• Korean Journal of Medicinal Crop Science
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• v.25 no.2
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• pp.89-94
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• 2017

Background: The purpose of improving the quality of oriental medicinal herbs is to contribute to the improvement of the income of farm. The present study investigated the effect of reasonable drying methods, different storage conditions and packageing materials on quality and stability of Scutellaria baicalensis Georgi and for developing GAP (good agricultural practice) guide book. Methods and Results: Three methods of drying Scutellaria baicalensis roots produced over two years were used to estimate loss rate owing to drying, storage, and packaging. The methods of drying were categorized into natural drying (36 - 60 h by sunshine), drying with heat dryer (2 - 10 h), or drying with gas bulk dryer (2 - 10 h). After cleaning, and initial drying for a few days under controlled temperature conditions, the second phase of drying was carried out at 35, 45 and $55^{\circ}C$. Changes in hunter color values and quality under the two studied storage treatments (at $20^{\circ}C$ indoors and at $4^{\circ}C$ in a refigerator) were evaluated. Storage period for 60, 120, and 180 days in three packaging materials, PE (polyethylene package), PP (polypropylene gunnysack), and WP (watertight packing paper) were studied. Conclusions: Initial cleaning, reasonable gas drying and hot air drying, and drying in an oven at 35 and $45^{\circ}C$ after cutting the roots resulted in the lowest loss rates in S. Baicalensis root. Hunter color valuse indicated that stroage of dry roots at room temperature was better than PP packaging, and that cold stroage was better than PE packaging for long-term stability.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.15 no.1
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• pp.39-44
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• 2005

A sheet type of green body was made with the mixture of 60 wt% red clay, 20 wt% fly ash, and 20 wt% stone sludge. Indentations were made on the surfaces of sheets to investigate fracture rate of 1 to 5 mm artificial light-weight aggregates by various drying, breaking, and forming methods. Drying methods of green bodies were natural, electric oven, microwave, and fast drying by torch. Breaking methods of green bodies were ballmill Ⅰ, ballmill Ⅱ, free dropping in the box, and mechanical breaking with roller mill. The depth and width of indent on the surface of the sheet were varied and the thickness of green bodies was also changed to investigate effects of indentation on fracture rates. The highest fracture rate of 42 % among the various drying methods was obtained by microwave drying for 210 sec and the highest fracture rate of 65 % among the various breaking method was obtained by ballmill Ⅱ method. In forming method, an yield of larger aggregates than Ф = 5 mm decreased and that of smaller aggregates than Ф = 5 mm in creased with increasing depth of indentation (only in 3 mm thick green body)and with increasing thickness of green body. The size of aggregates was most homogeneous (by judging from the measurement of aspect ratio of 1 to 5 mm aggregates.) when 3 mm thick green body was rapidly dried by torch and was broken by ballmill Ⅱ method.

• Journal of the Korean Geotechnical Society
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• v.33 no.1
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• pp.57-65
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• 2017

During a construction of embankment, sub base, or retaining wall backfill, the speedy measurement of water content is necessary. In this study, a test method for field determination of water content of soil by the calcium carbide gas pressure (speedy water content measurement method) was evaluated for its reliability and accuracy. Dry oven and microwave oven methods were also used for water content measurement. In the test, weathered granite and Nakdong River sand in the site and kaolinite were used for water content measurement. The mass of 20, 22, 24, 26, 28, and 30 g of soil was respectively tested for 1, 3, and 5 min. The effect of each sample on water content was compared one another and analyzed. As the mass and testing time increased, the water content increased. The amount of soil was more important factor than testing time for the speedy water content measurement. In order to obtain similar result to that of dry oven method, 3 min of testing time with 24 g of soil was necessary for weathered granite classified as SM and 3 min with 30 g for Nakdong River sand classified as SP. For Nakdong River sand with 20-50% of kaolinite, the water content by speedy measurement increased as the clay content increased.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.1
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• pp.101-110
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• 2022

In this study, water content tests were performed on various fresh concretes subjected to different binder compostions to review the estimation errors and reliability of water content test methods. Micro-oven drying method, air-meter method, capacitance method and microwave penetration method were used to estimate water content of fresh concrete. Errors in water content estimation were analyzed by each test method. Regardless of the test method of water content, the estimation error was less than 5 %, and in the case of the test using mortar, the error in the estimation value was relatively large. In addition, based on the test results of water content of various concrete, the probability density function in which the estimation error for each test method becomes the population was analyzed. Water content test methods of fresh concrete which using concrete samples showed high estimate reliability of 97 % within the estimation error range of ± 10 kg/m³. On the other hand, the reliability of water content test method using mortar samples was lower.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.4
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• pp.345-350
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• 1991

Rough rice samples of Chucheongbyeo, Bongkwangbyeo and Hwaseongbyeo were collected by the National Agricultural Products Inspection Office. Drying methods of rough rice were sun drying and forced ventilation drying by an oven dryer and temperature of the oven dryer was set to 43, 60, 70, or 8$0^{\circ}C$. Moisture content of samples was reduced from ca. 20% to 15% at the end of drying, and additionally to 12.5 % for the drying at 8$0^{\circ}C$. Characteristics related to rice grain quality, milling recovery, ratio of broken and cracked rices, percentage of germination, and sensory scores of the cooked rices were evaluated. Yielding percentage of brown rice and polished rice remarkably decreased by drying at 8$0^{\circ}C$. Percentages of cracked rice and broken rice were within the criterion of the second grade government brown rice (20%) only in the sun dried and the rices dried at 43$^{\circ}C$, on the basis of damaged rice, opaque kernel rice and colored rice. Broken rice percentage of the polished rice was within the criterion for the standard of government rice (5%) in the sun dried and the rices dried at 43$^{\circ}C$. Germination percentage of rough rice was higher than 80% in sun drying and drying at 43$^{\circ}C$, but remarkably decreased by drying rice at 6$0^{\circ}C$ and over. Sensory palatability of the cooked rice decreased with increase in drying temperature. The present governmental method of judging rough rice on the basis of moisture content and appearance of the rough rice appears to be improved to include the ratio of broken and cracked rices.

• Korean Journal of Food Science and Technology
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• v.26 no.6
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• pp.805-813
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• 1994

Zucchini slices, sweet potato stems, taro stems, and platycodon treated with various methods such as dipping in citric acid solution, sulfite solution, or sulfur fumigation were dried by the natural sun drying method or the forced air drying method at 50, 70, 90, or $105^{\circ}C$. Mold growth of the dried vegetables and sensory quality of the dried and rehydrated vegetables were investigated. Limiting moisture contents to prevent mold growth over 3 month storage under room temperature were 15, 20, 25, and 15% for zucchini slices, sweet potato stems, taro stems, and platycodon, respectively. The chlorophyll containing vegetables dehydrated by the forced hot air showed better sensory quality than those by the natural sun. Among the pretreatments, dipping in the sulfite solution provided the best sensory quality to the dried vegetables. The sensory quality of dried platycodon was improved to a small extent by sulfur fumigation and sulfite solution treatment. The sensory quality of the dried platycodon was not found to be affected by the drying methods. All the tested vegetables dried at $105^{\circ}C$ had the worst sensory quality. Except drying temperature of $105^{\circ}C$, the lower the drying temperature, the better the sensory quality and the rehydration rates were obtained for the tested vegetables except platycodon. The sensory quality of the platycodon was little affected by the drying temperature tested in the range of $50{\sim}90^{\circ}C$.

• Journal of the Korean Wood Science and Technology
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• v.43 no.6
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• pp.746-756
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• 2015

The goal of this study was to review the wood shrinkage published in Journal of The Korean Wood Science and Technology from 1976 to 2015. Previous studies reported that shrinkage from Larix kaempferi in the tangential, radial, longitudinal directions ranged from 4.21%-9.79%, 2.09%-4.67%, 0.17%-0.33%, respectively. When different drying methods including closed cylinder drying, oven drying, and room temperature drying were used, volumetric shrinkage of Dipterocarpus grandiflorus was different, ranging from 31.6% to 21.0%. With an increment of the drying temperature of $115^{\circ}C$, $120^{\circ}C$, $125^{\circ}C$, the shrinkage of Larix kaempferi did not show a consistent trend. When sample size of Pinus densiflora was increased from $20{\times}20{\times}20mm$ to $100{\times}100{\times}100mm$, the tangential, radial and volumetric shrinkage decreased 2.61%, 1.32%, 0.80%, respectively. When a caliper having a sensitivity of 0.01 mm was used to measure $20mm^3$ specimen from Cryptomeria japonica, the measurement error occurred 1.97% in the radial direction and 35.7% in the longitudinal direction. From the previous studies, wood shrinkage could be influenced by sample size, drying method and measurement technique.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.2 no.3
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• pp.25-31
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• 1999

The differences in seed germination rates of Korean Native Plants were observed depending on the harvest years, the seed companies, the storage periods, the drying methods and the plant morphological types. The seed germination rates were changed significantly by the harvest years and the seed companies in all 4 species tested. The seed germination rates were decreased after 1 year storage at $4^{\circ}C$ in all 8 species tested and three of them did not germinate at all. A rapid drying method at $35^{\circ}C$ with a convection oven was not suitable for Chrysanthemum spp., but there were no significant changes of germination rates in Aster spp. The germination rates were decreased more at seeding in soil than at lab. test with Dicotyledon but no significant changes with Monocotyledon. Especially, the germination rates of fine seed on 5mm soil covering treatment were significantly decreased.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.1318-1328
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• 1993

Expression of chinese cabbage was conducted in order to investigate its dewatering behavior. Chipped cabbage was packed into cylinder and pressed by piston up to the predetermined pressure on Instron-1000. The rates of dewatering were affected domintantly by the applied pressure, but not significantly by the packed amount of cabbage in the cylinder. The pressure effect was increased very abruptly at first, but the increase rate was very low at high pressure greater than 20 MPa, showing great deviation from linear dependence of flow rate on pressure in Darcy's Law. Therefore, water expression from cabbage was not Newtonian flow of water through cell wall. In fact, the squeezed water contained a lot of solid particles, showing destruction of cell wall. The content of solid particles in expressed water was only slightly lower than the dry matter content of fresh chinese cabbage, determined by drying oven method.

• Journal of Biosystems Engineering
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• v.18 no.3
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• pp.252-261
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• 1993

Nuclear magnetic resonance(NMR) was used to study a feasibility test for the possibility to develop a moisture sensor applicable for agricultural products such as raw and powdered grain. Samples of wheat flour and brown rice were tested with a 200MHz hydrogen NMR. The samples were loaded into 5mm NMR glass tubes and $30^{\circ}$ pulses were supplied to get resonance signals. Hydrogen spectrum intensities of the samples were compared to moisture content measured by a drying oven method. High linear correlations were obtained between the hydrogen spectrum intensity and moisture content. Therefore, moisure contents of agricultural products could be measured nondestructively utilizing the NMR principle. A low-cost design concept of the moisture sensor with the NMR principle was proposed for a practical use.