Background: In this research, thermomechanical analysis of a 3D model of dental bridge between the first mandibular premolar and first molar was analyzed in Ansys Workbench software. Materials and Methods: The dental bridge made of lithium disilicate ceramic and type II gold alloy was subjected to fluid at 4°C and 60°C for 5 seconds at occlusal and lingual surfaces. Moreover, the static and impact loads were applied at the center of the dental bridge. The first static load was a vertical force, and the second static load was in the form of an oblique force at an angle of 45° with respect to occlusal plane, oriented towards the buccal side. The impact loading simulation was performed for an impactor with different kinetic energy normal to the occlusal plane. Results: The maximum thermal stress in the bridge and dental tissue at 4°C is obtained at more than 60°C, yet dependent on the coefficient of thermal expansion, the elastic modulus, and the temperature field. The maximum thermal stress in gold bridges is about 30% higher than in ceramic bridges. In addition, it was found that in the case when only vertical occlusion forces are acting, there is a significant underestimation of the maximum stress of 40% compared to the case of an oblique force. The stress intensity under rigid impactor with an initial kinetic energy of 2. 2, 8. 6, and 19. 4 mJ was obtained at 1. 35, 2. 2, and 3 times the static stress, respectively, and the reaction force at roots was proportional to the magnitude of the kinetic energy of the impactor. Conclusion: As evidenced in this study, the stress created in the dental bridge in impact loading and cold thermal stimulation is more critical than other loadings. On average, the ceramic dental bridge demonstrates less stress in both tooth tissue and dental bridge.

Background and Aim: In patients with complete denture, some clinicians have used modelling plastic impression compound (MPIC) along tissue conditioner (TC) materials simultaneously. Little information is available on the composition of these materials and the interaction between them. The purpose of this study was to evaluate the influence of two components of MPIC on the structure and chemical composition of TC.Materials and Methods: In this experimental study, MPIC specimens were provided in 25×2 mm discs. Specimens were randomly divided into three groups and were immersed in ethanol 70%, plasticizer (dibutyl phthalate) and a mixture of them (ethanol 70% and dibutyl phthalate). All of the discs were weighed with a digital balance before and 2, 4, 6 and 24 hours after immersion. Values were analyzed by non parametric Kruskal-Wallis (a= 0.05) and SPSS 16 for Windows (SPSS Inc., Chicago, IL) was used for statistical analysis.Results: Statistical analysis indicated significant differences among all groups (p>.05).Conclusion: Dibutyl phthalate (DBP) had high impact on the solubility of MP, while the mixture of dibutyl phthalate (DBP) and ethanol demonstrated the highest impact.

A dynamic two dimensional problem of thermoelasticity with double porous structure has been considered to investigate the disturbance due to normal force and thermal source. Laplace and Fourier transform technique is applied to the governing equations to solve the problem. The transformed components of stress and temperature distribution are obtained. The resulting expressions are obtained in the physical domain by using numerical inversion technique. Numerically computed results for these quantities are depicted graphically to study the effect of porosity. Results of Kumar & Rani [42] and Kumar & Ailawalia [43] have also been deduced as special cases from the present investigation.

The vehicle braking system is considered to be one of the most fundamental safety-critical systems in modern vehicles, as its main purpose is to stop or decelerate the vehicle. The frictional heat generated during braking application can cause numerous negative effects on the brake assembly, such as brake fade, premature wear, thermal cracks and disc thickness variation. In the past, surface roughness and wear at the pad interface have rarely been considered in studies of the thermal analysis of a disc brake assembly using the finite element method. The ventilated pad-disc brake assembly is built by a three-dimensional model with a thermo mechanical coupling boundary condition and multi-body model technique. The numerical simulation for the coupled transient thermal field and stress field is carried out sequentially with the thermal-structural coupled method, based on ANSYS software, to evaluate the stress fields of deformations that are established in the disc with the pressure of the pads and in the conditions of tightening of the disc; thus, the contact pressure distributions field in the pads is obtained, which is another significant aspect in this research. The results obtained by the simulation are satisfactorily compared with those of the specialized literature.

Background and Aim: There are different methods of oral health education for child population. Theater show is a method that has not received enough attention until now. The aim of this study was to evaluate the effect of using theater show on dental health education in Yazd female elementary students.Materials and Methods: This was a quasi experimental study performed by using pre- and post-test method in Iran over the year 2004. One elementary school from each region of the city was selected. Twenty students from each grade of each school were included in the study (n=200). The information on knowledge, attitudes and practice of oral health were collected by using a valid and reliable questionnaire before and after theater show performance. Data were analyzed using SPSS and Wilcoxon signed rank test.Results: This study showed that the theater show could improve knowledge, attitude and proper oral health practice of children. The effect of the theater show on knowledge was more than attitude and was more on attitude than practice (P<0.001). Only literacy on the part of mothers was significantly correlated with practice (P=0.021). There were significant correlations between Knowledge (P=0.020), Attitude (P=0.0001) and oral health Practice (P=0.022) with students' grade level.Conclusion: This study showed that using theater show for oral health education, could improve the oral health related knowledge, attitude and proper oral health practice by elementary school students.

Digital printing is affected by several parameters therefore, Process changes aimed at improving printer engine performance must take into consideration not only the process variables, but also the melt rheological variables. The THERMO-MECHANICAL properties of Konica Minolta BizHub C350 toners (in four colors) have been investigated with TGA, DSC and rheometer, as well as the physical and optical properties that have been evaluated using optical microscope, laser scattering particle size analyzer and spectrophotometer. The thermo-rheological evolution of the electrophotographic printing toners in the fusing stage of the image development has been investigated thoroughly. It was found that by increasing the temperature, the toner particles undergo initial surface fusing at around 70 °C which is followed by reduction in viscosity. However, the melting of the particles takes place at 155-172 °C which is resulted in completely merged particles. The melting temperature of the fur colors are occurred at a specific order that matches the standard printing sequence of four-color printing.

A molecular dynamics simulation study is employed to investigate the elastic and basic thermal properties of thermoset polymer based nanocomposite sample reinforced by CNT. The COMPASS force filed was used to construct the simulation box. The simulation box contains the cured epoxy resin molecules obtained from cross linking process of DGEBA and DETA which were located around the CNT (10, 10). NVT and NPT ensembles were performed to equilibrate the system and convergence of temperature, energy and density have been checked. The elastic constants of molecular sample of nanocomposite were determined based on stiffness matrix and compared with the molecular results of pure resin. The results show that the Young's modulus in the transverse direction of nanocomposite model is less than that in longitudinal direction indicating the transversely isotropic behaviour at atomic scale. Glass transition temperature (Tg) and coefficient of thermal expansion (CTE) were calculated through the linear fitting of densitytemperature diagram for the CNT-reinforced nanocomposite model. Atomistic simulation results showed decrease in Tg and CTE comparing to the pure epoxy. Moreover, the simulation results were compared with the measured values and good agreements are observed.

Different types of contact, including contact between node pairs, any-contact of nodes, and contacts of the entire network, are used to characterize social relations in mobile social networks. Different modes of routing, from the point of view of message delivery semantics, encompass unicasting, multicasting, any-casting, and broadcasting. Studies have shown that using probability distribution functions of contact data, which is mainly assumed to be homogeneous for nodes, improves the performance of these networks. However, there exists an important challenge in studies on distributions. A lot of works apply the distribution of one type of contact to other types. Hence in routing applications, it causes to use of the distribution of one type of contact for any mode of routing. This study provides a complete solution to model each type of homogeneous contact data distribution and to use them in different modes of routing. We propose a routing algorithm that uses this new model. Results show that our solution improves the average latency of comparing methods Epidemic, TCCB, and DR about 3.5-times, 30%, and 45%, respectively. It achieves a delivery rate of about 5% and 6%, and average latency about 6% and 8% better than that of DR and TCCB, respectively.