Development of a realistic stress analysis for fatigue analysis of notched composite laminates

A finite element stress analysis which consists of a membrane and interlaminar shear spring analysis was developed. This approach was utilized in order to model physically realistic failure mechanisms while maintaining a high degree of computational economy. The accuracy of the stress analysis predictions is verified through comparisons with other solutions to the composite laminate edge effect problem. The stress analysis model was incorporated into an existing fatigue analysis methodology and the entire procedure computerized. A fatigue analysis is performed upon a square laminated composite plate with a circular central hole. A complete description and users guide for the computer code FLAC (Fatigue of Laminated Composites) is included as an appendix

Individualism-collectivism and interpersonal memory guidance of attention

Recently it has been shown that the allocation of attention by a participant in a visual search task can be affected by memory items that have to be maintained by a co-actor, when similar tasks are jointly engaged by dyads (He, Lever, & Humphreys, 2011). In the present study we examined the contribution of individualism-collectivism to this ‘interpersonal memory guidance’ effect. Actors performed visual search while a preview image was either held by the critical participant, held by a co-actor or was irrelevant to either participant. Attention during search was attracted to stimuli that matched the contents of the co-actor’s memory. This interpersonal effect correlated with the collectivism scores, and was enhanced by priming with a collectivistic scenario. The dimensions of individualism, however, did not contribute to performance. These data suggest that collectivism, but not individualism, modulates interpersonal influences on memory and attention in joint action

Accounting for the Salvation Army : a narrative approach

In 2015 The Salvation Army will celebrate 150 years of service to the community. The organisation which today has spread throughout the world traces its origins to the work of William and Catherine Booth, itinerant evangelists in Victorian England. Originally called the Christian Mission, the focus was on Christian evangelism, personal salvation for the individual based on the belief of the time that the spiritual change of an individual was the way to improve their position in society. By the 1880s William Booth realised religious attention was more likely when individuals were not economically and physically challenged, and assisting them in a practical way was demonstration of the Christian values. The rise of social service activity initially came about through the actions of individual Salvation Army members and ultimately by the official endorsement by the organisation of a separate social service arm. In the 1890s the social service of The Salvation Army was set up via its own unique trust deed. The rationale for the separation between the evangelical and social operations was to allow people to direct their support to the preferred area of activity being undertaken. The people who The Salvation Army served were often the least able to provide the financial support for the organisation. William Booth needed to make constant calls for money; this placed him into conflict with many sections of Victorian England. Financial accountability and integrity were at the forefront of both the criticism and the defence of the organisation. The use of financial reporting, annual reports and other narratives has been a constant feature of the organisation since its inception. In the current period The Salvation Army is generally recognized by the public as primarily a social service organization. This view is at odds with how the leadership of the organisation sees the organisation, namely as a part of the Christian church with a single mission expressed in the dual form of spiritual and social services. This potential identity mismatch forms an important component of this thesis. In particular the thesis draws on information from United Kingdom, Canada and Australia to examine how the organisation has grappled with its identity problem and the way this has been reflected in its diverse approaches to accountability. The research question looks at the identity of The Salvation Army as it is constructed through its narrative accountability. In the 1890s the dominant identity was the spiritual side of The Salvation Army and funds in the spiritual side subsidised the then newly formed social side. Post World War I the social side began to become the dominant funds source for the organisation. In the current period the financial flow is heavily dominated by the social service component of The Salvation Army activities. Drawing from the work of the philosopher Paul Ricoeur, a hermeneutic analysis of The Salvation Army is undertaken. By locating the formation of The Salvation Army within part of its historical context a ‘sense’ is developed as to how the organisation and its founder William Booth responded to its historical position and the rationale for setting the dual organisational structure. Documents produced by the organisation across a number of countries and in the public domain were accessed and analysed. Following Ricoeur the many narratives identified within these documents were reconfigured to recreate the description of The Salvation Army from a narrative accountability perspective. The stated forms of accountability are reflected in the context of the annual reports and how they approach fiscal compliance requirements. However the forms of accountability used by The Salvation Army have been contested since the 1890s. The outcome of this study shows how the organisation manages to cultivate an image of a social work dominated organisation. Any conflicts in identity and accountability are carefully minimised by the overwhelming success of the social service narrative. However internal narratives of The Salvation Army claim a holistic response to meeting its obligations by the dual mission of spiritual and social. The application of the narrative accountability as demonstrated through Ricoeur’s work allows for any organisation to have its identity validated through the use of a hermeneutic analysis. This research contributes to the ongoing discussion of organisational identity and accountability. RESTRICTED TO ABSTRACT ONLY UNTIL 15/08/201

Guidelines for composite materials research related to general aviation aircraft

Guidelines for research on composite materials directed toward the improvement of all aspects of their applicability for general aviation aircraft were developed from extensive studies of their performance, manufacturability, and cost effectiveness. Specific areas for research and for manufacturing development were identified and evaluated. Inputs developed from visits to manufacturers were used in part to guide these evaluations, particularly in the area of cost effectiveness. Throughout the emphasis was to direct the research toward the requirements of general aviation aircraft, for which relatively low load intensities are encountered, economy of production is a prime requirement, and yet performance still commands a premium. A number of implications regarding further directions for developments in composites to meet these requirements also emerged from the studies. Chief among these is the need for an integrated (computer program) aerodynamic/structures approach to aircraft design

A Dense Reference Network for Mass-Market Centimeter-Accurate Positioning

The quality of atmospheric corrections provided by a dense reference network for centimeter-accurate carrierphase differential GNSS (CDGNSS) positioning is investigated. A dense reference network (less than 20 km inter-station distance) offers significant benefits for mass-market users, enabling lowcost (including single-frequency) CDGNSS positioning with rapid integer ambiguity resolution. Precise positioning on a massmarket platform would significantly influence the world economy, ushering in a host of consumer-focused applications such as globally-registered augmented and virtual reality and improved all-weather safety and efficiency for intelligent transportation systems, applications which have so far been hampered by the several-meter-level errors in standard GNSS positioning. This contribution examines CDGNSS integer ambiguity resolution performance in terms of network correction uncertainty, and network correction uncertainty, in turn, in terms of network density. It considers the total error in network corrections: a sum of ionospheric, tropospheric, and reference station multipath components. The paper’s primary goal is to identify the network density beyond which mass-market users would see no further significant improvement in ambiguity resolution performance. It finishes by describing development and deployment of a low-cost dense reference network in Austin, Texas.Aerospace Engineering and Engineering Mechanic

The left intraparietal sulcus modulates the selection of low salient stimuli

Neuropsychological and functional imaging studies have suggested a general right hemisphere advantage for processing global visual information and a left hemisphere advantage for processing local information. In contrast, a recent transcranial magnetic stimulation study [Mevorach, C., Humphreys, G. W., & Shalev, L. Opposite biases in salience-based selection for the left and right posterior parietal cortex. Nature Neuroscience, 9, 740-742, 2006b] demonstrated that functional lateralization of selection in the parietal cortices on the basis of the relative salience of stimuli might provide an alternative explanation for previous results. In the present study, we applied a whole-brain analysis of the functional magnetic resonance signal when participants responded to either the local or the global levels of hierarchical figures. The task (respond to local or global) was crossed with the saliency of the target level (local salient, global salient) to provide, for the first time, a direct contrast between brain activation related to the stimulus level and that related to relative saliency. We found evidence for lateralization of salience-based selection but not for selection based on the level of processing. Activation along the left intraparietal sulcus (IPS) was found when a low saliency stimulus had to be selected irrespective of its level. A control task showed that this was not simply an effect of task difficulty. The data suggest a specific role for regions along the left IPS in salience-based selection, supporting the argument that previous reports of lateralized responses to local and global stimuli were contaminated by effects of saliency

Ground and surface water interaction near a plywood manufacturing facility on the Lake Roosevelt shoreline, Kettle Falls, Washington

From April 1994 to December 1996, a water quality investigation was performed at the Boise Cascade Plywood Plant in Kettle Falls, Washington. This investigation was required by the Washington Department of Ecology to assess possible contamination from the process water lagoon and wet log storage area on the groundwater and nearby Lake Roosevelt. Water samples were collected from 11 groundwater monitoring wells, the lagoon, and two lake-shore seeps, and the samples were analyzed for a variety of chemical parameters. Water elevation data were also collected to evaluate the physical nature of the interaction between ground and surface water. The primary water bearing zone at the site is the coarse-grained lower aquifer beneath the lagoon area where the occurrence and behavior of groundwater is strongly correlated with Lake Roosevelt. The groundwater elevations in the wells which monitor this aquifer rise and fall with the lake, and very little groundwater gradients were observed between wells. The groundwater beneath the log storage area also rises and falls with Lake Roosevelt, but more substantial groundwater gradients were observed. These gradients appear to be at least partly caused by the finer-grained sediments in this area, where the wells respond more slowly to changes in lake level. The groundwater beneath the log storage area is also generally higher than beneath the lagoon area. This is likely caused by additional groundwater entering the site from the hills to the east. The finer-grained sediments in the log storage area presumably retain this added head longer than the sediments in the lagoon area where the additional head would dissipate relatively quickly in the coarser-grained sediments. The direction of groundwater flow in the lagoon area is toward Lake Roosevelt when the lake is falling and away from Lake Roosevelt when the lake is rising. In the log storage area, the groundwater gradients indicate groundwater flow toward both the lagoon and the lake. However, a thick section of silt and clay separates the log storage area from the lake, so the majority of groundwater flow out of the log storage area is likely northward via the coarser-grained sediments beneath the lagoon area. A silt and clay layer overlies the lower coarse-grained aquifer and forms a basin of unconfined perched groundwater beneath the lagoon. This perched groundwater appears to have been impacted by the lagoon with respect to chemical oxygen demand, chloride, total dissolved solids, tannin and lignin and dissolved manganese. The lower aquifer in the lagoon area also appears to have been secondarily impacted to a lesser degree by gradual seepage of these contaminants from the overlying perched groundwater. However, the thick layer of silt and clay at the site largely mitigates surface impacts on the lower aquifer in the lagoon area and on all of the groundwater beneath the log storage area. Activities in the log storage area do not appear to have significantly impacted the groundwater beneath the site. The perched groundwater beneath the lagoon does not appear to discharge into Lake Roosevelt, and this groundwater is unlikely to directly impact the lake. The groundwater in the lower aquifer beneath the lagoon area is in direct communication with the lake, and over time, any contamination in this groundwater will eventually discharge into the lake. The seeps do not appear to represent discharge locations for any of the water bearing zones monitored at this site. Rather, the seeps appear to be discharge locations for a second perched groundwater zone which probably exists between the seeps and an unlined storm water collection area. Infiltrating storm water would contribute a relatively high organic load to any underlying perched groundwater and would explain the elevated chemical oxygen demand and tannin and lignin concentrations found in the seep water as well as the iron and manganese precipitation observed at the seep outlets

Reflexive and preparatory selection and suppression of salient information in the right and left posterior parietal cortex

Attentional cues can trigger activity in the parietal cortex in anticipation of visual displays, and this activity may, in turn, induce changes in other areas of the visual cortex, hence, implementing attentional selection. In a recent TMS study [Mevorach, C., Humphreys, G. W., & Shalev, L. Opposite biases in salience-based selection for the left and right posterior parietal cortex. Nature Neuroscience, 9, 740-742, 2006b], it was shown that the posterior parietal cortex (PPC) can utilize the relative saliency (a nonspatial property) of a target and a distractor to bias visual selection. Furthermore, selection was lateralized so that the right PPC is engaged when salient information must be selected and the left PPC when the salient information must be ignored. However, it is not clear how the PPC implements these complementary forms of selection. Here we used on-line triple-pulse TMS over the right or left PPC prior to or after the onset of global/local displays. When delivered after the onset of the display, TMS to the right PPC disrupted the selection of the more salient aspect of the hierarchical letter. In contrast, left PPC TMS delivered prior to the onset of the stimulus disrupted responses to the lower saliency stimulus. These findings suggest that selection and suppression of saliency, rather than being "two sides of the same coin," are fundamentally different processes. Selection of saliency seems to operate reflexively, whereas suppression of saliency relies on a preparatory phase that "sets up" the system in order to effectively ignore saliency