• Proceedings of the SAREK Conference
• /
• 2006.06a
• /
• pp.442-447
• /
• 2006

In semiconductor manufacturing clean rooms, it becomes important to remove airborne molecular contaminants as well as particulate contaminant in outdoor air introduced into clean rooms. One suitable control technique for these chemical contaminants is air washing by water in an outdoor air handling unit. In order to enhance the removal efficiency of chemical contaminants the effect of adding a heating and humidifying process before an air washer was examined.

• Nuclear Engineering and Technology
• /
• v.51 no.3
• /
• pp.867-876
• /
• 2019

Second harmonic generation using nonlinear ultrasonic waves have been shown to be an early indicator of possible fatigue damage in nuclear power plant components. This technique relies on measuring amplitudes, making it highly susceptible to variations in transducer coupling and instrumentation. This paper proposes an experimental procedure for in-situ surface wave nonlinear ultrasound measurements on specimen with permanently mounted transducers under high cycle fatigue loading without interrupting the experiment. It allows continuous monitoring and minimizes variation due to transducer coupling. Moreover, relations describing the effects of the measurement system nonlinearity including the effects of the material transfer function on the measured nonlinearity parameter are derived. An in-situ high cycle fatigue test was conducted using two 304 stainless steel specimens with two different excitation frequencies. A comprehensive analysis of the nonlinear sources, which result in variations in the measured nonlinearity parameters, was performed and the effects of the system nonlinearities are explained and identified. In both specimens, monotonic trend was observed in nonlinear parameter when the value of fundamental amplitude was not changing.

• Proceedings of the Korea Society of Environmental Biology Conference
• /
• 2001.12a
• /
• pp.132-132
• /
• 2001

• 한국지구물리탐사학회:학술대회논문집
• /
• 2007.06a
• /
• pp.135-138
• /
• 2007

A novel technique to estimate the dielectric constant of ground material by means of air launching GPR is proposed. The technique is an application of SAR algorithm. A laboratory experiment was conducted to examine the technique.

• BMB Reports
• /
• v.43 no.2
• /
• pp.97-102
• /
• 2010

Clenbuterol, a $\beta_2$-adrenoceptor agonist, has been proven to be a powerful repartition agent that can decrease fat deposition. Based on results from our previous cDNA microarray experiment of pig clenbuterol administration, a novel up-regulated EST was full-length cloned (4859 bp encoding 1041 amino acids) and found to be the pig homolog of large tumor suppressor 2 (Lats2). We mapped pig Lats2 to chromosome 11p13-14 by using FISH, and western blotting demonstrated that pig Lats2 protein was most abundant in adipose. In Drosophila, Lats2 ortholog was reported as a key component of the Hippo pathway which regulates cell differentiation and growth. Here, we show that pig Lats2 exhibit inverted expression to YAP1, another member of the Hippo pathway which positively regulates cell growth and proliferation, during the differentiation of 3T3-L1 preadipocytes. Our results suggested that Lats2 may involve in Hippo pathway regulating the fat reduction by inhibiting adipocyte differentiation and growth.

• Journal of Science and Technology Studies
• /
• v.10 no.1
• /
• pp.27-71
• /
• 2010

Scientific creativity is defined as the production of novel scientific facts, methods, theories, explanations, and instruments, as well as the entire process by which these novel facts, theories, explanations and instruments are generated. There have been many studies on scientific creativity, but there were few studies on the scientific creativity of a research team collaborating in laboratory settings. This paper aims to find the elements that constitute the creativity of a laboratory through empirical participant observation and theoretical analysis of RNA Biology Lab in Seoul National University - a lab which is considered to be the most creative laboratory in Korea. Creative accomplishments demand not just a sudden inspiration but also a complicated and continuous evolutionary process which requires a systematic division of labor and a corporation between researchers who have diverse knowledges and capabilities. Also, this paper shows that laboratory culture and leadership are an important factor for vitalizing the corporative structure of the laboratory.

• Proceedings of the KIEE Conference
• /
• 2002.07c
• /
• pp.1823-1826
• /
• 2002

The purpose of this experiment was to develope Triggered Vacuum Switch (TVS) for the high voltage and high current. The TVS has an array of rods of alternate polarity in which a fixed gap spacing is maintained between the rods. The cross section of each rod has trapezoidal shape. It consists of electrode, ceramic chamber, getter and trigger. Currently, triggered vacuum switch (TVS) with seal-off has been designed and fabricated at PAL. An experimentation and trigger devices for TVS were designed for testing characteristics of electricity. For making the prototype of TVS, it is developed of fabrication process and fined of electrode material. The fabrication of the TVS is a lot of process which have manufacturing of part, chemical clean, ceramic brazing and metal welding. The fabricated TVS is tested of leak for vacuum, hold-off voltage and conditioning of trigger system. The TVS has pinch-off after it is removed of gas in the TVS and activated of getter in degassing furnace. The prototype TVS tested about 20 kV, 75 kA, 83 ${\mu}s$ with 100 kJ capacitor bank and inductance 5 ${\mu}H$. This paper describes the results of tests and the characteristics of the switch.

• Journal of Veterinary Science
• /
• v.19 no.6
• /
• pp.817-826
• /
• 2018

The bursa of Fabricius (BF) is a central humoral immune organ unique to birds. Four bursal peptides (BP-I, BP-II, BP-III, and BP-IV) have been isolated and identified from the BF. In this study, the immunoadjuvant activities of BPs I to IV were examined in mice immunized with H9N2 avian influenza virus (AIV) vaccine. The results suggested that BP-I effectively enhanced cell-mediated immune responses, increased the secretion of Th1 (interferon gamma)- and Th2 (interleukin-4)-type cytokines, and induced an improved cytotoxic T-lymphocyte (CTL) response to the H9N2 virus. BP-II mainly elevated specific antibody production, especially neutralizing antibodies, and increased Th1- and Th2-type cytokine secretion. BP-III had no significant effect on antibody production or cell-mediated immune responses compared to those in the control group. A strong immune response at both the humoral and cellular levels was induced by BP-IV. Furthermore, a virus challenge experiment followed by H&E staining revealed that BP-I and BP-II promoted removal of the virus and conferred protection in mouse lungs. BP-IV significantly reduced viral titers and histopathological changes and contributed to protection against H9N2 AIV challenge in mouse lungs. This study further elucidated the immunoadjuvant activities of BPs I to IV, providing a novel insight into immunoadjuvants for use in vaccine design.

• Nuclear Engineering and Technology
• /
• v.54 no.1
• /
• pp.97-109
• /
• 2022

Multi-dimensional coupling analysis is a research hot spot in nuclear reactor thermal hydraulic study and both the full-scale system transient response and local key three-dimensional thermal hydraulic phenomenon could be obtained simultaneously, which can achieve the balance between efficiency and accuracy in the numerical simulation of nuclear reactor. A one-dimensional to three-dimensional (1D-3D) coupling platform for the nuclear reactor multi-dimensional analysis is developed by XJTU-NuTheL (Nuclear Thermal-hydraulic Laboratory at Xi'an Jiaotong University) based on the CFD code Fluent and system code RELAP5 through the Dynamic Link Library (DLL) technology and Fluent user-defined functions (UDF). In this paper, the International Standard Problem (ISP) No. 43 is selected as the benchmark and the rapid boron dilution transient in the nuclear reactor is studied with the coupling code. The code validation is conducted first and the numerical simulation results show good agreement with the experimental data. The three-dimensional flow and temperature fields in the downcomer are analyzed in detail during the transient scenarios. The strong reverse flow is observed beneath the inlet cold leg, causing the de-borated water slug to mainly diffuse in the circumferential direction. The deviations between the experimental data and the transients predicted by the coupling code are also discussed.

• The Journal of Engineering Geology
• /
• v.13 no.3
• /
• pp.281-292
• /
• 2003

We setup a continuous measurement system for electrical conductivity of fluid in a model borehole and verified the basic environments in electrical conductivity measurement for estimating hydraulic constants. The experiment was made by monitoring the conductivity change within the hole using NaCI solution of different salinities and incoming formation fluid using distilled water. The experiment was made under the state of constant flow rate by maintaining balance between inflow and outflow. Conductivity variation features were observed by controlling salinity contrasts and temperature differences between fluid within the hole and incoming formation fluid. flow rate and the location of inlet and outlet. The results of the experiment show well the role of each affecting factor on the conductivity distribution. and suggest appropriate environments for conductivity measurements. It is considered that the basis of the conductivity measurement for henceforward laboratory model and/or in-situ borehole experiment has been prepared.