Fertility Indices of Rats in Response to Dehydroepiandrosterone (DHEA) Administration

The aim of the present study is to evaluate the effect of oral administration of DHEA on fertility indices in female rats. A total of 18 adult female rats 2.5-3.5 months old and weighting 200-250g were divided into three equal groups: G1-control received saline solution, G2- received 2mg DHEA /kg B.Wt orally and daily for 2 weeks prior to gestation. G3- received the same dose for two weeks prior and during gestation. The was a significant increase in fertility, gestation indeces of rats received DHEA for two weeks prior and during gestation. At the meantime, the gestation length, viability and lactating indeces were decreased in this group as compared with others. In conclusion, administration of DHEA at dose of 2 mg /kg B.Wt for 2 weeks prior to and during gestation seems to be safe as no abortion and fetal abnormalities were recorded. Keywords: DHEA, Fertility indeces, rats

Antibiotic resistance pattern of HA-MRSA strains isolated from leukemia patients in Baghdad, Iraq

Digitalitzat per Artypla

Effect of etching time on optical and morphological features of N-type porous silicon prepared by photo-electrochemical method

Achieving efficient visible photoluminescence from porous-silicon (PSi) is demanding for optoelectronic and solar cells applications. Improving the absorption and emission features of PSi is challenging. Photo-electro-chemical etching assisted formation of PSi layers on n-type (111) silicon (Si) wafers is reported. Samples are prepared at constant current density (~30 mA/cm2) under varying etching times of 10, 15, 20, 25, and 30 min. The influence of etching time duration on the growth morphology and spectral properties are inspected. Room temperature photoluminescence (PL) measurement is performed to determine the optical properties of as-synthesized samples. Sample morphologies are imaged via Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). The thickness and porosity of the prepared samples are estimated using the gravimetric method. The emission and absorption data is further used to determine the samples band gap and electronic structure properties. Results and analyzed, interpreted with different mechanisms and compared

THE EFFECT OF VARIATION OF NONLINEAR LOAD ON POWER FACTOR OF THE AC SUPPLY NETWORK

The aim of this paper is to evaluate the effect of the converter system on the power factor of the supply network .Therefore a 3-phase, 6-pulse , bridge converter is assembled and connected to a power supply through a 3-phase ac voltage regulator .The theoretical analysis is simulated using Fourier series analysis and Fast Fourier Transform ( FFT ) algorithm . The experimental measurements of distortion factor , displacement factor and total power factor are recorded . The experimental results are shown to be coincident with the theoretical results. The consideration of power factor improvement relative to distortion and displacement factors is discussed

Optimization of gold and silver nanoparticles production by laser ablation in deionized water

Colloidal solutions of gold and silver nanoparticles (NPs) were synthesized using a Q-switched Nd:YAG laser (1064 nm, 6 ns, 1 Hz ) ablation. Gold and silver bars were immersed in deionized water and irradiated by laser pulses for 4 min. The laser fluence was verified within the range of 21 – 39 J/cm2 with a fixed beam diameter of 1.6 mm. The effect of laser pulse fluence on both size and ablation efficiency of gold and silver nanoparticles were studied. The optical spectral characterization and morphological analysis of these nanoparticles were carried out by UV-Vis spectrophotometer and transmission electron microscopy (TEM), respectively. The average particle size for Au and Ag are 38.0 ± 10.3 nm and 31.3 ± 10.5 nm at corresponding optimized laser fluence of 31 and 25 Jcm-2 respectively

Facile hydrothermal synthesis of flowerlike ZnOnanorods without catalysts

A very simple hydrothermal method (one step) was used at low temperature to synthesis flower-like ZnOnanorods on glass substrate without any template, catalyst or buffer layer before the reaction. Flower-like ZnOnanorods were synthesized by hydrothermally heating 0.1 M precursor solution of hexahedral zinc nitrate Zn(NO3)2.6H2O, hexamethylenetetramine (HMT) and NaOH were the starting materials for the chemical reaction under stirring. The field emission scanning electron microscopy (FE-SEM) images showed that the flower-like structures were formed in 3.5 h hydrothermally-heated for sample, whereas the experimental pattern of the films by X-ray diffraction show that diffraction peaks can be assigned to the wurtzite hexagonal-shaped ZnO as shown in the (FE-SEM) images, also the morphology of the films studied by atomic force microscope (AFM) shows that the films have high roughness. The energy gap was estimated and optical behavior was investigate

Surface plasmon resonance effects of gold colloids on optical properties of N719 dye in ethanol

In this work, the light absorption and emission effects of gold nanoparticles on some optical properties of N719 dye solution were studied via transmission electron microscopy, UV-vis absorption, and photoluminescence spectroscopy measurements. A facile method to fabricate four gold colloidal solutions with different concentrations containing ~15 nm gold nanoparticles was presented through pulsed laser ablation of a gold target immersed in ethanol, followed by a post-ablated size modification process. As-prepared gold colloids with different concentrations were mixed with certain dye solution. The absorption and fluorescence enhancement that resulted from the interaction between the dipole moments of the day and the surface plasmon resonance of gold nanoparticles were found to be strongly dependent on the gold colloid concentration. Fluorescence was enhanced by around 9-fold, which was achieved for the dye solution with the highest gold nanoparticles concentration

Photo-electrochemically synthesized light emtting nanoporous silicon based UV photodetector: influence of current density

Nanoporous silicon (n-PSi) with diverse morphologies was prepared on silicon (Si) substrate via photo-electrochemical etching technique. The role of changing current density (15, 30 and 45 mA cm−2) on the structure, morphology and optical properties was determined. As-prepared samples were systematically characterized using XRD, FESEM, AFM and photoluminescence measurements. Furthermore, the achieved n-PSi sample was used to make metal–semiconductor–metal (MSM) UV photodetector. The performance of these photodetectors was evaluated upon exposing to visible light of wavelength 530 nm (power density 1.55 mW cm−2), which exhibited very high sensitivity of 150.26 with a low dark current. The achieved internal photoconductive gain was 2.50, the photoresponse peak was 1.23 A W−1 and the response time was 0.49 s and the recovery time was 0.47 s. Excellent attributes of the fabricated photodetectors suggest that the present approach may provide a cost effective and simple way to obtain n-PSi suitable for sundry applications

Photophysical performance of radio frequency sputtered Pt/n-PSi/ZnO NCs/Pt photovoltaic photodetectors

The effect of the annealing temperature on the photoelectrical properties of the nanoporous silicon/zinc oxide nanocrystallites-based (Pt/n-PSi/ZnO NCs/Pt) photodetector was investigated. Different morphologies of 3D ZnO were synthesized onto the n-PSi substrates via radio frequency (RF) sputtering in the absence of a catalyst. The synthesis of ZnO NCs was controlled by varying the growth temperature between 600–700 °C and 800–900 °C. The effect of the synthesis temperature on the structural, morphological, and optical properties of the n-PSi/ZnO NCs was systematically studied using field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), atomic force microscopy (AFM), and photoluminescence spectroscopy (PL) techniques. The roughness was found to be dependent on the anodization current density. The optimal n-PSi/ZnO NCs-based metal-semiconductor-metal UV detector (MSM) was fabricated at 700 °C. The fabricated device showed a high sensitivity of 1007.14, an internal photoconductive gain of 11.07, and a responsivity of 5.99 A/W with a low dark current when illuminated with 380 nm light (1.55 mW/cm2) at +5 V bias voltage. In addition, the response and recovery times were determined to be 0.34 and 0.22 s, respectively. This approach offers a cost-effective substrate and simple synthesis method to improve the growth of the n-PSi/ZnO NCs and demonstrates the successful fabrication of nanoscale photodetectors with potential application in nano-optics devices