Main Subjects : Physics

Simulation of the Gamma Attenuation through Borate Glass Using Genat4

Shlair I. Mohammed; Ali H. Taqi; Abdulahdi M. Ghalib

Rafidain Journal of Science, 2021, Volume 30, Issue 2, Pages 11-22
DOI: 10.33899/rjs.2021.168339

In this study, the protection parameters of the gamma-ray of Borate glass system containing 10Li2O. 10K2O. 20Na2O. xPbO.                   (60-x) B2O3 where x to be varied as 0, 10, 20, 30, 40, 50 and 60, were investigated using the Monte Carlo simulation code Geant4. The coefficients of attenuation were calculated using the Monte Carlo simulation code Geant4 as a function of the incident photon 0.0015 MeV and 15 MeV. The accuracy of the simulated results was tested by using the XCOM program. The Geant4 and XCOM results showed a reasonable agreement. The results of the attenuation parameters showed that the sample of higher PbO concentration absorbs a greater number of photons, therefore the attenuation coefficients are increased while the tenth-value layer (TVL) values are decreased due to the increase in PbO from 0 to 60%. The linear and mass attenuation coefficients decreased when the photon energy increase and many peaks are observed.

Design of Microstrip Patch Antenna for GSM Applications and Study the Effect of Substrate Thickness on the Bandwidth

Mona R. Talab; Fares S. Alatallah; Ahmed A. Ahmed

Rafidain Journal of Science, 2021, Volume 30, Issue 2, Pages 42-52
DOI: 10.33899/rjs.2021.168345

In this paper, a microstrip patch antenna designed for GSM (Global System for Mobile) applications at the frequency 0.9GHz (0.89 - 0.96 GHz), using an epoxy FR-4 substrate with an isolation constant of 4.3 and a thickness of 1.6mm and improving its radiate properties. The thickness of the substrate was changed, where a thickness of 3.2 mm was taken, then a third thickness of 1.4 mm was taken, then the results of changing the frequency beam width for each thickness were compared and it was noticed that the frequency beam width at the thickness 3.2 is equal to 0.41018GHz and the working frequency is 0.939 GHz, but at the thickness of 1.6 mm, the beam width The frequency is 0.35448GHz With a working frequency of 0.963GHz and the beam width at the third thickness 1.4 is equal to 0.26998GHz and a working frequency of 0.94939GHz, the thin film antenna was designed and the results simulated using (CST) 2019 software.

The Development of Microwave Applications in Medical Field

Qusay Kh. Al_Dulamey

Rafidain Journal of Science, 2021, Volume 30, Issue 2, Pages 23-39
DOI: 10.33899/rjs.2021.168340

Through this analysis, we conclude that there is no fixed limit to the radiation threat, but that the risk begins at any stage. High frequency electromagnetic waves have detrimental effects, in particular, on the body and sensitive cells. One of the susceptible organs affected by radiation is the reproductive system, though it does not contain a high percentage of blood. This plays an important role in reducing the heat generated by the cumulative microwave effect. Most studies have agreed that these radiation communication systems have an effective effect on red and white blood cells due to the heme's cellular structure, which is influenced by magnetic and electrical fields, creating a change in the cellular composition and composition. Thus, a shift in cell function clinically visible symptoms of photo damage are fine lines and rhytides. Traditionally, for nonsurgical facial rejuvenation, truncated and non-truncated lasers were used, in addition to that its cumulative side effects and its heroes time are in the work. Initially used to target photo damage, radio frequency represents an idea of radiation surgery technology. It is different from lasers   such as current of an electric is used as well as a light source. It is widely used for treating slouch of skin, deflations, skin tags and freckles, and dimple in dermatology. This work aims to show the different kinds of radiofrequency tools and their application. Assessing the effectiveness of these tools is based on facts.  This paper discusses the latest RF function, applications, clinical advance.         Application guide for various RF applications. The findings were positive with multiple clinical tools of radio waves, although more trials were non-randomized, non-comparative trials using local methods of assessment. Most non- truncated radio waves are a healthy, suggest method that produces moderate results for skin rejuvenation and cellulite therapy. Radio wave is act as replace from surgery.

Estimating the Concentrations of Radioactive Radon Element along with the Radiation Risk Indicators at the Oncology and Nuclear Medicine Hospital in Mosul, Iraq

Firas Mohammed Ali Al-jomaily; Edrees Gh. Eedan; Mayan Khalil

Rafidain Journal of Science, 2021, Volume 30, Issue 1, Pages 100-115
DOI: 10.33899/rjs.2021.167691

The radioactive radon concentration was determined in addition to the radiation risk indicators represented by the effective annual dose and the effective alpha energy concentration, as well as the lung cancer cases per year at selected and different well-ventilated sites in the Oncology and NuclearMedicineHospital in Mosul. The long-term cumulative counting technique of nuclear traces deposited on the nuclear track detector CR-39. Twenty-five sites were chosen within the hospital in its multiple buildings (administration building, laboratory building and consulting building), where these reagents were installed in the lower part inside the radiometric dose room (Dosimetry) with certain geometric dimensions for 47 days as an irradiation time Calibration was performed with a 2µci radium(222Ra) source. The results showed that the radon concentrations recorded for all sites ranged between (41.44 - 79.88 Bq.m-3) with a rate of (59.32 ± 9.08 Bq.m-3) and could be considered within the global normal levels. As for the annual effective dose (HE), as its value ranged (1.3-2.52 mSv.y-1) with a rate of (1.84 ± 0.29 mSv.y-1), while the annual effective dose values ​​ranged between (4.48-8.6 mWL) with a rate of 1.08 mWL (± 5.92, and the risk index is lung cancer). It included within the values ​​(32.52-54.34 / 106 person) and a rate of (35.16 ± 5.39 / 106person), and these indicators can be considered in light of the results obtained as falling within the normal global levels. I indicated the sites of the refrigerator of refrigerated drugs, the office of mental health and the laboratory store the highest-level Radon concentration, as well as radiation hazard indicators, while its values ​​were within the lowest levels recorded in the advisory path. The highest level of radon concentration as well as radiation risk indicators were identified at the sites of the medication refrigerator, the mental health clinic, and the laboratory store, although their values were below the lowest levels documented in the advisory corridor. The results showed that the Oncology and Nuclear Medicine Hospital is logically radio-safe, despite the fact that some of its sites reported high levels of radon concentration compared to other sites, especially when combined with appropriate global levels that do not exceed ( (200-300 Bq . m-3).

New Formula for Negative Beta Decay Energy in the range

Aws Tariq Qasim; Firas Mohammed Ali Al-jomaily

Rafidain Journal of Science, 2020, Volume 29, Issue 4, Pages 53-65
DOI: 10.33899/rjs.2020.167316

In this research the negative beta decay energy  has been determine for light, medium, and heavy nuclei (even – even, even – odd, odd – even and odd – odd), which their atomic numbers are from . An equation of the negative beta decay energy was derived in terms of the nuclear binding energy of the parent and daughter nuclei instead of the mass difference between them as it known. After making the conceptual derivations, the Liquid Drop Model (LDM) was used to calculate the decay energy, which results in agreement with the experimental and theoretical values. With this, a new and general formula for negative beta decay energy () was achieved. The statistical relationship of standard deviation and root mean square deviation have been used to determine the reliability of this model to determine the negative beta decay value. The results showed that there is an acceptable agreement between the experimental and theoretical values, especially for medium and heavy nuclei, and less acceptable in light nuclei due to the presence of magic numbers and their interference in this spectrum of beta particles. 

Assessment of Natural and Industrial Radioactivity and Radiological Hazard in Sediments of Tigris River of Dhuluiya City, Iraq

Shaimaa J. Khudair; Abdullah M. Ali; Nada F. Tawfiq

Rafidain Journal of Science, 2020, Volume 29, Issue 4, Pages 14-22
DOI: 10.33899/rjs.2020.167309

Specific activity of Natural and industrial radionuclides in sediments samples collected from the Tigris river of Dhuliya city of Salah Uddin Governorate was measured using γ-ray spectroscopy. The γ-ray spectrometry was carried out using NaI(Tl) detector. The results indicated that specific activity of 226Ra ranged from 1.51Bq/kg to 84.68Bq/kg with average 15.48Bq/kg, 228Ac ranged from 1.47 to 49.84Bq/kg with average 8.36Bq/kg, 40K ranged from 56.51Bq/kg to 711.34Bq/kg with average 418.47Bq/kg and 137Cs ranged from 2.77Bq/kg to 9.78Bq/kg with average 2.88Bq/kg. The average concentrations of these radionuclides were less than the internationally accepted limit ​​except for 40K radionuclides. The radiological parameters of the radium equivalent activity (Raeq), absorbed gamma dose rate (Dγ), external and internal annual effective dose (AEDE), external and internal risks (Hex, Hin), and gamma radiation representative level index (Iγ) were calculated and found to be lower than the internationally acceptable limit value.

Physical Thermal Effect Test for Treatment of Polystyrene Plastic Waste

Ali Mohammed Ahmed; Ahmed N. Mahmood; Rasheed M. Yousuf

Rafidain Journal of Science, 2020, Volume 29, Issue 4, Pages 32-43
DOI: 10.33899/rjs.2020.167314

Two groups of plastic waste manufactured from polystyrene (PS) were used to manufacture samples, the first group of polystyrene (Ps) is not subject to recycling, while the second group was made of polystyrene (Ps), which was subject to a recycling process using the sulfonation method and by (19.3%). The first group was called the saturated polystyrene group, while the second group was called unsaturated polystyrene, Manufactured samples underwent surface hardness and bending durability checks before and after exposure to a thermophysical effect at temperatures ((T = 60, 80 and 100 C
)). The results indicated that the polystyrene cannot maintain its surface hardness in case it is exposed to a thermophysical effect. The amount of decrease in the value of the surface hardness takes the exponential form instead of the linear shape, the extent that the value of the surface hardness is fixed with the increase in the time period of exposure to the thermophysical effect. Even if the change in the effect value was relatively few. And that there is a critical time period in which the bending resistance of the polystyrene material reaches the maximum value, after which the ability of the material to resist the bending decreases with an increase in the time period of exposure to the thermophysical effect. The effects associated with the bending process (tension, compression, shear) collapse after exposure to the thermophysical effect during a critical time period due to the loss of the continuity property in the body of the polystyrene, and finally the material loses its ability to resist the bending, and this characteristic depends on the quality of the polystyrene .

Effect of Pole Face Thickness on Magnetization of the Single-pole Magnetic Lens

Sarah Akrm Sultan; Abdullah Idrees Alabdullah; Abdulsamee fawzi Abdel Azeez

Rafidain Journal of Science, 2020, Volume 29, Issue 4, Pages 44-52
DOI: 10.33899/rjs.2020.167315

An innovative design of a polepiece magnetic lens has been introduced so that the thickness of the pole face can be changed without affecting the other geometrical parameters of the lens, for a systematic study to develop the important region of ​​the pole face to improve the performance of  single polepiece magnetic lenses and to get a high intensity magnetic overflow and a narrow half width. A study was conducted for each design that includes calculating the axial magnetic field and studying the magnetization of the lens by means of the finite element method using the (EOD) program to get the best design for the polepiece proposed in this study, it was found that the best magnetic properties and the highest value of magnetic flux and the lowest value of the axial magnetic field strength half-width were at the value of the pole face thickness equal to (0.5 mm). The effect of the magnetic circuit iron and the magnetic field of the coil on the total magnetic field produced from the designed polepiece magnetic lens was also studied.

Single-Stage Amplifiers Simulation for Microwave Applications Using S-Parameters

laith Al Taan; Nawfal Y. Jamil; Salah I. Saleh

Rafidain Journal of Science, 2020, Volume 29, Issue 3, Pages 47-60
DOI: 10.33899/rjs.2020.166312

A single-stage amplifier circuits containing transistor as BJT or FET transistor were designed for the microwave application using S-parameters, and developed as a lumped circuit then converted to its equivalent microstrip distributed circuits on different substrates such as Alumina (er=9.8) and Beryllia (er=6.3). The output results as power gain Gp, noise figure NF, and stability factor K were obtained. These results were compared with other published worked included circuits having the same conditions. The comparison shows that in case of the feedback applied to the circuit the Gp achieved about (~1.5) dB for BJT circuits along (0.6-1) GHz and noise figure increased about double, where for FET circuit the increasing in Gp about (7) dB along (2) GHz, and noise figure was less than BJT circuit. The physical characteristics are discussed with respect to substrate and show that the substrate with high permittivity was helpful to reach the higher operating frequency and good power gain values.

The Effect of Sn, Cu -Doping on the Optical and Structural Properties of CdSe Film Deposed by CBD Technique

Laith M. Al Taan; Rahma N. Thannoon

Rafidain Journal of Science, 2020, Volume 29, Issue 3, Pages 38-49
DOI: 10.33899/rjs.2020.166317

Cadmium selenide (CdSe) thin films have been prepared by chemical bath deposition technique (CBD) on glass slides with a solution concentration of 0.5M, at temperature 50oC, pH=9 for 3 hours. The doping process was carried out with Tin (Sn) and Copper (Cu) with different concentrations 0.5%, 1%, 1.5% also by CBD tech. The effects of different doping concentration on the optical and structural properties of the doped CdSe films was studied. The energy gap was found decreased by increasing the concentration of Sn up to 1.81eV, while the energy gap increased with increasing the Cu concentration. The relation between the absorption coefficient and the incident photon energy was shown that the electronic transitions between the energy bands are direct type. XRD studies revealed that pure and doped thin films was polycrystalline with cubic structure (111) preferential orientation.

Multicore Photonic Crystal Fibres Designing for Multiplexers and Demultiplexers Applications

Miami Mohammed; Ahmad K. Ahmad

Rafidain Journal of Science, 2020, Volume 29, Issue 3, Pages 61-72
DOI: 10.33899/rjs.2020.166313

Coupling properties are significantly affective when the three cores of a photonic crystal fiber are identical or non-identical, we analyze this numerically using COMSOL Multiphysics software 5.5 to gain insight into the nature of the coupling between these cores. A non-identical core produced by a slight mismatch in the propagation constants which are sufficient to suppress coupling between the cores or may strengthen the coupling between the cores because they sometimes have equal propagation constants. By manipulating the central core diameter (increase or decrease) compared to the diameter of the other cores can limit the strength of the coupling between the cores, the coupling efficiency and the coupling length of the cores become decreasing. Introducing anisotropy in three core diameters resulting in the modes of these cores are isolated in a certain region of the array of photonic crystal fiber, as a result, the coupling is suppressed between the modes of cores at the wavelength 1064nm while some coupling appears between modes of the cores in the wavelength 1550nm where the coupling coefficient is evaluated as a function of wavelength. The coupling between three cores reveals novel characteristics more than two cores and this useful for Multiplexers and Demultiplexers applications

Assessment of Radiation Hazards in Soil Samples from some Selected Areas of Mosul City in Iraq

Zainab N. Hamoo; Laith A. Najam

Rafidain Journal of Science, 2020, Volume 29, Issue 2, Pages 86-94
DOI: 10.33899/rjs.2020.165370

Naturally radionuclides that present in soil such as 226Ra,232Th and 40K contribute in large amount of radiation that population exposed in these areas, the assessment of radiation levels is very important to evaluate radiological hazards  due to exposure radiation  and comparing these results with the recommended world average values.                                                                                                            
         In this study we measure the levels of natural radioactivity of some areas from Mosul city, north of Iraq. We used gamma-spectroscopy NaI(Tl) detector and estimated the activity concentration levels of natural radionuclides in soil. Results show that the concentration of radionuclides of 226Ra, 232Th and 40K was ranged from (6.2±0.10-26.51±0.44) Bq/kg with mean value 11.06±0.18 Bq/kg for 226Ra and between (11.33±0.82- 40.78±2.77) Bq/kg with mean value 24.82±1.75 Bq/kg for 232Th, While the concentration radio-isotope of 40K was (82.88±1.53-482.42±7.85)Bq/kg with mean value 228.83±3.93 Bq/kg.                                                                                  
         Radiological hazard Indices were determined according to the activity concentration for these radionuclides in the areas under study of Mosul city, the results show that the values of Radium equivalent Req were ranged between (36.89-104.61) Bq/kg with mean 69.98 Bq/kg which is less than the recommended world values that mustn`t exceed 370 Bq/kg. While the values of absorbed dose Dr were ranged between (17.5-48.05) nGy/h with mean 32.21 nGy/h which also less that the recommended world values that equal 60 nGy/h, where the external and internal radiological indices were ranged between 0.099-0.282 with mean value 0.188 for Hex and between (0.118-0.341) with mean 0.219 for Hin ,where these mean values are within the world mean values (not exceed from one) and finally the results show  that the magnitude of gamma index (Iɣ) ranged between (0.278-0.766) with mean value 0.522 and  also these values are less than the world average                  (not exceed from one).from this study we can concluded that there is no radiological hazard due to the direct and continuous exposure of radiation on human and organisms that lives in Mosul city.                

Using Different Equations of States to Study Volume Ratio, Bulk Modulus and Energy Gap in Nano Ge Under High Pressure

Asmaa fareed Abdulateef; Adnan M. Al-Shiekh

Rafidain Journal of Science, 2020, Volume 29, Issue 2, Pages 64-72
DOI: 10.33899/rjs.2020.165366

This research has been used EOSs (Birch-Muranghan, Vinet, mL-J, Thomsen and Madan) to study the effect of high pressure on  nano-Ge parameters by calculating compressed volume V/Vo, Bulk modulus BT, Energy gap Eg, under high pressure. All equations used showed compatibility with the experimental results for calculating V/Vo of nano-Ge under high pressure, an increase in the Bulk modulus BT with an increase in high pressure and an increase in the energy gap of nano Ge with high pressure.

Design and Implementation of Tri Band Microstrip Patch Antenna with Bandwidth Enhancement for GSM, WLAN, WiMAX system

Ahmed Abdulkareem Ahmed Luhaiby; Fares S. Alatallah; Yessar. E. Mohammed Ali

Rafidain Journal of Science, 2020, Volume 29, Issue 2, Pages 73-85
DOI: 10.33899/rjs.2020.165368

In this research design of tri-band microstrip antenna suitable for wireless GSM, WLAN and WiMAX application. The total size of the proposed antenna (107 × 110 × 1.6) mm3. The substrate material type is FR-4(epoxy). Return losses of -34.328 dB, bandwidth 24.8%, gain 2.8738 dB at frequency 0.912 GHz and return losses -37.375 dB, bandwidth 52.33%, gain 2.0411 dB at frequency 1.842 GHz and  return losses -27.753 dB , bandwidth 40%, gain 4.4762 dB at frequency 2.4 GHz and  return losses -33.471 dB, bandwidth 4%, gain 4.9543 dB at frequency 3.534 GHz.                     
The simulated results are obtained using the software computer simulation technology CST. The simulated results are verified with experimental results which are in acceptable agreement.

90 nm Current Mirror Based Transimpedance Amplifiers for Fiber Optic Applications

Asmaa Z. Al-Kawaz; Muhammed Subhi Hameed Alsheikhjader

Rafidain Journal of Science, 2020, Volume 29, Issue 2, Pages 10-22
DOI: 10.33899/rjs.2020.165355

This research displayed the new design of a 90 nm CMOS technology transimpedance amplifier (TIA) with current mirror executed. The goal and challenge in this research are to arrive at low consumption of power while activating other required performances. Integrated circuits CMOS(Complimentary Metal-Oxide Semiconductor) tend to be the best technology achieving the desired level of integration with appropriate speed, cost, and gain for this were used. The proposed transimpedance amplifier (TIA) consists of a common-gate (CG) topology with a current mirror to increase TIA gain and common-source (CS) TIA with the active feedback resistor. In addition, to verify the proposed TIA performance, circuit simulations are done in NI Multisim 14.1 using 90nm CMOS technology parameters. Therefore, the simulation results of the proposed TIA for 90 nm CMOS technology indicate a transimpedance gain of 66.63 dBΩ with -3dB frequency bandwidth of around 1.0 GHz for input capacitance of 250 fF, input-referred noise of 25.413 pA/and with the power consumption of only 1.08m at 1V supply voltage. This low power consumption and supply voltage are the main emphases of this work in comparison with other research literature.

Low Noise with Wide Band Transimpedance Amplifier for Nonlinear Fiber Optical Applications

Muhammed Subhi Hameed Alsheikhjader

Rafidain Journal of Science, 2020, Volume 29, Issue 1, Pages 71-78
DOI: 10.33899/rjs.2020.164476

A current-mirror based transimpedance amplifier with inductor feedback simulation is reported. A 90 nm channel length process technology was simulated using N-MOSFET and P-MOSFET transistors. A transimpedance gain of 43.92 dBΩ was achieved with a bandwidth of 10 GHz (from 5 GHz to 15 GHz). The whole process was simulated using 1V DC supply voltage. From simulated data, pole frequency was found to be around 19.25 GHz. At 35 ºC, the transimpedance amplifier circuit was simulated and it was found that the input referred noise current of the circuit is 14.14 pA/√Hz at 5 GHz, 10 pA/√Hz at 10 GHz and 16.32 pA/√Hz at 15 GHz to cover the entire bandwidth of the circuit.
Keywords: Optical Preamplifier, Front-End Preamplifier, Optical receiver, Transimpedance  Amplifier.

Single-Stage Amplifiers Simulation for Microwave Applications Using S-Parameters

laith Al Taan; Nawfal Y. Jamil; Salah I. Saleh

Rafidain Journal of Science, 2020, Volume 29, Issue 1, Pages 47-60
DOI: 10.33899/rjs.2020.166311

A single-stage amplifier circuits containing transistor as BJT or FET transistor were designed for the microwave application using S-parameters, and developed as a lumped circuit then converted to its equivalent microstrip distributed circuits on different substrates such as Alumina (er=9.8) and Beryllia (er=6.3). The output results as power gain Gp, noise figure NF, and stability factor K were obtained. These results were compared with other published worked included circuits having the same conditions. The comparison shows that in case of the feedback applied to the circuit the Gp achieved about (~1.5) dB for BJT circuits along (0.6-1) GHz and noise figure increased about double, where for FET circuit the increasing in Gp about (7) dB along (2) GHz, and noise figure was less than BJT circuit. The physical characteristics are discussed with respect to substrate and show that the substrate with high permittivity was helpful to reach the higher operating frequency and good power gain values.

Theoretical Study of the Effect of High Pressure on the Elastic and the Thermal Properties of MgO

Janan F. A. Ali

Rafidain Journal of Science, 2020, Volume 29, Issue 1, Pages 62-70
DOI: 10.33899/rjs.2020.164475

Elastic-Thermo properties of alkaline earth oxide MgO have been studied by using two types of Equation of State ( EOS ), Isothermal Shanker EOS and Modified Kumar EOS.
The elastic moduli, sound velocities and the pressure-compression relationship of MgO have been studied up to a pressure 150 GPa by using Shanker EOS which depends on volume short-range force constant of inter atomic potentials. The results show agreement with the researcher results Upadhyay and Sharma.
The relationship between the solid density and elastic moduli gave values both of compression and shear waves velocities, the theoretical results are below rate about 6% with the whole range of the experimental data.
The thermal properties at high( temperature and pressure) of MgO have been studied by applying unified theory of Kumar EOS, this theory based on thermodynamic analysis and to the thermal expansion,thus the inharmonic term is arising and used in the calculation of thermal properties of MgO.
The results which are obtained from the effect of high temperature and high pressure on MgO properties are fitting with an experimental data.
Keywords: MgO, elastic moduli, thermal properties under high pressure, equation of state (EOS).

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, 2018, 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.


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

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

Rafidain Journal of Science, 2018, 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.

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, 2014, 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, 2011, 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, 2010, 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, 2009, 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, 2009, 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, 2008, 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, 2006, 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).