the objective of this research work is to evaluate the surface roughness of polyacrylonitrile (pan) nanowebs. for this purpose the nanowebs have been prepared in different concentrations of pan solution from 11 to 15% (by wt). surface roughness of nanowebs was evaluated by entropy algorithm (ent) as well as atomic force microscopy (afm) and then the results of two methods have been compared. to...

height is amongst the most delicate subjects of geodesy. thanks to the global navigation satellite systems (gnss) like gps or glonass, 3d point positioning of points, by geometrical positioning, since years ago has become a common practice. the height derived from these ways has a geometrical concept. in civil projects the physical concept of the height is more demanded. orthometric height, , i...

Airborne lidar is a remote sensing method commonly used for mapping surface topography in high resolution. A water surface in hydrostatic equilibrium theoretically represents a gravity potential isosurface. Here we compare lidar-based ellipsoidal water surface height measurements all around the shore of a major lake with a local high-resolution quasi-geoid model. The ellipsoidal heights of the ...

As x → ±∞, z = ±y tan( 1 2 α)+(n+ 1 2 )π sec( 1 2 α), respectively for integers n. Thus Scherk’s first surface connects two infinite sets of parallel planes at x = ±∞, equally spaced by π and rotated by an angle α with respect to each other. It has been used as a model for grain boundaries in diblock copolymers and smectic liquid crystals [2,3] where the multi-valued height function represents ...

Estimation of the height of caved and fractured zones above a longwall panel along with the stability conditions of the goaf area are very crucial to determine the abutment stresses, ground subsidence, and face support as well as designing the surrounding gates and intervening pillars. In this work, the height of caving-fracturing zone above the mined panel is considered as the height of destre...