Background: Deterioration of maxillofacial silicone properties due to microbial colonization is a common problem and leads to the replacement of the prosthesis. Incorporation of the antimicrobial agent into the silicone could be a solution. The purpose of this study was to evaluate the effect of silver-zinc zeolite addition on some mechanical properties of a maxillofacial silicone (VST-50). Materials and methods: Total 120 specimens were fabricated and divided into 3 groups: 40 specimens for tear strength test, 40 specimens for tensile and percentage of elongation tests and 40 specimens for Shore A hardness and surface roughness. Each group was divided into 4 subgroups according to the amount of zeolite added (0% “control”, 0.5%, 1% and 1.5%). One-way ANOVA and Tukey’s HSD tests were used to analyze the study data. FTIR revealed a chemical interaction between zeolite and silicone. Results: Study results revealed a highly significant increase in tear strength (p<0.01) in all experimental subgroups. The tensile strength of 1% filler was significantly higher than the control group (p<0.01) while 0.5% and 1.5% showed a non-significant increase. All experimental groups demonstrated a highly significant decrease in the percentage of elongation and a highly significant increase in roughness (p<0.01). The subgroup with 1.5% zeolite showed a highly significant increase in hardness, other subgroups showed a non-significant increase. Conclusion: The addition of 1% Ag-Zn zeolite improved some mechanical properties of VST-50 maxillofacial silicone.
Effect of Silver-Zinc Zeolite Addition on Mechanical Properties of Maxillofacial Silicone
Ag-Zn zeolite
VST-50 maxillofacial silicone
Tear strength
Tensile strength
Shore A hardness
Roughness
Publication Date
Sun Oct 22 2023
Journal Name
Iraqi Journal Of Science
Elastic Electron Scattering form Factors for Odd-A 2s-1d Shell Nuclei
charge density distributions
elastic electron scattering form factors
odd- A 2s 1d shell nuclei
root mean square charge radii
occupation numbers of higher states for K Mg Al Si 19 25 27 29
and P 31 nuclei
The charge density distributions (CDD) and the elastic electron scattering form
factors F(q) of the ground state for some odd mass nuclei in the 2s 1d shell, such
as K Mg Al Si 19 25 27 29 , , , and P 31
have been calculated based on the use of
occupation numbers of the states and the single particle wave functions of the
harmonic oscillator potential with size parameters chosen to reproduce the observed
root mean square charge radii for all considered nuclei. It is found that introducing
additional parameters, namely; 1 , and , 2 which reflect the difference of the
occupation numbers of the states from the prediction of the simple shell model leads
to very good agreement between the calculated an
Publication Date
Mon Nov 01 2010
Journal Name
Al-nahrain Journal Of Science
Chemical Elements Diffusion in the Solar Interior
The standard solar model and equation of state have been used to study relative diffusion of Hydrogen and Helium in the present time for solar interior
as a function of distance and depth from the center of the star. The effects of temperature and density on diffusion velocity for these chemical elements have been explaned.
It is found that heat flow which is arising from these reactions leads to an increase in helium diffusion velocity
while the temperature and density leading to a decrease in Hydrogen diffusion velocity. This means that Hydrogen behaves inversely with that for helium does through these reactions. Accordingly
diffusion percentages for Hydrogen
Helium and other Heavy Elements could be determined for the main sequence stars and white dwarf stars.
Publication Date
Sat Oct 01 2016
Journal Name
Journal Of Theoretical And Applied Information Technology
Factors affecting global virtual teams’ performance in software projects
Today the trend is to perform software development work via distributed geographical area among team
individual or even as an organization. However
due to the global market and international presence of many companies
there is a need to implement a global virtual teams. The global virtual team members are gradually engaged in globalized business environments across space
time and organizational boundaries via information and communication technologies. A global virtual team relies on communication
collaboration
and information exchange are the most important criteria in global virtual teams’ operations. The purpose of this paper is to answer two research questions. The first research question is to identify the factors affecting global virtual teams’ performance. A systematic literature review was conducted to answer the first research question. The second research question is on what the rank of the factor affecting the global virtual teams’ performance according to their level of effect on global virtual teams’ performance. Online survey was conducted within 103 developers and IT managers from eight IT companies to answer the second research question. The Statistical Package for Social Science (SPSS 22) was used to analyze the collected data. In this study
we investigated factors that affect global virtual teams’ performance
factors considered include cultural differences
language problems
time-zone differences
team size
technical problems
lack of trust
lack of sufficient training
and ICT problems. Also the findings indicated that lack of sufficient training is the highest level of effect on global virtual teams’ performance. On the other hand
team size is the lowest level of effect on global virtual teams’ performance. © 2005 - 2016 JATIT & LLS. All rights reserved.
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