Rafidain journal of science

This research aimed to find the rang of the electromagnetic reaction. It does that
according to the theory of secondary photons, quantized time (T = 2πnћ/E), and the
photon rest mass (mo=hH/2c2), and by calculating the range of the photon at this time its
found that it is(T=2c/H), and it is with full agreement with the result that found
previously

Experimental studies have been made to determine the oxidation be havior of
several coatings system on commercial stainless steel alloy (S.S. 321). The oxidation
kinetics of a single stage coating such as Aluminized and Nickel - Aluminzed alloy have
been under atmospheric studies pressure at 1000Co using a thermal cyclic oxidation. Xray
technique was used to identify the coating structure and oxide scale.
Most coating use to enhance the formation of protective oxid scale, the results
showed that non of the coating was totally resistant to cyclic oxidation. But Nickel–
Aluminized coating, exhibited the greatest resistance to oxidation . The superiority
protection of Nickel – Aluminzed coating can be due to the formation of NiO and Al2O3

Samples of MOS devices which were prepared by anodic oxidation method in
which three electrodes used with HCl of 0.1 M. The thicknesses of SiO2 film were
between 45& 80Ao . The effect of γ -ray on the characteristic of these devices studied
through the measurements of I-V and C-V before and after irradiation. The results point
to that the capacitance decreased after irradiation and an increase in the conductivity
observed which indicates a decrease of potential barriers of these devices. The
measurement of I-V for these samples as solar cell showed a decrease in the output
power.

In this paper, the energy response of the solid state nuclear track detector PM-355
for α-particles within the energy range of ≤ 5.5MeV have been studied using an
241Am(1μci) source in irradiating the detectors pieces. It has been found that the threshold
energy, which defined as the minimum energy that could be detected, is about 0.3 MeV
for PM-355. While the track detector CR-39 responses to the α-energy approximately up
to 0.2 MeV, when a conventional chemical etching is used. The results also indicates that
the etching efficiency and sensitivity of the CR-39 is better than that of PM-355. Theyshowed a maximum values when the incident energy of the α-particle is about 1.5MeV,
where a maximum energy loss in the detector is taking place.

Two different types of aluminide coatings on cyclic austenitic stainless steel 321 AISI, were investigated. One is based on predeposition of nickel by electrodeposition followed by aluminization using a pack cementation technique (double step- coating), while the other coating is based on codeposition of nickel and aluminium powder simultansly using a pack cementation (single step- coating).
The coating microstructure and intermetallic compound of the coating layers, as well as, coating thickness were identified using metallugraphy and X-ray analysis
The cyclic Oxidation test of the coating at elevated temperature reveals the formation of stable and protective scale α-Al2O3 along the exposure time.

The aim of this research to study the effect of etching conditions such as the
concentration of the etchant solution, and temperature on the detecting properties of
nuclear track detector (cellulose nitrate) CN-85, in order to determine the optimum
etching conditions. An (NaOH) solution with (3, 4, 5, 6N) concentrations andtemperatures range (40,50,60o C) has been used for the following etching times (0.5-4 hr)
to develop tracks of alpha particles with energy 1.5MeV of emanated from 241Am source
of (1μCi) activity. It is found that an increment in the concentration and the temperature
of the solution leads to an increment in the diameter of the tracks, it was also noted that
an increment in the temperature by 10Co leads to an increment in the average radii of
tracks by (75 – 210 %) .Eventually it is found that for each specific temperature of
etchant optimum condition of specified etching time, (which appears the highest number
of tracks) and also specified the track diameter, these two condition will be changed
when the concentration of etchant is also change at a fixed temperature

The increase in the production of solid materials requires a simple and easy method
to measure the density of these materials. A method is suggested to measure the density
which is based on the absorption of gamma ray at certain energy which helps to measure
the density with error less than 4.6% and in case the error exceeds the previous
percentage the absorption material may contain impurities.

The aim of this research to study the effect of etching conditions such as the concentration of the etchant solution, and temperature on the detecting properties of nuclear track detector (cellulose nitrate) CN-85, in order to determine the optimum etching conditions. An (NaOH) solution with (3, 4, 5, 6N) concentrations and temperatures range (40, 50, 60oC) has been used for the following etching times (0.5-4 hr) to develop tracks of alpha particles with energy 1.5MeV of emanated from 241Am source of (1µCi) activity. It is found that an increment in the concentration and the temperature of the solution leads to an increment in the diameter of the tracks, it was also noted that an increment in the temperature by 10 oC leads to an increment in the average radii of tracks by (75-210 %). Eventually it is found that for each specific temperature of etchant optimum condition of specified etching time, (which appears the highest number of tracks) and also specified the track diameter, these two condition will be changed when the concentration of etchant is also change at a fixed temperature.

In this research ,a new pack design has been used for production of metallic coating
for alloys, in order to resist oxidation and corrosion at high temperatures. Such alloys are
manufactured for some parts of Gas Turbine engines and boilers.
In traditional pack cementation method for production of aluminide coating, a
mixture of powders, such as, Aluminium ,Ammonium chloride ,and Alumina were mixed
together at a certain percentage, and the parts to be coated are submerged in this mixture,
after coating time proceeds, the mixture is usually discarded and can not be used again
because the Ammonium chloride which has been dissociated can not be replaced with the
same percentage again.
This process could lead to a high loss of unused Aluminium powderThis new pack design can offers an opportunity to isolate Ammonium chloride
(activator) from the rest of pack mixture, by so, one can substitute the activator alone
without replacing the rest of mixture.
Such pack design has been used in the investigation of coating production at different
temperatures and the structure of the coating produced was compared with that produced in
traditional method for the same alloy , and the results were indicated to a good similarity of
structure except in thickness.

In this work, Metal-Polymer-semiconductor devices (MPS-Devices) have been
fabricated using a thin film of Poly carbonate (PC). From characterization of the devices,
threshold voltage (VT) and breakdown voltage (VB) were determined.The effect of
Polymer films thickness and the temperature on the (VT) and (VB) were studied.The
results show that both voltages increase with increasing Polymer film thickness and
decrease with the temperature. Illuminated (I-V) characteristics of the fabricated devicewere studied also, it was clear that the current and voltage increases with increasing
illuminated intensity, while (VT) decrease with increasing illumination intensity. Finally
the (C-V) characteristics was studied, the results showed that there are change in the
capacity with change a voltage within range, out of this range the capacity fixed and the
capacity of the device increases with increasing the frequency at same value of voltage.

In the present work, the effect of annealing temperature, annealing time and etching time on the track diameter of -particle have been studied using CR-39 Detector.
Two models were used to measure the activation energy (Ea) at each time periods.

Rubber is produced by volcanization which is achieved by different ways one of
theses is by compression in molds by which samples under research were produced in
jabir bin hayyan com. In this research the effect of compression temperature on the
homogeneity of rubber kind (MCG) which is used in protection masks was studied. After
the best degree of temperature was investigated to be (175 oC) then the effect ofcompression pressure on the characteristics of the rubber for two types of samples
prepared by this way, by studying their homogeneity and mechanical properties. This
study fixed the best pressure at (150 bar). The practical benefit for this study is to
decrease the damage of the product and get best product with best mechanical properties
and homogeneity.