• Korean Journal of Remote Sensing
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• v.11 no.3
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• pp.117-127
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• 1995

In this paper several methods for retriving appropriate values of effective soil moisture contents from natural soil surfaces are introduced and compared each other. The soil medium has usually a nonuniform moisture profile; i.e., relatively dry at the top layer and relatively wet at the bottom layer. The effective soil moisture represents the quantitative value of soil moisture of the inhomogeneous soil medium in an average sense. A simple method is an arithmetic averaging of soil moisture values obtained from several layers of a soil surface. Otherwise, the penetration depths can be computed from a homogeneous and an inhomogeneous soil surfaces and compared in order to obtain the effective soil mosture. The other method is to obtain the effective soil moisture by comparing the reflectivities from both of a homogeneous and an inhomogeneous surfaces. Those methods are compared and the reflectivity technique is examined in more detail since the rader scattering is dominated by the reflectivity instead of the penetration.

• Proceedings of the KIEE Conference
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• 2006.07e
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• pp.45-46
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• 2006

변압기 내부의 수분은 절연물의 절연내력에 악영향을 끼치므로 수분측정은 변압기 사고예방과 수명연장에 매우 중요하다. 변압기 내의 수분함유량을 검출하는 시험법으로 Karl-Fischer법과 Dew-Point법을 사용해 왔다. 그러나 이 시험법은 기기를 분해해야 하고, 국부적인 부분에 대한 정보일 뿐 아니라 분석을 즉시 현장에서 하지 못하는 단점이 있다. 따라서 기존 시험법의 단점을 보완하기 위해 회복전압법(RVM, Return Voltage Method)이 제안되었다. 본 논문에서는 모의 셀 내부에 수분을 강제로 주입하여 수분함유량 변화를 주고 Karl-Fischer법을 통한 수분함유량 측정 결과와 RVM 특성 곡선을 비교 분석하였다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.7
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• pp.660-663
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• 2016

This paper presents the effect of vegetation layer and radar parameters on soil moisture measurement using the vegetation layer scattering model and surface scattering model. The database of backscattering coefficients for various vegetation layer densities, incidence angles, frequencies, and polarizations is generated using $1^{st}$-order RTM(Radiative Transfer Model). Then, surface soil moisture contents were estimated from the backscattering coefficients in the database using the WCM(Water Cloud Model) and Oh model. The retrieved soil moisture contents were compared with the soil moisture contents in the input parameters of the RTM to estimate the retrieval errors. The effects of vegetation layer and radar parameters on soil moisture measurement are analyzed using the retrieval errors.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.39 no.3
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• pp.233-239
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• 2013

In this study, water content, sebum content, and transepidermal water content were investigated to provide basic data for the future cosmetics industry as comparing the skin characteristics of different ages. Water content of cheek area, sebum content of nose area, and transepidermal water loss (TEWL) of cheek and forearm of trial subjects (total 638 people of both male and female) were measured. Data were analyzed using Statistical Package for the Social Sciences program (version 19.00; SPSS Inc., Chicago, IL, USA). Water content, sebum content, and TEWL of skin were measured as mean ${\pm}$ standard deviation. As a result, water content of cheek from female was higher than male and the water content increased with the older ages. However, sebum content of nose from male was higher than female and the sebum content increased with the younger ages. TEWL of cheek from female was higher than male, but TEWL of forearm from male was higher than female. Therefore, these results can be used as basic data in the development of future cosmetics for different ages and genders.

• The Journal of the Convergence on Culture Technology
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• v.7 no.2
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• pp.443-451
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• 2021

This study compared and analyzed the thermal characteristics based on the ratio of moisture content of infected and non-infected Bursaphelenchus Xylophilus by heat of combustion experiment. The experiment results are as follows. The analysisresult of the ratio of water content shows that 19.92% on average for infected Bursaphelenchus Xylophilus and 26.27% for non-infected which decreases water content as the size of conduction, convection, and radiant heat increases in case of fire. As the vaporization of the moisture content accelerates, the average moisture content is reached, and the result is contrary to the thermal characteristics of the wood that the moisture content is not ignited by a heat source when the moisture content is under 15%. The combustion heat analysis result showed that infected and non-infected Bursaphelenchus Xylophilus had no significant difference in combustion heat at about 3%. However, it shows that combustion heat is higher than other species. In conclusion, decreasing in moisture content based on the increasing conduction, convection, and radiant heat is one of the direct causes of ignition, and the lower the moisture content, the faster the fire spreads.

• Composites Research
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• v.30 no.6
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• pp.422-428
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• 2017

The moisture absorption behavior, tensile properties, and thermal analysis properties of MWCNT embedded nanocomposites exposed to temperature and moisture were evaluated. The contents of MWCNT were 0 wt%, 1 wt%, and 2 wt%, respectively. The specimens were exposed to immersed conditions at $25^{\circ}C$ and $75^{\circ}C$ for up to 600 hours. According to the results, the apparent moisture content increased as the exposure time increased, but the difference between the maximum moisture content and the moisture content at 600 hours was almost constant. The tensile modulus decreased with increasing exposure time and the degree of decrease was increased significantly as the MWCNT content and exposure temperature increased. The tensile strength decreased with longer exposure time without MWCNT, but increased with MWCNT due to the reinforcing effect of MWCNT. The storage modulus, glass transition temperature, tan d peak magnitude were low as the exposure time increased, but tan d curves with two peaks appeared when exposed to high exposure temperature for more than 300 hours.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1999.07a
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• pp.185-190
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• 1999

대부분의 물질에 함유된 수분은 물질의 중요한 구성성분중의 하나이며 특히 농산물이나 식품 등에 함유된 수분은 각 품질을 평가하기 위한 중요한 인자중의 하나이다. 각종 농산물 및 식품가공공정 뿐만 아니라 저장단계에서 원료의 수분함량을 신속 정확하게 측정할 수 있는 시스템의 개발이 요구되고 있다. 이러한 원료의 수분함량을 간접적으로 측정하는 방법으로서 주로 전기저항, 고주파 정전용량, 근적외선, 마이크로파 등이 이용되고 있다. (중략)

• Journal of the Korean Society for Nondestructive Testing
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• v.19 no.4
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• pp.259-269
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• 1999

Elastic wave velocity measurement technique such as impact-echo method and ultrasonic pulse velocity method has been successfully used to evaluate the moduli and strength of concrete. However, estimation results obtained by the NDT methods do not agree well with real things because longitudinal wave velocity is influenced by various factors. In this paper, among several factors influencing P-wave velocity, the influence of moisture content in concrete was investigated through the experiment. Test results show that longitudinal wave velocity is significantly affected by the moisture content of concrete, i.e., the lower moisture content. the lower velocity. Moisture content influences rod-wave velocity measured by impact-echo method stronger than ultrasonic pulse velocity measured by transmission method. During drying process with ages. the difference of increasing rate between longitudinal wave velocity and compressive strength of concrete is gradually increased. Therefore, to establish more accurate relationship between longitudinal wave velocity and strength, the difference of the increasing rate should be considered.

• Korean journal of food and cookery science
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• v.23 no.4 s.100
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• pp.423-432
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• 2007

The purpose of this study was to investigate the seasonal variations in water, protein, lipid, ascorbic acid, and ${\beta}-carotene$ contents of 17 vegetables and 4 fruits that are available all the year round and frequently consumed by Koreans. The water contents of the fruits ranged from 83-89%, and the vegetables contained more water than the fruits. The apples and pears had more water in the spring and summer than in the fall and winter. The tangerines showed a high water content in the winter, whereas the strawberries contained more water in the fall. The vegetables also showed seasonal variations in water content. The protein contents of the fruits were lower than 1%; the cucumbers contained 0.1% protein, which was the lowest level, but spinach, lettuce, bean sprouts, sesame leaves, and mushrooms had more than 1% protein. The ascorbic acid and ${\beta}-carotene$ contents of the apples, pears, and tangerines were higher in the fall and winter than in the spring and summer. The vegetables, in general, contained more ascorbic acid than the fruits. The cabbage and radishes showed higher ascorbic acid contents in the fall and winter than in the spring and summer, indicating that vegetables as well as fruits are more nutritious during their harvest season. The zucchini, spinaches, and green peppers had higher ${\beta}-carotene$ contents in the winter than in the other seasons. The above results show that there were seasonal differences in the ascorbic acid and ${\beta}-carotene$ contents of the fruits and vegetables. In addition, the fruits and vegetables had a tendency to contain more ascorbic acid and ${\beta}-carotene$ in the season they were harvested. Therefore, we recommend the consumption of those fruits and vegetables during their harvest season.

• Asian Journal of Turfgrass Science
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• v.18 no.2
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• pp.97-104
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• 2004

Anaerobic soils limit the amount of free oxygen available in the rhizosphere and therefore will impede grass root development and restrain nutrient availability for turf growth. An in-situ study was conducted on existing greens to investigate the relationship between $CO_2$ content in the rhizosphere and turf quality. Nine greens were selected in the study. On each green, five 1-m diameter circular plots were randomly selected for conducting the experiment. The greens were sampled 7 times from August, 1998 to August, 1999. Data collected from each plot included turf quality index, $CO_2$ content, and physical properties of the rooting mixtures. Turf quality declined drastically when $CO_2$ content in rhizosphere increased to $5\;to\;6{\mu}LL^{-1}$ during the late summer season. The $CO_2$ content increased as water content in the root zone increased, but was inversely related to infiltration rate. Cultivation of a golf green may reduce $CO_2$ content in the rhizosphere, but the benefit of cultivation decreased with time.