Nanoroughness is becoming a very important specification for many nanostructures and nanodevices, and its metrology impacts not only the nanodevice properties of interest, but also its material selection and process development. This Ph.D. thesis presents an investigation into fabrication and nanoroughness characterization of nanoscale specimens and MIS (metal-insulator-semiconductor) capacitors with 2 HfO as a high k dielectric. Self-affine curves and Gaussian, non-Gaussian, self-affine as well as complicated rough surfaces were characterized and simulated. The effects of characteristic parameters on the CD (critical dimension) variation and the properties of these rough surfaces were visualized. Compared with experimental investigations, these simulations are flexible, low cost and highly efficient. Relevant conclusions were frequently employed in subsequent investigations. A proposal regarding the thicknesses of the deposited films represented by nominal linewidths and pitch was put forward. The MBE (Molecular Beam Epitaxy) process was introduced and AlGaAs and GaAs were selected to fabricate nanolinewidth and nanopitch specimens on GaAs substrate with nominal linewidths of 2nm, 4nm, 6nm and 8nm, and a nominal pitch of 5nm. HRTEM (High Resolution Transmission Electron Microscopy) image-based characterization of LER/LWR (Line Edge Roughness/Line Width Roughness) in real space and frequency domains demonstrated that the MBE-based process was capable of fabricating the desired nanolinewidth and nanopitch specimens and could be regulated accordingly. MIS capacitors with 2 HfO film as high k dielectric were fabricated, and SEM (Scanning Electron Microscope) image-based nanoroughness characterization, along with measurement of the MIS capacitor electrical properties were performed. It was concluded that the annealing temperature of the deposited 2 HfO film was an important process parameter and 700℃ was an optimal temperature to improve the properties of the MIS capacitor. Also, by quantitative characterization of the relevant nanoroughness, the fabrication process can be further regulated. The uncertainty propagation model of SEM based nanoroughness measurement was presented according to specific requirements of the relevant standards, ISO GPS (Geometric Product Specifications and Verification) and GUM (Guide to the Expression of Uncertainty in Measurement), and the method for implementating uncertainties was evaluated. The case study demonstrated that the total standard uncertainty of the nanoroughness measurement was 0.13nm, while its expanded uncertainty with the coverage factor k as 3 was 0.39nm. They are indispensable parts of LER/LWR measurement results.

Recently, Solar Photovoltaic has been reported to be one of the fastest growing renewable energy technologies for electricity generation due to its eco-friendly and flexible operation. The aim of this research is to investigate the effect of dust on the performance of photovoltaic panels in Kuwait and develop a Concentrated PV system utilizing three dimensional solar concentrators with water cooling to maintain low PV module temperature. A detailed investigation was carried out to develop a 3D concentrator for the Pseudo-Squared shaped PV cells (3D-PSCPV) including optical, electrical and thermal performance under the effect of dust. The optical performance of clean and dusty 3D-PSCPV systems was investigated through advanced ray tracing techniques using OptisWorksTM software. Results showed that with the increase of the concentrator surface reflectivity, the optical efficiency and irradiance uniformity improved where the highest optical efficiency of 91.6% was achieved with reflectivity of 90%. The optimal concentrators’ height for concentration ratio of 2X, 4X and 6X are 45, 145 and 250mm, respectively. Regarding the effect of dust on the system efficiency, results showed that the average irradiance received by the PV was reduced by up to 17%.

This thesis describes two experimental investigations concerned with condensing flows of steam in a cascade of turbine blading. The first considers the effect of heterogeneous nucleation on the flow of condensing steam. The second is concerned with the measurement of electrostatic charges generated on first nucleation in steam. The facility used in this investigation is a blow-down steam tunnel constructed for the study of two-phase flows in a cascade of turbine blading. To carry out the first part of the investigation, substantial modifications were introduced to generate a supply of ultra-pure steam for admission into the blade cascade. This allowed a base line set of blade surface pressure measurements to be recorded in the absence of impurities. In subsequent tests the steam was dosed with known quantities of aqueous ammonia to investigate the influence of chemical impurities on the condensation process. To investigate electrostatic effects a Langmuir probe for operation in steam was developed. Charge distribution was recorded with the probe mounted upstream and downstream of the blade cascade. Observations were recorded over two pressure ratios, using ultra-pure steam and, in subsequent tests, steam dosed with known quantities of aqueous ammonia. Comparisons are carried out between the base line measurements using ultra-pure steam and the measurements using dosed steam. Both sets of results are compared with those of previous investigators. The electrostatic measurements are compared with similar measurements recorded by investigators working in LP steam turbines. The results are discussed and conclusions drawn.

The utilisation of process chains is considered as a way forward to achieve cost effective and high throughput production of miniaturised devices. However there are no methodologies to analyse systematically process chains and thus to inform their development and design new ones for microfabrication. Thus, this research first proposes a methodology for assessing the maturity of micro and nano- manufacturing (MNM) technologies and their interfaces in process chains. The applicability and benefits of using it as a tool for assessing the maturity levels of individual processes and chains is demonstrated on existing and emerging MNM platforms. Then, to address the growing requirements for function and length scale integration (FLSI) in devices, two bulk metallic glass (BMG) enabled master-making process chains were designed and validated for serial replication of polymer components with sub-micron and micro size functional features. The empirical research proved that the use of BMG workpieces with their intrinsic atomic level homogeneity enables the integration of complementary MNM technologies for achieving FLSI in replication inserts. Furthermore, it was demonstrated that such process chains can be successfully employed for producing inserts incorporating both micro and nano- scale features that can be utilised for serial production of polymerbased FLSI devices.

Enhancing the heat output of the hydronic central heating system in buildings can play a major role in reducing energy consumption and CO2 emission. The main aim of this PhD research is to investigate the effect of pulsed flow input on the energy consumption of panel radiators in hydronic central heating systems and the user indoor comfort defined by ASHRAE standard 55 and EN ISO 7730. The research covers thermal performance of panel radiator and the indoor comfort. The work was performed using dynamic control modelling, CFD and experimental testing to prove the concept. Results from the mathematical and CFD modelling of the hydronic radiator with pulsed flow using various frequencies and amplitudes showed that 20% to 27% of energy saving can be achieved compared to the constant flow while maintaining the same radiator target surface temperature of 50oC as recommended by the BS EN442. The indoor comfort results were also achieved as recommended by international standards including CO2 concentration at 1000PPM±50PPM, relative humidity at 50±9%, comfort temperature at 20±1.6oC, air velocity of below 0.15m/s and draught risk parameters of less than 15%. The numerical results agreed well with experimental results with maximum deviation of radiator temperature output of ±4.1%, indoor temperature ±2.83% and energy saving of ±1.7%. The energy saved due to the pulsed flow is attributed to the enhancement of the radiator heat transfer performance that leads to higher heat output at lower average mass flow rate of the hot water.

This thesis describes experimental and theoretical investigation on the use of small diameter helically coiled tubes for the evaporator of miniature refrigeration systems. A detailed review of past experimental and theoretical work on boiling heat transfer inside helically coiled tubes is presented. As most of past work was conducted on helical coils with tube diameters larger than 6 mm, a brief review of the flow boiling heat transfer process inside straight tubes with small diameters of less than 3 mm is also presented. An experimental facility was constructed and instrumented to investigate the flow boiling of refrigerant R134a in helically coiled tubes with diameters ranging from 2.8 mm to 1.1 mm and coil diameter ranging from 30 mm to 60 mm. The experimental results showed that decreasing the tube diameter increases the boiling heat transfer coefficient by up to 58% while decreasing the coil diameter increased the boiling heat transfer coefficients more significantly by up to 130% before dryout. Dimensional analysis using Pi theorem and Artificial Neural Network (ANN) techniques were used to develop correlations to predict the flow boiling heat transfer coefficients inside helically coiled tubes. The ANN method produced a better prediction of the experimental results with ±30%. The experimental facility was equipped with a reciprocating compressor and a manual expansion device and instrumented to assess the performance of miniature vapour compression refrigeration system. A mathematical model of this miniature system was developed, validated and then used to optimise the system performance in terms of the geometry of the helical coils used in the evaporator and condenser. It was shown that the smaller the coil diameter, the better the performance of cooling system. For the same evaporator length, the larger the tube diameter, the larger surface area and better COP. Smaller tube diameters showed better performance at lower area ratios. However, smaller tube diameters showed lower performance at high area ratios due to the large pressure drop caused by smaller tubes in case of using high area ratios. Finally, the addition of AL2O3 nanoparticles to pure water was investigated using computational fluid dynamics technique (CFD) in terms of heat transfer and pressure drop of single phase laminar and turbulent fluid flow in both straight and helically coiled tubes. The tested AL2O3 nanofluid in helical coils produced up to 350% increase in the heat transfer coefficient of the laminar flow compared to pure water in straight tubes for the same flow conditions. However, insignificant enhancement of the heat transfer was obtained in the turbulent flow regime. Also, the use of high AL2O3 nanofluid concentration of above 2% was found to produce significant pressure drop penalty factor of 5 times that of pure water in straight tubes.

Hydrocarbon selective catalytic reduction (HC-SCR) of nitrogen oxides (NOˣ) over silver-alumina (Ag-Al₂O₃) catalysts, in diesel exhaust gas, has been investigated and presented in this research thesis. The work involved the use of H₂ to activate diesel-type HC reductants. Numerous HC-SCR studies have been conducted (to date) by various authors and research groups in an effort to improve the low temperature (< 350 °C) NOˣ reduction activity of the catalyst, but mainly at laboratory scale, using simulated diesel exhaust gases and the pelletized form of the catalyst. Conversely, the work presented and discussed herein is based on Ag-Al₂O₃ coated monolith substrates for the examination of the NOˣ reduction efficiency when utilizing the full diesel exhaust gas. The activity of the pelletized form of the catalyst and that of a coated monolith substrate could vary according to various characteristics, such as, the chemical (reaction kinetics) and physical (mass transfer, species filtration) processes. These effects were examined under 'passive' and 'active' operation of the respective catalysts. Diesel oxidation catalysts (DOCs) and unique prototype catalysts were also utilized in order to reduce possible poisoning species, which can lead to the deactivation of the Ag-based catalyst. Furthermore, variations in exhaust gas temperature and composition, by continually changing engine load and speed, were explored and the effects on catalyst activity presented. It was suspected that the fluctuating temperature profiles of the exhaust gas could limit the amount of poison species accumulation onto the catalyst active surface and, as a result, could slow down the deactivation mechanisms. Finally, fuel reforming of conventional diesel, RME and GTL fuels was conducted for the production of hydrogen (H₂). The produced H₂ could then be utilized in the combustion process itself or in a HC-SCR reactor, for reduced engine out or tailpipe emissions.

The air induction system plays a major role by providing necessary air charge for combustion to take place in an engine cylinder. The pressure drop across the air intake manifold is known to have a significant effect on the indicated power of the internal combustion engine. Most car manufacturers locate the air grill at the front of a vehicle to enhance the volumetric efficiency. However due to wading performance, for a sport utility vehicle like a Land Rover Freelander the air grill is located at the side of the front tyre. The air speed at the grill side is high and creates negative pressure, thus reducing the volumetric efficiency. Therefore, a thorough study of the design of the air induction system (AIS) with negative pressure at the air grill is vital, in order to fully understand the flow behavior in this AIS. Moreover, when the engine is equipped with turbocharger, the performance of the air intake system is also affected by the exhaust parameter which depends on the combustions of fuel in the engine cylinder. The properties of biodiesel are slightly different in density, viscosity and cetane number. These parameters are potentially affecting the combustion in engine cylinder. Thus, the investigation of the effect of fuel on the air intake system is vital for the study of the diesel engine operating with biodiesel. The analysis of the combustion of biodiesel in a V6 diesel engine includes the ignition delay, rate of heat release, in-cylinder peak pressure as well as the exhaust emissions. The study consists of 3 parts; (1) three-dimensional CFD analysis on the performance of the Land Rover Freelander AIS, (2) one-dimensional analysis of a V6 diesel engine with the effect of the AIS, (3) experimental study of a V6 diesel engine operating with RME and ULSD; The three-dimensional analyses on the performance 2 of a Freelander AIS have been conducted to study the effect of negative pressure on pressure-drop in the intake manifold. The results show that the magnitude of negative pressure gives significant effect not just to pressure drop but also to the flow behavior in the intake manifold. The steady flow tests on the actual intake manifold of a Freelander model have been conducted to validate the simulation outcome. The results show good agreement between experiment and simulation. In order to improve understanding on the flow wave action on the intake manifold of a V6 diesel engine, one-dimensional engine simulations have been conducted using commercial Ricardo WAVE v7.2 software. The result shows good agreement between simulation and experiment. The simulation result shows a significant affect on the wave action as pressure drop increases from zero to 20% in the intake manifold. The research continued further to investigate the effect of air induction parameters in the V6 diesel engine such as pressure drop and flow temperature on the performance and emissions of the engine. The effect of intake flow parameter to the engine when operated with RME has been studied and the comparisons have been made when ULSD is used as base fuel. The experimental results show that in general, the engine operating with RME produces lower power and higher bsfc due to low energy content of RME as compared to ULSD. The emissions of NOx are slightly higher, but lower CO and HC are produced. The pressure drop along the AIS has significantly affected the performance as well as emissions of the engine. The performance of the diesel engine drops significantly as the pressure drop increases and exhaust emissions increase considerably.

This work describes the development of Metal Organic Frameworks based adsorption system for producing ice, cooling, ice slurry and potable water using a CP0-27(Ni) and potable/sea water as working pair. Also a novel vacuum based direct freezing technique has been developed in the evaporator of the adsorption ice making system. In this new technique, cooling is generated in the evaporator to produce three outputs, namely, ice, ice slurry and cooling by lowering the freezing point of water using sea salt. The ice and ice slurry are produced in the evaporator during the adsorption-evaporation process, while the cooling process is produced by circulating the water/antifreeze to be cooled in the evaporator. Moreover, the usage of seawater as refrigerant offers producing fresh water as a fourth output in the condenser. A Single and a double bed CP0-27(Ni) MOF adsorption systems were developed to investigate the effect of this novel technique on the system performance in terms of producing of the four outputs. Compared to published literature, the proposed technology showed significantly higher Specific Daily Ice Production of 3 times those reported in literature with additional outputs of ice slurry, cooling and distilled water.

The utilisation of alternative fuels, specifically gaseous fuel, in diesel engines has some disadvantages such as reduced engine thermal efficiency and increased exhaust gas emissions, although showing good results in reducing soot and NOX, simultaneously. Therefore, the effect of the hydrogen – enriched gaseous fuel in the dual fuelled combustion process was studied as a mean of improving further the combustion process and control emissions. The hydrogen addition was very effective in overcoming the penalty of the biogas or LPG-diesel dual fuelled engine operation. With the presence of hydrogen the oxidation rate of combustion product was improved thus reducing emissions (HC, CO and PM except NOX) whilst the engine thermal efficiency was also improved. The implementation of exhaust gas recirculation (EGR) and advanced injection timing showed great potential for dual fuelled engine. The utilisation of EGR at high LPG concentration further improved soot – NOX trade-off through low in-cylinder temperatures and reduced amount of liquid fuel used for combustion. Moreover, the properties of the injected diesel fuels as a pilot fuel have been shown to significantly affect the combustion process, rate of heat release, and emissions formation and oxidation. Oxygenated fuel like RME contributed to the reduction of emissions, except NOX, while a high cetane number fuel like GTL showed better tolerance to EGR addition and soot – NOX trade-off.