• 대한기계학회논문집B
• /
• 제28권11호
• /
• pp.1417-1423
• /
• 2004

The thickness of laminar flame and preheat zone was computed from equation with burning velocity and the temperature profile, which is obtained by using premix code of Chemkin program for ethanol-air mixture. The computations were carried out under the unburned gas pressure 0.5bar-30bar and temperature of 300k-700K at 1.0. A difference flame thickness showed between temperature profile and equation with burning velocity. The ratio of flame thickness derived from the equation was about 45∼65% of the temperature profile, and the thickness of preheat zone was about 67.1% of the flame thickness. The flame thickness was decreased by increasing the pressure and temperature, but the effect of pressure is more significant than the effect of temperature on the flame thickness. The flame thickness was predicted by using the following equation. X(mm) = $X_{st}$ (T/300)$^{-0}$.65/(P)$^{-0}$.68/ (0.5bar$\leq$P$\leq$30bar, 300K$\leq$T$\leq$700K)K)

• Journal of information and communication convergence engineering
• /
• 제21권2호
• /
• pp.103-109
• /
• 2023

We investigated the antipodal-symmetric dispersion maps of a dispersion-managed link with a midway optical phase conjugator to compensate for the distorted 960 Gb/s wavelength division multiplexed (WDM) signal caused by these effects. The proposed antipodal-symmetric dispersion map has various shapes depending on the detailed design scheme. We confirmed that the dispersion-managed link designed with the dispersion map of the antipodal-symmetric structure is more advantageous than the conventional uniform dispersion map for compensating WDM channels. It was also confirmed that among the antipodal-symmetric structures, the dispersion map configured with the S-1-profile, in which S is inverted up and down, was more effective for distortion compensation than the dispersion map configured with the S-profile. In particular, we confirmed that the S-1-profile can broaden the optical pulse width intensively at a short transmission distance, more effectively compensating for the distorted WDM channel. Because this structure makes the intensity of the optical pulse relatively weak, it can decrease the nonlinear Kerr effect.

• 한국윤활학회:학술대회논문집
• /
• 한국윤활학회 1991년도 제13회 학술강연회초록집
• /
• pp.50-54
• /
• 1991

This paper shows the effect of axial profile on the elastohydrodnamic lubrication (EHL) behavior of axially profiled cylindrical roller. For two different type of profiles which have nearly similar elastostatic pressure distribution, the EHL results show large differences. Especially the difference in film shape is larger than that of pressure distribution. Therefore, the magnitude of the minimum film thickness should be a major criteria to design the axial profile of the roller and a new design procedure is presented which take into account the minimum film thickness as well as the pressure distribution.

• 한국군사과학기술학회지
• /
• 제5권2호
• /
• pp.207-216
• /
• 2002

In this paper, the study on the behavior of the deformation of brittle material, such as concrete, ceramic, was peformed by comparison of Lagrangian technique and Smoothed Particle Hydrodynamics using commercial nonlinear hydrodynamic numerical program, Autodyn_2D. The effect of SPH technique was proved by investigating the behavior of material deformation, velocity profile and pressure profile.

• 한국윤활학회:학술대회논문집
• /
• 한국윤활학회 2000년도 제32회 추계학술대회 정기총회
• /
• pp.385-396
• /
• 2000

The secondary motion of piston occurs due to the transient forces and moments in the clearances between piston skirt and cylinder liner The motions are very related to the skirt profile and the magnitude of piston-pin offset. Above all, the elastic deformation is another major effect on the piston secondary motion that has not been considered in the previous researches. In this work, the effects of elastic deformation of the piston skirt on the secondary piston motion are studied for the frictional power loss by using commercial softares, PISDYN and ANSYS.

• 대한약학회:학술대회논문집
• /
• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
• /
• pp.237.1-237.1
• /
• 2003

Cefuroxime axetil, a broad spectrum antibiotic, has been known to form a gelatinous mass in contact with aqueous media, which could lead to poor dissolution. Therefore, this study was conducted for removing the gelling phenomenon and thereby obtaining a favorable dissolution profile. We have found that the addition of poly (methacrylic acid, methyl methacrylate) could not only inhibit the tendency of cefuroxime axetil to form a gel but also showed the good dissolution profile compared to the formula without poly (methacrylic acid, methyl methacrylate). (omitted)

• Food Science and Biotechnology
• /
• 제17권2호
• /
• pp.413-416
• /
• 2008

Effects of extracts obtained from the flowers of Elsholtzia splendens on the serum lipid profile and hepatotoxicity in mice were investigated. Female ICR mice were given E. splendens ethanolic extract (ESEs) orally at a dose of 10 or 50 mg/kg BW for 50 days. Significant dose-dependent decreases in triglyceride and low-density lipoprotein (LDL)-cholesterol of serum were observed. In addition, ESEs prolonged the lag-time of LDL oxidation in vitro. In the serum of ICE mice given ESEs orally at 10 and 50 mg/kg BW, the serum levels of aspartate aminotransferase (AST) and lactic dehydrogenase (LDH) increased significantly, while total protein, albumin, creatinine, alanine aminotransferase (ALT), and total bilirubin did not change. Therefore, ESEs may be beneficial to human health, although it has some hepatotoxicity.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2006년도 추계학술대회논문집
• /
• pp.649-653
• /
• 2006

Engine Noise is composed of the mechanical and combustion noise. The contribution of combustion noise is generally bigger than the contribution of the mechanical noise at idle condition in DI diesel engine. That noise usually makes a roughness problem at the fundamental engine order. It is difficult to remove the modulation frequency so we have to directly reduce the combustion noise. The key effect of combustion noise reducing solution is the modification of the combustion pressure profile. It is accomplished by the multiple injection method and we solved the 400Hz combustion noise and improved the sound quality at idle condition in DI diesel engine.

• 한국윤활학회:학술대회논문집
• /
• 한국윤활학회 1998년도 제27회 춘계학술대회
• /
• pp.198-205
• /
• 1998

Recently, according as the supply of power steering system has been diffused, for the comfortable driving condition, the problem to reduce the noise and vibration of this system suddenly appeared. This system can be classified two systems of the pipe line and the pump. In this paper, it is described about the noise characteristic with the camring profile of the hydraulic vane pump. As a result, when it excesses tolerance, the noise is increased. Moreover, in the case of the same of cam-ring, the effect of the rotating speed is larger than the discharge pressure.

• 소성∙가공
• /
• 제25권1호
• /
• pp.61-66
• /
• 2016

In the current study, we present a new model for the prediction of the strip profile and the residual stresses. This new approach is an analytical model that predicts the residual stresses from the effect of post-deformation. Since the residual stress cannot exceed the yield strength of the material, post-yielding may possibly occur in the post-deformation zone prior to the strip reaching the steady-state zone. The prediction accuracy of the proposed model is examined through comparison with the predictions from 3-D finite element (FE) simulations.