Characterization of Warm Mix Asphalt (WMA) performance in different asphalt applications

With the prices of crude oil increasing and reserves of natural nonrenewable resources dwindling over time, the needs for adopting greener and more sustainable approaches in various construction activities are stronger. The asphalt production industry has been keen during the last few decades to reduce the impact of its activities on the environment especially regions adjacent to its operating activities and on natural resources. Thus, recycled materials such as reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS) are increasingly being used in the production of asphalt mixtures. Moreover, different techniques to produce and place asphalt mixtures at lower temperatures than the typical hot mix asphalt (HMA) temperatures are recently being used. These techniques are currently known as warm mix asphalt (WMA) technologies. The performance of three commonly used warm mix technologies: Advera, Evotherm J1 and Sasobit were examined in comparison to a control HMA mixture with respect to dynamic modulus and permanent deformation (flow number). Each mixture was developed using a PG 64-22 binder and two types of aggregates: limestone or quartzite. In addition, this study will look into whether WMA additives enable the production of high RAP content (30%) mixtures with comparable performance to HMA. Warm mix asphalt mixtures prepared at 120°C and compacted at 110°C showed no concerns regarding workability or compactability even in mixtures incorporating 30% RAP. Dynamic modulus and flow number tests were conducted to assess the stiffness and permanent deformation resistance, respectively. The performance tests data suggested that there is a significant difference in the performance of HMA mixtures and the three WMA technologies investigated. Dynamic modulus data of WMA mixtures were consistently lower compared to HMA, with the difference in E* values decreasing with increasing temperature. The incorporation of RAP increased the dynamic modulus of all mixtures but HMA mixture was still higher than WMA mixtures. The impact of RAP incorporation decreased as temperature increased. Finally, the rutting resistance of WMA mixtures was considerably lower compared to HMA mixes even after incorporation of RAP. Thus, WMA technologies suitability for hot regions needs to further investigated. MEPDG design runs were performed to assess the performance of lab produced asphalt mixtures incorporating WMA and RAP and compare it to the performance of corresponding control mixtures. MEPDG output agreed with laboratory test results specifically for rutting prediction and terminal IRI values. The statistical analysis of variance indicated that the EvothermTM mixtures performance was generally different from the control mixtures regardless of type of aggregates used. Finally, the rheological behavior of two binders: a base binder and a polymer modified binders incorporating two types of warm mix asphalt (WMA) additives were studied through an extensive testing scheme. The warm mix additives used were an organic wax and an oily chemical additive. Tests performed comprise basic rheological tests such as rotational viscometer, viscous flow, creep, temperature and frequency sweeps. The output data of these tests were used to construct Viscosity-Temperature Susceptibility (VTS) curves and master curves to study the behavior of the binders tested. The performance of the unmodified WMA binders was similar to the control binder at the midrange and high test temperatures. On the other hand, the modified binder incorporating the waxy WMA additive exhibited stiffer behavior indicating the presence of more advanced polymer networks within the binder structure. Moreover, the wax additive had an anti-oxidizing effect on the aging rate of the binder using pressure aging vessel (PAV)

A Learning System for a Computational Science Related Topic

AbstractComputational science is an interdisciplinary field in which mathematical models combined with scientific computing methods are used to study systems of real-world problems. One of such mathematical models is automata theory. This paper introduces a learning system for automata theory. The learning system is a combination of java and robots technologies. Learners can build their own automaton graphically in the systems’ interface, and then pass it to the robot, which can then simulate the automaton transitions. Learners can learn by observing the robot's motion. A preliminary evaluation shows the effectiveness of the system in classroom

Synthesis and studies on chromene based reactive azo dyes and their applications on different fabrics

A number of reactive azo dyes based on chromene moiety were prepared through two inversed routes using 2-amino-7-hydroxy-4-phenyl-4H-chromene-3-carbonitrile, which when coupled to different diazonium salts, yielded the corresponding dyes which were then further reacted with cyanuric chloride. The structures of the prepared dyes were elucidated from their spectral data, elemental analyses and colour measurements. Dyeing of cellulosic and nylon fibers using the prepared dyes was done under suitable conditions. Some properties of the prepared dyes such as fastness properties (washing, rubbing and perspiration) and colour measurements were investigated. The dyes showed very good fastness to washing properties when attached to nylon fibers but poor fastness to light properties were shown

SUPPRESSION OF N-NITROSODIETHYLAMINE INDUCED OXIDATIVE RENAL TOXICITY BY SULPHATEDPOLYSACCHARIDE AND AQUEOUS EXTRACT OF ULVA LACTUCA IN RATS

Objective: The ancient tradition habits of consuming seaweeds in Asian and Middle East countries have been made a key part of their diet, and as an antioxidant, sulphated polysaccharides have made a large number of researches as one of the ocean's greatest treasures. Therefore, the scope of the present study was conducted to investigate the chemopreventive actions of sulphated polysaccharides and aqueous extract of Ulva lactuca on N-nitrosodiethylamine (NDEA) promoted by phenobarbital (PB) induced renal toxicity in male albino rats. Methods: Adult male albino rats were divided into four groups. Group B received a single dose of NDEA intra peritonealy (200 mg/kg body weight) for 2, 12 and 24 weeks to induce renal toxicity. Groups (C& D) simultaneously received (50 mg/kg body weight) sulphated polysaccharides and aqueous extract of U. lactuca, respectively by oral gavage. Further, the B, C& D groups received PB (0.05%) in drinking water after two weeks of NDEA administration along the entire period of study. Saline (0.9%) treated control group (A) was also built-in. Several In vivo enzymatic antioxidant defense system like superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione-s-transferase (GST), myeloperoxidase (MPO), and non-enzymatic system like reduced glutathione (GSH) were evaluated to determine the reno-protective and antioxidant activity of U. lactuca extracts. The oxidative stress markers like lipid peroxidation (LPO) and nitric oxide (NOx) were also investigated as the products of NDEA metabolism. Results: NDEA followed by PB provoked renal and nephrotoxicity was evident from the decreased activity of almost antioxidant enzymes (SOD, CAT, GST, GR and MPO) and increased oxidants (LPO & NOx) in renal tissues. A significant rise in the levels of malondialdehyde (MDA) throughout the entire period of study along with the striking decline of the above enzymic and non-enzymic antioxidants marks the severity of oxidative stress in NDEA-induced rats. However, concomitant treatment with sulphated polysaccharides restored the above antioxidant enzyme levels in the kidneys near to normal better than the aqueous extract, and exhibited a significant dose dependent protective effect against NDEA induced nephrotoxicity, which might be attributed to the antioxidant properties of the extracts. Conclusion: The present study provides evidence, for the first time, that sulphated polysaccharides exert a chemoreceptive significant effect on NDEA-initiated nephrotoxicity through induction of apoptosis. In addition, the restoration effect of enzymic and non-enzymic antioxidant to their normal levels. The study justified the ethno-medicinal use of sulphated polysaccharide extract for protection against renal toxicity

Privacy-Preserving by Design: Indoor Positioning System Using Wi-Fi Passive TDOA

Indoor localization systems have become increasingly important in a wide range of applications, including industry, security, logistics, and emergency services. However, the growing demand for accurate localization has heightened concerns over privacy, as many localization systems rely on active signals that can be misused by an adversary to track users' movements or manipulate their measurements. This paper presents PassiFi, a novel passive Wi-Fi time-based indoor localization system that effectively balances accuracy and privacy. PassiFi uses a passive WiFi Time Difference of Arrival (TDoA) approach that ensures users' privacy and safeguards the integrity of their measurement data while still achieving high accuracy. The system adopts a fingerprinting approach to address multi-path and non-line-of-sight problems and utilizes deep neural networks to learn the complex relationship between TDoA and location. Evaluation in a real-world testbed demonstrates PassiFi's exceptional performance, surpassing traditional multilateration by 128%, achieving sub-meter accuracy on par with state-of-the-art active measurement systems, all while preserving privacy

Partial Redundancy Elimination for Multi-threaded Programs

Multi-threaded programs have many applications which are widely used such as operating systems. Analyzing multi-threaded programs differs from sequential ones; the main feature is that many threads execute at the same time. The effect of all other running threads must be taken in account. Partial redundancy elimination is among the most powerful compiler optimizations: it performs loop-invariant code motion and common subexpression elimination. We present a type system with optimization component which performs partial redundancy elimination for multi-threaded programs.Comment: 7 page

Effect of global postural correction exercises on stress urinary incontinence during pregnancy: A randomized controlled trial

Background: One of the many consequences of pregnancy that may negatively affect a woman’s quality of life is stress urinary incontinence caused by activities of daily living especially those associated with increased intraabdominal pressure. Objective: This research aimed to explore the impact of global postural correction exercises on stress urinary incontinence among pregnant women. Participants and Methodology: Forty primigravida female at their third trimester (aged between 26–36 years), with a single fetus, diagnosed with stress urinary incontinence take part in the research. Participants were assigned randomly into two groups: Study group (group A; n = 20) and control group (group B; n = 20). The participants were tested twice, before and after a 12-week period, during which group A received global postural correction exercises in addition to Kegel exercises, while group B performed only Kegel exercises. A perineometer was used to evaluate the change in vaginal squeeze pressure both before and after conducting the study. UDI-6 was utilized to assess changes in incontinence severity symptoms. Results: Findings revealed a significant increase in the mean value of vaginal squeeze pressure (p < .05) in the post-test condition in comparison to the pre-test in both groups A and B. Additionally, there was a main decrease (p < .05) in the mean value of UDI-6 in both groups. Moreover, findings showed a significant negative (inverse) correlation (p < .05) between the difference in vaginal squeeze pressure and the UDI-6 in all patients. Conclusions: Postural correction exercises in addition to Kegel exercises are effective in reducing urine leakage in women with stress urinary incontinence and should be an integral part of the management of such condition

Exploring Automated Code Evaluation Systems and Resources for Code Analysis: A Comprehensive Survey

The automated code evaluation system (AES) is mainly designed to reliably assess user-submitted code. Due to their extensive range of applications and the accumulation of valuable resources, AESs are becoming increasingly popular. Research on the application of AES and their real-world resource exploration for diverse coding tasks is still lacking. In this study, we conducted a comprehensive survey on AESs and their resources. This survey explores the application areas of AESs, available resources, and resource utilization for coding tasks. AESs are categorized into programming contests, programming learning and education, recruitment, online compilers, and additional modules, depending on their application. We explore the available datasets and other resources of these systems for research, analysis, and coding tasks. Moreover, we provide an overview of machine learning-driven coding tasks, such as bug detection, code review, comprehension, refactoring, search, representation, and repair. These tasks are performed using real-life datasets. In addition, we briefly discuss the Aizu Online Judge platform as a real example of an AES from the perspectives of system design (hardware and software), operation (competition and education), and research. This is due to the scalability of the AOJ platform (programming education, competitions, and practice), open internal features (hardware and software), attention from the research community, open source data (e.g., solution codes and submission documents), and transparency. We also analyze the overall performance of this system and the perceived challenges over the years