399 research outputs found
Analysis of the convergence history of fluid flow through nozzles with shocks
Convergence of iterative methods for the solution of the steady quasi-one-dimensional nozzle problem with shocks is considered. The finite-difference algorithms obtained from implicit schemes are used to approximate both the Euler and Navier-Stokes Equations. These algorithms are investigated for stability and convergence characteristics. The numerical methods are broken down into their matrix-vector components and then analyzed by examining a subset of the eigensystem using a method based on the Arnoldi process. The eigenvalues obtained by this method are accurate to within 5 digits for the largest ones and to within 2 digits for the ones smaller in magnitude compared the elgenvalues obtained using the full Jacobian. In the analysis we examine the functional relationship between the numerical parameters and the rate of convergence of the iterative scheme. Acceleration techniques for iterative methods like Wynn\u27s e-algorithm are also applied to these systems of difference equations in order to accelerate their convergence. This acceleration translates into savings in the total number of iterations and thus the total amount of computer time required to obtain a converged solution. The rate of convergence of the accelerated system is found to agree with the prediction based on the eigenvalues of the original iteration matrix. The ultimate goal of this study is to extend this elgenvalue analysis to multi-dimensional problems and to quantitatively estimate the effects of different parameters on the rate of convergence
Flipped classroom and psycholinguistic factors : an evaluation
Psycholinguistic factors, i.e., motivation, foreign language anxiety, and self-confidence, affect adult EFL learnersâ
learning process in a major way, positively or negatively. Research studies show that in a conventional classroom
setup psycholinguistic factors affect the learning process of a large number of adult EFL learners negatively because
their motivation and self-confidence are low while their foreign language anxiety is high. In the present research
study, a survey was conducted with pre-university students in Saudi Arabia who were taught English as a foreign
language using Flipped Classroom Model (FCM) as a pedagogy approach. The objective of this investigation was to
measure the degree of impact of psycholinguistic factors on the language learning process of students learning English
through an unconventional pedagogic approach, that is, Flipped Classroom Model. The results indicate that the
teaching approach, even if being highly learner-centred, hardly makes any significant difference to learnersâ anxiety,
motivation, or self-confidence as regards learning English as a foreign language. However, in comparison to the
conventional classroom environment, a slightly less number of learners reported the influence of affective factors on
their English learning process under the FCM approach
Management of oesophageal foreign bodies
AbstractObjectiveThe aim of the study was to evaluate the management of foreign bodies in the oesophagus and to determine the association with socioeconomic status.MethodsThis cross-sectional analytical study was carried out in the Department of Ear, Nose and Throat and head and neck surgery of Bahawal Victoria Hospital affiliated with Quaid-i-Azam Medical College, Bahawalpur, Pakistan, between December 2012 and May 2013. The medical records of 34 consecutive cases of foreign body ingestion were searched, and the data were recorded on a questionnaire prepared for this purpose.ResultsThe average age of the patients was 10.38 years; 29 cases (85.2%) were in children under 12 years. There were 18 females (52.9%) and 16 males (47.1%). Thirty patients (88%) presented with a history of dysphagia, and 25 (73.6%) had vomiting. The site of impaction was the post-cricoid region in 22 patients (66%), the lower oesophagus in 5 (15%), the mid-oesophagus in 4 (13%), the posterior pharyngeal wall in 1 (3%) and the pyriform fossa in 1 patient (3%). Coins were the most common foreign body (61.8%). Socioeconomic analysis showed that 18 patients (52.9%) were in the low socioeconomic class, 12 (35.3%) in the middle class and 4 (11.8%) in the upper class.ConclusionThe presence of a foreign body in the oesophagus is a serious condition, and early removal is recommended. Foreign body lodgement is commoner among poor families
The Impact of Using heat Insulation in Reducing Operational Energy and LCA Emission in Local Building,
The Building sector is one of the biggest sector in energy consumption and greenhouse gases emission, and the biggest phase of building life cycle that responsible of that consumption of energy and emission is operation phase (specially Heating and cooling) and itâs effected directly by building material thermal conductivity. There is a different ways to reduce operation consumption of energy and life cycle emission like using insulated wall and glazing. So the research problem will be âthe need of applied research that compare the energy consumption of energy and emissions change in masonry building when using different thermal performance skinsâ. So the goal of the research is âmeasure and compare Building energy consumption in operation phase and emissions in life cycle of Masonry Buildingâ. The conclusion of this research is that the possibility to reduce energy used in building to 44.8% and reducing emission to 56.4% using cavity wall and insulation in Masonry Building. Assessed by Life Cycle Assessment method. Key Words: Emissions, Life Cycle Assessment (LCA), Project Management â Environmental Management
Effect of plasmid replication deregulation via inc mutations on E. coli proteome & simple flux model analysis
When the replication of a plasmid based on sucrose selection is deregulated via the inc1 and inc2 mutations, high copy numbers (7,000 or greater) are attained while the growth rate on minimal medium is negligibly affected. Adaptions were assumed to be required in order to sustain the growth rate. Proteomics indicated that indeed a number of adaptations occurred that included increased expression of ribosomal proteins and 2-oxoglutarate dehydrogenase. The operating space prescribed by a basic flux model that maintained phenotypic traits (e.g. growth, byproducts, etc.) within typical bounds of resolution was consistent with the flux implications of the proteomic changes
Umbelliferone prevents isoproterenol-induced myocardial injury by upregulating Nrf2/HO-1 signaling, and attenuating oxidative stress, inflammation, and cell death in rats
The role of oxidative injury and inflammatory response in cardiovascular diseases and heart failure has been well-acknowledged. This study evaluated the protective effect of umbelliferone (UMB), a coumarin with promising radical scavenging and anti-inflammatory activities, on myocardial injury induced by isoproterenol (ISO) in rats. Rats received 50 mg/kg UMB orally for 14 days and 85 mg/kg ISO twice at an interval of 24 h. Administration of ISO elevated serum troponin I, creatine kinase-MB and lactate dehydrogenase, and caused histopathological alterations, including degeneration, fatty vacuolation, myolysis, and atrophy of myocardial fibers. Malondialdehyde (MDA), nitric oxide (NO), nuclear factor-kappaB (NF-ÎșB) p65, tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1ÎČ were increased, whereas reduced glutathione (GSH), superoxide dismutase (SOD), and catalase were decreased in ISO-administered rats. UMB effectively ameliorated myocardial injury, alleviated cardiac function markers, MDA, NO, NF-ÎșB p65, and the inflammatory mediators, and enhanced cellular antioxidants. Bax, caspase-3, and 8-OHdG were decreased, and Bcl-2 was increased in ISO-administered rats treated with UMB. In addition, UMB upregulated nuclear factor-erythroid factor 2-related factor 2 (Nrf2) and heme oxygenase (HO)-1 in the heart of ISO-administered rats. In conclusion, UMB can protect the myocardium from oxidative injury, inflammatory response, and cell death induced by ISO by upregulating Nrf2/HO-1 signaling and antioxidants
Interaction protocols for cross-organisational workflows
Workflow technologies are widely used in industry and commerce to assist in the specification, execution and completion of well defined processes within organisations. As industrial and commercial relations have evolved, based on advances on information and communications technologies, cross-organisational workflow integration has become an important issue. Since organisations can have very different workflows, the creation of compatible workflows so that organisations can collaborate and/or carry out mutual transactions automatically in an integrated fashion can be a very complex and time consuming process. As a consequence, the development of technologies to support the creation and execution of compatible workflows is a most relevant issue. In the present article we introduce the JamSession coordination platform as a tool to implement cross-organisational workflow integration. JamSession is declarative and based on algebraic specification methods, and therefore workflow integration implemented using this platform can profit from formal behavioural analysis, based on which desired features and properties can be verified and/or obtained
Treatment of Sewer Water Using Alum Salt
This investigation was carried out to study the effect of addition o
Evaluation of vaccine derived poliovirus type 2 outbreak response options: A randomized controlled trial, Karachi, Pakistan
Background: Outbreaks of circulating vaccine derived polioviruses type 2 (cVDPV2) remain a risk to poliovirus eradication in an era without live poliovirus vaccine containing type 2 in routine immunization. We evaluated existing outbreak response strategies recommended by the World Health Organization (WHO) for control of cVDPV2 outbreaks.Methods: Seronegative children for poliovirus type 2 (PV2) at 22âŻweeks of life were assigned to one of four study groups and received respectively (1) one dose of trivalent oral poliovirus vaccine (tOPV); (2) monovalent OPV 2 (mOPV2); (3) tOPV together with a dose of inactivated poliovirus vaccine (IPV); or (4) mOPV2 with monovalent high-potency IPV type 2. Stool and blood samples were collected and assessed for presence of PV2 (stool) and anti-polio antibodies (sera).Results: We analyzed data from 265 children seronegative for PV2. Seroconversion to PV2 was achieved in 48, 76, 98 and 100% in Groups 1â4 respectively. mOPV2 was more immunogenic than tOPV alone (pâŻ\u3câŻ0.001); and OPV in combination with IPV was more immunogenic than OPV alone (pâŻ\u3câŻ0.001). There were 33%, 67%, 20% and 43% PV2 excretors in Groups 1â4 respectively. mOPV2 resulted in more prevalent shedding of PV2 than when tOPV was used (pâŻ\u3câŻ0.001); and tOPV together with IPV resulted in lower excretion of PV2 than tOPV alone (pâŻ=âŻ0.046).Conclusion: mOPV2 was a more potent vaccine than tOPV. Adding IPV to OPV improved immunological response; adding IPV also seemed to have shortened the duration of PV2 shedding. mIPV2 did not provide measurable improvement of immune response when compared to conventional IPV. WHO recommendation to use mOPV2 as a vaccine of first choice in cVDPV2 outbreak response was supported by our findings
Hepatoprotective effect of leaves of aqueous ethanol extract of Cestrum nocturnum against paracetamol-induced hepatotoxicity
The hepatoprotective activities of Cestrum nocturnum (Queen of Night) was evaluated against the paracetamol induced hepatotoxicity in the mice. Aqueous ethanol (30:70) extract of plant was obtained by maceration. Results showed that aqueous ethanol extract of C. nocturnum (250 mg/kg and 500 mg/kg) produced significant (p<0.05) hepatoprotective activities against paracetamol induced liver injury in Swiss albino mice. Histopathalogical studied of liver further supported the hepatoprotective effects of C. notrunum. Phytochemical screening showed the presence of alkaloids, flavonoids, saponins, terpenes, phenolic compounds, carbohydrates and volatile oils. Most of the flavonoids have hepatoprotective activity. Therefore, the hepatoprotective activity of C. nocturnum may be due to the presence of flavonoids and phenolic components. It was concluded from the present study that aqueous ethanol extract of leaves of C. nocturnum has hepatoprotective activity against the paracetamol-induced hepatotoxicity in albino mice
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