• Journal of Sericultural and Entomological Science
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• v.43 no.2
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• pp.83-87
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• 2001

This study was carried out to investigate the optimal medium and optimal dextrose concentration of 12 entomopathogenic fungi. The colonies of Cordyceps gracilioides, C. sp.(J23), Paecilomyces farinosus(J5), P tenuipes, Paecilomyces sp.(J4), Beauveria bassiana and B. brongniartii on SLA(silkworm larva agar) medium are similar to those on PDA(Potato dextrose agar) medium. On the contrary, the colonies of 5 fungi are very various according to its medium. The optimal medium for 1 1 fungi was SLA-A medium, which was better than PDA medium with regard to the mycelial growth. The optimal concentration on mycelial growth was superior to 6% for 6 fungi. When silkworm larvae was injected with P. tenuipes on SLA medium for fruiting body production. Infection rate, fruiting body formation rate, synnemata number and synnemata length were 91.3 $\pm$ 1.5%, 88.6 $\pm$ 2.3%, 56.6 $\pm$ 3.2 and 33.4 $\pm$ 2.88 ㎜ respectively. In economical analysis, the prototype medium can reduce 61.9% of production cost per 1 liter compared with PDA medium.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.11
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• pp.981-988
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• 2002

Generally, the term "energy saving is economical" is appropriate for the national view point and for design and assessment of one system, but not appropriate when choosing the system by comparing alternative systems in the early design step. Sometimes, non-energy saving system is more economical than energy saving system because of the price of electricity, gas or oil, which are used for operating the air conditioning system. Therefore, when designing the system, we should consider the efficient alternatives through economic assessment of energy saving method. However, research on non-operating number control of the system is not sufficient because it is more common to use operating number control of the system for most economic assessment of air conditioning system. For this reason, this research can provide the economics through operating number control as basic design data. The data obtained through assesment of Life Cycle Cost based on amount of yearly energy use, were produced by system simulation of HASP/ACLD/8501 and HASP/ACSS/8502 for six alternative heating/cooling systems based on constant air volume conditioning system, which is widely used for medium and large office buildings in Busan.

• International Journal of Air-Conditioning and Refrigeration
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• v.11 no.4
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• pp.209-217
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• 2003

The term “energy saving is economical” is appropriate for the national view point and for design and assessment of one system, but not appropriate when choosing the system by comparing alternative systems in the early design step. Sometimes, non-energy saving system is more economical than energy saving system because of the price of electricity, gas or oil, which are used for operating the air conditioning system. Therefore, when designing a system, we should consider the efficient alternatives through economic assessment of energy saving method. However, research on non-operating number control of the system is not sufficient because it is more common to use operating number control of the system for most economic assessment of air conditioning systems. For this reason, this research can provide the economic operating number control method as basic design data. The data obtained through analysis of life cycle cost based on amount of yearly energy use, are produced by system simulation of HASP/ACLD/8501 and HASP/ACSS/8502 for six alternative heating$.$cooling systems based on seasonal air conditioning system, which is widely used for medium and large size office buildings in Busan.

• KSBB Journal
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• v.26 no.2
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• pp.143-150
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• 2011

The aim of the study was to optimize harvesting method for concentrating microalgae from microalgae mass culture. It is well known that the mass density of microalgae is usually very low and these are small size (5-20 ${\mu}m$) in the culture medium. It is essential that microalgae is harvested and concentrated economically for economical biodiesel production from microalgae. In this study, to determine optimized conditions for microalgae harvesting by chemical flocculation. Flocculation of three algae, Chlorella ellipsoidea, Dunaliella bardawil, and Dunaliella tertiolecta, was performed using various chemical flocculants, such as inorganic flocculants (aluminium sulfate, aluminium potassium sulfate, ferrous sulfate, ferric sulfate, ferric chloride, calcium hydroxide, sodium carbonate, sodium nitrite, and sodium aluminate), organic flocculant (polyacrylamide), and biopolymer flocculants (chitosan and starch). The results indicated that aluminium based inorganic flocculants is suitable for microalgae harvesting such as Chlorella ellipsoidea, Dunaliella bardawil, and Dunaliella tertiolecta. The results also recommended that flocculant doses, agitation speed, agitation time, sedimentation time for economical microalgae harvesting method using chemical flocculants.

• Journal of Energy Engineering
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• v.20 no.4
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• pp.330-337
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• 2011

In these days, the gas or kerosene boiler was usually used as heating system. This study was carried out to investigate the merits of X-L pipe boiler with electric heat line that was specially manufactured. The electric heat line was inserted into inside of X-L pipe and voltage was impressed to electric heat line and, as a result, temperature of X-L pipe filled with heat medium was increased. As changing the number of electric heat line and voltage, the characteristics of X-L pipe boiler and its mechanism on heat generation were studied. Furthermore, the economical efficiency was evaluated by comparing heating cost of X-L pipe boiler with those of kerosene boiler and natural gas boiler, respectively. As the results, it was confirmed that heating cost of X-L pipe boiler was showed as 28% of kerosene boiler and 58% of natural gas boiler.

• KSBB Journal
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• v.27 no.6
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• pp.347-351
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• 2012

This study was conducted to optim ize the composition of CEM (cabbage extract medium) and cryoprotectants on the growth of Lactobacillus plantarum, a probiotics growing in plant and milk. For this, we analyzed the growth characteristics of Lb. plantarum in CEM and subsequently optimized the medium composition by addition of carbon, nitrogen sources and buffering agents. Among carbon sources, glucose showed the best result to increase the cell density after dilution of CEM. When 0.5% yeast extract and 1% soy peptone were supplemented in the diluted CEM, Lb. plantarum grew up to the maximum cell density. Addition of buffering agents in CEM was not significantly effective to increase the cell density. Meanwhile, addition of 12% skim milk, 5% sucrose and 0.5% glycerol showed a cryoprotective effect against cell damage of Lb. plantarum during freeze drying process showing high survival rate after 150 days. This optimized CEM can be used for economical production of bacterial cells particularly originated from a plant-related ecosystem.

• Journal of Ocean Engineering and Technology
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• v.22 no.4
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• pp.78-83
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• 2008

In recent years, small boats used for marine leisure have been steadily increasing because of the increase in national income and the desire for marine leisure. But the repair of such small boats in dry dock has pointed out many faults in small FRP-shipbuilding in terms if workspace and manpower. Lifting a boat from the water to land is done with a crane or by hand using a sling around the bottom of the boat. But dry dock work is limited by the scale of the boat, which corresponds to the crane capacity, with carelessness making it possible to capsize a boat and endanger life. The purpose of this study was the development of a marine docking system that would improve economical efficiency and safety, for which we carried out concept design, model tests, structural analysis, etc.

• Journal of Plant Biotechnology
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• v.6 no.2
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• pp.107-111
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• 2004

To establish an efficient acclimation system for regenerated plantlets of soybean, we used various media with hydroponic nutrient solutions before regenerants were transplanted into soil. The hydroponic nutrient solution was essential for the survival of the plantlets. The vermiculite with nutrient solution at pH 5.5 was found to be the best medium with 97-100% survival rate and better growth of regenerants plantlets. Regeneraed grew best in the following order of solutions: Yoshida solution, modified Yoshida solution, SoyI, Soy II, and MS medium. However, Soy I solution (EC 2.9 mS/cm), developed by the Honam Agricultural Research Institute proved to be the most effective for acclimation in terms of the time required for vigorous growth and economical use of chemicals.

• Corrosion Science and Technology
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• v.5 no.1
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• pp.5-14
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• 2006

A lot of parts in FGD (Flue Gas Desulphurization) systems of fossil-fuel power plants show the environments in which are highly changeable and extremely acidic corrosive medium according to time and locations, e.g. in duct works, coolers and re-heaters etc.. These conditions are formed when system materials are immersed in fluid that flows on them or when exhausted gas is condensed into thin layered medium to contact materials of the system walls and roofs. The environments make troublesome corrosion and air pollution problems that are occurred from the leakage of the condensed solution. The frequent shut-down and repairing works of FGD systems also demand costs and low efficiencies of those facilities. In general, high corrosion resistant materials have been used to solve this problem. However, even the super alloys and Teflon linings sometimes have not been good enough to preventing corrosion. Further more, they are expensive and not easily repairable in short periods of operation stops. In this work, new technology that is effective, economical and easily repairable has proposed to solve the corrosion problems in FGD facilities. This technology contains cathodic protection, coatings and remote monitoring-controlling systems.

• Korean Journal of Food Science and Technology
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• v.21 no.2
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• pp.238-241
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• 1989

Double wall corrugated paperboard box are almost used for package of agricultural and fishery products in Korea. Flaps of the double wall corrugated paperboard box are consist of the three linerboard and two corrugating medium. But these flaps which are not affected to the compression strength for storage and distribution results in the reasonable cost-up of the packed box. Compared the strengths and economical evaluations between double wall and single wall corrugated paperboard box results as follows. Compression strength of single wall box is higher 49.3% to 98.0% than that of the double wall corrugated paperboard box and its cost are down 5% to 8%. Effect of the cost down on the saving materials of flap and corrugating medium is 13.9%.