A preventing shield for neutrons and gamma rays was designed using alternate layers of water and iron with pre-fixed dimensions in order to study the possibility of attenuating both neutrons and gamma-rays. ANISN CODE was prepared and adapted for the shield calculation using radiation doses calculation: Two groups of cross-section were used for each of neutrons and gamma-rays that rely on the one – dimensional transport equation using discrete ordinate's method, and through transforming cross-section values to values that are independent on the number of groups. The memory size required for the applied code was reduced and the results obtained were in agreement with those of standard acceptable document samples of cross –section, this assists the possibility of using this program for calculation of shields and adopting the shield design shield in this research for shielding from neutron and gamma-rays because the calculation of this designed proved the possibility of efficient attenuation of both of these kinds of radiations through from this theoritical study.
International Journal on Technical and Physical Problems of Engineering
In this study, thermal characteristics of a two-phase closed heat pipe were investigated experimentally and theoretically. A two-phase closed heat pipe (copper container, Fluorocarbon FC-72 (C6F14) working fluid) was fabricated to examine its performance under the effect of input heat flux range of 250–1253 W/m2 , 70% fill charge ratio and various tilt angles. The temperature distribution along the heat pipe, input heat to evaporator section, and output heat from condenser were monitored. A comprehensive mathematical model was developed to investigate the steadystate heat transfer performance of a two-phase closed heat pipe. A steady state analytical model, is presented to determine important parameters on the design of two-phase close
... Show MoreIn this work, silver (Ag) self-metallization on a polyimide (PI) film was prepared through autocatalytic plating. PI films were prepared through the solution casting method, followed by etching with potassium hydroxide (KOH) solution, sensitization with tin chloride (SnCl2), and the use of palladium chloride (PdCl2) to activate the surface of PI. Energy-dispersive X-ray analysis (EDX) showed the highest peak in the (Ag) region and confirmed the presence of AgNPs. The diffraction peaks at 2θ = 38.2°, 44.5°, 64.6°, and 78.2° represented the 111, 200, 220, and 311 planes of Ag, respectively. The FT–IR an
... Show MoreBackground: liver diseases may not be recognized by clinicians, who can lead to a subsequent delay
in the initiation of effective therapies, the commonest presenting signs and symptoms of pediatric liver
diseases include hepatomegaly, jaundice, coagulopathy or elevation of the liver enzymes or waste
products as ammonia.
Objectives: To highlight the etiologies, pattern of presentations and the route of diagnosis of all liver
diseases in children less than 10 years referred to the Gastroenterology and Hepatology Unit in
Children Welfare Teaching Hospital over a six months period.
Patients and methods: A prospective study was conducted in the Gastroenterology and Hepatology
Unit in the Children Welfare Teaching Hospi
The research aims to identify the effect of applying administrative decentralization to an educational performance by assessing educational performance before and after the process of transferring powers from the federal government (the Iraqi Ministry of Education) to local governments (governorates) as well as identifying the appropriate central or decentralized administrative system to advance the educational reality and performance. To achieve the goal of the research, educational data was collected and analyzed, as well as the measurement of educational performance indicators and analysis during two phases, the first represents the stage of applying the central system and spanned between the academic year (2011-2012) and the
... Show MoreThe corrosion behavior and corrosion inhibition of α-brass (65.3% Cu, 34.4% Zn and others 0.3%) in 0.6 mol.dm-3 NaCl solution have been investigated using potentiostatic polarization technique, the main results obtained were expressed in terms of corrosion (Ec) and corrosion current (ic). The research was performed in neutral and slightly acidic media [pH=7 and pH=4] over the temperature range (288-318)K. It was found that the rate of corrosion increases with the increase of acidity and the increase of temperature. The rate of corrosion increased with the increase of temperature in conformity with Arrhenius equation. Values of activation energy (Ea*), pre-exponential factor (A) and entropy of activation (∆S*) have been derived f
... Show MoreIn this paper,a prey-predator model with infectious disease in predator population
is proposed and studied. Nonlinear incidence rate is used to describe the transition of
disease. The existence, uniqueness and boundedness of the solution are discussed.
The existences and the stability analysis of all possible equilibrium points are
studied. Numerical simulation is carried out to investigate the global dynamical
behavior of the system.
Background:Image guided transthoracic needle biopsy (TTNB) has great diagnostic value for the definitive characterization of lung lesions and is an established primary procedure to diagnose pulmonary nodules. It is traditionally performed as an outpatient procedure. It is safe, accurate, sensitive, and can obviate surgical procedure.
Objective: to assess the accuracy and safety of CT-guided TTNB in Baghdad Teaching Hospital
Patients & Methods: From December 2009 to September 2011, we conducted a prospective study of 43 consecutive outpatient and inpatient lung biopsies. An informed consent was obtained from the patients. No sedation is required. All biopsies were performed using CT guidance withou
Many clinical isolates of proteus spp. (30 isolates of P
mirabilis and 30 isolates of P. vulgaris) from patients with urinary
tract infections (UTIs) were examined for their ability to produce
proteolytic enzymes and their ability to form swarming growth. Most
(90%) of P. mirabilis and 60% of P. vulgaris isolates secreta
proteolytic enzymes. A strong correlation was found between the
ability of a strain to secreted proteases and it's ability to form
swarming growth. Non- swarming isolates invariably appeared to be
non- proteolytic. However, some isolates (12 isolates of P. vagaries)
were non- proteolytic even when they formed swarming growth
There are no single materials which can withstand all the extreme operating conditions in modern technology. Protection of the metals from hostile environments has therefore become a technical and economic necessity.
In this work, for enhancing their wear-resistance, boride layers were deposited on the surface of low carbon steel by a pack cementation method at 850 °C for (2, 4, and 6) h using vacuum furnace. The boronizing process was achieved using different concentration of boron source (20, 25, and 30) % wt. into coating mixture to optimize the best conditions which ensure the higher properties with lower time. The coating was characteristic by X ray diffraction (XRD), and it is confirmed t
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