• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.319-320
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• 2016

아조벤젠 (Azobenzene)은 광스위치분자 소자로서 빛에 의해 분자의 구조가 바뀌는 성질을 가지고 있다. 이러한 특성은 전류를 적절히 조절하는 온/오프 기능의 수행 가능성을 제시한다. 빛의 파장에 따라 두 벤젠 고리를 연결하는 원자들 (CNNC)의 광학여기상태가 달라지며, 그 결과로 CNNC 각도의 변화가 나타난다. 이는 아조벤젠 구조의 변화를 가져오며, 크게 cis-, trans-(CNNC 각도 기준으로 각각 $0^{\circ}$, $180^{\circ}$)로 나눠진다. 이 연구에서는 LCAO-DFT 제일원리 계산을 이용하여, CNNC 각도에 따른 분자 구조의 변화와 안정성을 바닥상태($S_0$)와 광학여기상태($S{\text\tiny{1}},n{\grave{a}}{\pi}^*$)로 나누어 살펴보았다. 그 결과 바닥상태에서는 trans-구조가 가장 안정하였고, 광학여기상태에서는 CNNC 각도가 $90^{\circ}$ 부근에서 가장 안정한 구조를 가졌다. 또한, 바닥상태에서는 cis-, trans-사이에 에너지 장벽이 있는 반면 광학여기상태에서는 에너지 장벽이 없음을 관찰하였다.

• Journal of Astronomy and Space Sciences
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• v.4 no.2
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• pp.69-80
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• 1987

A photometric solutions of T LMi were derived with the Wilson and Devinney model using the BV photoelectric light curves of Okazaki(1977) and orbital period changes are discussed from the all of the collected times a available in the literature. We obtained a variation with a period of $62.^y01$ and an amplitude of $0.^d0425$ form the (O-C) diagram. According to the physical properties of T LMi on the basis of derived photometric solution, it have a doubt the credibility of the existence of "R CMa type".ype".uot;.

• Applied Biological Chemistry
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• v.24 no.4
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• pp.260-266
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• 1981

Some properties of cellulase and xylanase produced from Pleurotus ostreatus 301 and Lentinus edodes 3-1 during its growth in rice straw medium were investigated. The cellulase activities of P. ostreatus 301 and L. edodes 3-1 were increased in proportion to substrate concentration within 0.6% and 0.8%, respectively, and xylanase activities of two strains were increased within 1%. The reducing sugar production of cellulase and xylanase in two strains were proportionaly increased until 30 min. and 60 min. respectively. The opium pH for cellulase activities of P. ostreatus 301 and L. edodes 3-1 were pH 4.0 and pH 4.5, respectively, and xylanase activities of two strains were pH 5.0. The stable pH range for cellulase activities of P. ostreatus 301 was within 4.0 to 6.0 and L. edodes 3-1 was within 3.0 to 5.0, Xylanase activities of P. ostreatus 301 was within 4.5 to 6.0 and L. edodes 3-1 was within 3.5 to 6.0. The optium temperature for cellulase activities of P. ostraeatus 301 and L. edodes 3-1 were $40^{\circ}C$ and $50^{\circ}C$, respectively, but xylanase activities of P. ostreatus 301 and L. edodes 3-1 were $50^{\circ}C$ and $45^{\circ}C$, respectively. Thermal stability of enzymes were below of optimum temperature and these were mostly inactivate at $70^{\circ}C$ for 10 min of the metalic ions tested, cellulase activities of L. edodes 3-1 was increased by $Co^{++},\; Mg^{++}$ at the concentration of $10^{-2}M$, but were greatly inhibited by $Hg^{++},\;Cu^{++}$ in two strains. Xylanase activities were increased by $Ca^{++},\;Co^{++},\;Mg^{++}$ and $Cd^{++}$ but was greatly inhibited by $Hg^{++}$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.4
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• pp.562-568
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• 2016

This study investigated the effects of Yuza pectin extract (0, 0.1, 0.15, and 0.2%, w/v) on the physicochemical, microbial, rheological, and sensory properties of yogurt. Pectin extract was extracted from Yuza peel by using citrate after juicing the flesh. The total sugar content of Yuza pectin was 89.07%. The pH of Yuza pectin extract-added yogurt was 4.43. All Yuza pectin extract-added yogurt samples showed shear-thinning flow behaviors (n=0.33~0.44). The values for apparent viscosity ($0.34{\sim}0.47Pa{\cdot}s$), consistency index ($4.48{\sim}10.25Pa{\cdot}s^n$), yield stress (6.56~17.61 Pa), storage modulus (47.96~75.21 Pa), and loss modulus (19.79~26.06 Pa) for 0.1~0.2% (w/v) Yuza pectin extract-added yogurt were considerably higher than those of the control. These result indicated that Yuza pectin extract could enhance steady and dynamic shear rheological properties of yogurt. The sensory scores of Yuza pectin extract-added yogurt were higher than those of the control.

• Korean Journal of Food Science and Technology
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• v.23 no.5
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• pp.633-641
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• 1991

Mook, a traditional gel food in Korea, has been made from mainly acorn, buckwheat, and mungbean starches (Mook Starches). Corn, rice, wheat starches (Non-Mook Starches) are not used due to their weak gelation power. In order to know the effects of properties of starch on gelation, some physicochemical properties, molecular structure, and starch lipid of these six starches were investigated and compared with gel hardness. Both amylose content and gel hardness of starches were in order of mungbean, acorn, buckwheat, wheat, corn, and rice and these two parameters showed a very good correlation (r=0.95). The amyloses of Mook Starches had larger molecular size (${\overline}D.P._{n}=1,080{\sim}1,580\;vs\;670{\sim}1,120$ for Mook Starches and Non-Mook Starches, respectively), more average number of chain ($2.9{\sim}5.4\;vs\;1.7{\sim}2.5$), and shorter average chain length ($290{\sim}390\;vs\;390{\sim}450$) than those of Non-Mook Starches. Also, Mook Starches had longer average chain length ($22.2{\sim}22.6\;vs\;18.9{\sim}21.3$) of amylopectin and less starch lipid content ($0.12{\sim}0.49\;vs\;0.68{\sim}1.26%$) than Non-Mook Starches. These properties had good correlations with gel hardness (r=0.76-0.84). Consequently, the gelation power of Mook Starches was thought to be derived from their high amylose content and other properties of starches.

• Korean Journal of Agricultural Science
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• v.24 no.1
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• pp.29-40
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• 1997

Six different types of teas from box thorn leaves collected on mid May were prepared by using different tea making procedures. The selected physicochemical propentes and the sensory qualities of the 6 different teas were analyzed. The box thorn leaves contained 87.71% moisture, 0.69% crude fat, 4.77% crude protein, 2.13% fibers, 3.11% carbohydrates and 1.59% ash. Based on the sensory analysis, roasted tea(duckum tea) had the highest values in taste, flavor, color and overall preference. Eighteen free amino acids were identified in the roasted tea, showing the specially high levels of proline(170.15mg%) and glutamic acid(112.34mg%). The roasted tea also contained glucose(1.07%), maltose(0.87%), sucrose(0.63%) and fructose(0.55%). The content of citric acid(337.43mg%) in the roasted tea was the highest, followed by malonic acid(54.17mg%), oxalic acid(48.66mg%), malic acid(27.41mg%), succinic acid(4.48mg%), fumaric acid(1.08mg%) and lactic acid(trace amount), in a decreasing order.

• Korean Journal of Food Science and Technology
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• v.21 no.4
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• pp.468-479
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• 1989

The oxidative stability of the ramyon prepared with rapeseed oil fortified with antioxidants or blended with palm oil was studied to explore the possibility of substituting it for Imported frying fats and oils. Natural tocopherols, butylated hydroxyanisole(BHA), tertiarybutyl hydroquinone(TBHQ), and ascorbyl palmitate with citric acid were used at a level of 0.02 percent. Blended oils were prepared by adding a palm oil to the rapeseed oil at ratios of 7:3, 5:5, and 3:7(w/w), respectively. Ramyon samples were stored at $35.0{\pm}0.5^{\circ}C$. for 90 days. The values of parameters, such as peroxide value, unsaturation ratio, and dielectric constant, of the extracted oils were regularly determined. An organoleptic test for the flavor of the samples was also performed. The oxidative stability of the samples was estimated on the basis of the changes of the parameter values. The effectiveness of the antioxidants was in the order of TBHQ ${\gg}$ ascorbyl palmitate with citric acid>BHA>natural tocopherols. The oxidative stability of the ramyon prepared with the rapeseed oil containing 0.02 percent TBHQ was almost as good as that of the ramyon prepared with the palm oil. The stability of the ramyon prepared with the blended oil containing 70 percent palm oil was also as good as that of the ramyon prepared with the palm oil.

• Korean Journal of Food Science and Technology
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• v.15 no.3
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• pp.245-251
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• 1983

Nucleic acid degrading enzymes (RNase, PDase, PMase) isolated from rice Makgeoly brewing were purified by DEAE-cellulose column technique and their enzymological properties were examined. Changes of nucleotides and their related substances during the brewing were also investigated. The results obtained were as follows: 1. RNase activity was increased in the earlier phase of brewing and then decreased after 3 days brewing, while PDase and PMase activities were decreased with the lapse of time. 2. The optimum pH of RNase was 5.0 and those of PDase and PMase were 6.0. Activities of these three enzymes were almost stable in the range of pH 6.0-7.0. 3. The optimum temperature of RNase and PDase were in the range of $55{\sim}60^{\circ}C$ and that of PMase was about $50^{\circ}C$. When RNase was treated at $100^{\circ}C$ for 10 min., 80% to of activity was lost PDase lost 90% of activity when heated at $70^{\circ}C$ for 10 min, while PMase was completely inactivated at the same condition. 4. $CU^{++},\;Zn{++}$ inhibited the activity of NRase, Activity of PMase was reduced about 30% by adding $10^{-3}M\;Na_{2}HPO_{4}$5. Until 4 day brewing, IMP was increased, while UMP, GMP, AMP were decreased gradually.

• Journal of the Korean Ceramic Society
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• v.39 no.7
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• pp.704-709
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• 2002

To improve the mechanical properties of $Al_2$O$_3$/ZrO$_2$composites, the homogeneous dispersion of ultra low size ZrO$_2$ particles in $Al_2$O$_3$ceramics have been controlled by coprecipitation method. In case of mechanical mixing of ZrO$_2$ powders with $Al_2$O$_3$, homogeneous dispersion and controlling the ZrO$_2$ size were relatively difficult due to high sintering temperature. So nanosized Zr hydroxide was coprecipitated from ZrOCl$_2$/Y(NO$_3$)$_3$ solution with commercial sub-micron sized $\alpha$-alumina (Sumitomo : AES-11(0.4 ${\mu}{\textrm}{m}$)) and high purity ultra low sized $\alpha$-alumina (Taimei Chemical (0.22 ${\mu}{\textrm}{m}$)) for low temperature sintering. By this partial coprecipitation method, relatively low sized ZrO$_2$ dispersion in $Al_2$O$_3$/ZrO$_2$ composites was achieved at 150$0^{\circ}C$-1$600^{\circ}C$ of sintering temperature range and their mechanical properties were measured.

• Microbiology and Biotechnology Letters
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• v.10 no.3
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• pp.185-190
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• 1982

A strain of Streptomyces sp. (YS-40) which was able to produce penicillinase, was isolated from soil and the enzymatic characteristics of this enzyme were investigated. The crude enzyme was obtained with the fractionation by 80 % cold acetone. The optimal temperature and pH of this enzyme was 45$^{\circ}C$ and 5.0 respectively. The stable pH range of the enzyme was between pH 5.5 and 8.0 at 37$^{\circ}C$. By heat treatment at 6$0^{\circ}C$ and 8$0^{\circ}C$ for 10 min, the remained relative activities were about 50%, 30% respectively. The activity of the enzyme was inhibited by Cu$^{＋＋}$, $_Mn^{＋＋}$, Zn$^{＋＋}$ but Co$^{＋＋}$, Li$^{＋＋}$, $Ca^{＋＋}$, $Mg^{＋＋}$ $Ba^{＋＋}$ did not affect. Among 11 chemical reagents, ethylenedi aminetetra-acetic acid disodium salt (EDTA-2Na), sodium dodecyl sulfate (SDS) and sodium fluoride inhibited the enzyme activity.