3,441 research outputs found

    Duplication, Growth and return

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    Maintenance consumption is an expense recovered in product prices, yet also a source of taste satisfaction which must be exhausted, rather than reinvested, from the capital affording it. This riddle is solved in the "duplication rules": the cost of maintenance consumption is recovered in pay and prices, but an equal flow is exhausted from the human capital of the worker earning the pay. The rules impact tradition in several ways. If output is defined in principle as value added, then it cannot also be described as consumption plus net investment without double-counting the maintenance consumption recovered in prices. Also rate of return in the stationary state is not zero, but is the rate sufficient to offset the exhaustion of individual human capital. The rules lead to new insights into economic return, and support an argument that all growth at the scale of closure is due to productivity gain rather than to thrift.

    Evaluation of two designs for cryogenic insulation

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    Shingle-type, crinkled, aluminized polyethylene ester is thermally and structurally tested for cryogenic insulation. Insulation systems require thermal efficiency with minimum weight, and the ability to withstand vibration, acceleration, and rapid pressure drops

    Semiquantitative Infrared Analysis of Diketones and Anhydrides in a Reaction Mixture

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    The ozonolysis of a hydroxymethylene ketone yields a mixture of diketone and anhydride. Treatment of hydroxymethylene camphor with ozone affords, in addition to the expected camphor quinone, a surprisingly large amount of camphoric anhydride (56%) via Baeyer-Villager reaction. Use of infrared absorption to analyze the relative amounts of camphor quinone and camphoric anhydride in a reaction mixture was studied by comparing peak heights of their carbonyl stretching bands

    Frequency multiplication in high-energy electron beams Semiannual progress report, 1 Apr. - 1 Oct. 1967

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    High energy electron beam studies dealing with nonlinear analysis of beam-plasma interactions, cyclotron harmonic instabilities, and frequency multiplicatio

    Microwave device investigations Semiannual progress report, 1 Apr. - 1 Oct. 1968

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    Beam-plasma interactions, cyclotron harmonic instabilities, harmonic generation in beam-plasma system, relativistic electron beam studies, and materials test

    Microwave device investigations Semiannual progress report, 1 Oct. 1969 - 1 Apr. 1970

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    Beam-plasma interactions, cyclotron harmonic instability study, and millimeter and submillimeter wave detection by paramagnetic material

    Searching for the Transatlantic Freedom: The Art of Valerie Maynard

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    This thesis focuses on an African-American female artist, Valerie Maynard, examining how she synthesizes African and American elements in her works. It provides detailed formal and iconographical analyses, revealing concealed meanings and paying special attention to those works with which the artist mirrors the Black experience in the United States and Africa on the other side of the Atlantic. In the process, the thesis sheds new light on the significance of Valerie Maynard\u27s work and how she has used some of them to embody the Black quest for freedom and social justice during the Civil Rights struggle of the 1960s and 1970s and beyond

    Mutation in the guanine nucleotide-binding protein beta-3 causes retinal degeneration and embryonic mortality in chickens

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    PURPOSE. To identify the gene defect that causes blindness and the predisposition to embryonic death in the retinopathy globe enlarged (rge) chicken. METHODS. Linkage analysis, with previously uncharacterized microsatellite markers from chicken chromosome 1, was performed on 138 progeny of an rge/+ and an rge/rge cross, and candidate genes were sequenced. RESULTS. The rge locus was refined and the gene for guanine nucleotide-binding protein β-3 (GNB3), which encodes a cone transducin β subunit, was found to have a 3-bp deletion (D153del) that segregated with the rge phenotype. This mutation deleted a highly conserved aspartic acid residue in the third of seven WD domains in GNB3. In silico modeling suggested that this mutation destabilized the protein. Furthermore, a 70% reduction was found in immunoreactivity to anti-GNB3 in the rge-affected retina. CONCLUSIONS. These findings implicate the β-subunit of cone transducin as the defective protein underlying the rge phenotype. Furthermore, GNB3 is ubiquitously expressed, and the c.825C→T GNB3 splicing variant (MIM 139130) has been associated with hypertension, obesity, diabetes, low birth weight, coronary heart disease, and stroke in the human population. It therefore seems likely that the defect underlying these human diseases also causes reduced embryonic viability in the rge chicken, making it a powerful model for studying the pathology involved in these associations

    Enhanced-Adhesion Multi-Walled Carbon Nanotubes on Titanium Substrates for Stray Light Control

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    Carbon nanotubes previously grown on silicon have extremely low reflectance, making them a good candidate for stray light suppression. Silicon, however, is not a good structural material for stray light components such as tubes, stops, and baffles. Titanium is a good structural material and can tolerate the 700 C nanotube growth process. The ability to grow carbon nanotubes on a titanium substrate that are ten times blacker than the current NASA state-of-the-art paints in the visible to near infrared spectra has been achieved. This innovation will allow significant improvement of stray light performance in scientific instruments or any other optical system. This innovation is a refinement of the utilization of multiwalled carbon nano tubes for stray light suppression in spaceflight instruments. The innovation is a process to make the surface darker and improve the adhesion to the substrate, improving robustness for spaceflight use. Bright objects such as clouds or ice scatter light off of instrument structures and components and make it difficult to see dim objects in Earth observations. A darker material to suppress this stray light has multiple benefits to these observations, including enabling scientific observations not currently possible, increasing observational efficiencies in high-contrast scenes, and simplifying instruments and lowering their cost by utilizing fewer stray light components and achieving equivalent performance. The prior art was to use commercially available black paint, which resulted in approximately 4% of the light being reflected (hemispherical reflectance or total integrated scatter, or TIS). Use of multiwalled carbon nanotubes on titanium components such as baffles, entrance aperture, tubes, and stops, can decrease this scattered light by a factor of ten per bounce over the 200-nm to 2,500-nm wavelength range. This can improve system stray light performance by orders of magnitude. The purpose of the innovation is to provide an enhanced stray light control capability by making a blacker surface treatment for typical stray light control components. Since baffles, stops, and tubes used in scientific observations often undergo loads such as vibration, it was critical to develop this surface treatment on structural materials. The innovation is to optimize the carbon nanotube growth for titanium, which is a strong, lightweight structural material suitable for spaceflight use. The titanium substrate carbon nanotubes are more robust than those grown on silicon and allow for easier utilization. They are darker than current surface treatments over larger angles and larger wavelength range. The primary advantage of titanium substrate is that it is a good structural material, and not as brittle as silicon
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