Photoelectrochemical (PEC) etching is a simple and inexpensive wet etching approach that is widely used to fabricate porous gallium nitride (GaN) thin films. However, many fundamental issues on the etching mechanism and the optical response of the fabricated porous structure still remain unclear. In this book, PEC etched porous GaN thin films with a variety of morphologies such as circular, hexagonal, leaf like-, and honeycomb-like patterns were described in detail. The effects of semiconductor types, etching voltage and etching duration on the surface morphology and the optical response of the fabricated porous structure were discussed. Attenuated total reflection method which is very sensitive to the surface layer of the porous GaN was applied to extract the carrier concentration, porosity, and layer thicknesses or the porous layer. Through this book, a better understanding of the PEC etching of the porous GaN can be obtained.

Gallium nitride has become an important semiconductor material for a variety of device applications, including light emitting diodes (LEDs), lasers, and transistors. One of the main challenges in GaN device fabrication is the chemical stability of GaN which leads to a lack of wet etching techniques. Instead, dry etching is used almost exclusively, leading to ion damage and poor selectivity between different layers. In this dissertation, we discuss photoelectrochemical (PEC) etching, a photoassisted wet etch technique that can be used to etch GaN and its alloys. We develop new aspects of this technique to extend its applicability to a larger variety of devices and use the technique to fabricate a few optical devices, including microdisk lasers.

Accurately forecasting the building works is vital to the survival of any business or organization. Building consists of many elements that need to be properly priced. Building estimation is useful for owner and consultant to determine the project scope; while for contractor it is normally used for bidding or tendering process. This book provides a simple guideline in doing elementary estimation of building works. It consists of 12 chapters giving example calculations of various building elements covering from excavation and earthwork until rainwater disposal system. Besides students in the construction environment, this book is also relevant for practitioners in the construction related industries such as building contractors, subcontractors, consultants or clients and also individual who are looking for knowledge related to building costing. Globalization era in higher education system and a great demand on construction related programmes in Malaysia has contributed to the publication of this book. Thus, this book is purposely written in English for the benefit of local and international students. Universiti Sains Malaysia, Penerbit Universiti Sains Malaysia

"This guide shows how the power of communication can be harnessed for achieving the goal of promoting more sustainable lifestyles. It is designed to be read by local and national government authorities, and everyone else who wants to develop and implement public awareness campaigns on these issues."--Publisher website.