• Journal of the Korean Vacuum Society
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• v.14 no.4
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• pp.180-185
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• 2005

The possibility of generation of the vacuum scale using the vapour pressure of water was evaluated. The range of vacuum from 3.3 kPa to 101.3 kPa was corresponds the vapour pressure of water in the temperature range from $25^{\circ}C$ to $100^{\circ}C$ The measured values of the vapour pressure of water were agreed within the deviation of $5\%$ comparing to reference value. This result shows the vapour pressure of water can be used as an secondary reference of the vacuum scale. Moreover it shows the thermo-dynamical properties such as, triple point, temperature-pressure curve of a material have a applicability in the vacuum scale as a reference in corresponding range of vacuum.

• Journal of the Korean Society of Safety
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• v.4 no.1
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• pp.41-46
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• 1989

Molten salt-water explosion caused by the contact between molten salt and water is one of vapour explosions. An experimental study of the vapour explosion, which occurs when the molten mixture of Na$_2$CO$_3$-NaOH and water come in contact was performed. The pressure wave generated in each composition Of molten mixtures was measured. The results obtained are as follows： 1) The vapour explosion didn't occur for a molten salt of 100%-Na$_2$CO$_3$- 2) For a molten salt of Na$_2$CO$_3$ 80％-NaOH 20% mixture, a small vapour explosion occured initially, and a large vapour explosion, which showed the largest pressure wave among the present experiments, occurred after an induced period. 3) For molten salt of Na$_2$CO$_3$60％ - NaOH 40％ mixture and Na$_2$CO$_3$ 40％ - NaOH 60％ mixture, the vapour explosion occurred near the water surface shortly after they come in contact with water. This explosion would be caused by fragmentation of the molten salts due to impulse generated when thee molten salts and water come in contact.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.7 no.2
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• pp.73-79
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• 1978

This paper presents the experimental study on the design conditions of pressure between booster ejector and air ejector in the steam-jet water-vapour refrigeration system. In this experiment, the motive steam of booster ejector and ai. ejector was dry saturated from 6 ata to 8 ata and flash chamber pressure were about $10\∼540mmHg$ higher than mixing section in booster ejector. The investigation of air on the pressure of booster ejector was performed by changing the condenser pressure. The experimental results show that flash chamber vacuum and condenser pressure of steam-jet refrigeration cycle increased in accordance with the increase of motive steam Pressure. Among the several nozzle sires tested, No.4 nozzle were best in term of evaporator vacuum under the constant operating conditions of air ejector in condenser.

• Journal of Adhesion and Interface
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• v.7 no.3
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• pp.16-25
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• 2006

Water vapour permeable and water resistant film was laminated to made footwear woven fabric and non-woven fabrics by screen type with thermosetting reactive hot melt adhesive. Optimum conditions of each process were investigated, and the properties of film laminated fabric with optimum conditions are evaluated. The results are as follows. Thermosetting reactive polyurethane hot melt is retain proper heat resistance differently thermoplastic hot melt. Optimum melting adhesive process conditions are as follows ; drum temperature $95^{\circ}C$, hose temperature $97^{\circ}C$, feeding pipe temperature $100^{\circ}C$, screen temperature $105^{\circ}C$, pressure of opposite roller $1kgf/cm^2$, pressure of laminating roller $3kgf/cm^2$, finishing speed 15 m/min, melting temperature $120^{\circ}C$, cooling time 20 s, pressing temperature $130^{\circ}C$, pressing time 30 s. As the thickness of film was increased, the water vapour permeability was decreased but water resistance was increased, and the effect of film is dominant over all the others in the air permeability.

• Applied Chemistry for Engineering
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• v.23 no.2
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• pp.143-147
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• 2012

Since the expansion of perlite occurs in a few second in high temperature, it is difficult to identify an expansion phenomenon through experiments. In order to explain this phenomenon, a numerical study has been carried out by setting a model that water vapour diffuses to a tiny bubble existing in perlite melts and then makes the bubble grow and perlite expand. When the bubble grew and the perlite expanded due to the diffusion of water vapour, the dynamic temperature of perlite decreased. Meanwhile, the dynamic pressure of bubble increased at the beginning as water vapour diffuses in melts, but rather decreased after a rapid expansion of bubble.

• Journal of Bio-Environment Control
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• v.5 no.2
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• pp.160-166
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• 1996

Objective of this study was to investigate the effects of all current speed on the microclimates above and inside the plug stand under artificial light. Maximum air temperature appeared near the top of the plug stand. Difference in air temperature inside the plug stand increased with the decreasing air current speed. Difference in relative humidity(DRH) to the relative humidity at the Inlet of the main air flow conditioner Inside and above the plug stand decreased with the increasing air current speed. Relative humidity inside the plug stand was 10-15% higher than that above the plug stand. DRH inside a stand of plug at air current speed of 0.3m s$^{-1}$ was about two times as many as that at air current speed of 0.9 m s$^{-1}$ . DRH inside the plug stand was 2.8-6.5% higher at LAI of 2.6 than that at LAI of 0.5. Gradient for the vapour pressure deficit was distinctly appeared at the low air current speed. Direction of vapour pressure flux is from the medium surface upwards. Difference in vapour pressure(DVPD) to the vapour pressure deficit at the inlet of the main air flow conditioner inside and above the plug stand decreased with the increasing height above the medium surface. DVPD inside the plug stand was 0.3-0.4㎪ higher at air current speed of 0.9m s$^{-1}$ than that at air current speed of 0.3m s$^{-1}$ . Results for the effects of air current speed on the relative humidity and vapour pressure deficit indicated that the microclimates above and inside the plug stand at the rear region in plug trays were slightly unfavorable compared to those at middle region.

• Journal of Biosystems Engineering
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• v.29 no.6 s.107
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• pp.521-530
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• 2004

The solar powered water pump is very ideal equipment because solar power is more intensive when the water is more needed in summer and it is very helpful in the rural area, in which electrical power is not available. The average solar radiation power is $3.488\;kWh/(m^2{\cdot}day)$ in Korea. In this study, the experimental system of the water pump driven by the radiation energy were designed, assembled, tested and analyzed fur realizing the solar powered water pump. Energy conversion ken radiation energy to mechanical energy by using n-pentane as operating material was done and the water pumping cycles were able to be continued. The quantity of the water pumped per cycle ranged from 2 L to 10 L depending on the level of the valve open area far the vapour supply. The average quantity was about 4,366 cc. The thermal efficiency was about $0.018\%$. The pressure level of the n-pentane vapour in flash tank was about $110\~150\;kPa$ and that in the water tank was $93\~130\;kPa$. The pressure in the condenser during cycles was maintained as about 70 kPa. The condensation of the n-pentane vapour in the water tank was increased with the cycles even though the internal and external insulation were done. Air tank performance was better with increasing of the water piston displacement and the water could be pumped with the water piston displacement becoming higher than 6,500 cc.

• The Korean Journal of Ceramics
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• v.4 no.2
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• pp.128-135
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• 1998

The paper gives a brief introduction to protonic defects and their chemistry, thermodynamics and transport in oxides. The temperature dependence of the equilibrium concentration of protons is illustrated and compared for different acceptor-doped oxides. The difficulties of saturating as well as emptying the oxides of protons are discussed. In order to illustrate the possibility of lattice relaxation of defects, a conceptual study is made of a case where the enthalpy of dissolution of protons(water) at the cost of oxygen vacancies is assumed dependent on the concentration of vacancies. It is shown how this changes the behavior of hydration curves vs temperature and water vapour pressure. finally, a discussion is given on the water uptake in heavily oxygen deficient oxides; how water uptake may affect order-disorder in the oxygen sublattice and eventually lead to defective, disordered or ordered oxyhydroxides or hydroxides of potential interest as intermediate temperature proton conductions.

• The KSFM Journal of Fluid Machinery
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• v.12 no.4
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• pp.30-36
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• 2009

Recently, there has been growing interest in the oxyfuel combustion cycle since it enables high-purity $CO_2 capture with high$ efficiency. However, the oxyfuel combustion cycle has some important issues regarding to its performance such as the requirement of water recirculation to decrease a turbine inlet temperature and proper combustion to enhance cycle efficiency. Also, Some of water vapour remain not condensed at condenser outlet because cycle working fluid contains non-condensable gas, i.e., $CO_2$. The purpose of the present study is to analyze performance characteristics of the oxyfuel combustion cycle with different turbine inlet temperatures, combustion pressures and condenser pressure. It is expected that increasing the turbine inlet temperature improves cycle efficiency, on the other hand, the combustion pressure has specific value to display highest cycle efficiency. And increasing condensing pressure improves water vapour condensing rate.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.159-159
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• 2015

A new approach for antimicrobial is based on the overproduction of reactive nitrogen species (RNS), especially; nitric oxide (NO) and peroxinitrite (ONOO-) are important factors to deactivate the bacteria. Recently, non-thermal atmospheric pressure plasma jet (APPJ) has been frequently used in the field of microbial sterilization through the generation of different kinds of RNS/ROS species. However, in previous study we showed APPJ has combine effects ROS/RNS on bacterial sterilization. It is not still clear whether this bacterial killing effect has been done through ROS or RNS. We need to further investigate separate effect of ROS and RNS on bacterial sterilization. Hence, in this work, we have enhanced NO production, especially; by applying a 1% of HNO3 vapour to the N2 based APPJ. In comparison with nitrogen plasma with inclusion of water vapour plasma, it has been shown that nitrogen plasma with inclusion of 1% of HNO3 vapour has higher efficiency in killing the E. coli through the high production of NO. We also investigate the enhancement of NO species both in atmosphere by emission spectrum and inside the solution by ultraviolet absorption spectroscopy. Moreover, qPCR analysis of oxidative stress mRNA shows higher gene expression. It is noted that 1% of HNO3 vapour plasma generates high amount of NO for killing bacteria.