Resilient polymeric materials such as silicone elastomers are currently used for maxillofacial prostheses construction but the strength of these materials and their clinical performance need to be optimized with the addition of reinforcing fillers. This study investigates the effect of zirconia nanopowder addition on tear strength, tensile strength, elongation at break, Shore A hardness, surface roughness and cytotoxicity of VST-50 maxillofacial silicone. Silicone base was mixed with different amounts (1%, 2% and 3%) of zirconia nanopowder using a vacuum mixer. Silicone without filler was used as control for comparison. Scanning Electron Microscopy and Atomic Force Microscopy were utilized to assess the efficiency of high-shear vacuum mixing as filler dispersion method and the surface topography, respectively. Both SEM and AFM images showed that the zirconia nanopowder were distributed fairly well within the polymer. Statistically, highly significant increase in tear strength, tensile strength and hardness with non-significant decrease in elongation at break and non-significant increase in surface roughness were seen with 1% and 2% groups. Whereas with 3% group, there was significant improvement in tear strength, tensile strength and hardness but there was significant undesirable decrease in elongation and increase in roughness. Cytotoxicity test revealed that the addition of zirconia nanopowder was nontoxic to Rat Embryonic Fibroblast (REF) cells and there was non-significant change in the cell viability of all study groups after 24- and 72-hours incubation periods. In conclusion, the addition of 2% by weight nano zirconia to VST-50 maxillofacial silicone could be beneficial in enhancing its performance.
Autorías: Nuha Mohsin Dhahi, Muhammad Hamza Shihab. Localización: Revista iberoamericana de psicología del ejercicio y el deporte. Nº. 6, 2022. Artículo de Revista en Dialnet.
Mixed ligand complexes of bivalent metal ions, viz; M= Fe(II),Co(II),Ni(II),Cu(II), Zn(II), Cd (II), and Hg(II) of the composition Na2[M (Amox)(Sac)3] in 1:1:3 molar ratio, (where Amox = Amoxicillin tryhydrate (C16H19N3O5S.H2O) and Sac = Saccharine(C7H5NO3S) have been synthesized and characterized by repeated melting point determination, Solubility, Molar conductivity, determination the percentage of the metal in the complexes by flame(AAS), FT-IR, magnetic susceptibility measurements and electronic spectral data. The ligands and their metal complexes have been screened for their biological activity against selected microbial strains (gram +ve) and (gram -ve).
Fresh water resources in terms of water quality is a crucial issue worldwide. In Egypt, the Nile River is the main source of fresh water in the country and monitoring its water quality is a major task on governments and research levels. In the present case study, the physical, chemical and algal distribution in Nile River was monitored over two seasons (winter and summer) in 2019. The aims of the study were to check the seasonal variation among the different water parameters and also to check the correlations between those parameters. Water samples were collected from the Nile in Cairo governorate in EGYPT. The different physiochemical and microbiological properties in water samples were assessed. The studied parameters were included: te
... Show MoreThe research statement to the amount of the contribution of information and communication technology in the quality of tourism and hotel services, and determine the relationship between the impact of information and communication and the quality of tourism services technology, The importance of the research is to establish the philosophical thinking of the nature of variables, as a modern administrative terminology and employ them towards the quality of tourism and hotel services, the research dealt with a problem expressed by a number of intellectual and practical questions, Was formulated based on the current situation witnessed by the tourism sector and hotel in Iraq, and the real gap was the lack of awareness of the impo
... Show MoreMixed ligand complexes of bivalent metal ions, viz; M= Fe(II),Co(II),Ni(II),Cu(II), Zn(II), Cd (II), and Hg(II) of the composition Na2[M (Amox)(Sac)3] in 1:1:3 molar ratio, (where Amox = Amoxicillin tryhydrate (C16H19N3O5S.H2O) and Sac = Saccharine(C7H5NO3S) have been synthesized and characterized by repeated melting point determination, Solubility, Molar conductivity, determination the percentage of the metal in the complexes by flame(AAS), FT-IR, magnetic susceptibility measurements and electronic spectral data. The ligands and their metal complexes have been screened for their biological activity against selected microbial strains (gram +ve) and (gram -ve).
Abstract
The study aims to identify the levels of core competencies dimensions and types of organizational flexibility in the investigated organization, as well as to determine the nature of the relationship and the impact of core competencies dimensions with the process of organizational flexibility. Thus, a number of research questions were presented to express the research problem as follows:
- What is the level of the investigated individuals' awareness to core competencies and organizational flexibility across their dimensions and types in the investigated organization?
- To what extent are core competencies and organizational flexibility available in the Organiz
The practice by the administration of human resources on effectiveness of organization crisis as two knowledge fields , it were be until now as center for many studies, but the collect it, study of relation between them ,and The role of practices by the administration of human resources on effectiveness of organization crisis administration were considered a new study and first according to the available and showing studies at this field .
The problem of this research was specified by answer for the question that deal for size of consciousness at the ministry of interior for import of&nbs
... Show MoreThe present study aimed to asspssment the nutrition a program to sample of student from internal departments of Baghdad University (AL-Jadiriya Complex) and the University of AL-MustanSiriya four grades and aged (19-24) year study included 150 male and female students by (75) male and (75) of female register height, weight nd body mass index were study habits and food pattern of the same sample (150) and by aspecial form and take the personal information interviews and record information on food intake during 24 hour .noted adifference practie in the weights and longths of male and female (sample).
BMI rates were within the normal weight as the value of BMI for males aged (19- 21)and (22-24) and (22.21) and (23,37),respectively and th
The present research aims to identify and define the basic dimensions of the information management strategy and the administrative creativity in the Faculty of Management and Economics / the University of Kirkuk, as well as the role played by the dimensions of the information technology management strategy in achieving the administrative innovation in the college and the research problem was formulated in several questions. The research problem was formulated in several questions centered on the correlation between the research variables, and the research was based on a major hypothesis and five sub-hypotheses emerged from which it was subjected to several tests to ensure its validity. The researcher used the descriptive-analyti
... Show MoreThe research topic was chosen as a result of the importance of human resource in business organizations in general and the industrial process in particular. Without the human resource, business organizations cannot continue and achieve success and excellence, and the research problem has been diagnosed in the lack of sales of General Cement Company’s northern products, despite their distinctiveness, standing, and reputation in The market and its products with standard specifications, and through this problem, the following questions were raised: &nbs
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