thermal management system. A small 10s4p battery pack utilizing PCC material was constructed and subjected to discharge at various C-rates in order to validate the lumped model. The 18650 size Li-ion cells used in the pack were electrically characterized to determine their heat generation, and various PCC materials were thermally characterized to determine their apparent specific heat as a function of temperature. Additionally, a 2-D FEA thermal model was constructed to help understand the magnitude of spatial temperature variation in the pack, and to understand the limitations of the lumped model. Overall, good agreement is seen between experimentally measured pack temperatures and the 0-D model, and the 2-D FEA model predicts minimal spatial temperature variation for PCC-based packs at C-rates of 1C and below.
Surface modification of Zr0.9Ti0.1Ni1.1Co0.1Mn0.5V0.2Cr0.1 alloy was accomplished by mechanical grinding (MG). The decrepitation of alloy particles gave rise to a new surface. The effect of MG was systematically studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), pressure-composition (PC) isotherms and electrochemical impedance spectroscopy (EIS). Initial activation and rate capability of a negative electrode made from this alloy were significantly improved by MG treatment at 300 rpm for 0.5–1 h, but prolonged MG treatment (10 h) reduced the nominal discharge capacity from 350 mAh g−1 to 180 mAh g−1. Under these conditions the alloy particles disintegrate and become nanocrystalline, which reduces the discharge capacity owing to the change in the stereology of tetrahedral interstices available for hydrogen storage. The data based on PC isotherms and hydriding kinetics indicates that the equilibrium hydrogen pressure increases and the hydriding rate and storage capacity are significantly reduced by prolonged MG treatment. EIS data reveal that the improved rate capability can be ascribed to an enhanced charge-transfer reaction which is the rate-determining step in the hydriding and dehydriding reactions.
Introduction Attention-deficit/hyperactivity disorder (ADHD) and reading disability (RD) are complex childhood disorders that frequently co-occur, but the etiology of this comorbidity remains unknown. Method Participants were 457 twin pairs from the Colorado Learning Disabilities Research Center (CLDRC) twin study, an ongoing study of the etiology of RD, ADHD, and related disorders. Phenotypic analyses compared groups with and without RD and ADHD on composite measures of six cognitive domains. Twin analyses were then used to test the etiology of the relations between the disorders and any cognitive weaknesses. Results Phenotypic analyses supported the hypothesis that both RD and ADHD arise from multiple cognitive deficits rather than a single primary cognitive deficit. RD was associated independently with weaknesses on measures of phoneme awareness, verbal reasoning, and working memory, whereas ADHD was independently associated with a heritable weakness in inhibitory control. RD and ADHD share a common cognitive deficit in processing speed, and twin analyses indicated that this shared weakness is primarily due to common genetic influences that increase susceptibility to both disorders. Conclusions Individual differences in processing speed are influenced by genes that also increase risk for RD, ADHD, and their comorbidity. These results suggest that processing speed measures may be useful for future molecular genetic studies of the etiology of comorbidity between RD and ADHD.
Evoked and induced event-related neural oscillations have recently been proposed as a key mechanism supporting higher-order cognition. Cognitive decay and abnormal electromagnetic sensory gating reliably distinguish schizophrenia (SZ) patients and healthy individuals, demonstrated in chronic (CHR) and first-admission (FA) patients. Not yet determined is whether altered event-related modulation of oscillatory activity is manifested at early stages of SZ, thus reflects and perhaps embodies the development of psychopathology, and provides a mechanism for the gating deficit. The present study compared behavioral and functional brain measures in CHR and FA samples. Cognitive test performance (MATRICS Consortium Cognitive Battery, MCCB), neuromagnetic event-related fields (M50 gating ratio), and oscillatory dynamics (evoked and induced modulation of 8–12Hz alpha) during a paired-click task were assessed in 35 CHR and 31 FA patients meeting the criteria for ICD-10 diagnoses of schizophrenia as well as 28 healthy comparison subjects (HC). Both patient groups displayed poorer cognitive performance, higher M50 ratio (poorer sensory gating), and less induced modulation of alpha activity than did HC. Induced alpha power decrease in bilateral posterior regions varied with M50 ratio in HC but not SZ, whereas orbitofrontal alpha power decrease was related to M50 ratio in SZ but not HC. Results suggest disruption of oscillatory dynamics at early stages of illness, which may contribute to deficient information sampling, memory updating, and higher cognitive functioning.
Cave ecosystems are carbon limited and thus are particularly susceptible to anthropogenic pollution. Yet, how carbon quality and quantity that can modulate the pathways and amount of Mn cycling in caves remains largely unknown. To explore Mn cycling, baseline bacterial, archaeal, and fungal communities associated with Mn(III/IV) oxide deposits were assessed in both relatively ‘pristine’ and anthropogenically impacted caves in the Appalachian Mountains (USA). Cave sites were then amended with various carbon sources that are commonly associated with anthropogenic input to determine whether they stimulate biotic Mn(II) oxidation in situ. Results revealed patterns between sites that had long-term exogenous carbon loading compared to sites that were relatively ‘pristine,’ particularly among Bacteria and Archaea. Carbon treatments that stimulated Mn(II) oxidation at several sites resulted in significant changes to the microbial communities, indicating that anthropogenic input can not only enhance biotic Mn(II) oxidation, but also shape community structure and diversity. Additional carbon sources amended with copper were incubated at various cave sites to test the role that Cu(II) plays in in situ biotic Mn(II) oxidation. Media supplemented with 100 µM Cu(II) inhibited bacterial Mn(II) oxidation but stimulated fungal Mn(II) oxidation, implicating fungal use of multicopper oxidase (MCO) enzymes but bacterial use of superoxide to oxidize Mn(II). In sites with low C:N ratios, the activity of the Mn(II) oxidizing enzyme manganese peroxidase (MnP) appears to be limited (particularly by MnP-utilizing Basidiomycetes and/or Zygomycetes).
Abstract This paper presents a methodology for modeling and calculating PEM FCPP reliability. It includes the development of a state-space method to calculate the stand-alone PEM FCPP reliability using Markov Model (MM). The state-space method includes different states such as operation, derated, fully faulted or maintenance since FCPP (FC) power plants are subject to a number of possible outage and derated states. The aging failures in the state-space generation model of a PEM FCPP are estimated based on the assumption that failure and repair rates of the components change with operational age of FC. The functional relationship between FC age and transition rates, namely failure and repair rates are estimated based on the fuzzy set theory and expert knowledge. The simulation results are obtained using matlab software package for a 5kW stand-alone PEM fuel cell, which supplies power to a typical residential house.
Dendrite growth and low coulombic efficiency (CE) are the key issues to hinder the lithium (Li) metal anode in practical battery application. Naturally formed fragile and unstable solid electrolyte interphase (SEI) film between Li anode and electrolyte is one of the main reasons for them. Here we create a dual-layered artificial SEI (ASEI) film by controlled electrochemical method, which can simultaneously suppress dendrite formation and improve electrochemical performance of Li metal anode. The ASEI film with an average thickness of 40 nm shows a dual-layered structure with organic species (−(CH2CH2O)n− and lithium alkylcarbonate) in the outer layer and abundant inorganic species (LiF, Li2O, Li3N and Li2S) in the inner layer, providing enough flexibility, high mechanical modulus, high kinetic and thermodynamic stability. The ASEI film demonstrates extremely superior Li+ ion conductivity and low interface impedance, enabling a compact and dendrite-free Li deposition during cycling, and remarkably improving the CE to an average value of 97.5% for over 350 cycles. The superior electrochemical performance of lithium−sulfur (Li−S) full cells with the protection of ASEI film on Li anode further proves that the ASEI film has optimistic potential in Li metal batteries. This work provides a simple and feasible strategy for preparing ASEI film for dendrite-free Li metal anode, which has great prospects in high specific energy Li metal batteries.
The current collector fracture failure of lithium-ion batteries (LIBs) occurs during its winding production process frequently, and the consequent damages are usually large, but little research has been conducted on this phenomenon. This work stems from the difficulty and obstacles in the winding process of actual production of LIBs. The fracture failure of the current collectors is easily caused by the evolution and mutation of the mechanical behavior during the winding process, resulting in safety hazards and poor efficiency. The purpose of this work is to reveal the evolution and distribution mechanism of circumferential strain of the current collectors on the fracture failure under the constraint of winding process. Experimental tests, finite element calculations and theoretical model are used to study the evolution and distribution of circumferential strain. The dynamic evolution process of circumferential strain is tested accurately, and the mechanism of fracture failure of current collectors is revealed. The criterion for current collector strength is proposed based on the results of strain analysis and SEM observation.
Incremental capacity analysis (ICA) is a widely used technique for lithium-ion battery state-of-health (SOH) evaluation. The effectiveness and robustness of ICA for single cell diagnostics have been reported in many published work. In this study, we extend the ICA based SOH monitoring approach from single cells to battery modules, which consist of battery cells with various aging conditions. In order to achieve on-board implementation, an IC peak tracking approach based on the ICA principles is proposed. Analytical, numerical and experimental results are presented to demonstrate the utility of the IC peak tracking framework on multi-cell battery SOH monitoring and the effects of cell non-uniformity on the proposed method. Results show that the methods developed for single cell capacity estimation can also be used for a module or pack that has parallel-connected cells.
Nanostructured manganese oxide electrodes are fabricated directly by electrochemical deposition. Surface morphology of the electrode deposited at high-current density shows nanowires with diameter 12–16nm distributed randomly. Nanowires tend to aggregate to clumps when the deposition current density is low. Both annealing temperature and deposition current density affect the electrochemical performance of the deposited manganese oxide electrode in an aqueous lithium sulfate electrolyte. An optimal annealing temperature is found to be 300°C in terms of the electrode's specific capacity during high-rate charging/discharging. An electrode with thinner nanowires deposited at high-current density has a high-specific capacity because thinner nanowires shorten the diffusion of lithium ions and in favor of high-rate charging/discharging.
Li–CO2 batteries have attracted wide attention owing to their high energy density and ability to utilize carbon dioxide. However, current Li–CO2 batteries still suffer from several unresolved problems such as low coulombic efficiency and high charge potential, and hence much work is still required to optimize the electrochemical performance of Li–CO2 batteries. In this work, Ru nanoparticles have been deposited on Super P carbon using a solvothermal method and the resulting material (Ru@Super P) has been employed as a cathode in Li–CO2 batteries. The Li–CO2 battery with Ru@Super P as the cathode exhibits significantly reduced charge potential and can be operated for 80 cycles with a fixed capacity of 1000 mA h g−1 at 100 mA g−1, which is by far the best cycling stability among the reported Li–CO2 batteries. We found that Ru possesses a selective catalytic activity in promoting the reaction between Li2CO3 and carbon during charge. This characteristic of Ru helps to avoid electrolyte decomposition and improve the electrochemical performance of Li–CO2 batteries.
Motivated by recent productivity-based theories of diversification, we argue that only conglomerates with an optimal degree of diversification can utilize their comparative advantages across various industries and achieve economies of scope by eliminating redundancies. Evidence from both corporate bond and equity markets suggests that optimally diversified conglomerates consist of either (1) approximately five equally weighted divisions, or (2) one large core business segment that roughly accounts for 75 % sales. Moreover, the relative size of divisions has a critical impact on how diversification affects credit spreads and excess values. Nonparity among divisions correlates with greater costs that increase with the number of divisions.
Novel composite cathode materials, xLi2MnO3–(1−x)LiNi2/3Co1/6Mn1/6O2 (where x = 0.3, 0.5, and 0.7), were synthesized by sol–gel route and characterized by advanced techniques for rechargeable Li-ion battery applications. Phase purity of the composites was examined by XRD as well as Raman spectroscopy and the studies revealed good crystallinity and the formation of pure composite phases with monoclinic (C2/m) and hexagonal (R3m) crystal structures for Li2MnO3 and LiNi2/3Co1/6Mn1/6O2, respectively. Polyhedral agglomerates seen in the scanning and transmission electron microscopic images elucidated the better electrochemical properties of the composites. Valence states of transition metals in the composites were examined by X-ray photoelectron spectroscopy and the analysis suggested predominant oxidation states of Ni, Co, and Mn as 2+, 3+, and 4+, respectively. Galvanostatic charge–discharge tests, performed at different C-rates between 2.0 and 4.8 V, indicated high discharge capacity (∼250 mAh g−1), good rate capability, and excellent cycleability of the composite with x = 0.5 compared to the composites with x = 0.3 and 0.7. In-situ Raman spectroscopic studies revealed the activation of Li2MnO3 component in all composite cathode materials during the first cycle charging process with structural stability thereby enhancing performance of the composite with x = 0.5. These results demonstrated the feasibility of using 0.5Li2MnO3-0.5LiNi2/3Co1/6Mn1/6O2 composite as advanced cathode for high power Li-ion batteries.
Presently lithium hexafluorophosphate (LiPF6) is the dominant Li-salt used in commercial rechargeable lithium-ion batteries (LIBs) based on a graphite anode and a 3–4 V cathode material. While LiPF6 is not the ideal Li-salt for every important electrolyte property, it has a uniquely suitable combination of properties (temperature range, passivation, conductivity, etc.) rendering it the overall best Li-salt for LIBs. However, this may not necessarily be true for other types of Li-based batteries. Indeed, next generation batteries, for example lithium–metal (Li–metal), lithium–oxygen (Li–O2), and lithium–sulfur (Li–S), require a re-evaluation of Li-salts due to the different electrochemical and chemical reactions and conditions within such cells. This review explores the critical role Li-salts play in ensuring in these batteries viability.
The rhodamine B-attapulgite/polypyrrole (RhB-ATP/PPy) composites have been prepared by the in situ chemical oxidative polymerization method based on the self-assembly of pyrrole on the surface of the rhodamine B modified ATP (RhB-ATP). The morphologies of the RhB-ATP/PPy composites prepared with different feeding ratio of pyrrole and the RhB-ATP were compared with transmission electron microscope (TEM) technique. The electrochemical behaviors of the RhB-ATP/PPy composites were investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge–discharge. The results indicated that RhB did effectively improve the electrochemical performance and cycling stability of the RhB-ATP/PPy composite electrode, although RhB showed no obvious effect on the morphology of the nanocomposites. It was attributed to the fact that RhB and ATP provided a more convenient pathway to the charge carrier and RhB made the combination of the ATP and PPy much stronger. The maximum discharge capacity of the composites electrode achieved 587Fg−1 and kept 76% of its original speciﬁc capacitance after 500 cycles.
Background This study was conducted for to explore the plausible pathway of Chenopodium album seed extract (CAE)-mediated sperm cell death. Study Design The role of CAE for its spermicidal action was assessed by (a) measuring lipid peroxidation, protein carbonyl content and intracellular glutathione content in CAE exposed sperm cells; (b) assaying antioxidant enzymes like catalase and superoxide dismutase (SOD); (c) analyzing protein expressions by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot analysis; (d) fluorimetric measurement of intracellular H2O2 level and generation of reactive oxygen species (ROS) in CAE-treated sperm cells; and (e) DNA ladder formation study. Results CAE-induced sperm death is due to (a) lipid peroxidation of the sperm cell membrane, oxidation of some critical cellular proteins and depletion of intracellular reduced gluthathione, indicating production of ROS; (b) activation of Mn-SOD and inactivation of catalase favoring endogenous accumulation of H2O2; (c) generation of O2 − at an enhanced rate during oxidative stress as evidenced by increased Mn-SOD activity and protein expression; (d) accumulation of ROS in spermatozoa reflected in the fluorimetric experiments; and (e) increased production of O2 − and H2O2 induced apoptosis-like death in sperm cells as observed by DNA ladder formation. Conclusion The sperm death mediated by CAE is due to oxidative damage of cellular macromolecules by in situ generation of ROS.
A well-managed healthcare system improves the quality of the patient experience. However, many small healthcare clinics have suboptimal systems for scheduling and locating patients and medical staff, delaying the relay of information and creating poor resource and room utilization. This paper proposes a Radio Frequency Identification (RFID)-based Real-Time Tracking (R-RTT) System for optimizing small healthcare facility operations, enabling further optimization of throughput time, room utilization, and patient flow. In the proposed scenario, RFID readers were equipped in strategic locations throughout the facility. Patients and medical staff were issued personalized RFID tags. When they pass through the reader’s interrogation zone, it reads their RFID tag and sends the information to a central computer equipped with software capable of filtering the RFID data into useable information. A Visual Basic Application (VBA) program uses the information received from the ID tags to display the location of the patients and staff as they move throughout the facility. This increases their visibility within the facility by allowing medical staff to determine where their colleagues and patients are at all times. The VBA program was also able to record the data in order to track the time each stage of the appointment process takes to complete. The recorded time data can be broken into processes, making it easier to determine if it adds value. This data can then be transformed into a value stream map for further analysis and improvement.