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An Experimental Study on the Pore Structure and Thermal Properties of Lightweight Foamed Concrete by Foaming Agent Type (기포제 종류에 따른 경량기포콘크리트의 기포구조 및 열적특성에 관한 실험적 연구)

  • Kim, Jin-Man;Choi, Hun-Gug;Park, Sun-Gyu
    • Journal of the Korea Institute of Building Construction
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    • v.9 no.4
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    • pp.63-73
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    • 2009
  • Recently, the use of lightweight panels in building structures has been increasing. Of the various lightweight panel types, styrofoam sandwich panels are inexpensive and are excellent in terms of their insulation capacity and their constructability. However, sandwich panels that include organic material are quite vulnerable to fire, and thus can numerous casualties in the event of a fire due to the lack of time to vacate and their emission of poisonous gas. On the other hand, lightweight foamed concrete is excellent, both in terms of its insulation ability and its fire resistance, due to its Inner pores. The properties of lightweight concrete is influenced by foaming agent type. Accordingly, this study investigates the insulation properties by foaming agent type, to evaluate the possibility of using light-weight foamed concrete instead of styrene foam. Our research found thatnon-heating zone temperature of lightweight foamed concrete using AP (Aluminum Powder) and FP (animal protein foaming agent) are lower than that of light-weight foamed concrete using AES (alkyl ether lactic acid ester). Lightweight foamed concrete using AES and FP satisfied fire performance requirements of two hours at a foam ratio 50, 100. Lightweight foamed concrete using AP satisfied fire performance requirements of two hours at AP ratio 0.1, 0.15. The insulation properties were better in closed pore foamed concrete by made AP, FP than with open pore foamed concrete made using AES.

A Study on the Administration for the Han River Water Quality Control (漢江 水質保全 行政에 관한 硏究)

  • Kim, Kwang Hyop
    • Journal of Environmental Health Sciences
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    • v.10 no.2
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    • pp.9-40
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    • 1984
  • This thesis purports to overview the diverse administrative and organizational factors and plannings developed by the government organizations, municipal or otherwise, to tackle the Han River water pollution issues in the past years. This thesis also looks into the ever-worsening Han River water pollution problems, in particular, in terms of the various government plans ostensibly designed to reduce the pollution level but with little success. Also dealt with are the efficiencies with which the laws and decrees on water pollution the administrative organizations put to use in the prosecution of the diverse antiwater pollution projects involving the Han River basin. From the early 1960's up to the 1970's the government had concentrated on the growth-oriented economic policy with the result that little attention had been paid to the water pollution and other environmental issues that are bound to arise from the massive economic growth. Belatedly, the five-year Hah River Development Project was initiated in 1982 with emphasis on reducing the water pollution level at Hah River to the minimum. The following are the gists of the thesis and recommendations for the future antiwater pollution plans by the administrative organizations: 1. Documents to date indicate that the irrigation projects along the Han River area had been the main focus of attention during the Yi Dynasty and under the Japanese rule of the country. 2. Despite that the water pollution issue became the subject of many debates among the academic and research institutions in the 1960's and in the 1970's, the administrative organizations in charge of the Han River water quality control failed to come up with a concrete plan for the river's water quality control. 3. Nevertheless, the water pollution of the Han River area in fact began in the 1950's, with the unprecedented concentration into Seoul of population and the industrial facilities on a larger scale, in particular, enforced by the government's strong growthoriented policy in its Economic Development plans in the 1960's. 4. Starting in the 1960's, the Han River water pollution level dramatically increased, but the government was reluctant to promulgate or put into effect strong measures to curb the many factors contributing to the river water pollution, thus worsening the environmental issues along the Han River basin. 5. The environmental protection law and other laws and decrees relating to the antiwater and air pollution issues that were subsequently put into effect underwent so many changes that efficient anti-water pollution policies could not be effected for the Han River basin. The frequent organizational reshuffle within the administrative units concerned with environmental problems has resulted in the undue waste in personnel management and finance. 6. The administration on the environmental protection could not be efficiently carried out due to the organizational overlapping. Under the existing law, frequent organizational frictions and inefficiency are bound to occur among the central government offices themselves, as well as between the central government and the Seoul city administration, and among the city's administrative offices over the conservation of the Han River basin and over the river's anti-water pollution issue. 7. In the planning and prosecution of the Han River project, political influences from the president down to the lower-level politicious appear to have been involved. These political influences in the past had certainly had negative influence on the project, nevertheless, it appears that in the recent years, these political influences are not all that negative in view of the fact that they serve as a positive contributing factor in developing a better water quality control project along the Han River basin. The following are a few recommendations based on the data from the thesis: First, officials in charge of the Han River water quality control should pay attention to a careful screening of the opinions and recommendations from the academic circles and from the public should be made so that the government could better grasp the core issues in the environmental problems that require preventive and other necessary measures. Second, vigorous redistribution policies of population and industrial facilities away from the Seoul area should be pursued. Third, the government should refrain from revising or revamping too frequently the laws and decrees on the anti-water pollution, which is feared to cause undue inconveniences in the environmental administration. Fourth, a large-scale streamlining should be made to the existing administrative organization in an effort to do away with the inter- and intra-organizational friction. It is recommended that a secretariat for the Hah River basis conservation be established. Fifth, High-level administrative officials, with a thorough knowledge and vision on the Han River water quality control, should be prepared to better deal with the budgeting and personnel management for the Han River water pollution control not only at the control government, but also at the Seoul city municipal government levels. Environmental issues should be kept distinct from political issues. Environmental issues should not serve as a window-dressing for sheer political purposes. Sixth, the Hah River proiect should also include, along with the main Han River basin, those areas covering North Han River, South Han River, and the tributaries to the main river basin. The 'Han River Basin Water Quality Control Board' should be established immediately as a means of strengthening the current Han River basin water quality control policy. Seventh, in drawing up the Han River proiect, the administrative officials should be aware that Han River basin is a life line for those people in the region, providing them with not only a sheer physical space, but with a psychological living space for their everyday life.

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Framework on Soil Quality Indicator Selection and Assessment for the Sustainable Soil Management (지속가능한 토양환경 관리를 위한 토양질 지표의 선정과 평가체계)

  • Ok, Yong-Sik;Yang, Jae-E.;Park, Yong-Ha;Jung, Yeong-Sang;Yoo, Kyung-Yoal;Park, Chol-Soo
    • Journal of Environmental Policy
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    • v.4 no.1
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    • pp.93-111
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    • 2005
  • Defining soil quality in scopes and applications is one of the prerequisite for the sustainable management of soil environment to orient researches, strategies and policies. However, definition of soil quality is controversial depending upon a viewpoint of soil science or soil environment. Soil quality can be, irrespective of the disciplines, defined as the capacity of a soil to function within ecosystem boundaries to sustain biological productivity, maintain environmental quality and promote plant and animal health. Common to all of the soil quality concepts can be summarized as the capacity of soil to function effectively at present and in the future. The OECD includes soil quality as one of the agri-environment indicators. This article intends to i) summarize the current soil quality research, and ii) provide information on protocol of soil quality assessment. A framework for soil quality was divided into three steps: indicator selection as minimum data set (MDS), scoring of the selected indicators, and integration of scores into soil quality index. Korean government suggested possible physical and chemical indicators such as bulk density and organic matter for paddy and upland soils to OECD. The framework of soil quality assessment is not yet implemented in Korea. Countries such as USA, Canada and New Zealand have constructed the framework on soil quality assessment and developed a user-friendly version of soil quality assessment tools to evaluate the integrated effects of various soil management practices. The protocol provided in this review might help policymakers, scientists, and administrators improve awareness about soil quality and understand the way of soil environment management.

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Effects of Compositae Plants on Plasma Glucose and Lipid Level in Streptozotocin Induced Diabetic Rats (국화과 식물의 섭취가 Streptozotocin 유발 당뇨 흰쥐의 혈당과 지질 수준에 미치는 영향)

  • Han, Hye-Kyoung;Yoon, Su-Jin;Kim, Gun-Hee
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.38 no.6
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    • pp.674-682
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    • 2009
  • This study was designed to examine the effects of Compositae plants on plasma glucose and lipid levels in streptozotocin (STZ) induced diabetic rats. Sprague-Dawley rats were randomly assigned to 5 groups: normal, STZ-control and three experimental groups [Artemisia iwayomogi (A. iwayomogi), Atractylodes lancea (A. lancea), and Taraxacum mongolicum (T. mongolicum)]. Normal and STZ-control group were fed an AIN-93 diet and three experimental groups were each fed a modified diet containing 10% compositae powder for 4 weeks. The plasma glucose levels at 4 weeks of A. iwayomogi, A. lancea, and T. mongolicum groups were significantly lower than STZ-control group. The A. iwayomogi and A. lancea groups had significantly suppressed hypertrophy of liver and kidney. The hematocrit levels of A. lancea and T. mongolicum group were significantly lower than STZ-control groups. The total cholesterol and triglyceride levels and atherogenic index (AI) of A. lancea group were significantly lower than STZ-control group. Intake of Compositae plants may be effective in antihyperglycemia by lowering blood glucose levels. The A. iwayomogi, A. lancea, and T. mongolicum can be beneficial for the diabetic complications and damage from the lipid peroxidation.

Food Safety Knowledge and Home Food Safety Practices of Home-delivered Meal Service Recipients (가정배달 노인급식 수혜자의 위생지식 및 가정에서의 위생관리 습관)

  • Lee, Kyung-Eun;Yi, Na-Young;Park, Jung-Yeon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.38 no.5
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    • pp.618-625
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    • 2009
  • The purposes of this study were to evaluate food safety knowledge and to assess home food safety performance of home-delivered meal service recipients. Two facilities providing home-delivered meal services for older adults were located in Seoul. A total of 120 service recipients were surveyed using an individual interview technique and 97 responses were used for data analysis. A statistical data analysis was completed using SPSS program (ver.14) for descriptive analysis, t-test, ANOVA, and correlation analysis. The majority of the participants were 70 years old or older and females. They perceived their health status as poor or very poor and took more than one kind of medicines. An average score of the food safety knowledge test was 11.48 based on 18 points (63.8%). The results revealed that the older adults knew the importance of hand washing but were not aware of when and how to wash hands. There was room to improve knowledge on cleaning and sanitizing fresh fruits and using wiping cloth. The knowledge score for each category was not significantly different by gender and age. The home food safety practices of the older adults was rated as 2.8 out of 4 points; the highest score was associated for proper food handling category and the lowest score was for cleaning and sanitizing. The worst performance was related to managing hand cuts and wounds (1.96). The total knowledge score and an average performance score were significantly correlated (p<0.01). Food safety education programs targeting the older adults who receive home-delivered meal services would improve the recipients' food safety knowledge and practices related to consumption of the meals at home. The programs should focus on not only improving food safety knowledge but also changing food safety practices.

Effects of Zinc Plus Arachidonic Acid on Insulin Resistance in High Fructose-Fed Rats (Zinc와 Arachidonic Acid가 고 Fructose 식이로 유도된 인슐린 저항성에 미치는 영향)

  • Choi, Chul-Soo;Kim, Young-Wook;Lee, Hyo-Sun;Yoon, Tae-Ho;Cho, Byung-Mann;Lee, Soo-Il;Kim, Sung-Soo;Hwang, In-Kyung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.38 no.4
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    • pp.415-422
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    • 2009
  • We previously demonstrated that zinc plus arachidonic acid (ZA) treatment lowered blood glucose levels in streptozotocin-induced diabetic rats, genetically diabetic obese (ob/ob) mice, and genetically diabetic, non-obese Goto-Kakizaki rats. However, plasma insulin levels did not increase with ZA treatment, suggesting that ZA lowers blood glucose levels not by stimulating pancreatic insulin secretion. However, it is unclear whether these agents lower blood glucose levels by decreasing hepatic glucose output (HGO) or by increasing glucose utilization in peripheral tissues, or both. In order to determine ZA target organ of insulin action, we divided 18 Sprague-Dawley rats weighing ${\sim}130g$ into 3 groups (6 rats per group) and treated them for four weeks with: (1) Control diet (regular rat chow), (2) High fructose (60.0%) diet only, and (3) the same fructose diet plus zinc (10 mg/L) and arachidonic acid (50 mg/L) containing drinking water. After 4 weeks, insulin action was assessed using the hyperinsulinemic euglycemic clamp technique. Food intake and body weights were comparable in all three groups of rats throughout the study period. Plasma glucose and insulin concentrations, glucose uptake, and HGO in the basal state were all the same in these three rat groups. During the clamp study, fructose-treated and fructose+ZA treated rat groups did not exhibit any detectable change on insulin-mediated glucose uptake compared to controls. High fructose feeding impaired insulin mediated suppression of HGO, compared to controls during clamp (4.39 vs. 2.35 mg/kg/min; p<0.05). However, ZA treatment in high fructose-fed rats showed a remarkable increase in hepatic insulin sensitivity compared to high fructose-fed rats, reflected by a complete recovery in suppression of HGO during the clamp (4.39 vs. 2.18 mg/kg/min; p<0.05). This data suggests that ZA increases insulin sensitivity in liver but not glucose utilization of peripheral tissues in high fructose-fed rats.

Environmental Condition for the Butt-Rot of Conifers by Cauliflower Mushroom (Sparassis crispa) and Wood Quality of Larix kaempferi Damaged by the Fungus (꽃송이버섯에 의한 침엽수 심재부후 발생환경 및 낙엽송 피해목의 재질 특성)

  • Park, Hyun;Oh, Deuk-Sil;Ka, Kang Hyeon;Ryu, Sung-Ryul;Park, Joo-Saeng;Hwang, Jaehong;Park, Jun-Mo
    • Journal of Korean Society of Forest Science
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    • v.98 no.1
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    • pp.16-25
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    • 2009
  • Cauliflower mushroom (Sparassis crispa) is recently recognized as a new edible and/or medicinal mushroom cultivated with conifers. By the way, the mushroom is notorious as a brown-rot fungus that causes a buttrot of larch. So, there should be a careful consideration to apply the mushroom cultivation in coniferous stand. This study was conducted to clarify the seriousness of heartwood decay on conifers such as larch by cauliflower mushroom with surveying the mushroom producing environment and to examine whether the cultivation of cauliflower mushroom produce any problem in conifer stands or not. The mushroom occurred in various coniferous stands such as Larix kaempferi, Pinus koraiensis, P. densiflora and Abies holophylla on fertile soils with adequate moisture. Soil texture of the mushroom producing site was comparatively fine compared to general forest soils; sandy loam, loam and silty loam. Soil pH ranged from 4.6 to 5.2, and organic matter contents were 4~11%, which showed relatively wide range. We could find S. crispa by a DNA technique from the wood that seemed to have no heartwood decay by naked eyes. The damaged wood showed 30% higher moisture contents than that of sound wood, while the compressive strength was 30% lowered down compared to that of sound wood. The fungus may invade conifers through the scars occurred on roots or stems, in this case spore dispersion of the mushroom takes a great role. Thus, we concluded that forest tending activities need to be applied with considering the invasion of S. crispa, and cultivation of cauliflower mushroom in forest should be attempted very carefully. By the way, we also infer that conifer stands can be nurtured without heartwood decay by S. crispa if the stand be managed in good aeration conditions by proper silvicultural practices such as sanitary thinning.

Evaluation of Effectiveness of Vegetable-related Nutrition Education for Elementary School Students (초등학생 대상 채소 관련 영양교육의 효과 평가)

  • Lee, Sun-Ok;Kim, Hyun-Ah
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.42 no.5
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    • pp.713-720
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    • 2013
  • The purpose of this study was to evaluate the effectiveness of vegetable-related nutrition education for fourth grade elementary school students in Gyeongnam province. A comparative analysis of nutritional knowledge on vegetables, vegetable preferences, and vegetable intake in school foodservices were assessed between a control group and an experimental group. The control and experimental group contained 62 and 67 students, respectively, and the experimental group received nutritional education in four sessions (40 minutes each session) per week. A self-administered survey was conducted before and after this education, and 122 questionnaires (for 61 members of the experimental group and 61 members of control group) were analyzed. In the experimental group, there was a significant (p<0.001) increase in vegetable-related nutrition knowledge (form 5.02 to 6.10 out of a total score of 9), while there were no significant differences in the control group. Vegetable preference scores also significantly (p<0.001) increased (from 3.44 to 3.85 on the 5-point Likert scale) in experimental group, while there were no significant difference in control group. We also observed a significant (p<0.001) increase in vegetable intake from school foodservices (89.34% to 95.49%) in the experimental group, but there were no significant differences in the control group. In conclusion, a vegetable-related nutrition education for fourth grade elementary school students was effective at improving the nutritional knowledge of vegetables, vegetable preferences, and vegetable intake from school foodservices. Therefore, to encourage the vegetable-related right dietary habits, sustainable, and systematic nutrition education programs should be implemented for elementary students.

Effect of Rice Flour Prepared with Enzyme Treatment on Quality Characteristics of Rice Cookies (효소처리 쌀가루를 이용한 쌀 쿠키의 품질 특성)

  • Kim, Mi-Seon;Park, Jong Dae;Lee, Hyun Yu;Kum, Jun Seok
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.42 no.9
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    • pp.1439-1445
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    • 2013
  • The aim of this study was to investigate the quality characteristics of rice cookies specifically prepared with rice flour following enzyme treatment. In this study, three types of specific enzyme treatments, that is, ${\alpha}$-amylase, ${\beta}$-amylase, and cellulose+${\beta}$-glucanase were applied on the effect of rice flour with respect to desired quality characteristics of the rice cookies. Based on our study results, we have found that the density of dough in the rice cookies was not significantly different between that of the non-enzyme treated (control) and the enzyme treated group. However, we found that the spread factor of rice cookies, prepared with rice flour treated with ${\beta}$-amylase, was higher than that of the control. It was also found that the moisture content of rice cookies (with added enzyme-treated rice flour) was 3.20 to 3.90%; however, this range is much lower than that observed in the control. Further, we observed that Hunter color's L-values were significantly higher for the control than those of the enzyme-treated cookies. We also found that hardness of enzyme-treated cookies was comparatively better than that of the control. In addition, the sensory acceptability scores of the enzyme-treated cookies were found to be significantly higher than the control in decisive parameters such as aroma, appearance, flavor, taste, texture, and overall acceptability. Based on our findings, we suggest that ${\alpha}$-amylase treated rice flour is an effective ingredient for improving the overall quality of rice cookies.

Antioxidant and Anticancer Effects of Edible and Medicinal Mushrooms (식용 및 약용버섯의 항산화 및 In vitro 항암 효과)

  • Qi, Yongcai;Zhao, Xin;Lim, Yaung-Iee;Park, Kun-Young
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.42 no.5
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    • pp.655-662
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    • 2013
  • The antioxidant and anticancer effects of the edible mushrooms Lentinus edodes (LE, Pyogo mushroom) and Agaricus blazei (AB, Agaricus mushroom), and the medicinal mushrooms Cordyceps militaris (CM, Dong chunghacho), Ganoderma lucidum (GL, Youngji mushroom), Inonotus obliquus (IO, Chaga mushroom), and Phellinus linteus (PL, Sangwhang mushroom) were studied in vitro. The bioactive components were extracted by methanol. The antioxidant effects were evaluated using the DPPH and hydroxyl radical scavenging assays. The antioxidant activities of medicinal mushrooms (35~90%) were higher than edible mushrooms (4~23%). The in vitro anticancer effects of the mushrooms were evaluated using the MTT assay in AGS gastric adenocarcinoma cells, HCT-116 colon carcinoma cells, and HepG2 hepatoma cells. The medicinal mushrooms CM, GL, IO, and PL showed 28~91% inhibition, while the edible mushrooms LE and AB exhibited 5~40% inhibition. The medicinal mushrooms, compared to edible mushrooms, effectively down-regulated the gene expression of the anti-apoptosis related gene Bcl-2 and inflammation-related genes iNOS and COX-2, and up-regulated the pro-apoptosis gene Bax (p<0.05). Total polyphenol and flavonoids contents of the medicinal mushrooms were 9.1~35.7 mg/g, while the edible mushrooms showed 0~13.3 mg/g. This study showed that antioxidant activities and anticancer activities in vitro increased in the order LE, AB, GL, CM, IO and PL. LE and AB showed the lowest effects among the samples, GL and CM had medium effects, and IO and PL exhibited the highest effects in the antioxidant and anticancer effect for three different human cancer cells. Taken together, PL resulted in the highest and LE the lowest effects in this study.