Papers by Mohamed Aichouni
Computational study of the performance of the Etoile flow conditioner
International Journal of ADVANCED AND APPLIED SCIENCES, 2016
Numerical investigation of combined buoyancy-thermocapillary convection and entropy generation in 3D cavity filled with Al2O3 nanofluid
Alexandria Engineering Journal, 2016
Numerical Simulations of an Oscillating Flow Past an Elliptic Cylinder
Journal of Offshore Mechanics and Arctic Engineering, 2015
New Trends in Disinfection By-Products Formation upon Water Treatment
Journal of Research & Developments in Chemistry, 2015
ABSTRACT This review paper deals with the formation of disinfection by-products (DBPs). Water bas... more ABSTRACT This review paper deals with the formation of disinfection by-products (DBPs). Water basin remains a wonderful chemical reactor that allows the occurrence of intricate secondary disinfection chemical reactions, forming several hundreds of DBPs at the same time with microorganisms killing. The kinetics of DBPs formation is tightly dependent on water physicochemical characteristics such as temperature, hydrophobic/hydrophilic fractions in natural organic matter (NOM), pH, and pretreatment. Reducing DBPs levels in drinking water is not a relevant measure as the newly-developed analytical techniques and the health-related research reveal that the tolerable DBPs' levels must be further decreased and would be detected at ng L-1 instead of μg L-1 scale. Furthermore, because of the fact that man is being exposed to DBPs concentrations in drinking water in his lifetime, there will be a cumulative effect of these toxic chemical products even at their more reduced concentrations. Hence, the removal of these chemical products is sought for and is considered a real challenge and the main objective of water treatment technology for mankind survival.
This review concerns the using of Zeta and streaming potentials in the coagulation process contro... more This review concerns the using of Zeta and streaming potentials in the coagulation process control. Coagulation
process is usually explained by charge neutralization mechanism. The negative charge may be quantified by Zeta potential or streaming potential measures. Prior to the advent of streaming current monitors, Zeta meters were the primary instruments for measuring electrokinetic properties as related to coagulant dose. Both instruments measure the potential and indirectly the particle surface charge, but use very different methods. Even if the on-line streaming current monitor can provide coagulation process optimization when properly installed, maintained, and interpreted, jar tests experiments and Zeta meters remain indispensable.
An empirical study of quality management systems in the Saudi construction industry
Http Dx Doi Org 10 1080 15623599 2014 922724, Sep 9, 2014
ABSTRACT Construction firms work in a harsh competitive environment where every company struggles... more ABSTRACT Construction firms work in a harsh competitive environment where every company struggles to ensure that its projects are successfully completed with the constraints of best quality, cost and time. Quality management systems (QMS) have been widely used by world-class construction companies to ensure successful projects delivery. The main purpose of the present study is to evaluate the degree of readiness of Saudi construction firms operating in Hail region towards the implementation of QMS and the proper use of quality tools. The perception of both managerial and technical staff about QMS and quality tools is investigated and analysed. Based on previous research dealing with QMS and quality tools implementation in the construction industry, a comprehensive survey tool is designed and conducted. Results show a high degree of misunderstanding of QMS strategies, tools and techniques in the surveyed construction firms. The study indicates that organizational culture represents a real barrier impeding the implementation of QMS and quality tools in the Saudi construction sector.
Flow conditioners are widely used in industry to generate fully developed turbulent pipe flow con... more Flow conditioners are widely used in industry to generate fully developed turbulent pipe flow condition in relatively short distances for metering purposes. In the present study computational fluid dynamics technique was used to investigate the flow development after a flow conditioner developed by Laws and Ouazzane (1994). INTRODUCTION All flow meters are affected by the quality of the flow approaching the meter (mean flow distortions, swirl, turbulent fluctuations and pulsating flow). Numerous research workers have investigated experimentally and computationally these effects with reference to the shift in flow meter discharge coefficient. Aichouni et al. (1996,1998) reported errors up to ±30% on a Venturi flow meter while Yeh and Matingly (1996) reported errors up to ±17% on an ultrasonic flow meter when the meter is subject to distorted flow conditions. Given that most industrial installations include bends, valves, expanders and reducers, which are sources of both swirl, asymme...
On the theme: "The Application of Regional and International Indicators of Academic Quality and Accreditation in Universities in the Islamic World-Towards Excellence As a Means Not Merely On Outcome" 626 TOWARDS A SIMPLE APPROACH BASED ON PROCESS IMPROVEMENT TO MEASURE QUALITY INDICATORS IN HIGER...
The paper is dedicated to present a simple yet efficient approach to measure quality indicators i... more The paper is dedicated to present a simple yet efficient approach to measure quality indicators in higher education instsitutions. The approach is based on the fundamental concepts of total quality management; these are: Customer (Student/Teacher) Focus, Continuous Process Improvement, Management by facts and data and People involvement. The paper starts with a review of basic concepts on process improvement and ends up with a practical approach to apply these total quality concepts within the sphere of higher education environment in the Arab world. A special focus will be made on the use of the basic quality tools known as “the seven magnificent” by educators to measure quality indicators and to improve the quality of the learning process in courses at higher education institutions. A case study of an introductory engineering course delivered to first year engineering students at the University of Hail will be presented and discussed using these tools and techniques. The use of th...
Further analysis of the aerodynamic behaviour of flow conditioners
Accuracy and precision of flow meters are the most important metrological parameters in most indu... more Accuracy and precision of flow meters are the most important metrological parameters in most industries dealing with increasingly expensive fluids. The accuracy of these devices dependi not only on their construction and method of operation but also of their position in the pipe network. Pipe fittings such valve, bends and other fixtures generate turbulence and swirl and distort the flow distribution in the pipe. The present paper is concerned with an expe-rimental study of the decay process of highly swirling flow in a circular pipe and its effect on orifice flow meter reading. The efficiency of three flow conditioners (The Etoile and the Tube bundle straighteners described in the StandarOs tSd StOZ and the Laws perforated plate) to remove swirl and to reduce metering errors has been investigated using a two components Laser Doppler Anemometer. Highly swirling flow distortion was generated by a 90" out of planej double bend upstream the flow meter. Discharge coefficient shifts due to the flow distortion was determined for three orifice meters with a diameter ratio r:=0.5, 0.62 and 0.70 at flow Reynolds number ranging from 0.79 to 3.21x105. The results show that the disturbance causes important deviations in the meter's calibration cbefficient. The effectiveness of the flov, conditioning devices to remove the flow distortion and to reduce the resulting metering error was not evident for all the working conditions studied here.
Fundamentals of Dimensional Metrology for ISO 9000 Quality Standards
Computational treatment of initially distorted pipe flow
Résumé L'exactitude et la précision de mesure des débitmètres sont des paramètres métrologiqu... more Résumé L'exactitude et la précision de mesure des débitmètres sont des paramètres métrologiques très importants pour la majorité des industries. La précision des débitmètres dépend principalement de leur position dans le pipeline. Les éléments de conduites tels que les vannes, les coudes et les élargissements brusques sont des sources de distortions et de perturbations pour l'écoulement. Dans le présent travail on présente les résultats d'une étude expérimentale portant sur l'effet des conditions non standards crées par des éléments de conduites sur la précision de mesure des débitmètres à pression différentielle type Venturi et plaque à orifice. Les résultats montrent que les conditions perturbées de l'écoulement peuvent être la cause d'erreur de mesure qui dépassent largement les erreurs limites tolérées par les normes internationales. Abstract Accuracy and precision of flow meters are the most important metrological parameters in most industries dealing wi...
Analysis of the decay of turbulent pipe flow A preliminary study
A Comparative study of two turbulence Models in Predicting the development of initially distorted Turbulent Pipe flows
Experimental Study of the Decay of Swirling Turbulent Pipe Flow and Its Effect on Orifice Meter Performance
The present work is concerned with a preliminary study of the decay of swirling turbulent pipe fl... more The present work is concerned with a preliminary study of the decay of swirling turbulent pipe flow and its effect on the accuracy of orifice plate flow meter. The swirl was generated by a double 90 degrees elbows in perpendicular planes. The flow field has been investigated using a tow components Laser Doppler Anemometer. The effect of this piping system on the orifice flow meter accuracy has been assessed with the meter placed at different downstream locations.
Accuracy and precision of flow meters are the most important metrological parameters in most indu... more Accuracy and precision of flow meters are the most important metrological parameters in most industries dealing with increasingly expensive fluids (water, natural gas and petroleum). The accuracy of these devices depends mainly on their position in a pipe network. Pipe fittings such as valves, bends and other fixtures generate turbulence and swirl and distort the flow distribution in the pipe. The paper presents results of an experimental investigation on the effects of non-standards operating conditions (swirling flows generated by a double bend out of plane) on the accuracy of the orifice flow meter. The results showed that the error caused by such non-standards operating conditions can be very important and is well beyond the error limit tolerated by international standards.
Technical Requirements for a Portable Metrology Laboratory in Hot, Arid Regions
An evaluation of the accuracy of Hot-wire measurements
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Papers by Mohamed Aichouni
process is usually explained by charge neutralization mechanism. The negative charge may be quantified by Zeta potential or streaming potential measures. Prior to the advent of streaming current monitors, Zeta meters were the primary instruments for measuring electrokinetic properties as related to coagulant dose. Both instruments measure the potential and indirectly the particle surface charge, but use very different methods. Even if the on-line streaming current monitor can provide coagulation process optimization when properly installed, maintained, and interpreted, jar tests experiments and Zeta meters remain indispensable.