Abstract

      In this study, we compare between the autoregressive approximations (Yule-Walker equations, Least Squares , Least Squares ( forward- backword ) and Burg’s (Geometric and Harmonic ) methods, to determine the optimal approximation to the time series generated from the first - order moving Average non-invertible process, and fractionally - integrated noise process, with several values for d (d=0.15,0.25,0.35,0.45) for different sample sizes (small,median,large)for two processes . We depend on figure of merit function which proposed by author Shibata in 1980, to determine the theoretical optimal order according to min

The purpose of this research paper is to present the second-order homogeneous complex differential equation   , where   , which is defined on the certain complex domain depends on solution behavior. In order to demonstrate  the relationship between the solution of the second-order of the complex differential equation and its coefficient of function, by studying the solution in certain cases: a meromorphic function, a coefficient of function, and if the solution is considered to be a transformation with another complex solution. In addition, the solution has been provided as a power series with some  applications.

The most important topic for psychologist generally is factor of education and it's active tools because learning needs active perception for stimulus that recived by the educator and give it avalue and meaning , Need for cognition is
very important in the various daily fields of life , especially in learning and teaching and the academy work , it help with shifting the learning level for people , and icreas the intense and challenge between them
The research endeavored to achieve the following aim :
1- Measuring the level of peripheral perception for the university student .
2- Measuring the level of need for cognition for the university student .
3- Measuring the level of peripheral perception for the university student

The research included anatomical study of nine wild species of the genus
Athionema R.BR. from BrassicaceA family in Iraq, and these species are:
A.arabicum (L.), A.carneum (Banks et sol.),A. cordifolium (DC.), A.fimbriatum
(Boiss.),A. froedinii (Rech. F.), A. speciosum (Boiss. et Huet), A. syriacum
(Boiss.),A. grandiflorum (Boiss. et Hoh.) , A.trinervium (D.C.).The research
covered the anatomical characteristic of the leaf Epidermis as well as leaves
venation, also transvers sections for leaves were studied ,and revealed that some
anatomical characteristics have taxonomic importance in distinguishing the species.
This research also showed the presence of important variations in internal charecters
for leaves an

The main objective of" this paper is to study a subclass of holomrphic and univalent functions with negative coefficients in the open unit disk U= defined by Hadamard Product. We obtain coefficients estimates, distortion theorem , fractional derivatives, fractional integrals, and some results.

The imbalances and economic problems which it face the countries, it is a result of international economic developments or changes or global crises such as deterioration in trade, sharp changes in oil prices, increasing global indebtedness, sharp changes in foreign exchange rates and other changes, all that, they affect the economic features of any country. and These influences vary from one country to another according to the rigidity of its economy and its potential in maneuvering with economic plans and actions that would reduce the impact or avoidance with minimal damage. Therefore, the countries  that  suffer from accumulated economic problems as a result of mismanagement and poor planning or suffe

Zinc oxide (ZnO) nanostructures were synthesized through the hydrothermal method at various conditions growth times (6,7 and 8 hrs.) and a growth temperature (70, 90, and 100 ºC). The prepared ZnO nanostructure samples were described using scanning electron microscopy (SEM) and X-ray diffractometer to distinguish their surface morphologies and crystal structures. The ZnO samples were confirmed to have the same crystal type, with different densities and dimensions (diameter and length). The obtained ZnO nanostructures were used to manufacture gas sensors for NO2 gas detection. Sensing characteristics for the fabricated sensor to NO2 gas were examined at different operating temperatures (180, 200, 220, and 240) ºC with a low gas concentrati

     In this study, pure polylactic acid (PLA) and composite polylactic acid/ curcumin (PLA / Cur) were prepared by a suspension of ultrasonically agitated micrometer-sized curcumin powder, which was mixed with chloroform solvent  under slow mechanical stirring and incorporated into the PLA. The resulting suspension was used to cast free-standing PLA / Cur composite films. The filler content was chosen to be 2.0 wt % curcumin. Physical properties (glass transition, temperature, mechanical and thermodynamic) were analyzed by Positron Annihilation Lifetime Spectroscopy (PALS), which is a unique tool for analyzing the defects of polymer materials. The free volume and holebility of PLA and PLA / Cur were studied&nbsp

        Of the importance of the concept of ownership of real estate as the basic basis from which various projects are launched in various economic, tourism, and urban areas .... The need to research the diagnosis of real estate reality went astray in the difficulties, which played a decisive role in the process of urban development.

 This leads us to the research problem of the difficulty of implementing urban development plans in many cases due to the absence of a clear methodology for organizing and modernizing the ownership of real estate and its coordination with the management of urban land and to achieve the objective