batterydata/paper-abstracts huggingface dataset:
Silver zinc phosphate glasses with a composition (40−x/2) P2O5 – (40−x/2) Na2O–20ZnO–x AgNO3 (x=5, 10 and 15mol%) were prepared of the glasses via conventional melt-quenching technique. From the Raman spectrum, the structure of the glasses was analyzed. Conduction and relaxation mechanisms in these glasses were studied using impedance spectroscopy in a frequency range from 10Hz to 13MHz and a temperature range from 323K to 623K. The dependence of electrical data on frequency was analyzed in the framework of the Nyquist's plot and Jonscher’s power law. The semicircles observed in the plots indicate a double relaxation process. The studied materials exhibit a significant contribution of bulk and interfacial effect to electrical conduction and to non-Debye relaxation process. The dc conductivity (σdc) follows Arrhenius behavior with temperature. The ac and dc conductivities of the samples were found to increase with the increase in temperature. The conductivity variation for P2O5-Na2O-ZnO glasses doped with various concentrations of AgNO3 was explained by the presence of ionic contribution. The dielectric characterizations include measurements involving the variation of the dielectric constant as well as the dielectric loss with frequency. The dielectric studies show low values for the dielectric constant and loss at high frequencies. Dependence of the electrical modulus of the glasses on frequency and temperature presented a relaxation phenomenon.
In order to enhance the electrochemical properties, the spinel LiMn2O4 electrode surface was modified with amorphous Al2O3 nanoparticle as heterogeneous phase. LiMn2O4 was in preparation based on a conventional solid-state reaction. The LiMn2O4 procedure was soaked in aluminum tri 2-propoxide solution. The LiMn2O4 whose surface was modified by aluminum oxide was obtained through the heat treatment at 400°C for 4h. The Al2O3-modified LiMn2O4 electrode exhibits a capacity higher than that of the unmodified LiMn2O4 electrode. On the other hand, no variation was shown with open circuit potential and apparent chemical diffusion coefficient of Li ion for LiMn2O4 before and after the surface modification. The charge-transfer resistance of Al2O3-modified LiMn2O4 decreased significantly in comparison with the unmodified LiMn2O4. The improved charge-transfer kinetics was largely attributed to Al2O3 which plays an important role of increasing the chemical potential at the electrode/electrolyte interface.
Contamination with mercury is a real health issue for humans with physiological consequences. The main objective of the present study was to assess the neurotoxicological effect of inorganic mercury: HgCl2. For this, adult mice were exposed prenatally, postnatally, and during the adult period to a low level of the metal, and their behavior and antioxidant status were analyzed. First, we showed that mercury concentrations in brain tissue of treated animals showed significant bioaccumulation, which resulted in behavioral deficits in adult mice. Thus, the treated mice developed an anxiogenic state, as evidenced by open field and elevated plus maze tests. This anxiety-like behavior was accompanied by a decrease in social behavior. Furthermore, an impairment of memory in these treated mice was detected in the object recognition and Y-maze tests. The enzymatic activity of the antioxidant system was assessed in eight brain structures, including the cerebral cortex, olfactory bulb, hippocampus, hypothalamus, mesencephalon, pons, cerebellum, and medulla oblongata. The results show that chronic exposure to HgCl2 caused alterations in the activity of catalase, thioredoxin reductase, glutathione peroxidase, superoxide dismutase, and glutathione S-transferase, accompanied by peroxidation of membrane lipids, indicating a disturbance in intracellular redox homeostasis with subsequent increased intracellular oxidative stress. These changes in oxidative stress were concomitant with a redistribution of essential heavy metals, i.e., iron, copper, zinc, and magnesium, in the brain as a possible response to homeostatic dysfunction following chronic exposure. The alterations observed in overall oxidative stress could constitute the basis of the anxiety-like state and the neurocognitive disorders observed.
A novel design of lead–acid battery has been developed for use in hybrid electric vehicles (HEVs). The battery has current take-offs at both ends of each of the positive and negative plates. This feature markedly reduces battery operating temperatures, improves battery capacity, and extends cycle-life under HEV duty. The battery also performs well under partial-state-of-charge (PSoC)/fast-charge, electric-vehicle operation. The improvements in performance are attributed to more uniform utilization of the plate active-materials. The battery, combined with an internal-combustion engine and a new type of supercapacitor, will be used to power an HEV, which is being designed and constructed by an Australian industry–government consortium.
LiNi0.8Co0.15Al0.05O2 (LNCA) is a highly promising cathode material for lithium-ion batteries, but the low-rate capability and poor cycling stability of LNCA limit the expansibility of its commercial applications. Herein, Li4SiO4 with a small amount of Al is introduced to modify LNCA by combined wet-chemical and solid-state methods and improve its rate and cycle performance. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), High Resolution Transmission Electron Microscope (HRTEM), and Energy Disperse Spectroscopy (EDS) results confirm that a Li4SiO4 coating layer (2–5 nm) is firmly wrapped on the LNCA surface. The modified LNCA shows surprising rate performance and excellent cycle retention. Specifically, the LNCA material coated with 3 mol% Li4SiO4 displays a discharge capacity of 156.5 mAh g−1 at 10 C and exhibits a capacity retention of 88% after 100 cycles at 1 C rate(2.7–4.3 V). The excellent electrochemical performance of the LNCA@Li4SiO4 is due to the incorporation of the Li4SiO4 layer. This layer enhances the lithium-ion diffusion between electrode and electrolyte and suppresses the side reaction produced by direct contact between the active material and electrolyte during repeated charge–discharge cycles. All these findings indicate the high potential of this material for application in advanced lithium-ion batteries.
The effect of formation protocol was determined in tests using small pouch cells containing silicon-graphite/Li(Ni0.5Mn0.3Co0.2)O2 chemistry. The time for the formation protocol was either 13.2 or 186 h for the tested cells. It is demonstrated that the “fast” formation protocol produces cells with similar performance characteristics to that of the “slow” protocol. In addition, the solid-electrolyte interface layers from both formation protocols are stable and function analogously, albeit with different chemistry. The fast formation protocol may thus provide a more economical route to cell fabrication.
In the last decades, much effort has been made in order to couple desalination technologies with renewable energy systems consisting usually of photovoltaics, wind-turbines and batteries, in order, οn one hand to reduce cost, and, οn the other hand, to be able to power desalination units in regions where electricity availability is low. Normally, the reverse osmosis desalination units operate at nominal point of operation. However, it has been reported that operation of reverse osmosis desalination units at partial load presents lower specific energy consumption. In this paper a variable load Energy Management System (EMS) based on Fuzzy Cognitive Maps (FCM) is developed. In order to assess variable load operation two cases studies are investigated through simulation. For both cases studied, initially a PV-battery system is sized through optimization for a desalination unit operating only at full load. The difference between the two case studies is the capacity factor of the desalination unit considered; for the first case a capacity factor of the desalination unit of about 30% (which translates to about 7h daily operation at full load) is considered and for the second case study a capacity factor of about 70% (translating to about 17h of daily operation at full load). Then, the ON-OFF EMS is considered to be exchanged with the FCM variable load EMS that was developed and the yearly drinking water production is compared. The obtained results clearly show that, for an already installed PVROD system, an upgrade to a variable load operation scheme can present considerable increase in the drinking water production from the same system ranging from nearly 41% for the first case study to nearly 54% for the second.
Electrocatalytic oxidation of methanol in alkaline medium is studied using graphene nano-palladium/carbon cloth (G-Pd/CC). X-ray diffraction, scanning electron microscopy (SEM) and atomic absorption spectrometry are used to characterize G-Pd/CC electrode. Electrochemical characterizations are performed using cyclic voltammetry (CV), chronoamperometry and electrochemical impedance spectroscopy (EIS). The results show that the application of CC as a substrate for G-pd reveals excellent characteristics such as high catalytic activity, stability, tolerance toward poisoning effects for electrooxidation of methanol in alkaline medium. All results show that this electrode is a good candidate for application in direct methanol fuel cells.
Na-ion Battery is attractive alternative to Li-ion battery due to the natural abundance of sodium resource. Searching for suitable anode materials is one of the critical issues for Na-ion battery due to the low Na-storage activity of carbon materials. In this work, we synthesized a nanohybrid anode consisting of ultrafine SnO2 anchored on few-layered reduced graphene oxide (rGO) by a facile hydrothermal route. The SnO2/rGO hybrid exhibits a high capacity, long cycle life and good rate capability. The hybrid can deliver a high charge capacity of 324mAhgSnO2 −1 at 50mAg−1. At 1600mAg−1 (2.4C), it can still yield a charge capacity of 200mAhgSnO2 −1. After 100 cycles at 100mAg−1, the hybrid can retain a high charge capacity of 369mAhgSnO2 −1. X-ray photoelectron spectroscopy, ex situ transmission electron microscopy and electrochemical impedance spectroscopy were used to investigate the origin of the excellent electrochemical Na-storage properties of SnO2/rGO.
In the present study, reaction time of oblique and orthogonal saccades was investigated in normal subjects and in two groups of patients with right (RBD) and left (LBD) vascular cerebral lesions and no signs of spatial neglect. Clear altitudinal effects were present in each group of subjects: saccadic latencies were longer in the lower than in the upper part of the visual field for both orthogonal and oblique saccades. Asymmetry along the horizontal meridian was present only in case of right hemisphere damage. This supports the view that a lesion in the right hemisphere causes a greater deficit of visual-spatial processing than a left hemisphere lesion. A cerebral lesion in the right and/or left hemisphere produces a general slowing in the saccadic latency and a general reduction in the accuracy of saccades with respect to normal subjects performance. Further, it seems that making saccades in oblique direction reduces the general saccade efficiency.
Background Although there have been studies examining HIV knowledge among college population, current study is the first providing comparable information on HIV knowledge in general and testing specifically via online surveys among black and white college students. Methods Blacks (N=222) were recruited from 15 historically black college and universities (HBCUs) and whites (N=335) from a traditionally white institution. Results The majority of the students were aged 18–24 years. Reliability of the overall knowledge scale showed good internal consistency for both samples (alpha=0.70). Students overall scored higher on items related to HIV/AIDS in general (81.5% correct) and lower on items related to HIV testing (71.6% correct), with no significant difference between groups. However, blacks rated significantly higher on their subjective (or “perceived”) HIV general knowledge (item mean 3.55 vs. 3.26) and testing specific knowledge (item mean 3.13 vs. 2.54) (p<0.01). Results showed that blacks were 6.9 times more likely to have been tested for HIV. Subjective HIV testing knowledge (OR=2.9) and nonheterosex-ual orientation (OR=3.2) were also significant predictors to prior testing behavior. Conclusions The knowledge scale assessed via the Internet demonstrated satisfactory reliabilities among diverse college students. Data showed that HBCU black students perceived significant higher knowledge levels, despite results showing similar knowledge scores as white students. Results have implications on HIV prevention among students attending their race/ethnic dominant institutions.
Molybdenum oxide (MoO3) has been deposited on multiwalled carbon nanotubes (MWCNTs) using DC reactive magnetron sputtering of molybdenum for supercapacitor applications. The deposits of MoO3 have been developed under different intervals of time. The structure and surface morphology of the deposits have been characterized by means of X-ray diffraction (XRD) analysis and field emission scanning electron microscopy (FESEM). X-ray diffraction peaks of the composite films reveal the formation of crystalline structure of MoO3. The electrochemical performance of the composite films was studied using cyclic voltammetry (CV), galvanostatic charge discharge and electrochemical impedance spectroscopy measurements. The composite film exhibits maximum specific capacitance of 70Fg−1 at a scan rate of 10mVs−1 in 1M Na2SO4 electrolyte. The nanocomposite electrode material shows specific capacitance which is almost four fold increase with respect to that of bare MWCNTs. The effect of coating duration on specific capacitance has been studied. The nanocomposite film is found to display good cycleability, even up to 1000cycles.
The local current density related to the exfoliation process of graphite negative electrodes in mixed ethylene carbonate/propylene carbonate electrolytes was controlled by a variation of the current applied to lithium half-cells containing either single type graphite electrodes or electrodes consisting of mixtures of an exfoliating and a non-exfoliating graphite. The partial local current density attributed to graphite passivation and its distribution within the volume of the electrode was found to be a key parameter to explain differences in the exfoliation behaviour observed for graphite electrodes. The local current density is related with a local overpotential which may suppress one of several possible electrochemical processes. In a negative electrode consisting of a mixture of a non-exfoliating and an exfoliating graphite component, the exfoliation of the exfoliation-sensitive graphite component can be completely suppressed when increasing the partial local current density attributed to the graphite exfoliation process above a certain threshold, by either decreasing the amount of exfoliating graphite particles in the electrode or by increasing the total current density, i.e., the specific current. The consideration of the local current density distribution for the electrochemical processes throughout the electrode leads to a more general concept for the graphite passivation behaviour during the first lithium insertion in lithium-ion batteries.
To understand the toxicity of Pb-polluted shooting fields, oribatid mites Platynothrus peltifer were exposed to shooting field soils containing 47–2398 mg Pb/kg dry weight (DW) and having
The electrochemical behavior of three triphylite (LiFePO4) ores from different mining localities has been investigated. Two of them show clearly an activity corresponding to the triphylite phase. A discharge capacity of 85mAhg−1 was obtained. The benefit of heat treatment that allows to deposit the electronically conductive carbon-based coating on the particles is reported for both natural and synthetic LiFePO4 samples. Discharge capacity, kinetics and stability upon cycling were all improved after the heating process. The best results were obtained with carbon coatings coming from the decomposition of a modified polycyclic aromatic. In this case, for synthetic samples, the whole capacity was reversibly exchanged and less than 1% of the initial capacity was lost after 10 cycles.
Unknown Notes Cross-reference terms in italics are general cross-references, or refer to subentry terms within the main entry (the main entry is not repeated to save space). Readers are also advised to refer to each article for additional cross-references – not all of these cross-references have been included in the index cross-references. The index is arranged in set-out style with a maximum of three levels of subheading. Major discussion of a subject is indicated by bold page numbers. Page numbers suffixed by t, f, and b refer to Tables, Figures, and Boxes respectively. vs. indicates a comparison. The index entries are presented in word-by-word alphabetical sequence in which a group of letters followed by a space is filed before the same group of letters followed by a letter. For example, entries beginning ’air density’ are alphabetized before ’aircraft.’ Prefixes and terms in parentheses are excluded from the initial alphabetization. Where index subentries and sub-subentries pertaining to a subject have the same page number, they have been listed to indicate the comprehensiveness of the text.
Electrochemically cathodic exfoliation in room temperature ionic liquids N-butyl, methylpyrrolidinium bis(trifluoromethylsulfonyl)-imide (BMPTF2N) has been developed for few-layer graphene sheets, demonstrating low levels of oxygen (2.7at% of O) with a nearly perfect structure (I D/I G <0.05). The mechanism of cathodic exfoliation in BMPTF2N involves the intercalation of ionic liquids cation [BMP]+ under highly negatively charge followed by graphite expansion. Porous activated graphene sheets were also obtained by activation of graphene sheets in KOH. Transmission electron microscopy, X-ray photoelectron spectroscopy and Raman spectroscopy were used to characterize these graphene materials. The electrochemical performances of the graphene sheets and porous activated graphene sheets for lithium-ion battery anode materials were evaluated using cyclic voltammetry, galvanostatic charge–discharge cycling, and electrochemical impedance spectroscopy.
In 2006, the Centers for Disease Control and Prevention (CDC) recommended three changes to HIV testing methods in US healthcare settings: (1) an opt-out approach, (2) removal of separate signed consent, and (3) optional HIV prevention counseling. These recommendations led to a public debate about their moral acceptability.
We report on the electronic structure of three different types of N-containing carbon-based cathode catalysts for polymer electrolyte fuel cells observed by hard X-ray photoemission spectroscopy. Prepared samples are derived from: (1) melamine and poly(furfuryl alcohol), (2) nitrogen-doped carbon black and (3) cobalt phthalocyanine and phenolic resin. C 1s spectra show the importance of sp 2 carbon network formation for the oxygen reduction reaction (ORR) activity. N 1s spectra of the carbon-based cathode catalysts are decomposed into four components identified as pyridine-like, pyrrole- or cyanide-like, graphite-like, and oxide nitrogen. Samples having high oxygen reduction reaction activity in terms of oxygen reduction potential contain high concentration of graphite-like nitrogen. O 1s spectra are similar among carbon-based cathode catalysts of different oxygen reduction reaction activity. There is no correlation between the ORR activity and oxygen content. Based on a quantitative analysis of our results, the oxygen reduction reaction activity of the carbon-based cathode catalysts will be improved by increasing concentration of graphite-like nitrogen in a developed sp 2 carbon network.
Porous silicon prepared by low-cost and scalable magnesiothermic reactions is a promising anode material for Li-ion batteries; yet, retaining good cycling stability for such materials in electrodes of practical loading remains a challenge. Here, we engineered the nanoporous silicon from a modified magnesiothermic reaction by controlled surface oxidization forming a <5nm oxide layer on the 10–20nm Si nanocrystallites. High loading electrodes of ~3mAh/cm2 demonstrates stable cycling with ~80% capacity retention over 150 cycles. The specific discharge capacity based on the total electrode weight is ~1000mAh/g at the lithiation/delithiation current density of 0.5/0.75mA/cm2. This work reveals the importance of the surface treatment on nanostructured Si, which will lead to a well-controlled ratio of silicon and surface oxide layer and provide guidance on further improvement on silicon-based anode materials.
Facial expression processing and the attribution of facial emotions to a context were investigated in adults with Down syndrome (DS) in two experiments. Their performances were compared with those of a child control group matched for receptive vocabulary. The ability to process faces without emotional content was controlled for, and no differences appeared between the two groups. Specific impairments were found in the DS group according to the task modalities and the type of facial emotional expressions. In the emotion matching condition, the DS adults showed overall difficulties whereas in the identification and recognition conditions they were particularly impaired when processing the neutral expression. In the emotion attribution task, they exhibited difficulties with the sad expression only and the analysis of their error pattern revealed that they rarely selected this expression throughout the task. The sad emotion was the only one that showed a significant relationship with the facial expression processing tasks.
An available strategy is rationally designed to modify the electrode surfaces with specific electric property based on the controllable surface modifications. In this way, the substitution of oxygen with sulfur can be realized on the surfaces of nickel-cobalt-based molybdate with low temperature chemical vapor deposition method, in which the structures are well-retained. The obtained electrode materials after sulfuration at low temperature are transformed to be nickel-cobalt-based molybdate which is covered with a thin layer of sulfides. Compared with NixCoyMoO4 precursor, the formation of nanocrystalline particles (5–10 nm in size) on the surfaces of the nanosheets after sulfuration will supply much more electrochemical active centers, facilitating the improvement the electrochemical performance of the electrode materials. The oxides-sulfides electrode (NixCoyMoO4@MoS2/CoS/NiS) exhibits a good specific capacity of 1689 F g−1, satisfactory cycle performance with an outstanding retention (90.6%) after 5000 cycles. Besides, an excellent retention of the capacitances (85.3%) can be maintained as the current density is high to be 30 A g−1. Furthermore, the corresponding flexible all-solid-state battery hybrid supercapacitor is developed with the energy density high to be 60.4 W h kg−1 at 800.6 W kg−1 and remarkable stability (94.4% retention) after 5000 cycles.