A bibliography /with abstracts/ on gas-lubricated bearings Interim report

Gas lubricated bearings - annotated bibliograph

X-ray microtomography study of carious dentine and a comparison of its removal by three techniques

The wisdom on mechanical removal of carious dentine based on hardness has been challenged and chemo-mechanical technique has been proposed as a more conservative method. However, the extent and comparison of excessive removal of sound dentine and insufficient removal of carious dentine have not been studied. The aims of the present study are to use X-ray microtomography (XMT) to determine the mineral concentrations of sound and carious dentine, and the excavated dentine using a hand excavation (HE) technique, a hand excavation technique aided by Caries Detector Dye (CD) and a chemo-mechanical removal technique using Carisolv (CSS). Comparison of the three techniques with respect to the mineral concentrations of the excavated dentine caries and the volumes of sound dentine removed were investigated. It was aimed to identify the boundary between ―infected‖ and ―affected‖ using the X-ray linear attenuation coefficients (LAC) from the XMT results and the ultrastructural images obtained from the Back Scattered Electron (BSE) imaging and Atomic Force Microscopy (AFM). Thirty eight deciduous molars with open carious cavities were sectioned in half. One half of each molar had the carious tissue removed by HE and the other by CSS or hand excavation plus CD. XMT images were taken before and after caries removal. From the data set, an assessor, who was ‗blind‘ to which technique was used, used LAC histograms to assess the efficacy of the excavation techniques. The volumes of sound dentine removed by the 3 techniques were calculated and compared. Detailed analyses were carried out using XMT slices to investigate the mineral concentration of removed and residual dentine. Remineralisation experiments of residual dentine were performed 7 after caries removal. Backscattered electron (BSE) microscopy and atomic force microscopy (AFM) were used to investigate the ultrastructure of the carious dentine. The results showed that CSS was a better technique; conforming to the principles of minimally invasive dentistry. Volume analyses showed that both CSS and CD were effective in removing less sound dentine than conventional hand excavation. It was shown for the first time that the partially demineralised layer of dentine in a natural carious lesion, which was maintained by the CSS technique, had the potential to remineralise up to 80% of the mineral level for sound dentine. Combining XMT results with AFM and BSE images, ultrastructural changes were found at the boundary around a LAC value of 0.8 cm-1 which corresponded to a KHN of 7.66 kgmm-2. It was concluded that carious dentine removal up to a hardness level of 7.66 kgmm-2 could be recommended in order to preserve dentine that has potential to remineralise

3D Printing of Teeth from X-Ray Microtomography for the Purpose of Research and Training

Within dental education, there is a distinct need for hands-on pre-clinical training before a patient’s treatment is carried out for the first time. A combination of extracted teeth and artificial teeth (typodonts) are widely used. However, the availability of extracted teeth is low, and there is a dissatisfaction amongst undergraduate dental students that these artificial teeth do not look and feel like extracted teeth. This project aimed to produce an artificial tooth that looks and feels like an extracted tooth, utilising images collected from X-ray microtomography (XMT) and manufacturing techniques of three-dimensional (3D) printing. As well as to establish differences between extracted and artificial teeth from a haptic point of view. Extracted human teeth were imaged using high-contrast XMT. A method was developed to convert reconstructed XMT images into a 3D printing file format (STL). A technique was also developed to measure the forces imposed on the tooth from a dental handpiece, with forces being measured during the cutting process. Models were 3D printed to high accuracy from the original reconstructed XMT images. From the simulated ‘haptic’ feedback experiment, it was shown that commercially available artificial teeth required more force to cut compared to extracted teeth. The composites that were designed and printed closely resembled this force needed to cut, compared to artificial teeth. These teeth were provided to qualified dentists and undergraduate dental students. Feedback from them showed a promising basis for future development. To conclude, this project has investigated the consensus that dental students are unhappy with current commercially available teeth and has developed a force measuring technique to quantify this difficulty in cutting. Through material development, materials that required a similar cutting force were produced. This project provides the basis for future development in producing more accurate dental simulants for teaching and training

Asymmetric surface dielectric barrier discharge as a novel method for biological decontamination

Scope and Method of Study:The current study investigates the characteristics of a Surface Dielectric Barrier Discharge (SDBD) plasma actuator as a viable technology for biological decontamination, specifically asymmetric design in arrangements of electrodes. The aim of this work is to demonstrate biological decontamination and understand the plasma interaction mechanism with the cells. The effect of scaling an array of electrodes on power is analyzed and the range of voltage for optimum operation is identified. The improved effectiveness of the asymmetric SDBD is validated by a comparative analysis with a symmetric SDBD arrangement via inactivation of a 5-strain-mixture of Listeria monocytogenes. Variation in performance is analyzed using a variable distance between the actuators and the samples to demonstrate the impact of the asymmetric design. The dose dependence and plasma based effect on different cell types is analyzed using three different mammalian cells, namely, Endothelial cells (HUVECs), Neuroblastoma and Hepatocytes (HepG2). The higher tolerance of mammalian cells to plasma treatment when compared to prokaryotic cells is observed through analysis of viability, functionality and morphology. Finally, the primary mode of plasma interaction with cells was analyzed using different assays to quantify the role of each generated plasma species, such as ions, reactive oxygen/nitrogen species, etc.Findings and Conclusions:This study helped demonstrate specific trends in voltage requirements for scaling of linear electrodes. The asymmetric arrangement of electrodes demonstrated a 2.5 Log10 greater reduction when compared to symmetric configurations, which persisted until 3 cm away from the sample. This suggests the asymmetric design is capable of producing a larger area of plasma and pushing the species further away from the electrodes. The effective regime for plasma generation between uniform discharge and streamer formation was identified. The dose dependence on plasma was identified in different types of mammalian cells demonstrating a need for a proper matrix while treating different tissue. However, mammalian cells demonstrated higher resilience to plasma treatment with retention of functionality up to a treatment time of 4 minutes. Finally, Reactive Oxygen Species (ROS) were identified as the primary agent for plasma-cell interaction with synergistic effects from ions at close proximity to the sample in a non-aqueous medium. OH radicals (identified from Optical Emission Spectroscopy), Ozone (O3), and resulting acids such as nitric oxide form acids including nitric (HNO3) and nitrous acid (HNO2), and are hypothesized to be responsible for antimicrobial effects

11th International Conference on Business, Technology and Innovation 2022

Welcome to IC – UBT 2022 UBT Annual International Conference is the 11th international interdisciplinary peer reviewed conference which publishes works of the scientists as well as practitioners in the area where UBT is active in Education, Research and Development. The UBT aims to implement an integrated strategy to establish itself as an internationally competitive, research-intensive university, committed to the transfer of knowledge and the provision of a world-class education to the most talented students from all background. The main perspective of the conference is to connect the scientists and practitioners from different disciplines in the same place and make them be aware of the recent advancements in different research fields, and provide them with a unique forum to share their experiences. It is also the place to support the new academic staff for doing research and publish their work in international standard level. This conference consists of sub conferences in different fields like: Security Studies Sport, Health and Society Psychology Political Science Pharmaceutical and Natural Sciences Mechatronics, System Engineering and Robotics Medicine and Nursing Modern Music, Digital Production and Management Management, Business and Economics Language and Culture Law Journalism, Media and Communication Information Systems and Security Integrated Design Energy Efficiency Engineering Education and Development Dental Sciences Computer Science and Communication Engineering Civil Engineering, Infrastructure and Environment Architecture and Spatial Planning Agriculture, Food Science and Technology Art and Digital Media This conference is the major scientific event of the UBT. It is organizing annually and always in cooperation with the partner universities from the region and Europe. We have to thank all Authors, partners, sponsors and also the conference organizing team making this event a real international scientific event. Edmond Hajrizi, President of UBT UBT – Higher Education Institutio

2009 Calendar - Undergraduate

633pp. Includes an Index of Academic Programs and an Index of Courses.Contains academic program rules and syllabuses for all University of Adelaide undergraduate programs in 2009