the effective factors of forward speed, cylinder rotation, and clearance between a combine’s cylinder and concave on wheat kernel breakage and seed germination were studied in karaj area using a 955 model john dear combine. this study was conducted on three levels of adjustment for each of the variables, 1.2, 1.8 and 2.5 km/hr for forward speed, 800, 900, 1000 rpm for cylinder rotation as well ...

Granular media are prevalent in dynamic frictional processes throughout nature and technology, from earthquakes to grain transport. Empirical relations describing macroscopic friction as a function of the inertial number have proven successful in predicting experimentally observed velocity and stress profi les when combined with continuum models. However, these relations and the continuum model...

The Nijmegen breakage syndrome is a rare autosomal recessive chromosomal instability disorder characterized by early growth retardation, congenital microcephaly, immunodeficiency, borderline mental development, and a high tendency to lymphoreticular malignancies. Most Nijmegen breakage syndrome patients are of Slavonic origin, and all of them known so far carry a founder homozygous 5 nucleotide...

external fluted feed rolls are commonly used in grain drills. the fluted feed roll meters a volume of seeds and does not singulate the seeds as do the precision planters; therefore, there will be inherent variation in the number of seeds delivered per unit of time. this research was conducted to investigate the effect of seed meter drive shaft and ground speeds and outlet positions in a grain d...

Chromosome breakage as a result of replication stress has been hypothesized to be the direct consequence of defective replication fork progression, or "collapsed" replication forks. However, direct and genome-wide evidence that collapsed replication forks give rise to chromosome breakage is still lacking. Previously we showed that a yeast replication checkpoint mutant mec1-1, after transient ex...

It has been observed that the pattern of particle impact breakage in two-dimensional systems is a result of two mechanisms. AMechanism IB accounts for the breakage induced by the stresses that appear in unbroken particles. AMechanism IIB breakage is due to the buckling of the Mechanism I fragments. The purpose of this paper is to try and understand the parameters that govern the magnitude of th...

The transposable Dissociation (Ds) element of maize was first discovered as a site of high-frequency chromosome breakage. Because both Ds-mediated breakage and transposition require the presence of the Activator (Ac) element, it has been suggested that chromosome breakage may be the outcome of an aberrant transposition event. This idea is consistent with the finding that only complex structures...