• Transactions of Materials Processing
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• v.15 no.8 s.89
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• pp.581-585
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• 2006

Effects of V on both the formation of Ti-Nb-V carbonitrides and mechanical properties of Ti-Nb bearing low carbon HSLA steels were investigated. Hot rolling process was simulated by using Gleeble 3500 system with the steels containing three different levels of V ($0{\sim}0.1wt.%$). Vanadium precipitated as Ti-Nb-V carbonitrides at austenite region but it did not precipitate as VC during austenite to acicular ferrite or bainitic ferrite phase transformation. As V content increased, the amount of Nb precipitates was decreased but the average size of Ti-Nb-V carbonitrides was increased due to larger diffusivity of V than that of Nb. Coarsened Ti-Nb-V carbonitrides could act as heterogeneous nucleation site during ${\gamma}{\rightarrow}{\alpha}$ phase transformation, thus, acicular ferrite transformation was promoted as V content increased, resulting in increase of upper shelf energy.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2001.04b
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• pp.45-50
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• 2001

Stem firmness and flowering response of cut lily as influenced by medium composition (Control: Upland soil, Pt: Peatmoss, Pe: Perlite, Ve: Vermiculite, Rrh: Rotted rice-hull, RPt: Russian Peatmoss) were studied. For 'Casa Blanca', plant height and length of flower stalk increased when bulbs were planted in Pt:Rrh:Ve(1:1:1, v/v), and dried leaves of lower part plants decreased by RPt:Pe:Rrh(1:1:1, v/v). In case of 'Marco Polo' plant height and length of flower stalk increased with Pt:Rrh(1:1, v/v) as compared to other treatment, number of leaves and dried leaves increased when bulbs were planted in RPt:Pe:Rrh(1:1:1, v/v) as compared to control. Flowering of 'Casa Blanca' was promoted in Pt:Pe:Ve(1:1:1, v/v) and 'Marco Polo' was accelerated in Pt:Rrh:Ve(1:1:1, v/v). Flower length of 'Casa Blanca' was increased by RPt:Pe:Rrh(1 :1 :1, v/v) as compared with control and 'Marco Polo' was increased when bulbs planted to Pt:Rrh(1 :1, v/v). Flower-bud blasting of two cultivars was increased with Pt as compared with other treatment. Stem firmness of 'Casa Blanca' was increased by Pt:Pe:Ve (1:1 :1, v/v), and especially, stem firmness of upper part plants was increased by Pt:Rrh(1 :1, v/v) in 'Marco Polo' as compared to control plants. but generally, stem firmness of 'Casa Blanca' was not influenced with all cultural media as compared to control.

• Journal of Bio-Environment Control
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• v.10 no.2
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• pp.75-79
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• 2001

Stem firmness and flowering response of cut lily as influenced by medium composition (Control; Upland soil, Pt; Peatmoss, Pe; Perilite, Ve; Vermiculite, Rrh; Rotted rice-hull, RPt: Russian Peatmoss) were studied. For 'Casa Blanca', plant height and length of flower stalk increased when bulbs were planted in Pt:Rrh:Ve (1:1:1, v.v$^{-1}$ ), and dried leaves of lower part plants decreased in RPt:Pe:Rrh (1:1:1, v.v$^{-1}$ ). In case of 'Marco Polo', plant height and length of lower stalk increased in Pt:Rrh (1:1, v.v$^{-1}$ ) as compared to other treatment, number of leaves and dried leaves increased when bulbs were planted in RPt:Pe:Rrh (1:1:1, v.v$^{-1}$ ) as compared to the control. Flowering of 'Casa Blanca' increased in RPt:Pe:Rrh (1:1:1, v.v$^{-1}$ ) as compared to the control and that o 'Marco Polo' increased when bulbs planted in Pt:Rrh(1:1, v.v$^{-1}$ ). Flower-bud blasting of both cultivars increased with Pt as compared. Stem firmness of 'Casa Blanca' increased in Pt:Pe:Ve (1:1:1, v.v$^{-1}$ ), and especially stem firmness of upper part plant of 'Marco Polo' increased in Pt:Rrh (1:1, v.v$^{-1}$ ) as compared to the control. Generally, stem firmness of 'Casa Blanca' was not influenced by the culture medium.

• Economic and Environmental Geology
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• v.42 no.5
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• pp.487-494
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• 2009

The purpose of this study was to investigate the feasibility of As(V) reduction by aqueous Fe(II), and subsequent As(III) immobilization by the precipitation of As(III) incorporated magnetite-like material [i.e., co-precipitation of As(III) with Fe(II) and Fe(III)]. Experimental results showed that homogeneous As(V) reduction did not occur by dissolved Fe(II) at various pH values although the thermodynamic calculation was in favor of the redox reaction between As(V) and Fe(II) under the given chemical conditions. Similarly, no heterogeneous reduction of sorbed As(V) by sorbed Fe(II) was observed using synthetic iron (oxy)hydroxide (Goethite, ${\alpha}$-FeOOH) at pH 7. Experimental results for the effect of As(V) on the oxidation of Fe(II) by dissolved oxygen showed that As(V) inhibited the oxidation of Fe(II). These results indicate that As(V) could be stable in the presence of Fe(II) under the anoxic or subsurface environments.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.11a
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• pp.157-158
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• 2017

This tests examined bond stress-slip relationship of V-ties embedded into concrete as a supplementary lateral reinforcement proposed for ductility of concrete flexural members. The different leg shapes of V-ties were prepared as a test parameter. The V-tie with pressed end-legs exhibited 28% higher bond strength than the conventional V-ties, whereas bond stress-slip curves were insignificantly affected by the embedment length of V-ties.

• Journal of the Korean Chemical Society
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• v.17 no.6
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• pp.428-433
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• 1973

The quantitative separations of a mixture containing equal amount of each anion such as Si(IV), As(V), P(V), S(VI), W(VI) and Cr(VI) are carried out by the elution through 20${\times}3.14cm^2$ column of anion exchange resin, Dowex 1${\times}$8. The eluents are a mixture of 0.07 M hydrochloric acid and 0.03 M sodium chloride (pH = 1.30) for Si(IV), As(V) and P(V) species, a mixture of 0.6 M sodium chloride and 0.3 M sodium hydroxide for S(VI), W(VI) and Cr(VI) species, and 0.1 N sodium sulfite (pH = 3.48) for P(V) and As(V) species. The subsidiary anions in a standard mixture such as Si(IV), As(V), S(VI), P(V) and W(VI) are separated together from large amount of Fe(III) by the elution through 30cm${\times}3.14cm^2$ column of the resin, Dowex${\times}$50w${\times}$12, using a mixture of 0.1 M sodium nitrate and 2 percent dimethylsulfoxide aqueous solution as an eluent. Si(IV), As(V), S(VI), P(V) and W(VI) eluted together are separated quantitatively under the same conditions as in the separations of the anion mixture. By the conditions obtained in the separations of the standard mixture, Fe(III) and all of the subsidiary anions in steel are quantitatively separated.

• Electrical & Electronic Materials
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• v.10 no.7
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• pp.692-699
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• 1997

The silicon doped $Al_{0.33}$G $a_{0.67}$As were grown by molecular beam epitaxy. The electroreflectance(ER) spectra of Schottky barrier Au/n-Al/suu x/G $a_{1-x}$ As have been measured at various modulation voltage( $V_{ac}$ ) and dc bias voltage( $V_{bias}$). From the observed Franz-Keldysh oscillations(FKO) peak, the band gap energy of the $Al_{x}$G $a_{1-x}$ As is 1.91 eV which corresponds to an Al composition of 33%. The internal electric field( $E_{i}$)of this sample is 2.96$\times$10$^{5}$ V/cm. As the modulation voltage( $V_{ac}$ ) is changed, the line shape of ER signal does not change but its amplitude varies linearly. The amplitude as a function of modulation voltage has saturated at 0.8 V. The internal electric field has decreased from 6.47$\times$10$^{5}$ V/cm to 2.00$\times$10$^{5}$ V/cm as the dc bias voltage( $V_{bias}$) increases from -3.5 V to +0.8 V. The values of built-in voltage( $V_{bi}$ ) and carrier concentration(N) determined from the plot of $V_{bias}$ from the plot of $V_{bias}$ versus $E_{i}$$^{2}$ are 0.855 V and 3.83$\times$10$^{17}$ c $m^{-3}$ , respectively.ively.y.y.y.

• Electrical & Electronic Materials
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• v.7 no.5
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• pp.383-388
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• 1994

Deep levels in semi-insulating GaAs were observed by thermally stimulated current(TSC) measurement In the temperature ranges of 100-300K Tl(E$\_$c/-0.18eV), T2(E$\_$c/-0.20eV), T3(E$\_$c/-0.31eV), T4(E$\_$c/-0.40eV), and T5(E$\_$c/-O.43eV) traps have been observed. The TI, T2, and T5 traps seem to be related to the V$\_$As/, V$\_$Ga/-complex, and As$\_$Ga/$\^$++/ respectively. T4 trap is considered with respect to V$\_$Ga/-V$\_$As/ complex.

• Microbiology and Biotechnology Letters
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• v.42 no.3
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• pp.238-248
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• 2014

The metalloid arsenic (Z = 33) is considered to be a significant potential threat to human health due to its ubiquity and toxicity, even in rural regions. In this study a rural region contaminated with arsenic, located at longitude $85^{\circ}$ 32'E and latitude $25^{\circ}$ 11'N, was initially examined. Arsenic tolerant bacteria from the rhizosphere of Amaranthas viridis were found and identified as Bacillus licheniformis through 16S rRNA gene sequencing. The potential for the uptake and removal of arsenic at 3, 6 and 9 mM [As(V)], and 2, 4 and 6 mM [As(III)], and for the reduction of the above concentrations of As(V) to As(III) by the Bacillus licheniformis were then assessed. The minimal inhibitory concentrations (MIC) for As(V) and As(III) was determined to be 10 and 7 mM, respectively. At 3 mM 100% As(V) was uptaken by the bacteria with the liberation of 42% As(III) into the medium, whereas at 6 mM As(V), 76% AS(V) was removed from the media and 56% was reduced to As(III). At 2 mM As(III), the bacteria consumed 100%, whereas at 6 mM, the As(III) consumption was only 40%. The role of pH was significant for the speciation, availability and toxicity of the arsenic, which was measured as the variation in growth, uptake and content of cell protein. Both As(V) and As(III) were most toxic at around a neutral pH, whereas both acidic and basic pH favored growth, but at variable levels. Contrary to many reports, the total cell protein content in the bacteria was enhanced by both As(V) and As(III) stress.

• Journal of the Korea Organic Resources Recycling Association
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• v.23 no.4
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• pp.52-62
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• 2015

This study estimated the contribution rates of inlet air flow, moisture content, air-filled porosity and particle size on the total pressure drop for the sawdust used as the bulking agent in the composting. The statistical model for pressure drop including the affecting factors was proposed.($R^2=0.998{\sim}0.950$) While the laminar air flow(v) and particle size(SIZE*v) had the positive relations to the total pressure drop, the turbulent air flow($v^2$), moisture content(MC*v) and air-filled porosity(AFP*v) had the negative relations. Total pressure drop sharply increased with increasing of the inlet air flow. And the most significant factors affecting to total pressure drop were the particle size(SIZE*v) as positive factor and air-filled porosity(AFP*v) as negative factor. The contribution rate to total pressure drop by the particle size(SIZE*v) was continuously increased with increasing of the inlet air flow, but the contribution rate by air-filled porosity(AFP*v) was decreased. And total pressure drop was little changed even though the increasing of moisture content above the range of dry moisture content 0.25. The contribution rates of affecting factors had the different tendencies with increasing of the moisture content, especially in the negative factors as air-filled porosity(AFP*v) and moisture content(MC*v). For effective composting process, it is preferable to select the sawdust with higher air-filled porosity as bulking agent to enhance the air permeability.