• Title/Summary/Keyword: $^{232}Th$

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An Analysis of Elementary Students' Understanding of Number Line: Focused on Concept of Fractions and Addition and Subtraction of Fractions (초등학교 4학년 학생들의 수직선 이해 분석: 분수 개념 및 분수의 덧셈과 뺄셈을 중심으로)

  • Kim, Jeongwon
    • Education of Primary School Mathematics
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    • v.25 no.3
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    • pp.213-232
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    • 2022
  • With the importance of number line in learning fractions, this study investigated how 4th grade students understand fractions and its operations in number line. The questionnaire consisted 22 items which were related to representing fractions, comparing the size of fractions, and operating addition and subtraction of fractions. Both structured number line and sub-structured number line were presented in the items. As results of the study, the overall success rates were not high and even some items showed higher incorrect answer rates than the success rates. Also, the students showed a difficulty in solving non-structured number line tasks. It was also noticeable that students showed several types of incorrect answers, which means that students had incomplete understanding of both fractions and number line. This paper is expected to shed light on elementary students' understanding of fractions and number line and to provide implications of how to deal with number line in teaching and learning fractions in the elementary school.

Establishing a pre-mining baseline of natural radionuclides distribution and radiation hazard for the Bled El-Hadba sedimentary phosphate deposits (North-Eastern Algeria)

  • S. Benarous;A. Azbouche;B. Boumehdi;S. Chegrouche;N. Atamna;R. Khelifi
    • Nuclear Engineering and Technology
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    • v.54 no.11
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    • pp.4253-4264
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    • 2022
  • Since the implementation of the phosphate project in Bled El-Hadba (BEH) deposit, western region of Tébessa, no detailed study has been conducted to assess the natural radioactivity distribution and the associated radiological risk parameter for this open-pit mine. For the sake of determining a credible premining reference database for the region of interest, 21 samples were collected from different geological layers of the above-mentioned deposit. Gamma Spectrometry was applied for measuring radioactivity using a high resolution HPGe semiconductor detector. The obtained activity results have shown a significant broad variation in the radioactive contents for the different phosphate samples. The total average concentrations (in Bq·kg-1) for 226Ra, 238U, 235U, 232Th and 40K computed for the different type of phosphate layers were found to be 570 ± 169, 788 ± 280, 52 ± 18, 66 ± 6 and 81 ± 18 respectively. The mean activity concentrations of the measured radionuclides were compared to other regional and worldwide deposits. The ratios between the detected radioisotopes have been calculated for spatial distribution of natural radionuclides in the study area. Based on the aforementioned activity concentrations, the corresponding radiation hazard parameters were assessed. Correlations between the obtained parameters were drawn and a multivariate statistical analysis (Pearson Correlation, Cluster and Factor analysis) was carried out in order to identify the existing relationships.

A CLINICAL ANALYSIS OF BENIGN ODONTOGENIC TUMOR (양성 치성종양의 임상적 분석)

  • Lee, Tae-Hee;Kim, Chin-Soo
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.22 no.2
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    • pp.217-232
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    • 2000
  • The author studied on the 128 cases of benign odontogenic tumors which had been diagnosed with biopsy during the period of Jan. 1989 to Dec. 1998 at the Kyungpook National University Hospital, Yeungnam University Medical Center, Keimyung University Dongsan Medical Center, and Taegu Catholic Medical Center. This study contained the clinicostatistical analysis of the frequency in relation to sex, age, locations, chief complaints, duration, radiographic findings, recurrence, teeth, and treatment methods. The results were as follow : 1. Of a total of 128 benign odontogenic tumors, ameloblastomas(57 cases; 44.5%) and odontomas (44 cases ; 34.4%) mostly occupied. The other types of lesions were 8 calcifying odontogenic cysts, 7 benign cementoblastomas, 4 myxomas, 3 adenomatoid odontogenic tumors, 2 calcifying epithelial odontogenic tumors, 2 ameloblastic fibro-odontomas, and 1 odontogenic fibroma. 2. In age and sex distribution, benign odontogenic tumors occured slightly more often in males(53.9%) than females(46.1%) and the majority of cases(79.7%) were found during 2nd, 3rd, and 4th decade. 3. There was a predilection for mandibular lesions(mandible-maxilla ratio, 2.6 : 1). 4. The most common chief complaint was swelling(29.7%) and in respect to duration, the cases less than 1 year(50.0%) mainly appeared. 5. There were 7 cases(13.0%) of recurrence on ameloblastoma and there was no recurrence in the others. 6. In Ameloblastoma It commonly occured during 3rd and 4th decade(59.6%) and mean age was 30.2 years. The majority of cases were occurred in mandible(96.5%) , especially mandibular molar and angle area(71.9%). The most common chief complaint was swelling(47.4%) and in respect to duration, the cases less than 1 year(52.6%) mainly appeared. In relation to teeth, there were resorption of root(52.6%), displacement of teeth(31.6%), and in relation to impacted teeth(43.9%). There was higher recurrence rate in the cases by conservative treatment(14.7%) than radical treatment(10.0%). As regards radiographic findings, conservative treatments were prevalent in the cases of unilocular type(85.7%) as compared with multilocular type(48.5%). and there was higherrecurrence rate in the cases of multilocular type(18.2%) than unilocular type(4.8%). As regards the type of treatment in relation to age, conservative treatments were prevalent in patients younger than 20 years of age. 7. In Odontomas It commonly occured during 2nd decade(50.0%) and in maxillary anterior teeth(40.9%). The most common chief complaint was delayed retention and permanent impaction of teeth(72.7%), and most frequently associated with impacted teeth(79.5%).

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Effect of Various Levels of Perilla Seed Powder on the Fermentation of Puchukimchi (부추김치의 발효숙성에 들깨가루 첨가량이 미치는 영향)

  • 장명숙;박문옥
    • Korean journal of food and cookery science
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    • v.14 no.3
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    • pp.232-240
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    • 1998
  • The effect of various levels of perilla seed powder on physicochemical, microbiological, and sensory characteristics of Puchukimchi during fermentation was investigated. Puchukimchi is a kind of korean kimchi made with Leek (Allium odorum L.). In a laboratory model of Puchukimchi made with various levels (0, 1, 2, 3, 5%) of perilla seed powder fermentated at 10$^{\circ}C$ up to 45 days. As a fermentation progressed, the initial high decrease in pH has been retarded in all the treatments, of which the delaying extent was noted from Puchukimchi made with perilla seed powder. The pH dropped with accumulation of total acidity. The total vitamin C content increased sharply at the palatable period of Puchukimchi during initial fermentation and then, especially from the 8th-day, gradually decreased later following sigmoidal changing pattern. And the total vitamin C content was the highest in the Puchukimchi made with 5% perilla seed powder. The lactic acid bacteria count increased remarkably and then decreased gradually after optimum ripening period, i.e., the palatable period of Puchukimchi during fermentation. During the early stage of fermentation, sensory evaluation showed the higher scores on the overall taste of Puchukimchi made with 3, 5% on the 2nd-day, 1, 2% on the 5th-day of fermentation. However, the trend of acceptability has been reversed by the Puchukimchi made with little amount of perilla seed powder, more notably 2% at the later stage of fermentation.

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Evaluation of Growth Characteristics and Feed Value of Korean Native Sweet Sorghum as Forage Crop (사료작물로서 국내 재래종 단수수의 생육 특징 및 사료가치 평가)

  • Hyun-Sik Choi;Ha Guyn Sung
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.43 no.4
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    • pp.232-239
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    • 2023
  • This study was to evaluate the values of Korean native sweet sorghum as a new feed crop for ruminants. Sweet sorghum was the Muan native species (Bioenergy Crop Research Center, National Institute of Crop Science), and cultivated from May to October 2021 at Sangji University (Wonju-si, Gangwon-do, Korea). There were a non-treated group (Con), a recommended amount treatment (RD) and a treatment with double the recommended amount (Double RD) by an oil cake fertilizer. Plant height was measured at weekly intervals for 12 weeks after planting sweet sorghum seedlings, and was a significant difference in the order of Double RD, followed by RD and Con in 7 weeks (p<0.05). Feed values and sugar contents were measured in 7, 9, and 11 weeks. Crude protein of Double RD was higher than that of the other treatments in 7 and 9 weeks (p<0.05). Crude fat was higher at Double RD than the other one in 9 weeks (p<0.05). ADF and NDF of Double RD were higher than the other one (p<0.05). When it was compared to corn and sudangrass hybrids grown on farms, Crude protein was lower in sweet sorghum than other crops (p<0.05), and crude fat was higher in sweet sorghum than corn (p<0.05). Crude fiber, ADF and NDF were higher in sweet sorghum compared to corn and sudangrass (p<0.05). The sugar contents of sweet sorghum were 4.07 ± 0.12~7.63 ± 0.21 brix, and showed higher than corn and sudangrass hybrid (p<0.05). The rumen in situ digestibility of sweet sorghum was 30.73~38.13% at the 9th and 11th weeks, and showed higher than that of corn and sudangrass hybrids (p<0.05). Therefore, it is considered that Korean native sweet sorghum has sufficient value as a new forage crop for ruminants, and good value as yield, nutrients and digestibility, when the grass height is 273.33~332.50 cm.

Preservation of Kimchi by Ionizing Radiation (방사선에 의한 김치저장 연구)

  • 강세식;김중만;변명우
    • Journal of Food Hygiene and Safety
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    • v.3 no.4
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    • pp.225-232
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    • 1988
  • To improve the storage method for Kimchi, optimal ripening Kimchi was irradiated with doses of 1,3,5 kGy Co-GO gamma radiation, followed by the microbiological, physicochemical and sensory evaluations during storage at $5^{\circ}C$. 1. Total aerobic count increased in the beginning of storage and then decreased slowly as the number of total lactobacilli (anaerobe) increased. The above total aerobic and lactobacilli were reduced by 1 to 3 log cycles with irradiation and at the 90th day after storage the number of total lactobacilli remained $1.30{\times}10^{8}\;per\;ml$ in3 kGy irradiated group. Irradiation treatment at 3 kGy sterilized coli forms and molds contaminating the sample as the level of $2.0{\times}10^{4}\;per\;ml\;and\;5.4{\times}10^{2}\;per\;ml$, respectively and no apparent growth was observed in both control and 1 kGy irradiated groups after 20 days of storage. The population.of yeast, $3.5{\times}10^{3}\;per\;ml$ initially, in, creased steadily during Kimchi storage and at 90 days of storage the number was shown to be $5.6{\times}10^{4}\;per\;ml\;and\;6.5{\times}10^{2}\;per\;ml$ in control and 3 kGy irradiated groups, respectively. 2. In the physicochemical changes during Kimchi storage, pH, acidity and volatile acid of non-irradiated control at the 45th day after storage were 4.0,0.7% and 0.066%, while those of 3 kGy irradiated group were 4.2, 0.59 and 0.06% at the 90th day of storage, respectively. The reducing sugar content of all stored samples changed inversely total acidity content, indicating irradiation delayed the changes of them. The amount of aseorbic acid decreased gradually with the storage time and irradiation dose increase. Textural parameters of 3 kGy irradiated group were superior to those of other groups at the latter stage of storage. 3. Sensory evaluations showed that 3 kGy irradiation was the optimum dose level to extend tite shelf-life of Kimchi more than two months as compared to control.

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Variations of Isoflavone Contents in Seeds and Sprouts of Sprout Soybean Cultivars (나물용 콩 품종의 종실 및 콩나물 함유 Isoflavone 변이)

  • Kim, Young-Jin;Oh, Young-Jin;Cho, Sang-Kyun;Kim, Jung-Gon;Park, Myoung-Ryoul;Yun, Song-Joong
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.51 no.spc1
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    • pp.160-165
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    • 2006
  • Biofuctionality of soybean seeds and soy-bean products have been fortified by the uncovering of the multifuctional beneficial effects of isoflavones. As one way to fully utilize beneficial effects of isoflavones in soybean sprout is through the enhancement of isoflavone contents in soybean seeds, genetic selection for higher isoflavone and cultivational measures to increase isoflavone content in soybean seeds were attempted. Isoflavones (daidzein, gemstein) contents in soybean seeds and soybean sprouts were determined by high performance liquid chromatography. Total isoflavone contents in soybean seeds ranged from 756 to $1,682{\mu}g/g$ and Iksan #13 $(1,682{\mu}g/g)$ showed highest content among the 21 germplasms analyzed. Onetime treatment of soybean plants with Antipol or Piaster at the $V_4$ stage yielded seeds with higher isoflavones as $2,472{\mu}g/g\;or\;2,052{\mu}g/g$, respectively, which were higher by 37% and 14% than that of seeds in the control plants, respectively. In Eunhakong, Isoflavone contents of soybean sprout changed during sprouting. Daidzein content in hypocotyl increased to maximum on the third day of cultivation and decreased there-after, whereas the content changed little in cotyledon. In sprouts of Pungsannamulkong, daidzein content in hypocotyl showed a maximum level on the first day and decreased gradually thereafter but, the content changed little in cotyledon. Total isoflavone contents in lateral roots which developed on the 6th day after sprouting ranged from 4,416 to $5,232{\mu}g/g$ DW.

Effects of Change in Patient Position on Radiation Dose to Surrounding Organs During Chest Lateral Radiography with Auto Exposure Control Mode (자동노출제어장치를 적용한 흉부 측면 방사선검사 시 환자 위치 변화가 주변 장기의 선량에 미치는 영향)

  • Seung-Uk Kim;Cheong-Hwan Lim;Young-Cheol Joo;Sin-Young Yu
    • Journal of the Korean Society of Radiology
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    • v.17 no.6
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    • pp.903-909
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    • 2023
  • The purpose of this study is to compare and analyze the effect of changes in the patient's central position on the exposure dose and image quality of surrounding organs during a chest lateral examination using an Auto Exposure Control(AEC). The experiment was conducted on a human body phantom. A needle was attached to the lower part of the center of the coronal plane of the phantom, and a lead ruler was attached to the lower part of the detector so that the 50 cm point was located at the lower center of the AEC ion chamber. The exposure conditions were 125 kVp, 320 mA, the distance between the source and the image receptor was 180 cm, and the exposure field size was 14 × 17 inches. Only one AEC ion chamber was used at the bottom center, and the density was set to '0' and sensitivity to 'Middle', and the central X-ray was incident vertically toward the 6th thoracic vertebra. With AEC mode applied, the 50 cm point of the needle and lead ruler were aligned and the phantom was moved 5 cm toward the stomach (F5) and 5 cm toward the back (B5), and the dose factor was analyzed by measuring ESD. The ESD of the thyroid gland according to the change in patient center position was 232.60±2.20 μGy for Center, 231.22±1.53 μGy for F5, and 184.37±1.19 μGy for B5, and the ESD of the breast was 288.54±3.03 μGy for Center, F5 was 260.97±1.93 μGy, B5 was 229.80±1.62 μGy, and the ESD of the center of the lung was 337.02±3.25 μGy for Center, F5 was 336.09±2.29 μGy, and B5 was 261.76±1.68 μGy. As a result of comparing the average values of dose factors between each group, the difference in average values was statistically significant (p<0.01), and each group appeared to be independent. As a result of the study, there was no significant difference in the dose to the thyroid, breast, and center of the lung according to the change in the patient's central position, except for the breast (10%) when the patient moved forward about 5 cm. However, movement of about 5 cm posteriorly resulted in an average dose reduction of 23.7%. Additionally, when the patient's central position was moved to the rear, image quality deteriorated.

Evaluation of Indoor Radon Levels in a Hospital Underground Space and Internal Exposure (의료기관 지하시설의 라돈가스 측정과 내부피폭 조사)

  • Song, Jea-Ho;Jin, Gye-Hwan
    • Journal of the Korean Society of Radiology
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    • v.5 no.5
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    • pp.231-235
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    • 2011
  • Radium is rock or soil of crust or uranium of building materials and thorium after radioactivity collapse process are created colorless and odorless inert gas that accrue well in sealed space like mine or basement. It inflow to lung circulate respiratory organ and caused lung cancer because of deposition of lung or bronchial tubes. Radium sheath of medical institution treat person's life is possible big danger to professional regarding radioactivity who has much amount exposed radioactivity and weaker immune patient. so we do this test. Using measuring instrument at test is real time radium measuring instrument, Professional Continuous Radon monitor, and measuring places are basement first floor and second floor of two hospitals and measure from 10 a.m to 3 p.m. Measurement result of Professional Continuous Radon monitor is minimum 14.8 Bq/$m^3$ to maximum 70.3 Bq/$m^3$ and show domestic baseline below 148 Bq/$m^3$, effective dose-rate is minimum 0.296 mSv to maximum 1.406 mSv that show 2.4 mSv, 10~58.3% level, exposed radiation amount from nature radiation one year.

Korean adolescents' weight control behaviors by BMI(Body Mass Index) and body shape perception-Korea Youth Risk Behavior web-based Survey from 2010 (BMI와 주관적 체형인지에 따른 한국 청소년의 체중조절행동-제6차(2010) 청소년건강행태 온라인 조사를 중심으로)

  • Lee, Ye-Jong;Lee, Sook-Jeong;Kim, Chang-Gyu
    • Journal of Digital Convergence
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    • v.10 no.3
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    • pp.227-232
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    • 2012
  • The purpose of this research is to analyzed the Korean adolescents' weight control behaviors by BMI(Body Mass Index) and body shape perception. The data of this study abtained 73,238 adolescents, aged 12-18years from the '2010 6th Korea Youth Risk Behavior web-based Survey. The data were analyzed by frequency, percentile, chi-square test, Binominal Logistic Regression analysis. The results of this research were as following. First, the answer to question about adolescents' body shape perception is high in "normal" and "a little fat", but the result of BMI show that the most of them are in "underweight". Second, the female students tends to perceive themselves obese than male students do. Third, the female student try to lose weight but male student try to gain weight. Also the higher BMI is, the more the student have tendency to try to lose their weight. In conclusion, BSP leds directly weight control behavior, so in order to reduce unnecessary weight loss or improper methods weight control behavior. It is important to educate the students to have a sound perception about body shape.