• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.19 no.2
• /
• pp.251-259
• /
• 2010

It is presented in this study a new efficient intelligent machining strategy, which can be used to remove the uncut volume at the boundary region of curved surfaces caused by cutter interference. The geometric form definitions and recognition of topological features of the surface triangulation mesh are used to generate cutter paths along successive and interconnected steepest pathways, that minimize the cusp height left after flat end milling. In order to machine the uncut volume gradually, the z-map cutter centers are adjusted to avoid cutter interference for the 6 kinds of avoidance types. And then, the generative subsequent paths are sequenced to determine the second step cutter paths for the next uncut volume. For the 2 kinds of test models with convex and concave surface region, the implemented software algorithm is evaluated by investigating the residual swelling of uncut volume for each machining step.

• Journal of Biomedical Engineering Research
• /
• v.9 no.1
• /
• pp.67-72
• /
• 1988

Poly (HPMA/NVP) hydrogel was synthesized according to the composition and the con- centration of the crosslinking agent. The swelling degree of the P(HPMA/NVP) hydrogel decreased with increasing of P(HPMA) composition and crosslinking agent. The glass transi- tion and softening temperatures of the P(HPMA/NVP) increased with increasing of P(HPMA) composition. The composition of P(HPMA/NVP) : 70/30 and the concentration of the crosslin- king agent of 0.5 wt % gave the optimum condition in the application to the contact lens. There were also adequate in the mechanical, refractive properties and in vivo test in the P(HPMA/ NVP): 70/30 system.

• Korean Journal of Clinical Laboratory Science
• /
• v.36 no.1
• /
• pp.7-12
• /
• 2004

Trichophyton(T.) tonsurans has been identified for the first time in Korea in 1995 and has been increasing in number of reported in wrestlers, in judo players, and in korean - style wrestlers. Author tried mycological studies with T. tonsurans is isolated in Daegu Korea. The results are as follows: All 16 strains of T. tonsurans tested for nutritional requirement, showed strongly stimulated growth by thiamine, mild to moderate growth on casamino acid agar, poor growth on ammonium nitrates base agar. All 16 strains of T. tonsurans tested showed positive results for hair perforation and urease test. Gross findings of T. tonsurans showed that fine granular surface with light yellow hue or white color and mahogany brown color on the reverse side. Microscopic findings showed that septated hyphae, chlamydoconidia and microcondia. Microconidia were characteristic in their arrangerment and shape : round or oval shaped microconidia laterally to hyphae, some were match - head like terminal swelling.

• 대한생식의학회:학술대회논문집
• /
• 2001.06a
• /
• pp.62-63
• /
• 2001

• Journal of the Korean Graphic Arts Communication Society
• /
• v.18 no.2
• /
• pp.83-101
• /
• 2000

In this experiment butadiene rubber(BR)/acrylonitrile butadiene rubber(NBR) blends was prepared and then the applicability of BR/NBR blends as printing rubber roller was examined. With the aid of open 2-roll mill, BR, NBR and another chemical additives were compounded. Then rubber vulcanizates were manufactured by hot press and maximum torque, Mooney viscosity, mechanical properties and oil resistance of the test specimens were measured. With prolonged oil aged treating time, BR/NBR blends became soft and so the hardness of blends decreased. It could be explained by the swelling of rubber matrix with oil penetration in to rubber molecules. The undesirable low value of oil resistance of BR was significantly improved by blending BR with NBR.

• Reproductive and Developmental Biology
• /
• v.28 no.3
• /
• pp.167-172
• /
• 2004

This study was performed to examine the correlations among dog sperm viabilities evaluated by flow cytometry, by microscopic evaluation (ME), by carbo-xifluorescein diacetate and propidium iodide (CFDA/PI) and by hypoosmotic swelling (HOS) test. Semen were collected from 5 dogs ranging in age from 2 to 4 years. Each ejaculate was divided into 3 aliquots and different proportions of freeze-killed cells were added to each aliquot (1:0, 1:1 and 1:3). In the other experiment, semen was extended with Sweden extender containing 5% glycerol and equex STM paste, and frozen using liquid nitrogen vapor. Fresh and frozen-thawed dog sperm viability were assessed by flow cytometry using PI staining method. The accuracy of flow cytometry was evaluated by comparing with other classic assessments, microscopic evaluation, epifluorescence microscopic analysis using CFDA/PI, and HOS test. High correlations of sperm viabilities were found among flow cytometry, epifluorescence evaluation, HOS test (p<0.01) in fresh semen. Especially, sperm viability assessed by HOS test was highly correlated with viability by flow cytometry in all the ratios of live and dead spermatozoa, 1:0, 1:1 and 1:3 (p<0.01). The viability evaluated by ME were significantly correlated with that by flow cytometry in ratios of 1:0 and 1:3 (p<0.05) however, there was no significance in ratio of 1:1. The viability evaluated by C/p were highly correlated with that by flow cytometry in ratio of 1:0 and 1:1 (p<0.01) and significantly correlated in ratio of 1:3 (p<0.05). In frozen-thawed spermatozoa, the viability determined by HOS test was considerably correlated with that by flow cytometry (p<0.01). There was significant correlation between the viabilities by ME and by flow cytometry (p<0.05). But the viability evaluated by CFDA/PI was not correlated with viability by flow cytometry. The result from this study validate the use of flow cytometry as a precise method for assessing the viability of fresh and frozen-thawed dog spermatozoa.

• Korean Journal of Veterinary Service
• /
• v.21 no.1
• /
• pp.29-39
• /
• 1998

This study was carried out to investigate the prevalence of antibody against Toxoplasma gondii in the dog by Latex agglutination test and Indirect fluorescent antibody test. Two month-old dogs were infected intraperitoneally with T gondii to observe histopathological and immunohisto-chemical changes. Results obtained through this experiment were summarized as follows ; 1. Among the serum samples of 163 heads of the dog, 10 samples(6.1%) were positive. 2. In the sex, 6 heads (7.1%) out of 84 female dogs and 4 heads(5.1%) out of 79 male dogs were positive. However, there were no significant differences between the male and female. 3. Overall proportion of agreement between indirect fluorescent antibody and Latex agglutination test in 163 sera of dogs was 97.5%. 4. When 2 month-old dogs were infected intraperitoneally with T gondii, main clinical signs were intermittent fever, dyspnea, diarrhea. In general, the infected dogs recovered closely on the 11th day of post-inoculation. 5. At necropsy, petechial and ecchymotic hemorrages and swelling in small intestine, lung, spleen, liver and kidney were observed. 6. In histopathological observation, interstitial pneumonia, hyperemia and hemorrhages in lung were observed. Focal necrosis of hepatocytes, the neutrophil and basophil in the renal tubular epithelium were observed. 7. By immunohistochemical staining using Vectorstain ABC kit, the positive cells were recognized in the lung and the liver. 8. By indirect fluorescent antibody test, the Toxoplasma antibodies in the infected dogs were detected on the 15th day of postinoculation.

• Tunnel and Underground Space
• /
• v.17 no.6
• /
• pp.464-474
• /
• 2007

An enhancement in the performance and safety of a high-level waste repository requires a validation of its engineered barrier. An engineering-scale test (named "KENTEX") has been conducted to investigate the thermal-hydro-mechanical behaviors in the engineered barrier of the Korean reference disposal system The validation test started on May 31, 2005 and is still under operation. The experimental data obtained allowed a preliminary and qualitative interpretation of the thermal-hydro-mechanical behaviors in the bentonite blocks. The temperature was higher as it became closer to the heater, while it became lower as it was farther away from the heater. The water content had a higher value in the part close to the hydration surface than that in the heater part. The relative humidity data suggested that a hydration of the bentonite blocks might occur by different drying-wetting processes, depending on their position. The total pressure was continuously increased by the evolution of the saturation front in the bentonite blocks and thereby the swelling pressure. Near the heater region, there was also a significant contribution of the thermal expansion of bentonite and the vapor pressure in the pores of the bentonite blocks.

• Korean Chemical Engineering Research
• /
• v.43 no.6
• /
• pp.722-727
• /
• 2005

Dow99Ca350 (Dowex monosphere 99Ca/350 separation resin), MFG-220, and Finex CS-10GC are ion-exchange resins, and primarily used to separate sugars, and all of these resins have poly styrene DVB backbone, and sulfonyl group. These resins are already used to separate sugars continuously at sugar industry at constant temperature. These resins are used in experiments for understanding temperature effect on retention or adsorption behavior. Using Dow99Ca350, swelling test, porosity test, pulse test, and frontal analysis at various temperatures were performed. In the cases of MFG-220, and Finex CS-10GC, the effect of temperature variation was verified by pulse test. The experimental results are shown that Dow99Ca350, MFG-220, and Finex CS-10GC, which are commercial resins for sugar separation, are stable to temperature variation because the maximum change of retention time of fructose, and glucose are 1.76, and 3.37％ respectively.

• Journal of the Korean Geotechnical Society
• /
• v.18 no.5
• /
• pp.19-25
• /
• 2002

In this paper, a laboratory investigation was carried out to change the geotechnical properties of clayey soil with quicklime and rice husk ash for surplus soil strength improvement. The organic content of soils is 8.67%, 6.45% and 3.84% respectively. The geotechnical properties of treated soil were evaluated by a series of laboratory unconfined compression test, consolidation test and etc. The test results indicated that the presence of RHA enhanced the efficiency of lime stabilization. Especially, the increase in strength is very high at the first stage, while the significant improvement occurs in a sample C with organic content of 3.84%. These results can be identified by X-ray diffraction(XRD) and scanning electron microscope(SEM). The results of consolidation test indicate that the presence of RHA with lime reduces the properties of swelling of soil. Thus, it was verified that the addition of RHA is more effective than using only lime for soil stabilization.