This research thesis is focussed on the development of a novel low density explosive composition whose main application is wall control in open pit mining. The product has, however, the potential to be used in a variety of applications and rock conditions where customization of the explosive’s energy output is required. Experimental observations on the novel low density explosive showed that the product is capable of initiating and sustaining stable detonations at densities as low as 0.10 g/cm3. Given the extreme low densities at which the novel product maintains its detonating characteristics, it will be appropriate to treat it as a reactive bulking agent, hence its name: Low Density Reactive Agent or LDRA for short. When mixed with standard ANFO prills, the reactive nature of the LDRA ensures a detonable mixture regardless of the final dilution sought or the degree of segregation eventually produced during mixing and loading. If operational constraints are such that a lower energy is required, the LDRA can then be used on a stand‐alone basis, without mixing it with other explosive compositions, such as ANFO or emulsions. The detonation characteristics of the LDRA at a target density of 0.15 g/cm3 were evaluated, with particular effort placed on measuring the detonation and explosion pressures, parameters having the greatest influence on damage. The effects of diameter, confinement and primer on LDRA performance were evaluated through velocity of detonation (VOD) measurements. In addition, VOD experiments were conducted in the LDRA to evaluate the stability of propagation in longer columns, the behaviour in a decking configuration and the ability to initiate and be initiated by a column of ANFO. The low pressure regimes characterizing the LDRA provided the opportunity to investigate the full pressure history of the detonation gases by designing experiments of a non‐destructive nature that allowed the repetition of tests under different loading scenarios. Following the characterization stage, the opportunity to test the LDRA as a damage control tool under a true operational scenario arose at the Chuquicamata Mine, in northern Chile. The project provided important input as to the feasibility of manufacturing the LDRA at a semi‐industrial scale and to evaluate the performance of the product in the large diameter blastholes used at the mine / Thesis (Ph.D, Mining Engineering) -- Queen's University, 2007-11-09 12:19:49.747

No description available.

Considering the infection and second trauma caused by dressing changes, development of antibacterial and low-adherent wound dressings is urgently needed. Silver ion is a widely used antimicrobial agent, but its cytotoxicity remains a problem. In this study, low-adherent PAM (polyacrylamide) hydrogel incorporated with less toxic AgNP (silver nanoparticle), was immobilized onto PET (poly(ethylene terephthalate)) substrates by an IPN (interpenetrating polymer network) method. The modified PET is effectively antibacterial and the surface is significantly less adherent than untreated PET. However, silver-resistant bacteria become a potential problem. Thus, ionic 5,5-dimethylhydantoin (DMH) analogues containing either a quaternary ammonium moiety or a phosphonate functional group were designed and synthesized. The DMH analogues were converted to antibacterial N-chloramine counterparts through chlorination to serve as potential alternatives to AgNP. The N-chloramine with a structural cation exhibited distinctly enhanced antibacterial functions both in solution and after immobilization on fabrics.

Animal monitoring devices are deployed by the Department of Conservation (DOC) in remote areas. Currently this requires field workers to visit each device on a regular basis, which is costly and time consuming. This report details wireless technologies that would allow remote monitoring of these devices to bring about increased operational efficiency for DOC. Of particular interest is the wireless transmission of images through forested terrain. While traditionally recognised as a difficult environment for wireless communications, research undertaken has indicated transmissions at 27 MHz are capable of achieving the feat. Development of a working system is greatly reduced through the use of Slow Scan Television technology; however justification for the system requires further study into particular case studies.

No description available.

No description available.

Considering the infection and second trauma caused by dressing changes, development of antibacterial and low-adherent wound dressings is urgently needed. Silver ion is a widely used antimicrobial agent, but its cytotoxicity remains a problem. In this study, low-adherent PAM (polyacrylamide) hydrogel incorporated with less toxic AgNP (silver nanoparticle), was immobilized onto PET (poly(ethylene terephthalate)) substrates by an IPN (interpenetrating polymer network) method. The modified PET is effectively antibacterial and the surface is significantly less adherent than untreated PET. However, silver-resistant bacteria become a potential problem. Thus, ionic 5,5-dimethylhydantoin (DMH) analogues containing either a quaternary ammonium moiety or a phosphonate functional group were designed and synthesized. The DMH analogues were converted to antibacterial N-chloramine counterparts through chlorination to serve as potential alternatives to AgNP. The N-chloramine with a structural cation exhibited distinctly enhanced antibacterial functions both in solution and after immobilization on fabrics.

No description available.

No description available.

No description available.