• Title/Summary/Keyword: field coefficient

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Adsorption of Trace Metals on the Natural Amorphous Iron Oxyhydroxide from the Taebag Coal Mine Area (태백 탄전 지대의 비정질 철 수산화물에 대한 희귀원소의 흡착)

  • Yu, Jae-Young;Park, In-Kyu
    • Journal of the Korean Society of Groundwater Environment
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    • v.1 no.1
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    • pp.23-32
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    • 1994
  • To determine the apparent equilibrium constants, K$_{ad,app}$, for the adsorption reactions of trace metals on amorphous iron oxyhydroxide (AIO) in the Taebag coal mine area, time-adsorption and pH-adsorption experiments were performed for a selected bottom sediment mainly comprised of AIO from the study area. The results from the adsorption experiments indicate that most of the trace metals, except Pb, achieve equilibrium states with AIO and thus, the calculated K$_{ad,app}$ may represent the true apparent equilibrium constants. K$_{ad,app}$ and the stoichiometric coefficients of proton, x, of the adsorption reactions between the trace metals and AIO were respectively calculated from the intercepts and slopes of the regression lines of log($\Gamma$/ [M]$_{aq}$)against pH provided by pH-adsorption experiments. The calculated K$_{ad,app}$ this study has the values of the range from 10$^{-4.5}$ to 10$^{2.75}$ , which is much different from the reported values by other investigators for simple experimental systems. K$_{ad,app}$ of this study is more or less close but not exactly pertinent to the estimated values for the other natural systems. It indicates that K$_{ad,app}$ for the adsorption reactions in the aquatic system in the study area is unique and thus should be determined befor the adsorption modelling. The calculated x of this study has the values of the range from -0.3 to 0.7, which is also much different from what most geochemists generally accept. The discrepancy in x may be due to the competition among different kinds of ionic species on the adsorption site or simulataneous occurrence of different kinds of adsorption reactions. The results from this study should help construct an appropriate adsorption model for the aquatic systems polluted by the coal mine drainage in the Taebag area. With the constructed model, one can describe the concentration variations of trace metals due to the adsorption in the system, which is an essential part of the investigation on the water quality affected by coal mine drainage in the Taebag coal field.

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A Study of the Relationship between Personality Traits and Job Satisfaction of Community Health Practitioners in a Rural Area (일부 보건진료원의 성격특성과 직무만족도에 관한 연구)

  • Lee, Soon-Ryae;Park, Sang-Hag
    • Journal of agricultural medicine and community health
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    • v.24 no.2
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    • pp.331-350
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    • 1999
  • This study was attempted to examine relationship between personality traits and job satisfaction of community health practitioners(CHPs) working in remote rural area in order to suggest some methods to enhance their lob performance and the degrees of job satisfaction. The General Personality Test and the revised version of Job Satisfaction Questionnaire were administered to 200 of 348 CHPs in the Kwangju-Chonnam area and then the percentages, means, standard deviations and Pearson's correlation coefficients of these data were obtained, ANOVA and logistic analysis were used. The results of study were as follows : 1. CHPs without religion were more satisfied with their salary than those with religion. 2. CHPs who hoped for continuous education showed higher scores than the others on necessary job, professional pride and autonomy. Those who chose for independent job showed higher scores than the others on both necessary job and professional pride. Those who hope for long duration showed higher scores than the others on both necessary job and professional pride. Those who were satisfied with the present occupation showed higher scores than the others on pay satisfaction, necessary job, professional pride, interaction, autonomy and demand from organization. 3. Their autonomy scores differed significantly according to work status, both interaction and autonomy scores did so according to the fields of the past job in CHP, and their autonomy scores according to location of clinics. Their interaction scores differed significantly according to the frequency of home visits per mouth, both the degrees of salary satisfaction and professional pride scores did so according to the frequency of counseling education per mouth, and their professional pride scores did so according to total income per year. 4. The levels of their responsibility and self-confidence showed the highest of all personality traits variables. 5. The professional pride score of CHPs showed the highest of all job satisfaction variables. 6. Dominance were mostly correlated with autonomy and responsibility were mostly associated with professional pride. Both emotional stability and self-confidence were mostly related necessary job. In conclusion, religion, location of clinics, clinical experience, opportunity for education, dominance, self-confidence, the duration of services hoped for, satisfaction with the present occupation, the field of past job and administrative affairs were found to be the important factors in the degrees of their job satisfaction. Therefore, the methods to consider these variables will be necessary to develop for enhancing the efficiency of their Job performance and the degrees of job satisfaction.

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Comparison for Glomerular Filtration Rate in Gamma Camera Systems Using Dynamic Renal Phantom System (동적신장팬텀시스템 개발에 따른 장비별 사구체여과율의 비교)

  • Kang, Chun Goo;Park, Hoon-Hee;Oh, Shin Hyun;Lee, Han Wool;Kim, Jung Yul;Oh, Joo Yung;Lee, Ju Young;Kim, Jae Sam;Lee, Chang Ho
    • The Korean Journal of Nuclear Medicine Technology
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    • v.17 no.2
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    • pp.3-9
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    • 2013
  • Purpose: Currently commercially available phantom can reproduce and evaluate only a static situation, the study is incomplete research on phantom and system which is can confirmed functional situation in the kidney by time through dynamic phantom and blood flow velocity, various difference according to the amount of radioactive. Therefore, through this study, it has produced the dynamic kidney phantom to reproduce images through the dynamic flow of the kidney, it desire to evaluate the usefulness of nuclear medicine imaging. Materials and Methods: The production of the kidney phantom was fabricated based on the normal adult kidney, in order to reproduce the dynamic situation based on the fabricated kidney phantom, in this study it was applied the volume pump that can adjust the speed of blood flow, so it can be integrated continuously radioactive isotopes in the kidney by using $^{99m}Tc-pertechnate$. Used the radioactive isotope was supplied through the two pump. It was confirmed the changes according to the infusion rate, radioactive isotopes and the different injection speeds on the left and right, analysis of the acquired images was done by drawn ten times ROI in order to check the reproducibility of each on the front and rear of the kidney and bladder. Results: Under the same conditions infusion rate 40 mL/min fixed to adjust the pressure of the pump when the radiopharmaceuticals between 2-3 minutes in the most integrated in the kidney phantom was excreted inthe bladder. Glomerular filtration rate (GFR), respectively, by each device SYMBIA 1,091 mL/min, FORTE 1,232 mL/min, ARGUS 1,264 mL/min, INFINIA 1,302 mL/min in that there isno statistically significant difference was found, Tmax values and T1/2 values stars from all equipment with no statistically significant difference was found. CV values of the coefficient of variation less than 5% was found to be repeatable, and to 2.67% of the lowest SYMBIA appeared, INFINIA was the highest in the 4.86%. Conclusion: Through this study, the results showed that the dynamic kidney phantom system is able to similarly reproduce renogram in the actual clinical. Especially, the depicted over time for the flow to be excreted through the kidney into the bladder was adequately reproduce, it is expected to be utilized as basic data to check the quality of the dynamic images. In addition, it is considered to help in the field of functional imaging and quality control.

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The Study of Nano-vesicle Coated Powder (나노베시클 표면처리 분체의 개발연구)

  • Son, Hong-Ha;Kwak, Taek-Jong;Kim, Kyung-Seob;Lee, Sang-Min;Lee, Cheon-Koo
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.32 no.1 s.55
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    • pp.45-51
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    • 2006
  • In the field of makeup cosmetics, especially, powder-based foundations such as two-way cake, pact and face powder, the quality of which is known to be strongly influenced by the properties of powder, surface treatment technology is widely used as a method to improve the various characteristics of powder texture, wear properties, dispersion ability and so on. The two-way cake or pressed-powder foundation is one of the familiar makeup products in Asian market for deep covering and finishing purpose. In spite of the relent progress in surface modification method such as composition of powders with different characteristics and application of a diversity of coating ingredient (metal soap, amino acid, silicone and fluorine), this product possess a technical difficulty to enhance both of the adhesion power and spreadability on the skin in addition to potential claim of consumer about heavy or thick feeling. This article is covering the preparation and coating method of nano-vesicle that mimic the double-layered lipid lamellar structure existing between the corneocytes of the stratum corneum in the skin for the purpose of improving both of two important physical characteristic of two-way cake, spreadability and adhering force to skin, and obtining better affinity to skin. Nano-vesicle was prepared using the high-pressure emulsifying process of lecithin, pseudo ceramide, butylene glycol and tocopheryl acetate. This nano-sized emulsion was added to powder-dispersed aqueous phase together with bivalent metal salt solution and then the filtering and drying procedure was followed to yield the nano-vesicle coated powder. The amount of nano-vesicle coated on the powder was able to regulated by the concentration of metal salt and this novel powder showed the lower friction coefficient, more uniform condition of application and higher adhesive powder comparing with the alkyl silane treated powder from the test result of spreadability and wear properties using friction meter and air jet method. Two-wav cake containing newly developed coated powder with nano-vesicle showed the similar advantages in the frictional and adhesive characteristics.

Prediction Model of Weed Population in Paddy Fields - I. Practical Approach to Development of Prediction Model (논 잡초발생(雜草發生) 예측(豫測)모델 개발(開發) 연구(硏究) - I. 예측(豫測)모델 개발(開發) 접근방법(接近方法))

  • Lee, H.K.;Lee, I.Y.;Ryu, G.H.;Lee, J.O.;Park, Y.S.
    • Korean Journal of Weed Science
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    • v.13 no.2
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    • pp.104-113
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    • 1993
  • The experiment was conducted in 1992 to find out the approach to the development of prediction model of weed population in paddy fields. The weed seeds of 88% over were separated from the soil by using $K_2CO_3$ 50% solution with specific gravity 1.34. The weed seeds which were floated on the solution due to the difference of specific gravity between soil particles and the seeds were effectively withdrawn by using a vaccum pump attached with an aspirator. The seeds withdrawn together with solution were taken by filtering with a nylon net of $0.31{\times}0.16mm$ mesh. The pressing method was more efficient and practical for the viability test of weed seeds separated from the soil compared with the germination test and the TTC test. For the prediction of weed population by the number of weed seedlings emerged at the sampled soil, the sampling method of 0-10cm deep at 5-6 sites per field was applicable. At the prediction method by the number of seedlings emerged, the smaller the seed sizes, the lower the prediction coefficients of weed species. It was considered that the prediction method by the number of seedlings emerged was more practical than the prediction method by the number of seeds separated from sampled soil, in relation to similarities to weed population, time and expenses required for examining, technical difficulties and applicability of weed species.

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Yield Response of Rice Affected by Adverse Weather Conditions Occurred in 1999 (1999년에 발생한 기상재해 유형별 벼 수량반응조사 연구)

  • Ju Young-Cheoul;Lim Gab-June;Han Sang-Wook;Park Jung-Soo;Cho Young-Cheol;Kim Soon-Jae
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.2 no.1
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    • pp.1-8
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    • 2000
  • The objectives of this study were to investigate weather conditions which induced discolored grains and viviparous germination, and to evaluate yield responses following viviparous germination during mid- and late- ripening stage, the submergence during reproductive growth stage, and lodging in the yellow ripe stage. Weather conditions which caused glume discoloration at heading stage were 21.3-26.4$^{\circ}C$ in average temperature, 75.2-98.4% in relative humidity, 19.3 in transpiration coefficient and 10.8-13.8 m/sec. in wind speed. Yield reduction was 26-27% and 10~17%, respectively, when the glume discoloration rates were 63.2-65.7% and 38.3-45.2%, obviously due to the decrease in percent of fertile grain and ripening ratio. Weather conditions during continuous rain for 7 days were 96% in relative humidity, 18.9$^{\circ}C$ in average temperature, 21.9$^{\circ}C$ in maximum temperature, and 16.8$^{\circ}C$ in minimum temperature, causing the most viviparous germination in Juanbyeo(45.5%), followed by Jinbubyeo(14.5%), Bongkwangbyeo(14.2%), and Obongbyeo(12.6%). Lateral tillers started to occur when the submergence at the depth of 1.5-2 m lasted one day during the reproductive growth stage. The submergence for 2-3 days at 3-4 m of water depth induced 269-571 lateral tillers/m$^2$, supporting 32-52% of the total yield. The rice yield in the paddy fields which were left under the lodging conditions until harvesting was not different compared to that of the paddy fields which were kept upright by tieing them together after lodging, but perfect grain ratio decreased about 9.1% in the transplanting culture and 12.5% in the direct seeding culture on dry paddy field because of the increase in immature grains.

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Regionality and Variability of Net Primary Productivity and Rice Yield in Korea (우리 나라의 순1차생산력 및 벼 수량의 지역성과 변이성)

  • JUNG YEONG-SANG;BANG JUNG-HO;HAYASHI YOSEI
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.1 no.1
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    • pp.1-11
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    • 1999
  • Rice yield and primary productivity (NPP) are dependent upon the variability of climate and soil. The variability and regionality of the rice yield and net primary productivity were evaluated with the meteorological data collected from Korea Meteorology Administration and the actual rice yield data from the Ministration of Agriculture and Forestry, Korea. The estimated NPP using the three models, dependent upon temperature(NPP-T), precipitation(NPP-P) and net radiation(NPP-R), ranged from 10.87 to 17.52 Mg ha$^{-1}$ with average of 14.69 Mg ha$^{-1}$ in the South Korea and was ranged 6.47 to 15.58 Mg ha$^{-1}$ with average of 12.59 Mg ha$^{-1}$ in the North Korea. The primary limiting factor of NPP in Korea was net radiation, and the secondary limiting factor was temperature. Spectral analysis on the long term change in air temperature in July and August showed periodicity. The short periodicity was 3 to 7 years and the long periodicity was 15 to 43 years. The coefficient of variances, CV, of the rice yield from 1989 to 1998 ranged 3.23 percents to 12.37 percents which were lower than past decades. The CV's in Kangwon and Kyeongbuk were high while that in Chonbuk was the lowest. The prediction model based on th e yield index and yield response to temperature obtain ed from the field crop situation showed reasonable results and thus the spatial distributions of rice yield and predicted yield could be expressed in the maps. The predicted yields was well fitted with the actual yield except Kyungbuk. For better prediction, modification should be made considering radiation factor in further development.

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A Study on the Development of the Measuring Scale of Safety Consciousness (안전의식 측정 척도 개발 연구 : 서울시 일부 중학생을 중심으로)

  • 김혜원;이명선
    • Korean Journal of Health Education and Promotion
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    • v.19 no.1
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    • pp.87-107
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    • 2002
  • Recently, the industrialized world is suffering from accidents referring from the lack of safety consciousness. According to Korean Safety Regulation Department(1996), students at junior high schools are mostly involved in safety accidents, and this is due to lack of safety consciousness. To prevent these accidents, we need to have safety consciousness and attitude. To make junior high school students who are mostly affected in these accidents act safely, they need to know their level of safety consciousness. The purpose of this study is to develop a guideline of measuring the scale of safety consciousness and analyze the relationship between safety education, accident experiences and safety consciousness. This study is based on a survey of 708 junior high students in Seoul, which was carried out from 12 November, 2001 to 21 November, 2001. 1. The main fields of safety consciousness are home safety, school safety, fire safety, emergency management based on documents. Home safety is again divided into facility safety and livelihood safety, school safety is divided into facility safety, livelihood safety and laboratory safety, traffic safety is divided into pedestrian safety, bicycling safety and public transportation safety, fire safety divided into prevention and escaping during fire breakouts, emergency management safety is divided into general principles and escaping during emergency situations. 2. The primary safety consciousness scale was made according to every field of safety consciousness. A preliminary examination based on the scale and a study of reliance and the factors was held. Based on these results, 27 questions which were concerned to be impairing reliability or lacking in factor were deleted on the secondary safety consciousness scale development The secondary safety consciousness scale which constituted of 73 questions was put into another preliminary study and after analyzing reliability and the factors, 12 questions of low reliabilities were deleted and with these results, the third scale were made consisting of 61 questions. 3. A study based on the third safety scale which is made of 61 questions, were held and with a analysis of the reliability and factors made, the relationship between safety education, accident experience and safety mind were examined. (1) The study of reliability and factors show that Cronbach's coefficient in home safety fields is .7598, in school safety .7924, in traffic safety .8306, in emergency treatment .7775, in fire safety .7247. The questions indicating low reliability were deleted. The factor analysis revealed that home safety is converged on facility safety and livelihood safety. But one question was deleted because it showed incongruence of validity. School safety was converged on facility safety, livelihood safety and laboratory safety. But 2 questions showed incongruence of validity and these were deleted. Traffic safety fields were converged on pedestrian safety, bicycle safety and public transportation safety. One question showing incongruence of validity was deleted. Emergency treatment fields converged on general principles and acting in emergency situations and three questions showing incongruence of validity were deleted. Fire safety was converged on prevention and acting in fire breakouts. Totally, eight questions were removed and the final scale were consisted of 53 questions (2) The 3/sup rd/ grade students scored higher average safety mind scales than 1st graders(p〈.05). And students who had high scores at school tend to have a higher scale than those who do not(p〈.001). (3) Average scale of students who had experience in safety education were higher(p〈.001). Students who had previously been involved in home safety accidents had a low score(p〈.001). This was same to students with experience in school safety accidents(p〈.001). Students with traffic safety accidents and fire safety accidents tend to have a lower scale too(p〈.05, p〈.001).

Response for Lead Block Thickness of Parallel Plate Detector using Dielectric Film (유전체필름을 이용한 평행판검출기의 납 차폐물 두께변화에 대한 반응)

  • Kim Yong-Eun;Cho Moon-June;Kim Jun-Sang;Oh Young-Kee;Kim Jhin-Kee;Shin Kyo-Chul;Kim Jeung-Kee;Jeong Dong-Hyeok;Kim Ki-Hwan
    • Progress in Medical Physics
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    • v.17 no.1
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    • pp.1-5
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    • 2006
  • A parallel plate detector containing PTFE films in FEP film for relative dosimetry was designed to measure the response of detectors to S and 10 MV X-rays from a medical linear accelerator through different thicknesses of lead. The dielectric materials were 100 m thick. The set-up conditions for measurements with this detector were as follows: SSD=100 cm the test detector was at a depth of 5 cm and the reference chamber was at a depth of 10 cm from the phantom surface for 6 and 10 MV X-rays. Lead blocks were designed to cover the irradiated field. They were added to the tray to increase thickness sequentially. We found that the detector response decreased exponentially with the thickness of lead added. The linear attenuation coefficients of the test detector and reference chamber were 0.1414 and 0.541, respectively, for 6 MV X-rays and 0.1358 and 0.5279 for 10 MV X-rays. The test detector response was greater than that of the reference chamber. The response function was calculated from the measured values of the test detector and reference chamber using optimization. These optimized constants for the detector response function were independent of theenergy. As a result of optimizing the response function between detectors, the use of a relative dosimeter was validated, because the response of the test detector was 1% for 6 MV X-rays and 4% for 10 MV X-rays.

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Development of $14"{\times}8.5"$ active matrix flat-panel digital x-ray detector system and Imaging performance (평판 디지털 X-ray 검출기의 개발과 성능 평가에 관한 연구)

  • Park, Ji-Koon;Choi, Jang-Yong;Kang, Sang-Sik;Lee, Dong-Gil;Seok, Dae-Woo;Nam, Sang Hee
    • Journal of radiological science and technology
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    • v.26 no.4
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    • pp.39-46
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    • 2003
  • Digital radiographic systems based on solid-state detectors, commonly referred to as flat-panel detectors, are gaining popularity in clinical practice. Large area, flat panel solid state detectors are being investigated for digital radiography. The purpose of this work was to evaluate the active matrix flat panel digital x-ray detectors in terms of their modulation transfer function (MTF), noise power spectrum (NPS), and detective quantum efficiency (DQE). In this paper, development and evaluation of a selenium-based flat-panel digital x-ray detector are described. The prototype detector has a pixel pitch of $139\;{\mu}m$ and a total active imaging area of $14{\times}8.5\;inch^2$, giving a total 3.9 million pixels. This detector include a x-ray imaging layer of amorphous selenium as a photoconductor which is evaporated in vacuum state on a TFT flat panel, to make signals in proportion to incident x-ray. The film thickness was about $500\;{\mu}m$. To evaluate the imaging performance of the digital radiography(DR) system developed in our group, sensitivity, linearity, the modulation transfer function(MTF), noise power spectrum (NPS) and detective quantum efficiency(DQE) of detector was measured. The measured sensitivity was $4.16{\times}10^6\;ehp/pixel{\cdot}mR$ at the bias field of $10\;V/{\mu}m$ : The beam condition was 41.9\;KeV. Measured MTF at 2.5\;lp/mm was 52%, and the DQE at 1.5\;lp/mm was 75%. And the excellent linearity was showed where the coefficient of determination ($r^2$) is 0.9693.

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