68 research outputs found
The quantitative measurement of colour in minerals
The present study has been directed towards investigating quantitative measurements of colours in minerals, which might serve as a readily accessible means of identification and understanding related properties. A review of the concepts of colour measurement is described in the first part of the thesis. Attention has been paid to the improvement and application of methods of colour measurement,- in mineralogy and gemmology. Computational procedures and all the necessary computer programmes for calculating colour values are given with examples. For this purpose appropriate measurements of spectral reflectivity for opaque minerals, and spectral transmittance for non-opaque minerals and facetted gemstones are described. Quantitative measurements of other colour properties - colour constancy, bireflectance and reflection pleochroism - are described and defined. A study of some colour problems in ore minerals is made. Tables of colour values and spectral reflectivity data for 130 ore minerals are given, and these values are also presented in colour diagrams. The uses of quantitative colour values and colour diagrams are explained with examples
Framework for Industrial Control System Honeypot Network Traffic Generation
Defending critical infrastructure assets is an important but extremely difficult and expensive task. Historically, decoys have been used very effectively to distract attackers and in some cases convince an attacker to reveal their attack strategy. Several researchers have proposed the use of honeypots to protect programmable logic controllers, specifically those used to support critical infrastructure. However, most of these honeypot designs are static systems that wait for a would-be attacker. To be effective, honeypot decoys need to be as realistic as possible. This paper introduces a proof-of-concept honeypot network traffic generator that mimics genuine control systems. Experiments are conducted using a Siemens APOGEE building automation system for single and dual subnet instantiations. Results indicate that the proposed traffic generator is capable of honeypot integration, traffic matching and routing within the decoy building automation network
Cognitive aging in people living with HIV: concept development and empirical evidence from several longitudinal cohorts in Australia and beyond
With widespread access to combination anti-retroviral therapy (cART) and HIV suppression, life expectancy among people living with HIV (PLHIV) is increasing more than ever. According to UNAIDS, there were 8.1 million older PLHIV (i.e., 50 years of age and over) in 2020 globally. Although HIV-associated dementia has become rare in the cART era, mild neurocognitive impairments remain prevalent among PLHIV (~30% in virally suppressed). With aging, there is an increasing concern that HIV may precipitate neurocognitive abnormal aging because HIV is associated with increased markers of aging (e.g., immunosenescence and hyper-coagulopathy) and multiple age and HIV-related comorbidities (e.g., cardiovascular diseases). Importantly, these comorbidities occur at an earlier age and at a higher rate among PLHIV compared to age-matched HIV-negative persons. Earlier, more severe and more rapidly progressing neurocognitive impairment would have major public health consequences for the millions of PLHIV and the healthcare system. The overarching aim of this PhD thesis is to determine whether having chronic stable HIV infection and suppressive ART is associated with abnormal cognitive aging including premature cognitive aging (HIV and age synergistically/addictively lead to much lower cognitive performance at a younger age compared to controls), accentuated cognitive aging (HIV and age synergistically/addictively lead to much greater prevalence and severity of neurocognitive impairment), and/or accelerated cognitive aging (HIV and age synergistically/ addictively lead to much more rapid progression of neurocognitive impairment). To address these questions, we used a range of scientific methodologies including a systematic review, and several types of advanced statistical analyses using national and international longitudinal cohort data. First, to contextualise the potential public health consequences of cognitive aging in PLHIV, we conducted a narrative review of the burden of established dementia risk factors among PLHIV. We identified that the burden of several major dementia risk factors is much greater among PLHIV than in the general population. Second, we conducted the first-ever systematic review evaluating the current evidence for premature, accentuated and accelerated cognitive aging among PLHIV. We determined moderate evidence for premature cognitive aging and strong evidence for accelerated cognitive aging, while accentuated cognitive aging had not been optimally assessed. Lastly, addressing the previous literature major limitations (low sample size, cross-sectional study design, low proportion of older PLHIV, and inadequate controls/norms), we quantified the profiles of cognitive aging in four longitudinal studies of PLHIV. We demonstrated robust trends for premature cognitive aging among PLHIV compared to age-matched HIV-negative persons. We also demonstrated that older PLHIV had a higher risk for both neurocognitive impairment and neurocognitive decline compared to younger PLHIV, while controlling for normative age effect. These results are indicative of both accentuated and accelerated aging, although our research identified the need for longer-term studies using very large sample size to assess these trends especially in PLHIV older than 70+. Based on these findings, we discussed implications for clinical practice and future research directions
Causes and prevalence of traumatic injuries to the permanent incisors of school children aged 10-14 years in Maseru, Lesotho
Magister Scientiae Dentium - MSc(Dent)The aim of this study was to investigate the prevalence, etiology and types of injuries to permanent incisors among schoolchildren aged 10-14 years from Maseru, Lesotho. Upper and lower permanent incisors were examined for dental injuries.South Afric
Design and implementation of automated buffer cycling for applied material (AMAT) chemical vapor deposition (CVD) process producer tool
In the semiconductor manufacturing industry, qualification of the tool is the most important thing to do before the tool is being released to run for production. By doing that, the desired quality and specification of the product is achieved. The tool qualification is need to be done whenever the tool is completed with corrective maintenance or preventive maintenance. The maintenance time of the tool is directly affecting to the quantity of the product output. So the need for the minimum time taken for those corrective maintenance or preventive maintenance is crucial which can lead to more output of products.
This project is to design and implementation of automated buffer cycling for Applied Material (AMAT) Chemical Vapor Deposition (CVD) process tool which will reduce time taken and man hours’ requirement.
The design was verified and tested with a few tools. And the results were successfully achieved to the requirements. So, the implementation was done across all the tools.
Overall, this report is about how the silicon wafers are processed in the chemical vapor deposition (CVD) tools, how the qualification is done before processing the actual wafers as well as how to design and implement according the requirements.Bachelor of Engineering (Electrical and Electronic Engineering
Robust vector quantization for image transmission
Prove the performance improvement of the image quality over the noisy channel using the checksums embedded method.Master of Science (Signal Processing
Sequential Patterns Mining For DNA Sequences Based On Divided and Conquers Approach
Data mining is process of pattern extraction from a large collection of datasets.Main goal of data mining is to discover the frequent itemsets(patterns).Sequential pattern mining is an important data mining problem that generates a combinatorial explosive number of intermediate subsequences.Sequential pattern mining generates patterns based on item occurrence order.PrefixlSpan is one of the fast sequential pattern mining algorithms based on divide and conquer approach.PrefixSpan algorithm partitons databases based on currently identified frequent patterns and grow to longer ones using projected databases.This paper presented mining DNA sequential patterns based on divide and conquers approach.Divide and conquer strategy process is partitioning method.By using PrefixSpan method,projected databases are processed in parallel,therefore processing time can be reduced and it will support the bioinformatics field
Investigations in cordyceps militaris
For more than 2000 years, the medicinal value of Cordyceps militaris has been recognized. It has been widely used for a variety of medicinal purposes because of its diverse physiological behaviors. The numerous research on its elements are done in the universities and other research institutions which enable its medicinal value to be appreciated to a greater extent.Master of Science (Biomedical Engineering
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