• Title/Summary/Keyword: Over-G Protection

Search Result 94, Processing Time 0.022 seconds

Citic Tower Construction Key Technology

  • Xu, Lishan
    • International Journal of High-Rise Buildings
    • /
    • v.8 no.3
    • /
    • pp.185-192
    • /
    • 2019
  • Citic Tower is the first over-500 m-tall super highrise building in the world, located in the high seismic intensity area with paek ground acceleration over 0.2g in 475 years. This project is unique in its complexity, large volume, and challenging site conditions (zero site for construction). The traditional techniques can hardly meet safty, quality and schedule requirements of the construction. This article introduces the key construction technologies that are innovatively developed and applied in Citic Tower project construction, including intelligent super-high-rise building integrated construction platform system, independently developed by the CCTEB; Jump-Lift Elevator, which is the first of the kind with service height over 500 meters; combined temporary-and-permanent fire protection systems. The BIM technology is also applied in this project. Through technical innovation, and utilization of technologies, construction speed and safety had been greatly improved.

Evaluation and Performance Test of Arresters for Electric Power Distribution (전력용 피뢰기의 성능확인시험과 평가 분석)

  • Kim, S.S.;Kim, K.U.;Cho, H.G.;Park, T.G.
    • Proceedings of the KIEE Conference
    • /
    • 1999.07e
    • /
    • pp.2329-2331
    • /
    • 1999
  • Metal oxide surge arrester were developed in the late 1970s, and were immediately adopted as significant breakthrough in over voltage protection of power system. Work was continued throughout the world on the design, development and application of metal oxide surge arrester. This paper describes the evaluating test and results of practical use for analyzing the performance of gapless metal oxide surge arresters under various type test.

  • PDF

A periodic case study of diesel vehicle drivers exposed to diesel particulate matter in an underground coal mine

  • Lee, Sugil;Jankewicz, Ganyk;Kim, Jung-Hee;Chung, Kwang Bo
    • Environmental Engineering Research
    • /
    • v.23 no.3
    • /
    • pp.265-270
    • /
    • 2018
  • This study was to measure the exposure of diesel vehicle drivers to elemental carbon (EC) as an indicator of diesel particulate matter (DPM) emitted from diesel vehicles in an underground coal mine over 3 years as per NIOSH Method 5040. Our study results (range $10{\mu}g/m^3-377{\mu}g/m^3$ for the loader drivers, $19{\mu}g/m^3-162{\mu}g/m^3$ for the SMV drivers) were similar or less than previous study results (range $5{\mu}g/m^3-2,200{\mu}g/m^3$) for normal mine operations. From this study results, it appeared that the exposures decreased in the second and the third year. It is thought that the reasons for the decreased personal DPM (EC) exposures over the 3 years were related to the following recommendations; more frequent monitoring and maintenance of the diesel vehicles and their DPM filtration systems, more consistent monitoring of the mine's ventilation system and changes of work practices such as minimizing the opening of diesel vehicle windows. An educational program on adverse health effects of exposure to DPM and use of respiratory protection (P2 respirators) also assisted in minimizing driver exposure to DPM.

SITE-SPECIFIC ATMOSPHERIC DISPERSION CHARACTERISTICS OF KOREAN NUCLEAR POWER PLANT SITES

  • Han, M.H.;Kim, E.H.;Suh, K.S.;Hwang, W.T.;Choi, Y.G.
    • Journal of Radiation Protection and Research
    • /
    • v.26 no.3
    • /
    • pp.305-309
    • /
    • 2001
  • Site-specific atmospheric dispersion characteristics have been analyzed. The northwest and the southwest wind prevail on nuclear sites of Korea. The annual isobaric surface averaged for twenty years around Korean peninsula shows that west wind prevails. The prevailing west wind is profitable in the viewpoint of radiation protection because three of four nuclear sites are located in the east side. Large scale field tracer experiments over nuclear sites have been conducted for the purpose of analyzing the atmospheric dispersion characteristics and validating a real-time atmospheric dispersion and dose assessment system FADAS. To analyze the site-specific atmospheric dispersion characteristics is essential for making effective countermeasures against a nuclear emergency.

  • PDF

Full spectrum estimation of helicopter background and cosmic gamma-ray contribution for airborne measurements

  • Lukas Kotik;Marcel Ohera
    • Nuclear Engineering and Technology
    • /
    • v.55 no.3
    • /
    • pp.1052-1060
    • /
    • 2023
  • The airborne radiation monitoring has been used in geophysics for more than forty years and now it also has its important role in emergency monitoring. The aircraft background and the cosmic gamma-rays contribute to the measured gamma spectrum on the aircraft board. This adverse effect should be eliminated before the data processing. The paper describes two semiparametric methods to estimate the full spectrum aircraft background and cosmic gamma-ray contribution from spectra measured at altitudes where terrestrial contribution is negligible. The methods only assume to know possible peak positions in spectra and their full width at half maximum, that can be easily obtained e.g. from terrestrial measurement. The methods were applied to real experimental data acquired on Mi-17 and Bell 412 helicopter boards. The IRIS airborne gamma-ray spectrometer, with 4×4 L NaI(Tl) crystals, produced by Pico Envirotec Inc., Canada, was used on helicopters' boards. To obtain valid estimate of the aircraft background and the cosmic contribution, the measurements over sea and large water areas were carried out. However, the satisfactory results over inland were also achieved comparing with those acquired over large water areas.

Quantitative Evaluation of Radiation Dose Rates for Depleted Uranium in PRIDE Facility

  • Cho, Il Je;Sim, Jee Hyung;Kim, Yong Soo
    • Journal of Radiation Protection and Research
    • /
    • v.41 no.4
    • /
    • pp.378-383
    • /
    • 2016
  • Background: Radiation dose rates in PRIDE facility is evaluated quantitatively for assessing radiation safety of workers because of large amounts of depleted uranium being handled in PRIDE facility. Even if direct radiation from depleted uranium is very low and will not expose a worker to significant amounts of external radiation. Materials and Methods: ORIGEN-ARP code was used for calculating the neutron and gamma source term being generated from depleted uranium (DU), and the MCNP5 code was used for calculating the neutron and gamma fluxes and dose rates. Results and Discussion: The neutron and gamma fluxes and dose rates due to DU on spherical surface of 30 cm radius were calculated with the variation of DU mass and density. In this calculation, an imaginary case in which DU density is zero was added to check the self-shielding effect of DU. In this case, the DU sphere was modeled as a point. In case of DU mixed with molten salt of 50-250 g, the neutron and gamma fluxes were calculated respectively. It was found that the molten salt contents in DU had little effect on the neutron and the gamma fluxes. The neutron and the gamma fluxes, under the respective conditions of 1 and 5 kg mass of DU, and 5 and $19.1g{\cdot}cm^{-3}$ density of DU, were calculated with the molten salt (LiCl+KCl) of 50 g fixed, and compared with the source term. As the results, similar tendency was found in neutron and gamma fluxes with the variation of DU mass and density when compared with source spectra, except their magnitudes. Conclusion: In the case of the DU mass over 5 kg, the dose rate was shown to be higher than the environmental dose rate. From these results, it is concluded that if a worker would do an experiment with DU having over 5 kg of mass, the worker should be careful in order not to be exposed to the radiation.

Comparison of the Nutritional and Functional Compounds in Naked Oats (Avena sativa L.) Cultivated in Different Regions (재배지역 차이에 따른 쌀귀리 영양성분 및 기능성 성분 비교)

  • Ji-Hye Song;Dea-Wook Kim;Hak-Young Oh;Jong-Tak Yun;Yong-In Kuk;Kwang-Yeol Yang
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.68 no.4
    • /
    • pp.402-412
    • /
    • 2023
  • To cope with climate change, we compared the quality of naked oats (Avena sativa L.) cultivated in different regions. Naked oats were collected from domestic farms in different cultivation regions grouped as G1 and G2 for 3 years (2020-2022). The appearance, quality, and nutritional and functional compounds in the samples were assessed. In terms of appearance quality, the brightness and yellowness of the samples from the G1 region were significantly lower than those of the samples from the G2 region in 2020; however, no differences were observed between cultivation regions in the other 2 years. The results of testing the vitality of naked oats seeds showed that the electrical conductivity value was significantly lower in the samples from the G1 region than in those from the G2 region only in 2022. Among the nutritional components, moisture content was higher in the G2 region than in the G1 region over all 3 years, and the crude protein content was significantly higher in the G2 region than in the G1 region over all years. Carbohydrate content was significantly higher in the G1 region than in the G2 region in all 3 years and was inversely proportional to the crude protein content. The crude fat content tended to be significantly higher in the G1 region than in the G2 region, except in 2022. The levels of beta-glucan, a functional compound rich in naked oats, ranged between 3.4% and 4.2%, and except in 2020, there was no significant difference between cultivation regions. In addition, the content of avenanthramides, representative functional compounds that exist only in oats, was assessed. Over 2 years, in 2021 and 2022, the avenanthramide content was in the range of 2.4-20.7 ㎍/g and tended to be significantly higher in the G2 region than in the G1 region in both years. According to a survey of the average and minimum temperatures during the growing season of naked oats from 2020 to 2022, the average and minimum temperatures in January in the G2 region, which is the cultivation-limit area, were similar to those in Haenam in the G1 region. In conclusion, differences in nutritional and functional compounds were observed in naked oats grown in different cultivation areas. Therefore, considering the cultivation area of naked oats is expanding because of climate change, changes in the compounds that affect quality should be investigated.

Rhizosphere Inhibition of Cucumber Fusarium Wilt by Different Surfactinexcreting Strains of Bacillus subtilis

  • Jia, Ke;Gao, Yu-Han;Huang, Xiao-Qin;Guo, Rong-Jun;Li, Shi-Dong
    • The Plant Pathology Journal
    • /
    • v.31 no.2
    • /
    • pp.140-151
    • /
    • 2015
  • Bacillus subtilis B006 strain effectively suppresses the cucumber fusarium wilt caused by Fusarium oxysporum f. sp. cucumerinum (Foc). The population dynamics of Foc, strain B006 and its surfactin over-producing mutant B841 and surfactin-deficient mutant B1020, in the rhizosphere were determined under greenhouse conditions to elucidate the importance of the lipopeptides excreted by these strains in suppressing Foc. Results showed that B. subtilis strain B006 effectively suppressed the disease in natural soil by 42.9%, five weeks after transplanting, whereas B841 and B1020 suppressed the disease by only 22.6% and 7.1%, respectively. Quantitative PCR assays showed that effective colonization of strain B006 in the rhizosphere suppressed Foc propagation by more than 10 times both in nursery substrate and in field-infected soil. Reduction of Foc population at the cucumber stems in a range of $0.96log_{10}ng/g$ to $2.39log_{10}ng/g$ was attained at the third and the fifth weeks of B006 treatment in nursery substrate. In field-infected soil, all three treatments with B. subtilis suppressed Foc infection, indicated by the reduction of Foc population at a range of $2.91log_{10}ng/g$ to $3.36log_{10}ng/g$ at the stem base, one week after transplanting. This study reveals that the suppression of fusarium wilt disease is affected by the effective colonization of the surfactin-producing B. subtilis strain in the rhizosphere. These results improved our understanding of the biocontrol mechanism of the B. subtilis strain B006 in the natural soil and facilitate its application as biocontrol agent in the field.

Performance Evaluation and Analysis of ZnO Element for Distribution Line Arresters (피뢰기의 ZnO 소자 성능평가 분석)

  • Kim, S.S.;Kim, K.U.;Park, Y.C.;Cho, H.G.;Park, T.G.;Song, I.G.;Kim, J.Y.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2000.05a
    • /
    • pp.78-81
    • /
    • 2000
  • Metal oxide surge arrester were developed in the late 1970s, and were immediately adopted as significant breakthrough in over voltage protection of power system. Work was continued throughout the world on the design, development and application of metal oxide surge arrester. This paper describes the evaluating test and results of practical use for analyzing the performance of gapless metal oxide surge arresters under various type test. In the result, ZnO element exhibited badness rate of 6.95 percent.

  • PDF

Survey of Egg- and Cyst-parasitic Fungi of Potato Cyst Nematode in Indonesia

  • Indarti, Siwi;Widianto, Donny;Kim, Young-Ho;Mulyadi, Mulyadi;Suryanti, Suryanti
    • The Plant Pathology Journal
    • /
    • v.26 no.1
    • /
    • pp.32-36
    • /
    • 2010
  • Twelve fungal isolates out of 123 isolates obtained from cysts and soils of potato cyst nematode (PCN)-infested fields in Central Java, Indonesia had parasitic abilities of over 50% on PCN eggs or females (cysts) in vitro pathogenicity tests. Cultural and morphological characters and DNA sequences of ribosomal genes in ITS region revealed that they were four isolates of Gliocladium (Trichoderma) virens, three isolates of Fusarium oxysporum, one of F. lateritium, one of Penicillium tritinum and two of Taralomyces spp. A hundred percent infections occurred in eggs or cysts by three fungal isolates G. virens, F. oxysporum and P. oxalicum, suggesting that these fungi may have a good potential for the PCN biocontrol. Especially, G. virens isolates, which occurred most frequently in the PCN-infested potato fields and are known to be highly adaptable to varying habitats, may be developed as reliable agents for controlling PCN with both egg- and cyst-parasitic capabilities and with high ecological adaptabilities.