Single Channel Pulse Hight Analyzer에 의한 Gamma Ray Energy 測定에 관한 硏究

朴鼎悳 건국대학교 1969 學術誌 Vol.10 No.1

Measurment of Gamma ray energy is made possible by analyze of secondary electrons to be produced when gamma ray passes through material and is obtained by observation of pulse distribution which is proportional to energy loss of gamma photon that incdents to Scintillation crystal. Gamma ray spectrometer used in this measurement is RLP-5 Continuous Scanning Spectrometer System made in TRACERLAB Inc. which shows in 《Fig.1》 block-diagram. Gamma ray energy is measured with determination of pulse height which through threshold setting of photopeak location on the radiation spectrum Relations between pulse height and energy was obtained by the above measurement method for standard gamma source Cs-137 made in TRACERLAB Inc. The result is as 《table 1》 and 《Fig.7》 In this study gamma ray energy was measured on three samples of Co-60, Na-22 and Mn-54 by identical measurement condition. The result is as table 2 and 《Fig.8》

Se1-xTex 薄膜의 光電導特性

朴鼎德 建國大學校基礎科學硏究所 1985 理學論集 Vol.10 No.-

This study are investigated the photoconductive properties of the ?? thin film which was deposited by means of vacuum evaporator. The ?? thin film samples are prepared on the slide glass substrate at laboratory temperature with mixture in various mol ratio x equal to 2%, 4%, 6%, 8% and 10% of Te to Se. According to the experiments are obtained the results as follow. 1. The resistivity of the ?? thin film is measured about 1KΩ-cm at laboratoly temperature. 2. The photocurrent is measured about 2㎂ at 1,000 Lux illumination in the laboratory temperature. 3. The spectral photosensitivity of the ?? thin film are investigated in wave length from 300 to 700nm range and its maximum photosensitivity is found at about 500nm.

급성 카드뮴중독에 의한 랏트의 간, 신 및 고환조직의 손상에 미치는 Diethyldithiocarbamate의 방어효과

박정덕,정규철 중앙대학교 의과대학 의과학연구소 1989 中央醫大誌 Vol.14 No.2

To investigate the effects of diethyldithiocarbamate (DDTC) on acute toxicity in cadmium in toxicated rat, single doses of 5 mg/kg CdCl_2 were given to Sprague-Dawley male rats by intraperitoneal injection in Cd-treated group, 500 mg/kg DDTC IP injection 60 min after Cd treatment in DDTC-treated group, and saline treatment only in control group. Rats of each group were sacrificed by decapitation 48 hours after the injection. Average cadmium concentrations in liver, kidney and testis for control group were 0.027 ± 0.008㎍/g wet wt, 0.032 ± 0.006 ㎍/g wet wt and 0.004 ± 0,002 ㎍/g wet wt, and those for Cd-treated group were 8.748 ± 0.985 ㎍/g wet wt, 15.947 ± 3.723 ㎍/g wet wt and 0.617 ± 0.140 ㎍/g wet wt, respectively. In DDTC-treated group, hepatic, renal and testicular Cd concentrations were 6.209 ± 0.691㎍/g wet wt, 13.736 ± 1.692 ㎍/g wet wt and 1.438 ± 0.330㎍/g wet wt, respectively. DDTC caused the shift of Cd from liver and kidney to testis. The production of superoxide radicals was increased in liver and kidney of Cd-treated group, whereas catalase activities were reduced. The protein contents in tissue homogenates, cytosolic and mitochondrial fractions, and activities of Cu, Zn-SOD, Mn-SOD and ATPase were not significantly altered by the Cd treatment. In testis of Cd-treated group, although the production of superoxide radical was undetected, the catalase activity and specific activity of'Cu,Zn-SOD were increased, and protein contents of above fractions and activities of Mn-SOD and ATPase were reduced compared to control group. This implies that mechanism of cadmium toxicity to liver and kidney differs from that to testis, suggesting a possible role of oxygen radical induced by cadmium in injury to testis but not to liver and kidney. Since the pattern of change in protein contents, production of superoxide radical, activities of catalase, Cu, Zn-SOD, Mn-SOD and ATPase in the DDTC-treated group were similar to those in the control group, DDTC was considered to be effective in protecting the tissue damage caused by cadmium toxicity. Histopathological findings showing that the tissue destruction of testis was more extensive and severer than those of liver and kidney in Cd-treated group, suggest that testis is more susceptible to cadmium toxicity than liver and kidney. No significant change from control was noted in liver, kidney and testis in DDTC-treated group, indicating the protective effect of DDTC on tissue damages induced by cadmium.

Te 蒸着膜의 電氣的 性質

朴鼎悳 건국대학교 1982 學術誌 Vol.26 No.2

In this study the Te thin film is deposited on the microscope slide glass substrate by means of vacuum evaporator. Evaporation is done under the pressure of 2∼5×10-5 Torr. and the samples are heated at various temperature in electric furnace. After measuring the thickness of the film and its electrical conductivity, the dependence of the electrical properties of the film on its thickness and on the heat treatment of the samples are investigated as follows; 1.The sample evaporated in laboratory temperature does not completely crystalized, its electrical properties being very poor. 2.With heat treatment of 200℃, the electrical conductivity of the sample more than 2μ in thickness is constant but less than 2μ increase.

放射能絶對値測定에 있어서의 計數値補正法에 對하여

朴鼎悳 건국대학교 1969 理工學報 Vol.1969 No.2

Holography 干涉에 의한 變形의 測定

朴鼎悳 建國大學校基礎科學硏究所 1983 理學論集 Vol.8 No.-

Holography is a photographic technology in which an optical picture of an original object is reproduced from the hologram. In this case, the picture cannot be reproduced even by applying natural light to the hologram and a three-dimensional picture is reproducible by applying the light laser beam at the time of hologram preparation. For the preparation of the hologram, an interferometer having laser beams as light source is used. In this case, He-Ne laser(6328Å) is used. The make-up of the unit varies according to the type of an object, the purpose of tests and the kind of laser. Hologram preparation units are devided roughly into two types; i.e. a reflection type for dispersed reflection object and a transmission type for transmitted. Shown in Fig.4 is the make-up of the typical dual beam reflection type holography photographing unit that light beam applied to the specimen passes through two optical paths. In this paper, the results of observation for the strain by holography interferometer system are reported.

金屬 薄膜의 電氣 抵抗과 光 透過率 測定

朴鼎悳,魏明鏞 건국대학교 1972 學術誌 Vol.13 No.1

This is a study on investigation to physical properties of resistivity and transmittance for the Au, Ag and Al metal thin film. This sample's purity is 99.9%. Evaporation was done under the pressure 10 Torr. and microscope slide glass was used as substrate. The thickness was measured by Multiple-Beam Interferometry method, resistivity was measured by using Leeds & Northrup Wheatstone bridge and transmittance was measured by the Multiplier Photometer. The following results were obtained through the experiment : 1) Thickness of thin film was increased according to the evaporation time, but its relation was not linear. 2) Relationship between the thickness and the resistivity well agreed with Funcks-Sondheimer theory, and metal thin film of thickness greater than 1000 Å approximately behaved like bulk metal. 3) Transmittance of metal thin film in visible light was generally observed that was zero at thickness Al 400Å, Ag 500Å and Au 600Å.

放射線의 障害와 許容量

朴鼎悳 공군본부 의무감실 1958 항공의학 Vol.6 No.1

Mo-99의 감마崩壞에 관한 硏究

朴鼎悳 建國大學校基礎科學硏究所 1988 理學論集 Vol.13 No.-

韓國에너지硏究所 同位元素室에서 製造하여 使用者에게 공급하는 Molybdenum 의 放射性 同位元素인 ??에 대하여 放出하는 감마 放射線을 檢出하고 그 에너지를 測定하여 崩壞形態를 調査하였다. 實驗은 미국 Tracor Northern 社製 model No. TN-1750, 1024 Multichannel γ-Ray Spectrometer System을 利用하여 標準 γ放射能 試料 ??의 γ-ray spectrum을 測定하여 에너지 511keV와 1275keV에 해당하는 Photopeak의 channel number 140및 314를 택하여 tow point method로 channel number대 energy의 補正式을 作成하고 이것에 의거하여 同一한 條件으로 測定한 實驗試料 ??의 γ-ray spectrum을 얻어 放出하는 γ線의 에너지를 구하였다. 이것을 標準値와 比較檢討한 結果 그 誤差가 2keV以下로 대단히 적은 優秀한 製品임이 確認되었다. In this study, the decay form of ?? which is supplied by Korea Advanced Energy Research Institude(KAERI) had been investigated from the analysis of γ-ray energy spectrum radiating from the radioactive element ??. The γ-ray energy spectrum was obtained using Nal(T1) scintillation detector and multichannel pulse height analyser. The calibration curve and formula for γ-ray energy versus channel number were made from the two photopeaks of standard radioactive source ??, 140 and 314 channel corresponding to the γ-ray energy of 511keV and 1275keV, respectively. The γ-ray energies from ?? were detected at the same condition with the standard source, and compared with standard energies of ??. Experimental results show that the γ-ray energies from the sample are in good agreement with the values of standard source within energy error of 2 keV, which means that the Mo supplied by the KAERI can be used as a standard radioactive source.

Human Exposure and Health Effects of Inorganic and Elemental Mercury

박정덕,Wei Zheng 대한예방의학회 2012 예방의학회지 Vol.45 No.6

Mercury is a toxic and non-essential metal in the human body. Mercury is ubiquitously distributed in the environment, present in natural products, and exists extensively in items encountered in daily life. There are three forms of mercury, i.e., elemental (or metallic) mercury, inorganic mercury compounds, and organic mercury compounds. This review examines the toxicity of elemental mercury and inorganic mercury compounds. Inorganic mercury compounds are water soluble with a bioavailability of 7% to 15% after ingestion; they are also irritants and cause gastrointestinal symptoms. Upon entering the body, inorganic mercury compounds are accumulated mainly in the kidneys and produce kidney damage. In contrast, human exposure to elemental mercury is mainly by inhalation, followed by rapid absorption and distribution in all major organs. Elemental mercury from ingestion is poorly absorbed with a bioavailability of less than 0.01%. The primary target organs of elemental mercury are the brain and kidney. Elemental mercury is lipid soluble and can cross the blood-brain barrier, while inorganic mercury compounds are not lipid soluble, rendering them unable to cross the blood-brain barrier. Elemental mercury may also enter the brain from the nasal cavity through the olfactory pathway. The blood mercury is a useful biomarker after short-term and high-level exposure, whereas the urine mercury is the ideal biomarker for long-term exposure to both elemental and inorganic mercury, and also as a good indicator of body burden. This review discusses the common sources of mercury exposure, skin lightening products containing mercury and mercury release from dental amalgam filling, two issues that happen in daily life, bear significant public health importance, and yet undergo extensive debate on their safety.