This paper investigates the issue of surface-type effects on traffic noise in Baghdad. Since the raw materials for both flexible and rigid paving are available from local sources, the decision on selecting the type of paving which depends on the budget of the project and the road's importance and function. Knowing that for high traffic volumes and a high percentage of heavy vehicles, rigid pavement is more suitable compared to flexible pavement. In Baghdad, some highways consist of flexible pavement and others of combined pavement (flexible segments and rigid segments), so the study of the effect of surface type on traffic noise becomes an important matter. This study selected three highways: one with flexible pavement and two with combined pavement. The results showed that the traffic noise generated by traffic on rigid pavement generates more noise than traffic on the flexible pavement by about 2 dBA. A prediction model was generated to predict traffic noise depending on five variables (vehicle speed, traffic volume, skid number, distance between the edge of the inner lane and the sound level meter, and surface type). The measured traffic noise levels ranged from 73.23 to 82.86 dBA, which exceeded the permitted limits compared to the permissible Iraqi standards.
Background: Synthetic hydroxyapatite,(Ca10(PO4)6(OH2) can directly bond to bones without infection and fibrous encapsulation, thus is regarded as bioactive and biocompatible. The aim of the study was the estimation of microarchitecture bone parameters include bone mass (gm/cm2) cortical bone width (mm), thread width (mm), marrow space star volume analysis (V*m) and osteoblast, osteocyte cell number. Materials and methods: Ninety-six (96) commercially pure titanium CpTi) used in this study, (48) implants were coated with HA by dipping coating and (48) implants were used as control. They were inserted in (32) Newzland white rabbits and followed for 2 & 6 weeks. Mechanical torque removal test and histomorphometric analysis of bone microarchit
... Show MoreTo assess the environmental pollution of the soil at north Baiji City, the concentration of As, Se, Cr, Co, Cu, Cd, Sb, Mn, Mo, Ni, Pb, V, U, Sr, Ba, Ag, Rb, Li, Sn, Bi, Tl and Zn were determined in 18 sites. Results showed that the range concentrations of metal in mg/kg were Mo (0.84-2.15), Cu (17.62-78.77), Pb (9.89-19.19), Zn (39.5-374.7), Ag (0.064-0.14), Ni (90.7-210), Co (12.8-26.6), Mn (407-863), As (4-7.1), Cd (0.18-0.37), Sb (0.38-0.77), Bi (0.06-0.17), V (74-281), Cr (128-287), Li (15.3-24.4), Tl (0.14-0.24), Sn (0.6-1.7), Rb (28-51.2), U (1.2-1.5), Se (0.3-0.6), Ba (173-310), Sr (218-1270). Based on enrichment factor (EF) of trace elements, Mo, Cu, Pb, Mn, Bi, U, V, Li, Sn, Rb, Ba and Tl were showed deficiency to minimal enric
... Show MoreThis work studies the impact of input machining parameters of Electrical Discharge Machining (EDM) on the machining process performance. Tool steel O1 was selected as the workpiece material, copper as the electrode material, and kerosene as the dielectric medium. Experimental runs have been carried out with a Design of Experiment (DOE) technique. Twenty tests are accomplished with the current range of (18 to 24 Ampere), a pulse duration range of (150 to 200 µs), and a pulse-off time range of (25 to 75 µs). Based upon the experimental study's output results, the EDM parameter's effect (voltage of power supply, discharge current, pulse duration, and pulse pause interval) on the responses of the process represented by sur
... Show MoreThe hydrochemical study of the surface and groundwater in Khan AL-Baghdadi area included interpretation of physical, chemical and biological properties of 14 wells and 6 surface water samples collected from Euphrates River.. The study covered two periods representing dry and wet periods in October 2018 and April 2019, respectively. The surface water samples were characterized as slightly alkaline, fresh water, excessively mineralized, calcium-chloride type, and hard to very hard class. While the groundwater samples were characterized as slightly alkaline, brackish water, excessively mineralized, calcium-chloride and sodium-chloride type, and hard to very hard class. The assessment of water for irrigation purposes for bo
... Show MoreThis paper investigated the treatment of textile wastewater polluted with aniline blue (AB) by electrocoagulation process using stainless steel mesh electrodes with a horizontal arrangement. The experimental design involved the application of the response surface methodology (RSM) to find the mathematical model, by adjusting the current density (4-20 mA/cm2), distance between electrodes (0.5-3 cm), salt concentration (50-600 mg/l), initial dye concentration (50-250 mg/l), pH value (2-12 ) and experimental time (5-20 min). The results showed that time is the most important parameter affecting the performance of the electrocoagulation system. Maximum removal efficiency (96 %) was obtained at a current density of 20 mA/cm2, distance be
... Show MoreThis paper investigated the treatment of textile wastewater polluted with aniline blue (AB) by electrocoagulation process using stainless steel mesh electrodes with a horizontal arrangement. The experimental design involved the application of the response surface methodology (RSM) to find the mathematical model, by adjusting the current density (4-20 mA/cm2), distance between electrodes (0.5-3 cm), salt concentration (50-600 mg/l), initial dye concentration (50-250 mg/l), pH value (2-12 ) and experimental time (5-20 min). The results showed that time is the most important parameter affecting the performance of the electrocoagulation system. Maximum removal efficiency (96 %) was obtained at a current density of 20 mA/cm2, distance between
... Show MoreIn this study, the optimum conditions for chitin deacetylase (CDA) production by Aspergillus flavus F1 in solid-state fermentation were investigated via two optimization strategies: classical optimization based on the method of one factor at a time and statistical optimization using response surface methodology. The result of classical optimization showed that corn supplemented with 2% chitin moisturized with mineral salts solution at pH=7 and five days of incubation time were the optimum conditions for increasing CDA production with approximately yield of 219.5 U/g solid substrate. Furthermore, pH, moisture level and inoculum size were systemically evaluated to improve CDA production based on a central composite design using the Design
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