In this work, nanostructure porous silicon surface was prepared using electrochemical etching method under different current densities. I have studied the surface morphology and photoluminescence (PL) of three samples prepared at current densities 20, 30 and 40 mA/cm2 at fixed etching time 10 min. The atomic force microscopy (AFM) images of porous silicon showed that the nanocrystalline silicon pillars and voids over the entire surface has irregular and randomly distributed. Photoluminescence study showed that the emission peaks centered at approximately (600 – 612nm) corresponding energies (2.06 – 2.02eV).
While current-voltage characteristics shows, as the current density increase the current flow in the forward bias is decreasing, while the rectification ratio and ideality factor varied from one sample to another. Finally, as etching current density increases the built in potential (Vbi) decreases (Vbi= 0.95, 0.75 and 0.55 volt corresponding 20, 30 and 40 mA/cm2) respectively.
This research includes the principles of the democracy، and to which extent it can contribute in establishing these principles. Democracy is not only to hold parliamentary or presidential elections but also the result of these elections wills it lead to the emergence of an integrated regime that can actually expresses the citizen's rights and to which extent those citizens can contribute in that regime and control it. Since 2005، when the first elections took place in Iraq after the US occupation of Iraq 2003، Iraqi people are looking to a rule that represented them and achieve their interests after getting rid of the totalitarian regimes and establishing an institutional regime that work by democratic means in order to achieve the so
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consideration
In the purposes of faith and destiny
PV connected systems are worldwide installed because it allows consumer to reduce energy consumption from the electricity grid. This paper presents the results obtained from monitoring a 1.1 kWp. The system was monitored for nine months and all the electricity generated was fed to the fifth floor for physics and renewable energy building 220 V, 50 Hz. Monthly, and daily performance parameters of the PV system are evaluated which include: average generated of system Ah per day, average system efficiency, solar irradiation around these months. The average generated kWh per day was 8 kWh/day, the average solar irradiation per day was 5.6 kWh/m2/day, the average inverter efficiency was 95%, the average modules efficien
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New series of Schiff bases 2(a-j) and corresponding beta-lactam derivatives 3(a-j) were synthesized from cefalexin (1) as starting material. The compound (1) was reacted with different aldehydes and ketones to give Schiff bases derivatives 2(a-j). The synthesized Schiff bases were cyclized by chloroacetyl chloride in the presence of triethylamine to form beta-lactam derivatives 3(a-j). The compounds were characterized by deremination melting point, FT-IR and 1H NMR. The beta-lactam derivatives were screened in vitro antibacterial against some bacterial species
(1)
Some esters were prepared from reaction of different molecular weight of PVA with some acid chloride (prepared by reaction of acid with thionyl chloride or phosphorous pentachloride)in the presence of pyridine. The thermal and reological properties were studied. The increasing Of bulky groups decreasing stability of the thermal and reological properties.
As we have said that the reasons for abortion are many and varied them to be for
the purpose of treatment or the protection of the mother of the loss or that the abortion
of an act intended purpose of birth control or other reasons is the statistics that are
spread in the world that about 50-60 million abortions annually in the world If this
abortion criminal who is loss of the lives of fetuses and a disgrace to the preachers to
the progressive and liberal, secular, and because they were not able to maintain
human life after leaving the obligation to approach Islam and because life support is
the highest things, which is one of the necessities of the five obligatory street
maintenance came verses warn those who un
Recently, biometric technologies are used widely due to their improved security that decreases cases of deception and theft. The biometric technologies use physical features and characters in the identification of individuals. The most common biometric technologies are: Iris, voice, fingerprint, handwriting and hand print. In this paper, two biometric recognition technologies are analyzed and compared, which are the iris and sound recognition techniques. The iris recognition technique recognizes persons by analyzing the main patterns in the iris structure, while the sound recognition technique identifies individuals depending on their unique voice characteristics or as called voice print. The comparison results show that the resul
... Show More A series of N- benzoyl - 2 – alkyl -1- ( 2- thio – 1,3,4- thiadiazole -5- yl ) , have been synthesized from DL- α– amino acids , The methyl and sulfon thio ethers of these compounds were also prepared , representative samples of the prepared compounds were characterized from their IR- spectrum and elemental analysis .
Background: Echinococcosis is a zoonotic disease with high incidence.
Praise be to Allah, Lord of the Worlds, and peace and blessings be upon our master Muhammad and his good and pure family. At the end of this research, we summarize some of the most important findings of our research, namely:
Raising a child properly from childhood leads to integrity in the life of the individual society, and if the young raised bad education, this education will affect itself and society negatively, so on parents and government institutions in any country to take care of children, and Islamic countries Specifically to give the child great attention; he is raised on the Koran and watered from its fountains, and armed with a weapon of morality from a young age, and to understand the biography of Mustafa (peace be upon h