• Korean Journal of Soil Science and Fertilizer
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• v.45 no.1
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• pp.98-102
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• 2012

Organic farming has rapidly increased in Gangwon province, but there is a concern about nutrient accumulation and nutrient imbalance in the soil of organic farming. This study was conducted to investigate the impact of continuous application of organic amendments on growth and yield of red pepper and soil characteristics compared with chemical fertilizers application for four years. Treatments of organic amendments including oil cake, rice straw compost, amino acid compost, rice bran compost, and mushroom media (spent substrate) compost resulted in comparable growth and yield of pepper to chemical fertilizers. Organic amendments improved soil physical and chemical characteristics. Especially, rice bran compost and oil cake significantly increased soil organic matter compared with chemical fertilizer application and mushroom media compost and rice straw compost significantly improved soil aggregate stability. On the other hand, available phosphate level in the soil amended with rice bran compost or mushroom media compost was relatively high compared with the other treatments due to relatively high phosphate levels in the composts. It is not easy to adjust nutrient composition in the organic materials. Therefore, the results obtained from the study imply that nutrient imbalance needs to be carefully considered in organic farming without use of chemical fertilizers.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.163-170
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• 2005

In this paper, the rock bolts, soil nails with filling grout and the micro-piling with injecting grout by pressure were applied for the stabilization of the cut slopes consisting of sedimentary rocks, igneous rocks and metamorphic rocks respectively. The field measurements and 3-D FEM analyses to find out mobilized tensile stresses of the grouted-reinforcing members installed in the drilled holes were executed on each site. With assuming the increments of the cohesive strength in the improved ground, the back analysis using direct calibration approach of changing the elastic modulus of the ground was used to find out the improved elastic modulus which yields the same tensile stresses from field measurements. The results of back analysis show that the elastic modulus of the improved ground were 4 to 6 times as large as the elastic modulus of original ground. Consequently, the design for slope reinforcement to be more rational, it is proposed that not only the improved cohesive strength is to be used in the incremental ranges on well-known previous proposed data, but also the increased elastic modulus which is about 5 times as large as the original elastic modulus is to be considered in design.

• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.5
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• pp.991-1001
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• 2001

This study has examined effects of protease on the removal of hemoglobin and triolein mixed soil with changes of soil content and soil composition from cotton and PET filament fabrics. The results obtained were as follows: The results obtained were as follows: 1) The detergency of PET fabrics was higher than that of cotton fabrics. The removal of hemoglobin was much higher than that of triolein from cotton fabrics, while the removal of hemoglobin was similar to that of triolein from PET fabrics. 2) The removal efficiency of hemoglobin and triolein was improved by protease from cotton and PET fabrics. Especially the removal efficiency of those was remarkably improved from cotton fabrics which the removal of soil was lower than PET fabrics. And the removal of hemoglobin and triolein by adding protease was increased with increase of hemoglobin content of mixed soil from cotton fabrics. 3) With the increase of hemoglobin content of mixed soil, the removal of hemoglobin was drastically increased but the removal of triolein was slightly decreased from cotton and PET fabrics. With the increase of triolein content of mixed soil, the removal of hemoglobin and triolein was decreased from cotton fabrics, but those were generally increased from PET fabrics.

• Textile Coloration and Finishing
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• v.13 no.2
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• pp.18-18
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• 2001

This study has examined the removal of mixed soil of protein and fat by protease. Cotton and PET fabrics were soiled by spotting of hemoglobin and triolein, respectively. The soiling order and soil concentration were changed in this procedure. The soiled fabrics were aged at 130℃ for 20 minutes. Protease was added in the alcohol ethoxylate(AE) detergent solution. The removal effciency was evaluated by analysis of protein and/or fat on the fabrics before and after washing, respectively. The detergency of PET fabrics was higher than that of cotton fabrics. The removal efficiency of hemoglobin was improved by protease from cotton and PET fabrics. Especially the removal efficiency of hemoglobin was remarkably improved from cotton fabrics. With the increase of hemoglobin and triolein (1:1) mixed soil, the removal of mixed soil was increased in proportion to mixed soil content up to a certain point. but it began to decrease above the point from cotton fabrics, while it was generally increased from PET fabrics. The detergency of total mixed soil from cotton fabrics was higher in case of soiling order with triolein after hemoglobin than in case of soiling order with triolein before hemoglobin. But the soiling order was not greatly effected in the detergency of total mixed soil from PET fabrics.

• Textile Coloration and Finishing
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• v.13 no.2
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• pp.104-113
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• 2001

This study has examined the removal of mixed soil of protein and fat by protease. Cotton and PET fabrics were soiled by spotting of hemoglobin and triolein, respectively. The soiling order and soil concentration were changed in this procedure. The soiled fabrics were aged at $130^\circ{C}$ for 20 minutes. Protease was added in the alcohol ethoxylate(AE) detergent solution. The removal effciency was evaluated by analysis of protein and/or fat on the fabrics before and after washing, respectively. The detergency of PET fabrics was higher than that of cotton fabrics. The removal efficiency of hemoglobin was improved by protease from cotton and PET fabrics. Especially the removal efficiency of hemoglobin was remarkably improved from cotton fabrics. With the increase of hemoglobin and triolein (1:1) mixed soil, the removal of mixed soil was increased in proportion to mixed soil content up to a certain point. but it began to decrease above the point from cotton fabrics, while it was generally increased from PET fabrics. The detergency of total mixed soil from cotton fabrics was higher in case of soiling order with triolein after hemoglobin than in case of soiling order with triolein before hemoglobin. But the soiling order was not greatly effected in the detergency of total mixed soil from PET fabrics.

• Geomechanics and Engineering
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• v.38 no.4
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• pp.353-366
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• 2024

Organic soils pose significant challenges in geotechnical engineering due to their high compressibility and low stability, which can result in issues like differential settlement, rutting, and pavement deformation. This study explores effective methods for stabilizing organic soils. Rather than conventional ordinary Portland cement (OPC), the focus is on using environmentally friendly calcium sulfoaluminate (CSA) cement, known for its rapid setting, high early strength development, and environmental benefits. Mechanical behavior is analyzed through 1-D free swell, unconfined compressive strength (UCS), and bender element (BE) tests. Microstructural analyses, including Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), characterize the soil mixed with CSA cement. Experimental results demonstrate improved soil properties with increasing cement dosage and curing periods. A notable strength increase is observed in soil samples with 15% cement content, with UCS doubling after 7 days. This trend aligns with shear wave velocity results from the BE test. SEM and FTIR spectroscopy reveal how CSA cement hydration forms hydrated calcium silicate gel and ettringite, enhancing soil properties. CSA cement is recommended for reinforcing organic subgrade soil due to its eco-friendly nature and rapid strength gain, contributing to improved durability.

• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.5
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• pp.107-113
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• 2000

The purpose of this study is to investigate the effects of soil amendments for reducing soil compaction at heavy traffic area in golf course. Major results of this research are summarized at follows: 1. In the Lab. experiment, the porosity was improved significantly when the materials, such as peatmoss, charcoal, and tire chip mixtures were used respectively. Especially mixture of sand and 20% peatmoss showed higher effectiveness (10%) in porosity, comparing with ordinary sand. This soil mixture(sand 80%+peatmoss 20%) was observed the best in water retention, soil hardness and hydrauric conductivity. 2. In the greenhouse experiment, traffic pressure was given 7 times a day on several combination of mixture treatments to see the top dry weight. The soil mixture of 20% peatmoss showed the highest in the top dry weight. When the more traffic pressure(15 time/day) were given on the different treatment, the top dry weight was significantly reduced. However, the mixture of 20% peatmoss also had the least influence on this type of heavy traffic. 3. In the field experiment, the soil amendments were treated in traffic area f golf course, and observed at 30days, 60days, 90days, 120days after treatment. Visual turf quality(color), root length and soil compaction were compared to those of control. As a result, overall treatments with soil amendments were effective, which showed better turf quality and less soil compaction. 4. In the field test, physical characters of soil (such as soil hardness and hydrauric conductivity) in sand+tire chip+peatmoss(60:20:20, %, v/v) treatment was significantly improved. Also in the slow increasing of traffic, the soil compaction was the most effective in reducing soil hardness.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.1 no.1
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• pp.18-27
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• 1998

To investigate the restoration progression on soil physical properties and vegetation at the surface of logging road affected by timber harvesting operation. This study was carried out at logging roads constructed from 1989 to 1994 in Mt. Baekwoon, Kwangyang, Chollanam-do. Judging from the analysis of soil hardness, there were significant changes in the depth of soil between 5 and 10cm. Soil hardness was recovered from the compacted condition to the natural forest condition after 9 years passed. Soil macroporous ratio (pF2.7) of topsoil was higher than that of deep soil. Soil moisture retention of topsoil was more improved than that of deep soil. From the view of soil bulk density, the necessary time for recovering to the undisturbed condition of forest soil was about 10 years in the logging road left. Soil physical properties such as soil bulk density and porous ratio were recovered as time passed. Improved soil physical properties promoted the plant recovery on the logging road surface. The dominant species on the logging roads were Comus kousa, Prunus sargentii as overstory species, Rubus crataegifolius, Lespedeza bicolor as understory species, and Saussurea gracilis, Pteridium aquilinum var. latiusculum as herbaceous species. The plant recovery of bank-slopes was faster than that of cut-slopes and road surface. In progress of year, average plant coverage were 70 to 90% in cut- and bank-slopes and 30 to 60% on the logging road, surface which was elapsed 9 years after logging road construction. Therefore, additional planting and seeding work could be effective to the soil condition and vegetation restoration.

• Journal of Industrial Technology
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• v.22 no.B
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• pp.211-218
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• 2002

The paper is to show the behavior of composit ground which is installed with sheet pile in soft soil improved by sand compaction pile. The results of load-settlement relationship, earth pressure, stress concentration characteristics, and final water content were obtained by centrifuge model test. Two cases of tests, installation of sheet pile on the corner and both side of the loading plate for the improved SCP ground which was designed twice of the footing width, were performed for the tests under the vertical and horizontal loading and both side of corner. Finite element program(CRISP) for sand compaction pile using elasto-plastic model and numerical analysis for soft soil using modified cam-clay constitutive equation were compared and analized with the results of model tests. The result of analysis show the increased bearing capacity of soil after, SCP and sheet pile was installed.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.4
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• pp.311-324
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• 1992

Polymeric substances in organic matter of soils aggregate soil particles into a crumb structure which greatly influences such properties as water movement, aeration and heat transfer. Poorly-structured soils may be improved by the incorporation of synthetic polymers where the main objects are : promoting germination or establishing crops, improving drainage, combating wind and water erosion, and reducing evaporation from the surface of soil under arid condition.