• Korean Journal of Environment and Ecology
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• v.20 no.4
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• pp.425-435
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• 2006

The objectives of this research were to investigate the drought resistance as well as the growth of Wisteria floribunda seedlings with the soil water conditions. The seedlings for the research were grown in pots with strict water content control on a frame located outdoors. During the experiments, the soil water contents were adjusted to 5, 10, 20, 30, 40, 50, 60, and 70%. In addition, the effects of Rhizobium inoculation on the growth of seedlings were investigated. The experimental results are summarized as follows: 1. The seedlings in the pots with 5% soil water content withered to death due to the water stress. Withering or any distinct growth was not observed from the seedlings in the 10% soil water content. It can be inferred from these results that about 5% of soil water content is the wilting point of W. floribunda seedlings and about 10% is the critical soil water content of its growth in this experiment soils. Therefore, it seems that W. floribunda possesses a good drought resistance. 2. From the analyses of the main growth parameters such as stem elongation, diameter growth, leaf area growth and total dry weight, it was found that the seedling growth can be improved with increasing soil water contents. The relation between each growth parameter(Y) and the soil water contents(W) was well described by a quadratic equation, $Y=a+bW+cW^2$. 3. In soil water contents higher than 20%, the seedling growth(Y) was remarkable along with-its extended growing period, and related to the growing period(D) by a quadratic equation, $Y=a+bD+cD^2$. 4. The artificial inoculation of Rhizobiun promoted the growth of Wisteria floribunda seedlings. 5. Rhizobium was found to be more readily inoculated and to form more root nodules compared to seedlings grown in higher soil water contents.

• Journal of Applied Biological Chemistry
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• v.55 no.2
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• pp.129-133
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• 2012

To exploit plant growth promoting bacteria in the roots of Miscanthus sacchariflorus, a biomass energy crop, total 64 bacteria were isolated. For the investigation of plant growth promoting effects from the isolated bacteria, production of indole acetic acid (IAA) and 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activities were tested and other cultural conditions were examined. As results, 8 isolates showed plant growth promoting effects on the M. sacchariflorus and an isolate designated Agrobacterium sp. BE516 has the highest activity by enhancing the shoot elongation over 2-fold than the control. Agrobacterium sp. BE516 produced 64 ${\mu}g$ IAA per mL and showed ACC deaminase activity which is involved in the resistance to environmental stress such as high salt and drought. It could grow at low temperature in the range from 4 to $15^{\circ}C$, at pH 4.0 and at 4% NaCl. These results indicate that the Agrobacterium sp. BE516 can be useful as a bio-fertilizer for M. sacchariflorus under the stressed conditions.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.6
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• pp.727-731
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• 2009

Effects of various plasticizers (1.5%) such as glycerol, sorbitol, fructose, sucrose, and polypropylene glycol, and ferulic acid on the physical properties of Gelidium corneum (GC) film were examined. GC films containing plasticizer and ferulic acid were prepared by incorporating various amounts (10, 30, 50, 70, 100 mg/100 mL) of ferulic acid into the film. Water vapor permeability (WVP) of the GC film varied depending on the type of plasticizer, and among them the film containing sucrose had the lowest WVP. Tensile strength (TS) and % elongation (%E) of the film were in the range of $1.29{\sim}11.29$ MPa and $5.55{\sim}36.44$ %, respectively, and the WVP values were of $1.30{\sim}1.60\;ng\;m/m^{2}sPa$. In addition, the GC films were prepared using ferulic acid as a cross-linking agent. WVP of the film decreased with the addition of ferulic acid, and the film containing 30 mg ferulic acid had the lowest WVP value. TS value of the GC film containing 10 mg of ferulic acid was significantly higher than that of the control. However, further increase of ferulic acid concentration decreased the TS value. Therefore, 10 mg of ferulic acid was determined to be the optimal concentration for the film.

• Steel and Composite Structures
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• v.30 no.6
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• pp.551-565
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• 2019

A total of 36 carbon steel and stainless steel bolted connections subjected to shear loading at different strain rates was experimentally investigated. The connection specimens were fabricated from carbon steel grades 1.20 mm G500 and 1.90 mm G450, as well as cold-formed stainless steel types EN 1.4301 and EN 1.4162 with nominal thickness 1.50 mm. The connection tests were conducted by displacement control test method. The strain rates of 10 mm/min and 20 mm/min were used. Structural behaviour of the connection specimens tested at different strain rates was investigated in terms of ultimate load, elongation corresponding to ultimate load and failure mode. Generally, it is shown that the higher strain rate on the bolted connection specimens, the higher ultimate load was obtained. The ultimate loads were averagely 2-6% higher, while the corresponding elongations were averagely 8-9% higher for the test results obtained from the strain rate of 20 mm/min compared with those obtained from the lower strain rates (1.0 mm/min for carbon steel and 1.5 mm/min for stainless steel). The connection specimens were generally failed in plate bearing of the carbon steel and stainless steel. It is shown that increasing the strain rate up to 20 mm/min generally has no effect on the bearing failure mode of the carbon steel and stainless steel bolted connections. The test strengths and failure modes were compared with the results predicted by the bolted connection design rules in international design specifications, including the Australian/New Zealand Standard (AS/NZS4600 2018), Eurocode 3 - Part 1.3 (EC3-1.3 2006) and North American Specification (AISI S100 2016) for cold-formed carbon steel structures as well as the American Specification (ASCE 2002), AS/NZS4673 (2001) and Eurocode 3 - Part 1.4 (EC3-1.4 2015) for stainless steel structures. It is shown that the AS/NZS4600 (2018), EC3-1.3 (2006) and AISI S100 (2016) generally provide conservative predictions for the carbon steel bolted connections. Both the ASCE (2002) and the EC3-1.4 (2015) provide conservative predictions for the stainless steel bolted connections. The EC3-1.3 (2006) generally provided more accurate predictions of failure mode for carbon steel bolted connections than the AS/NZS4600 (2018) and the AISI S100 (2016). The failure modes of stainless steel bolted connections predicted by the EC3-1.4 (2015) are more consistent with the test results compared with those predicted by the ASCE (2002).

• Journal of the Korean Wood Science and Technology
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• v.47 no.3
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• pp.299-310
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• 2019

This study was carried out to investigate the effect of heat-treatment and particle size on the crystalline properties of the wood cellulose. The color of wood flours was changed from light yellow in control sample to dark yellow or deep brown by heat treatment at $100^{\circ}C$ to $200^{\circ}C$. Relative crystallinity of the heat treated wood cellulose decreased with decreasing particle size from wood chips to 200 mesh, and there was little change in the crystal width. As the temperature was increased, relative crystallinity of the wood increased and crystal width was not changed. As a result of the FT-IR analysis, it was confirmed that the peaks were gradually decreased at -OH elongation as the heat-treated temperature was increased. The lignin C-H bending of $1425cm^{-1}$ and the hemicellulose C-H bending of $1370cm^{-1}$ did not change with the increase of the heat treatment temperature. In addition, it was revealed that C-C stretching of carbohydrate near $1031cm^{-1}$ decreased with increasing heat treatment temperature. Consequently, it is suggested that particle size and heat treatment affected the crystalline properties of wood cellulose.

• Journal of Practical Agriculture & Fisheries Research
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• v.22 no.1
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• pp.99-112
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• 2020

A edible mushroom, Hypsizygus marmoreus is commercially cultivated. However, the researches of cultivation and physiological characteristics were not conducted in Korea. In this study, we conducted on artificial cultivation of H. marmoreus and elucidated the effect of light on the mycelial growth and fruit body development using LED light sources with different wavelength; blue (peak wave length 460nm), green(peak wave length 530nm), yellow(peak wave length 590nm), red(peak wave length 630nm), and white as positive control. Mycelial growth of H. marmoreus strains were inhibited about 30~40% in inhibition ratio under the illumination with blue, green, yellow LED light. However, red LED light was not inhibited. Elongation of stipe was effective under the long wave length such as yellow and red light. Abnormal fruit body was produced under the long wavelength and dark. However, development of pileus was effective under the short wavelength such as green and blue light. Also, as a result of cultivation with mixed light for high quality and harvest, many effective numbers and yields of fruiting bodies were obtained in the mixed treatment of blue and white light, and pileus developed well.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5A
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• pp.487-494
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• 2009

Friction coefficients of the prestressing tendon are the basic information required to control the prestressing force introduced to PSC structure during jacking. However, the friction coefficients show considerable differences depending on the specifications, causing much confusion to designers. In this study, the ranges of the friction coefficients presented in domestic and foreign specifications are compared together to clarify the differences. Then, a procedure is proposed that can be used to estimate the wobble and curvature friction coefficients from field data such as elongation and prestressing force and from theory related to the friction. The procedure is applied to various tendon profiles of several PSC bridges constructed by ILM, FCM and MSS. The resulting values are compared with those presented in some specifications and assumed in jacking and a reasonable range of the friction coefficient is discussed. Lift-off tests are also performed in some bridges to further verify the results. The resulting wobble friction coefficients are not as small as those presented in AASHTO specifications but range from the lower limit to mid point of domestic specifications, while the curvature friction coefficients approach or slightly exceed the upper limit.

• Journal of Korean Society of Forest Science
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• v.100 no.3
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• pp.432-440
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• 2011

The objective of this study was to investigate growth and fruiting characteristics (e.g., nut qualities) of chestnut (Castanea cerenata) after applying various fertilizer treatments at the cultivation site in Suncheon. Fertilizer treatments were designed as follow: liquid fertilizer, chemical fertilizer, organic fertilizer, and control. Both liquid and chemical fertilizer treatments provided the best growth in height and basal diameter. In addition, these two treatments were very effective for crown width of the trees between both east-west and north-south orientation. The liquid fertilizer treatment was effective on total length of the fruiting branch and length of the bearing to terminate part. Both liquid and chemical fertilizer treatments produced the longest length of basal to bearing part compared to the other two treatments. The liquid fertilizer treatment showed the most thickened basal diameter of the fruiting branch and the greatest diameter of above and below the bearing burr part. Elongation Index of the fruiting branch (EI) was the highest with liquid fertilizer treatment and the remaining four indices (Production Index of fruiting branch, PI; Ratio of Diameter between below and above bearing burr part, RD; Growth Index of fruiting branch diameter, GI; Thickness Index of fruiting branch or dormant branch, TI) were the highest with the chemical fertilizer treatment. Total number of produced branch per fruiting mother branch and number of small and weak branches per fruiting mother branch were highest on the control and liquid fertilizer treatment; however, all treatments produced similar numbers. The chemical and organic fertilizer treatments produced a high number of fruiting branches per fruiting mother branch, while organic and liquid fertilizer treatments produced a high number of burr per fruiting branch. The rate of commercializing on the basis of nut weight and quantity was higher on control (87.5%) than chemical fertilizer treatment (84.6%); however, the rate was even lower on liquid fertilizer treatment (84.3%) and organic fertilizer treatment (82.7%). The liquid fertilizer treatment showed the highest average of nut weight, while chemical fertilizer treatment showed the highest average number of fruiting burr. There was no significant difference in average number of normal nuts per burr among treatments. The yield per tree was high on chemical (8.2 kg) and liquid (8.0 kg) fertilizer treatments, but there was no significant difference among treatments. In the rate of nut grade on the basis of nut weight and quantity, the liquid fertilizer treatment, 43.5% and 34.3% more than large nut respectively, produced higher value chestnuts compared to other treatments.

• Journal of Korean Society of Forest Science
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• v.19 no.1
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• pp.1-23
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• 1973

The results of ground vegetation experiment conducted at completely denuded forestland in the mudstone region are summerized as follows: On the reaults of soiling quantity the effect of soiling was observed where depth of soiling over 10 cm was practiced, and a plot where treated with 15cm soiling and without fertilizer showed poor growth and it was even worser than the plot where soiling was practiced only 1 cm in thikness but applied adequate amount of fertilizers. The depth of slits between 30cm and 40cm showed no significant difference in the effect. A plot where covered with vegetation bag showed somewhat better results in seed loss and early growth but no differences observed in the fall result over the none covered plot. And then, it is recommendable to have soiling over 10cm in thikness with slit of 30cm and 30cm in depth and to apply 30 gram of fertilizer (22;22:11, 50 gram) per slit. On various soiling materials trial there were no striking differences in the effect of soiling between weathered granite soil, wheathered tuffs soil and weathered mudstone soil. In the treatment with various green materials, a plot treated with straw mat showed a significant difference at 1 percent. The results show that weathered mudstone soil is effective to use as soiling materials and straw mat treatment was better. On forest fertilization trial, in the mudstone region where red and black pine trees already existing at a rate of 2,000-3,000 trees per hectare had applied 110kg of compound fertilizers (9:12:3 and 22:22:11) per hectare basis in terms of plant nutrient. As a result, the difference in effect between the compound fertilizers was not found however the leaf color and leaf length of the fertilizer added plot showed darker and longer at 30 percent over the no fertilizer received plot. Compound fertilizers, 14:37:12 and 9:12:3 were applied to alder trees at a rate of 20 gram and 40 gram per tree in terms of plant nutrient and a remarkable growth accelerantion was observed where 40 grams of plant nutrient applied. The effect difference between the compound fertilizers was not found. On investigation of tree root elongation, forty years old red pine trees showed only 15cm tap root elongation through mudstone while black pine had 23 cm tap root elongation. The total length of supporting root elongtion of red and black pines showed 20 and 13 meters, respectively. The tap roots of Black locusts were not able to elongate through mudstone, however, the supporting roots tended to develop to the underneath of pine tree where some moisture content is available. Black locusts And grown on the residual soil of mudstone normally die between 8 to 10 years. The red pine trees show flat in tree shape while black pine had triangle in the shape. With the results it can be said that in an artificial reforestation in denuded forest land of the mudstone region the adequate slit and enough amount of fertiliizer application must be provided for the succesful performance of the program. On integrated experimental results of 1972. for the establishment of ground vegetation on the completely denuded forest land in mudstone region, soiling could be effectively practiced with weathered mudstone soil and it would not specially necessiate to have either weathered granite or tuffssoil for the soiling. And the soiling depth should be more than 10 cm in thickness. Among green materials used the straw mat proved to be the most effective reatment. Three major factors which enable to establish ground vegetation by the shortest period of time: A. Physical improvement of soil is necessary to breakdown of the horizontal cracks sushas Slit, contour line plot, seeding hole and etc., and soiling with weathered mudstone soil. B. Chemical improvement of soil: is needed sufficient amount of fertilizer application 300~400kg ha, $N+P_2O_5+K_2O$), and increased production of ground covering and expedite resolution of the vegetation (ground vegetation, fallen leaves and twigs). C. Complete establishment of the basic structure for the erosion control (Prevention of surface soil erosion)

• Korean Journal of Environmental Agriculture
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• v.36 no.3
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• pp.193-200
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• 2017

BACKGROUND: Plant growth under smart greenhouse (that is plant factory system) conditions of an artificial light type is significantly depending on the artificial light sources such as a fluorescent lamps or Light-Emitting Diodes (LEDs) with specific spectral wavelengths regardless of the outside environmental changes. In this experiment, characteristics on the growth and compound synthesis of kale seedlings affected by light qualities and intensities provided by LEDs were mentioned. METHODS AND RESULTS: The kale seedlings which developed 3~4 true leaves were exposed by fluorescent lamps or LEDs lights of red (R), blue+white (BW), blue+red (BR) with 50 (L) or $100(H){\mu}mol/m^2/s^1$ photosynthetic photon flux (PPF) under hydroponic culture system of deep flow technique for 50 days. Shoot fresh weight increased under the RH, BWH, and BRH treatments with higher PPF. Shoot elongation of the seedlings decreased, and polyphenol synthesis promoted by the higher light intensity conditions. Sugar synthesis in the leaves was above 2 times greater under the RH treatment of monochromic red light quality with $100{\mu}mol/m^2/s^1\;PPF$ than $50{\mu}mol/m^2/s^1\;PPF$. CONCLUSION: The results show that the control of light quality and intensity in the smart greenhouse conditions with artificial lights significantly affects the growth and compound synthesis in the fresh kale leaves with higher culture efficiency compared to the conventional soil culture under greenhouse or field conditions. Researches on the optimum light intensities of the LEDs with special spectral wavelengths are necessary for maximum growth and metabolism in the seedlings.