The results of theoretical and experimental investigations carried out to study the effect of load and relative sliding speed on the abrasive wear behavior in drilling bit teeth surfaces of an insert tungsten carbide bit have been presented. Experimentally, an apparatus for abrasive wear tests conducted on the modified ASTM-G65 was modified and fabricated to facilitate loading and measurement of wear rate for the sand/ steel wheel abrasion test, which involves two cases of contact; first is at dry sand and second is under wet condition. These tests have been carried under varied operating parameters of normal load and sliding speed. A theoretical model based upon the Archard equation has been developed for predicting wear simulation by u

The physicochemical behaviour of dodecyltrimethylammonium bromide (DTAB) in water and ethanol-water mixture in the presence and absence of ZnSO₄ were studied by measuring the conductivity at 298.15 K. The pre-micellar (S₁) and post-micellar slopes (S₂) were obtained and calculated the degree of dissociation (α) and the critical micelle concentration (cmc). With an increase in ethanol content, the cmc and α of DTAB increased whereas, in the presence of ZnSO₄, the cmc and α decreased. By using cmc and α, thermodynamic properties as the standard free energy of micellization ( ) were evaluated. With an increase in ethanol content, the negative values of  are decreased indicating less spont

The present work aimed to study the efficiency of nanofiltration (NF) and reverse osmosis (RO) membrane for heavy metal removal from wastewater and study the factors affecting the performance of these two membranes: feed concentrations for heavy metal ions, pressure, and flow rate. The experimental results showed, heavy metals concentration in permeate increase with raise in feed concentrations, decline with increase in flow rate. The raise of pressure, heavy metals concentration decreases for RO membrane, but for NF membrane the concentration decrease and then at high pressure increase. The rejection percentage for chromium in NF and RO is 99.7% and 99.9%, for copper is 98.4% and 99.3%, for zinc is 97.9% and 99.5%, for nickel is 97.2% and

Abstract

Theoretical and experimental methodologies were assessed to test curved beam made of layered   composite material. The maximum stress and maximum deflection were computed for each layer and the effect of radius of curvature and curve shape on them. Because of the increase of the use of composite materials in aircraft structures and the renewed interest in these types of problems, the presented theoretical assessment was made using three different approaches: curved beam theory and an approximate 2D strength of material equations and finite element method (FEM) analysis by ANSYS 14.5 program for twelve cases of multi-layered cylindrical shell panel differs in fibe

This study was carried out to evaluate parasitological and immunological of the effect of chitosan and chitosannanoparticles loaded with spiramycin on toxoplasmosis infected mice. After injection intra peritoneal with 103viable tachyzoites for acute infection, treatments given for seven days. Peritoneal fluid examination revealed a significant decrease in the number of Toxoplasmagondiitachyzoites in all treated infected mice compared with infected non-treated. The combined therapy gave better results than single. The best effect was observed in group of mice treated with spiramycin combined with chitosan nanoparticles. Also immunoglobulin Ig Manti body and gamma Interferon (INFγ), Tumor Necrosis Factor alpha (TNF-α) cytokines responses ag

Abstract: Background: Tribuls terrestris increases levels of various hormones in steroid family including testosterone, DEHA, and estrogen and for this reason improves sport performance, fertility in men and women, sexual function in men and women. There is, at present, lack of scientific confirmation of these supposed benefits. Therefore, this study aims to investigate the possible effect(s) of Tribuls terrestris on the mouse ovarian morphology and function, alone and in combination with other ovulation modulator agent (clomiphene citrate). Materials & Methods: A total of 49 sexually mature healthy Norway albino female mice were used in this study; 25 for pilot study and 24 for the experimental study. Experimental animals were divided

In this research Bi2S3 thin films have been prepared on glass substrates using chemical spray pyrolysis method at substrate temperature (300oC) and molarity (0.015) mol. Structural and optical properties of the thin films above have been studied; XRD analysis demonstrated that the Bi2S3 films are polycrystalline with (031) orientation and with Orthorhombic structure. The optical properties were studied using the spectral of the absorbance and transmission of films in wavelength ranging (300-1100) nm. The study showed that the films have high transmission within the range of the visible spectrum. Also absorption coefficient, extinction coefficient and the optical energy gap (Eg) was calculated, found that the film have direct ener

Water pollution has created a critical threat to the environment.‎‎ A lot of research has been done ‎recently to use surface-enhanced Raman spectroscopy (SERS) to detect multiple pollutants in water. This study aims to use Ag colloid nanoflowers as liquid SERS enhancer. Tri sodium phosphate (Na₃PO₄) was investigated as a pollutant using liquid SERS ‎based on colloidal Ag ‎nanoflowers. The chemical method was used to synthesize nanoflowers from silver ‎ions. Atomic Force Microscope (AFM), Scanning Electron Microscope (SEM), and X-ray diffractometer (XRD) were employed to characterize the silver nanoflowers. This ‎nanoflowers SERS action in detecting Na₃PO₄ was reported and analyzed

the pursue of social  systems history present to us solid evidence that the collapse of  that systems be caused by either the stagnancy aftermath maturity or unreal intellectual foundation which lead to sudden collapse, while the capitalism can avoided that intellectual damages due to its dynamic system with appropriate  auto adaptation mechanism and use it excellently in the right time.

The globalization had excrete (as one of the capitalism adaptation mechanism) its own targets and its methods in framework of multinationals corporations which consist with capitalism states that employed the international organizations to reconstruction the global economy to serve such targets. So the glob