Background: A great dental and biomedical interest had been paid to silver nanoparticles because of their antimicrobial activity. Objective: To evaluate the antimicrobial and cytotoxic activity of a newly developed Nano-silver fluoride that was synthesized from moringa oleifera leaf extract against S. mutants. Material and method: The green synthesis method was used to prepare Nano-silver fluoride from moringa oleifera leaf extract. The minimum inhibitory concentration and the minimum bactericidal concentration were evaluated using brain heart infusion plates, while the cytotoxicity was evaluated by the hemolytic activity. Results: Nano-silver fluoride had a bactericidal and bacteriostatic effect (MIC was 60 ppm and MBC was 120 ppm) the diameter of the inhibition zone increased as the concentration increased. It was toxic at high concentrations and nontoxic at low concentrations. Conclusion: Nano-silver fluoride is a good material to be used in arresting and preventing dental caries and it is safe to be used on humans.
The current paper investigates the effect of cut-out design parameters on load-bearing capacity and buckling behaviour of steel cylindrical shell using a nonlinear finite element analysis in modelling cylinder buckling under longitudinal compressive load. The effect of four geometry design parameters: shell diameter to thickness ratio, cut-out location, orientation, and size were investigated in this study. To enhance the prediction of buckling behaviour, both geometrical and material nonlinearities were considered. An ANSYS APDL code was written and tested by verifying its validity through comparison with former buckling study. The results showed that changing the cut-out location from mid-height of the cylindrical shell towards a
... Show MoreThe present study was conducted in the Tigris River within Baghdad (University of Baghdad campus). The study included some physicochemical parameters and qualitative of epiphytic algae on the host plant (Ceratophyllum demersum) during summer season 2013. The results revealed that the study area was alkaline, hard and oxygenated water. A total of 105 taxa of epiphytic algae was identified. Bacillariophyceae diatoms composed 44.7% of the total and were represented by 42.4% of the order Pennales and 1.9 %of the order Centrales. Chlorophyceae composed 32.3%, followed by Cyanophyceae composed 22.8 % of the total. The total number of epiphytic algae was fluctuated among the study period. Most of the identified algae were benthos type and a few
... Show MoreBackground: Synthetic hydroxyapatite,(Ca10(PO4)6(OH2) can directly bond to bones without infection and fibrous encapsulation, thus is regarded as bioactive and biocompatible. The aim of the study was the estimation of microarchitecture bone parameters include bone mass (gm/cm2) cortical bone width (mm), thread width (mm), marrow space star volume analysis (V*m) and osteoblast, osteocyte cell number. Materials and methods: Ninety-six (96) commercially pure titanium CpTi) used in this study, (48) implants were coated with HA by dipping coating and (48) implants were used as control. They were inserted in (32) Newzland white rabbits and followed for 2 & 6 weeks. Mechanical torque removal test and histomorphometric analysis of bone microarchit
... Show MoreThis research aims to determine the extent of the contribution of organizational downsizing strategies to enhance the health of the researched organization represented by the Directorate of Education in Nineveh, and to achieve this goal, the study provided a simplified intellectual framework for the most important topics covered by writers and researchers for search variables, reinforced by an applied analytical framework for the opinions of (79) individuals responsible for the researched organization. The research adopted organizational downsizing as an independent variable that includes three dimensions represented by (reduction of human resources, job redesign, systemic strategy), while the organizational health represented th
... Show MoreAbstract The wavelet shrink estimator is an attractive technique when estimating the nonparametric regression functions, but it is very sensitive in the case of a correlation in errors. In this research, a polynomial model of low degree was used for the purpose of addressing the boundary problem in the wavelet reduction in addition to using flexible threshold values in the case of Correlation in errors as it deals with those transactions at each level separately, unlike the comprehensive threshold values that deal with all levels simultaneously, as (Visushrink) methods, (False Discovery Rate) method, (Improvement Thresholding) and (Sureshrink method), as the study was conducted on real monthly data represented in the rates of theft crimes f
... Show MoreThe parameter and system reliability in stress-strength model are estimated in this paper when the system contains several parallel components that have strengths subjects to common stress in case when the stress and strengths follow Generalized Inverse Rayleigh distribution by using different Bayesian estimation methods. Monte Carlo simulation introduced to compare among the proposal methods based on the Mean squared Error criteria.