• International Journal of Highway Engineering
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• v.7 no.3 s.25
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• pp.23-30
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• 2005

Predicting distribution and variation of humidity inside concrete is essential to improve curing quality of concrete at field. The concrete humidity is predicted by numerical analysis using surface humidity as boundary condition. However, ambient humidity has been used instead of the surface humidity because the surface humidity could not be ccurately measured. Because it is hard to accurately measure the surface humidity, owever, the ambient humidity has been used instead of the surface humidity in the numerical analysis. In this paper, a methodology to accurately measure the surface humidity is suggested, and the ambient humidity and the humidity at the surface and inside the concrete measured by a series of laboratory tests are presented. The cause of low concrete humidity immediately after placement was investigated by a separately performed test. A surface humidity prediction model was developed using the measured humidity, and consequently validated through an additional test.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.2
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• pp.82-86
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• 2000

Humidity sensors using $TiO_2$ thin films were fabricated on the multi-electrode device by Sol-Gel method and their wettability, surface potential decays and humidity sensing characteristics were investigated. Contact angle of thin films was $28^{\cic}\;at\; 400^{\circ}C$ and surface potential decayed rapidly at $400^{\circ}C$. The specimen showed best humidity sensing characteristics at $400^{\circ}C$. From the results, they were confirmed that humidity sensing characteristics of thin films have connection with contact angle and surface potential decays.

• Tribology and Lubricants
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• v.19 no.5
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• pp.245-250
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• 2003

Water is known to playa crucial role on friction of moving parts in nanoscale contact. Little is, however, known about the tribological behavior of a solid surface that is covered with water adsorption layer. The objective of this study is to investigate the nanotribological behavior of the water layer in relation to water affinity of the surface and relative humidity. This paper presents an examination of the frictional behavior of water adsorption layer as 'confined liquid film'. It is shown that the friction is inversely proportional to the hydrophilicity of surface and relative humidity. On the other hand, friction of hydrophobic surface is not influenced by relative humidity. A model is proposed for the water-mediated contact in which it is shown that the water layer between two hydrophilic surfaces with high relative humidity behaves as a lubricant.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.424-426
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• 2002

The surface and volume resistivity in the polymers, PE(polyethylene) and PP(polypropylene) mixtures are tested and measured by the ASTM D257(KS M3015) standard. Humidity effects on surface and volume resistivity in two polymers have been studied qualitatively at room temperature. The results of resistivity in these polymers show that the values of surface resistivity (and volume resistivity) at the humidity of 90% are remarkably small compared with those at the humidity of 50%, independing on applied voltage. When we varied the humidity in two polymers, it was found to takes many hours to recover into original surface resistivity (and volume resistivity) of these polymers.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.4
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• pp.236-242
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• 2009

In finishing work, defects are often taken place by many factors. One of them is the thermo-humidity condition on the work surface as coating and anointing adhesives. Thus, the condition of thermo-humidity on work surface should be checked prior to the finishing work. However, many construction companies show a tendency to overlook it because not only are measurement tools so expensive but they don't have skilled hands about those tools. Therefore, we propose the measurement method that makes it easy to recognize surface thermo-humidity condition so as to reduce constructional flaws. And then we test this product. The test progresses to four stages with various conditions. We evaluate its usefulness and application possibility of this product in the field.

• Fashion & Textile Research Journal
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• v.24 no.1
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• pp.127-137
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• 2022

Recently, various clothing items are being developed using 3D printing technology, but comfort has become an issue while wearing them for a long time. Therefore, this study researched on how the temperature and humidity of the devices developed by 3D printing change depending on the material combination. Five types of material combinations (EVA foam, TPU density 10%, TPU density 30%, EVA foam+TPU density 10%, and EVA foam+TPU density 30%) were selected as variables, and the experiment was conducted for two different cases with and without a cover. All the ten types of samples were placed on the hot plate set at 36℃, and the surface temperature and humidity were measured at three different points for 10 minutes. As a result, the case with only TPU showed the greatest temperature change while the case with 100% EVA foam showed the least temperature change. The humidity of the surface layer gradually decreased with time for 100% EVA foam. For the case with TPU materials, the moisture was transferred to the surface layer at first, thereby increasing the humidity but then dropped significantly. Meanwhile, the cases with the cover on showed similar tendencies of change in both temperature and humidity where the overall temperature and humidity delivery were slow.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.12
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• pp.852-857
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• 2012

Recently, the indoor air pollution by microbes such as fungi and mites have become a concern as important research topic on indoor air quality. Fungal growth is significantly affected by humidity. In this study, we examined the influence of relative humidity on the surface of building materials and the water content of building materials on the fungal growth rate by measuring the mycelium length of fungi in the fungal detector placed on the surface of building materials. As a result, even if the relative humidity on the surface of building materials is identical, the more water content of building materials is, the more fungi grow faster. It was suggested that fungal growth rate depends on not only the relative humidity on the surface of building materials but also the water content of building materials.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2001.11a
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• pp.13-16
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• 2001

In this paper, the emission and aging properties of ZnS:Cu electroluminescent device were experiment respectively at room temperature and 7$0^{\circ}C$ relative humidity 100%. ZnS:Cu and BaTiO$_3$were respectively used for phosphor and dielectric. While AC 100V on 400Hz frequency were applied to the devices at room temperature and 70$_3$relative humidity 100%, the change of brightness were measured and compared. The surface of aged devices were investigated by scanning electron microscope. With the continuously operated environment of room temperature and 7$0^{\circ}C$ relative humidity 100%, the decay time were measured and the dark spot and aging status on the surface of the device were investigated. ZnS:Cu electroluminescent properties were deteriorated by the Increased temperature and humidity. Also the deteriorated properties were confirmed by the brightness and surface chanties of device, and the aging mechanism from the simulation on sulfur vacancy and deep tracts density.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.9
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• pp.732-737
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• 2012

This study made a specimen (contact surface size: $45\;mm{\times}0.02\;mm{\times}45{\sim}55\;mm$) with silicon rubber for low voltage cable with 50 phr silica filler. The electrification voltage of electrostatics were measured for different sizes of contact surface with the applied voltage of 10kV and the environmental settings of temperature ($25{\sim}40^{\circ}C$) and humidity (40~80%). The following conclusions were made. The electrification voltage of electrostatics decreased as the humidity increased. The electrification voltage of electrostatics increased as the temperature increased. The larger the surface size, the higher the electrification voltage of electrostatics. The property of the material had more effect on the relaxation time than the humidity.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.45 no.1
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• pp.93-99
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• 1996

The formation properties and oxidation mechanism of electrochemically oxidized porous silicon(OPS) films have been studied. To examine the humidity-sensitive properties of OPS films, surface-type and bulk-type humidity sensors were fabricated. The oxidized thickness of porous silicon layer(PSL) increases with the charge supplied during electrochemical humidity sensor shows high sensitivity at high relative humidity in low temperature. The sensitivity and linearity can be improved by optimizing a porosity of PSL. (author). refs., figs.