• 한국재료학회지
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• 제28권2호
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• pp.82-88
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• 2018

Stable slurries of YSZ in aqueous suspension with added polymer dispersants, namely, poly-methacrylic acid ammonium salt (PMMA), poly-acrylic acid (PAA) and poly-acrylic-co-maleic acid (PAMA), were mixed with the monomolecular dispersants citric acid and oxalic acid. The dispersion properties of the suspension were investigated using PSA, viscosity, sedimentation, and FT-IR. The polymer dispersants and monomolecular dispersants were attached to the YSZ surface by the carboxylic group, as shown by the FTIR results. A stabilized aqueous suspension was obtained when the polymer dispersant and citric acid were mixed and compared to the use of citric acid alone as a dispersant agent. When the polymer dispersant and citric acid were mixed and milled through attrition milling, there was a smaller particle size compared to when the polymer dispersant alone was used as a dispersant agent. This study determined that the particle size of the mixed dispersant was affected by the properties of the monomolecular dispersant and that the stability of the suspension was affected by the polymer dispersant. However, when slurries of YSZ were mixed with oxalic acid, the particle bridging behavior was the result of the high degree of viscosity and the small sedimentation height.

• 한국건강관리협회지
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• 제2권2호
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• pp.215-230
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• 2004

Along with a development of medical technology, a variety of tests, such as laboratory tests, x-ray and endoscopies are being used in health screening tests. As the tests determine the quality of health screening, test items and methods should be carefully selected. This study was to get hold of the test items of major health screening programs in Korea. Most of the health screening programmes focused upon detection of risk factors and diagnosis of life-style related diseases(diabetes, hypertension, cardiovascular diseases, hypercholesterolemia, overweight, drinking, smoking, cerebrovascular diseases, osteoporosis) ,cancers(stomach, cervix, lung, breast, liver, colon, prostate, ovary, pancreas, thyroid, esophagus), infectious diseases (hepatitis, tuberculosis, sexually-transmitted diseases, parasites),chronic obstructive respiratory diseases, chronic renal diseases(bacteriuria, hematuria, proteinuria), anemia, glaucoma, hearing loss, Alzheimer disease, stress, early Psychiatric diseases. The health screening tests were basic physical examination, basic laboratory tests(CBC, urinalysis, liver function tests, lipid tests, glucose, HbAlc, uric acid, electrolytes, serological tests(HBsAg, HBs-Ab, HCV-Ab, HIV-Ab, VDRL) EKG, x-ray(chest PA, CT), endoscopy (gastroscopy, colonoscopy) , sonography(abdormen, thyroid, pelvis, breast) , cytology(cervix) ,bone density, tumor markers(NMP22, alpha-FP, CEA, CA-19-9, CA12S, PSA) and eye tests. Advanced technologies, like CT, PET, MIRI, MIRI/Angio, molecular testings) were widely usedin hospital health screening programmes. In summary, a variety of were utilized by stages or programmes, however a few subjects. tests were utilized in health screening in Korea. Those tests according to sex and age in most of health screening program used tests to excess disregarding health screening subject.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2003년도 춘계 학술발표대회
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• pp.122-122
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• 2003

Expressed sequence tags (EST) are help to quickly identify functions of expressed genes and to understand the complexity of gene expression. In order to analyze gene expression of the leaf development in Panax ginseng, which is one of the most important medicinal plant, expressed sequence tags (EST) analysis was carried out. We constructed a cDNA library using the immature leaf of Chunpoong. Partial sequences were obtained from 3,170 clones. The ESTs could be clustered into 1,624 (56.1%) non-redundant groups. Similarity search of the non-redundant ESTs against public non-redundant databases of both protein and DNA indicated that 1,137 groups show similarity to genes of known function. These ESTs clones were divided into sixteen categories depending upon gene function. Most abundant transcripts in immature ginseng leaf were photosynthesis related protein, such as chlorophyll a/b binding protein LHCII type I (128), chlorophyll a/b binding protein (53), ribulose-1,5-bisphosphate carboxylase (41), and photosystem I psaH (26). The EST data from immature leaf generated in this study is useful in dissecting gene expression in leaf organ of ginseng.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.1132-1139
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• 2006

Railway risk is evaluated by a method of linking event trees and fault trees as the general PSA(Probabilistic Safety Assessment) model for the risk assessment of complex systems. Accident scenarios causing undesirable events are modeled by event trees comprised of several accident sequences. Each branch located in the accident progression of the event tree is modeled by an fault tree or can be represented by some value too simply. We usually evaluate the frequency of the whole sequence by adding them after calculating the frequency of each sequence at a time. However, since there are quite a number of event trees and fault trees in the railway risk assessment model, the number of sequence to evaluate increases and preparation for the risk assessment costs much time all the more. Also, it may induce errors when analysts perform the work of quantification. Therefore, the systematic maintenance and control of event trees and fault trees will be essential for the railway risk assessment. In this paper we introduce an integrated assessment method using one-top model and develop a risk assessment tool for the maintenance and control of the railway risk model.

• 환경영향평가
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• 제21권1호
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• pp.63-69
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• 2012

Sediment has been increasingly acknowledged as a carrier in water system and an available contamination. For this reason, dredging of sediment in reservoir to remediate water quality and secure storage capacity is conducted annually. However, disposal of numerous dredged sediment is necessary as a secondary problem. Currently, in Korea, dredged sediment is classified as waste to be reclamated or recycled into sandy soil, however, they are still in trouble because of spacial and environmental problem. Therefore, rather than simple disposal or reuse into sandy soil, it is necessary to research on method to manage main cause of pollution and increase the value as a resource. In this study, we intend to develop a recycle technology for numerous dredged sediment produced by dredging in deteriorated reservoirs using solidificator (stabilizer). To achieve this, we will consider utilization of dredged sediment and evaluation of use possibility as natural recycle by analysis the characteristics of soil-solidificator mixture in terms of physicochemical properties and the mixing ratio between sediment and solidificator.

• Nuclear Engineering and Technology
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• 제35권2호
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• pp.154-164
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• 2003

The explicit consideration of different pressurization rates in estimating the probabilities of containment failure modes has a profound effect on the confidence of containment performance evaluation that is so critical for risk assessment of nuclear power plants. Except for the sophisticated NUREG-1150 study, many of the recent containment performance analyses (through Level 2 PSAs or IPE back-end analyses) did not take into account an explicit distinction between slow and fast pressurization in their analyses. A careful investigation of both approaches shows that many of the approaches adopted in the recent containment performance analyses exactly correspond to the NUREG-1150 approach for the prediction of containment failure mode probabilities in the presence of fast pressurization. As a result, it was expected that the existing containment performance analysis results would be subjected to greater or less conservatism in light of the ultimate failure mode of the containment. The main purpose of this paper is to assess potential conservatism of a plant-specific containment performance analysis result in light of containment failure mode probabilities.

• International Journal of Industrial Entomology and Biomaterials
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• 제47권2호
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• pp.140-146
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• 2023

In recent years, the number of patients with benign prostatic hyperplasia (BPH), a condition that commonly occurs in elderly men, has increased due to aging and the adoption of western dietary habits. Treatment with chemical drugs, such as finasteride or dutasteride, can cause side effects such as erectile dysfunction or sexual problems. This necessitates the development of remedies using natural substances derived from food ingredients. In this study, we investigated the inhibitory effects of Oxya chinensis sinuosa hot water extract (OCH) on BPH production in LNCaP cells, a hormone-dependent prostate cancer cell line. We found that the mRNA expression of androgen receptor (AR), prostate specific antigen (PSA), and, 5α-reductases 1, and 2 decreased following treatment with OCH. Furthermore, OCH treatment resulted in reduced protein expression of BPH regulators, such as AR. Collectively, these results suggest that OCH exerts a beneficial effect on BPH by inhibiting the AR signaling pathway, indicating the potential of OCH as a therapeutic agent for the prevention and treatment of BPH.

• 농약과학회지
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• 제18권4호
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• pp.296-313
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• 2014

토양환경 중 잔류농약 동시분석을 위해 124종의 농약을 대상으로 QuEChERS 전처리와 LC-MS-MS를 이용한 분석법을 개발하고자 하였다. QuEChERS 전처리 과정은 토양시료에 0.2N $NH_4Cl$ 용액 침지하고 1% acetic acid 포함 acetonitrile 용매로 추출 후 $MgSO_4$ 및 NaOAc로 salting out하고 PSA 50 mg, $C_{18}$ 50 mg, $MgSO_4$ 150 mg를 이용해 정제하였다. 분석법의 검증을 위해 양토 및 사양토 두 토양에서 0.005, 0.01, 0.02, 0.1 mg/kg 4수준으로 처리 후 회수율 실험을 실시하였다. 회수율 실험결과 Benfuracarb, Ethiofencarb, Pymetrozine, Pyrethrin 성분을 제외하고 나머지 성분들은 사양토와 양토 모두 70~120%의 적정 회수율을 나타내었으며, 상대표준편차도 20% 이내를 양호한 결과를 나타내었다. 따라서 QuEChERS 전처리 및 LC-MS를 이용한 분석법은 토양 중 잔류농약 다성분동시분석에 적용이 가능할 것으로 판단되었다.

• 공업화학
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• 제16권1호
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• pp.123-130
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• 2005

산소 PSA용 흡착제의 제조를 위하여 표면적이 큰 제올라이트 X형 흡착제를 합성하고 양이온교환을 통하여 질소의 선택적 흡착 능력이 우수한 흡착제로 제조하였다. 제올라이트 X형 흡착제는 50 L급 대형 반응기에서 $SiO_2\;:\;Na_2O\;:\;H_2O\;:\;Al_2O_3$ = 2.5 : 3.5 : 150 : 1의 조성으로 $98^{\circ}C$, 18 h 동안 반응한 결과 표면적이 $650m^2/g$ 이상의 표면적을 나타내었다. 흡착제의 양이온교환은 Li, Ag, Ca, Br, Sr 등의 금속 이온을 대상으로 조사하였다. Ag 이온의 이온교환 속도가 가장 빠르게 일어났으며 모든 금속 이온이 제올라이트 X형에 포함된 Na 이온과 거의 당량적으로 이온 교환이 일어남을 알 수 있었다. 양이온 교환된 제올라이트 X형 흡착제의 질소와 산소의 흡착 성능을 $10{\sim}40^{\circ}C$, 0~9 atm의 범위에서 측정한 결과 이온교환을 하지 않은 NaX 흡착제에 비하여 월등히 높은 흡착 성능을 나타내었으며 이온 교환된 제올라이트 X형 흡착제의 질소 흡착량은 0.5 atm 이하의 저압에서는 Ag > Li > Ca > Sr > Ba > K 이온의 순으로 나타났으나 1 atm 이상의 고압에서는 Li > Ag > Ca > Sr > Ba > K 이온의 순으로 나타났다. 공기의 조성에 준하는 질소 및 산소의 분압에서 흡착량의 비를 조사하여 질소/산소 분리도를 측정한 결과 $20^{\circ}C$의 온도에서 Li으로 이온 교환된 흡착제의 분리도는 13.023을 나타내었다.

• 방사성폐기물학회지
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• 제11권4호
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• pp.259-269
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• 2013

무기 이온교환제인 ammonium molybdophosphate(AMP)와 자성을 가지는 산화철(iron oxides, IO)을 혼합하고, 유기 지지체인 polyacrilonitrile(PAN)을 결합하여 AMP/IO-PAN 복합체를 합성하였으며 액체 방사성폐액 내 방사성 핵종의 처리 적용성을 평가하였다. 합성된 AMP/IO-PAN 복합체의 물성을 X-선 회절분석(XRD), 퓨리에 변환 적외선 분광분석(FT-IR), 주사전자현미경(SEM), 입도분석기(PSA), 비표면적 및 공극 분석, 자성 측정(MPMS) 분석을 통해 파악하고, 코발트, 스트론튬, 세슘에 대한 흡착 성능을 평가하였다. 10wt%의 산화철이 함유된 AMP/IO-PAN 복합체의 자성 측정 결과, 2.038 emu/g으로 나타났다. 10wt%의 산화철이 함유된 AMP/IO-PAN 복합체의 Langmuir 모델로 예측한 코발트, 스트론튬, 세슘에 대한 최대흡착량($Q^0$)은 각 0.097 mmol/g, 0.087 mmol/g, 0.655 mmol/g으로 나타났다. 0, 10, 20, 30wt%의 산화철이 함유된 AMP/IO-PAN 복합체의 Langmuir 모델로 예측한 세슘에 대한 최대흡착량($Q^0$)은 각각 0.702 mmol/g, 0.655 mmol/g, 0.602 mmol/g, 0.559 mmol/g으로 나타났으며, 첨가된 산화철의 양이 증가할수록 AMP/IO-PAN 복합체의 세슘 흡착량이 감소하였다.