Biomachining
(old)
The metal to be machined is placed in a culture
solution containing this bacterium, the conditions set appropriately and the
solution oscillated, resulting in metal etching in proportion to the treatment
time. This new machining method utilizing bioactivity has been named
biomachining. Compared with conventional types of machining methods, the
treated material undergoes no dynamic degeneration or adverse effects of heat.
(Kagaku Gijutsuchö, Science&Technology in
Japan,p.67)
New(better)
Thşs technology is being used to fabricate arrays of
microprobes capable of penetrating
neutral tissues. The microneedles fabricated by the conventional
machining methods have diameters to the tune of 300 microns. Using this
technology, it has been possible to fabricate needles with much smaller
diameter than this.
(Pratiyogita Darpan Eyl 2006 , p.523)
Multi-Part Adhesives (Two-Part Adhesives)
(old)
The most important adhesives of this group are polyester, cold-setting
epoxy resins, polurethanes and acrylic adhesives. Common two-part adhesives
consists of several components that are mixed in a specific ratio before
application. For acrylic adhesives of the ‘second generation’, it is possible
to apply each of the components seperately to one of the adherent surfaces, and
then to press the adherents together, thereby initiating the curing process.
In addition to the specific mixing ratio, the so-called ‘pot life’ must
also be respected; this is the period of time during which the adhesive can be
used after mixing the components, and is dependent on the type of adhesive used
and the volume prepared. As the crosslinking process gradually starts during
the pot life, and the viscosity of the adhesive gradually increases during this
time, exceeding the pot life will cause a lack of wetting of the adherent
surfaces by the adhesive and result in poor adhesion properties within the
bond-line. The cross linking of two- part or multi- part adhesives,
respectively, almost always takes place as an exothermic reaction, so that the
adhesive will be heated up during this process.
(Walter Brockmann, Paul Ludwig Geiss, Adhesive Bonding, Materials, Applications
and Technology,p.36)
(New/better)
Multi-part adhesive are segregated into which compartments,
when or how the separated components are mixed prior to bonding, the chemical
details of the mechanisms that initiate hardening of the adhesive, and when or
how water is removed or segragated from the fluid adhesive to produce a solid
foam underwater. To address these and other questions morphological analyses of
the adhesive gland and secretion process were initiated and preliminary
findings are described here. These studies provide a map to investigate the
detailed organization of the adhesive system with spesfic proteiın and nucleic
acid probes.
(Janek Byern,
Biological
Adhesive Systems: From Nature to Technical and Medical Application, p. 170)
Hot molding
(old)
Hot molding is a term coined by Textron to describe a low-pressure hot
pressing porcess that is designed to fabricate shaped SiC-aluminum parts at
signifanctly lower cost than the typically diffusion bonding, solid-state
process. The SCS-2 fibers can withstand molten aluminum for long periods;
therefore, the molding temprature can now be raised into the liquid
–plus-solid region of the alloy to ensure aluminum flow and consolidation at
low pressure, thereby negating teh requirement for high-pressure die molding
equipment.
The best way of describing hot molding process is to draw an anology to the
autoclave molding of graphite epoxy where components are molded in an
open-faced tool. The mold in this case is a self-heated, slipcast ceramic toll
embodying the profile of the finished part. A plasma sprayed aluminum
preform is laid into teh mold, heated to a near molten aluminum
temperature, and pressure consolidated in an autoclave by a “metallic” vaccum
bag. The mold can be profiled as required to produce near net shape parts
including tapered thicknesses and section geometry variations.
(J.Füller, Developmenst in the Science and Technology of Composite
Materials, p. 331-332)
(new/better)
Hot molding is an
established process which has been very successful at producing lox cost
seating foams, especially backrests, allowing densities below 30 kg/m3 to be
reached.
Important savings can be
made, as the time and energy necessary to increase the interior mold
temperature to its optimum for foam curing (about 110C), are significantly
lower. Cooling time also quicker, permitting faster cycles to be run. The influence of the
increase in mold temperature on foam physical properties in shown table.
(David Reed,Carole Lee, Utech 94, p.1-2)
Bilineer surface
(old)
A bilinear surface is
a linear interpolation of the four corner points in the u and v direction. Only
four corner points need to be supplied, but the boundaries of the bilinear
surfaces are straight and surface generally tends to be flat. (CAD/CAM Theory and
Practice, İbrahim Zeid, McGrawHill,1991. p294)
(new/better)
A flat polygon is the
simplest type of surface . the bilineer surface is the simplest nonplat (curved)
surface because it is fully defined by means of its four corner points. It is
discussed here because its four boundary curves are straight lines and because
the coordinates of any point on this surface are derived by linear
interpolations. Since this patch is completely defined by its four corner
points, it cannot have a very complex shape.
(David Salomoi Curves And Surfaces for Computer Graphics ,p.59)
Newtonian flow
(old)
There is no old definition
(new/better)
A Newtonian flow is one in which
the viscosity M is a constant for a fixed temperature and pressure. A non-
Newtonian fluid such as jello, ink, milk, therefore, would be a fluid in which
the viscosity M varies.
(Robert Alan Granger, Fluid Mechanics , p. 54)
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