Modification of Dynamic Modulus Predictive Models for Asphalt Mixtures Containing Recycled Asphalt Shingles

Recycled asphalt shingles (RAS) have been used in road pavement construction for a number of years primarily on low volume roads. The use of RAS represents economic and environmental opportunities as it provides as good or better performance when processed and proportioned appropriately than commonly used asphalt mixtures. The primary components of RAS are asphalt, mineral filler, mineral granules, and felt. The effect of RAS fibers on an asphalt mixture\u27s dynamic modulus, which is a key input in the Mechanistic-Empirical Pavement Design Guide (MEPDG) and one of the critical properties of asphalt mixtures affecting flexible pavement responses that are related to its performance, are still uncertain. The National Pooled Fund Study #1208 conducted a series of researches to investigate various issues related to RAS utilization. Thirteen mix designs with RAS contents ranging from zero to six percent were developed and constructed in Indiana, Iowa, Minnesota, and Missouri. Field produced mixtures were procured and sent to Iowa State University Asphalt Lab for laboratory dynamic modulus tests. The testing results are used to evaluate two commonly used dynamic modulus predictive models, the Witczak and Hirsch models. Two versions of Witczak models, which were developed in 1999 and 2006, are evaluated in this research. It was found that the Witczak models were not very effective in estimating the modulus values of RAS mixtures and thus modifications were made to the models to account for the effects of RAS. The study did determine out that the commonly used dosage of RAS in asphalt mixtures does not affect the prediction accuracy of the Hirsch model, however updates were made to improve the Witczak model\u27s accuracy

Development of holding strategies for deteriorated low-volume roads and evaluation of performance of Iowa test sections

Highway agencies in Iowa are challenged by the imbalance between available financial resources for pavement maintenance and the growing number of roads that are due for major rehabilitation or reconstruction. Funding priority is usually given to those roads that are part of the National-Highway-System (NHS). Rural low-volume roads (LVR) are usually not included in the NHS and may be managed by state highway authorities, counties, or townships. These LVRs provide accesses to the areas that are less populated; and, are sometimes allowed to deteriorate to a poor condition due to lack of funding for rehabilitation. Highway agencies are interested in holding strategies that are more aggressive than preventative maintenance but not as extensive as rehabilitation, to improve such roadways. The Iowa Department of Transportation (IDOT) constructed test sections using ten holding strategy treatments to aid in the development of appropriate guidelines. Holding strategy treatments used various combinations of thin asphalt layers, surface treatments, and in-place recycling technologies, including cold in-place recycling (CIR) and full-depth reclamation (FDR). This dissertation presents a comprehensive study on these test sections based on various engineering criteria, including cost and life expectancy, and functional and structural performance measures. The current implementation of the technologies that were incorporated into the holding strategies was also reviewed. The findings in these studies show that the concept of holding strategy can be successfully achieved by selecting treatments that use a combination of various widely used thin hot mix overlays, thin surface treatments, and in-place recycling technologies. A treatment selection tool and recommendations to the structure design and safety performance are also developed in this dissertation

New Methods of Uncheatable Grid Computing

Grid computing is the collection of computer resources from multiple locations to reach a common goal. According to the task publisher's computing power, we will classify the deceptive detection schemes into two categories, and then analyze the security of deceptive detection schemes based on the characteristics of computational task function. On the basis of double check, we proposed an improved scheme at the cost of time sacrifice called the secondary allocation scheme of double check. In our scheme, the security of double check has been greatly strengthened. Finally, we analyzed the common problem of High-Value Rare Events, improved the deceptive detection scheme due to [1], and then put forward a new deceptive detection scheme with better security and efficiency. This paper is revised and expanded version of a paper entitled "Deceptive Detection and Security Reinforcement in Grid Computing" [2] presented at 2013 5th International Conference on Intelligent Networking and Collaborative Systems, Xi'an city, Shanxi province, China, September 9-11, 2013

Direct observation of the ground state of a 1/3 quantum magnetization plateau in SrMn3_3P4_4O14_{14} using neutron diffraction measurements

We can directly investigate the ground state in magnetization-plateau fields (plateau ground state) using neutron diffraction measurements. We performed neutron diffraction measurements on the spin-5/2 trimer substance SrMn$_3$P$_4$O$_{14}$ in magnetization-plateau fields. The integrated intensities of magnetic reflections calculated using an expectation value of each spin in a plateau ground state of an isolated-trimer model agree well with those obtained experimentally in the magnetization-plateau fields. We succeeded in direct observation of a plateau ground state in SrMn$_3$P$_4$O$_{14}$

MAP kinase activation by mu opioid receptor involves phosphatidylinositol 3-kinase but not the cAMP/PKA pathway

AbstractThe involvement of protein kinases was studied in mu opioid receptor activation of mitogen-activated protein (MAP) kinase using cells transfected with the receptor clone. The cAMP/protein kinase A (PKA) pathway is known to be the major biochemical pathway for mu opioid receptor signaling. However, our data showed that stimulating adenylyl cyclase or activating PKA had no effect on mu receptor enhancement of MAP kinase activity, suggesting that the cAMP/PKA pathway is not involved in mediating the mu receptor activation of MAP kinase. Inhibition of phosphatidylinositol (PI) 3-kinase reduced mu receptor enhancement of MAP kinase activity, suggesting PI 3-kinase involvement. Together, these results show that cross-talk between the mu opioid receptor and the MAP kinase cascade is not mediated by the cAMP/PKA pathway, but involves PI 3-kinase

Re-adhesion control for railway traction systems

Slip is a harmful phenomenon in railway. It causes the wear of wheel rail contact surface and mechanical stress of the traction system. Moreover, it may affect the stability of the whole system. The study is concerned with the development of a novel slip detection and re-adhesion control using practical position encoder. In detail, this thesis presents a powered wheelset system driven by an induction motor associated with vector control unit The ~heelset models developed from the study include a comprehensive model which involves longitudinal, lateral and yaw dynamics, a distributed parameter model and a. lumped parameter model with simplified longitudinal dynamics. The dynamics of a wheelset is ~tudied and compared in normal conditions and slip conditions. Simulation results show typical torsional vibration occurs when slip happens. Two possible approaches of slip detection based on the vibration phenomenon are discussed. The first one monitors the torsional torque to detect the slip based on the direct torsional torque measurement In the second approach, a Kalman filter based slip detection method is-presented and evaluated in different operation conditions. Finally a re-adhesion control scheme is developed based on the Kalman filter. The effectiveness of this approach is demonstrated using comprehensive computer simulations