• The Journal of Korean Academy of Prosthodontics
• /
• v.47 no.1
• /
• pp.21-28
• /
• 2009

Purpose: The purpose of this study was to compare the wear characteristics of human enamel opposing 2 heat-pressed ceramics (e.max Press and Empress Esthetic), conventional feldspathic porcelain (Ceramco 3) and type III gold alloy. Material and methods: Intact cusps of extracted premolars were used for enamel specimens. Five disk samples were made for each of two heat-pressed ceramics groups, conventional feldspathic porcelain group and type III gold alloy group. Wear tests were conducted in distilled water using a pin-on-disk tribometer. The amount of enamel wear was determined by weighing the enamel specimens before and after wear tests, and the weight was converted to volumes by average density. The wear tracks were analyzed by scanning electron microscopy and surface profilometer to elucidate the wear characteristics. Results: 1. Ceramco 3 led to the greatest amount of enamel wear followed by Empress Esthetic, e.max Press and type III gold alloy. However, there was no significant difference between Ceramco 3 and Empress Esthetic (P>.05), and there were also no significant differences among Empress Esthetic, e.max Press and type III gold alloy (P>.05). 2. The average surface roughness of e.max Press after wear test was smallest followed by Empress Esthetic and Ceramco 3, but there was no significant difference between Empress Esthetic and Ceramco 3 (P>.05). 3. There were no significant differences among the depth of wear tracks of all the groups (P>.05). The group that showed the largest width of wear track was Ceramco 3 followed by Empress Esthetic, e.max Press and type III gold alloy. However, there was no significant difference between e.max Press and Empress Esthetic (P>.05), and there was also no significant difference between Empress Esthetic and Ceramco 3 (P>.05). Conclusion: Within the limits of this study, heat-pressed ceramics were not more abrasive than conventional feldspathic porcelain.

• Journal of Life Science
• /
• v.18 no.11
• /
• pp.1561-1569
• /
• 2008

This study was conducted to investigate the effects of steam flaking of corn grains on in situ dry matter degradability in the rumen and contents of mycotoxins (aflatoxin, ochratoxin) during storage. Yellow dent corns imported from USA and India were flaked, and stored for 8 weeks under the standard temperature and pressure (STP; $25^{\circ}C$/ 1 atm.). Experimental treatments were composed of four corn grains (untreated-USA corn, USCW; steam flaked-USA corn, USCF; untreated-India corn, IDCW; steam flaked-India corn, IDCF) with 4 replications according to 9 storage periods (0, 1, 2, 3, 4, 5, 6, 7, 8 week). Two ruminally cannulated Holstein bulls were used for in situ trial. Pathogen contamination trial was performed by comparing the mycotoxin contents in corns during storage periods. Dry matter disappearance rate in the rumen was about 3.0 to 44.1% higher (P<0.05) for USCW than IDCW, but was not difference between USCF and IDCF. With steam flaking of corn, dry matter degradability in the rumen was significantly (P<0.05) increased in corn from India, but was not affected in corn from USA. Aflatoxin content was very low level in corns from USA and steam flaked corns, but was higher than the tolerance limit of domestic aflatoxin content regulation when IDCW was stored over 6 week under STP. Ochratoxin content was low level in all treatments. From above results, it is reasonable that the corn imported from India might be flaked for enhance the ruminal DM degradability and safe from aflatoxin pathogen.

• Journal of Food Hygiene and Safety
• /
• v.15 no.2
• /
• pp.61-67
• /
• 2000

Bacteriological quality evaluations were carried out for rice rolled in laver(Kimbab), Hamburger, Walnut cake and chinese noodle (Jajangmyun), which were on sale in April and May 1995, in May and July 1997 and in January 1999, at 20 different resting places on Kyung-Bu, Ho-Nam, Joong-Bu and Young-Dong Highway in Korea. Food poisoning bacteria were not detected. However numerous coliform bacteria were dectected saying that the sanitary condition of foods on sale at resting places of the highways was not hygienic. There exited 8.8$\times$10$^{4}$~6.6$\times$10$^{5}$ cells/g of coliform bacteria in all the Kimbab sold in 1995. As for Hamburger, 1.8$\times$10$^{2}$~4.7$\times$10$^{4}$ cells/g of coliform bacteria proliferated in all the samples. In 1997,E. coli was found in 16 cases and 21 cases respectively out of 22 Kimbab samples, Hamburger dealing at 7 resting places out of 14 were contaminated with 1.7$\times$10$^{2}$~1.9$\times$10$^{7}$ cells/g of coliform bacteria and Hamburgers dealing at 2 resting places were infected by 5. coli. In contrast to the Kimbab and Hamburger, all the 6 Walnut cake samples were free from the microbial pollution exhibitory that their hygienic condition was satisfactory. 3 samples out of 6 Jajangmyun were contaminated by 7.1$\times$10$^{2}$~2.0$\times$10$^{3}$ cells/g of coliform bacteria, but E. coli was not detected. Compared Kimbab sold in 1995 and 1997 with 1999, Kimbab sold in it can be said that hygienic control fur Kimbab should be performed more strictly during hot season than during cold season. Walnut cake was the safest against microbial contamination, followed by Jajangmyun, Hamburger and Kimbab in decreasing order, indicating that foods with mixed ingredients such as Kimbab and Hamburger were more susceptible to microbial infection, so that a more systematic safety control is needed for such foods during cooking, processing and distribution.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2007.05a
• /
• pp.1793-1797
• /
• 2007

한강 "수변구역"에서 비점오염물질의 공공수역 유입을 억제하기 위한 다양한 방법들 중에서 보편적이고 자연친화적인 방법은 다양한 생물의 서식공간이며, 동시에 본류로 유입되는 과정에서 수질을 정화시키는 수질개선 공간인 수변완충구역, 또는 지대를 설정하여 관리하는 것이다. 그러나 이러한 수변완충지대 효과 분석 및 설정에 관한 연구는 국내에서 아직 수행되지 않았다. 본 연구의 목적은 수변구역의 자정능력을 높이는 것은 물론 그 밖의 하천 연안에서 비점오염물질의 차단과 처리능력을 증진시키고 수변 생태계의 서식처 보전 및 복원을 위해서 수변완충지대의 수질정화 기술개발과 생물다양성을 창출하는 수변완충지대 조성 기법을 개발하는데 있다. 본 연구에서는 기존 수변완충지의 추가적인 조성과 보완, 시험완충지 생태구조 및 기능 기초조사, 시험완충지 오염부하 저감효과의 실험 및 분석, 수변완충지대 설치 구상 등의 연구를 수행하였다. 수행 지역은 한강수계 지역으로 남한강 수변인 경기도 양평군 병산리에서 실시하였으며, 잔디와 갈대, 갯버들, 혼합지역, 자연그대로의 상태(대조지역)의 5 구역으로 구분하였고, 깊이별로 샘플을 채취하여 유입수와 표면유출, 하부유출을 비교해 보았다. 연구 결과, 5 가지 구역 중 잔디 구역의 SS, T-N, T-P, TOC의 제거 효율이 각각 76.7%, 85.2%, 97.6%, 83.3%로 가장 좋은 오염물질 제거 효율을 보였으며, 깊이 별 분석에서는 표면유출에서 하부유출로 갈수록 월등한 효율을 보였다. 따라서 본 연구를 통하여 비점오염원에 대한 한강수계의 수자원 보호 효과를 기대할 수 있고, 수변완충지대의 조성, 유지관리기술의 개발을 통한 수변완충지대의 계획과 설계에 직접적인 기여를 할 수 있으며, 수변구역에 설치 가능한 Riparian Buffer Zone의 중요성과 효율성을 알려 현재 하상 저니 준설 및 폭기 위주의 사업에서 생태 공학적 복원을 적극 고려한 정화사업으로 확대 추진하고자 한다.해결책을 얻어내는 상호보완적인 결과를 추구한다. 그가 디자인하는 작품은 전형적인 이미지를 내포하지 않는다. 즉 그의 작품은 기존의 가치와 이념적인 것은 배제하고, 창의적인 개념을 도출하였다.형모서리는 건물 특화 성격이 강하므로 불가피할 경우 소형 액센트 광고 위치를 미리 벽면으로 할애하는 것이 경관 및 입면계획에 유리한 것으로 분석되었다. 불확실도 해석모형 등의 새로운 기능을 추가하여 제시하였다. 모든 입출력자료는 프로젝트 단위별로 운영되어 data의 관리가 손쉽도록 하였으며 결과를 DB에 저장하여 다른 모형에서도 적용할 수 있도록 하였다. 그리고 HyGIS-HMS 및 HyGIS-RAS 모형에서 강우-유출-하도 수리해석-범람해석 등이 일괄되게 하나의 시스템 내에서 구현될 수 있도록 하였다. 따라서 HyGIS와 통합된 수리, 수문모형은 국내 하천 및 유역에 적합한 시스템으로서 향후 HydroInformatics 구현을 염두에 둔 특화된 국내 수자원 분야 소프트웨어의 개발에 기본 토대를 제공할 것으로 판단된다.았다. 또한 저자들의 임상병리학적 연구결과가 다른 문헌에서 보고된 소아 신증후군의 연구결과와 큰 차이를 보이지 않음을 알 수 있었다. 자극에 차이가 있지 않나 추측되며 이에 관한 추후 연구가 요망된다. 총대장통과시간의 단축은 결장 분절 모두에서 줄어들어 나타났으나 좌측결장 통과시간의 감소 및 이로 인한 이 부위의 통과시간 비율의 저하가 가장 주요하였다. 이러한 결과는 차가운 생수 섭취가 주로 결장 근위부를 자극하는 효과를 발휘하는 것이 아닌가 해석된다. 이와 같은 연구결과를 통해 생다시마를 주원료로 개발된 생다시마차와 생다시마 음료가 만성 기능성 변비 증세를 개선하는 효능이 잠재적으로 있음을 확인하였다. 그러나 생약제재의 변비약 수준으로 변비 개선 효능을 증대하기 위해서는 재료 배합비의 개선이나 대장 운동기능을 향상시키는 유효성분의 보강 등이 필요하다는 점도 알 수 있었다.더불어 산화물질 해독에 관여하는

• Journal of Food Hygiene and Safety
• /
• v.28 no.4
• /
• pp.349-353
• /
• 2013

This study was performed to evaluate the bactericidal efficacy of Fumagari OPP$^{(R)}$, fumigation disinfectant, containing 20% ortho-phenylphenol against Staphylococcus aureus (S. aureus). In this research, efficacy test of fumigant against S. aureus was carried out according to French standard NF T 72-281. S. aureus working culture suspension number (N value), all of the colony numbers on the carriers exposed with the fumigant (n1, n2, and n3), the number of bacterial test suspentions by pour plate method (N1), the number of bacterial test suspentions by filter membrane method (N2) and the mean number of bacteria recovered on the control-carriers (T value) were obtained from the preliminary test. In addition, the reduction number of S. aureus exposed with the fumigant (d value) was calculated using T value, the mean number of bacteria in recovery solution (n'1) and the mean number of bacteria on carriers plated in agar (n'2). N value was $4.0{\times}10^8$ CFU/mL, and n1, n2, and n3 were higher than 0.5N1, 0.5N2 and 0.5N1, respectively. Additionally, T value was $3.4{\times}10^6$ CFU/mL. In the bactericidal effect of the fumigant, the d value was 6.43 logCFU/mL. According to the French standard for the fumigant, the d value for the effective bactericidal fumigant should be over than 5 logCFU/mL. The results indicated that Fumagari OPP$^{(R)}$ had an effective bactericidal activity against S. aureus, then the fumigant can be applied to disinfect food materials and kitchen appliances contaminated with pathogenic bacteria.

• Korean Journal of Agricultural Science
• /
• v.3 no.1
• /
• pp.77-84
• /
• 1976

The preservation efficiency, quality and utilization of silage from 3 species of pumpkins (Mammoth pumpkin, Queensland blue pumpkin, Korean pumpkin) without and with 10, and 20% wheat bran additive were studied in this experiment. Silages were analysised and tested the chemical composition, pH and quality of silages between at 40-60 days and egg performance were carried out with mammoth pumpkin silage without additive. The results were summaried as follows. 1. The losses of all silage ware lower and similar as about 15% at 6 monthes following after silage-making but all raw pumpkins were spoilaged during the winter storaging. 2. The moisture content of silages were higher as about 97% in mammoth pumpkin silage, 94% in Queensland pumpkin silage and 91% in Korean pumpkin silage without additive and all nutrient content of silage without and with additive were depended on its content of raw silage material of pumpkins and wheat bran. The contents of moisture and N-free extract were slightly decrease but not significantly difference during the silaging and other contents were not so much changed. 3. Good quality of silage were made from all pumpkins with and without additive. Organic acid contents were 2.09-2.93% of lactic acid, 0.68-1.71% of acetic acid and 0% of butyric acid and it was pH 3.8-4.0 in silages. 4. Feed intakes, egg production and quality of egg were showed good result in 5.0 and 7.5% silage feeding group as D.M. base for egg performance. (P<0.01) 5. It was concluded that good quality of silage were made from pumpkins with and without wheat bran additive and it was suggested that poor quality feedstuff may be improved it feeding value by extended palatability with pumpkin additive silage.

• The Journal of Korean Academy of Prosthodontics
• /
• v.50 no.4
• /
• pp.235-242
• /
• 2012

Purpose: The purpose of this study was to compare the fracture behavior of Zironia, glass infiltrated Alumina and PFM full crown system. Materials and methods: Fifteen crowns for each of 3 experimental groups (Zironia, glass infiltrated Alumina and PFM full crown) were made by the conventional method. The crowns mounted on the testing jig were inclined in 30 degrees to the long axis of the tooth and the universal testing machine was used to measure the fracture strength. Results: 1. The mean fracture strengths were $588.3{\pm}49.6MPa$ for zirconia system, $569.1{\pm}61.8MPa$ for PFM system and $551.0{\pm}76.5MPa$ for glass-infiltrated alumina system (P>.05). 2. The mean shear bond strengths were $25.5{\pm}5.6MPa$ for zirconia system, $38.9{\pm}5.0MPa$ for Ni-Cr alloy system and $39.4{\pm}5.1MPa$ for glass-infiltrated alumina system. 3. The chemical bonding was observed at interfaces between PFM or glass-infiltrated alumina and veneering porcelain, however, no chemical bonding was observed at interface between zirconia and veneering porcelain. Conclusion: With the study, the fracture strengths of PFM crown system had a higher fracture strength than conventional zirconia system crown and glass-infiltrated alumina crowns. and than the shear bond strengths glass-infiltrated alumina system had a higher shear bond strength than conventional PFM system and zirconia system.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.34 no.2
• /
• pp.177-183
• /
• 1989

Lower leaves of aromatic tobacco are also much lower in Quality than upper leaves. So feasibility test of no harvesting and curing of lower leaves was conducted under high planting density and high nitrogen conditions with conventional cultural system. Effect of harvesting time on yield and Quality were investigated under 2 nitrogen levels. Among harvesting methods of conventional harvest with priming under high planting density, no-harvest of first priming, removal of lower leaves which relevant to first prime stalk before maturity, no-harvest of first and second priming. no-harvesting or pruning of first prime stalk before maturity was best in yield, price and in crude income. The shortor the harvest period became, the lower the yield, price and contents of reducing sugar and nicotine became, but reverse in this trends with total nitrogen and protein nitrogen. So 6 or 8 days interval of harvest is most recommendable.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.64 no.4
• /
• pp.406-413
• /
• 2019

The purpose of this research was to analyze the effect of different sowing times on the flowering and maturing of major soybean cultivars by varying day length and temperature in the central plain region. The average of growth period and cumulative temperature in five test cultivars by sowing times were 121 days and 2,972℃ on June 1, respectively and gradually decreased to 85 days, 2,042℃, respectively on July 20. Analysis of the flowering response according to the sowing times showed that flowering was greatly influenced by the decrease of photoperiod until the sowing on July 10, and the minimum number of days for flowering were 27 days, 36 days, respectively in early and mid-rate maturing type in the central plain region. Daepung 2 is classified to the same ecotype with Daewonkong, the total number of growing days was not different between two cultivars, but ripening period (R2-R6) was longer by 5 days and yield was higher by 11% in Daepung 2. The maturity rate was also high and safe enough to maintain more than 90% through the entire sowing times. This ecological characteristic can be usefully applied as a section index for breeding environmental stress resistant and high yielding soybean varieties. The yield of 4 domestic cultivars (except TI196944) sowing on July 20 were 85~92% levels compared to sowing on June 20.

• Restorative Dentistry and Endodontics
• /
• v.34 no.2
• /
• pp.130-136
• /
• 2009

The aim of this study was to develop a method for measuring the slumping resistance of flowable resin composites and to evaluate the efficacy using rheological methodology. Five commercial flowable composites (Aelitefil flow:AF, Filtek flow:FF, DenFil flow:DF, Tetric flow:TF and Revolution:RV) were used. Same volume of composites in a syringe was extruded on a glass slide using a custom-made loading device. The resin composites were allowed to slump for 10 seconds at $25^{\circ}C$ and light cured. The aspect ratio (height/diameter) of cone or dome shaped specimen was measured for estimating the slumping tendency of composites. The complex viscosity of each composite was measured by a dynamic oscillatory shear test as a function of angular frequency using a rheometer. To compare the slumping tendency of composites, one way-ANOVA and Turkey's post hoc test was performed for the aspect ratio at 95% confidence level. Regression analysis was performed to investigate the relationship between the complex viscosity and the aspect ratio. The results were as follows. 1. Slumping tendency based on the aspect ratio varied among the five materials (AF