• 한국정밀공학회지
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• 제20권4호
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• pp.143-150
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• 2003

Frictional properties of ultra-thin carbon coatings on silicon wafer were investigated based on Taguchi experimental design method. Sensitivity analysis was performed with normal load, relative humidity, deposition process, and coating thickness as the variables. It was found that despite low thickness, the carbon coating resulted in relatively low friction coefficient. Also, the frictional behavior was affected significantly by humidity and normal load.

• 한국전기전자재료학회논문지
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• 제24권3호
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• pp.224-228
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• 2011

This research, integratable capacitive relative humidity sensor was produced using polyimide on glass substrate. Also, at the time of upper electrode formation, upper electrode grain size was affected by giving changes to sputtering condition. Through this analyzing electrical characteristics affect from capacitive relative humidity sensor was possible. Capacitance of capacitive relative humidity sensor was 330 pF, linearity of 0.6%FS and it showed less than 3% of low hysterisis. Specially, hysterisis was affected more from interface than interstitial. Also was affected by the grain size which is one of the formation condition of upper electrode.

• 한국포장학회지
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• 제7권1호
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• pp.16-20
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• 2001

In order to optimize designing process of corrugated fiberboard boxes for agricultural products, first of all, compression strength of each liner were experimentally evaluated on the various conditions of relative humidity and analyzed by liner regression analysis. At the 66 percents of relative humidity, IK(imported kraft liner) liner board lost little of its compression strength compared to others. At the relative humidity 93 percents, KA liner board lost its compression strength only 40 percents while SK liner board lost up to 56 percents. From the result of prediction modeling of ring crush strength in various humidity conditions, R square values were ranged from 0.59 to 0.97. At 56 percents of RH or below, R square values were relatively low, but at 66 percents of RH or higher, the values were 0.85 or higher. The significance values were lower than 0.001 at every RH condition. Level of significance of experimented values was about 80 percents of predicted values and R square values were between 0.89 to 0.95.

• 한국식품저장유통학회지
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• 제4권2호
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• pp.101-113
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• 1997

Temperature, relative humidity and ventilation are closely related one another, and they are the main factors to be controlled for the environmental control system of a storage facility. Conventional environmental control systems do not consider the interrelationship between temperature, relative humidity and ventilation, which results in low performance and high energy consumption. To overcome the inefficiency of the conventional ones, it was developed an on-off control system based on the interrelationship between the factors. The usefulness of the system was illustrated with the results produced by a set of experiments in a real world.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1994년도 추계학술대회 논문집
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• pp.113-117
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• 1994

In this paper, an experiment about humidity sensing properties of oxide aluminum films by Anodic oxidation method was made. The humidity sensing properties of films were investigated in the relative humidity range of 10∼85(%RH) , changing the frequency from 1[kHz] to 100[kHz]. The impedance of humidity sensing films were decreased in accordance with the increase of relative humidity. The decreasing rate of impedance were larger at low measuring frequency. The decreasing difference changes from 17.7M$\Omega$ to 3.68M$\Omega$ at low measuring frequency.

• 펄프종이기술
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• 제34권1호
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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.

• 한국세라믹학회지
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• 제48권4호
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• pp.293-297
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• 2011

The thermodynamic behavior of phenolic resin was investigated to verify the relation between the properties of porous ceramics with $ZrO_2$-C system for submerged entry nozzle and the characteristics of phenolic resin with various relative humidity. The green and the sintered density were decreased between 25% and 50% relative humidity, whereas they were gradually enhanced above 50% relative humidity. The highest value of apparent porosity was 20.1% and the minimum compressive strength was 69MPa in the specimen using the powder exposed to 50% relative humidity. As a result of thermal analysis for phenolic resin, the shift of endothermic peak to low temperature and the reduction of exothermic peak were observed, and the peaks corresponded to melting and curing of phenolic resin, respectively. The melting and the curing of phenolic resin generate the change of green density, and it can affect the properties of submerged entry nozzle.

• KSTLE International Journal
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• 제6권2호
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• pp.39-44
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• 2005

Friction and wear properties of the Boron carbide ($B_{4}C$) coating 100 nm thickness were studied under various relative humidity (RH). The boron carbide film was deposited on silicon substrate by DC magnetron sputtering method using $B_{4}C$ target with a mixture of Ar and methane ($CH_4$) as precursor gas. Friction tests were performed using a reciprocation type friction tester at ambient environment. Steel balls of 3 mm in diameter were used as counter-specimen. The results indicated that relative humidity strongly affected the tribological properties of boron carbide coating. Friction coefficient decreased from 0.42 to 0.09 as the relative humidity increased from $5\%$ to $85\%$. Confocal microscopy was used to observe worn surfaces of the coating and wear scars on steel balls after the tests. It showed that both the coating surface and the ball were significantly worn-out even though boron carbide is much harder than the steel. Moreover, at low humidity ($5\%$) the boron carbide showed poor wear resistance which resulted in the complete removal of coating layer, whereas at the medium and high humidity conditions, it was not. X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) analyses were performed to characterize the chemical composition of the worn surfaces. We suggest that tribochemical reactions occurred during sliding in moisture air to form boric acid on the worn surface of the coating. The boric acid and the tribochemcal layer that formed on steel ball resulted in low friction and wear of boron carbide coating.

• Journal of Biosystems Engineering
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• 제25권3호
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• pp.213-220
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• 2000

Grafting of fruit-bearing vegetables has been widely used to increase the resistance to soil-borne diseases, to increase the tolerance to low temperature or to soil salinity, to increase the plant vigor, and to extend the duration of economic harvest time. After grafting, it is important to control the environment around grafted seedlings for the robust joining of a scion and rootstock. Usually the shading materials and plastic films are used to keep the high relative humidity and low light intensity in greenhouse or tunnel. It is quite difficult to optimally control the environment for healing and acclimation of grafted seedlings under natural light. So the farmers or growers rely on their experience for the production of grafted seedling with high quality. If artificial light is used as a lighting source for graft-taking of grafted seedlings, the light intensity and photoperiod can be easily controlled. The purpose of this study was to develop a prototype system for the graft-taking enhancement of grafted seedlings using artificial lighting and to investigate the effect of air current speed on the distribution of air temperature and relative humidity in a graft-taking enhancement system. A prototype graft-taking system was consisted by polyurethane panels, air-conditioning unit, system controller and lighting unit. Three band fluorescent lamps (FL20SEX-D/18, Kumho Electric, Inc.) were used as a lighting source. Anemometer (Climomaster 6521, KANOMAX), T-type thermocouples and humidity sensors (CHS-UPS, TDK) were used to measure the air current speed, air temperature and relative humidity in a graft-taking system. In this system, air flow acted as a driving force for the diffusion of heat and water vapor. Air current speed, air temperature and relative humidity controlled by a programmable logic controller (UP750, Yokogawa Electric Co) and an inverter (MOSCON-G3, SAMSUNG) had an even distribution. Distribution of air temperature and relative humidity in a graft-taking enhancement system was fairly affected by air current speed. Air current speed higher than 0.1m/s was required to obtain the even distribution of environmental factors in this system. At low air current speed of 0.1m/s, the evapotranspiration rate of grafted seedlings would be suppressed and thus graft-taking would be enhanced. This system could be used to investigate the effects of air temperature, relative humidity, air current speed and light intensity on the evaportranspiration rate of grafted seedlings.

• 한국대기환경학회지
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• 제20권2호
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• pp.161-174
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• 2004

Aerosol formation and growth by water vapor reactions were investigated in a 2.5 -㎥ indoor smog chamber filled with the unfiltered ambient air. The relative humidity of test ambient air was elevated at 59～64% or 84～88% by adding water vapor. The aerosol number size distribution and the concentrations of $O_3$, NO, NO$_2$, and SO$_2$ were measured during the experiments. The $O_3$ and NO$_2$ gases were well reacted with the water vapor at high relative humidity of 84～88%, and the reaction rates of these gases seemed to be decreased at low relative humidity of 59～64%. The formation and condensational growth phenomena of ambient aerosols by water vapor reactions were observed in a Teflon bag, depending strongly on the initial particle size distribution. The water vapor reactions might be affected by the contents of oxidants produced by photochemical reactions under sunlight.