• Journal of Conservation Science
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• v.29 no.4
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• pp.421-435
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• 2013

The purpose of this study is to suggest environmental guidelines for the conservation of ceramics excavated from underwater. Accordingly, the conditional change of the soluble salt on surface of the excavated ceramics was examined by changing the relative humidity. Examining the relative ratio [high humidity(RH70%+RH80%)/low humidity(RH20%+ RH40%)] for 24 weeks using accumulated conductivity(${\mu}s/cm$), the result showed that the amount of ion elution increased more in high humidity than in low humidity. In particular, the ion elution increased significantly within the celadon sample. In addition, comparing the accumulated conductivity and physical characteristics of the samples in high humidity, the results indicated that the amount of the ion elution is proportioned to the increased rate of the sample's absorption capacity and porosity. Ceramics excavated from underwater has risks of the secondary physical and chemical attacks from remaining salts. Therefore, it is suggested these ceramics be stored in a storage which maintains proper temperature and low humidity conditions. Also, the collections need to be pre-classified according to the properties of the materials.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.3
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• pp.41-47
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• 2000

The atmospheric humidity is varied between 30% and 90% with season in Korea. Thus the influence of humidity on the behavior of wear for tools and dies. This paper presents the influence of atmospheric humidity on the wear of carbon the un-lubricated pin-on-disk sliding contact. it was found that the severe wear is dominant at a low humidity and the mild wear is strongly related with the carbon concentration of the steel at a high humidity in this study. The experiments were carried out in a chamber where the humidity was accurately maintained by humidifier. To investigate the relationship three different carbon steels such as 1020, 1041, and 1034 steels were used.

• Current Optics and Photonics
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• v.7 no.5
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• pp.504-510
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• 2023

An optical fiber dislocation fusion humidity sensor coated with graphene quantum dots is investigated. A Mach-Zehnder interferometer is fabricated with three dislocated single-mode fibers with graphene quantum dots coating humidity-sensitive materials. Humidity response experiments showed a good linear response and high sensitivity with easy fabrication and low-cost materials. From 22% to 98% RH, the humidity response sensitivity of the sensor is 0.24 dB/% RH, with 0.9825 linearity. To investigate the cross-response of humidity and temperature, temperature response experiments are conducted. From 30 ℃ to 70 ℃, the results showed 0.02 dB/℃ sensitivity and 0.9824 linearity. The humidity response experimental curve is compared with the temperature experimental curve. The big difference between humidity sensitivity and temperature sensitivity is very helpful to solve the cross-response of humidity and temperature. The influence of temperature fluctuations in humidity measurements is not obvious.

• Environmental Engineering Research
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• v.25 no.2
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• pp.171-177
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• 2020

Removal through adsorption is the most widely used and effective treatment method for volatile organic compounds (VOCs) in exhaust gases. However, at high temperatures and humidity, adsorption is competitive due to the presence of moisture and unsmooth physical adsorption thereby deteriorating adsorption performance. Therefore, water adsorption honeycomb (WAH) and VOCs adsorption honeycomb (VAH) were prepared to improve VOCs adsorption at high temperatures and humidity. Adsorbed toluene amounts on single honeycomb (SH), containing only VAH, and combined honeycomb (CH), containing WAH and VAH, were determined. Further, the toluene adsorption rates of honeycomb adsorbents mounted on rotary systems, VAH-single rotor (SR) and WAH/VAH-dual rotor (DR) were determined. Toluene adsorption by WAH/VAH-CH (inlet temperature: 40-50℃; absolute humidity: 28-83 gH₂O/kg-dry air) was 1.6 times that by VAH-SH, and the water adsorption efficiency of WAH/VAH-CH was 1.7 times that of VAH-SH. The adsorption/removal efficiency of the WAH/VAH-DR (inlet temperature: 45℃; absolute humidity: 37.5 gH₂O/kg-dry air) was 3% higher than that of VAH-SR. This indicates that the WAH at the rotor inlet selectively removed water, thereby improving the adsorption efficiency of the VAH at the outlet.

• Journal of the Korean Society of Safety
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• v.19 no.3 s.67
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• pp.51-56
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• 2004

Conductive polymer blends and composites are widely used for different safety application such as electrostatic charge dissipation(ESD), electromagnetic interference(EMI) shielding, electrostatic prevention and safety chemical sensor. In order to prepare a impedance-type humidity sensor that is durable at high humidities and high temperature, electically conductive polymer blends based on diallyldimethylammonium chloride(DADMAC) and epoxy were prepared in this study. The polymer blends type conductive ionomer exhibits reaction each other DADMAC and epoxy in FT-IR and DSC analysis. The blends material was traced by new peak at 1600cm-1 and appeard improvement of thermal resistance by melting point shift. Alumina substrate was deposited a pair of gold electrodes by screen printing. The blend material were spin-coated with a thin film type on the surface of alumina substrate. The polymer bleld type sensor exhibits a linear impedance increasing better than DADMAC coated humidity sensor. Also it shows good sensitivity, low hysteresis and durability against high humidity.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.4_2
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• pp.693-699
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• 2020

355nm UV pulse laser is irradiated on the surface of polyimide (PI) by LDW (Laser Direct Writing) method to produce a high sensitivity flexible humidity sensor using a simple one-step process. The LDW method continuously investigates 2-D CAD data using a galvano scanner and an F-lens. This method is non-contact, so it minimizes physical strain on the PI. Laser-induced graphene (LIG) produced by lasers has a high surface area due to its high flexibility and numerous pores and oxidizers compared to conductors. For this reason, it is highly useful as a flexible humidity sensor. The humidity sensor produced in this study was attached to the inside of a mask filter, which has become a hot topic recently, and its applicability was confirmed.The measurement of humidity measured the sensitivity, reactivity, stability and recovery behavior of the sensor by measuring changes in capacitance and resistance.

• Journal of the Korea Safety Management & Science
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• v.17 no.4
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• pp.397-401
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• 2015

In this study, analysed the characteristics of power drop and surface damage in solar cell through high temperature and humidity test in the 3 case of EVA(ethylene vinyl acetate) and 2 case ribbon thickness. The solar cells were tested during the 500hr in $85^{\circ}C$ temperature and 85% relative humidity conditions, that excerpted standard of PV Module(KS C IEC-61215). Through the EL(Electroluminescence) shots, specimen's surface have partialy damaged. Before and after high humidity and high temperature test, ribbon thickness $200{\mu}m$ EVA1 case power drop rate was 8.463%, EVA2 case was 6.667%, EVA3 case was 6.373%. In the ribbon thickness $250{\mu}m$ EVA1 case power drop rate was 6.521%, EVA2 case was 8.517%, EVA3 case was 6.019%. EVA3 case was the lowest power and FF(fill factor) drop rate at the 2 case of ribbon thickness, because EVA3 is laerger than EVA1 and EVA2 in thickness, elongation and tensile strength.

• Polymer(Korea)
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• v.33 no.1
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• pp.19-25
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• 2009

New polyelectrolytes derived from ionene-containing photocurable reactive oligomer (PIDM) were prepared for water-resistant humidity-sensitive membranes. The mixture of PIDM, hexamethylene dimethacrylate (HDM), pentaerythritol triacrylate dimer (SP1013), and photoinitiator was simultaneously coated on the sensor electrode with photoinitiated radical polymerization. The pretreatment of the substrates with vinyl-type silane-coupling reagent was performed for improving the water durability and stability of the sensors at high temperature and humidity. When the resistance dependences on the relative humidity of the crosslinked PIDMs were measured, it was found that the resistance varied three orders of magnitude between 20 and 90%RH, which was required for the humidity sensor operating at ambient humidity. Their hysteresis, temperature dependence, response time, water durability, and high temperature/humidity stabilities were measured and evaluated as a humidity-sensing membrane.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.34 no.1
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• pp.46-53
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• 2002

This study was carried out to analyze the effects of preservation temperature and relative humidity to the physical properties of corrugated fiberboard boxes for fruit and vegetable packaging. The preservation temperature did not affect severely to physical properties of corrugated fiber-board. Relative humidity was a major cause of corrugated fiberboard box quality deterioration. The burst and compressive strengths of experimental boxes measured with Mullen high pressure tester and tong crush tester were decreased gradually as relative humidity increased from 55% to 75%. But, the strength properties slightly decreased relative humidity at 75% or higher. This tendency was the greater for single wall (SW) corrugated fiberboard box than that for double wall (DW). It is suggested that development of the water-resistant corrugated fiberboard and box be needed that can be used under the condition of low temperature and high moisture content, which are being employed in the cold chain system.

• Journal of Fisheries and Marine Sciences Education
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• v.26 no.5
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• pp.1083-1089
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• 2014

The aims of this study are to find out the possibility of the charcoal as a desiccant. The only humidity control under high temperature and high humidity environment can be provided to the thermal comfort at indoor environment. Functionality of charcoal is known to be deodorization, antiseptic effect, filtering effect and humidity control. But research related to humidity control in the country not yet. Thus, the dehumidification capacity of the charcoal experimental results to see the results were as follows : 1) Entering the experimental humidification is 148.02 g/h, 161.05 g/h and 243.2 g/h when air velocity was changed 1.5 m/s, 1.7 m/s and 2.0 m/s. 2) When the basis weight of the charcoal 2.0 m/s air velocity to obtain the largest number of adsorption capacity. 3) Dru bulb temperature and dew point temperature ware measured at front and rear of the charcoal. Absolute humidity is calculated from the measured Dry bulb temperature and dew point temperature. The quantity of dehumidification is calculated from absolute humidity is the largest 129.6 g/h at the air velocity 2.0 m/s.