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Aircraft Lateral-Directional Stability in Critical Cases via Lyapunov Exponent Criterion
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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 .

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Publication Date
Wed May 10 2023
Journal Name
Journal Of Planner And Development
Analysis and evaluation of related factors affecting community Participation as a policy to upgrade residential slums area
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have suffered from deteriorating residential neighborhoods, poor economic, social and urban living conditions of the population and deteriorating the infrastructural and superior services. These problems were the secretions of these cities' rapid urbanization. Based on the principles of sustainable urban planning and in order to achieve adequate opportunities for the lives of the population and provide them with sustainable livelihoods, policies have emerged to upgrade along the lines of community participation and programmes to reform and develop those neighbourhoods, raise their efficiency and make them livable. Thus, the problem of research was identified "The absence of a comprehensive cognitive perception of the most prominent facto

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Publication Date
Wed Jun 30 2021
Journal Name
College Of Islamic Sciences
The footnote of The Scholar Abdul Rahman Al-Penjawni on collecting mosques and explaining it to the local by the scholar Abdul Rahman Ibn Mulla Mohammed Ibn Mulla Tahir Al-Penjweni Died in: 1319 AH School: (Absolute and restricted) Study and Observation
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Abstract

Indeed, being busy with the understanding of religion is the best sort of worship that the almighty God has given each period of time a number of scholars and wise men. They receive what has been passed down to them from their great ancestors, and those who are willing to learn will learn, their students preserve their knowledge through teaching and writing. Thus, the scholars were pioneers in this field due to the value and importance of their knowledge. They have strived in learning, explaining, and writing new subjects.

One of those scholars is sheikh (Abdulrahman Al-Penjweni) who passed away 1319 AH in one of the villages of the city of Sulaimani in Iraq. He was one of the wisest scholars, a br

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Publication Date
Thu Jan 01 2026
Journal Name
Chalcogenide Letters
Influence of Germanium Substitution on the DC Electrical Properties and Energy Density of States in Pb<sub>50−x</sub>Ge<sub>x</sub>Te<sub>50</sub> Ternary Chalcogenide Alloys
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Publication Date
Mon Dec 18 2017
Journal Name
Al-khwarizmi Engineering Journal
Cam Dynamic Synthesis
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The paper presents an original method to make the geometric synthesis of the rotary cam and translated tappet with roll. Classical method uses to the geometric synthesis and the reduced tappet velocity, and in this mode the geometric classic method become a geometric and kinematic synthesis method. The new geometric synthesis method uses just the geometric parameters (without velocities), but one utilizes and a condition to realize at the tapped the velocities predicted by the tapped movement laws imposed by the cam profile. Then, it makes the dynamic analyze for the imposed cam profile, and one modify the cam profile geometric parameters to determine a good dynamic response (functionality). In this mode it realizes the dynamic synthesis

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Publication Date
Fri Dec 01 2017
Journal Name
Ocean Engineering
Stresses and pore water pressure induced by machine foundation on saturated sand
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In this study, the response and behavior of machine foundations resting on dry and saturated sand was investigated experimentally. In order to investigate the response of soil and footing to steady state dynamic loading, a physical model was manufactured. The manufactured physical model could be used to simulate steady state harmonic load at different operating frequencies. Total of (84) physical models were performed. The parameters that were taken into considerations include loading frequency, size of footing and different soil conditions. The footing parameters were related to the size of the rectangular footing and depth of embedment. Two sizes of rectangular steel model footing were used (100 200 12.5 mm) and (200 400 5.0 mm).

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Publication Date
Sun Mar 01 2020
Journal Name
Journal Of Engineering
Evaluation of Fatigue Behavior of Epoxy Coatings used for Potable Water Storage Tanks
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In this paper, three types of epoxy-based coatings (Polyamide, pure Polyamine, and Polyamine reinforced by glass-flake) used as a lining for potable water tanks were studied using experimental and finite element methods. Tensile, impact, and fatigue tests were conducted on uncoated and coated AISI 316 stainless steel. The test results show that the applied epoxy based coating improves the mechanical properties, increases of fatigue crack resistance, and enhance the dynamic fracture toughness. The fatigue crack propagation is influenced by the compositions of epoxy coating, and the glass-flake improves the coating resistance to fatigue crack propagation compared to other types.

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Publication Date
Tue Mar 31 2026
Journal Name
Frontiers In Mechanical Engineering
Finite-element guided drilled-hole placement and fillet geometry effects on the structural and dynamic performance of spur gears
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In this research, a detailed finite-element (FE) analysis of the combined influence of the drilled-hole position, the shape of the hole, and the fillet design on the structural and dynamic performance of spur gears is investigated. ANSYS R16.2 was used to create a three-dimensional numerical model that can be used to assess the bending stress distribution and vibration response under realistic loading conditions. A trochoidal fillet and four circular fillet radii (0.5, 1.0, 1.5 and 2.0 mm) were studied to determine their effect on the stress concentration behavior. FE-guided hole-suggestion process was introduced which is an automated process in which low-stress zones to be cut away are identified so as to allo

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Publication Date
Mon May 15 2023
Journal Name
Alustath Journal For Human And Social Sciences
كاریگەری ستراتیژییەتی بەستن و ڕاكێشان لەسەر دەسكەوتی فێرخوازانی پۆلی هەشتەمی بنەڕەتی له بابەتی زمان و ئەدەبی كوردیدا/ اثر استراتيجية الشد والجذب في تحصيل طلاب الصف الثامن الاساسي في مادة اللغة والادب
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Publication Date
Wed Jul 01 2020
Journal Name
Journal Of Engineering
Design of Multi-Rate Multi-Zone Wireless Fuzzy Temperature Control System for Greenhouse Application
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sensor sampling rate (SSR) may be an effective and crucial field in networked control systems.  Changing sensor sampling period after designing the networked control system is a critical matter for the stability of the system. In this article, a wireless networked control system with multi-rate sensor sampling is proposed to control the temperature of a multi-zone greenhouse. Here, a behavior based Mamdany fuzzy system is used in three approaches, first is to design the fuzzy temperature controller, second is to design a fuzzy gain selector and third is to design a fuzzy error handler. The main approach of the control system design is to control the input gain of the fuzzy temperature controller depending on the cur

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Publication Date
Wed Dec 09 2015
Journal Name
Iraqi Journal Of Market Research And Consumer Protection
Effect of Sodium sulfite treatment on the trypsin inhibitors activity, protein isolate and protein solubility of complete and dehulling white bean seeds Phaseolus vulgaris.: Effect of Sodium sulfite treatment on the trypsin inhibitors activity, protein isolate and protein solubility of complete and dehulling white bean seeds Phaseolus vulgaris.
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The study aimed to increase the biological value of white bean. The effect of different concentrations 0.01 ,0.02,0.03,and 0.04 M of sodium sulfite solutions for 1hr at 70 ºC on the trypsin inhibitors activity, protein isolate and protein solubility of complete and dehulling white bean flour were studied.Trypsin inhibitors activity were reduced by 42.97, 58.69, 68.59 and 69.58% in complete white bean flour at 0.01 ,0.02, 0.03, 0.04 M respectively, while the corresponding values were 50.43, 61.00, 75.61 and 85.66% respectively in dehulling white bean flour .Protein isolate value was 13.41% and protein solubility was 2.2% in control sample, Furthermore, the using of chemical treatment showed that protein isolate was reduced gradually and

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