• Journal of Nutrition and Health
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• v.44 no.5
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• pp.355-365
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• 2011

This study investigated how dietary fat affects muscle atrophy and lipid metabolism in various muscles during hindlimb immobilization in rats. Twenty-four male Sprague?Dawley rats had their left hindlimb immobilized and were divided into four groups by dietary fat content and composition. The contralateral hindlimb (control) was compared with the immobilized limb in all dietary groups. Rats (n = 6/group) were fed a 4% corn oil diet (CO), 2.6% corn oil + 1.4% fish oil diet (FO), 30% corn oil diet (HCO), or a 30% beef tallow diet (HBT)after their hind limbs were immobilized for 10 days. Data were collected for the gastrocnemius, plantaris and soleus muscles. Muscle atrophy was induced significantly after 10 days of hindlimb immobilization, resulting in significantly decreased muscle mass and total muscle protein content. The protein levels of peroxisome proliferator activated receptor ${\delta}$ (PPAR${\delta}$) in the plantaris, gastrocnemius, and soleus increased following hindlimb immobilization irrespective of dietary fat intake. Interestingly, the PPAR${\delta}$ mRNA level in the plantaris decreased significantly in all groups and that in the FO group was lower than that in the other groups. The soleus PPAR${\delta}$ mRNA level decreased significantly following hindlimb immobilization in the FO group only. Muscle carnitine palmitoyl transferase 1 (mCPT1) mRNA level was not affected by hindlimb immobilization. However, the mCPT1 mRNA level in the FO group was significantly lower in the plantaris but higher in the soleus than that in the other groups. The pyruvate dehydrogenase kinase 4 (PDK4) mRNA level in the plantaris decreased significantly, whereas that in the soleus increased significantly following hindlimb immobilization. The plantaris, but not soleus, PDK4 mRNA level was significantly higher in the FO group than that in the CO group. The increased PPAR${\delta}$ protein level following hindlimb immobilization may have suppressed triglyceride accumulation in muscles and different types of dietary fat may have differentially affected muscle atrophy according to muscle type. Our results suggest that ${\omega}$-3 polyunsaturated fatty acids may suppress muscle atrophy and lipid accumulation by positively affecting the expression level and activity of PPAR${\delta}$ and PPAR${\delta}$-related enzymes, which are supposed to play an important role in muscle lipid metabolism.

• Journal of Advanced Marine Engineering and Technology
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• v.8 no.1
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• pp.17-36
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• 1984

Since 1973, the competition on the development of fuel saving type internal combustion engines has become severe by the two times oil shock, and new type engines are reported every several months. Whenever these new type engines are developed, new designs are required and they will be offered in the market after performing the endurance test for a long time. But the engine market is faced with a heavy burden of finance, as the developing of a new engine requires tremendous expenses. For this reason, the computer simulation method has been lately developed to cope with it. The computer simulation method can be available to perform the reasonable research works by the theoretical analysis before carrying out practical experiments. With these processes, the developing expenses are cut down and the period of development is curtailed. The object of this study is the development of simulation computer program for the small naturally aspirated four-stroke diesel engine which is intended to product by the original design of our country. The process of simulation is firstly investigated for the ideal engine cycle, and secondly for the real engine cycle. In the ideal engine cycle, each step of the cycle is simulated by the energy balance according to the first law of thermodynamics, and then the engine performance is calculated. In the real cycle imulation program, the injection rate, the preparation rate and the combustion rate of fuel and the heat transfer through the wall of combustion chamber are considered. In this case, the injection rate is supposed as constant through the crank angle interval of injection and the combustion rate is calculated by the Whitehouse-Way equation and the heat transfer is calculated by the Annand's equation. The simulated values are compared with measured values of the YANMAR NS90(C) engine and Mitsubishi 4D30 engine, and the following conclusions are drawn. 1. The heat loss by the exhaust gas is well agree with each other in the lower load, but the measured value is greater than the calculated value in the higher load. The maximum error rate is about 15% in the full load. 2. The calculated quantity of heat transfer to the cooling water is greater than the measured value. The maximum error rate is about 11.8%. 3. The mean effective pressure, the fuel consumption, the power and the torque are well agree with each other. The maximum error is occurred in the fuel consumption, and its error rate is about 7%. From the above remarks, it may be concluded that the prediction of the engine performance is possibly by using the developed program, although the program needs to reform by adding the simulation of intake and exhaust process and assumping more reliable mechanical efficiency, volumetric efficiency, preparation rate and combustion rate.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.4
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• pp.95-103
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• 2012

Precast concrete method is known to have advantages of minimizing works in the construction, controlling concrete quality easily and saving construction period due to only fabrication work in the construction field, but it needs to apply steam curing to accelerate early concrete strength. In the meanwhile, the oil cost for steam curing has been continuously increased because of political instability in the middle East and international economic shaky. Thus, this study addresses the development of precast/ prestressed concrete which has over 14MPa at 1 day age and specified concrete strength of 40MPa at low temperature, not applying steam curing. Tests were carried out in terms of material characteristics in fresh concrete and compressive strength using 3 types of cement such as Type I, Type III and rapid hardening compound cement. As results of tests, it is found that cements for rapid hardening had disadvantages with respect to slump, slump loss, and air content, but showed higher compressive strength than specified one, especially the highest value when using rapid hardening compound.

• Korean Journal of Food Science and Technology
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• v.5 no.2
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• pp.84-88
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• 1973

The antioxidant activity of some extracts from various stages of a Mailard type browning reaction mixture, a 0.2 M glucose + 0.2 M glycine solution heated at $100^{\circ}C$, was determined, using edible soybean oil as a substrate. The activity was compared with the length of reaction times, and also with the intensity of color of the reaction mixture at various stages. The absorbance, at $490\;m{\mu}$, of the reaction mixture appeared to increase almost in proportion to the length of the reaction times. All the extracts from the reaction mixture exhibited considerable antioxidant activity. However, unlike the Absorbance of the reaction mixture, the antioxidant activity of the extracts from the reaction mixture did not appear to increase in proportion to the length of the reaction times. The activity of the extract from the reaction mixture heated for 30 hours was indeed greater than that of the extract from the reaction mixture heated for 2 hours, but the difference of the activity was not so great as one might expect. The results appear to indicate that most of effective antioxidative compounds formed during the Mailard type browning reaction could not be brown-colored pigments formed during the reaction.

• Tunnel and Underground Space
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• v.28 no.3
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• pp.258-276
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• 2018

The accurate and quantitative ground information on the hydraulic conductivity characteristics of rock mass is one of the key factors for evaluation of the hydro-geological behaviour of rock mass around an excavated opening under high water pressure. For tunnel and rock structures in seabed, where the sea acts as an infinite source of water, its importance become greater with increasing construction depth below sea level. In this study, to improve the problems related with poor system configuration and incorrect data acquisition of previous hydraulic packer testing equipment, we newly developed an integrated main frame and 30 bar level waterproof downhole sonde apparatus, which were optimized for deep hydraulic packer test in seabed rock mass. Integration of individual test equipment into one frame allows safe and efficient field testing work on a narrow offshore drilling platform. For the integrated type main frame, it is possible to make precise stepwise control of downhole net injection pressure at intervals of $2.0kg_f/cm^2$ or less with dual hydraulic oil volume controller. To ensure the system performance and the operational stability of the prototype mainframe and downhole sonde apparatus, the field feasibility tests were completed in two research boreholes, and using the developed apparatus, the REV(Representative Elementary Volume) scale deep hydraulic packer tests were successfully carried out at a borehole located in the basalt region, Jeju. In this paper, the characteristics of the new testing apparatus are briefly introduced and also some results from the laboratory and in-situ performance tests are shown.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.62-71
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• 2017

This study classified cities across South Korea according to their urban characteristics, selecting representative cities for respective types, and drawing a relationship among urban characteristic elements, carbon emissions, and the energy consumption of cities. For the classification of cities, the elements of the urban characteristics were examined through a review of the related literature. Factor analysis was then carried out to select the variables from among these elements. The absolute coefficient value found in the analysis was set as a standard. A classification of cities across the country was performed using these variables, and representative cities were chosen for a comparison of the characteristics of each type. For an analysis of the relationships among the urban characteristics according to the type of city, the greenhouse gases, and the energy consumption of cities, emissions of greenhouse gases, electricity consumption, and oil consumption of the representative cities were compared and analyzed by correlation analysis. The analysis results indicated that the cause of greenhouse gas emissions and electricity consumption varies according to the elements of the characteristics of the representative cities, even when they show similar emissions and consumption.

• Journal of the Korean Society of Food Culture
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• v.20 no.2
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• pp.186-193
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• 2005

The antioxidative and antimicrobial activities were carried on the leeks (Allium tuberosun R.) ethanol extracts in order to find out new food functional components. Three species of leeks used in this study were Chinese leek(long type, LL), general leek(medium type, LM), and medicinal leek (short type, LS). Total amounts of polyphenol compounds in LS was shown as the highest (436.60mg%) value. All of ethanol extracts of these leeks were shown to be had good electron donating ability(EDA) and nitrite scavenging activity. Specialty, the ethanol extract of LS(LSEx) had the highest EDA 30.47% and nitrite scavenging activity 77.24% and the lowest was LMEx. The antioxidative activities of these ethanol extracts on the corn germ oil were measured by peroxide values(POV) and conjugated diene values (CDV) storaging for 30 days at $60{\pm}2^{\circ}C$. The antioxidative activities of these extracts by POV and CDV were determined as following order as LSEx> LLEx) LMEx. The antioxidative activities of all extract were presented as high tendency by increasing adding amounts (0.02%>0.05%>0.1%). When the antioxldative activities were compared with BHT and ${\alpha}-tocopherol$, the degree of the antioxidative activities of these extracts were certified as lower than BHT and higher than ${\alpha}-tocopherol$. And also LSEx, LMEx, and LLEx had antimicrobial effects on the several micro organisms, especially the effect on the Pseudomonas aeruginasa was remarkable. While LMEx had shown inhibit effect on most of micro organism used in this study.

• Journal of the Mineralogical Society of Korea
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• v.20 no.2 s.52
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• pp.71-81
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• 2007

The marble-type dolomite from the Jasung Mine, which was farmed by duplicated affects of contact metamorphism and subsequent hydrothermal alteration, corresponds to a high-purity dolomite ranging up to above 98wt.% in dolomite contents. The dolomite contain minor impurities such as quartz, muscovite, and pyrite. It is characteristic that the dolomite is fairy Fe-rich corresponding to 0.4 wt.% due to the presence of pyrite of possible hydrothermal origin. The dolomite is nearly white-colored and constituting with subhedral crystals ranging $0.35{\sim}0.46mm$M in size, forming equigranular texture. Compared to the typical high-Ca limestone from the Pungchon Formation, the powder characteristics of dolomite is rather superior in milling efficiency, yields of fine particles, and size distribution. In addition, except for iron contents, the dolomite powder is no less superior than the limestone in quality and characteristics as fillers with respects to not only whiteness, oil absorption, and specific surface area but also shape characters such as elongation ratio, aspect ratio, and sphericity. This good characteristics of dolomite powder seem to be originated basically from comparatively higher grade and crystallinity of dolomite. Higher iron contents and the presence of sulfides prevents the dolomite from application for uses by thermal treatment, except for metallic manufacture. However, if proper ore separation procedure is available, the dolomite can be sufficiently utilized as substitutes for high-Ca limestone in most fields of filler industries.

• Korean Chemical Engineering Research
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• v.45 no.3
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• pp.304-309
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• 2007

In this study, the "Multi Well Plate-type cell Apparatus" was designed and setup for performing the producing experiments of methane hydrate by depressurization, heat stimulating methods. In order to characterizing the producing mechanism of hydrate through porous materials, the experiments for various producing methods have been conducted with the aid of the apparatus which has high permeability. In the experimental result of depressurization method, the pressure is temporarily increased unlikely conventional gas reservoir due to the sourcing effect of hydrate dissociation in the pore. Meanwhile, the temperature is decreased because of the endothermic reaction while hydrate is dissociated. In the experimental results of heat stimulating method, the dissociation in depressurization method is more slowly processed than that in thermal method, and hence, its gas production is lower. In the case of production right after heating, hydrate is dissociated only near injecting point and the permeability becomes greater at that area only. It infers that the more gas is produced during relatively earlier producing period. Since then, the hydrate is more slowly dissociated than the case of production after heating and soaking. This time, the performances of pressure and production obtained by thermal method have been analyzed in order to investigate the effect of soaking time on gas recovery. As a result, the gas recoveries in the case of 2 min and 4 min soaking are higher than case in 6 min soaking. This is reason that hydrate is reformed due to the decrease of temperature. It is expected that the experimental results obtained in this work may be more clearly explained by utilizing the lower permeable porous system with the greater hydrate saturation.

• Journal of Environmental Health Sciences
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• v.36 no.5
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• pp.351-359
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• 2010

The objectives of this study were to understand the characteristics of residents in industrial areas and factors affecting exposure to the Volatile Organic Compounds(VOCs : Benzene, Toluene, Xylene) as well as to assess exposure levels according to house-type, and whether residents were indoors or outdoors. This research was designed to assess the differences in exposure levels to indoor, outdoor and personal VOCs in a case group and a control group across all areas, as well as in each different area, from May to October 2007, in. 110 residents of the G, Y and H industrial areas of the Jun-nam province. The geometric mea-levels of airborne benzene for the case group 1.31part per billion(ppb) indoor, 1.29 ppb outdoor, and 1.32 ppb for personal exposure were significantly higher than for the control group 0.99, 0.87 and 0.57 ppb, respectively. The geometric mean level for toluene personal exposure across the G, Y and H areas was 5.70 ppb for the case group and 6.31 ppb for the control group. While the outdoor level was 4.27 ppb for the case group and 5.06 ppb for the control group, The indoor level for the case group was 4.78 ppb, similar to that of the control group 4.69 ppb. The geometric mean levels for airborne xylene across the G, Y and H areas were 0.16 ppb(outdoor), 0.12 ppb(personal exposure) and 0.10 ppb(indoor) for the case group, and for the control group were 0.17(personal exposure) and 0.09 ppb(indoor and outdoor). The indoor/outdoor(I/O) ratio for case group is 1.19, while that of the control group is 1.15, indicating that the indoor level was higher than the outdoor level. The interrelationship differences among the three different types of levels in the air in the G, Y and H areas are statistically significant, except for the difference between the indoor and outdoor figures for xylene. In terms of the different types of houses and energy type uesd, the geometric mean level for airborne benzene, toluene and xylene for houses were 1.61, 5.39 and 0.12 ppb, respectively. while the figures for flats were 0.67, 3.32 and 0.05 ppb, respectively. Outdoors, the levels of benzene and toluene in flats were 0.71 and 2.62 ppb, respectively. and 1.58 and 5.35 ppb in houses. For personal exposure, the house levels of benzene, toluene and xylene were all higher than for flats. Houses using oil for heating have significantly higher levels than flats, which use gas for heating.