Influence of Polymeric Coating the Aggregate Surface on Moisture Damage of Hot Mix Asphalt

Moisture damage is one of the common causes of asphalt pavement failure in moisture presence. One of the convenient approaches to decreasing moisture sensitivity in hot-mix asphalt is coating the aggregate surface with a suitable agent. In this study, the effects of polyethylene terephthalate on moisture damage of asphalt mixtures were evaluated by applying indirect tensile strength and resilient modulus tests. The asphalt specimens were prepared with two types of aggregates (granite and limestone) and neat asphalt binder of 60/70 penetration grade. The results showed that the ratio of wet/dry values of indirect tensile strength and resilient modulus for mixtures containing limestone was higher than those of the samples with granite aggregate. Furthermore, the results of the laboratory tests indicate that polyethylene terephthalate improves resistance to moisture susceptibility. Because polyethylene terephthalate increases the wettability of asphalt binder over the aggregate and the adhesion between the asphalt binder and aggregate, especially in the mixtures containing acidic (granite) aggregate prone to moisture damage

Effects of Asphalt Binder Modifying with Polypropylene on Moisture Susceptibility of Asphalt Mixtures with Thermodynamically Concepts

In this study, the effect of using Polypropylene (PP) as an antistripping additive of asphalt mixtures is investigated. Here, the moisture susceptibility of asphalt mixtures is evaluated by determining the micro-mechanisms using the surface free energy (SFE) concept. The adhesion bond between the aggregate and asphalt binder and the cohesion strength of the asphalt binder are considered as the main factors that affect moisture damage of asphalt mixtures. Test results indicate that the use of PP improves the resistance of asphalt mixtures in both wet and dry conditions. Also, the results of the SFE tests showed that the modifying asphalt binder with PP increases free energy of adhesion that will improve adhesion resistance between asphalt binder-aggregates. The amount of debonding energy in the samples which are modified with PP is lower than the control samples. This shows that by modifying asphalt binders, the tendency of asphalt binder-aggregate stripping can be reduced. The results show the total SFE of the asphalt binders of the modified samples have more free energy rather than the control samples. This phenomenon shows that failure in the asphalt binder film and cohesion failure will be happened more rarely

Feasibility of Implementing Multi-factor Authentication Schemes in Mobile Cloud Computing

Abstract-Mobile cloud computing is a new computing technology, which provides on-demand resources. Nowadays, this computing paradigm is becoming one the most interesting technology for IT enterprises. The idea of computing and offloading data in cloud computing is utilized to overcome the inherent challenges in mobile computing. This is carried out by utilizing other resource providers besides the mobile device to host the delivery of mobile applications. However, this technology introduces some opportunities as new computing concept, several challenges, including security and privacy are raised from the adoption of this IT paradigm. Authentication plays an important role to mitigate security and privacy issue in the mobile cloud computing. Even some authentication algorithms are proposed for mobile cloud computing, but most of these algorithms designed for traditional computing models, and are not using cloud capabilities. In mobile cloud computing, we access to pooled computation resources and applying more complicated authentication schemes is possible. Using different authentication factors, which is called multifactor authentication algorithms, has been proposed for various areas. In this paper, feasibility of implementation of different kinds of multi-factor authentication protocols are discussed. Furthermore, the security and privacy of these algorithms are analyzed. Finally, some future directions are recommended

Assessment of attention bias in the cognitive processing of neutral and emotional words Using semantic Strop test

Objective: This aim of this study was to assessment of attention bias in the cognitive processing of neutral and emotional words, using Stroop's semantic test on students. Method: 50 students from Tabriz University were selected randomly and in addition to the demographic information, they responded to the Stroop's semantic test. Data analysis was done using descriptive statistics, independent groups T-test and paired groups T-test. Results: The mean percentages of correct responses in the sample (boys and girls) in emotional words were lower than neutral words. The mean percentage of incorrect responses in the sample in neutral and emotional words was not significant. There were significant differences in neutral and emotional words between the mean percentages of without respondent in the sample in 0/001. There were significant differences in mean percentages of responses in the sample between the neutral and emotional words in 0/005. On the one hand, there were not significant differences in mean percentages of correct responses in boys in neutral and emotional words but for the girls; there were significant differences in0/005. For both sex, there were significant differences in mean response time between neutral and emotional words in 0/001

Anonymity and untraceability assessment of authentication protocols in proxy mobile IPv6

The Proxy Mobile IPv6 or the PMIPv6 is a protocol for mobile management as established by the Internet Engineering Task Force or IETF to assist in the intense usage of mobile devices and to lower the overhead of signaling. As the inclusion of the mobile node in the signaling related to mobility is not necessary, this type of solutions based on networks optimize the performance of the handover based on signaling overhead and handover latency. Nevertheless, the PMIPv6 has several disadvantages such as issues of privacy and security. The process of authentication of users is usually needed at the time of connecting to a wireless network. The mobile users might wander away from their home networks and be approached by other network services. These network services would usually require the users' credentials to authorize the usage of the service. In order to retain a level of anonymity, various degrees of information are required to be safe guarded including the Local Mobility Anchor ID, Media Access Gateway, and Mobile Node. Nevertheless, a few methods of authentication have been suggested to enhance the PMIPv6's performance since 2008 when this protocol was first established [1]; however, the issues of privacy are often ignored. This study attempts to evaluate the authentication methods of the PMIPv6 according to the anonymity of several network mechanisms. The findings of this study reveal that it is important to suggest an appropriate method of enhancing the protection and privacy of network mechanisms

Security analysis method of recognition-based graphical password

One of the most important primitive security mechanisms is the authentication system. Authentication through the use of password is a commonly utilized mechanism for authentication of users. In general, users utilize characters as their password; however, passwords based on texts are hard to recall and if the passwords are too simple and predictable, then there is the danger of being susceptible to threats. In order to overcome the problems with authentication, an alternative and new approach has been introduced utilizing images for passwords. The idea gains support from the knowledge that the human's brain is highly capable of remembering many detailed images, however remembering texts are more difficult. Users who utilize the graphic authentication carry out certain functions on the images such as to click, drag, and movement of the mouse and so on. This research reviews several common Recognition-Based graphical password methods and analyzes their security based on the estimation criteria. Moreover, the research defines a metric that would make it possible for the analysis of the security level of the graphical passwords that are Recognition-Based. Finally, a table comparing the limits of each method based on the security level is presented

Energy efficient routing in wireless sensor networks based on fuzzy ant colony optimization

A Wireless Sensor Network (WSN) is a collection of sensor nodes that dynamically self-organizes themselves into a wireless network with- out the utilization of any pre-existing infrastructure. One of the major problems in WSNs is the energy consumption, whereby the energy will be caused to increase or reduce the network’s lifetime. In this paper, we propose an optimal routing protocol for WSN inspired by the foraging behavior of ants. The ants try to find existing paths between the source and base station. Furthermore, we have combined this behavior of ants with fuzzy logic in order for the ants to make the best decision. In other words, the fuzzy logic is applied to make the use of these paths optimal. Our algorithm uses the principles of the Fuzzy Ant Colony Optimization Routing (FACOR) to develop a suitable problem solution. The performance of our routing algorithm is evaluated by Network Simulation2 (NS2). The simulation results show that our algorithm optimizes the energy consumption amount, decrease the number of routing request packets and increase the network’s lifetime in comparison with the orig- inal AODV

Numerical and analytical length scale investigation on viscoelastic behavior of bituminous composites: Focusing on mortar scale

International audienceViscoelastic properties of asphalt mixture were studied through a multi-scale approach, including bitumen, mastic, mortar, and mixture length scale. Biphasic and triphasic finite element modeling were employed to construct the heterogeneous models of bituminous composites, including matrix, inclusions, and air voids. The 2S2P1D model consisting of two springs, two parabolic creep elements, and one dashpot was fitted on the output of the numerical model, i.e., dynamic modulus (E*) and phase angle (δ), to accurately determine the Prony series. Then, the data of each scale was utilized as a matrix for the next scale’s model. Three cutting sizes, including 3.35, 2.36, and 1.7 mm were selected based on the previous experimental study of Khodadadi et al. (2021) to generate the mortar model and find the best length scale of the matrix. In addition, the numerical results were compared with the results of the generalized self-consistent scheme model as an analytical approach. Both numerical and the generalized self-consistent scheme models yield adequate results; nevertheless, the numerical solution has more accuracy than the analytical model. The cutting size of the mortar scale had a considerable effect on the LVE properties of the mixture. The result showed that a cutting size of 3.35 mm is more suitable for a mixture with a nominal maximum aggregate size of 19 mm. These findings were consistent with the experimental results

An experimental length scale investigation on viscoelastic behavior of bituminous composites: Focusing on mortar scale

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