Preferred Language
Articles
/
joe-2783
Experimental Evaluation of Stability and Rheological Properties of Foam Cement for Oil Wells
...Show More Authors

Oilwell cementing operations are crucial for drilling and completion, preserving the well's productive life. However, weak and permeable formations pose a high risk of cement slurry loss, leading to failure. Lightweight cement, like foamed cement, is used to avoid these difficulties. This study is focused on creating a range of foamed slurry densities and examining the effect of gas concentration on their rheological properties. The foaming agent and foam stabilizer are tested, and the optimal concentration is determined to be 2% and 0.12%, respectively, by the weight of the cement.

Furthermore, the construction of samples of foam cement with different densities (0.8, 1.0, 1.2, 1.4, and 1.6) g/cc is performed to find the relation with different volumetric percentage gas in foamed cement slurry (57.5, 47, 36, 25.5, and 15%). The relationship between rheological properties and foam quality is discussed, as the presence of gas plays a significant role in enhancing rheological properties. The rheology of foam cement increases proportionally with increasing foam quality, especially the plastic viscosity, which is 26 cp at 0% foam quality and 50 and 65 cp at 15% and 57.5% foam quality, respectively. Also, yield points increase as foam quality improves. Therefore, it is feasible to exclude certain cement additives that increase viscosity.

 

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Thu Dec 01 2011
Journal Name
2011 Developments In E-systems Engineering
Enhanced Computation Time for Fast Block Matching Algorithm
...Show More Authors

View Publication
Scopus (1)
Scopus Crossref
Publication Date
Wed Sep 29 2021
Journal Name
Al-khwarizmi Engineering Journal
Robust Computed Torque Control for Uncertain Robotic Manipulatorss
...Show More Authors

This paper presents a robust control method for the trajectory control of the robotic manipulator. The standard Computed Torque Control (CTC) is an important method in the robotic control systems but its not robust to system uncertainty and external disturbance. The proposed method overcome the system uncertainty and external disturbance problems. In this paper, a robustification term has been added to the standard CTC. The stability of the proposed control method is approved by the Lyapunov stability theorem.  The performance of the presented controller is tested by MATLAB-Simulink environment and is compared with different control methods to illustrate its robustness and performance.

View Publication Preview PDF
Scopus (12)
Crossref (6)
Scopus Crossref
Publication Date
Wed Jun 07 2023
Journal Name
Journal Of Educational And Psychological Researches
Omani Second-Cycle Students’ Motivations for Electronic Games
...Show More Authors

The current study aims to investigate the second cycle students’ motives for using electronic games in Oman. The sample consisted of (570) students, (346 males and 224 females). The participants completed an open-ended question which was analyzed based on ground theory. The results showed that (46.820%) of the males and (77.678) of the females played electronic games for pleasure, entertainment, and fun. This first category of motivation got the highest percentage of frequency (58.947%). The motive to become a hacker, a popular YouTuber got the lowest percentage (2.280%). Other students’ motives toward playing electronic games included: filling the leisure time, overcoming boredom, feeling adventures, getting science fiction and chal

... Show More
View Publication Preview PDF
Publication Date
Tue Feb 01 2022
Journal Name
Chalcogenide Letters
Copper telluride thin films for gas sensing applications
...Show More Authors

Copper Telluride Thin films of thickness 700nm and 900nm, prepared thin films using thermal evaporation on cleaned Si substrates kept at 300K under the vacuum about (4x10-5 ) mbar. The XRD analysis and (AFM) measurements use to study structure properties. The sensitivity (S) of the fabricated sensors to NO2 and H2 was measured at room temperature. The experimental relationship between S and thickness of the sensitive film was investigated, and higher S values were recorded for thicker sensors. Results showed that the best sensitivity was attributed to the Cu2Te film of 900 nm thickness at the H2 gas.

View Publication
Crossref (6)
Crossref
Publication Date
Mon Sep 01 2014
Journal Name
2014 Ieee 25th Annual International Symposium On Personal, Indoor, And Mobile Radio Communication (pimrc)
Percolation condition for interference-limited cognitive radio networks
...Show More Authors

In this paper, we characterize the percolation condition for a continuum secondary cognitive radio network under the SINR model. We show that the well-established condition for continuum percolation does not hold true in the SINR regime. Thus, we find the condition under which a cognitive radio network percolates. We argue that due to the SINR requirements of the secondaries along with the interference tolerance of the primaries, not all the deployed secondary nodes necessarily contribute towards the percolation process- even though they might participate in the communication process. We model the invisibility of such nodes using the concept of Poisson thinning, both in the presence and absence of primaries. Invisibility occurs due to nodes

... Show More
Scopus (2)
Crossref (4)
Scopus Crossref
Publication Date
Thu Jun 30 2011
Journal Name
Al-kindy College Medical Journal
Are Indications For Esophago Gastro Duodenoscopy Properly Followed?
...Show More Authors

Background: Symptoms related to the upper gastro-intestinal tract are very common. Attribution of these symptoms to upper G. I. T.diseases are usually done on clinical bases, which could be confirmed by Esophago Gastro Duodenoscopy (EGD). The use of such tools might increase the diagnosis accuracy for such complaints. The indications for upper G I endoscopy might decrease the negative results of endoscopies.Objective: To follow strict indications for Esophago Gastro Duodenoscopy in order to decrease the negative endoscopy results. Methods: One thousand eight hundred and ninety cases were subjected to EGD from Feb. 1999 to Feb 2009 at Alkindy Teaching Hospital and Abd-Al-Majeed private hospital in Baghdad, Iraq. A special endoscopy unit f

... Show More
View Publication Preview PDF
Publication Date
Sat Sep 10 2022
Journal Name
Pakistan Journal Of Statistics And Operation Research
Continuous wavelet estimation for multivariate fractional Brownian motion
...Show More Authors

 In this paper, we propose a method using continuous wavelets to study the multivariate fractional Brownian motion through the deviations of the transformed random process to find an efficient estimate of Hurst exponent using eigenvalue regression of the covariance matrix. The results of simulations experiments shown that the performance of the proposed estimator was efficient in bias but the variance get increase as signal change from short to long memory the MASE increase relatively. The estimation process was made by calculating the eigenvalues for the variance-covariance matrix of Meyer’s continuous wavelet details coefficients.

View Publication
Scopus (5)
Crossref (3)
Scopus Clarivate Crossref
Publication Date
Tue Sep 01 2020
Journal Name
Iop Conference Series: Materials Science And Engineering
Sustainability Assessment System for Highrise Buildings in Iraq
...Show More Authors
Abstract<p>This study aims to preparation a standards code for sustainability requirements to contribute in a better understanding to the concept of sustainability assessment systems in the dimensions of Iraqi projects in general and in the high-rise building. Iraq is one of the developing countries that faced significant challenges in sustainability aspects environmental, economic and social, it became necessary to develop an effective sustainability building assessment system in respect of the local context in Iraq. This study presented a proposal for a system of assessing the sustainability requirements of Iraqi high rise buildings (ISHTAR), which has been developed through several integrated</p> ... Show More
View Publication
Scopus (1)
Crossref (1)
Scopus Crossref
Publication Date
Mon Nov 01 2010
Journal Name
All Days
Optimum Separation Pressure for Heavy Oils Sequential Separation
...Show More Authors
Abstract<p>The estimation of quantity of liquid that is collected from gas/oil separation system is a very complex task because it requires the application of the flash calculations which needs to solve the cubic equation of state and to use some numerical techniques. These difficulties can be overcome by a computer model which requires a lot of experimental data, long time, and experience.</p><p>This paper adopts a new technique to simplify this problem. It suggests new correlations for optimum separator pressure for separation station of heavy oils. The correlations have been achieved for two- and three- stage separation systems.</p><p>The co</p> ... Show More
View Publication
Scopus (4)
Crossref (5)
Scopus Crossref
Publication Date
Tue May 16 2023
Journal Name
Journal Of Engineering
System Identification Algorithm for Systems with Interval Coefficients
...Show More Authors

In this research a new system identification algorithm is presented for obtaining an optimal set of mathematical models for system with perturbed coefficients, then this algorithm is applied practically by an “On Line System Identification Circuit”, based on real time speed response data of a permanent magnet DC motor. Such set of mathematical models represents the physical plant against all variation which may exist in its parameters, and forms a strong mathematical foundation for stability and performance analysis in control theory problems.

View Publication Preview PDF
Crossref