• 대한기계학회논문집A
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• 제40권11호
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• pp.955-962
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• 2016

최근 산업 자동화 분야에서는 확장성을 고려한 표준화된 소프트웨어 기반 모션 제어 시스템 개발 방법과 다품종 소량 생산을 위한 다양한 동작 모드 지원에 대한 요구가 증대되고 있는 추세이다. 소프트웨어 기반 모션 시스템은 단일 장비 상에서 다양한 동작 모드 전환이 용이하게 하지만 다중 동작 모드를 쉽게 정의하는 도구와 동작 모드 변경에 대한 표준화된 동작 절차가 정의되어 있지 않은 상태에서 다중 동작 모드를 지원하는 모션 제어시스템을 구성하는 것은 쉽지 않다. 본 논문에서는 PLCopen 표준 호환 모션 블록들을 이용해 다중 동작 모드를 구성하고 모드 변경을 외부에서 구동하기 위한 프로토콜을 포함하는 모션 레시피 개념을 제안한다. 제안된 모션 레시피 개념은 IEC 61131-3 표준 호환 통합개발 환경인 Beremiz의 기능을 확장하여 구현하였으며, 실제 테스트베드 상에서 그 동작을 검증하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제14권8호
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• pp.1144-1148
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• 2001

The implications of incorporating deoiled rice bran (DORB) in diet on the utilization of certain nutrients had been examined through balance studies made with 6- and 10- week-old Japanese quails. The stuffs evaluated in this study had their origin from two different types of processes- a batch extraction (DORB-B) and another continuous process (DORB-C), and each included at 10, 20 or 30% level in an iso-nitrogenous and iso-caloric diet. On chemical analyses, the DORB-B was found to contain crude protein, 19.0; ether extract, 0.79; total ash, 17.05; Ca, 0.11; P, 1.92; glucose, 2.35 and starch 11.22 g/100 g day matter. Corresponding values for DORB-C were 15.02, 1.56, 13.0, 0.40, 2.76, 2.16 and 19.0, respectively. The data on nutrient balances with quails fed diets containing the two-types of DORB suggested no significant (p>0.05) differences in per cent retention of diet dry matter (DM), organic matter (OM), ether extract (EE), gross energy (GE), nitrogen (N), crude fiber (CF), calcium (Ca) or phosphorus (P) content attributable to the extraction process. The age of the birds also appeared to have no significant (p>0.05) effect on nutrient utilization by them. However, the level of inclusion of DORB had a significant (p<0.05) effect on nutrient utilization by quails in that the retention of dietary N, EE, CF, Ca and P was better at lower than at higher levels. It is concluded that the DORB, irrespective of extraction process, can safely be employed upto 20% level in diet of adult Japanese quails without noticeable interference in utilizing the major dietary nutrients.

• 한국응용과학기술학회지
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• 제24권4호
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• pp.436-443
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• 2007

Anaerobic reductive dehalogenation of perchloroethene (PCE) was studied with lactate as the electron donor in a continuously stirred tank reactor (CSTR) inoculated with a mixed culture previously shown to dehalogenate vinyl chloride (VC). cis-1,2- dichloroethene (cDCE) was the dominant intermediate at relatively long cell retention times (>56 days) and the electron acceptor to electron donor molar ratio (PCE:lactate) of 1:2. cDCE was transformed to VC completely at the PCE to lactate molar ratio of 1:4, and the final products of PCE dehalogenation were VC (80%) and ethene (20%). VC dehalogenation was inhibited by cDCE dehalogenation. Propionate produced from the fermentation of lactate might be used as electron donor for the dehalogenation. Batch experiments were performed to evaluate the effects of increased hydrogen, VC, and trichloroethene (TCE) on VC dehalogenation which is the rate-limiting step in PCE dehalogenation The addition of TCE increased the VC dehalogenaiton rate more than an increase in the $H_2$ concentration, which suggests that the introduction of TCE induces the production of an enzyme that can comtabolize VC.

• Journal of Microbiology and Biotechnology
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• 제18권1호
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• pp.183-187
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• 2008

Vascular endothelial growth factors (VEGFs) are a family of proteins that mediate angiogenesis. $VEGF_{165}$ is a VEGF-A isoform and has been extensively studied owing to its potential use in therapeutic angiogenesis. This study established Chinese hamster ovary (CHO) cells overexpressing recombinant human $VEGF_{165}$ $(rhVEGF_{165})$ protein. The production rate of the established CHO cells was over 80mg/l of $rhVEGF_{165}$ protein from a 7-day batch culture process using a 7.5-l bioreactor with a 5-l working volume and serum-free medium. The $rhVEGF_{165}$ protein was purified to homogeneity from the culture supernatant using a two-step chromatographic procedure that resulted in a 48% recovery rate. The purified $rhVEGF_{165}$ protein was a glycosylated homodimeric protein with a higher molecular weight (MW) than the protein expressed from insect cells, suggesting that the glycosylation of the $rhVEGF_{165}$ protein in CHO cells differed from that in insect cells. The purified $rhVEGF_{165}$ protein in this study was functionally active with a half-maximal effective concentration of 3.8ng/ml and specific activity of $2.5{\times}10^5U/mg$.

• Journal of Microbiology and Biotechnology
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• 제27권11호
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• pp.2010-2018
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• 2017

Mixotrophic microalgal growth gives a great premise for wastewater treatment based on photoautotrophic nutrient utilization and heterotrophic organic removal while producing renewable biomass. There remains a need for a control strategy to enrich them in a photobioreactor. This study performed a series of batch experiments using a mixotroph, Chlorella sorokiniana, to characterize optimal guidelines of mixotrophic growth based on a statistical design of the experiment. Using a central composite design, this study evaluated how temperature and light irradiance are associated with $CO_2$ capture and organic carbon respiration through biomass production and ammonia removal kinetics. By conducting regressions on the experimental data, response surfaces were created to suggest proper ranges of temperature and light irradiance that mixotrophs can beneficially use as two types of energy sources. The results identified that efficient mixotrophic metabolism of Chlorella sorokiniana for organics and inorganics occurs at the temperature of $30-40^{\circ}C$ and diurnal light condition of $150-200{\mu}mol\;E{\cdot}m^{-2}{\cdot}s^{-1}$. The optimal specific growth rate and ammonia removal rate were recorded as 0.51/d and 0.56/h on average, respectively, and the confirmation test verified that the organic removal rate was $105mg\;COD{\cdot}l^{-1}{\cdot}d^{-1}$. These results support the development of a viable option for sustainable treatment and effluent quality management of problematic livestock wastewater.

• Journal of Biosystems Engineering
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• 제35권2호
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• pp.91-99
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• 2010

A Model of small scale total mixed rations(TMR) plant which can be utilized round bales was developed, tested and analyzed in this study. This study consist of two parts. One is development of a small scale TMR plant model which was already reported at the previous paper. This is the second part of the study. For the study, a series of tests of the model plant were performed and its costs was analyzed. Also, the break-even point of the model plant by comparing with market price of commercial TMR feed was determined. Results of the research are summarized as follows ; As the results of mixing test, the average coefficient of variation(CV) value for mixing of the feed was 13.0 % at the gate of the mixer. The production cost was estimated as 8,298 won/head for dairy cattle farm and 2,495 won/head for beef cattle farm, when producing 8 batch a day. Also, it is recommended to utilize the model plant when farm size is over 79 heads for dairy cattle farm and 113 heads for beef cattle farm. As an overall conclusion, the model plant designed for farm size TMR feed mill will be very useful model for both beef cattle and dairy farms in Korea. Also it is expected that the capital investment for the model plant can be recovered with 8 months compare with purchasing commercial TMR feed if the model plant feeds 1,000 beef cattle approximately.

• 한국물환경학회지
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• 제36권4호
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• pp.322-331
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• 2020

By introducing chemically enhanced primary treatment (CEPT) in the first stage of sewage treatment, organic matter in sewage can be effectively recovered. Because CEPT sludge contains a high biodegradable organic matter in volatile solids (VS), it is feasible to convert the collected CEPT sludge into energy through anaerobic digestion. This study examined the properties and biochemical methane potential (BMP) of the CEPT sludge obtained from a sewage treatment plant located in an ocean area. The CEPT sludge contains a VS content of 37,597 mg/L, which is higher than that of excessive sludge (ES), i.e., 33,352 mg-VS/L. In the methane generation reaction, the lag period was as short as 1 to 2 days. The BMP for the CEPT sludge was 0.57 ㎥-CH₄/kg-VS_removed which is better than that of ES, i.e., 0.36 ㎥-CH₄/kg-VS_removed. Unfortunately, the CEPT sludge showed a high salinity as 0.56~0.75% probably due to the saline sewage. Due to the salinity, repeated BMP testing in a sequencing batch reactor showed significantly low methane production rates and BMPs. Also, the ES showed a strongly reduced BMP when the salinity was adjusted from 0.20 to 0.70% by NaCl. The ES mixture with higher CEPT content showed a better BMP, which is suitable for co-digestion. Besides, anaerobic digestion for 100% CEPT sludge can be a considerable option instead of co-digestion.

• 대한기계학회논문집A
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• 제41권3호
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• pp.181-186
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• 2017

점진 판재 성형은 금형을 제작하지 않고 판재를 가공하는 방법으로써 빠른 시제품 제작과 소량 생산에 적합한 성형법이다. 이러한 점진 판재 성형의 공정 변수로 공구 직경, 매 스탭당 z-방향 깊이, 공구 이송속도, 공구 회전 속도 등은 성형품의 품질에 크게 영향을 미친다. 본 연구에서는 Al5052-O(0.8mm) 판재를 사용하여 Varying Wall Angle Conical Frustum 모델의 점진성형을 실시하였으며, 각각의 변수들의 조합에서 성형성을 판단하였다. 다구찌 기법을 사용하여 점진성형 변수들의 조합을 찾아내고, 그레이 관계형 최적화를 통하여 최적 성형 변수 값의 조합을 찾아 내였다. 최종 성형물의 품질은 성형성, 스프링 백, 두께 감소량을 측정하여 판단하였다. 본 연구의 실험 조건에서의 최적의 변수 조합은 공구직경 6 mm, 회전속도 60rpm, 매 스탭당 z-방향 깊이 0.3 mm, 이송속도 500 mm/min으로 판단되었다.

• 한국물환경학회지
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• 제21권2호
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• pp.147-152
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• 2005

Fermentation efficiencies of organic wastes from the variety of sources were evaluated based on the production of total volatile acids(TVA) in batch reactor. Mixing and pH were not significant factors in producing TVA from the organic wastes. After a 10-day fermentation, final TVA concentrations in piggery, cattle, poultry, and primary settled sludge of domestic wastewater were 8,900, 2,900, 7,370 and 1,630 mg/L, respectively. The pH of organic wastes was decreased from neutral to 5.7. The ratio of TVA to $NH_4{^+}-N$ produced from the animal waste ranged from 11.5 to 30.1, whereas, that in the primary settled sludge of domestic wastewater, was 5.4. Possibility of fermented organic wastes as the electron donors for denitrification in the activated sludge was investigated. In both acclimated and nonacclimated activated sludge, higher denitrification rates were obtained with fermented piggery sludge added than with either methanol or acetate added. The fermented organic acids derived from the primary settled sludge gave the higher denitrification rate ($4.2mg\;NO_3-N/g\;vss{\cdot}hr$) in the acclimated activated sludge. Denitrification rate was $1.5mg\;NO_3-N/g\;vss{\cdot}hr$ in the nonacclimated sludge with the fermented acids from the primary settled sludge of domestic wastewater added.

• 한국물환경학회지
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• 제33권6호
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• pp.689-695
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• 2017

This study was carried out to investigate the physicochemical and adsorptive characteristics of black carbon (BC) materials for cesium in case of severe nuclear accidents. The BC was prepared with a xylem of oak and pine trees incompletely combusted with different ramp rate and final temperature. Carbon (C), hydrogen (H) and oxygen (O) atomic ratios, BET, pore structure, and zeta potential were characterized for the produced BC. A low cesium concentration ($C_w{\approx}10^{-7}M$) was used for sorption batch experiments. The H/C and O/C ratios of BC decreased with the increase of final temperature, which indicates a carbonization of the wood materials regardless of ramp rate and tree species. However, SEM images showed different pore structures depending on tree species such as steric and plate-like for oak-BC and pine-BC, respectively. The greatest sorption distribution coefficients of $K_{d,Cs}{\approx}1,200{\sim}1,800L\;kg^{-1}$ were observed for the oak-BC produced at $400^{\circ}C$, while comparatively low $K_{d,Cs}$ < $100L\;kg^{-1}$ for pine-BC. In addition, the sorption capabilities of BC declined with the increase of combustion temperature up to $600^{\circ}C$, because high temperature destroyed surface functionalities with the rise of ash components in the BC. Therefore, the sorption processes of BC for radioactive cesium are predominantly controlled by final production temperature of BC as well as raw materials (e.g., tree species).