Carbonate materials are mostly found in tropical areas, where exploiting gas and oil resources are of high concern. Their unique behavior under shear Loading first was recognized during oil resources investigations in the Persian Gulf. Off-shore structures have been placed on carbonate soils which are highly crushable. During storms cyclic Loading imposes on the bases of structures lied down on seabed. Cyclic Loading, therefore, may trigger liquefaction phenomenon which leads to soil collapse and a catastrophic event. Therefore, stability of these expensive structures need to be investigated. To this aim carbonates and in medium dense to medium dense state was considered and its response under varied cyclic shear stress ratio was studied.

The fracture of High Performance Concrete (HPC) occurs in a. very explosive manner without previously exhibiting any cracking pattern as a warning. By using special fibre cocktails, (combinations of steel and polypropylene fibres) the explosive failure behaviour of High Performance Concrete (HPC) may be avoided. With the variation of cocktail composition different seismic performance of the material could be adjusted. An experimental programme has been carried out to compare the behaviour of high performance concrete and cocktail fibre reinforced high performance concrete beam column joint under Reversed cyclic Loading. HPC mix has been designed to obtain a concrete grade of M 60.The mix was designed based on modified ACI 211 method suggested by M.S. Shetty [1]. Five numbers of exterior beam-column joints modeled to one fourth of a prototype of a building [10], designed according to Bureau of Indian Standards were cast and tested under Reversed cyclic Loading. The first specimen was made with high strength concrete and designed as per IS 456:2000 [16] and reinforced accordingly without considering the seismic requirement. The second specimen was made with high strength concrete and reinforcements in the beam column joint portion was detailed according to IS 13920-1993 [17], for seismic requirements. The remaining three specimens were similar to the first one but various combinations of cocktail fibre concrete in the joint region (constant %(1.5) of steel fibre and 0 to 0.4% of polypropylene fibre) were used. The cocktail fiber combinations of 1.5% of steel fibre and 0.2% of polypropylene fibre have best performance considering the strength, energy dissipation capacity, and ductility factor. Results indicate that the addition of polypropylene fibre to the steel fibre is optimum for a percentage of 0.2, which have more energy absorbing capacity, less joint rotation, more shear strength, more curvature ductility factor and less reinforcement strain.

The fracture of High Performance Concrete (HPC) occurs in a very explosive manner without previously exhibiting any cracking pattern as a warning. By using special fibre cocktails, (combinations of steel and polypropylene fibres) the explosive failure behaviour of High Performance Concrete (HPC) may be avoided. With the variation of cocktail composition different seismic performance of the material could be adjusted. An experimental programme has been carried out to compare the behaviour of high performance concrete and cocktail fibre reinforced high performance concrete beam column joint under Reversed cyclic Loading. HPC mix has been designed to obtain a concrete grade of M 60. The mix was designed based on modified ACI 211 method suggested by Shetty [1]. Five numbers of exterior beam-column joints modeled to one fourth of a prototype of a building [2], designed according to Bureau of Indian Standards were cast and tested under Reversed cyclic Loading. The first specimen was made with high strength concrete and designed as per IS 456:2000 [3] and reinforced accordingly without considering the seismic requirement. The second specimen was made with high strength concrete،designed as per 1893 (Part I) 2002 [4] and reinforcements in the beam-column joint portion was detailed according to IS 13920-1993 [5], for seismic requirements. The remaining three specimens were similar to the first one but various combinations of cocktail fibre concrete in the joint region (constant % (1.5) of steel fibre and 0 to 0.4 % of polypropylene fibre) were used. The cocktail fibre combinations of 1.5% of steel fibre and 0.2% of polypropylene fibre have best performance considering the strength, energy dissipation capacity, and ductility factor. Results indicate that the addition of polypropylene fibre to the steel fibre is optimum for a percentage of 0.2, which have more energy absorbing capacity, less joint rotation, more shear strength, more curvature ductility factor and less reinforcement strain.

In this study, the behavior of nine steel frames having various infill properties under Reversed-cycling Loading was investigated experimentally. The steel frame systems consist of a single story with span/height ratios of 1, ½ and 2. The selected infill properties are no infill, brick-wall infill and brick-wall + plaster infill. The Reversed-cycling Loading was applied to test the specimens laterally to simulate the seismic load. Then, the displacements occurring at the specimens were measured. Strength envelopes, rigidity decreases and energy dissipation properties of the infilled frames were determined and the results obtained are compared.

Rock structures are subjected to cyclic tension-compression Loading due to a blasting, earthquake, traffic, and injection-production in an underground storage case. Therefore, studying the fatigue behavior of rock samples under this type of Loading is required. In this study, the accumulated fatigue damage for a Green Onyx rock sample consisting only one mineral composition with two-step high-low sequences of Loading levels was investigated under a Completely Reversed Loading condition. New apparatus based on the R. R. Moore fatigue test machine was designed to assess this type of Loading. A comparison was conducted between the predicted behavior of the Linear Damage Rule and the experimental data and a new damage model was proposed based on the experimental observation. The results showed a good agreement between the proposed damage model and the experimental data.

A module M is said to be coretractable if there exists a nonzero homomorphism of every nonzero factor of M into M. We prove that all right (left) modules over a ring are coretractable if and only if the ring is Morita equivalent to a finite product of local right and left perfect rings.

For a Banach algebra A, we introduce c: c(A), the set of all  2 A such that   : A! A is a Completely continuous operator, where   is de ned by   (a) = a
 for all a 2 A. We call A, a Completely continuous Banach algebra if c: c(A) = A . We give some examples of Completely continuous Banach algebras and a su cient condition for an open problem raised for the  rst time by J. E Gal e, T. J. Ransford and M. C. White: Is there exist an in nite dimensional amenable Banach algebra whose underlying Banach space is re exive? We prove that a re exive, amenable, Completely continuous Banach algebra with the approximation property is trivial.