• Journal of Life Science
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• v.25 no.2
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• pp.237-242
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• 2015

The use of calcite-forming bacteria (CFB) in crack remediation and durability improvements in construction materials creates a permanent and environmentally-friendly material. Therefore, research into this type of application is stimulating interdisciplinary studies between microbiology and architectural engineering. However, the mechanisms giving rise to these materials are dependent on calcite precipitation by the metabolism of the CFB, which raises concerns about possible hazards to cement-based construction due to microbial metabolic acid production. The aim of this study was to determine target microorganisms that possibly can have bio-corrosive effects on cement mortar and to assess multi-functional CFBs for their safe application to cement structures. The chalky test was first used to evaluate the $CaCO_3$ solubilization feature of construction sites by fungi, yeast, bacterial strains. Not all bacterial strains are able to solubilize $CaCO_3$, but C. sphaerospermum KNUC253 or P. prolifica KNUC263 showed $CaCO_3$ solubilization activity. Therefore, these two strains were identified as target microorganisms that require control in cement structures. The registered patented strains Bacillus aryabhatti KNUC205, Arthrobacter nicotianae KNUC2100, B. thuringiensis KNUC2103 and Stenotrophomonas maltophilia KNUC2106, reported as multifunctional CFB (fungal growth inhibition, crack remediation, and water permeability reduction of cement surfaces) and isolated from Dokdo or construction site were unable to solubilize $CaCO_3$. Notably, B. aryabhatti KNUC205 and A. nicotianae KNUC2100 could not hydrolyze cellulose or protein, which can be the major constituent macromolecules of internal materials for buildings. These results show that several reported multi-functional CFB can be applied to cement structures or diverse building environments without corrosive or bio-deteriorative risks.

• Radiation Oncology Journal
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• v.18 no.4
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• pp.321-328
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• 2000

Purpose :NOS2 induce NO Production and NO activate TGF-${\beta}$. The TGF-${\beta}$ is a inhibitor of NOS2. If this negative feedback mechanism operating in radiation pneumonitis model, NOS2 inhibitor may play a role in TGF-${\beta}$ suppression. We planned this study to evaluate the expression patterns of NO, NOS2 and TGF-${\beta}$ in vivo radiation pneumonitis model. Materials and Methods : Sixty sprague-Dawley rat were irradiated 5 Gy or 20 Gy. They were sacrificed 3, 7, 14, 28 and 56 days after irradiation. During sacrifice, we peformed broncho-alveolar lavage (BAL). The BAL fluids were centrifuged and supernatents were used for measure NO and TGF-${\beta}$, and the cells were used for RT-PCR. Results : After 5 Gy of radiation, NO in BAL fluid increased at 28 days in both lung and TGF-${\beta}$ in left lung at 56 days. NO increased in BAL fluid at 28 days in both lung after irradiation and TGF-${\beta}$ in right lung at 28-56 days after 20 Gy of radiation. After 5 Gy of radiation, NOS2 expression was increased in right lung at 14 days, in both lung at 28 days and in left lung at 56 days. TGF-${\beta}$ expression was reduced in both lung at 28 days and increased in left lung at 56 days. Conclusions :The Proposed feedback mechanism of NO, NOS2 and TGF-${\beta}$ was operated in vivo radiation pneumonitis model. At 56 days, however, NOS2 and TGF-${\beta}$ expressed concurrently in left lung after 5 Gy and in both lung after 20 Gy of radiation.

• Korean journal of food and cookery science
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• v.32 no.4
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• pp.390-399
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• 2016

Purpose: The objective of this study was to examine the effect of plant scale and cooking conditions on the quality characteristics of sausages during refrigerated storage. Methods: Sausages used in this study were classified into two groups: those submitted to $1^{st}$ cooked treatments and those submitted to $2^{nd}$ cooked treatments. The pH, volatile basic nitrogen (VBN), gas production ratio, and microorganisms were measured in triplicate. Results: The change of quality in the products was assessed every 7 days by measuring pH, VBN levels, total microbes, coliform bacteria, Escherichia coli, and pathogenic bacteria in the products. Pathogenic bacteria such as Staphylococcus aureus, Listeria monocytogenes, Clostridium perfringens, and E. coli were not detected in the sausages with $1^{st}$ cooked treatments. The results showed that the pH of the sausages decline as storage time increased. The pH value of the sausages with $2^{nd}$ cooked treatments changed gradually. VBN levels were generally lower in products with $2^{nd}$ cooked treatments than in those with $1^{st}$ cooked treatments, but they varied with the type of products. On the $35^{th}$ day, the number of total microbes ranged between 6.13-7.12 log CFU/g in products with $1^{st}$ cooked treatments and 3.44-6.92 log CFU/g in products with $2^{nd}$ cooked treatments, showing fewer bacteria in the latter products. Conclusions: $1^{st}$ cooked treatments were effective in microbial control, but $2^{nd}$ cooked treatments could prolong the shelf life of the sausages, indicating a need for differential management of each product.

• Applied Biological Chemistry
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• v.18 no.2
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• pp.71-97
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• 1975

To improve the food qualities in Korea, two hundred and fourtynine kinds of food additives have been allowed in food processing, of which one hundred and nineteen kinds could be used under the limitted conditions. Hence, in practical uses in food processing, many kinds of them are mixed at random within the permitted amounts for their special purposes. For last several years, many kinds of the food additives were prohibited because they have been proved to be toxic even with the single dose. Until recently a few studies on the toxicity in the mixture of food additives were reported, however, they were shown to be no severe additional effect on the animal. This study was performed to see if any elevation of chronic or subacute toxicity of food additives occur especially when they are mixed with each other, using three kinds of food additives (DHA, AF-2, BHT) most widely used as food preservatives, antiseptics and antioxidants. One hundred and fifty young male rats were taken and divided into ten feeding groups, one first control group (food additives blank), three second control groups (DHA 0.1%, AF-2 0.1%, BHT 0.5%), three mixture groups of low level (mixture of each 60% of two second control level) and three mixture groups of high level (mixture of each 90% of two second control level). As the methods of biological and clinical tests, the change of body weight (growth rate), daily intake of diets, organ to body weight ratio, histopathological findings of organs, hematological observation, liver and kidney function tests were checked three times during the periods of 24 weeks. The following results were obtained. 1. The low level group of DHA, AF-2 mixture and DHA, BHT mixture revealed a little retardation in growth rate than the first control group, however, they were similar to the second controls, while all the mixture groups of high level showed a more remarkable retardation than the first and second controls. 2. Average daily intake of the diets was the same in each group, showing a similar decreasing tendency (70-100g/kg of body weight) in accordance with the growth rate. It was observed that there are no differences in the taste and appetite in each group of rats. 3. Abnormal enlargements of kidney and lung were not seen in all the mixture groups compared with the controls, while a slight hepatomegaly was observed in all mixture groups of low level as in the second controls. Significant differences (almost 1% level) were observed between the high level groups and the first control group. 4. Histopathological effects of the food additives on lung, kidney and liver tissues were found in all mixture group of high level. The less frequencies of the same effects were also seen in the low level groups. 5. The esterified cholesterol to total cholesterol ratio in the mixture groups of high level showed a little lower values, and the activities of serum glutamate oxaloacetate transaminase and alkaline phosphatase decreased almost with significance of 5% level compared with the first control group. The serum A/G ratio in the mixture groups also decreased. The results demonstrated that the liver function was decreased in the mixture groups compared with the controls. 6. In all groups throughout the test period, kidney functions (concentration of protein and creatinine excreated per hour in urine and renal filtration rate) were shown almost as normal as the first control. 7. Average values of hematocrit, erythrocytes and leucocytes in the mixture groups were in the normal ranges as in the controls, which denotes that the production of blood cells in bone marrow were also normal in all groups. With the above results, it is concluded that when the food additives (DHA, AF-2, BHT) were given together to the rats in several combinations even in less amount, they showed more toxic signs than the single doses.

• Cartoon and Animation Studies
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• s.26
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• pp.1-30
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• 2012

The purpose of animation is to give interesting stories to an audience through motion. To achieve the purpose, over the past century since its inception, animation has adopted many kinds of technologies, and thus developed diverse narrative methods and visual expression techniques. In addition, with the advancement of expression techniques, all elements making up animation have gradually been systemized, and at the same time, have helped express the worlds beyond the reality. As a result, people have faced the era when an audience can watch everything imaginated by an animation director on a big screen. These days, more efforts have been made in order for the audience to feel much more than enjoy pictures moving in a frame. In other words, the purpose of the animation is changing from the passive viewing of animation to feeling and sensing stuffs through the animation. In the center of the changing process is 3D technology which gives new interesting to an audience. Sometime ago, a 3D animation movie was produced in Korea. But it did not bring out box-office profits, for it failed to give satisfaction to an audience who expected high perfection and beauty being able to be rivalled to those of international 3D animation movies. The failure is attributable to the fact that the domestic 3D animation production industry is merely in the early stage, and has not sufficient human resources, technology, and experiences in producing 3D animation films. Moreover, the problem is that most studies on 3D focus on the technologies related to reenactment, but that few studies on the images, which an audience directly faces, have been conducted. Under the domestic circumstance, the study on stereoscopic image screen of , a 3D stereoscopic animation film which was released in 2010 and has been seen as the best successful 3D stereoscopic animation, is worthwhile. Thus this thesis conducted theoretical consideration and case analysis focusing on the visual direction that creates the pictures to deliver abundant three dimensional effect so that it can be used as a basic data when producing high quality-domestic 3D animation and training professional labor forces. In the result, it was found that the 3D animation was not a new area, but the area which has been expanded and changed by applying the characteristics of 3D image based on the principles of the existing media aesthetics. This study might be helpful to establish the foundation of the theoretical studies necessary for producing 3D animation contents for realizing the sense of reality.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.2
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• pp.165-174
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• 2010

The numerical modeling of a coal gasification reaction occurring in an entrained flow coal gasifier is presented in this study. The purposes of this study are to develop a reliable evaluation method of coal gasifier not only for the basic design but also further system operation optimization using a CFD(Computational Fluid Dynamics) method. The coal gasification reaction consists of a series of reaction processes such as water evaporation, coal devolatilization, heterogeneous char reactions, and coal-off gaseous reaction in two-phase, turbulent and radiation participating media. Both numerical and experimental studies are made for the 1.0 ton/day entrained flow coal gasifier installed in the Korea Institute of Energy Research (KIER). The comprehensive computer program in this study is made basically using commercial CFD program by implementing several subroutines necessary for gasification process, which include Eddy-Breakup model together with the harmonic mean approach for turbulent reaction. Further Lagrangian approach in particle trajectory is adopted with the consideration of turbulent effect caused by the non-linearity of drag force, etc. The program developed is successfully evaluated against experimental data such as profiles of temperature and gaseous species concentration together with the cold gas efficiency. Further intensive investigation has been made in terms of the size distribution of pulverized coal particle, the slurry concentration, and the design parameters of gasifier. These parameters considered in this study are compared and evaluated each other through the calculated syngas production rate and cold gas efficiency, appearing to directly affect gasification performance. Considering the complexity of entrained coal gasification, even if the results of this study looks physically reasonable and consistent in parametric study, more efforts of elaborating modeling together with the systematic evaluation against experimental data are necessary for the development of an reliable design tool using CFD method.

• Journal of Korean Society of Forest Science
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• v.78 no.3
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• pp.314-322
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• 1989

For the improvement of nursery condition and the study of eco-physiological characteristics of Pinus koraiensis(2-2) seedlings, the primary productivity was investigated and the growth characteristics and their correlationship were analyzed from May to September in 1987. Seedlings used in this study were grown at the nursery of Experimental Forestry of Kyung Hee Univ. The installation of experimental plots were divided into control plot (100%), 63%, 37% and 19% relative light intensity, and each relative light intensity plots were split into $15{\times}15/m^2$, $12{\times}12/m^2$, $9{\times}9/m^2$ and $6{\times}6/m^2$ plnting density by randomized black design method. To take into account the edge effect of plant population, material were selected from each plot by random sampling at 30 days interval. Each sampled material was divided into leaf and stem drived in a drying oven at the temperature of $85^{\circ}C$ until it had constant weight and weighed. and leaf area was surveyed. Growth analysis for RGR and NAR was done by Blackman method and correlation coefficient were investigated between RGR and NAR by analyzing the dry matter production and growth characteristics of the material, cultivated on the experimental nursery under the condition of different treatment the obtained result were as follows : 1. The increasing rate of dry matter was similar at early stage of growth, but not at late stage. 2. Leaf area growth was the maximum value at 63% relative light intensity and the minimum at 19% RLI 3. The value of RGR was the highest on June under $6{\times}6/m^2$ planting density in 63% relative light intensity, the lowest on September under $12{\times}12/m^2$ of 19% relative light intensity. 4. The change NAR decreased in early stage of growth, while it increased on August and September, The value of RGR on June under $6{\times}6/m^2$ planting density in 100 light intensity was the highest, and on September under $12{\times}12/m^2$ planting density in 19% relative light intensity was the lowest. 5. Regression and correlation between RGR and NAR showed significantly positive.

• Journal of Korean Society of Forest Science
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• v.86 no.1
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• pp.35-45
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• 1997

This study has been carried out to estimate carbon fixation, and carbon NPP based on equation form of $Wt=aD^bH^c$ in natural stand of Quercus mongolica and Quercus variabilis in Chungju. The effect of improvement of environment was also evaluated by estimating sink of $CO_2$ gas in forest ecosystem of Korea in a year. The following effects have been obtained in analysing estimate of allometric equation. Equation form of $Wt=aD^bH^c$ was the most adequate, those of $Wt=a(D^2H)^b$, $Wt=aD^b$ estimate of the biomass and the carbon fixation in Quercus natural stand of Chungju. Total above ground of Quercus mongolica was 130.58 t/ha and that of Quercus variabilis was 137.38 t/ha. Annual production of two stands was 9.96 t/ha/yr, 8.64 t/ha/yr, respectively. Carbon fixation of total above ground was 60.52t C/ha in Quercus mongolica stand, and was 62.22t C/ha in Quercus variabilis stand. Annual fixation of carbon was 4.78t C/ha/yr and 4.28t C/ha/yr, seperately. Annual emission of carbon estimated 2.44t C/ha/yr in contrast of forest area in Korea. It was showed that the annual fixation of carbon was higher 1.84t C/ha/yr~2.34t C/ha/yr than annual emission of carbon. But foliage was 2.39t C/ha/yr and 1.89t C/ha/yr, which occupied 40% and 50% of annual carbon fixation of total above ground. Annual carbon fixation may fluctuate about 1.89t C/ha/yr~2.39t C/ha/yr by seasons.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.4
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• pp.554-562
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• 2003

Xylitol has been used as sugar substitute to prevent dental caries. It is not fermented by most dental plaque bacteria and interferes with the growth of mutans streptococci. Therefore the production of acidic metabolites and the growth of mutans streptococci are inhibited. S. mutans strains which are inhibited to grow under the presence of xylitol are referred as xylitol-sensitive ($X^S$) strains. However, experimental and clinical studies have shown that there were mutated groups of S. mutans strains that are not affected by xylitol. They are referred as xylitol-resistant($X^R$) strains. The aim of the present study was to investigate that emergence of $X^R$ strain would effect on the anticariogenecity of xylitol by comparing the growth rate, the extracellular pH, hydroxyapatite adhesion and the agglutination of the $X^R/X^S$ strains. Overall we came out with following results : 1. No difference in the growth rate and the extracellular pH was found between the $X^S$ strain and the $X^R$ strain. 2. No difference in adhesion to hydroxyapatite surface was found between the $X^R$ strain and the $X^S$ strain (p>0.05) and adhesion of the $X^S$ strain was greater than that of $X^R$ strain in the sucrose-dependent adhesion to hydroxyapatite (p<0.05). 3. The $X^R$ strain was agglutinated in the lower concentration of saliva than that of $X^S$ strains.

• Journal of Korean Society of Forest Science
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• v.89 no.2
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• pp.208-215
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• 2000

In order to improve 'Salso' method (conventional tapping method) which was very inefficient in the aspects of collection time and labor, this study was carried out to investigate the effect of the application date and the distance from treatment point in the lactree(Rhus verniciflua) treated with 10% CEPA and to decide the possibility of application of the technique in the field. Bark thickness was significantly increased to the part 40cm above and below the treatment point, but urushiol content was increased to the part 20cm above and 10cm below the zone treated with 10% CEPA. The urushiol content of the bark was highest at 5cm above the treated zone and decreased in the order of 10, 20, and 40cm. And the urushiol contents of the bark of the upper part were higher than that of the low part. The effects of CEPA on bark thickness were similar to urushiol contents. Urushiol production of lactree is highly dependent on climatic conditions and particularly on the precipitation, and duration of sunshine. Ten percent of CEPA-lanolin pastes which was treated on June 16 affected bark anatomy and urushiol contents, while the treatment on August 24 did not affect. In the Rhus verniciflua treated with 10% CEPA, the urushiol contents was initially increased from 7 days after treatment, continued for the 4 weeks, and then slight decrease occurred at 5 weeks after the treatment. We measured a total sap yield by Salso method in lactree treated with 10% CEPA. By applying 10% CEPA, the sap yield was increased 3-4 times compared to that of untreated trees in the first tapping. But the relative ratio was gradually decreased from the second tapping to sixth, and after seventh tapping, the untreated trees secreted more sap than the treated trees. We discussed about the causes.