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        검색결과 107

        1.
        2023.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated the surface tension and foaming properties of the hot-water extracts of pumpkin leaf and chickpea, as well as the effects of the plant hot-water extracts on white pan bread baking. Propylene glycol alginate (PGA), a synthetic emulsifier widely used in bakery, was used as a control. Pumpkin leaf water extract showed lower surface tension and comparable foaming capacity, compared with chickpea water extract and PGA solution when total solid  0.15% (w/w). Chickpea water extract showed the highest foam stability when total solid  0.15% (w/w). The dough was found to have a weak gel structure, and its viscoelastic properties were not significantly influenced by adding 0.05% or 0.15% (w/w) (based on total solid content) plant water extracts or PGA. The specific volume of the bread increased, and the baking loss was reduced by adding the two plant water extracts of total solid 0.15% (w/w). The hardness and chewiness of the bread crumb were reduced to a level comparable to the crumb containing 0.05% (w/w) PGA. The results showed that the pumpkin leaf water extract could be an effective natural emulsifier with a high phenolic content for bakery products.
        4,000원
        2.
        2023.05 구독 인증기관·개인회원 무료
        The organic complexing agents such as ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), and isosaccharinic acid (ISA) can enhance the radionuclides’ solubility and have the potential to induce the acceleration of radionuclides’ mobility to a far-field from the radioactive waste repository. Hence, it is essential to evaluate the effect of organic complexing agents on radionuclide solubility through experimental analysis under similar conditions to those at the radioactive waste disposal site. In this study, five radionuclides (cesium, cobalt, strontium, iodine, and uranium) and three organic complexing agents (EDTA, NTA, and ISA) were selected as model substances. To simulate environmental conditions, the groundwater was collected near the repository and applied for solubility experiments. The solubility experiments were carried out under various ranges of pHs (7, 9, 11, and 13), temperatures (10°C, 20°C, and 40°C), and concentrations of organic complexing agents (0, 10-5, 10-4, 10-3, and 10-2 M). Experimental results showed that the presence of organic complexing agents significantly increased the solubility of the radionuclides. Cobalt and strontium had high solubility enhancement factors, even at low concentrations of organic complexing agents. We also developed a support vector machine (SVM) model using some of the experimental data and validated it using the rest of the solubility data. The root mean square error (RMSE) in the training and validation sets was 0.012 and 0.016, respectively. The SVM model allowed us to estimate the solubility value under untested conditions (e.g., pH 12, temperature 30°C, ISA 5×10-4 M). Therefore, our experimental solubility data and the SVM model can be used to predict radionuclide solubility and solubility enhancement by organic complexing agents under various conditions.
        3.
        2023.05 구독 인증기관·개인회원 무료
        The operation of nuclear power plants, nuclear waste depositories, and the decontamination and decommissioning of nuclear power plants all have the possibility of generating various kinds of radionuclides that can be formed as gaseous or liquid phases. Among the radionuclides, strontium is considered as most harmful substance due to its abundance in nuclear accident effluent, long half-life, high fission yield, high water solubility, and high mobility in aquatic environment. To remove strontium from aquatic environment, adsorption technique is mainly used with high economic feasibility, efficiency, and selectivity. Previously, we synthesized sodium titanates with mid-temperature hydrothermal method as selective strontium adsorbent in aqueous solution. Moreover, it was demonstrated that synthesized sodium titanates show high strontium adsorption rate with high selectivity with high surface area, pore diameter and volume. Herein, we investigated the surface structure of synthesized sodium titanates before and after strontium adsorption in aqueous solution using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS) analysis. According to SEM and EDS experimental results, aquatic strontium can be adsorbed as surface precipitation with formation of cube-shaped structure, which is quite similar strontium titanate structure crystals onto the surface of sodium titanates. In addition, XPS experimental results revealed that the titanium ions on the surface of sodium titanates were oxidized during strontium surface precipitation process, and the sodium ion on the surface of sodium titanates were exchanged with aquatic strontium ions via ion exchange process during strontium adsorption process.
        5.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Pseudo-pheochromocytoma is defined as an adrenal tumor that has the typical characteristics of pheochromocytoma likely hypertension but is histopathologically diagnosed to other types of adrenal tumors. 11-year-old, castrated male Maltese presented for a left adrenal mass with hypertension. According to clinical signs and radiological features, a temporary diagnosis was made of pheochromocytoma. The adrenalectomy was performed and the histopathological examination of the resected adrenal gland was diagnosed as cortical adenocarcinoma. This report describes the case of pseudo-pheochromocytoma in a dog and implies the salience that even if pheochromocytoma is diagnosed based on all test results, pseudo-pheochromocytoma should not be excluded.
        3,000원
        6.
        2022.10 구독 인증기관·개인회원 무료
        Cellulose-based wastes can be degraded into short-chain organic acids at the cementitious radioactive waste repository. Isosaccharinic acid (ISA), one of the main degradation products, can form the chelate complex with metals and radionuclides, and these complexes have a potential that can accelerate to move the radionuclides to far-field from the repository. This study characterized the amount of generated ISA from typical cellulosic materials in the repository. Two different degradation experiments were conducted under alkaline conditions (saturated with Ca(OH)2 at pH 12.4): i) cellulosic material mixture under an opened condition (partially aerobic), and ii) cellulosic material under an anaerobic condition in a nitrogen-purged glove box. In the first case, three different types of cellulosic materials–paper, cotton, and wood– were mixed at the same ratio, and the experiments were carried out at three different temperatures (20°C, 40°C, and 60°C). It revealed that both the cellulose degradation rate and generated ISA concentration were high at high reaction temperatures, and various soluble degradation products such as formic acid and lactic acid were generated. The cellulose degradation in this work seems to still stay at a peeling-off process. In the second study, each type of cellulosic material was applied in its own batch experiments, and the amount of generated ISA was in the order of paper > wood > cotton. The above two experiments are supposed to be a long-term study until the generated ISA reaches an equilibrium state.
        7.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 액체감쇠역전회복(FLAIR) 시퀀스를 대체하였던 방법 중에 비교적 간단하면서 높은 재현성을 나타내었던 고신호 강도제거 원리를 MAGiC에 적용하여 MAGiC-FLAIR와 기존의 고속스핀에코-FLAIR 영상과 비교하여 고신호 강 도제거영상의 유용성과 임상적으로 유의미한 기준을 제시하고자 하였다. 연구방법은 MAGiC 적용 후 MAGiC-FLAIR와 MAGiC-고신호 강도제거 영상을 재구성하여, 기존의 고속스핀에코-FLAIR 영상과 각각 정성적, 정량적 평가를 비교하였 다. 정성평가결과 MAGiC-고신호 강도제거는 MAGiC-FLAIR 보다는 월등히 우수하며, 고속스핀에코-FLAIR와 유사한 결과를 보였고, 정량평가결과 MAGiC-고신호강도제거는 MAGiC-FLAIR보다 백질과 회백질 대조도는 더 우수할 뿐만 아 니라, 뇌척수액의 신호 억제도 우수한 결과를 나타냈다. Synthetic 영상을 통하여 획득한 다양한 대조도 영상 중 FLAIR의 부정확도를 고신호 강도제거기법을 적용한다면 진단적 가치를 개선하여 제공할 수 있을 것이다.
        4,000원
        8.
        2022.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was undertaken to compare meal skipping, snacking, and weight perceptions between students on-campus living alone and off-campus living with parents, in an urban college in the United States. The self-report survey was completed by 219 college students (on-campus=100, off-campus=119) between April and May 2012. Two-thirds (67%) of the respondents skipped at least one meal in the past week, and most participants showed strong desires to lose weight despite their normal/under-weight status. Significant differences between the two groups were obtained for the reason to skip a meal and the type of snack consumed. Compared to on-campus students, significantly higher values were obtained for off-campus students for choosing ‘no time to prepare’ as a meal skipping reason for lunch and dinner, and ‘sweets’ as a preferred snack. In addition to the group comparison, multiple regression results indicate that the body mass index (BMI) positively correlates with meal skipping and snacking frequencies. Younger students and female students were determined to have a higher frequency of meal skipping and morning snacking. Future research is required to study the dietary factors associated with living arrangements, to help college students develop healthy eating habits.
        4,000원
        9.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A 13-year-old mixed dog was referred to the animal medical center, Gyeongsang National University. Lung masses were diagnosed at the left cranial and caudal lobes through diagnostic imaging, and consequently, left pneumonectomy was performed using a self-cutting linear endoscopic stapler. The pulmonary arteries, veins, and bronchus of each lung lobe were sealed and resected at once, and any air leakage or bleeding was not observed after the surgery. Compared to the conventional ligation method, the self-cutting linear endoscopic stapler has the advantage of significantly reducing the operation time and enabling simple and reliable sealing.
        3,000원
        13.
        2021.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Radiological impact analyses were carried out for a near-surface radioactive waste repository at Gyeongju in South Korea. The RESRAD-ONSITE code was applied for the estimation of maximum exposure doses by considering various exposure pathways based on a land area of 2,500 m2 with a 0.15 m thick contamination zone. Typical influencing input parameters such as shield depth, shield materials’ density, and shield erosion rate were examined for a sensitivity analysis. Then both residential farmer and industrial worker scenarios were used for the estimation of maximum exposure doses depending on exposure duration. The radiation dose evaluation results showed that 60Co, 137Cs, and 63Ni were major contributors to the total exposure dose compared with other radionuclides. Furthermore, the total exposure dose from ingestion (plant, meat, and milk) of the contaminated plants was more significant than those assessed for inhalation, with maximum values of 5.5×10−4 mSv‧yr−1 for the plant ingestion. Thus the results of this study can be applied for determining near-surface radioactive waste repository conditions and providing quantitative analysis methods using RESRAD-ONSITE code for the safety assessment of disposing radioactive materials including decommissioning wastes to protect human health and the environment.
        4,000원
        16.
        2020.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to investigate the densification behavior and the corresponding microstructural evolution of tantalum and tantalum-tungsten alloy powders for explosively formed liners. The inherent inhomogeneous microstructures of tantalum manufactured by an ingot metallurgy might degrade the capability of the warhead. Therefore, to overcome such drawbacks, powder metallurgy was incorporated into the near-net shape process in this study. Spark plasma-sintered tantalum and its alloys with finer particle sizes exhibited higher densities and lower grain sizes. However, they were contaminated from the graphite mold during sintering. Higher compaction pressures in die and isostatic compaction techniques also enhanced the sinterability of the tantalum powders; however, a full densification could not be achieved. On the other hand, the powders exhibited full densification after being subjected to hot isostatic pressing over two times. Consequently, it was found that the hot isostatic-pressed tantalum might exhibit a lower grain size and a higher density as compared to those obtained in previous studies.
        4,000원
        17.
        2020.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 관상가치가 뛰어난 산꼬리풀의 분화 재배법을 확립하고자 차광, 기비, 추비, 왜화제 및 적심처리를 각각 달리하여 수행하였다. 연구의 결과 차광 시 산꼬리풀의 생육이 감소 하였으며, 차광률이 증가할수록 크게 억제되었다. 기비 처리는 초장, 절간장, 경직경 및 엽수를 유의적으로 증가하였으나, Hyponex를 이용한 추비 처리는 무처리와 비교했을 때 생육증가에 큰 영향을 미치지 않았다. 왜화제 처리시 diniconazole은 농도에 관계없이 왜화효과가 나타났으며, 농도가 증가할수록 크게 억제되었다. Daminozide는 저농도 처리시 무처리와 비교하여 큰 차이가 없었으나, 2000mg·L-1 농도로 처리하였을 때 왜화효과가 나타났으며, 개화율은 diniconazole 저농도에서 가장 낮은 결과를 보였다. 한편 적심 처리에 따른 유의적인 생육 차이는 확인되지 않았다.
        4,000원
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