Preferred Language
Articles
/
pxYwPogBVTCNdQwC2XUL
Hydrodesulfurization of Thiophene over $γ$-Mo2N catalyst
...Show More Authors

Catalytic removal of the S-content from thiophene is a central step in efforts aiming to reduce the environmental burdens of transportation fuels. In this contribution, we investigate the hydrodesulfurization (HDS) mechanisms of thiophene (C4H4S) over γ-Mo2N catalyst by means of density functional theory (DFT) calculations. The thiophene molecule preferentially adsorbs in a flat mode over 3-fold fcc nitrogen hollow sites. The HDS mechanism may potentially proceed either unimolecularly (direct desulfurization) or via H-assisted reactions (hydrogenation). Due to a sizable activation barrier required for the first Csingle bondS bond scission of 54.6 kcal/mol, we predict that the direct desulfurization to contribute rather very insignificantly in the HDS mechanism. Transfer of adsorbed hydrogen atoms on the γ-Mo2N surface to the thiophene ring substantially reduces activation barrier required in the Csingle bondS bond scission to only 24.1 kcal/mol in a process that affords an adsorbed C4H6* species and an S atom. Further hydrogenation of the unsaturated C4H6* produces 2-butene. Kinetics and thermodynamics attributes dictate the occurrence of partial rather than full hydrogenation of C4H6*. Calculated rate constants for all individual steps could be utilized to construct a robust kinetic model for the overall HDS process. Estimated conversion values of thiophene predict 50–70% consumption of thiophene at 700 K and low values of gas hourly space velocities. Reaction routes and kinetic parameters provided herein are useful to design stand-alone γ-Mo2N-based catalysts for applications entailing partial hydrogenation and hydrodesulfurization of severely contaminated S-fuels.

Publication Date
Thu Oct 01 2015
Journal Name
International Journal Of Engineering And Advanced Technology (ijeat)
Optimization Process Parameters of Submerged Arc Welding Using Taguchi Method
...Show More Authors

Submerged arc welding (SAW) process is an essential metal joining processes in industry. The quality of weld is a very important working aspect for the manufacturing and construction industries, the challenges are made optimal process environment. Design of experimental using Taguchi method (L9 orthogonal array (OA)) considering three SAW parameter are (welding current, arc voltage and welding speed) and three levels (300-350-400 Amp. , 32-36-40 V and 26-28-30 cm/min). The study was done on SAW process parameters on the mechanical properties of steel type comply with (ASTM A516 grade 70). Signal to Noise ratio (S/N) was computed to calculate the optimal process parameters. Percentage contributions of each parameter are validated by using an

... Show More
View Publication Preview PDF
Publication Date
Tue Dec 01 2009
Journal Name
Iraqi Journal Of Physics
Analytical Performance Modeling of InP-InGaAs Hetero-junction Avalanche Photodiode
...Show More Authors

In this study, an analytical model depending on experimental results for InPInGaAs
avalanche photodiode at low bias was presented and the characteristics of
gain for this photodiode were determined directly by the impulse response. The
model have considered the most important mechanisms contributing the
photocurrent, they are trapping, photogeneration in the undepleted region and
charge-carriers velocity due to the built-in electrical field. Also, the bandwidth
was determined as a function to the total gain of photodiode and it was mainly
determined by diffusion and trapping processes at low gain regarding to the multilayer
structure considered in this study

View Publication Preview PDF
Publication Date
Tue Sep 01 2020
Journal Name
Al-khwarizmi Engineering Journal
Arduino-Based Controller for Sequence Development of Automated Manufacturing System
...Show More Authors

It has become necessary to change from a traditional system to an automated system in production processes, because it has high advantages. The most important of them is improving and increasing production. But there is still a need to improve and develop the work of these systems.

The objective of this work is to study time reduction by combining multiple sequences of operations into one process. To carry out this work, the pneumatic system is designed to decrease\ increase the time of the sequence that performs a pick and place process through optimizing the sequences based on the obstacle dimensions. Three axes are represented using pneumatic cylinders that move according to the sequence used. The system is implemented and con

... Show More
View Publication Preview PDF
Crossref (5)
Crossref
Publication Date
Thu Jun 15 2017
Journal Name
مجلة العلوم الاجتماعية
Self-compassion among university students in light of some variables
...Show More Authors

The study aimed to identify the self- compassion of the students as well as to identify the differences in the self- compassion according to the variables: sex - the academic specialization - Study level, the sample of the study of (200) students distributed equally by sex (male - female) Specialization (Scientific - Human) compassion. The results showed that there were no differences in the self- compassion according to the variables: gender, academic specialization, and Study level. In light of these results, the researcher Number of the recommendations and proposals

View Publication
Publication Date
Mon Mar 11 2019
Journal Name
Baghdad Science Journal
Properties of Fuzzy Compact Linear Operators on Fuzzy Normed Spaces
...Show More Authors

In this paper the definition of fuzzy normed space is recalled and its basic properties. Then the definition of fuzzy compact operator from fuzzy normed space into another fuzzy normed space is introduced after that the proof of an operator is fuzzy compact if and only if the image of any fuzzy bounded sequence contains a convergent subsequence is given. At this point the basic properties of the vector space FC(V,U)of all fuzzy compact linear operators are investigated such as when U is complete and the sequence ( ) of fuzzy compact operators converges to an operator T then T must be fuzzy compact. Furthermore we see that when T is a fuzzy compact operator and S is a fuzzy bounded operator then the composition TS and ST are fuzzy compact

... Show More
View Publication Preview PDF
Scopus (13)
Crossref (6)
Scopus Clarivate Crossref
Publication Date
Tue Jun 15 2021
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
The Pathological Mechanisms of Obesity-Related Glomerulopathy: A review article
...Show More Authors

The rising prevalence of obesity-related glomerulopathy (ORG) occurs in accordance with the rising prevalence of obesity worldwide. Clinically ORG is manifested by slowly progressing microalbuminuria that may develop to clinically evident proteinuria. Pathological characteristics of ORG include glomerular hypertrophy in the presence or absence of focal segmental glomerulosclerosis (FSGS). ORG can develop into clinically overt chronic renal insufficiency or even end-stage kidney disease. This article reviews the most important mechanisms for the development of ORG; that are abnormal renal hemodynamics, stimulation of renin-angiotensin-aldosterone system (RAAS), impairment of insulin sensetivity, ectopic lipid deposition, adipose tissue cy

... Show More
View Publication Preview PDF
Scopus (4)
Scopus Crossref
Publication Date
Fri Mar 01 2019
Journal Name
Al-khwarizmi Engineering Journal
Performance Estimation of Heat Exchanger Operates By Evaporative Cooling Manner
...Show More Authors

        In this study the design and installation of evaporative air cooler was carried out using completely outdoor air (fresh air) according to two stage evaporative cooling principle. The laboratory equipment was installed by designing and manufacturing a cross flow plate heat exchanger, where aluminum plates used for this purpose with dimensions (50 × 30 × 40 cm). The surfaces of heat exchanger were covered by sawdust from wetted channels side, to increase the percentage of wetting these surfaces and hence improve the performance and efficiency of air cooler.

        An experimental study was carried out to estimate the performance of cooling system, where som

... Show More
View Publication Preview PDF
Publication Date
Wed Aug 13 2025
Journal Name
Journal Of Baghdad College Of Dentistry
Evaluation of a new orthodontic bonding system (Beauty Ortho Bond)
...Show More Authors

Background: The purpose of the current study was to evaluate the efficacy of a new orthodontic bonding system (Beauty Ortho Bond) involving the shear bond strength in dry and wet environments, and adhesion remnant index (ARI) scores evaluation in regard to other bonding systems (Heliosit and Resilience Orthodontic Adhesives). Materials and methods: Sixty defect free extracted premolars were randomly divided into six groups of 10 teeth each, mounted in acrylic resin, three groups for a dry environment and three for a wet one. Shear bond strength test was performed with a cross head speed of 0.5 mm/min, while surfaces of enamel and bracket-adhesive-enamel surfaces were examined with stereomicroscope For ARI scores evaluation. Data were analyz

... Show More
View Publication Preview PDF
Publication Date
Tue Oct 02 2018
Journal Name
Iraqi Journal Of Physics
Synthesis and characterization of carbon nanospheres by catalytic CVD method
...Show More Authors

Carbon nanospheres (CNSs) were successfully prepared and synthesized by Catalytic Chemical Vapor Deposition (CCVD) by using camphor as carbon source only, over iron Cobalt (Fe-Co) saturated zeolite at temperature between (700 oC and 900 °C), with different concentrations of camphor, and reaction time. The synthesized CNSs were characterized using Scanning Electron Microscopy (SEM), X-ray diffraction spectroscopy (XRD), and Fourier Transform Infrared (FTIR). The carbon spheres in different sizes between 100 nm and 1000 nm were investigated. This work has done by two parts, first preparation of the metallic catalyst and second part formation CNSs by heat treatment.

View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Wed Mar 30 2022
Journal Name
College Of Islamic Sciences
The rule of need relegates to necessity controls and applications
...Show More Authors

Summary
This research is included in the study of one of the most important rules of jurisprudence, which is (necessity descends the status of necessity, controls and applications) branching from the major rule (hardship brings facilitation) and since the jurisprudential rule is defined as knowledge of a total or majority rule that applies to all its parts. He has to know all the branches that fall under him, which leads to understanding Sharia, controlling jurisprudential issues and linking them to its rules, so that no contradiction occurs, and he has the jurisprudential faculty that he promotes in consideration and diligence. And what is meant by need: is what is lacking in terms of expansion and raising the distress that often lea

... Show More
View Publication Preview PDF
Crossref