This study examines the relationships between the structure of fancy bouclé yarns and the bending stiffness of the input threads that are used to make those fancy yarns. Four fancy bouclé yarns and an extra two confirmation bouclé yarns... more
This study examines the relationships between the structure of fancy bouclé yarns and the bending stiffness of the input threads that are used to make those fancy yarns. Four fancy bouclé yarns and an extra two confirmation bouclé yarns were made to test the impact of the bending stiffness of the effect input threads. Six fancy yarns were made to test the impact of bending stiffness of the core thread on the fancy yarn structure. The structure of the fancy yarn was defined by the number of fancy profiles, the size of fancy profile, the circularity ratio of fancy profile and the shape factor of fancy yarn. It was found that increasing the value of the stiffness of the effect thread increased the size of fancy profile but decreased both the number of fancy profiles and the shape factor of fancy yarn. Those relationships were represented by regression models that were significant at α = 0.10. The deviation between the theoretical values and the real values was −14.39% and 2.07%. Furthe...
It is challenging to consummately predict the mechanical characteristics and behavior of polymeric hybrid composites, especially if they are produced with different weaving patterns, because of their anisotropic nature. However, polymeric... more
It is challenging to consummately predict the mechanical characteristics and behavior of polymeric hybrid composites, especially if they are produced with different weaving patterns, because of their anisotropic nature. However, polymeric hybrid composites are becoming an essential element in the major technologies due to its improved mechanical properties. This article focuses on study of flexural behavior of woven fabric like carbon, glass, basalt, and hybrid epoxy polymeric composites and the effect of fiber orientation on mechanical properties of hybrid and non-hybrid composites. Experimental study has been carried out to investigate flexural strength and flexural chord modulus of elasticity of glass fabric reinforcing polymeric composite (GFRPC), carbon fabric reinforcing polymeric composite (CFRPC), basalt fabric reinforcing polymeric composite (BFRPC) and hybrid composites. For this study, 0° and 45° fibers orientation were contemplated. Composite panels were fabricated using vacuum assisted resin transfer molding (VARTM) method. Test specimens were prepared from fabricated composite by using waterjet machine cutting. The specimens were tested in accordance with ASTM standards. The experimental testing using three points bending tests, it is observed that carbon fiber reinforced composite had better performance for all orientations, compared to other composites and the hybrid composite fabricated using woven fabric of carbon, basalt, and glass have shown improved flexural properties hybrid composites for structural application.
This study examines the relationships between the structure of fancy boucle´yarns and the bending stiffness of the input threads that are used to make those fancy yarns. Four fancy boucle´yarns and an extra two confirmation boucle´yarns... more
This study examines the relationships between the structure of fancy boucle´yarns and the bending stiffness of the input threads that are used to make those fancy yarns. Four fancy boucle´yarns and an extra two confirmation boucle´yarns were made to test the impact of the bending stiffness of the effect input threads. Six fancy yarns were made to test the impact of bending stiffness of the core thread on the fancy yarn structure. The structure of the fancy yarn was defined by the number of fancy profiles, the size of fancy profile, the circularity ratio of fancy profile and the shape factor of fancy yarn. It was found that increasing the value of the stiffness of the effect thread increased the size of fancy profile but decreased both the number of fancy profiles and the shape factor of fancy yarn. Those relationships were represented by regression models that were significant at a¼0.10. The deviation between the theoretical values and the real values was 14.39% and 2.07%. Further, up to a value of 8.636 g mm2, the bending stiffness of the core thread appeared not to have an effect on the structure of the fancy yarns. This study is important as it is the first that accounts statistically for the impact of bending stiffness of the input threads on the structure of the resultant fancy yarns. Therefore, it aids fancy yarn manufacturers when designing fancy yarns with predicted structures.
... Civil Engineering Department King Abdulaziz University, Jeddah, Saudi Arabia. ... The effect of concrete compressive strength, f' c , and tensile reinforcement ratio, ρ on the flexural behaviour of reinforced concrete beams... more
... Civil Engineering Department King Abdulaziz University, Jeddah, Saudi Arabia. ... The effect of concrete compressive strength, f' c , and tensile reinforcement ratio, ρ on the flexural behaviour of reinforced concrete beams has been investigated by Ashour [23]. ...
The actin regulatory protein, cofilin, promotes actin assembly dynamics by severing filaments and increasing the number of ends from which subunits add and dissociate. Recent studies provide biophysical descriptions of cooperative... more
The actin regulatory protein, cofilin, promotes actin assembly dynamics by severing filaments and increasing the number of ends from which subunits add and dissociate. Recent studies provide biophysical descriptions of cooperative filament interactions in energetic, mechanical and structural terms. A one-dimensional Ising model with nearest-neighbor interactions permits thermodynamic analysis of cooperative binding and indicates that one or a few cofilin molecules can sever a filament. Binding and cooperative interactions are entropically driven. A significant fraction of the binding free energy results from the linked dissociation of filament-associated ions (polyelectrolyte effect), which modulate filament structure, stability and mechanics. The remaining binding free energy and essentially all of the cooperative free energy arise from the enhanced conformational dynamics of the cofilactin complex. Filament mechanics are modulated by cofilin such that cofilin-saturated filaments are approximately 10- to 20-fold more compliant in bending and twisting than bare filaments. Cofilin activity is well described by models in which discontinuities in topology, mechanics and conformational dynamics generate stress concentration and promote fracture at junctions of bare and decorated segments, analogous to the grain boundary fracture of crystalline materials and the thermally driven formation of shear transformation zones in colloidal glass.
The Algerian margin formed through back-arc opening of the Algerian basin (Mediterranean Sea) resulting from the roll-back of the Tethyan slab. Recent geophysical data acquired along the Algerian margin showed evidence of active or recent... more
The Algerian margin formed through back-arc opening of the Algerian basin (Mediterranean Sea) resulting from the roll-back of the Tethyan slab. Recent geophysical data acquired along the Algerian margin showed evidence of active or recent compressive deformation in the basin due to the ongoing Africa–Eurasia convergence. Published data from four wide-angle seismic profiles have allowed imaging the deep structure of the Algerian margin and its adjacent basins. In this study,we converted these velocity models into density models, then into isostatic anomalies. This allowed us to image an isostatic disequilibrium (relative to a local isostasy model) reaching a maximum amplitude at the margin toe. Converting isostatic anomalies into Moho depth variations shows that the Moho extracted from wide-angle seismic data is deeper than the one predicted by a local isostasy model in the oceanic domain, and shallower than it in the continental domain. These anomalies can be interpreted by opposite flexures of two plates separated by a plate boundary located close to the margin toe. We use a finite element model to simulate the lithospheric flexure. The amplitude of the equivalent vertical Moho deflection is larger in the central part of the study area (6–7 km) than on the easternmost and westernmost profiles (3 km). The effective elastic thickness used to best match the computed deflection is always extremely low (always less than 10 km) and probably reflects the relatively low strength of the lithosphere close to the plate boundary. Comparison with other wide-angle seismic profiles across an active and a passive margin show that the North Algerian margin displays isostatic anomalies close to that of an active margin. Finally, plate flexure is highest at the southern tip of the ocean-continent transition, possibly indicating that a former passive margin detachment is reactivated as a crustal scale reverse fault pre-dating a future subduction.
A water intake basin is a buried box that functions as a water reservoir near shorelines. Number of these structures has been increased in the recent years and for a safe design, it is necessary to know their behaviour under applied... more
A water intake basin is a buried box that functions as a water reservoir near shorelines. Number of these structures has been increased in the recent years and for a safe design, it is necessary to know their behaviour under applied loads. In addition to common dead, live and seismic loads, the bottom of such a basin is usually located below sea water level and endures uplift pressure as well as reaction of supporting soils. Uncertainty of these special loads complicates the structural response of this buried basin to the applied loads. Therefore, the unreliability in the soil parameter and in the rigidity of the basin structure is studied in this research by calculating the generated internal bending moments. Different loads and load combinations have been taken into account and finite element analysis is carried out for modelling nonlinear behaviour of different types of supporting soils. It is concluded that the geometry and flexural stiffness of the basin affects the analysis more than the soil parameters because the contribution of the soil modulus in the total stiffness of the system is negligible than the structural rigidity of the basin structure. In addition, inner walls and geometry of t he basin should be modelled in detail to obtain acceptable results.
