Print ISSN: 1608-9391

Online ISSN: 2664-2786

Main Subjects : Physics


Calculate and Analysis of Air Mass and Solar Angles of Mosul City

Taha M. Al-Maula; Abdullah I. Al-Abdulla

Rafidain Journal of Science, Volume 27, Issue 3, Pages 57-65
DOI: 10.33899/rjs.2018.159386

The solar radiation energy of the city of Mosul was calculated according to the value of AM = 1.24 on 21 March and September, theoretically using formula 7 and measuring it practically using the radiometer of the intensity of the optical radiation emitted from the solar simulator that was designed in the laboratory. There are values of 982 W / m2 and 996 W / m2 , respectively, comparing these values in Table 1 with published values for other sites. Table (1) AM values and solar radiation intensity theoretically using formula (7) and practically for different angular values.
For the purpose of solar simulators manufacturing, the air mass (AM) were calculated for the city of Mosul at Altitude line (36.35o) and Longitude line (43.100) and at a height of 220 meters above sea level, this required the computation of the Solar inclination angle (δ), the hour angle ( , the Solar elevation angle (h) and the zenith angle (Z), in addition to that, the calculations were studied in specified day, chosen at the 21st of each month From sunrise to sunset, which is the daylight hours. The study showed that, the values of AM become equals to one at twelve o'clock and 1.24 on the 21st of March and September when the sun at the zenith angle 36.35o. Also it has been found that the variation of the angle of solar elevation and daylight hours rise to its maximum values at noon and then decreases gradually with daylight hours even the sunset hours. Also the zenith angle and daylight hour's decreases gradually to its minimum value at solar noon time and then rise again at the sunset hours. also it has been found that the relationship between the air mass values vary daily by changing the values of daylight hours.
The results show Vary daily by changing the values of daylight hours the AM values decreases with the solar elevation angle while its values increase with zenith angle. The values of AM have been computed for both daylight hour and hour angle its value decreases to minimum value at noon and raise the value of AM again at the end of daylight hour. The curves profile of AM variation with solar angle and zenith angle are of similar behavior with the published for other locations. The standard value of AM for Mosul City that adopted in this research work at altitude line 36.35o is equal to 1.24 on the 21st of March and September and 1.03 on the 21st of June and 1.8 on the 21st of December.
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The Effect of the Geometrical Parameters on the Characteristics of the Saddle Magnetic Deflector

Marwa T. Al-Shamma; Muna A. Al-Khashab

Rafidain Journal of Science, Volume 27, Issue 3, Pages 47-56
DOI: 10.33899/rjs.2018.159389

In this research work the saddle magnetic deflector has been designed, and studied the effect of the geometrical parameters on the characteristics of the magnetic deflector by using one of the simulation programs known as Electron Optical Design (EOD), which is written in Compaq Visual Fortran 6.6 uses the finite elements method. It has been found that the variations of the axial bore diameter and length of deflector have a great effect on its properties as well as the amount of magnetic deflections. The effect of variation of the thickness of deflector was very small. The effect of the angle of the deflector and its excitation was also studied and found that there is a direct effect on the value of a magnetic deflection only.

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Studying the Linear and the Mass Attenuation Coefficient of Gamma Rays for Certain Building Materials used in Iraq

Laith A. Najim; Israa M. Hassan

Rafidain Journal of Science, Volume 25, Issue 5, Pages 75-85
DOI: 10.33899/rjs.2014.131370

In this research, the photons of gamma rays emitted from radioactive sources (133 Ba, 137Cs,60Co) at energies (81, 356, 662, 1173, 1332) keV respectively have been used to examine the linear and the mass attenuation coefficient of different construction materials using gamma spectrometer UCS-20 which is connected with sodium Iodide activated thallium detector (NaI(Tl)) to express the decrease in the intensity of these photons when they pass through the targeted material by scintillation detector reading. According to the results obtained, it becomes possible to measure the two types of attenuation coefficients, the linear and the mass, as these coefficients are of great importance in studying the impact of these rays on the material and the accounts of the radiation dose in order to achieve the level of security against exposure to radiation and to prevent the dangers resulting from that exposure by designing suitable shields. The chemical composition of the material under discussion has also been studied using the technique of X-rays fluorescence (XRF) by (XRF) device and the results were put in the program (XCOM) to compare the values of attenuation coefficients. Results have shown that (Granite) is one of the best building materials to be used in shielding against gamma rays, whereas the (Thermostone) showed less ability to attenuation because of its too low density and the little concentration of elements of high atomic number of this Material.

The Effect of Coating on Alloy AISI 304 at High Temperature on Fatigue Resistance

Moayad Mohammad; Yahya A. Salman

Rafidain Journal of Science, Volume 22, Issue 8, Pages 107-118
DOI: 10.33899/rjs.2011.30179

In This research the effect of metallic coating namely, aluminizing and chromizing on fatigue resistance of austinitic alloy AISI 304 has been studied. The metallic coating were conducted using a cementation method at 1000°C such coatings are used to protect the alloys in severe corrosion environments. The results obtained showed some small reduction in fatigue life of aluminized alloy when compared to a bare alloy, this reduction could be attributed to formation of intermetallic compound Fe- Al and Ni-AI on the surface of aluminized specimens. The intermetallic compound could be suffer a phase transformation when treated at 1050°C, as a result of rediffusion processes, that can be promoting the fatigue resistance. However a significant deteration in fatigue life were accounted for chromizing corresponds to formation of a brittle FeCr and NiCr solid solution on the specimens surface, although some small increases in fatigue life was also detected after heat treatments at 1050°C, this is could be belong to the rediffusion of chromium element down word through the specimen. Generally, both types of coatings leads to a phase transformation of the base alloy itself from austenite to ferrite, this transformation could be occurred either because of Ni depletion to contribute in the formation of surface layer ( coating matrix ), as in case of aluminizing, or because of significant increases of chromium concentration in the base alloy, as in the case of chromizing, which can also leads to formation of intergranular chromium carbides, the formation of chromium carbides can increases the brittleuess, as well as, can offards an easy way for crack propagation in fatigue test. However, the results proved that the best fatigue resistance was obtained, when a base alloy itself treated at 1050°C the slowly cooled to obtain a single form of austenitic phase .

Evaluation of Cu Phonon Frequency Spectrum Under High Pressure Using Different (EOS)

Adnan M. Al- – Sheikh; Zena W. Al – Abady

Rafidain Journal of Science, Volume 21, Issue 3, Pages 65-76
DOI: 10.33899/rjs.2010.37357

In the present work evaluation of effect of high pressure on phonon frequency spectrum for copper has been performed by using different equations of state (EOS) and evaluating lattice vibrations frequencies shift and variations of mode density under high pressure. Variation of Grüneisen parameter under high pressure has been considered in our calculations

The Effect of Humidity on the Optical Storage BDK/MR and PMMA/BDK/MR Systems Using the Spectroscopic Eillpsometry

Taha. M. AL- Maula

Rafidain Journal of Science, Volume 20, Issue 5, Pages 95-102
DOI: 10.33899/rjs.2009.40078

The effect of humidity on the two optical storage systems PMMA/BDK/MR, BDK / MR has been studied by preparing the system of BDK/MR from the Azo – dye of the methyl red (MR) and it is mixed with benzyl dimethyl ketal (BDK) in certain rates of size. But the other system PMMA/BDK/MR has been prepared from the Azo – dye of methyl red (MR) doped with poly methyl methacylate (PMMA) benzyl dimethyl ketal (BDK) and was used as a photoinitiartor at certain rates of size. The effect of humidity has been studied by using device of spectroscopical Eillipsometry which has different angles on the two systems of optical storage, and its become clear that the effect of humidity on the system BDK/MR is greater than that of PMMA/BDK/MR. From this we conclude that the thin films which were prepared from PMMA / BDK / MR system are better than those of the BDK/MR system and adding these information to the programming library for spectroscopical device .

The Quenching Effect on Domestic Prepared Liquid Scintillation Detectors

Enas AL– Farha; Rasheed M. Yousuf

Rafidain Journal of Science, Volume 20, Issue 4, Pages 78-94
DOI: 10.33899/rjs.2009.41369

تم فی هذا العمل تصنیع کواشف ومیضیة سائلة باستعمال مواد ومیضیة عضویة هی النفثالین والانثراسین وإذابتها فی مذیب عضوی هو الزایلین وبعد إجراء القیاسات لصافی المساحة تحت المنحنی (Net Area) لمدى واسع من التراکیز للمحالیل الومیضیة العضویة المحضرة. وجد إن أفضل ترکیز (الترکیز الذی نحصل عنده على أعلى شدة للومیض) لکل من الکاشف الومیضی المکون من النفثالین المذاب فی الزایلین هو(40g/l)، وللکاشف الومیضی المکون من الانثراسین المذاب فی الزایلین هو(1.4g/l). ثم لغرض دراسة تأثیر الإخماد على هذه الکواشف فقد أضیفت تراکیز مختلفة من مواد مخمدة لهذه التراکیز المثالیة.

Determination of the Specific Activity of Cs137 and K40 in Environmental Nineveh Governorate

Ahmad Kh. Emhemed; Rasheed M. Yousuf; Hana Hassan

Rafidain Journal of Science, Volume 19, Issue 4, Pages 205-220
DOI: 10.33899/rjs.2008.42085

The background radioactivity of environmental Nineveh governorate was determined by measuring the radioactivity for each one of cesium Cs137 and potassium K40 in soil, plant and milk using highly parity germanium (HPGe) detector with crystal volume (76 cc) and energy resolution (2.2 keV) at the gamma line (1332 keV) of Co60 radioactive calibration source.
The measurements and sampling procedure cover (41) positions from different parts of Nineveh governorate, the results shows that Cs137 specific activity range is:
(15.89 – 70.97) Bq/kg in soil, (1.1 – 3.73) Bq/kg in plant and (o.63 – 2.1) Bq/kg in milk.
While the K40 specific activity range is: (323.86 – 1025.0) Bq/kg in soil,
(210.51 – 599.134) Bq/kg in plant and (200.25 – 480.1) Bq/kg in milk.
It is noted that the results in this work shows good agreement with other literatures and the activity levels are within the reasonable values denoted by authorized agency, as well as the fluctuations in results may be due to the geological and geographical differences.

X-ray Hazard from Colour Television Sets and Video Display Terminals

Qusay KH. AL; Mazin F. Mahrok

Rafidain Journal of Science, Volume 17, Issue 3, Pages 1-5
DOI: 10.33899/rjs.2006.43382

Measurement and assessment of dangerosity of X- ray leakage from coloured television (TV) and video display terminals (VDT) are attempted. Three different techniques have been used (X-ray film, scintillation counter and Geiger counter). A comparison of the X-ray film result with literature value is made. Another comparison of the three techniques with published values is also made.
Although big differences are noticed between most of the readings cited in the literature and those found in the present work, it can be seen that all reading are less than the maximum limit of the natural background radiation dose (2 m Sv/y).