Investigation of the Effect of Rising Temperature and Traffic Loading on the Behaviour of Rigid Pavements to Minimise Maintenance Requirements – Case Study of Lebanese Roads

The aim of this project is to study the effects of high temperature on the performance of rigid pavements including that of Lebanese roads and to develop suitable design and maintenance approaches that enable such pavements to sustain high loading of temperature and traffic. The objectives are to gain a deeper understanding of the condition and performance of existing highway rigid pavements and the need for a durable pavement. More specifically, to fully understand the effect of climate change in terms of temperature changes on rigid pavements and to identify structural layers configuration and material properties that enable the pavement to sustain high temperature and heavy traffic loading, and to develop more effective and sustainable rigid pavement structures to minimise maintenance requirements. The work also includes the design of suitable overlays to maintain and extend the life of the existing rigid pavements. The methodology used to complete the project is by analysing pavement deflection and the effect of high temperature using specialised highway and structural analysis software, particularly the packages KENPAVE, STREETPAVE12 and ABAQUS. The main findings are that fatigue and erosion are the two most significant failing scenarios for rigid pavement, but more specifically, as the temperature increases, the cracking index increases which may lead to fatigue failure. Finite element models and analyses were used to determine the distress caused by traffic loading and high temperature. This research has found that the main factors that strengthen the performance and sustainability of the rigid pavements under high temperature and traffic loading are: thicker slab, high modulus concrete, strong and thicker foundation layers and a subgrade with high CBR%, in addition to a strong and thicker overlay to extend the life of the pavement. The key conclusions are that rising temperatures and high traffic loading have been identified as having a major effect on the performance of rigid pavement, leading to fatigue failure criteria. Erosion is also a common failure criterion which establishes itself at times of high traffic loading. It has been found here that the cracking index of the concrete slab increases when the air temperature changes from 20°C to 60°C. At higher temperatures and with thinner slabs, the cracking index occurrence increases. In conclusion, in Lebanon a minimum of 260 mm rigid pavement would be more suitable to reduce pavement failing under fatigue criteria

Remittances and Institutions: Are Remittances a Curse?

This paper addresses the complex and overlooked relationship between the receipt of workers’ remittances and institutional quality in the recipient country. Using a simple model, we show how an increase in remittance inflows can lead to deterioration of institutional quality – specifically, to an increase in the share of funds diverted by the government for its own purposes. In a cross section of 111 countries we empirically verify this proposition and find that a higher ratio of remittances to GDP leads to lower indices of control of corruption, government effectiveness, and rule of law, even after controlling for potential reverse causality.Remittances, Institutions, Corruption

Shopping Centers in the Brain

Knutson et al. performed functional MRI on individuals while the subjects were deciding whether or not to purchase various items. Their results, reported in this issue of Neuron, support the theory that the decision to purchase involves the integration of emotional signals related to the anticipation of both obtaining the desired product and suffering the financial loss of paying for it

Resilience in Relation to Post-Traumatic Stress Disorder and Coping Behaviors in Combat-exposed Veterans

Resilience in Relation to Post-Traumatic Stress Disorder and Coping Behaviors in Combat-exposed Veterans Abigale Dagher, Dept. of Psychology, with Dr. Christina Sheerin, Dept. of Psychology and Virginia Institute for Psychiatric and Behavioral Genetics, and Dr. Ananda Amstadter, Dept. of Psychology and Virginia Institute for Psychiatric and Behavioral Genetics Post-Traumatic Stress Disorder (PTSD) is a psychiatric disorder that can occur following a traumatic experience. Many veterans who are exposed to combat develop PTSD, yet many also show resilience following these stressors. Resilience can be defined as adaptive functioning in the face of stress or trauma. PTSD is often associated with less resilience while coping skills often increase resilience outcomes. However, it is less known whether the relationship is different across the different clusters of PTSD symptoms and different types of coping behaviors, which can be adaptive (e.g., social support) or maladaptive (e.g., drug use). Thus, this study aimed to investigate in a combat trauma-exposed veteran population 1) whether there was a difference in resilience scores as a function of PTSD status, 2) whether there was a different association with resilience by PTSD symptom cluster total severity score, and 3) which types of coping behaviors were more strongly related to resilience above and beyond PTSD symptoms. It was hypothesized that combat trauma-exposed veterans without PTSD would have greater resilience scores than those with PTSD, that the avoidance symptom cluster would be the strongest predictor of lower resilience in the veterans who have PTSD, and that coping subscales would be associated with higher resilience above and beyond PTSD status, but some coping subscales would be more strongly related to resilience than others. Following informed consent, participants (N=226, Mean age=30.48, 90.3% Male) were interviewed with a structured clinical interview (Clinician-Administered PTSD Scale for DSM-IV; CAPS-IV) and then completed a large battery of self-report assessment measures, including the Connor-Davidson Resilience Scale (CD-RISC) and the Coping Orientation to Problems Experienced (COPE). A t-test analysis was run to determine if there is a difference between trauma-exposed veterans with and without PTSD. Those with PTSD had a significantly lower resilience score (M=30.16, SD=6.96) compared to those without PTSD (M=32.68, SD=4.54), t(174)=2.91, p=.004. Next, a regression analysis was run with each symptom cluster total score predicting resilience total score. Avoidance symptoms significantly predicted lower resilience, β=-.296, t=-2.397, p=.019, but not re-experiencing β=-.056, t=-.426, p=.672 or arousal symptoms β=.022, t=-.173, p=.863. Finally, significant COPE subscales from correlation analyses were included as predictors of resilience, covarying for total PTSD symptoms. Of the 14 coping skills examined, Positive reinterpretation and growth, Active coping, Turning to religion, and Acceptance were associated with greater resilience scores whereas Behavioral disengagement, and Focus on and venting of emotions were negatively associated with resilience scores (all ps \u3c .01). In conclusion, all hypotheses were supported. Combat exposed veterans with PTSD had lower resilience scores than those without PTSD. Likewise, avoidance behaviors predicted higher resilience compared to the other symptom clusters, perhaps given the importance of avoidance for impacting daily functioning and maintaining symptoms. Finally, coping subscales were variably associated with resilience, suggesting that not all coping approaches are necessarily beneficial. Limitations of the study included self-report bias, little variability in resilience measure, and limited generalizability given the restricted sample demographics.https://scholarscompass.vcu.edu/uresposters/1308/thumbnail.jp

On the Truth Values of Definite Descriptions: Examining the Russell-Strawson Dialectic

A well-known critique of Russell’s Theory of Descriptions, offered by P.F. Strawson, is that a central tenet of Russell’s theory, the claim that any particular utterance of a sentence with a non-referring definite description will be either true or false, is mistaken. Strawson provides a similarly well-known argument in support of this claim which at least in part rests on an analysis of such utterances as implying or presupposing, rather than asserting, parts of the logically existential proposition that Russell takes such sentences to be. For Strawson, propositions such as ‘the x is p’ instead presuppose ‘there is an x’ rather than commit to the truth of that proposition. And fulfilling this presupposition is a necessary condition for any such proposition to have a truth value at all. In this paper, I aim to challenge Strawson’s analysis and will argue that (i) we ought to take such utterances to really be asserting the logically existential proposition Russell analyzes them as, and thus that (ii) the utterances of sentences with a non-referring definite description do have truth values. I argue that taking these sentences to be presupposing certain propositions, rather than asserting them, better takes into account certain principles about which utterances ought to be declared false by an agent given their knowledge of other propositions

A Phenomenological Approach to the Bayesian Grue Problem

It is a common intuition in scientific practice that positive instances confirm. This confirmation, at least purely based on syntactic considerations, is what Nelson Goodman’s ‘Grue Problem’, and more generally the ‘New Riddle’ of Induction, attempt to defeat. One treatment of the Grue Problem has been made along Bayesian lines, wherein the riddle reduces to a question of probability assignments. In this paper, I consider this so-called Bayesian Grue Problem and evaluate how one might proffer a solution to this problem utilizing what I call a phenomenological approach. I argue that this approach to the problem can be successful on the Bayesian framework

Coercive inequalities and u-bounds on carnot groups

This thesis focuses on performance improvement strategies of a Flux Re- construction solver. Two different approaches based on numerical and im- plementation strategies are investigated. First, a numerical based strategy is developed to enable a bigger time-step for the explicit inner iterations in a dual time stepping scheme. A simplified preconditioner is developed par- ticularly for the stretched elements located in the near wall region. The pre- conditioner is constructed using the wall normal couplings only. Therefore, it requires relatively low storage and the application of the preconditioner increases a single iteration cost only around 10 to 30% while enabling a 4 to 15 times increase for the maximum time-step. Next, an implementation based strategy that particularly focuses on cache blocking approach is investigated. First, a data structure that will enable cache blocking is implemented in PyFR. Then, a theoretical study is con- ducted to predict the amount of bandwidth savings for three different kernel grouping configurations for the Euler solver in PyFR. All three kernel group- ing configurations are implemented in PyFR and the results are compared against PyFR v1.11.0. The most performant configuration leads to a 2.81x speedup in practice compared to PyFR v1.11.0. Subsequently, the cache blocking approach is extended to Navier-Stokes equations and anti-aliasing. Extension to Navier-Stokes solver requires forming a specific kernel grouping configuration considering the additional kernels in the Navier-Stokes solver. Anti-aliasing support on the other hand necessitates factorisation of the dense interpolation matrices into sparse components so that they become band- width bound and cache blocking approach can be used efficiently. Cache blocking approach for the Navier-Stokes solver with full anti-aliasing yields up to 3.88x speedup compared to PyFR v1.11.0. Furthermore, strong scala- bility of cache blocking approach is also investigated and it is demonstrated that PyFR with cache blocking achieves over 70% efficiency when scaled from 1 to 128 nodes on ARCHER2. Additionally, a cost analysis is carried out based on Amazon AWS pricing and it shows that PyFR with cache blocking on CPUs can be more cost efficient compared to PyFR on GPUs.Open Acces

Development And Commercialization of Advanced Wood-Based Composites In Maine

This award is to the University of Maine to support the activity described below for 36 months. The proposal was submitted in response to the Partnerships for Innovation Program Solicitation (NSF 0179).PartnersThe partners for the award include the University of Maine (Lead Institution), Maine Technology Institute, Eastern Maine Development Corporation, State Department of Economic and Community Development, The Manufacturing Extension Partnership, Maine Department of Transportation, Louisiana Pacific, Dow Chemical, State Farm Insurance, Henderson and Bodwell, The Kenway Corporation, Market Development Alliance of the FRP Composites Industry, APA the Engineered Wood Association, National Institutes of Standards and Technology, USDA Forest Products Laboratory.Proposed ActivitiesThe award will support the following activities: (1) strengthen partnerships among the University of Maine, private industry, state organizations, forest product industry organizations, and national laboratories to foster commercialization of composite reinforced wood, (2) develop innovative strategies for commercializing composite reinforced wood hybrids that can become models for other university research centers, establish commercialization projects (reinforced wood composite beams using low-grade hardwoods, disaster-resistant housing using reinforced sheathing panels, novel long-strand composite lumber beams and columns).Proposed InnovationHousing industry in the US accounts for 28% of the total construction industry, and most of the wood used is high-grade conventional wood lumber. The supply of high-grade lumber is declining in the US. Reinforced composite wood will allow the use of low-grade lumber from other species of trees in more abundant supply, and provide skilled jobs in Maine. These products will lower the cost of wood products for housing in the US. Increasing the resistance of housing to disasters such as hurricanes and earthquakes will make a major impact on the economy of the nation.Potential Economic ImpactNinety percent of Maine is forested, and 25% of the state\u27s economy is based on forest resources. The forest economy has traditionally been based on export of raw lumber with unskilled labor and few value added timber products. Other manufacturing jobs have moved from the state recently, leaving unskilled jobs and service industries (e.g., tourism) as the major source of income. Successful commercialization of composite reinforced wood will play a large role in developing a growing state economy. Lower costs for wood products for housing construction will have a major economic impact in the US. Increasing the resistance of housing to disasters will lower the cost of repair, maintenance, and insurance for disasters.Potential Societal ImpactMaine ranks 29th in the nation in terms of advanced degree scientists/engineers and 50th in science/engineering graduate students. The job market for young scientists and engineers is bleak in Maine. The educational program will include entrepreneurial education as well as science and engineering to provide a skilled workforce for the economy surrounding the new wood-based technology/economy. The housing industry amounts to $800 billion/year in the US alone