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Mitchell, M. J.

Publications and source records attributed to Mitchell, M. J..

11 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1988

OH(A-X) fluorescence from photodissociative excitation of HO2 at 157.5 nm

The OH(A-X) fluorescence from photodissociative excitation of HO2 by F2 laser photons (157.5 nm) was observed and compared with the OH fluorescence spectra of H2O2 and the O2+CH3OH mixture. The rotational population distributions of OH(A) were obtained from the fluorescence spectra. The most populated levels are J = 4 for photodissociative excitation of HO2, J = 20 for H2O2, and J = 21 for the O2+CH3OH mixture. The fluorescence from the gas mixture is attributed to the O + H recombination for which the atoms are produced from photodissociation of parent molecules.

Suto, M.↗
NASA NTRS1986

Weld Repair of Thin Aluminum Sheet

Weld repairing of thin aluminum sheets now possible, using niobium shield and copper heat sinks. Refractory niobium shield protects aluminum adjacent to hole, while copper heat sinks help conduct heat away from repair site. Technique limits tungsten/inert-gas (TIG) welding bombardment zone to melt area, leaving surrounding areas around weld unaffected. Used successfully to repair aluminum cold plates on Space Shuttle, Commercial applications, especially in sealing fractures, dents, and holes in thin aluminum face sheets or clad brazing sheet in cold plates, heat exchangers, coolers, and Solar panels. While particularly suited to thin aluminum sheet, this process also used in thicker aluminum material to prevent surface damage near weld area.

Beuyukian, C. S.↗
NASA NTRS1984

Data distribution in the NBS Automated Manufacturing Research Facility

The Automated Manufacturing Research Facility (AMRF) at the National Bureau of Standards was constructed as a testbed for research in the automation of small batch maufacturing, in particular for systems producing machined parts in lots of 1000 or less. Potential standard interfaces between existing and future components of small batch of factory floor metrology in an automated environment, delivering proven measurement techniques and standard reference materails industry to are identified. Commercially available product are used to construct the facility to expedite transfer of research results into the private sector.

Mitchell, M. J.↗
NASA NTRS1982

Cutting a Tapered Edge on Padding Material

Resilience and flexibility of felt, rubber, or other padding materials allow them to be clamped in form block, cut straight down, and then released to produce straight clean tapered edge. With material held in slanted position, edge can be cut straight down; hence cut depth is minimum.

Mitchell, M. J.↗
NASA NTRS1978

High-temperature brazing of stainless steel

Prevention of iron contamination of platens is eliminated by placing alumina/silica ceramic-fiber blankets between platens and carbon-steel plate. Carbon-steel plates provide rigidity and improve heat transfer.

Beuyukian, C. S.↗
NASA NTRS1978

Form die and glide plates for vacuum brazing

Die for fabricating steel retorts is made from commercial plywood with steel facing. Smooth-finished glide plates prevent partial bonding of plates to stainless-steel parts.

Beuyukian, C. S.↗
NASA NTRS1978

Internal grid for release of brazing retorts

Wire grid permits retorts to be opened more quickly after brazing. Grid also aids purging and evacuation, better control of vacuum in part area, and reduces thermocouple damage.

Beuyukian, C. S.↗
NASA NTRS1976

Diffusion brazing nickel-plated stainless steel

To bond parts, sandwich assembly is made up of aluminum core, aluminum face sheet with brazing alloy interface, and nickel plated stainless steel part. Sandwich is placed between bottom and top glide sheet that is placed in stainless steel retort where assembly is bonded at 580 C.

Beuyukian, C. S.↗