The purpose of this paper is to investigate analytically the fully grouted rock BOLT interaction with grout and rock in pullout test and to determine the load-displacement curve of the BOLT head (beginning of the bonded section). Usually, the pullout test output is only the load-displacement curve. This paper discusses how to use this curve to determine the BOLT-grout-rock interaction. For MODELING BOLT-grout interface behavior, coupling (compete for bonding), partial decoupling, decoupling with the residual shear strength, and complete decoupling have been considered. With increasing the applied load, two possible cases including complete pullout and BOLT shank yielding are considered. Based on experimental results, a model for the shear stress along a fully grouted BOLT is assumed. According to this model, the distribution of axial stress in the BOLT and displacement of the BOLT head is determined. It is also assumed that the BOLT is sufficiently long, which is usually used in underground excavations. Based on the presented analytical method, the BOLT head load-displacement curve is determined by assuming input parameters. This curve is compared with a pullout test result.

Using BOLT shear connectors in Steel-Concrete-Steel (SCS) slabs is very important due to producing a complete steel plates connection and adjusting the sandwich thickness desirably. Therefore, in the present research, a numerical study is conducted on the flexural behavior of SCS sandwich slabs with stud-BOLT shear connectors under the effect of the quasi-static concentrated load. For this purpose, first, the experimental specimens extracted from the previously published study were numerically modeled and quasi-statically analyzed using explicit dynamic analysis. Then based on the tests, the models were validated. Subsequently, the effect of the parameters, including the thickness of steel plates, stud-BOLTs diameter, the concrete core thickness, center-to-center distance of stud-BOLT connectors, and the concrete core strength was evaluated based on the numerical models on the failure modes and the force-displacement curve. Finally, using the experimental setup and gene expression programming (GEP) algorithm, several numerical models were planned to predict the maximum strength of the slabs and a simple relation was proposed. The maximum strength resulting from the proposed relation and numerical models had an acceptable agreement with an error of 11% based on mean absolute percentage error (MAPE).

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.

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.

For making rivet and BOLT connections, making a hole is necessary. While basic S-N graph can be extracted from design documents, analysis of stress can be used for two different approaches. The first approach is the theoretical derivation of analytical relations with simplified assumptions like planar stress or uniform BOLT load distribution. The other one is the numerical simulation using robust codes like Abaqus software. By using these two approaches, residual stress distribution around the hole can be extracted in various conditions. In this experiment, an aluminium 2024-T3 plate with 3.2 mm thickness is considered. The stress analysis results and basic S-N graph were combined and discursive S-N graphs were obtained for different cold-expanded BOLTed holes. These graphs were compared with experimental data in several steps. First, the BOLT fastening was considered. In the second step, cold expansion was considered and in the final step, the effects of fastening BOLTs and nuts and cold expansion was considered simultaneously. At last, a comparison between various steps was drawn. The results of this study showed that this new analytical method on distribution of residual stresses around cold expansion holes is as effectiveness as old methods.

Precise investigation of the connections in a steel structure is important, and inaccuracy in the design and implementation of connections not only does cause failure in the connection, but also has a devastating effect on other members of the structure. BOLTed end plate connections are commonly used in steel structures. There are two types of beam-to-column flange connections, four-BOLT and eight-BOLT. The four-BOLT connection is used for low anchor values and the eight-BOLT connection is used for large bending anchor values. In this study, the cyclic behavior of the restrained beam-to-column connections with end plate under cyclic loading has been evaluated. In the calculations, all of the parameters affecting the behavior of this connection have been investigated and solutions are proposed to reach the maximum connection capacity. Since the behavior of this connection depends on several factors, two general models of beam connection to different columns with beams of 30 and 40 cm depth are considered for research purposes. The thickness of end plate, shape of end plate, thickness of the column flange, strength or material of the BOLTs, the necessity of using continuity plate, stiffener and doubler plate are among the parameters considered in the analyzes. According to the results of this study, the use of a thin-walled end plate leads to local buckling of plate. The use of continuity plate is very important and prevents local buckling in the panel zone. Also, in cases where the thickness of the column web is low, the use of a doubler plate will also be necessary. In addition, the use of a stiffener improves the flexural strength of the section.