• Journal of Advanced Marine Engineering and Technology
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• v.32 no.3
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• pp.379-386
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• 2008

The 36 liter LNG tank is designed to fit in the limited installation space of a small truck. Two LNG tanks allow one ton truck to run about 432 km per fueling. which is about 1.8 times longer than CNG mileage for the same truck. The variation of BOG with car acceleration for the different fuel liquid/vapor ratios in a tank is analysed by the modified Fortran program "Pro-Heatleak". Computational analyses show that the relationship between the BOG and liquid/vapor ratio is linearly proportional at a given acceleration. Fuel consumption decreases the volume of liquid fuel in the tank but increases the specific BOG. BOG increases with increasing of car acceleration when fuel liquid/vapor ratio is greater than 0.5 and decreases with increasing of car acceleration when fuel liquid/vapor ratio is less than 0.5. The difference between maximum and minimum BOG for full tank is about 12 percents. For the fuel liquid/vapor ratio equal to 0.5 BOG does not depend on car acceleration.

• Journal of the Korean Society for Heat Treatment
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• v.26 no.3
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• pp.126-131
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• 2013

In this study, effects of silicon addition on the spheroidizing annealing of hyper-eutectoid steel was investigated. Heat treatment at various temperatures in the ${\gamma}+{\theta}$ region was also conducted in order to systematically control the kinetics of undissolved cementite. It was found that small amount of Si addition could increase both $A_1$ and $A_{cm}$ transformation temperature by both the JMat Pro evaluation and dilatometric measurement. It was also revealed by the microstructural observation that the volume fraction of retained cementite during heat treatment increased with decreasing temperature as well as increasing Si content. Based on the results obtained, it could be suggested that spheroidization at relatively higher temperature above $950^{\circ}C$ could be achieved by small addition of Si.

• Membrane and Water Treatment
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• v.6 no.2
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• pp.113-126
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• 2015

Salinity gradient power (SGP) systems have strong potential to generate sustainable clean electricity for 24 hours. Here, we introduce a solid-salt pressure-retarded osmosis (PRO) system using crystal salt powders rather than seawater. Solid salts have advantages such as a small storage volume, controllable solubility, high Gibbs dissolution energy, and a single type of water intake, low pretreatment costs. The power densities with 3 M draw solutions were $11W/m^2$ with exothermic energy and $8.9W/m^2$ without at 35 bar using a HTI FO membrane (water permeability $A=0.375L\;m^{-2}h^{-1}bar^{-1}$). These empirical power densities are ~13% of the theoretical value.

• Geotechnical Engineering
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• v.5 no.4
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• pp.47-60
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• 1989

Soft offshore sediments quite frequently contain undissolved gas, probably methane pro- duced biogenically. The presence of gas bubbles can have a significant effect on the engineering behaviours of the seabed. One of the main difference between saturated and gassy soils is that the undrained response is not incompressible, and without volume change, may be assumed for a fully saturated soil. This paper describes the basic experimental work to further understanding of a gassy soil. The test has been performed for a gassy soil under undrained and drained conditions. It was confirmed that the gas inclusions deformed due to changes in the total stress on the sample and also the pore gas pressure response to change in total stress. but not directly to those in pore water pressure. And the test which applied the repeated load under undrained state also showed the similar behaviour as the simple load.

• Hwankyungkyoyuk
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• v.11 no.2
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• pp.14-25
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• 1998

The Quality of human living depends on the environmental quality of the region sustaining the life. The environmental deterioration of the modern society is due to mechanical environmentalism. For the better quality of the life, The changes of recognition and attitude on the environments are required. These changes of mind are also important in environmental education for teenagers. The 7th national curriculum, officially anounced December 1998, focuses on the change of attitude to environments and practical behavior in real life for “Environments”, the environmental education curriculum in middle school. Basic elements of the curriculum are cultivation of the pro-environmental thinking, multi-levelling of teaching materials and methods, and encouraging of student participating activity. Actually, the curriculum construction is composed of stepped-levelling of teaching and learning, reasonable contents volume, encouraging of student practice, and suggesting of evaluation standards of textbook writing. Three main subjects of environmental education for middle school consist of (1) man and environment, (2) recognition of environmental problem, and (3) protection activity for environment. Methodology of environmental education can include multi-disciplinary approaches, variable teaching methods, and continuing evaluation of student practice and participation attitude. Environmental education for teenagers relating to the 7th national curriculum focuses on recognition of the environmental problems and practice activity in daily life. The recognition includes considering relationship of human life to environment, solving environmental problems in regional context, and development of comprehensive understanding concept of the environments. For the practice education, variable teaching methods, such as field survey and application of multi-media, are needed.

• Journal of Hydrogen and New Energy
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• v.30 no.6
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• pp.485-489
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• 2019

Hydrogen is known to be a clean fuel which does not generate a green house gas during the combustion. However, about 8 kg of carbon dioxide is generated during the course of producing 1 kg of hydrogen through reforming, water gas shift reaction and pressure swing adsorption in order to obtain a high purity hydrogen over 99.999% by volume. In this work, carbon dioxide generation is estimated according to four kinds of natural gas compositions supplied by Korea Gas Corporation and regarding natural gas as pure methane. For the simulation of the modeling, PRO/II with PROVISION V10.2 at AVEVA was utilized and Peng-Robinson equation of state with Twu's alpha function was selected.

• Herbal Formula Science
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• v.26 no.4
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• pp.283-294
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• 2018

Objectives : Mahaengeuigam-Tang (MHEGT) has been used as a traditional medicine for the treatment of rheumatic aerthritis, rheumatisim, eczema and asthma. The aim of this study was to investigate the molecular mechanisms of MHEGT for cartilage protection in monosodium iodoacetate(MIA)-induced osteoarthritis, particularly focusing on apoptosis. Method : Thirty young male Sprague-Dawley rats were used for the study. Rats were intra-articularly injected with 2 mg MIA in a total volume of 50 ㎕ saline. In MHEGT group, MHEGT extract was orally administered once daily to MIA-induced osteoarthritis rats, and rats of control group were given with saline only. At 4 weeks after MIA injection, all animals were sacrificed, and the histological changes and articular thickness were assessed by hematoxylin and eosin staining. Moreover, the immunohistochemical analyses of BAX and Bcl-2 were carried out. Results : The histomorphological examinations revealed that MHEGT reduced MIA-induced cartilage damage. And, MHEGT ameliorated the severity of cartilage surface damages after MIA injection. Furthermore, MHEGT suppressed the MIA-induced increases of pro-apoptotic BAX protein and increased the protein expression of anti-apoptotic Bcl-2 protein. Conclusion : These findings indicate that MHEGT protects against MIA-induced cartilage damage by inhibition of the apoptotic pathway, demonstrating significant protection of cartilage against osteoarthritis. These results suggest that MHEGT may potentially have clinical applications in the treatment of osteoarthritis.

• Journal of Hydrogen and New Energy
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• v.34 no.6
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• pp.748-757
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• 2023

Numerical analysis was conducted to confirm the characteristics of extinction behavior in NH₃/CH₄ counterflow symmetrical flames. Numerical simulations were run on CHEMKIN-PRO, using the OPPDIF code, with Okafor's mechanisms, which had the lowest error rate compared to Colson's experimental data in the our previous part I study. The chemical interactions of merged flames were examined by analyzing the production rate of major chemical species and key radicals with the volume fractional percentage of ammonia and global strain rate. The interaction phenomenon of the flames could be identified by observing the main chemical reaction path of the merged flames at the stagnation plane.

• Korean Journal of Food Science and Technology
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• v.14 no.1
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• pp.49-56
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• 1982

The effects of measurement conditions on the emulsifying capacity(EC) and emulsion stability(ES) of proteins were studied in order to develop laboratory standard methods for the evaluation of emulsifying properties. The EC of proteins decreased with the increments of protein concentration and mixing rate. It increased with the increasing oil addition rate up to 0.8 ml/sec, but did not change at $0.8{\sim}1.2\;ml/sec$. The addition of sodiumchloride enhanced EC of proteins, attaining to the highest EC at 0.3M NaCl for Pro-Fam and 0.1M NaCl for Na-caseinate. The ES of Pro-Fam was higher than that of caseinate. The ES was increased by the increments of protein concentration, oil addition volume, mixing rate and mixing time. The EC and ES showed a close relation to the NSI of proteins, reaching to the lowest values of EC and ES at the isoelectric regions of proteins. The laboratory methods for measurements of emulsifying properties of proteins were established. The emulsifying properties of a laboratory-made soybean protein isolate were compared to those of commercial products by using the methods.

• Journal of Korean Medicine Rehabilitation
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• v.25 no.2
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• pp.15-35
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• 2015

Objectives This study was performed to investigate the effects of Bujasasim-tang ethanol extract (BST) on oxidative stress, inflammation and osteoarthritic rat model. Methods To ensure safety of BST, heavy metal levels were measured and cytotoxicity test was done. In vitro, To evaluate antioxidative effects of BST, total phenolic contents, 1,1-diphenyl-2-picryl-hydrazyl (DPPH), 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) scavenging activity, reactive oxygen species (ROS) levels were measured. Also, to evaluate anti-inflammatory effects of BST treated group, total nitric oxide (NO) and pro-inflammatory cytokines (IL-$1{\beta}$, IL-6, TNF-${\alpha}$) levels were measured in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. In vivo, We injected MIA $50{\mu}l$ (60 mg/ml) into knee joints of rats to induce osteoarthritis. Rats were divided into total 3 groups (normal, control, BST treated group, each n=7). Normal group was not treated at all without inducing osteoarthritis and taken normal diet. Control group was induced osteoarthritis by MIA and taken with 2 ml of distilled water once a day for 4 weeks. BST treated group was induced osteoarthritis by MIA and taken BST 2 ml (200 mg/kg/mouse) once a day for 4 weeks. We evaluated dynamic weight bearing with the Incapacitance Test Meter. At the end of experiment, the rats were sacrificed to observe the functions of liver and kidney, changes of WBC, neutrophil, lymphocyte, monocyte levels in blood, to evaluate the levels of pro-inflammatory cytokines, tissue inhibitor of metallopreteinases-1 (TIMP-1), matrix metalloproteinase-9 (MMP-9), prostaglandin $E_2$ ($PGE_2$), leukotriene $B_4$ ($LTB_4$) within serum. We observed change of articular structures by Hematoxylin & Eosin (H&E), safranin-O staining method and measured amount of cartilage by micro CT-arthrography. Statistical analysis was done by unpaired student's t-test with significance level at p<0.05 in SPSS 11.0 for windows. Results 1. Safety of the BST was identified. 2. AST, ALT, BUN, creatinine levels of BST treated group were within normal limit. In vitro, 1. DPPH and ABTS free radical scavenging activities of BST showed dose-dependent increase. 2. ROS production were significantly decreased. 3. Total nitric oxide (NO) and IL-$1{\beta}$ production were decreased. 4. IL-6 and TNF-${\alpha}$ production were significantly decreased. In vivo, 1. Weight bearing ability was significantly increased. 2. WBC, neutrophil, lymphocyte, monocyte levels in blood were decreased. 3. IL-$1{\beta}$ and TNF-${\alpha}$ levels in serum were significantly decreased. and the IL-6 level was decreased. 4. TIMP-1, MMP-9, $LTB_4$, $PGE_2$ levels in serum were significantly decreased. 5. Cartilage volume of BST treated group was significantly increased. Also changes of cartilage, synovial membrane, fibrous tissue were suppressed. Conclusions The results obtained in this study Bujasasim-tang have effects of antioxidative, anti-inflammatory, relieve pain and protection of cartilage. Therefore we expect that Bujasasim-tang is effective treatment for osteoarthritis.