The laser Doppler interferometer reported here was developed to investigate the possibilities of remote vibration and motion measurements. The method is noncontacting and operates with unprepared targets, using the diffusely scattered light to measure the axial component of the motion. A full description of the motion requires both magnitude and direction of the target motion. The magnitude was found by standard heterodyning techniques, mixing light scattered from the target with a part of the original laser output in a controlled manner. A phase quadrature method was used to identify the direction of the target. This differs from the more usual method of frequency offsetting in requiring only passive optical components and therefore being considerably cheaper. This feature is believed to be novel to the LDI reported here. Measurements were recorded for target motions over the range 100 mm. to (c. ) 1 um. Because unprepared and therefore optically rough targets were used the light received by the detectors was not well behaved. This resulted in instability of the sense of motion signal due to loss of either of the detector signals for displacements above 500 um. However this should not be considered an upper limit to the range of the LDI, as serious loss of the sense signal was rare up to (c. ) 25 mm. and measurements were made up to a peak displacement of 200 mm. Correlations with an accelerometer and an LVDT show that the LDI can reliably measure displacement up to a range of 25 mm. with a maximum target velocity of 32 mm/s limited currently be the signal processing. Theoretical resolution with this device is better than 0.08 um. if full use is made of both detected signals.

Silicon nitride Si3N4 bearing elements have shown practical advantages over traditional steel elements due to their mechanical and physical properties. Leading technology and demands for high efficiency have caused loading bearing contacts in all kinds of machinery to be subjected to high speeds, high contact stresses and severe conditions of lubrication. In addition the introduction of a new generation of hydrocarbon refrigerants in various systems, where these rolling contact silicon nitride bearing elements are employed raises further demands to evaluate the rolling contact fatigue performance of these elements with refrigerant lubrication. Obtaining material wear properties of these refrigerants used in mechanical applications is difficult due to high saturation pressure of the refrigerants. It is important to investigate the influence of these refrigerants as lubricants on the rolling contact fatigue performance of ceramic bearing elements. This research responds to the need for bench testing of rolling contacts using the new generation refrigerants as lubricants. A novel pressurised chamber was designed to achieve a liquid state of the refrigerant as fluid for the rolling contact fatigue experiments. A high-speed rotary Tribometer was used for rolling contact fatigue tests. Experimental study of the influence of the liquid refrigerant lubrication on rolling contact wear of the silicon nitride/steel elements is presented. Investigations of the lubricated contact of silicon nitride rolling elements using the pressurised chamber reveal that wear rate is affected by the nature and geometry ofthe induced defect. A residual stress survey was also performed on failed ceramic elements. Analysing the relationship of residual stress with rolling contact fatigue is an important study which will provide guidelines on the design process and manufacturing of these elements. The residual stress field analysis shows that residual stresses are relieved due to sub-surface damage and are inversely related to stress cycles. Maximum tensile stresses at the edges of the contact path cause a weaker residual stress field at the sub-surface crack front.

Solenoid valves play a vital role in many machines and systems. If one of these devices breaks down the whole system can be affected. Because of this importance of valves, it is desirable to observe these parts to detect faults, both when they are occurring and before they can cause serious damage. Among several possible methods of observation (monitoring actuation time, electrical current, fluidic parameters and others) the observation of mechanical vibrations is a well known method of observing mechanical systems which is commonly used for observation of rotating machinery, but which includes several challenges for diagnosis of solenoid valves. This thesis investigates the possibilities and advantages of vibration analysis of fault detection for solenoid valves. New algorithms are developed to automatically segment the overall non- stationary raw data to smaller sections with a higher degree of stationarity. These new segments are interpretable in a mechanical sense and they separate different sources of vibration. Furthermore a new method to detect regions of interest in a spectrum for classification without "a priori knowledge" about the process has been developed. The experiments presented in this thesis give the evidence that these new methods of pre¬processing and feature extraction enable reliable classification results for transient signals as they occur in the vibration of a switching valve.

The growth of the photovoltaic market indicates that in the near future PV electricity generation may rise to a significant power source. As the proportion of electric power generated from PV systems becomes significant, the effect of these sources on transmission and distribution networks must be considered. This research work has investigated suitable representations of the PV resource and the output power of dispersed PV systems to study the effects of large-scale deployment of PV systems on the grid operation. The representation of solar radiation is very important since this dictates the output power of PV systems. In this work, the simple and reliable Markov Transition Matrix (MTM) method was selected to generate synthetic horizontal solar radiation data. A single MTM was developed to generate half-hour horizontal solar radiation data for different locations in the UK. Large-scale inclusion of PV systems in the UK electricity supply is expected to take the form of a large number of small, geographically dispersed building integrated PV systems. The study also developed a detailed PV cluster model to represent these dispersed PV systems. The variation of PV output power may impact the demand and generation balance on the network requiring additional reserve generation to ensure the system security. In this work, the variation of PV output power and the impact on the reserve requirement was analysed for different penetration levels. This is also the first study to analyse the correlation of solar radiation for different locations in the UK in regard to the impact on reserve requirements. Using data from three locations and according to the National Grid Company (NGC) requirements, it was found that PV capacities of 3750 MW could be added to the present network without additional reserve requirements. The additional reserve required is not on the basis of "MW of reserve per MW of PV capacity". Rather it is based on the aggregation of load demand and of PV output from all regions. The reduction in the reserve requirement by forecasting the weather profile of the day was also illustrated. In this case, a PV capacity of 22,500 MW, which can generate a little over 5% of the UK electricity demand, can be added with minimal increase in system cost. Therefore, the variation of PV output power is unlikely to be a threat to the system security.

Since the introduction of ISO 9000 in 1987 there has been a tremendous growth in the number of companies seeking registration and certification, both in developed and developing countries. Although there is a wealth of literature on ISO 9000 implementation in developed countries and in some developing countries, it was found that there is relatively little materials related to recent study on the factors that influence ISO 9000 implementation in Saudi manufacturing industry. This topic has not received enough attention and certainly there is lack of these studies in the Middle East countries. Therefore, the aim of this research is to investigate, identify and analyse the factors that influence implementation of ISO 9000 in Saudi manufacturing industries. Both questionnaires and pairwise comparison interviews were employed to achieve the study objectives. The questionnaire aimed to investigate the ISO 9000 implementation factors in Saudi manufacturing industry, while pairwise comparison interviews aimed to rank the priorities of the most important factors. In terms of data analysis, a variety of analytical tools were used to deal with qualitative/quantitative and objective/subjective nature of the study. The tools used include multiple regression analysis, hypothesis testing and Analytical hierarchy process (AHP), Data analysis is contribution of this research to enhance a body of knowledge concerning ISO 9000 in relation to manufacturing organizations in Saudi Arabia. The findings revealed that top management support, work system and quality guidelines are the most important factors influencing the successful implementation of ISO 9000 in the manufacturing industry. Additionally, AHP result shows that Saudi manufacturing organisations should be aware of three main factors in order to successfully implement ISO 9000. These factors are; top management commitment, customer satisfaction and training and education. This research will fill the gaps in the existing literature. Moreover, the result of the findings from this industrial survey is also applicable to some extent to ISO implementation in the other Arab countries.

In many sectors of commercial operation, the scheduling of workflows and the allocation of resources at an optimum time is critical; for effective and efficient operation. The high degree of complexity of a “Job Shop” manufacturing environment, with sequencing of many parallel orders, and allocation of resources within multi-objective operational criteria, has been subject to several research studies. In this thesis, a scheduling system for optimizing multi-objective job shop scheduling problems was developed in order to satisfy different production system requirements. The developed system incorporated three different factors; setup times, alternative machines and release dates, into one model. These three factors were considered after a survey study of multiobjective job shop scheduling problems. In order to solve the multi-objective job shop scheduling problems, a combination of genetic algorithm and a modified version of a very recent and computationally efficient approach to non-dominated sorting solutions, called “efficient non-dominated sort using the backward pass sequential strategy”, was applied. In the proposed genetic algorithm, an operation based representation was designed in the matrix form, which can preserve features of the parent after the crossover operator without repairing the solution. The proposed efficient non-dominated sort using the backward pass sequential strategy was employed to determine the front, to which each solution belongs. The proposed system was tested and validated with 20 benchmark problems after they have been modified. The experimental results show that the proposed system was effective and efficient to solve multi-objective job shop scheduling problems in terms of solution quality.

Thesis (B.S.)-- Massachusetts Institute of Technology, Dept. of General Science, 1924 [first author], and Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of General Engineering, 1924 [second author]. / Includes bibliographical references (leaf 29). / by Horacio Serrano Palma and Arthur M. Kallet. / B.S.

The Royal National Lifeboat Institution provides a marine search and rescue service using lifeboat stations sited along the coast of the UK and Ireland. In locations where there is no natural harbour or where there is a large tidal range it is necessary to use an inclined slipway to launch a large lifeboat. Lifeboat slipway stations consist of an initial section where the boat is held on rollers followed by an inclined keelway of nickel/chromium coated steel, the lifeboat is released from the top of the slipway and proceeds under its own weight into the water. The lifeboat is subsequently recovered to the top of the slipway using a winch line. With the introduction of the new, larger Tamar class lifeboat existing boathouses are being upgraded and existing low friction coated steel slipway lining materials replaced with a low-friction jute fibre/phenolic resin composite. The composite slipway lining material was selected in part because it was able to run unlubricated or water lubricated. However the friction problems have been such that it is usual to line the slipway with grease before every launch and recovery. This adds to the number of operations involved in a launch and has safety implications. The use of grease to line the slipway results in the grease being washed out to sea with effects on the surrounding area, it is likely that there is some environmental impact due to this as the grease is non-biodegradeable and not recommended for open water use according to the material data sheet. Because of these issues it is desirable to develop a set of working guidelines for crews to reduce both these risks by setting appropriate conditions for the manual application of grease along the slipway. These guidelines will also feature a method of assessing the wear of slipway panels so that panels can be replaced before they present a hazard to lifeboat operation. This thesis describes a method for assessing slipway lining materials and lubricants. Appropriate tribometer test machines are selected to assess slipway lining materials performance, the TE57 reciprocating tribometer and the TE92 rotary tribometer are used in conjunction to ascertain friction and wear performance respectively. These results are combined with detailed slipway panel surveys and case studies, and with Finite Element models to develop a method for assessing and predicting the friction and wear along a panel lined slipway. These results are used to develop slipway performance monitoring techniques for lifeboat crews and to develop design modification to combat high friction and wear on slipway panels. The adoption of a modified slipway panel and water lubrication system is proposed, this arrangement reduces panel misalignment contributions to slipway friction and wear resulting in more reliable slipway performance and is also projected to save the RNLI up to £195k annually compared with current practice.

The aim of this research project is to provide the academic and industrial community with a numerical tool that can be used for describing extreme flow cavitation scenarios and the atomisation process of these multiphase jets in a low-pressure environment. The research lies in the intersection of Numerical Analysis, Applied Physics and programming. From the physical point of view, the project has two different strands: The first is developing a methodology for channel flows due to a rapid pressure drop which is possible to result into various flow regimes inside the channel. The second step is to track the liquid fragmentation of the liquid jet downstream the channel exit and describing the atomisation process to liquid ligaments and blobs to droplets. Using a fully Eulerian approach, this research aims towards a holistic approach that addresses some of the major challenges that govern superheated jets atomisation. The finite volumes method in a compressible framework is used utilising various models for modelling the underpinning physics of flashing jets. Flashing occurs either if a liquid follows an isothermal depressurisation or isobaric heating. In both cases, the fluid fails to adjust to the local changes in pressure and temperature admitting a metastable state which makes the process more challenging to understand. The Homogeneous-Relaxation-Model (HRM) is used for modelling the heat transfer under sudden depressurisation conditions accounting for the non-equilibrium vapour generation. A new pressure equation is proposed which employs the continuity equation indirectly. The pressure responds to compressibility and density changes due to the rapid phase change and includes the surface tension contribution in the pressure-velocity coupling algorithm. The coupling of the continuity and momentum equation with the HRM and the interface tracking method is thoroughly described. The result of this coupling is a conserved numerical method that is capable of characterising the flow regimes and the impact of bubble nucleation on the mass flow rate. The present study presents a numerical approach for simulating the atomisation of flashing liquids accounting for the distinct stages, from primary atomisation to secondary break-up to small droplets Following the Eulerian-Lagrangian-Spray-Atomisation approach, the concept of the surface density Σ is introduced into the methodology for the spray dynamics. The proposed approach has the advantage of avoiding the unrealistic common assumption of pure liquid at the nozzle exit. It models the change in the regime inside the nozzle treating flashing in a unified approach simulating the metastable jet both inside and outside the nozzle. Important mechanisms such as thermal non-equilibrium, aerodynamic break-up, droplet collisions and evaporation are modelled in a novel atomisation model. The modified Σ- equation employed a new source term proposed for cryogenic jets. A wide range of numerical tests is presented for validation and obtaining insights for the underlying physics. Short and long nozzle geometries are tested for both low and high-pressure releases for flashing water, R134A, liquid nitrogen and LNG. Results for turbulent flows for both sub-cooled and superheated liquids are presented showing that the proposed approach can accurately simulate the primary atomisation.

<p> The original ARID (Algae Raceway Integrated Design) raceway was an effective method to increase temperature toward the optimal growth range. However, the energy input was high and flow mixing was poor. Thus, the ARID-HV (High Velocity Algae Raceway Integrated Design) raceway was developed to reduce energy input requirements and improve flow mixing. This was accomplished by improving pumping efficiency and using a serpentine flow pattern in which the water flows through channels instead of over barriers. A prototype ARID-HV system was installed in Tucson, Arizona, and the constructability, reliability of components, drainage of channels, and flow and energy requirements of the ARID-HV raceway were evaluated. Each of the electrical energy inputs to the raceway (air sparger, air tube blower, canal lift pump, and channel recirculation pump) was quantified, some by direct measurement and others by simulation. An algae growth model was used to determine the algae production rate vs. flow depth and time of year. Then the electrical energy requirement of the most effective flow depth was calculated. Channel hydraulics was evaluated with Manning's equation and the corner head loss equation. In this way, the maximum length of channels for several raceway slopes and mixing velocities were determined. Algae production in the ARID-HV raceway was simulated with a temperature and light growth model. An energy efficient design for the ARID-HV raceway was developed. </p>