In this study, the effect of ceramic coating on the performance and gases emission on diesel engine was investigated. A four-stroke, direct injected, single cylinder, diesel engine was tested at constant speed and at different load conditions without coating. Then, the inlet and exhaust valves faces were coated by about 500µm with ceramic materials. Ceramic layers were made of YttriaStabilized Zirconia (YSZ), and NiCrAl as a bond coat. The coating technique adapted in this work is the flame spray method. The engine with valves ceramiccoated research was tested for the same operation conditions of the engine (without coating). The results indicate a reduction in both fuel consumption by about 7.6% and particulate emissions by about (13

This research study the effect of Titanium dioxide on the tensile properties of
Polystyrene (PS) and Polycarbonate (PC) polymers. The stress – strain curve for pure PS
and pure PC, shows that Young modulus for PS is higher than Young modulus for PC,
because PS have higher ultimate strength than PC.
The addition of TiO2 to PS and PC will reduce the Young modulus and ultimate stress,
because the TiO2 particles will reduces or freeze the orientation of these molecular chain
and reduced the toughness of PC, while when the TiO2 were added to PS, the value of
toughness will be stabilized because TiO2 particles make these chains interlocked and the
mobility of the chains will be restrict.

 Thin  films   of  pure   tin mono-sulfide  SnS with thicknesses of   (0.85) μm  were prepared by chemical spray  pyrolysis  technique  and  annealed for  two  hours with 673K.The effect of annealing on structural and optical properties for films prepared was  studied.  X-Ray   diffraction  analysis  showed   the  polycrystalline  with   orthorhombic structure.  It was  found  that   annealing process increased the intensity of diffraction peaks. Optical   properties  of  all  samples  were studied by  recording  the  absorption  and  transmission &nbsp

This presented study is to make comparison of cross sections to produce 71As, 72As, 73As and 74As via different reactions with particle incident energy up to 60 MeV of alpha 100 MeV of proton as a part of systematic studies on particle-induced activations on enriched Ge, Ga, Rb and Nb targets and neutron capture. Theoretical calculation of production yield, and suggestion of optimum reaction to produce 71As, 72As, 73As and 74As, based on the main published and approved experimental results of excitation functions were calculated.

Background: Ideal root canal obturation depends on many factors; one of them is good sealing of root canal without pores. The aim of this study was to determine the radiographic density of GuttaFlow® 2 with different obturation techniques using spiral computed tomography. Materials and Methods: Forty palatal roots of permanent maxillary first molar were used in this study. Following working length determination, root canal was prepared using rotary PROTAPER universal system. They were randomly divided into four groups of 10 roots each, the groups are Conventional lateral condensation with Apexit Plus sealer, Conventional lateral condensation with GuttaFlow® 2 as a sealer, Soft Core Regular with GuttaFlow® 2 as a sealer and singl

 The behaviour of the electrical conductivity (σ) and the activation energies (Ea1, Ea2) have been investigated on a-InAs thin films as a function of thickness (250,350,450,550,650) nm, before and after heat treatment. The films were annealed at (373, 423, 473) K for one hour.          The films contain two types of transport mechanisms, and the electrical conductivity (σ) increases whereas the activation energy (Ea) would decrease as the films thickness increases.
 

The possible effects of COVID-19 vaccines on reproductive health and male fertility in particular have been discussed intensely by the scientific community and the public since their introduction during the pandemic. On news outlets and social media platforms, many claims have been raised regarding the deleterious effects of COVID-19 vaccines on sperm quality without scientific evidence. In response to this emerging conflict, we designed this study to evaluate and assess the effect of the Pfizer-BioNTech mRNA COVID-19 vaccine on male fertility represented by the semen analysis parameters.

    Text categorization refers to the process of grouping text or documents into classes or categories according to their content. Text categorization process consists of three phases which are: preprocessing, feature extraction and classification. In comparison to the English language, just few studies have been done to categorize and classify the Arabic language. For a variety of applications, such as text classification and clustering, Arabic text representation is a difficult task because Arabic language is noted for its richness, diversity, and complicated morphology. This paper presents a comprehensive analysis and a comparison for researchers in the last five years based on the dataset, year, algorithms and the accuracy th