• Journal of Korean Association for Spatial Structures
• /
• v.15 no.4
• /
• pp.107-114
• /
• 2015

Large spatial structures can not easily predict the dynamic behavior due to the lack of construction and design practices. The spatial structures are generally analyzed through the numerical simulation and experimental test in order to investigate the seismic response of large spatial structures. In the case of analysis for seismic response of large spatial structure, the many studies by the numerical analysis was carried out, researches by the shaking table test are very rare. In this study, a shaking table test of a small-scale arch structure was conducted and the dynamic characteristics of arch structure are analyzed. And the dynamic characteristics of arch structures are investigated according to the various column cross-section and length. It is found that the natural vibration periods of the small-scaled arch structure that have large column stiffness are very similar to the natural vibration period of the non-column arch structure. And in case of arch structure with large column stiffness, primary natural frequency period by numerical analysis is very similar to the primary natural frequency period of by shaking table test. These are because the dynamic characteristics of the roof structure are affected by the column stiffness of the spatial structure.

• Journal of the korean Society of Automotive Engineers
• /
• v.8 no.2
• /
• pp.51-64
• /
• 1986

There has been considerable interest over the last twenty years in the subject of the elastic properties of the cord-rubber laminate. This has been due to the rather intensive study of the composites materials characteristics brought about by the increased use of rigid composites materials characteristics brought about by the increased use of rigid composites in many structural applications. The object of this study is to obtain the natural frequencies and modes of the simply supported cord-rubber laminate plates prior to the study on the analysis of the dynamic properties of the pneumatic tire. To obtain these natural frequencies and modes, the 12 degrees of freedom orthotropic rectangular plate finite elements are developed. By using classical lamination theory, the stress-strain relations are represented. The governing equation for the finite element is derived by energy method. To find the natural frequencies and modes, he eigenvalues and corresponding eigenvectors are computed by the well known Jacobi power method. In order to verify the capability of this present finite element, the results of the specially orthotropic plate and the angle-ply laminate plate are compared with the analytical solution. The analytical and numberical results are in good agreement. The following problems of the simply supported plate are analyzed by the present finite element. a) the natural frequencies and mode shapes of the cord-rubber laminate plate for various aspect ratio. b) The natural frequencies and mode shapes of the orthotropic plate with the rectangular hole in its center.

• Nuclear Engineering and Technology
• /
• v.33 no.4
• /
• pp.397-408
• /
• 2001

A marine reactor shows very different thermal-hydraulic characteristics compared to a land- based reactor. Especially, study on the variation of flow field due to ship motions such as inclination, heaving and rolling is essential since the flow variation has great influence on the reactor cooling capability. In this study, the natural circulation characteristics of integral type marine reactor with modular steam generators were analyzed using computational fluid dynamics code, CFX-4, for inclined conditions. The numerical analyses are performed using the results of natural circulation experiments for integral reactor which are already conducted at Seoul National University. From the results, it was found that the flow rate in the ascending steam generator cassettes increases due to buoyancy effect. Due to this flow variation, temperature difference occurs at the outlets of the each steam generator cassettes. which is mitigated through downcomer by thermal mixing. Also, around the upper pressure header the flow from descending hot leg goes up to the ascending steam generator cassettes due to large natural circulation driving force in ascending steam generator cassettes. From this result, the increase of How rate in the ascending steam generator cassettes could be understood qualitatively.

• Proceeding of EDISON Challenge
• /
• 2016.03a
• /
• pp.203-208
• /
• 2016

In this paper, vibration characteristics in terms of the airfoil cross-sectional shape was examined by using the EDISON co-rotational plane beam-transient analysis. Assuming aircraft wing as a cantilevered beam with a constant cross-sectional shape, natural frequencies of each airfoil shape was compared while varying airfoil maximum thickness and maximum camber length, using Fast Fourier Transformation(FFT). When the airfoil maximum thickness was varied, natural frequency showed peak value at 18% chord, and decreased afterwards. When the airfoil maximum camber length was varied, natural frequency either increased or decreased at 6% chord, while at 8% the natural frequency showed its maximum. Applying such trends to B-737 wing airfoil, an improved B-737_mod airfoil shape was obtained with regard to the vibration characteristics.

• Journal of the Korean Applied Science and Technology
• /
• v.26 no.1
• /
• pp.51-59
• /
• 2009

Natural Artemisia extraction was extracted from Artemisia component using diethyl ether as a solvent, and we tested various pharmacetical and chemical characteristics of this extract. Characteristic experiments to use natural Artemisia extract tested antimicrobial experiment using microbe in pharmacetical material, and tested dye experiment using fiber in chemical material. From the result of characteristics experiment, some conclusions are obtained as follow. From the result of extraction experiment, it obtained about 10.4%-Artemisia extraction ratio as semi-solid state, and after dried in freezing from Artemisia extract of semi-solid state, it obtained about 10%-Artemisia extraction ratio as solid state of dark blue-green color. From result of antimicrobial experiment of Artemisia extract, number of staphylococcus aureus (ATCC-01) and aspergillus niger (ATCC-02) in microbe decreased more and more according to time passage. This phenomenon showed that Artemisia extract influences to antimicrobial effect. From the result of dye experiment of Artemisia extract, it appeared in direction of dark blue-green color after dyed to use cotton and silk with fiber to control in pH 7.5. Specially the result which confirmed dye of fiber with optical electron microscope (OEM), we could know that it appears darker silk than cotton.

• Korean journal of food and cookery science
• /
• v.22 no.2 s.92
• /
• pp.140-146
• /
• 2006

The sensory characteristics of bread prepared with the addition of Angelica plant(Bakluncho) and Jujube(Daechu) powders were investigated The moisture, crude protein, as reducing sugar and vitamin C content of Angelica plant(Bakluncho) powders were 7.78%, 6.07%, 7.37%, 6.13% and 50.10 mg% respectively, and those of Jujube(Daechu) powders were 11.19%, 4.43%, 2.36%, 14.23% and 49.20 mg% respectively. Lightness value decreased but redness and yellowness values increased with increasing natural pigment powders content. The mechanical hardness of the bread decreased with the addition of 3% Angelica plant(Bakluncho) powders, but increased with the addition of 1% and 5% Angelica plant(Bakluncho) powders. The mechanical hardness of bread decreased with the addition of 1% and 3% Jujube(Daechu) powders, but increased with the addition of 5% Jujube(Daechu) powders. In sensory characteristics, the crust color, mb color, moistness and springiness decreased, but aroma and hardness increased with the increasing natural pigment powders content. The savory taste and overall quality of breads with 1% Angelica plant(Bakluncho) powders and 3% Jujube(Daechu) powders were higher than those of the control without my addition. A negative correlation was observed between Hunter's color value and overall quality of the bread prepared with addition of Angelica plant(Bakluncho) and Jujube(Daechu) powders.

• Korean Journal of Medicinal Crop Science
• /
• v.18 no.1
• /
• pp.51-55
• /
• 2010

This study was conducted to investigate the effect of planting position on the growth characteristics, yield and ginsenoside content in Panax ginseng C.A. Meyer at different growth stages. Referring to shoot growth characteristics, stem length, stem diameter and leave area were higher at front than rear, increasing as the proceeding of growth stages. But a lower chlorophyll contents was caused at front compared to rear and decreased as the proceeding of growth stages contrarily. According to root characteristics, root length and main body length were higher at front, with a positive correlation to growth stages, which was also shown on fresh root weight and dry root weight with the maximum in August. Meanwhile, the effect of planting position on ginsenoside content could also be definite by the highest content at front showing high light intensity, increasing as the proceeding of growth stages as well.

• Plant Resources
• /
• v.3 no.3
• /
• pp.226-232
• /
• 2000

The availability of enokitake cultural waste for Lentinus edodes cultivation was investigated, although hardwood sawdust has traditionally been used as a substrate for this fungus. Firstly, physiochemical characteristics of cultural waste were analysed. Secondly, mycelial growth characteristics and fruiting yields of L. edodes on waste treated in some methods were determined. Physiochemical characteristics of enokitake cultural waste showed that the millwaste complex was a little degraded by enokitake fungus and suggested the probability that most component lost by enokitake could be rice bran. Mycelia of L. edodes grew and fruited well on waste supplemented by fresh rice bran and Quercus sawdust although didn't on waste only. Mycelial growths of these fungi on waste were accelerated when supplemented by rice bran to the percent of 40(w/w) but decreased or suppressed at above ratios(30, 40%, w/w). Supplementations of oak sawdust at above 40%(w/w) of the waste and rice bran at 20%(w/w) of the sawdust allowed such a good mycelial growth as to be selected as a pertinent mixing ratio for fruiting medium. A fruiting yield on enokitake cultural waste supplemented by oak sawdust (at 40% of the waste, w/w) and rice bran (at 20% of the sawdust, w/w) was not inferior to that on oak sawdust supplemented by rice bran only (at 20% of the sawdust, w/w). These results indicated strongly the potentiality of enokitake cultural waste as raw materials for shiitake cultivating substrates.

• Asian-Australasian Journal of Animal Sciences
• /
• v.32 no.11
• /
• pp.1641-1656
• /
• 2019

The present paper reviews the findings of different research studies on the effect of natural ingredients in the Japanese quail (Coturnix coturnix japonica) diet on carcass characteristics and meat quality. The results show a relationship between the type and concentration of ingredients used in diets and carcass characteristics and meat quality. The inclusion of medicinal herbs (thyme, black seed, and mint), plants (canola), seeds (chickpea), spices (cinnamon and coriander), worms (earthworms), bee products (propolis), phytochemicals (lycopene), and edible fungi (common mushrooms) in the diet improved carcass quality characteristics compared to the control diets (basal diets). The inclusion of medicinal herbs (spearmint and green tea), spices (cinnamon), vegetables (tomato), plants (verbena and canola), seeds (marijuana), and edible fungi (oyster mushrooms) improved meat quality. In conclusion, the use of ingredients of natural origin in the diet of Japanese quail improves carcass quality characteristics and meat quality.

• Journal of the Korean Society of Industry Convergence
• /
• v.3 no.4
• /
• pp.319-327
• /
• 2000

In this study, the hydraulic characteristics variation of flood level caused by tree-planting condition in channel section is evaluated through the examination and analysis of back water characteristics in a natural channel within urban area where the improvement is completed. The study channel is Sinchun runs through the center of Taegu metropolitan city. For the analysis, the comparative examination of runoff characteristics depend on tree- planting condition performed for the flood level of the most upstream point, and velocity of study channel when the project flood flows according to three cases that existing channel is improved to the pro-natural channel, the roughness condition of both riverside highlands is changed, and the composition rate of trees in the riverside highlands is changed. It is known that the variation ranges of the flood level increase remarkably in general, and of the velocity decrease from the result of the examination for the hydraulic characteristics parameters at the most upstream point depend on the tree-planting condition of the channel section when the project flood flows. From the results of the above study on the variation of the hydraulic characteristics according to the tree-planting condition in channel section, it is known that the hydraulic characteristics when the project flood flows in channel have close relationship with the section properties and the slope of channel.