• The Korean Journal of Food & Health Convergence
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• v.6 no.1
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• pp.17-20
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• 2020

Wheat is the most abundant crop in the world, accounting for one third of the world's population diet. In Ukraine, wheat is in fact, in addition to its nutritional value, a national symbol of the state. Therefore, the main thesis on the development of modern plant growing in Ukraine is the reduction of costs and the introduction of innovative technologies. The quality of grain and seed depends on many factors, namely: agro-climatic conditions, sowing condition of the seed material, quality characteristics of the soil, yielding properties of seeds, pre-sowing seed treatment. etc. For this purpose, the photosynthesis and intensity of photosynthesis need to be limited to the width of the leaf and the height of the leaves by a smaller cut of the stem. It is extremely important to ensure that the head and side pagons of wheat are in good condition. All parameters are often secured by the technology of grain preparation before delivery. Prior to this technology, it is possible to introduce processing of the material in the form for the development of the material. This article presents the effectiveness of the use of infrared irradiation for the pre-sowing treatment of winter wheat seeds in Sekobra Research, Germany.

• Geotechnical Engineering
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• v.12 no.3
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• pp.99-108
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• 1996

The physical and chemical properties of polyurethane-yieding twofomponent liquid injection mixture and those of the resulting polyurethane solid foam for chemical grouting are investigated. The chemical experiments on the factors influencing the properties of polyurethane show that the behaviors of polyurethane-yielding liquid material and those of the produced polyurethane solid foam are greatly affected by the ground conditions such as temperature, water content and density of soil. The ground reinforcing and water -blocking effects of polyurethane grouting are examined through field case history of tunnel ericavati on of the subway under construction.

• Korean Journal of Materials Research
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• v.18 no.1
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• pp.12-17
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• 2008

Carbon nanotube (CNT) cathodes were fabricated using nano-sized silver (Ag) powders as a bonding material between the CNTs and cathode electrodes. The effects of the powder size on the sintering behavior, the current density and emission image for CNT cathodes were investigated. As the diameter of the Ag powders decreases to 10 nm, the sintering temperature of the CNT cathode was lowered primarily due to the higher specific surface area of the Ag powders. In this study, it was demonstrated that nano-sized Ag powders can be feasibly used as a bonding material for a screen-printed CNT cathode, yielding a high current density and a uniform emission image.

• Steel and Composite Structures
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• v.14 no.2
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• pp.173-190
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• 2013

The major objective of this paper is to evaluate the behavior and ultimate resisting capacity of circular CFT columns. To consider the confinement effect, proper material models with respect to the confinement pressure are selected. A fiber section approach is adopted to simulate the nonlinear stress distribution along the section depth. Material nonlinearity due to the cracking of concrete and the yielding of the surrounding steel tube, as well as geometric nonlinearity due to the P-${\Delta}$ effect, are taken into account. The validity of the proposed numerical analysis model is established by comparing the analytical predictions with the results from previous experimental studies about pure bending and eccentric axial loading. Numerical predictions using an unconfined material model were also compared to investigate the confinement effects on various loading combinations. The ultimate resisting capacities predicted by the proposed numerical model and the design guidelines in Eurocode 4 are compared to evaluate the existing design recommendation.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.5
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• pp.542-550
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• 2020

The use of high-strength aluminum alloys for ships and of shore structures has many benefits compared to carbon steels. Recently, high-strength aluminum alloys have been widely used in onshore and of shore industries, and they are widely used for the side shell structures of special-purpose ships. Their use in box girders of bridge structures and in the topside of fixed platforms is also becoming more widespread. Use of aluminum material can reduce fuel consumption by reducing the weight of the composite material through a weight composition ratio of 1/3 compared to carbon steel. The characteristics of the stress strain relationship of an aluminum structure are quite different from those of a steel structure, because of the influence of the welding[process heat affected zone (HAZ). The HAZ of aluminum is much wider than that of steel owing to its higher heat conductivity. In this study, by considering the HAZ generated by metal insert gas (MIG) welding, the buckling and final strength characteristics of an aluminum reinforcing plate against longitudinal compression loads were analyzed. MIG welding reduces both the buckling and ultimate strength, and the energy dissipation rate after initial yielding is high in the range of the HAZ being 15 mm, and then the difference is small when HAZ being 25 mm or more. Therefore, it is important to review and analyze the influence of the HAZ to estimate the structural behavior of the stiffened plate to which the aluminum alloy material is applied.

• Earthquakes and Structures
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• v.10 no.4
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• pp.769-788
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• 2016

The present study aimed at investigating the effect of a special plaster on the out-of-plane behavior of masonry walls. A reference specimen, plastered with conventional plaster, and a specimen plastered with a special plastered were tested under reversed cyclic lateral loading. The specimens were identical in dimensions and material properties. The special plaster contained an additive, which increased the adherence strength of the plaster to the wall. The amount of the additive in the mortar was adjusted based on the preliminary material tests. The influence of the plaster on the wall behavior was evaluated according to the initial cracking load, type of failure, energy absorption capacity (modulus of toughness), and crack pattern of the wall. Despite having limited contribution to the ductility, the special plaster increased the ultimate load capacity of the wall about 25%. The failure mode of the wall with special plaster resembled the plastic failure mechanism of a reinforced concrete slab in the formation of yielding lines along the wall. The deflection at failure and the modulus of toughness of the wall with special plaster were measured to be in order of 60% and 75% of the corresponding values of the reference wall.

• Earthquakes and Structures
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• v.10 no.1
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• pp.1-23
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• 2016

Steel plate shear walls (SPSWs) have been shown to be efficient lateral force-resisting systems, which are increasingly used in new and retrofit construction. These structural systems are designed with either stiffened and stocky or unstiffened and slender web plates based on disparate structural and economical considerations. Based on some limited reported studies, on the other hand, employment of low yield point (LYP) steel infill plates with extremely low yield strength, and high ductility as well as elongation properties is found to facilitate the design and improve the structural behavior and seismic performance of the SPSW systems. On this basis, this paper reports system-level investigations on the seismic response assessment of multi-story SPSW frames under the action of earthquake ground motions. The effectiveness of the strip model in representing the behaviors of SPSWs with different buckling and yielding properties is primarily verified. Subsequently, the structural and seismic performances of several code-designed and retrofitted SPSW frames with conventional and LYP steel infill plates are investigated through detailed modal and nonlinear time-history analyses. Evaluation of various seismic response parameters including drift, acceleration, base shear and moment, column axial load, and web-plate ductility demands, demonstrates the capabilities of SPSW systems in improving the seismic performance of structures and reveals various advantages of use of LYP steel material in seismic design and retrofit of SPSW systems, in particular, application of LYP steel infill plates of double thickness in seismic retrofit of conventional steel and code-designed SPSW frames.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.10a
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• pp.291-311
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• 2006

The acceleration of consolidation by stone columns was mostly analysed within the framework of a basic unit cell model (i.e. a cylindrical soil body around a column). A method of converting the axisymmetric unit cell into the equivalent plane-strain model would be required for two-dimensional numerical modelling of multi-column field applications. This paper proposes two practical simplified conversion methods to obtain the equivalent plane-strain model of the unit cell, and investigates their applicability to multi-column reinforced ground. In the first conversion method, the soil permeability is matched according to an analytical equation, whereas in the second method, the column width is matched based on the equivalence of column area. The validity of these methods is tested by comparison with the numerical results of unit-cell simulations and with the field data from an embankment case history. The results show that for the case of linear-elastic material modelling, both methods produce reasonably accurate long-term consolidation settlements, whereas for the case of elasto-plastic material modelling, the second method is preferable as the first one gives erroneously lower long-term settlements, where plastic yielding of stone column are ignored.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.22 no.2
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• pp.174-181
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• 1996

The novel synthesis of 3-aminopropyl dihydrogen phosphate(3-APPA; 3-Aminopropane phosphoric acid), and its applicability to the skin as a cosmetic raw material in terms of its efficacy and toxicology were presented. The phosphorylation of 3-amino-1-propanol was carried out via cyclization into 6-membered 2, 6-oxaza-phosphoryl ring in the presence of phosphorous oxychloried and an organic base. The subsequent ring-opening hydrolysis and crystallization afforded the highly purified product in 90% isoloated yield. The method is much superior to the previous literature phosphorylation methodsm, as the procedure is simple and high-yielding. To confirm the efficacy of 3-APPA, several activities related to anti-aging capacity were measured. In-vitro human fibroblast, linear and 3-dimensional collagen matrix culture revealed that 3-APPA stimulated the proliferation of fibroblasts, and enhanced the synthesis of collagen, which showed 3-APPA's potency for skin wrinkle reduction. The toxicolgical aspect of 3-APPA was also extensively examined. In vivo toxicity tests such as acute oral toxicity, eye irritation, human patch, and the repeat insult human patch test proved 3-APPA to be a safe material. Thus 3-APPA can be used as an effective anti-aging agent for various cosmetic formulations.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.1
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• pp.23-28
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• 2006

In this paper, breakdown voltage and on-resistance characteristics of the surface doped SOI RESURF LDMOSFET were investigated as a function of surface doping depth. In order to verify the variation of characteristics, two-dimensional device simulation was carried out. Breakdown voltage of the proposed structure is varied from $73 {\~}138V$ while surface doping depth varied from $0.5{\~}2.0{\mu}m$. And on-resistance is decreased from $0.18{\~}0.143{\Omega}/cm^2$ while surface doping depth increased from $0.5 {\~}2.0{\mu}m$. Maximum breakdown voltage of the proposed structure is 138 V at $1.5{\mu}m$ depth of surface doping, yielding $22.1\%$ of improvement of breakdown voltage in comparison with that of the conventional SOI RESURF LDMOSFET with same epi-layer concentration. On-resistance characteristic is also improved about $21.7\%$.