the melt flow index mfi is a measure of the ease of flow of the melt of a thermoplastic polymer. it is defined as the mass of polymer, in grams, flowing in ten minutes through a capillary of a specific diameter and length by a pressure applied via prescribed alternative gravimetric weights for alternative prescribed temperatures.
police uniforms and equipment in the united kingdom have varied considerably from the inception of what were the earliest recognisable mainstream police forces in the early 19th century. as various pieces of legislation in the middle part of the 19th century standardised policing in the united kingdom, so too, did the uniforms and equipment become standardised.
the general radiotelephone operator license grol is a license granted by the u.s. federal communications commission fcc , which is required to operate certain radio equipment. it is required by any persons who adjust, maintain, or internally repair fcc licensed radiotelephone transmitters in the aviation, maritime, and international fixed public radio services.
the manufacturing process allows controlling the material properties such as electrical conductivity, thermal conductivity and viscosity . different forms of hybtonite are available for different purposes such as laminating glass fiber, carbon fiber , epoxy paints and glues.
these materials were developed in early 1960s as improved buoyancy materials for marine applications. other characteristics led these materials to aerospace and ground transportation vehicle applications. current applications for syntactic foam include buoyancy modules for marine riser tensioners, remotely operated underwater vehicles rovs , autonomous underwater vehicles auvs , deep-sea .
a welding procedure specification wps is the formal written document describing welding procedures, which provides direction to the welder or welding operators for making sound and quality production welds as per the code requirements . the purpose of the document is to guide welders to the accepted procedures so that repeatable and trusted welding techniques are used.
composite materials are used in a wide range of applications in aerospace, marine, automotive, surface transport and sports equipment markets. damage to composite components is not always visible to the naked eye and the extent of damage is best determined for structural components by suitable non destructive test ndt methods. the concept for .
copper alloys are important netting materials in aquaculture the farming of aquatic organisms including fish farming .various other materials including nylon, polyester, polypropylene, polyethylene, plastic-coated welded wire, rubber, patented twine products spectra, dyneema , and galvanized steel are also used for netting in aquaculture fish enclosures around the world.
near the seashore 316l is typically considered the minimum grade of for use in such a marine environment. concentrations of chloride in seawater can vary, and splash zones can cause concentrations to increase dramatically by evaporation, thus the corrosive severity of marine environments can vary.
advanced composite materials are also known as advanced polymer matrix composites. these are generally characterized or determined by unusually high strength fibres with unusually high stiffness, or modulus of elasticity characteristics, compared to other materials, while bound together by weaker matrices. these are termed advanced composite materials in comparison to the composite materials commonly in use such as reinforced concrete, or even concrete itself. the high strength fibers are also l
history of nanofiber production. nanofibers were first produced via electrospinning more than four centuries ago. beginning with the development of the electrospinning method, english physicist william gilbert 1544-1603 first documented the electrostatic attraction between liquids by preparing an experiment in which he observed a spherical water drop on a dry surface warp into a cone shape .
trip steel are a class of high-strength steel alloys typically used in naval and marine applications and in the automotive industry. trip stands for 'transformation induced plasticity,' which implies a phase transformation in the material, typically when a stress is applied.
marine propulsion is the mechanism or system used to generate thrust to move a ship or boat across water. while paddles and sails are still used on some smaller boats, most modern ships are propelled by mechanical systems consisting of an electric motor or engine turning a propeller, or less frequently, in pump-jets, an impeller. marine engineering is the discipline concerned with the .