116 research outputs found
Modification of crumb rubber cement interface and its effect on strength and viscoelastic properties
No full textDue to an increasing amount of waste tires being produced yearly, environmental concerns arise as waste tires in landfills pose both a fire hazard, and a habitat for rodents and mosquitos. As a result, the reuse of waste tires in the form of crumb rubber in concrete has been attempted. Previous research work has shown that the inclusion of crumb rubber in concrete results in a drastic decrease in compressive strength due to the incompatibilities between rubber and cement paste. The limitations related to the use of crumb rubber concrete are related to the interfacial transition zone between rubber and paste. Due to mismatches in free surface energy, coefficient of thermal expansion, and elastic modulus between rubber and cement paste, it has been observed that an interfacial gap is present; furthermore, entrapped air, microcracks, and inconsistent degree of hydration of cement paste has been observed at the transition zone. The research work presented here attempts to improve understanding about what conditions alter the local microstructure of crumb rubber cement interface; furthermore, the limitations and concerns in characterization of rubberized concrete from literature are detailed and studied, and modifications to testing matrix are attempted to better understand and quantify issues at the rubber-paste interface.
The research work presented is subdivided into four tasks. The first task involves altering the design mix of rubberized cement paste to improve interface and performance. Within the first task, uses Type I and Type K expansive cement blend as a means of physically interlocking rubber and paste. The first task also includes usage of shrinkage reducing admixture in bulk mixture and as a pretreatment to alter the surface chemistry of rubber, and testing its effect on the performance of rubberized cement paste samples. The second task involves understanding how curing conditions alter the interface and subsequent mechanical performance of rubberized samples; the effect of relative humidity and temperature are explored. The third task involves targeted testing of the interface of various rubberized cement paste mixtures; understanding of interface performance, interfacial gap, and entrapped air quantity are explored. The fourth task involves a specialized application of crumb rubber in concrete; low-density rubberized foam concrete samples are cast and tested for application as engineering materials arresting system.Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2022-05-01The student, Robbie Damiani, accepted the attached license on 2020-03-10 at 16:38.The student, Robbie Damiani, submitted this Dissertation for approval on 2020-03-10 at 16:46.This Dissertation was approved for publication on 2020-03-13 at 14:04.DSpace SAF Submission Ingestion Package generated from Vireo submission #14884 on 2020-08-25 at 17:26:51Made available in DSpace on 2020-08-26T23:51:23Z (GMT). No. of bitstreams: 3
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Previous issue date: 2020-03-13Embargo set by: Seth Robbins for item 115697
Lift date: 2022-08-26T23:51:32Z
Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 115697
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Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 115697
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Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 115697
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Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 115697
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Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemAuthor requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemU of I Onl
The effects of eye gaze and emotional facial expression on the allocation of visual attention
No full textThis thesis examines the way in which meaningful facial signals (i.e., eye gaze and emotional facial expressions) influence the allocation of visual attention. These signals convey information about the likely imminent behaviour of the sender and are, in turn, potentially relevant to the behaviour of the viewer. It is already well established that different signals influence the allocation of attention in different ways that are consistent with their meaning. For example, direct gaze (i.e., gaze directed at the viewer) is considered both to draw attention to its location and hold attention when it arrives, whereas observing averted gaze is known to create corresponding shifts in the observer’s attention. However, the circumstances under which these effects occur are not yet understood fully. The first two sets of experiments in this thesis tested directly whether direct gaze is particularly difficult to ignore when the task is to ignore it, and whether averted gaze will shift attention when it is not relevant to the task. Results suggest that direct gaze is no more difficult to ignore than closed eyes, and the shifts in attention associated with viewing averted gaze are not evident when the gaze cues are task-irrelevant. This challenges the existing understanding of these effects. The remaining set of experiments investigated the role of gaze direction in the allocation of attention to emotional facial expressions. Without exception, previous work looking at this issue has measured the allocation of attention to such expressions when gaze is directed at the viewer. Results suggest that while the type of emotional expression (i.e., angry or happy) does influence the allocation of attention, the associated gaze direction does not, even when the participants are divided in terms of anxiety level (a variable known to influence the allocation of attention to emotional expressions). These findings are discussed in terms of how the social meaning of the stimulus can influence preattentive processing. This work also serves to highlight the need for general theories of visual attention to incorporate such data. Not to do so fundamentally risks misrepresenting the nature of attention as it operates out-with the laboratory setting.ESRC Postgraduate Training Award, PTA-030-2002-00724
Attentional bias to angry faces using the dot-probe task? It depends when you look for it
No full textA number of studies using the dot-probe task now report the existence of an attentional bias to angry faces in participants who rate highly on scales of anxiety; however, no equivalent bias has been observed in non-anxious populations, despite evidence to the contrary from studies using other tasks. One reason for this discrepancy may be that researchers using the dot-probe task have rarely investigated any effects which might emerge earlier than 500 ms following presentation of the threat-related faces. Accordingly, in the current study we presented pairs of face stimuli with emotional and neutral expressions and probed the allocation of attention to these stimuli for presentation times of 100 and 500 ms. Results showed that at 100 ms there was an attentional bias towards the location of the relatively threatening stimulus (the angry face in angry/neutral pairs and the neutral face in neutral/happy pairs) and this pattern reversed by 500 ms. Comparisons of reaction time (RT) scores with an appropriate baseline suggested that the early bias toward threatening faces may actually arise through inhibition of the relatively least threatening member of a face pair rather than through facilitation of, or vigilance towards, the more threatening stimulus. However the mechanisms governing the observed biases are interpreted, these data provide evidence that probing for the location of spatial attention at 500 ms is not necessarily indicative of the initial allocation of attention between competing emotional facial stimuli
Effects of communication goals and expectancies on language abstraction.
No full textLanguage abstraction is an important aspect of the description of behavioral events (G.R. Semin & K. Fiedler, 1988) that is typically viewed as a medium by which describers transmit beliefs without conscious awareness or control. Complementary to this view, the authors propose that language abstraction may also be influenced by explicit communication goals such as aggrandizement or derogation, allowing describers to express beliefs that they do not themselves possess. Five studies are reported that support this proposal, showing that explicit communication goals have strong effects on language abstraction that are independent of effects of describers' beliefs or expectancies. Language abstraction is therefore both a medium for the transmission of existing beliefs and a tool by which communicators can create new belief
Benevolent sexism, perceived health risks, and the inclination to restrict pregnant women’s freedoms
No full textThe present study investigated the role of sexist ideology in perceptions of health risks during pregnancy and willingness to intervene on pregnant women’s behavior. Initially, 160 female psychology undergraduates at a university in the South East of England completed the
Ambivalent Sexism Inventory (Glick & Fiske, 1996). Two months later, in an apparently unrelated study, they rated the safety of 45 behaviours during pregnancy (e.g., drinking
alcohol, exercising, drinking tap water, and oral sex), and indicated their willingness to restrict pregnant women’s choices (e.g., by refusing to serve soft cheese or alcohol). As predicted, benevolent (but not hostile) sexism was related to willingness to restrict pregnant women’s choices. This effect was partially mediated by the perceived danger attributed to behaviours
Can reforming global institutions help developing countries share more in the benefits from globalization?
No full textGlobalization could significantly expand trade, international investment, and technological advances, but the gains from global integration have been unevenly distributed across and within nations. Greater global interdependence has also brought greater macroeconomic volatility, resulting in several serious financial crises in the second half of the 1990s. The global matrix of Bretton Woods and United Nations institutions that developed starting in the 1940s, formed under a different balance of power, in a world of fixed exchange rates and limited capital mobility. Since the 1960s regional financial institutions have emerged because of the greater autonomy of different regions and the greater financial needs of development. The author reviews different proposals for reform of the international financial institutions and changes in the roles of the International Monetary Fund (IMF) and the World Bank. He highlights the implications for developing countries of (1) Policy conditionality. (2) The countercyclical role of multilaterals'lending. (3) Greater lending to middle-income than to low-income developing countries. (3) Access to liquidity at times of crisis. (4) Mechanisms for giving low-income countries a greater voice in IMF and World Bank decisionmaking. The author streses the overlapping responsibilities of the Bretton Woods and regional financial institutions and the need to reassess the allocation of responsibilities and to develop better coordination mechanisms between these institutions. Those designing institutional reform must consider the corporate capabilities of each type of institution. The corporate cultures of global and regional institutions differ. So does the kind of knowledge they generate and disseminate, and so do patterns of interactions with, and mechanisms for representation of, client countries.Finally, the author calls attention to the need to harmonize national and global growth-oriented policies in a way that reduces volatility and promotes social equity.Environmental Economics&Policies,Governance Indicators,Financial Intermediation,Economic Theory&Research,Banks&Banking Reform
Sometimes, it’s not Right to go Left: The perceived consequences of endorsing political ideologies
No full textThe aim of the research within this thesis was to investigate lay people’s beliefs about political ideologies and related constructs. Specifically, I researched whether people recognise the functions of ideologies and recognise when strategically, it makes the most sense to endorse them. In nine studies, participants’ knowledge of ideological constructs was assessed. To begin with, participants’ knowledge was assessed indirectly by asking them about their own endorsement of variables, such as social dominance orientation, while imagining themselves embroiled within an international conflict. As the research progressed, more direct methods were used in which participants were asked whether endorsing left or right wing ideological constructs would promote inequality within society and palliative outcomes for individuals.
In my first empirical chapter, I present three studies which assess under what specific conditions people will endorse SDO. These studies demonstrate how people endorse SDO strategically in response to specific contextual features of intergroup conflicts. Study 1 showed that people endorse SDO more when locked in an intergroup dilemma with a group which defects (vs. cooperates). In Study 2, the presence (vs. absence) of sunk costs – previous investments by the ingroup in a conflict – increased SDO. In Study 3, high stakes (compared to none) increased the endorsement of SDO. In Studies 2 and 3, increases in SDO elicited indirect effects of contextual factors on participants’ willingness to make further investments in the conflict.
In my second empirical chapter, I consider whether this strategic adoption of ideological positions may be based on knowledge of their consequences for intergroup relations. In Study 4, participants evaluated a group described as being high (compared to low) in SDO as more likely to be committed to a conflict, more likely to invest in that conflict, and as a result, more likely to emerge successfully from that conflict. These results were replicated in Study 5, where I began to utilise more direct measures in order to explore lay theories of ideological variables. Participants were explicitly asked whether they thought endorsing ideological variables (SDO, conservatism and system justification) would promote outcomes including success in conflicts and maintaining inequality along with social cohesion within societies. Participants attributed both SDO and conservatism with promoting inequality and success within conflict whereas system justification was evaluated as likely to promote social cohesion. Chapter 5 provided compelling evidence that lay people have accurate knowledge of the functions of ideological constructs.
In my third and fourth empirical chapters, I empirically examine the folk beliefs about political ideologies that may draw people to them. Across four studies, participants attributed both left and right wing ideologies as likely to promote aspects of hedonic and eudaimonic wellbeing for others and themselves. Furthermore, participants recognised, with a compelling degree of accuracy, that there are marked differences between left and right wing political ideologies in terms of closed-mindedness and the attitudes they promote towards inequality, just world beliefs and concern for others.
Taken together, these findings suggest that lay individuals have accurate knowledge of the consequences of endorsing ideological variables and recognise when it makes strategic sense to do so. Although people’s ideological positions are determined by many factors, the present research suggests that one of these factors may be informed, strategic choice. That is, people may select or modify their ideological positions based on shared and surprisingly sophisticated understandings of their consequences. In the final chapter, I discuss how further research may explore the interplay between lay beliefs about political ideology and their consequences for political choice
Some properties of o-bounded and strictly o-bounded groups
No full textWe continue the study of (strictly) o-bounded topological groups initiated by the first listed author and solve two problems posed earlier. It is shown here that the product of a Comfort-like topological group by a (strictly) o-bounded group is (strictly) o-bounded. Some non-trivial examples of strictly o-bounded free topological groups are given. We also show that o-boundedness is not productive, and strict o-boundedness cannot be characterized by means of second countable continuous homomorphic images
Looking back at the stare-in-the-crowd effect: Staring eyes do not capture attention in visual search
No full textThe stare-in-the crowd effect refers to the finding that a visual search for a target of staring eyes among averted- eyesdistractersismoreefficientthanthesearchforan averted-eyes target among staring distracters. This finding could indicate that staring eyes are prioritized in the processing of the search array so that attention is more likely to be directed to their location than to any other. However, visual search is a complex process, which not only depends upon the properties of the target, but also the similarity between the target of the search and the distractor items and between the distractor items themselves. Across five experiments, we show that the search asymmetry diagnostic of the stare- in-the-crowd effect is more likely to be the result of a failure to control for the similarity among distracting items between the two critical search conditions rather than any special attention-grabbing property of staring gazes. Our results suggest that, contrary to results reported in the literature, staring gazes are not prioritized by attention in visual search
The effect of emotional faces on eye movements and attention
No full textThe present study investigated the nature of attention to facial expressions using an oculomotor capture paradigm. Participants were required to make a speeded saccade toward a predefined target and ignore distractors. The valence (happy or angry) and orientation (upright or inverted) of the target and distractors varied. We found evidence that irrelevant happy and angry face distractors did capture attention, but only when emotions were the target of search. Eye movements were not directed toward angry distractors any more often than toward happy distractors, and saccades to angry face targets were no faster than to other targets. The results provide evidence that emotion information can be used as a feature to voluntarily select targets and direct attention, suggesting attention is not necessary for the identification of emotional expression. There was no evidence, however, that angry face stimuli have a special priority for reflexively orienting attention
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