Development and Construction of a White Light Profiler for Industrial Applications

With the ever decreasing tolerances in modern manufacturing processes it has become more important to define surface topography measurements quickly and accurately. Though contact methods, using the stylus probe, have been used for a long time more optical techniques are being brought into the market place. The advantages in using optical methods is obvious; no contact with the surface eliminates damage due to a probing tip and also the surface may be scanned in a matter of seconds. Optical techniques also have the advantage that a full field of view may be acquired, unlike point measurement where the surface must be scanned many times to build up a 3 dimensional view of the surface. This thesis is concerned with the work carried out in the design and construction of a portable low cost-non contact profiler that is based on the analysis of interference fringe patterns produced by a Michelson interferometric setup. One system has been designed with the incorporation of two LabVIEW programs, with one program having the capability of profiling discontinuous smooth surfaces and the other having the capability of profiling smooth continuous surfaces. The algorithm used for profiling discontinuous smooth surfaces is based on the degree of mutual coherence that exists between two interacting beams. It analyses the visibility of the interference fringes to obtain a 3 dimensional profile of the surface. The second algorithm is based on phase shifting interferometry and uses a minimum of four intensity frames to calculate the relative phase difference of the two interfering beams. By calculating the phase difference of the two beams in the interferometer it is possible to extract the surface height of the sample. The profiler has a field of view of 3mm2, a lateral or spatial resolution of approximately 4 um with a vertical resolution between 5nm and o.06 um depending on the algorithm being used to acquire a profile. The design process and algorithms will be explained in greater detail in the proceeding chapters, also the limitations and advantages of the system will be discussed

Do looks matter? A case study on extensive green roofs using discrete choice experiments

Extensive green roofs are a promising type of urban green that can play an important role in climate proofing and ultimately in the sustainability of our cities. Despite their increasingly widespread application and the growing scientific interest in extensive green roofs, their aesthetics have received limited scientific attention. Furthermore, several functional issues occur, as weedy species can colonize the roof, and extreme roof conditions can lead to gaps in the vegetation. Apart from altering the function of a green roof, we also expect these issues to influence the perception of extensive green roofs, possibly affecting their acceptance and application. We therefore assessed the preferences of a self-selected convenience sample of 155 Flemish respondents for visual aspects using a discrete choice experiment. This approach, combined with current knowledge on the psychological aspects of green roof visuals, allowed us to quantify extensive green roof preferences. Our results indicate that vegetation gaps and weedy species, together with a diverse vegetation have a considerable impact on green roof perception. Gaps were the single most important attribute, indicated by a relative importance of ca. 53%, with cost coming in at a close second at ca. 46%. Overall, this study explores the applicability of a stated preference technique to assess an often overlooked aspect of extensive green roofs. It thereby provides a foundation for further research aimed at generating practical recommendations for green roof construction and maintenance

Self-Powered Microfluidic Device for Rapid Assay of Antiplatelet Drugs

We report the development of a microfluidic device for the rapid assay in whole blood of platelet-protein interactions indicative of the efficacy of antiplatelet drugs—e.g., aspirin and Plavix, two of the world’s most widely used drugs—in cardiovascular patients. Because platelet adhesion to surface-confined protein matrices is modulated by fluid shear rates at the blood/protein interface, and because such binding is a better indicator of platelet function than platelet self-aggregation, we designed, fabricated, and characterized the performance of a family of disposable, self-powered microfluidic chips with well-defined flow and interfacial shear rates suitable for small blood volumes (≤ 200 µL). We report a simple technique to fabricate single-use self-powered chips incorporating shear control, “SpearChips”. These parallel-plate flow devices integrate on-chip vacuum-driven blood flow, using a pre-degassed elastomer component to obviate active pumping, with microcontact-printed arrays of 6-µm-diameter fluorescently-labeled fibrinogen dots on a poly(cycloolefin) base plate as a means to quantitatively count platelet-protein binding events. The use of SpearChips to assess in whole blood samples the effects of GPIIb/IIIa and P2Y12 inhibitors—two important classes of “antiplatelet” drugs—is reported

A reciprocal effects model of children's body fat self-concept : Relations with physical self-concept and physical activity

This study investigated a reciprocal effects model (REM) of children’s body fat self-concept and physical self-concept, and objectively measured school physical activity at different intensities. Grade four students (N = 376; M age = 9.07, SD = .61; 55% boys) from the midwest region of the United States completed measures of physical self-concept and body fat self-concept, and wore accelerometers for three consecutive school days at the beginning and end of one school year. Findings from structural equation modeling analyses did not support reciprocal effects. However, children’s body fat self-concept predicted future physical self-concept and moderate-to-vigorous physical activity (MVPA). Multigroup analyses explored the moderating role of weight status, sex, ethnicity, and sex*ethnicity within the REM. Findings supported invariance, suggesting that the observed relations were generalizable for these children across demographic groups. Links between body fat self-concept and future physical self-concept and MVPA highlight self-enhancing effects that can promote children’s health and well-being

Academic and Psychosocial Outcomes of a Physical Activity Program with Fourth Graders: Variations Among Schools in Six Urban School Districts

The purpose was to examine academic achievement, school attachment, and peer acceptance before and after a comprehensive school-based physical activity program (CSPAP) with 378 children in 12 fourth-grade classrooms across six schools in primarily low-socioeconomic status (SES) districts of a large Midwestern metropolitan area. Both personal and normative rate of academic achievement improvement metrics were used. Overall, all students showed personal math and reading growth. However, effects varied by types of achievement indicator and comparison group, revealing noteworthy school-level demographic and implementation characteristics that are inextricably intertwined with program effectiveness and student growth. Implications, especially for minimizing generalizations, are significant

Physical Activity Change Through Comprehensive School Physical Activity Programs in Urban Elementary Schools

he impact of Comprehensive School Physical Activity Programs (CSPAPs) on urban children’s, educators’, and parents’ physical activity (PA) is relatively unknown. The purpose of this study was to explore overall changes in student, educator, and parent PA after an 8-month CSPAP-based program. This longitudinal, exploratory study implemented a CSPAP in 20 urban elementary schools, with six randomized for research. In-school PA was measured prepost for all fourth grade students using accelerometers. Parent and educator PA was self-reported using the IPAQ. RM-ANOVAs revealed significant prepost increases in minutes of student MVPA (P \u3c .001). Parents significantly increased PA (P \u3c .01) and although educators’ reported change in PA, it was not statistically significant (P = .50). This study provides unique information about the potential influence of one CSPAP on students’ overall PA, PA by individual context within the school, the differential PA patterns by race, and PA changes for educators and parents

An ecological approach to understanding academic achievement: Considering intrapersonal, physical activity, and support variables

The purpose of this study was to examine the relation between measures of students’ physical well-being and self-perception and their academic achievement. Specifically, we look at students’ social support for physical activity, physical activity perceptions, self-concept, self-efficacy, health behaviors, and cardiorespiratory fitness (as measured by the PACER test). Students (n = 697 fifth graders) were surveyed at the beginning of the school year. A two-group path analysis revealed notable relationships between the predictor variables and proximal and distal outcomes, with some paths moderated by sex. One relationship that was significant for both sexes was cardiorespiratory fitness, as it was the only significant predictor of achievement. This effect was moderate to large for the female students (R_Math^2 = 36%; R_Read^2 = 15%) and small to large for the male students (R_Math^2 = 26%; R_Read^2 = 10%). These findings can be used to guide future research and educational prevention and intervention efforts

Considering Physical Well-Being, Self-perceptions, and Support Variables in Understanding Youth Academic Achievement

The purpose of this study was to examine the relation between measures of students’ physical well-being and self-perception and their academic achievement. Specifically, we look at students’ social support for physical activity, physical activity perceptions, self-concept, self-efficacy, health behaviors, and cardiorespiratory fitness (as measured by the progressive aerobic cardiovascular endurance run [PACER] test). Students (n = 697 fifth graders) were surveyed at the beginning of the school year. A two-group path analysis revealed notable relationships between the predictor variables and proximal and distal outcomes, with some paths moderated by sex. One relationship that was significant for both sexes was cardiorespiratory fitness, as it was the only significant predictor of achievement. This effect was moderate to large for the female students (R2Math=36%; R2Read=15%) and small to large for the male students (R2Math=26%; R2Math=10%). These findings can be used to guide future research and educational prevention and intervention efforts

A Spatially Resolved `Inside-out' Outburst of IP Pegasi

We present a comprehensive photometric dataset taken over the entire outburst of the eclipsing dwarf nova IP Peg in September/October 1997. Analysis of the lightcurves taken over the long rise to the peak-of-outburst shows conclusively that the outburst started near the centre of the disc and moved outwards. This is the first dataset that spatially resolves such an outburst. The dataset is consistent with the idea that long rise times are indicative of such `inside-out' outbursts. We show how the thickness and the radius of the disc, along with the mass transfer rate change over the whole outburst. In addition, we show evidence of the secondary and the irradiation thereof. We discuss the possibility of spiral shocks in the disc; however we find no conclusive evidence of their existence in this dataset.Comment: 8 pages, 8 figures, to be appear in MNRA