The centers of cities and historical quarter are exposed to a severe threat to the values of the physical and legal urban environment as a result of the value deterioration and the emergence, emergence and spread of new values on the intellectual and urban context, which generates the loss of the urban environment for its spatio-temporal continuity, flexibility, adaptation and continuity, and thus urban obsolescence, Hence the problem of the research in “the lack of comprehensiveness of studies on the phenomenon of urban obsolescence and its impact on the decline in the values of the quality of the built environment in historic

Receipt date:3/13/2021 accepted date:5/26/2021 Publication date:12/31/2021

 This work is licensed under a Creative Commons Attribution 4.0 International License.

energy is one of the strategic resources within international politics, and this is through the existing competition between the international powers on it, and the global powers have begun to rely on interest in new areas, such as import, depending on new projects an

The materials of soil were affected by multi reasons; such as human activities, floods, tidal waves, ... etc. The change of the soil contents could be measured through different indexes; such as electric conductivities, salinity, concentration of the heavy elements, and concentration of essential elements ... etc. The land cover is affected by natural influences, like tidal energy, which plays a negative role in the salinization of land adjacent to the coasts, causing a problem for soils in all its details represented in changing of the dissolved elements in soil. One of the most important natural factors that cause soil salinity is human activity in all its forms, and one of the most important causes of salinity is the phenomenon o

In this work, chemical oxidation was used to polymerize conjugated polymer "Polypyrrole" at room temperature Graphene nanoparticles were added by in situ-polymerization to get (PPY-GN) nano. Optical and Electrical properties were studied for the nanocomposites. optical properties of the nanocomposites were studied by UV-Vis spectroscopy at wavelength range (200 -800 nm). The result showed optical absorption spectra were normally determined and the result showed that the maximum absorbance wave length at 280nm and 590nm. The optical energy gap has been evaluated by direct transition and the value has decreased from (2.1 eV for pure PPy) to (1.3 eV for 5 %wt. of GN). The optical constants such as the band tail width ΔE was evaluated, the

Abstract

The entities responsible for regulating the financial market are seeking to provide high quality accounting information, to provide appropriate protection to investors, and thus encourage them and attract them to increase their investments. the research reached several conclusion, the most prominent of which comes  :-

1-The production of high quality accounting information reduces investment costs and costs of processing accounting information.

2- The production of high quality accounting information helps investors identify the best investment opportunities.

3- The results of the statistical analysis showed that there is significant

Over the course of six decades, Iraq exposed to many events that have affected the Iraqi people from the social, physical and mental aspects. In this study, two groups of people (2369), from Iraq (G1) and the Michigan, United States (U.S) of America (G2) selected to compare the prevalence rate and effects of trauma factors such as mental illness (anxiety, depression and PTS), somatic diseases (heart disease, hypertension, and diabetes), substances abuse (illicit drugs, alcohol and tobacco), and chemicals pollution), and self-rated health among the two groups. The study results reveals a significant different between the two groups in the all indicators for trauma. The study conclude that Iraqi in U.S. (G2) suffer from factors completely dif

Three different distribution modules of silicon solar cells in a panel are used in this study . Each module consists of five identical circular silicon solar cells of radius (5cm) and then the total panel areas are identical. The five solar cells are arranged in the panel in different shapes: circular, triangular and rectangular .The efficiency for these three panel distribution are measured indoor and outdoor. The results show that the efficiency is a function of the cells distribution.

The paper presents an investigation to the flutter speed of composite wing for different ply orientation. Structurally the composite wing was idealized as a composite beam load carrying structure. Theodorsen’s expression was used to get the 2- dimension unsteady lifting force and pitching moment in the limit of incompressible flow and subsonic speed which were integrated over the wing span. A free vibration analysis was first carried out to get the natural frequencies and mode shapes .The velocity-damping (V-g) method was used to calculate the flutter speed and the flutter frequency. A wing of unmanned aerial vehicle was manufactured from woven glass and polyester resin where the flutter speed was calculated experimentally by the wind

This paper is illustrates the sufficient conditions of the uniformly asymptotically stable and the bounded of the zero solution of fifth order nonlinear differential equation with a variable delay τ(t)