1,293 research outputs found
Infallability as a theological concept : A study in the use of the concept 'infallible' in the writings of B.B. Warfield and C.A. Briggs.
SIGLELD:D49722/84 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
Superior sperm competitors sire higher-quality young
The evolution of polyandry remains controversial. This is because, unlike males, in many cases multiple mating by females does not increase fecundity and inevitably involves some costs. As a result, a large number of indirect benefit models have been proposed to explain polyandry. One of these, the good sperm hypothesis, posits that high-quality males are better sperm competitors and sire higher-quality offspring. Hence, by mating multiply, females produce offspring of superior quality. Despite being potentially widely applicable across species, this idea has received little attention. In a laboratory experiment with yellow dung flies ( Scathophaga stercoraria ) we found that males that were more successful in sperm competition also had offspring that developed faster. There was no relationship between paternal success in sperm competition and the ability of offspring to survive post-emergence starvation. Since faster development times are likely to be advantageous in this species, our data provide some support for polyandry evolving as a means of producing higher-quality offspring via sperm competition
Magnetohydrodynamic Effects on Insulating Bubbles and Inclusions in the Continuous Casting of Steel
The magnetohydrodynamic effects associated with a magnetic field perpendicular to the movement of insulating inclusions or bubbles in a conducting liquid are investigated in this article. An increase in drag coefficient as a result of the presence of a magnetic field is argued to have a significant effect on their terminal rise velocity. Inside a continuous steel caster, this lower terminal velocity has a potentially negative effect on the removal rate of unwanted inclusions, degrading the steel quality. Simulations of an insulating rigid sphere moving in the presence of an electrical current show an electromagnetophoretic force per unit volume of , with a shape factor . Numerical fluid and dispersed gas phase simulations of the flow inside a submerged entry nozzle show that, because of this force, inhomogeneous magnetic fields can cause nonuniform gas distributions in accordance with a theoretical analysis. In particular, the magnetic field can be tailored to increase or decrease the amount of gas near the side walls
Topology and morphology influences on the onset of ductile failure in a two-phase microstructure
Multi-phase material are frequently applied in a wide variety of products, as they posses a unique set of properties by combining two or more distinct phases at the level of the microstructure. Although the macroscopic stiffness and hardening are reasonably well understood, questions remain about the dominant failure mechanism(s). We identify the role of the microstructural topology (the distribution of phases) on damage "hot-spots" in the microstructure, by performing a numerical study on a large set of randomly generated topologies. The result identifies a distinct probability distribution of phases around a typical damage "hot-spot". This work is focused on assessing the sensitivity of the result to the assumptions made on the microstructural geometry
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