batterydata/paper-abstracts huggingface dataset:
Layered LiMn0.4Ni0.4Co0.2O2 with the α-NaFeO2 structure was synthesized by the “mixed hydroxide” method, followed by a high temperature calcination at 800°C giving a single phase material of surface area 5m2 g−1. A combined X-ray/neutron diffraction Rietveld refinement showed that the transition metals in the 3b layer are randomly distributed at room temperature, and that only nickel migrates to the lithium layer and in this case 4.4%. Addition of excess lithium reduces the amount of nickel on the lithium sites. The magnetic susceptibilities of the compounds LiMn y Ni y Co1−2y O2 (y =0.5, 0.4, 0.333) follow the Curie–Weiss law above 100K and are consistent with the presence of Ni2+, Mn4+ and Co3+ cations; their magnetization curves, measured at 5K and showing a pronounced hysteresis, are also consistent with the nickel content on the lithium sites increasing with decreasing cobalt content. This material shows a stable capacity of 140–170mAhg−1 for more than 90 cycles within the voltage window of 2.5–4.4V. The layered rhombohedral structure is maintained as lithium is removed down to at least a lithium content of 0.05; the total volume change on cycling is under 2%. The nickel ions pin the lattice so that MO2 slab sliding to form the 1T structure cannot readily occur. The capability of aqueous acids to leach lithium from the lattice decreases with increasing nickel content in the lithium layer; however, the thermal stability of the delithiated compounds increases with cobalt content.
Introduction. It has been suggested that evidence of developmental disturbance of cognition and lateralisation in schizophrenia can be best understood from the perspective of developmental stability (DS), an indicator of the extent to which an individual develops according to a specified ontogenic programme in the presence of environmental noise. Higher levels of fluctuating asymmetry (FA; the difference between right and left side of a quantitative morphological trait such as dermatoglyphics) are thought to reflect less DS. We examined this issue for dimensions of schizotypy. Methods. Associations between FA, measures of laterality and cognitive function on the one hand, and negative and positive dimensions of schizotypy on the other, were examined in a sample of 260 healthy adolescents aged 11.9–15.6years. FA was measured as a–b ridge count right–left differences. Neuropsychological measures yielded a general cognitive ability score and a frontal function score. Laterality was assessed with the Annett scale. Results. Measures of psychosis proneness were normally distributed. Negative schizotypy was associated with more FA and lower general cognitive ability in a dose–response fashion. The association with FA was more apparent in boys. No associations existed with laterality or frontal function. Conclusion. The negative dimension of schizotypy may be associated with early developmental instability, resembling the pattern seen in the negative symptom dimension of schizophrenia. Measures of fluctuating asymmetry may be more sensitive with regard to the schizotypy phenotype than measures of laterality.
The aim of this study was to compare the efficiency of sonic, ultrasonic, and hydrodynamic devices in the removal of a root canal sealer from the surface and from simulated irregularities of root canals.
We investigate a series of three La2O3/Al2O3 samples, with a lanthana loading close to the theoretical monolayer, obtained by calcination at 773K, 973K, or 1173K from a common precursor. The samples were characterized by N2 adsorption at 77K, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), a variety of nano-analytical and nano-structural electron microscopy techniques, temperature programmed desorption (TPD-CO2), and volumetric CO2 adsorption techniques. By combining the information obtained from all these studies, a detailed description of their texture, nano-structure, lanthana distribution, and chemical properties could be gained. Three different forms of supported lanthana have been identified, and their relative weight evaluated quantitatively. As revealed by CO2 adsorption, these forms show strong, weak, or not measurable surface basicity, respectively. Upon increasing the calcination temperature, a progressive inter-conversion of the co-existing lanthana forms with inherent loss of surface basicity is observed. The effect, though moderate, is particularly noticeable on the sample calcined at 1173K. The amount of CO2 irreversibly chemisorbed on the different samples, including the alumina support, correlates well with their catalytic activity for the Meerwein–Ponndorf–Verley reaction of cyclohexanone with 2-propanol. This behavior is discussed with reference to that expected for pure lanthana. We conclude that our supported lanthana samples represent an advantageous alternative to pure La2O3 as highly basic catalytic materials.
CS Energy Materials (CSEM), a joint venture between H.C. Stark and Japanese chemical company New Chisso Corp, has started production of cathode materials for high performance lithium-ion batteries. CSEM's newly built production facility, based in Minamata Japan, has successfully commenced test operations. In the near future, the plant will manufacture cathode materials for high-performance lithium-ion batteries, using a patent-pending manufacturing technology. Research and development of the cathode material and the manufacturing technology take place at the CSEM site in Goslar (Germany), at H.C. Starck's registered office. The plant is intended to supply industrial-scale volumes cathode materials to the electric and hybrid vehicle industry.
This study examined the relative involvement of rapid auditory and visual temporal resolution mechanisms in the reading of phonologically regular pseudowords and English irregular words presented both in isolation and in contiguity as a series of six words. Seventy-nine undergraduates participated in a range of reading, visual temporal, and auditory temporal tasks. The correlation analyses suggested a general timing mechanism across modalities. There were more significant correlations between the visual temporal measures and irregular word reading and between the auditory measures and pseudoword reading. Auditory gap detection predicted pseudoword reading accuracies. The low temporal frequency flicker contrast sensitivity measure predicted the accuracies of isolated irregular words and pseudowords presented in contiguity. However, when a combined speed-accuracy score was used, visible persistence at both low and high spatial frequencies and auditory gap detection were active the in the reading of pseudowords presented in contiguity. Sensory processing skills in both visual and auditory modalities accounted for some of the variance in the reading performance of normal undergraduates, not just reading-impaired students.
The largest increment in the global light-duty vehicle fleet in the medium- and long-term will happen in developing countries. Advanced vehicles can outweigh increments in CO2 emissions of a growing vehicle fleet; however, cost remains a barrier for their diffusion. A stock turnover model of the passenger car fleet was developed to estimate the potential of advanced vehicle deployment for CO2 emissions reduction, and used in the case of Colombia. Vehicle types included internal combustion engine vehicles (ICEVs), battery electric vehicles (BEVs) and fuel cell hybrid electric vehicles (FCHEVs); using two glider types: conventional and lightweight materials-intensive. Five scenarios were considered: the base scenario that relies on conventional ICEVs, and four alternative scenarios targeting the penetration of (A) BEVs, (B) BEVs and lightweight vehicles, (C) FCHEVs, and (D) FCHEVs and lightweight vehicles. Deployment of BEVs and lightweight vehicles offers the largest cumulative well-to-wheel CO2 emissions reductions, 22.01% compared to the base scenario; with cost of avoided CO2 going from 930USD/t-CO2 avoided in 2020 to 31USD/t-CO2 avoided in 2050. Despite advanced vehicle deployment, gasoline will be the main fuel and iron and steel the main materials until 2050 in the Colombian passenger car fleet.
Sediment microbial fuel cells (SMFCs) are used as renewable power sources to operate remote sensors. However, increasing the electrode surface area results in decreased power density, which demonstrates that SMFCs do not scale up with size. As an alternative to the physical scale-up of SMFCs, we proposed that it is possible to scale up power by using smaller-sized individually operated SMFCs connected to a power management system that electrically isolates the anodes and cathodes. To demonstrate our electronic scale-up approach, we operated one 0.36-m2 SMFC (called a single-equivalent SMFC) and four independent SMFCs of 0.09 m2 each (called scaled-up SMFCs) and managed the power using an innovative custom-developed power management system. We found that the single-equivalent SMFC and the scaled-up SMFCs produced similar power for the first 155 days. However, in the long term (>155 days) our scaled-up SMFCs generated significantly more power than the single-equivalent SMFC (2.33 mW vs. 0.64 mW). Microbial community analysis of the single-equivalent SMFC and the scaled-up SMFCs showed very similar results, demonstrating that the difference in operation mode had no significant effect on the microbial community. When we compared scaled-up SMFCs with parallel SMFCs, we found that the scaled-up SMFCs generated more power. Our novel approach demonstrates that SMFCs can be scaled up electronically.
As a novel Na-ion battery anode, we studied electrochemical reactions of a LaSn3 electrode, and evaluated its cycling performance by comparison with that of a SmSn3 electrode. The LaSn3 electrode showed a reversible capacity of 580mAhcm−3 at the first cycle, and a gradual increase in the capacity with cycling number. The LaSn3 electrode exhibited a high capacity of 1470mAhcm−3 even at the 400th cycle, which is three times higher than that of a hard carbon electrode. The electrode reactions of elemental Sn were observed in a cyclic voltammetry profile of the LaSn3 electrode, indicating that a phase separation of LaSn3 gradually occurs to form Sn. We suggested that the phase separation provides a Na-inactive La3Sn5 matrix, which can suppress the aggregation of Sn particles and can improve the cyclability. On the other hand, the SmSn3 electrode showed a higher initial capacity of 970mAhcm−3 and an earlier capacity decay by the 200th cycle. It is suggested that the phase separation of SmSn3 progresses more rapidly while that of LaSn3 slowly occurs because of a higher thermodynamic stability for LaSn3 than SmSn3.
The stability of NASICON-type conducting glass–ceramic electrolyte, Li1+x+yAlxTi2−xSiyP3−yO12 (Ohara LICGC) has been characterized after prolonged exposure to deionized water and HCl(aq) solutions supported with LiCl. X-ray diffraction shows that the bulk crystallographic structure of the LICGC membranes remains unchanged when exposed to these solutions. Electrochemical impedance spectroscopy (EIS) shows that the conductivity of LICGC membranes immersed in deionized water remains stable over a one month period, while there is a significant increase in resistance when exposed to the acidic solutions. When exposed to pH 4 and 2 solutions for just 24 h, the resistances of the LICGC membrane increase by a factor of 8.5 and 23.5, respectively. EIS coupled with morphological characterization by scanning electron microscopy, shows that this resistance growth is due to the development of a surface layer on the LICGC membrane. However, this substantial increase in resistance can be mitigated by adding LiCl to the HCl solutions. For a pH 4 solution supported with 6.75 M LiCl, the impedance spectrum and surface morphology are qualitatively comparable to pristine, dry LICGC material, suggesting that surface layer formation was suppressed. This was also confirmed via cyclic voltammetry measurements in four-electrode electrochemical cells.
Psychiatric disorders are a source of significant comorbidity in patients with refractory epilepsy, yet are often underrecognized. We assessed the prevalence of DSM-IV Axis I psychiatric disorders using a short structured clinical interview (Mini-International Psychiatric Interview [MINI]) in patients with medically refractory complex partial seizures. Consecutive patients with refractory epilepsy being evaluated with video/EEG monitoring and imaging for seizure focus localization and lateralization underwent MINI evaluation to assess for the presence of psychiatric disorders. Among 117 patients (74 male, 43 female) studied, 57 (48.7%) had at least one psychiatric disorder; 19 (16.2%) had depression, 10 (8.5%) dysthymia, 27 (23.0%) anxiety disorder, and 11(9.4%) other disorders. Most clinical features and epilepsy-related variables had no significant association with psychiatric disorder on logistic regression analysis. Almost half of the patients with refractory focal seizures have a coexistent psychiatric disorder, and its presence or absence cannot be predicted by their clinical profiles. All patients should be assessed and treated for psychiatric comorbidity to improve overall quality of life.
Spinel lithium manganese oxide LiMn2O4 powders were synthesized by a flame-assisted spray technology (FAST) with a precursor solution consisting of stoichiometric amounts of LiNO3 and Mn(NO3)2·4H2O dissolved in methanol. The as-synthesized LiMn2O4 particles were non-agglomerated, and nanocrystalline. A small amount of Mn3O4was detected in the as-synthesized powder due to the decomposition of spinel LiMn2O4 at the high flame temperature. The impurity phase was removed with a post-annealing heat-treatment wherein the grain size of the annealed powder was 33nm. The charge/discharge curves of both powders matched the characteristic plateaus of spinel LiMn2O4 at 3V and 4V vs. Li. However, the annealed powder showed a higher initial discharge capacity of 115mAhg−1 at 4V. The test cell with annealed powder showed good rate capability between a voltage of 3.0 and 4.3V and a first cycle coulombic efficiency of 96%. The low coulombic efficiency from capacity fading may be due to oxygen defects in the annealed powder. The results suggest that FAST holds potential for rapid production of uniform cathode materials with low-cost nitrate precursors and minimal energy input.
Electrochemical properties of graphite electrode are studied in propylene carbonate (PC) electrolytes containing both LiN(SO2CF3)2 and Ca(N(SO2CF3)2)2 salts, and the influence of the salt concentrations on the intercalation/de-intercalation properties of graphite electrode is clarified. In the higher concentration electrolytes, reversible lithium-ion intercalation/de-intercalation at graphite electrode takes place. In contrast, only the exfoliation of graphite occurs in the lower concentration electrolytes. The effect of the salt concentrations on the electrochemical properties of graphite is discussed.
The electrochemical performances of solid oxide fuel cells with thin yttria-stabilized zirconia (YSZ) electrolytes and YSZ/Ni anodes were studied with two intergrowth oxides cathodes (Sr2.7La0.3Fe1.4Co0.6O7−δ and LaSr3Fe1.5Co1.5O10−δ) and the results compared to a related perovskite cathode (La0.6Sr0.4Co0.5Fe0.5O3−δ). It was found that cells produced with LaSr3Fe1.5Co1.5O10−δ exhibited peak power densities close to 0.75Wcm−2, despite the relatively modest electrical conductivity of this compound. In contrast, cells produced with Sr2.7La0.3Fe1.4Co0.6O7−δ and La0.6Sr0.4Co0.5Fe0.5O3−δ cathodes both exhibited peak power densities of less than 0.4Wcm−2. The greater performance for the cells produced with LaSr3Fe1.5Co1.5O10−δ may be attributed to a higher catalytic activity for this compound or to an improved adhesion of the cathode to the interlayer/electrolyte.
ABSTRACT Background Light-emitting diode, or LED, technology provides certain advantages over halogen-based light polymerization of resin-based composites. The authors investigated the adequacy of cure of LED light-curing units, or LCUs. Methods The authors used two halogen-based light-curing units (Optilux 400 and 501, Demetron Research Corp., Danbury, Conn.) and two commercially available LED LCUs (LumaCure, LumaLite, Spring Valley, Calif., and VersaLux, Centrix, Shelton, Conn.) to polymerize top surfaces of hybrid (Filtek Z-250, 3M, St. Paul, Minn.) and microfilled (Renamel, Cosmedent, Chicago) resin-based composite specimens. Specimens were indented on their top and bottom surfaces with a Knoop hardness tester and measured for hardness. Bottom:top hardness ratios determined the percentage of cure. The authors separated the data into eight groups (two composites cured with four different lights) with 15 observations per group, for a total sample size of 120. Results The authors compared composites and curing lights by a two-way analysis of variance, and results indicated significant main effects. The main effect of composite was statistically significant (P < .0001) when micro-filled composite was compared with hybrid composite, regardless of curing light, for all top and bottom hardness measurements, with the hybrid producing much higher hardness measurements overall. The main effect of light was significant as well (P < .0001), regardless of composite type, with the two halogen-based lights producing harder top and bottom composite surfaces than the two LED LCUs. Conclusions The light output of commercially available diodes for resin-based composite polymerization still requires improvement to rival the adequacy of cure of halogen-based LCUs. Additional studies are necessary. Clinical Implications Commercially available LED LCUs were introduced just in the past year. However, they may not adequately polymerize resin-based composites, which can lead to restoration failures and adverse pulpal responses to unpolymerized monomers.
During the past 20 years, lead acid batteries manufacturers have modified grid manufacturing processes and the chemical composition of the used alloys in order to decrease battery grid weight as well as to reduce the production costs, and to increase the battery life-time cycle and the corrosion resistance. The aim of this study was to evaluate the effects of cellular and dendritic microstructures of two different Pb–Sb alloys on the resultant corrosion behavior. A water-cooled unidirectional solidification system was used to obtain cellular and dendritic structures. Macrostructural and microstructural aspects along the casting have been characterized by optical microscopy and SEM techniques. Electrochemical impedance spectroscopy and potentiodynamic polarization curves were used to analyze the corrosion resistance of samples in a 0.5M H2SO4 solution at 25°C. For cellular microstructures the corrosion rate decreases with increasing cell spacing. In contrast, finer dendritic spacings exhibit better corrosion resistance than coarser ones. The microstructural pre-programming may be used as an alternative way to produce Pb alloy components in conventional casting, rolled-expanded, and continuous drum casting with better corrosion resistance.
Young's modulus for Li12Si7 was determined from nanoindentation testing. Young's modulus for Li12Si7 was 52.0±8.2GPa. This value is in excellent agreement with estimated values of Young's modulus calculated from predicted values of bulk modulus using density functional theory.
Supercapacitors, as a fresh class of electrochemical energy storage devices are currently of widespread interest in energy storage, which has become a research area due to outstanding performance features such as high lifetime, high power density, high safety, and low maintenance costs. In this study, we synthesize Co, Ni and Fe layered double hydroxides (NiCoFe–LDHs) on Nickel–foam as novel positive electrode and Fe2O3/Graphene as novel negative electrode for supercapacitve energy storage application. The electrochemical efficiencies of NiCoFe–LDHs have been explored and optimized by changing the amounts of Ni, Co and Fe via electrochemical method. The NiCoFe–LDH sample with Ni:Co:Fe ratio of 2:1:1 has the maximum specific capacity, that is related to the synergistic effect of the presence of Co, Ni and Fe which causes increased conductivity, increased oxidation rate of insulators such as Ni(OH)2, increases the formation rate of CoIV active sites and facilitates the penetration of OH−and therefore accelerates the kinetic of process. NiCoFe-LDHs nanocomposite shows a significant and high specific capacitance of 3130 Fg-1 at a density of current of 1 Ag-1. Furthermore, an asymmetric supercapacitor are created using NiCoFe-LDHs as the positive and the Fe2O3/Graphene as the negative electrode exhibits the maximum energy density of 101 Whkg−1and the power density of 91.5 KWkg−1, as well as a long-term cycling stability (82.5% capacity retention after 5000 cycles).
Sediments, mosses and algae, collected from lake catchments of the Larsemann Hills, East Antarctica, were analysed to establish baseline levels of trace metals (Ag, As, Cd, Co, Cr, Cu, Ni, Sb, Pb, Se, V and Zn), and to quantify the extent of trace metal pollution in the area. Both impacted and non-impacted sites were included in the study. Four different leaching solutions (1M MgCl2, 1M CH3COONH4, 1M NH4NO3, and 0.3N HCl) were tested on the fine fraction (<63μm) of the sediments to extract the mobile fraction of trace metals derived from human impact and from weathering of basement lithologies. Results of these tests indicate that dilute HCl partly dissolves primary minerals present in the sediment, thus leading to an overestimate of the mobile trace metal fraction. Concentrations of trace metals released using the other 3 procedures indicate negligible levels of anthropogenic contribution to the trace metal budget. Data derived from this study and a thorough characterisation of the site allowed the authors to define natural baseline levels of trace metals in sediments, mosses and algae, and their spatial variability across the area. The results show that, with a few notable exceptions, human activities at the research stations have contributed negligible levels (lower than natural variability) of trace metals to the Larsemann Hills ecosystem. This study further demonstrates that anthropogenic sources of trace metals can be correctly identified and quantified only if natural baselines, their variability, and processes controlling the mobility of trace metals in the ecosystem, have been fully characterised.
An investigation into the suitability of several carbon composites materials as substrates for the negative electrode in the zinc–cerium redox flow cell has been carried out. The zinc deposition process was carried out in a methanesulfonic acid electrolyte over the temperature range between 25°C and 60°C. Elevated temperatures increased the kinetics of the zinc deposition and dissolution reactions and also shifted the onset (nucleation) potential at more positive values. Galvanostatic charge/discharge cycles were performed in order to test the performance of these composite materials under a variety of operating conditions. For all the materials, the highest charge/discharge coulombic efficiencies (∼95%) were found at elevated temperatures. Yet, the voltage efficiencies were found to be higher at lower temperatures (viz. 25°C). Increased methanesulfonic acid concentrations promoted the hydrogen evolution reaction which in turn led to lower coulombic efficiencies. Three of the composite carbon materials tested (viz. PVE, PVDF, HDPE-1) were found to be robust with no surface deterioration or loss in efficiency observed over 250 cycles. Scanning electron microscopy revealed the formation of zinc clusters/grains on all the substrates tested whilst dendritic and granular growth was also present on some of the carbon samples.