• Title/Summary/Keyword: $^{232}Th$

Search Result 161, Processing Time 0.029 seconds

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
    • /
    • v.55 no.5
    • /
    • 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
    • /
    • v.44 no.4
    • /
    • 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.

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

  • Lee, Gill-Jae;Koh, Sang-Mo;Chang, Byung-Uck;Kim, Tong-Kwon;Kim, Young-Ug
    • Economic and Environmental Geology
    • /
    • v.44 no.1
    • /
    • pp.37-48
    • /
    • 2011
  • Some industrial minerals used in domestic industries such as monazite, apatite, bauxite, and ilmenite belong to NORM (Naturally Occurring Radioactive Materials) because they show a high radioactivity. Products, semi-products, wastes, and by-products which show higher radioactivity than NORM belong to TENORM (Technologically Enhanced Naturally Occurring Radioactive Materials). Apatite used for manufacturing phosphate fertilizer in Namhae Chemical company belongs to NORM, and its by-product, phospo-gypsum, belongs to TENORM. A geological investigation is needed for the future environmental impact assessment of the Namhae Chemical company's site. According to survey results of the Namhae Chemical company's site, soil mineral composition indicated the mixture of minerals derived from the country rock (quartz, feldspar, mica, $l4{\AA}$ mineral, kaolin and amphibole) and minerals from the gypsum open-air storage yard (gypsum and apatite). Soil samples showed average content of U 4.6 ppm and Th 10 ppm, which are similar to average crustal abundances. They also show average contents of $^{40}K$ 191-1,166 Bq/kg, $^{226}Ra$ 15.6-710 Bq/kg, and $^{232}Th$ 17.4-72.7 Bq/kg, which indicate moderate levels of radio nuclide. But $^{226}Ra$ anomaly in the gypsum open storage yard is clearly confirmed and $^{232}Th$ anomaly is also confirmed in the east road side of the factory and nearby mountain areas. Soil external hazard indices ranged 0.24-2.01 with the average 0.54. Although most external hazard indices were lower than 1, which means radiation hazard index to be negligible, 5 samples out of total 40 samples showed higher values than 1, and further detailed investigation is needed.

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
    • /
    • v.42 no.1
    • /
    • 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.

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

  • 우일탁;김명현
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
    • /
    • 1999.11a
    • /
    • 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
    • Journal of Animal Reproduction and Biotechnology
    • /
    • v.35 no.3
    • /
    • 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-

  • Cho, Kyu-Hwa
    • Journal of Fashion Business
    • /
    • v.11 no.4
    • /
    • 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 .

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

  • 이경희
    • Journal of the Korean Home Economics Association
    • /
    • v.35 no.1
    • /
    • 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

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

  • Myung-hwan Yu;Jae-Heung Cho
    • The Journal of Korean Medicine
    • /
    • v.45 no.1
    • /
    • 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.