• Journal of the Korea Organic Resources Recycling Association
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• v.10 no.1
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• pp.61-67
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• 2002

Sawdust, peat, and sawdust+peat were used as bulking agent in the compost production process using three different origin of manure; cow, pig, and chicken. The organic content and individual N, P, K content of the final manure compost were higher when peat or peat+sawdust were used to control the moisture. The carbon to nitrogen ratio and moisture content were low when peat or peat+sawdust were employed. In the case of cow and pig manure compost produced with peat or peat+sawdust, beneficial microorganism content was also higher than that of the manure samples produced with sawdust only. These results indicate that peat can be a useful component in the production of high quality manure compost.

• Journal of Environmental Health Sciences
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• v.24 no.2
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• pp.118-125
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• 1998

This study investigates the react characteristics to suggest the condition of the utilization and disintegration of food garbage as composting by varying the supply amount of air of the fermentation reactors. With the initial temperature and agitation velocity maintained 50$\circ$C and 1 rpm, the supply amount of air gives variety to 0.5, 1, 2, 4 l/kg$\cdot$ min. In the case of the amount of air operated at the 0.5 l/kg$\cdot$ min, reaction temperature shows a rising to the maximum 66$\circ$C after the 48hr, and the oxygen used rate of the micro-organisms shows the largest level at 18.4% after the 8hr. In the case of $NH_3, H_2, H_2S$ and SO$_2$ among the react gas, the sanitary utilization shows the possibility of the microorganisms gas disintegration, with most high gas generate rate. In the case of the amount of air operated at the 1, 2 and 4 l/kg$\cdot$ min, initial react was advanced rapidly and the product of the 72 hr after shows big weight reduction. As the experimentation result, when the amount of air operated at the 1 l/kg$\cdot$ min over, the reduction by disintegration would be more effectively, for the reactor maintains the color tone and shape of the straw (bulking agent).

• Journal of the Korea Organic Resources Recycling Association
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• v.4 no.2
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• pp.19-25
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• 1996

A fundamental study on composting garbage was performed in a laboratory scale of a high-speed composting reactor. Major parameters were moisture content, temperature and C/N ratio. The results are as follows; pH of the compost was the highest at moisture 60% and anaerobic condition occurred at 70%. It was, also, found that C/N ratio, caused a nitrogen loss due to an occurrence of plentiful $NH_3$. Under controlling Temperature, pH was the highest at $60^{\circ}C$ and an inverse effect for Composting occurred under excessive Temperature as pH at $70^{\circ}C$ was lower than that of soil. The variation of pH and C/N ratio was the lowest when C/N ratio was 25. The results obtained from composting garbage revealed that the best condition of composting occurred under 50 to 60% of moisture content, $60^{\circ}C$ of temperature, and 25 of C/N ratio. It is believed that composting may be finished with in 56 hours if an optimal condition is setting up.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.89-94
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• 2004

A steel plated is typically composed of plate panels. The overall failure of the structure is certainly affected and can be governed by the bulking and plastic collapse of these individual members. In the ultimate limit state design, therefore, a primary task is to accurately calculate the buckling and plastic collapse strength of such structural members. Structural elements making up steel palated structures do not work separately, resulting in high degree of redundancy and complexity in contrast to those of steel framed structures. To enable the behavior of such structures to be analyzed, simplifications or idealizations must essentially be made considering the accuracy need and degree of complexity of the analysis to be used. Generally the more complex the analysis the greater is the accuracy that may be obtained. The aim of this study is the investigation of the effect of the tripping behaviour including section characteristic for a plate under uniaxial compression. For this purpose of study, in used elasto-plasticity deformation FEA method are used for this study.

• Journal of Bio-Environment Control
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• v.2 no.1
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• pp.16-26
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• 1993

A sundry system is one of popular systems for composting livestock manure, of which main honest is to utilize unlimited, clean, and free solar radiation. A sundry system with a composter of two horizontal screw-type concrete ducts at different height, was constructed and operated for three days for each test in May, 1993, to evaluate its composting performance. Four treatments of the mixture ratio of swine manure and saw dust (manure : sawdust= 1 : 1.25, 1 : 1, 1 : 0.7, 1 : 0.5) were implemented to evaluate the effect of the mixture ratio on degradation of the composting materials of a sundry system with a screw-type composter. Maximum temperature of the composting materials was over 5$0^{\circ}C$ at D1 or D2 (one or two days after operation starts) for each test. Mean C/N ratio and water contents of the materials were reduced by more than 15 and 20％, respectively. Microbial density of each test showed a typical variation with the lapse of the composting time. Mesophilic microorganism seemed to play more important role on degradation of the materials than thermophilic. A sundry system with a screw-type composter can be considered as a feasible system on basis of maturity data. The conclusion was completely reverse from that of Choi et at., although both adopted a sundry system. A further study is recommended to pursue the cause of better performance of the screw-type composter, whether it was due to affirmative weather or more efficient composter.

• Journal of the Korean Wood Science and Technology
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• v.51 no.1
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• pp.1-13
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• 2023

Sengon (Falcataria moluccana Miq.) tree offers a wood of low quality and durability owing to its low density and thin cell walls. This study aimed to improve the properties of sengon wood by making the wood magnetic, producing new functions, and characterizing magnetic sengon wood. Each wood sample was treated using one of the following impregnation solutions: Untreated, 7.5% nano magnetite-furfuryl alcohol (Fe₃O₄-FA), 10% nano Fe₃O₄-FA, and 12.5% nano Fe₃O₄-FA. The impregnation process began with vacuum treatment at 0.5 bar for 2 h, followed by applying a pressure of 1 bar for 2 h. The samples were then tested for dimensional stability and density and characterized using scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM-EDX), Fourier transform infrared spectrometry (FTIR), X-ray diffraction (XRD) analysis, and vibrating sample magnetometry (VSM) analysis. The results showed that the Fe₃O₄-FA impregnation treatment considerable affected the dimensional stability, measured in terms of weight percent gain, anti-swelling efficiency, water uptake, and bulking effect, as well as the density of sengon wood. Changes in wood morphology were detected by the presence of Fe deposits in the cell walls and cell cavities of the wood using SEM-EDX analysis. XRD and FTIR analyses showed the appearance of magnetite peaks in the diffractogram and Fe-O functional groups. Based on the VSM analysis, treated sengon wood is classified as a superparamagnetic material with soft magnetic properties. Overall, 10% Fe₃O₄-FA treatment led to the highest increase in dimensional stability and density of sengon wood.

• Advances in environmental research
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• v.12 no.1
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• pp.51-64
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• 2023

The sustainable management of rice straw is essential for protection of human health and environment. This study assesses the impact of stock density of earthworm (Eisenia fetida) and Neem leaves (Azadirachta indica) on the quality of the final vermicompost. The vermicompost is produced using different combinations of rice straw, Neem leaves, and cow dung (bulking agent) by varying stock density of earthworms. The vermicomposting experiments are performed in plastic containers (32 cm × 28 cm × 28 cm) in open for 90 days under laboratory conditions. The stock density of the earthworm is found to be an important factor to influence nutritional quality of the final vermicompost. There is observed significant improvement in the total nitrogen (91.8%), phosphate (73.4%), potassium (38.8%), and calcium (59.05%) content of the vermicompost produced with the highest stock density of the earthworms. All the treatments showed decrease in TOC and C:N content after 90 days of vermicomposting. The treatment with Neem leaves showed maximum growth of earthworms (2.65 fold). Neem leaves brought positive changes in the quality of final vermicompost by enhancing the growth and reproduction of the earthworms. The calcium content increased by 39% in the final vermicompost with the addition of Neem leaves at the same stock density of the earthworms. The stock density of the earthworms and Neem leaves are found to significantly improve quality of the final vermicompost as compared with the compost (control). The surface morphology in SEM images showed high degree of fragmentation in the vermicompost as compared with the compost. The combined action of microbes and earthworms resulted in high degree of disintegration in the vermicompost.

• Journal of Bio-Environment Control
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• v.23 no.3
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• pp.256-261
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• 2014

This study was carried out to determine the effect of the artificial pollination on fruit set, seed formation and fruit quality in kiwifruit and to confirm the effective pollination time for optimal fruit set in the shelter greenhouse cultivation. Also, the effect of artificial pollination practice by the pollen diluent solution was tested. By artificial pollination, fruit set, seed formation, and fruit quality was improved both in the open field condition and in the shelter greenhouse cultivation. In order to find the effective pollination period (EPP), artificial pollination was carried out every day until 7 days after full bloom. Number of seeds and fruit set rate and fruit growth of kiwifruit were no significantly different until 4 days after full bloom (DAFB), but, those of kiwifruit from 5 DAFB significantly decreased. Consequently, the effective pollination period of kiwifruit in the shelter greenhouse was 4 days after full bloom. Also, artificial pollination by the pollen diluent solution was showed the similar fruit set and fruit quality compare to that by lycopodium powder. Accordingly, artificial pollination by the pollen diluent solution should be very effective practice for labor saving in kiwifruit cultivation.

• Journal of Nutrition and Health
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• v.25 no.6
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• pp.450-460
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• 1992

The study was performed to investigate the effect of corn bran as a fiber source on the utilization of thiamin niacin and pantothenic acid in human subjects for 8 weeks. Four different corn bran diets were fed : dry milled fine(DF) dry milled coarse(DC) wet milled fine(WF) and wet milled coarse(WC) Basal diet no corn bran bread added was employed as a control Apparent recovery of each B complex vitamin in urine was estimated to evaluate the vitamin and compared. The utilziation of three B vitamins was affected by the corn bran treatment. Dry milled corn bran had a higher recovery rate of thiamin(dry milled : 233% wet milled : 1.70%) than those receiving wet milled corn bran. Similar recovery pattern of niacin(dry milled : 1.94% wet milled : 1.50%) to that of thiamin was also observed. Particle size seemed to affect the vitamin utilization regardless of type of corn bran. Coarse bran gave a lower recovery value than fine corn bran in genreral. For pantothenic acid the recovery of the vitamin was affected to a greater extent by particle size of corn bran than by type of corn bran milling(fine: 60.22% coarse : 51.51%) Groups consuming wet milled corn bran\ulcorner(5`.57%) excreted more NDF than those fed dry milled corn bran(42.29%) Dry milled corn bran showed little or no water holding capacity poor fecal bulking properties and increased fecal transit time. The results suggest that corn bran supplementation exerts an negative effect on three B vitamin utilization.

• Journal of the Korean Wood Science and Technology
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• v.3 no.1
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• pp.3-15
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• 1975

How to stabilize wood against shrinking and swelling in variable atmospheric moisture conditions is important to the wood-using industry and a challenge to research. Polyethylene glycol stabilize wood by bulking the fiber. PEG also serve as a chemical seasoning agent, suppress decay in high concentrations, and have slight effect on physical properties, gluing or finishing. The study designed to determine the effect of PEG-400 on the dimensional stabilization of local hardwoods for wood carvings that could supply a greatly expanding tourist trade and making curved furniture parts, lamp stands and other decorative objects, and possible gunstock. The species examined were 6 species, Seo-Namoo (Carpinus laxiflora), Cheungcheung-Namoo (Cornus controversa), Gorosae-Namoo (Acer mono), Karae-Namoo (Juglans mandshurica), Jolcham-Namoo (Quercusserrata) and Sanbud-Namoo (Prunus sargentii), used as block of 5cm thick radially to the grain, 7cm wide tangentially, and 70cm long parallel to the wood grain. All these test piecies were conditioned above the fiber saturation point before impregnation. The stabilization effects were determined for PEG-400 treated woods in a 50 percent solution for 20 days. The following conclusions were obtained. PEG retentions increased with treating time. It was more effective to treat at 60$^{\circ}C$ than at room temperature. In degree of PEG-400 impregnation on species, Cheungcheung-Namoo havinglow specific gravity had the highest retentions, 68.77% but the lowest, 56.33% was shown in Jolcham-Namoo with high specific gravity. Specific gravity of treated wood increased considerably with effectiveness of polymer loading. The increases in specific gravity were 5.36 to 13.16 percent. The highest was Jolcham-Namoo, the lowest Karae-Namoo. On the dimensional stability, a 40 percent of effectiveness of polymer loading was just as effective as 60 percent in reduction in water absorptivity (RWA), antishrinkage efficiency (ASE) and antiswelling efficiency (AE), and from over 60 percent they increased more rapidly. Also species response varied considerably. ASE was 30.12 to 69.97 percent tangentially and 27.86 to 56.37 percent radially, AE 34.06 to 73.76 percent tangentially and 30.11 to 70.12 percent radially, and RWA 42.31 to 65.32 percent. No differences in volume swelling among the 6 species were observed. Its values were ranged from 14.98 to 19.55 percent and also increased with PEG retentions. On the mechanical properties, the strengths very much decreased with PEG-400 loadings as shown in Figure 12; that were 11.41 to 22.90 percent in compression, 21.61 to 34.35 percent in bending and 22.83 to 36.83 percent in tensile strength. PEG retention in cell wall was less than 1 percent and the most of PEG were immersed in cell lumen. Except for Korae-Namoo, effectivenesses of polymer loading were as much high as 61.58 to 75.02 percent. This is believed to be due to the effect of PEG-400 on excellant dimensional stability of treated woods.