An experimental and theoretical study has been done to investigate the thermal performance of different types of air solar collectors, In this work air solar collector with a dimensions of (120 cm x90 cm x12 cm) , was tested under climate condition of  Baghdad city with a (43° tilt angel)  by using  the absorber plate (1.45 mm thickness, 115 cm height x 84 cm width), which was manufactured from iron painted with a black matt.

The experimental test deals with five types of absorber:-

 Conventional smooth flat plate absorber , Finned absorber , Corrugated absorber plate, Iron wire mesh on absorber And matrix of porous media  on absorber .

The hourly and average efficiency of the collectors

Comparative Analysis of Economic Policy Stability between Monarchical and Republican Systems: A Theoretical Fundamental Research

The accurate determination of nuclear radius is fundamental to understanding nuclear structure and interactions. The present study conducts a comprehensive theoretical analysis of nuclear radius measurements using various nuclear structure models, including the empirical mass-number scaling model, the Hartree-Fock approach, and the relativistic mean-field (RMF) theory. These models are systematically compared against experimental nuclear radii to evaluate their predictive accuracy and assess their strengths and limitations. The study also incorporates an uncertainty analysis to quantify the reliability of theoretical predictions, employing Monte Carlo simulations and Bayesian inference techniques to refine estimations. The results r

ABSTRACT

A field experiment was carried out in the fields of the college of agricultural engineering sciences, university of Baghdad during the fall season of 2021, in order to find out which of the cultivated genotypes of maize are efficient under nitrogen fertilization. The experiment was applied according to a RCBD (split plot design with three replications). The genotypes of experiment (Baghdad, 5018 and Sarah) and  supplying three levels of nitrogen fertilizer, which are N1 (100 kg/ha),  N2 (200 kg/ha) and N3  (300 kg/ha), the results of the statistical analysis are showed the superiority of the cultivar Sarah in the trait of number of days until 50% silking, chlorophyll

The Libyan-Egyptian relations since 1952 to 1969, which studies two neighboring states ,and the geographical proximity has an effect in documenting and cementing the relationship between the two states. They share 1094 m long borders. That was reflected on the kind of relationship the two countries has shares. The Libyan-Egyptian relationship is not a superficial one, as the two countries have shared borders. What lies between them is a mixture of geography and human. It is an undying history. Our choice of the topic is limited to the period 1952 the beginning of the LibyanEgyptian. The revolution of 23rd July 1952 in Egypt and the declaration of republic there. For Libya, it was the monarchy in 1969 with the September 1 revolution.

The Current research aims at building a scale for the time management for the faculty members at the University of Baghdad. To achieve this goal, the researcher formulates (45) paragraphs by using verbal expressions. In front of each expression, five alternatives have been placed reflecting the extent of the emergence of this behavior (always, often, sometimes, rarely, never). For the purpose of verifying the validity of the paragraphs of the scale; the researcher has consulted a group of experts who revised these paragraphs and show their remarks. In the light of these remarks, the researcher excludes two paragraphs, and thus the number of the scale's paragraphs becomes (43). These paragraphs have been applied by the researcher on an ex