Alice Springs Orogeny (ASO) Footprints Tracing in Fresh Rocks in Arunta Region, Central Australia, Using Uranium/Lead (U-Pb) Geochronology

Kouame Yao(Kouame Yao ),Mohammed O. Idrees(Mohammed O. Idrees ),Abdul-Lateef Balogun(Abdul-Lateef Balogun ),Mohamed Barakat A. Gibril(Mohamed Barakat A. Gibril ) 대한자원환경지질학회 2023 자원환경지질 Vol.56 No.6

This study investigates the age of the surficial rocks in the Arunta region using Uranium-Lead (U-Pb) geochronological dating. Rock samples were collected at four locations, Cattle-Water Pass (CP 1610), Gough Dam (GD 1622 and GD 1610), and London-Eye (LE 1601), within the Strangways Metamorphic Complex and crushed by selFragging. Subsequently, the zircon grains were imaged using Cathodoluminescence (CL) analysis and the U-Pb (uranium and lead) isotope ratios and the chrono-stratigraphy were measured. The imaged zircon revealed an anomalous heterogeneous crystal structure. Ellipses of the samples at locations GD1601, CP1610, and GD1622 fall below the intercept indicating the ages produced discordant patterns, whereas LE1601 intersects the Concordia curve at two points, implying the occurrence of an event of significant impact. For the rock sample at CP1610, the estimated mean age is 1742.2 ± 9.2 Ma with mean squared weighted deviation (MSWD) = 0.49 and probability of equivalence of 0.90; 1748 ± 15 Ma -MSWD = 1.02 and probability of equivalence of 0.40 for GD1622; and 1784.4 ± 9.1 Ma with MSWD of 1.09 and probability of equivalence of 0.37 for LE1601. But for samples at GD1601, two different age groups with different means occurred: 1) below the global mean (1792.2 ± 32 Ma) estimated at 1738.2 ± 14 Ma with MSWD of 0.109 and probability of equivalence of 0.95 and 2) above it with mean of 1838.22 ± 14 Ma, MSWD of 1.6 and probability of equivalence of 0.95. Analysis of the zircon grains has shown a discrepancy in the age range between 1700 Ma and 1800 Ma compared to the ASO dated to have occurred between 440 and 300 Ma. Moreover, apparent similarity in age of the core and rim means that the mineral crystallized relatively quickly without significant interruptions and effect on the isotopic system. This may have constraint the timing and extent of geological events that might have affected the mineral, such as metamorphism or hydrothermal alteration.

Fluid Mechanical Characteristics Induced by Various Stents in Blood Vessel

서태원,Abdul Barakat 대한기계학회 2014 대한기계학회 춘추학술대회 Vol.2014 No.4-4

고리형 약물분출 스텐트 주위 벽전단응력의 영향에 대한 수치해석

서태원,Abdul Barakat 대한기계학회 2007 大韓機械學會論文集B Vol.31 No.1

The assessment of the performance of drug-eluting stent using computational fluid dynamics

서태원,Abdul I. Barakat 한국유변학회 2009 Korea-Australia rheology journal Vol.21 No.4

Numerical investigations have been conducted on the assessment of the performance of drug-eluting stent. Computational fluid dynamics is applied to investigate the flow disturbances and drug distributions released from the stent in the immediate vicinity of the given idealized stent in the protrusion into the flow domain. Our simulations have revealed the drug concentration in the flow field due to the presence of a drug-eluting stent within an arterial segment. Wall shear stress increases with Reynolds number for a given stent diameter, while it increases with stent diameter for a given Reynolds number. The drug concentration is dependent on both Reynolds number and stent geometry. In pulsatile flow, the minimum drug concentration in the zone of inter-wire spacing occurs at the maximum acceleration of the inlet flow while the maximum drug concentration gains at the maximum deceleration of the inlet flow. These results provide an understanding of the flow physics in the vicinity of drug-eluting stents and suggest strategies for optimal performance of drug-eluting stent to minimize flow disturbance.

Numerical simulations of fluid mechanical interactions between two abdominal aortic branches

서태원,김태동,Abdul.I. Barakat 한국유변학회 2004 Korea-Australia rheology journal Vol.16 No.2

Assessment of Jordanian Patient's Colorectal Cancer Awareness and Preferences towards CRC Screening: Are Jordanians Ready to Embrace CRC Screening?

Omran, Suha,Barakat, Husam,Muliira, Joshua Kanaabi,Bashaireh, Ibrahim,Batiha, Abdul-Moni'm Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.10

Background: Colorectal cancer (CRC is increasingly becoming a major cause of cancer morbidity and mortality in Jordan. However the population's level of awareness about CRC, CRC screening test preferences and willingness to embrace screening are not known. The aim of this study was to assess the level of CRC awareness and screening preferences among Jordanian patients. Materials and Methods: A survey assessing the CRC knowledge levels was distributed among patients attending outpatient gastroenterology clinics in public hospitals throughout Jordan. A total of 800 surveys were distributed and of these 713 (89.1%) were returned. Results: Only 22% of the participants correctly judged CRC among the choices provided as the commonest cause of cancer related deaths. The majority of participants (68.3%) underestimated their risk for CRC. Only 26.8% correctly judged their life time risk while 5% overestimated their risk. Two thirds of participants (66%) were willing to pay 500 Jordanian Dinars (equivalent to 706 US$) in order to get a prompt colonoscopy if recommended by their physician, while 25.5% reported that they would rather wait for 6 months in order to get a free colonoscopy. Conclusions: Although the participants tended to underestimate their risk for CRC, they were mostly aware of CRC as a major cause of mortality and were willing to embrace the concept of CRC screening and bear the related financial costs. These findings about CRC awareness and propensity for screening provide a good foundation as the Jordanian health system moves forward with initiatives to promote CRC screening and prevention.

전산유체역학을 이용한 스텐트 설계

김태동,서태원,Abdul Barakat 대한기계학회 2005 大韓機械學會論文集B Vol.29 No.9

The assessment of the performance of drug-eluting stent using computational fluid dynamics

Seo, Tae-Won,Barakat, Abdul I. The Korean Society of Rheology 2009 Korea-Australia rheology journal Vol.21 No.4

Numerical investigations have been conducted on the assessment of the performance of drug-eluting stent. Computational fluid dynamics is applied to investigate the flow disturbances and drug distributions released from the stent in the immediate vicinity of the given idealized stent in the protrusion into the flow domain. Our simulations have revealed the drug concentration in the flow field due to the presence of a drug-eluting stent within an arterial segment. Wall shear stress increases with Reynolds number for a given stent diameter, while it increases with stent diameter for a given Reynolds number. The drug concentration is dependent on both Reynolds number and stent geometry. In pulsatile flow, the minimum drug concentration in the zone of inter-wire spacing occurs at the maximum acceleration of the inlet flow while the maximum drug concentration gains at the maximum deceleration of the inlet flow. These results provide an understanding of the flow physics in the vicinity of drug-eluting stents and suggest strategies for optimal performance of drug-eluting stent to minimize flow disturbance.

여러 형상을 고려한 약물분출 스텐트의 성능에 대한 수치해석적 연구

서태원(Taewon Seo),Abdul I. Barakat 대한기계학회 2012 大韓機械學會論文集B Vol.36 No.6

본 연구는 내피세포 표면에 약물방출 스텐트에서 방출되는 약물의 농도와 약물분출 스텐트의 형상과 설계가 스텐트 주위 유동특성에 어떤 영향을 미치는지를 조사하기 위해 전산유체역학을 이용하여 연구를 수행하였다. 본 연구에서는 이상적으로 가정된 세 종류의 스텐트 모델과 임상결과를 거쳐 상용화 되고 있는 세 종류의 스텐트 모델에 대하여 전산수치해석을 수행하였다. 본 연구의 목적은 스텐트의 성능을 정량적으로 평가할 수 있는 스텐트 영향 지수의 개념을 소개하고, 성능을 비교하는 것이다. 비교 결과, 연구된 세 종류의 상용 스텐트 모델 중 수치 모사에 적용된 모든 레이놀즈 수에 대하여 BX Velocity 스텐트의 스텐트 영향 지수가 가장 낮게 나타났다. 그러나 여섯 종류의 스텐트 모델 가운데에서는 전산 수치 모사에 적용된 모든 유동조건하에서 Spiral 스텐트의 스텐트 영향 지수가 가장 낮고 성능 역시 가장 좋은 것으로 나타났다. In this study, we performed computational fluid dynamic simulations to explore how the detailed design of drug-eluting stents affects both the flow field in the vicinity of the stent as well as the concentration of the eluted drug at the endothelial cell surface. Simulations were performed on three idealized stent geometries we developed and on geometries approximating three commercial stents,: Medtronic’s Aurora stent, Cordis’s BX Velocity stent, and Boston Scientific’s Wallstent. An important contribution of the present study is the introduction of the stent effectiveness index (EI), which provides a quantitative assessment of stent performance and an objective basis for comparing the performance of different stents. Among the three commercial stents studied, our simulations have revealed that the BX Velocity stent is associated with the lowest in-stent EI values for the range of flowReynolds numbers studied (200 ≤ Re ≤ 800). In addition to commercial stent designs, we investigated the EI in three idealized stents and determined that a spiral stent provides excellent performance (low EI) under all flow conditions investigated.

약물분출 스텐트에서의 유동특성에 대한 수치해석적

서태원(Taewon Seo),Abdul I. Barakat 대한기계학회 2011 대한기계학회 춘추학술대회 Vol.2011 No.10

In this study, we performed computational fluid dynamic simulations to explore how the detailed design of drugeluting stents affects both the flow field in the vicinity of the stent as well as the concentration of the eluted drug at the endothelial cell surface. Simulations were performed on three idealized stent geometries we developed and approximating three commercial stents, Medtronics Aurora stent, Cordis BX Velocity stent, and Boston Scientifics Wallstent. An important contribution of the present study is the introduction of the stent effectiveness index (SEI) which provides a quantitative assessment of stent performance and an objective basis for comparing the performance of different stents. Among the three commercial stents studied, our simulations have revealed that the BX Velocity stent is associated with the lowest in-stent SEI values for the range of flow Reynolds numbers studied (200≤Re≤800). In addition to commercial stent designs, we investigated the SEI in three idealized stents and determined that a spiral stent provides excellent performance (low SEI) under all flow conditions investigated.