In this paper a simple tool for seismic design of steel structures for a selected ductility level is presented. For this purpose, a consistent set of earthquakes is selected and sorted based on the maximum acceleration of ground surface. The selected records are applied as the base motion to a single-degree-of-freedom system with strain hardening and the maximum response acceleration is determi...

A solution is presented to a doubly mixed boundary value problem of the torsion of an elastic layer, partially resting on a rigid circular base by a circular rigid punch attached to its surface. This problem is reduced to a system of dual integral equations using the Boussinesq stress functions and the Hankel integral transforms. With the help of the Gegenbauer expansion formula of the Bessel f...

PURPOSE The purpose of this study is to evaluate and compare the shear bond strength of the gingiva-colored composite resin and the tooth-colored composite resin to porcelain, metal and zirconia. MATERIALS AND METHODS Sixty cylindrical specimens were fabricated and divided into the following 6 groups (Group 1-W: tooth-colored composite bonded to porcelain, Group 1-P: gingiva-colored composite...

A series of fatal commercial aviation accidents starting in the 1970s led to the identification of thunderstorm-related wind shear as a critical hazard to aircraft takeoffs and landings. In aggregate, these accidents resulted in over 400 fatalities and pressured the Federal Aviation Administration (FAA) to develop effective warning technologies. In response, the aviation community invested in a...

abstract background and aim: one of the major problems with resin composite restorations is the weakness of bonding between the new and aged composites. since appropriate micromechanical retention is necessary for the repair of aged resin composite restorations, the level of surface roughness after sandblasting can be influential in this regard. considering the diverse composition of available ...

OBJECTIVE It is proved that acidic soft drinks that are commonly used, have an adverse effect on dental structures, and may deteriorate oral heath of our patients and orthodontic appliances. The aim of this study was to compare the effect of yoghurt drink with other soft drinks on the shear bond strength of orthodontic brackets. MATERIALS AND METHODS Seventy-five first premolar teeth extracte...

The quality characteristics of velvet antlers obtained from Formosan sambar deer (Cervus unicolor Swinhoi) (SDVA), harvested from 63 to 81 d during the velvet antler growth period, were evaluated by investigating the relationships between antioxidant levels; including content, activity, and content/activity ratios, and physical properties; including shear force values, color, and Ca content. Th...

Two modeling techniques for practical nonlinear static analysis are implemented to support the development and usage of a new Limit Design method for special reinforced masonry shear walls. The new seismic design alternative is under consideration for future versions of the building code requirements for masonry structures in the U.S. The proposed simplified models were applied to a planar one-...

The resistance of shallow foundations to lateral loads is often relied upon to transmit the base shear forces from the ground to a building during an earthquake. Considering the importance of this link in the lateral load path it receives little attention in current design practice in New Zealand. An assumption is commonly made, either explicitly or implicitly, that the combination of sliding f...

This paper considers the problem of shear building damage estimation subject to earthquake ground excitation using the Kalman filtering approach. The structural damage is assumed to take the form of reduced elemental stiffness. Two damage estimation algorithms are proposed: one is the multiple model approach via the optimal two-stage Kalman estimator (OTSKE), and the other is the robust two-sta...