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.
The aim of this work is the preparation of a biodegradable polymeric blend
(LDPE/AD+S) to be used for eco-friendly packaging purposes. The polymer matrix
consists mainly of low density polyethylene( LDPE), starch (S), and low quantities of
additiv
es (AD) as compatibilizers. The additives are: maleic acid, acetic acid, benzoyl
peroxide, and zinc stearate. The polymer blend LDPE/AD+S was prepared by extrusion, in
three compositions according to the percentage of starch (15,20,40%). Then, films were
prepared from the blend by thermal hydraulic compression to study their microstructure by
optical microscopic at magnification of 055 The results showed that the starch granules
were homogeneously distributed within the polymer matrix, and the compatibility
additives played an important role in enhancing the microstructure of the prepared blends.
The results also indicate that the starch promotes the onset of the bioegradation process.
Beams are considered as one of the most loaded concrete elements, which needs to
be strengthened either as a result of insufficient of concrete section, or insufficient rebar or
increased loads, or the result of a superficial steel or corrosion of
internal steel
reinforcement, and other reasons that we will mention them what we need to study this.
The damaged structural elements and their inability to function fully as a result of exposure
to different environmental factors damage materials and lead to lower resistance, or
because of the existence of of an executive defects or inappropriate investment for its,
leads to the need to rehabilitate maintenance and repair or reinforcement. So it was
resorting to strengthen either magnify sections or supply necessary reinforcement or steel
platelets linking external supported well to concrete section, and because of the difficulty
of execution the recent studies has been implemented on the use of more efficient material
which is concentrated fiber reinforced polymers.
We will present here to methods of strengthening the shear up to the global studies
conducted using these materials from polymers, which are characterized by high resistance
to tensile and large resistance to environmental factors and weather conditions and ease of
application in the specified permissible sites.
In this research a proper amount solvent has been for Neoprene
rubber to give it the required viscosity. Zinc oxide has also been
added with different ratios to improve the process of adhesion. We
made compound substances on the basis of Neoprene
and
improved them with glass fibers by means of different ways of
solidification, and with different weight ratios by means of manual
molding through designing a wooden mould containing five parts
with certain measurements, and studying the orientation of these
fibers and their effects on some mechanical characteristics of
Neoprene rubber.
In this research we studied the relationship between the optical conductivity Ϭop and
photon energy (hν), the absorbance coefficient (α), transmittance (T), the refractive index
(no), and the real part and imaginary part of dielectric constant (εr,
εi), the spinning velocity
of deposition device (v), for a specific wave length (600nm), for a pure thin film prepared
from an organic polymer material, Polystyrene (PS), by spin coating technique, on three
velocities ( 1000-2000-3000)RPM, in room temperature and 1atm.
It was shown that the PS film is a transmittive film with a transmittance values
reach ( 85 – 90 )% in the infrared region, and the optical conductivity Ϭop increased with
the photon energy, and for the velocity 1000RPM it took the highest value ( 1.67 X
1014 )1/sec, at the photon energy (hν =3.1 ev) and the wave length ( λ= 400nm ),
which means that the optical conductivity Ϭop is active in the visible region, and also it
decreases with the spinning velocity.
The values of energy gap for allowed direct transitions were (2.5ev), (2.4ev), (2.3ev)
for the films prepared on 1000RPM, 2000RPM, 3000RPM, and for the forbidden direct
transitions were (2.3ev), (2.2ev), (2.1ev) respectively .
The biggest value of Urbach energy Eu was (163mev) on the velocity 1000RPM and
the lowest value was (109mev) on the velocity 3000RPM.
The research aims to study the effect of the distribution water on
Proton Exchange membrane fuel cell (PEMFC), and the
relationship of membrane thickness and the effects of changes in
thickness depending on the amount of water contained within the
membrane. The research also aims to change the effect of humidity
on the effectiveness of the membrane proton through the diffusion
coefficient and the coefficient of the flow electral osmotic. The
research includes the study of humidity on the cell performance at
constant temperature and its effect on the input interface.
The present research aims at synthesizing micro-porous and fluorescent polymer by microwave assisted synthesis allowing to reduce preparation time of 3 days at 180 °C using conventional method.
In this research we have prepared thin films from poly vinyl chloride (PVC) by spin
coating technique in three velocities (1000,2000,3000)RPM on glass substrate (Micro
scope cover glass), at room temperature. The absorbance A, and transmittance T f
or the
films were studied in the visible and ultra-violet region (UV-VIS). In addition,we have
calculated the absorbance coefficient α, skin depth δ, refractive index no, dielectric
constant ε (the real part and the imaginary part), also we have calculated the energy band
gap of allowed and forbidden direct transitions.
The films showed high transmittance (80-90)%, in the infrared region as a function
of the spinning velocity and took the maximum value 80% for the velocity 1000RPM, and
90% for the velocity 3000RPM, and the refractive index was decreased with the velocity
increase, we found it between3.67 and 4.56 for the velocities 3000RPM and 1000RPM
respectively. Whereas the skin depth δ decreased with the increasing of velocity, the
minimum value was 0.0000531cm for the velocity 3000RPM and the maximum value was
almost 0.00023cm for the velocity 1000RPM.
This paper makes an experimental and analytical investigation of cracks characteristics in Fiber Reinforced Polymer strengthened RC beams under different levels of sustained load and Reinforced ratio.
As the equations available for conventional RC b
eams are inappropriate for the calculation of the short-term crack width in FRP-strengthened RC beams[8], a statistical analysis is carried out on available test data from international sources [6-9-10] and from the test results obtained in the current study (Concrete Labor- Civil engineering Department- Damascus University-2014) to establish a new equation that considers the effect of the FRP laminates. This equation is a correlation of stress in steel bars, concrete surface tension , and effective side cover.
The long-term crack width is then related to the instantaneous crack width by empirical equations which are derived from the test results obtained in the current study.
This research was performed to improve the quality of Bituminous mixes, and improve the thermal resistance of the surface bituminous layer, the bitumen has a various changes, that which begins from the production of the bituminous mixture in high tem
peratures, these changes continues to the phase of it's use. For this purpose, SBS(Styrene Butadien Styrene) was selected to be an improving material to bitumen according to the rate: 3.5% for SBS.in my research I work on modifying the local bitumen by adding the SBS so that the modified bitumen can be used to design bituminous mixes within the limits of bituminous mixes designed specifications, and improve it's thermal resistance. some experiments were held to determine the qualities of the modified and unmodified bitumen,befor and after Lose Of Heating, the results were within the specifications 'limits. According to Marshal's method, samples of Bituminous mixes were prepared for all Bituminous sorts used in our research. These samples were put under required tests, and samples were prepared according to an ideal rate of Bitumen. the result was the Bitumen modified by adding SBS improve the quality of Bitumen to thermal resistance.
