• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2006년도 영호남 합동 학술대회 및 춘계학술대회 논문집 센서 박막 기술교육
• /
• pp.27-30
• /
• 2006

In this paper, the undoped and Co-doped $Zn_4SnSe_6$ single crystals grown by the chemical transporting reaction(CTR) method using iodine as a transporting agent are investigated. For the crystal growth, the temperature gradient of the CTR furnace was kept at $680^{\circ}C$ for the source zone and at $780^{\circ}C$ for the growth zone for 7days. It was found from the analysis of x-ray diffraction that the $Zn_4SnSe_6$ and $Zn_4SnSe_6Co^{2+}$ compounds have a monoclinic structure. The direct optical energy band gap of the $Zn_4SnSe_6$ and $Zn_4SnSe_6Co^{2+}$ single crystals at 300K were found to be 2.146eV and 2.042eV.

• 대한화학회지
• /
• 제5권1호
• /
• pp.66-72
• /
• 1961

A small size Fischer-Tropsch Catalyst testing apparatus, designed for an operating pressure of 150 psig, was test fabricated from ordinary schedule 40 iron pipes. The operability of the apparatus was tested by charging the reactor tube with the Lurgi Fischer-Tropsch iron Catalyst and passing through it the water gas obtained by gasifying the Korean anthracite using steam and oxygen. With the kind of catalyst charged, the apparatus was proven to daily produce about 50c.c. of synthetic greasy product, water and water soluble compounds, by running at a temperature of $250^{\circ}C$ and at a space velocity of 180 volume of gas per volume of catalyst/hr. About 20 consecutive days of operation is claimed to be sufficient for gathering an enough amount of synthetic products for such ordinary tests as distillation analysis, density measurement, iodine value determination etc. This trial fabrication of apparatus may be the first case of its kind in Korea in that the work has been conducted out in much a pilot plant scheme rather than a routine laboratory way which depends on small glass ware apparatus.

• 대한방사성의약품학회지
• /
• 제8권2호
• /
• pp.139-150
• /
• 2022

Theranostics, a composite word of therapy and diagnosis, is known as personalized medicine and the concept of diagnosis and treatment at the same time. In nuclear medicine, it means performing both therapeutic and diagnostic radioisotope therapy using the same target molecule. The increased production and utilization of ⁶⁴Cu opens a new era of theranostics. The studies introduced here have shown that ⁶⁴CuCl₂ and various compounds or biomolecules labeled with ⁶⁴Cu are unique radiopharmaceuticals with physiological properties suitable for use as diagnostic and therapeutic agents. So far, these two abilities have been described only for radioactive iodine. Although ⁶⁴Cu has complex chemical properties compared to other PET radioisotopes such as ⁶⁸Ga, it has an appropriate half-life and enables high-quality PET images similar to ¹⁸F, which is an advantage in terms of diagnosis. In addition, since it also has therapeutic properties through the release of β^- particles and Auger electrons by electron capture, radiopharmaceuticals using ⁶⁴Cu stand for innovative radiopharmaceuticals for theranostic purposes. Therefore, based on the initial results obtained using ⁶⁴Cu as a therapeutic agent, it is expected that additional research on the application of ⁶⁴Cu will lead to a new era in the theranostics field.

• 방사선산업학회지
• /
• 제5권4호
• /
• pp.337-345
• /
• 2011

In order to provide an effective preparedness for a nuclear or radiological emergency happening in the domestic or neighborhood countries and to solve the vague fear of the people for the ingestion of radioactive livestock products, the establishment of national guideline level for radionuclides in feed is urgently necessary. This is because it is important to secure the safety and to manage the crisis in the agricultural, fishery and food sector by performing the effective safety control during and after nuclear incident. This study was performed to investigate the report cases of international organizations and foreign countries to set up a domestic control standard for managing radioactive substances that may be contaminated in animal feeds due to the nuclear power plant incident. In addition, an attempt was made to provide a useful reference that can help prepare a domestic control standard, using a coefficient that can consider the transfer into livestock through the intake of radioactive contaminated animal feeds. The standard radioisotopes investigated were confined to radioactive cesium ($^{137+134}Cs$) and iodine ($^{131}I$). Guideline level for the radionuclides was calculated by using the transfer coefficient factor and the maximum daily intake of animal feed provided by IAEA. For example, the maximum daily intake of animal feed was set as $25kg\;d^{-1}$ for dairy cows, $10kg\;d^{-1}$ for beef cattle, $3.0kg\;d^{-1}$ for pigs and $0.15kg\;d^{-1}$ for chickens. The result values for radioactive cesium were calculated as $8,696Bq\;kg^{-1}$, $4,545Bq\;kg^{-1}$, $1,667Bq\;kg^{-1}$ and $2,469Bq\;kg^{-1}$, respectively. The results for radioactive iodine showed the ranges between $741Bq\;kg^{-1}$ and $76,628Bq\;kg^{-1}$. These data can be utilized as a scientific reference for the preparation of a crisis management manual for the emergency control due to nuclear power plant accident in Korea and neighboring country. These results will contribute to establish the safe feed management system at national level as manual for responding the radioactive exposure of agricultural products and animal feeds, which are currently not established.

• 한국식품과학회지
• /
• 제51권6호
• /
• pp.524-530
• /
• 2019

열풍 건조와 일광 건조는 건조 다시마를 제조하는데 매우 일반적으로 사용하는 방식이다. 본 연구에서는 건조 다시마의 주요한 생리활성물질인 후코잔틴이 열풍 건조에 의해 노출되는 열과 일광 건조에 의해 노출되는 자외선에 의해 받는 영향에 관하여 연구하였다. 본 연구를 통하여 후코잔틴이 건조 다시마의 폴리페놀 조성에 중요한 비중을 차지하며, 총 항산화 능력에도 기여하고 있음을 확인하였다. 또한 열풍 건조에서 발생하는 열과 일광건조에 의해 건조 다시마에 노출되는 자외선에 의해 후코잔틴 및 총 폴리페놀 함량 및 총 항산화 능력이 감소되는 것을 확인하였다. 그러므로 본 연구를 통해 건조 다시마의 가공, 유통 및 저장 그리고 포장재의 선택 등이 건조 다시마의 생리활성물질의 잔존 및 총 항산화 능력에 중요한 요소임을 확인하였다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
• /
• 제48권1호
• /
• pp.12-17
• /
• 1999

$MgIn_2Se_4 and MgIn_2Se_4 : Ni^{2+}$ single crystals were grown in the rhombohedral structure by the chemical transport reaction (C.T.R.) method using iodine as a transport agent. The optical absorption measured near the fundamental band edge showed that the optical energy band structure of these compounds had a direct band gap. The fundamental absorption band edge of these single crystals shift to a shorter wavelength region by decreasing temperature and the temperature dependence of the optical energy gaps in these compounds satisfy Varshni equation. The impurity optical absorption peaks due to nickel are observed in $MgIn_2Se_4 and MgIn_2Se_4 : Ni^{2+}$ single crystal. These impurity optical absorption peaks can be attributed to the electronic transitions between the split energy levels of $Ni_{2+}$ ions located at $T_d$ symmetry site of $MgIn_2Se_4$ host lattice. In the hotoluminescence spectrum of the single crystal at 10 K, a blue emission with a peak at 687nm and a green emission with a peak at 815nm for the $MgIn_2Se_4$ single crystal were observed.

• Journal of the Korean Wood Science and Technology
• /
• 제26권1호
• /
• pp.7-13
• /
• 1998

In order to reconstruct the traditional technology of Korean golden varnish(Hwangchil) made from the exudates of D. morbifera, this study in the second step was carried out to analyze the chemical composition and oil properties of the exudates for coatings and bark extractives made from the trees of D. morbifera more than 20 years old grown in Wando and Jejudo islands in the southwestern part of Korean peninsula according to the physiological seasons. The results obtained are as follows: 1. The exudates appeared to be a phytoalexin because it exudated after several days in tapping only in summer season. 2. Both the exudates and bark-extracts with acetone contained 50~60% unsaponifiables and 30~50% saponifiables 3. A major component of essential oil in bark-extractives was ${\beta}$-cubebene and reached to 60~80%, while that of exudates included only 34% ${\beta}$-cubebene and some other compounds such as ${\beta}$-cadinene of 12%, aromadendrene of 9%, ${\beta}$-selinene of 9%, CAS030021-74-0 of 10%, etc. in GC-MS spectrometer. 4. A mjor component of fatty oil fraction in bark-extractives was linoleic acid and reached to more than 60%, while the exudates had mostly other components such as terpenes and phenolics instead of fatty acids accordint to GC-MS spectrometer. 5. Iodine value of samples after oil refining had 214mg/g in the exudates and more than than 150mg/g in bark-extractives, so the latter belonged to a drying oil.. 6. Therefore, the exudates from D. morbifera for traditional Korean golden varnish seems to have beeen used to a good varnish because it has some specific compounds different from its bark-extractives or general varnishes.

• 공업화학
• /
• 제8권5호
• /
• pp.737-741
• /
• 1997

휘발성 유기용제의 주된 제거방법은 흡착제를 이용한 흡착 공정이 추천된다. 본 연구에서는 입상활성탄과 활성탄소섬유에 휘발성 유기용제를 흡착시킨 후 폐흡착제를 탈착컬럼에 넣고 318.15 K의 온도에서 압력을 변수(2000~3000 psi)로 하는 초임계 이산화탄소를 이용하여 재생하였다. 초임계 이산화탄소의 압력이 증가함에 따라 탈착율과 요오드 흡착가는 증가하였으며, 재생시간은 MEK와 benzene의 경우 각각 70분과 60분이었다. 최대 탈착율은 3000psi의 압력에서 MEK가 흡착된 입상활성탄과 활성탄소섬유의 경우 각각 초기 흡착량의 64.0%, 55.3%가 탈착되었으며, 벤젠이 흡착된 입상활성탄과 활성탄소섬유의 경우에는 각각 59.1%, 45.2%가 탈착되었다. 또한 Tan과 Liou의 모델로 출구농도를 예측할 수 있었다. 따라서 입상활성탄뿐만 아니라 활성탄소섬유의 재생공정에도 초임계유체 재생법의 적응 가능성을 확인할 수 있었다.

• 한국식품영양과학회지
• /
• 제14권1호
• /
• pp.61-66
• /
• 1985

취반(炊飯) 중의 가열반응(加熱反應)에 의하여 일어나는 주요 쌀성분(成分)의 화학적(化學的) 변화(變化) 및 휘발성(揮發性) carbonyl 화합물(化合物)의 생성(生成) 양상(樣相)을 쌀밥 및 누른밥으로 나누어 살펴 본 결과는 다음과 같다. 취반에 의한 가열반응(加熱反應) 결과 총(總)아미노산 및 유리아미노산 중의 몇 가지 아미노산이 감소되었으며 그 감소율은 유리아미노산에서 더 높았고, 환원당 역시 감소되었다. 또한 유지획분에 있어서 구성지방산 조성(組成)의 경미한 변화, 요오드가(價)의 감소, 지방산(價)의 증가 등을 주목할 수 있었다. 한편 휘발성향기성분에서 carbonyl 화합물을 분리하여 GC, GC-MS, TLC 방법에 따라 잠정적으로 8개의 carbonyls을 확인하였고(4개는 완전히 동정(同定)함) 이들의 조성을 비교하였다. 전반적으로 쌀밥보다는 누른밥에서 이와 같은 화학적 변화가 심하였고 쌀밥과 누른밥의 주요 휘발성 carbonyl 화합물 조성도 상이(相異)하였다. 그리고 이러한 취반과정에서는 변화와 관련되는 가열반응(加熱反應) mechanism을 아울러 검토하였다.

• 공업화학
• /
• 제20권1호
• /
• pp.109-115
• /
• 2009

본 연구는 현재 크게 문제가 되고 있는 하수슬러지를 처리하고 흡착제로 재활용하기 위해 탄화와 수증기 활성화를 동시에 진행시켜 하수슬러지 흡착제를 제조하고 흡착특성을 파악하였다. 양질의 흡착제를 제조하기 위해 변수별 연구를 진행하였고, 그 결과 최적 탄화 수증기활성화 조건은 유입 탄화활성화 온도 $840^{\circ}C$, 수증기량 70 g/min, 탄화활성화 시간 30 min, 건조슬러지 주입량 10.8 kg/d로 결정되었다. 이때 요오드 흡착능은 328.1 mg/g으로 나타났다. nanoPOROSITY, FE-SEM, EDS를 이용하여 각각의 세공 발달과 구조, 원소성분 및 함량을 확인하였다. 이를 통해 하수슬러지 흡착제의 경우 매립장 침출수 흡착제, VOCs 처리용 흡착제 등의 사용이 가능함을 확인할 수 있었다.