• 제목/요약/키워드: $^{232}Th$

검색결과 161건 처리시간 0.025초

Assessment of occupational radiation exposure of NORM scales residues from oil and gas production

  • EL Hadji Mamadou Fall;Abderrazak Nechaf;Modou Niang;Nadia Rabia;Fatou Ndoye;Ndeye Arame Boye Faye
    • Nuclear Engineering and Technology
    • /
    • 제55권5호
    • /
    • pp.1757-1762
    • /
    • 2023
  • Radiological hazards from external exposure of naturally occurring radioactive materials (NORM) scales residues, generated during the extraction process of oil and gas production in southern Algeria, are evaluated. The activity concentrations of 226Ra, 232Th, and 40K were measured using high-purity gamma-ray spectrometry (GeHP). Mean activity concentration of 226Ra, 232Th and 40K, found in scale samples are 4082 ± 41, 1060 ± 38 and 568 ± 36 Bq kg-1, respectively. Radiological hazard parameters, such as radium equivalent (Raeq), external and internal hazard indices (Hex, Hin), and gamma index (Iγ) are also evaluated. All hazard parameter values were greater than the permissible and recommended limits and the average annual effective dose value exceeded the dose constraint (0.3 mSv y-1). However, for occasionally exposed workers, the dose rate of 0.65 ± 0.02 mSv y-1 is lower than recommended limit of 1 mSv y-1 for public.

Current progress on development of respiratory syncytial virus vaccine

  • Chang, Jun
    • BMB Reports
    • /
    • 제44권4호
    • /
    • pp.232-237
    • /
    • 2011
  • Human respiratory syncytial virus (HRSV) is a major cause of upper and lower respiratory tract illness in infants and young children worldwide. Despite its importance as a respiratory pathogen, there is currently no licensed vaccine for prophylaxis of HRSV infection. There are several hurdles complicating the development of a RSV vaccine: 1) incomplete immunity to natural RSV infection leading to frequent re-infection, 2) immature immune system and maternal antibodies of newborn infants who are the primary subject population, and 3) imbalanced Th2-biased immune responses to certain vaccine candidates leading to exacerbated pulmonary disease. After the failure of an initial trial featuring formalin-inactivated virus as a RSV vaccine, more careful and deliberate efforts have been made towards the development of safe and effective RSV vaccines without vaccine-enhanced disease. A wide array of RSV vaccine strategies is being developed, including live-attenuated viruses, protein subunit-based, and vector-based candidates. Though licensed vaccines remain to be developed, our great efforts will lead us to reach the goal of attaining safe and effective RSV vaccines in the near future.

인광석 사용업체 주변 환경시료의 자연방사능 조사 (Investigation on Natural Radioactivity of Environmental Samples Near the Phosphate Rock Processing Facility)

  • 이길재;고상모;장병욱;김통권;김용욱
    • 자원환경지질
    • /
    • 제44권1호
    • /
    • pp.37-48
    • /
    • 2011
  • 국내에서 유통되는 산업원료물질 중 모나자이트, 인회석, 저어콘, 보오크사이트, 티탄철석 등은 천연방사성핵종을 함유한 원료광물로서 '자연기원방사성물질 (NORM)'에 속한다. 이러한 원료광물을 사용하여 제조된 제품, 반제품, 부산물 또는 폐기물이 원료광물보다 천연방사성핵종의 농도가 증가된 물질은 '인위적으로 농축된 자연기원방사성물질 (TENORM)'로 분류한다. 인산비료를 제조하는 남해화학(주)에서 사용하는 인회석은 NORM에. 부산물로 생산되는 인산석고는 TENORM에 해당된다. 이와 같은 NORM을 대량 사용하는 사용시설인 남해화학(주) 내부 및 주변 지역 지질환경에 대한 영향평가가 필요하다. 이러한 배경에서 이 공장 내부 및 주변 지역의 지질특성, 토양에 대한 광물학적 및 지화학적 분석을 수행하여 향후 관리를 위한 과학적인 기초자료를 제공하고자 한다. 남해화학(주) 공장 내부 및 인근 지역 토양의 광물조성은 석영, 장석, 운모, $14{\AA}$광물, 고령토, 각섬석 등 모암으로부터 유래된 광물조성과 석고, 인회석 등 석고 야적장에서 유래된 광물조성으로 혼화되어 있다. 이 지역 토양의 평균 U 함량은 4.6 ppm, Th 함량은 10 ppm으로서 지각의 평균 함량과 거의 유사하다. 토양의 $^{40}K$의 농도는 191-1,166 Bq/kg, $^{226}Ra$의 농도는 15.6-710 Bq/kg이고 $^{232}Th$의 농도는 17.4-72.7 Bq/kg으로서 극히 높은 핵종 농도는 보이지 않으나 상대적으로 높은 $^{226}Ra$ 농도는 인산석고 적재장에서 뚜렷이 확인되며 $^{232}Th$ 농도가 높은 지점은 공장 동편 도로변 및 산체에서 잘 확인된다. 토양시료의 외부위해지수 범위는 0.24-2.01이며 평균 0.54로서 전체적으로는 위해 기준치로 제시되는 1.0 이하이지만 일부 지점에서는 1.0 이상이다.

The Transport Characteristics of 238U, 232Th, 226Ra, and 40K in the Production Cycle of Phosphate Rock

  • Jung, Yoonhee;Lim, Jong-Myoung;Ji, Young-Yong;Chung, Kun Ho;Kang, Mun Ja
    • Journal of Radiation Protection and Research
    • /
    • 제42권1호
    • /
    • pp.33-41
    • /
    • 2017
  • Background: Phosphate rock and its by-product are widely used in various industries to produce phosphoric acid, gypsum, gypsum board, and fertilizer. Owing to its high level of natural radioactive nuclides (e.g., $^{238}U$ and $^{226}Ra$), the radiological safety of workers who work with phosphate rock should be systematically managed. In this study, $^{238}U$, $^{232}Th$, $^{226}Ra$, and $^{40}K$ levels were measured to analyze the transport characteristics of these radionuclides in the production cycle of phosphate rock. Materials and Methods: Energy dispersive X-ray fluorescence and gamma spectrometry were used to determine the activity of $^{238}U$, $^{232}Th$, $^{226}Ra$, and $^{40}K$. To evaluate the extent of secular disequilibrium, the analytical results were compared using statistical methods. Finally, the distribution of radioactivity across different stages of the phosphate rock production cycle was evaluated. Results and Discussion: The concentration ratios of $^{226}Ra$ and $^{238}U$ in phosphate rock were close to 1.0, while those found in gypsum and fertilizer were extremely different, reflecting disequilibrium after the chemical reaction process. The nuclide with the highest activity level in the production cycle of phosphate rock was $^{40}K$, and the median $^{40}K$ activity was $8.972Bq{\cdot}g^{-1}$ and $1.496Bq{\cdot}g^{-1}$, respectively. For the $^{238}U$ series, the activity of $^{238}U$ and $^{226}Ra$ was greatest in phosphate rock, and the distribution of activity values clearly showed the transport characteristics of the radionuclides, both for the byproducts of the decay sequences and for their final products. Conclusion: Although the activity of $^{40}K$ in k-related fertilizer was relatively high, it made a relatively low contribution to the total radiological effect. However, the activity levels of $^{226}Ra$ and $^{238}U$ in phosphate rock were found to be relatively high, near the upper end of the acceptable limits. Therefore, it is necessary to systematically manage the radiological safety of workers engaged in phosphate rock processing.

가압경수로에서 비순환 토륨 핵연료 주기의 적용 타당성 (A Feasibility of Once-Through Thorium Fuel Cycle for PWR)

  • 우일탁;김명현
    • 한국에너지공학회:학술대회논문집
    • /
    • 한국에너지공학회 1999년도 추계 학술발표회 논문집
    • /
    • pp.131-136
    • /
    • 1999
  • 토륨은 자연계에서 유일한 동위원소인 Th-232로 존재하며 반감기는 1.4$\times$$10^{10}$년으로 U-238의 4.5$\times$$10^{9}$년에 비하여 약 3배 길고 매장량도 약 3배 많은 것으로 알려져 있다. 토륨은 원자력 초기 개발단계인 1950년대부터 우라늄에 관한 연구와 함께 시작되었지만, 70년대 중반 이후로는 토륨 핵연료 재처리의 어려움과 여러 정치적 이유로 이에 관한 연구가 거의 중단되었다.(중략)

  • PDF

Studies on the induction of pregnancy and the number of fetuses during pregnancy in rats

  • Choi, Seung-Hee;Cho, Yong-Seong;Kim, Min-Ji;Lee, Chae-Hyeok;Seong, Hwan-Hoo;Baek, Soon-Hwa;Lee, Jang-Hee
    • 한국동물생명공학회지
    • /
    • 제35권3호
    • /
    • pp.232-238
    • /
    • 2020
  • This study used adult wistar-based rats to observe the sexual cycle as a morphological characteristic of vaginal epithelial cells by vaginal smearing, and investigated the fetal number through mating with male rats of the same strain. The target animal was a 12 to 13-week-old Wistar-based mature unlighted rat (weight 220 g to 240 g), room temperature 23 ± 2℃, 14 hours artificial lighting (05:00 to 19:00 hours), 10 hours Adapted individuals were used for rearing for at least 2 weeks under the conditions of the darkroom (19:00 to 05:00). The feed was managed for free feeding of pellet feed for animals and water. The vaginal smearing method was used for the experiments by observing the sexual cycle every morning and confirming that the normal sexual cycle of 4 or 5 days was repeated at least 2 cycles or more. As a result, the proestrus was found to have few red blood cells, the cells and nuclei were rather large and round, and many nucleated cells were identified. In the case of the estrus, the cells were large and the nuclei were not stained, and most of the keratinocytes were found. In addition, in the metestrus and diestrus, there were many white blood cells, and it was confirmed that nucleated epithelial cells and keratinocytes were significantly reduced. The pregnancy period was 21 ± 1.8 days, and the number of live births per delivery was 11.9 on average. The number of fetuses on the 8th and 10th days of pregnancy were 15.2 ± 0.4 and 15.4 ± 0.3, respectively. On the contrary, the number of fetuses on the 12th day of pregnancy was 12.9 ± 0.6, which was significantly (p < 0.05) decreased compared to the 10th day of pregnancy, and the number of fetuses was similar until delivery. As a result of investigating the change of body weight according to the birth weight and growth stage after delivery, the birth weight of female and male was 9.2 ± 2.0 g and 9.8 ± 2.5 g, respectively. After that, until the 16th day, the female and the male showed similarly moderate weight gain, and then showed a rapid weight gain until the 21st day of lactation. With reference to the results of this study, it is expected to be used as basic data for determining the mating time of rodents and controlling pregnancy and fetal number.

일본(日本) 패션의 미적(美的) 특성(特性)에 관(關)한 연구(硏究) -<모드 자포니슴>을 중심(中心)으로-

  • 조규화
    • 패션비즈니스
    • /
    • 제11권4호
    • /
    • pp.232-246
    • /
    • 2007
  • The purpose of this study is to investigate aesthetic characteristics and aesthetic consciousness of the style that European fashion(Paris, London, Netherlands) has accepted the since $19^{th}$ century. The mode Japonisme's development process in around $20^{th}$ century and 21st century has 6 characteristics as follows; 1. Accepting kimono as dressing gown 2. Accepting kimono as Japanese style's objet of Japanese taste 3. Accepting Japanese textile's skills, patterns, and asymmetry. 4. Accepting kimono's formative nature : flat pattern, flexibility, style etc. 5. Shocking of Japanese style's beauty 6. Accepting characters and casual wear Japanese aesthetic consciousness expressed on unconstructed design or deconstructed design that is the aesthetic characteristic of Japanese fashion is , , and the aesthetic consciousness expressed on Zen(Seon) style, cartoons of character fashion, and costume play is .

아동의 성역할 태도와 사회적 능력간의 관계 (The Relationship between Children's Gender role Attitude and Social Competency)

  • 이경희
    • 대한가정학회지
    • /
    • 제35권1호
    • /
    • pp.47-58
    • /
    • 1997
  • The purpose of this study was to investigate the relationship between children's gender role attitude measured by component model and social competency. Subjects were 232 elementary school children: 113 4th graders and 119 6th graders. The main results were as follows. First there were significant differences in mean scores of gender role attitude with age and sex variable. And among three dimensions of component model(i.e, gender label-component links within-component links between-component links) the difference was most discriminant in gender label-component links. Second there were significant relationship between gender role attitude and social competency. Among three dimensions of gender role attitude the most predictor variable for social competency was gender label-component links. And among four dimensions of social competency the most effective criterion variable for gender role attitude was leadership. And there were significant differences in social competency score with mother's educational level and sex of children as well as gender role attitude. In conclusion children's gender role attitude influence their social competency. More flexible gender role attitude they have more improved in their social competency , especially in boys.

  • PDF

공간척추도인안교법의 타교법을 병행한 추나 치료만으로 증상 호전을 보인 기능성 소화불량 환자 1례 (Chuna therapy include Space Spinal Conduction Exercise and Manipulation Treatment for Functional dyspepsia patients: A case report)

  • 유명환;조재흥
    • 대한한의학회지
    • /
    • 제45권1호
    • /
    • pp.225-232
    • /
    • 2024
  • Objectives: The purpose of this case study was to report the effect of Chuna therapy include Space Spinal Conduction Exercise and Manipulation Treatment for Functional dyspepsia patients. Methods: A 32-years-old male patients with functional dyspepsia visited the clinic ten times from March 17th 2023 to April 22th 2023. To assess the treatment outcomes, we used the Standard tool for pattern identification of Functional dyspepsia and Nepean Dyspepsia Index-Korean version (NDI-K) symptom score. Result: After treatment, Standard tool for pattern identification of Functional dyspepsia and Nepean Dyspepsia Index-Korean version (NDI-K) score decreased. Conclusion: Chuna therapy include Space Spinal Conduction Exercise and Manipulation Treatment was effective in the treatment of patient with Functional dyspepsia.