Investigation of seismicity and related effects at NASA Ames-Dryden Flight Research Facility, Computer Center, Edwards, California

This report discusses a geological and seismological investigation of the NASA Ames-Dryden Flight Research Facility site at Edwards, California. Results are presented as seismic design criteria, with design values of the pertinent ground motion parameters, probability of recurrence, and recommended analogous time-history accelerograms with their corresponding spectra. The recommendations apply specifically to the Dryden site and should not be extrapolated to other sites with varying foundation and geologic conditions or different seismic environments

Evaluation of liquid methane storage and transfer problems in supersonic aircraft

Evaluation of liquid methane storage and transfer problems for future supersonic aircraft cryogenic fuel requirement

Time Series Forecasting: The Case for the Single Source of Error State Space

The state space approach to modelling univariate time series is now widely used both in theory and in applications. However, the very richness of the framework means that quite different model formulations are possible, even when they purport to describe the same phenomena. In this paper, we examine the single source of error [SSOE] scheme, which has perfectly correlated error components. We then proceed to compare SSOE to the more common version of the state space models, for which all the error terms are independent; we refer to this as the multiple source of error [MSOE] scheme. As expected, there are many similarities between the MSOE and SSOE schemes, but also some important differences. Both have ARIMA models as their reduced forms, although the mapping is more transparent for SSOE. Further, SSOE does not require a canonical form to complete its specification. An appealing feature of SSOE is that the estimates of the state variables converge in probability to their true values, thereby leading to a formal inferential structure for the ad-hoc exponential smoothing methods for forecasting. The parameter space for SSOE models may be specified to match that of the corresponding ARIMA scheme, or it may be restricted to meaningful sub-spaces, as for MSOE but with somewhat different outcomes. The SSOE formulation enables straightforward extensions to certain classes of non-linear models, including a linear trend with multiplicative seasonals version that underlies the Holt-Winters forecasting method. Conditionally heteroscedastic models may be developed in a similar manner. Finally we note that smoothing and decomposition, two crucial practical issues, may be performed within the SSOE framework.ARIMA, Dynamic Linear Models, Equivalence, Exponential Smoothing, Forecasting, GARCH, Holt's Method, Holt-Winters Method, Kalman Filter, Prediction Intervals.

Tests to experimentally determine the natural frequencies of the saturn s-ic test stand, phase i

Natural frequencies of Saturn test stand during horizontal vibrations at several force level

Applications of Small Molecule-Carbon Nanotube Interactions

The interactions of single-walled carbon nanotubes (SWNTs) with small molecules are critical to harnessing their remarkable electronic properties. Due to quenching effects, properties such as near infrared fluorescence are only seen in individually dispersed SWNTs. Individually dispersing SWNTs in aqueous solution using surfactants such as sodium dodecylbenzene sulfate has allowed SWNTs to be studied spectroscopically but only at low concentration. I demonstrate that by combining small molecules additives such as sucrose, trehalose, and glycerine into the surfactant dispersion process, the efficiency of the process is greatly increased. Utilizing the additive sucrose allows for the production of individually dispersed SWNT solutions at a concentration 100 times greater (up to 3.3 g/L) than the highest concentration reported previously. Spectroscopic studies suggest the small-molecule additives do not interact electronically with the surfactant-encapsulated SWNTs in solution but instead increase the solution's viscosity, slowing down Brownian motion of molecules in solution. In solution, SWNTs move slower than surfactant molecules due to the large size difference between the two molecules. After sonication induced cavitation breaks apart a SWNT bundle, the rebundling process is slowed allowing the surfactant molecules more time to stabilize the individualized nanotubes. When dried, the nanotubes from these solutions retain their near-infrared fluorescence, indicating that the nanotubes do not become highly bundled upon solvent evaporation. While the small-molecules do not induce spectral shift in the SWNT solution spectra, in dried films these additives cause the fluorescence of individually dispersed SWNTs to red-shift by nearly 30 nm. Wax based inkjet printing is a popular method to create paper microfluidic devices. The wax is first printed on paper and then reflowed. During reflow, the paper is heated to the wax's melting point causing the wax to wick into the paper and create a hydrophobic barrier. Wax-reflowing is an inexpensive method to create paper microfluidic devices but gives poor resolution due to a high wicking rate in the lateral direction of the paper. To demonstrate how small-molecules such as trehalose can interact with structures other than SWNTs, I studied the transport kinetics of molten wax through paper. When paper is saturated with trehalose, the wax diffuses more slowly in the lateral direction due to blockage of the transport mechanism through cellulose fibers. Transport through larger fiber-created pores is still available but is omnidirectional due to the structure of paper. This mechanism was used to create high-resolution paper microfluidic devices

NASA technology utilization survey on composite materials

NASA and NASA-funded contractor contributions to the field of composite materials are surveyed. Existing and potential non-aerospace applications of the newer composite materials are emphasized. Economic factors for selection of a composite for a particular application are weight savings, performance (high strength, high elastic modulus, low coefficient of expansion, heat resistance, corrosion resistance,), longer service life, and reduced maintenance. Applications for composites in agriculture, chemical and petrochemical industries, construction, consumer goods, machinery, power generation and distribution, transportation, biomedicine, and safety are presented. With the continuing trend toward further cost reductions, composites warrant consideration in a wide range of non-aerospace applications. Composite materials discussed include filamentary reinforced materials, laminates, multiphase alloys, solid multiphase lubricants, and multiphase ceramics. New processes developed to aid in fabrication of composites are given

Integrated analysis of lncRNA and mRNA expression in rainbow trout families showing variation in muscle growth and fillet quality traits

Muscle yield and quality traits are important for the aquaculture industry and consumers. Genetic selection for these traits is difficult because they are polygenic and result from multifactorial interactions. To study the genetic architecture of these traits, phenotypic characterization of whole body weight (WBW), muscle yield, fat content, shear force and whiteness were measured in ~500 fish representing 98 families from a growth-selected line. RNA-Seq was used to sequence the muscle transcriptome of different families exhibiting divergent phenotypes for each trait. We have identified 240 and 1,280 differentially expressed (DE) protein-coding genes and long noncoding RNAs (lncRNAs), respectively, in fish families exhibiting contrasting phenotypes. Expression of many DE lncRNAs (n = 229) was positively correlated with overlapping, neighboring or distantly located protein-coding genes (n = 1,030), resulting in 3,392 interactions. Three DE antisense lncRNAs were co-expressed with sense genes known to impact muscle quality traits. Forty-four DE lncRNAs had potential sponge functions to miRNAs that affect muscle quality traits. This study (1) defines muscle quality associated protein-coding and noncoding genes and (2) provides insight into non-coding RNAs involvement in regulating growth and fillet quality traits in rainbow trout