153 research outputs found

    Photocatalytic destruction of volatile organic compounds from the oil and gas industry.

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    Heterogeneous photocatalysis is an advanced oxidation technology widely applied in environmental remediation processes. It is a relatively safe and affordable technology with a low impact on the environment, and has found applications in a number of fields including chemical engineering, construction, microbiology and medicine. It is not catalysis in the real sense of the word, as the photons that initiate the desired photocatalytic reaction are consumed in the process. The cost of these photons is by far the limiting economic factor in its application. From a technical standpoint, the inefficient use of the aforementioned photons during the photocatalytic reaction is responsible for the limited adoption of its application in industry. This inefficiency is characterised by low quantum yields or photonic efficiencies during its application. The technique of controlled periodic illumination - previously proposed as a way of enhancing the low photonic efficiency of TiO2 photocatalysis - has been investigated using a novel controlled experimental approach. The results showed no advantage of periodic illumination over continuous illumination at equivalent photon flux. When the technique of controlled periodic illumination is applied in a photocatalytic reaction where attraction between substrate molecules and catalyst surface is maximum and photo-oxidation by surface-trapped holes, {TiIV OH'}+ads is predominant and photonic efficiency is significantly improved. For immobilized reactors, which usually have a lower illuminated surface area per unit volume compared to suspended catalyst and mass transfer limitations, the photonic efficiency is even lower. A novel photocatalytic impeller reactor was designed to investigate photonic efficiency in gas-solid photocatalysis of aromatic volatile organic compounds. The results indicate photonic efficiency is a function of mass transfer and catalyst deactivation rate. The development of future reactors which can optimise the use of photons and maximize photonic efficiency is important for the widespread adoption of heterogeneous photocatalysis by industry

    Biomechanical Evaluation of an Optical System for Quantitative Human Motion Analysis

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    An eight-camera Optitrack motion capture system was evaluated by performing static, linear dynamic, and angular dynamic calibrations using marker distances associated with upper and lower extremity gait and wheelchair models. Data were analyzed to determine accuracy and resolution within a defined capture volume using a standard Cartesian reference system. Two additional cameras along with AMASS and Visual3D (C-Motion, Inc., Germantown, MD) biomechanical modeling software were used to determine joint kinematics at the pelvis, hip, knee, and ankle of ten control subjects (mean age 21.5 ± 1.65 years). The same data were processed through Nexus (Vicon Motion Systems, Oxford, England) modeling software. The joint angle data was statistically compared between the two systems using a variance components model which determined the variability between maximum, minimum, and range values. Static accuracy ranged from 99.31% to 99.90%. Static resolution ranged from 0.04 ± 0.15 mm to 0.63 ± 0.15 mm at the 0.05 level of significance. The dynamic accuracy ranged from 94.82% to 99.77 %, and dynamic resolution ranged from 0.09 ± 0.26 mm to 0.61 ± 0.31 mm at the 0.05 level of significance. These values are comparable to those reported for a standard Vicon 524 (Vicon Motion Systems, Oxford, England) motion analysis system. Gait cycle maximum, minimum, and range values showed no significant difference when comparing Visual3D and Nexus at the pelvis, hip, and knee. Significant differences were seen at the tibia (rotation) and foot due to foot model variations between the two systems. The results support application of the lower cost Optitrack cameras and Visual3D software for 3D kinematic assessment of lower extremity motion during gait. Additional potential applications supported by these findings include other lower extremity models, assisted ambulation, and wheelchair mobility

    Multi-perspective modelling for knowledge management and knowledge engineering

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    ii It seems almost self-evident that “knowledge management ” and “knowledge engineering” should be related disciplines that may share techniques and methods between them. However, attempts by knowledge engineers to apply their techniques to knowledge management have been praised by some and derided by others, who claim that knowledge engineers have a fundamentally wrong concept of what “knowledge management” is. The critics also point to specific weaknesses of knowledge engineering, notably the lack of a broad context for the knowledge. Knowledge engineering has suffered some criticism from within its own ranks, too, particularly of the “rapid prototyping ” approach, in which acquired knowledge was encoded directly into an iteratively developed computer system. This approach was indeed rapid, but when used to deliver a final system, it became nearly impossible to verify and validate the system or to maintain it. A solution to this has come in the form of knowledge engineering methodology, and particularly in the CommonKAD

    BIOMECHANICAL MARKERS AS INDICATORS OF POSTURAL INSTABILITY PROGRESSION IN PARKINSON'S DISEASE

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    The long term objective of this research is to identify quantitative biomechanical parameters of postural instability in patients with Parkinson’s disease (PD) that can in turn be used to assess fall risk. Currently, clinical assessments in PD are not sufficiently sensitive to predict fall risk, making a history of falls to be the best predictor of a future fall. Identifying biomechanical measures to predict risk of falls in PD would provide a quantitative justification to implement fall-reducing therapies prior to a first fall and help prevent the associated debilitating fractures or even morbidity. While past biomechanical studies have shown the presence of balance deficits in PD patients, which often include a broad spectrum of disease stages, compared to healthy controls (HC), no studies have assessed whether such parameters can distinguish the onset of postural instability prior to clinical presentation, and if such parameters persist following clinical presentation of postural instability. Toward this end this study had three goals: ‱ Determine if biomechanical assessment of a quasi-static task, postural sway, could provide preclinical indication of postural instability in PD. ‱ Define a mathematical model (based on principal component analysis, PCA) with biomechanical and clinical measures as inputs to quantitatively score earlier postural instability presence and progression in PD. ‱ Investigate if biomechanical assessment of a dynamic task, gait initiation, could provide preclinical indication of postural instability in PD. Specific Aim 1 determined that some biomechanical postural sway variables showed evidence of preclinical postural instability and increased with PD progression. This aim distinguished mild PD (Hoehn and Yahr stage (H&Y) 2, without postural deficits) compared to HC suggesting preclinical indication of postural instability, and confirmed these parameters persisted in moderate PD (H&Y 3, with postural deficits). Specifically, trajectory, variation, and peak measures of the center of pressure (COP) during postural sway showed significant differences (p < .05) in mild PD compared to healthy controls, and these differences persisted in moderate PD. Schwab and England clinical score best correlated with the COP biomechanical measures. These results suggest that postural sway COP measures may provide preclinical indication of balance deficits in PD and increase with clinical PD progression. Specific Aim 2 defined a PCA model based on biomechanical measures of postural sway and clinical measures in mild PD, moderate PD, and HC. PCA modeling based on a correlation matrix structure identified both biomechanical and clinical measures as the primary drivers of variation in the data set. Further, a PCA model based on these selected parameters was able to significantly differentiate (p < .05) all 3 groups, suggesting PCA scores may help with preclinical indication of postural instability (mild PD versus HC) and could be sensitive to clinical disease progression (mild PD versus moderate PD and moderate PD versus HC). AP sway path length and a velocity parameter were the 2 primary measures that explained the variability in the data set, suggesting further investigation of these parameters and mathematical models for scoring postural instability progression is warranted. Specific Aim 3 determined that a velocity measure from biomechanical assessment of gait initiation (peak COP velocity towards the swing foot during locomotion) showed evidence of preclinical postural instability in PD. Because balance is a complex task, having a better understanding of both quasi-static (postural sway) and dynamic (gait initiation) tasks can provide further insight about balance deficits resulting from PD. Several temporal and kinematic parameters changed with increasing disease progression, with significant difference in moderate PD versus HC, but missed significance in mild PD compared to HC. Total Unified Parkinson’s Disease Rating Scale (UPDRS) and Pull Test clinical scores best correlated with the biomechanical measures of the gait initiation response. These results suggest dynamic biomechanical assessment may provide additional information in quantifying preclinical postural instability and progression in PD. In summary, reducing fall risk in PD is a high priority effort to maintain quality of life by allowing continued independence and safe mobility. Since no effective screening method exists to measure fall risk, our team is developing a multi-factorial method to detect postural instability through clinical balance assessment, and in doing so, provide the justification for implementing fall reducing therapies before potentially debilitating falls begin

    Working Notes from the 1992 AAAI Workshop on Automating Software Design. Theme: Domain Specific Software Design

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    The goal of this workshop is to identify different architectural approaches to building domain-specific software design systems and to explore issues unique to domain-specific (vs. general-purpose) software design. Some general issues that cut across the particular software design domain include: (1) knowledge representation, acquisition, and maintenance; (2) specialized software design techniques; and (3) user interaction and user interface

    Development and clinical application of assessment measures to describe and quantify intra-limb coordination during walking in normal children and children with cerebral palsy

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    A thesis submitted in partial fulfilment of the requirements of the University of Wolverhampton for the degree of Doctor of PhilosophyThis thesis investigates coordination of the lower limb joints within the limb during walking. The researcher was motivated by her clinical experience as a paediatric physiotherapist. She observed that the pattern of lower limb coordination differed between normal children and those with cerebral palsy. Many of the currently used interventions did not appear to influence this patterning. As a precursor to evaluating the effectiveness of treatments in modifying coordination, a tool to measure coordination was required. The researcher initially investigated qualitative and then quantitative methods of measuring within limb coordination. A technique was developed that used relative angular velocity of two joints to determine when joints were in-phase, antiphasic or in stasis. The phasic parameters of hip/knee, knee/ankle and hip/ankle joints coordination were quantified. There were some significant differences between normal children and children with cerebral palsy. Asymmetry of these phasic parameters was identified, with children with cerebral palsy being more asymmetrical than normal children. The clinical utility of this technique was tested by comparing 2 groups of children before and after 2 surgical procedures. This showed some significant differences in phasic parameters between pre and post-operative data for one procedure. Low samples sizes mean that further work is required to confirm these findings. Data from this work has been used to calculate sample sizes to give an a priori power of 0.8 and further research is proposed and potential applications discussed. It is hoped that this technique will raise awareness of abnormal intra-limb coordination and allow therapists to identify key interactions between joints that need to be facilitated during walking training

    Exploring the development and impact of an Olympic wrestling sport program in Miawpukek Mi’kamawey Mawi’omi (Miawpukek First Nation): A case study

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    Physical activity has been shown to increase the physical and mental health of youth. Many rural and Indigenous communities offer sport programs. However, many of these sports are not highly accessible to youth for reasons such as social standing, gender, genetics, and physical fitness levels. The sport of Olympic wrestling if implemented correctly can be accessible to participants and could offer Indigenous youth another, more accessible option of physical activity. The purpose of this thesis is to examine the impact of developing and implementing an Olympic wrestling program with Indigenous youth. Working within a Community Based Participatory Research framework and the Indigenous School Health framework, the first part of this thesis examines the needs of the Indigenous community in question and determines how the Olympic wrestling program should be developed and implemented. Following the needs assessment, the program was developed, implemented, and evaluated and the results showed that some youth gained significant changes in their physical and mental health. The program was further evaluated by some of participating youth through the use of photovoice, which showed increases in youth self-perception and self-esteem. Lastly, the changes in youths’ holistic health were determined to have improved after competing with a team of other Indigenous youth at a major competition. The Olympic wrestling program continues in the community with little help from the researcher and is showing a strong likelihood of being offered for the foreseeable future. Thus, this thesis demonstrates that by first creating a relationship built upon reciprocity, respect, and relationality, between implementers and an Indigenous community, in which the researcher is a resource and conduit to be used by the community, a highly accessible sport program such as Olympic wrestling, may have a positive impact on Indigenous youths’ physical and mental health

    Development of an integrated platform combining up- and downstream processing features

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    This thesis deals with the development of an integrated platform combining up- and downstream processing features coupled with the latest technologies in high-throughput (HT) screening systems and mechanistic modeling. Additionally, HT compatible analytical tools were developed, meeting the quality attributes for creating mechanistic models. In contradiction to the general practice in industry, this study emphasized that the downstream process is highly influenced by the cultivation conditions
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