Unlike welding, soldering does not involve melting the work pieces. Soldering is a process in which two or more items are joined together by melting and putting a filler metal (solder) into the joint. Failure in the solder joint may make the system components lose their functions. Electrical wiring and electronic components are joined to devices and printed circuit boards using soldering. Soldering and brazing are both used in the assembly of musical instruments. Lead-tin alloy solder employed in the current investigation which has a diameter of 4 mm and a density of 11.0103 kg/m3 with continuous heat flux heating from the domain's left side and complete insulation on the other side. The melting of PCM was simulated using the ANSYS (Fluent) melting model. Three procedures were followed during the heating stage of the reflow process to perform the melting heat-transfer analysis. The simulation's results were recorded at regular intervals of 15 seconds. The results show melting rate increases as time proceeds. It is almost the same at the initial stages and increases in the middle and the end of the melting process. Heat transfer happens mostly through conduction during the first 0–30 seconds of the melting process, changing to natural convection as the material continues to heat up.
The neighbourhood unit is a small local community in a city dwelled by certain number of dwellers who are characterized by common features, mostly economic. They daily deal with each other & unified with the feeling of neighbourhood. The daily primary services are available in this small community (like education, shopping & entertainment). This community is separated from other communities by physical boundaries like streets, gardens… etc. The neighbourhood is not an exotic notion on human community but it is as ancient as history itself since it was there in ancient communities that dwelled on earth. Complications of urban life needs, caused by cities’ expansion, and the weakness of social relationships, imposed phy
... Show MoreThe visual stimulus is the effective force in visual attraction that achieves visual and perceptual co-optation and is important in wooing the recipient, and many procedural processes in the design are interpreted on it as the visual stimulus achieves visual comfort and a sense of pleasure and gives (place) the interior space a transformation in its plastic structure as well as arousing attention through The kinetic rhythm and the formal diversity, which increases the possibility of breaking the routine and traditional constraints of design patterns through the coating and encapsulation of the vertical and horizontal levels . Thus, the research problem was launched based on the following question: What are the stimuli of the visual stimu
... Show MoreThe design processes in general and the design system in particular need to be studied and knowledge. Based on this vision, we find the need for constant research on the design processes, and the subject of the techniques of the designs of the covers of children magazines did not have the view of the researchers to make them the subject of study, For the subject of this research, the problem of research is determined according to the following question:
- What are the methods used in designing children magazine covers in Iraq?
Through this research we seek to find solutions to this question as well as it will serve the cognitive side of a modern study and development of a broader understanding of the subject. Through four
... Show MoreThe aim of the present research is to study the dissolution and transport process of
benzene as a light nonaqueous phase liquid (LNAPL) in saturated porous media.
Unidirectional flow at water velocities ranged from 0.90 to 3.60 cm/hr was adopted to study
this process in a three dimensional saturated sand tank (100 cm×40 cm×35 cm). This tank
represents a laboratory-scale aquifer. The aquifer was constructed by packing homogeneous
sand in the rectangular tank. The experimental results were used to characterize the
dissolution behavior of an entrapped nonaqueous phase benzene source in a three dimensional
aquifer model. The time invariant average mass transfer coefficient was determined at each
interstitial velocit
Polyaniline polymer has been prepared by chemical oxidation
polymerization method in laboratory successfully. The PANI and
(PVA+PVP) as a polymer blends in different percentage (30%, 50%,
70%) from Polyaniline was prepared. The sample was studies as
optical properties by UV-vis spectrophotometer at (400-700) nm.
The result of optical energy gap was 2.23 eV for pure (PVA+ PVP)
and with additive was increasing with increasing PANI concentration
to become (2.49 for 30% to 2.52 for 70%) PANI. The goal of this
project is prepare triple blend polymer and study the effect when add
conductive polymer (Polyaniline) on the optical properties and
calculate optical constant as energy gap, refractive index, dielectric
Porous asphalt paving is a modern design method that differs from the usual asphalt pavements' traditional designs. The difference is that the design structure of porous pavements allows the free passage of fluids through their layers, which controls or reduces the amount of runoff or water accumulated in the area by allowing the flow of rain and surface runoff. The cross-structure of this type of paving works as a suitable method for managing rainwater and representing groundwater recharge. The overall benefits of porous asphalt pavements include environmental services and safety features, including controlling the build-up of contaminated metals on the road surface, rainwater management, resistance to slipping ac
... Show MoreMarriage as a social case began Almighty God created Adam, peace be upon him then created from the rib Eve to be the first couple of human beings on the face of the earth and the formation of the first social family in the land, human and picked up this social reality through the generations, but in different shapes and purposes, but the mating process is one. So I got the divine religions and organized that life, especially in Islam, as explained every aspect of the life of the role and practice of marriage and had a large share in this organization and I got many Quranic verses and the Hadith.
With different civilizations, many of the marriage ceremony appeared in ancient societies take several forms of marriage.
But marriage and
The aim of the research is to assess the quality of the university accounting education system in Iraq. The researcher relied on the opinions of a sample of academics specialized in this field by preparing a checklist focusing on a set of axes that would affect the quality of accounting education in the Iraqi environment.
The most prominent finding of the research is that the quality of accounting education in Iraqi universities is medium and differs from one university to another in some quality components. In addition, the prescribed curricula and study plans applied in the accounting departments do not live up to the required level, as the largest proportion of those curricula are theoretically d
... Show MoreAbstract: The term extremism refers to the distance from moderation, excess and hyperbole, and it is a relative term that varies from one society to another, according to the prevailing traditions, values and culture, as the problem of extremism is one of the main issues that contemporary societies are concerned with is a phenomenon that has its roots in the intellectual formation of societies. By knowing the concept of extremism, we can identify the reasons that contributed to the existence of extremism as a phenomenon, on the one hand; on the other hand, to clarify the role of women in combating extremism and developing effective solutions to reduce this phenomenon. As women play a major role in society, starting from the family to educa
... Show MoreABSTRACT Studying the positive and negative effects resulted from the industrial projects and laying down the comprehensive planning bases to the urban development projects which insure retaining the social, economic and environmental development, taking in to consternation the time factor within the planning process which is considered the most important factor that determine the extent of the efficient selection to the site and not interpenetrate in the industrial activities and efficiency and calculating its future expansions away from the residential areas. It is more favorable to plan the industrial areas of apparent pollution outside the bounds of the basic plan to limit the negative effects on the environment and providing
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