Preferred Language
Articles
/
ijcpe-732
Certain Assessment of Using MWCNT Nps in Drilling Fluid to Mitigate Stick-Slip Problem during Drilling Operation System
...Show More Authors

   Stick- slip is the continuous stopping& release of the Bit/BHA due to the irregular down-hole rotation prompted by the existing relationship between the friction torque and the torque applied from the surface to free the bit.

   Friction coefficient between BHA and wellbore is the main player of stick slip amount, which can be mitigated by support a good lubricators as additives in drilling mud.

   Mathematical (or empirical) solves should be done through adjusting all parameters which supposed to reduce stick- slip as low as possible using different models, one of the main parameters is drilling mud. As per Nanoparticles drilling fluid is a new technology that offers high performance it’s necessary to find out the relationship between the use of Nano fluid and the minimum stick- slip vibration. In this study (multiwall carbon Nano tube) will be used as a Nanoparticles in Fresh water bentonite mud and polymer mud by five tests per each one to find out the coefficient of friction and used it in a special torque and drag software as a part of drilling vertical well simulation to calculate expected bottom hole torque within five different Nano concentration per each mud type. In fresh water bentonite mud torque reduction was from 4000 ft-lb to 3500 ft-lb, while in polymer mud torque failed and didn’t reduce, so it raised from 2050.88 ft-lb to be around 2200 ft-lb.

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Fri Jun 15 2018
Journal Name
Journal Of Baghdad College Of Dentistry
Comparison of certain radiomorphometric facial indices in different facial types of Iraqi adults using Cone Beam Computed Tomography
...Show More Authors

Background: The human face has its special characteristics. It may be categorized into essentially three kinds in horizontal and vertical directions: short or brachyfacial, medium or mesofacial and long or dolichofacial. The aim of this study was to describe several orofacial indices and proportions of adults, according to gender in Iraqi subjects by using cone beam computed tomography . materials and methods: This prospective study included 100 Iraqi patients (males and females) ranging from 20 to 40 years. All subjects attended the Oral and Maxillofacial Radiology Department of Health Specialist Center for Dentistry in AL Sadr city in Baghdad taking cone beam computed tomography scan for different diagnostic purposes from October 2016 to

... Show More
View Publication
Crossref
Publication Date
Fri Jan 01 2016
Journal Name
Journal Of Computer And Communications
Parallel Quick Search Algorithm for the Exact String Matching Problem Using OpenMP
...Show More Authors

String matching is seen as one of the essential problems in computer science. A variety of computer applications provide the string matching service for their end users. The remarkable boost in the number of data that is created and kept by modern computational devices influences researchers to obtain even more powerful methods for coping with this problem. In this research, the Quick Search string matching algorithm are adopted to be implemented under the multi-core environment using OpenMP directive which can be employed to reduce the overall execution time of the program. English text, Proteins and DNA data types are utilized to examine the effect of parallelization and implementation of Quick Search string matching algorithm on multi-co

... Show More
View Publication Preview PDF
Crossref (3)
Crossref
Publication Date
Mon Oct 12 2020
Journal Name
Molecules
Phase Change Process in a Zigzag Plate Latent Heat Storage System during Melting and Solidification
...Show More Authors

Applying a well-performing heat exchanger is an efficient way to fortify the relatively low thermal response of phase-change materials (PCMs), which have broad application prospects in the fields of thermal management and energy storage. In this study, an improved PCM melting and solidification in corrugated (zigzag) plate heat exchanger are numerically examined compared with smooth (flat) plate heat exchanger in both horizontal and vertical positions. The effects of the channel width (0.5 W, W, and 2 W) and the airflow temperature (318 K, 323 K, and 328 K) are exclusively studied and reported. The results reveal the much better performance of the horizontal corrugated configuration compared with the smooth channel during both melti

... Show More
View Publication
Scopus (37)
Crossref (34)
Scopus Clarivate Crossref
Publication Date
Fri Jun 29 2018
Journal Name
Journal Of The College Of Education For Women
THE PROBLEM RELATED TO WORKING IN KINDERGARTEN FROM THE POINT OF VIEW OF TEACHERS
...Show More Authors

           kindergarten teacher is one of the fundamental pillars upon which the kindergarten environment so that exposure to a number of problems that could affect its functioning in addition to any deficiencies in this environment leads to deprive a child of some activities and acquisition of concepts so the researcher studying the problems of working in kindergartens from the perspective of the parameters, so the researcher based measuring instrument for labour problems of (30) search sample was paragraph (50) parameter that was chosen at random and have been extracted Sincerity and strength tool researcher used statistical methods and discriminatory (Pearson correlation coefficient, t

... Show More
View Publication Preview PDF
Publication Date
Fri Jan 01 2021
Journal Name
Journal Of Engineering
A Computational Fluid Dynamics Investigation of using Large-Scale Geometric Roughness Elements in Open Channels
...Show More Authors

The hydraulic behavior of the flow can be changed by using large-scale geometric roughness elements in open channels. This change can help in controlling erosions and sedimentations along the mainstream of the channel. Roughness elements can be large stone or concrete blocks placed at the channel's bed to impose more resistance in the bed. The geometry of the roughness elements, numbers used, and configuration are parameters that can affect the flow's hydraulic characteristics. In this paper, velocity distribution along the flume was theoretically investigated using a series of tests of T-shape roughness elements, fixed height, arranged in three different configurations, differ in the number of lines of roughness element

... Show More
View Publication Preview PDF
Crossref (3)
Crossref
Publication Date
Wed May 10 2023
Journal Name
Journal Of Engineering
A Proposal Algorithm to Solve Delay Constraint Least Cost Optimization Problem
...Show More Authors

Traditionally, path selection within routing is formulated as a shortest path optimization problem. The objective function for optimization could be any one variety of parameters such as number of hops, delay, cost...etc. The problem of least cost delay constraint routing is studied in this paper since delay constraint is very common requirement of many multimedia applications and cost minimization captures the need to
distribute the network. So an iterative algorithm is proposed in this paper to solve this problem. It is appeared from the results of applying this algorithm that it gave the optimal path (optimal solution) from among multiple feasible paths (feasible solutions).

View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Thu Jan 05 2023
Journal Name
Mathematical Theory And Modeling
(Tc) Technique for Finding Optimal Solution To Transportation Problem
...Show More Authors

Given the importance of increasing economic openness transport companies’ face various issues arising at present time, this required importing different types of goods with different means of transport. Therefore, these companies pay great attention to reducing total costs of transporting commodities by using numbers means of transport methods from their sources to the destinations. The majority of private companies do not acquire the knowledge of using operations research methods, especially transport models, through which the total costs can be reduced, resulting in the importance and need to solve such a problem. This research presents a proposed method for the sum of Total Costs (Tc) of rows and columns, in order to arrive at the init

... Show More
Preview PDF
Publication Date
Wed May 03 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Employing Ridge Regression Procedure to Remedy the Multicollinearity Problem
...Show More Authors

   In this paper we introduce many different Methods of ridge regression to solve multicollinearity problem in linear regression model. These Methods include two types of ordinary ridge regression (ORR1), (ORR2) according to the choice of ridge parameter as well as generalized ridge regression (GRR). These methods were applied on a dataset suffers from a high degree of multicollinearity, then according to the criterion of mean square error (MSE) and coefficient of determination (R2) it was found that (GRR) method performs better than the other two methods.
 

View Publication Preview PDF
Publication Date
Sun Dec 12 2010
Journal Name
Alustath Journal For Human And Social Sciences
Suggested Approach to deal with Multicollinearity Problem – with Application –
...Show More Authors

This research introduce a study with application on Principal Component Regression obtained from some of the explainatory variables to limitate Multicollinearity problem among these variables and gain staibilty in their estimations more than those which yield from Ordinary Least Squares. But the cost that we pay in the other hand losing a little power of the estimation of the predictive regression function in explaining the essential variations. A suggested numerical formula has been proposed and applied by the researchers as optimal solution, and vererifing the its efficiency by a program written by the researchers themselves for this porpuse through some creterions: Cumulative Percentage Variance, Coefficient of Determination, Variance

... Show More
Preview PDF
Publication Date
Wed Feb 01 2023
Journal Name
Baghdad Science Journal
A Heuristic Approach to the Consecutive Ones Submatrix Problem
...Show More Authors

Given a matrix, the Consecutive Ones Submatrix (C1S) problem which aims to find the permutation of columns that maximizes the number of columns having together only one block of consecutive ones in each row is considered here. A heuristic approach will be suggested to solve the problem. Also, the Consecutive Blocks Minimization (CBM) problem which is related to the consecutive ones submatrix will be considered. The new procedure is proposed to improve the column insertion approach. Then real world and random matrices from the set covering problem will be evaluated and computational results will be highlighted.

View Publication Preview PDF
Scopus (1)
Scopus Clarivate Crossref