289 research outputs found
Position-Dependent Performance in 5 nm Vertically Stacked Lateral Si Nanowires Transistors
In this work, we investigated the performance of vertically stacked lateral nanowires transistors (NWTs) considering the effects of series resistance. Also, we consider the vertical positions of the lateral nanowires in the stack and diameter variation of the lateral NWTs as new sources of process variability
Variability-Aware Simulations of 5 nm Vertically Stacked Lateral Si Nanowires Transistors
In this work, we present a simulation study of vertically stacked lateral nanowires transistors (NWTs) considering various sources of statistical variability. Our simulation approach is based on various simulations techniques to capture the complexity in such ultra-scaled device
Scalability Improvement Of Multicast Source Movement Over Mobile Ipv6 Using Clustering Technique
Mobile IPv6 (MIPv6) describes how a mobile node can change its point of attachment to the Internet. While MIPv6 focuses on unicast communications, it also proposes two basic mechanisms, known as bi-directional tunnelling and remote subscription, to handle multicast communications with mobile members. In the mean time, the deployment of Source-Specific Multicast (SSM) is of great interest, using the Protocol Independent Multicast-Sparse Mode (PIM-SM) and Multicast Listener Discovery (MLDv2) protocols. In the particular case of mobile IPv6 SSM sources, the mechanism proposed in MIPv6 to support multicast communications introduced a number of problems that need to be addressed. First, in most scenarios the MIPv6 solution leads to suboptimal routing by setting up a tunnel to forward packets between the home agent in its home network and the current location in the foreign network. The use of a third party when roaming which is the home agent leads to suboptimal routing. Second, it introduces a central point of failure (i.e. the Home Agent (HA)) that is not to be neglected. The proposed MIPv6 solution also induces a great traffic concentration around this central point. Third, the processing task of the central point increases with the number of mobile sources it serves, thus reducing the efficiency of multicast delivery. The objective of this thesis is to remove some of the obstacles encountered in the way of multicast deployment in the Internet, thereby making Mobile IPv6 better equipped to support mobile SSM sources.
Recent proposals to provide multicasting over mobile IP focuses mainly on recipient mobility but little attention has been given to the case of source mobility. This thesis attempts to address this problem. The basic essence of the problem is that while the effect of receiver movement on the multicast tree is local, the effect of source movement may be global and it may affect the complete multicast delivery tree. The initial design was motivated by the need to support one-to-many and many-to-many applications in a scalable fashion. Such applications cannot be serviced efficiently with unicast delivery.
As the overall problem statement of “Scalability Improvement of Multicast Source Movement over IPv6 Using Clustering Technique” is extremely complex, we divide the problem into the following components: build the multicast delivery tree for source specific multicast which is a routing issue; clustering receivers based on their IPv6 addresses; improve the state scalability of these clusters which is a deployment issue; find an efficient way for service distribution which is a deployment issue as well; and finally, the seamless integration of the work with Mobile IPv6 allowing it to support multicast efficiently for mobile nodes. The combined solution provides a comprehensive procedure for planning and managing a multicast-based IPv6 network.
The outcome of this thesis are: a software to represent an architecture of a multicast delivery tree for one-to-many type of group communication, a group management scheme that could handle the end nodes subscription/un-subscription process with the required updates, an average subscription delay of between 0.255 ms-0.530 ms and un-subscription delay of between 0.0456 ms-0.087 ms for up to 50000 nodes, an approach to multicast forwarding state reduction that could support small-size groups as well as large-size groups, and finally the integration of the work with Mobile IPv6 to handle the multicast source movement
Machining and Tensile Properties of Warm Squeezed 7075 Aluminum Alloy
تهدف هذه الدراسة إلى تحسين خواص سبائك الألومنيوم 7075 عن طريق إجراء المعالجة الحرارية والمعالجة الميكانيكية. وتم تنفيذ تجربة التطوير من خلال إخضاع العينات لعملية العصر الدافئ، بالإضافة إلى المعالجة الحرارية التقليدية. وقد لوحظ تحسن في خصائص الشد والتشغيل للعينات بعد عملية العصر الدافئ. أدى العصر الدافئ إلى زيادة نسبة الاستطالة، ومقاومة الخضوع، ومقاومة الشد للعينة المعالجة حرارياً بنسبة 11%، 40%، و19% على التوالي. بالإضافة إلى ذلك، لوحظ زيادة ملحوظه قدرها 62%، 94% و 191% في السلوك اللدن للعينة المعصورة أثناء اختبار الشد عند درجات حرارة 200، 250 و 300 درجة مئوية على التوالي. أظهر العصر الميكانيكي الدافئ تحسنًا في خصائص تشغيل السبيكة، حيث قلل من خشونة السطح بنسبة 66%، لكنه زاد من قوة القطع بنسبة 34%. This study is aims to improve the properties of aluminum alloy 7075 by conducting heat treatment and mechanical processing. The development experiment was carried out by subjecting the samples to the process of warm squeezing, as well as conventional heat treatment. An improvement in the tensile and machining properties of the samples was noticed after the warm squeezing process. The warm squeezing caused the elongation percentage, yield strength, and the tensile strength of the heat-treated sample to increase by 11%, 40%, and 19% respectively. In addition, a significant increase of 62%, 94% and 191% in the plastic behavior of the squeezed sample was observed during the tensile test at temperatures 200, 250 and 300°C respectively. The mechanical warm squeezing showed an improvement in the machining characteristics of the alloy, as it reduced the surface roughness by 66%, but it increased the cutting force by 34%
Performance of Vertically Stacked Horizontal Si Nanowires Transistors: A 3D Monte Carlo / 2D Poisson Schrodinger Simulation Study
In this paper we present a simulation study of 5nm vertically stacked lateral nanowires transistor (NWTs). The study is based on calibration of drift-diffusion results against a Poisson-Schrodinger simulations for density-gradient quantum corrections, and against ensemble Monte Carlo simulations to calibrate carrier transport. As a result of these calibrated results, we have established a link between channel strain and the device performance. Additionally, we have compared the current flow in a single, double and triple vertically stacked lateral NWTs
Paper Review: Flutter Phenomenon in Aero-Elasticity
Flutter is aero-elasticity phenomenon concerning the analysis of the relationship among aerodynamic and elastic forces, aerodynamic forces (static-aeroelasticity). Inertia, elastic and aerodynamic forces (dynamic-aeroelasticity). Elastic forces and laws of control (aero-servo-elasticity). Modern airplane designs can be very versatile and this versatility of the airframe allows aero-elastic analysis an essential part of airplane construction and Procedures for validation. Torsional and wing flutter are the two major aero-elastic phenomena considering in airplane architecture. Hopf bifurcation is a instability case that happens when the torsional stiffness of the system is counteracted by static aerodynamic impact. Flutter is a fluctuating motion due to instability in aero-elastic influences defined by a continuous fluctuation of the system resulting from the interaction among the inertial, elastic and aerodynamic forces operating on the entire body. This article provides a better understanding for flutter phenomena and aero-elasticity issues that seek to offer readers an understanding of the topic
Iraqi porcelanite Rocks for Efficient Removal of Safranin Dye from Aqueous Solution
يتضمن هذا البحث دراسة قابلية مسحوق صخور البورسلينايت العراقية على إزالة صبغة السفرانين القاعدية من محاليلها المائية عن طريق الامتزاز ، وأجريت التجارب عند 298 كلفن من أجل تحديد تأثير تركيز الابتدائي لصبغة السفرانين ، زمن التماس ، الدالة الحامضية ، وتأثير الشدة الأيونية. كانت الظروف الفضلى لامتزاز صبغة السفرين عند 0.0200 غرام من وزن السطح الماز ووجدت نسبة الازالة 96.86٪ عند تركيز 9 ملغم / لتر ، ووقت الامتزاز 20 دقيقة وعند دالة حامضية = 8 و درجة حرارة 298 كلفن . تم ايجاد ايزوثيرمات الامتزاز واختبار القيم العملية بتطبيق معادلات لانكماير وفريندليش وتيمكين عند درجات حرارة مختلفة (298-338) كلفن ، وكانت نتائج الامتزاز مطابقة لايزوثيرم فريندليش ولانكماير أكثر من ايزوثيرم تيمكين. تشير قيم الدوال الثرموديناميكية التي تم حسابهاΔG0 ،ΔH0 ، ΔS0 إلى أن عملية الامتزاز تجري تلقائية وباعثة للحرارة وتشير إلى انخفاض عشوائية جزيئات الصبغة الممتزة. ايزوثيرامات الامتزازالتي تم الحصول عليها من التجارب جاءت مطابقة للشكل S حسب تصنيف جيليز .This research includes a study of the ability of Iraqi porcelanite rocks powder to remove the basic Safranine dye from its aqueous process by adsorption. The experiments were carried out at 298Kelvin in order to determine the effect of the starting concentration for Safranin dye, mixing time, pH, and the effect of ionic Strength. The good conditions were perfect for safranine dye adsorption was performed when0.0200g from that adsorbed particles and the removal max percentage was found be 96.86% at 9 mg/L , 20 minutes adsorption time and at PH=8 and in 298 K. The isothermal equilibrum stoichiometric adsorption confirmed, the process data were examined by Langmuir, Freundlich and Temkin adsorption equations at different temperatures (298-338)K.The results of the adsorption were good suited for Freundlich and Langmuir Isotherm more than Temkin. Thermodynamic data found for adsorption processes ΔG0, ΔH0, ΔS0 indicates this is the removal step is through the adsorption operations which is spontaneity, exothermic and indicates a decrease in the randomness of that adsorbed dye molecules. Isotherms obtained from the experiments were identical to (S-curve) in form at Giles' discretion
Environmental Study of Some Water Characteristics at Um-Al-Naaj Marsh, South of Iraq.
Um-Al-Naaj region in Al-Hawiezah Marsh, Southern Iraq was chosen to study the environmental variations of some water characteristics during 2008, seasonally. The results showed clear seasonal changes in values of some environmental variables (temperature, depth, light penetration, turbidity, total suspended solids, pH, dissolved oxygen, reactive phosphate, reactive nitrite, and reactive nitrate), while there were no clear seasonal changes in electrical conductivity and salinity values. In addition, high nutrients concentrations and light penetration were noted. Statistical analysis showed significant positive relationship between air and water temperature; electrical conductivity and salinity. Water turbidity was significantly affected by total suspended solids. On the other hand, some of the studied variables had significant negative effects (relative relationships) to each other, when water pH and dissolved oxygen were affected by temperature; total suspended solids and turbidity affected also light penetration
Digital architecture and designing architecture space and ITS effect on future life strategy
Technological advancements have altered nearly every aspect of individuals’ existence and operation in society. When technologies develop, architecture evolves as well: the architectural techniques change, as does the architectural outcome. The digital revolution reflected on architecture, as did other scientific and life fields. Its impact on the work and architectural space was evident. The architectural production became not limited to designing in traditional ways and directing it as computer drawings. Still, it went beyond that, as the designs produced became the product of an intelligent design process directly influenced by the digital community in general. Architectural space has gone through many developments throughout history influenced by technology and building techniques on the one hand and by functional and environmental issues and human factors on the other hand. The architectural space appeared in the form of a living being that grows over time and is influenced by all the variables of the times and expresses the personality of its inhabitants. If the architect determines space and its composition according to human needs, it is also influenced by the imagination of architecture and its vision of freedom. Therefore, the problem of research was determined by "the lack of a clear vision of the development of architectural space and how it is affected by the digital revolution," where the research aims to identify indicators of the development of architectural space in light of digital development and how architectural thought deals with the changes brought about by information technology, and how it was expressed in the form of areas that meet the needs of users, which in turn changed in terms of sensory needs or physical needs. The research thus assumed "the existence of mechanisms, strategies, levels, and degrees of digital use within the process of designing architectural and urban space to generate digital space," and to achieve this will begin to learn about the evolution of space and what it is over time with a quick presentation of the most prominent developments in the architectural and urban space, especially in the recent years, to a final formulation of the characteristics of knowledge of digital areas
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