Electro-optical spin measurement system

An electro-optical spin measurement system for a spin model in a spin tunnel includes a radio controlled receiver/transmitter, targets located on the spin model, optical receivers mounted around the perimeter of the spin tunnel and the base of the spin tunnel for receiving data from the targets, and a control system for accumulating data from the radio controlled receiver and receivers. Six targets are employed. The spin model includes a fuselage, wings, nose, and tail. Two targets are located under the fuselage of the spin model at the nose tip and tail. Two targets are located on the side of the fuselage at the nose tip and tail, and a target is located under each wing tip. The targets under the fuselage at the nose tip and tail measure spin rate of the spin model, targets on the side of the fuselage at the nose tip and tail measure angle of attack of the spin model, and the targets under the wing tips measure roll angle of the spin model. Optical receivers are mounted at 90 degree increments around the periphery of the spin tunnel to determine angle of attack and roll angle measurements of the spin model. Optical receivers are also mounted at the base of the spin tunnel to define quadrant and position of the spin model and to determine the spin rate of the spin model

Miniaturization of flight deflection measurement system

A flight deflection measurement system is disclosed including a hybrid microchip of a receiver/decoder. The hybrid microchip decoder is mounted piggy back on the miniaturized receiver and forms an integral unit therewith. The flight deflection measurement system employing the miniaturized receiver/decoder can be used in a wind tunnel. In particular, the miniaturized receiver/decoder can be employed in a spin measurement system due to its small size and can retain already established control surface actuation functions

Coatings for directional eutectics

Coating compositions were evaluated for oxidation protection of directionally solidified composite alloy NiTaC-13. These coatings included three NiCrAlY compositions (30-5-1, 25-10-1 and 20-15-1), two FeCrAlY compositions (30-5-1 and 25-10-1), a CoCrAlY composition (25-10-1), and one duplex coating, Ni-35Cr + Al. Duplicate pin samples of each composition were evaluated using two cyclic furnace oxidation tests of 100 hours at 871 C and 500 hours at 1093 C. The two best coatings were Ni-20Cr-15Al-lY and Ni-35Cr + Al. The two preferred coatings were deposited on pins and were evaluated in detail in .05 Mach cyclic burner rig oxidation to 1093 C. The NiCrAlY coating was protective after 830 hours of cycling, while the duplex coating withstood 630 hours. Test bars were coated and cycled for up to 500 hours. Tensile tests indicated no effect of coatings on strength. In 871 C air stress rupture, a degradation was observed for coated relative to bare material. The cycled NiCrAlY coating offered excellent protection with properties superior to the bare cycled NiTaC-13 in 1093 C air stress rupture

Physical and Electrochemical Area Determination of Electrodeposited Ni, Co, and NiCo Thin Films

The surface area of electrodeposited thin films of Ni, Co, and NiCo was evaluated using electrochemical double-layer capacitance, electrochemical area measurements using the [Ru(NH$_3$)$_6$]$^{3+}$/[Ru(NH$_3$)$_6$]$^{2+}$ redox couple, and topographic atomic force microscopy (AFM) imaging. These three methods were compared to each other for each composition separately and for the entire set of samples regardless of composition. Double-layer capacitance measurements were found to be positively correlated to the roughness factors determined by AFM topography. Electrochemical area measurements were found to be less correlated with measured roughness factors as well as applicable only to two of the three compositions studied. The results indicate that in situ double-layer capacitance measurements are a practical, versatile technique for estimating the accessible surface area of a metal sample.Comment: Accepted for publication in Nano Convergence, 6 figure

An Integrated Risk Analysis Methodology in a Multidisciplinary Design Environment

Design of complex, one-of-a-kind systems, such as space transportation systems, is characterized by high uncertainty and, consequently, high risk. It is necessary to account for these uncertainties in the design process to produce systems that are more reliable. Systems designed by including uncertainties and managing them, as well, are more robust and less prone to poor operations as a result of parameter variability. The quantification, analysis and mitigation of uncertainties are challenging tasks as many systems lack historical data. In such an environment, risk or uncertainty quantification becomes subjective because input data is based on professional judgment. Additionally, there are uncertainties associated with the analysis tools and models. Both the input data and the model uncertainties must be considered for a multi disciplinary systems level risk analysis. This research synthesizes an integrated approach for developing a method for risk analysis. Expert judgment methodology is employed to quantify external risk. This methodology is then combined with a Latin Hypercube Sampling - Monte Carlo simulation to propagate uncertainties across a multidisciplinary environment for the overall system. Finally, a robust design strategy is employed to mitigate risk during the optimization process. This type of approach to risk analysis is conducive to the examination of quantitative risk factors. The core of this research methodology is the theoretical framework for uncertainty propagation. The research is divided into three stages or modules. The first two modules include the identification/quantification and propagation of uncertainties. The third module involves the management of uncertainties or response optimization. This final module also incorporates the integration of risk into program decision-making. The risk analysis methodology, is applied to a launch vehicle conceptual design study at NASA Langley Research Center. The launch vehicle multidisciplinary environment consists of the interface between configuration and sizing analysis outputs and aerodynamic parameter computations. Uncertainties are analyzed for both simulation tools and their associated input parameters. Uncertainties are then propagated across the design environment and a robust design optimization is performed over the range of a critical input parameter. The results of this research indicate that including uncertainties into design processes may require modification of design constraints previously considered acceptable in deterministic analyses

Trade flows and marketing practices of Louisiana and Gulf States nurseries

The markets facing nursery producers have changed dramatically in the past decade. These changes in nursery markets have outdated previous research. New research into nursery marketing will assist nursery producers in making marketing decisions. Nursery producers can market their plants to five different marketing channels: Mass-merchandisers, garden centers, other retailers, landscapers and re-wholesalers. This study described the 1998 Louisiana nursery industry, analyzed nursery market changes over the past decade in Louisiana and the Southeast and analyzed characteristics of Louisiana and Southeastern nurseries to estimate marketing channel choice. Data was collected via mail using the third Trade Flows and Marketing Practices survey. Non-respondents to the mail survey were contacted by telephone to obtain survey information. The resulting data set was compiled and tabulated to form a description of the 1998 Louisiana nursery industry. Data from the 1998 TFMP survey was compared with data from the 1988 and 1993 surveys. An analysis of variance for each of the marketing channels was performed to determine if and how marketing channel use had changed over the decade. In order to estimate marketing channel use, a model was designed with the proportion of sales through each channel as a function of a set of market oriented variables such as sales, acreage, age, contract sales, transaction methods, in-state sales and sales to four or more marketing channels . A system of five equations was designed to estimate marketing channel use, one equation for each marketing channel. Analysis of the Louisiana nursery market over the past decade showed that Louisiana nurseries have increased sales to retailers and re-wholesalers at the expense of landscapers. Analysis of nursery marketing channel choice revealed that nurseries have little market power to make marketing decisions. It appears that the retailers and the market dictate marketing decisions in the nursery industry

Material Morphology and energy barriers to electrical ageing

A distribution of the parameters representing activation energy of the ageing process within the Dissado-Montanari-Mazzanti (DMM) lifetime model has been shown to model experimental lifetime distributions of PET films well. The results imply small differences in the local environments of the moieties involved in the ageing process. Very small changes in the minimum activation energy values have a pronounced effect on the resultant lifetimes of polymer specimens. Changes in the distributions of activation energies with field and temperature can be explained by assuming the ageing process to be one whereby polymer segments on lamella surfaces crystallise to create free volume within the polymer

A Versatile Magnetorquer Design for Microsatellite Constellation Missions

Attitude determination and control hardware for small satellites is constantly transforming to improve pointing accuracy and stability for target tracking missions. Magnetic attitude control is an effective and inexpensive approach when developing microsatellites for low earth orbit constellation missions. The Space Flight Laboratory (SFL) has implemented magnetic torquers (magnetorquers) and permanent magnets in previous missions for active and passive magnetic attitude control. A magnetorquer generates a magnetic dipole that torques the spacecraft when in the presence of Earth’s magnetic field. This paper outlines the design, analysis, and testing of an embedded coil magnetorquer for SFL’s SPARTAN and DEFIANT platforms. The SPARTAN magnetorquer was designed to be easily adaptable to other SFL platforms, including the DEFIANT platform which is shown to have only minor modifications. Simulations of sample missions for both platforms show how the magnetorquers are able to detumble the spacecraft after launch vehicle separation as well as mitigate reaction wheel saturation. All flight magnetorquers must go through environmental acceptance testing before they are ready for spacecraft integration. A set of three identical magnetorquers are orthogonally mounted in their respective platforms to enable magnetic dipole generation in all three body axes