Because of Cadmium selenide quantum dots (CdSe quantum dots) has a tuning energy gap in the visible light range, therefore; it is provided a simple theoretical model for the absorption coefficient of CdSe quantum dots, where the absorption coefficient determines the extent to which the light of a material can penetrate a specific wavelength before it is absorbed. CdSe quantum dots have an energy gap can be controlled through two effects: the temperature and the dot size of them. It is found that; there is an absorption threshold for each directed wavelength, where CdSe quantum dots begin to absorb the visible spectrum at a size of 1.4 nm at room temperature for a directed wavelength 300 nm. It has been observed that; when the wavelength is increasing its absorption threshold is increased. For wavelengths (400, 500, 600) nm, the absorption thresholds for each quantum sizes are (1.8, 2.2. 3.2)nm respectively. On the other hand, a rising of the temperature led to reduces the absorption coefficient value, that at 400 K for all quantum sizes, the absorption coefficient increases >2000cm−1(According to the directed wavelength) than it is at 0 K. CdSe quantum dots can be considered as one of the most promising materials because it has a tuning gap for the visible wavelengthsfor different applications, such as light-emitting diodes in different colors of the visible spectrum. It is found that; there is a good agreement between our theoretical calculations and experimental results.
In the name of of Allah the Merciful
Introduction:
Praise be to Allah, Lord of the Worlds, and prayers and peace be upon our master Muhammad and his family and companions.
After
I have looked at a part of the jurisprudence of Hajj jurisprudence, which is needed now, especially after it facilitated travel to perform Hajj and Umrah, so the need was an advocate and a list for writing in it, which is beneficial to Hajj, Umrah and the guide.
And this important part is the things that contravene the woman's man in the Hajj and after the search and tracking found that there are ten things that get the violati
... Show MoreBackground: Except for the tight correlation to nasopharyngeal carcinoma, accumulating evidences show that Epstein-Barr virus (EBV) is correlated to other carcinomas. This study was to investigate the association of EBV with colorectal tumors.
Materials & methods: Forty paraffin embedded blocks of colorectal tumors (thirty were adenocarcinoma and ten were benign tumors) were all examined for the presence of EBV DNA with
the application of In Situ hybridization.
Results: In Situ EBV DNA signals was detected in 6 out of 30 (20%) of colorectal carcinoma with no observed signals in the sections from benign group.
Conclusion: Our results showed that infection of EBV exists in human colorectal adenocarcinoma
Although severe epistaxis is uncommon, it is serious. The systematic endoscopic nasal examination is an essential step in identifying the bleeding point and aiding electrocauterization. Currently, the S-point, which is located in the superior part of the nasal septum behind the septal body and corresponding to the axilla of the middle concha, is identified in about 30% of cases with severe epistaxis. Cauterization of this point has an excellent rate of controlling the bleeding and preventing its recurrence. We aimed to highlight the significance of the S-point in the management of severe cases of epistaxis.
Objective: The aim of this study is to determine the role of spiral Computerized Tomography in the diagnosis and
detection the types of stroke.
Methodology: One hundred sixty two patients (162) (99 males and 63 females) their ages ranging from (13 – 80)
year, all of them are suffering from stroke. They were collected randomly from spiral Computerized Tomography
unit in Baquba Teaching hospital during the period from November / 2010 to December / 2011 .All the patients
were examined clinically and then done spiral Computerized Tomography examination.
Results : The results of this study showed that the stroke effected different age groups and both sex but males is
more affected than the females .The results of spiral
The methodology of the concept of sovereignty in contemporary Islamic thought
We have chosen the subject of the research (the letters at Ibn Jinnie in the lexicon of the tongue of the Arabs) in order to know the opinion of Ibn Jinnie in this range of words and compare them with the opinions of scientists who preceded him to know the personality of this linguistic world.