• Title/Summary/Keyword: $T_{50},\

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Effect of Gamma Irradiation on the Mechanical and Thermal Properties of Biodegradable Packaging Materials

  • Lim, DaeGyu;Kim, Youngsan;Kwon, Sangwoo;Jang, Hyunho;Park, Su-il
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.27 no.2
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    • pp.85-90
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    • 2021
  • The gamma irradiation was on to Poly(butylene sebacate-co-terephthalate) (PBSeT), Poly(butylene adipate-co-terephthalate) (PBAT), Poly(lactic acid) (PLA) and casting polypropylene (CPP) at dose levels from 0 to 50 kGy. The properties of gamma irradiated samples were analyzed using DSC, TGA, UTM and FT-IR spectra. The mechanical and thermal properties of PBSeT and PBAT after gamma irradiation were less affected than CPP. The tensile strength and elongation of PBSeT was not affected by gamma irradiation, while these of PBAT, PLA and CPP were significantly decreased at 50 kGy gamma-ray dose. The thermal stability of PBSeT, PBAT, PLA and CPP showed a similar tendency to tensile strength. The glass transition temperature(Tg) and melting temperature(Tm) of PBSeT and PBAT were not altered by increasing gamma-ray dose, while these of PLA and CPP decreased. The chemical composition of all samples was not modified by gamma irradiation, and it was confirmed by FT-IR spectra. Based on mechanical and thermal stability studies of gamma irradiation on bioplastics, tested biodegradable packaging materials showed a potential to be used in sterilization process up to 35 kGy.

Quality Changes of Ground Pork Containing Safflower Seed during Frozen Storage (홍화씨를 첨가한 분쇄돈육의 동결저장 중 품질변화)

  • Park, Kyung-Sook;Choi, Young-Joon;Park, Hyun-Suk;Cha, Kyung-Sook;Lee, Kyung-Sook;Jung, In-Chul
    • Korean journal of food and cookery science
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    • v.29 no.4
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    • pp.417-424
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    • 2013
  • This study was carried out to investigate the effect of safflower seed on the physicochemical properties of ground pork during frozen storage. Three types of ground pork were evaluated: 20% pork back fat added (T0, control), 10% pork back fat and 10% added safflower seed (T1), and 20% added safflower seed (T2). Water holding capacity decreased with longer storage period, and that of T2 was the highest (p<0.05). Cooking loss increased with longer storage period, and that of T1 and T2 was higher than that of T0 (p<0.05). The reduction in diameter of T0 increased, but that of T1 and T2 was not significantly different with longer storage period. Hardness and chewiness increased, but springiness decreased with longer storage period (p<0.05). Hardness, springiness and chewiness of T2 was the highest (p<0.05). The pH decreased with longer storage period (p<0.05), and those of T0, T1 and T2 were pH 5.41, 5.43 and 5.32, respectively, after 50 days of storage. The TBARS (2-thiobarbituric acid reactive substances) values of T0 and T1 increased, but that of T2 was not significantly different with longer storage period. The TBARS values of T0, T1 and T2 were 4.76, 2.77 and 0.54 mg malonaldehyde/kg, respectively, after 50 days of storage. The $L^*$, $a^*$ and $b^*$ value of T0 was the highest among the samples (p<0.05), the $a^*$ value of the samples decreased with longer storage period (p<0.05). In conclusion, this study demonstrates that the addition safflower seed tended to improve physiological properties and antioxidative effects.

Effect of Red Ginseng Marc, Mineral and Black Sugar® Supplementation on the Production of Holstein Steers (Bos taurus) (홍삼박, 무기물® 및 흑설탕® 첨가 급여가 Holstein 거세 비육우 생산성에 미치는 영향)

  • Lee, Sang Moo
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.41 no.4
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    • pp.273-279
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    • 2021
  • This study was carried out to investigate the effects of a dietary addition of red ginseng marc, mineral® and black sugar® on the dry matter intake, daily gain, yield grade and quality grade of Holstein steers(Bos taurus). A total of 32 fattening Holstein steers(avg. BW 590kg) were assigned to four treatments which included a control diet(mixed concentrate and forage; namely, C) and three treatments diet(T1; control diet+red ginseng marc 200g, T2; control diet+red ginseng marc 100g+mineral 50g, T3; control diet+mineral 50g+ black sugar 20g). The results are summarized as follows; the total feed intake and daily feed intake were significantly(p<0.05) higher in T2 and T3 than in the other two treatments(C and T1). The daily gain was higher in T2 than in the other treatments, but there was no significant difference. The back fat thickness, longissimus muscle area and meat yield grade were no significant difference. The marbling score showed significantly(p<0.05) higher in order of T3(4.5) > T1(4.0) > T2(2.7) > C(2.5). The meat color, fat color, texture and maturity were no significant difference. The quality grade was higher in T3 than in the other treatments(C, T1 and T2), but there was no significant difference. T3, which numerically had a higher daily gain and carcass quality grade, showed higher economic efficiency, whereas C showed low economic efficiency. Based on the above results, T3 treatment compared to the other treatments improved the daily gain, carcass quality grade and economic efficiency.

TWO GENERALIZATIONS OF LCM-STABLE EXTENSIONS

  • Chang, Gyu Whan;Kim, Hwankoo;Lim, Jung Wook
    • Journal of the Korean Mathematical Society
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    • v.50 no.2
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    • pp.393-410
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    • 2013
  • Let $R{\subseteq}T$ be an extension of integral domains, X be an indeterminate over T, and R[X] and T[X] be polynomial rings. Then $R{\subseteq}T$ is said to be LCM-stable if $(aR{\cap}bR)T=aT{\cap}bT$ for all $0{\neq}a,b{\in}R$. Let $w_A$ be the so-called $w$-operation on an integral domain A. In this paper, we introduce the notions of $w(e)$- and $w$-LCM-stable extensions: (i) $R{\subseteq}T$ is $w(e)$-LCM-stable if $((aR{\cap}bR)T)_{w_T}=aT{\cap}bT$ for all $0{\neq}a,b{\in}R$ and (ii) $R{\subseteq}T$ is $w$-LCM-stable if $((aR{\cap}bR)T)_{w_R}=(aT{\cap}bT)_{w_R}$ for all $0{\neq}a,b{\in}R$. We prove that LCM-stable extensions are both $w(e)$-LCM-stable and $w$-LCM-stable. We also generalize some results on LCM-stable extensions. Among other things, we show that if R is a Krull domain (resp., $P{\upsilon}MD$), then $R{\subseteq}T$ is $w(e)$-LCM-stable (resp., $w$-LCM-stable) if and only if $R[X]{\subseteq}T[X]$ is $w(e)$-LCM-stable (resp., $w$-LCM-stable).

Morphometric Study of the Upper Thoracic Sympathetic Ganglia

  • Lee, Sang-Beom;Chang, Jae-Chil;Park, Sukh-Que;Cho, Sung-Jin;Choi, Soon-Kwan;Bae, Hack-Gun
    • Journal of Korean Neurosurgical Society
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    • v.50 no.1
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    • pp.30-35
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    • 2011
  • Objective : Morphometric data for the sympathetic ganglia (SG) of the upper thoracic spine was investigated to identify the exact location of the SG in order to reduce normal tissue injury in the thoracic cavity during thoracoscopic sympathectomy. Methods : In 46 specimens from 23 formalin-fixed adult cadavers, the authors measured the shortest distance from the medial margin of the T1, T2 and T3 SG to the most prominent point and medial margin of the corresponding rib heads, and to the lateral margin of the longus colli muscle. In addition, the distance between the most prominent point of the rib head and the lateral margin of longus colli muscle and the width of each SG were measured. Results : The shortest distance from the medial margin of the SG to the prominent point of corresponding rib head was on average 1.9 mm on T1, 4.2 mm, and 4.1 mm on T2, T3. The distance from the medial margin of the SG to the medial margin of the corresponding rib head was 4.2 mm on T1, 5.9 mm, and 6.3 mm on T2, T3. The mean distance from the medial margin of the SG to the lateral margin of the longus colli muscle was 6.7 mm on T1, 8.8 mm, 9.9 and mm on T2, T3. The mean distance between the prominent point of the rib head and the lateral margin of the longus colli muscle was 4.8 mm on T1, 4.6 mm, and 5.9 mm on T2, T3. The mean width of SG was 6.1 mm on T1, 4.1 mm, and 3.1 mm on T2, T3. Conclusion : We present morphometric data to assist in surgical planning and the localization of the upper thoracic SG during thoracoscopic sympathectomy.

Development of Cheap Substrate for Fruiting of Pleurotus ostreatus using Paper Sludge (제지 부산물을 이용한 느타리버섯(Pleurotus ostreatus) 자실체 형성용 염가배지개발)

  • Jo, Woo-Sik;Yun, Yeong-Seok;Park, Sun-Do;Choi, Boo-Sull
    • The Korean Journal of Mycology
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    • v.23 no.3 s.74
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    • pp.197-201
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    • 1995
  • For 2 years $(1993{\sim}1994)$, study on development of cheap medium for Pleurotus ostreatus revealed that paper sludge contain more CaO and similar T-C, T-N, $P_2O_5$, MgO but less $K_2O$ than any other medium material in chemical property. Mixed treatment (rice straw + paper sludge 10, 30, 50%, cotton waste + paper sludge 10, 30, 50%, cotton waste + rice hull 20 + paper sludge 10, 30, 50, 70%) is similar or fast a little in mycelial growth and is similar or fast $1{\sim}2$ day in period of primordia formation than cotton waste medium, and in the yield to each medium type also increased but excepted in rice hull 20% + paper sludge 70%, especially mixed medium at 7:3 ratio of cotton waste and paper sludge is best treatment because it is increased to 21%. In economical analysis, mixed medium at 7:3 ratio of cotton waste and paper sludge is increased to 50% compared to cotton waste medium in relative income.

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Effects of Pre-sowing Treatments of Tobacco Seed on Germination and Seedling Uniformity (담배종자의 파종 전처리가 발아 및 묘의 균일성에 미치는 영향)

  • 민태기
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.38 no.6
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    • pp.507-512
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    • 1993
  • Pre-sowing treatments of tobacco seeds (cv. NC82) were evaluated as a means of improving the speed of emergence, early seedling growth and uniformity of the seedlings. Seeds were treated through the use of polyethylene glycol 6000(PEG), solid matrix priming(SMP), chilling and dark-preincubati(DPI). Under the laboratory condition of 15$^{\circ}C$, all the treated seeds germinated more rapid and the time to 50% germination(T50) reduced than control. Among the treatments, SMP was the best to reduce the T50 for germination. All the treatments did not affect the final germination percentage, while the chilling showed of little benefit for germination and T50. Under the greenhouse condition, seedling from SMP emerged earlier and more uniformity and also greater mean fresh and dry weight showed than other treatments. The advantage of T50 from SMP was affected more in temperature than in water content of Agro-Lig during the treatment.

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Mechanical Properties of Bulk Amorphous Ti50Cu20Ni20Al10 Fabricated by High-energy Ball Milling and Spark-plasma Sintering

  • Nguyen, H.V.;Kim, J.C.;Kim, J.S.;Kwon, Y.J.;Kwon, Y.S.
    • Journal of Powder Materials
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    • v.16 no.5
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    • pp.358-362
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    • 2009
  • Ti$_{50}$Cu$_{20}$Ni$_{20}$Al$_{10}$ quaternary amorphous alloy was prepared by high-energy ball milling process. A complete amorphization was confirmed for the composition of Ti$_{50}$Cu$_{20}$Ni$_{20}$Al$_{10}$ after milling for 30hrs. Differential scanning calorimetry showed a large super-cooled liquid region ($\Delta$T$_x$ = T$_x$ T$_g$, T$_g$ and T$_x$: glass transition and crystallization onset temperatures, respectively) of 80 K. Prepared amorphous powders of Ti$_{50}$Cu$_{20}$Ni$_{20}$Al$_{10}$ were consolidated by spark-plasma sintering. Densification behavior and microstructure changes were investigated. Samples sintered at higher temperature of 713 K had a nearly full density. With increasing the sintering temperature, the compressive strength increased to fracture strength of 756 MPa in the case of sintering at 733 K, which showed a 'transparticle' fracture. The samples sintered at above 693 K showed the elongation maximum above 2%.

The Formation and Crystallization of Amorphous Ti50Cu50Ni20Al10 Powder Prepared by High-Energy Ball Milling

  • Viet, Nguyen Hoang;Kim, Jin-Chun;Kim, Ji-Soon;Kwon, Young-Soon
    • Journal of Powder Materials
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    • v.16 no.1
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    • pp.9-15
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    • 2009
  • Amorphization and crystallization behaviors of $Ti_{50}Cu_{50}Ni_{20}Al_{10}$ powders during high-energy ball milling and subsequent heat treatment were studied. Full amorphization obtained after milling for 30 h was confirmed by X-ray diffraction and transmission electron microscope. The morphology of powders prepared using different milling times was observed by field-emission scanning electron microscope. The powders developed a fine, layered, homogeneous structure with prolonged milling. The crystallization behavior showed that the glass transition, $T_g$, onset crystallization, $T_x$, and super cooled liquid range ${\Delta}T=T_x-T_g$ were 691,771 and 80 K, respectively. The isothermal transformation kinetics was analyzed by the John-Mehn-Avrami equation. The Avrami exponent was close to 2.5, which corresponds to the transformation process with a diffusion-controlled type at nearly constant nucleation rate. The activation energy of crystallization for the alloy in the isothermal annealing process calculated using an Arrhenius plot was 345 kJ/mol.

Effect of Melissa officinalis L. leaf extract on lipid accumulation by modulating specific adipogenic gene transcription factors in 3T3-L1 adipocytes

  • Lee, Hyun Jeong;Lim, Jonghak;Peak, Junoh;Ki, Mun-sang;Lee, Sang-bong;Choe, Gayong;Jung, Jaeyun;Jung, Hansang;Jeon, Suwon;Park, Tae-Sik;Shim, Soon-Mi
    • Journal of Applied Biological Chemistry
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    • v.63 no.2
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    • pp.169-174
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    • 2020
  • The objective of this study was to investigate the effects of a hypodermic injectable solution comprised of an LPM LB meso solution containing Melissa officinalis L. leaf extract (LPM) on the lipogenesis in the 3T3-L1 cells line. The lipid accumulation measured by oil red o staining in the 3T3-L1 adipocytes treated with LPM, which was reduced in a dose dependent manner and showed 91.7 to 62.9% compared to control group. Its effectiveness with a 50% solution was significantly higher than the hydroxycitric acid (positive control) treatment without showing cell cytotoxicity. In a quantitative real-time PCR, it was demonstrated that the LPM treatment appeared to upregulate the mRNA expression of the adipogenesis-related genes, which included the peroxisome proliferator-activated receptor gamma (50% concentration) while down-regulating the CCAAT-enhancer binding protein alpha (50% concentration) and the sterol regulatory element-binding protein 1c (10, 25, and 50% concentrations). The results from the current study suggest that the LPM could be useful biomaterials that can inhibit obesity in the 3T3-L1 cells, which could possibly be by regulating the specific adipogenic gene transcription factors.