The effect of the microstructure on the wear modes in structural ceramic materials was studied in two SIC and three A120s materials. In each class of materials, it was observed that the predominant damage mode is determined by the microstructure of the material. The materials with weak grain boundaries were found to wear primarily by grain pluckout and so showed more wear than did (the one, cr-...

Barsoum and El-Raghy [1] have recently developed reactive hot-pressing techniques to form bulk, polycrystalline Ti3SiC2 from powders of Ti, SiC, and graphite. This ternary carbide, first synthesized by Jeitschko and Nowotny [2] in the late 1960s, exhibits a rather surprising combination of properties. Not only is the ratio of hardness (;4 GPa) to elastic modulus (;320 GPa) more typical of ducti...

new sources of maize resistance to the maize weevil, sitophilus zeamais infestation are indispensable in successful breeding programs against post harvest grain damage. the study investigated the characters and mechanisms that confer resistance to weevil infestation using twenty elite maize genotypes. detailed morphological and physical studies were conducted on whole-maize grain. the grain hul...

The damage of seeds in grain augers has been divided into shearing and jamming, occurring at the inlet and the casing wall, respectively. The shearing was strongly reduced by a displacement body attached to the screw blade. Measures for the reduction of jamming, partly based on a theoretical approximation, have been summarized. A number of experiments, performed for verification, agreed with th...

there are different methods used for threshing of grain crops. usual threshers operate based on the impact force (in threshing unit) that may damage the grains. in another method named axial-flow, grain damage is less so these types of the harvesting machines are being used more than before. in this study one of the common rice threshers (model t30) locally made in ashtad company was modified t...

the yield loss simulation (yls) and the macros liq.csm models were used to simulate the effect of stem borer damage at a detillering rate of 5, 15, 30, 60% at vegetative, panicle initiation and grain filing stages, on yield of rice cultivar?s ratna. this stem borer damage during vegetative and panicle initiation stages was not simulated appropriately by both the models. relatively macros simula...

Damage nucleation from repeated dislocation absorption at a grain boundary is simulated with molecular dynamics. At the grain boundary–dislocation intersection site, atomic shuffling events determine how the free volume brought by the incoming dislocation is accommodated. This process in turn determines the crack nucleation mechanism, as well as the critical strain and number of dislocations th...