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Mechanical Engineering

  • Osama Khayal
    The effect of several hot pressing parameters on the internal mat environment was
    investigated by using the mathematical model and the results were compared to data collected experimentally. The different pressing parameters included three initial mat moisture contents (5, 8.5, 12 %), three final panel densities (609, 641, 673 kg/m3 or 38, 40, 42 lb/ft3), two press platen temperatures (150, 200 °C), and three press closing times (40, 60, 80 s). The variation of temperature and total gas pressure during the press cycle at six points in the vertical mid-plane of a single layer, random mat structure was predicted with the heat and mass transfer model using the different pressing conditions. Twenty-four boards were manufactured according to the same
    specifications, and the temperature and internal gas pressure were measured with thermocouples and gas pressure probes at the same six locations. The model predicted data described the major trends during the hot-compression operation qualitatively. However, further work is needed to make quantitative predictions.
    A hot-compression model was developed based on fundamental engineering principles. The material physical and transport properties were the best available values from the literature or best estimates based on engineering judgment. A sensitivity study assessed the relative importance of the different transport properties during the hot-compression process. The response of selected variables of the hot-compression model for a perturbation of the parameter values was investigated. The sensitivity analysis of the model parameters revealed
    that the thermal conductivity and gas permeability of the mat have the greatest influence on model results. The assessment of these transport properties experimentally, as a function of mat structure, is highly desirable and can considerably improve the model predictions.

    Osama Khayal
    Very little investigation has been carried out to study the performance of flat heat pipes, though researchers recently turned their attention to the same. The results of the literature review on heat pipes indicate the necessity and scope for further theoretical and experimental studies on flat rectangular heat pipes. The present work is an attempt to study the steady state operation of the flat rectangular heat pipes, both theoretically and experimentally. It also aims at the study of the influence of the amount of working medium and wick porosity on the performance of heat pipes.
    Heat Transfer and Fluid Flow Studies on Flat Heat Pipes.pdf

    Osama Khayal
    This research study has been done in Aljabalein Power Plant at White Nile State. The objective of the study is to compare and differentiate between two types of fuel, light fuel oil (LFO) and crude oil (CRO) used in power plant situated in Aljabalein site. The comparison have been done on different viewpoints including the impact of exhaust gases on the surrounding environment, the performance of engines at different loads, and the operation and maintenance costs. It is found that CRO fuel oil is preferred to LFO fuel due to less operation costs. But it has many disadvantages such as high pollution rates and high consumption of spare parts.
    Technical and Environmental Study On Using Light Fuel Oil and Crude Oil in Internal Combustion Engines (ICE).pdf

    Osama Khayal
    Chemical engineers are accustomed to software for designing processes and simulation. Simulation systems such as Matlab and Aspen Plus are commonly referenced in chemical engineering curricula as required courseware and study tools. Automation professionals are also becoming used to applying simulation to operator training, system testing, and commissioning of plant process control systems. Plant
    design simulation programs are substantially different from systems used for training and commissioning. Many of the most common plant design simulation programs are steady state, low-resolution simulations that are not usable for automation or plant life-cycle management.

    Osama Khayal
    Hydropower is important from an operational standpoint as it needs no "ramp-up" time, as many combustion technologies do. Hydropower can increase or decrease the amount of power it is supplying to the system almost instantly to meet shifting demand. With this important load-following capability, peaking capacity and voltage stability attributes, hydropower plays a significant part in ensuring reliable electricity service and in meeting customer needs in a market driven industry. In addition, hydroelectric pumped storage facilities are the only significant way currently available to store electricity.
    Water is one of our most valuable resources, and hydropower makes use of this renewable treasure. In managing hydropower, Reclamation is helping the Nation meet its present and future energy needs in a manner that protects the environment by improving hydropower projects and operating them more effectively.

    Osama Khayal
    Composite materials have been utilized to solve technological problems for a long time but only in the 1960s did these materials start capturing the attention of industries with the introduction of polymeric-based composites. Since then, composite materials have become common engineering materials and are designed and manufactured for various applications including automotive components, sporting goods, aerospace parts, consumer goods, and in the marine and oil industries. The growth in composite usage also came about because of increased awareness regarding product performance and increased competition in the global market for lightweight components.
    Among all materials, composite materials have the potential to replace widely used steel and aluminum, and many times with better performance. Replacing steel components with composite components can save 60 to 80% in component weight, and 20 to 50% weight by replacing aluminum parts.

    Osama Khayal
    The article presents a brief outline of the history of  Bajaj rickshaw vehicles industry. Vehicle design, the incorrect usage of petrol and lubricating oil mixture, safety risks in riding rickshaw, and environmental impact  were integral activities. Almost all of the engine designers mentioned in the article also were automobile designers, and a few went on to become major manufacturers of automobiles. All of these inventors and more made notable improvements in the evolution of the Bajaj rickshaw vehicles.

    Osama Khayal
    In the some gasoline engines port fuel injection systems are used. This technique has achieved a high development point. As these engines operate with stoichiometric mixture, fuel economy and emissions of these engines cannot be improved further. However, GDI engines have been popular since these engines have potential for reduction of toxic, CO2 emissions and fuel consumption to comply with stringent environmental protection standards. To attain this potential, it is required that use of the GDI engines with supercharging and/or turbo charging.
    The primary drawback of direct injection engines is theirs cost. Direct injection systems are more expensive because their components must be well-made. In these engines, high-pressure fuel injection system and exhaust gas treatment components are required. The cost of the GDI engines is high at the present day, but GDI engines with turbocharger that have more fuel economy are expected to be cheaper than diesel or hybrid engines in future.
    In GDI engine, as the spark plugs operate under high temperature, the fouling of them can cause the misfiring. To increase the life-time of the spark plug and engine efficiency, the system such as laser-induced ignition can be applied. Thus, engine efficiency can be more increased. The GDI engines are very suitable for the operating with alternative fuel. The studies on GDI engine with alternative fuel such as natural gas, ethanol, and LPG have continually increasing at present day. If GDI engines with turbo charger use spray guided combustion process which has piezoelectric injector and high energy ignition system, the use of these engines are expected to increase more in short term.

    Osama Khayal
    In its triennial report, the International Ergonomics Association (IEA, 2000) defined ergonomics as the scientific discipline that deals with understanding the interaction between humans and other elements of a socio-technical system. In this definition, ergonomics is the profession that applies theory, principles, data and design methods to optimize human well-being and the overall performance of a system. It is in particular responsible for the design and evaluation of tasks, jobs, products, environments and systems to make them compatible with the abilities, needs and limitations of people.
    The word "Ergonomics" comes from the Greek "Ergon" meaning work and "Nomos" which means law. Therefore, etymologically, this is the science of work. The term has been used historically in the European tradition. In the American tradition one finds the term "Human Factor Engineering" to refer to the same issues, so both terms can be now considered as synonyms and are used interchangeably. The latter is evidenced by the fact that the "Human Factor Society”, founded in Tulsa (Oklahoma) in 1957, is now called the "Human Factor and Ergonomics Society” (HFES). Another term which is often used in the same context is “Engineering psychology” (Wickens & Hollands, 2000).
    The early precursors of the new discipline could be set around the time of the World War I. They had their background in the pioneering studies of Frederic Bartlett (1886-1969), Hugo Munsterberg (1863-1916) and Frederick Winslow Taylor (1856- 1915) on applied psychology and industrial management. The design of new machines (for example, the first cars or tanks) revealed the importance of taking into account the characteristics of people who should operate them. It was found that many people had difficulties to operate with more complex machines, especially with warplanes. This led the army to recruited psychologists who were assigned the task of developing and administering tests to select soldiers and to assign them to different tasks. These applied psychologists first human factors laboratories that continued their work after the war ended. But it was the World War II which provided the final impetus for the establishment of ergonomics as a discipline with industrial and academic recognition. Moreover, this war involved an enormous amount of people and artefacts, many of them newly created, such as radar, which made the idea of selecting a few special individuals to use previously designed artefacts unworkable. The idea that emerged and has had an enormous impact on the development of the discipline was that the devices should be designed by taking into account characteristics of human beings who will use them, and not adapted to people once they are designed.
    In Europe, the focus of ergonomics is to be found in industry and it has been linked to an interest in improving worker performance and satisfaction. The discipline began with an emphasis on the design of equipment and workplaces although in principle themes were related to biological, rather than to the psychological aspects. In this way, studies began on anthropometry, work medicine, architecture, lighting, etc. Back in the 1980s, the Europeans ergonomists began to worry largely about advanced psychological aspects and the "European Association of Cognitive Ergonomics" (EACE) emerged leading to a confluence of interests with human factors and cognitive science professionals in the other side of the Atlantic.
    The definition of ergonomics is extended today to all human activities in which artefacts are implemented. Ergonomists (with many applied psychologists among them) are in a permanent search for comprehensive approaches in which physical, cognitive, social and environmental aspects of human activities can be considered. Although ergonomists often work on different economic sectors or particular tasks, these application domains are constantly evolving, creating new ones and changing the perspective of the old ones. Accordingly, one can recognize today four main domains of expertise crucial for investigating interaction between humans and socio-technical systems.
    Human Factors and Ergonomics.pdf

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