This paper reports an experimental study of welding of dissimilar materials between transparent Polymethylmethacrylate (PMMA) and stainless steel 304 sheets using a pulsed mode Nd:YAG laser. The process was carried out for two cases; laser transmission joining (LTJ) and conduction joining (CJ). The former is achieved when the joint is irradiated from the polymer side and the latter when the joint is irradiated from the opposite side (metal side). The light and process parameters represented by the peak power (Pp), pulse duration (τ), pulse repetition rate (PRR), scanning speed (ν) and pulse shape have a significant effect on the joint strength (Fb), joint bead width (b), joint quality and appearance. The optimum parameters were determined according to joint quality, joint strength and bead width. The optimum results for the joint strength and bead width for both LTJ and CJ are 925 N, 7.25 mm and 495 N, 8 mm respectively using a rectangular pulse shape (RC). Further modeling studies were carried out based on two methods; one factor at a time method (OFM) and surface response methodology (RSM) method. RSM was used to determine optimum parameters for the experimental data building mathematical models for correlating parameters and responses (Fb and b) as well as to investigate how different parameters interact with each other and their effect on the weld quality.
The current study performs an explicit nonlinear finite element simulation to predict temperature distribution and consequent stresses during the friction stir welding (FSW) of AA 7075-T651 alloy. The ABAQUS® finite element software was used to model and analyze the process steps that involve plunging, dwelling, and traverse stages. Techniques such as Arbitrary Lagrangian–Eulerian (ALE) formulation, adaptive meshing, and computational feature of mass scaling were utilized to simulate sequence events during the friction stir welding process. The contact between the welding tool and workpiece was modelled through applying Coulomb’s friction model with a nonlinear friction coefficient value. Also, the model considered the effect of nonlin
... Show MoreA field experiment was conducted at experimental field of Mechanization Agriculture , the College of Agriculture , Abu – Ghraib , University of Baghdad .To measure transmitted vibration to seat tractor during operation tillage , mold board plow with New Holland 66-S- 80 tractor as one machinery unit , Soil was treated at soil constant moisture ( 18 – 20 % ) with two depths of plowing (15 and 20 cm ) and three speed of tractor 2.0 , 3.5, 6.8 km / h . Three main dimensions in seat tractor measurement vertical, longitudinal and lateral acceleration. Split plot design under completes block design with three replicates .
In this study the adsorption of cefixime on to selected Iraqi clay bentonite. The aim of this study is to search for selective active surface in adsorption of the drug and to act as physical antidotes in treatment of poisoning if the drug is taken in quantities higher than the recommended dosages. Quantitative estimation of the drug adsorption has been done by utilizing the technique of UV spectrophotometry in λmax (273) nm at different conditions of temperature (25, 37, 45) ˚C found the adsorption decrease with increase the temperature. Study of clay weight of bentonite (0.1-1.5) gm found the adsorption increase with increase of clay weight, study effect of pH (1.2, 3, 5, 7) on adsorption of bentonite found the optimum adsorption
... Show MoreA field experiment was conducted at experimental field of Mechanization Agriculture , the
College of Agriculture , Abu – Ghraib , University of Baghdad .To measure transmitted vibration to
seat tractor during operation tillage , mold board plow with New Holland 66-S- 80 tractor as one
machinery unit , Soil was treated at soil constant moisture ( 18 – 20 % ) with two depths of plowing
(15 and 20 cm ) and three speed of tractor 2.0 , 3.5, 6.8 km / h . Three main dimensions in seat
tractor measurement vertical, longitudinal and lateral acceleration. Split plot design under
completes block design with three replicates
act : A soluble cytoplasmic antigen (Brucellin) was prepared from Brucella melitensis Rev1 and used to diagnose brucellosis in experimentally infected mice with virulent strains of Brucella melitensis and Brucella abortus two weeks after infection. The best result was obtained with the third peak of the four peaks. All four peaks were used as antigen for skin test in a group of mice two weeks after vaccinated with S19 vaccine and the best result was obtained with third peak. All four peaks were also used as antigen for skin test in a group of mice previously vaccinated with Listeria monocytogenes live attenuated vaccine. All four fractions of the extracted brucellin antigens exhibited a negative skin test result in Listeria monocytogenes ex
... Show MoreThe bubbled slab, a type of reinforced concrete (RC) slab with plastic voids, is an innovative design that employs a biaxial distribution of voiding formers within the slab to reduce the slab’s self-weight while preserving a load-carrying capacity that is approximately comparable to that of solid slabs. This paper presents a new approach for figuring out the effective critical shear perimeter of voided slabs using the reduced-volume concept of concrete. This approach aims to reduce the coefficient of variation of the current design standards, namely the ACI 318-19 and Eurocode 2, for assessing the slabs’ resistance to punching shear. Our experimental program investigated the impact of voiding former patterns and the location of
... Show MoreAllah legislated marriage and made it dwelling, fellowship and mercy between
the two couples, Prophet Moh'd (peace of Allah and blessing be upon him) ordered a
husband to look after his wife, treat her with full charity and make love with here
every kindly. On the other hand, he ordered a wife to obey her husband and respect
him deeply, nevertheless, some obstacles may sometimes be appeared within the life
of their marriage, this may be caused by either a husband or a wife. This problem is
called lifely disobedience (AL-Noshooz).
In the other words, this means that a wife begins to hate her husband, refuse his orders
and not obey him.
In brief, they hate each other which leads to some marks appear in their
m
The aim of the present study is to identify the level of prosoical behavior of Baghdad University's students and to recognize the differences between male and female students. Moreover, it also aims to identify the level of openness to experience for these students. A random sample of (123) students has been selected; 77 males and 46 females. Two scales have been used in the study. The Prosocialness scale for adults by Caprara. Et al (2005) has been translated into the Arabic language and relies on four types of actions (Helping, Sharing, Taking care, and feeling Empathetic with others) and the other scale is the Openness to Experience Scale, which is one of the Big Five Inventory by John and Srivastava (1999). The main results showed a
... Show MoreThe study aims to integrate the visually impaired people into the art connoisseur community through producing special print artworks to enable the visually impaired people to use their other senses to feel artworks by using artistic printing techniques through adding some prominent materials to the printing colors or making an impact that visually impaired people can perceive using their other senses. This study also aims to set up art exhibitions that display tangible works that can enable visually impaired people to feel artwork and understand its elements to enable them to feel it through other senses.
The study follows the experimental method, through using artistic printing techniques, which allow printing with prominent textur
Abstract
The current research aims to reveal the extent to which all scoring rubrics data for the electronic work file conform to the partial estimation model according to the number of assumed dimensions. The study sample consisted of (356) female students. The study concluded that the list with the one-dimensional assumption is more appropriate than the multi-dimensional assumption, The current research recommends preparing unified correction rules for the different methods of performance evaluation in the basic courses. It also suggests the importance of conducting studies aimed at examining the appropriateness of different evaluation methods for models of response theory to the
... Show More