Conformal vector fields on doubly warped product manifolds and applications

In this article, we present a complete study of two disjoint classes of conformal vector fields on doubly warped product manifolds as well as on doubly warped space-times. Then we study Ricci solitons on doubly warped product manifollds admitting these types of conformal vector fields

Optimization and visualization of rapid prototyping process parameters.

The optimal selection of rapid prototyping (RP) process parameters is a great concern to RP designers. When dealing with this problem, different build objectives have to be taken into consideration. Using virtual rapid prototyping (VRP) systems as a visualization tool to verify the optimally selected process parameters will assist designers in taking critical decisions regarding modeling of prototypes. This will lead to substantial improvements in part accuracy using minimal number of iterations, and no physical fabrication until confident enough to do so. The purpose of this thesis is to demonstrate that virtual validation of optimally selected process parameters can significantly reduce time and effort spent on traditional RP experimentation. To achieve the goal of this thesis, a multi-objective optimization technique is proposed and a model is generated taking into consideration different build objectives, which are surface roughness, support structure volume, build time and dimensional accuracy. The multi-objective method used is the weighted sum method, where a single utility function has been formulated, which combines all the objective functions together. The orders of magnitudes have been normalized, and finally weights have been assigned for each objective function in order to create the general formulation. (Abstract shortened by UMI.)Dept. of Industrial and Manufacturing Systems Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2004 .E47. Source: Masters Abstracts International, Volume: 43-03, page: 0959. Adviser: Waguih ElMaraghy. Thesis (M.A.Sc.)--University of Windsor (Canada), 2004

Progress in Vaccine Development for HCV Infection

Hepatitis C virus (HCV) is a blood-transmitted disease that spreads among 3% of the world’s population causing seriously increasing mortality rates. The HCV prevalence in Egypt in October 2008 was 14.7% and declined to 6.3% in the survey carried out in October 2015. Nowadays, the new direct-acting antivirals (DAAs) show amazing results especially with regard to HCV genotype 1, but there is still a great necessity to produce a vaccine to avoid this viral infection. Additionally, neutralizing anti-HCV antibodies could be utilized in combination with DAAs empowering their effect. A powerful candidate HCV vaccine should create comprehensively cross-receptive T cells CD4 and CD8 and effectively neutralizing antibodies to successfully clear the virus. The current clinical trials for HCV vaccines comprise synthetic peptides, DNA-based vaccines, or recombinant protein vaccines. Several preclinical vaccine studies are under research including cell culture-derived HCV (HCVcc), HCV-like particles, and recombinant adenoviral vaccines. This mini-review will discuss the prevalence of HCV worldwide and in Egypt. We will present the recent progress in basic research and preclinical and clinical studies for HCV vaccine. Finally, it will present the phenomena of spontaneous clearance of HCV without treatment as a model for study of HCV vaccine development

Exergy-based Index for the assessment of building sustainability

ABSTRACT Exergy-based Index for the assessment of building sustainability Ahmed El shenawy, Ph.D. Concordia University, 2013 The declining state of the environment, combined with the increasing scarcity of natural resources and economic recession, presents us with the need to discover building practices that are capable of producing sustainable buildings. Building promoters are racing to certify the sustainability of their projects, aware that building sustainability assessment will delineate the features of current and future building practice. A sustainable building implies that resource depletion and waste emissions are considered during its whole life cycle. This research project proposes a new methodology and Exergy-based Index to assess building sustainability and to assist decision makers comparing building alternatives, since the wrong decisions can lead to serious consequences and even precipitate crises. The proposed methodology uses the SBTool that has been utilized for defining the criteria for analysing and ranking the environmental performance of buildings. Over the past decade, significant efforts have been made in developing Sustainable Building (SB) assessment tools that allow all stakeholders/actors to be aware of the consequences of various choices and to assess building performance. These SB tools, approaches, rating systems, indices and methods of assessment have already been utilized in the market (e.g., Multi-Criteria Assessment (MCA) methods, such as LEED and SBTool, Life Cycle Analysis (LCA) systems, like ATHENA, and the Single Index (SI) approach (Ecological footprint)). However, are existing SB assessment tools actually capable of considering the regional issues? Is it possible to use them to assess all types of buildings? Are they objective, easy to customize? Is it easy to interpret their final assessment results and are those results transparent to the end users? Despite the usefulness of the current assessment methods in contributing towards a more sustainable building industry, some of the limitations and critiques of these assessment methods indicate that the tools should evolve toward a genuinely generic and scientifically global SB assessment tool. After discussing and summarizing the limitations of the existing definitions, indices and rating systems for building sustainability assessment, a definition of a sustainable building in terms of thermodynamics is proposed, mainly based on the exergy concept. This proposal is supported by a general mathematical calculation for the exergy-based index of building sustainability. The index uses the comparison between the available solar exergy (considered to be the only renewable energy source) and the exergy lost due to a building’s construction and operation to measure the a building’s sustainability. Moreover, the selection and transfer of data from the SBTool, and the assumptions and additional calculations required for the assessment of the exergy-based index of sustainability are presented and quantified. A rating scale is also presented along with the index of building sustainability. Finally, case studies of residential and commercial buildings are used to demonstrate the framework’s reliability. The contribution of the proposed Exergy-based index is evaluated by comparing its similarities and differences with a selection of the available building assessment tools and methods

Effect of irrigation with fish farm effluent on two legume crops interplanted with orange trees in a sandy soil

This research was conducted to study the effect of applying three irrigation water quality treatments (Full irrigation using Nile water and 100% NPK fertilizer (Irr I, control); full irrigation using 50% fish farm effluent + 50% Nile water + 50% NPK fertilizer (Irr II); full irrigation using fish farm effluent (Irr III) to two legume crops (faba bean and lupine) interplanted under young orange trees, in addition to the solid planting of all crops in a two-year experiment. The highest yield of the two legume crops under interplanting systems with orange and its solid planting was obtained using only fish farm effluent (Irr III). The highest values of orange yield and water equivalent ratio were obtained when lupine was interplanted under orange trees using Irr III. Similarly, the highest values of land equivalent ratio were obtained for lupine interplanted under orange trees using Irrigation III in the first growing season and faba bean in the second growing in the same treatment. Thus, to reduce pressure on Nile water, we recommend the use of fish farm effluent in irrigation, in general, and use it particularly to irrigate lupine interplanted under orange trees, which increase land and water equivalent ratios. Keywords: Faba bean, lupine, fish farm effluent, water equivalent ratio, land equivalent rati

Motion Control of Holonomic Wheeled Mobile Robot with Modular Actuation

This thesis proposes a control scheme for a new holonomic wheeled mobile robot. The platform, which is called C3P (Caster 3 wheels Platform), is designed and built by the Automation Lab., University of Heidelberg. The platform has three driven caster wheels, which are used because of their simple construction and easy maintenance. The C3P has modular actuators and sensors configurations. The robot’s actuation scheme produces singularity difficulties for some wheel steering configuration, described as the following: When all wheels yield the same steering angle value, the C3P cannot be actuated in the direction perpendicular to the wheel velocity vector. The C3P has a modular sensing scheme defined by sensing the steering angle and the wheel angular velocity of each caster wheel. This work has four main contributions 1- developing a controller based on an inverse kinematics solution to handle motion commands in the singular configurations; 2- modeling the C3P’s forward dynamics of the C3P for the simulation purpose; 3- developing a motion controller based on an inverse dynamics solution; and 4- comparing the C3P with other standard holonomic WMRs. In order to escape singularity condition, the actuated inverse kinematics solution is developed based on the idea of coupling any two wheel velocities to virtually actuate the steering angular velocity of the third wheel. The solution is termed as the Wheel Coupling Equation (WCE). The C3P velocity controller consists of two parts: a) the WCE regulator to avoid singularities and adjust the steering angles to the desired value, and b) the regular PID controller to maintain the reference robot velocities with respect to the floor frame of coordinates. The solution reaches acceptable performance in the simulation examples and in the practical experiments. However, it generates relatively large displacement errors only during the steering angles adjustment period. The Euler-Lagrangian method is used for obtaining the forward dynamic and the inverse dynamic models. The forward dynamic model consists of two equations of motion: the WTD (Wheel Torque Dynamics) to calculate the wheel angular velocities with respect to the actuated wheels’ torques, and the DSE (Dynamic Steering Estimator) for calculating the steering angles and steering angular velocities corresponding to the angular wheels’ velocities and accelerations. The inverse dynamics solution defines the forces and torques acting on each actuator and joint. The solution is used in the development of the C3P velocity and position controllers. In comparison to the proposed inverse kinematics solution, the inverse dynamics solution yields less displacement errors. Lyapunov stability analysis is carried out to investigate the system stability for different steering angles’ combinations. The steering angles’ values are considered as the disturbances affecting the platform. Finally, a comparison is made between the C3P and three other holonomic wheeled mobile robots configurations. The comparison is based on the simulation results in relation to the following aspects: a) mobility, b) total energy consumed by each robot in a finite interval of time and c) hardware complexity. The C3P platform shows its advantage in the aspects “b” and “c”