Shear Behaviour of Ligthweight Sandwich Reinforced Concrete Slabs

A new lightweight sandwich reinforced concrete (LSRC) section has been developed using prefabricated autoclaved aerated concrete (AAC) blocks as infill in the section where concrete is considered ineffective under bending. This paper presents an investigation into the strength and behaviour of LSRC slabs subjected to shear. Eight tests were conducted on four slabs, one solid and three different types of LSRC slabs. Based on the test results, all LSRC slabs exhibited similar behaviour to the equivalent solid slab and had varying shear capacities depending on the profile of AAC blocks infill. The obtained shear capacities were compared with the design values based on several major design codes and found to be within the safety predictions of the codes. ANSYS was employed to develop nonlinear finite element models of LSRC slabs. The numerical results agree well with the experimental one

Paracellular absorption is relatively low in the herbivorous Egyptian spiny-tailed lizard, Uromastyx aegyptia

Extent: 9 p.Absorption of small water-soluble nutrients in vertebrate intestines occurs both by specific, mediated transport and by nonspecific, passive, paracellular transport. Although it is apparent that paracellular absorption represents a significant route for nutrient absorption in many birds and mammals, especially small, flying species, its importance in ectothermic vertebrates has not previously been explored. Therefore, we measured fractional absorption (e) and absorption rate of three paracellular probes (arabinose, L-rhamnose, cellobiose) and of 3-O-methyl D-glucose (absorbed by both mediated and paracellular pathways) by the large herbivorous lizard, Uromastyx aegyptia, to explore the relative importance of paracellular and mediated transport in an ectothermic, terrestrial vertebrate. Fractional absorption of 3-O-methyl D-glucose was high (e = 0.7360.04) and similar to other vertebrates; e of the paracellular probes was relatively low (arabinose e = 0.3160.03, Lrhamnose e = 0.1960.02, and cellobiose e = 0.1460.02), and decreased with molecular mass, a pattern consistent with other vertebrates. Paracellular absorption accounted for approximately 24% of total 3-O-methyl D-glucose uptake, indicating low reliance on this pathway for these herbivorous lizards, a pattern similar to that found in other terrestrial vertebrates, and different from small flying endotherms (both birds and bats).Todd J. McWhorter, Berry Pinshow, William H. Karasov and Christopher R. Trac