• Title/Summary/Keyword: a-value

Search Result 67,973, Processing Time 0.105 seconds

Study on the Development and Properties of Ceramics Restoration Purpose Urethane resin with Excellent Reversibility (가역성이 우수한 도자기 복원용 Urethane resin의 개발 및 물성에 대한 연구)

  • Oh, Seung Jun;Park, Gi Jung;Wi, Koang Chul
    • Journal of Conservation Science
    • /
    • v.31 no.1
    • /
    • pp.37-46
    • /
    • 2015
  • In the case of adhesives & restoration agents currently being used for the preservation treatment of ceramics and earthenware, epoxy type, cellulose type and cellulose type are mainly being used. However, they are showing various problems such as re-detachment from severe contraction, color change from yellowing, work inconvenience of staining on tools and hand during usage and irreversibility. For the purpose of solving the issues of yellowing and irreversibility of epoxy resin being used to restore ceramics, urethane synthetic resin with low yellowing excellent reversibility has been developed in this study. The adhesive strength of urethane resin that has been developed has excellent properties with 2.07MPa for undiluted solution, which is 1.5 times higher than that of existing material EPO-$TEK301^{(R)}$ 1.21MPa. The result of workability measurement showed that the wear rate of urethane resin (in Talc 50wt%) was 1.09%, which was somewhat higher than that of existing material Quick $Wood^{(R)}$ (1.02%). In addition, its wear rate is two times higher than that of $EPO-TEK301^{(R)}$ (0.41%) and $L30^{(R)}$ (0.39%), thereby showing an advantage in its forming process compared to existing materials. As for the advantage of urethane resin of reversibility experiment, 12 hours after acetone, ethyl alcohol deposition, urethane resin and filler talc were dissolved 100% while showing powdering phenomenon. Compared to 0% reversibility of existing epoxy resin, it has much superior reversibility. The result of UV rays experiment to evaluate its durability showed that ${\Delta}E^*ab$ color change value based on undiluted solution of urethane resin was 2.76 before & after UV rays exposure, which was a decrease by about 7-20 times compared to that of existing resin, thereby minimizing the issue of heterogeneity.

The Origin and Geochemical Behavior of Fluoride in Bedrock Groundwater: A Case Study in Samseung Area (Boeun, Chungbuk) (화강암 지역 암반 지하수 내 불소 이온의 기원 및 거동: 충북 보은 삼승면 일대의 현장 조사와 실내 실험 연구)

  • Chae, Gi-Tak;Koh, Dong-Chan;Choi, Byoung-Young
    • The Journal of Engineering Geology
    • /
    • v.18 no.4
    • /
    • pp.555-566
    • /
    • 2008
  • Hydrogeochemical study in Samseung area (Boeun, Chungbuk) and waterrock interaction experiment using rock samples from the area were performed to elucidate the fluoride source in groundwater and explaining geochemical behavior of fluoride ion. Fluoride concentration of public water supply mostly using groundwater in Boeun area was significantly higher in South Korea. The maximum fluoride concentration of the study area was 3.9 mg/L, and 23% of samples exceeded the Korean Drinking Water Standard of fluoride (1.5 mg/L). The average concentration of fluoride was 1.0 mg/L and median was 0.5 mg/L. Because of high skewness (1.3), median value is more appropriate to represent fluoride level of this area. The relationships between fluoride ion and geochemical parameters ($Na^+$, $HCO_3$, pH, etc.) indicated that the degree of waterrock interaction was not significant. However, high fluoride samples were observed in $NaHCO_3$ type on Piper's diagram. The negative relationship between fluoride and $NO_3$ ion which might originate from surface contaminants was obvious. These results indicate that fluoride ion in groundwater is geogenic origin. The source of fluoride was proved by waterrock interaction batch test. Fluoride concentration increased up to 1.2 mg/L after 96 hours of reaction between water and biotite granite. However, the relationship between well depth and fluoride ion, and groundwater age and fluoride ion was not clear. This indicates that fluoride ion is not correlated with degree of waterrock interaction in this area but local heterogeneity of fluoriderich minerals in granite terrain. High fluoride concentration in Boeun area seems to be correlated with distribution of permeable structures in hard rocks such as lineaments and faults of this area. This entails that the deep bedrock groundwater discharges through the permeable structures and mixed with shallow groundwater.

Quality and Antioxidant Characteristics of Cooked Rice with Various Mixed Grains in Korea (혼합잡곡 첨가 취반 밥의 품질 및 항산화특성)

  • Woo, Koan Sik;Kim, Hyun-Joo;Kim, Mi-Jung;Sim, Eun-Yeong;Ko, Jee Yeon;Lee, Choon Ki;Jeon, Yong Hee
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.62 no.4
    • /
    • pp.352-360
    • /
    • 2017
  • This study evaluated the quality characteristics, polyphenolic compounds, and radical scavenging activity of cooked-rice added to commercially available mixed grains. L-value of cooked-rice with various mixed grains decreased compared to that of cooked-white rice; however, a- and b-values increased. Hardness and elasticity of cooked-rice added to various mixed grains were significantly lower in the pressure cooker compared to the electric cooker. There was no significant difference in adhesiveness and stickiness between rice from the electric cooker and pressure cooker. Total polyphenol and flavonoid contents of cooked-rice added to various mixed grains were significantly increased. The average total polyphenol content of cooked-rice added to various mixed grains cooked in an electric cooker and pressure cooker were $16.50{\pm}3.86$ and $15.88{\pm}3.52mg$ gallic acid equivalent /100 g, and flavonoid contents were $1.58{\pm}0.00$ and $1.55{\pm}0.02mg$ catechin equivalents/100 g, respectively. The average of 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity was $9.27{\pm}2.62$ and $8.72{\pm}2.41mg$ trolox equivalent (TE)/100 g, and 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity was $22.89{\pm}4.60$ and $23.07{\pm}4.49mg$ TE/100 g for cooked-rice added to various mixed grains cooked in an electric cooker and pressure cooker, respectively. Phenol content and radical scavenging activity of cooked rice was in proportion to the amount of added grains, such as brown rice, colored rice, barley, soybean, and sorghum.

Complications of PCL Reconstruction using Tibial Inlay Technique (경골 Inlay 방법을 이용한 후방 십자 인대 재건술의 합병증)

  • Kim Myung-Ho;Park Hee-Gon;Yoo Moon-Jib;Byun Woo-Sup;Shim Shang-Ho
    • Journal of Korean Orthopaedic Sports Medicine
    • /
    • v.3 no.2
    • /
    • pp.128-133
    • /
    • 2004
  • Purpose: This study was planned to evaluate complications? of posterior cruciate ligament (PCL) reconstruction with tibial inlay technique using autogenous bone-patellar tendon-bone graft. Materials and Methods: From September 1994 to January 2004, we analyzed surgical complications in fifty-seven patients with fifty-eight cases who underwent PCL reconstruction. Fifty of them were male and seven female. The mean age of the patients was 35(15$\~$73). Twenty eight cases of injury were isolated PCL, while thirty cases had associated injury of knee. The causes of injury were thirty-nine cases of traffic accident, seven sport injuries, seven fall down injuries, and five of others. The follow-up study was done at 4 weeks, 3 months,6 months and 1 year after surgery. KT-2000 arthrometer and posterior stress X-ray were used to examine the stability of the knee joint and the Lysholm Knee Score and a variety of clinical complications were evaluated. Results: Although the mean score of the preoperative Lysholm Knee Score was 43.2, the postoperative score was increased to 87.9. The preoperative mean value of knee stability using KT-2000 arthrometer was 8.75 mm(6.2$\~$14.3 mm) but the postoperative mean was 3.41 mm(2.1$\~$10.6 mm). The intraoperative complications were: one case of popliteal artery injury with compartment syndrome, one case of patellar fracture, two cases of 20$^{\circ}$ flexion loss, and two cases of anterior cortical penetration of the screw through proximal tibia during screw fixation. The postoperative complications were: eleven cases of knee instability, one case of patellar fracture, five cases of extension loss, thirteen cases of flexion loss, twenty-one cases of around knee pain and eight cases of kneeling pain. Conclusion: After PCL reconstruction with tibial inlay technique using autogenous bone-patella tendon-bone graft, complications were observed in this study. Careful attention during and after the operation, as well as rehabilitation must be required.

  • PDF

Gonadal Development and Reproductive Cycle of the Sand Snail, Umbonium thomasi (서해비단고둥 (Umbonium thomasi)의 생식소 발달과 생식주기)

  • Lee Ju Ha
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.35 no.6
    • /
    • pp.702-708
    • /
    • 2002
  • Although Umboniunm thomasi is one of marine mollusc (Archaeogastropoda: Trochidae) inhabiting the sands in the intertidal zone of the west coast of Korea, aspects of its reproductive biology are still not too well known. Reproductive cycle, gametogenesis, and first sexual maturity of U. thomasi collected at the west coast of Buan-gun, Jeollabuk-do, Korea were investigated monthly from January to December 1999. U. thomasi was dioecious, and an oviparous. The gonad was placed in the rear of the flesh part in the spiral shell. The external colors of the ripe ovary and testis appeared to be green and milk-white or yellowish white, respectively. Meat weigh rate peaked in July ($37.5\%$). And then the value sharply decreased in September ($28.3\%$), thereafter, gradually increased in November ($31.7\%$). Fully ripe oocytes were approximately 100$\~$110 $/mu$m in diameter, and their cytoplasm contained a great number of yolk Branules. Based on the monthly changes of the Bonadal development, gametogenesis, and meat weight rate, the reproductive cycle of U. thomasi could be devided into five successive stages: early active (November to April), late active (February to May), ripe (April to August), spawning (July to October), and recovery (September to February). Gonadal development and spawning were closely related to the seawater temperature, the main spawning occurred in September when the temperature reached above 24.2$^{\circ}C$. Individuals of 4.4 mm and less in shell height could not take part in reproduction in both sexes. Percentages of first sexual maturity of female and male shells ranging from 5.5 to 6.4 mm were $55.0\%$ and $61.9\%$, respectively, and $100\%$ of those over 7.5 mm in shell heights in both sexes participated in the reproduction.

Survey on the Content and Intake Pattern of Sugar from Elementary and Middle School Foodservices in Daejeon and Chungcheong Province (대전.충청지역 초.중학교 급식의 당 함량 및 급식을 통한 당류의 섭취실태 연구)

  • Park, You-Gyoung;Lee, Eun-Mi;Kim, Chang-Soo;Eom, Joon-Ho;Byun, Jung-A;Sun, Nam-Kyu;Lee, Jin-Ha;Heo, Ok-Soon
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.39 no.10
    • /
    • pp.1545-1554
    • /
    • 2010
  • Korean government will set up the nationwide food safety system with strict control of hazardous nutrients like sugar, fatty acids and sodium as well as advanced nutrition education system. In addition, almost one hundred percent of school food service rate forced the government to consider more effective ways to upgrade the nutritional status of school meals. The object of our study was to provide the data on content and consumption of sugar in school meal for the nationwide project. For this purpose, we surveyed the sugar content of 842 school meal menus and their intake level for 154 days in 8 schools in Daejeon and Chungcheong Province. Sugar contents, the sum of the quantity of 5 sugars commonly detected in food, were analysed with HPLC-RID (Refractive Index Detector). Sugar intakes were calculated by multiplying the intake of each menu to the sugar content of that menu. The sugar content was highest in the desserts, which include fruit juices, dairy products and fruits. Sugar content of side dish was high in sauces and braised foods. Sugar intake from one dish is high in beverage and dairy product, and one dish meals contribute greatly to sugar intake because of their large amount of meal intake. The average lunch meal intakes of second grade and fifth grade elementary school students were 244 g/meal and 304 g/meal, respectively. The meal intake of middle school student was 401 g/meal. The average sugar intake from one day school lunch was 4.22 g (4.03 g on elementary and 5.31 g on middle school student), which is less than 10% of daily sugar reference value for Koreans. The result of this study provides exact data of sugar intake pattern based on the content of sugar which is matched directly to the meals consumed by the students.

Physicochemical Properties and Physiological Activities of Rhus verniciflua Stem Bark Cultured with Fomitella fraxinea (장수버섯 균사체가 배양된 옻피의 이화학적 특성 및 생리활성)

  • Choi, Han-Seok;Kim, Bo-Hyun;Yeo, Soo-Hwan;Jeong, Seok-Tae;Choi, Ji-Ho;Park, Hyo-Suk;Kim, Myung-Kon
    • The Korean Journal of Mycology
    • /
    • v.38 no.2
    • /
    • pp.172-178
    • /
    • 2010
  • The contents of proximate composition, free amino acids and phenolic acids in the Fomitella fraxinea cultivated-Rhus verniciflua stem bark(FRVSB), and its adipogenesis effect were investigated. The proximate composition(%) of FRVSB was as follows: moisture(7.64), ash(6.30), crude fat(3.86), crude protein(3.59) and sugar(not detected); while Rhus verniciflua stem bark(RVSB) contained 1.64, 8.09, 7.28, 6.48 and 5.39, respectively. The total free amino acids concentration was 97.41 mg% in FRVSB and 71.91 mg% in RVSB. Phosphoserine(55.06 mg%), ammonia(17.84mg%) and aspartic acid(6.05mg%) were predominant amino acids. The content of total phenolic acids was 422.89 ppm in ethanol extract and 283.86 ppm in water extract, with syringic and gallic acid as the main component. The FRVSB extracts showed a potent free radical scavenging activity for DPPH(2,2-diphenyl-1-picrylhydrazyl hydrate) with $IC_{50}$ of $28.54\;{\mu}g$(EtOH) and $54.70\;{\mu}g$(water), respectively, whereas $IC_{50}$ value of gallic acid was $1.84\;{\mu}g$. The protective effect of both ethanol and water extract the extracts against UV-induced oxidative stress in NIH3T3 was observed. The water extracts of FRVSB may promote adipogenesis in 3T3-L1 cells.

Echocardiographic Follow-up after Arterial Switch Operation for Transposition of the Great Arteries (동맥전환술을 시행한 대혈관전위 환자에서 심초음파를 이용한 술후 추적)

  • 한승세;정태은;이동협;오정훈;이정철
    • Journal of Chest Surgery
    • /
    • v.34 no.10
    • /
    • pp.754-762
    • /
    • 2001
  • Background: To evaluate the efficacy of arterial switch operation for transposition of great arteries, serial echocardiographic studies were performed in 8 patients who underwent the surgery between 1989 and 1998 at Dept. of Thoracic & Cardiovascular Surgery, Yeungnam University Hospital in Daegu City, Korea. Material and Method: Follow-up period ranged from 6 months to 11 years(average of 4.1 years). Body weight ranged from 2.6kg to 4.8kg, with average of 3.6kg. 5 of 8 patients were preoperatively diagnosed as TGA+VSD, and 3 as TGA+IVS. LV function was evaluated by the measurement of LV shortening fraction, LVSTI, and LVEF. RVSTI was also measured. Postoperative function of valve and growth of great vessels were analyzed by the measurement of PSPGV, valvular regurgitation, LA/AO ratio, root dimension of aorta and pulmonary artery, comparing with the age matched controls, respectively. Result: LVEF had an average of 65.0+9.03% which is tended to increase serially. LVAOPG had an average of 15.9mmHg. RVPAPG, 27.5mmHg. From the measurement of aortic root dimension of 6 patients at end-systole, aortic root growth was assumed to increase more than the mean value of normal growth. PA root dimension at end-systole showed a similar growth progress when compared with age matched normal controls. Postoperative pulmonic valve regurgitation was noted in 5 of total 8 patients, in which 1 patient who showed grade 2 and 4 showed below grade 1. AR, in 6 patients and all grade 1 Except 1 patient, all the valvular regurgitations were below grade 1, which was presumed to be clinically insignificant.

  • PDF

Significance of Apoptotic Cell Death after $\gamma-Irradiation$ (방사선 조사에 의한 세포사에 있어서 세포고사의 의미)

  • Wu H.G.;Kim I.H.
    • Radiation Oncology Journal
    • /
    • v.19 no.3
    • /
    • pp.252-258
    • /
    • 2001
  • Purpose : The objectives of this study are to investigate the significance of apoptotic death compared to total cell death after $\gamma-ray$ irradiation in human H&N cancer cell lines and to find out correlation between apoptosis and radiation sensitivity. Materials and method : Head and neck cancer cell lines (PCI-1, PCI-13, and SNU-1066), leukemia cell line (CCRF-CEM), and fibroblast cell line (LM217) as a normal control were used for this study. Cells were irradiated using Cs-137 animal experiment irradiator. Total cell death was measured by clonogenic assay. Annexin-V staining was used to detect the fraction of apoptotic death. Results : Surviving fraction at 2 Gy (SF2) were 0.741, 0.544, 0.313, 0.302, and 0.100 for PCI-1, PCI-13, SNU-1066, CCRF-CEM, and LM217 cell lines, respectively. Apoptosis was detected in all cell lines. Apoptotic index reached peak value at 72 hours after irradiation in head and neck cancer cell lines, and that was at 24 hours in CCRF-CEM and LM217. Total cell death increased exponentially with increasing radiation dose from 0 Gy to 8 Gy, but the change was minimal in apoptotic index. Apoptotic fractions at 2 Gy were $46\%,\;48\%,\;46\%,\;24\%,\;and\;19\%$ and at 6 Gy were $20\%,\;33\%,\;35\%,\;17\%,\;and\;20\%$ for PCI-1, PCI-13, SNU-1066, CCRF-CEM, and LM217, respectively. The radioresistant cell lines showed more higher apoptotic fraction at 2 Gy, but there was not such correlation at 6 Gy. Conclusion : All cell lines used in this study showed apoptosis after irradiation, but time course of apoptosis was different from that of leukemia cell line and normal fibroblast cell line. Reproductive cell death was more important mode of cell death than apoptotic death in all cell lines used in this study. But there was correlation between apoptotic fraction and radiation sensitivity at 2 Gy.

  • PDF

Quality changes in Agaricus bisporus varieties due to period and temperature during their storage (양송이버섯 품종별 저장기간 및 온도에 따른 품질변화)

  • Oh, Youn-Lee;Jang, Kab-Yeul;Jhune, Chang-Sung;Kong, Won-Sik;Yoo, Young-Bok;Shin, Pyung-Gyun;Seo, Jang-Sun
    • Journal of Mushroom
    • /
    • v.11 no.3
    • /
    • pp.137-144
    • /
    • 2013
  • This study was carried out to investigate storage stability of harvested mushroom in developed varieties of button mushroom through identification of quality change during 35 days. The mushroom harvested up to $2^{nd}$ flush mushroom was stored on different storage temperature(4, 7, $10^{\circ}C$) and weight, length, thickness, color of pileus and stipe in fruit body was tested every 7 days. The morphological trait and color of stipe in fruit body were influenced by harvesting period and storage temperature. On the morphological traits of fruit body, mushroom harvested at $2^{nd}$ flush showed smaller difference than those at $1^{st}$ flush and mushroom stored at $4^{\circ}C$ indicated more difference than ones at the other temperature. Mostly color of pileus in brown button mushroom had lower ${\Delta}E$ (color difference) than white mushroom during storage period. The color of pileus of fruit body in white mushroom had low ${\Delta}E$ at $4^{\circ}C$ whereas that of brown mushroom was low at $10^{\circ}C$. The safe period of storage based on the L value is 7 days under a specified environmental condition. 'Seolgang' was stored for 14 days as good quality of mushroom, 'Saedo' had best quality after harvesting and 'Seojeong' was most stable during storage change in white mushroom varieties.