• Bulletin of the Korean Chemical Society
• /
• v.19 no.9
• /
• pp.1000-1002
• /
• 1998

• Journal of the Korean Society of Propulsion Engineers
• /
• v.4 no.3
• /
• pp.45-54
• /
• 2000

Ignition transient is a. very rapid process lasting only in the order of 100 milliseconds and therefore it is difficult to measure all relevant ballistic properties. Numerical simulation is thus useful to quantify some of these hard to measure flow and ballistic properties. One-dimensional model was employed to study the effects of aging using simplified aging scenarios for both N-H sustainer and booster motors. Also the effects of newly designed igniter on the ignition of N-H sustainer was simulated. Radiation effects could be significant in terms of energy flux increase to the propellant surface and the energy exchange between the combustion gas itself. One dimension implementation of radiation showed significant effects for rear-mounted igniter. Implementation of radiation effects into 2-D axi-symmetric numerical model was completed and its effects on the N-H sustainer were examined. To have a reliable prediction of computer model on ignition transient, accurate chemical property data on the propellant and igniter gas are required. It was found that such property data on aged N-H motors are not available. Chemical aging model can be used to predict to some degree of accuracy effects of aging on chemical and mechanical properties. Such a model was developed, albeit 2-dimensional, to study migration of moisture through a representative solid rocket motor configuration.

• The Journal of Korean Medicine
• /
• v.22 no.4
• /
• pp.107-113
• /
• 2001

Objectives : The aim of this study was to investigate effects of Chungganhaeju-tang on alcoholic fatty liver. Methods : Thirty patients with alcoholic fatty liver were included in this study. Chungganhaeju-tang was administered to subjects for 1 month. The changes of clinical symptoms and chemical liver function tests were evaluated before and after treatment. Results : Chungganhaeju-tang has effects on the improvement of clinical symptoms such as fatigue, anorexia, dyspepsia, nausea, and RUQ (Right Upper Quadrant) pain. On the chemical liver function test, serum AST, ALT, GGT, and TG level significantly decreased (P<0.05, by paired t-test). Conclusions : These results suggest that Chungganhaeju-tang has significant effects on the improvement of clinical symptoms and chemical liver function test with alcoholic fatty liver.

• Journal of Welding and Joining
• /
• v.19 no.3
• /
• pp.334-341
• /
• 2001

The chemical and geometric effects of weld on flow-accelerated corrosion (FAC) of SA106 Gr.C low alloy steel pipe in 3.5wt% NaCl and simulated feedwater of nuclear power plant have been investigated by using rotating cylinder electrode. Polarization test and weight loss test were conducted and compared at rotating speed of 2000rpm (3.14m/s) with the variables of chemical and geometric parameters. The results showed that the chemical effects were relatively larger than the geometric effects, and the welded parts were the local anode and preferentially corroded, which could be explained by the differences between microstructural and compositional parameters. On the other hand, under active corrosion conditions, the heat affected zone were severely corroded and microstructural effects became the important role in the whole process.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.18 no.1
• /
• pp.212-222
• /
• 1994

In the annular Modified Chemical Vapor Deposition process using two concentric tubes, the inner tube is heated to maintain high temperature gradients to have high thermophoretic force which can increase particle deposition efficiency. However, higher axial velocity in a narrow gap between inner and outer tubes can result in a longer tapered entry length. In the present paper, a new concept using an annular jet from the inner tube is presented and shown to significantly reduce the tapered entry length with maintaining high efficiency. Effects of a jet injection on heat transfer, fluid flow and particle deposition have been studied. Of particular interests are the effects of jet velocity, jet location and temperature on the deposition efficiency and tapered length . Torch heating effects from both the previous and present passes are included and the effect of surface radiation between inner and outer tubes is also considered.

• Proceedings of the PSK Conference
• /
• 2003.04a
• /
• pp.143.2-144
• /
• 2003

Joins (SKI 306X) is now clinically used for the treatment of osteoarthritis (OA). In previous reports, Joins a natural herbal product extracted from three herbs Clematis Radix. Trichosanthes Radix and Prunella Flos, was shown to have good analgesic and anti-inflammatory effects in several in vivo models. e.g., acetic acid-induced pain, carrageenan-induced paw edema and adjuvant-induced arthritis. (omitted)

• 한국정보디스플레이학회:학술대회논문집
• /
• 2007.08a
• /
• pp.307-310
• /
• 2007

We describe effects of ionic and neutral additives on phase and structural behavior of the lyotropic chromonic liquid crystals used in preparation of optical elements such as polarizers and compensators.

• Bulletin of the Korean Chemical Society
• /
• v.2 no.1
• /
• pp.12-16
• /
• 1981

Alkyl and alkenyl substituent effects on nonbonded interactions of hexatriene were examined using CNDO/2 method. The results showed that: (1) rapid rate of thermal electrocyclization of 3-vinyl hexa-1, 3, 5-triene is due to increased overlap population between atom pair reacting resulting from strong electron repelling interaction of vinly group on the triene moiety; (2) stability of a conformer is determined by additive effect of composite ${\pi}$ structures; (3) a substituent on positions 2 and 3 increases the HOMO AO coefficient of sites 1 and 4 considerably and activates interactions with these sites.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2009.02a
• /
• pp.257.1-257.1
• /
• 2009

• Proceedings of the Korean Vacuum Society Conference
• /
• 2009.02a
• /
• pp.258.2-258.2
• /
• 2009