Pure and Fe-doped zinc oxide nanocrystalline films were prepared
via a sol–gel method using -
C for 2 h.
The thin films were prepared and characterized by X-ray diffraction
(XRD), atomic force microscopy (AFM), field emission scanning
electron microscopy (FE-SEM) and UV- visible spectroscopy. The
XRD results showed that ZnO has hexagonal wurtzite structure and
the Fe ions were well incorporated into the ZnO structure. As the Fe
level increased from 2 wt% to 8 wt%, the crystallite size reduced in
comparison with the pure ZnO. The transmittance spectra were then
recorded at wavelengths ranging from 300 nm to 1000 nm. The
optical band gap energy of spin-coated films also decreased as Fe
doping concentration increased. In particular, their optical band gap
energies were 3.75, 3.6, 3.5, 3.45 and 3.3 eV doping concentration of
0%, 2%, 4%, 6% and 8% Fe, respectively. The performance of the
pure and doped ZnO thin films was examined for the photocatalytic
activity using organic dyes (methyl orange, methyl blue, methyl
violet). The samples ZnO with concentration of Fe showed increased
photocatalytic activity with an optimal maximum performance at
0.8 wt%.
In this study, the optical and thermal performance of a Parabolic Trough Collector PTC system is investigated theoretically. A series of numerical simulations and theoretical analysis has been conducted to investigate the effect of the receiver geometry and location relative to the focal line on its optical performance. The examined receiver geometries are circular, square, triangular, elliptical and a new design of circular‐ square named as channel receiver. The thermal performance of PTC is studied for different flow rates from (0.27 to 0.6 lpm) theoretically. Results showed that the best optical design is the channel receiver with an optical efficiency of 84% while the worst is the elliptical
This paper is concerned with introducing an explicit expression for orthogonal Boubaker polynomial functions with some important properties. Taking advantage of the interesting properties of Boubaker polynomials, the definition of Boubaker wavelets on interval [0,1) is achieved. These basic functions are orthonormal and have compact support. Wavelets have many advantages and applications in the theoretical and applied fields, and they are applied with the orthogonal polynomials to propose a new method for treating several problems in sciences, and engineering that is wavelet method, which is computationally more attractive in the various fields. A novel property of Boubaker wavelet function derivative in terms of Boubaker wavelet themsel
... Show MoreMethods of teaching plays an important vole in the educational process
because is the link between the teacher and the learner. The process of
teaching doesut fulfill the desirable results unless the methods of guiding and
teaching are provided and through a qualified educationalist capable of
communicating the syllabus to the students in an easy and clear way. In spite
of the diversity of the methods of teaching ,there is no one way suitable for all
the educational purposes , all the sciences ,all the subjects ,all the levels of
growth ,levels of teaching, maturity and intelligences ,all teachers and
educationalists and all the circum stances surrounding the teaching processes
.The teacher is the one who choos
The contemporary development applications on scientific areas of acyclic and cyclic Schiff bases and their complexes.
This topic is considered to be of a high degree of importance to every Muslim, and its importance is due to the fact that monotheism is:
Prove that God Almighty is the God who created everything and everything opposite to monotheism is polytheism, and it is taking other than God Almighty as a deity.
Therefore, we have to know the concept of God. If he is known, then he knows the concept of monotheism and the concept of polytheism
Show the greatness of Allah Almighty when contemplating the benefits of trees and plants in
Life in general and trees mentioned in the Koran in particular, do not have to meditate that
He acknowledges the greatness of the Almighty Creator, and his preference over man, that he is prepared for his livelihood
And give him what he can do in this life to the fullest.
The study also stressed the need to urge people to this great blessing trees
By preserving them and wasteful wastefulness.
The study also pointed to the need to guide people towards the aesthetics and improvements of
Look through and enjoy the beauty of trees, flowers, greenery and fruits ..
