• Title/Summary/Keyword: Natural radiation dose rate

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The radioprotective effects of Bu-Zhong-Yi-Qi-Tang and its major ingredients in irradiated mice (방사선 피폭 마우스에서 보중익기탕 및 구성단미의 효과)

  • Kim, Sung-ho;Oh, Heon;Kim, Se-ra;Jo, Sung-kee;Byun, Myung-woo;Shin, Dong-ho
    • Korean Journal of Veterinary Research
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    • v.40 no.2
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    • pp.221-228
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    • 2000
  • We performed this study to determine the effect of Bu-Zhong-Yi-Qi-Tang, as a prescription of traditional Oriental medicine, and its major ingredients on jejunal crypt survival, endogenous spleen colony formation, apopotosis in jejunal crypt cells, lethality and hematological change of mice irradiated with high and low dose of Y-radiation. Bu-Zhong-Yi-Qi-Tang administration before irradiation protected the jejunal crypts (p<0.0001), increased the formation of endogenous spleen colony (p<0.05) and reduced the frequency of radiation-induced apoptosis (p<0.05). The survival rate and mean survival time of the groups treated with Bu-Zhong-Yi-Qi-Tang within 30 days after the treatment were far better than the irradiation control group. In the experiment on the effect of ingredients of Bu-Zhong-Yi-Qi-Tang, the result indicated that the extract of Rensan (Panax ginseng), Danggui (Angelica sinensis), Shengma (Cimicifuga heracleifolia) and Chaihu (Bupleurum falcatnosa) might have a major radioprotective effect. Although the mechanisms of this inhibitory effect remain to be elucidated, these results indicated that BU-Zhong-Yi-Qi-Tang might be a useful radioprotector, especially since it is a relatively nontoxic natural product. Further studies are needed to characterize better the protective nature of Bu-Zhong-Yi-Qi-Tang extract and its ingredients.

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Distribution of natural radioactivity in soil and date palm-pits using high purity germanium radiation detectors and LB-alpha/beta gas-flow counter in Saudi Arabia

  • Shayeb, Mohammad Abu;Baloch, Muzahir Ali
    • Nuclear Engineering and Technology
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    • v.52 no.6
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    • pp.1282-1288
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    • 2020
  • In the first study, the Radon emanation and radiological hazards associated with radionuclides in soil samples, collected from 9 various date palm farms located in 3 different districts in Saudi Arabia were determined through a high purity Germanium (HPGe) gamma-ray spectrometer. The estimated average values of Radon emanation coefficient and Radon mass exhalation rate for soil samples were 0.535 ± 0.016 and 50.063 ± 7.901 mBqkg-1h-1, respectively. The annual effective dose of radionuclides in all sampling locations was found to be lower than UNSCEAR's recommended level of 0.07 mSvy-1 for soil in an outdoor environment. In the secondary study, gross α and gross β activities in soil and date palm pits samples were measured by a low background α/β counting system. Average values of gross α and gross β activities in soil and date palm pits samples were 5.761 ± 0.360 Bqkg-1, 38.219 ± 8.619 Bqkg-1 and 0.556 ± 0.142 Bqkg-1, 24.266 ± 1.711 Bqkg-1, respectively.

Dosimetry of $^{222}Rn$ Component in Outdoor Natural Background Radiation (자연 방사선량 중 $^{222}Rn$기여 성분 정량 해석)

  • Jun, Jae-Shik;Oh, Hi-Peel;Chae, Ha-Suk;Lee, Byung-Young;Kim, Do-Sung
    • Journal of Radiation Protection and Research
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    • v.14 no.2
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    • pp.10-17
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    • 1989
  • A study for the assessment of dose given by outdoor radon to respiratory system has been carried out by making use of radon-cups containing CR-39 plastic track detectors. Detection efficiencies were determined by irradiation of the radon-cups in a standard radon chamber of known concentration. Thus determined detection factors of CR-39 plastic track detector in bare, open cup and filtered cup geometry are found to be 0.273, 0.0813 and 0.0371 $trmm^{-2}$/(37$Bqm^{-3}{\cdot}d$), respectively, which are chemically etched in 30% NaOH solution of $70^{\circ}C$ for 220 minutes. The outdoor radon concentrations measured at Taejeon(Chungnam National University) from May 1988 to March 1989 are in the range of 27.4 - 135.8 Bq/$m^3$(0.74 - 3.67pCi/l)by open cup and 16.7 - 143.9 Bq/$m^3$(0.45 - 3.89 pCi/l) by filtered cup, which yield overall annual average value of outdoor radon concentration of $70.8Bq/m^3$(1.91 pCi/l). Corresponding effective dose equivalent rate to respiratory system of ICRP standard man is assessed to be 520 nSv /h.

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Thermoluminescence Dating of Pottery Shards by Subtraction Method (Subtraction 방법을 이용한 TL 연대측정법에 의한 토기 시편의 절대연대 결정)

  • Shin, Hyun-Sang;Lee, Chang-Woo;Nam, Young-Mee;Jee, Kwang-Yong;Park, Byung-Bin
    • Analytical Science and Technology
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    • v.13 no.4
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    • pp.403-411
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    • 2000
  • This study described a method of thermoluminescence dating of pottery shards using subtraction method. TL measurement was achieved using two different types of samples prepared by quartz inclusion method and fine-grain technique. Fine grains (size range: $5-10{\mu}m$) were separated by suspending grounded pottery samples into acetone solution and sedimentation quantitatively. In quartz inclusion method quartz grains in the size range of 90 to $125{\mu}m$ diameter were obtained by extracting the quartz crystals embed in the pottery shards and etching them with 1.0 M HF solutions. The archaeological dose of both the quartz and fine grains was determined from the dose calibration curves obtained from sequential irradiation of $^{137}Cs$ gamma and $^{241}Am$ alpha source to the samples and TL measurement of natural samples, in which the alpha dose of 4.60 Gy for the Packjae pottery was obtained using subtraction method. Annual alpha dose rates ($3.05{\pm}0.11$ mGy/yr.) were determined by the analysis of U, Th contents in the pottery shards and evaluation of the values with Bell's equation. Dividing the alpha dose accumulated in the pottery shards by the annual alpha dose rate, we found age of approximately $1508{\pm}80$ years B.P. (AD. ca. 492 yr.) for the Packjae pottery. It matches well with the archeological age estimate (middle of 5th century) within 10 percent uncertainty and thereby conforms the age of the pottery sample.

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Evaluation of the formation and occupation of Gosan-ri archaeological site in Jeju Island using OSL dating (OSL 연대측정을 통한 제주 고산리 유적의 형성과 점유시기 결정)

  • Kim, Myung-Jin
    • Analytical Science and Technology
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    • v.29 no.6
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    • pp.269-276
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    • 2016
  • Gosan-ri site is known as the early Neolithic cultural heritage, in which an archaic plainware, called as the Gosan-ri-type pottery, was excavated regarding as the first pottery manufactured in Korea. In this study, OSL dating was carried out to five soil layer samples collected in stratigraphic cross-section for evaluating the formation and occupation of the Gosan-ri site. Paleodose of each soil sample was calculated using the single aliquot regenerative dose (SAR) method with preheat of $220^{\circ}C$ and finally determined using maximum age model, considering its deposition process. The OSL age was determined from the ratio of paleodose to annual dose rate. From the resultant OSL ages and the related 14C dates, it was concluded that the Gosan-ri site was formed after 9,000 BC and a variety of cultural feature including the Gosan-ri-type pottery were occupied ranging from the early Neolithic to the middle of 4,000 BC. Finally, the Gosan-ri site was discarded in the middle of 4,000 BC and has been arrived at present through natural deposits.

Effect of Rudbeckia laciniata Extract on Physiological Activity of HaCaT Cells (삼잎국화 추출물의 피부세포 생리활성 효과)

  • Kim, Jun-Sub
    • The Korean Journal of Food And Nutrition
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    • v.29 no.3
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    • pp.335-340
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    • 2016
  • The objective of the present investigation was to obtain vitamin, mineral, flavonoid, and polyphenol profiles of Rudbeckia laciniata (RL), and to examine the effects of extract of RL (RLE) on various physiological activities of HaCaT keratinocyte for the utilization of RL as natural raw materials to develop functional food. To accomplish this purpose, we checked the contents of the general nutrients of RL. The contents of vitamin A, vitamin $B_1$ and vitamin $B_2$ were $7.49{\mu}g/g$, $51.96{\mu}g/g$, and $132{\mu}g/g$ respectively, while vitamin C and vitamin $D_3$ were not detected. The contents of mineral such as Ca, K and Fe were 2.01 mg/g, 6.06 mg/g and 0.03 mg/g respectively. Total flavonoid contents of RLE were 0.25 mg/g, and total polyphenol were estimated as 1.43 mg/g. Because RL contains high levels of vitamin A which is associated with skin aging, we investigated the effect of RLE on physiological function of keratinocytes with respect to skin aging. We found that RLE significantly increased the growth rate of HaCaT cells and reduced ultraviolet radiation B (UVB)-induced cellular toxicity. Also, the extract of Rudbeckia laciniata attenuated the UVB-induced reactive oxygen species (ROS) generation in a dose-dependent manner in HaCaT cells. In addition, treatment with the extract dose-dependently increased migration activity of HaCaT cells. Thus, these findings indicated that RLE could regulate the physiological activity of keratinocytes, and may be used to develop functional foods.

Batch Scale Storage of Sprouting Foods by Irradiation Combined with Natural Low Temperature - I. Storage of Potatoes - (방사선(放射線) 조사(照射)와 자연저온(自然低溫)에 의한 발아식품(發芽食品)의 Batch Scale 저장(貯藏)에 관(關)한 연구(硏究) - 제(第) 1 보(報) : 감자의 저장(貯藏) -)

  • Cho, Han-Ok;Byun, Myung-Woo;Kwon, Joong-Ho;Yang, Ho-Sook;Lee, Chul-Ho
    • Korean Journal of Food Science and Technology
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    • v.14 no.4
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    • pp.355-363
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    • 1982
  • In order to develop the commercial storage method of potatoes by irradiation combined with natural low temperature, storage room($450{\times}650{\times}250cm$; year round temperature change, $2-17^{\circ}C;\;70-85%\;R.H.$) on a batch scale followed by irradiation with optimum dose level. Irish cobbler and Shimabara were 100% sprouted after 3 months storage in control, whereas in 15 Krad irradiated group, sprouting was completely inhibited at Irish cobbler for 9 months storage, and at Shimabara for 12 months. The extent of loss due to rot attack after 9 months storage was 6% in control, 6-8% in 10-15 Krad irradiated group at Irish cobbler and weight loss was 16.5% in control, 5.1-5.6% in irradiated group, whereas rotting rate of Shimabara after 12 months storage was 100% in control, 15% in irradiated group and the weight loss of its was 12.6% in control, $7.3{\sim}7.4%$ in irradiated group. The moisture content in whole storage period of two varieties were $72{\sim}82%$ without remarkable changes. The total sugar and ascorbic acid contents were slightly decreased according to the dose increase and elapse of storage period, whereas reducing sugar content was increased. Irish cobbler was 90% marketable after 9 months storage and 85% in Shimabara after 12 months storage.

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Method for Evaluating Radionuclide Transport in Biosphere by Calculating Elapsed Transport Time (이동 경과 시간 계산을 이용한 생물권에서의 방사성 핵종 이동 평가 방법)

  • Ko, Nak-Youl;Ji, Sung-Hoon
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.18 no.2_spc
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    • pp.305-315
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    • 2020
  • For geological disposal of radioactive wastes, a method was proposed to evaluate the radionuclide transport in the biosphere by calculating the elapsed time of nuclide migration. The radionuclides were supposed to be introduced from a natural barrier and reached a large surface water body following a groundwater flow in a shallow subsurface. The biosphere was defined as a shallow subsurface environment that included aquifers on a host rock. Using the proposed method, a calculation algorithm was established, and a computer code that implemented the algorithm was developed. The developed code was verified by comparing the simulation results of the simple cases with the results of the analytical solution and a public program, which has been widely used to evaluate the radiation dose using the radionuclide transport near the surface. A case study was constructed using the previous research for radionuclide transport from the hypothetical geological disposal repository. In the case study, the code calculated the mass discharge rate of radionuclide to a stream in the biosphere. Because the previous research only demonstrated the transport of radionuclides from the hypothetical repository to the host rock, the developed code in the present study could help identify the total transport of radionuclide along the complete pathway.