Introduction: This study was designed to examine the effects of addition of the combination of polymerized polymethyl methacrylate (PMMA) and zirconia (ZrO2) particles to heat cure PMMA resin on impact strength, surface hardness, and roughness. Methods: The 70% (w/w) of polymerized PMMA powder (particle size: 0.70mm) was mixed with 30% (w/w) of zirconia powder (ZrO2) (1mm) to produce PMMA-ZrO2 filler. Ninety acrylic specimens created were divided into three groups containing 0% wt (Control group), 2% wt, and 4% wt, PMMA-ZrO2 filler. Ten specimens were used for impact strength, surface hardness and roughness test, blindly. Data were analyzed via oneway ANOVA and the Tukey post hoc test using R 3.6.3. Results: There was statistically significant difference among study groups regarding surface hardness and roughness (p < 0.001). Yet, nonsignificant difference was found on the subject of impact strength (p=0.33). Post hoc test showed statistically significant difference for all pairwise comparisons as regards surface hardness and roughness (p < 0.05). Conclusion: The incorporation of PMMA-ZrO2 filler did not improve impact strength (resistance during an unexpected blows or dropping). Yet, increased surface roughness and hardness, concentration-dependently.
The influence of bias current on the bandwidth of chaotic signals in semiconductor lasers by optical feedback has been studied experimentally and numerically. The measured data reveal that the bandwidth increase when the system becomes chaotic and this chaotic signal has a broadband spectrum so it can be used as a carrier for the quantum key. Mixing chaotic signal and quantum key make a very small change in chaotic bandwidth that does not affect the security of data transmitted.
The research included four chapters starting with the chapter dealing with the problem of child abuse which was one of the most important educational and social problems faced by children from their parents or family members. The most common forms of abuse are physical and psychological violence. The problem of school delays is also one of the most important educational and psychological issues that concern educators, which occur because of violence and neglect of the family. The study pointed out that domestic violence is one of the issues that has started to alarm both the global and local communities, because childhood is one of the most important stages of the human development system, which is healthy in terms of physical, mental, p
... Show MoreThe research aims to study strategic training and its impact on improving the performance of the inspectors general offices in Iraqi ministries, through two variables strategic training Which include Four Dimensions ( Strategic analysis , Formulation of Training Strategy , Implement the Training Strategy , Evaluation ) and Performance included Three dimensions ( Efficiency , Effectiveness , Added-Value).
This research problem is that the Offices of Inspectors rely on pre-made training Programs received from training centers without designing the training programs that provide the employees with the skills and abilities that lead to the implementation of the current and future goals of the orga
... Show MoreThe aim of the research is to know the level of time management application and its impact on the performance of the job, a survey search in the general company for communication and information technology and provide recommendations that help employees to optimize the use of time and improve performance, which is an important element in controlling the various functions of the company. In order to achieve the objectives of the research, the questionnaire was based on two main variables and distributed to a random sample of (44) employees in the company out of (308) employees, thus the proportion of the sample (14%). After collecting the samples from the sample, there are (6) incomplete forms that have been retri
... Show MoreThis research studies the effect of addition of some nanoparticles
(MgO, CuO) and grain size (30,40nm) on some physical properties
(impact strength, hardness and thermal conductivity) for a matrix
blend of epoxy resin with SBR rubber. Hand –Lay up method was
used to prepare the samples. All samples were immersed in water for
9 weeks.
The Results showed decreased in the values of impact strength and
hardness but increased the coefficient of thermal conductivity.
In this research, dynamical study of an SIR epidemical model with nonlinear direct incidence rate (Beddington-De Angelis ) type, and regress of treatment investigated .An analytical study to the model shows that there are two equilibrium points appear, the discussed successfully with sufficient condition, the existence of local bifurcation and Hopf bifurcation was analyzed, finally numerical simulations are done to explain the analytic studies.
Based on the needs of the scientific community, researchers tended to find new iterative schemes or develop previous iterative schemes that would help researchers reach the fixed point with fewer steps and with stability, will be define in this paper the multi_implicit four-step iterative (MIFSI) which is development to four-step implicit fixed point iterative, to develop the aforementioned iterative scheme, we will use a finite set of projective functions ,nonexpansive function and finite set from a new functions called generalized quasi like contractive which is an amalgamation of quasi contractive function and contractive like function , by the last function and a set of sequential organized steps, we will be able to prove the existen
... Show MoreUmbilical cord blood (UCB) contains hematopoietic and mesenchymal stem cells(HSCs,MSCs) that have proven useful clinically to reconstitute the hematopoietic system in children and some adults . Fifteen cord blood samples were collected from placenta of newly delivered women in AlKadhemia hospital in Baghdad for normal vaginal delivery. Mono nucleated cells (MNCs) were isolated by using density gradient centrifugation and the MNCs count and viability were determinated by trypan blue.MNCs were cryopreserved using the cryoprotectant solution of 10% concentration of dimethyl sulfoxid (DMSO)using slow cooling and rapid thaw. The aim of the present study
... Show MoreDuring this article, we have a tendency to show the peristaltic activity of magnetohydrodynamics flow of carreau fluid with heat transfer influence in an inclined tapered asymmetric channel through porous medium by exploitation the influence of non-slip boundary conditions. The tapered asymmetric channel is often created because of the intrauterine fluid flow induced by myometrial contraction and it had been simulated by asymmetric peristaltic fluid flow in an exceedingly two dimensional infinite non uniform channel, this fluid is known as hereby carreau fluid, conjointly we are able to say that one amongst carreau's applications is that the blood flow within the body of human. Industrial field, silicon oil is an example of carreau
... Show MoreThis research aims to identify how organizational compatibility, which represents the independent variable, affects higher performance, which is considered a dependent variable, given the importance of these variables in industrial organizations and their clear impact on their stability, survival, and growth in the light of changing environmental challenges. Where the practical research problem was represented by the weakness of awareness of the importance toward organizational compatibility and its dimensions (organizational loyalty, organizational similarity, affiliation or membership, compatibility with goals, and compatibility with values), which is meant by the individual's compatibility with the organization in which he/she w
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