Background: Poly (methyl methacrylate) has been widely utilized for fabrication of dentures for many years as it has good advantages but not achieved all demands of the mechanical properties such as low transverse strength, low impact strength, low surface hardness, high water solubility and high water sorption. Material and method: To provide bonding between ZrO2 nanoparticles and PMMA matrix, the ZrO2 Nano-fillers were surface-treated with a saline coupling agent. Plasma surface treatment of polyethylene (PE) fiber was done to change surface fiber by using DC- glow discharge system. For characterization of interring any functional groups, the (FTIR) spectrum were done .then the mechanical properties studied to choose the appropriate percentages to complete study. Results: The results revealed that highly significant difference between groups in transverse strength, the highest mean value (96.1700 N/mm2) found in 2.0% polyethylene fibers and 1.5% salinized Zirconium oxide nanoparticles group, highly significant increase in impact strength (7.69 Kj/m2), surface hardness (92.35) and highly significant decrease in water sorption (0.0016 mg/cm2) and water solubility (0.0013 mg/cm2). Conclusion: the use of saline coupling agent with ZrO2 and oxygen plasma treatment PE fiber provided an effective procedure for getting good bonding with the PMMA matrix to give enhanced properties for the composite.
As a result of the development and global openness and the possibility of companies providing their services outside their spatial boundaries that were determined by them, and the transformation of the world due to the development of the means of communication into a large global market that accommodates all products from different regions and of the same type and production field, competition resulted between companies, and the race to obtain the largest market share It ensures the largest amount of profits, and it is natural for the advertising promotion by companies for their product to shift from an advertisement for one product to a competitive advertisement that calls on the recipient to leave the competing product and switch to it
... Show MoreThe statistical distributions study aimed to obtain on best descriptions of variable sets phenomena, which each of them got one behavior of that distributions . The estimation operations study for that distributions considered of important things which could n't canceled in variable behavior study, as result this research came as trial for reaching to best method for information distribution estimation which is generalized linear failure rate distribution, throughout studying the theoretical sides by depending on statistical posteriori methods like greatest ability, minimum squares method and Mixing method (suggested method).
The research
... Show MoreIn this paper, the effect of wear in the fluid film journal bearings on the dynamic behavior of rotor bearing system has been studied depending on the analytical driven of dynamic stiffness and damping coefficients of worn journal bearing. The finite element method was used to modeling rotor bearing system. The unbalance response, critical speed and natural frequency of rotor bearing system have been studied to determine the changes in these parameters due to wear. MATLAB software was used to find the analytical values of dynamic coefficients of journal bearing. The results of rotor mounted on fluid film journal bearings showed that the wear in journal bearing increases the amplitude of unbalance response and decrease critical speed, sta
... Show MoreAneurysms of the cortical branches of the middle cerebral artery (MCA) are rare. They usually are secondary to traumatic or infectious etiologies and are rarely idiopathic. The specific characteristics of idiopathic aneurysms in such location are not well defined in the literature. The authors report a rare case of a ruptured giant idiopathic cortical MCA aneurysm with review of the available literature on this clinical entity.
A 24-year-old female presented with headache, disturbed level of consciousness, and right-sided weakness. Imaging studies showed a left frontoparietal intracer
A simple, rapid spectrophotometric method has been established for the determination of chlorpromazine hydrochloride (CPZ) in its pure form and in a tablet formulations. The suggested method is based on the oxidative coupling reaction with4-nitroainlline using KIO3 in acidic solution to produce a violet colored product with maximum absorption at λ=526 nm.The analytical data obtained throughout this study could be summarid as follows: 1ml of 1M HCl (pH=2.2), 1 ml of 4-nitroanilline (1x10-2M), and 1.5ml of (1x10-2)KIO3 per 25 ml reaction medium. The order of a
... Show MoreThe genus Larra Fabricius, 1793 (Hymenoptera: Crabronidae) is recorded for the first time from Vietnam. Three species and two subspecies belonging to this genus as follows: L. amplipennis (F. Smith, 1873); L. carbonaria (F. Smith, 1858); L. fenchihuensis Tsuneki, 1967; L. polita polita (F. Smith, 1858) and L. polita luzonensis Rohwer, 1919 are presented. Keys to both sexes of the three species and two subspecies reported here are provided.
lar water heating systems with heat pipes of three diameter groups of 16, 22 and 28.5 mm. The first and third groups had evaporator lengths of 1150, 1300 and 1550 mm. The second group had an additional length of 1800 mm. all heat pipes were of fixed condenser length of 200 mm. Ethanol at 50% fill charge ratio of the evaporator volume was used as the heat pipes working fluid. Each heat pipe condenser section was inserted in a storage tank and the evaporator section inserted into an evacuated glass tube of the Owens- Illinois type. The combined heat pipe and evacuated glass tube form an active solar collector of a unique design.
The resulting ten solar water heating systems were tested outdoors under the meteorological conditions of Bag
Abstract\
In this research, estimated the reliability of water system network in Baghdad was done. to assess its performance during a specific period. a fault tree through static and dynamic gates was belt and these gates represent logical relationships between the main events in the network and analyzed using dynamic Bayesian networks . As it has been applied Dynamic Bayesian networks estimate reliability by translating dynamic fault tree to Dynamic Bayesian networks and reliability of the system appreciated. As was the potential for the expense of each phase of the network for each gate . Because there are two parts to the Dynamic Bayesian networks and two part of gate (AND), which includes the three basic units of the
... Show MoreAn encryption system needs unpredictability and randomness property to maintain information security during transmission and storage. Although chaotic maps have this property, they have limitations such as low Lyapunov exponents, low sensitivity and limited chaotic regions. The paper presents a new improved skewed tent map to address these problems. The improved skew tent map (ISTM) increases the sensitivity to initial conditions and control parameters. It has uniform distribution of output sequences. The programs for ISTM chaotic behavior were implemented in MATLAB R2023b. The novel ISTM produces a binary sequence, with high degree of complexity and good randomness properties. The performance of the ISTM generator shows effective s
... Show MoreObjective: determine the effectiveness of an education program on youth's level of awareness towards
household waste control.
Methodology: A Quazi-experimental study was conducted. Non-probability (quota sample) of (80) young
persons is selected from Baghdad Governorate. They are divided into two equal groups of (40) subjects for the
study group which is exposed to the household waste control educational program. The remaining is the
control group which is not exposed to the educational program.
Results: The findings of the study indicated that youth of the study group have got benefits from the
implementation of the educational program towards household waste control and change has occurred to
their awareness tow