• Nuclear Engineering and Technology
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• 제26권1호
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• pp.54-62
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• 1994

중저준위 방사성폐기물 처분장 되메움재 후보물질로 제안되고 있는 국산 천연점토와 분쇄암석의 혼합물의 수리특성을 조사하였다. 혼합물의 수분함량 변화에 따른 혼합물의 밀도 변화를 조사하여, 동일 압축력 하에서 최대밀도를 얻을 수 있는 최적수분함량을 찾고자 하였으며, 혼합물 중의 점토함량에 따른 수리전도도 변화를 조사하였다. 혼합물 중 점토함량이 감소할수록 얻어 지는 최대밀도가 증가하였으며, 최적수분함량도 보다 명확해졌으나, 혼합물의 밀도는 수분함량에 그다지 민감하지 않았다. 혼합물의 수리전도도는 점토 함량이 감소할수록 증가하여 건조밀도 1.2 Mg/㎥ 일 때 100% 점토인 경우의 3 $\times$ $10^{-12}$ m/s에서 25% 점토함량의 경우에는 7 $\times$ $10^{-10}$ m/s로 증가하였으나, 건조밀도가 1.5 Mg/㎥ 일 때에는 25% 점토함량의 경우에도 5 $\times$ $10^{-12}$ m/s 의 낮은 값을 유지하였다. 혼합물의 수리전도도 추장을 위한 유효점토건조밀도 개념이 제안되었으며. 이 개념은 다양한 건조밀도와 분쇄암석 함량을 가진 혼할물의 수리전도도를 잘 설명할 수 있었다.

• Nuclear Engineering and Technology
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• 제31권6호
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• pp.608-617
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• 1999

The powder mixture which has a bimodal size distribution, with a large mode corresponding to AUC-UO$_2$ powder and a small one corresponding to ADU-UO$_2$ powder, was prepared, pressed into compacts, and sintered at 1680t for 4 hours in hydrogen gas. The compact density of the powder mixture increases with increasing ADU-UO$_2$content within a content of 20 wt %, since small ADU-UO$_2$ particles can fill interstices between large AUC-UO$_2$particles. The UO$_2$ pellet made using the powder mixture has a lower open porosity than that made using AUC-UO$_2$ powder alone. The mechanism for the formation of a flake-like pore is proposed, and the decrease in open porosity may be ascribed to the decrease in the number of flake-like pores.

• Geomechanics and Engineering
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• 제9권2호
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• pp.219-241
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• 2015

In this paper, a series of repeated load tests were carried out on a 150 mm diameter plate simulative of vehicle passes, to demonstrate the benefits of soil-rubber shred mixture in decreasing the soil surface settlement of road embankment. The results show that the efficiency of rubber reinforcement is significantly a function of the rubber content, thickness of rubber-soil mixture and soil cap thickness over the mixture. Minimum surface settlement is provided by 2.5% of rubber in rubber-soil mixture, the thickness of mixture layer and soil cap of 0.5 times the loading surface diameter, giving values of 0.32-0.68 times those obtained in the unreinforced system for low and high values of amplitude of repeated load. In this installation, in contrast with unreinforced bed that shows unstable response, the rate of enhancement in settlement decreases significantly as the number of loading cycles increase and system behaves resiliently without undergoing plastic deformation. The findings encourage the use of rubber shreds obtained from non-reusable tires as a viable material in road works.

• Nuclear Engineering and Technology
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• 제55권2호
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• pp.780-791
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• 2023

To study oscillation characteristic of steam and non-condensable gas direct contact condensation through multi-hole sparger at low mass flux, a series of experiments of pure steam and mixture gas condensation have been carried out under the conditions of steam mass flux of 20-120kg/m²s, water temperature of 20-95 ℃ and mass fraction of non-condensable gas of 0-5%. The regime map of pure steam condensation through multi-hole sparger is divided into steam chugging, separated bubble, aggregated bubble and escaping aggregated bubble. The bubbles behavior of synchronization in the same hole columns and desynchronized excitation between different hole columns can be found. The coalescence effect of mixture bubbles increases with water temperature and non-condensable gas content increasing. Pressure oscillation intensity of pure steam condensation first increases and then decreases with water temperature increasing, and increases with steam mass flux increasing. Pressure oscillation intensity of mixture gas condensation decreases with water temperature and non-condensable gas content increasing, which is significantly weaker than that of pure steam condensation. The oscillation dominant frequency decreases with the rise of water temperature and non-condensable gas content. The correlations for oscillation intensity and dominant frequency respectively are developed in pure steam and mixture gas condensation at low mass flux.

• 한국응용과학기술학회지
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• 제41권2호
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• pp.520-529
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• 2024

Lycium barbarum extract has a high potential to be developed as a health functional food due to the various health-promoting effects of Lycium barbarum. This study analyzed changes in nutritional and functional components depending on the extraction solvent (purified water and a mixture of purified water and alcohol) and the condition of the sample. The nutritional components (carbohydrates, protein, fat, ash), organic acids, amino acids, total phenolic compounds, and total flavonoids of the extract produced during the extraction process were analyzed. The nutritional composition and functional substances of the extracts showed some differences depending on the type of solvent and the condition of the sample. The amounts of crude protein (7.61%), crude fat (1.63%), carbohydrate (90.22%), and ash (0.54%) of dried Lycium barbarum extract using purified water as a solvent were similar to those of the powder sample extract. The highest content of citric acid was 4.31 mg/mL, similar to the case of acetic acid, when the powder sample used a mixture of purified water and alcohol as a solvent. The highest amino acid content was 357.39 mg/mL when the powder sample was mixed with purified water and alcohol as a solvent. The total amount of phenolic compounds was 686.16 g/L when the powder sample was extracted with a mixture of purified water and alcohol as a solvent. The highest total flavonoid content was 111.32 g/L when the powder sample was extracted with a mixture of purified water and alcohol as a solvent.

• Environmental Engineering Research
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• 제7권3호
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• pp.121-127
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• 2002

• 생명과학회지
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• 제29권10호
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• pp.1086-1095
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• 2019

이 연구는 Red allium cepa (RA), Cucurbita moschata Duch (CM), and Angelica gigas Nakai (AG)의 혼합물을 이용한 새로운 기능성 물질을 개발하기 위해 수행되었다. RA와 CM은 수분 함량이 높아 저장 안정성이 매우 낮다. 따라서 각 재료들의 주요성분들을 추출하여 함량 분석 후 연구에 사용하였다. RA는 에탄올 추출 후 Bacilus subillis KJ-3 (BS3)에 의해 생물전환하였다. 생물전환 후, RA의 Quercetin 함량은 128.9% 증가되었음을 확인하였다. CM의 에탄올 추출물에서는 ${\beta}$-카로틴을 검출하였고 함량은 0.2 mg/g으로 낮았다. AG 에탄올 추출물(1 mg)의 데커신 및 데커시놀 엔젤레이트(D/DA)는 각각 0.4146 mg과 0.3659 mg을 함유했다. D/DA의 순도는 약 78%로 나타났다. 이들 각각의 물질 및 혼합물(혼합물 1 (RA:CM:AG = 5:2:3), 혼합물 2 (RA:CM: AG = 3:5:2), 혼합물 3 (RA:CM:AG = 3:2:5)의 총 플라보노이드 함량과 폴리페놀 함량을 측정하였다. 세포 생존율, 항염증 활성, 항산화 능력 또한 평가하였다. 모든 결과를 종합하여 볼 때, 혼합물 3 (RA:CM:AG=3:2:5)의 항산화 작용이 가장 효과적이었다. 따라서 이러한 연구 결과는 향후 RA, CM, AG의 3:2:5 혼합물을 이용한 식품개발을 위한 기초자료로 활용하고자 한다.

• 한국도로학회논문집
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• 제20권1호
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• pp.47-58
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• 2018

PURPOSES : The purpose of this study is to evaluate the mechanical properties of a cold-recycling asphalt mixture used as a base layer and to determine the optimum emulsified-asphalt content for ensuring the mixture's performance. METHODS : The physical properties (storage stability, mixability, and workability) of three types of asphalt emulsion (CMS-1h, CSS-1h, and CSS-1hp) were evaluated using the rotational viscosity test. Asphalt emulsion residues, prepared according to the ASTM D 7497-09 standard, were evaluated for their rheological properties, including the $G*/sin{\delta}$and the dynamic shear modulus (${\mid}G*{\mid}$). In addition, the Marshall stability, indirect tensile strength, and tensile-strength ratio (TSR) were evaluated for the cold-recycling asphalt mixtures fabricated according to the type and contents of the emulsified asphalt. RESULTS : The CSS-1hp was found to be superior to the other two types in terms of storage stability, mixability, and workability, and its $G*/sin{\delta}$ value at high temperatures was higher than that of the other two types. From the dynamic shear modulus test, the CSS-1hp was also found to be superior to the other two types, with respect to low-temperature cracking and rutting resistance. The mixture test indicated that the indirect tensile strength and TSR increased with the increasing emulsified-asphalt content. However, the mixtures with one-percent emulsified-asphalt content did not meet the national specification in terms of the aggregate coverage (over 50%) and the indirect tensile strength (more than 0.4 MPa). CONCLUSIONS : The emulsified-asphalt performance varied greatly, depending on the type of base material and modifying additives; therefore, it is considered that this will have a great effect on the performance of the cold-recycling asphalt pavement. As the emulsified-asphalt content increased, the strength change was significant. Therefore, it is desirable to apply the strength properties as a factor for determining the optimum emulsified-asphalt content in the mix design. The 1% emulsified-asphalt content did not satisfy the strength and aggregate coverage criteria suggested by national standards. Therefore, the minimum emulsified-asphalt content should be specified to secure the performance.

• 한국초지조사료학회지
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• 제10권3호
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• pp.172-178
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• 1990

This experiment was conducted to enhance nutritional value of whole crop corn silage and increase mixture levels of broiler excreta by adding of corn meal. Treatments were included non mixture(control), adding 10, 20, 30% of broiler excreta and adding 10, 20, 30% of broiler excreta and corn meal as a fresh matter basis, respectively. One liter laboratory silos were prepared. The characteristics of fermentation and micro-organisms during the silage process were assessed. The results obtained are summarized as follows: 1. The crude fiber, NDF and ADF contents were high in whole crop corn(P(O.Ol), crude protein and crude ash contents were high in the broiler excreta(P<0.05), and NFE content was high in corn meal (P< 0.05). 2. Crude protein content of silage was increased(I'$NH_3$-N contents of silage were markedly increased with increasing levels of broiler excreta and corn meal, and was the highest in the 30% broiler excreta treatment(P$meal$ <0.05), and Flieg's value gains "very good" by showing organic acids. 5. Numbers of total bacteria and lactobacilli were $10^5$ to $10^7$ and $10^5$ to $10^6$ , respectively, and were similar in all treatment. Colliform was all but annihilated in the treatment with mixture of broiler excreta and corn rneal.orn rneal.

• 한국약용작물학회지
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• 제27권1호
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• pp.1-8
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• 2019

Background: This study was conducted to investigate the effects of fertilization with the application of mixed organic matter after cultivating green manure crops on the growth and saponin content of Codonopsis lanceolata Trautv. Methods and Results: Five type of cultivation of green manure crops were done: hairy vetch as a single seedling crop (HV), hairy vetch and rye as a mixture of seedling (HV/R), additional fertilization with mixed organic matter after cultivation of a seedling mixture (HV/R/MO), chemical fertilizer (CF), and a non-treated control (NT). The total nitrogen content was the highest in the HV/R/MO treatment, followed by the HV, CF, HV/R and NT treatments, respectively. Nitrogen fixation was higher in the single seedling treatment with hairy vetch (HV) than in the treatment with a mixture of hairy vetch and rye seedling (HV/R). Moreover, the growth of C. lanceolata was greatly increased by the application of additional fertilizer after treatment with the mixture of hairy vetch and rye seedlings. The HV/R/MO treatment produced the highest total lancemaside content among the treatments, followed by HV, HV/R, CF, and NT, respectively. Conclusions: It was verified that C. lanceolata experienced superior growth with the application of mixed organic matter as additional fertilizer after the cultivation of green manure crops, and the content of its major saponins, lancemasides were also increased by this treatment.