The increase, in recent years, in the size and efficiency of gas turbines burning natural gas in combined cycle has occurred against a background of tightening environmental legislation on the emission of nitrogen oxides. The higher turbine entry temperatures required for efficiency improvement tend to increase NOx production. First-generation emission control systems involved water injection and catalytic reduction and were relatively expensive to operate. Dry low-NOx combustion systems have therefore been developed but demand more primary air for combustion. This gives added incentive to the reduction of air requirements for cooling the combustor and turbine blading. This paper reviews the various approaches adopted by the main gas turbine manufacturers which are achieving very low levels of NOx emission from natural gas combustion. Further developments, however, are necessary for liquid fuels.

Granular materials flowing down an inclined chute were studied experimentally and analytically. Characteristics of convective heat transfer to granular flows were also investigated experimentally and numerically.

Experiments on continuous, steady flows of granular materials in an inclined chute were conducted with the objectives of understanding the characteristics of chute flows and of acquiring information on the rheological behavior of granular material flow. Two neighboring fibre optic displacement probes were employed to measure mean velocity, one component of velocity fluctuations, and linear concentration at the wall and free surface boundaries. A shear gauge was also developed to make direct measurement of shear stress at the chute base. Measurements of solid fraction, velocity, shear rate, and velocity fluctuations were analyzed to understand the chute flow characteristics, and the rheological behavior of granular materials was studied with the present experimental data. The vertical profiles of mean velocity, velocity fluctuation, and solid fraction were also obtained at the sidewalls.

The physical and chemical characteristics of the two differential weathering effects, case hardening and core softening, are examined to determine their formation mechanisms by investigating several field areas exhibiting differential weathering effects. The terms differential weathering effects, factors, mechanisms, processes, morphologies and their cause and effect relationships are defined in the context of the overall problem.

An experimental and theoretical investigation on a series of three centrifugal pump impellers has been made in order to determine the usefulness and validity of tyro-dimensional potential theory for the description of the flow. Computed values of the developed head and distribution of pressure on the vane surfaces are compared with measurements an two-, four-, and six- bladed impellers which have 30[degree] logarithmic spiral vanes and a radius ratio of about one-half.

This thesis describes a mathematical theory that interrelates the basic concepts of complexity, cost, information and reliability. The accessibility of information, as opposed to its availability, is characterized. Universal bounds for complexity distribution, implementation cost and decision reliability are estimated. These bounds give rise to a methodology for any consistent definition of a complexity measure. The basic notions of pattern recognition and information theory are directly related to computational complexity.