• Korean Journal of Food Science and Technology
• /
• v.43 no.6
• /
• pp.766-772
• /
• 2011

This study was conducted to evaluate the daily intakes of propyl gallate, EDTA (ethylenediamine tetra acetate), and erythorbic acid for average consumers by age group and the intake of high consumers ($95^{th}$ percentile) in Korea. The average intake of EDTA was $1.14{\mu}g/kg{\cdot}bw/day$, and 0.0% of the ADI (acceptable daily intake) established by JECFA (Joint FAO/WHO Expert Committee on Food Additives). The $95^{th}$ percentile intake of EDTA was $141.24{\mu}g/kg{\cdot}bw/day$ (5.6% of ADI). The average intake of erythorbic acid was $16.93{\mu}g/kg{\cdot}bw/day$, and the 3-6 year-old group had the highest consumption ($58.43{\mu}g/kg{\cdot}bw/day$), which was <1.0% of the ADI established by the EU (European Union). The $95^{th}$ percentile intake of erythorbic acid was $1,320.31{\mu}g/kg{\cdot}bw/day$ and 22.0% of the ADI. In conclusion, daily intakes of propyl gallate, EDTA, and erythorbic acid in Korea were at safe levels in all age groups and also in high consumers.

• Journal of Korea Foundry Society
• /
• v.14 no.3
• /
• pp.267-273
• /
• 1994

The structure of austempered ductile cast iron, called ADI, consists of graphite, retained austenite, and bainite. The bainite component of them is considered a useful structure for exriting materials for roll of rolling mill. Therefore, the ADI can be considered applicable to material for rolling contact element. The diverse tests, such as rolling contact friction test, impact test, and X-ray reflection test, were carried out to investigate the possibility of it`s application. The result of this study showed that the expected fact was confirmed. The specimen showed that the best performance had the structure of the low bainite containing the stable retained austenite of about 20%.

• Journal of the Korean Society for Heat Treatment
• /
• v.11 no.2
• /
• pp.82-91
• /
• 1998

The elastic modulus and wear resistance in austempered ductile cast iron(ADI) are two important mechanical properties for automobile parts. Therefore, the effect of Cu, Ni, Mo and special austempering treatment such as preheated, prequenched, and step austempering treatments on elastic modulus and wear resistance has been investigated systomatically. As a result, elastic modulus and wear resistance were increased by the addition of Mo-Cu and preheated austempering treatment.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.9 no.1
• /
• pp.90-97
• /
• 1989

Austempered ductile cast iron (ADI) which has been recently developed shows good mechanical properties. These properties are related to the microstructure which is greatly affected by processing variables such as austempering time and temperature. In this study, the relationships between mechanical properties from impact test, and hardness test and the results from ultrasonic velocity measurement and electrical resistivity measurement are studied on the ADI samples which are heattreated at different austempering temperature and time. From the results, we conclude the followings. The ultrasonic velocity measurement could be used for the study of austempering reaction mechanism. The electrical resistivity measurement could be used as quality assurance technique for the ADI.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.17 no.9 s.112
• /
• pp.890-894
• /
• 2006

To make the best use of known characteristics of the alternating-direction-implicit finite-difference time-domain (ADI-FDTD) method such as unconditional stability and modeling accuracy, an efficient time domain solution with variable time-step size is proposed. Numerical experiment shows that a time-step size for a given mesh size can be increased preserving a desired numerical accuracy over frequencies of interest. The proposed method can be used to analyze electromagnetic problems with reduced computation time.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1993.10a
• /
• pp.126-130
• /
• 1993

소경드릴가공은 많은 기계가가공중에서도 가장 곤란한 가공의 하나이다.그것은 가공구멍단면 이하의 공간속에서 공구강성이나 칩처리들이 고려되어야 한다는 엄격한 제한이 소경이란 형태에서 한층 어려워지기 때문이다.소경의 구멍가공은 최근 전자제품,우주항공기 부품,소형정밀부품, 섬유산업의 광섬유관련품 등에 까지 수요가 증가함에 따라 레이져가공,전자빔가공,전해가공과 같은 전기물리적가공법이 많이 사용되고 있지만 생산성 및 가공정밀도의 관점에서 만족스러운 결과를 얻을 수 없는 실정이다, 이에반해 기계가공인 소경드릴가공은 공구강성저하로 인해 쉽게 파손된다는 점은 있지만 가공정도가 양호하고 종횡비가 높은 가공이 가능하여 실용화가 가장 좋은 분야라고 할수 있다. 이로 인해 최근에는 여기에 관한 많은 연구가 지행되고 있다. 또한 기계가공의 자동화가 진전됨에 따라서 단일공국의 대표적 공구인 바이트의 결함을 검출하는것 못지않게 드릴의 마멸이나 절손의 검출 또는 예측이 중요한 문제로 부각됨에 따라 절삭저항의 이용이 증가할 것으로 생각된다. 따라서 본 연구에서는 ADI에 포함된 Si량이 드릴가공시 ADI의 피삭성에 미치는 영향을 절삭조건을 변화시켜 고찰함과 동시에 공구수명에 대하여 고찰하였다.

• Journal of Korea Foundry Society
• /
• v.10 no.5
• /
• pp.408-416
• /
• 1990

The application of this new design approach called fracture mechanics allow one to determine the maximum allowable stress from the knowledge of the largest expected flow size and the plane strain fracture toughness of a material. In this study we examined the relation between retained austenite, mechanical property and fracture toughness accompanied by austempering heat treatment. Fracture toughness values and retained austenite volume were higher with the ADI(austempered ductile iron) which were austempered at $380^{\circ}C$ than austempered at $320^{\circ}C$. Additionally, fracture toughness values were increased for 1~2 hour austempering time but it was slowly decreased for 5 hour ADI maintaining the predominant fracture toughness($K_{IC}:83MPa{\sqrt{m}}$) is obtained following condition, namely, austempering temperature and time ($380^{\circ}C$ and 1 hour).

• Journal of Food Hygiene and Safety
• /
• v.28 no.4
• /
• pp.293-298
• /
• 2013

In this study, sorbic acids and benzoic acids frequently used in foods retailed in Korea were monitored and their estimated daily intakes were assessed for a purpose to ensure food additives safety management. The estimated daily intakes were calculated by categorizing the assessment items into the national average, by gender, by age and the high intake ($95^{th}$) groups based on concentrations of preservatives in foods as well as national health and nutrition survey data. The calculations were then compared with the ADI of the JECFA and the possibility of risk to be imposed on the people was examined. The results indicated that the estimated daily average intakes of preservatives were $221.60{\mu}g/kg{\cdot}bw/day$ of sorbic acids and $27.30{\mu}g/kg{\cdot}bw/day$ of benzoic acids. Compared to the ADI, the intake levels were 0.89 and 0.55% respectively, which were in a safe range. The estimated daily intakes of sorbic acids and benzoic acids in the high intake group ($95^{th}$) were $1140.27{\mu}g/kg{\cdot}bw/day$ and $194.95{\mu}g/kg{\cdot}bw/day$, which were 4.56% and 3.90% of the ADI (%) respectively, indicating that the intake levels of sorbic acids and benzoic acids in the high intake group were within a safe range. As for gender difference, the amount of benzoic acids intake was slightly larger in men than in women. However, gender differences were not observed in terms of the intake of sorbic acids. In terms of the levels of intake by age, the rates were found to be in the range of 0.52-2.10% for sorbic acids and 0.15-1.23% for benzoic acids. Therefore, the levels of sorbic acids and benzoic acids intakes were found not to exceed the ADI in all groups, and thus were within the safe ranges.

• The Korean Journal of Pesticide Science
• /
• v.15 no.4
• /
• pp.335-349
• /
• 2011

100 residual pesticides in 1,565 medicinal herbs being on sale in Seoul was analyzed by a simultaneous multiresidue method. The recovery ratio was 71.0~119.7%. The detection rate of pesticide residues was 5.3% and the rate of excess to Maximum Residue Limits (MRLs) was 0.9% of the total samples. The medicinal herbs which had the high detection rate of residual pesticides were Alismatis Rhizoma, Citri Unshii Pericarpium, Lycii Fructus and Zyzyphi Fructus. The medicinal herbs detected pesticide over Maximum Residue Limits (MRLs) were Alismatis Rhizoma (4), Cnidii Rhizomain (4), Chrysanthemi Zawadski Herba (1), Citri Unshii Pericarpium (1), Lycii Radix Cortex (1), Menthae Herba (1), Schisandrae Fructus (1) and Taraxaci Herba (1). The residual pesticides which had the high detection frequency were cypermethrin, chlorpyrifos, phenthoate, endosulfan, isoprothiolane, chlorothalonil and chlorfenapyr. Estimated Daily Intake (EDI) of detected pesticides was compared to Acceptable Daily Intake (ADI) in order to assess risk. Ethoprophos detected in Cnidii Rhizomain showed the highest %ADI, 26.85. And pyraclofos and endosulfan in Cnidii Rhizomain, endosulfan and isoprothiolane in Alismatis Rhizoma and cyprodinil in Taraxaci Herba showed more than 1 %ADI, but others showed below 1 %ADI.

• Korean Journal of Food Science and Technology
• /
• v.42 no.6
• /
• pp.762-767
• /
• 2010

This study evaluated daily intakes of BHT, BHA, and TBHQ in Korean. The daily intakes were estimated using both a dietary survey approach and food supply survey approach. In the dietary survey approach, individual dietary intake data from the Korea National Health and Nutrition Survey in 2005, as well as analytical results of BHT in 131 samples, BHA in 134 samples, and TBHQ in 104 samples, were used to assess daily intakes of the antioxidants. In the food supply survey approach, both total production amounts of BHT, BHA and TBHQ and maximum permitted levels of the antioxidants were used to calculate daily intakes. In the dietary survey results, the average daily intakes of BHT, BHA and TBHQ were 0.8, 0.5, and 0.3 ${\mu}g$/kg body weight/day, respectively, and below 0.2% of the ADI (acceptable daily intake) set by JECFA (Joint FAO/WHO Expert committee on Food Additives). In the food supply survey approach, the average daily intakes of BHT, BHA,and TBHQ were all 0.3 mg/kg body weight/day. The ratios of ADI were 97, 60, and 40%, respectively. According to these results, daily intakes of BHT, BHA, and TBHQ in Korean are lower than the ADI.