• Title/Summary/Keyword: oven dry

Search Result 212, Processing Time 0.027 seconds

Estimation of the Moisture Content of Wood by Density - Moisture Variation with Annual Ring Width - (목재의 밀도에 의한 함수율 추정 - 연륜폭에 따른 변이 -)

  • Hwang, Kweon-Hwan;Lee, Weon-Hee
    • Journal of the Korean Wood Science and Technology
    • /
    • v.23 no.3
    • /
    • pp.58-65
    • /
    • 1995
  • The possibilities of the estimation of the moisture content(MC) for sitka-spruce (Picea sitchensis Carr.) by measuring density have been investigated. The method is based on the relationships between the wood density and moisture content of wood expressed by Equations (8)~(9). The purpose of this study is examining the estimation of the moisture content of wood by density and the variation of moisture content with annual ring width of wood. The following conclusions were obtained; 1. This method is very convenience because of the average moisture content of wood can be obtained by a simple estimation. This estimation can be made from the easy measurement of the weight and volume of wood. 2. Coefficient of determination between the experimental MCs and theoretical MCs which is calculated by the oven-dry densities of each specimens and Equations (8), (9) is 0.98. This Correlation is very remarkable. Therefore the model Equations on the estimation of moisture content by wood density was available. 3. Relationship between experimental MCs and theoretical MCs which is estimated by average oven-dry density of total specimens showed positive correlation(Fig.2). But from the Fig.4. we can concluded that the number of specimens is two groups. This phenomenon is considered that the variation of MC by the annual ring width from the specimens' observations. Consequently, the MCs of wood by density, is likely to be successful method. can be estimate using by the average oven-dry densities divided with the annual ring widths of wood.

  • PDF

Experimental on the Accuracy of Soil Water Content Measurement Using TDR (TDR을 이용한 토양함수비 측정의 정확성에 대한 실험)

  • 윤춘경
    • Magazine of the Korean Society of Agricultural Engineers
    • /
    • v.41 no.1
    • /
    • pp.86-96
    • /
    • 1999
  • Laboratory experiment was performed for the TDR to measure the soil moisture, and the results, were compared with the design water content and the one measured by oven-try method. Sand and kaolinite were used . Varaiables for the experiment were water content (10-50%), void ration (0.7 -1.3), mixture rate of kaolinite (10-30%), and measurement methods (TDR and oven-dry). In all cases , TDR method showed very accurage and reliable results , and average error and error range were far lews than the oven-dry method which is widely used. Considerable error was noticed when water contnet was 50% where saturation was achieved for both methods. Therefore, TDR was thought to be applicable to the field moisture measurement if it is unsaturated. For field scale application of TDR, more research and verification of the accuracy with diverse soil conditions including physical ,chemical and mineral properties are recommended.

  • PDF

Drying Characteristics of Conductive Thin Films (전도성 잉크 박막의 건조특성)

  • Yoon, Seong Man;Jo, Jeongdai;Kim, Kwang Young
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.31 no.6
    • /
    • pp.505-511
    • /
    • 2014
  • In this paper, silver pastes were printed on polyethylene terephthalate (PET) film using screen printing and evaluated the drying characteristics by using dry oven and NIR drying system. The printed Ag films were dried at $140^{\circ}C$ and the drying time was changed from 10 to 90 seconds. To evaluate the electrical properties of printed Ag film, sheet resistance was compared. The sheet resistance of the dried thin silver film by using NIR drying system more rapidly decreased. To clarify this phenomena, the morphology and component of the dried surfaces were measured by using the scanning electron microscope (SEM) and the energy dispersive X-ray Spectroscopy (EDX), respectively. In the EDX measurement results, the oxidation of the surface was observed in the dried thin film by using the dry oven. The NIR drying system is more applicable than conventional hot air drying to apply continuous printing system.

A Study on Lunar Soil Simulant Pretreatment for Effective Simulation of Lunar Surface Environment (달 지상 환경의 효과적 모사를 위한 인공월면토 전처리에 관한 연구)

  • Chung, Taeil;Kim, Young-Jae;Ryu, Byung-Hyun;Shin, Hyu-Soung
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.40 no.1
    • /
    • pp.51-58
    • /
    • 2020
  • As interest in lunar exploration increases, studies on lunar surface environment simulation including a lunar soil simulant are being conducted. One of the problems when creating a vacuum environment with lunar soil is that it takes long time to reach high vacuum due to outgas from the soil. Most of the outgas is water, and the time to reach high vacuum can be significantly reduced by a pretreatment process that removes moisture adhering to the surface of the lunar soil before putting soil into a vacuum chamber. The existing soil drying methods were examined to determine how these methods were effective to remove moisture from the lunar simulant soil. Drying experiments of lunar soil samples were carried out using a dry oven, a microwave oven, direct heating method and a vacuum oven, and the results of the drying experiment were presented. Drying soil at 110℃ using a dry oven and drying soil by a microwave oven were not enough to remove moisture, and vacuum oven drying method and direct heating drying method at more than 200℃ were effective in water removal.

Quality Characteristics of Backsulgi with Dextrinized Rice (호정화에 의한 백설기의 품질특성)

  • Doo, Hwa-Jin;Lee, Eun-Suk;Kim, Yong-Ro;Shim, Jae-Yong
    • Food Engineering Progress
    • /
    • v.13 no.4
    • /
    • pp.289-296
    • /
    • 2009
  • The purpose of this study was to investigate the effect of dextrinization methods (dry oven and roaster) and the ratio of dextrinized rice on the quality of Backsulgi during storage. The moisture content significantly increased with increasing the amount of dextrinized rice regardless of dextrinization methods. As the ratio of dextrinized rice increased, the L value of the Backsulgi decreased, but the a and b values increased. The a and b values of dry oven method were higher than those of roaster method due to their thermal denaturalization. However, there were no significant pattern's change in sample's colors during storage. In the texture profiles, the hardness, cohesiveness, gumminess and chewiness significantly decreased with increasing the amount of dextrinized rice depending on the dextrinization methods and the ratios. The time constant (1/k) of the Backsulgi with dextrinized rice comparatively higher than that of control and appeared to be the highest in the Backsulgi formulated by 100% of dextrinized rice. In the sensory evaluation, Backsulgi with dextrinized rice over 30% after 1day storage showed higher value in overall quality and lower value in hardness than control. The addition of 30% dextrinized rice made by roaster showed the most effective on the quality and retrogradation of Backsulgi.

Modeling for a Coke Dry Quenching Process Using a Theory of a Porous Material (다공질 물질의 냉각현상 연구를 통한 코크스냉각공정의 모델링)

  • Kim, Joo-Han;Lee, Yong-Ju;Kim, Ki-Seok
    • Journal of the Korean Society of Manufacturing Technology Engineers
    • /
    • v.21 no.5
    • /
    • pp.697-701
    • /
    • 2012
  • Numerical modeling for a coke dry quenching process was developed and evaluated. The cokes had similar characteristics to a porous material, therefore, its quenching analysis was simplified as a cooling process of porous blocks. A uniform inlet temperature and constant properties of materials in the oven were also assumed. With given operating conditions, temperature profiles in the cokes were calculated and compared to the actual values. The calculated temperature gradient was high at the upper part of the coke flow and the cooling rate decreased as cokes came down to the exit port. The exit port temperature of cokes was similar to the measured value, however, temperature-dependent material properties and operating conditions must be considered to predict the temperature precisely. The calculated results could be applied to design a coke oven to produce high quality cokes.

Development of a Kiln Dry Schedule for Lindera erythrocarpa Grown in Hongsung, Chungnam Province, Korea (충남 홍성지역에서 자란 비목나무(Lindera erythrocarpa)의 열기건조스케쥴 개발)

  • Kang, Chun-Won;Kang, Ho-Yang
    • Journal of the Korean Wood Science and Technology
    • /
    • v.46 no.1
    • /
    • pp.10-16
    • /
    • 2018
  • Lindera erythrocarpa is a less utilized species in Korea although that it has straight stem and it grows up to 40 cm in diameter. A proper kiln-dry schedule is required in advance to utilize an unknown species. Terazwa's quick oven-dry method was used to find it and which was confirmed by drying 25 mm thick boards in a kiln. The average green moisture content and the average green specific gravity of Lindera erythrocarpa are 72.3% and 0.53, respectively. Prospective kiln-drying conditions obtained by Terazwa's quick oven-dry method are a initial dry-bulb temperature of $50^{\circ}C$, a initial wet-bulb depression of $4^{\circ}C$ and a final dry-bulb temperature of $75^{\circ}C$, which are in a good agreement with USDA FPL kiln-dry schedule of T5-D4. 25 mm thick boards dried in a kiln with T5-D4 kiln-dry schedule did not have any severe drying defects such as honycombing and warping. A severer kiln-dry schedule of T8-C5 was developed and applied to another kiln-drying run to confirm it.

Experimental Study of the Oven Dried Soil Weight Measurement Using Singularity Analysis (특이점 분석에 의한 노건조된 흙의 건조무게 측정에 관한 실험적 연구)

  • Sukjoo Kim
    • Journal of the Korean GEO-environmental Society
    • /
    • v.24 no.3
    • /
    • pp.5-14
    • /
    • 2023
  • The dry unit weight of the soil can be obtained by measuring the weight of the oven dried soil. According to the Korean Industrial Standards (KS F), oven dried soil at 110±5℃ continuously increases in weight when exposed to air. However, there is no regulation on the weight measurement time of oven dried soil, making it difficult to accurately measure the dry weight. In this study, a method to easily determine the dry weight was presented through the analysis of the weight singularity that appears during weight measurement. The weight singularity represents the smallest value among the measured weights, and is the weight at which the effect of moisture absorption in the air of the sample is minimized. In the course of the experiment, a container was selected using a statistical analysis method, and a photograph of the soil samples were presented using an optical microscope. In addition, the temperature of the weight singularity was measured using a non-contact infrared thermometer. As a result of analyzing the weight singularity of six types of soil, including Jumunjin sand, Naeseong stream sand, Yecheon weathered granite soil, Jeju sand, Sabkha sand, and Ulleung sand, the weight singularity of oven dried sample appeared between 8 and 27 seconds after weight measurement, and the temperature ranged from 103.4 to 108.13℃. The weight decrease rate of the singularity was 0.0066 to 0.0085% depending on the soil samples.

Rapid Moisture Content Determination Technique Using Microwave Oven (마이크로웨이브 오븐을 이용한 금속 함수율 측정법에 관한 연구)

  • Lee, Hyoung-Woo;Kim, Kyung-Yong
    • Journal of the Korean Wood Science and Technology
    • /
    • v.29 no.4
    • /
    • pp.16-24
    • /
    • 2001
  • Conventional hot-air oven-drying method takes at least four hours to determine the moisture content of wood sample and this method is not always acceptable to wood industry. In this study samples of six different specifications from Paulownia coreana, Pinus densiflora and Quercus acutissima were dried in domestic microwave oven to their oven dry weights to investigate the possibility of rapid moisture content determination technique using microwave-oven drying method. Continuous heating time, cooling time and intermittent heating time were determined by each species and sample specifications. Temperatures of surface and center of samples were also measured during drying. Oven-drying times were reduced to 1/7~1/10 of conventional hot-air oven-drying method. Therefore microwave heating and drying techniques appear attractive for wood industry as a rapid moisture content determination method.

  • PDF

Analyses of Essential Oil Components and Contents in Artemisia sp According to Heat Treatments (가열처리 방법에 따른 쑥의 정유 성분 및 함량 분석)

  • Kim, Choong-Ho
    • Culinary science and hospitality research
    • /
    • v.17 no.4
    • /
    • pp.273-284
    • /
    • 2011
  • The essential oil obtained by steam distillation from a medicinal plant of Artemisia princeps. The essential oil was analyzed by GC-MS. The heat treatments in roasted condition of temperatures were $80^{\circ}C$, $110^{\circ}C$, and $230^{\circ}C$, and the lengths of the time were 6 min, 10 min, and 14 min, respectively. The blanching conditions($100^{\circ}C$) of the treatments lasted 1 min, 2 min, and 5 min while the times of oven dry ($50^{\circ}C$) was 5 min. As the result, the essential oil content of the control plot was higher than the others, and that of the roasted ones was the second highest in low temperature with short treatment time. The major components were eucalyptol, cyclohexadience, phenol, terpineol, and caryopbyllene.

  • PDF