The investigation of the effect of tempering on thermal analysis of
Al-Ti-Si alloy and its composites with MgO and SiC particles was
performed. Thermal analysis was performed before and after
tempering by DSC scan. Optical microscopy was used to identify the
phases and precipitations that may be formed in base alloy and
composites. X-ray diffraction test indicated that the Al3Ti is the main
phase in Al-Ti-Si alloy in addition to form Al5Ti7Si12 phase. Some
chemical reactions can be occurred between reinforcements and
matrix such as MgO.Al2O3 in Al-Ti/MgO, and Al4C3 and Al(OH)3 in
Al-Ti/SiC composite. X-ray florescence technique is used to
investigate the chemical composition of the fabricated specimens.
Heat treatment (Tempering) changes the microstructure of base alloy
and its composites which was assessed by DSC scan. Generally,
three main peaks appeared in DSC represented by GP zone, S phase
(precipitations) and dissolution of phases or precipitations. After
tempering, composite with SiC particles showed better results than
base alloy and composite with MgO. Since the optical microscopy
revealed reforming the stable phase Al3Ti with evaporation some
gases from composite. DSC analysis showed the stability of
composite with SiC was up to 270oC.
An energy and exergy thermodynamic analysis using EES program was done for a domestic refrigerator working with R-134a using vapor compression refrigeration cycle. The analysis deals with the system component, i.e. compressor, condenser, evaporator and the expansion device. The analysis depends on the entropy generation minimization approach to improve the refrigerator performance by exploring the optimum design points. These design points were derived from three different theories governing the entropy generation minimization using exergy analyzing method. These theories were first applied to find the optimum balance between the hot inner condenser area and the cold inner evaporator area of the refrigerator and between
... Show MoreBackground: This study designed to shade light on the important role of CBCT in accurate localization of the impacted maxillary canines. Materials and method: Fifty two unilateral and bilateral impacted maxillary canines from 30 patients (24 females and 6 males) were evaluated by a volumetric 3D images obtained from cone beam CT. All samples attended to the specialist health center of dentistry in Al-Sadder City referred to CBCT by oral surgeons or orthodontists to detect the exact position of impacted upper canine in cases when there was no bulging buccally or palatally which aids to detect the exact position. Results: Mesio-palatal angulations had the highest rate (63.5%) followed by mesio-labial (19.2%), vertical (labial) (9.6%), disto-p
... Show MoreThe study was performed to analyze the oropharynx airway and examine the influence of age and gender on the oropharynx volume configuration using cone beam computed tomography.
This study examined the cone beam computed tomographic images of 51 patients 25 male and 26 females, group matched for age and gender. The oropharynx airway volume and area between the posterior nasal spine and top of the epiglottis were measured and compared.
The major objectives of this research are to analyze the behavior of road embankments
reinforced with geotextiles constructed on soft soil and describe the finite element analysis by using
ANSYS program ver. (5.4). The ANSYS finite element program helps in analyzing the stability of
geo- structure (embankment) in varied application of geotextiles reinforcement to enhance the best
design for embankment.
The results of analysis indicate that one of the primary function of geotextiles reinforcement was to
reduce the horizontal displacement significantly. With the inclusions of reinforcement, the horizontal
displacement reduced by about (81%), while the vertical displacement reduced by (32%). The effect
of geotextiles
The bony pelvis has a major role in weight transmission to the lower limbs. The complexities of its geometric form, material properties, and loading conditions render it an open subject to biomechanical analysis.
The present study deals with area measurement, and three-dimensional finite element analysis of the hip bone to investigate magnitudes, load direction, and stress distribution under physiological loading conditions.
The surface areas of the auricular surface, lunate surface, and symphysis pubis were measured in (35) adult hip bones. A solid model was translated into ANSYS parametric design language to be analyzed by finite element analysis method under different loading conditions.
The surface
... Show MoreIn this paper, photometric analysis of two short period group of the eclipsing binaries (RS CVn); RT And and BH Vir is presented. New physical and geometric parameters were obtained by performing two computer modeling. The first model is software package PHOEBE based on the Wilson–Devinney method, and the second is Binary Maker 3 (BM3).Our results are in good agreement with those obtained using the same modeling.
The study aims to identify the relationship between Dogmatism and the behavioral problems among preparatory school students. To do this, the researcher adopted Rokeach’s scale of dogmatism, which was modified to be more appropriate of the Iraqi context. A sample of (300) students was chosen randomly to collect the needed data for the current study. To process the data, the researcher employed T-test, Pearson correlation coefficient, and Weighted Mean. The finding revealed that the study sample experience too many behavioral problems, as well as there is a positive strong relationship between Dogmatism and behavioral problems. To conclude, the researcher recommended holding counseling sessions targeting school students to mitigate
... Show MoreAfrican countries are among the countries in the world that suffer from the phenomenon of child recruitment in wars and conflicts. There are many reasons behind it, including the nature of the human formation of children, the societal violence to which they are exposed, lack of access to education, economic hardships, as well as the role of African wars and conflicts and other reasons that compelled children to join armed groups and participate in military operations. The recruitment of children is divided into two types, compulsory and voluntary, and this leads to many humanitarian and security repercussions that are not limited to a specific period of time but extend to subsequent generations, and due to its seriousness, t
... Show MoreThe research aims at Identifying family dialogue of kindergarten’s parents. 2) Exploring the fears that kindergarteners suffer from. 3) Identifying family dialogue of kindergarteners’ parents and the fears of their children. To achieve the aim of the research, the researcher designed two scales: one for the family dialogue of kindergarteners’ parents, and the other for the fears of the kindergarten’s child. To identify the relationship between these two elements, the scale subjected to the consultation of a group of specialized expertise in educational and psychological sciences to certify the propriety of the items. The reliability of the scale of the family dialogue recorded (0.85). As for the scale of children’
... Show MoreIncrease in unconventional resources of calcium (Ca+2) for fowls, aquaculture and native animals was improved. This work was planned to define the most polymorph of calcium carbonate (CaCO3) that take place in the two types of chicken eggshells (local and imported type). In this research, the comparative analysis of calcium carbonate (CaCO3) content was approved for nominated eggshells of native strain and imported chicken via Field Emission Scanning Electron Microscope (FESEM), Transmission Electron Microscope (TEM), Fourier-Transform Infrared Spectroscopy (FTIR) and Powder X-Ray Diffraction (PXRD) analysis. The results demonstrate that native and imported chicken eggshells comprise calcite morph that ha
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