• Journal of Korean Neurosurgical Society
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• 제53권4호
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• pp.252-254
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• 2013

Textiloma is an inflammatory mass containing surgical sponges that are unintentionally left behind in a surgical wound. This complication has been most commonly described by abdominal and gynecologic surgeons. However, the occurrence of textiloma after intracranial procedures especially under the temporalis muscle has not been documented. The author reports a rare case of textiloma of the pterion in a patient who presented with a subcutaneous tumor developed eight years after frontotemporal craniotomy for aneurysm clipping.

• Journal of Microbiology and Biotechnology
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• 제12권1호
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• pp.162-165
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• 2002

With the objective of identifying the commercial potential of new direct-fed microbials, several temperature-tolerant strains were isolated from cane molasses at $39^{\circ}C$ and tested for their tolerance to pH, bile salts, and a mixture of volatile fatty acids (acetic acid:propionic acid:butyric acid=6.5:2.0:1.5). It was found that the isolated strain DY 252 grew very well up to pH 2.0 and was resistant to relatively high concentrations of bile salts. Among the strains tested, DY 252 was least inhibited by the addition of volatile fatty acids to the growth medium at $39^{\circ}C$. Accordingly, it would appear that strain DY 252, identified as yeast Issatchenkia orientalis, may be a potential candidate for use as a microbial feed additive.

• Journal of Radiation Protection and Research
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• 제22권1호
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• pp.29-33
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• 1997

중성자교정실내에서 $D_2O$ 감속 $^{252}Cf$중성자선원을 사용하여 계측기를 교정할 때는 그 계측기에 대한 교정실산란보정 인자를 미리 결정하여야 한다. 이러한 교정실산란보정인자는 계측기의 종류, 교정거리, 교정실형태에 따라 다르게 결정된다. 본 연구에서는 한국원자력연구소에서 운영하는 2차 표준중성자교정실에서 한가지의 열형광선량계와 2가지의 구형검출기에 대한 교정실산란보정인자를 실험적으로 결정하였고 본소의 2차 표준중성자교정실조건에 의하여 이론적으로 예측한 값과 비교하였다. 비교한 결과 실험하여 얻어진 상기의 3가지 계측기에 대한 교정실산란보정인자가 이론적으로 예측한 결과와 최대 약 10% 이내에서 일치하였다.

• Nuclear Engineering and Technology
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• 제49권1호
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• pp.277-284
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• 2017

This paper presents the establishment and characterization of a neutron calibration field using a bare $^{252}Cf$ source of low neutron source strength in Vietnam. The characterization of the field in terms of neutron flux spectra and neutron ambient dose equivalent rates were performed by Monte Carlo simulations using the MCNP5 code. The anisotropy effect of the source was also investigated. The neutron ambient dose equivalent rates at three reference distances of 75, 125, and 150 cm from the source were calculated and compared with the measurements using the Aloka TPS-451C neutron survey meters. The discrepancy between the calculated and measured values is found to be about 10%. To separate the scattered and the direct components from the total neutron flux spectra, an in-house shadow cone of 10% borated polyethylene was used. The shielding efficiency of the shadow cone was estimated using the MCNP5 code. The results confirmed that the shielding efficiency of the shadow cone is acceptable.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2014년도 춘계 종합학술대회 논문집
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• pp.251-252
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• 2014

• Nuclear Engineering and Technology
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• 제52권6호
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• pp.1252-1258
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• 2020

This study explores the ability of non-destructive assay techniques to detect a partial material defect in which 100 g of plutonium are diverted from the center of a 1000 g can of PuO₂ powder. Four safeguards measurements techniques: neutron multiplicity counting, calorimetry, gravimetry, and gamma ray spectroscopy are used in an attempt to detect the defect. Several materials are added to the partial defect PuO₂ can to replicate signatures of the diverted material. ²⁵²Cf is used to compensate for the doubles neutron counts, ²⁴¹Am is used to compensate for the decay heat, and aluminum is used to compensate for the weight. Although, the doubles and triples difference before and after diversion are statistically indistinguishable with the AWCC in fast and thermal mode, the difference in the singles counts are statistically detectable in both modes. The relatively short half-life of ²⁵²Cf leads to a decrease (three sigma uncertainty) in the doubles neutron counts after 161 days. Combining this with the precise quantity of ²⁴¹Am needed (10.7 g) to mimic the heat signature and the extreme precision in ²⁵²Cf mass needed to defeat neutron multiplicity measurements gives reassurance in the International Atomic Energy Agency's ability to detect partial material defects.

• 센서학회지
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• 제22권3호
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• pp.223-226
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• 2013

We designed a single polyethylene bonner sphere with several thermo-luminescence dosimeters (TLD), for measurement of neutron energy spectrum. For the separation of the neutron dosage in the neutron-gamma mixed field, we used 21 ea TLD-600s and TLD-700s, respectively. Because, TLD-600 is sensitive to neutron and gamma rays, and, TLD-700 is sensitive only to gamma-rays, we could determine the each dose by neutron and gamma rays. The neutron response function of the bonner sphere with TLDs was calculated by MCNPX (ver. 2.5.0) Monte Carlo simulation in the energy range from $10^{-1}$ to 20 MeV. For the Cf-252 standard neutron source in KRISS, we could estimate the neutron energy spectrum by unfolding method using the response function.

• 한국전기전자재료학회논문지
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• 제28권4호
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• pp.252-256
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• 2015

In this study, we propose a novel fabrication of an oxide-based lateral thermoelectric pn couple and investigate the characteristics of the thermoelectric couple. Electrospun ZnO and $LaSrCoO_3$ nanofibers are used as n- and p-legs of the couple, respectively. The Seebeck coefficients of the n- and p-type nanofibers and the pn couple are $-98.1{\mu}V/K$, $42.4{\mu}V/K$, and $118.8{\mu}V/K$, respectively. The thermoelectric couple generates an output voltage of $484.7{\mu}V$ at a temperature difference of 4.1 K.

• Investigative Magnetic Resonance Imaging
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• 제21권4호
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• pp.252-258
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• 2017

Primary mesenteric liposarcoma is rare. It is difficult to make an accurate preoperative diagnosis of the myxoid type of liposarcoma by using imaging such as ultrasound or computed tomography (CT) due to the very small amount of fat that is located in the tumor. We report a case of primary myxoid liposarcoma of the mesentery which was difficult to differentiate from other solid mesenteric tumors with a myxoid component such as low grade fibromyxoid sarcoma, myxoid leiomyosarcoma or myxoma. Use of chemical shift magnetic resonance (MR) imaging to detect small fat components and its cystic appearance with solid components on the MR images can be useful to differentiate myxoid liposarcoma from the other mesenteric tumors with a myxoid component.

• 한국환경보건학회지
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• 제29권2호
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• pp.50-55
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• 2003

3,3'-디클로로벤지딘(DCB)는 실험동물에 발암물질로 밝혀졌고, 사람에게 암을 유발시킬 수 있는 발암물질로 의심되고있다. 많은 연구자들이 사업장에서 DCB에 폭로된 근로자들을 대상으로 뇨중에 배설된 대사물질, 헤모글로빈 부가체, 그리고 암 발생율 등에 대하여 연구를 하고 있다. 이러한 연구를 하기 위해서는 표준물질로 되어 있는 DCB의 대사물질이 꼭 필요하다. 따라서 본 연구의 목적은 DCB를 이용하여 이들의 대사물질을 합성하여 표준물질로 사용코자 합니다. DCB는 벤젠. 에테르, 에탄올, 메탄올 등에 부분적으로 용해되지만, 구연산이 1 % 이하로 함유된 70% 아세트산, 피리딘, 0.1N NaOH와 톨로엔이 1:2로 섞인 혼합물, 20 mM TRIZA염으로 포화된 페놀 등에는 완전히 용해되기 때문에 본 연구에서는 DCB를 피리딘에 녹여서 사용하였다. DCB와 대사물질인 mono-acetyl-DCB 및 diacetyl-DCB는 가스크로마노그래피(GC/MS)로 분석하였고, 검출기는 NPD와 SIM를 사용하였다. DCB의 기본피크는 252 m/z이었고, mono-acetyl-DCB의 기본피크는 252와 294 m/z로 구성되어 있었으며. diacetyl-DCB의 기본피크는 252, 294, 336 m/z로 구성되어 있었다. Discetyl-DCB는 피리딘에 용해된 DCB에 염소아세틸를 충분히 적정하여 합성하였다. 이렇게 얻은 diacetyl-DCB의 순도는 98.7%이었다. 침전물위에 있는 용해물질 속에는 DCB. mono-acetyl-DCB, diacetyl-DCB가 함유되어 있었는데, 아세트산을 아세틸화를 조절하는 물질로 사용하여 DCB를 모두 아세틸화시키었고, diacetyl-DCB로부터 mono-acetyl-DCB를 분리하여 추출하였다. 추출된 mono-acetyl-DCB는 아세톤으로 세척하여 98.8%의 순도를 얻었다.