• Korean Journal of Materials Research
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• v.23 no.12
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• pp.714-721
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• 2013

A stoichiometric mixture of evaporating materials for $ZnAl_2Se_4$ single-crystal thin films was prepared in a horizontal electric furnace. These $ZnAl_2Se_4$ polycrystals had a defect chalcopyrite structure, and its lattice constants were $a_0=5.5563{\AA}$ and $c_0=10.8897{\AA}$.To obtain a single-crystal thin film, mixed $ZnAl_2Se_4$ crystal was deposited on the thoroughly etched semi-insulating GaAs(100) substrate by a hot wall epitaxy (HWE) system. The source and the substrate temperatures were $620^{\circ}C$ and $400^{\circ}C$, respectively. The crystalline structure of the single-crystal thin film was investigated by using a double crystal X-ray rocking curve and X-ray diffraction ${\omega}-2{\theta}$ scans. The carrier density and mobility of the $ZnAl_2Se_4$ single-crystal thin film were $8.23{\times}10^{16}cm^{-3}$ and $287m^2/vs$ at 293 K, respectively. To identify the band gap energy, the optical absorption spectra of the $ZnAl_2Se_4$ single-crystal thin film was investigated in the temperature region of 10-293 K. The temperature dependence of the direct optical energy gap is well presented by Varshni's relation: $E_g(T)=E_g(0)-({\alpha}T^2/T+{\beta})$. The constants of Varshni's equation had the values of $E_g(0)=3.5269eV$, ${\alpha}=2.03{\times}10^{-3}eV/K$ and ${\beta}=501.9K$ for the $ZnAl_2Se_4$ single-crystal thin film. The crystal field and the spin-orbit splitting energies for the valence band of the $ZnAl_2Se_4$ were estimated to be 109.5 meV and 124.6 meV, respectively, by means of the photocurrent spectra and the Hopfield quasicubic model. These results indicate that splitting of the ${\Delta}so$ definitely exists in the ${\Gamma}_5$ states of the valence band of the $ZnAl_2Se_4/GaAs$ epilayer. The three photocurrent peaks observed at 10 K are ascribed to the $A_1$-, $B_1$-exciton for n = 1 and $C_{21}$-exciton peaks for n = 21.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.2
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• pp.105-107
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• 2005

A field study was conducted to investigate and ascertain the effects of boron and molybdenum with recommended N P K S Zn fertilizers (RFD) for sustained sugarcane yield in the sandy acidic soil in Old Himalayan Piedmont Plain of Bangladesh. Results revealed that the treatment $T_7$ having recommended fertilizers of N 120, P 35, K 100, S 25 and Zn 2kg $ha^{-1}$ + B 2kg $ha^{-1}$ + Mo 2 kg $ha^{-1}$ produced significantly higher number of millable cane (126.96\times10^3\;ha^{-1})$ except in $T_9$ with RFD + B 2 kg $ha^{-1}$ + Mo 4kg $ha^{-1}$, and higher cane yield (92.83 Mg $ha^{-1}$) among all except in $T_3$ with RFD + B2 kg $ha^{-1}$, $T_5$ with RFD + Mo 2kg $ha^{-1}$ and $T_9$ where the effects were statistically identical. The increase in cane yield by $T_7$ was $164.6\%$ over control. The treatment $T_7$ having RFD + B 2kg $ha^{-1}$ + Mo 2kg $ha^{-1}$ further gave the highest additional net economic benefit of Taka 16, 500.00 for added Band Mo at 2kg $ha^{-1}$ among all the treatments in the study.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.1
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• pp.46-52
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• 2004

Hisardale male lambs (n=24, 4-5 month of age) were maintained on a conventional ration for a month, to equilibrate the body mineral status. Six lambs were sacrificed after one month of feeding; the samples of organs were analyzed to ascertain mineral status. The remaining 18 lambs were divided into 3 groups of 6 each on body weight basis. Three dietary treatments containing 100 ($T_1$), 110 ($T_2$) and 120% ($T_3$) of minerals (Ca, P, S, Zn and Mn) as specified by NRC (1985) were formulated and each treatment was alloted ad libitum to a group for 120 days. Blood and wool samples were collected at monthly intervals. At the end of the experiment a balance trial of 5 days duration was conducted to study the balance of mineral elements. The effective intake of minerals was Ca, 111 and 120, P, 110 and 122; S, 112 and 129; Zn, 112 and 126 and Mn, 109 and 123 percent in $T_2$ and $T_3$, respectively, in comparison to $T_1$ (100). The additional mineral supplementation had no significant effect on dry matter intake. The average daily weight gain was higher (p<0.01) in $T_2$ and $T_3$ than the control ($T_1$). The lambs under treatments $T_2$ (8.72) and $T_3$ (8.47 kg) consumed apparently lesser amount of dry matter per unit gain as compared to $T_1$ (10.81 kg). Significantly higher (p<0.05) dry matter and crude protein digestibility (%) were observed in $T_2$ and $T_3$ than in $T_1$. The mean balances for different elements were Ca, 1.14, 1.68 and 1.67 g; P, 1.70, 1.95 and 2.18 g; S, 0.54, 0.92 and 1.11 g; Zn, 22.56, 25.30 and 28.71 mg; Cu, 7.94, 5.71 and 5.53 mg; Fe, 33.19, 32.94 and 31.03 mg and Mn, 8.24, 14.40 and 16.07 mg/lamb/day. The retention of supplemental minerals increased (p<0.01) while that of Cu decreased (p<0.01) due to supplementation of minerals (Ca, P, S, Zn and Mn). Retention as per cent of intake increased statistically for S and Mn while that of Cu decreased. It can be concluded that supplementation of minerals (Ca, P, S, Zn and Mn) higher than the recommended level improved body weight gain and feed to gain ratio. The retention of minerals increased due to supplementation. Therefore, an additional supplementation of deficient minerals (Ca, P, S, Zn and Mn) by 10% was beneficial for Hisardale male lambs under tropical condition in India.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.167-170
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• 2000

Proteolytic hydrolysis is one of the main enzymatic reaction of waste activated sludge (WAS) digestion. Pretense excreted from Bacillus stearothermophilus (ATCC 31197) showed optimum temperature of $75^{\circ}C$ for maxium heat stable proteolytic activity against azo casein. The dependency of $Ca^{2+}$, $Zn^{2+}$ on heat stability of proteolytic enzymes were measured with various concentrations. It was shown that $Ca^{2+}$ ion enhanced heat stability of these enzymes. Then thermophilic aerobic digestion (TAD) was performed using B. sterothermophilus with the addition of divalent ions. Performance of TAD process with ATCC 31197 activated by $Ca^{2+}$, $Zn^{2+}$ions in terms of dissolved organic carbon (DOC) concentration, extracellular protein concentration, and scanning electrion microscopy (SEM) analysis. The best result of protein reduction concentration in digestion test was obtained with the addition of 2 mM $Ca^{2+}$ ion.

• Journal of the Korean Chemical Society
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• v.11 no.4
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• pp.165-169
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• 1967

Eine neue Methode zur Herstellung von Meßpraparation wird die Bestimmng der Spurenelemente Quecksilber, Kupfer, Blei, Zink, Nickel, Kobalt und Eisen durch Rontgenflureszenzspektrometrie entwickelt. Die Spurenelemente werden aus waßrigen Losungen durch Einleitung von Schwefelwasserstoff mit Aluminiumsulfat als Trager bei pH8 ausgefallt. Die Niederschlage der Metallsulfide werden uber Membranfilter filtriert, mit Gelatine fixiert und ihre Absolutmengen durch Rontgenfluoreszenz analyse bestimmt. Bei der geringen Dicke der auszumessenden Schichten treten Matrixeffekte nicht auf. Durch den Zusatz von Aluminiumsulfat-Trager wird eine gute Reproduzierbarkeit erzielt: Quecksilber, Kupfer, Blei, Zink, Nickel und Kobalt werden bei einer Konzentration von 50 bis 1000 p.p.b. mit einer relativen Standard-abweichung von 5.0% und Eisen bei einer Konzentration von 50∼1000 p.p.d. mit einer relativen Standardabweichung von 6.1% gemessen.

• Journal of the Korean Chemical Society
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• v.13 no.1
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• pp.45-48
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• 1969

Spuren von Blei und Zink werden aus großen Wassermengen mit benzolischer Dithizonlosung in einer Pulsationskolonne durch kontinuirliche Flussig-Elussig-Extraktion angereichert. Nach der Extraktion wird das Benzoly-peroxid oxydiert und die Spurenelemente durch verdunnte Salzsaure zuruckextrahiert. Die angereicherten Metalle werden durch Einleiten von Schwefelwasserstoff aus der Losung bei pH 8 unter Zusatz von Aluminium Trager ausgefallt. Die Niederschlage der Metallsufide werden durch Membranfilter filtriert, mit Gelatine fixiert und ihre Absolutmengen durch Rontgenfluoreszenzanalyse bestimmt. Blei wird bei einer Konzentration von 2.5 bis 100 p.p.b. mit einer relativen Standardabwechung von 9.0% und Zink bei einer Konzentration von 2.5-100 p.p.b. mit einer relativen Standardabwechung von 10.3% gemesssen.

• Journal of the Korean Vacuum Society
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• v.19 no.4
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• pp.275-280
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• 2010

The influence of $O_2$-plasma treatment on $H_2$ post-treated BZO (ZnO:B) thin film using MOCVD (Metal-Organic Chemical Vapor Deposition) are investigated. An $O_2$-plasma treatment of the $H_2$ post-treated BZO thin films resulted in XRD peak of (100), (101) and (110). Also, electrical properties resulted in an increase in sheet resistance and work function. The weighted optical transmittance and haze at 300~1,100 nm of BZO thin films with $O_2$-plasma treatment on the $H_2$ post-treatment show approximately 86% and 15%, respectively.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.543-543
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• 2013

Thin-film transistors (TFTs) based on oxide semiconductors have been regarded as promising alternatives for conventional amorphous and polycrystalline silicon TFTs. Oxide TFTs have several advantages, such as low temperature processing, transparency and high field-effect mobility. Lots of oxide semiconductors for example ZnO, SnO2, In2O3, InZnO, ZnSnO, and InGaZnO etc. have been researched. Particularly, zinc-tin oxide (ZTO) is suitable for channel layer of oxide TFTs having a high mobility that Sn in ZTO can improve the carrier transport by overlapping orbital. However, some issues related to the ZTO TFT electrical performance still remain to be resolved, such as obtaining good electrical contact between source/drain (S/D) electrodes and active channel layer. In this study, the bottom-gate type ZTO TFTs with staggered structure were prepared. Thin films of ZTO (40 nm thick) were deposited by DC magnetron sputtering and performed at room temperature in an Ar atmosphere with an oxygen partial pressure of 10%. After annealing the thin films of ZTO at $400^{\circ}C$ or an hour, Cu, Mo, ITO and Ti electrodes were used for the S/D electrodes. Cu, Mo, ITO and Ti (200 nm thick) were also deposited by DC magnetron sputtering at room temperature. The channel layer and S/D electrodes were defined using a lift-off process which resulted in a fixed width W of 100 ${\mu}m$ and channel length L varied from 10 to 50 ${\mu}m$. The TFT source/drain series resistance, the intrinsic mobility (${\mu}i$), and intrinsic threshold voltage (Vi) were extracted by transmission line method (TLM) using a series of TFTs with different channel lengths. And the performances of ZTO TFTs were measured by using HP 4145B semiconductor analyzer. The results showed that the Cu S/D electrodes had a high intrinsic field effect mobility and a low effective contact resistance compared to other electrodes such as Mo, ITO and Ti.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.289.1-289.1
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• 2014

In this study, we made a organic thin film device in MIS(Metal-Insulator-Semiconductor) structure by using PVP (Poly vinyl phenol) as a insulating layer, and CdSe/ZnS nano particles which have a core/shell structure inside. We dissolved PVP and PMF in PGMEA, organic solvent, then formed a thin film through a spin coating. After that, it was cross-linked by annealing for 1 hour in a vacuum oven at $185^{\circ}C$. We operated FTIR measurement to check this, and discovered the amount of absorption reduced in the wave-length region near 3400 cm-1, so could observe decrease of -OH. Boonton7200 was used to measure a C-V relationship to confirm a properties of the nano particles, and as a result, the width of the memory window increased when device including nano particles. Additionally, we used HP4145B in order to make sure the electrical characteristics of the organic thin film device and analyzed a conduction mechanism of the device by measuring I-V relationship. When the voltage was low, FNT occurred chiefly, but as the voltage increased, Schottky Emission occurred mainly. We synthesized CdSe/ZnS and to confirm this, took a picture of Si substrate including nano particles with SEM. Spherical quantum dots were properly made. Due to this study, we realized there is high possibility of application of next generation memory device using organic thin film device and nano particles, and we expect more researches about this issue would be done.

• Transactions of Materials Processing
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• v.23 no.6
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• pp.386-391
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• 2014

In the current study, Al-Mn-Zn alloys are strip-cast and used as the base alloy for the core of aluminum clad sheets used in automotive condenser fins. Transition elements such as Cu and Cr are added to the base core alloy in order to improve the properties of the clad sheets. The AA4343/Al-Mn-Zn-X(X: Cu, Cr)/AA4343 clad sheets are fabricated by roll bonding and further cold-rolled to a thickness of 0.08 mm. Clad sheets were intermediately annealed during cold rolling at $450^{\circ}C$ in order to obtain 40% reduction at the final thickness. Tensile strength and sag resistance of the clad sheets are improved by Cu additions to the core alloy, while corrosion resistance is also increased. Cr-additions to the clad sheets enhance sag resistance and provide low enough corrosion, although tensile strength is not improved. The effect of Cu and Cr additions on the properties of the clad sheets is elucidated by microstructural analysis.