5,347 research outputs found
Predoctoral Dental Students’ Perceptions of Dental Implant Training: Effect of Preclinical Simulation and Clinical Experience
The aims of this study were to assess 1) differences in perceptions of dental implant training between dental students who received didactic training alone (control group) and those who received didactic plus simulation training (test group); 2) differences in response between students with and without clinical experience in implant dentistry; and 3) the interaction effect of simulation training and clinical experience on students’ satisfaction. A survey was distributed to the control group in 2014 and to the test group in 2015; both groups were at the same U.S. dental school. Data were collected on confidence levels with various implant restorative procedures along with overall satisfaction and number of implant restorations performed by each student. The response rate was 78.7% in the control group and 81.3% in the test group. In the control group, 85.7% of students reported being satisfied with implant training compared to 90.8% of students in the test group. The interaction effect of simulation training and clinical experience on overall student satisfaction was OR=1.5 at 95% CI: 0.8, 3.0. The students who had clinical experience with implant restorative procedures had significantly greater satisfaction than those who did not (OR=4.8, 95% CI: 2.1, 11.1,
On the relationship between the modifications to the Raychaudhuri equation and the canonical Hamiltonian structures
The problem of obtaining canonical Hamiltonian structures from the equations
of motion, without any knowledge of the action, is studied in the context of
the spatially flat Friedmann-Robertson-Walker models. Modifications to
Raychaudhuri equation are implemented independently as quadratic and cubic
terms of energy density without introducing additional degrees of freedom.
Depending on their sign, modifications make gravity repulsive above a curvature
scale for matter satisfying strong energy condition, or more attractive than in
the classical theory. Canonical structure of the modified theories is
determined demanding that the total Hamiltonian be a linear combination of
gravity and matter Hamiltonians. In the quadratic repulsive case, the modified
canonical phase space of gravity is a polymerized phase space with canonical
momentum as inverse trigonometric function of Hubble rate; the canonical
Hamiltonian can be identified with the effective Hamiltonian in loop quantum
cosmology. The repulsive cubic modification results in a `generalized
polymerized' canonical phase space. Both of the repulsive modifications are
found to yield singularity avoidance. In contrast, the quadratic and cubic
attractive modifications result in a canonical phase space in which canonical
momentum is non-trigonometric and singularities persist. Our results hint on
connections between repulsive/attractive nature of modifications to gravity
arising from gravitational sector and polymerized/non-polymerized gravitational
phase space.Comment: 22 pages with two new plots. Discussion on uniqueness added, and
possible links with existing models expanded. Periodicity for 'generalized
polymerized' theory and its comparison with standard polymerization
discussed. References added. To appear in CQ
Optical tweezer for probing erythrocyte membrane deformability
We report that the average rotation speed of optically trapped crenated
erythrocytes is direct signature of their membrane deformability. When placed
in hypertonic buffer, discocytic erythrocytes are subjected to crenation. The
deformation of cells brings in chirality and asymmetry in shape that make them
rotate under the scattering force of a linearly polarized optical trap. A
change in the deformability of the erythrocytes, due to any internal or
environmental factor, affects the rotation speed of the trapped crenated cells.
Here we show how the increment in erythrocyte membrane rigidity with adsorption
of ions can be exhibited through this approach.Comment: Published in Appl. Phys. Lett. 95, 233703 (2009); Two supplementary
multimedia files are available at the journal page:
http://link.aip.org/mm/APPLAB/1.3272269/083949aplv1.mov and
http://link.aip.org/mm/APPLAB/1.3272269/083949aplv2.mo
Geometry modeling and multi-block grid generation for turbomachinery configurations
An interactive 3D grid generation code, Turbomachinery Interactive Grid genERation (TIGER), was developed for general turbomachinery configurations. TIGER features the automatic generation of multi-block structured grids around multiple blade rows for either internal, external, or internal-external turbomachinery flow fields. Utilization of the Bezier's curves achieves a smooth grid and better orthogonality. TIGER generates the algebraic grid automatically based on geometric information provided by its built-in pseudo-AI algorithm. However, due to the large variation of turbomachinery configurations, this initial grid may not always be as good as desired. TIGER therefore provides graphical user interactions during the process which allow the user to design, modify, as well as manipulate the grid, including the capability of elliptic surface grid generation
Algebraic grid adaptation method using non-uniform rational B-spline surface modeling
An algebraic adaptive grid system based on equidistribution law and utilized by the Non-Uniform Rational B-Spline (NURBS) surface for redistribution is presented. A weight function, utilizing a properly weighted boolean sum of various flow field characteristics is developed. Computational examples are presented to demonstrate the success of this technique
Theoretical Study of 2 x 2 Planar Array of Equilateral Triangular Patch Microstrip Antenna on Ferrite Substrate
Russian Policy towards Northeast Asia: The Mongolia Factor
Mongolian Journal of International Affairs Vol.19 2014: 34-4
Evaluating Mongolia’s Experience of Democratization: The Post-Soviet Scenario
DOI: http://dx.doi.org/10.5564/mjia.v0i18.68 Mongolian Journal of International Affairs No.18 2013: 30-4
- …