• 대한방사성의약품학회지
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• 제3권1호
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• pp.44-51
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• 2017

Herein we report an efficient radiolabeling method based on a rapid condensation reaction between N-terminal cysteine and 2-cyanobenzothiazole (CBT). Radioiodination of 2-cyano-6-hydroxybenzothiazole 2 was carried out using chloramine-T to give $^{125}I$-labeled CBT ([$^{125}I$]1) with a high radiochemical yield ($90{\pm}6%$ isolated yield, n=3) and radiochemical purity (>99%). To evaluate the radiolabeling efficiency of $^{125}I$-labeled CBT, model compounds, L-cysteine and N-terminal cysteine conjugated cRGD peptide were reacted with [$^{125}I$]1 under mild conditions. The radiolabeling reactions rapidly provided the $^{125}I$-labeled products [$^{125}I$]5 and [$^{125}I$]6 with excellent radiochemical yields and radiochemical purity. Therefore, we demonstrate that [$^{125}I$]1 will be a useful prosthetic group for radioactive iodine labeling of N-terminal cysteine bearing biomolecules.

• 대한기계학회논문집B
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• 제28권3호
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• pp.349-358
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• 2004

A low pressure impactor is an impaction device to separate airborne particles into aerodynamic size classes at low pressure condition. We designed a two-stage low-pressure impactor to classify submicron sized environmental aerosols. Performance evaluation was carried out for stages 1 and 2 by using an electrical method. Monodisperse liquid dioctyl sebacate (DOS) particles were generated using evaporation-condensation process followed by electrostatic classification using a DMA (differential mobility analyzer). The test particles were in the range of 0.08∼0.8$\mu\textrm{m}$. For the evaluation of the impactor we used two electrometers; one was connected to the impaction plate of the impactor and the other was to the Faraday cage used as a backup filter. The effect of polydispersity of test aerosols on the performance was investigated. The results showed that the experimental 50-% cutoff diameters at each impactor's operation pressure were 0.53 and 0.187$\mu\textrm{m}$ for stages 1 and stage 2, respectively. The effects of operation pressure on the cutoff diameter and the steepness of collection efficiency curves were also investigated.

• 한국포장학회지
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• 제10권1호
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• pp.55-62
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• 2004

Synthesis of poly[N-(formyloxyphenyl)maleimide](PFOMI) as photopolymer were investigated with various kinds of photosensitive groups. Generally, photopolyimide have some deficiencies in solubility, sensitivity, reserve stability of the photosensitive solution, and the precision of image pattern. The study has been required on those polymers which have high glass transition temperature and photo efficiency, and low dielectricity. The existing condensation resins require high curing temperature and perfect elimination of subreacted materials that are produced during the process after irradiation and various membrane damages such as the deformation and contraction in image pattern cure. In this study poly[N-(hydroxyphenyl)maleimide](PHPMI) was synthesized. The PHPMI were analyzed by H-NMR and FT-IR. The measured number average molecular weight of PHPMI was produced was $1.06{\times}10^4$. Poly[N-(formyloxyphenyl)maleimide](PFOMI) as a type of photo-Fries rearrangement was synthesized by NHPMI and formic acid followed by radical polymerization. PFOMI was analyzed by FT-IR, and photocharacteristics was investgated by UV spectra and FT-IR before and after UV irradiation. Based on the image characteristics of PFOMI measured from optical micrographs, it was formed that the resolution of positive type PFOMI was $0.5{\mu}m$.

• 한국산업융합학회 논문집
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• 제5권3호
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• pp.165-171
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• 2002

The thermosyphon has been used as a heat transmission device in the heat recovery of low level energy and cooling for heat generating equipments. Many studies on the working fluids and wicks have been reported to improve the heat transfer efficiency of the thermosyphon. A low temperature heat pipe with acetone is chosen in the present study to compare the heat transfer characteristics due to pouring amount of working fluid, magnitude of power supplied and tilt angles. The thermosyphon made ⵁ$15.88{\times}0.8t{\times}600mm$ of copper, evaporation section 200mm, insulation section 25mm, condensation 375mm. Heat transfer rate of the thermosyphon increase as magnitude of power supplied increase and observe dry out phenomenon at 5~10% of pouring amount of working fluid. So thermosyphon at the 150kJ/s judged to need 12% or more. Heat transfer rate of the thermosyphon have nothing to do with tilt angles. Dry out phenomenon of the thermo syphon makes it possible that a low temperature thermosyphon may be used to control temperature and heat transfer of a system when the critical quantity of a working fluid is supplied in the thermosyphon.

• 한국수소및신에너지학회논문집
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• 제25권2호
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• pp.200-208
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• 2014

This paper presents thermodynamic performance analysis of organic Rankine cycle (ORC) using low temperature heat source in the form of sensible energy and using liquefied natural gas (LNG) as heat sink to recover the cryogenic energy of LNG. LNG is able to condense the working fluid at a very low condensing temperature in a heat exchanger, which leads to an increased power output. Based on the mathematical model, a parametric analysis is conducted to examine the effects of eight different working fluids, the turbine inlet pressure and the condensation temperature on the system performance. The results indicate that the thermodynamic performance of ORC such as net work production or thermal efficiency can be significantly improved by the LNG cold energy.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집B
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• pp.276-281
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• 2000

A simulation program using the mass transfer correlation was constructed to analyze 1-D simplified condensing flow across the tube bank. Higher efficiency was anticipated by reducing the flue gas temperature down below the dew point where the water vapor in the flue gas is condensed at the surface of the heat exchanger; that is, the heat transfer by the latent heat is added to that by the sensible heat. Thus, there can be an optimum operating condition to maximize the heat recovery from the flue gas. The temperature rises of the flue gas and the cooling water between the inlet and the outlet of the tube bank were compared with the experimental data reported previously. The predicted results agree well with the experimental data. Using this simulation program, the parametric studies have been conducted fur various operating conditions, such as the velocities and temperatures of the vapor/gas mixture and the cooling water, the number of the rows, and the conductivity of the wall material.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2001년도 가을 학술발표회 논문집
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• pp.3-10
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• 2001

The box system that is composed only of reinforced concrete walls and slabs are adopted on many high-rise apartment buildings recently constructed in Korea. And the framed structure with shear wall core that can effectively resist horizontal forces is frequently adopted for the structural system for high-rise building structures. In these structures, a shear wall may have one or more openings for functional reasons. It is necessary to use subdivided finite elements for accurate analysis of the shear wall with openings. But it would take tremendous amount of computational time and memory if the entire building structure is subdivided into a finer mesh . An efficient analysis method that can be used regardless of the number, size and location of openings is proposed in this study, The analysis method uses super element, substructure, matrix condensation technique and fictitious beam technique. Three-dimensional analyses of the box system and the framed structure with shear wall core having various types of openings were performed to verify the efficiency of the proposed method. It was confirmed that the proposed method have outstanding accuracy with drastically reduced time and computer memory from the analyses of example structures.

• Bulletin of the Korean Chemical Society
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• 제33권11호
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• pp.3581-3588
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• 2012

A new series of acyclic mononuclear gadolinium(III) complexes have been prepared by Schiff-base condensation derived from 5-methylsalicylaldehyde, diethylenetriamine, tris(2-aminoethyl) amine, triethylenetetramine, N,N-bis(3-aminopropyl)ethylene diamine, N,N-bis(aminopropyl) piperazine, and gadolinium nitrate. All the complexes were characterized by elemental and spectral analyses. Electronic spectra of the complexes show azomethine (CH=N) within the range of 410-420 nm. The fluorescence efficiency of Gd(III) ion in the cavity was completely quenched by the higher chain length ligands. Electrochemical studies of the complexes show irreversible one electron reduction process around -2.15 to -1.60 V The reduction potential of gadolinium(III) complexes shifts towards anodic directions respectively upon increasing the chain length. The catalytic activity of the gadolinium(III) complexes on the hydrolysis of 4-nitrophenylphosphate was determined. All gadolinium(III) complexes were screened for antibacterial activity.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 춘계 학술논문 발표대회
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• pp.59-60
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• 2019

Thermal bridge on a building envelope causes additional heat loss which increases the heating energy consumption. As the higher building insulation performance is required, heat loss through thermal bridge becomes higher proportion among total building heating energy consumption. For the exterior insulation and finish system, thermal bridge between window frame and concrete wall should be constidered as one of main reasons of heat loss. In this study, the thermal bridge barrier between window frame and concrete wall(STAR) was proposed as the best practice for reducing thermal bridge. The STAR was confirmed that the use of thermal bridge barrier imporved the annual heat energy capacity by 35% or more and the innitial construction cost by 7.4% or less because of additional interior insulation against condensation. Finally the life cycle cost during 20 year by heating energy of a building reduced by 25% or more compared with the exist technology. This STAR thermal bridge barrier will be used as the main technology to improve the energy efficiency of building.

• 대한기계학회논문집A
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• 제31권2호
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• pp.221-230
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• 2007

An iterated improved reduced system (IIRS) procedure combined with sub-structuring scheme for nonclassically damped structural systems is presented. For dynamic analysis of such systems, complex eigenproperties are required to incorporate properly the nonclassical damping effect. In complex structural systems, the equations of motion are written in the state space from. Thus, the number of degrees of freedom of the new equations of motion and the size of the associated eigenvalue problem required to obtain the complex eigenvalues and eigenvectors are doubled. Iterated IRS method is an efficient reduction technique because the eigenproperties obtained in each iteration step improve the condensation matrix in the next iteration step. However, although this reduction technique reduces the size of problem drastically, it is not efficient to apply this technique to a single domain finite element model with degrees of freedom over several thousands. Therefore, for a practical application of the reduction method, accompanying sub-structuring scheme is necessary. In the present study, iterated IRS method combined with sub-structuring scheme for nonclssically damped structures is developed. Numerical examples demonstrate the convergence and the efficiency of a newly developed scheme.