• Korean Journal of Organic Agriculture
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• v.24 no.4
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• pp.699-717
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• 2016

This study was carried out to investigate the effect of no-tillage on sequential cropping supported from recycling of first crop ridge on the growth of pepper plant and physical properties of soil under green house condition. 1. Degree of crack on soil by tillage and no-tillage Soil cracks found in ridge and not found in row. At five months of tillage, crack number and crack length in length ridge were 3 and 37~51 cm in tillage. Maximum width and maximum depth in length ridge were 30 mm and 15.3cm in tillage. Crack number and crack length in width ridge were 7.5 and 7~28 cm in tillage. Maximum width and maximum depth in width ridge were 29 mm and 15.3 cm in tillage. At a year of no-tillage, crack number and crack length in length ridge were 1.0 and 140~200 cm in tillage. Maximum width and maximum depth in length ridge were 18 mm and 30 cm in a year of no-tillage. Crack number and crack length in width ridge were 11 and 6~22 cm in a year of no-tillage. Maximum width and maximum depth in width ridge were 22 mm and 18.5 cm in a year of no-tillage. Soil crack was not found at 2 years of no-tillage in sandy Jungdong series (jd) soil. Soil crack was found at 7 years of no-tillage in clayish Jisan series (ji) soil. 2. Penetration resistance on soil Penetration resistance was increased significantly at no-tillage in Jungdong series (jd). Depth of cultivation layer was extended at no-tillage soil compared with tillage soil. Penetration resistance of plow pan was decreased at 1 year of no-tillage compared with than tillage soil. Penetration resistance was linearly increased with increasing soil depth at tillage in Jisan series (ji). Penetration resistance on top soil was remarkably increased and then maintained continuously at no-tillage soil. 3. Drainage and moisture content of soil Moisture content of ridge in top soil was not significant difference at both tillage and no-tillage. Moisture content of ridge in 20 cm soil was 14% at no-tillage soil and 25% at tillage soil. 4. Change of capacity to retain water in soil Capacity to retain water in top soil was not significant difference at 1 bar both tillage and no-tillage. Capacity to retain water in soil was slightly higher tendency in 1 year and 2 years of no-tillage soil than tillage soil. Capacity to retain water in soil was increased at 15 bar both tillage and no-tillage. Capacity to retain water in subsoil was slightly higher tendency at 1 bar and 3 bar in 2 years of no-tillage than tillage soil and a year of no-tillage soil.

• Korean Journal of Food Science and Technology
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• v.29 no.2
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• pp.273-278
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• 1997

In order to investigate the punch properties of some vegetables-cucumber, radish, garlic, ginger and potato-force, distance, and time were measured with a texturometer, and the correlations between compositions and cell characteristics of samples were characterized. Many reflection and rupture points on the force-distance and distance-time curve were observed, and these points appeared when the cells of sample were resisted and yielded against the applied force. They were big and clear at the slow crosshead speed. The regression analysis for force-time and distance-time to the rupture point showed $R^{2}>0.95$. The rupture time and rupure force were 5.63 sec, 4.88 N in ginger and 4.15 sec, 2.00 N in cucumber. The rupture forces become large values at the fast crosshead speed. As cell sizes were increased, the moisture content and rupture distance were increased, while the viscosity of juice, density, regularity of cell, and slope of force-time were decreased. Rupture force, time and distance were decreased at the large specific gravity of samples. The slopes of distance-time curve were inversely proportional to slope of force-time curve.

• Journal of the Korean Geotechnical Society
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• v.19 no.5
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• pp.189-197
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• 2003

The treatment and hauling of surplus soils which occur from construction activity are costly and have been demanding a reasonable recycling method. This study presents laboratory test results regarding the mechanistic properties of asphalt stabilized soils. The foamed asphalt equipment which generates the asphalt bubble was used to mix the soil. The marshall stability, indirect tensile test, resilient modulus, creep test and triaxial test(UU) were conducted to find out the performance of the asphalt stabilized soil. The test results were compared with the samples that fabricated in different conditions(the samples without asphalt and the reinforced samples using 2% cement). The inclusion of the asphalt in the soil has improved the marshall stability, resilient modulus and moisture susceptibility, and the addition of the 2% cement has even more increased these properties. The amount of the fines and the optimum moisture contents for mixing affects the mechanistic properties and important parameters for mix design.

• Korean journal of food and cookery science
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• v.12 no.2
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• pp.207-213
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• 1996

Effects of replacement of corn starch with Amylomaize Vll starch and addition of enzyme-resistant starch on texture characteristics of com bread (CON) were investigated. Amylomaize-substituted corn bread (AMZ) was made by replacing corn starch with Amylomaize Vll starch. 15% (RSl5) and 30％ (RS30) of butter, was replaced with enzyme-resistant starch (RS) from Amylomaife Vll starch, respectively. Textu,e describing terms were classified according to their physical properties. Result of sensory evaluation characteristics showed that the size of air cells increased as butter replacement level decreased and that hardness increased but springiness decreased as com starch was replaced with Amylomaize Vll starch. The results of Texture Profile Analysis with deformation of 30% and 50% showed that hardness inclosed but cohesiveness decreased as cooling time increased.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.594-601
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• 2021

In order to expanding of the use of steel slag, a by-product of steel industry, as a road paving construction material, this present study confirmed the possibility of the rust formation of steel slag aggregate and evaluated the durability performance and the noise reduction characteristics of asphalt concrete mixture. As a result of conducting the rust formation test of aggregate, no rust was observed in both aggregate, so it is judged that the possibility of rust formation in the actual road water environment is very low. As a result of performing the moisture resistance test, all mixtures showed a tensile strength ratio exceeding 85%, satisfied the standard as asphalt mixture. In addition, the sound absorption coefficient of the steel slag aggregate mixture was measured to be higher than that of the general aggregate mixture. Accordingly, it is speculated th at th e steel slag aggregate mixture can more effectively respond to road noise reduction than the general mixture.

• Korean Journal of Food Science and Technology
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• v.26 no.6
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• pp.791-798
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• 1994

Ohmic heating is a food processing operation in which heat is internally generated within foods by the passage of alternating electric current. The process enables highly viscous paste foods such as Kochujang, and fermented soybean paste to be heated very fast. In order to develope the novel pasteurization process of paste foods, static Ohmic heating system was built, and heating characteristic during Ohmic heating under various conditions were studied. Electric conductivities of Kochujang and fermented soybean paste at room temperature were 1.865 S/m and 2.510 S/m, respectively and increased linearly with increasing temperature. Specific heating rate was highly dependent on the frequency. The highest heating rate was achieved at 5 KHz for Kochujang and 20 KHz for fermented soybean paste. Uniform heating throughout the sample was achieved during Ohmic heating with low frequency electrical currents, however above 5 KHz frequency, surface temperature was several degrees higher than the bulk.

• Journal of the Korean Wood Science and Technology
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• v.36 no.6
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• pp.1-12
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• 2008

A series of the studies on the applied physical properties of domestic species have been conducted last three years. Liriodendron tulipifera, Betula costata, Paulownia coreana were examined on sorption property, thermal property, electric property, acoustic property. Because the same apparatus and experimental procedures were used for all species, their results can be easily comparable. The experiments for sorption property were conducted with 80 mesh wood powder and resulted in their EMC's and sorption isotherms. The thermal conductivity and diffusivity, and electric resistance and volumetric electric resistivity were measured with a thermal-wire device and a high electric resistance meter. The differences of the thermal and electric properties between quarter-and flat-sawn specimens were observed, which was partially attributed to their anatomical differences. An acoustic measurement system was used to evaluate dynamic MOE and internal friction. This paper provides the useful fundamental data for designing a wood structure, correcting a portable resistance-type moisture meter, and acoustic properties of wood.

• The Journal of Engineering Geology
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• v.18 no.2
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• pp.127-136
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• 2008

Geophysical survey for establishing a wide site for the distribution of water content, wetting front infiltration due to the rainfall, and distribution of groundwater level has been performed by using 8round penetration radar (GPR) method, electrical resistivity method, and so on. On the other hand, a narrow area survey was performed to use a permittivity method such as time domain reflectometry, frequency domain reflectometry, and amplitude domain reflectometry methods for estimating volumetric water content, soil density, and concentration of contaminant in surface and subsurface. The permittivity methods establish more corrective physical parameters than different found survey technologies mentioned above. In this study for establishment of infiltration behaviors for wetting front in the unsaturated soil caused by an artificial rainfall, soil physical parameters for volumetric water content, pore water pressure, and pore air pressure were measured by FDR measurement device and pore water pressure meter which are installed in the unsaturated weathered granite soil with different depths. Consequently, the authors were proposed to a new establishment method for analyzing the variations of volumetric water content and wetting front infiltration from the responses of infiltrating pore water in the unsaturated soil.

• Journal of Conservation Science
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• v.35 no.6
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• pp.670-680
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• 2019

This study attempts to identify whether there were preferred wood species or any required properties depending on the use of wooden objects by comparing wood species analysis results of wooden objects, which are classified specifically by their uses like comb, wooden tablets, containers, etc., excavated from Haman Seongsansansung mountain fortress, which is the archaeological site of the Three Kingdoms era and those excavated from archaeological sites in Gyeongsang province considered to be the similar era of Haman Seongsansansung mountain fortress site. Wooden tablets and combs show the preferred species clearly and containers preferred wood species with the mid-ranged strength and the resistance against moisture migration.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.1A
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• pp.101-108
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• 2009

The performance of high-early strength pavement concrete for large areas is influenced by the physical and chemical environment during service life. Generally, penetration, diffusion, and absorption of harmful materials that exist outside the concrete cause damage to its structure. Thus, we have to use a mixture for durability to keep the required quality for the planned service life. Moreover, in using high-early-strength cement and accelerators, a high heat of hydration to create the initial strength can cause cracks. Based on evaluations from optimal mix proportions of high-early-strength pavement concrete for large areas, we conducted water permeability, abrasion resistance, freeze-thaw, plastic, drying, and autogenous shrinkage tests. Test result showed that a mix of accelerator and PVA fibers showed excellent performance.