In this research the effect of cooling rate and mold type on mechanical properties of the eutectic
and hypoeutectic (Al-Si) alloys has been studied. The alloys used in this research work were (Al- 12.6%Si
alloy) and (Al- 7%Si alloy).The two alloys have been melted and poured in two types of molds with
different cooling rates. One of them was a sand mold and the other was metal mold. Mechanical tests
(hardness, tensile test and impact test) were carried out on the specimens. Also the metallographic
examination was performed.
It has been found that the values of hardness for the alloys(Al-12.6%Si and Al-7%Si) which poured in
metal mold is greater than the values of hardness for the same alloy when it poured in a heated metal
mold at different temperatures or in sand mold. The strength and impact resistance for the alloys (Al-
12.6%Si and Al-7%Si) are greater when these were poured in a metal molds than that when it poured in a
sand mold.
Furthermore, the higher cooling rates enhance the strength, hardness and impact resistance for the
two alloys, while the low cooling rates reduces these mechanical properties.
The percentage of elongation and the amounts of formed porosity decreased when the cooling rates
increased
In the present investigation two different types of fiber reinforced polymer composites were prepared by hand lay-up method using three different parameters (curing temperature, pressing load and fiber volume fraction). These composites were prepared from the polyester resin as the matrix material reinforced with glass fibers as first group of samples and mat Kevlar fibers as the second group, both with different volume fractions (4%, 8%, and 12%) of fibers. They were then tested by tensile strength and impact strength. The main objective in this study is to use Taguchi method for predicting the better parameters that give the better tensile and impact strength to the composites, and then preparing composites at
... Show MoreIn this work laser detection and tracking system (LDTS) is designed and implemented using a fuzzy logic controller (FLC). A 5 mW He-Ne laser system and an array of nine PN photodiodes are used in the detection system. The FLC is simulated using MATLAB package and the result is stored in a lock up table to use it in the real time operation of the system. The results give a good system response in the target detection and tracking in the real time operation.
Background: Bloody diarrhea plays a major role in
morbidity and mortality especially in developing
countries, it is usually a sign of invasive enteric
infection, there is a thought that amoebic dysentery is
more common than bacillary dysentery in Iraq, and
from 1989 to 1997 amoebic dysentery increase from
20000to 550000 patients.
Objectives: This study aims to:
1. Outline the incidence of various infectious causes of
bloody diarrhea in Erbil district.
2. Assess the effect of multiple factors like age, sex,
source of water supply, etc... On the incidence of
amebic and bacillary dysentery.
3. To provide baseline data for making strategic plan to
reduce the diarrhoeal mortality and morbidity.
Met
LO Hamza, Indian Journal of Natural Sciences, 2018 - Cited by 3
This research is marked by " lighting and processors formalism for spaces of shops selling mobile phones ," aims to " reveal about the relationship between lighting treatments formal designs spaces own internal selling mobile phone in addition to the recognition criteria Altsamama to lighting techniques and processes formality spaces shops competent to sell mobile phone " and lies the importance of this research in the " active role of the lighting in the building processors formalities and processes to prepare designs and show the final form integrated functionally and aesthetically so as to be ready for implementation , taking into consideration the role expressionist in the recipient and to make these spaces more than meet the require
... Show MoreOur creator has honored human beings and granted them a noble place, the provisions of the Islamic system are designed to strengthen and consolidate this dignity and respect. Since women are human beings, they have their respect, status and dignity. There are some prophetic sayings concerning women that may be understood as contrary to this value, the value of dignity and respect for human beings. One example is the Hadith of a woman cutting off a man’s prayer if she passed in front of his prayer. The study examines this topic and presents answers for it.
In dealing with the subject, the study followed the descriptive, analytical and deductive approach of mentioning legislative texts, analyzing them and deducing
... Show MorePolymeric hollow fiber membrane is produced by a physical process called wet or dry/wet phase inversion; a technique includes many steps and depends on different factors (starting from selecting materials, end with post-treatment of hollow fiber membrane locally manufactured). This review highlights the most significant factors that affect and control the characterization and structure of ultrafiltration hollow fiber membranes used in different applications.
Three different types of polymers (polysulfone PSF, polyethersulfone PES or polyvinyl chloride PVC) were considered to study morphology change and structure of hollow fiber membranes in this review. These hollow fiber membranes were manufactured with different pro
... Show MorePersuasion is a process studied by many scholars from the Greek time until the present. One persuasion strategy is metadiscourse, which refers to the writers' awareness of their text, the way they present themselves to the readers. The writers use metadiscourse markers to help the readers understand the real meaning of the text (Hyland 2005). The paper carries out a qualitative and quantitative analysis of the employment of persuasive metadiscourse markers in two English trade agreements and two Arabic agreements has provided in terms of Hyland's (2005) model of interactive and interactional markers. The aim is to find out whether all types of metadiscourse markers are used or not, and also to see whether English or Arabic employs
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