β Diversity is an ecological concept used to describe the turnover of species across a wide range of spatial and temporal scales, but such knowledge is lacking for macroalgal assemblages of the Red Sea. β Diversity patterns for Red Sea macroalgae were evaluated from different sites (Hurghada, Safaga, and Al-Quseir) and seasons across different environmental disturbances. β Diversity was studied by partitioning the total number of species (γ diversity) into additive components. Geographical heterogeneity was more important than seasonal heterogeneity in structuring macroalgae both at species and functional group levels. Species replacement as a component of β diversity produced dissimilarity in species composition and taxonomic structure. Replacement of species between sites was responsible for the presence of new functional groups of macroalgae. High β diversity and taxonomic similarity values were characteristic of the macroalgae of the Red Sea. The occurrence of small macroalgal thalli that have short life cycles induced high species replacement and subsequently high β diversity, with spatial heterogeneity and environmental gradient as drivers of β diversity. Anthropogenic disturbance at the Safaga site was suggested to induce variation of macroalgal assemblages and functional groups. Excluding rare species from the data set did not change the high values of b diversity.

β Diversity is an ecological concept used to describe the turnover of species across a wide range of spatial and temporal scales, but such knowledge is lacking for macroalgal assemblages of the Red Sea. β Diversity patterns for Red Sea macroalgae were evaluated from different sites (Hurghada, Safaga, and Al-Quseir) and seasons across different environmental disturbances. β Diversity was studied by partitioning the total number of species (γ diversity) into additive components. Geographical heterogeneity was more important than seasonal heterogeneity in structuring macroalgae both at species and functional group levels. Species replacement as a component of β diversity produced dissimilarity in species composition and taxonomic structure. Replacement of species between sites was responsible for the presence of new functional groups of macroalgae. High β diversity and taxonomic similarity values were characteristic of the macroalgae of the Red Sea. The occurrence of small macroalgal thalli that have short life cycles induced high species replacement and subsequently high β diversity, with spatial heterogeneity and environmental gradient as drivers of β diversity. Anthropogenic disturbance at the Safaga site was suggested to induce variation of macroalgal assemblages and functional groups. Excluding rare species from the data set did not change the high values of b diversity.

β Diversity is an ecological concept used to describe the turnover of species across a wide range of spatial and temporal scales, but such knowledge is lacking for macroalgal assemblages of the Red Sea. β Diversity patterns for Red Sea macroalgae were evaluated from different sites (Hurghada, Safaga, and Al-Quseir) and seasons across different environmental disturbances. β Diversity was studied by partitioning the total number of species (γ diversity) into additive components. Geographical heterogeneity was more important than seasonal heterogeneity in structuring macroalgae both at species and functional group levels. Species replacement as a component of β diversity produced dissimilarity in species composition and taxonomic structure. Replacement of species between sites was responsible for the presence of new functional groups of macroalgae. High β diversity and taxonomic similarity values were characteristic of the macroalgae of the Red Sea. The occurrence of small macroalgal thalli that have short life cycles induced high species replacement and subsequently high β diversity, with spatial heterogeneity and environmental gradient as drivers of β diversity. Anthropogenic disturbance at the Safaga site was suggested to induce variation of macroalgal assemblages and functional groups. Excluding rare species from the data set did not change the high values of b diversity.

This paper introduces a new technique for deep drawing of elliptic cups through a conical die without blank holder or draw beads. In this technique an elliptic-cup is produced by pushing a circular blank using a flat-headed elliptic punch through a conical die with an elliptic aperture in a single stroke. A 3D parametric finite element (FE) model was built using the commercial FE-package ANSYS/APDL. Effects of die and punch geometry including, half-cone angle, die fillet radius, die aperture length and punch fillet radius on limiting drawing ratio (LDR), drawing load and thickness strain of the cup have been investigated numerically for optimal process design. A die with half cone angle of 18◦ has shown the best drawability for the new technique. An experimental set-up has been designed, manufactured, and used for experimental production of elliptical shaped sheet-metal cups. A total of seven punches having aspect ratios ranging from 2 to 2.25 and a die with an aspect ratio of 2 have been manufactured and used. Tensile tests were carried out to obtain the stress–strain behavior for the formed sheet metal. Experiments were conducted on blanks of brass (CuZn33) with initial thicknesses of 1.5, 1.9, 2.4 and 3 mm at different clearance ratios (c/t). Effects of blank thickness and clearance ratio on limiting drawing ratio, drawing load and thickness strain were numerically and experimentally investigated. Finite element model results showed good agreement with experimental results. An elliptic cup with a limiting drawing ratio (LDR) of 2.28 has been successfully achieved using the proposed technique and set-up.

This paper introduces a new technique for deep drawing of elliptic cups through a conical die without blank holder or draw beads. In this technique an elliptic-cup is produced by pushing a circular blank using a flat-headed elliptic punch through a conical die with an elliptic aperture in a single stroke. A 3D parametric finite element (FE) model was built using the commercial FE-package ANSYS/APDL. Effects of die and punch geometry including, half-cone angle, die fillet radius, die aperture length and punch fillet radius on limiting drawing ratio (LDR), drawing load and thickness strain of the cup have been investigated numerically for optimal process design. A die with half cone angle of 18◦ has shown the best drawability for the new technique. An experimental set-up has been designed, manufactured, and used for experimental production of elliptical shaped sheet-metal cups. A total of seven punches having aspect ratios ranging from 2 to 2.25 and a die with an aspect ratio of 2 have been manufactured and used. Tensile tests were carried out to obtain the stress–strain behavior for the formed sheet metal. Experiments were conducted on blanks of brass (CuZn33) with initial thicknesses of 1.5, 1.9, 2.4 and 3 mm at different clearance ratios (c/t). Effects of blank thickness and clearance ratio on limiting drawing ratio, drawing load and thickness strain were numerically and experimentally investigated. Finite element model results showed good agreement with experimental results. An elliptic cup with a limiting drawing ratio (LDR) of 2.28 has been successfully achieved using the proposed technique and set-up.

External confinement of concrete columns by means of carbon fiber reinforced polymer (CFRP) sheets can be considered as an efficient technique for their structural strengthening. An experimental research program including 18 circular short column specimens were tested under axial compression load, to investigate the gain strength of reinforced concrete (RC) columns confined with CFRP sheets. The parameters studied were both the volume and configurations of CFRP sheets, the size of cross-section, the percentage of main reinforcement, and the volume of internal stirrups. On the basis of the obtained results, mathematical models (Egyptian code and American Concrete Institute code) proposed to predict the axial compressive strength of non-slender RC column strengthened by means of CFRP sheets are evaluated. These codes showed an underestimation in predicting the axial compressive strength of RC strengthened columns. This, from the authors’ point of view, is attributed mainly to the fact that the proposed models overlooked the amount of internal stirrups when calculating the strength of strengthened columns. Therefore, modifications in the studied models were considered. The modifications take the effective lateral confining pressure due to presence of internal steel stirrups into account. The modified codes showed an acceptable approach to the experimental results