Encyclopedia of materials

... Damping of Acoustic Waves: High Damping Alloys and Inorganic Noise Absorbing Materials Machinery noise and vibration reduction can be achieved by using ...

Socio-economics of fishing communities on Uganda water bodies

Control and management of Uganda fishery resources has been hindered by among other factors the multispecies nature of the resource and the characteristic behaviour of the fishing communities. Fishermen have both genuine and uncompromising attitudes as to why they carry out certain fishing technologies.All fishing activities aim at maximizing the catches or profits while others may fish on a small scale for subsistence. Sensitizing the fisherfolk on the appropriate fishing technologies, importance of a well regulated fishery exploitation and their participation in control and management of the resource would enhance or lead to increased and sustainable fish production. Socio-economics of fishing technologies were therefore examined using prepared questionnaires and reasons why the fishing communities behave the way they do established

Fiber laser processing of amorphous rare earth NeFeB magnetic materials

Since the exchange coupling theory was proposed by Kneller and Hawig in 1991 there has been a significant effort within the magnetic materials community to enhance the performance of rare earth magnets by utilising nano-composite meta-materials. Inclusions of magnetically soft iron smaller than approximately 10 nm in diameter are exchange coupled to a surrounding magnetically hard Nd2Fe14B matrix and provide an enhanced saturisation magnetisation without reducing coercivity. For such a fine nanostructure to be produced, close control over the thermal history of the material is needed. A processing route which provides this is laser annealing from an amorphous alloy precursor. In the current work, relationships between laser parameters, thermal histories of laser processed amorphous stoichiometric NdFeB ribbons and the magnetic properties of the resulting nanocrystalline products have been determined with a view to applying the process to thick film nanocomposite magnet production.

Efficient registration of nonrigid 3-D bodies

We present a novel method to perform an accurate registration of 3-D nonrigid bodies by using phase-shift properties of the dual-tree complex wavelet transform (DT-CWT). Since the phases of DT-\BBCWT coefficients change approximately linearly with the amount of feature displacement in the spatial domain, motion can be estimated using the phase information from these coefficients. The motion estimation is performed iteratively: first by using coarser level complex coefficients to determine large motion components and then by employing finer level coefficients to refine the motion field. We use a parametric affine model to describe the motion, where the affine parameters are found locally by substituting into an optical flow model and by solving the resulting overdetermined set of equations. From the estimated affine parameters, the motion field between the sensed and the reference data sets can be generated, and the sensed data set then can be shifted and interpolated spatially to align with the reference data set. © 2011 IEEE.