• 대한영상의학회지
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• 제85권3호
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• pp.596-606
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• 2024

Purpose To examine the technical considerations of endovascular treatment for aortoiliac occlusive disease (AIOD) based on a 10-year experience in Songklanagarind Hospital. Materials and Methods This retrospective cohort study included 210 patients who underwent endovascular treatment for symptomatic AIOD between January 2010 and December 2020. The patients' clinical and lesion characteristics, including technical considerations of the procedure, were collected, analyzed, and stratified using the Transatlantic Inter-Society Consensus (TASC). Results Most patients (80%) in this study had chronic limb-threatening ischemia lesions, with an occlusion rate of 37%. The technical success rate of TASC C & D was lower than that of TASC A & B, 84.4% vs. 99.2% p ≤ 0.001. A technical success rate of 93.3% (14/15) was found for the femoral and brachial approach, compared with a success rate of 89.0% (57/64) for the unibifemoral approach in TASC C & D, without a statistically significant difference (p = 0.076). However, the puncture site complications in this route were up to 17.6%, which is the highest rate compared with other techniques. These complications could be treated either conservatively or minimally invasively. Conclusion In cases of failed femoral access, simultaneous femoral and brachial approaches improved the technical success rate of endovascular recanalization of TASC C & D aortoiliac occlusions.

• 한국세라믹학회지
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• 제50권1호
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• pp.43-49
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• 2013

${\beta}$-SiC was deposited onto a graphite substrate by a LPCVD method and the effect of the crystallographic orientation on mechanical properties of the deposited SiC was investigated. The deposition was performed at $1300^{\circ}C$ in a cylindrical hot-wall LPCVD system by varying the deposition pressure and total flow rate. The texture and crystallographic orientation of the SiC were evaluated by XRD. The deposition rate increased linearly with the gas flow rate from 800 sccm to 1600 sccm. It also increased with the pressure but became saturated above a total pressure of 3.3 kPa. In the range of 3.3 - 10 kPa, the preferred orientation changed from the (220) and (311) planes to the (111) plane. The hardness and elastic modulus showed maximum values when the SiC had the (111) preferred orientation, though it gradually decreased upon a change to the (220) and (311) preferred orientations.

• 한국가축번식학회지
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• 제14권1호
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• pp.43-49
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• 1990

To improve the freezing techniques of animal embryos using vitrification solution as a cryoprotectant rabbit embryos, by cell stages, dehydration temperature and dehydration temperature and dehydratin time, were frozen-thawed and cultured. Following are the main results obtained. 1. The damage rate of zona pellucida after thawing was higher(13.6%) when the cell stage of embryos was less than 4 cells than when the cell stage was 8~16 cell or morula. The damage rate was higher when the dehydration temperature was 4$^{\circ}C$ than -3$0^{\circ}C$ or -50~-8$0^{\circ}C$. The zona pellucida was damaged more when dehydrated for 5 min than when dehydrated for 10~15 min. 2. After being cultured for 72 hours, 5.3% of 4 cell(or less) embryos were developed to morula, while 86.4% of morula embryos were developed further. 3. More percentage of embryos(73.2%) was developed when dehydrated at -3$0^{\circ}C$ than when dehydrated at 4$^{\circ}C$ at -5$0^{\circ}C$~-8$0^{\circ}C$. 4. The hatching rate was higher when dehydrated for 5 min. When the embryos were dehydrated for 10~15 min and cultured for 24 hours, they were not even developed or development was not good in later stages.

• 한국식품과학회지
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• 제18권5호
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• pp.372-375
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• 1986

콩을 $106^{\circ}{\sim}121^{\circ}C$의 가압조건에서 일정시간 조리하면서 최대 절단력을 측정하고 이로부터 조리속도를 계산하였다. 콩의 조리속도는 1 차반응의 속도로 표시될 수 있었으며 반응속도상 수는 조리온도가 4 또는 $5^{\circ}C$ 상승함에 따라 약 2배 정도 증가하였다. 동일한 조리도를 나타내는 온도-시간과의 관계로부터 계산한 콩의 연화에 따른 Z-값은 $13.3^{\circ}C$ 이었다.

• 한국미생물·생명공학회지
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• 제9권4호
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• pp.231-236
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• 1981

성홍열, 단독, 패혈증의 원인균인 Streptococcus pyogenes중에서 항암효과가 좋은 균주를 선정하여 항암제 생산을 위한 기초실험으로서 열 처리에 따른 적정 살균조건을 검토하여 다음과 같은 결과를 얻었다. Streptococcus pyogenes의 생육 최적온도는 37$^{\circ}C$이었고 대수기에서 평균 세대시간은 20분이었으며, 5$0^{\circ}C$ 이상으로 열 처리하면 생존균이 감소하였다. 균 현탁액을 pH6, 7, 8, 9로 조절한 후, 5$0^{\circ}C$에서 열 처리하였을 때는 대수적으로 사멸하였고, 사멸속도상수 k값은 각각 0.1448, 0.1194, 0.1273, 0.1707(min.$^{-1}$)이었으나 60, 70, 80, 9$0^{\circ}C$로 열 처리하면 10분만에 99%이상이 사멸되었으며 10$0^{\circ}C$에서는 완전히 사멸되었다.

• 대한가정학회지
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• 제19권3호
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• pp.41-45
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• 1981

This study was carried out to observe the changes of Vitamin C content and to preserve the quality for the circulation periods of hot green pepper fruits wrapped with polyethylene film under the indoor temperature, as well as to find the proper time for harvest of hot green pepper fruits as a hot taste food and vegetable. the results obstained were as follows: 1. The consignment rate of hot green pepper fruits was highest, 60.2% on the 25th day after flowering, the nest 25.4% on the 20 th day, 10.3% on the 30th day and 4.1% on the 35th day. 2. the content of Vitamin C I each pepper fruits was highest o the 30th day, considerably high on the 25th day and 20th day. 3. The total content of Vitamin C in each part of hot green pepper fruits; the content in pericarp was much higher than in placenta and seed, and that of hydro type Vitamin C was almost the same. 4. The reduction rate of vitamin C during circulation periods was highest on the 3rd day; 42% in pericarp, 50% in placenta, 65% in seed. But in the package wrapped up with polyethylene film, the reduction rate in the same period was 5% in pericarp, which was very low in reduction, and those in placenta and seed were almost the same as in the unwrapped state.

• 대한기계학회논문집B
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• 제33권7호
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• pp.535-540
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• 2009

Experiments are conducted to elucidate effects of counterflow burner diameter on flame extinction behaviors in C-curve. Present experimental results with burner diameters of 18, 26, and 50 mm in normal-gravity are compared with the numerical result of Oppdif code as well as the previous experimental results in micro-gravity. The turning point migrates to a higher global strain rate as burner diameter decreases. It is shown that the C-curve with the burner diameter of 50mm is best-fitted to the numerical result of Oppdif code and the previous micro-gravity results also excurse to the numerical result. This suggests that the precise C-curve can be obtained only with an appreciably large burner. The main reason why these differences appear is shown to be attributed to the transition of shrinking flame disk to flame hole due to strong effects of radial conduction heat loss, which is the typical extinction characteristics of low strain rate flames with a finite burner diameter in a counterflow diffusion flame.

• 열처리공학회지
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• 제4권3호
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• pp.39-46
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• 1991

The effects of austenitizing temperatures and times and cooling rate on the characteristics of continuous air cooling have been investigated for 0.3%C-Mn steels microalloyed with vanadium. Transformation start temperatures have been found to be measured from temperature-time curve directly obtained with continuous air cooling and to decrease with increasing austenitizing temperature, cooling rate and Mn contents. The coarsening behavior of austenite grain size has been measured to abnormally grow at $1050^{\circ}C$ and rapidly grow at $1200^{\circ}C$. It has been found that the volume fraction of pearlite was linealy proportional to the reciprocal square root of austenite grain size. The hardness has been measured to increase with increasing cooling rate up to $250^{\circ}C/min.$ and to remain relatively unchanged in the range of $250{\sim}400^{\circ}C/min.$ showing that hardness valves for steel with a higher Mn content increase more than those for steel with a lower Mn content. The impact property has been found to decrease with increasing of austenite grain size but does not linealy change with the reciprocal square root of austenite grain size.

• 한국가축번식학회지
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• 제8권1호
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• pp.22-28
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• 1984

This experiment was carried out to investigate effects of DMSO or ethylene glycol as a cryopotectant and of freezing methods on survival rate of forozen-thawed rat 2-cell embryos by morphological observation. 2-cell embryos were recovered from oviducts of Sprague Dawley females mated with males of same strain on day 2 of pregnancy after inducing superovulation by intrapertioneal injection of PMSG and HCG. In slow freezing and thawing groups, embryos were frozen to -79$^{\circ}C$ or -196$^{\circ}C$ in a glass test tube containing 0.2ml PBI with 1.5M DMSO or 1.2M ethylene glycol at a rate of 0.3-1.0C/min. and thawed slowly. When samples were frozen to -79$^{\circ}C$, higher survival rate was obtained in the medium containing DMSO (43.9%) than ethylene glycol (41%). And similar result was obtained (32.5% in DMSO vs. 31.4% in ethylene glycol) when samples were frozen. In rapid freezing and thawing groups, embryos were frozen to -79 or -196$^{\circ}C$ in a glass test tube containing 0.2ml of PBI with 1.5M DMSO or 1.2M ethylene glycol by rapid cooling, and thawed rapidly. When samples were frozen to -79$^{\circ}C$, 1.5M DMSO (13.2%) was more effective than 1.2M ethylene glycol (6.1%). When the storage temperature was -196$^{\circ}C$, survival rates were 9.8% in 1.5M and 5.4% in 1.2M ethylene glycol.

• 한국세라믹학회지
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• 제30권8호
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• pp.664-670
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• 1993

Potassium tetratitanate (K2Ti4O9) and Potassium hexatitanate (K2Ti6O13) fibers have been prepared by the slow-cooling calcination process in a temperature range from 125$0^{\circ}C$ to 95$0^{\circ}C$ using the K2CO3 and TiO2 as the starting materials. Optimum fiber growth conditions have been also investigated by changing the physical parameters, such as calcination time and temperature, and cooling rate. Relatively long K2Ti4O9 fibers ( 1.2mm) have been grown with quite a high aspect ratio (c/a 500)when the starting material with a nominal composition of K2O and TiO2 with 1:4 was calcined at 115$0^{\circ}C$ for 4h, and then was slowly cooled to 95$0^{\circ}C$ with a rate of 2$0^{\circ}C$/h. In case of a K2O.6TiO2 composition, acicular shaped K2Ti6O13 fibers with 20~300${\mu}{\textrm}{m}$ long and low aspect ratio (c/a 10~15) have been formed irrespective of the coolign rate. The growth condition of fibers have been discussed based upon the phase diagram of K2O-TiOa2.