Preferred Language
Articles
/
alkej-156
Aircraft Lateral-Directional Stability in Critical Cases via Lyapunov Exponent Criterion
...Show More Authors

Based on Lyapunov exponent criterion, the aircraft lateral-directional stability during critical flight cases is presented. A periodic motion or limit cycle oscillation isdisplayed. A candidate mechanism for the wing rock limit cycle is the inertia coupling between an unstable lateral-directional (Dutch roll) mode with stable longitudinal (short period) mode. The coupling mechanism is provided by the nonlinear interaction of motion related terms in the complete set equations of motion. To analyze the state variables of the system, the complete set of nonlinear equations of motion at different high angles of attack are solved. A novel analysis including the variation of roll angle as a function of angle of attack is proposed. Furthermore the variation of Lyapunov exponent parameter as function of time is introduced. The numerical result indicated that the system became lightly damped at high angle of attack with increasing the amplitude of aircraft state variables limit cycle. A good agreement between the numerical result and published work is obtained for the onset of limit cycle oscillation, almost at .

View Publication Preview PDF
Quick Preview PDF
Publication Date
Tue Dec 01 2020
Journal Name
Iraqi Journal Of Physics
Enhancement of thermal stability and wettability for epoxy/Cu coated carbon fiber composites
...Show More Authors

    This research study the effect of surface modification and copper (Cu) plating carbon fiber (CF) surface on the thermal stability and wettability of carbon fiber (CF)/epoxy (EP) composites. The TGA result indicates that the thermal-stability of carbon fiber may be enhanced after Cu coating CF. TGA curve showed that the treatment temperature was enhanced thermal stability of Ep/CF, this is due to the oxidation during heating. The Cu plating increased the thermal conductivity, this increase might be due to reduce in contact resistance at the interface due to chemical modification and copper plating and tunneling resistance.

   The increase of surface polarity after coating cause decreas

... Show More
View Publication Preview PDF
Crossref (7)
Crossref
Publication Date
Sat Dec 15 2018
Journal Name
Journal Of Baghdad College Of Dentistry
Clinicopathological and Immunohistochemical Analysis of 21 cases of Traumatic Ulcerative Granuloma with Stromal Eosinophilia Using CD30, CD68 and TGF-β1
...Show More Authors

Background: Traumatic ulcerative granuloma with stromal eosinophilia is an impressive benign chronic ulcerative lesion of the oral mucosa with vague etiopathogenesis. It was supposed to represent an oral counterpart of primary cutaneous CD30+ lymphoproliferative disorder. Histopathologically, it is characterized by mixed inflammatory infiltrate predominated by histiocytes, lymphocytes and eosinophils along with presence of scattered large atypical mononuclear cells. It has worrisome clinical presentation. It may heal spontaneously, but in most occasions it persists and never heal unless removed surgically (incisional or excisional biopsy). A rare subset may show worrisome immunohistochemical features. Follow up is highly recommended. Mat

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Dec 20 2021
Journal Name
Baghdad Science Journal
Dosimetric Verification of Gamma Passing Rate for Head and Neck Cases Treated with Intensity Modulated Radiation Therapy (IMRT) Treatment Planning Technique
...Show More Authors

Each Intensity Modulated Radiation Therapy (IMRT) plan needs to be tested and verified before any treatment to check its quality. Octavius 4D-1500 phantom detector is a modern and qualified device for quality assurance procedure. This study aims to compare the common dosimetric criteria 3%/3 mm with 2%/2 mm for H&N plans for the IMRT technique. Twenty-five patients with head and neck (H&N) tumor were with 6MV x-ray photon beam using Monaco 5.1 treatment planning software and exported to Elekta synergy linear accelerator then tested for pretreatment verification study using Octavius 4D-1500 phantom detector. The difference between planned and measured dose were assessed by using local and global gamma index (GI) analysis method at

... Show More
View Publication Preview PDF
Scopus (2)
Scopus Clarivate Crossref
Publication Date
Sun Dec 18 2022
Journal Name
Journal Of The College Of Languages (jcl)
The Challenges of Translation from Persian to Arabic In Light of the Equivalence Theory of Mona Baker; Equivalence at the Word Level
...Show More Authors

This dissertation studies the application of equivalence theory developed by Mona Baker in translating Persian to Arabic. Among various translation methodologies, Mona Baker’s bottom-up equivalency approach is unique in several ways. Baker’s translation approach is a multistep process. It starts with studying the smallest linguistic unit, “the word”, and then evolves above the level of words leading to the translation of the entire text. Equivalence at the word level, i.e., word for word method, is the core point of Baker’s approach.

This study evaluates the use of Baker’s approach in translation from Persian to Arabic, mainly because finding the correct equivalence is a major challenge in this translation. Additionall

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Feb 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
Evaluation of real estate investment projects with framework theory of real options: A case study in the shopping center project (Baghdad Mall)
...Show More Authors

 

Focused research aims to provide a framework cognitive analytical nature of real estate investments and how they evaluated in the light of the assessment tools of modern theory of real options, and the possibility to rely on that theory in the detection of the true value of projects, real estate investments that would maximize the value of the investment decision taken, and the analysis of those projects that arise in the real estate markets and environments is the organization, which she was to make sure cases and high-risk, compared with entrances techniques, discounted cash flow (net present value). Based on the assumption lies in the possibility of the application of the implic

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Sun Sep 15 2024
Journal Name
Journal Of Baghdad College Of Dentistry
The reliability of insertion torque as an indicator for primary stability in immediate dental implant: A prospective clinical study
...Show More Authors

Background: The primary stability of the dental implant is a crucial factor determining the ability to initiate temporary implant-supported prosthesis and for subsequent successful osseointegration, especially in the maxillary non-molar sites. This study assessed the reliability of the insertion torque of dental implants by relating it to the implant stability quotient values measured by the Osstell device. Material and methods: This study included healthy, non-smoker patients with no history of diabetes or other metabolic, or debilitating diseases that may affect bone healing, having non-restorable fractured teeth and retained roots in the maxillary non-molar sites. Primary dental implant stability was evaluated using a torque ratc

... Show More
View Publication Preview PDF
Scopus Crossref
Publication Date
Tue Oct 01 2024
Journal Name
Renewable And Sustainable Energy Reviews
A critical review on the efficient cooling strategy of batteries of electric vehicles: Advances, challenges, future perspectives
...Show More Authors

View Publication
Scopus (31)
Crossref (29)
Scopus Clarivate Crossref
Publication Date
Mon Mar 18 2019
Journal Name
Al-khwarizmi Engineering Journal
Best Level of Parameters for a Critical Buckling Load for Circular Thin- Walled Structure Subjected to Bending
...Show More Authors

Circular thin walled structures have wide range of applications. This type of structure is generally exposed to different types of loads, but one of the most important types is a buckling. In this work, the phenomena of buckling was studied by using finite element analysis. The circular thin walled structure in this study is constructed from; cylindrical thin shell strengthen by longitudinal stringers, subjected to pure bending in one plane. In addition, Taguchi method was used to identify the optimum combination set of parameters for enhancement of the critical buckling load value, as well as to investigate the most effective parameter. The parameters that have been analyzed were; cylinder shell thickness, shape of stiffeners section an

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Dec 15 2022
Journal Name
Al-academy
Strategies of brain-based learning theory and its impact on the achievement of students of the Department of Art Education in Teaching Methods
...Show More Authors

The aim of the current research is to reveal the effect of using brain-based learning theory strategies on the achievement of Art Education students in the subject of Teaching Methods. The experimental design with two equal experimental and control groups was used. The experimental design with two independent and equal groups was used, and the total of the research sample was (60) male and female students, (30) male and female students represented the experimental group, and (30) male and female students represented the control group. The researcher prepared the research tool represented by the cognitive achievement test consisting of (20) questions, and it was characterized by honesty and reliability, and the experiment lasted (6) weeks

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Nov 17 2019
Journal Name
Journal Of Interdisciplinary Mathematics
Fuzzy preinvexity via ranking value functions with applications to fuzzy optimization problems
...Show More Authors

View Publication
Scopus (5)
Crossref (3)
Scopus Clarivate Crossref