Asphalt plays the role of envelope and bonding in asphalt gable, and is exposed to a range
of changes that start from the stage of production of asphalt mosses to the stage of
investment under the influence of traffic loads and weather factors. The
aim of this
research is to investigate the possibility of using polypropylene polymer to modify the
properties of the asphalt binder and to increase its resistance to high temperatures and
different climatic conditions by modifying the asphalt by adding polypropylene by (1, 2, 3,
4, 6, 8%) And perform traditional tests on modified asphalt samples . Using Thin film oven
test RTFOT test to perform the short-term Aging on normal and modified asphalt samples,
heat loss, residual Penetration and aging index, And conduct a structural composition test
to determine asphalt compounds. The results of the study showed that the values of
Penetration tend to decrease with the increase of the percentage of addition while the
degree of Softening point. The results showed increased resistance of asphalt modified to
the thermal conditions. The optimum percentage of polypropylene is 3% Loss on heat at
the lowest level.
This study deals with the most important problems related to the age of aging,
especially the social - psychological ones, which appear little by little as the age of man,
and from the increase in this segment on the one hand, and then seek to help
the elderly
and solve their problems on the other hand. This study deals with several aspects: First: the
concept of aging, its limits, its manifestations, second: the fertility that characterizes this
stage, the social problems of the elderly, the psychological problems of the elderly,
Problems of older persons. In conclusion, they made several proposals in order to
contribute to the goal of the study to focus attention on the elderly and to understand their
various problems in order to move towards solving them.
This research was done to improve the local bitumen specifications 60-70 (Banias
refinery output) using Cement Bypass DUST(CBPD) so that it becomes more resistant to
high temperatures (Short- Term- Aging), in addition to reduce the harmful waste ma
terials.
The cement bypass was supplied by Tartous Cement Company and added to
bitumen with different percentages namely, 12%, 14%, 16% and 18% (by the weight of
bitumen). some experiments were held to determine the properties of modified and
unmodified bitumen (Penetration )25, 15, 4(∁°- Ductility- Softening point), then We
returned previous experiences after (Loss- on- heating test) and exposure to (Short- Term-
Aging) on the modified and unmodified bitumen, and the results were within specification
limits, were Compatible with previous reference studies and these additions have to
improve the resistance of bitumen to high temperatures. The optimum cement Bypass Dust
ratio was found to be 14% of the weight used bitumen.
In this research the effect of Nickel addition by various
percentages on the mechanical properties of
Aluminum-Copper alloy was studied. After
adding Nickel the alloys was artificially aged for different
times, and the effect of Nickel on
the re
sponse of alloy to precipitation hardening was studied.
Where the effect of Nickel on the microscope structure was
studied, and on the mechanical properties as hardness, tensile
strength, yield strength and elongation. The results showed that
the increase of Nickel improve this properties, where the highest
values were obtained when the Nickel's percentage was 5% Wt.
The study aimed to optimize the formability and mechanical properties of aluminum
alloy 2024-T6 by Retrogression and Re-Aging (RRA), and evaluating that by means
of tensile test, hardness test, and ball punch test.
The effect of artificial aging on the revolution of mechanical
properties of aluminum alloy 6063-T5 has been studied. Samples of
aluminum profiles which are formed by extrusion process have
chosen, then studied the effect of artificial aging on th
e hardness
and mechanical properties by applied two aging stages and many
stages comparing to the traditional way which be done in one stage.
The aim of this work is to study the effect of the aging heat treatment on the pitting corrosion resistance of martensitic stainless steel. In this research a number of specimens from martensitic stainless steel were subjected to solution treatment a
t 1050 for one hour followed by water quenching then aging in the temperatures range (400-750) for different holding times (1-16 hrs).
After heat treatment, two types of corrosion tests (accelerated test and immersion test) were conducted. The results obtained in this research showed that the pitting corrosion resistance was
affected by Aging temperature and three critical temperatures were found in corrosion test: the
specimens aged at 475 0C had maximum corrosion rate. This may be due to the presence of stringer δ-
ferrite and precipitation of very fine precipitates which precipitated heterogeneously in the martensitic
matrix, which led to an increase in corrosion rate. The specimens aged at temperatures range (550 – 625) 0C had minimum values of corrosion rate, this is attributed to the high volume fraction of retained austenite. The specimens aged at temperatures above 625 had intermediate corrosion rate.
The type of pits, which resulted from two pitting corrosion tests, was independent form the form of δ-ferrite and carbides which presence in microstructure.
This research aims to study the effect of heat treatment on curing of reinforced Unsaturated Polyester Resin (UPR) with fiberglass, and to study the effect of storage time and the time of exposure to natural aging on curves absorption.
The results
showed that it is very difficult to reach a fully curing to UPR matrix, and
Storage samples for three years reveal resistance to degradation in fresh and seawater comparing with storage samples for three months, or aging by exposed to environmental for three years. The results showed also that the absorption occurs by thin film, and not prevent by increasing the layers of reinforcement
The influence of thermomechanical treatments on the microstructural properties of stainless steel D9 alloy
steel was studied.
There is considerable evidence supporting the role of gonadotrophins and
progesterone on follicular growth and maturation and functional maintenance
of the ovary in the hen. Recently, however, there are ever-expanding list of
factors may be involv
ed in establishing follicular growth and ovulation
currently including germinal disc region, growth factors, macrophages,
plasminogen activator, ornithine decarboxylase, inhibin, activin, follistatin,
relaxine, arginin vasotosin, oxytocin, prostaglandines, vasoactive intestinal
peptide, and their interactions.
