• Korean Journal of Soil Science and Fertilizer
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• v.6 no.1
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• pp.17-26
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• 1973

A survey on nutrient recovery by rice plant was carried out countrywide in 1967 and 1968. The relationships between percent recovery of fertilizer nutrient and climatic zone or deposition mode, drainage grade, and texture of paddy soil profile, or chemical characteristics of surface soil were as follows. 1. The percent recovery of fertilizer nitrogen was highest in south and least in north, and that of potassium was highest in south and least in middle climatic zone. 2. Since the percent recovery of Phosphorus variates yearly with climatic zone, mode of deposition drainage grade or soil texture, it seemed to depend greatly on soil-weather interaction. 3. Nitrogen recovery was highest in alluvial colluvial (AC) and it was followed by alluvial (A), fluvomarine (FM) and old alluvial in decreasing order while potassium recovery was OA>AC>A>FM. 4. The greater the drainage was, the higher the nitrogen recovery. The recovery of potassium and phosphorus tended to show high in moderately well drain, and low in poorly and well drain. 5. Nitrogen recovery was highest in fine silty and gradually decreased with coarseness. That of potassium or phosphorus was greater in those below fine loamy than in those above coarse silty. 6. Nitrogen recovery was high in Jisan, Geugrag, and Sindab series, and low in Hwadong, Gyuam, Yongji and Hwabong series. 7. Nitrogen recovery showed significant positive correlation with the content of organic matter (OM), Ca, CEC of surface soil and only in the year of high phosphorus recovery it had significant negative correlation with soil phosphorus. Phosphorus recovery had significant posititive correlation with CEC, Mg or Ca. 8. Potassium recovery showed negative correlation with K/(Ca+Mg), P, OM or K while positive correlation with Ca, Mg, CEC but significant only with K/(Ca+Mg) in the year of low potassium recovery. In the year of high K recovery it showed positive correlation with P, OM, K/(Ca+Mg) or K while negative with CEC, Mg or Ca but significant only with P, OM or CEC. Soil potassium has significant positive correlation with soil OM and P only in the year of low potassium recovery. 9. The percent recovery of N, P or K showed negative correlation coefficient with pH without significant. 10. There was significant positive correlation between OM and P, K or K/(Ca+Mg), P and K or K/(Ca+Mg), K and K/(Ca+Mg), Mg or CEC, Ca and K/(Ca+Mg), Mg, CEC or pH, Mg and CEC while significant negative correlation between Mg and OM, P or K/(Ca+Mg), P and CEC, Ca and K/(Ca+Mg). 11. From the percent rcovery of fertilizer and soil chemical characteristics it was known that soil organic matter increase nitrogen uptake, that K uptake has closer relation to K/(Ca+Mg) than K, that Mg affects P ugtake, and that the annual difference of P and K recovery was partly explainable.

• Journal of the Korea Organic Resources Recycling Association
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• v.16 no.2
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• pp.29-37
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• 2008

In this work, it was investigated that various aspects of process, application situation, merits and short-coming results of the thermophilic methane fermentation with highly concentrated organic waste substances such as sewage sludges, food wastes and excretions. The merits of this methane fermentation were that it had a very fast reaction rate and was possible to proceed in high loads. It was also high in mortality for pathogenic microorganism and the digested sludge was more hygienic. However, the short-comings were that more energy was required for heating in the fermentation facility, no surplus energy could be gained from low concentration of organic waste, the fermentation treatment dropped level of water quality, thus burdens discharging process of water. Especially, the high concentration of methane fermentation could possibly lack nutritious salt and could face the disturbance by ${NH_4}^+-N$, a proper alternative was required. In general, thermophilic methane fermentation was considered as a better mean in disposing of cow excretion and food waste which were highly concentrated organic wastes. On the other hand, under the condition where the concentration of waste material was low and the high concentrate waste material became higher than 3,000 mg/L in ${NH_4}^+-N$, thermophilic methane fermentation resulted less desirable outcome.

• Journal of Preventive Medicine and Public Health
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• v.23 no.3 s.31
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• pp.309-315
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• 1990

The purpose of this study was to evaluate the effect of zinc administration on the autistic children. The subject diagnosed as infantile autism were 24 male and 10 female children of a special school in Taegu city. Control group were selected from 1:2 ratio matched with cases on sex and age. The results were as followings. In female autistic group, the mean content of zinc in hair was significantly lower than control group, but in male the result was inverse at all age group. The content of zinc in hair showed significant correlation with age in male autistic group and control group. Zinc content of hair, age and sex accounted for 37.2% of the variance of autistic score and the most significant variable was zinc content. Autistic group were divided into two group. Group I which zinc content of hair below 150 ppm were administrated with multi-vitamin contained 10 mg of zinc, Group II which zinc content of hair above 150 ppm were administrated with placebo. Total administration period was eight weeks. In zinc administration group, there was a decreasing tendency of autistic score as the zinc content of hair was increased but the relationship was not statistically significant.

• Journal of the Korea Concrete Institute
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• v.20 no.5
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• pp.661-668
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• 2008

It is necessary to develop a new technology for effectively reducing hydration heat and controlling thermal cracking caused increasing construction of large size massive concrete structures such as mat foundation of high-rise building, grandiose bridge, and LNG tank. Therefor, to develop a new technology for reducing hydration heat of large size massive concrete in this study, after developing the latent heat binder for controling hydration heat of concrete by application of latent heat material, it was investigated basic properties and durability such as slump, air content and compressive strength, shrinkage properties, permeability, freezing and thawing resistance, corrosion, and hydration heat generation properties of concrete using latent heat binder. As a test result, it was confirmed that latent heat binder was not affected adversely the basic property and durability of concrete, and was advanced on the reduction of hydration heat and control of thermal crack. It is expected to be applied as the excellent technology on the management of hydration heat and thermal crack in large size mass concrete structures.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.15 no.2
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• pp.173-180
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• 2017

In this study, air sampling locations in the stack of the Advanced Fuel Science Building (AFSB) at the Korea Atomic Energy Research Institute (KAERI) were assessed according to the ANSI/HPS N13.1-1999 specification. The velocity profile, flow angle and $10{\mu}m$ aerosol particle profile at the cross-section as functions of stack height L and stack diameter D (L/D) were assessed according to the sampling location criteria using COMSOL. The criteria for the velocity profile were found to be met at 5 L/D or more for the height, and the criteria for the average flow angle were met at all locations through this assessment. The criteria for the particle profile were met at 5 L/D and 9 L/D. However, the particle profile at the cross-section of each sampling location was found to be non-uniform. In order to establish uniformity of the particle profile, a static mixer and a perimeter ring were modeled, after which the degrees of effectiveness of these components were compared. Modeling using the static mixer indicated that the sampling locations that met the criteria for the particle profile were 5-10 L/D. When modeling using the perimeter ring, the sampling locations that met the criteria for particle profile were 5 L/D and 7-10 L/D. The criteria for the velocity profile and the average flow angle were also met at the sampling locations that met the criteria for the particle profile. The methodologies used in this study can also be applied during assessments of air sampling locations when monitoring stacks at new nuclear facilities as well as existing nuclear facilities.

• Korean Journal of Environmental Agriculture
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• v.17 no.3
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• pp.200-204
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• 1998

Physical and chemical properties of artificial soil produced by firing process were analyzed and compared with normal dry field soil and soil quality standards. Material used for production was water and wastewater treatment sludge, chabizite, and lime. The mixed material was thermally treated in the firing kiln at about $300^{\circ}C$ and $1,000^{\circ}C$, respectively, as per designed process. General properties of the artificial soil were classified as sand by unified soil classification method and similar to the dry-field soil, and even soil conditioning effect were expected when it is mixed properly with normal soil. The artificial soil is high in pH and permeability compared to the dry-field soil. Heavy metal concentrations of the artificial soil met the soil quality standards for the farmland. Overall, the artificial soil was thought to be an appropriate soil which can be returned safely to the nature without significant adverse effect. The cost for the artificial soil production process needs to be lowered for practical application as a sludge treatment, therefore, commercializing of the artificial soil is under review.

• Korean Journal of Environment and Ecology
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• v.28 no.2
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• pp.161-170
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• 2014

This study classified the types of major forest vegetation and analyzed the syngeographical characteristics of the vegetation in the Mt. Deokhang with exhumed lime rocks. The forest vegetation on the ridge of Mt. Deokhang was classified into 1 community group, 3 communities, 2 groups, and 2 subgroups, 5 types in total. The syngeographical form of Deokhangsan fully exhibited the topographical peculiarity, proximity to subalpine, and limestone zone. In addition, Carex ciliato-marginata, Carex humilis var. nana, and so forth which appear as species with high consistency in the well-drained semiarid zone represent the soil environment of the lime stone area and northern plants such as Carex ussuriensis and Asplenium ruta-muraria represent the characteristics of the vegetation in alpestrine in close proximity. Moreover, the Carpinus turczaninowii in the area appears to show the characteristics of migratory vegetation due to the peculiarity of the habitat. The syngeographical characteristics of this study area show both the characteristics of the habitat and phytogeographic characteristics. Furthermore, they are expected to contribute to the diversity in community and habitat form in Korean peninsula in terms of vegetation science.

• Journal of Periodontal and Implant Science
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• v.36 no.3
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• pp.767-782
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• 2006

이 연구의 목적은 DNA microarray 분석법을 이용하여 건강한 사람치주인대섬유모세포, 건강한 사람치은섬유모세포, 복제노화된 사람치은섬유모세포, 염증성 사람치주인대 섬유모 세포의 유전자 발현 형태를 상호비교하고자 하였다. 환자의 동의하에 충치, 치주염이 없이 교정발치된 치아의 치주인대세포를 배양하여 건강한 치주인대섬유모세포로, 만성치주염으로 발거된 치아에서 채취하여 배양한 세포를 염증성 치주인대섬유모세포로 선정하였다. 구강에서 채취한 치은결체조직에서 배양한 사람치은섬유모세포를 일차 배양한 후 계대배양을 통해 복제 노화를 유도하였다. $-198^{\circ}C$의 액화질소에 저장되어 있던 2, 4, 8, 15, 16세대 세포를 실험에 이용하였다. 위의 모든 세포들은 60 mm 배양접시에서 세포들이 80-90%의 밀생이 될 때까지 5% $CO_2$, $37^{\circ}C$, 100% 습도의 배양기에서 2일 간격으로 10% FBS가 함유된 DMEM 세포 배양액을 교체하면서 세포를 배양하였다. Trizol Reagent (Invitrogen, USA)를 이용하여 제조회사의 지시에 따라 total RNA를 추출하였다. 18S RNA와 28S RNA를 확인한 후 DNA microarray 분석을 실시하였다. 4배수 이상의 변화양상을 비교시 상호 유전자 발현의 차이를 나타내었다. 건강한 사람치은섬유모세포(2세대)와 노화된 치은섬유모세포에서 가장 높은 발현변화를 나타낸 반면 DMC1 dosage suppressor of mck1 homolog, meiosis-specific homologous recombination,은 건강한 치은섬유모세포에서 가장 높게 나타났다. 염증성 치은인대섬유모세포와 건강한 치주인대 섬유모세포를 비교시, Regucalcin은 염증성 치주인대섬유모세포에서 가장 높게 나타났고, Vascular cell adhesion molecule 1도 두 번째로 높게 나타났다. 건강한 치주인대섬유모 세포와 건강한 치은섬유모세포를 비교시, IL-11과 periostin이 치주인대섬유모세포에서 높은 발현을 나타낸 반면, Prostaglandin D2 synthase 21kDa과 Thioredoxin interacting protein은 치은섬유모세포에서 높은 발현을 나타내었다. 염증성 치주인대섬유모세포와 노화된 치은섬유모세포(15세대 이상)를 비교시 149개의 유전자가 유사한 발현 수준을 나타내었다. 이 연구는 노화, 염증, 세포 형태에 따라서 유전자 수준에서 가장 높거나 높은 수준 변화를 보이는 유전자가 다를 수 있음을 나타낸다. 향후, 치주염 환자들에서, 노염, 염증, 세포 특이성에 관한 유전자 표시지를 이용하여 진단하거나 치료에 응용하기 위해서는 더 많은 연구가 필요하리라 사료된다.

• Journal of vocational education research
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• v.35 no.6
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• pp.1-19
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• 2016

This study is to analyze the effect of job relatedness of content in learning, job stress and organization communication on turnover intention and to examine whether the job satisfaction has a mediating effect by using HCCP 2013 panel data. The data was analyzed through Windows SPSS 23.0 program. Major findings of the study were as follows. First, It has significant result that job relatedness of content in learning, job stress and organization communication affects turnover intention. Second, job satisfaction mediates between job relatedness of content in learning and turnover intention. The job relatedness of content in learning level is higher, the turnover intention will be lower through mediating job satisfaction. Third, job satisfaction is also significant effect between job stress and turnover intention. Although the job stress gets higher, the turnover intention can be lower because of job satisfaction. Finally, the relationship between organization communication and turnover intention is mediated by job satisfaction. Therefore, the company should prepare employee's turnover intention to control through this study.

• Therapeutic Science for Rehabilitation
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• v.12 no.3
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• pp.61-77
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• 2023

Objective : This study analyzed the correlation between cognitive function and oral health-related quality of life (OHQoL). Methods : Demographic and clinical characteristics were extracted and utilized for subjects aged 45 years or older who participated in the 8th Korean Longitudinal Study on Aging in 2020. The dependent variable was the Geriatric Oral Health Assessment Index, and the independent variable was the level of cognitive function classified by the Mini-Mental State Examination scores. The analysis method used inverse probability of treatment weighting (IPTW). Then, the association between cognitive function and OHQoL was analyzed by multiple regression analysis. Results : Among the participants, 4,367 (71.40%) had normal cognition, 1,155 (18.89%) had moderate cognitive impairment, and 594 (9.71%) had severe cognitive impairment. As a result of analysis by applying IPTW, there was a negative correlation between the cognitive function group and OHQoL (normal vs. moderate: β = -2.534, p < .0001; normal vs. severe: β = -2.452, p < .0001). Conclusion : After propensity score matching, mild cognitive impairment showed a more negative association than severe cognitive impairment. Therefore, patients with cognitive impairment require oral health management education to improve OHQoL regardless of the level of cognitive impairment.