The performance of asphalt concrete pavement has affected by many factors, the temperature is the most important environmental one which has a large effect on the structural behavior of flexible pavement materials. The main cause of premature failure of pavement is the rutting, Due to the viscoelastic nature of the asphalt cement, rutting is more pronounced in hot climate areas because the viscosity of the asphalt binder which is
inversely related to rutting is significantly reduced with the increase in temperature resulting in a more rut susceptible paving mixtures. The objective of this study is to determine the effect of temperatures variations on the permanent deformation parameters (permanent strain (p), intercept (a), slope (b), Alpha and Mu) as well as resilient strain (r) and resilient modulus (Mr). To achieve this objective, one aggregate gradation with 12.5mm nominal maximum size, two grades of asphalt cements (40-50 and 60-70) brought form Al- Daurah refinery, limestone dust filler has been used to prepare the asphalt concrete mixtures. 30 Marshall specimens were prepared to determine the optimum asphalt cement content. Thereafter, 30 cylindrical asphalt concrete specimens (102mm in diameter and 203 mm in height) are prepared in optimum asphalt cement and optimum ±0.5 percent. The prepared specimens were used in uniaxial repeated load test to evaluate the permanent deformation parameters of asphalt concrete mixes under the following testing temperature (5, 15, 25, 40 and 60c). The test result analyses appeared that Mr is decrease 51 percent when temperature increased from 5 c to 25 c and then decrease 22 percent with further increase in temperature from 25 c to 60 c. Also, the Alpha value decreases by a factor of 1.25 and 1.13 when temperature increases from 5 c to 25 c and 25 c to 60 c, espectively.
Finally, statistical models were developed to predict the Alpha and Mu parameters of permanent deformation.
The extraction of iron from aqueous chloride media in presence of aluminum was studied at different kinds of extractants(cyclohexanone, tributyl phosphate, diethyl ketone), different values of normality (pH of the feed solution), agitation time, agitation speed, operating temperature, phase ratio (O/A), iron concentration in the feed, and extractant concentration]. The stripping of iron from organic solutions was also studied at different values of normality (pH of the strip solution) and phase ratio (A/O). Atomic absorption spectrophotometer was used to measure the concentration of iron and aluminum in the aqueous phase throughout the experiments.The best values of extraction coefficient and stripping coefficient are obtained under the
... Show MoreThe purpose of the present study is to identify the comprehensive concept of desertion through the Holy Qur’an and to derive some educational implications related to the concept of desertion and its editing. The also aims to explain the images and forms of desertion. The researcher used the qualitative analytical method. The study concluded that the comprehensive concept of desertion was represented in moving from the country of polytheism to the country of Islam, singularity, alienation, and isolation, leaving, repelling and showing off, abandoning the wife in bed, and reciting from the Qur’an recitation, action, and arbitration, insulting, abandoning, delirium, intersection, and manipulation. The researcher has drawn many education
... Show MoreSummary of the research in English:
the research seeks to define the provisions of voluntary charity and some of its contemporary applications, so the research is after the definition of charity and voluntary charity, define the provisions of the Most important thing charity, where the one who is given charity, in the introduction, he talked about the importance of charity in social solidarity,As for the first topic ,it deait with a statement and definition of charity in the Quran,sunnah and comparative juris prudence,whil the second topic was conducted with clarifying the provisions of the ratified, the ratified,while the third topic was concerned with clarifying the application of voluntary charity contemporary investing the Mo
... Show MoreBackground: Chronic periodontitis defined as “an infectious inflammatory disease within supporting tissues of the teeth, progressive attachment loss and bone loss". Aggressive periodontitis is rare which in most cases manifest themselves clinically during youth. It characterized by rapid rate of disease progression .Pro-inflammatory chemokines organized inflammatory responses. Granulocyte chemotactic protein 2 is involved in neutrophil gathering and movement. The purpose of the study is to detect serum of Granulocyte Chemotactic Protein 2 and correlate to periodontal condition in patients with chronic periodontitis, Aggressive periodontitis and Healthy Control subjects and measurement the count of neutrophils for the studied groups. S
... Show MoreGranular carbon can be used after conventional filtration of suspended matter or, as a combination of filtration - adsorption medium. The choice of equipment depends on the severity of the organic removal problem, the availability of existing equipment, and the desired improvement of adsorption condition.
Design calculations on dechlorination by granular - carbon filters considering the effects of flow rate, pH , contact time, head loss and bed expansion in backwashing , particle size, and physical characteristics were considered assuming the absence of bacteria or any organic interface .
The concept of environmental debt, which has several dimensions, emerged in the nineties. One of these dimensions is spatial, referring to the debts that southern countries sustain due to the extraction of natural resources and environmental damage inflicted upon northern countries. Another dimension, the temporal dimension, concerns the environmental debts that current generations owe to their predecessors. That means past generations are culpable for overuse of natural resources and mismanagement. The debt issue is complex, despite many mechanisms to resolve it. Most important are the recently introduced environmental bonds, an important step forward in the field of sustainable financing of environmental debts.