• Transactions of the Korean hydrogen and new energy society
• /
• v.27 no.4
• /
• pp.357-364
• /
• 2016

Recently, the world faces the environmental problem such as air pollution due to harmful gas discharged from car and abnormal climate due to the green-house gases increased by the discharge of $CO_2$. Compressed Natural Gas (CNG), one of alternative for this problem, is less harmful, compared to the existing fossil fuel, as gaseous fuel, and less carbon in fuel ingredients and carbon dioxide generation rate relatively favorable more than the existing fuel. However, CNG fuel has the weakness of slow flame propagation speed and difficult fast burn. On the other hand, hydrogen does not include carbon in fuel ingredients, and does not discharge harmful gas such as CO and HC. Moreover, it has strength of quick burning velocity and ignition is possible with small ignition energy source and it's has wide Lean Flammability Limit. If using this hydrogen with CNG fuel, the characteristics of output and discharge gas is improved by the mixer's burning velocity improved, and, at the same time, is possible to have stable lean combustion with the reduction of $CO_2$ expected. Therefore, this research tries to identify the characteristics of engine and emission gas when mixing CNG fuel and hydrogen in each portion and burning them in spark igniting engine, and grasp the combustion stability and emission gas characteristics according and use it as the basic data of hydrogen-CNG premixed engine.

• Korean Journal of Community Nutrition
• /
• v.11 no.4
• /
• pp.520-533
• /
• 2006

The purpose of this study was to investigate satisfaction and preference for current military meal service and food behaviors and food habits of some military personnel in Chunchen and Wonju of the Kwangwon area. The results are as follows. In the anthropometric survey, average height of the subjects was 175.03 $\pm$ 5.30 cm, average weight was 69.15 $\pm$ 7.74 kg. As a result of surveying satisfaction in the current food service, an item high in satisfaction was adequacy of serving hours, whereas an item of low satisfaction was diversity of menu. The item of food service improvement needs of the subjects were in order more variety of menu, nutrition, preference, sanitation, cooking method. As a result of surveying eating behavior of the subjects, most items were high medium response. They preferred soju and relish and also they liked the bokkum cooking method. As a result of surveying food habits of the subjects, items of good habits were regularity of meals, marginal meals, diversity of food intake, dairy and dairy products, avoiding too exciting meals and natural food diet; whereas, items of bad habits were fast food intake, alcohol, smoking, carbonated and caffeine beverages, skipping breakfast. snacks, fatty food intake, yellow or green vegetable intake and fruit and seaweed intake. Following is the result of a survey on the preference of meals by cooking method serving the current military meal service. They liked one-dish meals such as Bokkeumbap, Bibimbap, Tteokguk, whereas, they disliked curryrice, Jajangbap. In case of soup, they liked soup made from meat better than vegetable soup or soup made with fish. Also they liked pot stem better than soup. Generally they liked meals containing meat in most cooking methods. These results suggest that continuous and practical nutrition education to change food habits in military life are necessary to Prevent chronic disease with increasing age.

• Bulletin of the Korean Chemical Society
• /
• v.23 no.3
• /
• pp.447-453
• /
• 2002

In this paper we have presented the results of thermodynamic, structural, and dynamic properties of model systems for liquid benzene, toluene and p-xylene in an isobaric-isothermal (NpT) ensemble at 283.15, 303.15, 323.15, and 343.15 K using molecular dynamics (MD) simulation. This work is initiated to compensate for our previous canonical (NVT) ensemble MD simulations [Bull. Kor. Chem. Soc. 2001, 23, 441] for the same systems in which the calculated pressures were too low. The calculated pressures in the NpT ensemble MD simulations are close to 1 atm and the volume of each system increases with increasing temperature. The first and second peaks in the center of mass g(r) diminish gradually and the minima increase as usual for the three liquids as the temperature increases. The three peaks of the site-site gC-C(r) at 283.15 K support the perpendicular structure of nearest neighbors in liquid benzene. Two self-diffusion coefficients of liquid benzene via the Einstein equation and via the Green-Kubo relation are in excellent agreement with the experimental measures. The self-diffusion coefficients of liquid toluene and p-xylene are in accord with the trend that the self-diffusion coefficient decreases with increasing number of methyl group. The friction constants calculated from the force auto-correlation (FAC) function with the assumption that the fast random force correlation ends at time which the FAC has the first negative value give a correct qualitative trends: decrease with increase of temperature and increase with the number of methyl group. The friction constants calculated from the FAC's are always less than those obtained from the friction-diffusion relation which reflects that the random FAC decays slower than the total FAC as described by Kubo [Rep. Prog. Phys. 1966, 29, 255].

• Transactions of the Korean Society of Automotive Engineers
• /
• v.20 no.5
• /
• pp.71-80
• /
• 2012

To improve the $NO_X$ conversion over a SCR (selective catalytic reduction) catalyst, the DOC (diesel oxidation catalyst) is usually placed upstream of the SCR catalyst to enhance the fast SCR reaction ($4NH_3+2NO+2NO_2{\rightarrow}4N_2+6H_2O$) using equimolar amounts of NO and $NO_2$. Here, a ratio of $NO_2/NO_X$ above 50% should be avoided, because the reaction with $NO_2$ only ($4NH_3+4NO+O_2{\rightarrow}4N_2+6H_2O$) is slower than the standard SCR reaction ($4NH_3+4NO+O_2{\rightarrow}4N_2+6H_2O$). In order to accurately predict the performance characteristics of SCR catalysts, it is therefore desired to develop a more simple and reliable mathematical and kinetic models on the oxidation kinetics of nitric oxide over a DOC. In the present work, the prediction accuracy and limit of three different chemical reaction kinetics models are presented to describe the chemicophysical characteristics and conversion performance of DOCs. Steady-state experiments with DOCs mounted on a light-duty four-cylinder 2.0-L turbocharged diesel engine then are performed, using an engine-dynamometer system to calibrate the kinetic parameters such as activation energies and preexponential factors of heterogeneous reactions. The reaction kinetics for NO oxidation over Pt-based catalysts is determined in conjunction with a transient one-dimensional (1D) heterogeneous plug flow reactor (PFR) model with diesel exhaust gas temperatures in the range of 115~$525^{\circ}C$ and space velocities in the range of $(0.4{\sim}6.5){\times}10^5\;h^{-1}$.

• Korean Journal of Pharmacognosy
• /
• v.43 no.2
• /
• pp.167-172
• /
• 2012

Osteoarthritis (OA) is an age-related joint disease characterized by degradation of articular cartilage and its association with chronic pain. Purified Bee venom (PBV) has been traditionally used to the treatment for inflammatory diseases. The purpose of the current study is to examine whether PBV regulates the pro-inflammation against a mouse model of knee OA induced by papain. We studied the effect of PBV on papain-induced OA in the knee joints of mice. Mice were split into following groups: normal control, papain induced OA, OA treated with PBV, OA treated with meloxicam as positive control. Proteoglycan deposition was analyzed by safranin O-fast green staining and H&E staining. Papain injection significantly degraded the proteoglycan in OA mice at 42 days. Cartilage proteoglycan density was significantly higher in PBV treated OA group than those of the positive control groups. These results demonstrate that PBV efficiently suppresses pathological processes in an OA model. Thus, PBV could be a potential therapeutic strategy for the treatment of OA.

• Journal of the Korean Society of Food Culture
• /
• v.31 no.1
• /
• pp.33-41
• /
• 2016

The purpose of this study was to examine the difference in nutritional knowledge and food preferences according to food-related lifestyle among 400 married women. Using the K-average clustering method, food-related lifestyles of subjects were categorized into three clusters: rational and diversity-oriented group, convenience-oriented group, and health-oriented group. The nutritional knowledge level and food preferences among three clusters were compared to each other using ANOVA test. The findings were summarized as follows: For the nutritional knowledge level, health-oriented group showed the highest mean score, whereas the lowest score was detected in the convenience-oriented group. The convenience-oriented group showed higher preferences for fish, meat, eggs, fruits, milk/dairy products, seaweed, grains, etc. among natural food than the other groups. Meanwhile, the rational and diversity-oriented group preferred legumes, and green vegetables, whereas the health-oriented group showed preferences for other vegetables. However, the convenience-oriented group reported more preferences for breads, noodles, pancakes, fried/stir-fried food, and processed food such as sausage, ham, and fast food, This study found that nutritional knowledge level and food preferences were significantly different according to food-related lifestyles of married women living in Seoul and Gyonggie areas. Thus, it is suggested that nutritional education targeting married women needs to be carefully designed by considering their food-related lifestyle.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.47
• /
• pp.150-162
• /
• 2002

Perilla, Perilla frutescens. (L.) Britton, is a traditional oil seed crops grown in Korea. The seeds and seed oil is used for edible and some industrial sectors. The seeds of perilla contains 35-54% of a drying oil which is similar to the linseed oil. The fatty acids of seed oil is composed with linolenic acid, linoleic acid, and oleic acid. The majority of fatty acids of the oil is $\alpha$-linolenic acid proportioned 51-71% of the oil. This high linolenic acid makes it unstable of the oil and owing to the fast oxidation. Therefore, the plant breeders are challenges to develope a new varieties with low linolenic acid for edlible oil and high linolenic acid for industrial uses. Perilla foliage is also used as a potherb. The green leaves contains a special flavor, perilla aldehyde, and some abundant minerals and vitamins. The vitamin C and $\beta$-carotene is more available than lettuce and crown-daisy of which used for similar potherb and vegetables in traditional Korean food table. The authors are reviewed and discussed on the current status and prospects of the quality evaluations and researches in perilla seeds and leaves to provide and refers the condensed informations on their quality.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2018.10a
• /
• pp.444-447
• /
• 2018

Baculovirus expression systems have many known advantages including fast and cost-effective methods to generate large amounts of recombinant proteins in comparison to bacterial expression systems, particularly those requiring complex post-translational modifications. Especially, recombinant baculoviruses can transfer their vectors and express their recombinant proteins in a wide range of mammalian cell types. In this study, baculoviral vectors which were reconstructed from pcDNA3.1 vector, were recombined with cytomegalovirus (CMV) promoter,uroplakin II promoter, polyhedron promoter, vesicular stomatitis virus G (VSVG), enhanced green fluorescent protein (EGFP), and protein transduction domain (PTD). These recombinant vectors were infected with various cells and cell lines. The baculovirus vector thus developed was analyzed by comparing the metastasis and expression of the recombinant genes with conventional vectors. These results suggest that the baculovirus vector has higher efficiency in metastasis and expression than the control vector.

• Journal of the East Asian Society of Dietary Life
• /
• v.9 no.3
• /
• pp.289-301
• /
• 1999

The purpose of this study is to investigate the food habits and the dietary intake of female college students at day and night class in the Kyunggido area. The questionnaires were collected from 294 students(151 day class and 143 night class students) out of 350 in total. The results are as follows: Breakfast for day class students and breakfast and dinner of night class students were skipped more than 3 times a week. The main reason was short of time. In the behavior of food intake, the frequency of yellow-green vegetables, milk and seaweeds intake was low in all respondents. 18.4% of night class students ate out 3 times a day. In the kind of menu for eating out, Korean food was the most frequent. snack food the second, and fast food came last. 23.9% of students ate something 2 or 3 times a day between meals. The main reason for eating between meals was the desire to eat for day class students, and hunger for the night time students. Consumption of coffee was 0.76 cup a day Daily mean of calory intake was 1.394 kcal and the ratio of carbohydrate. protein lipid was 61:14:25. The intakes of iron and niacin of the day class students were higher than those of night class students. There was no significant difference in intake of other nutrients between day and night class students. Intake of calcium and iron did not reach 50% of Korean RDA.

• Ocean Systems Engineering
• /
• v.5 no.1
• /
• pp.1-19
• /
• 2015

The water jetting system for a jack-up spudcan requires the suitable design considering the platform/spudcan particulars, environments, and soil conditions, either the surficial clay or surficial sand. The usage of water jetting depends critically on soil conditions. The water jetting is usually used for the smooth and fast extraction of the spudcan in the surficial clay condition. It is also required for inserting spudcan up to the required depth in the surficial sand condition, which is investigated in this paper. Especially, it should be very careful to use the water jetting during an installation of spudcan in the surficial sand condition, because there is a risk of overturning accident related to the punch-through. Therefore, in this study, the effect of water jetting flow rate and time on the change of soil properties and penetration resistance is analyzed to better understand their interactions and correlations when inserting the spudcan with water jetting in surficial sand condition. For the investigation, a wind turbine installation jack-up rig (WTIJ) is selected as the target platform and the multi layered soil (surficial sand overlaying clays) is considered as the soil condition. The environmental loading and soil-structure interaction (SSI) analysis are performed by using CHARM3D and ANSYS. This kind of investigation and simulation is needed to decide the proper water jetting flow rate and time of spudcan for the given design condition.