• The Journal of Advanced Prosthodontics
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• 제1권2호
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• pp.63-67
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• 2009

STATEMENT OF PROBLEM. Use of custom tray and tray adhesive is clinically recommended for elastomeric impression material. However there is not clear mention of drying time of tray adhesive in achieving appropriate bonding strength of tray material and impression material. PURPOSE. This study is to investigate an appropriate drying time of tray adhesives by evaluating tensile bonding strength between two types of polyvinylsiloxane impression materials and resin tray, according to various drying time intervals of tray adhesives, and with different manufacturing company combination of impression material and tray adhesive. MATERIAL AND METHODS. Adhesives used in this study were Silfix (Dentsply Caulk, Milford, Del, USA) and VPS Tray Adhesive (3M ESPE, Seefeld, Germany) and impression materials were Aquasil Ultra (monophase regular set, Dentsply Caulk, Milford, Del, USA) and Imprint II Garant (regular body, 3M ESPE, Seefeld, Germany). They were used combinations from the same manufacture and exchanged combinations of the two. The drying time was designed to air dry, 5 minutes, 10 minutes, 15 minutes, 20 minutes, and 25 minutes. Total 240 of test specimens were prepared by auto-polymerizing tray material(Instant Tray Mix, Lang, Wheeling, Il, USA) with 10 specimens in each group. The specimens were placed in the Universal Testing machine (Instron, model 3366, Instron Corp, University avenue, Nowood, MA, USA) to perform the tensile test (cross head speed 5 mm/min). The statistically efficient drying time was evaluated through ANOVA and Scheffe test. All the tests were performed at 95% confidence level. RESULTS. The results revealed that at least 10 minutes is needed for Silfix-Aquasil, and 15 minutes for VPS Tray Adhesive-Imprint II, to attain an appropriate tensile bonding strength. VPS Tray Adhesive-Imprint II had a superior tensile bonding strength when compared to Silfix-Aquasil over 15 minutes. Silfix-Aquasil had a superior bonding strength to VPS Tray Adhesive-Aquasil, and VPS Tray Adhesive-Imprint II had a superior tensile bonding strength to Silfix-Imprint II at all drying periods. CONCLUSION. Significant increase in tensile bonding strength with Silfix-Aquasil and VPS Tray adhesive-Imprint II combination until 10 and 15 minutes respectively. Tray adhesive-impression material combination from the same company presented higher tensile bonding strength at all drying time intervals than when using tray adhesive-impression material of different manufactures.

• Journal of Biosystems Engineering
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• 제28권5호
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• pp.411-420
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• 2003

Physical and cultural properties were investigated on the rice-seed pellets made by the pelleting machine(Yu, 2003) as the changes with mixing ratios of soil to rice seed of 6 : 1, 7 : 1, and 8 : I, and rotating speeds of forming rolls of 7, 10, and 13 rpm. Average weight, average diameter, and average sphericity of the pellets were 1.70 g, 12.0 ㎜, and 99.1 ％, respectively. Average number of seeds per pellet was more than 3, and almost all pellets had more than 3 seeds in the cases of mixing ratios of 6 : 1, and 7 : 1 at the forming rolls' speed of 7 rpm. Gradual drying was needed because rapid drying caused cracks on surface of the pellets. Compression strength of the pellets dried in shady room was in the range of 132 ∼ 152 N, which was enough for handling. Comparing with the previous pellets(Park, 2002), average number of seeds per pellet, ratio of pellets including more than 3 seeds, and compression strength increased due to the effects of pressure feed of pellet materials, and improvements of the forming rolls. Emergence ratio of the pellets made at the mixing ratio of 6 : 1 and the forming rolls' speed of 7 rpm, was 100 % on dry paddy and was 97 % on flooded paddy surface. Good growth characteristics, and yield except number of seedling stand and ratio of missing plant were shown in planting of the pellets made at the mixing ratio of 7 : 1 and the forming rolls' speed of 7 rpm on flooded paddy surface field. Considering the cultural results, the mixing ratio of 6 : 1, and the forming rolls' speed of 7 rpm seems to be optimum operating condition for the improved pelleting machine.

• 한국의류산업학회지
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• 제11권6호
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• pp.947-952
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• 2009

The purpose of this study is to analyze skin wettedness($w$) used as the rate index of thermal comfort, and to evaluate the wear comfort of outdoorwear. Skin wettedness is widely used to express the degree of thermal comfort. If skin wettedness exceeds a certain threshold, the body feels damp and discomfort. An experiment which consisted of rest(30 min), exercise(30 min) and recovery(20 min) periods was administered in a climate chamber with 10 healthy male participants. Two kinds of outdoorwears made of 100% cotton fabrics (Control) and specially engineered fabrics having feature of quick sweat absorbency and high speed drying fabric (Functional) were evaluated in the experiment. The condition of climate chamber was controlled according to the thermal insulation of 4 kinds of experimental ensembles(E1~E4). Total sweat loss, sweat loss absorbed into clothing and skin temperature were measured. Skin wettedness was calculated from the ratio of evaporative rate to the maximal evaporative capacity. Skin wettedness of 'Functional' was lower than 'Control' in the 3 kinds of ensembles(E1, E2, E4) because the materials of 'Functional' were composed of quick sweat absorbency and high speed drying fabrics, water vapour permeability and waterproof fabrics.

• 한국정밀공학회지
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• 제23권8호
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• pp.154-162
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• 2006

By laying its drum horizontally, front-loaded washing machine mostly used in Europe that uses the head of the water to launder was appropriate for washing only small amount of laundry. However, the demands of customers are requiring front-loaded washing machine to handle big capacity laundry as well, and have faster rotation speed to increase drying ability. To meet such demands, more stress from bending and twisting are complexly loaded onto the shaft supporting the horizontal drum, causing problems in fracture strength and fatigue life. Shafting system is mainly divided into flange and shaft. Flange is located between the drum and shaft, transferring power from the shaft to drum, and acting as a supporter of the back of the drum. Shaft is connected from the flange to insert production, transferring power from the motor to drum, and mainly acting as stiffness against the horizontal weight of the shafting system. In this paper, strength analysis and experiment were executed on both the shaft and flange of front-loaded washing machine to suggest the design improvement of shafting system for big capacity, high-rotation drying. Also, verification of this evaluation was executed on fracture strength and fatigue life for studied shaft system.

• 수산해양기술연구
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• 제59권2호
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• pp.110-116
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• 2023

In this study, samples of sea anchor canopy cloth mainly used in Korean jigging fishing vessels were collected and tested for performance evaluation. The canopy cloth of sea anchor is a basic element of form composition that is known to have the greatest influence on anchor performance. In order to evaluate the performance of sea anchor canopy cloth, five types of samples were tested for new metric count, tensile strength, water vapour transmission rate and drying speed according to the national standard (KS), and some correlations were identified. As a result of the test, the new metric count of cloths was 335.5-443.4 denier in warp and 217-447.6 denier in weft, and the minimum tensile strength was 860 N in warp direction and 430 N in weft direction. The apparent number and tensile strength of cloth were proportional, the water vapour transmission rate of the sample was 206.8 g/m²h, and the drying speed was 90-100 min. This study partially confirmed the performance evaluation based on speculation by the standard test method, and further research is needed on the clear relationship between the research results and the performance of the sea anchor.

• 한국식품과학회지
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• 제29권5호
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• pp.925-931
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• 1997

전갱이의 조미 반건품을 대량으로 생산하기 위한 기초자료를 얻기 위해, 전갱이를 조미 반건조한 후 나일론+폴리에틸렌+선형 저밀도폴리에틸렌$(0.015/0.045/0.04\;{\mu}m)$의 적층필름으로 진공포장하여 빙결점 동결$(-3{\pm}0.5^{\circ}C)$ 저장하면서 저장 중의 품질변화를 비교 검토하였다. 전갱이 조미 반건품을 제조하기 위한 가장 적합한 건조온도 및 시간은 상대습도 $50{\pm}5%$, 풍속 2m/sec 조건에서 각각 $20^{\circ}C$ 및 4시간이었으며 진공포장제품의 저장기한은 42일이었고 비포장제품의 경우는 28일이었다.

• 한국응용곤충학회지
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• 제61권4호
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• pp.675-688
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• 2022

홍잠은 숙잠(熟蠶)을 수증기로 익혀서 인간이 섭취할 수 있도록 제조한 다양한 건강 증진 효과가 있는 천연 건강 식품이다. 현재 표준 제조방법은 수증기로 찐 홍잠을 보관과 판매의 편의를 위하여 급속 냉동하여 동결 건조를 진행하는 것이다. 그런데, 홍잠을 동결 건조하는 과정은 많은 시간과 비용을 필요로 하여 홍잠 제품 가격의 인상 요인으로 작용하고 있다. 본 연구에서는 홍잠을 수증기로 찐 후 바로 균질 액으로 제조하여 분무 건조하면 분말 제조 비용을 절감할 수 있음을 발견하였다. 그리고 홍잠 균질 액에 식용 단백질 분해 효소를 첨가하여 분해시킨 후, 단 1회의 분무 건조로 제품을 제조할 수 있는 방법을 개발하였다. 특히 홍잠 균질 액이나 효소 분해 홍잠 균질 액은 바로 액상이나 젤리 형태로 일반 또는 환자용 특수 의료 용도 식품에 활용이 가능함을 보여주었다. 본 연구에서는 생산비용이 감소된 홍잠의 가공 방법을 제안하며 이는 제품 생성의 단가를 낮추어 제품의 대중화와 양잠 농가의 연관산업 육성을 불러올 것으로 기대된다.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.926-936
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• 1996

Field hulling of high-moisture paddy followed by brown rice drying offers many advantages over the present paddy harvesting and drying offers many advantages over the present paddy harvesting and drying system. We did a preliminary study of the parameters for efficient hulling of high-moisture paddy using the IRRI Centrifugal Huller and two India rice varieties. Hulling capacity , hulling efficiency , brown rice recovery and percent whole bown rice were generally best at the impeller peripheral speed of 44m/s. A second pass through the huller increased hulling capacity , brown rice revery and hulling efficiency, but reduced percent whole brown rice. To solve this , we recommed separation of paddy after hulling and aspiration such that only unhulled and partially -hulled grains will be fed back to the huller. Paddy at even 23% m.c. could be effectively hulled by the impeller-type huller , but the results were generally better at 14 to 17% m.c. Only in percent whole brown rice did the 17 to 23% m.c. range performed better than that of 14% m.c. Difference invarietal response to hulling was observed.

• 한국세라믹학회지
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• 제50권5호
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• pp.326-332
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• 2013

In this study, we prepared yttria stabilized zirconia granules for thermal barrier coatings using a spray drying process. First, we characterized the properties of granules such as flow rate and packing density for utilizing the air plasma spray process. The flow rate and packing density data showed 0.732 g/sec and 2.14 $g/cm^3$, respectively, when we used larger and denser particles, which are better than hollow granules or smaller spherical granules. Second, we chose larger, spherical granules fabricated in alcohol solvent as starting powders and sprayed it on the bondcoat/nimonic alloy by an atmospheric plasma spray process varying the process parameters, the feeding rate, gun speed and spray distance. Finally, we evaluated representative thermal and mechanical characteristics. The thermal expansion coefficients of the coatings were $11{\sim}12.7{\times}10^{-6}/^{\circ}C$ and the indentation stress measured was 2.5 GPa at 0.15 of indentation strain.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 2003년도 추계학술대회 논문집
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• pp.1311-1318
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• 2003

최근 흡한 속건성은 사이언스 소재로 가장 보편적으로 이용되고 있는 소재 성능이다. 하지만 아직 제대로 된 측정 평가법이 존재하고 있지 않고, 몇몇 의류업체에서는 단순히 객관적 속성만을 측정하고 있다. 본 연구에서는 객관적 속성인지들의 연속적이 값들이 실제 인체에서는 얼마만큼의 변별력으로 인식되는지 정신물리학적 측정법으로 최소 자극치(PSE)를 구하여 등급을 나누어 보았다. 시료는 흡한속건성 직물로 가장 많이 이용되고 있는 Coolmax(R), Coolever(R), 친수성 이중직물의 3개 그룹으로 나누었고, 측정 인자로 객관적 속성인자는 cling force, drying time을, 이와 대응하는 주관적 속성인자는 clinginess, dampness를 측정하고 각각의 PSE값을 구하였다. 그룹에 따라 객관적 속성인자 값들이 이라고 느끼는 PSE 구간까지 도달하는 시간과 속력을 측정하여 그룹마다의 흡한속건 등급을 정하였다. 또한 설계된 소재의 성능을 간접적으로 알 수 있는 transmissibility라는 인자도 도입하여 수분 전달성도 객관적으로 살펴볼 수 있었다. Clinginess, Dampness, Transmissibility 각 인자들을 평가해본 결과 Coolmax(R) 가 가장 우수함을 알 수 있었다.