• 제목/요약/키워드: Local irradiation

검색결과 235건 처리시간 0.024초

SOFT RECOVERY CHARACTERISTICS OF POWER DIODE BY PROTON IRRADIATION

  • Zhang Changli;Chen Zhiming;Park, J.M.;Min, W.G.;Kim, S.C.;Kim, N.K.;Kim, E.D.
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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    • pp.231-234
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    • 1998
  • The soft reverse recovery characteristics of P-I-N power diodes by different lifetime killer were compared in this paper. It was concluded that the best local lifetime control at N- base was achieved through the optimization of penetrated depth into the wafer by 5 MeV proton irradiation, resulting in significant soft recovery performance in our study. The results of 5∼12 MeV electron irradiation and platinum diffusion were also discussed here.

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입자 조사에 의한 PT형 전력 다이오드의 스위칭 특성 향상 (Switching Characteristics Enhancement of PT type Power Diodes by means of Particle Irradiation)

  • 김병길;최성환;이종헌;배영호
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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    • pp.16-17
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    • 2005
  • Local lifetime control by ion implantation has become an useful tool for production of modern power devices. In this work, punch-through diodes were irradiated with protons for the high speed power diode fabrication. Proton irradiation was executed at the various energy and dose conditions. Characterization of the device was performed by I-V, C-V and Trr measurement. We obtained enhanced reverse recovery time characteristics which was about 45% of original device and about 73% of electron irradiated device. The measurement results showed that proton irradiation was able to effectively reduce minority carrier lifetime.

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경부 유건종(Desmoid Tumor)의 방사선치료 - 증례보고 - (Radiation Treatment of Desmoid Tumor in the Neck - A Case Report­)

  • 표홍렬;신현수;김귀언;박정수
    • 대한두경부종양학회지
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    • 제7권1호
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    • pp.35-39
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    • 1991
  • A 66 years old female who had a huge desmoid tumor on her left neck was treated by partial excision and postoperative irradiation. Detailed summary of this rare tumor are included with a review of the literature about treatment modality including irradiation. We suggest that local irradiation is one of the effective treatment tools in the management of desmoid tumor, especially, in the case of unresectable or postoperative residual tumors on the neck.

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Effect of Irradiation on the Color, Microbiological Quality, and Sensory Attributes of Frozen Ground Beef, Pork, and Chicken after 6 Months at $-6^{\circ}C$

  • Waje, Catherine;Kim, Mi-Yeung;Nam, Ki-Chang;Jo, Cheo-Run;Kim, Dong-Ho;Lee, Ju-Woon;Kwon, Joong-Ho
    • Food Science and Biotechnology
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    • 제17권1호
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    • pp.212-215
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    • 2008
  • The effect of gamma irradiation on the Hunter color values, microbiological quality, and sensory attributes of frozen ground beef, pork, and chicken was investigated. Fresh meat samples were purchased from local markets, packed and frozen in polyethylene bags, and irradiated at 5 kGy. The Hunter's L-values (lightness) were not significantly different in all the meat samples after irradiation, but the a-values (redness) were higher in the irradiated beef and pork than the non-irradiated ones. After 6 months of storage at $-6^{\circ}C$, the L-values increased in all the meat samples and the a-value in chicken was lower in the irradiated sample than that of the control. The microbial counts decreased in all the samples right after irradiation, but the coliforms and yeasts & molds increased by 1-2 log cycles after 6 months even under frozen state. The overall acceptability of the meat was not affected by irradiation. Panelists had a higher likeness for the increased redness in irradiated beef. In general, only the color changes in meat as a result of irradiation were found to be species-dependent.

Assessment of INSPYRE-extended fuel performance codes against the SUPERFACT-1 fast reactor irradiation experiment

  • L. Luzzi;T. Barani;B. Boer;A. Del Nevo;M. Lainet;S. Lemehov;A. Magni;V. Marelle;B. Michel;D. Pizzocri;A. Schubert;P. Van Uffelen;M. Bertolus
    • Nuclear Engineering and Technology
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    • 제55권3호
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    • pp.884-894
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    • 2023
  • Design and safety assessment of fuel pins for application in innovative Generation IV fast reactors calls for a dedicated nuclear fuel modelling and for the extension of the fuel performance code capabilities to the envisaged materials and irradiation conditions. In the INSPYRE Project, comprehensive and physics-based models for the thermal-mechanical properties of U-Pu mixed-oxide (MOX) fuels and for fission gas behaviour were developed and implemented in the European fuel performance codes GERMINAL, MACROS and TRANSURANUS. As a follow-up to the assessment of the reference code versions ("pre-INSPYRE", NET 53 (2021) 3367-3378), this work presents the integral validation and benchmark of the code versions extended in INSPYRE ("post-INSPYRE") against two pins from the SUPERFACT-1 fast reactor irradiation experiment. The post-INSPYRE simulation results are compared to the available integral and local data from post-irradiation examinations, and benchmarked on the evolution during irradiation of quantities of engineering interest (e.g., fuel central temperature, fission gas release). The comparison with the pre-INSPYRE results is reported to evaluate the impact of the novel models on the predicted pin performance. The outcome represents a step forward towards the description of fuel behaviour in fast reactor irradiation conditions, and allows the identification of the main remaining gaps.

Optical Scattering as a Probe of Local Field Effect in Micron-sized Cds Spheres

  • 김성규;Alan L. Huston;Anthony J. Campillo
    • Bulletin of the Korean Chemical Society
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    • 제16권2호
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    • pp.96-101
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    • 1995
  • The optical properties of individual 3-to 14-micron diameter CdS crystalline spheres embedded in poly(methyl methacrylate) were studied using elastic scattering. The presence of well defined sharp peaks in the 550 to 600 nm elastic scattering spectra confirmed that each microcrystal acts as an optical cavity with cavity quality factors exceeding 104. Such natural resonator microcrystals should lead to greatly enhanced local field effects near the surface of CdS, quantum electrodynamic modification of optical transition rates of nearby species and altered photochemistry. Absorptive heating following high intensity laser irradiation was found to induce a transient washout of the high Q modes.

불완전절제된 수막종에서 수술 후 방사선치료의 역할 (The Role of Postoperative External Irradiation for the Incompletely Resected Meningiomas)

  • 김태현;양대식;김철용;최명선
    • Radiation Oncology Journal
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    • 제18권2호
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    • pp.85-91
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    • 2000
  • 목적 : 불완전절제된 수막종 환자에서 수술 후 방사선치료의 성적을 분석하여, 방사선 치료의 효과를 알아보고자 하였다. 대상 및 방법 :본 연구는 1981년 8월부터 1997년 1월까지 수술 후 방사선 치료를 시행한 수막종 환자 44명을 대상으로 하였다. 연령분포는 23세부터 66세였고, 평균연령은 51세였으며, 여자 32예, 남자 12예였다. 병리조직학 분류에 따라 보면, 수막성 수막종이 13예, 이행성 수막종이 18예, 섬유아세포성 수막종이 2예, 혈관주위세포성 수막종이 6예, 이형성 수막종이 4예, 악성 수막종이 1예였다. 병리조직학 소견을 양성군(수막성, 이행성과 섬유아세포성 수막종)과 악성군(이형성, 혈관주위세포성과 악성 수막종)으로 재분류 하였으며, 양성군과 악성군은 각각 33예, 11예였다. 불완전절제술이 시행된 경우가 37예였고, 조직검사만 시행한 환자가 7예였다. 방사선치료는 Co-60과 4MV X-ray를 이용하여 일일선량 1.8$\~$2.0 Gy씩 주 5회 치료하였고 원발병소에 50.4$\~$66 Gy의 방사선을 조사하였다. 전체환자의 평균 추적기간은 48개월이었다. 결과 : 국소재발된 경우는 6예였고, 5년 국소제어율은 87.4$\%$였다. 양성군의 5년 국소제어율은 93.8$\%$였고, 악성군의 5년 국소제어율은 51.8$\%$로 차이를 보였다(p=0.0110). 사망한 경우는 2예로, 1예는 유암으로, 1예는 재발에 의한 사망이었고, 5년 생존율은 97.3$\%$이었다. 결론 : 불완전절제된 수막종 환자에서 방사선치료는 국소 재발을 감소시킬 수 있는 효과적인 치료방법이 될 수 있음을 확인할 수 있었다.환자의 5년생존율은 43$\%$였다. 40세 이하 46명의 환자는 5년생존율이 69$\%$로서 41세 이상 26명의 환자에서의 5년생존율 45$\%$보다 좋은 생존율을 나타내었다. 비록 환자 한명이 치료중 치료를 중단하였으나 유의한 방사선치료에 의한 급성합병증은 관찰되지 않았다. 결론 : 뇌 신경교종의 수술후 방사선치료는 안전하고 효과적인 치료요법였다. 그러나 뇌 신경교종 환자에서 최적의 방사선 시기 및 계획을 수립하고 서로 다른 치료방침에 맞는 환자를 구분하기 위하여 보다 잘 짜여진 선행적 임상연구가 필요하리라 사료된다.상시키는데 기여하는 것으로 생각된다. 다만, 병기 및 조직분화도에 따라 질내조사를 추가하지 않는 경우 질 재발이 호발하는 환자군에 대한 연구가 더 진행되어야 할 것으로 판단된다.중 6명에서 원격전이가 발생하였으며, 2명에서 골반부 림프절에 재발하였다. 원격전이 부위로는 페 3명, 뼈 3명, 쇄골상관절종에 3명이었다. 치료에 대한 혈액학적 급성합병증으로 1명이 grade 4백혈구 감소로 약 3주간 방사선치료를 중단하였으며 grade 3 이상의 백혈구 감소가 2명이었고, grade 2이상의 혈색소 감소 및 혈소판 감소가 각각 2명, 1명이었다. 상부위장관에 대한 급성합병증으로는 grade 2 이하의 오심 및 구토가 8명에서 발생하였으나 대부분 수용할만 하였다. 추적관찰 중 복부 또는 골반부위에 만성합병증은 관찰되지 않았다. 결론 : 대동맥주위림프절에 재발된 자궁경부암 환자에서 방사선민감제로 Taxol을 병행한 과분할 방사선치료를 하여 적은 합병증의 발생과 매우 높은 치료반응율을 보였다. 따라서 이러한 환자들에게 적극적인 치료로 사용될 수 있을 것으로 사료된다로써 복강내 악성종양으로

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양성자 조사법에 의한 고속스위칭 사이리스터의 제조 (Fabrication of a fast Switching Thyristor by Proton Irradiation Method)

  • 김은동;장창리;김상철;김남균
    • 한국전기전자재료학회논문지
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    • 제17권12호
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    • pp.1264-1270
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    • 2004
  • A fast switching thyristor with a superior trade-off property between the on-state voltage drop and the turn-off time could be fabricated by the proton irradiation method. After making symmetric thyristor dies with a voltage rating of 1,600 V from 350 $\mu$m thickness of 60 $\Omega$ㆍcm NTD-Si wafer and 200 $\mu$m width of n-base drift layer, the local carrier lifetime control by the proton irradiation was performed with help of the HI-13 tandem accelerator in China. The thyristor samples irradiated with 4.7 MeV proton beam showed a superior trade-off relationship of $V_{TM}$ = 1.55 V and $t_{q}$ = 15 $\mu$s attributed to a very narrow layer of short carrier lifetime(~1 $\mu$s) in the middle of its n-base drift region. To explain the small increase of $V_{TM}$ , we will introduce the effect of carrier compensation at the low carrier lifetime region by the diffusion current.ffusion current.t.

방사선치료 후 전신적증세의 발현을 나타낸 Midline Malignant Reticulosis 환자군에 대한 재고 (Reevaluation of Midline Malignant Reticulosis with Systemic Manifestation after Irradiation)

  • 김귀언;서창옥;김병수;홍원표
    • Radiation Oncology Journal
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    • 제2권1호
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    • pp.71-79
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    • 1984
  • During a 10 year periods, 42 patients with well-documented Midline Malignant Reticulosis were treated with local irradiation and followed for extended periods of time. 13 cases with systemic manifestation after irradiation illustrate the protean features of this disease. Although it commonly Presents in upper airway tracts such as nasal cavity and/or septum, soft palate and palatine tonsil, the lesion may be localized as well as diffuse. 2 cases among them showed systemic relapse on lung, pancreas and scrotum probably from either a multifocal or metastatic deposits. Another 3 eases were associated with systemic diseases such as stomach carcinoma, typhoid enteritis and CNI of fat tissue. Remained cases were diagnosed by clinical or radiological examination. Possibility of close relation to lymphoma with Midline Malignant Reticulosis are also suggested in 1 case. In Midline Malignant Reticulosis, the best results of treatment are obtained in localized lesion of the upper airway treated early with irradiation: A poorer outcome is associated with multifocal systemic involvement, which necessitates a systemic therapy.

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고선량율 강내 조사를 이용한 두경부암의 방사선 치료 (Radiation Therapy of Head and Neck Cancer with CO-60 HDR Transcatheteric Irradiation)

  • 신세원;김성규;김명세
    • Journal of Yeungnam Medical Science
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    • 제7권2호
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    • pp.109-114
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    • 1990
  • 저자들은 두경부암의 포괄적인 치료의 일부로서 외부 방사선 조사와 고선량율 경관조사를 시행하여 12명중 9명에서 완전 관해를 얻었으며, 치료중이나 치료후 경관조사와 직접 관련된 급성 부작용이나 합병중의 발생이 없었다. 그러나 대상환자가 적고 추적기간이 짧은관계로 생존율의 향상은 추측하기 어려우나 완전 관해를 얻은 환자는 장기간 무병 상태로 추적되고 있어서 외부방사선 조사와 경관 조사는 두경부암 치료에 큰 역할을 하리라 기대된다.

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