• Korean Journal of Animal Reproduction
• /
• v.8 no.1
• /
• pp.46-55
• /
• 1984

The purpose of the experiment was to clarify morphologically normal growth pattern of the ductus deference in accordance with the sex maturity of meat-type cockerels. 1. Diameter of lumens in u, pp.r, mid and lower parts of ductus deferens, the most conspicuous enlargement of lumen was observed in the lower part. Heights of epithelial layers of ductus deferens showed abrupt growth at 12 weeks of age with subsequent gradual growth in all the part of u, pp.r, mid and lower, and heights of those at 30 weeks were a, pp.oximately 4 times as large in the u, pp.r and mid parts and 5 times as large in the lower part in contrast to those at 4 weeks of age. Thickness of muscular layer of ductus showed gradual growth in contrast with the diameter of lumen and height of epithelial layer, showing 1.3 times as large in the u, pp.r part, 1.6 times in the mid part and 1.9 times in the lower part at 30 weeks of age in contrast to the thickness at 4 weeks of age. 2. Within 10 weeks after hatching, lining cells of ductus deferens were mainly composed of round cells and columnar cells in simple columnar epithelium. During 10th to 20th week, the lining cells were mainly composed of high columnar cells and round cells in pseudostratified epithelium. From 22nd week, the lining cells were composed of pseudostratified columnar cells. Whereas round cells disa, pp.ared gradually. Enlargement of lumen and pooling of sperms in ductus deferens coincided with the maturation of seminiferous tubules. 3. In simple correlation between the values of testis weight and the values from various measurements in the ductus deferens, there was significant correlation coefficient with each other. 4. In the India ink absorption test, India ink granules were not absorbed on the epithelium of the ductus deferens, but the granules reactive to acid phosphatase a, pp.ared in a line on the free border of each parts of the ductus deferens. The granules reactive to alkaline phosphatase were noted on the luminal border of ductus deferens mainly, but weak reaction showed than acid phophatase were a, pp.ared. The granules reactive to PAS were a, pp.ared mostly near on the free border of hte epithelial cells of ductus deferens. 5. Number of sperm, Indes of sperm vitality and MRT in the different parts of ductus deferens were tended to be somewhat dominant in the mid and lower parts than in u, pp.r part, even though not significant in the statistical analysis. Ratio of sperm abnormality was tended to be relatively high in the u, pp.r part too, and in the sperm of abnormality blunted head was less in number significantly in the mid and lower part than in the u, pp.r part.

• Environmental and Resource Economics Review
• /
• v.15 no.3
• /
• pp.505-530
• /
• 2006

For the district heating and cooling business, it is required to install energy-saving facilities using energy from waste and land fill gases such as combined heat and power(CHP). The current issues that this business faces can be summarized as below: which facilities including CHP can be economically introduced and how much of their capacities should be. Most of such issues are clearly related to the optimal plant design of the district heating and cooling business, and the prices of energy services such as heating and cooling energy, and electricity. The purpose of this study is to establish linear program model of least cost function and to practice the empirical test on a assumed district heating and cooling business area. The model could choose the optimal type of energy-producing facilities among various kinds available such as CHP's, absorption chillers, the ice-storage system, etc. CHP with the flexible heat and power ratio is also in the set of available technologies. And the model show us the optimal ration of heat producing facilities between CHP and historical heat only boiler in the service area. Some implications of this study are summarized as below. Firms may utilize this model as a tool for the analysis of their optimal size of the facilities and operation. Also, the government may refer the results to regulate resonable size of business.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.42 no.5
• /
• pp.497-502
• /
• 1997

A seed pelleting technique was developed for easy handling of small sesame seeds (Chinbaeckkae) and for direct seeding in field. The mixture of pelleting material, binder(sodium alginate) and seeds were dropped in 100mM CaCl$_2$ solution. Charcoal was appeared as a best material among all to make pellets with the characters of hardness, breakdown, destruction rate and germination percentage. Zeolite formed the hardest pellet seeds among the materials and 1~3 seeds contained in a pellet on the treatment of 87g of sesame seeds mixed in 1$\ell$ CaCl$_2$ solution was estimated optimum rate of seed mixure with few appearance of seedless pellet. The moisture absorption rate was greater in the order of peat＋charcoal > peat > charcoal > zeolite. Germination percentage of pelleted seeds with charcoal was the best and similar to that of common non-treated seeds. Germination percentage of pelleted seeds by sowing depth of exposing a quarter of pellet seeds on the surface of vermiculite germination test box and were 92％ in charcoal treatment and was the best among all released materials.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.21 no.4
• /
• pp.307-316
• /
• 2019

In the agricultural sector, greenhouse gas emissions vary depending on the interaction of all ecosystem changes such as soil environment, weather environment, crop growth, and anthropogenic farming activities. Agricultural sector greenhouse gas emissions resulting from many of these interactions are highly variable. Uncertainty-based evaluation that defines the interval with confidence level of greenhouse gas emission and absorption is necessary to take account of the variance characteristics of individual emissions, but research on uncertainty evaluation method is insufficient. This study aims to decide on the effect of reducing N₂O emissions from upland soils using an uncertainty-based approach. An uncertainty-based approach confirmed whether there was a difference between confidence intervals in the 5 different fertilizer treatment groups to reduce greenhouse gas emissions. Unlike the statistically significant test with three repetition averages, the uncertainty-based approach method estimated in this study is able to estimate the confidence interval considering the distribution characteristics of the emissions, such as the dispersion characteristics of individual emissions. Therefore, it is considered that the reliability of emissions can be improved by statistically testing the variance characteristics of emissions such as the uncertainty-based approach. It is hoped that the direction of the uncertainty-based approach for the effect of reducing greenhouse gas emissions in agriculture will be helpful in the future development of agricultural greenhouse gas emission reduction technology, adaptation to climate change, and further development of sustainable eco-social system.

• Korean Journal of Food Science and Technology
• /
• v.15 no.3
• /
• pp.269-276
• /
• 1983

Experiments were performed to study the rheological and baking properties of bread fortified with various amounts of filefish protein concentrate (FPC). Doughs were prepared from mixtures containing wheat flour and 5,10,15 and 20% of FPC. Standard methods were used to evaluate the rheology of doughs and characteristics of bread. The results were as follows. 1. The water absorption of the fortified doughs increased as FPC increased. FPC caused an increase in development time and stability as measured by Farinograph. 2. In the extensigraph test, FPC yielded a decrease in extensibility and an increase in resistance to extension. 3. Baking tests demonstrated that addition of FPC decreased the volume of loaf and made the crumb darker and coarser. 4. Additional tests were made to examine effect of sodium stearoyl lactylate (SSL) added at 0.25, 0.50, 1.00 and 2.00% on doughs containing 10% headed & gutted FPC. The most appropriate amount of SSL as an additive was 0.5%. 5. In the farinograph, adding 0.5% SSL could delay dough development time and greatly increase stability. 6. When 0.5% SSL was added on doughs containing 5,10,15 and 20% headed & gutted FPC, baking quality was greatly improved. The breads containing up to 10% were acceptable by the addition of SSL, but not in higher level of FPC. 7. The results of sensory evaluations of bread showed that the color, texture and taste of bread containing 5% whole FPC and 5, 10% headed & gutted FPC were reasonably gacceptable.

• The Journal of Korean Academy of Prosthodontics
• /
• v.44 no.3
• /
• pp.284-294
• /
• 2006

Statement of problem. Proliferation of Candida albicans is primarily within the plaque on the fitting surface of the denture rather than on the inflamed mucosa. Consequently, the treatment of the denture is equally important as treatment of the tissue. Cleansing and disinfection should be efficiently carried-out as the organisms can penetrate into the voids of the acrylic resin and grow in them, from which they can continue to infect and reinfect bearing tissues. Purpose. The purpose of this study was to evaluate the applicability of photocatalytic reaction to eliminate Candida albicans from acrylic resin denture base, and to investigate the anti-fungal effect with various UVA illumination time. Materials and Methods. The specimens were cured by the conventional method following the manufacturer's instruction using thermal polymerized denture base resin (Vertex RS: Dentimex, Netherlands). $TiO_2$ photocatalyst sol(LT), which is able to be coated at normal temperature, was made from the Ti-alkoxide progenitor. The XRD patterns, TEM images and nitrogen absorption ability of the $TiO_2$ photocatalyst sol(LT) were compared with the commercial $TiO_2$ photocatalyst P-25. The experimental specimens were coated with the mixture of the $TiO_2$ photocatalyst sol(LT) and binder material (silane) using dip-coater, and uncoated resin plates were used as the control group. Crystallinity of $TiO_2$ of the specimen was tested by the XRD. Size, shape and chemical compositions were also analyzed using the FE-SEM/ EDS. The angle and methylene blue degradation efsciency were measured for evaluating the photocatalytic activity of the $TiO_2$ film. Finally, the antifungal activity of the specimen was tested. Candida albicans KCTC 7629(1 ml, initial concentration $10^5$ cells/ ml) were applied to the experiment and control group specimens and subsequently two UVA light source with 10W, 353 nm peak emission were illuminated to the specimens from 15cm above. The extracted $2{\mu}l$ of sample was plated on nutrient agar plate ($Bacto^{TM}$ Brain Heart Infusion; BD, USA) with 10 minute intervals for 120 minute, respectively. It was incubated for 24 hours at $37^{\circ}C$ and the colony forming units (CFUs) were then counted. Results. Compared the characteristics of LT photocatalyst with commercial P-25 photocatalyst, LT were shown higher activity than P-25. The LT coated experimental specimen surface had anatase crystal form, less than 20 nm of particle size and wide specific surface area. To evaluate the photocatalytic activity of specimens, methylene blue degradation reaction were used and about 5% of degradation rate were measured after 2 hours. The average contact angle was less than $20^{\circ}$ indicating that the LT photocatalyst had hydrophilicity. In the antifungal activity test for Candida albicans, 0% survival rate were measured within 30 minute after irradiation of UVA light. Conclusion. From the results reported above, it is concluded that the UVA-LT photocatalytic reaction have an antifungal effect on the denture surface Candida albicans, and so that could be applicable to the clinical use as a cleaning method.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.31 no.3 s.52
• /
• pp.245-251
• /
• 2005

Safety is one of the key issue in the regulation of cosmetics. Cosmetic Act deals with it in Korea. The guidance for the testing cosmetic ingredients and their safety evaluation are prepared by Korea Food and Drug Administration. Ultraviolet radiation could Induce skin damage, edema, erythema, photoaging, immune dysfunction and skin cancer. Ultraviolet radiation is classified as Group 2A(probably carcinogenic to humans) by International Agenry for Reaserch on Cancer(IARC). The in vitro methodologies for evaluating the toxic potential of ingredients reported in the literature have not yet been sufficiently validated for use in areas other than the study for mutagenicity/genotoxicity, for pre-screening for severe irritancy, for screening of phototoxicity and for evaluating the percutaneous absorption. The 3T3 neutral red uptake photoxicity test (3T3 NRU PT) was accepted as OECD toxicity guideline in 2002. The 3T3 NRU PT is an in vitro method based on a comparison of the cytotoxicitv of a chemical when tested in the presence and in the absence of exposure to a non-cytotoxic dose of UVA/visible light.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.30 no.2
• /
• pp.119-125
• /
• 2017

Ablative material in a rocket nozzle is exposed to high temperature combustion gas, thus undergoes complicated thermal/chemical change in terms of chemical destruction of surface and thermal decomposition of inner material. Therefore, method for conjugate analysis of thermal response inside carbon/phenolic material including rocket nozzle flow, surface chemical reaction and thermal decomposition is developed in this research. CFD is used to simulate flow field inside nozzle and conduction in the ablative material. A change in material density and a heat absorption caused by the thermal decomposition is considered in solid energy equation. And algebraic equation under boundary layer assumption is used to deduce reaction rate on the surface and resulting destruction of the surface. In order to test the developed method, small rocket nozzle is solved numerically. Although the ablation of nozzle throat is deduced to be higher than the experiment, shape change and temperature distribution inside material is well predicted. Error in temperature with experimental results in rapid heating region is found to be within 100 K.

• Journal of the Korean Wood Science and Technology
• /
• v.22 no.4
• /
• pp.19-25
• /
• 1994

The purpose of this study was to determine the technical feasibility of making 3-dimensional thin hardboard panels for overlay substitutes of low grade particleboard and plywood panels. Experimental studies were directed at assembling bench-top apparatus, learning the characteristics of different types of lignocellulosic waste papers, for making thin hardboard with several combinations of them with and without resin addition. The raw materials used are waste corrugated cartons, cereal boxes, and old magazines which contain substantial amount of lignin in it. The experimental results showed that satisfactory thin(0.21~0.16cm) hardboard could be made from the residential mixed waste papers that have selected properties comparable to commercial 0.32cm hardboard. The significant mixing ratio effect of the waste papers was present on the thickness swelling, water absorption, linear expansion, and modulus of elasticity including Taber abrasion tests of the thin hardboard made. The mixing ratio of waste papers and resin in the thin hardboard prominently affected the specific gravity of it, which led to affect modulus of elasticity and those physical properties sensitively. And it was shown that the hardboard containing those physical properties can be used for overlay substitutes of low grade plywood and particleboard panels.

• Journal of Pharmaceutical Investigation
• /
• v.30 no.3
• /
• pp.191-199
• /
• 2000

Genomics is providing targets faster than we can validate them and combinatorial chemistry is providing new chemical entities faster than we can screen them. Historically, the drug discovery cascade has been established as a sequential process initiated with a potency screening against a selected biological target. In this sequential process, pharmacokinetics was often regarded as a low-throughput activity. Typically, limited pharmacokinetics studies would be conducted prior to acceptance of a compound for safety evaluation and, as a result, compounds often failed to reach a clinical testing due to unfavorable pharmacokinetic characteristics. A new paradigm in drug discovery has emerged in which the entire sample collection is rapidly screened using robotized high-throughput assays at the outset of the program. Higher-throughput pharmacokinetics (HTPK) is being achieved through introduction of new techniques, including automation for sample preparation and new experimental approaches. A number of in vitro and in vivo methods are being developed for the HTPK. In vitro studies, in which many cell lines are used to screen absorption and metabolism, are generally faster than in vivo screening, and, in this sense, in vitro screening is often considered as a real HTPK. Despite the elegance of the in vitro models, however, in vivo screenings are always essential for the final confirmation. Among these in vivo methods, cassette dosing technique, is believed the methods that is applicable in the screening of pharmacokinetics of many compounds at a time. The widespread use of liquid chromatography (LC) interfaced to mass spectrometry (MS) or tandem mass spectrometry (MS/MS) allowed the feasibility of the cassette dosing technique. Another approach to increase the throughput of in vivo screening of pharmacokinetics is to reduce the number of sample analysis. Two common approaches are used for this purpose. First, samples from identical study designs but that contain different drug candidate can be pooled to produce single set of samples, thus, reducing sample to be analyzed. Second, for a single test compound, serial plasma samples can be pooled to produce a single composite sample for analysis. In this review, we validated the issue whether the second method can be applied to practical screening of in vivo pharmacokinetics using data from seven of our previous bioequivalence studies. For a given drug, equally spaced serial plasma samples were pooled to achieve a 'Pooled Concentration' for the drug. An area under the plasma drug concentration-time curve (AUC) was then calculated theoretically using the pooled concentration and the predicted AUC value was statistically compared with the traditionally calculated AUC value. The comparison revealed that the sample pooling method generated reasonably accurate AUC values when compared with those obtained by the traditional approach. It is especially noteworthy that the accuracy was obtained by the analysis of only one sample instead of analyses of a number of samples that necessitates a significant man-power and time. Thus, we propose the sample pooling method as an alternative to in vivo pharmacokinetic approach in the selection potential lead(s) from combinatorial libraries.