• Applied Chemistry for Engineering
• /
• v.25 no.2
• /
• pp.121-133
• /
• 2014

Block copolymers including ABA triblock architectures are useful as thermoplastic elastomers and toughened plastics depending on the relative glassy and rubbery content. These materials can be blended with other polymers and utilized as additives, toughening agents, and compatibilizers. Most of commercially available block copolymers are derived from petroleum. Renewable alternatives are attractive considering the finite supply of fossil resources on earth and the overall economic and environmental expenses involved in the recovery and use of oil. Furthermore, tomorrow's sustainable materials are demanding the design and implementation with programmed end-of-life. The present review focuses on the preparation and evaluation of new classes of renewable ABA triblock copolymers and also emphasizes on the use of carbohydrate-derived poly(lactide) or plant-based poly(olefins) having a high glass transition temperature and/or high melting temperature for the hard phase in addition to the use of bio-based amorphous hydrocarbon polymers with a low glass transition temperature for the soft components. The combination of multiple controlled polymerizations has proven to be a powerful approach. Precision-controlled synthesis of these hybrid macromolecules has led to the development of new elastomers and tough plastics offering renewability, biodegradability, and high performance.

• Fire Science and Engineering
• /
• v.28 no.6
• /
• pp.82-89
• /
• 2014

Disasters that destroy homes and infrastructure and cause significant financial damage are becoming more common as population centers grow. In addition, several natural disasters have resulted in a major loss of life and created countless refugees due to damage to housing. After major catastrophic disasters, it is very important that the government agencies respond to post-disaster housing issues and provide resources such as temporary housing before the full rehabilitation and reconstruction of destroyed and damaged housing. To provide affordable temporary housing for residents who may lose their homes as the result of a catastrophic disaster including storms, government agencies must develop a post-disaster housing prototype. In general, government agencies should explore several different forms of factory-built single-story, single family housing, such as modular homes, panelized homes, and precut homes. In urban cities including New York and Seoul, it is very important to provide housing which supports the demand for higher-density living spaces than single-family homes or trailers typically available due to the high population density and the desire to resettle as many residents as possible in their former neighborhoods. This study identified the urban post-disaster housing prototypes that may provide higher density housing with high quality living spaces, high air quality, and energy efficiency as well as rapid deployment. A case study of "Urban Post-Disaster Housing Prototype Program in New York" was conducted through a detailed interview process with a designer, engineer, contractor, the Office of Emergency Management (OEM) in New York, the U.S. Army Corps of Engineers (USACE), and temporary occupants. An appropriate disaster housing program that can provide living spaces for victims of disasters that keeps residents in their community and allows them to live and work in their neighborhoods was developed.

• International Journal of Highway Engineering
• /
• v.11 no.3
• /
• pp.41-49
• /
• 2009

Cement concrete pavement has become more common in Korean highway systems. However, as its service period increases, there are some technical problems occurs and no clear solution is available primarily due to the lack of active researches. This research, hence, aims to develop a new mix proportion that may provide better strength and durability with extended service life. Based on a variety of literature reviews, the experimental variables were determined as unit cement content, S/a ratio and W/C ratio. From the experimental works, it is recommended to increase the unit cement content up to 375kg/$m^3$, 400kg/$m^3$ and 425kg/$m^3$. The target slump and air content were set 40mm and 5%, respectively. The maximum size of coarse aggregate was decided to be 25mm because of the easiness of supply in the field. The reduction of W/C ratio was necessarily required and decreased to 0.4 which was proven not to cause any mixing problem with the increased unit cement contents along with polycarbon-based high range water reducing agent. In addition, it was known that the S/a ratio could be reduced to 0.34. The lowered S/a might be possible because of the increased cement paste and hence increased cohesiveness and workability.

• Parasites, Hosts and Diseases
• /
• v.26 no.4
• /
• pp.255-262
• /
• 1988

An epidemiological study on brugian filariasis was carried out in endemic areas including Cheju Island in Korea, with a brief review of literatures. The results showed that the incidence among residents has remarkably decreased in Cheju Island, which was the main endemic area. Reviewing available informations on the prevalence of filariasis reported in recent years and also judging from the present socio·economic conditions which enable people to practice personal protection against mosquitos, it can be said with confidence that alariasis has almost disappeared from Cheju Island and inland areas. The disease is considered to remain at a low level of endemicity in Hugsan Islands. Certainly mass diethylcarbamasine (DEC) treatment carried out in Cheju Island in the 1960s and 1970s and remarkable economic growth followed by improved living standard and altered life-style of inhabitants could all have combined effects on the disappearance of this mosquito-borne disease in this island. If the present trends go on, the possibility of resurgence of filariasis in Cheju Island is hardly postulated.

• Korean Journal of Veterinary Research
• /
• v.15 no.2
• /
• pp.187-198
• /
• 1975

Although considerable research has been done on the blood chemistry of domestic animals, little work has been made of the changes associated with age. Moreover, the records about physiology of the goat were not much available in Korea, and a comprehensive survey of the blood values of the Korean native goat has not been made. The object of the present investigation was to make good this deficiency and to suggest standards for the blood chemical values of Korean native goats from birth to maturity. The goats were kept under average farming conditions in Korea. Blood samples were collected from the jugular vein at birth, at one and four days, at one, two, three and four weeks, and at two, three, six, nine and twelve months of age. The results obtained in this work were summarized as follows: 1. The highest concentration of serum glucose was observed at birth and it decreased gradually until three months of age, showing a steady state thereafter. 2. The concentration of total serum protein was a little higher at one day of age than at birth and showed a steady state until seven days of age; then it decreased slightly at two weeks of age and recovered at three weeks of age and showed a steady state until twelve months of age. The concentration of serum albumin was increased a little at one day of age and revealed a steady state thereafter. The concentration of serum globulin showed three phases - a fall during the first two weeks to reach minimum, a rise to the fourth week, and a fall at two months of age, showing a steady state thereafter. The lowest value of albumin fraction was observed at birth, then the value increased gradually until three months of age and revealed a stealer state thereafter. The highest value of globulin fraction was observed at birth, then the gradual decrease of the value was seen until three months of age; thereafter the value showed a steady state. 3. Albumin/globulin ratio was the minimum at birth, then it increased to reach a maximum at two weeks of age and decreased a little thereafter. 4. The concentration of total serum cholesterol showed a gradual increase during the first three months and fell to reach adult revel at six months of age. 5. Urea nitrogen in serum decreased during the first week to reach a minimum, then it increased at three months of age, and showed a fell to mature level at six mouths of age. 6. The concentration of serum creatinine was not affected by age. 7. The concentration of total serum calcium was a little higher during the first two weeks than the other period during the first year of life. 8. The concentration of serum inorganic phosphorus showed a gradual rise to reach a maximum and a gradual fall to reach adult level at nine months of age. 9. No significant sex differences of serum chemical values were recognized.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.31 no.4
• /
• pp.311-319
• /
• 2013

As heavy rains occur more frequently due to the recent climate change, slope collapses are increasing, and damage to human life and properties is accordingly increasing every year. The most proper method to take preventive measures against slope collapses is to remove the cause after understanding the cause of slope collapse in advance, and for such, slope safety inspection is implemented for preventive purposes, to investigate the cause, and as a measure for restoration. Thus, this Research was able to reach the following conclusion after utilizing LiDAR, which obtains detailed topographic information in a short period of time with point cloud data on slopes subject to safety inspection. First, as a result of analyzing the errors after installing a check point in the subject area, the RMSE of the horizontal location error appeared to be ${\pm}2.2cm$ and the RMSE of the vertical location error appeared to be ${\pm}3.0cm$, which shows a practically satisfactory result. Second, the economic feasibility was outstanding and obtaining accurate topographic information was available. Third, an area once scanned allowed to accurately obtain an unprescribed cross-sectional diagram in a short period of time, thus, appeared to be convenient for experts to detect dangerous sections.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.21 no.3
• /
• pp.1-12
• /
• 2018

This study was conducted to obtain a reliable result assessing proper amount of solid swine manure for the growth of Deutzia crenata seedlings. Seedling growth dry weight, chlorophyll content inorganic nutrients and soil chemical properties were investigated. 1. When treated with solid swine manure, seed germination rate was highest on the control. However, germination rates tended to decrease when treated with swine manure at high concentrations. 2. The growth of seedlings treated with swine manure was always higher than that of in control. At the 1.0% of swine manure treatment, the growth rate of the seedlings was highest. 3. Seedling dry weight was highest at the 1.0% swine manure treatment. The amount of inorganic nutrients absorbed by the seedling was generally high with the 1.0% treatment, declined sharply with the 2.0% treatment. 4. For the planting soil of Deutzia crenata, the higher the concentration of swine manure, the lower the soil pH. However, nitrogen, available P, K, Na, Mg and Ca contents in the soil have increased with higher concentrations.

• Korean Journal of Ecology and Environment
• /
• v.50 no.1
• /
• pp.116-125
• /
• 2017

Alpine plants with a scarcity of pollinators in harsh environments have been believed to undergo selfing for reproductive assurance; however, contradictory evidence is also available. Snowmelt regimes in alpine areas function to change life history characteristics of alpine plants such as flowering time and duration; yet the effects of snowmelt regimes have never been tested in alpine plants in Korea. This study was conducted to investigate the dichogamy, mating systems, and flowering characteristics of Megaleranthis saniculifolia populations [early and late snowmelt plots (ESP and LSP, respectively)] in a subalpine area of Sobaeksan Mountain in Korea. M. saniculifolia exhibited incomplete protogyny in that despite early maturation of pistils, maturation times of pistils and stamens within flowers were partly overlapped. Control and hand-outcrossing treatments produced significantly higher number of follicles and seeds per flower than autonomous and hand-selfing treatments. Based on the aggregate fruit set, the auto-fertility index (AI) and self-compatibility index (SI) were 0.33 and 0.50, respectively. Snowmelt occurred 10 days earlier in ESP than in LSP, thereby ESP and LSP showed distinct differences with regard to flower longevity and season, but showing no difference in peak flowering dates. We concluded that M. saniculifolia is an incomplete protogynous and largely outcrossing plant requiring pollinator service. Temporal variation in snowmelt time and subsequent changes in flowering characteristics under climate change may further threaten the population persistence of M. saniculifolia which has already been designated as endangered species in Korea.

• Journal of Nutrition and Health
• /
• v.41 no.8
• /
• pp.887-899
• /
• 2008

Recently the Ministry of Health and Welfare, Republic of Korea, announced the “Dietary Guidelines for Korean Adults (DGKA)”, which includes ten Dietary Goals, six Dietary Guidelines, and twenty-three Action Guidelines. DGKA are developed as the revision of the 2003 Dietary Guidelines for Koreans, targeting adult population. Dietary Guidelines are developed for general purpose as well as for different age groups. They are revised periodically to accommodate changes in diet and health problems of the population. The process of developing new DGKA can be summarized as 1) selection of focus areas, 2) analysis and review of available data for each area selected, and 3) derivation of guidelines based on the analyzed data, and 4) finalizing the guidelines after open discussions among the experts and general public. Five focus areas were selected by examining the Nutrition Goals of the Health Plan 2010 of Korea, soliciting proposals from the experts in the related fields, and reviewing existing and international guidelines. Five areas selected were 1) adequate intake of nutrients and foods, 2) balance of energy intake and physical activities, 3) alcohol intake, 4) food security and nutrition service, and 5) food safety. Adequacy of nutrient and food intakes of the Korean adult population was assessed using 2005 Korea National Health and Nutrition Examination Survey (KNHANES) data. Newly developed Dietary Reference Intakes for Koreans were used as reference values to assess the prevalence of inadequacies and excesses in nutrient intakes. Energy balance was examined with energy intake of 2005 KNHANES survey and results of physical activity questionnaire in the survey. Alcohol intake was also examined using 2005 KNHANES results of dietary intakes as well as the results of questionnaire survey on alcohol intakes. Food security, nutrition services, and food safety were analyzed using various government data and published results on the issues. Ten Dietary Goals and six Dietary Guidelines were developed after data analysis and were subjected to reviews of experts and general public. The final DGKA are: 1) Eat a variety of foods from each food group, 2) Increase physical activity and maintain healthy weight, 3) Eat proper amount of clean foods, 4) Avoid salty foods and try to eat foods with bland taste, 5) Avoid foods with high fat contents and deep-fried foods, and 6) When you drink alcohol, limit the amount. Twenty-three action guidelines are developed in order to achieve these guidelines in actual diet and life among the population. The government is disseminating the guidelines with “337” slogan and emblem. “337” indicates everyone should practice “3” guidelines of promoting good eating practice, “3” guidelines to limit or decrease in your diet, and you should practice them for “7” days a week. The guidelines will be useful in promoting healthy food habits and good nutritional status which will result in decrease nutrition related health problems in Korea.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.43 no.5
• /
• pp.495-502
• /
• 2010

Pure lines were isolated from young gametophytic blades of pigmentation and morphological mutants in Porphyra tenera. Growth, blade-shape and photosynthetic pigment content of pure lines were compared with the wild type. Growth of blade length in the wild type (W, R-B), with round shape and brown color, was fastest at $5{\sim}10^{\circ}C$ and became slower as temperature increased. The blade-shape of the wild type changed from linear to round as temperature increased. The green type (R-G), with round shape and green color, showed slower growth, and the red type (R-R) 'with round shape and red color' showed faster growth than the wild type. The blade-shapes of the green and red types changed from elliptical or linear to round as temperature increased. The phycoerythrin (PE) / phycocyanin (PC) ratio of the green type was markedly lower and the PE/PC ratio of the red type was markedly higher than that of the wild type. The linear type (L-B), with liner shape and brown color, showed faster growth in blade length than the wild type at $10{\sim}20^{\circ}C$ and maintained its linear shape at $5{\sim}15^{\circ}C$. The content of photosynthetic pigments of the linear type was similar to that of the wild type. Each of the pure lines of pigmentation and morphological mutants that were isolated in the present study showed particular patterns in growth, blade-shape and photosynthetic pigment composition. Therefore, they are expected to be useful as new varieties by themselves and to be available for breeding and biotechnological studies.