Feasibility and assessment of using recycled rubber for infrastructure applications

“The United States needs to mine billions of tons of raw natural aggregate each year. At the same time, millions of scrap tires are stockpiled every year. Therefore, replacing natural aggregate with recycled crumb rubber aggregate will be beneficial to the construction industry and environment. This research aimed to investigate the feasibility of using recycled rubber in new construction applications. Based on size, recycled rubber was selected to match its natural counterpart. Different ratios of recycled crumb rubber were used as a fine aggregate replacement in concrete masonry units (CMUs) where the rubberized units showed a lower unit weight, higher ultimate strain, and better durability. In addition, the thermal conductivity of rubberized masonry units decreased with increasing the rubber content resulting in a reduction in heating energy consumption. In a different application, recycled crumb rubber was used as a full or partial replacement of coarse aggregate in chip seal surfacing where it shows better retention especially with longer curing time. The rubberized chip seal had a rougher surface which increases driving safety. Environmentally, the toxic heavy metals leached from the rubberized chip were below that of the EPA drinking water standards with a significant reduction of heavy metal leaching when rubber was used with emulsion in the form of chip seal. The third application was utilizing the waste of scrap tire processing in a form of rubber- fiber powder (RFP) as a sand replacement within cement mortar. RFP was used as an additive to provide more corrosion resistance and less heat of hydration of cement mortar. Incorporating RFP within plastering mortar disclosed that RFP can be used as an eco-friendly additive to provide better crack resistance, thermal and acoustical insulation as well as noise reduction”--Abstract, page iv

Effect Of Vehicle Speed And Weight On Raveling Of Chip Seal Constructed Using Mineral And Tire Derived Aggregate

The characteristics of the load applied by traffic, namely, vehicle speed and load magnitude, play a critical role in the raveling performance of chip seal pavement, which is often overlooked in literature. Furthermore, a sustainable chip seal constructed out of tire derived aggregate (TDA) has been recently introduced. Unlike mineral aggregate, rubber is a time-dependent material, and its properties are greatly influenced by the magnitude and rate of loading. Introducing TDA in chip seal has increased the significance and need to investigate the effects of vehicle speed and load on chip seal. This study investigated the raveling performance of different chip seal specimens constructed out of mineral and TDA, as well as a hybrid tire derived–mineral aggregate, under various loading speeds and magnitudes using a small-wheel traffic simulation device. The findings revealed that both load and speed significantly affect the texture loss of conventional and TDA chip seals, but in opposite ways. Conventional chip seals experienced increased texture loss with higher load and speed, while TDA chip seals showed a decrease. The use of TDA as an aggregate in chip seal resulted in a 23% reduction in macrotexture loss under increased load and a 56% reduction in macrotexture loss under increased speed compared with conventional chip seal. This improved performance is attributed to the dynamic properties of TDA, such as internal hysteresis, time-dependent behavior, and load transmissibility

Raveling Performance of Conventional and Rubberized Chip Seal under Field and Laboratory Traffic Loading

Raveling, or the Loss of Surface Aggregate, is a Major Concern in Chip Seal Pavement. Previous Studies Have Used the Standard Sweep, Vialit, and Pennsylvania Tests to Evaluate Raveling, But These Tests Do Not Replicate the Stresses of Rolling Vehicle Tires on Chip Seal and Have Produced Inconsistent Results. Additionally, These Tests Mainly Evaluate Early-Stage Raveling Due to their Short Curing Time. in This Study, a Small-Wheel Traffic Simulation Device (SWTS) Was Used to Apply Similar Stresses as Rolling Vehicle Tires and Produce Comparable Raveling Results. This Was Confirmed through a 13-Month Field Observation of Chip Seal, Where the Laboratory and Field Data Were Compared and Correlated. Both Conventional (Mineral Aggregate) and Eco-Friendly Rubberized Chip Seal with 25%, 50%, and 100% Crumb Rubber as Aggregate Were Tested in the Laboratory and Field. the Effects of Different Aggregate Types, Binder Application Rates, and Crumb Rubber Contents Were Studied. the Results Showed that Each Wheel Application by SWTS is Equivalent to 2.5 to 3 Passenger Car Passes in the Field. It Was Also Found that the Majority of Macrotexture Loss Occurred in the First 50,000 Passenger Car Equivalent Load. Up to 50% Replacement of Mineral Aggregate with Crumb Rubber Did Not Significantly Affect the Raveling Resistance But using More Than 50% Rubber Impaired the Raveling Resistance. using Crumb Rubber Instead of Mineral Aggregate Also Significantly Reduced Tire Wear and Microplastic Emissions from Vehicle Tires. Moreover, It Was Found that Pennsylvania and Vialit Tests May Not Be Suitable for Assessing Aggregate Retention under Traffic Load

A Hybrid Neural Based Dynamic Branch Prediction Unit

Modern high performance processor architectures have come to depend upon highly pipelined operation in order to achieve improvements in operating speed. As a result, the cost associated with flushing the pipeline and refilling it when a branch instruction is mis-predicted can significantly impact processor performance. Many schemes, from the extremely simple to the highly complex, have been proposed to improve branch prediction accuracy. Conventional two-level branch predictors predict the outcome of a branch either based on the( local branch history) information, comprising the previous outcomes of a single branch (intra-branch correlation), or based on the (global branch history) information, comprising the previous outcomes of all branches (inter-branch correlation). The misprediction rates for these predictors are very high when they predict branch instructions with hybrid correlations. In this paper we suggest a hybrid perceptron based predictor which employs up to 31-bits of both local and global branch history information to minimize the misprediction rates. The software written for simulation and testing shows that the suggested hybrid predictor achieves a high accuracy. Our results shows that the best response of the predictor is obtained on history length of 16- bits

Utilizing Waste Latex Paint Toward Improving The Performance Of Concrete

In this paper, incorporating the waste latex paint (WLP) into the conventional concrete as a partial replacement of sand to improve its durability was investigated. The fresh and hardened characterizations, in addition to the durability of concrete, were examined. The slump test was used to evaluate the fresh properties, while the hardened properties were evaluated through the volume of voids and absorption rate, in addition to the compressive, splitting tensile, and flexural strengths tests. The durability performance was evaluated by the surface resistivity, bulk electrical resistivity, as well as freeze and thaw resistance tests. The results showed a reduction in the workability with the addition of WLP, which required high dosages of superplasticizer to maintain the same slump in all the mixtures. Although there was a reduction in the compressive, splitting tensile, and flexural strengths, incorporating the WLP into the OPC concrete improved the durability significantly. Specimens had 5% and 10% of WLP passed the 300 freeze and thaw cycles without deterioration in the relative dynamic modulus of elasticity, compared with the reference mixtures that failed after only 144 cycles. Simultaneously, the surface and bulk electrical resistivity increased by approximately 125% and 138%, respectively, as result of reducing the volume of air voids that was decreased by 9%. The SE images and EDS spectrums showed denser cementitious matrixes with a film of polymeric layer covered the hydration products with adding waste latex paint

Measuring the Global Virtual Teams (GVTs) performance: confirmation study

Objectives: This paper found that there is a need to propose a framework to measure the global virtual teams’ performance involving online training and development, organizational commitment, and motivation in global IT projects. Also this research aims to examine the relationship among online training and development, organizational commitment, motivation, and virtual teams’ performance in global IT projects success, propose a framework to assist the project manager to measure the global virtual teams’ performance in global IT projects involving the online training and development, organizational commitment, and motivation based on defined measures and Key Performance Indicators (KPIs) for the global virtual teams in global IT projects which is our contribution for this study. Method: The Confirmation study were conducted which is including study (expert-questionnaire interview, pilot study, and empirical study (the survey) then the framework proposed. The proposed framework was evaluated through experts from academics and industries. Findings: The results of the confirmation/preliminary study confirmed the validity of the conceptual framework and the validity and reliability of the instrument. Confirmation/empirical study were verified the conceptual framework and the final framework was proposed. Applications: This framework is to assist the project manager to measure the global virtual teams’ performance in global IT projects

Global virtual teams’ (GVTs) performance: online training and development, organizational commitment, and motivation

The global virtual teams (GVTs) comprise of team members who are geographically dispersed, culturally varied, and mainly depends on information and communication technologies (ICT) to communicate with each other's. In spite of technological leverages, the GVTs facing many challenges that affect their performance. Hence, the online training and development is very important for GVTs to perform. The main goal of online training and development is to improve the skills and behaviors of the GVTs, which leads to increase the performance of the team. A systematic literature review was conducted to answer two research questions. The first research question is to investigate the relationship between online training and development and global virtual teams' performance. The second research question is to find out the existing frame works involving online training and development in GVTs. Then, the related frameworks are analyzed to highlight the gaps and limitations for each of them. The findings indicated that there is a positive relationship between online training and development and global virtual teams' performance. The existing frameworks are overlapped in some variables such as online training and global virtual teams' performance. However, the existing frameworks are still not sufficient to measure the performance of GVTs. A Performance Measurement Framework for GVTs was proposed to assist the project manager on measuring the global virtual teams' performance involving the online training and development, organizational commitment, and motivation based on defined key performance indicators (KPIs)

A stand-alone hydrogen photovoltaic fuel cell hybrid system for efficient renewable energy generation

Today the main concern for World is energy and power age. By and by, out of around 7 billion populaces, just 65-69% approaches power. Essentially to carry the populaces into the office of power access however much as could be expected inside the restricted assets, we have used the regular assets like sun oriented and wind to satisfy this assumption. Utilizing sun based and wind energy in relationship with the power gadgets, we can supply the power to the buyers inside their capacity and we will want to limit the power issue as could really be expected. Hydrogen Photovoltaic Fuel (HPF) cell is the mix of force gadgets which lessens the major sun oriented emergency of expenses, where expenses are the enormous issue for non-industrial nations. Presently a-days, the coordinated circuits (IC) are entirely solid and modest, to the point that make the conveying and reversing or changing over components simplest than the massive and expensive instruments utilized in the traditional power supply framework. The examination expects that the lattice joining of the environmentally friendly power assets utilizing HPF inverter might cause a colossal comment in satisfying the absence of force use across the world. Solar energy is a rapidly growing resource, already providing 4.5% of electricity in the World and projected to supply up to 35% by 2050. On the other hand, the default model’s predictions were far from the actual metered HPF data. For renewability, the simulated renewable energy consumption with modified inputs is 3.9% below of actual metered renewable data while the default model’s prediction was more than 52% below actual renewable use. Using PV-HPF hybrid model indices to represent how well a simulated model describes the variability in the measured data; the modified model has achieved accurate renewability results; with a Solar of 10.99 % and Wind of 9.90%, while the hybrid model has a solar of 57.16% and a Wind of 57.20% in renewable energy comparison being performed in MATLAB

A performance measurement framework for Global Virtual Teams (GVTs) in global IT projects

In spite of the increasing prevalence of global virtual teams (GVTs), It should be noted that in spite of the advantages of technology provides, most of global IT projects tend to face problems and risks, and great deal of such projects fail to reach all their objectives. According to the literature review we found that there is a lack of communication within global virtual teams in global IT projects and this problem affect the global IT project performance and leads to global IT project failure. So there is a need to develop a framework to measure the performance for global virtual teams in global IT projects. Early stage and before developing the instrument and conducting the pilot test, the researchers conducted a structured interview with 6 experts to validate the proposed framework. In conclusion, The validity and reliability of the instrument were tested through experts, typical respondents, and analyzed by SPSS 22. The results confirmed the validity of the proposed framework and the validity and reliability of the instrument

Factors for communication technologies selection within virtual software teams

Virtual teams are established to during software development environment. Virtual team members are gradually engaged in globalized business environments across space, time and organizational boundaries with links ensured by information and communication technologies. A virtual team relies on communication, collaboration, and information exchange is the most important criteria in virtual teams operations and their efficiency directly influences team performance. The aim of this paper is to identify the factors of selecting and using of technologies within virtual teams communication to improve virtual team communication to enhance the virtual team performance. This researcher uses systematic literature review by Kitchenham to review existing literature on the issues and implementation of virtual team members. In this review 22 papers were analyzed to answer the research questions