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Spectroscopic Observations were made to study 42 emission line objects. The analysis of these long slit spectra shows that 15 out of 42 galaxies are blue compact galaxies (BCGs). 21 of them are starforming or HII galaxies and 3 were found to be normal galaxies.
We report on the results of CCD photometric observations of the open cluster NGC 2539. Eight new variable stars have been found in the observed field of this cluster. However, no γ Doradus-type variability was found among the member stars.
A time-series CCD photometric survey of variable stars in open clusters has been in progress using 1.8-m telescope at the Bohyunsan Optical Astronomy Observatory (BOAO) in Korea. We present preliminary results of time series photometry for the intermediate-age open cluster NGC 2301.
We have presented photometric results for two asteroids (895) Helio and (165) Loreley. The observations were performed from 2000 Oct. to 2001 Jan. using the 61cm telescope installed at Sobaeksan Optical Astronomy Observatory in Korea.
Aerobic exercise training has been shown to attenuate cognitive decline and reduce brain atrophy with advancing age. The extent to which resistance exercise training improves cognition and prevents brain atrophy is less known, and few studies include long-term follow-up cognitive and neuroimaging assessments. We report data from a randomized controlled trial of 155 older women, who engaged in 52 weeks of resistance training (either once- or twice-weekly) or balance-and-toning (twice-weekly). Executive functioning and memory were assessed at baseline, 1-year follow-up (i.e., immediately post-intervention), and 2-year follow-up. A subset underwent structural magnetic resonance imaging scans at those time points. At 2-year follow-up, both frequencies of resistance training promoted executive function compared to balance-and-toning (standardized difference [d]=.31–.48). Additionally, twice-weekly resistance training promoted memory (d=.45), reduced cortical white matter atrophy (d=.45), and increased peak muscle power (d=.27) at 2-year follow-up relative to balance-and-toning. These effects were independent of one another. These findings suggest resistance training may have a long-term impact on cognition and white matter volume in older women. (JINS, 2015, 21, 745–756)
In this study, we aim to trace formation of the primordial globular cluster, ultra faint dwarf galaxy, and ultra compact dwarf in a cosmological context of a high-resolution hydrodynamic zoom-in simulation. We show that the baryon-dominated systems have experienced more interactions with the mini halos before infalling to the main halo.
A radio-frequency magnetron sputtering technique and subsequent rapid thermal annealing (RTA) at 600, 700, 800, and 900 °C were implemented to grow high-quality Ga-doped MgxZn1-xO (GMZO) epi-layers. The GMZO films were deposited using a radio-frequency magnetron sputtering system and a 4 inch ZnO/MgO/Ga2O3 (75/20/5 wt %) target. The Hall results, X-ray diffraction (XRD), and transmittance were determined and are reported in this paper. The Hall results indicated that the increase in mobility was likely caused by the improved crystallization in the GMZO films after thermal annealing. The XRD results revealed that MgxZn1-xO (111) and MgO2 (200) peaks were obtained in the GMZO films. The absorption edges of the as-grown and annealed GMZO films shifted toward the short wavelength of 373 nm at a transmittance of 90%. According to these results, GMZO films are feasible for forming transparent contact layers for near-ultraviolet light-emitting diodes.
The electrode materials for VRFB should possess higher electric conductivity, corrosion resistance and hydrophilic properties in sulfuric acid. The characteristics of the electrode materials affect the stability and the energy efficiency of VRFB. Carbon materials are the best suited for VRFB applications. In this study, the calcined treatment, acid treatment and ozone treatment were used to modify the surface of carbon papers. The redox reaction of [VO]2+/[VO2]+ on the modified carbon papers was evaluated by cyclic voltammetry (CV). The surface compositions of carbon materials were analyzed by X-ray photoelectron spectrometry (XPS). The experimental results reveal that three oxidative methods enhance the redox reaction of [VO]2+/[VO2]+. The calcined treatments and acid treatments also enhanced hydrolysis reaction. The mole ratio of O/C apparently increased, but the binding energy of C1s and O1s were not chemically shifted in the acid treatment. The intensity of binding energy of O1s, between 532 eV and 534 eV, apparently increased in the ozone and calcined treatments. The Ox treated samples were more hydrophilic than the Oz treated samples. In the Ox treated samples, the decrease of Rct value indicates that was contributed from the redox reaction of [VO]2+/[VO2]+ and hydrolysis reaction. It does not completely benefit the energy efficiency of VRFB. The 5 x 5 cm2 modified carbon papers were used as electrode materials in the VRFB. The voltage efficiency, coulomb efficiency and energy efficiency reached 93 %, 90 % and 83 %, respectively, at a current density of 12 mA．cm-2 at 0.8-1.8 V.
The stability of the negative electrode electrolyte affects the efficiency and capacity of energy storage in the vanadium redox flow battery (VRFB) system. To explore the stability of vanadium electrolytes, the study prepared five types of V(II) electrolytes that were exposed to air in a fixed open area and monitored the charge state of vanadium ions over time by UV/Visible spectrophotometer. This study succeeded in preparing pure V(II) electrolytes. Five characteristics are found in the UV/Visible spectra, respectively, during the oxidation process from V(II) electrolytes to V(III) electrolytes and V(III) electrolytes to V(IV) electrolytes. The experimental results show that the oxidation rate of a solution of 1 M V(II) electrolytes to V(III) electrolytes and 1 M V(III) electrolytes to V(IV) electrolytes under an atmosphere of air is 4.79 and 0.0089 mol/h per square meter. The oxidation rates of 0.05-1 M V(II) electrolytes to V(III) electrolytes are approximately 96-538 times than that of V(III) electrolytes to V(IV) electrolytes.
In the USA, infant formulas contain long-chain PUFA arachidonic acid (ARA) and DHA in a ratio of 2:1 and comprise roughly 0·66 g/100 g and 0·33 g/100 g total fatty acids (FA). Higher levels of dietary DHA appear to provide some advantages in visual or cognitive performance. The present study evaluated the effect of physiologically high dietary ARA on growth, clinical chemistry, haematology and immune function when DHA is 1·0 g/100 g total FA. On day 3 of age, formula-reared (FR) piglets were matched for weight and assigned to one of six milk replacer formulas. Diets varied in the ratio of ARA:DHA as follows (g/100 g FA/FA): A1, 0·1/1·0; A2, 0·53/1·0; A3-D3, 0·69/1·0; A4, 1·1/1·0; D2, 0·67/0·62; D1, 0·66/0·33. A seventh group was maternal-reared (MR) and remained with the dam during the study. Blood collection and body weight measurements were performed weekly, and piglets were killed on day 28 of age. No significant differences were found among any of the FR groups for formula intake, growth, clinical chemistry, haematology or immune status measurements. A few differences in clinical chemistry, haematology and immune function parameters between the MR pigs and the FR groups probably reflected a difference in growth rate. We conclude that the dietary ARA level up to 1·0 g/100 g total FA is safe and has no adverse effect on any of the safety outcomes measured, and confirm that DHA has no adverse effect when ARA is at 0·66 g/100 g FA.
We report top-gate n channel μc-Si:H TFTs with saturated electron mobilities up to 40 cm2V−1s−1 and ON/OFF ratios up to ~106. The μc-Si:H was grown from silane, dichlorosilane, and hydrogen. The glow discharge was excited at a frequency of 80 MHz to raise the growth rate to ∼1Å/sec, which is above that achievable with 13.56 MHz. Deposition temperatures were 230°C for the i-layer and 280°C (the highest temperature in the process) for the n+ source and drain layers. The TFTs were fabricated from 340-nm thick μc-Si:H films, and with a 300-nm thick gate insulator of plasma deposited SiO2.
New hydrothermal technology for the preparation of hydroxyapatite designer particulates has been developed. Phase diagrams were constructed for the pH dependent equilibrium between monetite and HA from 50 to 200°C. Thermodynamic calculations were completed using temperature dependent functions for the relevant solution phase and solid-liquid equilibria and solute species activity coefficients. Model accuracy was evaluated through experiment at 50, 100, and 200°C and pHs between 2.2 and 8.9. The thermodynamic calculations and experimental results are in good agreement. Stoichiometric, crystalline HA has also been prepared by heterogeneous reaction of Ca(OH)2 powder and aqueous (NH4)2HPO4 at room temperature using mechanochemical-hydrothermal methods. This method appears to have very good reproducibility in terms of crystallinity and chemical composition.
The effects of atomic hydrogen (H) on formation of In(Ga)As quantum dots (QDs) by self-organizing process have been investigated. The low size fluctuation and uniform-shaped QDs are obtained at growth temperature above 450°C. The average size of InGaAs QDs are decreased from 40 nm to 20 nm by atomic H irradiation. The InGaAs QDs are formed uniformly on growth surface in with-H condition while preferentially formed and distributed along the step edges in without-H case. The photoluminescence (PL) peak intensities and full width at half maximum (FWHM) are also improved by atomic H irradiation. The waiting time before GaAs cap layer deposition is a important factor on the optical properties of QDs.
In performing compression-expansion-recompression process during preparation of diacetylene (DA) monolayer, the change in colour of polydiacetylene (PDA) LB films was observed and more ordered structure of the films was achieved. The effect on optical properties could be ascribed to better arrangement of DA monomer which favoured the formation of PDA films in blue-form in polymerization.
The electrical characteristics of thin gate dielectrics prepared by low temperature (850 °C) two-step N20 nitridation (LTN) process are presented. The gate oxides were grown by wet oxidation at 800 °C and then annealed in N2O at 850 °C. The oxide with N2O anneal, even for low temperature (850 °C), had nitrogen incorporation at oxide/silicon interface. The charge trapping phenomena and interface-state generation (ΔDitm) induced by constant current stressing were reduced and charge-to-breakdown (Qbd) under constant current stressing was increased. This LTN oxynitride was used as gate dielectric for N-channel MOSFET, whose hot-canrier immunity was shown improved and reverse short channel effect (RSCE) was suppressed.
Epitaxial magnetite (Fe3O4) thin films have been grown on MgO(001) substrates by pulsed laser deposition. The films have characteristics of the “Verwey transition”: the electric conductivity decreases by about one order of magnitude and the magnetization curve shows anomaly at the transition temperature, i.e. about 125 K. Effects of annealing the Fe3O4 thin films at various oxygen partial pressures have also been investigated. Phase identification was made using XRD techniques and infrared reflectivity measurements. The surface morphologies were studied by SEM and AFM. Under an oxidizing atmosphere, the Fe3O4 phase is transformed mainly into α-Fe2O3, and this transformation is accompanied by development of needle-like structures along <110> directions of MgO substrate. It is also found that electrical and magnetic properties of the iron oxide films are changed significantly by the annealing process.
In this work we demonstrate that in MOS devices the reliability of ultrathin (< 100Å) gate oxide is a strong function of growth conditions, such as, temperature and the growth rate. In addition, for constant current gate injection the degradation of SiO2 is enhanced as the thickness is reduced. We attribute this to physical stress in SiO2 resulting from the growth process. The degradation is always more for those growth conditions which result in higher physical stress in SiO2. Higher temperatures and slower oxidation rates allow stress relaxation through viscous flow and hence result in SiO2 of better reliability. We also found that for constant current stressing, the interface damage is more at the collecting electrode than at the injecting electrode. ΔDit (stress induced interface state generation) can be reduced after a high temperature Ar post anneal after the gate oxide growth.