• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.6 no.4
• /
• pp.307-327
• /
• 2008

Geochemical study on the rocks and minerals of the Gyeongju low and intermediate level waste repository was carried out in order to provide geochemical data for the safety assessment and geochemical modeling. Polarized microscopy, X-ray diffraction method, chemical analysis for the major and trace elements, scanning electron microscopy(SEM), and stable isotope analysis were applied. Fracture zones are locally developed with various degrees of alteration in the study area. The study area is mainly composed of granodiorite and diorite and their relation is gradational in the field. However, they could be easily distinguished by their chemical property. The granodiorite showed higher $SiO_2$ content and lower MgO and $Fe_2O_3$ contents than the diorite. Variation trends of the major elements of the granodiorite and diorite were plotted on the same line according to the increase of $SiO_2$ content suggesting that they were differentiated from the same magma. Spatial distribution of the various elements showed that the diorite region had lower $SiO_2,\;Al_2O_3,\;Na_2O\;and\;K_2O$ contents, and higher CaO, $Fe_2O_3$ contents than the granodiorite region. Especially, because the differences in the CaO and $Na_2O$ distribution were most distinct and their trends were reciprocal, the chemical variation of the plagioclase of the granitic rocks was the main parameter of the chemical variation of the host rocks in the study area. Identified fracture-filling minerals from the drill core were montmorillonite, zeolite minerals, chlorite, illite, calcite and pyrite. Especially pyrite and laumontite, which are known as indicating minerals of hydrothermal alteration, were widely distributed in the study area indicating that the study area was affected by mineralization and/or hydrothermal alteration. Sulfur isotope analysis for the pyrite and oxygen-hydrogen stable isotope analysis for the clay minerals indicated that they were originated from the magma. Therefore, it is considered that the fracture-filling minerals from the study area were affected by the hydrothermal solution as well as the simply water-rock interaction.

• Horticultural Science & Technology
• /
• v.33 no.1
• /
• pp.93-105
• /
• 2015

This study was performed to analyze genetic relationships of the four major cucurbitaceous crops including watermelon, melon, cucumber, and squash/pumpkin. Among 120 EST-SSR primer sets selected from the International Cucurbit Genomics Initiative (ICuGI) database, PCR was successful for 51 (49.17%) primer sets and 49 (40.8%) primer sets showed polymorphisms among eight Cucurbitaceae accessions. A total of 382 allele-specific PCR bands were produced by 49 EST-SSR primers from 24 Cucurbitaceae accessions and used for analysis of pairwise similarity and dendrogram construction. Assessment of the genetic relationships resulted in similarity indexes ranging from 0.01 to 0.85. In the dendrogram, 24 Cucurbitaceae accessions were classified into two major groups (Clade I and II) and 8 subgroups. Clade I comprised two subgroups, Clade I-1 for watermelon accessions [I-1a and I-1b-2: three wild-type watermelons (Citrullus lanatus var. citroides Mats. & Nakai), I-1b-1: six watermelon cultivars (Citrullus lanatus var. vulgaris S chrad.)] a nd C lade I -2 for melon and cucumber accessions [I-2a-1 : 4 melon cultivars(Cucumis melo var. cantalupensis Naudin.), I-2a-2: oriental melon cultivars (Cucumis melo var. conomon Makino.), and I-2b: five cucumber cultivars (Cucumis sativus L.)]. Squash and pumpkin accessions composed Clade II {II-1: two squash/ pumpkin cultivars [Cucurbita moschata (Duch. ex Lam.)/Duch. & Poir. and Cucurbita maxima Duch.] and II-2: two squash/pumpkin cultivars, Cucurbita pepo L./Cucurbita ficifolia Bouche.}. These results were in accordance with previously reported classification of Cucurbitaceae species, indicating that watermelon EST-SSRs show a high level of marker transferability and should be useful for genetic study in other cucurbit crops.

• Analytical Science and Technology
• /
• v.36 no.6
• /
• pp.300-314
• /
• 2023

The quality of the products was investigated by analyzing fluorine content, pH, preservatives and tar colors in 31 dentifrice products (6 items for children) and 15 mouthwash products (2 items for children) marketed. It was intended to provide correct information to consumers by checking whether the standards and product indications match. As a result of measuring the fluoride concentration, 26 dentifrice and 15 mouthwash products contained from 48 to 1,472 ppm and from 85 to 225 ppm, respectively. Fluorine detection rates of dentifrice and mouthwash products were 83.9 and 83.3 %, respectively showing similar levels. Of the 41 fluoride-detected dentifrice and mouthwash products, 40 were 90.7~109.8 % of the displayed amount and suitable for the fluorine content standard of 90.0 to 110.0 %, but one dentifrice was found to be inappropriate at 36.3 % of the content indicated on the product. The pH of the dentifrice was 5.1~9.4, and the mouthwash was 4.2~6.2, which met all standards. As a result of simultaneous analysis of the concentration of six preservatives, benzoic acid was detected the most in 15 cases with a 30.6 % detection rate, sorbic acid was detected in 9 cases (detection rate of 18.4 %), and all four types of methyl p-hydroxybenzoate, ethyl p-hydroxybenzoate, propyl p-hydroxybenzoate, butyl p-hydroxybenzoate were not detected. As a result of analyzing the concentration of 10 types of tar colors, six types including red40, yellow4, yellow5, yellow203, green3, and blue1 were detected in a total of 9 cases (2 dentifrices and 7 mouthwashes) with blue1 being the most frequently detected. Detected fluorine concentration, added preservatives and tar colors were consistent with the product markings and it was well written on product packaging. The detected preservatives and tar colors were at a safe level due to low risk compared to Acceptable Daily Intake.

• Journal of radiological science and technology
• /
• v.32 no.4
• /
• pp.401-410
• /
• 2009

Purpose : Pelvis and lumbar spine radiography, among various types of diagnostic radiography, include gonads of the human body and give patients high radiation dose. Nevertheless, diagnostic reference levels for patient radiation dose in pelvis and lumbar spine radiography has not yet been established in Korea. Therefore, the radiation dose that patients receive from pelvis and lumbar radiography is measured and the diagnostic reference level on patient radiation dose for the optimization of radiation protection of patients in pelvis and lumbar spine radiography was established. Methods : The conditions and diagnostic imaging information acquired during the time of the postero-anterior view of the pelvis and the postero-anterior and lateral view of the lumbar spine at 125 medical institutions throughout Korea are collected for analysis and the entrance surface dose received by patients is measured using a glass dosimeter. The diagnostic reference levels for patient radiation dose in pelvis and lumbar spine radiography to be recommended to the medical institutes is arranged by establishing the dose from the patient radiation dose that corresponds to the 3rd quartile values as the appropriate diagnostic reference level for patient radiation dose. Results : According to the results of the assessment of diagnostic imaging information acquired from pelvis and lumbar spine radiography and the measurement of patient entrance surface dose taken at the 125 medical institutes throughout Korea, the tube voltage ranged between 60~97 kVp, with the average use being 75 kVp, and the tube current ranged between 8~123 mAs, with the average use being 30 mAs. In the posteroanterior and lateral views of lumbar spine radiography, the tube voltage of each view ranged between 65~100 kVp (average use: 78 kVp) and 70~109 kVp (average use: 87 kVp), respectively, and the tube current of each view ranged between 10~100 mAs(average use: 35 mAs) and between 8.9~300 mAs(average use: 64 mAs), respectively. The measurements of entrance surface dose that patients receive during the pelvis and lumbar spine radiography show the following results: in the posteroanterior view of pelvis radiography, the minimum value is 0.59 mGy, the maximum value is 12.69 mGy and the average value is 2.88 mGy with the 1st quartile value being 1.91 mGy, the median being 0.59 mGy, and the 3rd quartile value being 3.43 mGy. Also, in the posteroanterior view of lumbar spine radiography, the minimum value is 0.64 mGy, the maximum value is 23.84 mGy, and the average value is 3.68 mGy with the 1st quartile value being 2.41 mGy, the median being 3.40 mGy, and the 3rd quartile value being 4.08 mGy. In the lateral view of lumbar spine radiography, the minimum value is 1.90 mGy, the maximum value is 45.42 mGy, and the average value is 10.08 mGy with the 1st quartile value being 6.03 mGy, the median being 9.09 mGy and the 3rd quartile value being 12.65 mGy. Conclusions : The diagnostic reference levels for patient radiation dose to be recommended to the medical institutes in Korea is 3.42 mGy for the posteroanterior view of pelvis radiography, 4.08 mGy for the posteroanterior view of lumbar spine radiography, and 12.65 mGy for the lateral view of lumbar spine radiography. Such values are all lower than the values recommended by 6 international organizations including World Health Organization, where the recommended values are 10 mGy for the posteroanterior view of pelvis radiography, 10 mGy for the posteroanterior view of lumbar spine radiography and 30 mGy for the lateral view of lumbar spine radiography.