Reflection cracking in asphalt concrete (AC) overlays is a common form of pavement deterioration that occurs when underlying cracks and joints in the pavement structure propagate through an overlay due to thermal and traffic-induced movement, ultimately degrading the pavement’s lifespan and performance. This study aims to determine how alterations in overlay thickness and temperature conditions, the incorporation of chopped fibers, and the use of geotextiles influence the overlay’s capacity to postpone the occurrence of reflection cracking. To achieve the above objective, a total of 36 prism specimens were prepared and tested using an overlay testing machine (OTM). The variables considered in this study were the thickness of the overlay (40, 50, and 60 mm), temperature (20, 30, and 40 °C), mix type (reference mix and mix modified with 10% chopped fibers by weight of asphalt cement), and the inclusion of geotextile fabric at two positions (one-third of the depth from the base and at the bottom). The research outcomes revealed that a decreased temperature and thicker overlay led to a higher resistance to crack initiation and full propagation, as indicated by the values of critical fracture energy (Gc) and crack progression rate (CPR). Furthermore, the study observed the enhanced crack resistance of overlays in the presence of geotextiles, whether at the bottom or one-third of the depth from the bottom, with superior performance of the former. Despite a slight enhancement in certain properties, the incorporation of chopped fibers in the overlays did not substantially improve the overall performance compared to the reference specimens. Overall, the study provides valuable insights into the variables that influence the ability of AC overlays to mitigate reflection cracking. These findings will aid engineers and designers in making informed decisions regarding overlay design and construction.
Jatropha L. is an exotic genus to Iraq and it has been cultivated in gardens for ornamental purposes because of the shiny red color of the flowers. The plant adapted to environmental conditions and succeeded in growing and blooming, which is why the species was interested to study. The species Jatropha integerrima Jacq. was examined and diagnosed for the first time in Iraq. Morphological and anatomical characteristics for leaves (considering that the variations are the most reliable and taxonomically important) were provided. The Phytochemical screening showed the presence of alkaloids, flavonoids, terpenes, tannins and saponins. The qualitative analysis by TLC indicated the presence of alkaloids and flavonoid that was detected by specia
... Show MoreThis study looked at how the synthetic chitosan-AgNPs-Doxorubicin-folic acid combination affected the A549 cell line in terms of cytotoxicity and anticancer activity. By reducing silver nitrate (AgNO3) and biodegradable chitosan, silver nanoparticles were biosynthesized. The produced conjugate was examined by using FT-IR spectroscopy, atomic force microscopy (AFM), and field emission scanning electron microscopy (FE-SEM). The cytotoxicity assay for the viability of A549 cells revealed that the combination of chitosan, AgNPs, doxorubicin, and folic acid decrease cell viability in a dose-determined by method over 48 hours, which direct to a dependent reduce in the activity of A549 cells. The mechanism analysis of the impacted living cells lea
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Here we determined the structure of a cold active family IV esterase (EstN7) cloned
In this research, an enhancement in lubricating, rheological, and filtration properties of unweighted water-based mud is fundamentally investigated using XC polymer NPs with 0.2gm, 0.5gm, 1gm, 2gm, and 4gm concentrations. Bentonite, that had been used in the preparation of unweighted water-based mud, was characterized using XRF-1800 Sequential X-ray Fluorescence Spectrometer, XRD-6100/7000 X-ray Diffractometer, and Malvern Mastersizer 2000 particle size analyzer, respectively. Lubricating, rheology and filtration properties of unweighted water-based mud were measured at room temperature (35°C) using OFITE EP and Lubricity Tester, OFITE Model 900 Viscometer, and OFITE Low-Pressure Filter Press, respectively. XC Polymer N
... Show MoreThe aim of the research is to demonstrate the concept, characteristics, efficiency and adequacy of infrastructure in Khor Al-Zubair, as it represents an important benchmark for judging the development of the city. The researchers thus aim to measure the efficiency, adequacy and personal impression of each service in Khor Al-Zubair city and its residential neighborhoods. To meet this objective, the researchers used the descriptive and analytical approach that involves randomly distributing a questionnaire with specific questions to the neighbors of the city. The study has reached a set of results and recommendations that contribute to addressing the problems to the sector of infrastructure services in the city, such as: the per capita sha
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يجمع المختصون أن ليس من نقد إلا وكان مُرحِّلا لنظرية لسانية إلى فضائه، فكان أثر اللسانيات السوسيرية، ومن ثم اللسانيات التوليدية التحويلية معروفا، ولم يكن هذا الأثر محدودا باللسانيين أو نقاد الأدب فحسب، بل امتد إلى الشعراء والجماليين أيضا. وفي هذا البحث سنتوقف عند أثر اللسانيات الوظيفية، وهو ما لم يتوقف عنده إلا قلة من المختصين. ولن نقف عند نقد الوظيفيين للشعر، بل سنقف عند نقدهم للرواية، بقراءة
... Show More In this research we prepared thin films from pure polymer (polyvinyl alcohol PVA )and doped with CuO with concentration 8% ,and Fe2Cl3 at different concentrations (1,5,8)%.This films were prepared by casting method and placed in Britidish (4cm diameter )with thickness(200±5)μm.Through the investigation of(X-ray )diffraction it is found all that the samples have polycrystalline structure .Also we measurement the optical properties from this films such as absorption ,transmittion spectra ,absorption coefficient ,energy gap ,extinction coefficient ,refraction index ,finesse coefficient ,the dielectric constant with two parts the real and the imaginary and the optical conductivity .
Undoped and Co-doped zinc oxide (CZO) thin films have been prepared by spray pyrolysis technique using solution of zinc acetate and cobalt chloride. The effect of Co dopants on structural and optical properties has been investigated. The films were found to exhibit maximum transmittance (~90%) and low absorbance. The structural properties of the deposited films were examined by x-ray diffraction (XRD). These films, deposited on glass substrates at (400? C), have a polycrystalline texture with a wurtzite hexagonal structure, and the grain size was decreased with increasing Co concentration, and no change was observed in lattice constants while the optical band gap decreased from (3.18-3.02) eV for direct allowed transition. Other parameters
... Show MoreTransparent nano- coating was prepared by Sol-Gel method from titanium dioxide TiO2 which has the ability to self-cleaning coating used for hospitals, laboratories, and places requiring permanent sterilization. Three primary colors are selected (red, blue, and yellow) as preliminary study to the effect of these colors on the nano-coating. Three traditional oil paints color were used as base, then coated by a layer of TiO2-Sol and deposited on the paints. The optical properties of TiO2-Sol were measured; the maximum absorption wavelength at (λmax=387 nm), the refractive index (n=1.4423) and the energy band gap (Eg=3.2 eV). The structure properties found by X-ray diffraction of TiO