The performance of asphalt pavements is crucial due to heavy traffic loads from civil and industrial developments. Various additives and modifiers are used in flexible roads to improve their resistance to deterioration caused by climatic changes. From this context, modifying the asphalt binder with polymers is popular in asphalt pavement construction. The present research investigates the effect of Polyethylene (PE) polymers in powder form on the characteristics of asphalt mixtures since these polymers are composed of hydrocarbons. It is similar to asphalt binders, making them very effective in enhancing the performance of neat asphalt produced from the oil refinery. To confirm this, two types of PE, High-Density PE (HDPE) and Low-Density PE (LDPE), were blended with neat asphalt binder at different dosages of 0%, 2%, 4%, and 6% by the weight of asphalt binder. The physical tests, including penetration, ductility, softening point, and weight loss on heat, were conducted to examine neat and PE-modified binders' rheological properties, durability, and temperature sensitivity. Marshall stability, stiffness index, tensile strength, and Scanning Electron Microscope (SEM) were also employed to assess the performance of PE-modified asphalt mixtures. The findings reveal that incorporating PE into asphalt mixtures significantly improves their mechanical properties, and the most optimal results are achieved when using 6% of both HDPE and LDPE. Specifically, modifying the asphalt binder with the inclusion of 6% HDPE and LDPE presents a remarkable increase in stability of 167.6% and 150.9%, respectively, compared to conventional mixtures. The stiffness index is improved for HDPE and LDPE-modified mixtures, which offers these mixtures superior resistance to permanent deformation. The moisture damage resistance can be enhanced by modification of the asphalt binder with HDPE and LDPE, especially at the inclusion of 6%. SEM images of asphalt pavement demonstrate HDPE's superiority in terms of distribution and dispersion in asphalt binder. In conclusion, the properties of HDPE-modified mixtures are better than those of LDPE-modified and untreated mixtures.
The Electro-Fenton oxidation process is one of the essential advanced electrochemical oxidation processes used to treat Phenol and its derivatives in wastewater. The Electro-Fenton oxidation process was carried out at an ambient temperature at different current density (2, 4, 6, 8 mA/cm2) for up to 6 h. Sodium Sulfate at a concentration of 0.05M was used as a supporting electrolyte, and 0.4 mM of Ferrous ion concentration (Fe2+) was used as a catalyst. The electrolyte cell consists of graphite modified by an electrodepositing layer of PbO2 on its surface as anode and carbon fiber modified with Graphene as a cathode. The results indicated that Phenol concentration decreases with an increase in current dens
... Show MoreUndoubtedly, rutting in asphalt concrete pavement is considered a major dilemma in terms of pavement performance and safety faced by road users as well as the road authorities. Rutting is a bowl-shaped depression in the wheel paths that develop gradually with the increasing number of load applications. Heavy axle loadings besides the high pavement summer temperature enhance the problem of rutting. According to the AASHTO design equation for flexible pavements, a 1.1 in rut depth will reduce the present serviceability index of relatively new pavement, having no other distress, from 4.2 to 2.5. With this amount of drop in serviceability, the entire life of the pavement in effect has been lost. Therefore, it is crucial to look at the mechani
... Show MoreBasrah crude oil Vacuum residue 773+ K with specific gravity 1.107 and 4.87wt. % sulfur, was treated with hexane commercial fraction provided from Al-Taji Gas Company for preparing deasphaltened oil(DAO)suitable for hydrotreating process. Deasphaltening was carried out with 1h mixing time, 10ml:1g solvent to oil ratio and at room temperature. Hexane deasphaltened oil was hydrotreated on presulfied commercial Co-Mo/γ-Al2O3 catalyst in a trickle bed reactor. The hydrotreating process was carried out at temperature 660 K,LHSV 1.3 h^ –1, H2/oil ratio 300 l/l and constant pressure of 4MPa. The hydrotreated product was distillated under vacuum distillation unit. It is found that the mixture of 75% of vacuum residue with 25% anthracene satisfie
... Show MoreBackground: Lateral cephalometric radiography is commonly used as a standard tool in orthodontic assessment and treatment planning. This study aimed to determine the tongue and surrounding space area in a sample of Iraqi adults with class I dental and skeletal pattern. Materials and methods: The study included thirty healthy subjects (15 males and 15 females) with an age ranged between 23-34 years and class I dental and skeletal pattern with no history of any sleep related disorders. The assessed cephalometric measurement included length and height of the tongue and position of hyoid bone from cervical line. Descriptive statistics were obtained for the data. Genders difference was evaluated by independent sample t-test. Results: There wer
... Show MoreBackground: Periodontal diseases are bacterial infections of the gingiva, bone and attachment fibers that support the teeth and hold them in the jaw. α-amylase is an enzyme, produced mainly by parotid gland and it seems to play a role in maintaining mucosal immunity. Aims of the study: Determine the salivary levels of α-Amylase and flow rate and their correlations with clinical periodontal parameters(Plaque Index , Gingival Index , Bleeding on Probing , Probing Pocket Depth , and Clinical Attachment Level ) and the correlation between α-Amylase with flow rate of study groups that consist of ( patients had gingivitis and patients had chronic periodontitis with different severities(mild ,moderate ,severe) and control group . Ma
... Show MoreA polycrystalline CdSe thin films doped with (5wt%) of Cu was fabricated using vacuum evaporation technique in the substrate temperature range(Ts=RT-250)oC on glass substrates of the thickness(0.8?m). The structure of these films are determined by X-ray diffraction (XRD). The X-ray diffraction studies shows that the structure is polycrystalline with hexagonal structure, and there are strong peaks at the direction (200) at (Ts=RT-150) oC, while at higher substrate temperature(Ts=150-250) oC the structure is single crystal. The optical properties as a function of Ts were studied. The absorption, transmission, and reflection has been studied, The optical energy gap (Eg)increases with increase of substrate temperature from (1.65
... Show MoreNew derivative molecular absorption spectrophotometric methods have been developed for the determination of Al (III) , Mn (II) , individually and binary mixtures . The aim of this model of study is to obtain analytical results characterized by adequate standard of analytical figures of merits through application of derivative Spectrophotometry (dnA/d?n). The two metals acetyl acetonates are chemically stable and are widely used as catalysts . Where Interferences are probable due to very close or nearby peaks or Summits, the Zero – Crossing derivative measurement technique is used to avoid interfering effects between two metals pairs.
This research deals with a shrinking method concernes with the principal components similar to that one which used in the multiple regression “Least Absolute Shrinkage and Selection: LASS”. The goal here is to make an uncorrelated linear combinations from only a subset of explanatory variables that may have a multicollinearity problem instead taking the whole number say, (K) of them. This shrinkage will force some coefficients to equal zero, after making some restriction on them by some "tuning parameter" say, (t) which balances the bias and variance amount from side, and doesn't exceed the acceptable percent explained variance of these components. This had been shown by MSE criterion in the regression case and the percent explained v
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