• Journal of Microbiology and Biotechnology
• /
• 제25권7호
• /
• pp.988-998
• /
• 2015

The filamentous fungus Aspergillus oryzae is a well-known expression host used to express homologous and heterologous proteins in a number of industrial applications. To facilitate higher yields of proteins of interest, we constructed the pAsOP vector to express heterologous proteins in A. oryzae. pAsOP carries a selectable marker, pyrG, derived from Aspergillus nidulans, and a strong promoter and a terminator of the amyB gene derived from A. oryzae. pAsOP transformed A. oryzae efficiently via the PEG-CaCl₂-mediated transformation method. As proof of concept, green fluorescent protein (GFP) was successfully expressed in A. oryzae transformed by pAsOP-GFP. Additionally, we identified a novel fungal α-amylase (PcAmy) gene from Penicillium sp. and cloned the gene into the vector. After transformation by pAsOPPcAmy, the α-amylase PcAmy from Penicillium sp. was successfully expressed in a heterologous host system for the first time. The α-amylase activity in the A. oryzae transformant was increased by 62.3% compared with the untransformed A. oryzae control. The PcAmy protein produced in the system had an optimum pH of 5.0 and optimum temperature of 30^oC. As a cold-adapted enzyme, PcAmy shows potential value in industrial applications because of its high catalytic activity at low temperature. Furthermore, the expression vector reported in this study provides promising utility for further scientific research and biotechnological applications.

• Geomechanics and Engineering
• /
• 제38권2호
• /
• pp.125-137
• /
• 2024

In paste backfill mining, cemented coal gangue-fly ash backfill (CGFB) can effectively utilize coal-based solid waste, such as gangue, to control surface subsidence. However, given the pressurized water accumulation environment in goafs, CGFB is subject to coupling effects from water pressure and chloride ions. Therefore, studying the influence of pressurized water on the chlorine salt erosion of CGFB to ensure green mining safety is important. In this study, CGFB samples were soaked in a chloride salt solution at different pressures (0, 0.5, 1.5, and 3.0 MPa) to investigate the chloride ion transport characteristics, hydration products, micromorphology, pore characteristics, and mechanical properties of CGFB. Water pressure was found to promote chloride ion transfer to the CGFB interior and the material hydration reaction; enhance the internal CGFB pore structure, penetration depth, and chloride ion content; and fill the pores between the material to reduce its porosity. Furthermore, the CGFB peak uniaxial compression strain gradually decreased with increasing soaking pressure, whereas the uniaxial compressive strength first increased and then decreased. The resulting effects on the stability of the CGFB solid-phase hydration products can change the overall CGFB mechanical properties. These findings are significant for further improving the adaptability of CGFB for coal mine engineering.

• 한국융합학회논문지
• /
• 제8권7호
• /
• pp.7-13
• /
• 2017

공공장소에서의 로봇 공연은 전용 무대가 아닌 행사, 전시장 및 길거리 등에서 로봇 기술 홍보 및 흥미유발을 목적으로 실시된다. 이를 위해 본 논문은 그린 크로마키 천 앞에서 동작하는 로봇에서 실시간으로 로봇 이미지만을 추출, 다양한 무대 영상에 합성될 수 있도록 한다. 이 때 별도의 크로마키 조명 없이 환경 조명만을 사용하기 때문에 크로마키 배경의 그린 색조가 다양하고 로봇 그림자가 배경에 포함될 수 있다. 본 논문은 단순하고 명확하며 사전 설정 없이 크로마키 배경에서 전경인 로봇을 추출하는 방법을 제안한다. 이 방법은 배경과 전경의 색 차를 크게 한 후 이 정보에 대한 히스토그램을 토대로 배경을 자동으로 제거함으로써 사전 크로마키 설정이 필요 없어 현장에서 손쉬운 공연 제어가 가능하다. 시뮬레이션 결과 비교 대상 보다 1.5% 개선된 98.8%의 전경 분리 비율을 보이며 로봇 공연 영상 실험에서 로봇을 효과적으로 분리할 수 있음을 보인다.

• 한국자동차공학회논문집
• /
• 제20권1호
• /
• pp.95-105
• /
• 2012

The selective catalytic reduction (SCR) system is a highly-effective aftertreatment device for NOx reduction of diesel engines. Generally, the ammonia ($NH_3$) was generated from reaction mechanism of SCR in the SCR system using the liquid urea as the reluctant. Therefore, the precise urea dosing control is a very important key for NOx and $NH_3$ slip reduction in the SCR system. This paper investigated NOx and $NH_3$ emission characteristics of urea-SCR dosing system based on model-based control algorithm in order to reduce NOx. In the map-based control algorithm, target amount of urea solution was determined by mass flow rate of exhaust gas obtained from engine rpm, torque and $O_2$ for feed-back control NOx concentration should be measured by NOx sensor. Moreover, this algorithm can not estimate $NH_3$ absorbed on the catalyst. Hence, the urea injection can be too rich or too lean. In this study, the model-based control algorithm was developed and evaluated on the numerical model describing physical and chemical phenomena in SCR system. One channel thermo-fluid model coupled with finely tuned chemical reaction model was applied to this control algorithm. The vehicle test was carried out by using map-based and model-based control algorithms in the NEDC mode in order to evaluate the performance of the model based control algorithm.

• Journal of electromagnetic engineering and science
• /
• 제19권1호
• /
• pp.48-55
• /
• 2019

Unmanned aerial vehicles (UAVs) using communications, sensors, and navigation equipment will play a key role in future warfare. Currently, UAVs are monitored to prevent misfire and accidents, and the conventional method adopted uses wires for data transmission and power supply. The repeated connection and disconnection of cables increases maintenance time and harms the connector. For convenience and stability, a wireless power transfer system to power UAVs is needed. Unlike other wireless power transfer (WPT) applications, the size of the receiving coils must be small, so that the WPT systems can be embedded inside space-limited UAVs. The small size reduces the coupling coefficient and transfer efficiency between the transmitting and the receiving coils. In this study, we propose a toroidal-shaped coil for a WPT system for UAVs with high coupling coefficient with minimum space requirements. For validation, conventional coils and the proposed toroidal-shaped coil were used and their coupling coefficient and power transfer efficiency were compared using simulated and measured results. The simulated and measured results were strongly correlated, confirming that the proposed WPT system significantly improved efficiency with negligible change in the space requirement.

• 디지털융복합연구
• /
• 제9권2호
• /
• pp.141-152
• /
• 2011

오늘날 데이터센터는 비즈니스에서 핵심영역으로 인식되고 있으며, 이들에 대한 많은 서비스 요구는 보다 많은 에너지 소비를 낳고 있다. 따라서 데이터센터의 높은 수준의 에너지 효율성은 구축, 운영, 폐기 등 그들의 생명주기에 있어서 핵심이슈로 등장하였다. 본 연구에서는 이러한 생명기상에서 데이터센터의 그린화 수준을 진단할 수 있도록 성숙도모델에 기초한 그린데이터센터 수준진단모델을 제시한다. 본 연구에서 제시한 수준진단 모델은 엑션추어 GMM, DCEEF 등 기존 에너지평가모델 및 그린데이터센터 성숙도평가 모델을 참조하였으며, 최종적으로 건축, 공조, 전기, IT, 조직 등 데이터센터의 5개 핵심영역에 대한 진단지표를 제안하였다.

• 산경연구논집
• /
• 제13권7호
• /
• pp.17-25
• /
• 2022

Purpose: Environmental contamination has lately been seen as a consequence of the rise in environmental challenges brought on by rapid industrial expansion. At this point, the current research asks an important question about what the factors are to motivate employees' green performance, increasing corporate sustainability. Research design, data and methodology:The current author selected total 19 items to obtain real data and achieve the purpose of this research. For measuring of the causality between the worker's innovative capability and green performance, the current author used the multiple regression statistical tool using U.S. 215 responses in four industry. Results: The statistical finding definitely indicated that there exists the causal linkage between two key factors (Innovation capability and green performance) as well as the strong direction between two constructs. As a result, the current author could accept all hypotheses, checking no existing the multicollinearity of the present constructs with 'TOL' and 'VIF' values. Conclusions: The present research concluded that literature and business management scholars and practitioners will benefit from this study's statistical results. Furthermore, rewarding staff creativity, encouraging quick answers to market movements, and incorporating technology into everyday operations are all ways that companies may cultivate an environmental stewardship culture.

• 한국건설관리학회논문집
• /
• 제13권3호
• /
• pp.34-42
• /
• 2012

국내 공동주택의 리모델링 수월성 및 이에 따른 장수명화를 위해 그린 프레임 공법이 개발되었다. 그린 프레임 공법은 합성 프리캐스트 콘크리트 부재를 이용한 라멘구조로 벽식 구조와는 달리 양중 및 설치가 골조공사의 주공정으로 작용한다. 따라서 그린 프레임에 의한 적정 골조공사 공기 산정을 위해서는 체계적인 양중계획이 필요하다. 그러나 양중계획은 그린 프레임을 구성하는 요소인 합성 PC 부재(기둥, 보)의 단위 양중공정에 대한 분석이 선행되어야 한다. 따라서 본 연구는 그린 프레임 합성 PC 부재의 양중공정을 분석하는 것을 목적으로 한다. 이를 위해 합성 PC 기둥과 보의 양중절차와 시간을 도출하고, 그 결과를 사례 프로젝트에 적용하여 기준층의 양중 사이클을 분석한다. 본 연구의 결과는 향후 그린 프레임에 의한 골조공사 양중계획 시 핵심자료로 사용된다.

• 한국생산제조학회지
• /
• 제22권3호
• /
• pp.364-371
• /
• 2013

Because of the increases in international oil prices and the level of global warming, the automotive industry has much interest in developing green cars with high fuel efficiencies. In addition, researchers in Korea are actively responding to high oil prices and $CO_2$ emission regulations in many ways. One example is, the multi-mode hybrid system, which is being studied to improve its performance. Because a multi-mode hybrid system is able to overcome the weaknesses of a system that uses simple planetary gears, excellent fuel efficiency and driving performances are the key features of the system. This paper analyzes the driving performance of the power-train system of GM-2MT70, which consists of one engine, two electric motors, one simple planetary gear, one double planetary gear, two clutches, and two brakes. The driving performance of the system's steady state is analyzed using performance modeling. The dynamic performance is analyzed using Matlab Simulink.

• Steel and Composite Structures
• /
• 제31권1호
• /
• pp.13-25
• /
• 2019

Reactive powder concrete (RPC) is a type of ultra-high strength concrete that has a relatively high brittleness. However, its ductility can be improved by confinement, and the use of RPC in composite RPC filled steel tube columns has become an important subject of research in recent years. This paper aims to present an experimental study of axial capacity calculation of RPC filled circular steel tube columns. Twenty short columns under axial compression were tested and information on their failure patterns, deformation performance, confinement mechanism and load capacity were presented. The effects of load conditions, diameter-thickness ratio and compressive strength of RPC on the axial behavior were further discussed. The experimental results show that: (1) specimens display drum-shaped failure or shear failure respectively with different confinement coefficients, and the load capacity of most specimens increases after the peak load; (2) the steel tube only provides lateral confinement in the elastic-plastic stage for fully loaded specimens, while the confinement effect from steel tube initials at the set of loading for partially loaded specimens; (3) confinement increases the load capacity of specimens by 3% to 38%, and this increase is more pronounced as the confinement coefficient becomes larger; (4) the residual capacity-to-ultimate capacity ratio is larger than 0.75 for test specimens, thus identifying the composite columns have good ductility. The working mechanism and force model of the composite columns were analyzed, and based on the twin-shear unified strength theory, calculation methods of axial capacity for columns with two load conditions were established.