10,079 research outputs found
Portable lightweight bandsaw
Bandsaw of aluminum-6061 weighs about five kg and is operable by one or two men. Spiral blade cuts in any direction and at any angle. Hardness of materials to be cut is limited by material and dimension of blade
The ACIGA Data Analysis programme
The Data Analysis programme of the Australian Consortium for Interferometric
Gravitational Astronomy (ACIGA) was set up in 1998 by the first author to
complement the then existing ACIGA programmes working on suspension systems,
lasers and optics, and detector configurations. The ACIGA Data Analysis
programme continues to contribute significantly in the field; we present an
overview of our activities.Comment: 10 pages, 0 figures, accepted, Classical and Quantum Gravity,
(Proceedings of the 5th Edoardo Amaldi Conference on Gravitational Waves,
Tirrenia, Pisa, Italy, 6-11 July 2003
The Manufacture of Marine Propellers in Moulded Anisotropic Polymer Composites
This thesis examines the feasibility of manufacturing small marine propellers from
continuous fibre reinforced polymer composite materials. An appraisal of some current
applications of composite materials in the marine industry is given, together with the
moves shown towards the use of composites in the area of propeller design. It has been
shown that manufacturing propellers in composite materials is theoretically more cost
effective than traditional materials.
The manufacturing route investigated is Resin Transfer Moulding, where some detailed
investigations have highlighted some of the critical processing parameters necessary for
successful production of laminates suitable for propellers and other high performance
marine structures.
A thorough testing programme of 4 novel designs of composite propeller is reported.
Trials at sea on university run vessels has enabled many hours use to be logged, which has
shown the fitness for purpose of propellers made from glass reinforced, epoxy composite.
Experimental tank testing has helped to shape the remainder of the research by identifying
the possibility of using hydroelastic tailoring to improve the efficiency of the propeller
when a variety of operating conditions are required from the propulsion system. Further
experience is required with respect to the the tooling construction and the life assessment
of the propeller.
To facilitate appropriate modelling of the propeller, spreadsheet based load prediction
models have been used. Finite element analysis (FEA) was used to model the elastic
characteristics of one particular design of novel composite propeller. This indicated that
traditional geometries may be too stiff to allow significant performance advantages from
the anisotropy of the material. However the potential does exist for modified propeller
geometries made from composite to give some performance benefit.
For specific applications, small marine propellers made from continuous glass fibre
reinforced epoxy composite are likely to yield cost savings over traditional propeller
materials
Optical and infrared spectrophotometry of 18 Markarian galaxies
Slit spectra, spectrophotometric scans and infrared broad band observations are presented. Eight of the program galaxies can be classified as Seyfert galaxies. Arguments are given that thermal, nonthermal and stellar radiation components were present. One group of Seyfert galaxies was characterized both by the presence of a high density region of gas and by a continuum dominated by nonthermal radiation. The continua of the remaining program Seyferts, which did not have a high density region of gas, were dominated by thermal radiation from dust and a stellar continuum. Ten of the galaxies, which are not Seyfert galaxies, are shown to be examples of extragalactic H 2 regions
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