57 research outputs found
Essays on the effect of inflation volatility and institutions on growth and development
No full textThe purpose of this dissertation is to analyze empirically and theoretically the impact of the decrease in inflation volatility versus the impact of the improvement in institutions on growth and development. The first chapter of this dissertation estimates the effects of inflation and inflation volatility on economic growth in the presence of different degrees of legal and financial institutions. The main contribution of this chapter is to show that while the level of inflation does not have a significant effect on growth, which is in line with previous studies; inflation volatility does significantly impact growth even for countries with moderately high levels on inflation. In addition, improving either legal or financial institutions has a statistically significant positive impact on growth and helps to reduce the negative impact of inflation volatility on growth.
The second chapter analyzes the channel through which inflation volatility and financial institutions affect a country's ability to borrow on international capital markets; which affects their ability to invest and therefore grow. The findings of this chapter show that reducing inflation volatility or improving financial institutions will significantly improve a country's sovereign debt rating leading to a drop in its cost of borrowing, which is to be quantified. One important contribution of this chapter is to show that it is inflation volatility that is important in determining a country's sovereign debt rating rather than the level of inflation which has been argued in the literature.
The welfare implications of the decrease in inflation volatility versus the improvement in institutions are quantified in chapter three. This chapter analyzes a micro-foundation based small open economy model that is used to help fully understand the dynamics of a decrease in inflation volatility and an improvement in institutions for a developing economy. The study finds that the welfare effect of improving institutions and of reducing inflation volatility is large with the largest effect being caused by an improvement in financial institutions. One policy implication of these results is that developing economies can get larger welfare gains from improving their institutions than from reducing inflation volatility.Ph.D.Includes bibliographical references (p. 177-188)by Noha Emar
CFD Analysis and Experimental Investigation of a Heavy Duty D.I. Diesel Engine Exhaust System
No full textExhaust manifold is one of the most critical components of an internal combustion engines and overall engine performance can be obtained from the proper optimized design of engine inlet and exhaust systems. In this study two exhaust system models with different configuration (the existing as base one and the modified one) are simulated using ANSYS-CFX 15 with the appropriate boundary conditions and fluid properties specified to the system with suitable assumptions. The model is based on solving NAVIERE STOKES and energy equations in conjunction with the standard K-ε turbulence model. The first design is a single pipe receives exhaust gases from all runners and delivers the exhaust gases to turbocharger inlet. But the second design consists of two tubes each of one receives the exhaust gases coming from the three cylinders only. This design makes the intensity of the exhaust pulses of high pressure, which leads to increase the speed of the turbocharger. The uniformity of the flow field and back pressure variations in the two models are discussed in. A decrease in backpressure and increase in velocities are shown using the pressure contour and the velocity contour in the exhaust manifold as well as temperature distribution inside the exhaust manifold system. The best design is also simulated at different engine speed. Finally the modified model with limited back pressure was fabricated and experiments are carried out on a fully instrumented six cylinder in line water cooled heavy duty direct injection diesel engine; (350 hp@2200 rpm and 1400 Nm@1350 rpm).The pressure and temperature are measured at definite points in the exhaust gas manifold. The results obtained by experimental work were compared with the analytic CFD and found to be closely matching with accepted error.</jats:p
Turbocharging of a Heavy Duty Diesel Engine for a Specific Power and Performance Enhancement
No full textThe impact of ghrelin on oxidative stress and inflammatory markers on the liver of diabetic rats
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Numerical Study for Progressive Failure of High Rise Stepped Steel Building
No full textAbstract: Progressive collapse of a structure happens when one or more primary members are suddenly lost due to an unfortunate accident such as a gas explosion, bomb attack, fire, or overloaded. Building irregularity is one aspect that might aggravate the damage caused by gradual failure. The progressive failure of high rise stepped frames was investigated using 3-dimensional modelling and the finite element approach in this paper. The steel structure has 30 stories and rigid moment-resisting steel frames. Abaqus software is used to perform nonlinear dynamic analysis in accordance with GSA criteria. The results of Abaqus model are verified with an experimental data and good agreement is achieved. The structural behaviour of the building under sudden column loss was studied in detail using this model for several scenarios of column removal.
Keywords: Progressive failure; Nonlinear dynamic analysis; High rise steel building; Finite element; Column removal.
Title: Numerical Study for Progressive Failure of High Rise Stepped Steel Building
Author: Mohamed Basel Emara, Sameh Moustafa Gaawan, Mahmoud Shahat Mahmoud, Mohamed Mohamed Yahia
International Journal of Civil and Structural Engineering Research
ISSN 2348-7607 (Online)
Vol. 10, Issue 1, April 2022 - September 2022
Page No: 110-118
Research Publish Journals
Website: www.researchpublish.com
Published date: 20-June-2022
DOI: https://doi.org/10.5281/zenodo.6670584
Paper Download Link (Source)
https://www.researchpublish.com/papers/numerical-study-for-progressive-failure-of-high-rise-stepped-steel-buildingInternational Journal of Civil and Structural Engineering Research, ISSN 2348-7607 (Online), Research Publish Journals (Publisher), Website: www.researchpublish.co
Behaviour of high rise irregular plan steel building in progressive failure due to sudden column removal
No full textAbstract: Progressive failure can be described as step-by-step failure in building caused by the sudden loss of one or a few structural elements, which generates a chain reaction of failures for the adjacent structural elements, which leads to the entire structure failing. One of the factors that can amplify the damage caused by progressive failure is building irregularity. Three dimensional modeling, using the finite element method was developed to investigate the progressive failure of high rise irregular plan building consist of 30 storey with rigid moment resisting steel frames. Non-linear dynamic analysis is carried out following GSA guidelines using ABAQUS software. The modeling techniques were described in detail. The obtained numerical results are compared with experimental data and good agreement is attained. Using this model, the structural behavior of the building under the sudden columns loss for different scenarios of column removal were assessed in detail.
Keywords: Progressive failure; Nonlinear dynamic analysis; High rise steel building; Finite element; Column removal.
Title: Behaviour of high rise irregular plan steel building in progressive failure due to sudden column removal
Author: Mohamed Basel Emara, Sameh Moustafa Gaawan, Mahmoud Shahat Mahmoud, Mohamed Mohamed Yahia
International Journal of Civil and Structural Engineering Research
ISSN 2348-7607 (Online)
Vol. 10, Issue 1, April 2022 - September 2022
Page No: 99-109
Research Publish Journals
Website: www.researchpublish.com
Published date: 12-June-2022
DOI: https://doi.org/10.5281/zenodo.6635695
Paper download Link (Source)
https://www.researchpublish.com/papers/behaviour-of-high-rise-irregular-plan-steel-building-in-progressive-failure-due-to-sudden-column-removalInternational Journal of Civil and Structural Engineering Research, ISSN 2348-7607 (Online), Research Publish Journals
Website: www.researchpublish.co
The value of pericardial window in preventing pericardial effusion after cardiac surgery
Get PDFBackground: Pericardial window (PW) is a technique that allows the passage of fluid from the pericardial to the pleural cavity to reduce the postoperative pericardial effusion. The purpose of this study was to evaluate the effectiveness of the pericardial window in decreasing pericardial effusions after cardiac surgery.
Methods: The study included 400 adult patients who underwent cardiac surgery from 2017 to 2020. Patients were randomly assigned into two groups; the pericardial window (PW) group included 200 patients who underwent posterior pericardiotomy, and the control group included 200 patients who did not undergo this procedure.
Results: Preoperative data were comparable between both groups. More patients in the PW group had chest tube drainage more than 500 cc/ 24 hours (40 (20%) vs. 5 (2.5%), respectively; p=0.005). The drainage of 500 cc/24 hours or more in the mediastinal tube was lower in the PW group (10 (5%) vs. 40 (20%) patients in the PW and control groups, respectively; p<0.001). Early pericardial collection occurred in 6 patients in the PW group (3%) vs. 46 (23%) in the control group (p<0.001), and no patient had late effusion in the PW group vs. 26 (13%) in the control group (p< 0.001). Six patients in the PW group (3%) had postoperative atrial fibrillation and 12 patients (6%) in the control group (p= 0.23). Pulmonary complications were nonsignificantly higher in the PW group (Lung collapse: 40 (20%) vs. 26 (13%); p=0.08 and pleural effusion: 34 (17%) vs. 26 (13%); p= 0.3, in the PW vs. control groups, respectively).
Conclusion: Posterior pericardiotomy is a simple technique that could reduce postoperative pericardial effusion, atrial fibrillation, and the pericardial tamponade. The technique did not increase the postoperative complications compared to the standard method
Homogeneous degradation of 1,2,9,10-tetrachlorodecane in aqueous solutions using hydrogen peroxide, iron and UV light
No full textThe homogeneous degradation of the polychlorinated n-alkane, 1,2,9,10-tetrachlorodecane (T4C10), was studied in aqueous solutions of hydrogen peroxide, including Fenton and photo-Fenton reaction conditions. All solutions were adjusted to a pH of 2.8 and an ionic strength of 0.1 M NaClO4 prior to photolysis. T4C10 (2 x 10(-6) M) was substantially degraded by the H2O2/UV system (1.0 x 10(-2) M H2O2), with 60% disappearance in 20 min of irradiation in a photoreactor equipped with 300 nm lamps of light intensity 3.6 x 10(-5) Ein L(-1) min(-1) (established by ferrioxalate actinometry). The reaction produced stoichiometric amounts of chloride ion indicating complete dechlorination of the chlorinated n-alkane. T4C10 degraded very slowly under Fenton (Fe2+/H2O2/dark) and Fenton-like (Fe3+/H2O2/dark) conditions. However, when the same solutions were irradiated, T4C10 degraded more rapidly than in the H2O2/UV system, with 61% disappearance in 10 min of exposure. The rapid degradation is related to the enhanced degradation of hydrogen peroxide to oxidizing *OH radicals under photo-Fenton conditions. Degradation was inhibited in both the H2O2/UV and photo-Fenton systems by the addition of KI and tert-butyl alcohol due to *OH scavenging
An Investigation Study of the Thermomechanical Loading on the Piston of a Diesel Engine with Design Improvements
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