• 방사선산업학회지
• /
• 제4권3호
• /
• pp.259-263
• /
• 2010

Carbon fibers are used as a reinforcement material in an epoxy matrix in advanced composites due to their high mechanical strength, rigidity and low specific density. An important aspect of the mechanical properties of composites is associated to the adhesion between the surface of the carbon fiber and the epoxy matrix. This paper aimed to evaluate the effects of electron beam irradiation on the physicochemical properties of carbon fibers to obtain better adhesion properties in resultant composite. Chemical structure and surface elements of carbon fiber were determined by FT-IR, elemental analysis and X-ray photoelectron spectroscopy, which indicated that the oxygen content increased significantly with increasing the radiation dose. Thermal stability of the carbon fibers was studied via the thermalgravimetric analysis. Surface morphology of carbon fiber was analyzed by scanning electron microscope. It was found that the degree of surface roughness was increased by electron beam irradiation.

• 방사선산업학회지
• /
• 제7권1호
• /
• pp.23-28
• /
• 2013

In this study, we fabricated high density polyethylene (HDPE) composites filled with antioxidants and UV stabilizers. The electron beam irradiation on the fabricated composites was carried out over a range of absorbed doses from 50 to 200 kGy to confirm the changes of discoloration. The changes of discoloration were characterized using a color difference meter and FT-IR for confirming the changes of the color difference and structural change. It was observed that the color difference of IRGANOX 1010-, IRGAFOS 168-, and TINUVIN 328- added HDPE was higher than that of the control HDPE by electron beam irradiation. The melting temperature of UV stabilizer-added HDPE was not significantly changed by electron beam irradiation. However, the melting temperature of phenol-containing antioxidant-added HDPE was increased with increasing the absorbed dose. And the melting temperature of phosphorus-containing antioxidant-added composite was decreased with increasing the absorbed dose.

• 한국식품영양과학회지
• /
• 제37권9호
• /
• pp.1190-1195
• /
• 2008

수산 가공 부산물을 천연 기능성 소재로 개발하기 위한 기초 자료를 마련하고자 문어 자숙액 에탄올 추출물을 전자선 조사하여 이에 대한 항산화, 항고혈압 및 미백효과를 평가하였고, 이와 더불어 대조군(0 kGy)의 생리활성과 비교하였다. 전자선 조사 문어 자숙액 에탄올 추출물의 색도를 측정한 결과 감마선 조사와는 달리 조사선량이 증가함에 따라 색상이 변화되었음을 확인하였다. DPPH 라디칼 소거능은 전자선 조사선량의 증가에 따라 유의적으로 증가하였으며, 이러한 소거능의 증가는 단백질의 항산화력의 증가가 원인인 것으로 판단되었다. ACE 및 tyrosinase 저해 활성 측정결과 조사선량이 증가함에 따라 각 활성이 증가하였다. 따라서 수산가공 폐자원인 자숙액이 전자선 조사에 의하여 생리활성이 개선된 기능성식품 소재로 활용될 수 있으며, 또한 전자선 조사의 산업적인 활용이 더욱 활발할 것으로 기대한다.

• 한국식품영양과학회지
• /
• 제37권3호
• /
• pp.362-366
• /
• 2008

본 연구는 감마선 조사가 재구성 돈육포의 이화학적 및 관능적 품질에 미치는 영향을 파악하고자 0, 3, 5, 7, 10 kGy 선량으로 조사된 재구성 돈육포의 일반성분, 지방산패도, 색도, 전단력 및 관능검사를 실시하였다. 일반성분 분석 결과에서 감마선 조사에 따른 수분, 조단백, 조지방의 함량 및 TBA값의 변화는 없었다. 그러나 색도 측정 결과 적색도인 a값이 유의적으로 증가함을 확인할 수 있었다(p<0.05). 전단력 측정 결과 조사선량이 증가할수록 전단력은 낮아졌으며, 관능검사 결과 모든 조사구에서 유의적인 차이를 보였다(p<0.05). 관능평가에서 기호도는 감마선 조사에 의해 낮아졌다. 따라서 재구성 돈육포에 있어 감마선의 조사는 육색 및 조직감을 개선시킬 수 있는 좋은 수단이나 관능적 개선을 위한 추가적인 연구가 필요하였다.

• Food Science and Biotechnology
• /
• 제14권1호
• /
• pp.137-142
• /
• 2005

The genotoxicological safety of fermented vegetables pasteurized by gamma irradiation was examined to consider the possibility of the application of irradiation for extending of fermented vegetables. A fermented vegetable was irradiated at 20 kGy to assure its toxicological safety even at a high dose of radiation. The Ames test with Salmonella typhimurium (TA98, TA100, TA1535, TA1537) and Escherchia coli (WP2), and the chromosomal aberration test in Chinese hamster lung (CHL) cells were performed. In vivo micronucleus test were conducted in mouse bone marrow cells. With or without metabolic activation, negative results were obtained in the Ames test and the chromosomal aberration test. In the micronucleus test, there was no enhancement in the formation of micronucleus, and there were no such significant differences between the irradiated and non-irradiated samples. The observed results indicated that, a level of 20 kGy of gamma irradiation on the fermented vegetable did not bring about any genotoxic effects under the described experimental conditions.

• Preventive Nutrition and Food Science
• /
• 제9권3호
• /
• pp.232-235
• /
• 2004

Since ready-to-use (RTU) products are not fully cooked, the shelf-life of the product is comparably short and the products are easily spoiled when contaminated with food-borne pathogens. Low-dose gamma irradiation of 0.5, 1, or 2 kGy effectively reduced the total aerobic bacterial counts in 2 Korean manufactured RTU products by 1.63 to 2.95 log CFU/g during cold storage. Irradiation at 2 kGy reduced the psychrotrophic bacterial counts in most of the samples to below the limit of detection (< log CFU/g). Irradiation at 0.5 kGy completely eliminated Escherichia coli from the commercial RTU samples.

• 방사선산업학회지
• /
• 제2권1호
• /
• pp.9-14
• /
• 2008

Livestock wastewater containing high concentrations of organic matters and ammonia-nitrogen has been known as one of the recalcitrant wastewater. It is difficult to treat by conventional wastewater treatment techniques. This study was carried out to evaluate the feasibility of zeolite ion exchange and gamma-ray irradiation treatment of livestock wastewater. The removal efficiencies of $SCOD_{Cr}$ and $NH_3-N$ were significantly enhanced by gamma-ray irradiation after zeolite ion exchange as a pre-treatment. However, the effects of zeolite particle size on the $SCOD_{Cr}$ and $NH_3-N$ removal efficiencies were insignificant. These results indicate that the combined process of zeolite ion exchange and gamma-ray irradiation has potential for the treatment of livestock wastewater.

• 한국식품저장유통학회지
• /
• 제16권4호
• /
• pp.590-593
• /
• 2009

감마선 조사가 미역의 저장성 개선에 미치는 영향을 평가하였다. 미생물 오염도 평가 결과 3 kGy 이하의 선량에서 미생물이 검출되지 않았다. 2주 저장한 후, 조사처리 하지 않은 미역의 미생물이 6 log CFU/g이 증가하였다. 그러나 5 kGy 조사 처리한 미역의 경우 미생물이 검출되지 않았다. 5 kGy의 감마선 조사를 적용하였을 때, 미역의 명도 값이 소폭 증가하였다. 미역의 경도 측정 결과 3 kGy 이하의 감마선 조사에 의해 영향을 미치지 않았으며, 저장기간에 따른 차이는 없는 것으로 나타났다. 이상의 결과를 종합하여 볼 때, 3 kGy 감마선 조사는 미역의 품질에 영향을 받지 않고, 저장성을 연장시킬 수 있는 효과적인 기술이라고 판단된다.

• 방사선산업학회지
• /
• 제6권2호
• /
• pp.165-169
• /
• 2012

This study was conducted to determine the prevention effect of poly-gamma-glutamic acid (${\gamma}-PGA$) on tissue damage induced by gamma irradiation for development of xenograft. Porcine tendons were treated at various doses of ${\gamma}-PGA$ (0.1, 0.5, 1 and 5%) and then gamma-irradiated (30 kGy). Prevention effects on tissue damage were measured as the result of tensile strength, hydroxyproline contents and viscosity of ${\gamma}-PGA$. Tensile strength was remarkably decrease in gamma-irradiated porcine ligament, but increased by ${\gamma}-PGA$ treated one. Among the ${\gamma}-PGA$ treatment doses, 1% treated group showed the highest values of tensile strength compared to non-treated group. Hydroxyproline contents was significantly increased by gamma irradiation, but decreased by the ${\gamma}-PGA$ treatment. Particularly, 1 and 5% ${\gamma}-PGA$ treated group were exhibited lower values of hydroxyproline contents than other group. In the result of viscosity, gamma-irradiated ${\gamma}-PGA$ (1%) was remarkably increased. Base on the results, it demonstrated that gamma irradiation induces severe alteration of mechanical property and collagen contents on porcine ligament, but ${\gamma}-PGA$ can effectively prevent these tissue damage.

• Journal of Semiconductor Engineering
• /
• 제2권1호
• /
• pp.119-124
• /
• 2021

Along with the needs for feasibility in the field of space applications, interests in radiation-hardened electronics is growing rapidly. Gallium nitride (GaN)-based devices have been widely researched so far owing to superb radiation resistance. Among them, research on the most abundant protons in low earth orbit (LEO) is essential. In this paper, proton irradiation effects on parameter changes, degradation mechanism, and correlation with reliability of GaN-based devices are summarized.