This work studies the ability to produce effective surfactant and adhesive formulations using surface active biological material extracted from different biomass sources using alkaline extraction methods. Two urban waste biomass sources were used to produce surfactants, Return Activated Sludge (RAS), and solid Urban Refuse (UR). The third biomass source investigated was isolated mustard protein (MP). RAS and MP extracts were investigated for adhesive production. The results indicate that extracts from the waste biomass sources, RAS and UR, can be combined with a commercial surfactant, sodium dioctyl sulfosuccinate (AOT), to produce surfactants with low interfacial tensions against various oils. These highly surface-active formulations were shown to be useful in the removal of bitumen from contaminated sand. RAS and MP showed potential as protein-based wood adhesives. These sources were used in adhesive formulations to produce a strong bond strength under low-pressure, ambient pressing conditions.

No description available.

The demand for posterior aesthetic restorations has dramatically increased in recent years. Several new materials have been developed with improved aesthetic, adhesive and mechanical properties. However, microleakage elimination, especially if the margins are on dentine or cementum, and attainment of optimum mechanical properties for posterior use, are still questionable. The aim of this study was to investigate microleakage and surface microhardness of a nanofilled, a nanohybrid and an ormocer based nano-ceramic composite restorative material.

<p>The use of provisional acrylic crowns is common practice with prosthodontic treatment. Provisional crowns are prone to marginal leakage and poor retention due to weak interim cements. The aim of this study was to assess the effect of the application of two different dentine-bonding agents on the microleakage of provisional crowns.</p>

<p>Amalgam bonding agents have been shown to enhance retention of amalgam restorations by mechanical means. However, recent studies showed that the use o glass ionomer cements and resin cements as lining and bonding materials to amalgam restorations will increase the retentive strength of the amalgam restorations, hence reducing the micro leakage and secondary caries. The purpose of this study was to compare the relative retentive strength of conventional amalgam restorations and bonded amalgam restorations using resin adhesive, glass ionomer cements and resin cements.</p>

<p>The objectives of this study were to create an in vitro situation which closest resembled the clinical situation by inclusion of human dentine discs at a specified anatomic location as barrier and evaluating if comparable or graded perfusion could be identified as well as whether a link existed between dentine thickness and permeability. The other leg of the study was to evaluate the cytotoxicity of Xeno III, one of the newly released new generation dentine bonding agents and to evaluate its cytotoxicity in an in vitro pulp chamber device, determining which thickness of dentine would be able to protect the dental pulp from noxious substances in the bonding agent.</p>

The use of Fibre Reinforced Polymers (FRP) has grown in popularity in the construction industry. FRP has proven useful in the retrofit of various types of structural elements. It may be used for the strengthening of beams, the seismic upgrade of walls panels, as well as the jacketing of columns to provide confinement. There exist several methods of FRP application for the case of structural retrofits. These include the application of pre-prepared FRP mats, or application of FRP via the wet lay-up process. However, a new technique developed at the University of British Columbia allows for the application of FRP in the form of a spray. Externally bonded Sprayed FRP (SFRP) is known to increase strength and energy absorption capacity of a retrofitted member as well as, or better than, FRP sheets. However, tests have primarily been carried out on concrete members only. An area of interest, into which not much research has been conducted, is the application of SFRP to timber. Timber bridges are extensively used in many parts of the world. Often due to remoteness and practical constraints, it is impossible to apply FRP sheets to retrofit these bridges. SFRP would be a much easier method of FRP application. This study looked at the application of SFRP to Douglas Fir (D.Fir) Beam specimens subjected to 3-Point Flexural Loading only. The specimens were treated with either a water based (Borocol) or oil borne (Creosote) antifungal preservative prior to being sprayed with FRP. Different combinations of adhesives/bonding agents including Hydroxymethylated Resorcinol and Polymeric Isocyanates were used to try to develop a strong bond. When considering using only chemical adhesives to obtain a proper bond between the two constituents of the composite, use of HMR is recommended for timber which is untreated or has been treated with a water borne preservative such as Borocol, while a pMDI adhesive such as AtPrime 2 is recommended for timber treated with an oil borne preservative such as Creosote. For Non Creosoted beams, adhesives did not generate as significant of a strength gain. For Creosoted beams, adhesives may be sufficient to generate significant strength gain when SFRP is applied to a beam. Considering that most structures in use would probably have been treated with a preservative similar to Creosote, in practice, AtPrime 2 or some other some sort of pMDI would probably be the adhesive of choice. Based on the results of the study, it is possible to say that the application of SFRP to retrofit/rehabilitate timber structures shows considerable promise. If a decent bond is achieved between the composite constituents, it is possible to substantially increase the ultimate flexural strength of the member, as well as drastically increase its ductility and energy absorption capacity. It is recommended that further tests be carried out using different types of loading schemes, geometrical configurations of SFRP, other types of anchorage, and development of a proper analytical model before the method is adopted for widespread use.

Thesis (M.D.S.)--University of Adelaide, Dept. of Dentistry, 1987. / Bibliography: p. 110.

Thesis (M.S.E.E.)--State University of New York at Binghamton, Watson School of Engineering and Applied Science, 2006. / Includes bibliographical references.

Thesis (M. D. S.)--University of Hong Kong, 2008. / Also available in print.