• Journal of Microbiology and Biotechnology
• /
• 제8권1호
• /
• pp.74-80
• /
• 1998

CS-2l lymphoma cells that preferentially metastasize to lymph nodes after s.c. inoculation into BALB/c mice were grown in vitro in the presence of CA- 12 stromal cells isolated from lymph nodes. In order to obtain fundamental data on the identification and characterization of the soluble factors produced by CA-12 stromal cells, the conditioned medium of CA-12 stromal cells that inhibited apoptosis of CS-21 cells was examined. Various analytical treatments revealed that the soluble factors in CA-12 conditioned medium are very sensitive to heat treatment and trypsinization. Moreover CA-12 conditioned medium has an affinity with heparin but not with Con-A. In addition to these, the activity of CA-12 conditioned medium was blocked by H-7, a PKC inhibitor, but the conditioned medium could not induce the differentiation of thymocytes. We concluded that CA-12 conditioned medium contains stromal cell-derived apoptosis-inhibitory molecules that play an important role in proliferation of CS-2l cells by suppressing cell apoptosis.

• 한국가축번식학회지
• /
• 제20권3호
• /
• pp.289-297
• /
• 1996

This study was conducted to investigate the effects of maturaton medium and porcine follicular fluid on in vitro maturation of porcine follicular oocytes. The results obtained are as follows; 1. When the oocytes were cultured for 42 hours, the maturation rate was significantly (P<0.05) higher in TCM-HEPES(75.5%) than Ham's F-10(60.9%) and mKRB(60.7%) medium. The optimal medium for the maturation of porcine oocytes in vitro was the TCM-HEPES medium. 2. When the oocytes were cultured for 42 hours in TCM-HEPES medium with 10, 20 and 30% of porcine follicular fluid(pFF), the maturation rates of porcine oocytes were 69.1, 65.6 and 63.3%, respectively. The maturation rate(51.4%) of oocytes cultured without pFF was significantly(P<0.05) lower than that of oocytes cultured with pFF. 3. The maturation rates of porcine oocytes cultured for 42 hours in TCM-HEPEs medium with 3 different porcine follicular fluid treatments were 68.6%(centrifused), 72.3%(filtered) and 73.1%(heat treated), respectively. The maturation rate(49.4%) of control group without pFF treatment was significantly(P<0.05) lower than that of oocytes cultured with pFF treatment.

• 설비공학논문집
• /
• 제4권4호
• /
• pp.332-341
• /
• 1992

An absorption heat pump cycle has been modeled and simulated to analyze the system performance of water-cooled, series-flow, double-effect absorption heat pump, which can be applied to a direct gas fired cooling system with the medium range of cooling capacity (15RT level). Effect of absorption cooling system parameters, such as concentration difference, inlet temperature of cooling water, 1st generator temperature, leaving temperature differences of condenser and evaporator and efficiency of solution heat exchanger, has been investigated in the view of system cooling performance.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2000년도 추계학술대회논문집B
• /
• pp.347-352
• /
• 2000

In the present study, DOM and FVM have been used to analyze the radiative heat transfer in an axisymmetric cylindrical enclosure with obstacles. Heat flux distributions on the wall of enclosure form DOM and FVM are compared to those from simplified zone analysis for a nonparticipating medium. The comparison of DOM and FVM is also presented. Results show that there is a good agreement between FVM and simplified zone analysis. In addition, the effect of the thickness of the obstacle on the results is considered. Heat flux distribution on the surface of the obstacle is also presented.

• 대한설비공학회:학술대회논문집
• /
• 대한설비공학회 2009년도 하계학술발표대회 논문집
• /
• pp.1215-1219
• /
• 2009

In this study, the performance of solar assisted hybrid heat pump system with cloud cover were analyzed by using experimental method in spring season. It was consisted of concentric evacuated tube solar collector, heat medium tank, heat storage tank, heat pump, and so on. As a result, the solar radiation should be maintained over $4.1\;MJ/m^2$ in order to operate solar heating system for heating. Solar heat of collector wasn't affected by ambient temperature, but cloud cover has a big effect to collector efficiency. In addition, the collector efficiency is about 50-60%, and solar fraction is 40% for this system.

• 한국지열·수열에너지학회논문집
• /
• 제9권2호
• /
• pp.16-24
• /
• 2013

A multi-heat pump provides the benefits of comfort, energy conservation and easy maintenance. Recently, the multi-heat pump has been widely employed in small and medium-sized buildings. However, the control algorithm of the multi-heat pump are limited in the open literature due to complicated operating conditions. In this study, the MIMO control algorithm using integral optimum regulator was designed and the control performance of it was analyzed. In addition, system model of the control plant was developed by PRBS system identification scheme. The MIMO controller adopting the integral optimum regulator yielded satisfactory control performance results.

• 설비공학논문집
• /
• 제16권9호
• /
• pp.788-795
• /
• 2004

Cooling characteristics of protruding heat sources in a parallel channel with or without baffles are studied experimentally, The test section consists of two channels formed by two covers and one board made of polycarbonate which has three uniform heat source blocks. Five different cooling methods are considered to find out the most efficient cooling method in a given geometry and heat sources. The velocity and temperature of cooling medium, the temperature of the block surface are measured. The results are compared to examine the cooling characteristics of the different cooling methods.

• 태양에너지
• /
• 제8권1호
• /
• pp.5-12
• /
• 1988

One of the effective means to transfer the heat into and from the energy storage medium is thermosyphon. In this study, a two-phase closed thermosyphon with circular fins was used to extract the thermal energy stored in paraffin wax (Sunoco p-116). Heat transfer characteristics along the heat flow path were investigated as well as the overall performance. Some of the important results are as follows: (1) The temperature distribution of the wax in the radial direction was always maintained fairly uniformly; (2) Compared with bare thermosyphon, the heat transfer rate was vastly improved in the early stage of the experiment; and (3) Heat transfer coefficient between the wax and evaporating section of thermosyphon remained nearly constant during the experiment.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• 제21권4호
• /
• pp.245-275
• /
• 2017

The present investigation deals, Dufour and heat source effects on radiative MHD slip flow of a viscous fluid in a parallel porous plate channel in presence of chemical reaction. The non-linear coupled partial differential equations are solved by using two term perturbation technique subject to physically appropriate boundary conditions. The numerical values of the fluid velocity, temperature and concentration are displayed graphically whereas those of shear stress, rate of heat transfer and rate of mass transfer at the plate are presented in tabular form for various values of pertinent flow parameters. By increasing the slip parameter at the cold wall the velocity increases whereas the effect is totally reversed in the case of shear stress at the cold wall. It is observed that the effect of Dufour and heat source parameters decreases the velocity and temperature profiles.

• 설비공학논문집
• /
• 제15권8호
• /
• pp.667-673
• /
• 2003

Recent trends in the electronic equipment indicate that the power consumption and heat generation in a chip increase as the components are miniaturized and the computing speed becomes faster. Suitable heat dissipation is required to ensure the guaranteed performance and reliable operation of the electronic devices. The aim of the present study is to investigate the forced-convective thermal-hydraulic characteristics of a pin-fin heat exchanger as a candidate for cooling system of the electronic devices. The influence of the structure of the pin-fin assembly on heat transfer is investigated by porous medium model. The results are compared with the experimental data or correlations of several researchers for the heat transfer coefficients for the channel flow with pin-fin arrays. Finally, the effects of design parameters such as the pin-fin diameter and the spacing are examined.