• Analytical Science and Technology
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• 제19권5호
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• pp.400-406
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• 2006

Hydrogen analysis by elastic recoil detection has been performed utilizing polyimide film as a reference sample of known hydrogen content assuming the soundness of ion beam current integration. However beam current integration at higher incidence angle is not reliable. Scattering yield per unit fluence by current integration which is normalized per unit path length decreases as the sample tilt angle is getting higher. Moreover because beam current integration at high tilt angle is incomplete, hydrogen evaluation is very risky by direct comparison of sequentially collected recoil spectra between reference and target sample. In this study, primary ion beam dose is determined by backscattering spectrum that is collected simultaneously with recoil spectrum instead of ion beam current integration in order to reduce uncertainty arising in the process of current integration and to enhance the reliability of quantitative analysis. Three test samples are selected $-7.6{\mu}m$ polyimide film, hydrogen implanted silicondioxide and Au deposited carbon wafer- and analyzed by two methods and compared.

• Journal of the Korean Society of Food Science and Nutrition
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• 제30권6호
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• pp.1076-1081
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• 2001

Gamma-irradiated peanuts, Korean and Chinese origins, were investigated on detection properties by thermoluminescence (TL), electron spin resonance (ESR), and DNA comet assay (single cell gel electrophoresis). TL measurement showed that the non-irradiated sample revealed a glow curve with low intensity at about 25$0^{\circ}C$, while the irradiated samples showed higher intensity around at 18$0^{\circ}C$. TL ratio (TL$_1$/TL$_2$) of area for TL$_1$ glow curve to TL$_2$ was below 0.05 for the non-irradiated sample and 0.2 or more for the irradiated ones, thus identifying each other. ESR spectroscopy for the irradiated peanuts using outer skin showed negligible signals induced by irradiation, indicating ESR is little applicable to the detection of irradiated peanuts. In DNA comet assay, the non-sample had no or very short tails, whereas the irradiated samples revealed the cells with long tails. Significance in the increase of their lengths depending on irradiation dose (r=0.761/Korean, r=0.768/Chinese) was also found. There was no remarkable difference in detection properties by origins of samples in all determinations, It is concluded that TL analysis or DNA comet assay is suitable for detection of irradiated peanuts and a combined method is recommendable for enhancing the reliability of detection results.

• The korean journal of orthodontics
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• 제20권1호
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• pp.183-195
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• 1990

The purposes of present study were to identify possible relationships between post-treatment changes and post-retention changes. The patient's models were composed of 58 samples, and were classified non-extraction group (30 samples) and extraction group (28 samples). For each sample the first models were taken prior to the start of treatment, the second models just after the end of treatment, and the third models two years after. The results were as follows: 1. In the cases of non-extraction group, increases were in intermolar width of maxilla, interbicuspid width of maxilla and arch perimeter of mandible during treatment period, but decreases were in the same measurements during post-retention period. 2. In the cases of extraction group, decreases were in intermolar width of mandible, interbicuspid widths of maxilla and mandible, arch length of mandible, arch perimeters of maxilla and mandible during treatment period. 3. Significant decreases were in the irregularity index of both extraction and non-extraction group during treatment period. 4. There were significant differences of arch dimensional changes in intermolar widths of maxilla and mandible, interbicuspid widths of maxilla and mandible, arch lengths of maxilla and mandible, arch perimeters of maxilla and mandible between non-extraction and extraction group.

• Journal of Korean Society of Forest Science
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• 제96권2호
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• pp.197-202
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• 2007

This study is conducted to investigate the factors affecting lumber conversion rate of sawmill industry in South Korea. Data were obtained from the survey of 38 sawmills in all geographic regions of South Korea. The variables examined in this study were region, softwood/hardwood log, domestic/imported/both log, the number of power-driven carriages (PDC) installed, the year when and country where PDCs was manufactured, the horse power of PDC, the number of labors required to operate each PDC, the sawing capacity of mill (mill size), and the types of major product and by-products. The lumber recovery factor (LRF) of sawmills were significantly influenced by the origin of logs, level of PDC automation, sawmill size, and size of logs (measured in diameter and length) while not by the location of the mill, types of major product and by-product, log species, and characteristics of PDC. Although these results provide useful information for understanding the technological characteristics of the Korean sawmill industry, further investigation with larger sample is necessary to reveal the more reliable characteristics of sawmill industry in South Korea.

• The Research Journal of the Costume Culture
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• 제5권3호
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• pp.159-175
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• 1997

The purpose of the study is to analyze the pattern of human developmental growth with empirical anthropometric data for the establishment of the sizing system of junior high school student\`s uniforms. The sample size was 881 boys and 762 girls between age 12 and 14. An anthropometric database used for this study was the 1992 national anthropometric survey of Korea. The result obtained are as follows ; 1. Several items of anthropometric data on junior high school students students showed significant differences in accordance with age and sex. In the meantime, there was no difference on the item of height under the age of 12 between sex, however, significant difference on that age of 13 or over. The hip girth was the biggest growth rate among tyhe item of girth. The somatotype of boys is straight, while girls\` shows a curved line. The bodytype of girls shows slim waist, fat belly and hip girth. 2. The result of factor analysis indicated that the first factor was composed with girth, depth and width-measures, and the second factor of height, length-measures. The third factors were consisted of items of representing bodytype of trunk, and the fourth, bodytype of lower part of trunk. 3. The result of cluster analysis indicated that boys were sybdivided into 3 types and girls 4 types.

• Anatomy and Cell Biology
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• 제55권2호
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• pp.142-147
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• 2022

The frontal sinus is one of the four paranasal sinuses in humans, and knowledge of its anatomy is important when performing surgery involving the frontal bone or sinus. Although many studies have measured the frontal sinus using radiography and computed tomography (CT), few studies have evaluated by using three-dimensional (3D) analysis. The purpose of this study was to analyze the frontal sinus using 3D reconstruction analysis and determine the differences in linear and volumetric measurements between sexes, sides, and ages. The sample comprised 281 facial CT scans: 173 and 108 from males and females, respectively. The width, height, and length of each frontal sinus and total volume were all larger in males than in females. Almost all linear and volumetric measurements were larger in young adults than in older for both sexes, but not all of the differences were statistically significant. Linear and volumetric measurements were larger for males than females regardless of age group. There were no statistically significant differences between the right and left sides except the width in males. The size of the frontal sinus was strongly influenced by sex and age. The measurements reported here might be useful for improving surgical procedures involving the frontal sinus.

• The Journal of Asian Finance, Economics and Business
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• 제7권11호
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• pp.1105-1111
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• 2020

The study aims to investigates and explore the quality of work life (QWL) and also to find out which QWL factors are considered as primary factors among employees of PT. Duta Transformasi Insani, a consulting service management in Indonesia. The factors of QWL in this study consist of nine components, which are: work environment, organizational culture and climate, relation and cooperation, training and development, reward and compensation, facilities, job satisfaction and job security, work autonomy, and resource adequacy. This study conducted a survey of every employee who works for PT. Duta Insani, which consists of various sample characteristics, such as gender, education level, and length of employment. The descriptive analysis also analyzes how the QWL condition in this company. The method in this research using quantitative descriptive and factor analysis, together with validity and reliability tests, to fulfill the study objectives. The results showed that most dimensions of employees' QWL are within a valid category, with an 80 percent average of this variable. Furthermore, the results also indicate there are two major factors constituting the quality of work life of the employees of PT. Duta Transformasi, which are supportive organizational culture, accounting for 47.75 percent, and organizational facilities, accounting for 13.03 percent.

• Journal of Korean Society of Forest Science
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• 제98권5호
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• pp.576-583
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• 2009

Based on the stem analysis and biomass measurement of 36 trees and 1,576 branches in Pinus sylvestris var. mongolica (Mongolian pine) plantations of Northeast China, this study was conducted to develop estimation model equation for leaf biomass of a single tree and branch, to examine the vertical distribution of leaf biomass in the crown, and to evaluate the proportional ratios of biomass by tree parts, stem, branch, and leaf. The results indicated that DBH and crown length were quite appropriate to estimate leaf biomass. The biomass of single branch was highly correlated with branch collar diameter and relative height of branch in the crown, but not much with stand density, site quality, and tree height. Weibull distribution function would have been appropriate to express vertical distribution of leaf biomass. The shape parameters from 29 sample trees out of 36 were less than 3.6, indicating that vertical distribution of leaf biomass in the crown was displayed by bell-shaped curve, a little inclined toward positive side. Apparent correlationship was obtained between leaf biomass and branch biomass having resulted in linear function equation. The stem biomass occupied around 80% and branch and leaf made up about 20% of total biomass in a single tree. As the level of tree class was increased from class I to class V, the proportion of the stem biomass to total biomass was gradually increased, but that of branch and leaf became decreased.

• Bulletin of the Korean Chemical Society
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• 제31권10호
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• pp.2791-2796
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• 2010

In the present study, we constructed a membrane inlet assembly for selective permeation of volatile airborne organic compounds for subsequent analysis by time-of-flight mass spectrometry. The time-dependent diffusion of analytes through a $75\;{\mu}m$ thick polydimethylsiloxane membrane was measured by monitoring the ion signal after a step change in the sample concentration. The results fit well to a non-steady-state permeation equation. The diffusion coefficient, response time, and sensitivity were determined experimentally for a range of polar (halogenated) and nonpolar (aromatic) compounds. We found that the response times for several volatile organic compounds were greatly influenced by the alkyl chain length as well as the size of the substituted halogen atoms. The detection limits for benzene, ethylbenzene, and 2-propanol were 0.2 ppm, 0.1 ppm, and 3.0 ppm by volume, respectively, with a linear dynamic range greater than three orders of magnitude. These results indicate that the membrane inlet/time-of-flight mass spectrometry technique will be useful for a wide range of applications, particularly for in situ environmental monitoring.

• Korean Journal of Materials Research
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• 제30권8호
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• pp.399-405
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• 2020

In the present investigation we show the effect of Al doping on the length, size, shape, morphology, and sensing property of ZnO nanorods. Effect of Al doping ultimately leads to tuning of electrical and optical properties of ZnO nanorods. Undoped and Al-doped well aligned ZnO nanorods are grown on sputtered ZnO/SiO₂/Si (100) pre-grown seed layer substrates by hydrothermal method. The molar ratio of dopant (aluminium nitrate) in the solution, [Al/Zn], is varied from 0.1 % to 3 %. To extract structural and microstructural information we employ field emission scanning electron microscopy and X-ray diffraction techniques. The prepared ZnO nanorods show preferred orientation of ZnO <0001> and are well aligned vertically. The effects of Al doping on the electrical and optical properties are observed by Hall measurement and photoluminescence spectroscopy, respectively, at room temperature. We observe that the diameter and resistivity of the nanorods reach their lowest levels, the carrier concentration becomes high, and emission peak tends to approach the band edge emission of ZnO around 0.5% of Al doping. Sensing behavior of the grown ZnO nanorod samples is tested for H₂ gas. The 0.5 mol% Al-doped sample shows highest sensitivity values of ~ 60 % at 250 ℃ and ~ 50 % at 220 ℃.