• Magazine of the Korea Concrete Institute
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• v.10 no.5
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• pp.189-195
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• 1998

콘크리트 구조물이 초기재령에서 외기에 노출될 때, 수부확산으로 인하여 수분의 이동이 일어나고, 또한 자체건조도 발생한다. 이러한 콘크리트 내부의 수분확산과 자체건조에 의하여 콘크리트의 위치에 따라 상대습도가 변호한다. 특히 고강도 콘크리트의 경우에 단위 시멘트량을 많이 사용하기 때문에 , 초기재령에서 콘크리트 단면의 수분분포는 자체건조에 의하여 큰 영향을 받는다. 본 연구에서는 초기재령에서 외기에 노출된 콘크리트 내부의 여러 위치에서 상대습도를 측정하였다. 또한 자체건조로 인한 콘크리트의 상대습도 변화를 측정하여 초기재령에서 수분확산과 자체건조가 콘크리트 내부의 각 위치에서 상대습도에 미치는 영향을 검코하였다. 그리고 수분확산 이론에 의하여 해석결과와 실험결과를 비교하여 \ulcorner재령에서 수분확산 이론의 타당성을 검증하였다. 저강도 콘크리트 단면의 수분분포는 주로 수분확산에 의하여 영향을 받았으며, 자체건조의 영향은 매우 작게 나타났다. 그렇지만 고강도 콘크리트는 수분확산 뿐만 아니라 자체건조에 의하여도 영향을 받았다. 또한 수분확산 이론에 의한 해석결과는 실험결과를 잘 예측하였다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.5
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• pp.116-122
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• 2016

This study was intended to evaluate the properties of concrete incorporating stone powders which are created during crushing natural stones to produce crushed aggregates. For concretes with 0~30 wt.% partial replacement fine aggregates with stone powders, experiments of slump, air content, strength and drying shrinkage were carried out. The experiments found that the increase of the amount of stone powders sharply decreased slump and air content. Partially using stone powders instead of fine aggregates was found to increase both compressive and tensile strength slightly. Substituting higher amount of stone powders presented higher drying shrinkage. When HRWRA was added into the concrete with stone powders in order to obtain workability similar to that of plain concrete without stone powders for the same water-cement ratio and unit weight of cement, air content increased with the amount of HRWRA but strength and drying shrinkage were hardly affected by adding HRWRA.

• Korean Journal of Food Science and Technology
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• v.43 no.5
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• pp.603-610
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• 2011

This study was performed to examine the physicochemical characteristics and sensory properties of makgeolli with dried citron peel and levels (3, 6, and 9%) of citron (Citrus junos) in makgeolli during fermentation with two-step-brewing. The pH of makgeolli with citron dried peel increased within 5 days of fermentation, and decreased until 11 days of fermentation. Total acidity increased after 3 days of fermentation then decreased after 5 days of fermentation, but continued to increase slightly up to 12 days. Changes in alcohol content and amino acidity increased during fermentation. A sensoryevaluation of appearance, flavor, sourness, sweetness, bitterness, and overall acceptance of makgeolli with citron dried peel showed lower values than those of the control.

• Journal of the Korea Concrete Institute
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• v.14 no.3
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• pp.331-340
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• 2002

In this paper, finite element analysis is applied for simulation of cracks due to restraining autogenous and drying shrinkage at early-age concrete. A micro-level heat hydration model and a shrinkage prediction model along with a moisture diffusion model are adopted for the finite element analysis. Then, an axial restraint test is carried out for concrete specimens containing different amounts of chloride ions to evaluate stress development and cracking due to the restraining shrinkages at early ages. Test results show that the increase of contents of chloride ions increases restrained stress, but does not increase strength. By this increase of shrinkage strain at early-age, time to occur the crack is accelerated. Finally, stress development and cracking of concrete specimens containing different amount of chloride ions we simulated using the finite element analysis. Results of the analysis using the Proposed model are verified by comparison with test results.

• Journal of the Korea Society of Computer and Information
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• v.27 no.12
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• pp.259-266
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• 2022

In this paper, we propose a study is to prepare basic data for integrated health promotion education by preventing dry mouth and dry eyes through lifestyle management. From October 7 to 17, 2022, a total of 516 respondents who voluntarily agreed and responded through a self-written structured questionnaire were statistically analyzed for university students in their 20s across the country. As for the factor of feeling dry mouth among the living habits of the study subjects, the more smoking per day, the higher(8.41±2.041) and very high(7.75±2.927) felt dry mouth(p=.015), and the time spent using smart phones. The shorter this was, the lower(1.16±0.784) and very low(1.83±1.672) felt dry mouth(p=.022). The main factors contributing to dry mouth and dry eyes were dry eyes (odds ratio 3.651, p=.000), and high smoking(odds ratio 0.916, p=.038), and the more you use your smart phone (odds ratio 0.256, p=.004), the more you feel dry mouth. When feeling dry eyes, they felt dry mouth more(odds ratio 4.002, p=.000), and the more they exercised, the more dry eyes they felt(odds ratio 1.600, p=.009). As a result, since dry mouth and dry eyes appear as common inconveniences, it was found that lifestyle management is necessary to maintain and promote a healthy life. Therefore, it is proposed to build an integrated health platform that can improve the quality of life and implement personalized health management programs.

• Korean Journal of Food Science and Technology
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• v.33 no.2
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• pp.245-251
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• 2001

This research was conducted to study the changes in physical characteristics of mushrooms (Agaricus bisporus) as influenced by drying methods. Samples were dried using either hot air drying, vacuum drying, or freeze drying and changes in the color, browning index, hardness and rehydration rate were evaluated by response surface methodology. Hot air drying resulted in the fastest drying of sample as compared to other methods. The rate of drying was most affected by the environmental temperature rather than air velocity or vacuum pressure. The overall color difference increased as the temperature and air velocity increased. The overall color changes of the freeze dried samples were minimal as compared to those of fresh mushrooms. The hot air dried samples showed the greatest changes in the overall color, browning index as well as hardness. The freeze dried samples showed the best rehydration characteristic and maintained the best overall quality after drying.

• Bulletin of the Society of Naval Architects of Korea
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• v.13 no.3
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• pp.25-43
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• 1976

조선소(造船所)를 기획(企劃)함에 있어 우선 수행(遂行)해야 할 일은 선박시장분석(船舶市場分析)이다. 이에 따라서 건조대상선박(建造對象船舶)을 선정(選定)하게되고 적정작업량(適定作業量)을 결정(決定)하게 되며 Layout 작업(作業)에 들어갈 수 있다. 조선소(造船所) Layout 작업(作業)에서는 건조기술(建造技術)과 밀접(密接)한 관계(關係)를 지어 건조과정(建造過程)의 Network에서 Outlined Layout를 구(求)한다. 각(各) Work stage별(別) Detailed layout는 채택(採擇) 하려는 건조기술(建造技術)과 그 Stage의 물동량(物動量)에 따라서 결정(決定)지어진다. Layout의 마지막 단계(段階)는 이 Layout된 조선소(造船所)에서 건조(建造)하고자 하는 선박(船舶)의 추정건조선가(推定建造船價)와 현재(現在) 선박시장(船舶市場)에서의 선가(船價)와의 비교(比較)에 의한 Layout의 경제성(經濟性) 평가(評價)가 되겠다. 조선소(造船所) Layout는 단순히 Layout 작업(作業) 만으로는 수행(遂行)할수없고 건조(建造)하고자 하는 선박(船舶)의 개발작업(開發作業)과 병행(竝行)되어야 한다.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.2
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• pp.61-71
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• 2004

These studies were conducted to investigate the effects of feeding dried leftover food (DLF) on growth, feed conversion and carcass characteristics of growing and finishing pigs. In experiment 1, seventy-five three-way cross-hybrids ($Yorkshire{\times}Landrace{\times}Duroc$) pigs weighing approximately 22 kg of body weight on average were assigned to five treatments in a completely randomized design. Each treatment had three replications with five pigs per replication. All pigs were fed experimental diets for 60 days. In experiment 2, seventy-five three-way cross-hybrids pigs weighing approximately 70 kg of body weight were fed experimental diets for 49 days. Each treatment had three replications with five pigs per replication. The treatments included 1) group offered control diet without DLF, 2) group offered diet containing DLF at 25%, 3) group offered diet containing DLF at 50%, 4) group offerred diet containing DLF at 25% with 10% higher protein level and 5) group offerred diet containing DLF at 50% and 20% higher protein level. Average daily gain of growing pigs was highest in control group among all the treatment groups except group offered diet containing DLF at 25% with no significant difference (P>0.05). Feed intake of DLF-offered groups were lower than that of control group while feed intake of groups fed diets containing DLF at 50% with 20% higher protein level was significantly higher (P<0.05) than that of control group. Feed conversion of growing pigs was not significantly different amont treatments although it seemed to be slightly improved in groups fed diets containing DLF at 25%. Average daily gain of finishing pigs fed diets containing DLF was significantly lower than that of control group. However there was no significant differences in average daily gain between groups fed diets containing DLF at 25% with 10% higher protein level and control group (P>0.05). Feed intakes were significantly decreased in DLF-fed groups compared to control group while there was no significant differences in feed intake between groups fed diets containing DLF with 10% and 20% higher protein levels and control group (P>0.05). Feed conversion was lowest in groups fed diets containing DLF at 25% with 10% higher protein level. However, there were no significant differences in feed conversion between groups fed diets containing DLF at 25% with 10% higher protein level and control group. Feed conversion of groups fed diets containing DLF at 50% was significantly higher than that of control group (P<0.05). Carcass weight was decreased with increasing levels of DLF in the diets. There were no significant differences in dressing percentage, backfat thickness and carcass grade among treatments. Feed cost per 1 kg body weight gain of finishing pigs was lowest in groups fed diets containing DLF at 25% with 10% higher protein level.

• Applied Biological Chemistry
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• v.40 no.1
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• pp.43-47
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• 1997

The weight ratio of the seed in jujube averaged to 19.1%. The chemical components of dried pitted-jujube were moisture 20.4%, protein 5.3%, fat 1.3%, ash 2.7%, fiber 4.4% and nitrogen-free extract 65.9%. Alcohol insoluble solid content of dried pitted-jujube was 17.4%, in which ammonium oxalate-soluble pectin was 3.7%, water-soluble pectin 3.0%, hydrochloric acid-soluble pectin 1.0%, and sodium hydroxide-soluble pectin 1.0%. Jujube contained sucrose, glucose and fructose as free sugar. The sugars of dried pitted-jujube was composed of sucrose 48.1%, fructose 18.7%, and glucose 11.3%. Drying experiments of pitted-jujube and unpitted-jujube were carried out. Moisture content and brix of dried pitted-jujube were reached at that of dried unpitted-jujube(11%, 78 brix in 48 hours of dry) in 11 hours of drying. And this means that dried pitted-jujube dried 4 times faster than dried unpitted-jujube. The extracts of dried pitted-jujube and dried unpitted-jujube were examinet according to the amount of water added and the extraction time. The brix of dried pitted-jujube extract for 30 min is similar to that of dried unpitted-jujube extract for 150 min. The brix of the extracts did not increase after 150 min extraction. As to the color of extract, 'L' value was higher in dried unpitted-be, while 'a' and 'b' values were higher in dried pitted-jujube.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.12
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• pp.821-827
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• 2012

Air drying is a technology to dry sludge at the ejector and multi cyclone as intaking and blowing air from outside. So, this technology has a weak point that operating fluctuation is large according to an outside conditions as well as energy consumption is also large due to open loop structure. This is to develop the closed-loop air drying system to be built the dehumidifier consisted of condenser, cooler and compressor at rear side of separator of air dryer, as a way to solve some problem. Air is circulation by the method of blowing-drying-dehumidifying-blowing within this system. It is analyzed that an air circulated at closed-loop air drying equipment contains the energy of 50% more compared with open-loop air drying and is operated regularly because of quality maintenance of air to dry sludge. And also it is analyzed that the cost of drying sludge of 1 ton by closed-loop air drying equipment is lower about 35% than conventional equipment. Therefore, this is evaluated by useful drying technology to face an unexpected climatic conditions due to regular operation as well as low energy consumption.