• Journal of Dental Rehabilitation and Applied Science
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• v.26 no.2
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• pp.197-204
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• 2010

The purpose of the study was to observe the time serial changes in proximal contact tightness after single crown restoration. Initial proximal contact tightness before crown preparation and after prosthesis restoration were measured repeatedly in 12 subjects. In consequence proximal contact tightness of temporary setting on prosthesis was bigger than contact tightness before initial preparation, contact tightness of the prostheses of 1-2 weeks after the setting was similar to that before the preparation, tightness of 2-4 weeks after the setting showed little change and maintained constant contact tightness.

• Elastomers and Composites
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• v.36 no.4
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• pp.225-236
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• 2001

In order to improve the properties of the copolymer and the terpolymer that was used as removal-type pressure sensitive adhesive(PSA), we synthesized quaterpolymer with the variation of the types of monomer, initiator, and solvent, and concentration, the monomer/solvent ratio, reaction temperature and time. and determined the properties of this adhesive: the viscosity, molecular weight, conversion, solid content and structure of polymer. The prepared polymer was crosslinked by changing the type of crosslinking agent and concentration, and then we investigated the characteristics or adhesive such as peel adhesion, shear adhesion, heat resistance, weathering resistance and peel adhesion to aging. The optimum performance of RA/2- EHA/MMA/2-HEMA as a PSA were obtained when benzoyl peroxide was used as an initiator with the reactant mixture consisted of 80% BA and 2-EHA, 15%, MMA, and 5% 2-HFMA. The optimum reaction temperature and time were $80^{\circ}C$ and 8 hours, respectively. For BA/2-EHA/MMA/AA, the optimum performance was obtained when the polymerization was performed at the monomer composition of 80% BA/2-EHA, 15% MMA, and 5% AA. BPO was used as initiator and the optimum reaction temperature and time were identical to those of BA/2-EHA/MMA/ 2-HEMA. Isocyanate and melamine were used to crosslink BA/2-EHA/MMA/2-HEMA and BA/2-EHA/MMA/AA, respectively. No effect on the type of cross-linking agent on the peel adhesion was observed with aging. The quarterpolymers crosslinked with melamine left residues on the counter surface after weathering resistance test, while the polymers crosslinked with isocyanate did not.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.1
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• pp.43-48
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• 1986

The experiment was conducted to know the varietal difference in changing aspect of daily filling sink during of rice using three cultivars; ‘Suweon 295’ (japonica), ‘Suwoen 264’ and ‘IR 1317-70-1’ (semi-dwarf indica) cultivated in the field and green house of the Crop Experiment Station in 1983. There was not significant varietal difference in flowering habit and duration of flowering period each panicle. Semi-dwarf indica cultivars showed shorter days to physiological maturity of rice kernel than the japonica one. The former also displayed earlier decrease in water content of rice grain during ripening than the latter. Japonica variety revealed larger difference in ripening advancement between vigorous florets and inferior one than semi-dwarf indica varieties. The semi-dwarf indica rice cultivars expressed significantly shrewder parabola of daily filling of sink per panicle during ripening than the japonica one. The time showing maximum capacity of daily filling of sink per panicle during ripening was 10-12 days after anthesis. The filling capacity of daily sink filling per panicle for 'IR 1317-70-1', 'Suweon 264' and 'Suweon 265' at this time were about 240 mg, 165 mg and 145 mg, respectively. Pattern of sink filling per panicle during ripening was slightly changed by the cultural environment. ‘Suweon 295’ showed slightly sharper parabola and 2-3 days earlier time showing maximum capcity of daily sink demand per panicle during ripening in the field than those in the green house.

• Journal of the Korean Society of Clothing and Textiles
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• v.13 no.2 s.30
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• pp.117-127
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• 1989

여성 파운데이션용 편포의 압력특성에 관한 문제를 공학적 관점에서 검토해보기 위하여 거들용 편포와, 또한 비교를 위하여 드로우어즈용 편포를 시료로하여 완전강체 및 완전탄성체, 그리고 강체와 탄성체를 동시에 가지는 수압체를 모델로 제작하고, 시료를 고리형태로 만들어 피복시킨후 그 압력을 12시간 동안 연속측정하였다. 이때 시료의 신장정도, 수압체의 탄성체 구성비 등을 여러가지로 달리 하여 그에 따른 압력의 변화를 봄과 동시에 시간경과의 효과도 검토하여본 바 다음과 같은 결과를 얻었다. 1. 강체를 수압체로한 경우는 시료의 신장률 증가에 따라 압력이 거의 직선적으로 증가하였고, 그 정도는 거들의 재료가 드로우어즈의 재료에 비하여 훨신 크게 나타났다. 2. 수압체의 탄성체구성비가 증가할수록 신장률 증가에 따른 시료의 실질신장률의 증가 경향이 둔화되어, $40\%$신장률의 경우는 그 이전보다 오히려 감소하는 경향을 나타내었다. 3. 수압체에 탄성체가 포함된 경우는 매우 적은 압력을 나타내었으며, 시료 신장률의 증가에 따른 변화도 매우 적게 나타남으로써 시료 신장률이 클수록 강체수압체에 대한 압력과의 차이가 더욱 커지게 됨을 알 수 있었다. 그러나드로우어즈 재료의 경우는 탄성체가 받는 부담은 크지 않은 것으로 나타났다. 4. 압력의 경시변화는 초기의 압력분포 안정화 과정을 제외하고는 12시간까지 어떤 경우에도 크게 나타나지 않았다.

• Applied Biological Chemistry
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• v.25 no.3
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• pp.166-172
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• 1982

The changes of hydrogen ton concentration, viscosity and free sugars in the water-soluble mucilage of Ulmus Coreana, Nakai root upon storage at 10^{\circ}C were studied. Hydrogen ion concentration in the mucilage changed $pH7{\rightarrow}pH4{\rightarrow}pH6$ or 7. The viscosity of mucilage decreased very slowly. The mucilage contained glucose and galacturonic acid. The hydrolyzed products of mucilage consisted of rhamnose, mannose, galactose, arabinose, xylose, glucose and galacturonic acid.

• Applied Biological Chemistry
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• v.32 no.3
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• pp.232-239
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• 1989

Three types of Korean strawberries, Gardian cultivated in vinyl house, Gardian cultivated on the field and Bogyo, at early variety, on the field were harvested after $10{\sim}34$ days from falling of flowers to investigate the chemical changes of fruits during maturing. The initial pH range after 10 days from falling of flowers was $4.13{\sim}4.28$, which was decreased to $3.40{\sim}3.49$ with maturing. The total acid was steadily increased for 26 days and then decreased thereafter. Vitamin C, not detected until 14 days, was gradually increased to $15.83{\sim}24.90mg%$ in 34 days. Reducing sugar content was increased for 24 days and then decreased, while total sugar, glucose and fructose were generally increased during maturing. Xylose was detected a little. For minerals, potassium was measured the highest value, followed by magnessium, and sodium. A trace amount of manganese, zinc and copper were detected. The strawberries had the content range of $6.00{\sim}24.60mg%$ of methyl alcohol and $6.00{\sim}24.40mg%$ of ethyl alcohol.

• 한국양묘협회지
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• s.2
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• pp.15-27
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• 1974

이상 묘포토양의 제문제점에 대해서 한측면으로 고찰을 해보았다. 묘포토양은 곳에 따라 다양복잡하고 재배수종 그리고 생태환경, 작업기술등 변화가 많은 것이므로 그러한 영향하에 있다고 할 수 있다. 그러나 토양분석이 잘 되고 그것을 토양관리에 합리적으로 적응한다는 것은 묘목양성기술의 과학화라는 뜻에서 결코 경시할수 없는 일이다. 다음과 같은 토양관리사항을 이곳에 적요할수 있다. (가) 토양산도는 재배수종에 알맞도록 조정이 되어야 한다. 토양산도(pH가)는 5

• Journal of Life Science
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• v.25 no.10
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• pp.1124-1131
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• 2015

Consumer interest in the stability of medicinal herb extracts during storage has increased. Although the advent of new technologies has improved preservation conditions, increasing the storage time, there are few studies on the preservation of herb extracts. The purpose of this study was to perform microscopic observations of Samul-tang decoctions under various preservation conditions. The storage temperature (a high temperature, room temperature, with or without light, refrigeration, or cryopreservation) and storage time (0, 15, 30, 90, and 180 days) were given to each condition Macroscopic morphology, pH, UV absorption, HPLC, and bacteriological studies were performed to determine microscopic changes in Samul-tang decoctions. The biological activity (tyrosinase inhibition) of the Samul-tang decoctions was also examined. There were no major changes in the indicated observation items when the extracts were stored in each condition. However, at higher storage temperatures and longer storage times, microscopic changes increased, although no bacteria were detected. Furthermore, the higher the storage temperature was and the longer the storage time was, the bigger the change was, despite of minor microscopic changes. Therefore, to maintain the stability of herbal extracts during storage, it is recommended to keep the Samul-tang decoction in the preservation condition of refrigeration and cryopreservation or without light rather than high temperature and room temperature as possible.

• Culinary science and hospitality research
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• v.8 no.2
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• pp.197-206
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• 2002

The present study attempted to obtain a basic data concerning the effect of $\pi$-water, a sort of physiological water, on the maintenance of chicken freshness. The meats were divided into three groups: the control, 20% - dilution, and 5% - dilution groups. In the experiment, the changes of the TBA-values of the meats started to appear on the 3rd day in the control group, and from the 4th day in the 20% - and 5% - dilution groups. The changes of pH didn't appear in the meats as the storage time passed. The number of general bacteria increased rapidly on the 3th day in the control, and on the 5th day in the 20% -, and 5% - dilution groups. As for the color, the meats turned greenish on the 5th day in the control, 7th, in 20% - dilution, and, l0th in the 5%-dilution groups. As for the order, the meats emitted the unpleasant order, such as that of ammonia, on the 3rd day in the control, 5th, in the 20% - dilution, and, 7th, in the 5ft-dilution group.

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.64-67
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• 2003

Poly(trimethylene terephthalate)(이하 PTT)는 1941년 Caligo Printing Ink사의 Whinfield와 Dickson에 의해 중합 방법이 보고[1]된 이후 상업화를 위한 많은 학문적 연구가 이어져왔다. 그럼에도 불구하고 아직 PET에 비하여 기초 연구가 미비하며 상업적으로 사용하기에는 많은 불안정한 요소들을 가지고 있다. 앞선 연구자들이 밝힌바와 같이 PTT의 결정구조는 2개의 단량체가 1개의 unit cell을 이루면서 결정격자 내에서 O-C $H_2$-C $H_2$-C $H_2$-O가 trans-gauche-gauche-trans형의 coiled spring처럼 형성되어 좋은 elastic recovery와 뛰어난 신축성, 염색성 등 우수한 물성을 가지며 전반적인 성질은 PET와 Nylon의 중간성질을 뛰고 있지만 [2,3] 유리전이온도 (Tg : dir 4$0^{\circ}C$)와 냉결정화오도 ( $T_{ c cold}$ : dir 55$^{\circ}C$)사이의 차이가 15$^{\circ}C$ 정도이므로 섬유상에 많은 경시변화가 일으켜 구조적 불안정성을 가지게 한다 [4]. (중략)