Abstract: Recently, there is increasing interest in using mode-division multipelexing (MDM) technique to enhace data rate transmission over multimode fibers. In this technique, each fiber mode is treated as a separate optical carrier to transfer its own data. This paper presents a broadband, compact, and low loss three-mode (de)multiplexer designed for C+L band using subwavelength grating (SWG) technology and built-in silicon-on-insulator SOI platform. SWG offers refractive index engineering for wider operating bandwidth and compact devices compared to conventional ones. The designed (de)multiplex deals with three modes (TE0, TE1, and TE2) and has a loss > -1 dB and crosstalk < −15 dB, and its operation cover 160 nm (1490 to 1650) nm wavelength span. The overall size of the designed device is 80 × 4 μm2.
تشير الادبيات الى ان العنف قد رافق الانسان منذ بدء الخليقة حتى يومنا هذا، الا ان التطور العلمي والتكنلوجي والسرعة الفائقة في التغيير قد زاد من حجمه، وعدد مثيراته واختلفت نوعيته تبعاً لارتقاء الانسان ( العكيلي، 2000، ص91).
يتسم القرن الحادي والعشرين بظاهرة العنف بشكل عام، حيث لم تسلم منطقة منه، وهذا لا يمثل تهديداً لمنجزات الانسان المادية والاجتماعية فقط، ولكنه يمتد نحو الانسان ذاته. وسلوك الع
... Show Moreيعد موضوع الاتجاهات ((Attitudes)) من الموضوعات الهامة في مجال علم النفس الاجتماعي، فالاتجاه هو المحرك للسلوك، ويرى البورت أن مفهوم الاتجاه يمثل حجر الزاوية في علم النفس الاجتماعي وتحتل دراسة الاتجاهات مكاناً بارزاً في دراسات الشخصية وديناميات الجماعة وتوجيه الرأي العام، وان العلاج النفسي ما هو إلا محاولة لتغيير اتجاهات الفرد نحو ذاته ونحو الآخرين ونحو عالمه الذي يعيش فيه.
وي
... Show Moreاستهدفت هذه الدراسة تحليل واقع الاقتصاد العراقي على خلفية تحليل القدرة التنافسية بما يفضي الى وضع ملامح عامة لإستراتيجية بناء للقدرة التنافسية الوطنية للنهوض بالواقع الاقتصادي. وقد افترضت الدراسة ان الاقتصاد العراقي يعاني من اخفاقات شديدة في الاداء لا تتصل بطبيعته ولاتعتبر سمة اصيلة من سماته بل هي ظرفية وطارئة رغم وجودها منذ عقود.
ان حالة الوهن المرافق للفعاليات الاقتصادية تتصل بغيا
... Show MoreThe goal of this study is to investigate the relationship between optimism and life orientation for a subject of female students in the collage of education for women including the first and fourth stage students ,the sample contained (319) students ,(153)of them were a first stagers ,(166) of them were at the fourth stage.
The scale of optimism was built according to a questionnaire pointed to a sample of the students, adding to that reviewing a number of previous scales & studies which was about the same topic.
For the life orientation scale the researcher used a scale built by Scheier & Carver 1985 – tran
... Show MoreArabic language the timeless language of the Qur'an ((I made it read Arabic you may understand)) (Al-Zukhruf No 3). It is a way to express his thoughts and feelings and capable of giving constant absorbed the needs of the times and meet the General requirements and interactive needs of life to achieve social and intellectual aspects.
The aim of current research to identify what teaching the contemporary trends in teaching, what the nature of knowledge and teaching methods, how do you rate the modern Arabic language teaching methods, the criteria for evaluating the effectiveness of teaching where the researcher has reached some recommendations: 1. establish the basics of environmental ed
... Show MoreThe propagation of laser beam in the underdense deuterium plasma has been studied via computer simulation using the fluid model. An appropriate computer code “HEATER” has been modified and is used for this purpose. The propagation is taken to be in a cylindrical symmetric medium. Different laser wavelengths (1 = 10.6 m, 2 = 1.06 m, and 3 = 0.53 m) with a Gaussian pulse type and 15 ns pulse widths have been considered. Absorption energy and laser flux have been calculated for different plasma and laser parameters. The absorbed laser energy showed maximum for = 0.53 m. This high absorbitivity was inferred to the effect of the pondermotive force.
This paper develops a nonlinear transient three-dimensional heat transfer finite element model and a rate independent three-dimensional deformation model, developed for the CO2 laser welding simulations in Al-6061-T6 alloy. Simulations are performed using an indirect coupled thermal-structural method for the process of welding. Temperature-dependent thermal properties of Al-6061-T6, effect of latent heat of fusion, and the convective and radiative boundary conditions are included in the model. The heat input to the model is assumed to be a Gaussian heat source. The finite element code ANSYS12, along with a few FORTRAN subroutines, are employed to obtain the numerical results. The benefit of the proposed methodology is that it
... Show Moreشكلت التطورات التكنولوجية في وسائل التواصل الاجتماعي الناجمة عن العولمة معلم رئيسي في تحولات التنظيمات الإرهابية، وإنتاج انماط جديدة من الإرهابيين والمتطرفين القادرين على التفاعل مع الثورة المعلوماتية والاتصالية. ان معظم الجرائم الإرهابية الإلكترونية مرتبطة بالإنترنت وهو المسرح المفضل للمتطرفين فالأول يقتل والثاني يسوغ ويحرض ويجند، والذي جعل الإنترنت وسيلة فعالة كونها سهلة الاستخدام وسريعة الوصول إلى
... Show MoreCoagulation is the most important process in drinking water treatment. Alum coagulant increases the aluminum residuals, which have been linked in many studies to Alzheimer's disease. Therefore, it is very important to use it with the very optimal dose. In this paper, four sets of experiments were done to determine the relationship between raw water characteristics: turbidity, pH, alkalinity, temperature, and optimum doses of alum [ .14 O] to form a mathematical equation that could replace the need for jar test experiments. The experiments were performed under different conditions and under different seasonal circumstances. The optimal dose in every set was determined, and used to build a gene expression model (GEP). The models were co
... Show MoreThe adsorption of Pb(II) ions onto bentonite and activated carbon was investigated. The effects of pH, initial adsorbent dosage, contact time and temperature were studied in batch experiments. The maximum adsorption capacities for bentonite and activated carbon were 0.0364 and 0.015 mg/mg, respectively. Thermodynamic parameters such as Gibbs free energy change, Enthalpy change and Entropy change have been calculated. These thermodynamic parameters indicated that the adsorption process was thermodynamically spontaneous under natural conditions and the adsorption was endothermic in nature. Experimental data were also tested in terms of adsorption kinetics, the results showed that the adsorption processes followed well pseudo second- order
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