Investigation of Weld Corrosion Eff ects on the Stress Behavior of a Welded Joint Pipe Using Numerical Simulations

Yong‑Sang Kim,Jung‑Gu Kim 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.4

In this paper, the infl uence of weld corrosion on the mechanical behavior of a welded joint pipeline was investigated usingcorrosion and mechanical simulations simultaneously. In the corrosion simulation, the modeling results (i.e., the corrosionpotential and current density) revealed that the welded joint is preferentially corroded and the corrosion rate is higher in theoutside environment due to the severe corrosion factors. The increase in corrosion degradation according to the operationtime increases the stress concentration on the welded joint, indicating that the failure risk of the welded joint is increasedwith increasing corrosion degradation. These results can be used to evaluate the lifetime of welded joints exposed to corrosionand suggest guidelines for the maintenance of structures.

Computational Interpretation of the Relation Between Electric Field and the Applied Current for Cathodic Protection Under Different Conductivity Environments

Yong‑Sang Kim,Sang‑Jin Ko,Sangkyu Lee,Jung‑Gu Kim 대한금속·재료학회 2018 METALS AND MATERIALS International Vol.24 No.2

An interpretation of the relation between the electric field and the applied current for cathodic protection is investigated usinga boundary element method simulation. Also, a conductivity-difference environment is set for the interface influence. Thevariation of the potential distribution is increased with the increase of the applied current and the conductivity differencedue to the rejection of the current at the interface. In the case of the electric field, the tendencies of the increasing rate andthe applied currents are similar, but the interface influence is different according to the directional component and field type(decrease of Ez and increases of Ex and Ey) due to the directional difference between the electric fields. Also, the changetendencies of the electric fields versus the applied current plots are affected by the polarization curve tendency regardingthe polarization type (activation and concentration polarizations in the oxygen-reduction and hydrogen-reduction reactions). This study shows that the underwater electric signature is determined by the polarization behavior of the materials.

Introduction and application of a composite insect trap for the National Ecosystem Survey of Korea

Han Yong‐Gu,Hong Eui jeong,Kim Do‐Sung,Kim Chulgoo,Cha Jin Yeol 한국곤충학회 2020 Entomological Research Vol.50 No.10

This study aimed to establish the best applicable method for the National Ecosystem Survey (NES) guidelines by (i) verifying the efficiency of an insect trap that combined the Malaise trap, flight intercept trap, and pitfall trap (MFP trap) as part of the improvement for the terrestrial insect field in the fifth NES, and (ii) comparing the result with the currently used Malaise trap and pitfall trap (MP traps). We found that the efficiency of attaining species diversity was much higher with the added flight intercept trap function than the current Malaise trap alone for flying insect collection. For collecting ground insects, the efficiency of attaining species diversity of the pitfall trap from the MFP trap was lower than that from the MP trap. Besides, the Malaise trap of the MP trap showed superior efficiency than that of the MFP trap in species diversity. The results suggested that modification, supplementation, and re‐testing should be performed by analyzing various factors such as the trap material, barrier size, capturing container inlet, and mesh size, with consideration of the design of the current Malaise trap. Therefore, in survey‐based research, which aims at identifying insects species diversity and inhabiting status—such as the NES, it is necessary to introduce the MFP trap with the flight intercept trap function added to the Malaise trap function, and for the pitfall trap function of the MFP trap, it can be operated as a separate trap from the MFP trap.

내시경적 점막절제술로 치험한 식도 과립상 세포종 1례

강혁주,김성욱,최석진,이중현,장재식,서영범,윤병구,박건욱,김성자,김용섭,강승완,이구,양창헌,이창우,김욱년,이광헌,서정일 동국대학교 의학연구소 2000 東國醫學 Vol.7 No.-

과립상 세포종은 Schwann 세포 기원으로 생각되며 인체에 비교적 드물게 발생한다. 과립상 세포종은 전신 어느 곳에서나 발견될 수 있으나 주로 혀, 구강, 피부 혹은 유방 등에서 호발하며 드물게 위장관에서 발견된다. 위장관에서는 식도에서 가장 호발하며 다음으로 위, 대장 순이다. 과립상 세포종은 대부분, 특히 위장관에서는 양성이며 소수의 악성 병변이 보고되었다. 이러한 이유와 함께 수술 전의 진단이 어렵기 때문에 과립상 세포종에 대한 근본적인 치료는 현재까지 외과적 절제술이다. 최근에 시도되는 치료방법들로는 내시경적 레이저 치료, 용종절제술, 내시경적 점막 절제술 등이 있다. 저자들은 상부 소화관 내시경검사를 시행하여 식도 과립상 세포종을 진단하고 내시경적 점막 절제술을 시행하여 합병증 없이 퇴원하여 현재 재발없이 경과 관찰중인 1례를 경험하였기에 보고하는 바이다. Granular cell tumors, which occur infrequently, are probably of Schwann cell origin. They can occur almost anywhere in the body but usually affect the tongue, oral cavity, skin, or breasts and are rarely found in the gastrointestinal tracts. The esophagus is the most frequent gastrointestinal site, followed by the stomach and the colon. Granular cell tumors are generally benign, especially in the gastrointestinal tract, some malignant lesions have been reported. For this reason, and also because preoperative diagnosis is difficult, the standard treatment for granular cell tumor has until now been surgical excision. In recent years, other therapeutic methods is endoscopic laser therapy (ELT), polypectiomy, endoscopic mucosal resection (EMR). We report a case of esophageal granular cell tumor which was diagnosed by an endoscopy and managed using an endoscopic mucosal resection without complication.

말단 비대증의 임상적 특성

박은미,안용환,김현정,김병수,임종주,김하영,박병현,조정구 圓光大學校 醫科學硏究所 2004 圓光醫科學 Vol.19 No.2

Pollen Viability of Common Buckwheat (Fagopyrum esculentum Moench.) in in vitro Germination and its Application to Male Gametophyte Isolation

Woo, Sun-HeeㆍKeun-Yook ChungㆍHeung-Tae, KimㆍYong-Gu, ChoㆍHong-Sig, KimㆍBeom-Heon, Songㆍ Chul-Won, Lee and Seung-Keun Jong 忠北大學校 農業科學硏究所 2004 農業科學硏究 Vol.21 No.-

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Molecular Cloning, Expression and Genomic Structure of Glyceraldehyde-3-Phosphate Dehydrogenase from the Entomopathogenic fungus, Paecilomyces tenuipes Jocheon-1

Nam Sook Park,Han Seok Kang,Seon Ku Kim,Yong Gyun Kim,Byung Uuk Cho,Teak Soon Shin,Keun Ki Kim,Hyun Chul Park,Hong Joo Son,Hong Gu Lee,Sang Mong Lee 한국응용곤충학회 2011 한국응용곤충학회 학술대회논문집 Vol.2011 No.05

Presently, We have constructed an olig-d(T) primed directional cDNA library from the silkworm Dongchunghacho, an entomopathogenic fungus, of which species is belonging to Paecilomyces tenuipes Jocheon-1. To isolate and screen genes in the fungus, 626 expressed sequence tags(ESTs) were generated by a partial sequencing from the cDNA library. Paecilomyces tenuipes Jocheon-1 cDNA encoding the glyceraldehyde-3-phosphate dehydrogenase(Pt-GAPDH) of Paecilomyces tenuipes Jocheon-1 was cloned from the above cDNA library. The complete cDNA sequence of Pt-GAPDHis comprised of 1,014bp encoding 338 amino acid residues. The deduced protein sequence of Pt-GAPDH showed higher homology with Beauberia bassiana-GAPDH(93% amino acid identity). Hydropathy analysis revealed that Pt-GAPDH protein is hydrophilic. The major three amino acids in its composition of amino acid residues were alanine(11.54%), valine(9.47%) and glycine(8.88%). The cDNA encoding Pt-GAPDH was expressed as a 37 kDa polypeptide in baculovirus-infected insect Sf9 cells. The Pt-GAPDH gene of Paecilomyces tenuipes entomopathogenic fungus consisted of three exons and two introns coding for 338 amino acid residues, and the genomic DNA length of the gene spans 1302bp. The accession number of the gene in GenBank are GU997099 for Pt-GAPDH cDNA and GU997102 for Pt-GAPDH genomic DNA.

cDNA Cloning and Genomic Structure of Glyceraldehyde-3-Phosphate Dehydrogenase from the Entomopathogenic fungus, Paecilomyces tenuipes-Jocheon

Nam Sook Park,Han Seok Kang,Seon Ku Kim,Yong Gyun Kim,Byung Uuk Cho,Teak Soon Shin,Keun Ki Kim,Hyun Chul Park,Hong Joo Son,Hong Gu Lee,Sang Mong Lee 한국응용곤충학회 2010 한국응용곤충학회 학술대회논문집 Vol.2010 No.05

Fungi belonging to the Paecilomyces spp. have recently been used as food and herbal medicines in Korea and are greatly popular as commercially available powdered supplement or dried fruiting body. Despite this acceptance and its use, little is known of the genes related to its reactive agents. Presently, We have constructed an olig-d(T) primed directional cDNA library from the silkworm Dongchunghacho, an entomopathogenic fungus, of which species is belonging to Paecilomyces spp. based on the previous identification of ITS1 and ITS2 at the molecular level and collected from Jocheon Miryang, Korea. To isolate and screen genes in the fungus, 626 expressed sequence tags(ESTs) were generated by a partial sequencing from the cDNA library. cDNA encoding the glyceraldehyde-3-phosphate dehydrogenase(Pt-GAPDH) of Paecilomyces tenuipes- Jocheon was cloned from the above cDNA library. The complete cDNA sequence of Pt-GAPDH is comprised of 1,014bp encoding 338 amino acid residues. The deduced protein sequence of Pt-GAPDH showed higher homology with Beauberia bassiana-GAPDH(93% amino acid identity). Hydropathy analysis revealed that Pt-GAPDH protein is hydrophilic. The major three amino acids in its composition of amino acid residues were alanine(11.54%), valine(9.47%) and glycine(8.88%). The Pt-GAPDH gene of Paecilomyces tenuipes entomopathogenic fungus consisted of three exons and two introns coding for 338 amino acid residues, and the genomic DNA length of the gene spans 1302bp. The accession number of the gene in GenBank are GU997099 for Pt-GAPDH cDNA and GU997102 for Pt-GAPDH genomic DNA. More investigation works including gene expression, immunological analysis etc. will be carried continuously without hesitation after this presentation.

턴디슈용 SiC 코팅材의 특성에 관한 硏究

김행식,최태현,이용구,전병세 경남대학교 신소재연구소 1995 論文集 Vol.5 No.-

턴디쉬 내장용으로 사용할 내화재료의 여러 가지 특성들을 시험하였다. 납석 70%, 점토 10% 그리고 탄화규소 20%을 혼합하여 18 가지의 조성을 가지는 시험편을 제조하였다. 탄화규소는 각각 순도 85%와 65%인 유럽산, 일본산, 중국산을 택하여 최종 제품에 미치는 영향을 알아보았다. 여러 가지 시험의 결과 10% 탄화규소를 포함한 시험편의 경우 점토질 내화벽돌 보다 수명이 2배 정도 향상되었으며 차지당 용손 두께도 1.5∼1.7㎜/ch였다. Various properties of refractory materials for the tundish lining were examined. The refractory samples with 18 different composition were prepared by mixing powders of 70 wt.% pyrophyllite. 10 wt.% clay and 20 wt.% Sic. SiC was selected from three sources, European. Japanese and Chinese-made, having 85% and 65% purities, to examine their effects on the final properties. As a results of several testings. the sample with 10% SiC(European1 was best suitable for tundish lining as a refractory coating materials. The wear depth was 1.2-1.5 mm per charge at the wall and 1.7 mm per charge a t the slag line, having shown that this service life was about 2 times longer than the ordinary lining made of clay firebricks(SiO₂-Al₂O₃).

석회석의 표면개질에 의한 기능성 원료 개발

김경남,손세구,김영도 강원대학교 부설 석재복합신소재 제품연구센터 2003 석재연 논문집 Vol.8 No.-

본 연구는 균일침전법에 의해 calcite, aragonate, vaterite의 lime(CaC0₃) 분체를 합성하였으며, 출발원료로 CaCl₂와 urea를 이용하였다. Lime의 코팅은 lithium을 이용하여 침전제와 침전제를 사용하지 않고 합성하였으며 출발원료로 Ni(NO₃)₂ㆍ6H₂0와 침전제는 urea(or NaHCO₃, NH₄HCO₃)를 사용하였다. Ni수화물은 수용액계에서 CaC0₃의 표면에 균일하게 코팅이 되었다. Lime표면에 NiO를 코팅함으로서 lime의 성질을 개선시킬 수 있었다. 표면에 코팅된 니켈 수화물은 500℃의 하소 과정에 의해 NiO로 전이되었다. 얻어진 lime분체의 특성은 주사전자현미경(SEM), X-선 회절분석기(XRD), 시차열분석기(DTA), EDS 등을 이용하여 조사하였다. Lime(CaC0₃) powders were prepared by the homogeneous precipitation method using CaC1₂, urea as the starting materials. Uniform lime(calcite, aragonite, vatrite) powders were obtained by various conditions. The surfaces of lime were modified by coating them with an lithium precursor using two different precipitation techniques: homogeneous decomposition of precipitating agents(urea, NaHCO₃, NH₄HC03) and forced hydrolysis in pure water. Selecting the Ni(NO₃)₂ㆍ6H₂O and urea(or NaHCO₃, NH₄HC0₃) as Ni-source and precipitating agent respectively, the NiO could be uniformly coated on the CaCO₃ powder in the aqueous system. The coating NiO layer dominated the surface properties of the coated lime powders. Calcination of these nickel hydroxide crystals in air at 500℃ transformed them into NiO. Scanning electron microscopy(SEM), X-ray diffractiometry, differential thermal analysis(DTA), and EDS were used to characterize the coated powders.