• Journal of Biosystems Engineering
• /
• v.36 no.4
• /
• pp.267-272
• /
• 2011

The latent heat of vaporization in rough rice, brown rice, white rice and rice hull was calculated by Clausius-Clapeyron equation, which does not require complex constraints as in Othmer method. Equilibrium relative humidity and ratio of the latent heat of vaporization with ln$P_{\upsilon}$ and ln$P_S$ were estimated with moisture contents ranging from 10% (d.b.) to 36% (d.b.) with 2% (d.b.) increment and temperatures ranging from $10^{\circ}C$ to $50^{\circ}C$ with $2.5^{\circ}C$ increment. An empirical equation for calculating the latent heat of vaporization in rice was developed as a function of moisture content and temperature. The equation agreed well with the calculated results. The ratio for latent heat of vaporization were the greatest for white rice while they were similar among rough rice, brown rice and rice hull.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.45 no.1
• /
• pp.1-5
• /
• 2013

Printing papers published in between 1950's and 1990's were treated with three methods such as distilled water washing, $CaCO_3$ solution washing and methyl cellulose solution coating for improving their conservational properties. Accelerated aging with $80^{\circ}C$ and 80% RH for 14 days was applied to the testing papers. Results showed that distilled water and $CaCO_3$ washing kept increased pH even after accelerated aging, but did not improve folding endurances for 1950's-60's papers. Methyl cellulose treatment did not increased pH of the old papers, but increased folding endurances remarkably for 1950's-60's papers even after accelerated aging. It suggests that methyl cellulose treatment after $CaCO_3$ washing should give improvements both in pH and folding endurance.

• Journal of Advanced Marine Engineering and Technology
• /
• v.25 no.6
• /
• pp.1341-1352
• /
• 2001

Vacuum freeze drying process by which frozen water in a drying material is removed sublimation under vacuum condition, is now applied to various industrial field such as the manufacturing and packaging of pharmaceuticals in pharmaceutical industry, the drying of bio- products in bio-technology industry, the treatment of various quality food stuff in food technology, and so on. The Knowledge about the heat and mass transfer characteristics related with the vacuum freeze drying process is crucial to improve the efficiency of the process as well as the quality of dried products. In spite of increasing needs for understanding of the process, the research efforts in this fields are still insufficient. In this paper, a numerical code that can predict primary drying in a vial is developed based on the finite volume method with a moving grid system. The calculation program can handle the axis- symmetric and multi-dimensional characteristics of heat and mass transfer of the vial freeze drying process. To demonstrated the usefulness of the present analysis, a practical freeze drying of skim Milk solution in a vial is simulated and various calculation results are presented.

• Korean Journal of Pharmacognosy
• /
• v.37 no.2 s.145
• /
• pp.97-102
• /
• 2006

Garlic(Allium sativum Linn) is widely used as a common condiment for a variety of foods and beverages. It has been well known that fresh garlic and garlic supplement of commercial preparations have various therapeutic properties including antimicrobial activity, antiplatelet aggregation, antihypertension, and cholesterol-lowering effects, which contribute to its increasing uses for an alternative medicine. Allicin(diallyl thiosulfinate), the major bioactive components of garlic, is formed by alliinase cleavage of the naturally occurring alliin upon crushing or mincing of garlic, and is the progenitor of a number of other products, such as diallyl disulfide. CYP3A4, heme-containing monooxygenase, is a key enzyme responsible for drug metabolism. Therefor, in the present study, we isolated and examined the compounds with CYP3A4-inhibiting activities from garlic. Among EtOAc extracts of garlic, we found that N-p-coumaroyltyramine and N-feruloyltyramine showed remarkable CYP3A4-inhibiting activities, compared to diallyl disulfide. Structures of the isolated active compounds were established by chemical and spectroscopic means.

• Journal of the Korean Society of Industry Convergence
• /
• v.21 no.4
• /
• pp.159-165
• /
• 2018

In electric agricultural machine a reduction gear is needed to convert the high speed rotation motion generated by DC motor to lower speed rotation motion used by the vehicle. The reduction gear consists of several spur gears. Spur gears are the most easily visualized gears that transmit motion between two parallel shafts and easy to produce. The modelling and simulation of spur gears in DC motor reduction gear is important to predict the actual motion behaviour. A pair of spur gear tooth in action is generally subjected to two types of cyclic stress: contact stress and bending stress. The stress may not attain their maximum values at the same point of contact fatigue. These types of failure can be minimized by analysis of the problem during the design stage and creating proper tooth surface profile with proper manufacturing methods. To improve its life expectation in this study modal and stress analysis of reduction gear is simulated using ANSYS workbench based on finite element method (FEM). The modal analysis was done to understand reduction gear deformation behaviour when vibration occurs. FEM static stress analysis is also simulated on reduction gear to simulate the gear teeth bending stress and contact stress behaviour.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.50 no.5
• /
• pp.616-620
• /
• 2017

The feeding habits of post-larval Yatabe blenny Parablennius yatabei (2.0-9.8 mm SL) were examined on the basis of 158 individuals collected from June to October in the coastal waters of eastern Jinhae Bay, South Korea. Based on the index of relative importance (IRI), post-larval P. yatabei fed 94.4% on copepods and 5.6% on tintinnids. The preference of post-larval P. yatabei for copepods to other prey items results from ontogenetic changes. The dietary percentage of copepods increased as fish size increased and tintinnids became less important. The feeding rate of post-larval P. yatabei was consistent at all times of day.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.53 no.3
• /
• pp.456-463
• /
• 2020

The diet of the walleye pollock Gadus chalcogrammus, was studied by examining the stomach contents of 864 individuals. Using gill nets, samples were collected monthly from January to December 2017 in Jugwang, Sokcho, Yangyang, Uljin, Ganggu, and Gampo, Korea. The specimens ranged in total length (TL) from 16.6 to 75.2 cm. G. chalcogrammus fed mainly on Euphausia pacifica (Euphausiacea) and less on Cephalopoda, Pisces, Mysidacea, and Macrura. The results indicated that G. chalcogrammus is a specialist feeder, feeding mainly Euphausiacea. With growth, however, its diet shifted from Euphausiacea to Cephalopoda, Macrura and Pisces. Smaller individuals (<40.0 cm TL) consumed mainly Euphausiacea. The proportion of Euphausiacea decreased with increasing body size, whereas the consumption of Cephalopoda and Macrura increased gradually.

• Food Science and Biotechnology
• /
• v.14 no.2
• /
• pp.190-195
• /
• 2005

The conditions for the extraction of effective substances from the stem of Opuntia ficus-indica were optimized by a response surface methodology. The total extract yield was maximized under the temperature of $97.77^{\circ}C$, at a time duration of 145.82 min and a water to sample ratio 16.59 mL/g. Moreover, the optimum conditions for the extraction of effective substances were as follows: $84.95^{\circ}C$, 156.50 min and a water/sample ratio of 7.46 mL/g for the phenolics content; and $97.11^{\circ}C$, 139.03 min and a water/sample ratio of 10.91 mL/g for the pectin content. The range of optimum extraction conditions in consideration of the physicochemical properties of the extracts were shown to be as $95-100^{\circ}C$ as the extraction temperature, 120-180 min as extraction time and a water to sample ratio of 5-18 mL/g.

• BMB Reports
• /
• v.43 no.9
• /
• pp.604-608
• /
• 2010

Tumor necrosis factor-$\alpha$ (TNF-$\alpha$) mediates proinflammatory responses in primary human umbilical vein endothelial cells (HUVECs), and it upregulates the expression of secretory group IIA phospholipase $A_2$ ($sPLA_2$-IIA). $sPLA_2$-IIA plays a pivotal role in inflammation, and antithrombin (AT) possesses properties that are beneficial to endothelial cells. Therefore, we investigated the effects of AT on the expression of $sPLA_2$-IIA in TNF-$\alpha$-stimulated HUVECs. TNF-$\alpha$ potently upregulated the expression of $sPLA_2$-IIA, and prior treatment of cells with AT inhibited the expression of $sPLA_2$-IIA in HUVECs. Also, antibodies or siRNA for syndecan-4 blocked the protective effect of AT. Furthermore, PI3-kinase and the AKT pathway are significantly involved in the AT-mediated inhibition of the expression of $sPLA_2$-IIA. These results show that AT effectively suppresses the upregulated $sPLA_2$-IIA expression, which might contribute to the cytoprotective effects of AT in the treatment of severe inflammatory diseases.

• Journal of Biosystems Engineering
• /
• v.32 no.6
• /
• pp.389-394
• /
• 2007

The power output of the stirling engine is influenced by the regenerator effectiveness. The regenerator effectiveness is influenced by heat transfer and flow friction loss of the regenerator matrix. In this paper, in order to provide basic data for the design of the regenerator matrix, characteristics of working fluid velocities were investigated by a packed method of matrix in the oscillating flow as the same condition of operation in a Stirling engine. As matrices, two different wire screens were used. The results are summarized as follows; 1. When a regenerator is not filled with any wire screen, working fluid velocity of the oscillating flow shows 1.3 times faster than that of one directional flow. 2. When a regenerator is filled with the wire screen of No.50, working fluid velocity of the oscillating flow reveals 2.5 times faster than that of one directional flow. 3. When a regenerator is filled with the wire screen of No. 100, working fluid velocity of the oscillating flow shows 2 times faster than that of one directional flow, regardless of the number of packed wire screens. 4. Working fluid velocity is decreased wire the increase in number of meshes and packed wire screens.