Thesis (M. Sc.)--University of Hong Kong, 1998. / Includes bibliographical references (leaf 99-102).

Zugl.: Rostock, Univ., Diss., 2008

The goal of this project was to develop a recycling program for the Shalom Institute, a multi-use outdoor learning facility located in Malibu, California.

Increasing the content of Reclaimed Asphalt in hot asphalt mixtures is one of the current issues in road construction, to which society's attention is paid. The higher content of Reclaimed Asphalt brings higher technological demands not only for the production of asphalt mixture plants, but also for the handling of materials in general. The benefit for higher demands on asphalt mixture production is the subsequent reduction of the environmental burden associated with the construction of road infrastructure caused by the mining industry and use of natural resources. The dissertation is focused on studying recycling agents which are used in the production of asphalt mixtures containing Reclaimed Asphalt. Emphasis is put on comparing the properties of recycled binders with paving bitumen and binders from Reclaimed Asphalts whereas the effect of repeated recycling is taken into account. A large part of the thesis is devoted to the design of the optimal dosage of recycling agents. Certain findings were used to draw a methodology describing the design of dosing of these agents. At the same time, the properties and behaviour of the recycling agents themselves were evaluated.

published_or_final_version / Mechanical Engineering / Doctoral / Doctor of Philosophy

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

An annular control valve was developed for the extrusion of wood slurries and polymers. The objective was to determine the optimal valve geometry: (1) to provide a linear pressure drop across the valve as a function of valve opening and (2) to eliminate the problem of valve plugging caused by the high solid content of the wood slurries. The approach was to model the non-Newtonian flow in a plasticating single-screw extruder. A finite-difference scheme was developed to model the flow through annular surfaces. The two flow equations were solved simultaneously and a parametric study was performed to determine the optimal valve geometry. The valve operability was evaluated for the extrusion of various mixtures of low-density polyethylene, sawdust, wood flour, and vacuum bottom. The experimental results were in good agreement with the model. In general, a linear valve characteristic was observed and the problem of valve plugging was not evident.

This thesis means to find out how preschool teachers are working to demonstrate the importance of recycling and reuse for children. My hope is to contribute knowledge about various practical methods to establish the idea of sustainable development in the operation. I have used the method of qualitative research and done semi-structured interviews with preschool teachers on certified green flag preschools. The questions I have asked for example concerned how the preschool teachers have worked with recycling and reuse, how much the children have been able to influence and if other didactic subjects are implicated. Six interviews were made and these are summarized in the result part. The analysis shows that all teachers want to teach the children the importance of protecting our earth and what actions each person can contribute with. Even in my search through earlier literature, this has been emphasized since the children absorb a lot of knowledge during the preschool age. Reuse and recycling is integrated into the operation and are not something that is done out of the ordinary. The preschool teachers did not consider it to be any difficulties or obstacles. It rather simplified their work because the policy document gets integrated.