In this article we present a new and effective method to Estimate the static fatigue age for
springs, when it works by static load or static strain for a long time at deferent
temperature, this case is very important because the spring is a battery
for force and it must
save allow value of the force.
At the first we present a theory study for “creep and relaxation “and how we can accelerate
the test to get the results, then we suggest method to accelerate the test to know when the
spring retch to the minimum allowable value of the force at work temperature degree, this
method depend on tests at samples at deferent temperature degrees, higher than work and
storage temperature, and then use the results to estimate the static fatigue age for springs at
real storage and work temperature.
In this research, it has been studied the Fermi-Liquid density wave depending on
Landau theory. The kinetic equation has been solved using relaxation time approximation
at collision less condition. This is by expanding particle density function of
order Plus, Zero sound modes have been calculated and attenuation rate at low
temperatures.The results have been discussed and compared to the set ones and
the offered theory in this domain.
This paper deals with the study of abnormalities crawl that occur in
soils Algdharyh bulging Khat turns out that these abnormalities are
not related only to enter the water to the soil, but there are
distortions in order to get the bulge constant moisture and these
distortions you get with the times. This research aims to
theoretical and practical study of the behavior of creep in
Algdharyh bulging soil.
This research is conducted in the department of pediatric dentistry at the faculty of dentistry, Tishreen University in the period between 10/2011 to 10/2012. It included 150 children (100 males and 50 females), their ages between 6-15 years.
This r
esearch was carried out on the models of the jaws, by measuring the vertical dimension occlusal (VDO).
And the results were:
1- The average of the first group (6-8 years) = 33,41 mm
2- The average of the second group (9-11 years) = 35,22 mm
3- The average of the third group (12-15 years) = 38,40 mm
The final result of the average of (VDO) in children was 34,79 mm
The importance of this study is how to return the correct vertical dimension when it is lost.
A series of polymer blends are prepared by sequential mixing of epoxy resin
EP with polyurethane PU. The effect of different amount of polyurethane 10%,
20%and 30% wt fraction on conduction and dielectric relaxation has been
reported. It was found
that all blends showed three activation energies (Eac) at
all frequencies, and the glass transition temperature (Tg) was increased with
PU wt fraction. The exponent s values were estimated to be less than unity for
all blends. Cole-Cole diagram was used to evaluate the polarizability (α),
molecular relaxation time (τ) and optical dielectric constant (εOP). The
thermodynamic parameters also determined, the result showed that the Gibbs
free energy of activation (ΔG) and enthalpy (ΔH) are high for all blends.
