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Effects of Gas Metal Arc Welding Techniques on the Mechanical Properties of Duplex Stainless Steel  [PDF]
Tanimu Ibrahim, Danjuma S. Yawas, Shekarau Y. Aku
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2013, DOI: 10.4236/jmmce.2013.15035
Abstract: The study has compared the effect of gas metal arc welding techniques on some mechanical properties of duplex stainless steel. The samples after welded were given post weld heat treatment (quenching in engine and neem oil). After the analyses, it was established that duplex stainless steel can be weld successfully using gas metal arc welding process (GMAW). Both Lubricating oil and neem oil can serve as quenching medium for post welding heat treatment of duplex stainless steel. The results of the studies also show that welding and heat treatment really affect the mechanical properties of the alloy; the control strength was 811.47 MN/m2 while that of the welded samples ranged from 177.07 to 257.32 MN/m2. The control impact energy was 162.70 J, while that of the welded samples ranged from 38.64 J to 56.20 J. The research also shows that the stress relief heat treatment gives better strength (A3 = 331 MN/m2) compared to those that were quenched in lubricating oil (A2 = 329 MN/m2) and neem oil (A1 = 222 MN/m2), but the reverse is the case in terms of toughness.
Anomalous Viscosity of Vortex Hall States in Graphene  [PDF]
Rabiu Musah, Samuel Y. Mensah, Ibrahim Y. Seini, Sulemana S. Abukari
Journal of Applied Mathematics and Physics (JAMP) , 2015, DOI: 10.4236/jamp.2015.312190
Abstract: We study temperature effect on anomalous viscosity of Graphene Hall fluid within quantum many-vortex hydrodynamics. The commonly observed filling fraction, in the range is considered. An expression for anomalous viscosity dependent on a geometric parameter-Hall expansion coefficient is obtained at finite temperatures. It arises from strained induced pseudo-magnetic field in addition to an anomalous term in vortex velocity, which is responsible for renormalization of vortex-vortex interactions. We observed that both terms greatly modify the anomalous viscosity as well as an enhancement of weakly observed v fractions. Finite values of the expansion coefficient produce constant and infinite viscosities at varying temperatures. The infinities are identified as energy gaps and suggest temperatures at which new stable quantum hall filling fractions could be seen. This phenomenon is used to estimate energy gaps of already measured fractional Quantum Hall States in Graphene.
Some Characteristics of Amberlite XAD-7-adsorbed Lipase from Pseudomonas sp. AK
Lo, Y. S.,Ibrahim, C. O.
Malaysian Journal of Microbiology , 2005,
Abstract:
Steam Power Plant Design Upgrading (Case Study: Khoms Steam Power Plant)
Hesham G. Ibrahim,Mokhtar S. Elatrash,Aly Y. Okasha
Energy and Environment Research , 2011, DOI: 10.5539/eer.v1n1p202
Abstract: Built during the seventies and commissioned in 1980, Khoms Steam Power Plant consists of four units. A proposed design modifications based on Hysys simulation is to improve the overall efficiency, reduce gas emissions and lower operation and maintenance costs. Five proposed modifications based on reduction of heat loss from the condenser and lowering heating rate reveal that a single open feedwater heater process is the optimum design modification of Rankine cycle to achieve the targeted objectives.
Magnetoplasmon excitations at graphene vortex Hall fluid edge
M. Rabiu,S. Y. Mensah,S. Y. Ibrahim,S. S. Abukari
Physics , 2015,
Abstract: We investigate magnetoplasmon dynamics localized on the edges of graphene vortex Hall fluid. The vortex matter captures an anomalous term that causes vortex localization near fluid boundary and creates a double boundary layer, $\Delta_0\propto (\beta-1)\ell_B$ with $\beta$ being filling factor. The term also has qualitative effect on resonant excitations of edge magnetoplasmons. We found that for sharp edges under experimental conditions, graphene Edge Magnetoplasmon (EMP) resonances have similar behavior as in recent experiments. Gradual distinctions arise for smooth edges in the presence of the anomalous term, where a weak EMP peak appear. The second peak becomes well noticed as the smoothness is increased. We identified the resonant mode as an Inter-EMP. It originates from the oscillations of charges in the inner boundary of the double layer. The present observation brings to light the direct cause of Inter-EMP which remained to be detected in graphene experiments.
Management for Pediatric Pleural Empyema in Resource-Poor Country: Is Chest Tube Drainage with Antiseptic Lavage-Irrigation Better than Tube Thoracostomy Alone?  [PDF]
Seydou Togo, Moussa Abdoulaye Ouattara, Ibrahim Sangaré, Jacque Saye, Cheik Amed Sékou Touré, Ibrahim Boubacar Maiga, Dokore Jerome Dakouo, Liang Guo, Sékou Koumaré, Adama Konoba Koita, Zimogo Zié Sanogo, Sadio Yéna
Surgical Science (SS) , 2015, DOI: 10.4236/ss.2015.612077
Abstract: Drainage by chest tube thoracostomy is widely used in treatment of early empyema thoracis in children, but drainage with antiseptic lavage-irrigation is more frequent in our context since the last 20 years. This study was to determine which was more effective in our experience comparing chest tube drainage with catheter antiseptic lavage-irrigation versus drainage by chest tube thoracostomy alone in the management of empyema thoracis in children. Patients and Methods: Demographic, clinical and microbiological data on children with thoracic empyema undergoing drainage by chest tube thoracostomy alone or with antiseptic lavage-irrigation were obtained from 2 thoracic surgical centers from September 2008 to December 2014. It was a retrospective study included 246 children (137 boys and 109 girls) who were managed for empyema thoracis at the author’s different department of surgery. Outcomes analysis with respect to treatment efficacy, hospital duration, chest tube duration, hospital costs, and need for subsequent procedures was analyzed and compared in the 2 groups. Results: Drainage of pus and antiseptic irrigation resulted in resolution of pyrexia with improvement in general condition in 85.82% of patients in group 1 and by tube thoracostomy alone in 73.95% in group 2. There are a significant difference in the length of hospital stay (p = 0.022), duration of chest tubes in situ (p = 0.040), treatment coast (p = 0.015) and outcome of stage 2 empyema disease (p = 0.037) between the 2 groups. Conclusion: it seems that chest tube drainage with antiseptic lavage-irrigation method is associated with a higher efficacy, shorter length of hospital stay, shorter duration of chest tube in situ, less cost and better outcome of stage 2 empyema diseases than a treatment strategy that utilizes chest tube thoracostomy alone.
Anomalous viscosity of vortex hall states in graphene
Rabiu Musah,Samuel Y. Mensah,Ibrahim Y. Seini,Suleimana S. Abukari
Physics , 2015,
Abstract: We study temperature effect on anomalous viscosity of Graphene Hall fluid within quantum many-vortex hydrodynamics. The commonly observed filling fractions, $\nu$ in the range $0 < \nu < 2$ is considered. An expression for anomalous viscosity dependent on a geometric parameter-Hall expansion coefficient, is obtained at finite temperatures. It arises from strained induced pseudo-magnetic field in addition to an anomalous term in vortex velocity, which is responsible for re-normalization of vortex-vortex interactions. We observed that both terms greatly modify the anomalous viscosity as well as an enhancement of weakly observed v fractions. Finite values of the expansion coefficient produce a constant and an infinite viscosity at varying temperatures. The infinities are identified as energy gaps and suggest temperatures at which new stable quantum hall filling fractions could be seen. This phenomenon is used to estimate energy gaps of already measured fractional quantum Hall states in Graphene.
Mycobiota and Mycotoxins of Egyptian Peanut (Arachis hypogeae L.) Seeds
M.S. Youssef,O.M.O. El-Maghraby,Y.M. Ibrahim
International Journal of Botany , 2008,
Abstract: Sixty-three species in addition to 3 varieties of 21 genera were isolated from 20 samples of each of untreated (51 species + 3 varieties of 21 genera and 51.24x103 cfu g-1 dry weight seeds), roasted (28 + 2 of 12 and 11.5x103 cfu) and roasted with salt (28 + 2 of 7 and 7.5x103 cfu) on dextrose-Czapek`s agar at 28 °C using dilution-plate method. The dominant fungal genera with their respective species on three types of seeds were Aspergillus (A. niger, A. flavus and A. ficuum), Penicillium (P. citrinum) and Fusarium (F. oxysporum). Based on biological, TLC, spectrophotometeric and ELISA assays, fourteen samples (23.3%) out of 60 tested proved to be toxic with different mycotoxins; aflatoxins, sterigmatocystin, ochratoxins, diacetoxyscirpenol and zearalenone. Also, mycoflora and myctoxins of six cultivars, widely cultivated in Upper Egypt were studied as pre-storage and post-storage in normal store for 3, 6, 12 and 24 months. A total of 28 species belonging to 14 genera were identified on dextrose-Czapek`s agar medium (25 species of 12 genera) and cellulose-Czapek`s agar medium (24 of 12) using dilution-plate method at 28 °C. Aspergillus (A. niger, A. flavus and A. fumigatus), Fusarium (F. oxysporum) and Penicillium (P. citrinum) were the most prevalent fungal genera and species and their counts increased with lengthening of storage period. Cultivars were non-toxic, but toxins production appeared after 12 and 24 months of storage on two and three cultivars, respectively.
Cryptography Using Multiple Two-Dimensional Chaotic Maps
Ibrahim S. I. Abuhaiba,Amina Y. AlSallut,Hana H. Hejazi,Heba A. AbuGhali
International Journal of Computer Network and Information Security , 2012,
Abstract: In this paper, a symmetric key block cipher cryptosystem is proposed, involving multiple two-dimensional chaotic maps and using 128-bits external secret key. Computer simulations indicate that the cipher has good diffusion and confusion properties with respect to the plaintext and the key. Moreover, it produces ciphertext with random distribution. The computation time is much less than previous related works. Theoretic analysis verifies its superiority to previous cryptosystems against different types of attacks.
Studies on effects of lactose on experimental Trypanosoma vivax infection in Zebu cattle. 1. Plasma kinetics of intravenously administered lactose at onset of infection and pathology
M. Y. Fatihu,S. Adamu,I. A. Umar,N. D.G. Ibrahim
Onderstepoort Journal of Veterinary Research , 2010, DOI: 10.4102/ojvr.v75i2.15
Abstract: Lactose in normal saline was administered intravenously to a group of Zebu cattle infected with Trypanosoma vivax to determine the bloodplasma kinetics at onset of an experimental infection and its ability to protect tissues against damage as part of preliminary studies to determine its suitability for use in the treatment of trypanosomosis. Significant (P <0.01) higher lactose concentrations were observed in the T. vivax-intecled bulls at 30 min and 1h (P< 0.05) post-infectio (p.i.) and by 4 h p.i. the plasma lactose remained above the level prior to infusion, after which it fell slightly below the preinfusion level in the uninfected group. Calculated pharmacokinetic parameters revealed delayed excretion of lactose in the T. vivax-intected group soon after infection. The total body clearance (C/B )was significantly (P < 0.05) reduced. The biological half-life (t1/2), elimination rate constant (kel) and apparent volume of distribution (Vd) were relatively decreased (P > 0.05) as a result of the T. vivax infection. Retention of lactose in the plasma was attributed to decreased plasma clearance l.t is suggested that the presence of trypanosomes in circulation rather than organic lesions could have been responsible for the delay observed in the excretion of lactose. At 12 weeks p.i., when the experiment was terminated, the group infected and given lactose infusion (despiteh igherp arasitaemia) had no gross or histopathological lesions in the brain, spleen, lymphnodes, heart, kidneys, liver and testes. However, the group infected but not infused with lactose were emaciated, had pale mucosae, watery blood, general muscular atrophy, serous atrophy of coronary fat and other adiposet issue, hepatomegalys, plenomegalys, wollen and oedematous lymph nodes, all of which are suggestive of trypanosomosis. Histopathological lesions included arrowing of Bowman's space and hypercellularity of glomerular tufts in the kidneys with the mean glomerula truft nucleairn dices (GTNs) in the group significantly higher (P <0.01)than the mean GTNs of the lactoseinfused and control bulls. Degenerative changes occurred in the myocardium, spleen, testes and epididymides. The tesicular and epididymal lesions are indicative of male reproductive dysfunction.
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