mechanical damage due to harvesting, handling, and other processes is an important factor that affects the seeds quality. seed damage results in lower grain value and more storability problem and reduces seed germination and seedling vigor and subsequent yield of crops. tests were conducted to determine the percentage of physical damage (ppd) and percentage of loss in germination (plg) of wheat...

one of the most important forms of preharvest damage to wheat is caused by sunn pests. the insects insert their mouth parts into the immature grain and while injecting their saliva suck the milky juices. flour from damaged wheat results in low baking performance due to the bug proteolytic enzymes’ injected which cause the breakdown of gluten structure in the dough. in the present study three wh...

Salinity and flooding are as two very important factors of soil degradation. They often occur together and cancause severe damage to plants. However, plant response to environmental stresses may vary with growth stage atwhich exposure occurs. A pot study was conducted in 2005-2006 in northern Aq Qala (northern Iran) to studycombine effects of waterlogging and soil salinity at different growth s...

A study was conducted to assess the performance of maize hybrids with Bt event MON810 (Bt-hybrids) against the maize stem borer Busseola fusca (Fuller) in a biosafety greenhouse (BGH) and against the spotted stem borer Chilo partellus (Swinhoe) under confined field trials (CFT) in Kenya for three seasons during 2013-2014. The study comprised 14 non-commercialized hybrids (seven pairs of near-is...

It is commonly proposed that the fatigue strength can be enhanced by increasing the tensile strength, but this conclusion needs to be reconsidered according to our study. Here a recrystallized α-Cu-15at.%Al alloy with moderate grain size of 0.62 μm was fabricated by cold rolling and annealing, and this alloy achieved exceptional high fatigue strength of 280 MPa at 10(7) cycles. This value is mu...

There have been numerous efforts to understand and control the resistance of materials to fracture by repeated or cyclic stresses. The micromechanical behaviours, particularly the distributions of stresses on the scale of grain size during or after mechanical or electrical fatigue, are crucial to a full understanding of the damage mechanisms in these materials. Whether a large microstress devel...

FATIGUE BEHAVIOR AND MICROSTRUCTURE EXAMINATIONOFAISI D2 TRIM DIESbyXINCHEN WANGDecember 2013Advisor: Dr. Xin WuMajor: Mechanical EngineeringDegree: Master of ScienceAISI D2 steels are widely used as tools for forming, drawing and trimming diesdue to its high wear resistance, high compressive strength and low distortion, and itsperformance as a tr...

The competition between transverse surface and sub-surface cracks in a thin, hard coating bonded to polycarbonate substrate due to spherical indentation is investigated in real-time as a function of coating thickness and indenter radius. Fine grain (Y-TZP) and medium grain (alumina) ceramics and pre-abraded amorphous glass are used for the coating. As the coating thickness is reduced, the famil...

We have analyzed by transmission electron microscopy silicon and GaAs crystals polished with sandpapers of different grain size. The surface damage induced a crystal permanent convex curvature with a radius of the order of a few meters. The curvature is due to a compressive strain generated in the damaged zone of the sample. Contrary to what was reported in the literature, the only defects dete...