• Title/Summary/Keyword: Radiation hardness

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Comparison of the Quality of Gamma Ray- or Electron Beam-irradiated Minced Pork and Pork Patties (감마선 또는 전자선 조사된 분쇄돈육과 돈육패티의 저장 중 품질특성 비교)

  • Song, Beom-Seok;Park, Jin-Gyu;Kim, Wang-Geun;Kim, Jae-Hun;Choi, Jong-Il;Yoon, Yo-Han;Byun, Myung-Woo;Kim, Cheon-Jei;Lee, Ju-Woon
    • Food Science of Animal Resources
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    • v.29 no.2
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    • pp.194-202
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    • 2009
  • This study was conducted to determine the effects of gamma and e-beam irradiation on the quality of minced pork and pork patties. Each sample was irradiated at 5 to 20kGy, and its quality characteristics were then evaluated during storage at 30. The results of the total bacterial populations in the minced-pork and pork patty samples showed that the antimicrobial effect of gamma irradiation was superior to that of e-beam irradiation. The 2-thiobarbituric acid reactive substances (TBARS) value of all the samples significantly increased (p<0.05) as the irradiation dose and storage period increased. In addition, the gamma-irradiated (GI) samples had higher (p<0.05) TBARS values than the e-beam-irradiated (EI) samples. The volatile basic nitrogen contents of the GI samples were lower (p<0.05) than those of the EI samples. The color values, such as the $L^*$(brightness), $a^*$(redness), and $b^*$(yellowness) of the minced pork and pork patties, were increased (p<0.05) by irradiation. The hardness and sensory properties, such as the color, chewiness, taste, and overall acceptability of the pork patties, were decreased when the irradiation dose increased, and the hardness and sensory scores of the GI samples were lower than those of the EI samples.

A Study on the Preparation of Wood-Plastic Combinations (IV)

  • Kim, Jaerok;Lee, Kyung-Hee;Pyun, Hyung-Chick
    • Nuclear Engineering and Technology
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    • v.5 no.1
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    • pp.3-12
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    • 1973
  • Some physical and chemical properties of wood-plastic combinations(W.P.C.) made of domestic soft woods such as pinus densiflora, pinus rigida and poplus deltoides were measured. The rates of improvement in properties were roughly proportional to the contents of polymer or polymer mixtures in W.P.C. For the W.P.C. obtained by means radiation curing and containing 80% of polymer or polymer mixture, the hardness and water absorptirity were improved 2.2 times and 4 times those of the original wood, respectively. The improvement of hardness was especially remarkable in the W.P.C. made of pinus densiflora and polystyrene(120%) to show 7 times increased hardness. For the W.P.C. obtained by means of thermal curing and containing 80% of polymer or polymer mixture, the hardness and water absorptivity were improved 2.4 times and 3.4 times those of the non-treated woods, respectively. These data indicate that the properties of W.P.C. prepared by means of radiation curing are not much different from those of W. p. C. prepared by means of thermal curing. Both of acid resistancy and alkali resistancy of the W.P.C. were also improved remarkably in comparison with the non-treated wood.

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A Study on the Mechanical Properties of Composite Materials of Polyurethane Resin and CuO (PUR/CuO 복합재료의 기계적 특성 연구)

  • Kim, Eun-Bong;Koo, Su-Jin;Jeong, Sang-Gu;Kim, Seok-Hyeon
    • Journal of Power System Engineering
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    • v.18 no.5
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    • pp.106-114
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    • 2014
  • For the purpose of development of polyurethane sealing material, polyurethane resins reinforced with CuO were prepared from polyol and MOAC(4,4'-Methylenebis(2-chlorobenzeneamine)). And the effects of compositions on the mechanical properties of the reinforced polyurethane resin were experimentally examined. The polyurethane resin got to be thermally decomposed at $260^{\circ}C$ and completely carbonized around $500^{\circ}C$. Tensile strength, elongation and hardness of the polyurethane resin increased with the content of MOCA. CuO was uniformly dispersed in the polyurethane resin by 1 minute's ultrasonic radiation. Tensile strength, elongation and hardness of the polyurethane resin reinforced with CuO increased with the content of CuO. Tensile strength and hardness of the reinforced polyurethane resin increased with particle size of the CuO, but elongation decreased. CuO showed higher tensile strength and hardness than any other additives, and lowest elongation.

V-Y Latissimus Dorsi Musculocutaneous Flap for Reconstruction of Radiation-induced Skin Injuries on the Back (V-Y 광배근피판을 이용한 등의 방사선 유발 피부 손상의 치험)

  • Shim, Seung-Hyun;Chung, Chul-Hoon;Kim, Kuyl-Hee
    • Archives of Plastic Surgery
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    • v.38 no.5
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    • pp.707-710
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    • 2011
  • Purpose: Cardiac radiofrequency catheter ablation procedures using fluoroscopy were performed for the treatment of supraventricular and selected ventricular tachyarrhythmia. Fluoroscopy is used to localize the position of the intracardiac catheter. Fluoroscopically-guided procedures often involve high radiation doses to patient's skin, but the incidence of serious radiation injuries in these patients is rare. We reported two cases of severe postradiation skin injury on the back treated with the V-Y latissimus dorsi musculocutaneous flap. Methods: These two patients underwent radiofrequency catheter ablation under the diagnosis of Woff Parkinson White syndrome (WPW syndrome). They had radiation-induced skin injuries on the subscapular area and these lesions represented chronic ulceration, surrounding induration, hardness, and dyspigmentation. We treated these lesions with complete excision and coverage with V-Y latissimus dorsi musculocutaneous flap. Results: These two patients had no recurrence and no special complications during 20 months and 12 months follow-up periods and were satisfied aesthetically and functionally. Conclusion: V-Y latissimus dorsi musculocutaneous flap obtained better results functionally and aesthetically compared with conservative management and skin graft in severe radiation-induced skin injuries after cardiac radiofrequency catheter ablation procedure.

Growth of LiF Single Crystal by Floating Zone Method (Floating Zone법에 의한 LiF 단결정 성장)

  • 오원석;신건철
    • Journal of the Korean Ceramic Society
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    • v.27 no.5
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    • pp.631-637
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    • 1990
  • Lithium fluolide single crystals were grown by a floating zone method, with infrared radiation convergence type heater, which is free of contamination from the crucible wall. The crystals grown by this apparatus are 5cm in length and 5-6mm in diameter. The grown cryatal was examined by an optical microscope, XRD, Laue camera, Vickers hardness tester, and FTIR.

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A SOI Technology for Micromachining (마이크로머신을 위한 SOI 기술)

  • 정귀상
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1994.05a
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    • pp.145-146
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    • 1994
  • A SOI technology is promising for micromachining: high temperature operation, the fabrication easiness of sophisticated and 3D microstructures, radiation hardness, integrated sensors etc. This paper describes reviews of SOI technologies, and their applications microsensors and microactuators

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A Study on the Preparation of Wood-Plastic Combination(I) - General Properties and Radiation Durabilities of Woods

  • Pyun, Hyung-Chick;Lee, Kyung-Hee;Kim, Jaerok
    • Nuclear Engineering and Technology
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    • v.5 no.2
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    • pp.150-158
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    • 1973
  • General physical properties and radiation durabilities of some domestic woods and imported lauans were measured and discussed as a preliminary study on the preparation of W. P. C. The data obtained indicate that 1) the hardness of wood is generally proportional to the specific gravity and to the bending strength, 2) the hardness of wood measured in tangential direction to the annual ring increases along with the distance from the center of the annual ring to the peel, 3) the changes of specific gravity under 100 Mrad gamma irradiation are not remarkable, 4) the hardnesses of the soft woods are decreased more -readily than those of the hard woods, but the decreases of hardnesses are not extreme upto 10 Mrad sugges ting that the woods are sufficiently durable to gamma irradiation of below 10 Mard in the preparation of W. P. C.

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Development of charge sensitive amplifiers based on various circuit board substrates and evaluation of radiation hardness characteristics

  • Jeong, Manhee;Kim, Geehyun
    • Nuclear Engineering and Technology
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    • v.52 no.7
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    • pp.1503-1510
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    • 2020
  • Ultra-low noise charge sensitive amplifiers (CSAs) based on various types of circuit board substrates, such as FR4, Teflon, and ceramics (Al2O3) with two different designs, PA1 and PA2, have been developed. They were tested to see the noise effect from the dielectric loss of the substrate capacitance before and after irradiation. If the electronic noise from the CSAs is to be minimized and the energy resolution enhanced, the shaping time has to be optimized for the detector, and a small feedback capacitance of the CSA is favorable for a better SNR. Teflon- and ceramic-based PA1 design CSAs showed better noise performance than the FR4-based one, but the Teflon-based PA1 design showed better sensitivity than ceramic based one at a low detector capacitance (<10 pF). In the PA2 design, the equivalent noise and the sensitivity were 0.52 keV FWHM for a silicon detector and 7.2 mV/fC, respectively, with 2 ㎲ peaking time and 0.1 pF detector capacitance. After 10, 100, 103, 104, and 105 Gy irradiation the ENC and sensitivity characteristics of the developed CSAs based on three different substrate materials are also discussed.

Effect of Gamma Irradiation on the Softening of Dried Fernbrake at Different Moist-Heating Conditions (습열 조리 조건에 따른 방사선 조사 건고사리의 연화도)

  • Seung, Tae-Hwa;Lee, Ju-Woon;Byun, Myung-Woo;Kim, Mee-Ree
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.1
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    • pp.104-108
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    • 2006
  • Effect of gamma irradiation on the softening of dried fernbrake at different moist-heating conditions was investigated. Dried fernbrake packaged in controlled atmosphere $(CO_2\;25\%,\;N_2\;75\%)$ was irradiated up to 7 kGy with $\gamma-ray$. Hardness of dried fernbrake was significantly decreased at the irradiation dose of above 5 kGy. Hardness of cooked fernbrake was significantly decreased with increasing irradiation dose level as well as heating temperature and time. $DT_{50}$ value (The heating time required to reach the $50\%$ reduction of hardness) for irradiated fernbrake was shortened according to dose level as well as heating temperature and heating time: $DT_{50}$ value of control: 23 min, 5 or 7 kGy: $2.2\~5.0$ min at $60^{\circ}C$. Also, the activation energy for softening of irradiated fernbrake ($1.85\~1.88$ kcal/mole for $5\~7kGy$) decreased compared to control (4.30 kcal/mole). Moisture content, swelling and rehydration rate of gamma irradiated fernbrake during moist heating increased according to the irradiation doses. Sensory results showed that scores of off-flavor and odor in irradiated fernbrake upto 7 kGy were not significantly different from control. Based on these results, gamma irradiation was effective for the reduction of cooking time and the activation energy for softening of dried fernbrake with increasing dose levels.

Evaluation of radiation resistance of an austenitic stainless steel with nanosized carbide precipitates using heavy ion irradiation at 200 dpa

  • Ji Ho Shin ;Byeong Seo Kong;Chaewon Jeong;Hyun Joon Eom;Changheui Jang;Lin Shao
    • Nuclear Engineering and Technology
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    • v.55 no.2
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    • pp.555-565
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    • 2023
  • Despite many advantages as structural materials, austenitic stainless steels (SSs) have been avoided in many next generation nuclear systems due to poor void swelling resistance. In this paper, we report the results of heavy ion irradiation to the recently developed advanced radiation resistant austenitic SS (ARES-6P) with nanosized NbC precipitates. Heavy ion irradiation was performed at high temperatures (500 ℃ and 575 ℃) to the damage level of ~200 displacement per atom (dpa). The measured void swelling of ARES-6P was 2-3%, which was considerably less compared to commercial 316 SS and comparable to ferritic martensitic steels. In addition, increment of hardness measured by nano-indentation was much smaller for ARES-6P compared to 316 SS. Though some nanosized NbC precipitates were dissociated under relatively high dose rate (~5.0 × 10-4 dpa/s), sufficient number of NbC precipitates remained to act as sink sites for the point defects, resulting in such superior radiation resistance.