• Bulletin of the Korean Chemical Society
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• v.34 no.5
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• pp.1521-1524
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• 2013

N-Propylsulfamic acid supported onto magnetic $Fe_3O_4$ nanoparticles (MNPs-PSA) was used as an efficient and magnetically recoverable catalyst for synthesis of 2H-Indazolo[2,1-b]phthalazine-1,6,11(13H)-trione derivatives from the three-component, one-pot condensation reaction of phthalhydrazide, aromatic aldehydes and cyclic 1,3-diones, in good to excellent yields at $100^{\circ}C$ under solvent-free conditions. The catalyst was easily separated with the assistance of an external magnetic field from the reaction mixture and reused for several consecutive runs without significant loss of its catalytic efficiency. In order to compare, the synthesis of 2H-Indazolo[ 2,1-b]phthalazine-1,6,11(13H)-trione derivatives in the presence of catalytic amount of sulfamic acid (SA) under same reaction condition was also reported.

• Journal of the Society of Disaster Information
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• v.15 no.2
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• pp.165-174
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• 2019

Purpose: In this study, we investigated the relationship between the causes of ESS container fire accidents. Method: We investigated the possibility of reducing the container fire accident by improving the air environment of the container which is necessary for improvement of these. Result: Through this study, we can be confirmed that the condensing condition of water in the air caused by the difference of internal and external temperature is improved and the dielectric strength of BMS board is reduced. Conclusion: The correlation between the BMS board condensation and the dielectric strength was confirmed.

• Land and Housing Review
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• v.5 no.4
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• pp.291-296
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• 2014

The apartment buildings were hard to emission of water vapor by reduced infiltration. The purpose of this study was to investigate the generation of indoor temperature and humidity in the recent construction of small size apartment buildings. The temperature and humidity were measured in 3 apartments in Seongnam and Daejeon city. During the winter indoor temperature and relative humidity were measured ranged from 20 to $24^{\circ}C$ and 40 to 60%. Generated humidity caused by various characteristics of the residents, rather than external influences. Compare daytime (6:00 to 22:00) and nighttime (22:00 to 6:00), the temperature is low and absolute humidity is high at nighttime. Condensation is likely to occur at nighttime. Using the cumulative relative frequency and absolute humidity, small apartments design criteria (temperature, relative humidity) can be set.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.267-268
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• 2018

The purpose of this study was to analyze the thermal performance of a cladding system which developed for easy maintenance and flexibility and installed on a long-life housing. The developed cladding systems were finished mock-up test at an authorized certification laboratory and were satisfied with the standard of the external wall system. The surface temperature and linear thermal transmittance of the cladding system were investigated by using the THERM as a simulation program. The joining part between the cladding systems had a weakness of condensation resistance. The surface temperature of the joining part was improved by filling and adding insulation.

• Analytical Science and Technology
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• v.19 no.2
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• pp.121-130
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• 2006

In this study, silver pre-treated activated carbons are transformed using sulfuric acid. From the results of adsorption, each isotherm shows a distinct knee band, which is characteristic of microporous adsorbents with capillary condensation in micropores. In order to reveal the causes of the differences in adsorption capacity and specific surface area after the samples were washed with various strengths of sulfuric acid, surface morphology and external pore structure were investigated by SEM. X-ray diffraction patterns indicated that Ag-activated carbons show better performance for silver and silver compounds removal by post-treatment with acid. The FT-IR spectra of silver-activated carbon samples show that the acid post-treatment was consequently associated with the removal of silver with an increased surface functional group containing oxygen of the activated carbon. The type and quality of oxygen groups are determined on the method proposed by Boehm. For the chemical composition microanalysis of silver-activated carbons transformed by post-treatment with sulfuric acid, samples were analyzed by EDX.

• Journal of the Korean Society of Propulsion Engineers
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• v.27 no.1
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• pp.49-57
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• 2023

The autogenous pressurization has been widely adopted for propulsion systems of next-generation reusable rockets due to its low cost and high reliability. The autogenous pressurization has a simple structure, but an understanding of the heat and mass transfer occurring inside the tank is essential. For this reason, a simulation test of the autogenous pressurization was conceived. The experiment equipment was constructed based on overseas pressurization test facilities cases and expert advice. Unlike the actual autogenous pressurization system, the propellant tank was insulated to exclude external influences. The pressurized gas supply line and the propellant pipe were separated. Using the manufactured autogenous pressure experiment equipment, it is possible to evaluate the condensation phenomenon of pressurants in cryogenic propellants, comparison of the efficiency of pressurization using helium and evaporated gas and the pressurization capacity according to the temperature of pressurant.

• Journal of Conservation Science
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• v.32 no.4
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• pp.521-534
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• 2016

Ancient tombs are typically comprised of confined rooms, which have different spatial characteristics than the external environment because they are covered by heavy layers of soil. In this study, we examined the thermal energy flow from the outside to inside of Songsan-ri tomb No. 6. External heat flows slowly to the inside because of heavy soil layer, and the presence of several rooms and entrances. For this reason, it takes about two months for the air temperature to travel from the outside to the inside of the tomb. Interestingly, the gradational inflow of thermal energy from outside the tomb leads to delicate horizontal and vertical variations in the wall temperature. These micro-environmental differences occur in the inner tomb every year, so we can expect them to cause condensation with regularity. In addition, we show that the previously installed forced circulation air conditioning system risks fatal damage to the mural wall painting. The results of this research suggest an optimal air conditioning system and optimized space planning to conserve Songsan-ri tomb No. 6 and its mural painting.

• Korean Institute of Interior Design Journal
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• v.17 no.1
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• pp.30-38
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• 2008

Borrowed landscape is an Oriental gardening method to draw inside external natural landscape, and borrowed landscape of Japan has a different characteristic from that of Korea or China nature is manipulated and re-interpreted by human will in the course of applying it to architectural space. In other words, not the original scenery, but manipulated one appears which is cut, reduced, or deleted by architectural elements such as wall, window, or fence. Therefore, this study examined how architectural structure of Ando Tadao symbolizing modernist architecture understood and adopted Japanese traditional views on nature, that is, borrowed landscape. To this end, on the basis of the understanding on 'polymerization of abstraction and form' he mentioned, his geometric architectural principles are discussed, since this serves to be an important beginning of architectural concretization by the concept of 'form' experienced and perceived by human being through geometric means called architecture 'abstraction.' The findings of this study are as follows: first, it was found that Ando Tadao generates borrowed landscape effects by polymerizing and manipulating his simple and geometric structures with each other and thereby editing natural scenery, while Japanese traditional borrowed landscape introduces source scenery inside, through condensation and symbolization. Second, the results of this study revealed that his architecture functions to transcend external and internal realm of a space, which is also observed in Japanese traditional architectural borrowed landscape. Therefore, this study is considered significant in the sense that it proved that Ando Tadao's architectural language is based on borrowed landscape as a specific Japanese traditional element, going beyond the scope of previous studies focusing simply on the introduction of natural elements.

• The Transactions of the Korean Institute of Power Electronics
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• v.20 no.2
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• pp.105-114
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• 2015

Heated glasses are widely used to prevent surface condensation and freezing in ship and building windows. This study proposes a heated glass temperature control system composed of power and control circuits to control the temperature of heated glasses. The proposed temperature control system adopts a digital controller instead of a conventional analog controller. Thus, the proposed system has better characteristics, such as precise setup and control of glass temperature, setup and control of output power, and control mode change between ON/OFF and phase controls. The system can also implement multi-functional control algorithms. The control characteristics are not dependent upon external disturbances, such as ambient temperature and electrical noises. Furthermore, the proposed temperature control system utilizes the power line communication (PLC) method to control the number of heated glasses without any extra communication lines. The system proposes a new communication protocol with strong immunity to electrical switching noises. A new sensorless algorithm is used to detect the temperature of the heated glass. This study presents the design guidelines in detail and its effectiveness are confirmed by implementing a 4-kw prototype temperature control system.

• Bulletin of the Korean Chemical Society
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• v.25 no.8
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• pp.1189-1194
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• 2004

The adsorption isotherms of N2 onto the metallic silver treated activated carbon fiber samples after acid treatment are Type I with a small amount of capillary condensation hysteresis. Increasing amount of acid treatment leads to a decrease in SBETs and external surface area. But, micropore volume and average pore diameter are presented in constant regular values with increasing amount of sulfuric acid treatment. SEM observes the surface morphology and crystal grown state of metal on the fiber surface. The results of EDX of Ag-activated carbon fiber pre-treated with acid show the spectra corresponding to almost all samples rich in silver with increasing the amount of acid treated. The FT-IR spectra of Ag-activated carbon fiber show that the acid pre-treatment is consequently associated with the homogeneous dispersion of metal with the increased surface acidity of the activated carbon fiber. The type and quality of oxygen groups are determined with Boehm titration method. From the those results, a positive influence of the acidic groups on the carbon fiber surface by acid treatment is also demonstrated by an increase in the contents of metallic silver with increasing of acidic groups.