By using Berwald connection, we show that there are linear connections Ñ which are projectively equivalent and belong to the same projective structure on TM. We found a condition for the geodesics of the Berwald connection under which Ñ is complete.

Fixity of column base connection plays a major role in overall behavior of steel structures. Several parameters influence the real behavior of the column base connections, among them base plate thickness, anchor bolts and stiffeners details can be mentioned. A nonlinear three dimensional finite element method has been utilized for numerical studying of the behavior of the column base connection. Thickness of the base plate and stiffeners and also sizes and numbers of the anchor bolts were changed in a number of models to determine their effects on the nonlinear behavior of the regular column base connection. It was observed that column base connection characteristics such as its moment-rotation behavior, yielding pattern of base plate and anchor bolts and local stress concentration of the connection elements can be significantly affected by changing any detail of the connecting elements. The effects of each parameter on the behavior of column base connection were categorized and presented in this paper.

In an editorial entitled ‘Time to Connect’, the editors of the magazine Nature1 extended an invitation to Iranian scientists to connect with their western counterparts in various scientific fields in a spirit of cooperation. The subject alluded to in that article concerned Iran’s nuclear energy program, which is so charged by political issues on both sides that I am sure they had little response from Iranian scientists in that respect. We Iranians fully realize that we are considered a pariah state and are thus ostracized by the international community as they rightly mentioned in their editorial. It is unfortunate that in this light, all our historical achievements in science, poetry, or statesmanship are ignored and mocked with historically incorrect depictions….

For buildings to resist and properly dissipate energy during earthquake, suitable connections are those which allow plastic hings develop in beam neither connection elements or welds should fail or break, nor panel zone should be damaged during earthquake. Buttress connection is one that meets all such requirements. A full scale model of this connection is tested in the University of Berkeley. During the research the connection is modeled by finite element method with special consideration of post buckling effects and calibrated with experimental data. Two buttress plates in the top and bottom of beam as well as web stiffeners of beam and column are arranged in the form of a truss and created a rigid zone so plastic hinge is developed in the beam, the elements of connection do not fail, stress concentration in weldes is low and weldes do not damage during loading and plastic zone remained elastic. The effect of buttress plates in top and bottom and web stiffener of beam is studied. For studying, any of these plates are removed and under a new connection is loaded. The results show that if buttress plates are removed, even though plastic hing is developed in the beam but stress concentration is increased in the weld, connection zone is damaged and plasticity is developed in panel zone. If web stiffener of beam is removed, plastic hinge is developed in connection zone and the connection fails.