6 resultados para welding power source control

em Brock University, Canada


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Legal provisions in the US have extended the idea of the border to the inside of US territory. Border Patrol Agents confront people in different spaces to inquire about their status. I examine border policing along the northern border of the United States through textual and discourse analysis. This thesis asks: How do border agents exercise power and control the movement of people within 100 miles of the border? In whose interest is the border, the “nation,” secured? The spaces in which these mobile borders are practiced become the sites where “citizens” and “aliens” are produced, reproduced and contested. These border policing practices create the illusion of a “nation” that is secured for “our” interests. However, the interests of these vulnerable groups are not reflected in the immigration policy and along the “border. Therefore the very existence of immigrants and their basic right to be in the US is undermined.

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There is much evidence to support an age-related decline in source memory ability. However, the underlying mechanisms responsible for this decline are not well understood. The current study was carried out to determine the electrophysiological correlates of source memory discrimination in younger and older adults. Event-related potentials (ERPs) and continuous electrocardiographic (ECG) data were collected from younger (M= 21 years) and older (M= 71 years) adults during a source memory task. Older adults were more likely to make source memory errors for recently repeated, non-target words than were younger adults. Moreover, their ERP records for correct trials showed an increased amplitude in the late positive (LP) component (400-800 msec) for the most recently presented, non-target stimuli relative to the LP noted for target items. Younger adults showed an opposite pattern, with a large LP component for target items, and a much smaller LP component for the recently repeated non-target items. Computation of parasympathetic activity in the vagus nerve was performed on the ECG data (Porges, 1985). The resulting measure, vagal tone, was used as an index of physiological responsivity. The vagal tone index of physiological responsivity was negatively related to the LP amplitude for the most recently repeated, non-target words in both groups, after accounting for age effects. The ERP data support the hypothesis that the tendency to make source memory errors on the part of older adults is related to the ability to selectively control attentional processes during task performance. Furthermore, the relationship between vagal tone and ERP reactivity suggests that there is a physiological basis to the heightened reactivity measured in the LP response to recently repeated non-target items such that, under decreased physiological resources, there is an impairment in the ability to selectively inhibit bottom-up, stimulus based properties in favour of task-related goals in older adults. The inconsistency of these results with other explanatory models of source memory deficits is discussed. It is concluded that the data are consistent with a physiological reactivity model requiring inhibition of reactivity to irrelevant, but perceptually-fluent, stimuli.

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Reduced capacity for executive cognitive function and for the autonomic control of cardiac responsivity are both concomitants of the aging process. These may be linked through their mutual dependence on medial prefrontal function, but the specifics ofthat linkage have not been well explored. Executive functions associated with medial prefrontal cortex involve various aspects ofperformance monitoring, whereas centrally mediated autonomic functions can be observed as heart rate variability (HRV), i.e., variability in the length of intervals between heart beats. The focus for this thesis was to examine the degree to which the capacity for phasic autonomic adjustments to heart rate relates to performance monitoring in younger and older adults, using measures of electrocortical and autonomic activity. Behavioural performance and attention allocation during two age-sensitive tasks could be predicted by various aspects of autonomic control. For young adults, greater influence of the parasympathetic system on HRV was beneficial for learning unfamiliar maze paths; for older adults, greater sympathetic influence was detrimental to these functions. Further, these relationships were primarily evoked when the task required the construction and use of internalized representations of mazes rather than passive responses to feedback. When memory for source was required, older adults made three times as many source errors as young adults. However, greater parasympathetic influence on HRV in the older group was conducive to avoiding source errors and to reduced electrocortical responses to irrelevant information. Higher sympathetic predominance, in contrast, was associated with higher rates of source error and greater electrocortical responses tq non-target information in both groups. These relations were not seen for 11 errors associated with a speeded perceptual task, irrespective of its difficulty level. Overall, autonomic modulation of cardiac activity was associated with higher levels of performance monitoring, but differentially across tasks and age groups. With respect to age, those older adults who had maintained higher levels of autonomic cardiac regulation appeared to have also maintained higher levels of executive control over task performance.

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This thesis investigated attention focus and balance control in eighteen healthy young adults and eighteen healthy older adults. All participants performed sixteen consecutive trials of a balance task which involved standing for 30-s on an unstable platform that could rotate only in the roll direction. There were no attention focus instructions provided on any of the sixteen trials. Following the completion of the initial and final attempt in the series, participants reported "where" their attention had been focused when performing the task. The results showed differences in balance between young and older adults and improvements in balance with practice in both young and older adults. However, there were no differences in attention focus strategies between young and older adults. Both age groups directed attention to multiple sources during the balance task. An equal focus on internal (i.e., feet, trunk, and other body parts) and external (i.e., the platform) sources with little focus on events not related to the task dominated on the first attempt of the balance task. Focus on internal sources was maintained and focus on events not related to the task increased at the expense of focus on external sources on the final attempt of the balance task. Following the series of sixteen trials to establish "natural" attention focus, participants performed three randomly presented trials, each with specific attention focus instructions (i.e., think about minimizing movements of the feet, the trunk, or the platform). The results showed that, in contrast to the literature, instructions to focus on an internal source, the trunk, actually augmented control of the task as reflected in reduced trunk sway whereas instructions to focus on an internal source, the feet, or an external source, the platform, did not benefit performance on the task. Thus, the distance fi-om the interaction point of the body with the external source is critical and may not depend on whether the source is internal or external. Thus, a global attention focus instruction may not be beneficial and the nature of the task should be considered when adopting attention focus instructions for young and older adults.

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This thesis takes some steps in examining the child protection system from a position that is rarely discussed. Specifically, I explore how Foucault's concept of disciplinary power can be used to demonstrate how power operates within the client/worker relationship. This relationship is shown to be quite complex with power flowing bidirectionally, rather than hierarchically. Instead of viewing power imbalances as a function of state control, I show how the client/worker relationship is constituted by the worker, the client, the organization and the social body. A postmodern auto ethnography is used to document my journey as I expose the disciplinary practices and instruments that I was subject to and used with my clients. 2 Given that the child protection system is constantly shifting and changing in order to improve its ability to safeguard children a greater emphasis is required to examine how workers operate within this complex, overwhelming and multi-dimensional world. This thesis has shown that by engaging in a reflexive examination of my position of power different approaches to making intervention beneficial to all involved become available. This is important if child protection work aims to work with clients rather than on clients.

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The Welland Power and Supply Canal Company Limited, established in 1893 and incorporated in 1894 with a capital stock of $500,000. The aim of the company was to harness the natural water supply of the Niagara and Welland Rivers. In 1898 the Canadian Electrical News published a report by Henry Symons, QC outlining the main project of the company. This project involves the construction of a canal from the Welland River to the brow of the mountain at Thorold, a distance of 8 miles; the construction at Thorold of a power house, and from Thorold to Lake Ontario, a raceway by which to carry water into the lake. The estimate for the machinery to generate 100,000 horse power is £125,000; for transmission line to Toronto at a voltage of 10,000….The total estimate therefore amounts to £2,452,162, or roughly speaking, $12,000,000. Source: Canadian Electrical News, August 1898, p. 172. In 1899 the company officers petitioned the federal government desiring a name change to the Niagara-Welland Power Company Limited. Officers of the company were Harry Symons, President; Charles A. Hesson, Vice-President; and M.R. O’Loughlin, James B. Sheehan, James S. Haydon, Frederick K. Foster, directors; John S. Campbell, secretary-treasurer. The company’s head offices were located in St. Catharines, with a New York (City) office on Broad Street. In 1905 and 1909 the company petitioned the federal government for additional time to construct its works, which was granted. The company had until May 16, 1915 to complete construction. John S. Campbell (1860-1950) was a graduate of the University of Toronto and Osgoode Hall. During his university years John began his military career first in "K" Company, Queens Own rifles and then later as Commanding Officer of the 19th Lincoln Regiment, from 1906 to 1910. Upon his return to St. Catharines John Campbell served as secretary in the St. Catharines Garrison Club, a social club for military men begun in 1899. After being called to the Bar, he became a partner in the firm of Campbell and McCarron and was appointed to the bench in 1916, serving until retirement in 1934. Judge Campbell served as an alderman for several terms and was the mayor of St. Catharines in 1908 and 1909. He also served as the first chairman of the St. Catharines Public Utilities in 1914. John S. Campbell was married to Elizabeth Oille, daughter of Jerome B. and Charlotte (St. John) Oille. The family home "Cruachan" was located at 32 Church St.