Preferred Language
Articles
/
joe-2598
Influence of Aging Time on Asphalt Pavement Performance
...Show More Authors

Aging of asphalt pavements typically occurs through oxidation of the asphalt and evaporation of the lighter maltenes from the binder. The main objective of this study is to evaluate influence of aging on performance of asphalt paving materials.nAsphalt concrete mixtures, were prepared, and subjected to short term aging (STA) procedure which involved heating the loose mixtures in an oven for two aging period of (4 and 8) hours at a temperature of 135 o C. Then it was subject to Long term aging (LTA) procedure using (2 and 5) days aging periods at 85 o C for Marshall compacted specimens. The effect of aging periods on properties of asphalt concrete at optimum asphalt content such as Marshall Properties, indirect tensile strength at 25 o C, Resilient Modulus and resistance to permanent deformation were evaluated. The impact of Short-term and long-term aging on asphalt concrete properties was evaluated. The stiffness of the mixture increases by increasing aging period that lead to increase of Marshall Stability, indirect tensile strength, and the resilient modulus, which leads to increases the resistance of mixtures against permanent deformation. The 8 hr. short term aging causes the Marshall stability, indirect tensile strength at 25 o C and resilient modulus to be increased by 52%, 34 % , 20% respectively as compared with control mixture while, the permanent deformation decreased by (33 %) as compared with control mixture.

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Tue Sep 01 2009
Journal Name
Al-khwarizmi Engineering Journal
Time Prediction of Dynamic Behavior of Glass Fiber Reinforced Polyester Composites Subjected to Fluctuating Varied Temperatures
...Show More Authors

The reduction of vibration properties for composite material (woven roving E-glass fiber plies in thermosetting polyester matrix) is investigated at the prediction time under varied combined temperatures (60  to -15) using three types of boundary conditions like (CFCF, CCCF, and CFCC). The vibration properties are the amplitude, natural frequency, dynamic elastic moduli (young modulus in x, y directions and shear modulus in 1, 2 plane) and damping factor. The natural frequency of a system is a function of its elastic properties, dimensions, and mass. The woven roving glass fiber has been especially engineered for polymer reinforcement; but the unsaturated thermosetting polyester is widely used, offering a good balance of vibration p

... Show More
View Publication Preview PDF
Publication Date
Sun Dec 01 2002
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
EFFICIENCY OF PARASITOIDS OF PEA LEAFMINER PHYTOMYZA HORTICOLA GOUREAU AND THEIR APPEARANCE TIME IN THE FIELD
...Show More Authors

Eleven hymenopterous species: two braconids, seven eulophids and two pteromalids
parasitized the larvae of Phytomyza horticola Goureau. The activity of the parasites began at
the end of April and evidently increased during May. The female of the parasites fed and
parasitized mostly on the second and third larval instars of P. horticola . Diglyphus iseae
Walker and Cirrospilus vittatus Walker were dominant larval parasites. Chrysocharis
pentheus Walker and Pediobius acantha Walker were main pupal parasites.

View Publication Preview PDF
Publication Date
Wed Dec 01 2010
Journal Name
Al-khwarizmi Engineering Journal
Properties of High Performance Concrete
...Show More Authors

The research deals with a new type of high-performance concrete with improved physical properties, which was prepared by using metal additives minutes (Metakaolin) and by studing their impact on the properties of mortar and concrete high-performance through destructive and non destructive tests. This type of concrete is used broadly in public buildings and in other structures . The research involved a number of experiments such as finding the activity index of burned at a temperature of 750 º C according to the standard ( ASTM C-311/03), as well as casting models for the cubic mortar mixtures and concrete containers at different rates of metakaolin ranging between (5% - 20%) as an added part to the cement mix to get a high- compressive

... Show More
View Publication Preview PDF
Publication Date
Tue Jun 01 2010
Journal Name
Al-khwarizmi Engineering Journal
Enhancement of Hoisting System Performance
...Show More Authors

In this paper it is required to enhance the performance of a mechanical system (here: a Hoisting System) where it is preferred to lift a different payloads with approximately the same speed of lifting and keeping at the same time the good performance, and this of course needs some intelligence of the system which will be responsible on measuring the present load and taking into account the speed and performance desired in order to achieve the requirements or the criteria. The process therefore is a Mechatronics System design which includes a measuring system, a control or automation technique, and an actuating system. The criteria built here in this research using a given Hoist system's characteristics and parameters and changing one of

... Show More
View Publication Preview PDF
Publication Date
Sun Mar 30 2008
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Characteristic Performance of Deionized Columns
...Show More Authors

The reclamation of makeup water is studied in terms of breakthrough time (i.e., the leakage of the cations). Makeup water was subjected to lab-scale ion exchangers of two types: strong acid cation and weak base anion exchanger. The experimental investigation was directed to study the ion exchanger performance in terms of four different parameters (i.e., copper concentration, total dissolved solids (TDS), feed rate and bed depth). Box-Wilson composite rotatable design was adopted in designing the experiments. Breakthrough times of the effluent stream are measured in terms of copper concentration of 2 to 25 ppm, TDS concentration of 250 to 1250 ppm, feed rate of 0.38 to 5.34 l/h and bed depth of 5 to 70 cm. Simulation the effect of the stu

... Show More
View Publication Preview PDF
Publication Date
Tue Dec 01 2015
Journal Name
Journal Of Economics And Administrative Sciences
The Effect of Social Responsibility initiatives in Financial Performance on economic unit and create value for it
...Show More Authors

        Many of researchers have written about social responsibility and business strategy and competitive advantage, and they have given particular attention to the relationship between economic and social responsibility , but what is missing in this aspect is how the economic units that use their core competencies to advance social responsibility initiatives so that they can achieve a significant competitive advantage and create value for it ?

The current research aims to verify the view that "the economic and social objectives in the long term is not contradictory in nature but complementary objectives essential", as well as make sure that the s

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Jan 24 2017
Journal Name
Journal Of Madenat Alelem College
Effect of Prey Type on Relationship between Reproductive Performance and Female's Age in Macrocyclops albidus (Jurine 1820)
...Show More Authors

The present study was conducted to investigate effect of prey type on the relationship between age of females of Macrocyclops albidus and reproductive performance, which included each of mean number of nauplii, age at first brood, and age at first clutch. Results revealed that the correlation coefficient between the age at first brood and clutch and age of females fed on Artemia was significant P <0.05, being 0.65 and 0.81 respectively, while the correlations were not significant P>0.05 in females fed on mosquito larvae (Culex quinquefasciatus) and Paramecium nauplii. It was also found that the correlation coefficients between mean number of the nauplii and longevity in M. albidus were significant P<0.05 whereas, the correlations were not s

... Show More
Publication Date
Sat Jun 01 2019
Journal Name
Journal Of Economics And Administrative Sciences
Research Title: Strategic Orientation Reflections on Organizational Performance (Applied research in the Ministry of Defense / Inspector General)
...Show More Authors

The aim of the study was to study the implications of the strategic direction on organizational performance. The research was carried out in the Iraqi Ministry of Defense / Inspector General's Office for the purpose of identifying the nature of the relationship and the impact between the two variables. A sample of 60 people managers, department managers and directorates was targeted.

The researcher tried to test hypotheses in the first chapter, which was devoted to the methodology of research and previous studies and found the following: (1) validity of the first hypothesis of the existence of a relationship of positive significance of the strategic direction in its sub-dimensions with organizational perf

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Feb 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
Using financial ratio to compare performance of the commercial and the Islamic banks Listed on Palestine Exchange
...Show More Authors

        The research aimed to compare the performance of the commercial and the  Islamic banks listed in the Palestinian's Stock Exchange .To achieve the objectives of the study we selected all  the commercial and the Islamic banks listed in the Palestinian Stock Exchange  to obtain the necessary data for the analysis process during the period of (2009-2013) .the comparison based on the performance indicators ( liquidity rate, profitability rate ,the activity rate and the market rate).

        a statistical method was used to analyze the date to find the performance differences between the commercial banks,

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Tue Aug 16 2022
Journal Name
Heat Transfer
Experimental study on thermo‐hydraulic performance of metal foam twisted tape in a double pipe heat exchanger
...Show More Authors
Abstract<p>A recent study compared experimentally the hydraulic and thermal activity of twisted tape inserts for two types, metal foam twisted tape (MFTT) and traditional twisted tape (TTT), in a double pipe heat exchanger. The investigation goal of the innovatively designed MFTT is to enhance the heat transfer process, which provides a higher thermal enhancement factor over those of TTT under the same conditions. Heat transfer activity in terms of Nusselt number (<italic>Nu</italic>) and Nusselt number ratio (<italic>Nu</italic>/<italic>Nu</italic><sub>o</sub>) as the heat exchanger equipped with the proposed MFTT and TTT inserts with various tape‐twist ratios (<i></i></p> ... Show More
View Publication
Scopus (10)
Crossref (10)
Scopus Clarivate Crossref