Laminar Lifted Methane Jet Flames in Co-flow Air

Narayan P. Sapkal,Won June Lee,Jeong Park,Byeong Jun Lee,Oh Boong Kwon 한국연소학회 2015 KOSCOSYMPOSIUM논문집 Vol.2015 No.12

The Laminar lifted methane jet flames diluted with helium and nitrogen in co-flow air have been investigated experimentally. The chemiluminescence intensities of OH* and CH₂O* radicals and the radius of curvature for tri-brachial flame were measured using an intensified charge coupled device (ICCD) camera, monochromator and digital video camera. The product of OH* and CH₂O* is used as a excellent proxy of heat release rate. These methane jet flames could be lifted in buoyancy and jet dominated regimes despite the Schmidt number less than unity. Lifted flames were stabilized due to buoyancy induced convection in buoyancy-dominated regime. It was confirmed that increased OH* and CH₂O* concentration caused an increase of edge flame speed via enhanced chemical reaction in buoyancy dominated regime. In jet momentum dominated regime lifted flames were observed even for nozzle exit velocities much higher than stoichiometric laminar flame speed. An increase in radius of curvature in addition to the increased OH* and CH₂O* concentration stabilizes such lifted flames.

A Study of Efficient Connection using Mobility Property in Mobile Ad-hoc Network

Youngj-jun Oh1,Kang-whan Lee 보안공학연구지원센터 2014 International Journal of Multimedia and Ubiquitous Vol.9 No.12

In this paper, we proposed the context-awareness routing algorithm DDV (Dynamic Direction Vector)-hop algorithm at Mobile Ad-hoc Networks. Existing algorithm in MANET, it has a vulnerability that the dynamic network topology and the absence of network expandability of mobility of nodes. This proposed algorithm forms cluster formation using a range of direction and threshold of velocity by base-station, and we calculate exchange cluster head node probability using direction and velocity for maintaining cluster formation. DDV algorithm forms a cluster based on the cluster head node. As a result of simulation, our scheme could maintain the proper number of cluster and cluster members regardless of topology changes. In response to maintain cluster formation, we prove a continuous connection between nodes.

DNA 포렌식에 의한 DNA 증거의 증거능력에 관한 고찰

김동준(Kim, Dong­Jun),오경식(Oh, Kyung­Sik) 한국피해자학회 2018 被害者學硏究 Vol.26 No.1

Advances in forensic DNA analysis have led to tremendous improvements in identifying and confirming perpetrators and victims. This has added credibility to DNA evidence, resulting in cases where criminals are more likely to be forced to own up to their criminality and culpability. This paper addresses scientific and technical theories the DNA analytical technologies are founded on as well as the suitability of individual analytical procedures. Beyond these issues, it went on to discuss the requirements that need to be met in order for DNA evidence, collected through forensic DNA testing, to be admissible in court in Korea. DNA testing results are presented in court in the form of certified expert testimony. And according to Article 313, “Statement, etc.” of the Criminal Procedure Act, as long as the DNA evidence offered is free from errors in laboratory procedures and concluding interpretations of the person responsible for producing the expert opinion recording, such procedures and outcomes will be admissible as legitimate evidence in court. In other words, the aforementioned expert testimony is nothing short of legislative intent at acknowledging the testimony as admissible in court, thus should not be understood as standards with which the scientific evidence concerned is admissible and tried at court. For this reason, admissibility in court of DNA evidence from DNA forensic analysis should not only be based on whether it meets the requirements as expert testimony, but also whether its theories of reasoning and analyses are founded on acceptable scientific principles. Furthermore, the tools and methods used in DNAprofiling need to be validated, allowing the analyzed result in question to be assessed for admissibility in criminal court. Trends of precedents regarding DNA evidence seem to require that the relevancy of DNA analytical theories, suitability of DNA analytical methods that have implemented these theories, and maintenance of the chain of custody of evidence by applying scientific procedures to the targets concerned, be met for the evidence to be admissible in court. Furthermore, it may be fair to say that within the structure of Korea’s criminal prosecution, the processes involved in determining whether or not DNA evidence is credible may be part of what is needed to assess its probative value. At the moment, theoretical foundations of DNA analysis are deemed reliable with the overall approval of scientific circles, however there are improvements made all the time in standard analytical methodologies and procedures regarding their implementation and analytical techniques. This has created an unbridgeable gap between common knowledge and the outcomes of scientific research activities that legal experts, particularly trial judges, are left with no choice but to be more and more dependent on expert testimony when they assess the credibility of DNA evidence. Still, the more weight DNA analysis carries, the more likely serious errors in laboratory testing occur; thus, there is increased emphasis on how to keep the chain of custody in determining the admissibility of DNA evidence, for example, the qualification of those involved in testing, sample collection and preservation, stability of the testing methods that have been utilized, and conformance to analytical procedures. Therefore, if there is evidence that is crucial in determining guilt in crime, and the continuity of its preservation is closely related to the presence and integrity of the evidence concerned, namely DNA evidence, the defendant should be afforded the opportunity for the credibility of evidence to be tried in court during the entire processes of such evidence being collected, stored and analyzed to: prevent wrongful accusations; to make court proceedings more impartial; and to comply with appropriate procedures. To this end, cross examination of witnesses, disclosure of extensive evidence of the parties involved, and cross examinat

Identification and characterization of Dunaliella salina OH214 strain newly isolated from a saltpan in Korea

Minjae, Kim,Hyeon Jun, Oh,Khanh, Nguyen,EonSeon, Jin The Korean Society of Phycology 2022 ALGAE Vol.37 No.4

Carotenoids are effective antioxidants that are found in various photosynthetic organisms. Marine microalgae are an advantageous bioresource for carotenoid production because they do not compete with other crops for freshwater and arable land. This study reports a newly isolated Dunaliella strain from the Geumhong Saltpan on Yeongjong Island, West Sea, Korea. The new strain was isolated and classified as Dunaliella salina through phylogenetic analysis and was named the OH214 strain (Deposit ID: KCTC14434BP). The newly isolated strain can survive in a wide range of NaCl concentrations (0.3-5.0 M NaCl), but grows well in 0.6 to 1.5 M NaCl culture medium. Under high-light conditions (500 ± 10 μmol photons m^-2 s^-1), the cells accumulated three times more β-carotene than under low-light conditions (50 ± 5 μmol photons m^-2 s^-1). The cells accumulated 2.5-fold more β-carotene under nitrogen-deficient (1 mM KNO₃) conditions (3.24 ± 0.36 ㎍ 10⁶ cells^-1) than in nitrogen-sufficient conditions (>5 mM KNO₃). The lutein content under nitrogen-deficient conditions (1.73 ± 0.09 ㎍ 10⁶ cells^-1) was more than 24% higher than that under nitrogen-sufficient conditions. Under the optimized culture condition for carotenoid induction using natural seawater, D. salina OH214 strain produced 7.97 ± 0.09 mg g DCW^-1 of β-carotene and 4.65 ± 0.18 mg g DCW^-1 of lutein, respectively. We propose that this new microalga is a promising strain for the simultaneous production of β-carotene and lutein.

Scanning tunneling microscopy investigation of nano-structured α-K5PW11(M x OH2)O39(M = Mn(II), Co(II), Ni(II), and Zn(II)) Keggin heteropolyacid catalyst monolayers.

Choi, Jung Ho,Kang, Tae Hun,Bang, Yongju,Yoo, Jaekyeong,Jun, Jin Oh,Song, In Kyu American Scientific Publishers 2014 Journal of nanoscience and nanotechnology Vol.14 No.11

<P>Nano-structured α-K5PW11(M x OH2)O39 (M = Mn(II), Co(II), Ni(II), and Zn(II)) Keggin heteropolyacids (HPAs) were investigated by scanning tunneling microscopy (STM) and tunneling spectroscopy (TS) measurements in order to elucidate their redox property and oxidation catalysis. HPA molecules formed two-dimensional self-assembled monolayer arrays on highly oriented pyrolytic graphite (HOPG) surface. Furthermore, HPAs exhibited a distinctive current-voltage behavior referred to as negative differential resistance (NDR) phenomenon. The measured NDR peak voltage of HPAs was correlated with the reduction potential and the absorption edge energy determined by electrochemical method and UV-visible spectroscopy, respectively. NDR peak voltage of HPAs appeared at less negative voltage with increasing reduction potential and with decreasing UV-visible absorption edge energy. The correlations strongly suggested that NDR phenomenon was closely related to the redox property of HPAs. Vapor-phase oxidation of benzyl alcohol to benzaldehyde was carried out as a model reaction to track the oxidation catalysis of HPAs. NDR peak voltage appeared at less negative voltage with increasing yield for benzaldehyde.</P>

Lysophosphatidic acid increases mesangial cell proliferation in models of diabetic nephropathy via Rac1/MAPK/KLF5 signaling

Kim, Donghee,Li, Hui Ying,Lee, Jong Han,Oh, Yoon Sin,Jun, Hee-Sook Nature Publishing Group UK 2019 Experimental and molecular medicine Vol.51 No.2

<▼1><P>Mesangial cell proliferation has been identified as a major factor contributing to glomerulosclerosis, which is a typical symptom of diabetic nephropathy (DN). Lysophosphatidic acid (LPA) levels are increased in the glomerulus of the kidney in diabetic mice. LPA is a critical regulator that induces mesangial cell proliferation; however, its effect and molecular mechanisms remain unknown. The proportion of α-SMA<SUP>+</SUP>/PCNA<SUP>+</SUP> cells was increased in the kidney cortex of <I>db/db</I> mice compared with control mice. Treatment with LPA concomitantly increased the proliferation of mouse mesangial cells (SV40 MES13) and the expression of cyclin D1 and CDK4. On the other hand, the expression of p27<SUP>Kip1</SUP> was decreased. The expression of Krüppel-like factor 5 (KLF5) was upregulated in the kidney cortex of <I>db/db</I> mice and LPA-treated SV40 MES13 cells. RNAi-mediated silencing of KLF5 reversed these effects and inhibited the proliferation of LPA-treated cells. Mitogen-activated protein kinases (MAPKs) were activated, and the expression of early growth response 1 (Egr1) was subsequently increased in LPA-treated SV40 MES13 cells and the kidney cortex of <I>db/db</I> mice. Moreover, LPA significantly increased the activity of the Ras-related C3 botulinum toxin substrate (Rac1) GTPase in SV40 MES13 cells, and the dominant-negative form of Rac1 partially inhibited the phosphorylation of p38 and upregulation of Egr1 and KLF5 induced by LPA. LPA-induced hyperproliferation was attenuated by the inhibition of Rac1 activity. Based on these results, the Rac1/MAPK/KLF5 signaling pathway was one of the mechanisms by which LPA induced mesangial cell proliferation in DN models.</P></▼1><▼2><P><B>Kidney disease: Mechanisms of diabetes-related damage</B></P><P>A potent molecular mediator of diabetic kidney disease induces its pathogenic effects via proteins that could be targeted with future drug therapies. Yoon Sin Oh
from Eulji University in Seongnam-si and Hee-Sook Jun from Gachon University in Incheon, both in South Korea, and colleagues treated certain cells found in the kidney’s glomerulus, the organ’s filtering unit, with a signaling molecule called lysophosphatidic acid (LPA) that is elevated in the blood of diabetic mice. They showed that LPA stimulated cellular proliferation and boosted the expression of proteins involved in regulating the cell cycle and a multipurpose signaling pathway. They then inhibited the activity of these proteins to prevent the kidney cells’ hyperproliferation, both in cell culture and in diabetic mice. The results highlight the potential of blocking mediators of LPA signaling to treat kidney-related complications of diabetes.</P></▼2>

微生物農藥(Bacillus thuringiensis)의 殘留毒性이 누에에 미치는 影響

吳駿植 건국대학교 1980 論文集 Vol.12 No.1

This experiment were carried out to investigate the effect of thuricide and Bactospeine of microbial insecticide (Bacillus Thuringiensis) on Silk Worm Bombyx mori. The results were as follow: 1) Bacillus thuringiensis were less toxic than chemical insecticides to silk worm. The toxicity of Bacillus thuringiensis showed slowly and gradually and killed the tested worms in 20 houre on the 3rd instar and in 4 days on 5th instar. 2) The ranges of LD 50 value to the 3rd and 5th instar were from 7,698×10/ml to 1,893 ×103/ml. 3) The toxicity to the silk worm varieties showed the highest to jam 107×jam 108 and low to jam 112×jam 111 amont the 3rd instar, but no different toxicity in 5th instar. 4) Thuricide wettable powder was more toxic to the silk worm than Bactospeine. 5) The leaves of mulberry which was Bacillus thuringiensis for 12day did not show the toxicity to silk worm.

수돗물염수액 전기분해에 의한 살균소독

박준오, 김완석, 최영기, 이영민, 김형규, 차은종, 김석용 충북대학교 동물의학연구소 2008 Journal of Biomedical and Translational Research Vol.9 No.2

본문참고

별'에 대한 초등학교 교사와 학생들의 幼年的 槪念과 核心 信念 비교

오준형,채동현 경북대학교 사범대학 부속 중등교육연구소 2004 중등교육연구 Vol.52 No.1

This article presents the results which investigated elementary school students' and teachers' conceptions about the stars. Samples consisted of one hundred forty eight 5th-grade students, one hundred seventy four 6th-grade students, and thirty eight primary science teachers. Research method was paper-pencil test. Their responses to these questions revealed considerable apparent naive conceptions. and the study results proved that the items showing a high response rate of teachers' childhood concept also resulted in a high response rate of students' naive concept. A great of this apparent inconsistency could be explained by assuming that the students used, a naive core belief of the stars other than a target scientific concept of the stars. And, elementary school students and teachers often held a different naive core beliefs based on their other experiences rather than scientific theories. this paper was also discussed the core beliefs that elementary school students and teachers held to overcome these naive conceptions.

기저질환이 없는 사람에서 발생한 Campylobacter fetus에 의한 재발성 심내막염 1예

전재범,정진원,김성혜,송문희,오형철,안성기,최상호,김남중,김양수,우준희,류지소 대한감염학회 2004 감염과 화학요법 Vol.36 No.6

C. fetus 심내막염은 드물게 발생하는 질환으로 주로 면역능이 저하된 환자에서 발병하고 대동맥판을 침범하는 경우가 많으며 적절한 치료가 되지 않을 경우 치사율이 높다. 저자들은 기저질환이 없던 69세 남자에서 C. fetus 심내막염을 경험하였기에 문헌고찰과 함께 보고하는 바이다. 환자는 발열로 내원하여 시행한 혈액배양 검사상 C. fetus가 동정되었고 경식도 초음파 검사상 삼첨판에 증식증이 발견되어 심내막염 진단하에 ceftriaxone에 이어 meropenem으로 총 4주간 항생제를 투여받고 호전되었다가 한달 후 다시 재발하였고 판막부전 소견 진행하여 삼첨판 치환술을 시행받고 전신상태 호전되어 퇴원하였다. Campylobacter fetus is a rare cause of endocarditis. To date, only about 30 cases of C. fetus endocarditis have been reported mainly in the elderly with chronic underlying illnesses. Most cases showed tendency to involve aortic valve. This report describes a case of native tricuspid valve infective endocarditis in a 69-year-old man without any underlying disease. Despite adequate antibiotic therapy for 4-weeks, endocarditis recurred and leading to surgical valve replacement.