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Continuous Production of Fish Skin Gelatin Hydrolysate Using a Two-Stage Membrane Ractor (2단계 막반응기를 이용한 어피젤라틴 가수분해물의 연속적 생산)

  • Kim, Se-Kwon;Byun, Hee-Guk;Jeon, You-Jin;Yang, Hyun-Phil;Jou, Duk-Je
    • Applied Biological Chemistry
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    • v.37 no.2
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    • pp.130-141
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    • 1994
  • A continuous two-stage membrane (1st-SCMR, MWCO 10,000; 2nd-SCMR, MWCO 5,000) reactor was developed and optimized for the production of fish skin gelatin hydrolysate with different molecular size distribution profiles using trypsin and pronase E. The optimum operating conditions in the 1st-step membrane reactor using trypsin were: temperature, $55^{\circ}C$ ; pH 9.0; enzyme concentration, 0.1 mg/ml; flux, 6.14 ml/min; reaction volume, 600 ml; and the ratio of substrate to trypsin, 100 (w/w). After operating for 1 hr under the above conditions, 79% of total amount of initial gelatin was hydrolysed. In the 2nd-step using pronase E under optimum operating conditions[temperature, $50^{\circ}C$ ; pH 8.0; enzyme concentration, 0.3 mg/ml; flux, 6.14 ml/min; reaction volume, 600 ml; and the ratio of substrate to pronase E, 33 (w/w)], the 1st-step hydrolysate was hydrolysed above 80%. Total enzyme leakages in the 1st-step and 2nd-step membrane reactors were about 11.5% at $55^{\circ}C$ for 5hrs and 9.0% at $50^{\circ}C$ for 4 hrs, respectively. However, there was no apparent correlation between enzyme leakage and substrate hydrolysis. The membrane has a significant effect on activity lose of trypsin and pronase E activity for 1 hr of the membrane reactors operation. The loss of initial activity of enzymes were 34% and 18% in the 1st-step and 2nd-step membrane reactor, whereas were 23% and 10% after operating time 3 hr in the 1st-step and 2nd-step membrane reactor lacking the membrane, respectively. The productivities of 1st-step and 2nd-step membrane reactor for 8 times of volume replacement were 334 mg and 250 mg per mg enzyme, respectively.

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Meat Quality and Storage Characteristics of Finishing Pigs by Feeding Stevia and Charcoal (스테비아와 숯이 급여된 비육돈의 육질 및 저장특성)

  • Lee, Jae-Joon;Park, Sung-Hyun;Jung, Dong-Soon;Choi, Yang-Il;Choi, Jung-Soek
    • Food Science of Animal Resources
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    • v.31 no.2
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    • pp.296-303
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    • 2011
  • This study was conducted to determine the effects of stevia (Stevia rebaudiana Bertoni) and charcoal supplementation on meat quality traits in finishing pigs. A total of 420 pigs (LYD) were randomly allocated into seven treatments with three replications. The dietary treatments were T1 (control, basal diet), T2 (basal diet+0.3% stevia), T3 (basal diet+0.6% stevia), T4 (basal diet+0.3% charcoal), T5 (basal diet+0.6% charcoal), T6 (basal diet+0.3% stevia+0.3% charcoal), and T7 (basal diet+0.6% stevia+0.6% charcoal). Pigs were slaughtered conventionally on each marketing day and chilled overnigth. At 24 h postmortem, the Longissimus muscle from left side between the 6th and 14th rib was removed for the meat quality traits. The T6 group showed a higher pH, water holding capacity (p<0.05), and lower drip loss (p<0.05) than those in the T1 group. The T6 group showed lower (p<0.05) $L^*$ (lightness) and $b^*$ (yellowness) values and higher $a^*$ (redness) color value than those in the T1 group, resulting in a redder surface meat color. In the subjective evaluation, marbling and color scores improved in the T6 group compared to those in the other treatments. In the panel test, the T6 group tended to have higher tenderness and juiciness scores than those in the T1 group. In the storage characteristics, all treatments showed similar 2-thiobarbituric acid and volatile basic nitrogen values as well as total microbial counts during 7 d of cold storage. As a result, dietary supplementation with 0.3% stevia and 0.3% charcoal showed the highest meat quality traits and storage characteristics in finishing pigs.

Double Bronchial Lesions Detected by Bronchoscopic Examination (기관지 내시경 검사상 발견된 2부위의 기관지 병변에 관한 연구)

  • Lee, Chang-Hee;Yoon, Jong-Kil;Kwak, Young-Im;Kim, Hyun-Kag;Lee, Choon-Taek;Lee, Jhin-Oh;Kang, Tae-Woong
    • Tuberculosis and Respiratory Diseases
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    • v.41 no.3
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    • pp.277-288
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    • 1994
  • Objectives : Multiple lung cancers and/or precancerous lesions can be developed because many bronchi are exposed to carcinogens simultaneously according to the concept of "Field Cancerization". We had performed a careful bronchoscopic examination and analysed the patients of double bronchial lesions who received the separate pathologic evaluation. Methods : We studied 21 patients of double bronchial lesions among 1855 patients of bronchoscopic examination from April 1990 to December 1993 in Korea Cancer Center Hospital. We classified the patients into three groups(double malignancies of different histology, double malignancies of same histology, and combination of malignant and benign lesions) and analysed the histologic type, location, radiologic findings, and clinical parameters. Results : Among 21 patients, six patients had double malignancies of different histology, eight had double malignancies of same histology, and seven had combination of malignant and benign lesions. Out of 14 double malignant cases, 11 cases are considered as synchronous multiple primary lung cancers. Combination of squamous cell carcinomas was found in 5 cases, combination of small cell carcinoma and squamous cell carcinoma was found in 4 cases. Combination of adenocarcinoma and squamous cell carcinoma and combination of squamous cell carcinoma and poorly differentiated carcinoma were found in 1 case respectively. All patients of synchtonous multiple primary lung cancers were male and had long smoking history(average 40 pack years). Among 21 cases of double bronchial lesions, only one lesion could be detected by prebronchoscopic radiologic examination including chest CT in 15 cases. Conclusions : The presence of double bronchial lesions including multiple primary lung cancers and the limitation of radiologic examination to detect early bronchial lesions encourage us to examine the whole bronchi carefully and to perform pathologic evaluations.

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The Physical and Thermal Properties Analysis of the VOC Free Composites Comprised of Epoxy Resin, and Dicyandiamide (VOC Free Epoxy Resin/Dicyandiamide 경화물의 배합비 변화에 따른 물리적 특성 및 열적특성 분석)

  • Kim, Daeyeon;Kim, Soonchoen;Park, Young IL;Kim, Young Chul;Lim, Choong-Sun
    • Clean Technology
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    • v.21 no.1
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    • pp.76-82
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    • 2015
  • Volatile organic compounds (VOC) free adhesives have been interested by many scientists and engineers due to environmental regulations and the safety of industrial workers. In this work, a series of composites composed with bisphenol A epoxy resin used as solvent, dicyandiamide, and promoter were prepared to investigate the most appropriate molar ratio for steel-steel adhesion. The cured test specimen of each composite were measured with universal testing machine (UTM) to figure out mechanical properties such as tensile strength, Young’s modulus, and elongation. Furthermore, the lap shear strength of the specimen was tested with UTM while impact resistance was measured with Izod impact tester. The composite whose molar ratio of epoxy resin to curing agent is 1 : 0.9 (sample 3), showed better tensile strength, coefficient of elastic modulus, elongation, and impact strength than other composites did. The highest tanδ from dynamic mechanical analysis (DMA) was observed from sample 2 (epoxy resin: dicy = 1 : 0.7) while sample 3 showed slightly lower tanδ than that of 2. The morphology of the fracture surface of the cured composites from SEM showed that the number of subtle lines on the surface caused by impact increase as the contents of amine curing agent accrete. Furthermore, the viscosity change of sample 5 (epoxy resin: dicy = 1 : 1.3) was observed to confirm its storage stability.

Meat Quality of Pork Muscles from Low-fat Cuts (돼지 저지방 부의 근육들의 육질 특성)

  • Seong, Pil-Nam;Cho, Soo-Hyun;Kim, Jin-Hyoung;Hah, Kyung-Hee;Park, Beom-Young;Lee, Jong-Moon;Kim, Dong-Hoon
    • Food Science of Animal Resources
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    • v.29 no.3
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    • pp.364-373
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    • 2009
  • This study was conducted to provide fundamental information in developing muscle-specific strategies to improve the quality and value of low-fat pork cuts upon evaluating meat qualitative parameters of twenty one (21) muscle samples selected from ten (10) market-weighted crossbred pigs. The following observations were made. The pH was highest for subscpularis and lowest for gluteus superrificialis (p<0.05); the subscpularis can hold water the most (p<0.05), biceps femoris loses the most content upon cooking, while subscpularis loses the least content (p<0.05); gluteus superrificialis (p<0.05) has the most purge loss contents, and infraspanatus and gastrocneminus contained the most collagen, while adductor had the least collagen (p<0.05); biceps femoris has the most WB-shear force values while subscpularis (p<0.05) has the least; pectoralis profundi-fan was the most protein soluble; semitendinosus has the most gel strength (p<0.05). In the properties of meat color, tensor fasciae latae shows the highest CIE $L^*$ (lightness) values (p<0.05) and supraspinatus, brachiocephalicus and infraspanatus have the highest CIE $a^*$ (redness, p<0.05) values; vastus intermedius has the most myoglobin content while longissimus dorsi (p<0.05) has the least; infraspanatus is the most tender (one of the sensory properties) while biceps femoris was the most tough among all tested muscles (p<0.05); the pectoralis profundi-fan was the most flavorful pork while vastus intermedius was the least (p<0.05); supraspinatus, infraspanatus, semitendinosus, and vastus intermedius were juiciest while longissimus dorsi was the driest (p<0.05). In overall likeness, the semitendinosus and infraspanatus were most liked while biceps femoris and longissimus dorsi were the least (p<0.05). This study presents the results of several parameters in selected pork muscle samples which are useful information for developing new muscle-specific strategies to improve the quality of consuming meat and meat products.

Inter-Rater Reliability of Carotid Intima-Media Thickness Measurements in a Multicenter Cohort Study (다기관 코호트 연구에서 경동맥 내막-중막 두께 측정의 측정자간 신뢰도 평가)

  • Lee, Jung Hyun;Choi, Dong Phil;Shim, Jee-Seon;Kim, Dae Jung;Park, Sung-Ha;Kim, Hyeon Chang
    • Journal of health informatics and statistics
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    • v.41 no.1
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    • pp.49-56
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    • 2016
  • Objectives: Carotid intima-media thickness (CIMT) and the presence of carotid artery plaque are widely used as preclinical markers of atherosclerosis. Due to operator dependency in measuring CIMT, it is important to evaluate the reliability of measuring CIMT and plaque between centers in a multicenter study. The purpose of this study is to evaluate the inter-rater reliability of CIMT and plaque presence among three clinical centers of the Cardiovascular and Metabolic Disease Etiology Research Center (CMERC). Methods: Twenty people without known cardiovascular disease (age 37-64) were enrolled during 2014-2015, and their left and right carotid arteries were examined repeatedly with ultrasonography for CIMT measurements at three clinical centers according to a predetermined protocol. Maximum and mean values of CIMT at distal common carotid artery were recorded. Plaque presence at a carotid artery was checked by an operator. The reliability of CIMT and carotid plaque presence was assessed using an intraclass correlation coefficient (ICC) and kappa statistics, respectively. Results: Calculated ICC was 0.647 (95% CI: 0.487-0.779) for maximum CIMT, and 0.758 (95% CI: 0.632- 0.854) for mean CIMT. In Bland Altman plot, most observed values were distributed within mean difference ${\pm}1.96$ SD ranges. Kappa statistics of plaque presence between two centers were 0.304 (center 1 and 2), 0.507 (center 1 and 3), and 0.606 (center 2 and 3), respectively, while Fleiss kappa for overall agreement was 0.445. Conclusions: The inter-rater reliability of CIMT measurements among three clinical centers turned out to be high, and the agreement of measuring carotid plaque presence was fair.

Numerical modeling of secondary flow behavior in a meandering channel with submerged vanes (잠긴수제가 설치된 만곡수로에서의 이차류 거동 수치모의)

  • Lee, Jung Seop;Park, Sang Deog;Choi, Cheol Hee;Paik, Joongcheol
    • Journal of Korea Water Resources Association
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    • v.52 no.10
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    • pp.743-752
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    • 2019
  • The flow in the meandering channel is characterized by the spiral motion of secondary currents that typically cause the erosion along the outer bank. Hydraulic structures, such as spur dike and groyne, are commonly installed on the channel bottom near the outer bank to mitigate the strength of secondary currents. This study is to investigate the effects of submerged vanes installed in a $90^{\circ}$ meandering channel on the development of secondary currents through three-dimensional numerical modeling using the hybrid RANS/LES method for turbulence and the volume of fluid method, based on OpenFOAM open source toolbox, for capturing the free surface at the Froude number of 0.43. We employ the second-order-accurate finite volume methods in the space and time for the numerical modeling and compare numerical results with experimental measurements for evaluating the numerical predictions. Numerical results show that the present simulations well reproduce the experimental measurements, in terms of the time-averaged streamwise velocity and secondary velocity vector fields in the bend with submerged vanes. The computed flow fields reveal that the streamwise velocity near the bed along the outer bank at the end section of bend dramatically decrease by one third of mean velocity after the installation of vanes, which support that submerged vanes mitigate the strength of primary secondary flow and are helpful for the channel stability along the outer bank. The flow between the top of vanes and the free surface accelerates and the maximum velocity of free surface flow near the flow impingement along the outer bank increases about 20% due to the installation of submerged vanes. Numerical solutions show the formations of the horseshoe vortices at the front of vanes and the lee wakes behind the vanes, which are responsible for strong local scour around vanes. Additional study on the shapes and arrangement of vanes is required for mitigate the local scour.

Effect of Ta/Cu Film Stack Structures on the Interfacial Adhesion Energy for Advanced Interconnects (미세 배선 적용을 위한 Ta/Cu 적층 구조에 따른 계면접착에너지 평가 및 분석)

  • Son, Kirak;Kim, Sungtae;Kim, Cheol;Kim, Gahui;Joo, Young-Chang;Park, Young-Bae
    • Journal of the Microelectronics and Packaging Society
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    • v.28 no.1
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    • pp.39-46
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    • 2021
  • The quantitative measurement of interfacial adhesion energy (Gc) of multilayer thin films for Cu interconnects was investigated using a double cantilever beam (DCB) and 4-point bending (4-PB) test. In the case of a sample with Ta diffusion barrier applied, all Gc values measured by the DCB and 4-PB tests were higher than 5 J/㎡, which is the minimum criterion for Cu/low-k integration without delamination. However, in the case of the Ta/Cu sample, measured Gc value of the DCB test was lower than 5 J/㎡. All Gc values measured by the 4-PB test were higher than those of the DCB test. Measured Gc values increase with increasing phase angle, that is, 4-PB test higher than DCB test due to increasing plastic energy dissipation and roughness-related shielding effects, which matches well interfacial fracture mechanics theory. As a result of the 4-PB test, Ta/Cu and Cu/Ta interfaces measured Gc values were higher than 5 J/㎡, suggesting that Ta is considered to be applicable as a diffusion barrier and a capping layer for Cu interconnects. The 4-PB test method is recommended for quantitative adhesion energy measurement of the Cu interconnect interface because the thermal stress due to the difference in coefficient of thermal expansion and the delamination due to chemical mechanical polishing have a large effect of the mixing mode including shear stress.