Preparation of photochromic calcium fluoride by additive coloration
Photochromic calcium fluoride preparation by rare earth additive coloration techniques
Duncan, R. C., Jr.↗
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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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The preparation and properties of vapor-grown In/1-x/Ga/x/P
Single crystal indium gallium phosphide p-n junction preparation by epitaxial vapor phase growth technique, determining energy gap dependence on alloy composition
Clough, R. B.↗
Evaluation of chromatographic techniques for the preparative separation of steranes and triterpanes from Green River formation oil shale
Gas-liquid chromatographic milligram preparative separation of steranes and triterpanes from hydrocarbon fraction of Green River oil shale
Burlingame, A. L.↗
Preparation of samples for sintering of submicron particles by transmission electron microscopy
Monolayer submicron self supporting particle film samples preparation for sintering by transmission electron microscopy
Sipe, J. J.↗
Apollo 14 mission food preparation unit leakage
A bubble of water collected on the delivery probe of the food preparation unit after hot water was dispensed by the Apollo 14 crew. Postflight tests showed that dimensional interference between the cylinder and the piston at hot water temperatures produced the apparent leak by causing erratic and slow stroke time of the valve assembly.
Source record↗
Preparation and evaluation of Apollo 14 composite experiments
An account is given of the work aimed at flight experiments on Apollo 14, in relation to space manufacturing processes. Evaluation of suitable materials, definition of in-flight processing procedures, preparation of preprocessed materials and delivery, and evaluation of the space-processed samples after return from the Apollo 14 flight are presented.
Steurer, W. H.↗
New methods for preparing N,N-dialkyltrifluoroacetamides
The customary preparative methods for N,N-dialkyltrifluoroacetamides involve the acylation of an amine by trifluoroacetic acid or its derivatives. The synthesis of N,N-dialkyltrifluoroacetamides by reacting trifluoroacetic anhydride or acid with disubstituted formamides and acetamides is discussed. These reactions were interpreted with the aid of gas chromatographic analysis. Different reaction mechanisms are proposed for the reactions of formamides and acetamides with trifluoroacetic anhydride or acid. The use of the proposed reaction mechanisms for the synthesis of other fluorinated compounds is discussed.
Hsu, L.↗
Geographic applications program: Reports completed and in preparation
The purpose of the present compilation is to bring together for ready reference a list of all reports, both completed and in preparation, resulting from NASA sponsorship of the geography program. Wherever possible, complete bibliographic citations are given. Since some of the 141 reports listed are not yet completed, citations can not all be in complete form. The reason for including incomplete citations is the sponsor's need for rather rapid feed-back of information so that it can have a bearing on on-going program planning. This should, therefore, be considered a working bibliography.
Alexander, R. H.↗
Preparation, verification, and operational control of a large space-environment-simulation chamber for contamination sensitive tests
A 2-year program to prepare chamber A at the NASA Manned Spacecraft Center for Apollo telescope mount thermal-vacuum tests is discussed. This program covers modification to existing chamber systems, the development of facility and chamber operating procedures, the selection of chamber cleaning and control methods, and the development and evaluation of diagnostic instrumentation. Extensive efforts to ensure a minimum contamination environment for the Apollo telescope mount test series are illustrated. Recent thermal-vacuum tests of this chamber at progressive stages of cleanliness have demonstrated the success achieved in reducing the particulate and molecular contamination levels of the basic chamber interior.
Visentine, J. T.↗
New methods for preparing n, n-dialkyltrifluoroacetamides
The customary preparative methods for N,N-dialkyltrifluoroacetamides involve the acylation of an amine by trifluoroacetic acid or its derivatives. In this report the synthesis of N,N-dialkyltrifluoroacetamides by reacting trifluoroacetic anhydride or acid with disubstituted formamides and acetamides is discussed. These reactions are interpreted with the aid of gas chromatographic analysis. Different reaction mechanisms are proposed for the reactions of formamides and acetamides with trifluoroacetic anhydride or acid. The use of the proposed reaction mechanisms for the synthesis of other fluorinated compounds is discussed.
Hsu, L.↗
Preparing thermoplastic aromatic polyimides
Method prepares aromatic polyimides with significantly reduced glass-transition temperatures and without accompanying loss of high-level thermo-oxidative stability which has been typical. This has been made possible by use of diamine monomers with specific stereoisomeric features.
Bell, V. L.↗
Space environment: A new dimension in the preparation of unique solids
The preparation of solids, particularly electronic solids in space is discussed. Particular attention is given to the effect of non-gravational environments on the development of homogeneous materials that cannot be manufactured on earth.
Gatos, H. C.↗
Preparation and properties of polytetrafluoroethylene impregnated with rhenium oxides
The results of tests carried out to determine the properties of polytetrafluorethylene (PTFE) impregnated with rhenium oxides are presented. The tests included measurement of physical properties of the impregnated material and investigation of the effects of preparation process variables. Based on the latter tests a mechanism to describe the permeation process is postulated which identifies the rate controlling step to be diffusion of ReF6 molecules into the solid during the initial ReF6 soak. Physical property tests indicated that the electronic conductance is increased by many orders of magnitude while the desirable properties of the PTFE remain virtually unchanged.
Leibecki, H. F.↗
Crew interface specifications preparation for in-flight maintenance and stowage functions
The findings and data products developed during the Phase 2 crew interface specification study are presented. Five new NASA general specifications were prepared: operations location coding system for crew interfaces; loose equipment and stowage management requirements; loose equipment and stowage data base information requirements; spacecraft loose equipment stowage drawing requirements; and inflight stowage management data requirements. Additional data was developed defining inflight maintenance processes and related data concepts for inflight troubleshooting, remove/repair/replace and scheduled maintenance activities. The process of maintenance task and equipment definition during spacecraft design and development was also defined and related data concepts were identified for futher development into formal NASA specifications during future follow-on study phases of the contract.
Parker, F. W.↗
An investigation of the preparation of high molecular weight perfluorocarbon polyethers
High molecular weight perfluorocarbon polyether gums were obtained by photolysis of perfluorodienes and discyl fluorides containing a perfluorocarbon polyether backbond. The materials obtained are represented by chemical formulas. A method was developed whereby reactive acyl fluoride and trifluorovinyl end groups are converted into inert structures. In order to investigate the possible preparation of difunctional molecules which may be useful in polymer synthesis, the reactions of hexafluoropropene oxide (HFPO) with Grignard and organolithium reagents have been studied. Reactions of various nucleophilic reagents with HFPO were also investigated.
Watts, R. O.↗
Preparation of Urban Land Use Inventories by Machine Processing of ERTS MSS Data
Preparation of urban land use inventories by machine processing of ERTS-1 MSS data of Milwaukee County, Wisconsin and Marion County, Indiana and Chicago, Illinois
Todd, W. J.↗
Preparation of composite materials in space. Volume 2: Technical report
A study to define promising materials, significant processing criteria, and the related processing techniques and apparatus for the preparation of composite materials in space was conducted. The study also established a program for zero gravity experiments and the required developmental efforts. The following composite types were considered: (1) metal-base fiber and particle composites, including cemented compacts, (2) controlled density metals, comprising plain and reinforced metal foams, and (3) unidirectionally solidified eutectic alloys. A program of suborbital and orbital experiments for the 1972 to 1978 time period was established to identify materials, processes, and required experiment equipment.
Steurer, W. H.↗
Intumescent composition, foamed product prepared therewith, and process for making same
An intumescent composition and the foamed product prepared by heating are discussed wherein the composition comprises the reaction product of para-benzoquinone dioxime and a concentrated mineral acid such as sulfuric acid, phosphoric acid, and polyphosphoric acid. The composition is useful as an intumescent agent either by itself or when combined with other materials. A fire-resistant and heat-insulating composition is provided by heating the intumescent composition above its intumescent temperature.
Riccitiello, S. R.↗