Introduction: According to appropriate characteristics of glass ionomer cementum and constant increase of its usage in restorative field, so comparison of conventional and resin- MODIFIED glass ionomers seems to be useful. This study was designed to determine the shear bond strength of conventional and resin- MODIFIED glass Ionomers on enamel, dentin and cementum.Methods: This was an experimental study. Totally 60 molar intact teeth were divided into six groups. In groups A and D the surface of enamel was prepared 1mm, in groups B and E, the preparation was continued until the surface of dentin was exposed and in groups F and C the surface of cementum was only refreshed.In groups A, B, and C conventional glass ionomer and in groups F, E, and D resin-MODIFIED glass ionomer was used. For each specimen a plastic cylinder with 2mm diameter and 3mm height was bonded on treated surface and the teeth were filled by the relevant glass ionomer. In groups F, E, and D glass ionomer was light cured for 40 seconds. specimens were loaded to failure in a universal testing machine Then statistical analysis was performed using one- way ANOVA and LSD test (P=0.05).Results: The mean shear bond strength of groups A, B, C, D, E and F were 17.25, 14.77, 15.37, 27.30, 57.80, 23.50 Mpa, respectively. The difference between shear bond strength of groups F, E, and D with groups A, B, and C was statistically significant (P=0.001).Conclusion: The shear bond strength of the resin-MODIFIED glass Ionomers was significantly higher than that of conventional glass ionomer in all three surfaces.

Simultaneous capillary dominated displacement of the wetting and non-wetting phases are processes of interest in many disciplines including modeling of the penetration of polluting liquids in hydrology or the secondary migration in petroleum reservoir engineering. Percolation models and in particular invasion percolation is well suited to characterize the slow immiscible displacement of two fluids when both the GRAVITY and viscous effects are negligible. In particular, the characteristic of the percolating cluster and the other important percolation properties at the breakthrough can be inferred. However, with the inclusion of the GRAVITY forces, the behavior may change. For example, as the magnitudes of the GRAVITY forces are comparable to the capillary forces, we have observed a transition in the structure of the interface (i.e. invasion front) depending on the dimensionless Bond number (i.e. ratio of GRAVITY to capillary forces).We have taken a numerical study of the displacement of two immiscible fluids in the presence of the GRAVITY force in a network of random pores. The main contribution is to investigate the effect of heterogeneity by considering various throat size distributions. We consider the injection to take place from one side of the system and displace the displaced fluid from the other side. The condition of the stability or instability of the front (or interface) is observed to be dependent on the dimensionless bond number as well as the heterogeneity of the system. 

We give in this paper an explicit construction of the covariant quantization of the rank-2 “massless” tensor field on de Sitter (dS) space (linear covariant quantum GRAVITY on a dS background). The main ingredient of the construction is an indecomposable representation of de Sitter group with different indecomposability channels. We here make the choice of a specific gauge fixing in order to get the simplest possible structure of the involved Gupta-Bleuler triplets. We describe the related Krein space structure and covariant field operators kab(c). We show that our gauge fixing eliminates any infrared divergence in the two-point function for the traceless part of this field. But it is not possible to do the same for the pure trace part (conformal sector). This work is in the continuation of our previous ones concerning the “minimally coupled scalar fields and the “massive” tensor field on dS.

This study deals with modeling of GRAVITY anomalies by Compact Inversion Method of Last and Kubic (1983) and Lewi et al (1994). The principle used is to minimize the volume, to maximize of the causative body. The anomalous density distribution is obtained using an iterative technique which is numerically stable and rapidly convergent. This principle can also be adapted to include modeling of GRAVITY anomalies by single density sources. The advantage of this method is that desirable geological characteristics are automatically incorporated into the model with minimum subjective judgments on the part of interpreter. The treatment of noise in data fits naturally into formulations of the inversion procedure. The practical effectiveness of this method is assessed by inversion of synthetic and real acquired over chromite ore in Hormozgan province of Iran.

To interpret the GRAVITY anomaly of a Koromite mine in south - west of Iran, we have used the three dimensional inversion problems. The method introduced by Last and Kubik (1983) and improved by Lewi (1997) for high precision GRAVITY data has been tested to determine the 3-dimensional form of the anomaly. The results of the inversion process have been approved by exploration drill holes in the area recently.

Introduction: Practical problems such as rushing roots toward pot, difficulty of manually filling with water and deficit irrigation due to permeation from regular pots prevents the development of pot irrigation. With regard to increasing irrigation efficiency importance and preventing water loss to fix the problems of this irrigation method. Changing physical structure of pot could solve many problems and issues which this irrigation technique is facing. Comparison of the two major characteristics of localized irrigation hydraulic characteristics (coefficient of variation and distribution uniformity) and also using GRAVITY pressure can achieve a solution for water and energy shortage problems. So far, with knowledge of the role of water pressure at gravitational pressures in hydraulicproperties of these methods, some effective features in these methods application is specified. …

As it is well known, symmetry plays a crucial role in the theoretical physics. On other hand, the Noether symmetry is a useful procedure to select models motivated at a fundamental level, and to discover the exact solution to the given lagrangian. In this work, Noether symmetry in f(T) theory on a spatially homogeneous and anisotropic Bianchi type I universe is considered. We discuss the Lagrangian formalism of f(T ) theory in anisotropic universe. The point-like Lagrangian is clearly constructed. The explicit form of f(T) theory and the corresponding exact solution are found by require-ment of Noether symmetry and Noether charge. A power-law f(T), the same as the FRW universe, can satisfy the required Noether symmetry in the anisotropic universe with power-law scale factor. It is regarded that positive expansion is satisfied by a constrain between parameters.