• Applied Biological Chemistry
• /
• 제28권4호
• /
• pp.271-277
• /
• 1985

소량의 시료로서 미토콘드리아 및 SMP호흡의 속도론적 연구에 이용할 수 있는 적하수은전극 polarograph를 제작하여 그 성능, 실험조건 및 응용성을 검토하였다. 산소의 제 2단계환원이 일어나는 전위 (약 -1.2 vs SCE)는 막에 결합된 환원성물질의 환원전류로 해석되는 상당한 크기의 잔존전류를 일으키기 때문에 부적절한 것으로 판단되었다. 그러나 산소의 제 1단계환원이 일어나는 -0.4V(vs SCE)하에서는 잔존전류가 관찰되지 않았으며 산소농도의 변화는 정량적으로 추적되었다. 호흡기질의 농도를 충분히 크게 유지하는한 호흡에 의한 용존산소 소모는 O차반응의 처리가 가능하였으며, 그속도 상수와 미토콘드리아 호흡활성간에는 비례관계가 성립되었다. 내냉성이 서로 다른 몇가지 식물조직으로부터 분리한 미토콘드리아의 호흡활성에 미치는 온도효과를 조사하고 호흡활성전이온도를 측정하므로서 제작한 장치의 효용성을 확인하였다.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
• /
• pp.413-416
• /
• 2003

Experimental tests on the high strength self-compacting concrete with light-weight fine aggregate and light-weight coarse aggregate(LHSSC) were performed with slump-flow, reaching time to the slump-flow of 500mm, V-funnel dropping time and U-box difference level and compressive strength. LHSCC with light-weight fine aggregate of 75% and light-weight coarse aggregate of 100% was only satisfied with the property conditions of second self-compacting concrete(SCC), like as flowability, resistance to segregation and filling ability. The 28-day compressive strength of LHSCC indicated above 300kgf/$\textrm{cm}^2$ in all concrete mixtures, and it was increased to increase the replacement ratio of light-weight fine aggregate or to decrease the replacement ratio of light-weight coarse aggregate. Therefore, for satisfying the properties of fresh SCC and hardened concrete with above 350kgf/$\textrm{cm}^2$, it would expected that the replacement ratio of light-weight fine aggregate and light-weight coarse aggregate will be determined with 50~75% and 25~50%, respectively.

• 한국원자력학회:학술대회논문집
• /
• 한국원자력학회 1996년도 추계학술발표회논문집(1)
• /
• pp.283-288
• /
• 1996

Direct safety injection into the reactor vessel downcomer annulus(DVI) is a fundamental feature of the KNGR(Korean Next Generation Reactor) four-train safety injection system. The numerical analysis of thermal mixing of ECC(Emergency Core Cooling) water through DVI with the water in the RVDC(Reactor Vessel Downcomer) annulus has been performed, in order to study the impact of nozzle location on the pressurized thermal shock and safety analysis. The results of this study show that the thermal mixing due to the natural circulation induced by the limiting accident conditions is sufficient to prevent temperature in the RVDC from dropping to the level of concern for PTS. When the DVI nozzle is located right above the cold leg, the temperature distribution at the outlet of flow field is most uniform. The tool used for numerical analysis is CFDS-FLOW3D.

• 한국응용과학기술학회지
• /
• 제29권4호
• /
• pp.626-630
• /
• 2012

Diagnosis with an ex-vivo gold sensor was done using a modified fluorine-doping sensor, and cyclic voltammetry (CV) redox potentials of 0.4 V anodic and -0.2 V cathodic were obtained. Both peak currents were optimized using square-wave (SW) stripping voltammetry, and an analytical working range of 10-80 ug/L SW was attained. The precision of the 10-mg/L Au was 0.765 (n=8) RSD under the optimum conditions, and the analytical detection limit approached 0.006 ug/L (S/N=3) with only a 60 sec accumulation time. The developed method was used to examine the mouse droppings for medicinal diagnosis.

• 동력기계공학회지
• /
• 제13권3호
• /
• pp.53-58
• /
• 2009

The importance of cost reduction has grown bigger to ensure the competetive power of products in the electric home appliances industry. Thus, it is necessary to assess the reliability due to drop-impact happenning in process of distribution of microwave ovens with the panel and cavity of thinner thickness for cost reduction. In the present study, the drop/impact simulation using the explicit code LS-DYNA3D has been carried out for improving the impact resistance of a microwave oven. This CAE-based design approach can be successfully applied to enhance the deteriorated dynamic behavior under the impact conditions of dropping height 70cm according to ISTA procedure 2A.

• Smart Structures and Systems
• /
• 제30권4호
• /
• pp.371-383
• /
• 2022

A novel impact localization method is presented based on impact induced elastic waves in sensorized composite structure subjected to temperature fluctuations. In real practices, environmental and operational conditions influence the acquired signals and consequently make the feature (particularly Time of Arrival (TOA)) extraction process, complicated and troublesome. To overcome this complication, a robust TOA estimation method is proposed based on the times in which the absolute amplitude of the signal reaches to a specific amplitude value. The presented method requires prior knowledge about the normalized wave velocity in different directions of propagation. To this aim, a finite element model of the plate was built in ABAQUS/CAE. The impact location is then highlighted by calculating an error value at different points of the structure. The efficiency of the developed impact localization technique is experimentally evaluated by dropping steel balls with different energies on a carbon fiber composite plate with different temperatures. It is demonstrated that the developed technique is able to localize impacts with different energies even in the presence of noise and temperature fluctuations.

• 한국응용과학기술학회지
• /
• 제16권2호
• /
• pp.171-177
• /
• 1999

The objectives of this study is to investigate the optimum reaction conditions and to identify the product formula in the synthesis of a silicone/acrylic resin that curing in moisture at room temperature. By the addition polymerization of monomers, n-butyl acrylate, methyl methacrylate, n-butyl methacrylate, and 3-methacryloxypropyltrimethoxysilane. a quarter polymer was obtained. Among various initiators investigated in this study, 2.2'-azobisisobutyronitrille was found to be the most suitable initiator. The optimum reaction conditions found in this study are 70 wt% of initial solvent amount, 120 minutes of dropping time, 3 times of initiator addition, $82{\sim}105^{\circ}C$ of reaction temperature, and 8 hrs of reaction time. Also, number average molecular weight of $11700{\sim}33100$ and molecular weight distribution of $1.81{\sim}3.44$ were obtained.

• Advances in concrete construction
• /
• 제2권2호
• /
• pp.145-162
• /
• 2014

In this study, the fracture toughness $K_{IC}$ of high performance concrete (HPC) was determined by conducting three-point bending tests on eighty notched HPC beams of $500mm{\times}100mm{\times}100mm$ at high temperatures up to $450^{\circ}C$ (hot) and in cooled-down states (cold). When the concrete beams exposed to high temperatures for 16 hours, both thermal and hygric equilibriums were generally achieved. $K_{IC}$ for the hot concrete sustained a monotonic decrease tendency with the increasing temperature, with a sudden drop at $105^{\circ}C$. For the cold concrete, $K_{IC}$ sustained a two-stage decrease trend, dropping slowly with the heating temperature up to $150^{\circ}C$ and rapidly thereafter. The fracture energy-based fracture toughness $K_{IC}$' was found to follow similar decrease trends with the heating temperature. The weight loss, the fracture energy and the modulus of rapture were also evaluated.

• 정보처리학회논문지C
• /
• 제13C권2호
• /
• pp.171-176
• /
• 2006

최근 무선통신 기술의 비약적인 발전과 함께, 이동 셀룰러 네트워크 상에서 다양한 형태의 멀티미디어 서비스에 대한 수요가 폭발적으로 증가하고 있다. 그러나, 무선 네트워크의 특성상 유선 네트워크에 비해 상대적으로 제한된 대역폭을 가지기 때문에 효율적인 대역폭 관리가 중요한 이슈이다. 본 논문에서는 이동 셀룰러 네트워크상에서의 멀티미디어 서비스를 효율적으로 지원할 수 있는 적응적 온라인 대역폭 관리 알고리즘을 제안하였다. 이 기법은 현재 네트워크의 트래픽 상황을 기반으로 하여 실시간으로 시스템을 관리하여 우선순위가 높은 서비스의 QoS 보장과 동시에 효율적인 대역폭 사용률을 제공한다. 컴퓨터 시뮬레이션을 통하여 대역폭 관리를 위해 제안된 기존의 타 기법들과의 비교, 분석을 수행하여 제안된 방법이 다앙한 네트워크 트래픽 상황에서 우수한 성능을 가지는 것을 확인할 수 있었다.

• 한국작물학회지
• /
• 제15권
• /
• pp.141-143
• /
• 1974

본답에서 재배되고 있는 방사선돌연변이계통들의 도열병 저항성 검정을 위하여 절리엽편접종법이 시도되었다. 즉 포장에서 절취한 잎을 항온항습실내에서 punch압상을 만들고 그 위에 도열병균의 포자현탁액을 접종한 후 형성된 병반의 크기를 측정하여 계통간의 저항성정도를 비교한 결과 방사선조사된 풍광으로부터 Upland short row method에 의하여 선발된 저항성계통들은 모품종 풍광에 비하여 저항성으로 나타났다. 따라서 이 방법은 포장에서 재배되는 성숙식물체의 도열병저항성 검정을 위한 하나의 선발방법으로서 효과적이라 생각되었다.