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Ibrahim Ali,Henry Saari 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.9
Following decades of laboratory research and nearly zero carbon emissions, supercritical carbon dioxide (S-CO 2 ) gas turbine power plants are poised to replace steam power plants. A S-CO 2 gas turbine power plant can provide sustainable power generation systems for higher plant operations’ efficiency. However, the purity of the working fluid is one of the power plant’s most crucial sustainability factors, and it must be analyzed and fully understood. This work aims to investigate the effect of common impurities on the 10 MW S-CO 2 gas turbine performance, using the software program reference fluid thermodynamic and transport database version 10 to calculate pure and mixed CO 2 and determine the fluid density at the main compressor inlet. The analysis reveals that non-condensable impurities in N 2 , O 2 , Ar, CH 4 , and He have a negative effect on the cycle performance. The presence of 1 % impurity in O 2 , CH 4 , Ar, N 2 , and He in 99 % rich CO 2 decreases the cycle efficiency from 48.25 % to 47.27 %, 44.86 %, 44.12 %, 35.71 %, and 23.95 %, respectively. The results show that the presence of 1 % He raises the turbine and recompressor inlet temperatures from 973.15 K to 1774.9 K and 361.37 K to approximately 801.52 K, respectively. Impurities such as CH 4 and O 2 must have limited tolerance, whereas N 2 and He must have a zero-tolerance level. The condensable impurities in H 2 O, H 2 S, and SO 2 have a positive effect on the cycle efficiency. The presence of 1 % in H 2 O, H 2 S, and SO 2 in 99 % CO 2 increases the cycle efficiency by 2.3 %, 1.7 %, and 1.2 %, respectively, and can corrode turbine blades and materials. Continued work is necessary to fully understand the effects of impurities in the working fluid of an S-CO 2 gas turbine power plant performance over time so as to ensure quality construction and safe and efficient operations.
Ali M. Ali,Ahmed M.A. Ibrahim 한국응용곤충학회 2018 Journal of Asia-Pacific Entomology Vol.21 No.2
Two plant essential oils; camphor and castor were tested for insecticidal and antifeedant activity against the 4th instar larvae of Spodoptera littoralis, a serious pest on cotton in Egypt. Also the impact of LC10 of both oils on some physiological parameters in larvae was studied by using leaf dipping technique. Analysis of both oils using GC–MS revealed several insecticidal and antifeedant compounds. Our results showed higher insecticidal activity and antifeedant index of camphor oil against S. littoralis. The LC50 and the antifeedant indices were 163.1, 246.8 mg/ml and 12.69, 6.62% for camphor and castor bean oil, respectively. The total hemocyte count (THC) and differential hemocyte count (DHC) were reduced significantly after 48 h of treatment compared to controls. Both oils reduced all types of hemocytes except plasmatocytes which were reduced only by castor oil. Camphor oil decreased total proteins and carbohydrates while castor oil targeted only carbohydrate content. Both oils didn't affect the amount of total lipids. Lipase, α-amylase and glucose-6-phosphate dehydrogenase (G6PD) enzyme activities were increased significantly in larvae treated with camphor oil than other treatments. These results clearly indicate that castor and camphor oils can affect the nutritional status in S. littoralis larvae, thereby changing the internal metabolic processes in the larvae which make them as potential control agents in IPM programs against S. littoralis.
Significance of endangered and threatened plant natural products in the control of human disease
Ibrahim, Mohamed Ali,Na, MinKyun,Oh, Joonseok,Schinazi, Raymond F.,McBrayer, Tami R.,Whitaker, Tony,Doerksen, Robert J.,Newman, David J.,Zachos, Louis G.,Hamann, Mark T. National Academy of Sciences 2013 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.110 No.42
<P>One in five of the world’s plant species is threatened with extinction according to the 2010 first global analysis of extinction risk. Tilman et al. predicted a massive ecological change to terrestrial plants within the next 50–100 y, accompanied by an increase in the number of global plant species facing extinction [Tilman D, et al. (2001) <I>Proc Natl Acad Sci USA</I> 98(10):5433–5440]. Most of the drug-producing plant families contain endangered species never previously studied for their utility to human health, which strongly validates the need to prioritize protection and assessment of these fragile and endangered groups [Zhu F, et al. (2011) <I>Proc Natl Acad Sci USA</I> 108(31):12943–12948]. With little prior attention given to endangered and rare plant species, this report provides strong justification for conservation of the rare plant <I>Diplostephium rhododendroides</I> Hieron., as well as other potential drug-producing endangered species in this and other groups.</P>
Ali, Ibrahim K.,Sansare, Kaustubh,Karjodkar, Freny R.,Vanga, Kavita,Salve, Prashant,Pawar, Ajinkya M. Korean Academy of Oral and Maxillofacial Radiology 2017 Imaging Science in Dentistry Vol.47 No.1
Purpose: This study aimed to evaluate the prevalence of Haller cells and accessory maxillary ostium (AMO) in cone-beam computed tomography (CBCT) images, and to analyze the relationships among Haller cells, AMO, and maxillary sinusitis. Materials and Methods: Volumetric CBCT scans from 201 patients were retrieved from our institution's Digital Imaging and Communications in Medicine archive folder. Two observers evaluated the presence of Haller cells, AMO, and maxillary sinusitis in the CBCT scans. Results: AMO was observed in 114 patients, of whom 27 (23.7%) had AMO exclusively on the right side, 26 (22.8%) only on the left side, and 61 (53.5%) bilaterally. Haller cells were identified in 73 (36.3%) patients. In 24 (32.9%) they were present exclusively on the right side, in 17 (23.3%) they were only present on the left side, and in 32 (43.8%) they were located bilaterally. Of the 73 (36.3%) patients with Haller cells, maxillary sinusitis was also present in 50 (68.5%). On using chi-square test, a significant association was observed between AMO and maxillary sinusitis in the presence of Haller cells. Conclusion: Our results showed AMO and Haller cells to be associated with maxillary sinusitis. This study provides evidence for the usefulness of CBCT in imaging the bony anatomy of the sinonasal complex with significantly higher precision and a smaller radiation dose.
Ibrahim K. Ali,Kaustubh Sansare,Freny R Karjodkar,Kavita Vanga,Prashant Salve,Ajinkya M. Pawar 대한영상치의학회 2017 Imaging Science in Dentistry Vol.47 No.1
Purpose: This study aimed to evaluate the prevalence of Haller cells and accessory maxillary ostium (AMO) in cone-beam computed tomography (CBCT) images, and to analyze the relationships among Haller cells, AMO, and maxillary sinusitis. Materials and Methods: Volumetric CBCT scans from 201 patients were retrieved from our institution’s Digital Imaging and Communications in Medicine archive folder. Two observers evaluated the presence of Haller cells, AMO, and maxillary sinusitis in the CBCT scans. Results: AMO was observed in 114 patients, of whom 27 (23.7%) had AMO exclusively on the right side, 26 (22.8%) only on the left side, and 61 (53.5%) bilaterally. Haller cells were identified in 73 (36.3%) patients. In 24 (32.9%) they were present exclusively on the right side, in 17 (23.3%) they were only present on the left side, and in 32 (43.8%) they were located bilaterally. Of the 73 (36.3%) patients with Haller cells, maxillary sinusitis was also present in 50 (68.5%). On using chi-square test, a significant association was observed between AMO and maxillary sinusitis in the presence of Haller cells. Conclusion: Our results showed AMO and Haller cells to be associated with maxillary sinusitis. This study provides evidence for the usefulness of CBCT in imaging the bony anatomy of the sinonasal complex with significantly higher precision and a smaller radiation dose.
Metathesis of 2-pentene over Mo and W supported mesoporous molecular sieves MCM-41 and SBA-15
Mohamed Ali Ibrahim,Muhammad Naseem Akhtar,Ji rí Cejka,Erica Montanari,Hynek Balcar,Martin Kubu,Sulaiman S. Al-Khattaf 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.53 No.-
Molybdenum and tungsten oxides were supported on silica, MCM-22, MCM-41 and SBA-15. XRD and N2 adsorption–desorption revealed that architecture and textural character of supports were preserved. The catalysts were investigated in transformation of 2-pentene at different reaction temperatures. MoO3/ MCM-22 exhibited highest conversions with isomerization and cracking as major reactions. MoO2(acac)2, MoO3 and WO3 supported on MCM-41 and SBA-15 showed metathesis reaction of 2-C5 = producing propylene, C4 = and C6+ =as major products. Catalysts based on MCM-41 exhibited higher activity and stability than SBA-15. Addition of ethylene to 2-C5 = increased selectivity to propylene due to metathesis of ethylene with 2-pentene.
Embedded Systems: Teaching and Design Challenges for Nonhomogeneous Classes
Intisar Ibrahim Ridwan,Izzeldin Ibrahim Mohamed,Rosmah Ali,Nazar ElFadil 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.10
The growth of technology leads the industry to move beyond and crosses the boundaries of its own disciplines. The changes from pure mechanical system, to electronics systems and the integration with control software brings new challenges to the engineers working in the industry and to the source shaped the engineers. As a result, institutes of higher education need to make the necessary changes to meet this continuing market demands. This work address the issue and describes a new systematic and an effective approach for teaching hardware based courses for large non-homogenous (Computer Science and Electronics students) class setting using existing e-learning system in the university to promote powerful, long-lasting learning outcomes. It is a blend of several approaches with an insightful goal to provoke deeper understanding in various topics in microprocessors and microcontrollers details, intended to teach the computer science students to learn low-level hardware interfacing, interrupt handling, and other microprocessors issues, as well as embedded systems through learning microcontrollers. Our methodology revolute around three steps: using visual simulators, incrementally weighted exercises, from easiest to hardest, and finally working on real hardware controllers. The proposed approaches developed for the course “Embedded Controller Technology”, but any other hardware based course can apply them. The approach comprises a 3-hour a week lecture and 2-hour a week laboratory, both taught in the 3rd semester. Imposing the approach leads to the overall improvement of the course quality: student satisfaction and interest, increased number of completed hardware projects and significant improvement in grade distribution and it has been observed that students feel better prepared to face the challenges to be found in their future professional activities.
Privatizing Public Sector Companies for Maritime Transport: Assessing the Egyptian Experiment
( Mohamed M. Ali Ibrahim ),( Hyun Deok Kim ) 한국해운물류학회(구 한국해운학회) 2004 해운물류연구 Vol.41 No.-
This paper aims at assessing the Egyptian experiment in privatising public sector companies for maritime transport through: first, reviewing the economic thought regarding privatisation and the history of Egyptian public sector; second, researching the role of IMF and the WB programs in privatising public sector in Egypt and developing countries : third, assessing the Egyptian experiment in privatising maritime transport companies which are the Alexandria shipping agencies company and the Arab United stevedoring company.