تم في هذا البحث تحضير وتشخيص تسعة معقدات مع الليكاند [N, N- Bis(2- hydroxy ethyl) Glycine] ومختصره (Bicine) وثمانية معقدات مع الليكاند [N- Tris(hydroxy Methyl) Methyl Glycine] ومختصره (Tricine) مع بعض الايونات الفلزية وقد جرى التفاعل على مرحلتين وكما ياتي:- أ. تحضير ملح البوتاسيوم لليكاندات وذلك من مفاعلة الليكاند مع هيدروكسيد البوتاسيوم وبنسب (1:1) (قاعدة: ليكاند) في محيط كحولي للحصول على ملح الليكاند. ب. وفي المرحلة الثانية: تم مفاعلة الملح الناتج مع املاح الفلزات المختارة للحصول على المعقدات المطلوبة. ولقد تم مفاعلة ملح الليكاند (Bic-k+) مع ايونات املاح العناصر الفلزية الاتية (Cd+2,Ag+,Pd+2, Zn+2,Cu+2, Ni+2, Co+2,Cr+3,VO+2), وكذلك مفاعلة ملح الليكاند (Tric-k+) مع كل من (Cd+2, Ag+, Zn+2, Cu+2, Ni+2, Co+2, Mn+2,Cr+3), للحصول على المعقدات المطلوبة. وقد درست هذه المعقدات بالطرائق الاتية:- أ. الدراسات الطيفية وتضمنت اطياف الاشعة تحت الحمراء والاشعة فوق البنفسجية- المرئية. ب. الامتصاص الذري. ج. التوصيلية المولارية وقابلية الذوبان. د. قياس الحساسية المغناطيسية. ه. استخدام طريقة النسب المولية وتعين ثوابت الاستقرارية لبعض المعقدات المحضرة. ومن هذه الدراسات التشخيصية اعلاه وبالمقارنة مع ما ورد في الادبيات من المعقدات المتشابهة اقترحت الصيغ التركيبية الاتية لمعقدات المحضرة: أ. المعقدات السداسية التناسق ذات الشكل الثماني السطوح ,إذ اعطت الصيغة العامة [M(Bicine)3] و [M(Tricine)3],إذ M تمثل ايون الكروم الثلاثي التكافؤ. ب. المعقدات الخماسية التناسق ذات الشكل الهرم المربع القاعدة (Square Pyramid) واعطيت لها الصيغة العامة[VO(Bicine)2]. ج. المعقدات الرباعية التناسق واعطيت لها الصيغة العامة:-.xH2O[M(Bicine)2] و .xH2O[M(Tricine)2] .
Support vector machines (SVMs) are supervised learning models that analyze data for classification or regression. For classification, SVM is widely used by selecting an optimal hyperplane that separates two classes. SVM has very good accuracy and extremally robust comparing with some other classification methods such as logistics linear regression, random forest, k-nearest neighbor and naïve model. However, working with large datasets can cause many problems such as time-consuming and inefficient results. In this paper, the SVM has been modified by using a stochastic Gradient descent process. The modified method, stochastic gradient descent SVM (SGD-SVM), checked by using two simulation datasets. Since the classification of different ca
... Show Moreالاهمية الاقتصادية للموانىء الحرة مع الاشارة الى المنطقة الاقتصادية الحرة المقترحة في ميناء الفاو
Robot manipulator is a multi-input multi-output system with high complex nonlinear dynamics, requiring an advanced controller in order to track a specific trajectory. In this work, forward and inverse kinematics are presented based on Denavit Hartenberg notation to convert the end effector planned path from cartesian space to joint space and vice versa where a cubic spline interpolation is used for trajectory segments to ensure the continuity in velocity and acceleration. Also, the derived mathematical dynamic model is based on Eular Lagrange energy method to contain the effect of friction and disturbance torques beside the inertia and Coriolis effect. Two types of controller are applied ; the nonlinear computed torque control (CTC
... Show MoreThis work deals with determination of optimum conditions of direct diffusion bonding welding of austenitic stainlesssteel type AISI 304L with Oxygen Free High Conductivity (OFHC) pure copper grade (C10200) in vacuum atmosphere of (1.5 *10-5 mbr.). Mini tab (response surface) was applied for optimizing the influence of diffusion bonding parameters (temperature, time and applied load) on the bonding joints characteristics and the empirical relationship was evaluated which represents the effect of each parameter of the process. The yield strength of diffusion bonded joint was equal to 153 MPa and the efficiency of joint was equal to 66.5% as compared with hard drawn copper. The diffusion zone reveals high microhardness than coppe
... Show MoreThe proposal of nonlinear models is one of the most important methods in time series analysis, which has a wide potential for predicting various phenomena, including physical, engineering and economic, by studying the characteristics of random disturbances in order to arrive at accurate predictions.
In this, the autoregressive model with exogenous variable was built using a threshold as the first method, using two proposed approaches that were used to determine the best cutting point of [the predictability forward (forecasting) and the predictability in the time series (prediction), through the threshold point indicator]. B-J seasonal models are used as a second method based on the principle of the two proposed approaches in dete
... Show MoreThe presented work shows a preliminary analytic method for estimation of load and pressure distributions on low speed wings with flow separation and wake rollup phenomena’s. A higher order vortex panel method is coupled with the numerical lifting line theory by means of iterative procedure including models of separation and wake rollup. The computer programs are written in FORTRAN which are stable and efficient.
The capability of the present method is investigated through a number of test cases with different types of wing sections (NACA 0012 and GA(W)-1) for different aspect ratios and angles of attack, the results include the lift and drag curves, lift and pressure distributions along the wing s
... Show MoreThe study addresses the problem of stagnation and declining economic growth rates in Arab countries since the eighties till today after the progress made by these countries in the sixties of the last century. The study reviews the e
... Show MoreThe linear segment with parabolic blend (LSPB) trajectory deviates from the specified waypoints. It is restricted to that the acceleration must be sufficiently high. In this work, it is proposed to engage modified LSPB trajectory with particle swarm optimization (PSO) so as to create through points on the trajectory. The assumption of normal LSPB method that parabolic part is centered in time around waypoints is replaced by proposed coefficients for calculating the time duration of the linear part. These coefficients are functions of velocities between through points. The velocities are obtained by PSO so as to force the LSPB trajectory passing exactly through the specified path points. Also, relations for velocity correction and exact v
... Show MoreAbstract
Objectives: this study aims to: (1). Assess self-esteem level and academic achievement for students of nursing colleges in southern Iraq. (2). Determine the relationship between levels of self-esteem and academic achievement of the student in the first semester. (3). Identify differences of self-esteem with gender and different age groups.
Methodology: a sample of (426 students) was purposively selected then collected by using a questionnaire which consisted of: I- Sociodemographic characteristics for assessing some important aspects of students, II- Rosenberg's Self-Esteem Scale (RSES) III- Iraq Grading Scale for assessing student achievement. Finally statistical analysis (SPSS) for data processing.
Results: study resu