• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.6
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• pp.465-470
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• 2020

Heterolayered K(Ta,Nb)O₃/Pb(Zr,Ti)O₃ thin films on Pt/Ti/SiO₂/Si substrates were prepared by a sol-gel process and spin-coating method. The structural and electrical properties were measured to investigate the possibility of application as an electrocaloric effect device. All specimens exhibited dense and uniform cross-sectional structures without pores, and the average thickness of the specimen coated six times was approximately 394 nm. Curie temperatures were observed at 5℃ or less in type-I and 10℃ in type-II specimens, respectively. Type-II specimens coated 6 times showed a relative dielectric constant of 758 and remanent polarization of 9.71 μC/㎠ at room temperature. The maximum electrocaloric effect occurred between 20 and 25℃, slightly higher than their Curie temperature, and the electrocaloric property (ΔT) of the type-II specimens coated 6 times was approximately 1.2℃ at room temperature.

• Animal Systematics, Evolution and Diversity
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• v.36 no.2
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• pp.167-174
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• 2020

A halacarid species of the genus Copidognathus is newly reported from Korea: C. daguilarensis Bartsch, 1997, which was described from Hong Kong. It is redescribed herein with detailed illustrations. Korean specimens coincide well with the original description, however, they showed two minor morphological discrepancies from it: quite shorter second palpal segment than the fourth and a modified dorsal seta on the second palpal segment. Korean specimens were rather smaller than the type specimens from Hong Kong, however, they did not show significant differences in the length to width ratios of important body parts. The number of perigenital setae was more variable in the Korean males, ranged 24-29 setae, versus 25-26 in Hong Kong's. Copidognathus daguilarensis is reported for the first time outside the type locality, and joins as the second member of the gibbus group in the northwest Pacific.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.551-554
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• 2002

As a general rule, the brazing process between cemented carbides and steel used by Silver (Ag) type brazing filler. The composition of Ag type filler were used Ag-Cu-Zn-Cd type filler mainly. But, the demand of Cadmium (Cd)-free in Ag type filler was raised recently. The reason why Cd-free in Ag brazing filler were occupied to vaporize as a CdO$_2$ when brazing process, because of Cd element was almost low boiling point of all Ag type filler elements. And, CdO$_2$ was a very harmful element for the human body. This experiment was developed Cd-freeing on Ag type filler that was used Indium (In) instead of Cd element. In this experiment, there were changed from 0 to 5% In addition in Ag brazing filler and investigated to most effective percentage of Indium. As a result, the change of In addition instead of Cd, there was a very useful element and obtained same property only 3% In added specimens compared to Cd 19% added specimens. These specimens were obtained same or more deflective strength. In this case, there were obtained 70 MPa over strength and wide brazing temperature range 650-800 C. A factor of deflective strength were influenced by composition and the shape of $\beta$ phase and between $\beta$ phase and cemented carbides interface. Indium element presented as $\alpha$ phase and non-effective factor directly, but it's occupied to solid solution hardening as a phase. $\beta$ phase were composed 84-94% Cu-Ni-Zn elements mainly. Especially, the presence of Ni element in interface was a very important factor. Influence of condensed Ni element in interface layer was increased the ductility and strength of brazing layer. Therefore, these 3% In added Ag type filler were caused to obtain a high brazing strength.

• Journal of Korean Society of Steel Construction
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• v.20 no.4
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• pp.539-548
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• 2008

This study aims to determine the applicability of the previously published T-type modular profile beam in the manner of producing specimens designed specially for the said purpose, determining their bending and shear behaviors depending on the presence of shear reinforcement, and analyzing the results in comparison with the theoretical equation of plastic deformation. The modular profile beam contributes to bending and shear resistance with the addition of the profile to the form function, and enhances the molding performance through the modular concept. The experimental results showed that the TS series specimens with shear reinforcement have bending behaviors superior to those of the T series specimens without shear reinforcement, which suggests that the used shear reinforcement appropriately bears the shear force. However, it was considered that all the specimens except for the T1-1 specimen failed to have adequate bending performance because of the intermodular slipping caused by the shear failure of the bolts. It is expected that further studies on the T-type modular profile beam, in which shear connectors will be considered as a variable,be performed to develop optimal intermodular connection methods.

• Biomedical Science Letters
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• v.9 no.4
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• pp.183-187
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• 2003

Pseudomonas aerugionsa is a commonly isolated nosocomial pathogen. DNA fingerprinting of P. aerugionsa is examined by randomly amplified polymorphic DNA (RAPD). In this study, P. aeruginosa were isolated from environmental and clinical specimens and the molecular typing of the microorganisms was investigated by RAPD. Thirty strains of P. aeruginosa were selected from the strains isolated formerly and submitted for type identification to the University Hospital. 15 strains of P. aeruginosa were received from Chungnam University Hospital and 14 strains from Gyeongsang University Hospital. DNA of P. aeruginosa was extracted by Qiagen genomic DNA kit. PCR mixtures were set up and incubated, Reactions mixtures were made to be optimal for P. aeruginosa. RAPD typing analysis was carried out by the multivariate statistical program (MVSP) V3.0. RAPD type I was the most common pattern and included 23 strains. Most of strains from Gyeongsang University Hospital belonged to RAPD type lb and 15 strains from Chungnam University Hospital to RAPD type I or II. RAPD typing of P. aeruginosa isolated from the environmental and clinical specimens was very simple and reproducible.

• Biomedical Science Letters
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• v.10 no.4
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• pp.507-514
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• 2004

The Pseudomonas aeruginosa isolated from the clinical specimens has a mutation on the QRDR (quinolone resistance determining region). There were obvious mutations in both gyrA and parC gene which are major targets of quinolone. Simultaneous mutations were found two sites or more on these genes in all of ten strains. GyrB or parE gene had only silent mutation without converted amino acids. We confirmed that P. aeruginosa from clinical specimens exhibited decreased sensitivity to fluroquiolone due to changed Thr-83→lle and Asp-87→Asn types on gyrA and altered Ser-87→Leu type on parC. This is the first finding that a new Met-93→Thr type on parC as well as mutations on gyrB or parE genes differed from existing patterns. This study showed more mutations of gyrA rather than parC, suggesting that change of Type Ⅳ topoisomerase is more serious than that of type Ⅱ (DNA gyrase).

• Journal of the Korean Wood Science and Technology
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• v.24 no.1
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• pp.95-99
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• 1996

The bending and compression strength properties of two types Rhus verniciflua specimens, which made of no heat-treated wood and heat-treated wood for urushiol extraction, were measured. The heat-treated specimens were finger-jointed with either resorcinol-phenol or polyurethane resin adhesives, and the vertical type bending strength property was also measured in these specimens. The results obtained are as follows ; 1. The correlation coefficient between the compression strength and specific gravity in the specimens of no heat-treated and heat-treated wood was high. However there was no difference in compression strength property as affected by heat treatment. 2 The correlation coefficient between the bending strength and specific gravity in the specimens of no heat-treated and heat-treated wood was also high. However, there was no difference in bending strength property as affected by heat treatment. 3 The bending test showed high correlation between modulus of elasticity and modulus of rupture for the specimens made of no heat-treated and heat-treated wood. However, there was no difference in bending strength property between the specimens made of heat-treated and no heat-treated wood. 4. The efficiencies of bending strength test on the finger-jointed specimens of heat-treated wood with resorcinol-phenol and polyurethane resin adhesives were 0.85, 0.81. respectively.

• Korean Journal of Plant Taxonomy
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• v.48 no.2
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• pp.123-128
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• 2018

Earlier taxonomic studies of Korean Scutellaria reported a new record of Scutellaria hastifolia L. in Korea based on three herbarium sheets. During a reexamination of these specimens, we found that the leaf characters of these specimens differ from those in the type specimen of S. hastifolia. Based on a literature survey and confirmation of the type specimen, the specimens identified as S. hastifolia thus far were a misidentification of S. barbata D. Don. S. hastifolia is clearly different from S. barbata by single conspicuous teeth on both sides of the leaf margins and larger leaves. In addition to the distribution sites of the three specimens used in the previous study, a distribution site of the S. barbata was newly found in the southern part of Korea. In this study, we report a new distribution of S. barbata in Korea, correct a previous report of S. hastifolia, describe the morphological characters of S. barbata, and suggest a taxonomic key to Korean Scutellaria including S. barbata.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.1 s.173
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• pp.38-51
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• 2000

The study on the mechanical behavior of a spot-welded specimen is largely divided into the quasi-static overload failure analysis and the fatigue failure prediction. The main issue in an overload analysis is to examine the critical loads, thereby providing a generalized overload failure criterion. As the welding spot forms a singular geometry of an external crack type, fatigue failure of spot-welded specimens can be evaluated by means of a fracture parameter. In this study, we first present the limit loads of 4 representative types of single spot-welded specimens in terms of the base metal yield strength and specimen geometries. Recasting the load vs. fatigue life relationships experimentally, obtained here, we then predict the fatigue life of spot-weld specimens with a single parameter denoted the equivalent stress intensity factor. This crack driving parameter is demonstrated to successfully describe the effects of specimen geometry and loading type in a comprehensive manner. The suggested fatigue life formula for a single spot weld can play a key, role in the design and assessment of spot-welded panel structures, in that the fatigue strength of multi-spots is eventually determined by the fatigue strength of each single spot.

• Anatomy and Cell Biology
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• v.52 no.1
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• pp.38-42
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• 2019

This study investigated and classified the various types of moderator band (MB) in relation to the anterior papillary muscle, with the aim of providing anatomical reference information and fundamental knowledge for use when repairing the congenital defects and understanding the conduction system. The study investigated 38 formalin-fixed human hearts of both sexes obtained from donors aged 38-90 years. The MB was evident in 36 of the 38 specimens (94.7%). The morphology of the MB and its connection with the APM took various forms. The MBs that had a distinct shape were classified into three types according to their shape: cylindrical column, long and thin column, and wide and flat column. Types 2 and 3 were the most common, appearing in 15 (41.7%) and 14 (38.9%) of the 36 specimens, respectively, while type 1 was observed in seven specimens (19.4%). Type 3 was divided into subtypes based on their length. The MB usually originated from a single root (91.7%), with the remainder exhibiting double roots. The pairs of roots in the latter cases had different shapes. The originating point of the MB ranged from the supraventricular crest to the apex of the ventricle. The most-common originating point was in the middle (25 of 36 specimens, 69.4%), followed by the upper third (13.9%), the lower third (11.1%), and the top fifth (5.6%) of the interventricular septum. This study has produced fundamental anatomical and clinical information that will be useful when designing cardiac surgical procedures.