In this study, investigations of structural properties of n-type porous silicon prepared by laser assisted-electrochemical etching were demonstrated. The Photo- electrochemical Etching technique, (PEC) was used to produce porous silicon for n-type with orientation of (111). X-ray diffraction studies showed distinct variations between the fresh silicon surface and the synthesized porous silicon surfaces. Atomic force microscopy (AFM) analysis was used to study the morphology of porous silicon layer. AFM results showed that root mean square (RMS) of roughness and the grain size of porous silicon decreased as etching current density increased. The chemical bonding and structure were investigated by using fourier transformation infrared spectroscopy (FTIR). Porosity of the porous silicon layer and thickness were determined gravimetrically. Increasing the etching current density led to increase the surface porosity and thickness. Porosity between77% and 82% were observed for current densities between 24 mA/cm2 and 116 mA/cm2
A theoretical study was done in this work for Fatigue. Fatigue Crack Growth (FCG) and stress factor intensity range for Ti2 SiC 3 . It also includes Generalized Paris Equation and the Fulfillment of his equation which promise that there is a relation between parameters C and n. Simple Paris Equation was used through which we concluded the practical values of C and n and compared them with the theoretical values which have been concluded by Generalized Paris Equation. The value of da/dN and ∆K for every material and sample were concluded and compared with the data which was used in the computer p
... Show MoreMy study here is about the (possible for itself) features especially in the (Alashaira) opinion, also I touch to the other logicians opinions, I clarified these features concisely in the preface to be clear in front of the reader, I made it in two studies and five subjects.I talked about the meaning of the existence in the ((possible for itself) theme, and I clarified its types in the logicians and the philosophers' opinions, through which the existence and the nonexistence are equal in it, as it cannot be existed nor be nonsexist unless with a separated reason, and there is no necessity to oblige its existence, or its nonexistence is impossible.Then I talked about the outweighing of the (possible for itself) as one side of the exi
... Show MoreAnew mathematical formula was proposed to describe the behavior of the extinction coefficient as a function of ambient temperature and wavelengths for some of infrared materials. This formula was derived depending on some experimental data of transmittance spectrum versus wavelengths for many ambient temperatures. The extensive study of the spectrum characteristics and depending on Bose-Einstein distribution led to derive an equation connecting the extinction coefficient or the absorption coefficient with the ambient temperature and wavelengths of the incident rays. The basic assumption in deriving process is the decreasing in transmittance value with the increasing temperature which is only due to the changing in extinction coeffi
... Show MoreA total of 41 patients with gastro duodenal symptoms (show signs of inflammation with or without duodenal ulcer) . 21 males (51.2%) and 20 female (48.8%) with an average age 0f (20 – 80) years old under going gastrointestinal endoscopy at Baghdad teaching hospital in internal disease clinical laboratory , between (February – June) 2009 . Biopsies specimen of antrum , gastric fundus ,& duodenal bulb were examined by the following methods (rapid urease test , Giemsa stain section to detect bacteria , & Haematoxilin and Eosin stained section for pathological study which are considered the gold standard methods , sera or plasma from these patients were tested by immunochromotography (ICM),serological m
... Show MoreThe study was trail to treated secondary hydatid cysts in white micepost-infection with Echinococcosis of sheep origin, by immunization with a mixture of CFAgs/PSAgs prepared from haydatid Cyst Fluid antigens (CFAgs) and Proto scolices antigens (PSAgs) respectively, two concentrations (7.5 &15 mg/ml) in addition to two derivatives of benzimidazole; albendazole (A) and mebendazole (M) 10 and 40μg/gm body weight, respectively, one week after challenged dose with protoscolices. to determine the efficacy of immunization and chemotherapy simultaneously in reduction the number of growing cysts, then measured both humoral and cell-mediated immunity. Results: elevation the immune responses that reflected decrease number and diameter of hydatid cys
... Show MoreThis study has contributed to identify convenience of the land Usifiya of Mahmudiya district baghdad province for the cultivation of sensitive and salt resisting crops and growing pasture .The nine pedons (tracks) of the study have spread over three transects to cover the whole area the north, middle and south .
Depending on Visual Space tupe (TM) for 2007 which is super classified, samples are distributed on all classes of land cover
It is detected the presence of nine series soils namely
MM5- MW96- DM 115 for 1st transect
MF12- DM46 - DM96 for 2nd transect
DM56- DF56 - MW5 for 3rd transect
Soils are classified to the level of sub great group according to (soil Survey Staff) to :
*Typic Torri Fluvents , Typic Haplos
The present study is a linguistic study of comment clauses in the American Series „Friends‟ .Comment clauses refer to those clauses which comment on the content of the main clause or the attitude of the speaker towards the way of speaking .The problem of this study is to answer the following questions ; what types of comment clauses can be used in the face- to –face conversations , for what functions these comment clauses could be used , and how these comment clauses are used by the participants of these conversations . This study is a qualitative one . The study aims to investigate the types of comment clauses used in the American Series “Friends‟. The study also aims to investigate the pragmatic functions of these comment clause
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