• Korean Journal of Animal Reproduction
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• v.22 no.3
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• pp.293-300
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• 1998

The objective of this study was to determine effects of $\beta$-mercaptoethanol ($\beta$-ME) and cyst-eine (CYS) on the development of bovine em-bryos obtained from in vitro matured and fertil-ized oocytes. Cumulus-oocyte-complexes (COC-s) were matured in micro-drop of TCM-199 medium containing 10% FBS, 17$\beta$-Estradiol and FSH-p under paraffin oil at 39$^{\circ}C$ for 24 hrs. The fertilization of COC were induced in Fert-TALP medium supplemented with PHE, heparin, BSA and then the fertilized oocytes were cultured in CR1aa medium for 24 hrs. To investigate the effects of the agents on the development of the embryos, the embryos developed to the late 2-cell stage were cultured in the media with and without $\beta$-ME, CYS for 9 days. In experiment 1, to select appropriate concentration of $\beta$-ME and CYS during whole culture period (9 days), various concentrations of $\beta$-ME and CYS were add ded to the CR1aa medium. Addition of 25TEX>$\mu$M of $\beta$-ME and O.1mM of CYS to the culture medium 1 increase the incidence of embryos developed to the blastocyst. In experiment 2, we evaluated the effects of 25$\mu$M of $\beta$-ME and O.1mM of CYS addition on the blastocyst formation when emb bryos at different stages were exposed to 25$\mu$M $\beta$-ME and O.1mM of CYS. $\beta$-ME and CYS enhanced in vitro development of embryos to the blastocyst stage. The effect was greater in 8-ceII to morula embryos than in embryos fewer than 2-cells at the initiation of treatment. These results suggested that the addition of 25$\mu$M B-ME and O.1mM cysteine enhanced development to the blastocyst and hatching stage of in vitro derived bovine embryos, also addition of $\beta$-ME and cysteine were effective later stage embryo than early embryo development.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.1
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• pp.94-131
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• 2007

A review on the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering in 2004 and 2005 has been done. Focus has been put on current status of research in the aspect of heating, cooling, air-conditioning, ventilation, sanitation and building environment. The conclusions are as follows. (1) Most of fundamental studies on fluid flow were related with heat transportation of facilities. Drop formation and rivulet flow on solid surfaces were interesting topics related with condensation augmentation. Research on micro environment considering flow, heat, humidity was also interesting for comfortable living environment. It can be extended considering biological aspects. Development of fans and blowers of high performance and low noise were continuing topics. Well developed CFD and flow visualization(PIV, PTV and LDV methods) technologies were widely applied for developing facilities and their systems. (2) The research trends of the previous two yews are surveyed as groups of natural convection, forced convection, electronic cooling, heat transfer enhancement, frosting and defrosting, thermal properties, etc. New research topics introduced include natural convection heat transfer enhancement using nanofluid, supercritical cooling performance or oil miscibility of $CO_2$, enthalpy heat exchanger for heat recovery, heat transfer enhancement in a plate heat exchanger using fluid resonance. (3) The literature for the last two years($2004{\sim}2005$) is reviewed in the areas of heat pump, ice and water storage, cycle analysis and reused energy including geothermal, solar and unused energy). The research on cycle analysis and experiments for $CO_2$ was extensively carried out to replace the Ozone depleting and global warming refrigerants such as HFC and HCFC refrigerants. From the year of 2005, the Gas Engine Heat Pump(GHP) has been paid attention from the viewpoint of the gas cooling application. The heat pipe was focused on the performance improvement by the parametric analysis and the heat recovery applications. The storage systems were studied on the performance enhancement of the storage tank and cost analysis for heating and cooling applications. In the area of unused energy, the hybrid systems were extensively introduced and the life cycle cost analysis(LCCA) for the unused energy systems was also intensively carried out. (4) Recent studies of various refrigeration and air-conditioning systems have focused on the system performance and efficiency enhancement. Heat transfer characteristics during evaporation and condensation are investigated for several tube shapes and of alternative refrigerants including carbon dioxide. Efficiency of various compressors and expansion devices are also dealt with for better modeling and, in particular, performance improvement. Thermoelectric module and cooling systems are analyzed theoretically and experimentally. (5) According to the review of recent studies on ventilation systems, an appropriate ventilation systems including machenical and natural are required to satisfied the level of IAQ. Also, an recent studies on air-conditioning and absorption refrigeration systems, it has mainly focused on distribution and dehumidification of indoor air to improve the performance were carried out. (6) Based on a review of recent studies on indoor environment and building service systems, it is noticed that research issues have mainly focused on optimal thermal comfort, improvement of indoor air Quality and many innovative systems such as air-barrier type perimeter-less system with UFAC, radiant floor heating and cooling system and etc. New approaches are highlighted for improving indoor environmental condition as well as minimizing energy consumption, various activities of building control and operation strategy and energy performance analysis for economic evaluation.