• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2002년도 생물공학의 동향 (X)
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• pp.121-125
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• 2002

Rhodococcus rhodochrous IGTSS (ATCC 5396S) can break organo sulfur compounds such as dibenzothiophene. Since the environment for biodesulfurization process is invariably hydrophobic, parameters in hydrophobic systems should be examined. For the model oil, hexadecane-containing 5.43mM dibenzothiophene, the volumetric desulfurization rate was decreased with the oil-to-aqueous phase ratio up to 50%. The rate declined sharply after 48h because the cell activity, which is refreshed by medium exchange, was lost. To supply the exhausted nutrients, medium exchange was performed. At 30% oil phase, most of DBT was removed by medium exchange on 48h, and the rate was 2.03mg $DBT_{removed}/L_{dispersion}-hr.$ At 50% oil phase, medium exchange on 60h was performed and the rate was 1.79mg $DBT_{removed}/L_{dispersion}-hr.$ The 300mL flask system was scaled up to a 5-L bioreactor system. On 60 h, a medium exchange was performed and the rate was 5.28mg $DBT_{removed}/L_{dispersion}-hr.$ and all of DBT was removed. It means that we can use the biodesulfurization process even 10 the high oil-to-water phase by some appropriate methods such as controlled feeding of key nutrients and the dilution or removal of some toxic metabolites by continuous reactor.

• 한국유기농업학회지
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• 제24권4호
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• pp.931-944
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• 2016

본 연구는 한우의 성별 발육성적, 혈액성상 및 도체특성을 비교하고자 수행되었다. 처리구는 12개월령 한우 수소구(4두, 체중 $339.8{\pm}18.5kg$), 거세우구(4두, 체중 $309.8{\pm}13.2kg$), 암소구(3두, 체중 $290.0{\pm}16.7kg$)를 개체 사료급여기가 부착된 우사에 배치하여 총 20개월간 시험을 수행하였다. 일당증체량은 비육전기에는 한우 수소, 거세우 및 암소간에 차이가 없었으나 비육중기부터 수소구가 높았으며 암소구가 가장 낮았다(p<0.05). 공시축의 체형차이는 24개월령부터 나타나, 한우 암소는 체고와 체장에서 가장 작았으나(p<0.05), 체고는 32개월령대에서는 처리구간에 차이가 없었다. 12개월령 공시축의 혈액성분 중, cholesterol, triglyceride, glucose 및 total protein함량은 암소구에서 높았으며, GPT 수준은 수소구에서 높았다(p<0.05). 혈청 GOT 수준은 처리구 공히, 비육후기에 높았으며, 수소구에서 가장 높았다(p<0.05). 육량지수는 수소구와 암소구가 비슷한 수준이었으며, 거세우구가 가장 낮았다(p<0.05). 육질평가에서 근내지방도는 거세우구와 암소구가 수소구보다 유의적으로 높았고(p<0.05), 육질등급은 거세우구가 가장 높았다. 본 시험은 한우사양표준 개정에 있어서 성별간 비교를 위한 기초자료로 사용될 수 있을 것으로 사료된다.

• Journal of Animal Science and Technology
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• 제59권8호
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• pp.18.1-18.8
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• 2017

Background: In 2006, the European Union (EU) has decided to forbid use of antibiotics as growth promoters. Although many researches had been conducted about fiber source as alternatives of antibiotics, there are still lack of reports in the literature about the optimum level of sugar beet pulp supplementation, affecting growth performance and nutrient digestibility in weaning pigs. Therefore, different level of sugar beet pulp was added to diets to determine the effects of sugar beet pulp supplementation on growth performance, nutrient digestibility, fecal microflora, blood profile and incidence of diarrhea in weaning pigs. Methods: A total of 200 weaning pigs [$(Yorkshire{\times}Landrace){\times}Duroc$], averaging $9.01{\pm}1.389kg$ of initial body weight were, allotted to 5 treatments in a randomized complete block (RCB) design. Each treatment was composed of 4 replicates with 10 pigs per pen. The treatments were control treatment: Corn-SBM basal diet + ZnO (phase 1: 0.05%; phase 2; 0.03%) and four different levels of sugar beet pulp were supplemented in Corn-SBM basal diet (3, 6, 9 or 12%). Two phase feeding programs (phase 1: 1-2 weeks; phase 2: 3-5 weeks) were used for 5 week of growth trial. Results: In feeding trial, there were no significant differences in growth performance and incidence of diarrhea among treatments. The E.coli counts were not significantly different among dietary treatments but linear response was observed in Lactobacillus counts as sugar beet pulp supplementation increased (P < 0.05). In addition, IGF-1, IgA and IgG were not affected by dietary treatments. However, the BUN concentration was decreased when pigs were fed the treatments of diets with SBP compared to that of control treatment (P < 0.05). In nutrient digestibility, crude fiber and NDF digestibilities were improved as the sugar beet pulp increased (P < 0.05). However, digestibilities of crude ash, crude fat, crude fiber and nitrogen retention were not affected by dietary sugar beet pulp levels. Conclusion: This experiment demonstrated that sugar beet pulp can be supplemented in weaning pigs' diet instead of ZnO to prevent postweaning diarrhea without any detrimental effect on growth performance.

• Journal of Animal Science and Technology
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• 제49권3호
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• pp.341-350
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• 2007

본 연구는 목초 사일리지를 기초사료로 급여한 젖소에 있어서 보리와 유채박 급여가 제 3위 소화액 내 soluble non-ammonia nitrogen fractions(SNAN fractions; 아미노산, 펩티드, 용해성 단백질 및 total SNAN)의 flow 패턴변화를 측정하기 위하여 실시하였다. 반추위 캐뉼라가 장착된 4마리 젖소는 4×4 라틴방각법에 의해 기초사료로 grass-red clover silage를 자유급여하여 사일리지 단독급여구(GS), 기초사료 + 보리6.0kg/d 급여구, 기초사료 + 유채박2.1kg/d 급여구 및 기초사료 + 보리6.0kg/d + 유채박2.1kg/d 급여구로 배치하였다. 제 3위 소화액은 제 3위 소화액 채취기구를 이용하여 사료급여 후 1.5h 간격으로 채취하였고, 그 소화액 내 SNAN fractions 정량은 ninhydrin assay를 이용하여 분석하였다. 보충사료 급여는 GS구에 비해 비록 통계학적 유의성은 없었지만 total SNAN flow를 증가시켰다. 제 3위 소화액 내 펩티드 flow 패턴은 12시간 feeding cycle 내내 SNAN fractions 중 양적으로 가장 높았으며, GS구에 비해 보충사료급여구에서 높은 펩티드 flow 패턴을 보였다. GS구를 제외한 보충사료처리구간에는 SNAN fractions flow 패턴 차이가 없었다. 15N을 이용하여 분석된 사료유래 SNAN fractions flow 패턴에서는 보충사료급여구가 GS구에 비해 높게 나타났다. 이상의 결과 제 3위로 유입되는 펩티드 flow는 전체 SNAN flow 중 양적으로 가장 중요한 N 이며, 보충사료 급여 시 그 펩티드 flow의 증가 가능성을 시사한다.

• 조명전기설비학회논문지
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• 제19권4호
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• pp.98-107
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• 2005

브러시리스 DC 전동기(BLDCM)는 일반적으로 $120[^{\circ}]$ 구형파 전압을 인가하여 구동하며 속도 제어를 위하여 2상 PWM 형태의 펄스로 이를 인가한다. 본 논문은 네 가지 PWM 방법을 이용한 BLDCM 제어 시스템을 소개하고, 2차원 시간차분 유한요소법을 이용하여 각 PWM 방식에 따른 전동기 성능 특성을 해석하고 비교한다. 또한 제안한 해석 기법의 타당성을 입증하기 위하여 BLDCM 시작기를 제작, 실험을 통하여 해석치와 실험치를 비교한다.

• Macromolecular Research
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• 제9권2호
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• pp.122-128
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• 2001

Monodisperse composite latex particles with size of ca. 300 nm, which consist ofn-butyl acrylate as a soft phase and methyl methacrylate as a hard phase with different morphology, were synthesized by seeded multi-stage emulsion polymerization. Three types of composite latex particles including random-, core/shell-, and gradient-type particles were obtained by using different monomer feeding methods during semi-batch emulsion polymerization. Effect of poly(butyl acrylate)-poly(methyl methacrylate) rubber particle morphology on the mechanical and rheological properties of rubber toughened poly(methyl methacrylate) was investigated. Among three different rubber particles, the gradient-type rubber particle showed better toughening effect than others. No significant variation of rheological property of poly(methyl methacrylate)/rubber blends was observed for the different rubber particle morphology.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권12호
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• pp.709-717
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• 2004

Flux-reversal machine (FRM) is a new brushless doubly salient permanent magnet machine. Its operation is similar to that of the brushless DC motor, so it can be driven by 120 degree square wave voltage and use PWM pulse patterns in two-phase feeding scheme to control the speed. In this driving method, the back electromotive force (BEMF) current in the open phase is generated by the BEMF. It can be appeared or disappeared according to the changes of the neutral voltage of the machine. In this paper, the time-stepped voltage source finite-element method taking BEMF current into account is proposed. Its influences on the performances of the FRM are also investigated. To prove the propriety of the proposed analysis method, a Digital Signal Processor (DSP) installed experimental devices are equipped and the experiment is performed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 A
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• pp.306-308
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• 1997

In this paper, We present the transient analysis method of induction motor by TDFE(Time Domain Finite Element) method. For simulation of transient performance, Maxwell's equations are solved using 2-Dimensional TDFE method, and the circuit equations from the stator and rotor are solved simultaneously. The time derivatives are discretized with Euler scheme and the Newton-Raphson iteration method is applied to a large system of equations which are representing the whole magnetic and feeding circuit equations because of the magnetic nonlinearity of the stator and rotor core. The presented method is applied to three phase induction motor. And we obtained the phase currents, torque and rotor position until the steady state.

• Journal of Power Electronics
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• 제16권1호
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• pp.173-181
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• 2016

In this paper, a new technique for harmonic optimization in cascaded H-bridge 7-level inverters is proposed. The suggested strategy is based on minimizing an objective function which simultaneously optimizes the converter utilization and Total Harmonic Distortion (THD). The Switch Utilization Ratio (SUR) is formulized for both the phase and line-line voltages of a 7-level inverter and is considered in the final objective functions. Based upon the SUR formula, utilization ratio enhancement will reduce the value of feeding DC links, which improves the efficiency and lifetime of the circuit components due to lower voltage stresses and losses. In order to achieve more effective solution in different modulation indices, it is assumed that the DC sources can be altered. Experimental validation is presented based on a three-phase 7-level inverter prototype.

• Asian-Australasian Journal of Animal Sciences
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• 제14권5호
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• pp.651-654
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• 2001

A study was made of the efficiency of ammonia N retention by Jowar kadbi (sorghum straw), initially 6.41% crude protein (CP), treated with 4% urea solution. After 30 days the CP in straw that was unchaffed and had been left uncovered was 10.02, and in chaffed straw that had been covered with a polythene sheet was 10.9%. The two treated straws were each fed to six crossbred (HF$\times$Deoni) calves, initially $12{\pm}2$ months old and $86.7{\pm}3.2kg$ bodyweight. They were also given two isocaloric (70% TDN) and isonitrogenous (20% CP) concentrate mixtures differing in calculated Rumen Degradable to Undegradable Dietary Protein ratio (RDP:UDP). Those fed the unchaffed uncovered treated straw (treatment C) received 65 RDP:35UDP and the other group (T1) received concentrate with a 55:45 ratio. The T1 group had the higher DM intake (p<0.01) in total (306 vs 268 kg), per day (4.1 vs 3.6 kg) and per unit bodyweight. Digestibility of DM, OM, CP and NDF, but not ADF, was higher in T1 and that group had the higher daily gain (517 vs 333 g) and higher total gain (38.8 vs 25.0 kg) over the 75 d of the feeding trial. It is concluded that chaffing and covering of Jowar kadbi treated with urea, not likely to be adopted by farmers because of financial constraints, does not confer important benefits. A concentrate supplement (estimated 45% of the CP as UDP) to calves given the treated straw has a beneficial effect on their growth and development.