• Journal of Industrial Convergence
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• v.18 no.5
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• pp.1-13
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• 2020

The purpose of this study is to find out how much the investment effect of convertible bond(CB) is from the perspective of investors and to present efficient investment plans to investors. The research method is to investigate the coupon interest rate, maturity interest rate, conversion price, etc. for CBs. As a result of the study, it was analyzed that CB's investment efficiency was low because the conversion price excess days ratio was only about 1/4 of the conversion date. The conversion day yield was -6.3% and the maturity day yield was -5.2% on average. It was analyzed that the number of stocks with negative conversion day yield was 2.4 times higher than the number of positive stocks and 3.7 times higher than the number of positive stocks with a maturity day yield, so the expected return on equity conversion of CB was low.

• Journal of Microbiology and Biotechnology
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• v.1 no.1
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• pp.63-69
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• 1991

Performance of column type bioreactor packed with immobilized cyclodextrin glucanotransferase (CGTase) on chitosan and Amberite IRA 900 was evaluated for cyclodextrin(CD) production. For CGTase immobilized on chitosan, the maximum CD conversion yield of 42% was achieved at the range of 88-168 units of immobilizied CGTase per gram of chitosan, retention time of 0.3 hr, and from 5.0% (w/v) of partially cyclized soluble starch. On the other hand, for CGTase immobilized on Amberite IRA 900, the maximum conversion yield of 40% was obtained at the range of 3.6-11.0 units of immobilized CGTase per gram of carrier and retention time of 1.2 hr from 5.0% of substrate. Above CD conversion yields are almost identical level with that can be obtained with soluble CGTase of 47%. The productivities of bioreactor packed with immobilized CGTase were 17.0g of CD/lㆍhr for amberite IRA 900 and 15.5g of CD/lㆍhr for chitosan. The partially cyclized starch with soluble CGTase were more suitable as substrate to achieve better CD conversion yield, and 5% (w/v) of partially cyclized soluble starch containing 10% (w/w) of CD was found to be most suitable to obtain maximum CD conversion yield.

• Journal of Life Science
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• v.11 no.3
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• pp.230-234
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• 2001

The cyclodextrin glucanotransferase(CGTase) gene of Bacillus macerans was expressed in Saccharomyces cerevisiae and the recombinant CGTase was partially purified from the yeast culture supernatant. The optimal pH and temperature of the CGTase were found to be 6.0 and 5$0^{\circ}C$, respectively. The pH and temperature stabilities of the recombinant enzyme were significantly enhanced and the half life at 55$^{\circ}C$ was about 60 hr. When the recombinant CGTase was reacted with 5% soluble starch, the conversion yield of total cyclodextrin (CD) from starch was estimated to be 41% at 48 hr, whereas the wild type enzyme showed the yield of 12%. This improvement of conversion yield and thermal stability of CGTase may be useful for the development of low-cost CD production process.

• Microbiology and Biotechnology Letters
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• v.19 no.2
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• pp.171-178
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• 1991

The two-stage enzyme reactor, packed with cyclodextrin glucanotransferase (CGTase) immobilized on Amberite IRA 900, coupled with ultrafiltration membrane was investigated for continuous production of cyclodextrin (CD). 5% (w/v) of soluble starch was partially cyclized, in the 0.1 l first-stage immobilized enzyme reactor, up to CD conversion yield of 10% (w/w) at retention time of 0.56hr and 1.5 units of immobilized CGTase/1g of carrier. In the second stage main immobilized enzyme reactor capacity of 1.5 l, the maximum CD conversion yield of 39% (w/v) was achieved at retention time of 2.8hr and 0.47 unit of CGTase/1 g of carrier. Unreacted residual dextrin was fractionated with ultrafiltration membrane, and then, recycled into the second-stage main bioreactor to increase the CD conversion yield. The most suitable membrane size and the volume concentration ratio (concentrate: filterate) for recycling of unreacted residual dextrin were found to be 5K dalton and 4:6, respectively. CD conversion yield was increased about 3~4% upon co-immobilization of pulluanase along with CGTase. Spent Amberite IRA 900 can be reutilized consecutively more than 3 times for immobilization of CGTase after regeneration.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.6
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• pp.387-393
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• 2005

The effect of cattle manure with the rates of 2 and 4 ton $l0a^{-1}$ for winter rye and summer corn cultivation, respectively, on the dry matter (DM) yield and nitrogen (N) uptake were investigated during successive three­year conversion period from paddy to upland condition in paddy field. The changes in soil properties and soil N sup­plying capacity during repetitive manure application were a1so examined. Growth and DM yield of upland forage crops, especially. winter rye were hindered highly by poor soil condition in the first year after conversion from paddy to upland condition, so apparent recovery of cattle manure N by crops was very low in the first conversion year. But, DM yield and N uptake of upland forage crops were increased linearly by accumulative input of cattle manure along with mineral N enrichment in soil, which also increased apparent recovery of cattle manure-No It seemed that those increases were mainly due to the improvement of soil properties such as soil mineral N, soil organic matter (soil carbon), potentially mineralizable N and bulk density by accumulative input of cattle manure rather than the increase of soil N supply according to accumulative conversion period from paddy to upland condition. It was derived that conversion period from paddy to upland condition over 2 years is needed to obtain proper DM yield in paddy field and accumulative inputs of cattle manure during the conversion period is more influential to the continuous increment of DM yield and N uptake of upland crop as well as of potential N supplying capacity of soil.

• Journal of the Korean Wood Science and Technology
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• v.50 no.6
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• pp.475-489
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• 2022

The objective of this study was to understand the conversion characteristics of glucose and xylose using the major monosaccharide standards for lignocellulosic biomass. The acid-catalyzed organosolv pretreatment conducted using ethanol was significantly different from the acid-catalyzed process conducted in an aqueous medium. 5-hydroxymethylfurfural (5-HMF), levulinic acid and furfural were produced from glucose conversion. The maximum yield of 5-HMF was 5.5%, at 200℃, when 0.5% sulfuric acid was used. The maximum yield of levulinic acid was 21.5%, at 220℃, when 1.0% sulfuric acid was used. Furfural was produced from xylose conversion and under 0.5% sulfuric acid, furfural reached the maximum yield 48.5% at 210℃. Ethyl levulinate and methyl levulinate were also formed from the glucose standard following the esterification reaction conducted under conditions of the combined conversion method, which proceeded under both ethanol-rich and water-rich conditions.

• Journal of Service Research and Studies
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• v.10 no.4
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• pp.71-88
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• 2020

CB(Convertible bond) is mezzanine security that have the characteristics of bonds and stocks. From the perspective of investors, the purpose of the research is to empirically investigate the degree of investment efficiency of CB and to suggest efficient investment plans. The research method investigated the maturity interest rate, conversion price, and conversion date for CB, and then linked it with daily stock price fluctuations after the conversion date to determine the degree of investment efficiency and stock conversion effect of CB. As a result of the study, it was analyzed that the ratio of the conversion price exceeded days was only about 1/4 of the conversion date, so the investment efficiency was low. The conversion day yield was -6.3% on average and the maturity day yield was -5.2% on average, showing a minus return on average, which was calculated differently from investor expectations. It was analyzed that the number of stocks with a minus conversion day is 2.4 times greater than the number of plus stocks and 3.7 times more than the number of plus stocks with a minus maturity return, so the expected return on stock conversion of CB is low. The research contribution was derived from the problem that the expected rate of return of CB is not high, and it is that the investor's point of view when purchasing CB was established.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.313-316
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• 2000

The effects of initial sugar concentration and the various nitrogen sources on the fermentation characteristics of Thraustochytrium aureum were investigated. The sugar conversion ratios decrease with increase in the initial sugar concentration regardless of the kinds of nitrogen sources. The specific growth rate, the biomass yield, and the DHA yield also decreased but approached constant values higher than the concentration of 30g/L. The sugar conversion ratios and the specific growth rate showed the highest values in case of using the yeast extract as nitrogen source. It was difficult to conclude that the variation of nitrogen source had some effects on the biomass yield. However, the initial sugar concentration had a rather effects on the biomass yield for the sugar concentration of 40 g/L showed 0.27. The nitrogen source that showed the greatest yield of DHA was sodium glutamate.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.9 no.3
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• pp.389-400
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• 1997

A thermodynamic cycle analysis is performed for refrigerator-precooled Linde-Hampson hydrogen liquefiers, including catalysts for the ortho-to-para(o-p) conversion. three different configurations of the liquefying system, depending upon the method of the o-p conversion, are selected for the analysis. After some simple and justifiable models are introduced, a general analysis program to predict the liquid yield and the figure of merit(FOM) is developed with incorporating the commercial computer code for the hydrogen properties. The discussion is focused on the effect of the two primary design parameters-the precooling temperature and the high pressrure of hydrogen. When the precooling temperature is in the range between 45 and 60 K, the optimal high pressure for the maximal liquid yield is found to be in the range between 100 to 140 bar, regardless of the o-p conversion. However, the FOM can be maximized at slightly smaller values of high pressures. It is remarkable to observe that the lower precooling temperatures are favorable since both the liquid yield and the FOM can be obtained without compressing hygrogen to extremely high pressures.

• International Journal of Air-Conditioning and Refrigeration
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• v.6
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• pp.124-135
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• 1998

A thermodynamic cycle analysis is performed for refrigerator-precooled Linde-Hampson hydrogen liquefiers, including catalysts for the ortho-to-para conversion. Three different configurations of the liquefying system, depending upon the method of the o-p conversion, are selected for the analysis. After some simplifying and justifiable assumptions are made, a general analysis program to predict the liquid yield and the figure of merit (FOM) is developed with incorporating the commercial computer code for the thermodynamic properties of hydrogen. The discussion is focused on the effect of the two primary design parameters - the precooling temperature and the high pressure of the cycle. When the precooling temperature is in a range between 45 and 60 K, the optimal high pressure for the maximal liquid yield is found to be about 100 to 140 bar, regardless of the ortho-to-para conversion. However, the FOM can be maximized at slightly lower high pressures, 75 to 130 bar. It is concluded that the good performance of the precooling refrigerator is significant in the liquefiers, because at low precooling temperatures high values of the liquid yield and the FOM can be achieved without compression of gas to a very high pressure.