52,760 research outputs found

    System cost performance analysis (study 2.3). Volume 1: Executive summary

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    A study is described which was initiated to identify and quantify the interrelationships between and within the performance, safety, cost, and schedule parameters for unmanned, automated payload programs. The result of the investigation was a systems cost/performance model which was implemented as a digital computer program and could be used to perform initial program planning, cost/performance tradeoffs, and sensitivity analyses for mission model and advanced payload studies. Program objectives and results are described briefly

    Effects of the thermal sterilization procedure on polymeric products

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    Properties of samples are tested, after thermal exposure, and values are compared with unexposed samples. Thermal stability or compatibility ratings of formulated or compounded organic polymers using trade names are made and degree of change in measured properties is assessed. Products are rated compatible, marginal, or not compatible

    Heterologous carriers in the anamnestic antihapten response

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    Anamnestic antihapten responses were obtained to trinitrophenyl (TNP) when rabbits sensitized to trinitrophenyl-hemocyanin (TNP-KLH) were challenged with TNP-heterologous protein conjugates. Hapten-heterologous carrier conjugates elicited antihapten titers similar in magnitude to those elicited by the homologous carrier conjugate. Hapten-heterologous carrier recall of antihapten was successful as early as 37 days and as late as 11 months after sensitization. There was no correlation between anti-TNP-precipitating antibody titer after sensitization and the ability to respond to challenge by hapten-heterologous carrier. The results are discussed in terms of immunogenicity of sensitization, suppressive effects of persisting postsensitization antibody, and submolecular haptenic environment as factors possibly affecting the heterologous recall process

    ENCOMPASS: A SAGA based environment for the compositon of programs and specifications, appendix A

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    ENCOMPASS is an example integrated software engineering environment being constructed by the SAGA project. ENCOMPASS supports the specification, design, construction and maintenance of efficient, validated, and verified programs in a modular programming language. The life cycle paradigm, schema of software configurations, and hierarchical library structure used by ENCOMPASS is presented. In ENCOMPASS, the software life cycle is viewed as a sequence of developments, each of which reuses components from the previous ones. Each development proceeds through the phases planning, requirements definition, validation, design, implementation, and system integration. The components in a software system are modeled as entities which have relationships between them. An entity may have different versions and different views of the same project are allowed. The simple entities supported by ENCOMPASS may be combined into modules which may be collected into projects. ENCOMPASS supports multiple programmers and projects using a hierarchical library system containing a workspace for each programmer; a project library for each project, and a global library common to all projects

    Effects of the thermal sterilization procedure on polymeric products

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    Effects of thermal sterilization on polymeric products used on Ranger and Mariner spacecraf

    Effects of ethylene oxide-Freon 12 decontamination and dry heat sterilization procedures on polymeric products

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    Effects of ethylene oxide-Freon 12 decontamination and dry heat sterilization procedures on potential spacecraft polymeric material

    Studies on Ethylene Oxide-freon 12 Decontamination and Dry-Heat Sterilization Cycles

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    Ethylene oxide-Freon decontamination and heat sterilization cycle

    Estimating Lunar Pyroclastic Deposit Depth from Imaging Radar Data: Applications to Lunar Resource Assessment

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    Lunar pyroclastic deposits represent one of the primary anticipated sources of raw materials for future human settlements. These deposits are fine-grained volcanic debris layers produced by explosive volcanism contemporaneous with the early stage of mare infilling. There are several large regional pyroclastic units on the Moon (for example, the Aristarchus Plateau, Rima Bode, and Sulpicius Gallus formations), and numerous localized examples, which often occur as dark-halo deposits around endogenic craters (such as in the floor of Alphonsus Crater). Several regional pyroclastic deposits were studied with spectral reflectance techniques: the Aristarchus Plateau materials were found to be a relatively homogeneous blanket of iron-rich glasses. One such deposit was sampled at the Apollo 17 landing site, and was found to have ferrous oxide and titanium dioxide contents of 12 percent and 5 percent, respectively. While the areal extent of these deposits is relatively well defined from orbital photographs, their depths have been constrained only by a few studies of partially filled impact craters and by imaging radar data. A model for radar backscatter from mantled units applicable to both 70-cm and 12.6-cm wavelength radar data is presented. Depth estimates from such radar observations may be useful in planning future utilization of lunar pyroclastic deposits

    Systems cost/performance analysis (study 2.3). Volume 2: Systems cost/performance model

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    A methodology which was developed for balanced designing of spacecraft subsystems and interrelates cost, performance, safety, and schedule considerations was refined. The methodology consists of a two-step process: the first step is one of selecting all hardware designs which satisfy the given performance and safety requirements, the second step is one of estimating the cost and schedule required to design, build, and operate each spacecraft design. Using this methodology to develop a systems cost/performance model allows the user of such a model to establish specific designs and the related costs and schedule. The user is able to determine the sensitivity of design, costs, and schedules to changes in requirements. The resulting systems cost performance model is described and implemented as a digital computer program
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