SYNTHESIS AND FABRICATION OF REFRACTORY URANIUM COMPOUNDS. Quarterly Report No. 5, August 1 through October 31, 1960

Additional quantities of UC, UN, and U/sub 3/Si/sup 2/ were prepared to be used in fabrication of test specimens for property determinations. A reduction in oxygen contamination of UN and U/sub 3/Si/sup 2/as achieved by improved techniques of synthesis.>s Preliminary values for thermal expansion, modulus of elasticity, and corrosion in boiling water were also obtained for these materials. (For preceding period see TID-6591.) (J.R.D.

SYNTHESIS AND FABRICATION OF REFRACTORY URANIUM COMPOUNDS. Monthly Progress Report No. 10 for September 1 through September 30. 1960

Several synthesis experiments were carried out to provide a stock of U/ sub 3/Si/sub 2/, powders for fabrication of test specimens. Initial thermal- expansion characteristics were determined on U/sub 3/Si/sub 2/ bars. High densities were obtained in the preparation of UN bodies. Thermal-expansion tests were made on bars of UN with a high-density silicon carbide tube dilatometer in a flowing argon atmosphere. (W.L.H.

Photointerpretation of Skylab photography

The author has identified the following significant results. In terms of film grain texture and object definition, the S190B color positive film is distinctly superior to the S190A films, when both are compared in the 9 x 9 inch format. Within the six S190A films, the panchromatic black and white films are superior to the infrared black and white, and the color positive film is superior to the color infrared. Minimum relief differences on the order of 500 to 100 feet could be detected by stereoscopic study, however, it is not possible to determine to what extent vegetation and cultural practices assist in such delineations. Water and wind gaps through major ridges were easily seen. Streams of third order and larger were clearly visible and easy to trace; second order streams were not identified with consistency. Differences in color, tone, and textural patterns rarely supplied clues for differentiating soils or bedrock. The separation of naturally forested areas from areas of cultivation and pasture was effective and a valuable clue to the underlying geology. Suburban and industrial developments were clearly differentiated from urban areas and surrounding agricultural fields. Soil associations could be identified on a regional basis, but no sharp boundary could be drawn separating soil associations

SYNTHESIS AND FABRICATION OF REFRACTORY URANIUM COMPOUNDS. Monthly Progress Report No. 11, November 1-November 30, 1960

Batches of UC were synthesized for use in fabrication of specimens for physical property determinations. This synthesis was carried out with mixed loose powders in a graphite crucible. Two and one-half pound batches of UN were synthesized using a stainless steel boat and an Inconel muffle furnace. Three batches of U/sub 3/Si/sub 2/ were synthesized with particular emphasis on controlling the rate of the reaction by limiting the maximum temperature to 1500 deg C. In addition, determinations were made of modulus of rupture, shear modulus, and Poisson's ratio of sintered UC, UN, and U/sub 3/Si/sub 2/ specimens. (M.C.G.

Genome-Wide Linkage Analysis to Identify Chromosomal Regions Affecting Phenotypic Traits in the Chicken. II. Body Composition

The current study is a comprehensive genome analysis to detect QTL affecting metabolic traits in chickens. Two unique F2 crosses generated from a commercial broiler male line and 2 genetically distinct inbred lines (Leghorn and Fayoumi) were used in the present study. The plasma glucagon, insulin, lactate, glucose, tri-iodothyronine, thyroxine, insulin-like growth factor I, and insulin-like growth factor II concentrations at 8 wk were measured in the 2 F2 crosses. Birds were genotyped for 269 microsatellite markers across the entire genome. The program QTL Express was used for QTL detection. Significance levels were obtained using the permutation test. For the 10 traits, a total of 6 and 9 significant QTL were detected at a 1% chromosome-wise significance level, of which 1 and 6 were significant at the 5% genome-wise level for the broiler-Leghorn cross and broiler-Fayoumi cross, respectively. Most QTL for metabolic traits in the present study were detected in Gga 2, 6, 8, 9, 13, and Z for the broiler-Leghorn cross and Gga 1, 2, 4, 7, 8, 13, 17, and E47 for the broiler-Fayoumi cross. Phenotypic variation for each trait explained by all QTL across genome ranged from 2.73 to 14.08% in the broiler-Leghorn cross and from 6.93 to 21.15% in the broiler-Fayoumi cross. Several positional candidate genes within the QTL region for metabolic traits at the 1% chromosome-wise significance level are biologically associated with the regulation of metabolic pathways of insulin, triiodothyronine, and thyroxine

Evaluation of Sialon internal combustion engine components and fabrication of several ceramic components for automotive applications

Fabrication development work was carried out on a push-rod tip having a stepped OD design and a 90[degree] shoulder in the transition area. Spray-dried Sialon premix was used in dry press tooling, and components were densified to about 98% of theoretical density using pressureless sintering conditions. Upon evaluation of the sintered components, it was found that afl components showed defects in the transition area. Modifications of the pressing parameters, incorporation of a 45[degree] angle in the shoulder area, and the use of tailored premix did not lead to the fabrication of defect-free parts. From these observations, it was concluded that the original part design could not easily be adapted to high-volume ceramic manufacturing methods. Subsequently, a modification to the desip was implemented. An SiC material with improved toughness (Hexoloy SX) was used for fabricating several test components with a closely machined, straight OD design. Pressureless-sintered and post-hot isostatically pressed (HIPed) Hexoloy SX components were supplied to The American Ceramic Engine Company (ACE) for assembly and testing. Fuel pump push-rod assemblies with Hemoloy SX tips were prepared by ACE, but no testing has been carried out to date

Insulin-Like Growth Factor-I Gene Polymorphism Associations with Growth, Body Composition, Skeleton Integrity, and Metabolic Traits

Molecular genetic selection on individual genes is a promising method to genetically improve economically important traits in chickens. A resource population was developed to study the genetics of growth, body composition, skeletal integrity, and metabolism traits. Broiler sires were crossed to dams of 2 diverse, highly inbred lines (Leghorn and Fayoumi), and the F1 birds were intermated by dam line to produce broiler-Leghorn and broiler-Fayoumi F2 offspring. Growth, body composition, skeletal integrity, and hormonal and metabolic factors were measured in 713 F2 individuals. Insulin-like growth factor-I (IGF1) was selected for study as a biological and positional candidate gene. A single nucleotide polymorphism (SNP) was identified between the founder lines in the IGF1 promoter region, and a PCR-RFLP assay was developed. A mixed model was used to statistically analyze associations of IGF1-SNP1 with phenotypic traits. The IGF1-SNP1 had significant associations with most recorded traits, except metabolic traits. Strong interactions between the IGF1 gene and genetic background on growth traits in the 2 F2 populations suggest that genetic interaction is an important aspect for consideration before using the IGF1-SNP1 in marker-assisted selection programs. Several beneficial effects (improved growth, increased breast muscle weight, decreased abdominal fat, and enhanced skeletal integrity) associated with 1 allele indicate the presence of 1 or more loci near IGF1-SNP1 controlling biologically diverse and economically important traits in chickens

Flight test investigation of the vortex wake characteristics behind a Boeing 727 during two-segment and normal ILS approaches (A joint NASA/FAA report)

Flight tests were performed to evaluate the vortex wake characteristics of a Boeing 727 aircraft during conventional and two-segment instrument landing approaches. Smoke generators were used for vortex marking. The vortex was intentionally intercepted by a Lear Jet and a Piper Comanche aircraft. The vortex location during landing approach was measured using a system of phototheodolites. The tests showed that at a given separation distance there are no readily apparent differences in the upsets resulting from deliberate vortex encounters during the two types of approaches. The effect of the aircraft configuration on the extent and severity of the vortices is discussed

SYNTHESIS AND FABRICATION OF REFRACTORY URANIUM COMPOUNDS. Quarterly Report No. 4 for March 1 to April 30 and July 31, 1960

Additional work on the synthesis and fabrication of uranium nitride produced an improved product free of oxide contamination as indicated by x-ray analysis. Further work to increase the density of the sintered pellets is needed. A stock of several pounds of stoichiometric uranium monocarbide was prepared by carbon reduction of uranium dioxide. Pellets having bulk densities ranging from 93 to 96% theoretical were obtained by cold pressing and sfntering. Initial experiments on the fabrication of bars, 3 by 1/2 by 1/4 in., by cold pressing and sintering, resulted in sound but somewhat low-density bodies. A few experiments were conducted on the production of uranium monocarbide from ammonium diuranate. The results indicate that considerable addftional work may be necessary to consistently produce a stoichiometric product. The simultaneous synthesis ard hot pressing of uranium monocarbide was funther studied and pellets with balk densities as high as 96.6% theoretical (based on 100% UC) were produced. However, metallographic examination disclosed the presence of some free uranium metal in all pellets. The synthesis of 1-lb batches of U/sub 3/Si/sub 2/ of improved quality was successfully carried out by a nonquench method. Using the U/ sub 3/Si/sub 2/ so produced, sound pellets with bulk densities up to 98.5% theoretical were prepared by cold pressing and sintering. The sintering technique was also used to produce 3- by 1/2- by 1/4-in. bars for physical- property tests. (auth