• International Journal of Fluid Machinery and Systems
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• v.7 no.2
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• pp.68-79
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• 2014

The type of turbine developed is based on the very low head of water potential source for the electric power production. The area of research is focused for the axial water turbine that can be applied at the simple site open channel with has a very low cost and environmental impact compared to the conventional hydro installation. High efficiency of axial turbine which applied to the very low potential head will made this type of turbine can be used at wider potential site. Existing irrigation weir and river area will be the perfect site for this turbine. This paper will compare the effects of the variation of swirl velocity criterion during the design of the blade of guide vane and rotor of the turbine. Effects of the swirl velocity criterion is wider known as a vortex conditions (free vortex, force vortex and swirl velocity constant), and the free vortex is the very popular condition that applied by most of turbine designer, therefore will be interesting to do a comparison against other criterion. ANSYS Fluent will be used for simulation and to determine the predictive performance obtained by each of design criteria.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2003.05a
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• pp.32-36
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• 2003

This paper deals with a theoretical method for the design of a biased asymmetric preswirl stator propulsion system which has been used to increase efficiency by the recovery of a propeller slipstream rotational energy by the counter rotating flow of a stator. In the case of full slow-speed ship, the upward flow is generated at the propeller plane by the after body hull form. The generated upward flow cancells the rotating flow of the propeller at the starboard part while it increases at port part. A biased asymmetric preswirl stator propulsion system consists of three blades at the port and one blade at the starboard which can recover the biased rotating flow effectively. This paper provides the design concept which gives more simple and a high degree of efficiency. The model tests for the designed compound propulsion system will be carried out later.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.222-224
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• 2006

A non-vacuum process for $Cu(In,Ga)Se_2$ (CIGS) thin film solar cells from nanoparticle precursors was described in this work CIGS nanoparticle precursors was prepared by a low temperature colloidal route by reacting the starting materials $(CuI,\;InI_3,\;GaI_3\;and\;Na_2Se)$ in organic solvents, by which fine CIGS nanoparticles of about 20nm in diameter were obtained. The nanoparticle precursors were mixed with organic binder material for the rheology of the mixture to be adjusted for the doctor blade method. After depositing the mixture of CIGS with binder on Mo/glass substrate, the samples were preheated on the hot plate in air to evaporate remaining solvents ud to burn the organic binder material. Subsequently, the resultant (porous) CIGS/Mo/glass simple was selenized in a two-zone Rapid Thermal Process (RTP) furnace in order to get a solar ceil applicable dense CIGS absorber layer. Complete solar cell structure was obtained by depositing. The other layers including CdS buffer layer, ZnO window layer and Al electrodes by conventional methods. The resultant solar cell showed a conversion efficiency of 0.5%.

• Steel and Composite Structures
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• v.30 no.6
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• pp.567-576
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• 2019

Time-dependent creep analysis of a rotating functionally graded cantilever beam with trapezoidal longitudinal cross section subjected to thermal and inertia loading is investigated using first-order shear deformation theory (FSDT). The model described in this paper is a simple simulation of a turbine blade working under creep condition. The material is a metal based composite reinforced by a ceramic where the creep properties of which has been described by the Sherby's constitutive model. All mechanical and thermal properties except Poisson's ratio are assumed to be variable longitudinally based on the volume fraction of constituent. The principle of virtual work as well as first order shear deformation theory is used to derive governing equations. Longitudinal distribution of displacements and stresses are investigated for various volume fractions of reinforcement. Method of successive elastic solution is employed to obtain history of stresses and creep deformations. It is found that stresses and displacements approach their steady state values after 40000 hours. The results presented in this paper can be used for selection of appropriate longitudinal distribution of reinforcement to achieve the desired stresses and displacements.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.36 no.4
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• pp.175-180
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• 2023

Objectives : The purpose of this study is to report a case of lipoma removed by surgical method. Methods : A 69-year-old female was diagnosed with lipoma on the left upper shoulder. Bufonis venenum pharmacopuncture was used for local anesthesia. The 11th blade and the CO₂ laser was used for incision. After removal of lipoma, irrigation with soyeom pharmacopuncture solution and simple interrupted suture were carried out. For 7 days, Yeonkyopaedok-san was given and the suture was removed after 14 days. At last, saengkigo was applied. Results : Local anesthesia was maintained. Lipoma sized 3.0×1.0×1.0cm was clearly removed. Adverse effects were not reported until the clear skin adhesion. Conclusions : Lipoma were surgically removed without any complications by using pharmacopuncture and oral herbal medicines that have anti-inflammatory effects. Korean medicine has the potential for surgery and needs to extend the range of surgical treatment.

• Journal of Conservation Science
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• v.30 no.2
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• pp.111-122
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• 2014

In Bongseon-ri site, the central type and the local type of the Baekje tombs co-exist together. Many swords with ring pommel which to regional leaders in Seocheon the Beekje government granted are excavated from these tombs. These represent that the regional leaders were controlled by the Baekje government gradually. Four swords with ring pommel and one simple sword are investigated metallurgically and we seek what swords have a function of weapon or what sword produce for grave goods. The simple sword is made by solid carburizing technology and quenching of heat treatment so it's possibly used as a weapon. In contrast, four swords with ring pommel has little chance of weapon because the blade of swords consists of microstructure that have low hardness and the back of swords don't have microstructure can absorb the shock. The most identical characteristic of the simple sword and swords with ring pommel is that they are possible to classify clearly into practical/non-practical tools. Additionally, according to non-metallic inclusion analysis result of these swords, w$\ddot{u}$stite and glass phase are found together. Thus, it is able to say that reduction method in low temperature is applied during smelting process.

• Journal of Life Science
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• v.16 no.5
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• pp.723-728
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• 2006

The species of Grateloupia filicina, Grateloupia divaricata in East Sea were investigated taxonmically in order to clarify taxonomic position. The ecological character, external morphology, anatomy of vegetative structure. Blade length are $15{\sim}40\;cm$, erect from discoidal holdfast of $3{\sim}10\;mm$ in diameter. Stipe $1{\sim}2.5\;cm$ long, narrowly cylindrical below, compressed above Grateloupia filicina. Main axis are long and compressed, $3{\sim}7\;mm$ broad in broadest part. Colors are scarlet to light red. Blade length are $10{\sim}25\;cm$, erect from discoidal holdfast of $3{\sim}8\;cm$ in diameter Grateloupia divaricata. Stipe are single and simple $2{\sim}5\;mm$ broad. Thallus composed of cortex and medulla in section ; cortex composed of $9{\sim}10$ layers of anticlinally arranged cortical cell, divided into outer, middle and inner parts. Partial fragments of nuclear 18S rDNAs from the two species of Grateloupia (Rhodophyta) were amplified using the PCR reaction and sequenced to compare their similarity. The partial sequences showed 98.9% similarity each other. Grateloupia filicina has 371 bp sizes and Grateloupia divaricata has 372 bp size. The G+C contents of Grateloupia filicina is 54.3% and Grateloupia divaricata is 53.64%.

• Korean Journal of Plant Taxonomy
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• v.37 no.3
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• pp.275-308
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• 2007

For 20 taxa of Korean Allium, including 16 species and 5 varieties, examined were morphological characters (i.e. sexuality, structure and shape of underground part, types and growing patterns of leaf and scape, and shapes of perianth, filament and pistil). The specialization and the evolutionary trends of taxonomic characters were inferred from morphological examination. Taxonomic relationships and system of Korean Allium were also studied. The characters showing evolutionary trends were the structure and shape of underground part including rhizome and bulb, leaf, scape, inflorescens, filament and ovary. It seemed that thin and short rhizome developed from thick and long one, and the membranous simple bulb tunic evolved into fibrous reticulate one. The presence of hyaline sheath in A. monanthum of sect. Microscordum was apomorphic. Both angular leaf blade with 2-rowed vascular bundle and flat blade with 1-rowed vascular bundle were developed from terete one with 2-rowed vascular bundle. The base of filament have differentiated from entire to toothed, and 2-ovuled ovary as well as erect scape before flowering was plesiomorphic type. In addition, sexuality, structure of underground part, the presence of hyaline sheath and cross-section structure of leaf were taxonomic characters with the level of the subgenus in this genus. Shape of rhizome, bulb, leaf, scape and pedicel discriminated each section from other ones in the subgenera easily. The shape and arrangement of perianth and filaments were the diagnostic characters for species level along with shape of ovary and stigma.

• Journal of the Society of Naval Architects of Korea
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• v.43 no.5 s.149
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• pp.568-577
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• 2006

With the increase of ship size and speed, the loading on the propeller is increasing, which in turn increases the rotational speed in the propeller slipstream. The rudder placed in the propeller slip stream is therefore subject to severe cavitation with the increased angle of attack due to the increased rotational induction speed of the propeller. In the present paper the surface panel method, which has been proved useful in predicting the sheet cavitation on the propeller blade, is applied to solve the cavity boundary value problem on the rudder. The problem is then solved numerically by discretizing the rudder and cavity surface elements of the quadrilateral panels with constant strengths of sources and dipoles. The strengths of the singularities are determined satisfying the boundary conditions on the rudder and cavity surfaces. The extent of the cavity, which is unknown a priori, is determined by iterative procedure. Series of numerical experiments are performed increasing the degree of complexity of the rudder geometry and oncoming flows from the simple hydrofoil case to the real rudder in the circumferentially averaged propeller slipstream. Numerical results are presented with experimental results.

• Archives of Plastic Surgery
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• v.37 no.2
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• pp.199-201
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• 2010

Purpose: Except for continuous suture in skin layer, stitching out in facial laceration, we have to hold each knots up and cut the knots by No. 11 blade or small scissors. However, we often have difficulty in stitching out the knots on children who do not cooperate well. Therefore we introduce an easy and fast stitch out method of pediatric lacerations. Methods: From January to May 2009, we studied 15 pediatric patients (mean age 5.6 years old) who had facial laceration on face or underwent any surgery on operation room. For easy stitch out, we left the one string of the first knot long enough to extend at the opposite end of laceration site. And then the extended string was fixed to skin using Steri-strip. Next we do simple interrupted suture including the extended traction nylon string inside the knot. Through this method, we can stitch out all knots simply by lifting up the traction nylon needless to hold the each knot one by one. Results: Until stitching out, the traction nylon was just right position and there was no normal tissue injury during stitch out all knots. Patients were satisfied with the short stitch out time. Conclusion: By using the traction nylon on pediatric laceration suture, we can stitch out all the knots with no normal tissue injury in less time.