• 방사선산업학회지
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• 제8권3호
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• pp.161-168
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• 2014

Increasing utilization of radiation and RI (Radioisotope) in nuclear industry including non-power area has achieved sustainable development of radiation industry. Industries are no longer confined by a single technology or abilities but expanded for application gradually. RI-Biomics fields are one of the convergence technology that is recognized on a high-tech industry. Unlike the conventional industry, RI-Biomics field needs to various specialists to perform related task. There is no domestic training program to educate the whole process. This study aims to suggest the plan for improvement of practical skills for specialists in RI-Biomics through development of our training program. For this purpose, we have first investigated the opinion about classification scheme from experts and then analyzed the results in order to reflecting our training program. Based on analyzed results, conformity assessment was executed to organize curriculum through status of constructed device and instructor in domestic. Our training program was performed jointly with KAERI (Korea Atomic Energy Research Institute). RI-Biomics center is prepared with facilities of overall experiment to improve quality of education. Due to the fact that specialists have routine task, we organized a five-day short course to reflect temporal difficulties. We performed a trial operation to 6 participants in RI-Biomics field. Through the survey for the specialists who participated in the program, we evaluated the efficiency of our training program. The results showed that participants were satisfied with the organized curriculum and educational materials. Therefore, our program is expected to be utilized as basic research data to develop feasible program for policy development and to improve practical skills in RI-Biomics.

• 방사선산업학회지
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• 제5권2호
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• pp.131-135
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• 2011

In this study, we fabricated the HDPE and ${\alpha}-Al_2O_3$ composites with PE-g-MA as a function of the ${\alpha}-Al_2O_3$ nanopowder weight ratios. The electron beam irradiations on HDPE/${\alpha}-Al_2O_3$ composites were carried out over a range of absorbed doses from 20 to 200 kGy to make three-dimensional network structures. The mechanical properties were characterized using UTM for confirming the changes of the flexural strength and tensile strength. It was observed that the mechanical properties of HDPE were enhanced by the addition of ${\alpha}-Al_2O_3$. However, the strength of the 5 wt% ${\alpha}-Al_2O_3$ added composites decreased due to the nano-powder aggregation. The mechanical properties of composites were increased as increasing the electron beam irradiation up to 150 kGy. We believed that the electron beam irradiated HDPE/${\alpha}-Al_2O_3$ composites can be a good candidate for a variety of industrial applications.

• 방사선산업학회지
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• 제5권4호
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• pp.371-376
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• 2011

The surface property of the materials used in tissue engineering application has been essential to regulate cellular behaviors by directing their adhesion on the materials. To modulate surface property of the synthetic biodegradable materials, a variety of surface modification techniques have used to introduced surface functional groups or bioactive molecules, recently polydopamine coating method have been introduce as a facile modification method which can be coated on various materials such as polymers, metals, and ceramics regardless of their surface property. However, there are no reports about the degree of polydopamine coating on the materials with different hydrophilicity. In the present study, we prepared acrylic acid grafted nanofibrous meshes using electron-beam irradiation, and then coated meshes with polydopamine. Polydopamine successfully coated on the all meshes, both properties of acrylic acid and polydopamine were detected on the meshes. In addition, the degree of polydopamine deposition on the materials has been altered according to surface hydrophilicity, which was approximately 8-times greater than those on the non-modified materials. In conclusion, dual effect from the acrylic acid grafting and polydopamine may give a chance as a alternative tool in tissue engineering application.

• 방사선산업학회지
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• 제5권4호
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• pp.365-370
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• 2011

Electrospun nanofibers prepared with synthetic biodegradable polymer have some limitations in regulating adhesion, proliferation, and spreading of cells because of their surface hydrophobicity and absence of cell-interaction. In this study, we functionalized the electrospun poly(L-lactide-co-${\varepsilon}$-caprolactone) (PLCL) nanofibers with acrylic acid (AAc) to modulate their surface hydrophilicity using electron-beam irradiation method and then measured grafting ratio of AAc, water contact angle, and ATR-FTIR of AAc-grafted nanofibers. A grafting ratio of AAc on the nanofibers was increased as irradiation dose and AAc concentration were increased. AAc-grafted nanofibers also have higher wettability than non-modified nanofibers. In conclusion, those surface-modified nanofibers may be an essential candidate to regulate cell attachment in tissue engineering applications.

• 방사선산업학회지
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• 제5권2호
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• pp.145-149
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• 2011

Poly(butylenes terephthalate) have made large strides in applications of injection, extrusion, and molding material due to their excellent thermal resistance and appropriate mechanical properties. However, PBT was not hard polymer but a soft polymer which caused low absorption of external energy and the defect of being easily broken with the strong impact. Thus, the electron beam irradiation was carried out over a range of irradiation doses from 100 to 1,000 kGy for enhancing the properties. The decreases of $T_m$, $T_c$, and enthalpy were observed as increasing the absorbed dose in the results of DSC analysis. The improvement in the impact strength of PBT was clearly observed as the absorbed dose was increased. This was probably due to the 3-dimensional network structures, resulting in increasing the absorption of impact energy. In addition, the wear properties had increased at higher than 300 kGy. The negative deviation of weight loss confirmed the improvement of the wear properties of PBT, as evidenced by SEM observation on the wear surfaces.

• 방사선산업학회지
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• 제4권4호
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• pp.313-317
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• 2010

The struvite crystallization was applied to remove $NH_4{^+}$ in livestock wastewater. The ammonium ions can be very toxic to the aquatic creatures. In this experiments, the livestock wastewater from Gongju livestock wastewater treatment plant was used. The behaviors of various parameters such as pH, mole ratio of $Mg^{2+}$ : $NH_4{^+}$ : $PO{_4}^{3-}$ and reaction temperature for struvite crystallization of livestock wastewater and the effect of gamma ray irradiation were evaluated. As results, for the pH variation, the $NH_4{^+}$ removal efficiency showed the highest, 88%, at pH 9~9.25. The removal efficiency of $NH_4{^+}$, $Mg^{2+}$ and $PO{_4}^{3-}$ was showed highest when same molar ratio of $Mg^{2+}$ and $PO{_4}^{3-}$ were applied. The $NH_4{^+}$ removal efficiency showed 82% at $7^{\circ}C$, and 90% at $30^{\circ}C$ with temperature. When the wastewater was irradiated with 20 kGy of gamma ray, $NH_4{^+}$ was removed as much as 83%.

• 폴리머
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• 제34권1호
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• pp.20-24
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• 2010

본 연구에서는 방사선 동시조사법을 이용하여 다양한 그래프트율과 두께를 가진 ETFE-g-PSSA막을 제작하였다. 다양한 방사선 조사조건에서 제조된 ETFE-g-PSSA 막들은 SEM-EDX 기기를 이용하여 막 내부의 황(sulfur) 원소의 상대적 분포도를 측정하여 그래프트 고분자의 막 단면 분포경향을 연구하였다. 본 연구 결과 균일한 그래프트 고분자의 분포도를 갖는 ETFE-g-PSSA막을 제작하기 위해서는 스타이렌 단량체는 디클로로메탄 용액에서 60(v/v%) 이하여야 하고 두께가 두꺼울수록 높은 그래프트율을 얻어야 함을 확인하였다. 다양한 두께와 그래프트율을 가진 막들의 이온교환용량(IEC)과 함수율(water uptake)을 측정하여 막 두께와 그래프트율에 의한 영향을 평가하였다.

• 방사선산업학회지
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• 제2권1호
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• pp.43-51
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• 2008

방사선처리기술은 현재 멸균, 폴리머가교, 식품조사, 생고무가황 등 산업적으로 많은 곳에서 이용되고 있다. 현재 감마선과 전자선을 이용한 것은 방사선처리기술의 대표적인 기술이다. 이 논문의 목적은 최근의 방사선 기술을 이해하기 위해 외국의 방사선기술 동향을 살펴보고 산업현장 작업자가 방사선 관련 기술이 친숙해지기를 목적으로 그들에게 유용한 정보를 제공하기 위함이다. 본 조사를 통해 방사선이용기술이 지속적으로 성장함을 알 수 있었고, 또한 이 기술을 이용하면 제품의 다양성을 줄 수 있다는 사실도 알아냈다.

• 방사선산업학회지
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• 제4권3호
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• pp.285-288
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• 2010

Polyimide films have excellent thermal stability, reliable mechanical properties and low dielectric constant. Therefore, this material is widely used in many industrial fields such as microelectronics, flexible circuits, semiconductor products and aerospace materials. In space applications, earth-orbiting hardware operates in environments that generally include neutral particles, charged particles such as trapped protons and electrons, solar protons, and cosmic rays. Under these conditions, polyimide films were changed in the optical, electrical and mechanical properties. Therefore, in this study, we evaluated the effects of electron beam irradiation on polyimide. The O-H functional groups were created on the polyimide film surface in the results of FT-IR spectra. And it was found that the dielectric constants were changed as a function of electron beam dose.

• 방사선산업학회지
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• 제6권1호
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• pp.61-65
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• 2012

Polyacrylonitrile (PAN) is one of the most widely used precursor polymers for making high performance carbon fibers. Conversion of PAN fibers to good quality carbon fibers requires an essential stabilization step prior to carbonization. Electron beam irradiation is an excellent technique for modifying the physical properties of materials. This study aimed to elucidate the effects of electron beam irradiation on the stabilization reactions of PAN nanofibers. FT-IR analysis indicated that the stabilization of irradiated PAN nanofibers was initiated at a lower temperature. The TG curve of PAN nanofibers showed a significant decrease of weight loss step between 280 and $320^{\circ}C$. In the case of irradiated PAN nanofibers, weight loss sudden weight did not loss occurs.