Search results

1

Stopping Power Calculations for Partially Stripped Projectiles in High Energy Region

100%

Tufan M., Köroğlu A., Gümüş H.

Acta Physica Polonica A

|

2005

|

vol. 107

|

issue 3

459-472

EN

The electronic stopping cross-section is calculated in the spirit of the Bethe theory. Interaction potential between projectile and target is regarded to have a Coulombic character and we have modified it to take into account velocity dependences on a number of bound electrons of projectile and an effective charge of projectile and target. These velocity dependences are obtained from the Bohr adiabatic criterion using the Thomas-Fermi atomic model. We have get the electronic stopping cross-section expression using the Bethe approximation; we obtained the stopping cross-section of C and Al for C, O, and Si ions from this expression and compared our results with experiment and other theoretical calculations.

2

Electronic Energy Loss of the Partially Stripped Boron-Like and Carbon-Like Fast Ions

100%

Gümüş H., Özalp C., Köroğlu A.

Acta Physica Polonica A

|

2003

|

vol. 103

|

issue 4

349-363

EN

An analytical formula of the electronic stopping power expression in this study was derived for swift boron-like and carbon-like ions by using first-order perturbation theory and frozen-charge-state model. The Hartree- Fock-Slater determinant was used for the description of the bound electrons attached to ions in the ground state and orbital-screening parameter was determined by variational method. The calculated ground state energies in this study were compared with the results of Clementi-Roetti and they are in good agreement with 5%. It has been observed that the difference of energy loss for boron-like and carbon-like projectiles in a frozen-charge state increases as an atomic number increases. Furthermore, the analytical expression of the effective charge of boron-like and carbon-like projectiles was derived.

3

Nanomechanical Comparison of Commonly Used Dental Crown Cements to a Newly Developed One

76%

Kale E., Arslanoğlu Z., Altan H., Bılgıç F., Tuzlali M., Köroğlu A., Özarslan S.

Acta Physica Polonica A

|

2017

|

vol. 132

|

issue 3

954-958

EN

The main goal of nanoindentation tests is to obtain elastic modulus and hardness of the specimen material from load-displacement measurements. With this study, it was aimed to establish a quantitative relationship between the nanomechanical properties of commonly used dental cements in comparison to a newly developed crown cement and to predict its performance potential. Nanomechanical properties of polycarboxylate cement (PCC), glass-ionomer cement (GIC), dual-cure self-adhesive cement (SAC) and a newly developed glass-carbomer cement (GCC) were investigated by nanoindentation tests. All samples were fabricated according to their respective manufacturer's instructions. Available damage on the surface due to manipulation was removed by grinding with 1200, 2400 and 4000 grit sandpaper, and then polishing on 6, 3, and 1 μm diamond-lap-wheel was performed. Nano-mechanical measurements were done using nanoindenter machine with resolution less than 1 nN and displacement resolution of 0.04 nm. Berkovich diamond indenter tip was used for the nanoindentation tests. For each indentation, a set of nanoindentation tests at least on 6 different locations per specimen surface were performed to obtain more representative mean results. Indentation test load-displacement curves were analysed using Oliver-Pharr method, and one-way ANOVA or Kruskal-Wallis test, following Kolmogorov-Smirnov and Shapiro-Wilk, was used to compare the results. Nanohardness (H_{nano}) values were 0.52± 0.25, 0.45± 0.18, 1.03± 0.82 and 0.43± 0.18 GPa for GIC, GCC, PCC, and SAC, respectively. Reduced elastic modulus (E_{r}) values were 9.51± 6.17, 11.77± 5.04, 27.37± 20.61, 10.33± 5.08 GPa for GIC, GCC, PCC, and SAC, respectively. There was no statistical difference between the tested materials. PCC was the hardest, and GIC was the least hard material, whereas the newly developed GCC was the second, in terms of H_{nano}, before SAC. PCC also had the highest E_{r} mean, compared to the other dental crown cements, suggesting lower elastic properties. SAC was more elastic than GCC and less elastic than GIC. GCC had the second highest E_{r}, standing closer to SAC and GIC. Within the limitations of the current study, it can be concluded that the newly developed glass-carbomer cement is comparable to the other tested commonly used dental crown cements, regarding H_{nano} and E_{r}.

Refine search results

3 Acta Physica Polonica A

1 2017

1 2005

1 2003

3 Köroğlu A.

2 Gümüş H.

1 Altan H.

1 Arslanoğlu Z.

1 Bılgıç F.

1 Kale E.

1 Tufan M.

1 Tuzlali M.

1 Özalp C.

1 Özarslan S.

Stopping Power Calculations for Partially Stripped Projectiles in High Energy Region

Electronic Energy Loss of the Partially Stripped Boron-Like and Carbon-Like Fast Ions

Nanomechanical Comparison of Commonly Used Dental Crown Cements to a Newly Developed One