In this work, HgBa2CaCu2-xSbxO8+δ compounds with (x = 0.2, 0.4, 0.6 and 0.8) have been prepared by the solid-state reaction method. Structural, morphological, and electrical properties were investigated using X-ray diffraction (XRD) and scanning electron microscope (SEM) techniques. Using the 4-probe technique to study the effect of antimony-substitution for Copper on the electrical properties of HgBa2CaCu2-xSbxO8+δ (Hg-1212) phase was investigated by measuring the resistivity as a function of temperature. Results indicate that the addition of antimony (Sb) increases the volume fraction of the phase and changes the superconducting transition temperature Tc of the superconductor to a normal state. The dielectric loss factor and ac conductivity have been investigated at room temperature. It was found that dielectric properties decreased with increasing electric field frequency. It was observed that the best value was 0.8 of the Sb content. Generally, with increasing antimony content, at lower frequencies, higher dielectric criteria are achieved, while at higher frequencies, lower dielectric criteria are achieved. On the other hand, the dissipation of the energy in the dielectric is directly proportional to the dielectric loss factor. Considering this, the increase in the values of ac conductivity is increasing with an increased frequency range to 5 MHz.
Abstract Twelve isolates of bacteria were obtained from samples of different soils and water amended with 100µg/ml of five heavy metals chlorides (i.e: Aluminum Al+2, Iron Fe+2, Lead Pb+2, Mercury Hg+2 and Zinc Zn+2). Four isolates were identified as Bacillus subtilis and B. subtilis (B2) isolate was selected for this study according to their resistance to all five heavy metals chlorides. The ability of B. subtilis (B2) isolate for growing in different concentration of heavy metals chlorides ranging from 200-1200 µg/ml was tested. The highest conc. that B. subtilis (B2) isolate tolerate was 1000 µg/ml for Al+2, Fe+2, Pb+2, and Zn+2and 300 µg/ml for Hg+2 for 24hour. The effect of heavy metals chlorides on bacterial growth for 72 hrs was
... Show MoreBackground: Dietary intakes are critical during pregnancy, because inadequate amounts of key nutrients may compromise fetal development or maternal health. In addition to that maternal diet could be one of the methods to select the gender of the baby. The aim of the study is to correlate the level of the minerals in the mother’s blood with the gender and wellbeing of the baby after delivery.Patients and Methods: Fifty women were involved in this study with a mean age (23.92 ± 4.75), collected from the labor room during labor in the period between December 2013 and May 2014, in Baghdad teaching hospital. After taking a full history from the women, 10 ml of blood was withdrawn from them, 2ml in EDTA tubes for lead estimation and 8 ml in pl
... Show MoreThis work presents the study of the dark current density and the capacitance for porous silicon prepared by photo-electrochemical etching for n-type silicon with laser power density of 10mw/cm2 and wavelength (650nm) under different anodization time (30,40,50,60) minute. The results obtained from this study shows different chara that different characteristic of porous diffecteristics for the different porous Silicon layers.
Thin films samples of Bismuth sulfide Bi2S3 had deposited on
glass substrate using thermal evaporation method by chemical
method under vacuum of 10-5 Toor. XRD and AFM were used to
check the structure and morphology of the Bi2S3 thin films. The
results showed that the films with law thickness <700 nm were free
from any diffraction peaks refer to amorphous structure while films
with thickness≥700 nm was polycrystalline. The roughness decreases
while average grain size increases with the increase of thickness. The
A.C conductivity as function of frequency had studied in the
frequency range (50 to 5x106 Hz). The dielectric constant,
polarizability showed significant dependence upon the variation of
thic
In current research Copper was employed for preparing a ternary system of Al–Si alloy in different (0.2–2.5 wt. %) the best was taken is (1.5%wt) of copper that circumstances of solidification for improving the mechanical performance of the available in aluminium alloy. Cast iron molds were prepared to obtain tensile strength testing specimens. Alloys were prepared by employing gas furnaces. The molten metal was poured into a preheated cast-iron mold. The obtained alloy structures were studied using an X-ray diffractometer and optical microscopy. The mechanical performance of the prepared alloys was examined under the influence of different hardening conditions in both heat and non-heat-treated conditions. The outcomes showed at the
... Show MoreThe current work studies the effect of adding chopped carbon fiber (CCF) on gypsum plaster properties (precisely the compressive strength and the modulus of rupture). The research plan consists of using six mixes of gypsum plaster; these mixes are divided into two groups according to the (Water/Gypsum) ratios (0.5 & 0.6). Each group was divided into three subgroups according to CCF volume fraction (Vf): 0.0%, 0.2% and 0.4%. Three cubic (50×50×50) mm and three prismatic (40×40×160) mm samples were performed for each mix. It was found that, the addition of CCF to the gypsum plaster mixes increases both the compressive strength and the modulus of rupture for both (W/G) ratios, an
Using photo electrochemical etching technique (PEC), porous silicon (PS) layers were produced on n-type silicon (Si) wafers to generate porous silicon for n-type with an orientation of (111) The results of etching time were investigated at: (5,10,15 min). X-ray diffraction experiments revealed differences between the surface of the sample sheet and the synthesized porous silicon. The largest crystal size is (30 nm) and the lowest crystal size is (28.6 nm) The analysis of Atomic Force Microscopy (AFM) and Field Emission Scanning Electron Microscope (FESEM) were used to research the morphology of porous silicon layer. As etching time increased, AFM findings showed that root mean square (RMS) of roughness and po
... Show MoreBackground: The aim of this study was to evaluate the effect of three types of light curing devices QTH, LED and Flashmax on the surface microhardness of three types of bulkfill composite resins; Filtek Bulkfill posterior composite ( 3M), Tetric Evo Ceram ( Ivoclar Vivadent) and Sonicfill composite ( Kerr) Materials and methods: Total number of 90 samples was prepared, 30 samples for each type of bulkfill composite, were divided into three main groups, group A: Filtek posterior bulkfil (3M), group B: Tetric Evo Ceram (Ivoclar Vivadent) and group C: contain Sonicfill composite (kerr). Which then divided into three subgroups (n= 10) (1) Samples cured by QTH system (2) Samples cured by LED system and (3) samples cured by Flashmax system the
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