Evaluating Corrosion Resistance of Biomedical Ti-6Al-4 V Alloys Fabricated via Additive Manufacturing Using Electrochemical Critical Localized Corrosion Potential

Jae‑Bong Lee,Dong‑Il Seo,Hyeon‑Yeong Chang 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.7

High entropy alloys (HEAs) have received tremendous attention in diferent applications because of their excellent corrosion resistance and superior mechanical properties. In the present work, a novel TiNbMoMnFe high entropy alloy systemwas synthesized and deposited on AISI 316L by DC magnetron sputtering system. The microstructure of the resulting thinflm was evaluated by grazing incidence X-ray difraction and feld emission electron microscope. It was found that the thinflm microstructure is composed of a crystalline solid solution (grain size of 76 nm) and an amorphous phase. The electrochemical investigations in Ringer’s solution revealed that a thin flm of 670 nm thick high entropy alloy has a low corrosioncurrent density of 0.024 μA cm−2, approximately 30% lower than that of the uncoated 316L. Meanwhile, the HEA thin flmshowed the highest pitting corrosion resistance and stability of the passive flm. The wettability examinations exhibited thatthe coated sample has a high contact angle of 90° in contrast to 60° for the uncoated ones. In summary, the TiNbMoMnFehigh entropy alloy thin flm shows great potential for use in biomaterial applications.

Two new records of the genus Nola Leach, 1815 (Lepidoptera: Nolidae, Nolinae) from Laos

Yeong–Bin Cha,Ulziijargal Bayarsaikhan,Sol–Moon Na,Dong–June Lee,Jae–Ho Ko,Tak–Gi Lee,Hyeong–Kyu Kim,Chang–Moon Jang,Han–Ul Kim,Yang–Seop Bae 한국응용곤충학회 2019 한국응용곤충학회 학술대회논문집 Vol.2019 No.04

The genus Nola (Nolidae, Nolinae) was established by Leach (1815), with the Noctua palliola Denis & Schiffermüller, 1775 (a junior subjective synonym of Phalaena cucullatella Linnaeus, 1758) from Vienna, Austria. Nola comprises over 200 species: Africa and western Palearctic approximately described 100 speices (Hacker et al., 2012); Oriental and Eastern Palearctic regions have over 100 species (László et al., 2010; Sasaki et al., 2011; Kononenko and Pinratana, 2013). Two species of the genus Nola Leach; Nola euryzonata (Hampson, 1900) and Nola lucidalis (Walker, 1865), reported for the first time in Laos. Illustrations of adults and genitalia of all the examined species are provided.

비응축성 기체 존재 시 수직관 외벽에서의 응축 열전달계수 상관식 개발

장영준(Yeong-Jun Jang),최동재(Dong-Jae Choi),김신(Sin Kim),정동욱(Dong Wook Jerng),이연건(Yeon-Gun Lee) 대한기계학회 2018 大韓機械學會論文集B Vol.42 No.3

본 연구에서는 비응축성 기체(공기)가 존재할 때, 10 mm의 직경을 갖는 수직 튜브 외벽에서의 응축 열전달계수를 측정하였다. 압력 2~5 bar, 공기 질량분율 10~75 %의 범위에서 실험을 수행하였다. 응축튜브 직경의 차이가 열전달계수에 미치는 영향을 평가하기 위해 측정 결과를 외경 40 mm의 응축튜브로부터 얻은 Lee의 실험 결과와 비교하였다. 본 연구의 측정결과와 Lee, 그리고 Dehbi의 실험결과를 이용하여 전열관의 직경에 의한 영향을 고려할 수 있는 실험적 상관식을 제안하였다. 제안된 상관식의 검증을 위해 Kawakubo의 실험결과와 예측값을 비교하였고, 평균 표준편차는 약 27 %로 나타났다. In this study, condensation heat transfer coefficients are measured in the presence of noncondensable gas (i.e., air) on a vertical tube with a 10-mm outer diameter. Experiments are conducted at pressures ranging from 2 to 5 bar and an air-mass fraction from 10 to 75 %. The experimental results are compared to the heat transfer coefficients obtained on a 40-mm O.D. tube, researched by Lee et al. Using the consolidated data from this study and Lee"s and Dehbi"s tests, a new empirical correlation for the condensation heat transfer coefficient of an air-steam mixture is developed. The proposed correlation is assessed against Kawakubo"s experimental results, and the mean standard deviation is ~27 %.

지역사회획득 폐렴의 치료지침 권고안

송재훈,정기석,강문원,김도진,배현주,서지영,심태선,안중현,안철민,우준희,이남용,이동건,이미숙,이상무,이영선,이혁민,정두련,지역사회획득 폐렴 치료지침 제정위원회 대한감염학회 2009 감염과 화학요법 Vol.41 No.3

A successful therapy of community-acquired pneumonia requires appropriate empirical antimicrobial therapy. Etiology and antimicrobial susceptibility of major pathogens of pneumonia can differ by country. Therefore, an ideal treatment guideline of community-acquired pneumonia should be based on the studies performed in each country. We developed a treatment guideline for community-acquired pneumonia in immunocompetent adults in Korea. This guideline was developed by the joint committee of the Korean Society for Chemotherapy, the Korean Society of Infectious Diseases, and the Korean Academy of Tuberculosis and Respiratory diseases.

GC/NPD를 이용한 다성분 잔류농약의 동시분석

김우성,이선화,김상엽,정동윤,김재이,이영자,이홍재,정성욱,박흥재 한국환경과학회 2003 한국환경과학회지 Vol.12 No.10

Pesticides were extracted from samples with 70% acetone and methylene chloride in order, and then cleaned up via open-column chromatography apparatus packed with fiorisil, and finally analyzed simultaneously the organophosphorus pesticides using GC/NPD, Ultra-2 and Ultra-1 fused silica capillary columns were used to separate and identify the products. Recovery of most analytes from soybean sample, taken from pesticide residues well, was greater than(80%) for all except(6) analytes. This method can simultaneously determine multiple pesticides with a high degree of accuracy and precision.

GC-ECD를 이용한 유기염소계 및 Pyrethroid계 농약 동시 분석법

김우성,이선화,김재이,정지윤,이명자,박영채,이영자,정성욱,이봉헌,박흥재 한국환경과학회 2003 한국환경과학회지 Vol.12 No.4

Pesticides were extracted from samples with 70% acetone and methylene chloride in order, and then cleaned up via open-column chromatography apparatus packed with florisil, and finally analyzed simultaneously the organochlorine and pyrethroid pesticides using GC(ECD). An ultra-2 fused silica capillary column was used to separate and identify the products. The resolution between the last isomeric peak of cypermethrin(59.987min) and the first isomeric peak of flucythrinate(60.043min) was not satisfactory. The last isomeric peak of fenvalerate(62.344min) and the first isomeric peak of fluvalinate(62.397min) were overlapped. Recoveries of soybean sample for the most pesticides were 73.3% to 102.4%. Detection limits were between 0.004 and 0.063 ㎍/㎎ when this method was used.

전신성 홍반성 루프스에서 고용량 경정맥 당질코르티이드로 치료된 단백질 소실성 장질환 1예

이규형,권창모,김현도,윤대영,이재웅,홍여훈,이충기 영남대학교 의과대학 2005 Yeungnam University Journal of Medicine Vol.22 No.2

Generalizes edema and hypoalbuminemia are relatively common presenting manifestations in many clinical situations. The differential diagnosis of hypoalbuminemia include; Kwashiorkor, synthetic dysfunction of the liver, and excessive protein loss as in nephrotic syndrome. In systemic lupus erythematosus (SLE), hypoalbuminemia and generalized edema are most commonly due to protein loss associated with lupus nephritis; gastrointestinal involvement is uncommon, and therefore protein loss through the gastrointestinal tract is quite rare. We report a case of a protein losing enteropathy (PLE) associated with SLE. The patient was referred to out hospital for generalized edema, arthralgia and facial rash. After clinical evaluation, the patient met the criteria for the SLE diagnosis; hypoalbuminemia with general edema was consistent with a protein losing enteropathy. After two weeks of therapy with parenteral high dose glucocorticoid, the patients was improved in laboratory findings as well as clinical symptoms.

SOAP 보안에 대한 연구

이재동,곽현영 慶南大學校 附設 工業技術硏究所 2003 硏究論文集 Vol.21 No.1

SOAP(Simple Object Access Protocol)은 인터넷을 통한 원격 애플리케이션을 원활하게 지원하기 위한 목적의 HTTP를 보완하는 차세대 인터넷 프로토콜이다. SOAP 메세지의 보안을 위해 'SOAP보안 확장 : 전자서명' 표준이 제시되었다. 본 논문에서는 SOAP 보안을 위해 XML 서명기술을 사용한다. SOAP 메세지를 보낼 때 SOAP의 Body요소를 전자서명 하여 Header요소에 첨부하여 보내고, SOAP서비스에서 전자서명을 검사토록 하여 메시지를 인증한다. SOAP(Simple Object Access Protocol) is the next generation internet protocol to complement HTTP which is to support harmoniously with remote application using internet. 'SOAP Security Extension : Digital Signature' standard is proposed for the security of SOAP messages. In this paper we use XML signature technology for SOAP security. At sending SOAP message to service Header element contains the signature of Body element. SOAP service validate the SOAP message and authorize the message.

대구지역 대수층 사암의 광물상 안정 및 지하수의 화학적 조성과의 관계

이재영,이인호,김은지 慶北大擧校 師範大學 科學敎育硏究所 2000 科學敎育硏究誌 Vol.24 No.-

대구지역 주요 대수층인 반야월층과 함안층 사암의 구성광물을 조사하고 이 중 석영, 사장석, 정장석, 미사장석, 방해석 등 주요 광물과 미량이나마 흔히 관찰되는 고령석, 백운모, 녹니석, 스멕타이트의 안정관계를 나타내는 활성도 다이어그램 log([M^(n+)])/[H^(+)]^(n))-log[H_(4)SiO_(4)] (M: K, Na, Ca, Mg, n: 원자가)을 열역학적 자료를 이용하여 작성하고 여기에 반야월층과 함안층 지하수의 화학 분석치를 점시하였다. 그 결과 지하수는 거의 전부가 고령석의 안정영역에 점시되므로 대수층암석의 구성광물 중 지하수의 화학적 조성과 평형에 있는 고령석은 안정하나 평형상태에 있지 않는 다른 광물 즉, 장석류, 백운모, 녹니석, 스멕타이트 및 방해석은 불안정하여 분해된다. 따라서 이 과정에서 용탈되어 나온 K^(+), Na^(+), Ca^(2+), Mg^(2+)과 관련 음이온 HCO_(3)^(-), Cl^(-), SO_(4)^(-2) 등이 지하수의 주요 화학적 조성이 된다. The mineral compositions of sandstones in the Panyawoel and Haman formations which are major aquifers in Daegu area were investigated, and the activity diagrams of log([Mn^(+)]/[H]^(n))-log[H_(4)SiO_(4)] (M: K, Na, Ca, Mg, n: atomic value) showing their phase stability relationships were drawn using thermodynamic data for plagioclase, K-feldspar, calcite and the minor minerals of muscovite, chlorite and smectite which occur in the sandstone. The chemical compositions of the groundwaters sampled from 42 wells in the Panyawoel and Haman formations area were nearly all plotted in the kaolinite region. Therefore, kaolinite in equilibrium with chemical compositions of the groundwaters is stable, and other unstable minerals such as feldspars, muscovite, chlorite and smectite including calcite will be decomposed and converted into secondary minerals producing K^(+), Na^(+), Ca^(2+), Mg^(2+), HCO_(3)^(-), Cl^(-), SO^(2-) as major chemical compositions of the groundwaters in Daegu area.

외상에 의해 설측 변위된 하악 제1유구치의 가철성 장치를 이용한 치료

이명성,이긍호,최영철,박재홍 大韓小兒齒科學會 2005 大韓小兒齒科學會誌 Vol.32 No.1

유치열에서 가장 외상이 호발하는 부위는 상악 유중절치이며, 영구치열에서 치관부 파절이 많이 나타나는 것과는 달리, 정출, 함입, 측방 변위, 탈구 등 지지조직에 한정된 손상이 많이 나타난다. 그러나, 유구치는 외상에 의해 손상을 받는 경우가 매우 드물게 보고되고 있으며, 단일 치아 또는 다수 치아의 파절이 주를 이루고 있다. 즉, 탈구 또는 변위되는 경우가 매우 드물고 이러한 경우의 치료에 대한 보고도 거의 없다. 본 증례는 4세 5개월 된 여아에서 외상으로 인해 하악 좌측 유측절치의 정출, 유견치의 탈구와 함께 제1유구치의 설측 변위가 발생하였는데, 계승 영구치의 맹출 시기와 환아의 협조도를 고려하여 가철성 장치를 이용한 하악 제1유구치의 재위치를 시도하여 양호한 결과를 얻었기에, 유구치의 외상으로 인한 변위 시 치료 방법의 선택에 도움이 되고자 보고하는 바이다. In the primary dentitions, the majority of dental injuries involve the anterior teeth, especially the maxillary primary central incisors. When injuries affecting primary and permanent teeth are compared, it appears that trauma to the primary dentition is usually confined to the supporting structures, i.e. luxation and exarticulation, while the largest proportion of injuries affecting the permanent dentition is represented by crown fractures. But, cases reporting trauma affecting primary molars are unusual in the literature and several reports describe fractures of posterior teeth. The main goal of this report is to describe the repositioning treatment using removable appliances to an uncommon case of lingual displacement of primary molar that happened to a 4 year 5 month-old female child.