• Journal of Aquaculture
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• v.10 no.1
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• pp.55-61
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• 1997

The experiment was conducted to understand the effect of HCG upon ovulation induction and egg maturation in the sevenband grouper, Epinephelus septemfasciatus, as a part of the research for its resources management and seed production. Three different size groups of sevenband groupers showing 300~400g, 1,500~2,000g and 2,500~4,000g, were collected from June to August, 1996. They were treated two or three times with HCG (500~1,000 IU/kg). Gonadal development of the sevenband groupers were examined using the paraffin section method and then stained with haematoxylin and eosin. When smaller groups of sevenband grouper having 300~400g, 1,500~2,00g and 2,500~3,200g in weight were treated two or three time with HCG 9500~1,000 IU/g), their gonads contained oogonia, oocytes with the size of 20~30${\mu}{\textrm}{m}$, and stroma tissues. However, in case of two HCG treatments with a dosage of 1,000 IU/kg on sevenband groupers of 3,400~4,000g, both healthy eggs of $800\mu$m in diameter and regressing eggs were ovulated. A sevenband grouper of 4,000g obvulated 4,252 eggs in total. Of these, healthy and regressing eggs turned out to be 20.8% and 79.2%, respectively. In addition, previtellogenic oocytes of around $50\mu$m, oocytes of 20~$30\mu$m, and ovulation trace were also observed in the gonad.

• The Journal of Fisheries Business Administration
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• v.35 no.1
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• pp.23-56
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• 2004

The offshore trawl fishery is seeking its survival way to overcome current management conditions in red, resulted from the bilateral agreement with China and Japan. However, this movement magnifies conflicts between fisheries on the contrary and it is thought to be impossible to get over current situations. For all that, this study is aimed at investigating how this current situations have occurred. The management freedom as response to the change in fishing conditions of a certain fishery, in case of Korea, is affected by institutional regulations. The example of this is controls on fishing gears, fishing vessels, and fishing grounds. The most exposure of this control is a segmentation of institutional fisheries. The initial segmentation of the offshore trawl fishery in Korea was occurred in the period of Japan's colonization when the degree of use of fishing grounds was limited geographically. At that time, fisheries were divided by fishing areas, but it did not divide the fishery itself. The large - sized fishing vessels were developed politically to be more competative to Japanese fishing vessels since 1950s. During this time, the trawl fishery was merged into current Eastern trawl fishery and South - Western trawl fishery. It was also inevitable to divide into the pair trawl and single trawl fishery as a result of the physical mergency between Western trawl and Southern trawl fishery. In order to develop the trawl fishery, new licenses were issued on the shrimp trawl fishery, through which it was expected to boost the trawl fishery. As opposed, the shrimp trawl fishery was changed into the mid - sized trawl fishery, targeting on the eastern fishing areas and the large - sized trawl fishery was developed since the late of 1970s with the development of filefish processing industry. The large trawl fishery that led in development of offshore trawl fishery since the late of 1950s was started to divide into a pair trawl and single trawl according to the fishing method and capital power. It finally became an institutionally independent fishery in 1980s, respectively. Looking into these historical process, the segmentation of the trawl fishery is thought as a result of the lack of long - term perspective and as a production of trial and error resulted by unprepared policy. As a result, these segmentation of fisheries roles as critical obstacles in harmonization of fisheries and in overcoming of current situations. Therefore, the review of this institutional segmentation of the offshore trawl fishery should be taken for an optimal redistribution of fishing grounds suits with business and fishing technology. For this, the fishery must be divided into large capitalized fishery and small - mid fishery with consideration of capital, fishing method, and the condition of use of fishing grounds. In addition to this, by limiting outline of fishing ground that the large fishery can harvest, it must allow for the small - mid fishery to catch with its own boundary. Furthermore, by launching buyback programs on the trawl, eastern trawl, pair trawl, it can provide broader fishing grounds where the fishery can harvest with management freedom.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.1
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• pp.68-74
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• 2010

Since ${NO_3}^-$ is amore favorable electron acceptor than Fe, high ${NO_3}^-$ loads function as a redox buffer limiting the reduction of Fe and following release of ${PO_4}^{3-}$ in flooded paddy soil. The effect ${NO_3}^-$ loaded through irrigation water on Fe reduction and ${PO_4}^{3-}$ release in paddy soil was investigated. Pot experiment was conducted where irrigation water containing 5 or 10 mg N $L^{-1}$ of ${NO_3}^-$ was continuously applied at 1 cm $day^{-1}$, and changes of ${NO_3}^-$, $Fe^{2+}$ and ${PO_4}^{3-}$ concentrations in soil solution at 5 and 10 cm depths beneath the soil surface were monitored as a function of time. Irrigation of rice paddy with water containing 5 mg N $L^{-1}$ of ${NO_3}^-$ led to reduced release of $Fe^{2+}$ and prevented solubilization of P at 5 cm depth beneath the soil surface. And application of irrigation water containing 10 mg N $L^{-1}$ of ${NO_3}^-$ could further suppress Fe reduction and solubilization of P through 10 cm depth soil layer beneath the surface. These results suggest that the introduction of high level ${NO_3}^-$ with irrigation water in rice paddy can strongly limit Fe reduction and P solubilization in root zone soil layer in addition to the excessive supply of N to rice plants.

• Proceedings of the Korea Crystallographic Association Conference
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• 1999.04a
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• pp.1-1
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• 1999

부유대용융법에 의하여 불순이온의 종류와 각 이온의 주입 농도를 달리하는 Rutile 단결정을 성장하였다. 성장된 결정으로부터 제조한 박편시료를 이용하여 결정결함과 광투과도에 미치는 각 불순이온의 영향을 조사하였다. 결정성장용 주원료로 99.99%의 TiO2를 사용하고, 불순이온 주입을 위한 원료로서 99.99%의 Al2O3, H3BO3, Ga2O3, Sc2O3, V2O5, Fe2O3, ZrO2, Er2O3, Cr2O3를 각각 사용하였다. 불순이온의 종류에 따르는 영향을 조사하기 위하여 TiO2 99.8 atomic%-불순이온 0.2atomic%의 조성이 되도록 각 이온별로 원료를 정밀하게 평량하고 균일 혼합하였다. 불순 이온의 첨가량에 따르는 영향을 조사하기 위하여 Al2O3는 각각 pure, 0.2, 0.4, 0.6 atomic%를, Cr2O3는 pure, 0.003, 0.05, 0.2 atomic%를 각각 치환하여 원료를 조합하였다. 균일 혼합된 원료를 직경 8mm의 고무 튜브에 넣고 CIP(Cold Isostatic Press0에서 2000kg/$\textrm{cm}^2$의 압력으로 성형한 후 150$0^{\circ}C$에서 1시간 소결함으로서 결정성장용 다결정 원료를 합성하였다. 합성된 다결정을 double ellipsoidal mirror 내에 설치하고,halogen lamp로 가열하여 원료의 한쪽 끝을 용융한 다음, 20rpm의 회전속도, 3-5mm/hr의 성장속도로 하는 유속 1$\ell$/min의 O2 분위기속에서 부유대용융법에 의하여 결정을 성장하였다. 성장된 결정을 성장축에 수직한 방향으로 각각 절단, 연삭, 연마한 박편을 이용하여 편광하에서 low-angle grain boundaries 및 기타의 결정결함을 관찰하였으며, 0.3$\mu\textrm{m}$~0.8$\mu\textrm{m}$ 범위 및 0.6$\mu\textrm{m}$~3.4$\mu\textrm{m}$ 범위에서의 투과 및 흡수 스펙트럼을 측정하였다. 결정 성장 결과 B3+, Er3+, Cr3+ 이온은 Ti4+ 이온과 이온의 크기 차이가 심하여 결정의 정상적인 성장을 방해하는 물성을 나타냈고, V5+, Cr3+ 이온은 흑색의 결정, Fe3+ 이온은 적갈색의 결정으로 성장되었다. Al3+, Zr4+, Al3+의 순서로 투과도가 높아지는 것이 관찰되었다. 불순이온의 농도에 따른 영향으로서 Al3+ 이온의 경우 주입농도가 높아질수록 low angle boundary와 oxygen deficiency가 감소하였고, 투과율은 조금 감소하거나 큰 차이가 없는 것으로 나타났다. 반면에 Cr3+ 이온을 주입한 경우 0.003 atomic%에서 최적의 물성을 보였으며, 주입농도가 높아질수록 결정성장이 어려워지고 광의 투과도가 급격히 저하되었다.

• Journal of the Korean Magnetics Society
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• v.10 no.4
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• pp.165-170
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• 2000

The purpose of this study is to investigate the effect of annealing conditions on physical and magnetic properties of Fe-Hf-N thin films. When the thin films were annealed in $N_2$ gas, a surface oxide layer, comprised of Fe$_2$O$_3$ and Fe$_3$O$_4$, was formed at the surface of the thin films and a Fe-Hf-O-N layer was also formed under this surface oxide layer. It was found that the thicknesses of the surface oxide layer and the Fe-Hf-O-N layer increased, as the annealing temperature increased. It was also found that if the thickness of the surface oxide layer was excluded in the property calculation, the soft magnetic properties of the annealed thin films were not much different from those of the as-deposited thin films. Therefore, it was suggested that the Fe-Hf-O-N layer formed under the surface oxide layer did not lose significantly the soft magnetic properties of the Fe-Hf-N films and the Fe-Hf-N films annealed in $N_2$gas showed the soft magnetic properties of the Fe-Hf-N and Fe-Hf-O-N multi-layers.

• Korean Journal of Food Science and Technology
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• v.37 no.4
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• pp.567-573
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• 2005

Compatability of films made of chitosan, gelatin, and their blends prepared by aqueous solution casting was investigated using a thermogravimetric analyzer(TGA) and a dynamic mechanical analyzer (DMA). TGA showed gelatin is more thermally stable than chitosan, and thermal stability of chitosan in blends was higher than that of pure chitosan due to interaction among functional groups of component polymers in blend. Glass transition temperature $(T_g)$ of blends was dependent on chitosan content of blends. Blend films exhibited good miscibility. Moisture and glycerol contents of blend strongly affected thermal properties of two component polymers.

• Journal of the Microelectronics and Packaging Society
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• v.9 no.4
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• pp.11-16
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• 2002

In this study, the dry etching characteristics of $SrBi_2Ta_2O_9$ (SBT) thin films were investigated by using ICP-RIE (inductively coupled plasma-reactive ion etching). The etching damage and degradation were analyzed with XPS (X-ray photoelectron spectroscopy) and C-V (Capacitance-Voltage) measurement. The etching rate increased with increasing the ICP power and the capacitively coupled plasma (CCP) power. The etch rate of 900$\AA$/min was obtained with 700 W of ICP power and 200 W of CCP power. The main problem of dry etching is the degradation of the ferroelectric material. The damage-free etching characteristics were obtained with the $Ar/C1_2/CHF_3$ gas mixture of 20/14/2 when the ICP power and CCP power were biased at 700 W and 200 W, respectively. The experimental results show that the dry etching process with ICP-RIE is applicable to the fabrication of the single transistor type ferroelectric memory device.

• Journal of Navigation and Port Research
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• v.39 no.4
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• pp.277-283
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• 2015

MS(Mild Steel), HTS(High Tensile Steel), HYS(High Yield Steel), AL(Aluminum Alloy) and Composite Materials are used for vessels. Steel Materials are mostly used for vessels because body of a ship have to perform the basic functions such as watertight, preserving the strength and supporting the equipments. The vessels primarily carry out a mission at ocean, so that body of a ship is necessarily rusted. There are several methods to protect the corrosion of vessels such as painting, SACP(sacrificial anode cathodic protection) and ICCP(impressed current cathodic protection). For the sacrificial anode cathodic protection, Al and Zn alloys are normally used. Heavy metals are added to the Al and Zn Alloys for improving the corrosion properties but they are so harmful to the human and environment. Therefore, the use of these heavy metals is strictly regulated in the world. In this paper, Al and Zn Alloys are made by adding the trace elements(Ma, Ca, Ce and Sn) which is not harmful to the human and environment. SEM, XRD, Potentiodynamic Polarization test and Current Efficiency test are conducted for evaluation of Al and Zn Alloys. As a result of the experiment, Al-3Zn-0.6Sn and Zn-3Sn Alloys are more efficient than other Alloys.

• Korean Journal of Organic Agriculture
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• v.19 no.3
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• pp.343-355
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• 2011

This work was studied the effects of spore density and infection of arbuscular mycorrhizal fungi (AMF) for no-tillage organic cultivation of pepper with wintering green manure crops cultivation in greenhouse field. Spore density of arbuscular mycorrhizal fungi (AMF) in green manure crops was 189 spores/30g fresh soils in control including alive spore (82 spores). Spore density of AMF in all green manure crops was totally 196~226 spores/30g fresh soil and alive spore was 84~112 spores/30g fresh soil. Spore density of AMF in soils of Pepper crop was range of 48.0~56.7 spores/30g fresh soils after cultivation of green manure crops. Infection structure of AMF was not significantly difference in soils of green manure crops and Pepper crop after cultivation of green manure crops. Infection rate of AMF in roots of green crops was low level by 2.8% in giant chickweed, 7.4% in rye, 9.3% in hairy vetch. Infection rate of AMF in roots of barley was the highest level by 20.3%. Infection rate of AMF in roots of Pepper crop was range of 5.2~7.2% after cultivation of green manure crops Also, infection rate of AMF in roots of Pepper crop was 8.1% after the harvest of barley. Infection structure of AMF in barley very well consisted of network with internal hyphae, while hairy vetch and rye tended to no network. There was not a significant relationship between spore density in soils and infection rate of AMF in rhizosphere of Pepper.

• Food Engineering Progress
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• v.14 no.3
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• pp.249-255
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• 2010

Ten commercial activated carbons (ACs) prepared from four different sources (bamboo, wood, peat, and coal) were evaluated for their adsorptive efficiency of six volatile compounds (isoamyl alcohol, hexanal, furfural, ethyl lactate, ethyl octanoate, 2-phenyl ethanol) which were dissolved in a 30% alcoholic model solution. These six volatile compounds are frequently found in alcoholic beverages and possibly contribute to physiological hangover due to their high concentrations. They are also generally regarded as off-flavor compounds at certain levels in alcoholic beverages such as whisky and vodka. Two hundred mL of 30% alcoholic solutions containing these six volatile compounds were treated with 0.2 g of ACs while stirring for 16 hr; the treated solutions were then measured for their adsorptive efficiencies (or removal efficiencies) by gas chromatographic analysis using two different sampling methods (direct liquid injection and headspace-solid phase microextraction). The adsorptive efficiencies of the ACs varied depending on the identity of the volatile compounds and the source material used for making the ACs. Ethyl octanoate, 2-phenyl ethanol, and hexanal were removed at high efficiencies (34-100%), whereas isoamyl alcohol, ethyl lactate, and furfural were removed at low efficiencies (5-13%). AC prepared from bamboo showed a high removal efficiency for isoamyl alcohol, aldehydes (hexanal and furfural), and 2-phenyl ethanol; these major fusel oils have been implicated as congeners responsible for alcohol hangover.