• Applied Chemistry for Engineering
• /
• v.7 no.6
• /
• pp.1078-1086
• /
• 1996

The peroxo-polytungstic acid was formed by the direct reaction of tungsten powder with the hydrogen peroxide solution. Peroxo-polytungstic powder were prepared by rotary evaporator using the fabricated on to ITO coated glass as substrate by dip-coating method using $2g/10mL(W-IPA/H_2O)$ sol solution. A substrate was dipped into the sol solution and after a meniscus had settled, the substrate was withdrawn at a constant rate of the 3mm/sec. Thicker layer could be built up by repeated dipping/post-treatment 15 times cycles. The layers dried at the temperature of $65{\sim}70^{\circ}C$ during the withdrawn process, and then tungsten oxides thin film was formed by final heating treatment at the temperature of $230{\sim}240^{\circ}C$ for 30min. A linear rotation between the thickness of thin film and the number of dipping/post-treatment cycles for tungsten oxides thin films made by dip-coating was found. The thickness of thin film had $60{\AA}$ after one dipping. From the patterns of XRD, the structure of tungsten oxides thin film identified as amorphous one and from the photographs of SEM, the defects and the moderate cracks were observed on the tungsten oxides thin film, but the homogeneous surface of thin films were mostly appeared. The electrochemical characteristic of the $ITO/WO_3$ thin film electrode were confirmed by the cyclic voltammetry and the cathodic Tafel polaization method. The coloring bleaching processes were clearly repeated up to several hundreds cycles by multiple cyclic voltammetry, but the dissolved phenomenon of thin film revealed in $H_2SO_4$ solution was observed due to the decrease of the current densities. The diffusion coefficient was calculated from irreversible Randles-Sevick equation from the data obtained by the cyclic voltammetry with various scan rates.

• Proceedings of the Korean Society of Tobacco Science Conference
• /
• 1997.10a
• /
• pp.134-152
• /
• 1997

Plant viruses of tobacco including tobacco mosaic virus (TMV) and potato virus Y (PVY) cause severe economic losses in leaf-tobacco production. Cultural practices do not provide sufficient control against the viruses. Use of valuable resistant cultivars is most recommendable for the control of the viruses. However, conventional breeding programs are not always proper for the development of virus-resistant plants mostly owing to the frequent lack of genetic sources and introduction of their unwanted properties. Therefore, we tried to develop virus-resistant tobacco plants by transforming commercial tobacco cultivars, NC 82 and Burley 21, with coat protein (CP) or replicase (Nlb) genes of TMV and PVY necrosis strain (PVY-VN) with or without untranslated region (UTR) and with or without mutation. Each cDNA was cloned and inserted in plant expression vectors with 1 or 2 CaMV 35S promotors, and introduced into tobacco leaf tissues by Agrobacterium tumefaciens LBA 4404. Plants were regenerated in kanamycin-containing MS media. Regenerated plants were tested for resistance to TMV and PVY In these studies, we could obtain a TMV-resistant transgenic line transformed with TMV CP and 6 genetic lines with PVY-VN cDNAs out of 8 CP and replicase genes. In this presentation, resistance rates, verification of gene introduction in resistant plants, stability of resistance through generations, characteristics of viral multiplication and translocation in resistant plants, and resistance responses relative to inoculum potential and to various PVY strains will be shown. Yield and quality of leaf tobacco of a promising resistant tobacco line will be presented.

• Korean Journal of Soil Science and Fertilizer
• /
• v.19 no.2
• /
• pp.157-165
• /
• 1986

This experiment was conducted to find out the some physiological characteristics and nitrogen fixation activities under free-living conditions of indigenous rhizobia isolated from soybean-cultivated (30 fields) and un-cultivated (30 fields) soil. The results were summerized as follows: 1. In free-living condition, only 12.8% and 6.4% of the indigenous rhizobia isolated from soybean cultivated (133 strains) and un-cultivated (125 strains) soils were nitrogenase positive as more than 4 n mole $C_2H_4$ per tube per hour by acetylene reduction assay. 2. The acid-producing rhizobia on litmus milk test was observed to be 20% of the total 160 strains isolated from soybean cultivated soil but about 34% of 166 strains isolated from un-cultivated soil. And the serum zone positive strains were higher in the soybean un-cultivated soil than cultivated soil. 3. The population ratio of fast-to slow-growing indigenous rhizobia based on growth pattern of AMA medium was 35.6% to 64.4% of the total 346 strains. 4. The population of indigenous Rhizobium japonicum counted by MPN method was ranged from $9.2{\times}10^2$ cells per gram of soil in soybean un-cultivated soil to $2.3{\times}10^4$ cells per gram of soil soybean cultivated soil. The number of indigenous R. japonicum in 0-10cm depth of surface layer was higher than low layer.

• Journal of Animal Science and Technology
• /
• v.49 no.5
• /
• pp.677-688
• /
• 2007

돼지를 포함한 대부분의 동물은 일정한 발정주기를 가지고 일정한 시기에 배란을 하는 자연배란동물이지만, 토끼, 고양이, 밍크 등의 암놈은 교미자극에 의해 배란이 일어나는 유기배란동물이다. 또한 1년에 한 번만 발정하는 단발정동물과 1년에 수차례 발정하는 다발정동물이 있다. 이 중에서 모돈은 1년에 수차례 발정하는 다발정 동물로서 발정기에 들면 비발정기와는 다른 행동을 나타낸다(Diehl 등, 2001). 양돈가의 수익을 최대화하기 위해서는 비생산일수를 최소로 줄여야 한다. 모돈의 비생산일수를 줄일 수 있는 한 가지 방법은 성공적으로 교배를 시키는 것이다. 이처럼 성공적으로 교배를 시키기 위해서는 수정적기를 정확히 예측해야 한다. 만약 수정적기를 정확히 판단하지 못하여 수태가 되지 않으면, 비생산일수가 늘어나 손실을 입게 된다. 따라서 수정적기를 정확히 판단하는 것은 모돈의 성공적인 인공수정에 있어서 중요한 요소이다. 수정적기는 배란이 일어나기 전 10시간에서 12시간 사이이며, 발정이 시작되는 시점을 기준으로 하였을 때 경산돈의 경우 26시간에서 34시간 사이이고 미경산돈의 경우는 18시간에서 26시간 사이이다(Evans 등, 2001). 현재 하루에 두 번 모돈의 발정을 확인하는 것이 일반화되어 있으며, 이 때 웅돈을 접촉시키거나 육안관찰을 통하여 발정 유무를 판단한다. 이러한 방법에는 숙련된 기술과 풍부한 경험이 요구될 뿐만 아니라 총 소요노동력의 30% 정도가 요구된다(Perez 등, 1986). 하루에 두 번밖에 발정을 감지하지 않기 때문에 발정이 언제 시작되었는지를 정확히 알 수 없으며, 또한 발정의 대부분이 새벽에 시작되므로 수정적기를 정확히 판단하기란 매우 어렵다. 만약 발정을 감지했더라도 적기에 인공수정을 하지 못한다면, 수태율이 낮아지므로 경제적 손실이 초래된다. 현재 이러한 문제점 때문에 2회에서 3회에 걸쳐 인공수정을 하고 있으나 이에 따른 소요비용과 소요노동력 등은 양돈가의 부담을 가중시키는 요인이 되고 있다. 돼지는 발정기가 되면 비발정기에 나타내지 않던 외음부의 냄새를 맡는 행동, 귀를 세우는 행동 및 승가허용 행동 등을 나타낸다(Diehl 등, 2001). 또한 돼지는 비발정기에 비하여 발정기에 더 많은 활동량을 나타낸다(Altman, 1941; Erez and Hartsock, 1990). Freson 등(1998)은 스톨에서 개별적으로 사육되고 있는 모돈의 활동량을 적외선센서를 이용하여 측정함으로써 발정을 86%까지 감지하였다고 보고하였다. 그러나 이 연구는 단지 모돈의 발정을 감지하였을 뿐 번식관리에 있어서 가장 중요한 수정적기의 판단 기준을 제시하지 못하였다. 따라서, 본 연구는 스톨에서 사육되는 모돈의 활동량을 측정함으로써 발정시작시각을 감지하고 이를 기준으로 인공수정적기를 예측할 수 있는 인공수정적기 예측 장치를 개발한 후 이의 성능을 농장실증실험을 통하여 시험하고자 수행되었다.

• Reproductive and Developmental Biology
• /
• v.29 no.1
• /
• pp.1-7
• /
• 2005

Telomeres consisting of (TTAGGG)n tandem repeat DNA sequences and associated proteins are essential for chromosome stability and related with cell senescence, apoptosis and cancer. The telomerase is a ribonucleoprotein which act as a template for the synthesis of telomeric DNA. This study was carried out to identify the distribution of telomeres on mouse chromosomes and also to analyze the amount of telomeres and telomerase activity of mouse embryos at early embryonic stages. Germ cells and early embryos from 1 cell to blastocyst stage were analyzed. The amount of telomeres was analyzed by quantitative fluorescence in situ hybridization technique(Q-FISH) using a human telomeric DNA probe, and telomerase activity was measured by telomeric repeat amplification protocol assay(TRAP). In results, the telomeres on mouse chromosomes were distributed at the ends of all autosomes and sex chromosomes. Although the quantity of telomeres varied among chromosomes, most of chromosomes had higher amount in q-arm telomeres than in p-arm telomeres. The results of Q-FISH indicated that the relative amount of telomeres of mouse embryos in each embryonic stage was approximately the same except the higher amount in blastocysts. Using TRAP assay on mouse embryos, telomerase activity was detected in all preimplantation stages from mature oocytes to blastocysts. Especially the telomerase activity was significantly increased at the morula and blastocyst stage. In conclusion, there may be a close association between the amount of telomeres and telomerase activity in early embryonic stages, and analysis of telomere quantity and telomerase activity on early development will be helpful for the investigation of embryogenesis and embryonic cell differentiation in mice.

• Economic and Environmental Geology
• /
• v.40 no.4
• /
• pp.347-360
• /
• 2007

In order to evaluate the degree and extent of heavy metal pollution and the environmental impacts of abandoned Cu mines in Goseong-gun, soils and paddies were collected from the mine area and have been analysed for heavy metal contents. The heavy metal contents were much higher in mountain soils than in paddy soils. Total content of heavy metals decreased in order of Cu>Zn>Pb>As>Cr>Cd in mountain soils whereas Zn>Pb>Cu>Cr>As>Cd in paddy soils. The extractable amount of heavy metals by 0.1/1N HCl decreased in order of Cu>Pb>Zn>As>Cd>Cr in mountain soils whereas Pb>Cu>Zn>As>Cd>Cr in paddy soils. Although the extraction ratios were highly various depending on the sampling site, their average values were in order of Cd(16%)>Pb(10%)>Cu(9%)>As(4.5%)>Zn-Cr(${\le}2.5%$). The soils investigated were enriched in heavy metals relative to the averages of earth crust as In order of $As{\ge}Cd$>Pb>Zn>Cu>Cr. Pollution index calculated from total or extractable heavy metals of soils indicated that the heavy metal pollution was restricted to mountain soils around abandoned Cu mines, especially the Samsan I mine. The metal contents of brown rice showed no significantly contaminated level as follows; As $nd{\sim}0.87mg/kg,\;Cd\;0.02{\sim}0.34mg/kg,\;Cu\;1.01{\sim}6.25mg/kg,\;Mn\;13.4{\sim}43.2mg/kg,\;Pb\;0.09{\sim}2.83mg/kg,\;and\;Zn\;16.5{\sim}79.1mg/kg$. From the extraction and dispersion properties of heavy metal with the soil pH ($4.5{\sim}7.8$), it can be deduced the conclusion that the heavy metal pollution is spreading in the study area mainly by the detrital migration of waste ore and gangue minerals rather than the dissolution and circulation of heavy metal.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.11
• /
• pp.435-442
• /
• 2020

This study was conducted to investigate the effect of different raising periods (24 and 48 months) on the physico-chemical quality and fatty acid composition of meat from Korean native black goats. In terms of proximate composition, the meat from the 24-month age-group of the goats contained lower moisture and protein content and higher fat and ash content than that from the 48-month age-group. With an increase in age, moisture and protein content increased, whereas fat and ash content decreased. The pH was higher as was the cooking loss in the meat from the 24-month age-group than in the meat from the 48-months age-group (p < 0.05). However, there was no significant difference in the water-holding capacity and shear force of the meat from the two breeding periods (p > 0.05). A color analysis showed that the meat from the 24-month age-group had higher L*, a*, and b* values than the 48-month age-group (p < 0.05). The fatty acid composition and palmitic acid content increased with an increase in rearing periods, whereas stearic acid and oleic acid content decreased. The proportion of saturated and unsaturated fatty acid content was lower and higher, respectively, at 24 months of age and 48 months of age (p < 0.05).

• Journal of Animal Science and Technology
• /
• v.55 no.5
• /
• pp.483-488
• /
• 2013

To develop a sustainable composting method for livestock mortality, a natural aeration-composting process was designed and the influences of bulking materials on the mortality composting process were studied. Bulking materials (e.g., compost, swine manure, sawdust, and rice husks), easily supplied at the scene of an animal mortality outbreak, were tested in this research. A lab-scale composting system (W34 ${\times}$ L60 ${\times}$ H26 cm) was made using 100 mm styrofoam, and natural aeration was achieved through pipes installed on the bottom of the system. Four treatments were designed (compost, compost + swine feces, sawdust, and rice husks treatment groups) and all experiments were done in triplicates. During composting for 40 days, no leachate was observed in compost and sawdust treatment groups, whereas 18 and 8.2 ml leachate/kg-mortality was emitted from the compost + feces and rice husks treatment groups, respectively. Dimethyl disulfide (DMDS) emission during the composting was very low in all treatment groups, possibly due to the bio-filtering function of the compost cover layer on the pile. The mortality degradability in compost, compost + feces, sawdust, and rice husks groups was 25.3, 25.8, 13.5, and 14.5%, respectively, showing significantly higher levels in compost and compost + feces groups (p<0.05). Also, only the compost + feces group produced enough heat (over $55^{\circ}C$) and lasted for 7 days, indicating that bio-security cannot be guaranteed without feces supplementation.

• Microbiology and Biotechnology Letters
• /
• v.7 no.2
• /
• pp.75-89
• /
• 1979

One strain of Penicillium sp. (175-66-B), isolated from soil, was able to produce a substance that has a strong inibition activity against the Agkistrodon and Trimeresurus venoms. In this experiment, the chemical and biological properties of the sample were investigated. As an inhibitory substance, it was effective to the proteinase, hemorrhagic and lethal factors of Agkistrodon and Trimeresurus venoms, and also effective to several fractions of the proteinases and hemorrhagic factors of Agkistrodon halys blomhoffi venom. Moreover, in the addition of prednisotone, it was more effective for the cure of the mouse envenomated with the venom amount of two fold of MLD$_{100}$. This substance was very stable to the acid, alkali and heat. Its melting point was high enough to sublime at 222$^{\circ}C$ without any decomposition. This sample was easily dissolved only in hot water, but not in several organic solvents except for a little dissolution in elate. It did not have the chelating activity. It had very strong specificity to the snake venoms. but its activity was depressed by the addition of zinc or cupric salts. This sample had no acute toxicity to the mouse. Its chemical formula was $C_{16}$ $H_{12}$$N_2$ $O_{10}$ with the molecular weight of about 392. It has two epoxy groups and four carboxyl radicals, but amino, nitrite and nitrate radicals, unsaturated bonds and aromatic ring were not detected. Theuchemical configuration of this sample was suggested to be;

• Korean Journal of Environmental Agriculture
• /
• v.37 no.1
• /
• pp.15-20
• /
• 2018

BACKGROUND: The global mean surface temperature change for the period of 2016~2035 relative to 1986~2005 is similar for the four representative concentration pathway (RCP)'s and will likely be in the range of $0.3^{\circ}C$ to $0.7^{\circ}C$. Climate change inducing higher temperature could affect not only crop growth and yield, but also dynamics of carbon in paddy field. METHODS AND RESULTS: This study was conducted to evaluate the effect of elevated temperature on the carbon dynamics in paddy soil and rice growth. In order to control the elevated temperatures, the experiments were set up as the small scale rectangular open top chambers (OTCs) of $1m(width){\times}1m(depth){\times}1m(height)$ (Type 1), $1 m(W){\times}1m(D){\times}1.2m(H)$ (Type 2), and $1m(W){\times}1m(D){\times}1.4m(H)$ (Type 3). The average temperatures of Type 1, Type 2, and Type 3 from July 15 to October 30 were higher than the ambient temperatures at $0.4^{\circ}C$, $0.5^{\circ}C$, and $0.9^{\circ}C$, respectively. For the experiment, Wagner's pots (1/2,000 area) were placed inside chambers. The pots were filled with loamy soil, and chemical fertilizer and organic compost were applied as recommended after soil test. The pots were flooded with agricultural water and rice (Shindongjin-byeo) was planted. It was observed that TOC (total organic carbon) of the water increased by the elevated temperatures and the trend continued until the late growth stage of the rice. Soil TOC contents were reduced by the elevated temperatures. C/N ratios of the rice plant decreased by the elevated temperature treatments. Thus, it was assumed that the elevated temperatures induced to decompose soil organic matter. Elevated temperatures significantly increased the culm length (P<0.01) and culm weight (P<0.05) of rice, but the number and weight of rice panicle did not showed significant differences. CONCLUSION: Based on the results, it was suggested that the elevated temperatures had an effect on changes of soil and water carbons under the possible future climate change environment.