• 대한치과기공학회지
• /
• 제42권2호
• /
• pp.81-89
• /
• 2020

Purpose: This in vitro study was conducted to evaluate the marginal and internal fit of three-unit Co-Cr frameworks fabricated by computer-aided metal milling and direct metal laser sintering(DMLS) systems in comparison to conventional casting method. Methods: Three-unit Co-Cr frameworks were fabricated by conventional wax up with casting(CWC), computer-aided metal milling(MM) and direct metal laser sintering(DMLS)(n=10 each). The marginal and internal fit of specimens were examined using a light-body silicone impression material. The thickness of light-body silicone was measured at eight reference points each, divided in the mesio distal and bucco lingual directions. All measurements were conducted by a stereomicroscope. Digital photos were taken at 150× magnification and then analyzed using a measurement software. The Kruskal-Wallis test and Bonferroni correction were used for analyzing the results. Results: The mean(SD) is ㎛ for fabrication methods, the mean marginal fit were recorded respectively, DMLS 39(27), followed by CWC 63(38), MM 220(128). and the mean internal fit CWC 95(47), DMLS 116(49), MM 210(152). In addition, the largest gap was found in the occlusal surface area among the internal measurement areas of all groups. Conclusion: As a result, the direct metal laser sintering method showed better marginal and internal fit than the metal milling method. The marginal and internal fit were statistically different according to the three fabrication methods(p<0.001). Except the MM group, the marginal fit of the CWC and DMLS groups was below the clinical standard of 120 ㎛. Based on the results of this study, it can be applied to clinical use in the future.

• 대한의생명과학회지
• /
• 제5권1호
• /
• pp.11-15
• /
• 1999

갑상선 질환의 진단에 필요한 갑상선 호르몬의 측정시 thyroxine (T$_4$)농도 측정방법이 가장 흔히 이용되고 있다. 과거에 많이 활용되어온 방사면역측정법 (RH)이 폐기물 처리 및 관리인원 등의 인적, 물적인 문제가 크게 대두되고 있는 점을 감안하면 효소결합면역측정법의 확립은 큰 의미가 있다고 하겠다. 본 연구에서는 thyroxine (T$_4$)에 대한 단클론 항체 (monoclonal antibody)를 이용하여 T$_4$에 horseradish-peroxidase를 화학적으로 결합시킨 microtiter plate에 HRP-conjugate T$_4$와 혈청내의 T$_4$간의 서로 경쟁적인 반응을 이용한 표준곡선을 얻었다. 그리고 이렇게 확립한 기법을 임상적인 갑상선질환 환자의 혈청을 기존의 chemiluminescence 방법을 이용하여 얻은 결과와 비교하여 본 실험에서 확립한 ELISA검사 수치의 유용성을 검토하였으며 이 방법의 임상이용 가능성을 검토하였다.

• 한국식품영양학회지
• /
• 제32권6호
• /
• pp.745-752
• /
• 2019

The purpose of this study was to determine the difference in vitamin B₆ content according to the varieties, regions, and harvest times of vegetables and fruits in Korea using high performance liquid chromatography. We verified the accuracy of the analytical method with standard reference material 1849a and achieved reliability for internal analysis quality control with a mixture of cereal, whole wheat, and flour. As a result of the analysis, vitamin B₆ contents (㎍/100 g) were 6.9~86.5 in peppers, 5.1~17.2 in paprika, 4.4~5.0 in strawberries, 4.0~52.9 in tomatoes, 7.7~7.8 in Chinese cabbage, 17.3~23.3 in radishes, 13.4~37.6 in apples, 2.3~12.7 in peaches, and 3.7~12.7 in grapes. In general, the difference in vitamin B₆ content showed by varieties, harvest times, and regions. Peppers showed the most difference as 79.6 ㎍/100 g among the varieties, and apples showed a difference as 22.8 ㎍/100 g by regions. According to the harvest times in grape 'Mihwang', there was a difference of 7.5 ㎍/100 g. We will collect an amount of nutritional data on various food materials, and continue to build a reliable and integrated nutritional database. And then the database will be used in the 10th revision of the Korean Food Composition Table.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
• /
• pp.230-235
• /
• 2001

There are more than 15 millions cars or motors in Taiwan. According to the statistics from Environmental Protection Administration, the number of resulting scrap tires are near 110 thousand tons each year. The tire recycle programs in Taiwan were first conducted in 1989 and executed by ROC Scrap Tire Foundation. However, the current efficiency of the tire recycling industry still needs to be improved to minimize the environmental problem or fire hazards caused by scrap tires storage. Ten major tire-recycling factories are surveyed in this study. The investigations include the source of scrap tire, the shredding process, the market of products, the management of wastes disposal, and the difficulties of these sectors. As the varieties of the shredding machines of the recycle factories, there are three kinds of final products which include powder, granular, and chips. The wastes, wires and fibers, produced by the shredding process are the major problems fur all the factories. The percentage of the wire and fiber removal from rubbers still needs to be increased. The best approaches found in this study to increase the efficiency of scrap tire recycling processes are proposed which include the improvement of magnetic separation system fiber/rubber separation system and the minimization of waste disposal. A categorized standard of the processing outputs is suggested as a reference for the decision-making of the tire-recycling factories.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2008년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.226-228
• /
• 2008

In recent years, the companies of electric power equipment for MV and HV classes trend to develop the eco-friendly insulated(solid, eco-gas, air etc.) switchgear which replaces existent SF6 gas insulated switchgear due to environmental problems such as global warming and so on. This paper makes reference to the newly developed Solid Insulated Switchgear (SIS) which uses the eco-friendly material such as epoxy for insulation. The insulation of the solid insulated switchgear (SIS) is composed of an epoxy, vacuum and air. The solid insulated switchgear (SIS) is a slate of the art product. The advantages of SIS are advanced reliability, economical efficiency, safety, maintenance free, reduction of installation area and the protection of environment. The solid insulated switchgear (SIS) is FE Analyzed such as electromagnetic, mechanical, thermal and fluid in order to find the optimal design. Thens SIS has been verified by international standard test. (IEC 62271 - 100 and so on.) As a result of this, the solid insulated switchgear (SIS) has been estimated as an alternative for eco-friendly MV class switchgear.

• 한국축산식품학회지
• /
• 제31권2호
• /
• pp.191-199
• /
• 2011

The objective of this study was to develop a method to simultaneously quantify vitamins A and E in infant formula. To determine the vitamin A and E content, vitamin A and four different vitamin E isomers (${\alpha}$-, ${\beta}$-, ${\gamma}$-, and ${\delta}$-tocopherol) were separated by high performance liquid chromatography with a photodiode array detector using a Develosil RPAQUEOUS RP-$C_{30}$ column ($4.6{\times}250$ mm, 5 ${\mu}M$). The vitamin A and E contents in the certified reference material determined using this method were within the certified range of standard values. The limits of detection (LODs) and limits of quantitation (LOQs) for vitamin A were 0.02 and 0.06 ${\mu}g/L$, respectively. LODs and LOQs for the vitamin E isomers ranged from 0.20 to 0.55 and from 0.67 to 1.81 ${\mu}g/L$, respectively. Linear analyses indicated that the square of the correlation coefficient for the vitamin A and E isomers was 0.9997-0.9999. The recovery of vitamins ranged from 96.69 to 97.79%. The results demonstrate that this novel method could be used to reliably analyze vitamin A and E content in infant formula.

• 복식문화연구
• /
• 제16권3호
• /
• pp.588-594
• /
• 2008

Lookism is spread largely because many people think beautiful people are treated better and receive more favors. This trend has been influenced by mass media and impacted by commercial marketing strategy. The expectation for the beauty have risen higher than ever. People expect beautiful body and beautiful face which are more difficult to meet the standard of beauty. People desire tall and skinny body. The purpuse of this study was to find out body image from college females in the age which they are very sensitive to appearance. This research focused to find out how they perceived their own body shape and their perception of the most ideal body shape. Measuring tool for the research was 9 pictures of body silhouette from very skinny to very fat. To analyse the respondents' objective body image, Body Mass Index were employed. The result of this research indicated that there were distinct differences between their subjective body images and ideal body images. This result indicated that they were not satisfied with their own body shape and hence they were not confident towards their body images. Even though their objective bodies were normal or under weight, they still felt they were over weight. This meant their body images were misrepresented. They preferred thinner bodies even though their bodies were perfectly normal and healthy. But these misrepresented body images could be unhealthy physically, psychologically, or socially. These results showed that college females were overly obsessive with superficial appearance rather than improving ones capability to be more competitive in the society. From this research, I tried to find out perception of body image and it's distortion which was debated a lot in our society. I also want to provide basic reference material for establishing the body image study.

• 한국태양에너지학회 논문집
• /
• 제31권1호
• /
• pp.68-77
• /
• 2011

The concern of green building has been increased with an environmental problem or a rising oil price by industrialization. Therefore offices, schools and some buildings are expected to acquire the green building certification increasingly, but the information such as a process of green building certification, the state of certificated buildings, a score as specific clauses on green building certification is to seek. For not only school facilities make an effect to an student's learning achievement, but is the place where adolescents in a period of growth almost spend their life, eco-friendly school facilities is absolutely required. For this reason, systematizing the information related with the green building certification is to be needed in school field as well Therefore the effort to systematize certification management of eco-friendly school and provide information of certificated building, certification application procedure and sources related with certification for convenience is needed. Also reference material to decrease an inefficient time and expenses and to systematize certification evaluation is be able to beneficial. On the study, for such as the purpose above-mentioned, as the appraisal standard with 12 selected schools randomly is arranged. Based on the assessed scores table, features or something in common as a cause of the score change between preliminary and main certification is to be classified and anaylized.

• Bulletin of the Korean Chemical Society
• /
• 제33권11호
• /
• pp.3727-3734
• /
• 2012

An analytical method has been developed for the rapid determination of perfluorinated compounds (PFCs) in human serum samples. The extraction and purification of PFCs from human serum were performed by the modified method of previous report. Ten PFCs were rapidly separated within 3.3 min by C18-monolithic column liquid chromatography (LC) and detected by electrospray ionization (ESI) tandem mass spectrometry (MS/MS) in negative ion mode. The runtime of PFCs on monolithic column LC was up to 4-fold faster than that on conventional column LC. The effect of triethylamine (TEA) to the mobile phase has investigated on the overall MS detection sensitivity of PFCs in ESI ionization. Quantification was performed by LC-MS/MS in multiple-ion reaction monitoring (MRM) mode, using $^{13}C$-labeled internal standards. Method validation was performed to determine recovery, linearity, precision, and limits of quantification, followed by, the analysis of a standard reference material (SRM 1957 from NIST). The overall recoveries ranged between 81.5 and 106.3% with RSDs of 3.4 to 16.2% for the entire procedure. The calibration range extended from 0.33 to 50 $ng\;mL^{-1}$, with a correlation coefficient ($R^2$) greater than 0.995 and the limits of quantification with 0.08 to 0.46 $ng\;mL^{-1}$. This approach can be used for rapid and sensitive quantitative analysis of 10 PFCs in human serum with high performance and accuracy.

• 한국안전학회지
• /
• 제33권4호
• /
• pp.90-97
• /
• 2018

As the result(also after it's been carried out the damping force test with 800ea lateral dampers of 50ea trainset from entering heavy maintenance workshop to implement heavy maintenance inspection cycle, there were 86.25%(650ea) which were out of $350kg{\pm}15%$ of the standard value of damping force compared to the reference value. After the implementation of heavy maintenance inspection cycle, it's been examined damping force test with total samples 32ea(samples 8ea per a trainset) from actual running EMU 4ea trainset. As the result, percent defective was 84.4%(27ea), which was a very high level. System. The lateral damper's the failure cause of damping force defective was oil leakage caused by tearing crack of oil seal and foreign material in oil iron 473 ~ 1932 times higher than that of new oil, copper 36 ~ 98 times higher than that of new oil reduced oil amount cycling damping valve. It resulted from the change cause of damping force. In the static analysis on the shape of lateral damper oil seal's the existing and improved product, the stress of the improved product was smaller than that of the existing product. In the fatigue analysis, the existing product showed a low life in the upper area. However, in case of the improved product, it could be confirmed that the destruction did not occur up to the specified 1.0e + 006 cycles and the lifetime was further improved in most areas.