An Najaf al Ashraf, Iraq
An Najaf al Ashraf, Iraq

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Jaber H.L.,University of Thi-Qar | Pouranvari M.,Sharif University of Technology | Salim R.K.,Technical Institute | Hashim F.A.,University of Technology, Iraq | Marashi S.P.H.,Amirkabir University of Technology
Ironmaking and Steelmaking | Year: 2016

The paper aims at investigating the microstructure, failure mode transition, peak load and energy absorption of DP600 dual phase steel during the tensile-shear test. It was found that the welding current has profound effect on the load–displacement characteristics. In the low welding current, welds failed in interfacial failure mode. Increasing welding current resulted in sufficient weld nugget growth to promote double-sided pullout failure mode with improved mechanical properties. Further increase in the welding current caused expulsion and failure mode was changed to single-sided pullout with reduced energy absorption capability. It was found that the fusion zone size is the key parameter controlling the mechanical properties of DP600 resistance spot welds in terms of peak load, maximum displacement and failure energy. © 2016 Institute of Materials, Minerals and Mining

Goudarzian N.,Islamic Azad University at Shiraz | Gholinejad M.,Shiraz University | Ghahramani P.,Technical Institute
Journal of Chemical Sciences | Year: 2011

In this report, Suzuki-Miyaura coupling reaction was performed in the presence of polyethyleneimine (PEI) as ligand, NiCl2·6H 2O and K2CO3 in ethylene glycol at 80-100°C under phosphinefree conditions. By this method, structurally different aryl bromides and iodides were reacted with phenylboronic acid and potassium phenyltrifluoroborate. Under these simple reaction conditions a different iaryl derivatives have been prepared in high to excellent yields. Recycling experiments showed that catalyst can be used as recyclable catalyst in the Suzuki-Miyaura cross-coupling reactions. © Indian Academy of Sciences.

Dudziak M.,Technical Institute | Domek G.,Kazimierz Wielki University in Bydgoszcz | Kolodziej A.,Technical Institute
Procedia Engineering | Year: 2016

During designing the profiles of construction elements are defined as a perfect shape of line, circle or cylinder etc. Due to the production process the elements macrogeometry can be distorted in many ways. The direct measure of deviation of the real shape of a part from its nominal shape (the designed one) is a form deviation. If any additional restrictions concerning form deviations are not given in a production drawing, then the influence of these form deviations should be taken into account in allowable area of dimensions variation which is defined with tolerance zone. High values of rectilinearity deviations of a generating line, roundness deviations and cylindricity deviations can be a reason of changes of the assumed functional requirements. On the basis of saddleback shafts with oval cross-sections manufactured in three accuracy classes, i.e. IT4, IT6 and IT9, the authors have presented the variation of static parameters of cooperation. The shafts were coupled with sleeves (with a nominal circular cross-section) on experimental test stand. The obtained values of friction forces and moments of friction which are necessary to disassemble the connection were compared with the results of FEM numerical analyses. The applied method also allowed to determine the values of contact pressures in a connection. © 2016 The Authors.

Dudziak M.,Technical Institute | Dudziak M.,Poznan University of Technology | Domek G.,Kazimierz Wielki University in Bydgoszcz | Kolodziej A.,Technical Institute | Talaska K.,Poznan University of Technology
Procedia Engineering | Year: 2014

The actual state of the macrogeometry of the surfaces of mating elements, particularly form deviations, has a direct influence on constructional features and the functionality of the connections which are applied in mechanical engineering. The authors made an attempt to assess the influence of radial deviations, cross-section deviations and their compilations on the occurrence of the variable values of local stresses and displacements which are caused by the limited contact zone in the connection. The contact problems are represented on the example of the numerical simulation of the contact between rigid and non-deformable hub and the shaft with a three-angular cross-section and a saddleback distortion for different angular positions of the shaft. The authors have proved the occurrence of variable relative stresses and contact pressures. The authors have also showed the convergence of the calculated values of the forces and moments which are needed to move and rotate the shaft in the hub with the values obtained during the experimental investigations which were preformed in advance. © 2014 The Authors.

Cyklis P.,Cracow University of Technology | Cyklis P.,Technical Institute | Janisz K.,Technical Institute
Chemical and Process Engineering - Inzynieria Chemiczna i Procesowa | Year: 2015

Searching for new refrigerants is one of the most significant scientific problems in refrigeration. There are ecological refrigerants commonly known: H2O and CO2. H2O and CO2 known as natural refrigerants, but they hav e problems: a high freezing point of H2O and a low tripl e point of CO2. T hese problems can be solved by the application of a hybrid sorption-compression refrigeration cycle. The cycle combines the application possibility of H2O in the high temperature sorption stage and the low tempera ture applica tion of CO2 in the compre ssion stage. T his solution gives signific ant energy sa vings in comparison with the two-stage compressor cycle and with the one-stage transcri tic al CO2 cycle. Besides, the sorption cycle may be powered by low temperature waste heat or renewable heat. This is an original idea of the authors. In the paper an analysis of the possible extension of this solution for high capacity industrial refrigeration is presented. The estimated energy savings as well as TEWI (Total Equivalent Warming Impact) index for ecological gains are calculated.

Budzik G.,Rzeszow University of Technology | Cygnar M.,Technical Institute | Marciniak-Podsadna L.,Poznan University of Technology | Grzelka M.,Poznan University of Technology | And 2 more authors.
Tehnicki Vjesnik | Year: 2014

The article presents simulation researches on the combustion process in the four-cylinder testing engine, based on the spark ignition engine Toyota Yaris 1,3 dm3 which was equipped with two systems of power supply i.e.: fundamental and ignition. Two methods of initiating the combustion process were applied: by spark ignition and, after it was turned off, by means of the ignition dose injection. The researches aimed at revealing the differences in the combustion process and engine performance, above all the changes in pressure that occurred in the cylinder for that kind of two-fuel power supply of the engine. The ignition dose injected into the cylinder was equal to about 5 ÷ 8% of the general mass of the fuel supplied to the engine. The mass of the fuel injected into the approach collector determined the remaining part, and the direct injection of the fuel took place over several dozen of rotation degrees of the crankshaft before TDC (Top Dead Centre). A spatial grid of the engine's model (pre-processor) was prepared, and also a modification to the source KIVA 3V program was made consisting in taking into account of two systems of injection. It is necessary to mention that the standard KIVA 3V program contains, as a default, only one source of fuel injection.

Yahya L.S.,Technical Institute | Saleem T.M.,University of Mosul | Hasan B.M.,University of Mosul
Journal of Engineering and Applied Sciences | Year: 2012

In this study, neuro based intelligent methods for electrical motors'sound recognition system are proposed. The sound signals were used to recognize the loads speed and fault diagnosis of the motors. The sound signals were processed by two separate methods, the FFT and Discrete Wavelet Transform (DWT). The results of both methods were compared to obtain the most suitable of them. © Medwell Journals, 2012.

Bazarov V.V.,Technical Institute | Togulev P.N.,Technical Institute | Nizamov F.A.,Technical Institute | Lyadov N.M.,Technical Institute | And 2 more authors.
Solid State Phenomena | Year: 2015

Microwave absorption histeresis is measured in superconducting composites, prepared from MgB2, carbon nanotubes, graphene particles and iron nanoparticles. Iron nanoparticles were synthesized using of isopropanol in the supercritical fluid state. Measurements showed that the greatest increase in the pinning force is observed in the “MgB2 - (CNT-α-Fe)” composite. © (2015) Trans Tech Publications, Switzerland.

Du X.,Technical Institute
International Journal of Applied Environmental Sciences | Year: 2013

This paper based on the previous findings, orthogonally compounds three inhibitors of cerium chloride, lanthanum chloride and 8-hydroxyquinoline to study the corrosion inhibition effect of compound corrosion inhibitor on 2024 aluminum alloy for crevice corrosion in seawater. It can determine the optimal compound corrosion inhibitor formulations by observations on corrosion morphology and chemical immersion, polarization curve fitting, AC impedance as well as x-EDS analysis, and then analyzes its synergistic effect and inhibition mechanism. The results show that inhibition rate of compound corrosion inhibitor is better than single inhibitor. When the concentration of matching cerium chloride, lanthanum chloride and 8-hydroxyquinoline is respectively 1.0g/L, 1.5g/Land 0.02g/L, the rate is the highest reaching 90.52% and the crevice corrosion sensitivity is greatly reduced. This is because the adsorption of 8-hydroxyquinoline which can adsorb in areas of weaker cerium and lanthanum corrosion scales, allowing uniform and close scale, further enhancing the performance of anticorrosion of aluminum. Therefore, this compound corrosion inhibitor has a broad applicability which can be used by aluminum in seawater as corrosion inhibitor. © Research India Publications.

Al-Obaidi F.A.,University of Baghdad | Al-Shadeedi S.M.J.,University of Baghdad | Al-Dalawi R.H.,Technical Institute
International Journal of Poultry Science | Year: 2011

The objective of this study was to determine the shelf life of marketed table eggs in some retail stores of Baghdad city through determination some quality, chemical and microbial characteristics of the eggs. A total of 1680 chicken eggs (10 eggs were locally produced and 10 eggs were imported) were collected biweekly from retail stores in different seven popular regions of Baghdad city during the period from January 14th to July 15th of 2010. The data obtained revealed that locally produced eggs had lower egg weight, albumen weight and albumen height and higher albumen and yolk pH compared with imported, also Psychrophilic, Coliform, Staphylococci and Fungi counts were high in locally produced eggs compared with imported. No significant differences between locally and imported eggs chemical composition except moisture which was significantly (p<0.05) higher in imported eggs. The total percentage of the incidence of Salmonella in table eggs at retail stores in Baghdad were 20.0% and 38.7% for locally and imported eggs respectively. This survey showed that marketed table eggs in retail stores of Baghdad city were of good quality and within the Iraq standard specification for eggs and where fit for consumption as shell eggs. © Asian Network for Scientific Information, 2011.

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