<p>The geometry of CMOS processes has decreased in a steady pace over the years at the same time as the complexity has increased. Even if there are more requirements on the designer today, the main goal is still the same: to minimize the occupied area and power dissipation. This thesis investigates if a prediction of the costs in future CMOS processes can be made. By implementing several processes on a test circuit we can see a pattern in area and power dissipation when we change to smaller processes.</p><p>This is done by optimizing a two-stage operational transconductance amplifier on basis of a given specification. A circuit optimization tool evaluates the performance measures and costs. The optimization results from the area and power dissipation is used to present a diagram that shows the decreasing costs with smaller processes and also a prediction of how small the costs will be for future processes. This thesis also presents different optimization tools and a design hexagon that can be used when we struggle with optimization trade-offs.</p>

The expansion of the electrical grid and infrastructure is an essential part of development since it contributes to improved standard of living among the population. Solar home systems (SHS) are one solution to generate electricity for households where the national grid does not reach or is too sparsely populated to build a local mini-grid. Solar home system programs have been used as a solution for rural electrification in developing countries all over the world with various success, one of these countries is Namibia. A large fraction of the population in Namibia lacks access to electricity where most of the people live in rural areas not reached by the national electrical grid. However, several SHS clients in Namibia have been dissatisfied with their systems due to several issues regarding the service providers. Several service providers have limited technical know-how and therefore frequently over- and undersize system components and make mistakes during installations. An opportunity to improve SHS in Namibia is to develop a software tool that service provider can use to quickly calculate an optimum SHS in a user friendly way based on the electricity demands of the clients. An optimization model was developed using MS Excel which calculates the optimal SHS component capacities regarding cost and reliability with the use of Visual Basic macros. Various field studies and sensitivity analyses were conducted with the MS Excel model. The results were validated and compared with other software programs such as PVsyst and a Matlab model used in a previous study regarding solar power. Results show that several components in existing systems are incorrectly sized and that the MS Excel model could improve future installations and improve the reputation of SHS. The sensitivity analyses focused on cost, system reliability, system size and PV-module tilt and were implemented in the MS Excel model to optimize the results in a techno-economic perspective. The MS-Excel model was approved by Namibia Energy Institute and will be available for all service providers in Namibia.

The geometry of CMOS processes has decreased in a steady pace over the years at the same time as the complexity has increased. Even if there are more requirements on the designer today, the main goal is still the same: to minimize the occupied area and power dissipation. This thesis investigates if a prediction of the costs in future CMOS processes can be made. By implementing several processes on a test circuit we can see a pattern in area and power dissipation when we change to smaller processes. This is done by optimizing a two-stage operational transconductance amplifier on basis of a given specification. A circuit optimization tool evaluates the performance measures and costs. The optimization results from the area and power dissipation is used to present a diagram that shows the decreasing costs with smaller processes and also a prediction of how small the costs will be for future processes. This thesis also presents different optimization tools and a design hexagon that can be used when we struggle with optimization trade-offs.

Tooling design is crucial for the production of cost-effective and durable composite products. As part of the current search for cost reduction (by reducing capital investment, energy use and cycle time), integrally-heated tooling is one of the technologies available for ‘out-of-autoclave’ processing of advanced thermoset polymer composites. Despite their advantages, integrally-heated tools can suffer from uneven distribution of temperature, variability in heat flow rate and inconsistency in heating/cooling time. This research, therefore, investigates a number of design variables such as shape and layout of heating channels in order to improve the heating performance of an integrally-heated tool. Design of Experiments (DoE) has been carried out using Taguchi’s Orthogonal Array (OA) method to set several combinations of design parameters. Each of these design combinations has been evaluated through numerical simulation to investigate heating time and mould surface temperature variation. The simulation results suggest that the layout of the channels and their separation play a vital role in the heating performance. Signal-to-Noise (S/N) ratio and analysis of variance (ANOVA) have been applied to the results obtained to identify the optimal design combination of the integrally-heated tool. Statistical analysis reveals that the heating performance of an integrally-heated tool can be significantly improved when the channels’ layout is parallel. The shape of the channels has negligible effect and the distance between the channels should be determined based on the production requirement. According to the predicted optimal design, a developed integrally water-heated tool is manufactured. The actual thermal properties of the constituent materials of the produced tool are also measured. Then a numerical model of the experimental tool model is simulated in ANSYS software, with setting the actual material properties and boundary condition to define the temperature uniformity and heating rate of the experimental tool. Comparison of the experimental and numerical results of the experimental tool confirmed the well assigning of the boundary conditions and material properties during simulation the heated tool. The experimental results also confirmed the predicted optimal design of the integrally heated tool. Finally, in order to define its thermomechanical behaviour under the effective (in service) thermal loads, a tool model is simulated. Numerical results presented that the produced extremes of thermal deformation, elastic strain, normal and plane shear stresses, under the effective thermal loading, are within the allowable elastic limits of the participated materials.

The dissertation thesis is focused on the issue of energy recovery of waste. It contributes to optimization models developed in the author's workplace in the long term, which serve to simulate material flows in waste management and to search for an optimal waste management strategy. The main objective is to assess the potential for the use of heat produced in waste-to-energy plants as a key factor for the economy of these facilities. The thesis therefore represents an activity on the border of the fields of waste management and heating. Partial mathematical models were developed within the scope, for which it was necessary to collect input data, especially in relation with district heating networks. These models were then used in a comprehensive optimization model describing the integration of waste-to-energy plants with other heat sources. This main model was extended to include the environmental aspect.