Preferred Language
Articles
/
LkIg2ZkBMeyNPGM3YbnO
Polyalphaolefin as a potential modifying agent for hard asphalt cement: Physical, rheological, and chemical characterization
...Show More Authors

Hard-grade asphalt binders like AC20-30 typically exhibit excessive stiffness, reduced penetration, and compromised workability, necessitating modification before use in paving applications. This study evaluates the efficacy of regular polyalphaolefin (PAO), a synthetic olefin-based lubricant, as a performance-enhancing modifying agent for such binders. AC20-30 was blended with PAO at dosages ranging from 2 wt.% to 10 wt.%, and the modified binders were characterized via penetration, ductility, softening point, and rotational viscosity measurements, alongside advanced rheological and chemical-morphological analyses. Incorporating PAO in AC20-30 asphalt progressively reduced the binder stiffness and enhanced its flexibility, with all modified formulations satisfying AASHTO M332 Grade E specifications. Linear amplitude sweep (LAS) testing indicated a substantial improvement in fatigue performance, with the 10% PAO modification exhibiting an 18 times increase in fatigue life at 5% strain relative to the unmodified control. Fourier-transform infrared spectroscopy (FTIR) spectra revealed increased aliphatic and unsaturated functional groups associated with PAO incorporation, while scanning electron microscopy (SEM) imaging indicated a morphological transition toward more continuous and less compact microstructures. Optimal performance was observed at a PAO dosage of 6 wt.%, which provided the best balance of low-temperature flexibility, fatigue resistance, and high-temperature rheological properties. Cost analysis demonstrated that even at 10 wt.% PAO, the modified binder remains below the price of AC40-50, supporting economic feasibility. These findings show that PAO functions effectively as a dual-purpose modifier, providing a practical and cost-effective approach to enhance the performance of hard-grade asphalt binders for heavy-duty pavement applications.

Scopus Clarivate Crossref
View Publication
Publication Date
Thu Mar 31 2016
Journal Name
Al-khwarizmi Engineering Journal
Experimental Study of the Performance of Compound Parabolic Concentrating Solar Collector
...Show More Authors

The design, construction and investigation of experimental study of two compound parabolic concentrators (CPCs) with tubular absorber have been presented. The performance of CPCs have been evaluated by using outdoor experimental measurements including the instantaneous thermal efficiency. The two CPCs are tested instantly by holding them on a common structure. Many tests are conducted in the present work by truncating one of them in three different levels. For each truncation the acceptance half angle (θc) was changed. Geometrically, the acceptance half angle for standard CPC is (26o). For the truncation levels for the other CPC 1, 2 and 3 the acceptance half angle were 20o, 26o and 5

... Show More
View Publication Preview PDF
Publication Date
Tue Aug 15 2023
Journal Name
Journal Of Economics And Administrative Sciences
The Impact of Developmental Leadership on Adaptive Performance- Analytical Research General Directorates of Education in Baghdad province
...Show More Authors

The research aims to reveal the impact of developmental leadership in its dimensions (ideal model, interest in employees, inspiration and motivation) as an independent variable in achieving adaptive performance in its dimensions (Creative problem solving, learning and motivation, Training efforts, adaptability, work stress management, dealing with crises and emergencies) as a dependent variable, and the research aims to enhance the quality of developmental leadership in the research sample through this leadership style, which is a modern style and is still under research and study with a focus on the benefit of adaptive performance From a psychological and organizational research sample consisting of (106) respondents from the middle adm

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Apr 03 2023
Journal Name
Journal Of Educational And Psychological Researches
The Role of Digital Repositories in Developing Teacher Performance in the Primary Stage
...Show More Authors

Abstract

Digital repositories are considered one of the integrated collaborative educational environments that help every researcher interested in developing the education and educational process. The learning resources provided by the repositories are suitable for every researcher, so digital information can be stored and exchanged by ensuring the participation and cooperation of researchers, teachers, and those who are interested, as well as curricula experts, teachers, and students, to exchange each other’s experiences in constantly updating that information as a reason for developing their performance in education. This reveals the importance of the role of educational digital institutions by providing and

... Show More
View Publication Preview PDF
Publication Date
Thu Dec 13 2018
Journal Name
Iraqi National Journal Of Nursing Specialties
Impact of Job Satisfaction on Job Performance of Nurses at Al-SuwairaGeneral Hospital
...Show More Authors

Objective(s): To measure the level of job satisfaction and job performance of nurses and to find out
the association between participants' socio-demographic characteristic of nurse and their job
satisfaction and job performance.
Methodology: A descriptive analytic study design was carried out to measure the nurses' level of job
satisfaction and job performance in Al-Suwaira general hospital and to find out the association between
nurses and their socio-demographic characteristic. The study was started from March 5th, 2017 to
September 31th, 2017. The sample was Non - probability (purposive) sample of (100) nurses were
selected according to the study that are actual working in nursing department in Al-Suwaira General<

... Show More
View Publication Preview PDF
Publication Date
Mon Feb 28 2022
Journal Name
Journal Of Educational And Psychological Researches
Evaluating Supervision’s Performance of Specialist Supervisors in Secondary Schools from Principals’ Perspectives
...Show More Authors

The objective of the research is to identify the level of supervisory performance of the educational supervisor from the point of view of headmasters at secondary schools. The problem was the need to evaluate performance. A sample of (97) school headmasters was chosen to collect the needed data, they proportionated (38%) of the total community. the researcher designed a questionnaire consisted of (43) paragraphs with five areas. The results showed that there is a good level of performance among supervisors; there are no significant differences in the variable of the certificate, while there were significant differences in terms of gender for the benefit of males. The research concluded with a number of recommendations and suggestions.

... Show More
View Publication Preview PDF
Publication Date
Fri Jan 01 2021
Journal Name
Journal Of Economics And Administrative Sciences
The reality of succession planning Under the retirement law No. (26) of 2019 / Applied research in the medical city
...Show More Authors

This research aims to know the reality of succession planning in the researched organization and how it occupies the important jobs in the organization and its readiness for sudden and urgent events that lead to the vacancy of these jobs, and the importance of this research is that it is one of the rare Arab and Iraqi studies and research in this field, as it is one of the first researches It deals with the reality of succession planning in light of the retirement law No. (26) of 2019, and the research problem was the absence of consecutive planning programs and the weak preparation of suitable candidates to face sudden and urgent conditions as replacements for current leaders who occupy the leading and key positions in the depar

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Nov 03 2018
Journal Name
Iraqi National Journal Of Nursing Specialties
Quality Assurance of Nursing Performance in Surgical Wards
...Show More Authors

Objective: The study deafs with nursing performance in the surgical wards in general hospital at
Baghdad city.
Methodology : A descriptive evaluation design using, observational method was carried out. Non
probability (purposive) sample of (151) nurses was selected for the study and comprised all nurses who
worked in general surgical wards in the four health sectors( Rusaffa , Al-Karkh, Al-Yarmok, Medical
city health sector) at time of collecting the data. A check list questionnaire was constructed by the
researcher for the purpose of the study; it is composed of (2) major parts, part (I) is concerned with
socio-demographic data and the second part is composed of two minor parts thev concerned with
availability of

... Show More
View Publication Preview PDF
Publication Date
Sat Sep 30 2023
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The reflection of environmental quality costs on the evaluation of environmental performance
...Show More Authors

Abstract:

               The research aims to achieve defining the concept of environmental quality and associated costs. Studying the impact of environmental quality costs on the performance of economic units. Measuring the relationship between environmental quality and environmental performance of the units. Where the research problem is represented in the weak awareness of some economic units of the importance of environmental quality costs and their impact on evaluating environmental performance, and this leads to neglecting environmental considerations and not improving environmental performance effectively, which negatively affects the en

... Show More
View Publication Preview PDF
Publication Date
Mon Jan 16 2023
Journal Name
Iraqi National Journal Of Nursing Specialties
Effectiveness of an Intervention Program on Nurses’ Performance toward Neonatal Endotracheal Suctioning Procedure
...Show More Authors

Objective(s): To evaluate nurses’ Practice toward neonatal endotracheal suctioning procedure, and to determine the effectiveness of the interventional program on nurses’ practices, as well as to find out the relationship between nurses’ practice and their demographic characteristics.

Methodology: A Pre-experimental, one group design, was carried out to achieve the objectives of the current study using the evaluation approach and the implementation of the education program for the period from January 17 to June 31, 2022. A non- probability, purposive sample of (24) nurses were selected from the Neonatal Intensive Care Unit at Pediatric Teaching Hospital/ Medical City Department. A checklist w

... Show More
View Publication Preview PDF
Publication Date
Fri Oct 28 2022
Journal Name
Political Sciences Journal
Decentralization in Iraq: Addressing The State – Society Gap
...Show More Authors

The implementation of decentralization in Iraq was asymmetrical, leading to different forms and paces of implementation. Comparing four cases of Basra, Kirkuk, Nineveh, and Sulaymaniyah indicate that these cases differ in their political stability and autonomy in a way that led to a different forms of decentralization. This paper argues that the higher the level of political autonomy from the federal government, the more efficient the governance model, and the more efficient the governance model, the more legitimate the system (trust), and the more legitimate a system, the more accountable elected officials. Therefore, it recommends reforming the institutional setup of decentralization by having districts, instead of provinces, as the bu

... Show More
View Publication Preview PDF
Crossref