The photo-electrochemical etching (PECE) method has been utilized to create pSi samples on n-type silicon wafers (Si). Using the etching time 12 and 22 min while maintaining the other parameters 10 mA/cm² current density and HF acid at 75% concentration.. The capacitance and resistance variation were studied as the temperature increased and decreased for prepared samples at frequencies 10 and 20 kHz. Using scanning electron microscopy (SEM), the bore width, depth, and porosity % were validated. The formation of porous silicon was confirmed by x-ray diffraction (XRD) patterns, the crystal size was decreased, and photoluminescence (PL) spectra revealed that the emission peaks were centered at 2q of 28.5619° and 28.7644° for et

In this research, a sensor for chemical solutions was designed and formed using optical fiber-based on a surface Plasmon resonance technology. A single-mode optical fiber with three different diameters (25, 45 and 65) µm was used, respectively.  The second layer of the low refractive fiber was replaced by gold, which was electrically deposited at 40 µm thickness. For each of the three types of optical fiber, different saline concentrations (different index of refraction) were used to evaluate the performance of the refractive index sensor (chemical sensor) by measuring its sensitivity and resolutions. The highest values we could get for these two parameters were 240mm/RIU, and 6*10^-5 RIU respectively, when the diameter of a

       Thin films of pure yttrium oxide (Y₂O₃) and doped with cerium oxide (CeO₂) were prepared by the chemical spray pyrolysis(CSP)method. The structural, optical and electrical properties of the prepared films were investigated. The analysis of X-ray diffraction (XRD) thin films revealed that the undoped and doped Y₂O₃  were amorphous with a broad hump around 27^o and narrow humps around 48^o and 62^o for all samples. Except for the Y₂O₃:6wt.%CeO₂ thin film, all had signal preferential orientation along the (100) plane at 2θ=12.71^o which belongs to CeO₂, Field emission scanning electron mic

Transparent thin films of CdO:Ce has been deposited on to glass and silicon substrates by spray pyrolysis technique for various concentrations of cerium (2, 4, and 6 Vol.%). CdO:Ce films were characterized using different techniques such as X-ray diffraction (XRD), atomic force microscopy(AFM) and optical properties. XRD analysis show that CdO films exhibit cubic crystal structure with (1 1 1) preferred orientation and the intensity of the peak increases with increasing's of Ce contain when deposited films on glass substrate, while for silicon substrate, the intensity of peaks decreases, the results reveal that the grain size of the prepared thin film is approximately (73.75-109.88) nm various with increased of cerium content. With a sur

    This work is an experimental study conducted to study the effects of iron oxide dust particles (Fe₂O₃) on the characteristics of DC discharge plasma in argon gas under vacuum. Electron temperature ( ) and electron density (n_e) were calculated by Boltzmann plots and Stark broadening, respectively. The results show that both the electron density and plasma frequency ( ) increased with the operating pressure. While,  and Debye length ( ) decreased with pressure. The glow discharge is more stable with the Fe₂O₃-dust particles; all dust plasma parameters have lower values  than those of the dust-free plasma.

Frictional heat is generated when the clutch starts to engag. As a result of this operation the surface temperature is increased rapidly due to the difference in speed between the driving and driven parts. The influence of the thickness of frictional facing on the distribution of the contact pressure of the multi-disc clutches has been investigated using a numerical approach (the finite element method). The analysis of contact problem has been carried out for a multiple disc dry clutch (piston, clutch discs, separators and pressure plate). The results present the distribution of the contact pressure on all tShe surfaces of friction discs that existed in the friction clutch system. Axisymmetric finite element models have been developed to ac

Background: The purpose of this study was to compare the parametric measurements of transient otoacoustic (TEOAEs) in normal hearing subjects between two clinical centers in Iraq and to examine the community effect on TEOAEs characteristics.
Patients and Methods: Transient otoacoustic emission (TEOAEs) were obtained from eighty subjects (160 ears)-males and females aged (10-20 years), with Forty (40) subjects in Baghdad audiology center and forty subjects in Sulaimania audiology center (North of Iraq)[ Kurdistan-Iraq], in standard, non-linear “Fast Screen” mode. Hearing thresholds, tympanometric, and TEOAE-parameters were recorded between two clinical center groups.
Results: The cross correlation (

This paper presents an investigation to the effect of the forming speed on healing voids that inhabit at various size in an ingot. The study was performed by using finite element method with bilinear isotropic material option, circular type voids were considered. The closure index was able to predict the minimum press force necessary to consolidate voids and the reduction. The simulation was carried out, on circular cross-section lead specials containing a central void of different size. At a time with a flat die, different ratio of inside to outside radius was taken with different speed to find the best result of void closure.