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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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The integration of image processing capabilities with interactive computer mapping systems is discussed. It is noted that the accomplishment of this integration will result in powerful geographic information systems which will enhance the applicatons of LANDSAT and other types of remotely sensed data in solving problems in the resource planning and management domain.
A three-man wastewater recovery preprototype subsystem using a hollow fiber membrane evaporator with a thermoelectric heat pump to provide efficient potable water recovery from wastewater on extended duration space flights was designed, fabricated, and tested at one-gravity. Low power, compactness and gravity insensitive operation are featured in this vacuum distillation subsystem. The tubular hollow fiber elements provide positive liquid/gas phase control with no moving parts, and provide structural integrity, improving on previous flat sheet membrane designs. A thermoelectric heat pump provides latent energy recovery. Application and integration of these key elements solved problems inherent in all previous reclamation subsystem designs.
To place the arguments advanced in this paper in alternative points of view with regard to mental models are reviewed. Use of the construct in areas such as neural information processing, manual control, decision making, problem solving, and cognitive science are discussed. Also reviewed are several taxonomies of mental models. The available empirical evidence for answering questions concerning the nature and usage of mental models is then discussed. A variety of studies are reviewed where the type and form of humans' knowledge have been manipulated. Also considered are numerous transfer of training studies whose results provide indirect evidence of the nature of mental models. The alternative perspectives considered and the spectrum of empirical evidence are combined to suggest a framework within which research on mental models can be viewed. By considering interactions of dimensions of this framework, the most salient unanswered questions can be identified.
The edge between technology and humanism is discussed. Advances in biology, in medicine, energy technology, tools and weapons, communications, psychology, problem solving and information storage, transportation, and other fields are presented. Ecology in self-transcendence and space travel as a survival tool are considered.
Research since the launch of LANDSAT-1 has been primarily directed to the development of analysis techniques and to the conduct of applications studies designed to address resource information needs in the United States and in many other countries. The current measurement capabilities represented by MSS, TM, and SIR-A and B, coupled with the present level of remote sensing understanding and the state of knowledge in the discipline earth sciences, form the foundation for NASA's Land Processes Program. Science issues to be systematically addressed include: energy balance, hydrologic cycle, biogeochemical cycles, biological productivity, rock cycle, landscape development, geological and botanical associations, and land surface inventory, monitoring, and modeling. A global perspective is required for using remote sensing technology for problem solving or applications context. A successful model for this kind of activity involves joint research with a user entity where the user provides a test site and ground truth and NASA provides the remote sensing techniques to be tested.
The objective of the Probabilistic Structural Analysis Methods (PSAM) project is to develop analysis techniques and computer programs for predicting the probabilistic response of critical structural components for current and future space propulsion systems. This technology will play a central role in establishing system performance and durability. The first year's technical activity is concentrating on probabilistic finite element formulation strategy and code development. Work is also in progress to survey critical materials and space shuttle mian engine components. The probabilistic finite element computer program NESSUS (Numerical Evaluation of Stochastic Structures Under Stress) is being developed. The final probabilistic code will have, in the general case, the capability of performing nonlinear dynamic of stochastic structures. It is the goal of the approximate methods effort to increase problem solving efficiency relative to finite element methods by using energy methods to generate trial solutions which satisfy the structural boundary conditions. These approximate methods will be less computer intensive relative to the finite element approach.
The effect of axial pinion displacement on gear meshing conditions during cutting and correction of the rolling chain gear ratio are analyzed. The so-called inverse problem-solving method is used.
A large array of models were applied in a unified manner to solve problems in space flight physiology. Mathematical simulation was used as an alternative way of looking at physiological systems and maximizing the yield from previous space flight experiments. A medical data analysis system was created which consist of an automated data base, a computerized biostatistical and data analysis system, and a set of simulation models of physiological systems. Five basic models were employed: (1) a pulsatile cardiovascular model; (2) a respiratory model; (3) a thermoregulatory model; (4) a circulatory, fluid, and electrolyte balance model; and (5) an erythropoiesis regulatory model. Algorithms were provided to perform routine statistical tests, multivariate analysis, nonlinear regression analysis, and autocorrelation analysis. Special purpose programs were prepared for rank correlation, factor analysis, and the integration of the metabolic balance data.
Integrations trends in aircraft are discussed with an eye to manifestations in future aircraft designs through interdisciplinary technology integration. Current practices use software changes or small hardware fixes to solve problems late in the design process, e.g., low static stability to upgrade fuel efficiency. A total energy control system has been devised to integrate autopilot and autothrottle functions, thereby eliminating hardware, reducing the software, pilot workload, and cost, and improving flight efficiency and performance. Integrated active controls offer reduced weight and larger payloads for transport aircraft. The introduction of vectored thrust may eliminate horizontal and vertical stabilizers, and location of the thrust at the vehicle center of gravity can provide vertical takeoff and landing capabilities. It is suggested that further efforts will open a new discipline, aeroservoelasticity, and tests will become multidisciplinary, involving controls, aerodynamics, propulsion and structures.
Attention is given to the application of the adjoint variable method under the special combination of displacement and stress boundary conditions which occur when static test conditions are simulated. In the two-step problem-solving method employed, calculation of internal stresses, displacements and total reaction force at the boundary is followed by the calculation of the applied load and the total reaction force due to unit displacements.
Numerous public administration studies have indicated that local government agencies for a variety of reasons lack access to comprehensive information resources; furthermore, such entities are often unwilling or unable to share information regarding their own problem-solving innovations. The NASA/University of Kentucky Technology Applications Program devotes a considerable effort to providing scientific and technical information and assistance to local agencies, relying on its access to over 500 distinct online databases offered by 20 hosts. The author presents a subjective assessment, based on his own experiences, of several databases which may prove useful in obtaining information for this particular end-user community.
Method calculates admittance from easily obtainable values. New method for calculating acoustic-liner admittance in rectangular duct with grazing flow based on finite-element discretization of acoustic field and reposing of unknown admittance value as linear eigenvalue problem on admittance value. Problem solved by Gaussian elimination. Unlike existing methods, present method extendable to mean flows with two-dimensional boundary layers as well. In presence of shear, results of method compared well with results of Runge-Kutta integration technique.
This report describes the results of a small study program in support of the design studies for NASA's proposed Atmospheric General Circulation Experiment (AGCE). The proposed experiment will model the atmosphere using a hemispherical layer of a dielectric fluid such as silicone oil, heated at the equator, and with a large radial AC electric field producing a temperature-dependent radial body force similar to radial gravity. The effect of terrestrial gravity on the experiment can be eliminated by doing the experiment in space flight. The author developed a series of three computer models to support these design studies. The first two calculate axisymmetric solutions and their stability to small non-axisymmetric perturbations. The third computes three-dimensional solutions. These codes allow the option of solving problems in a cylindrical geometry as well as a rather generally defined spherical layer.
Prebiotic chemistry is faced with a major problem: how could a controlled and selective reaction occur, when there is present in the same solution a large number of alternative possible coreactants? This problem is solved in the modern cell by the presence of enzymes, which are not only highly efficient and controllable catalysts, but which also can impose on their substrates a precise structural requirement. However, enzymes are the result of billions of years of evolution, and we cannot invoke them as prebiotic catalysts. One approach to solving this problem in the prebiotic context is to make use of template-directed reactions. These reactions increase the number of structural requirements that must be simultaneously present in a molecule for it to be able to react, and thereby increase the selectivity of the reaction. They also can give a large increase in the rate of a reaction, if the template constrains two potential coreactants to lie close together. A third benefit is that information that is present in the template molecule can be passed on to the product molecules. If the earliest organisms were based on proteins and nucleic acids, then the investigation of peptide synthesis on an oligonucleotide template is highly relevant to the study of the origin of life.
The design of high speed local area networks (HSLAN) for communication among distributed devices requires solving problems in three areas: the network medium and its topology, the medium access control, and the network interface. Considerable progress was already made in the first two areas. Accomplishments are divided into two groups according to their theoretical or experimental nature. A brief summary is given.
This bibliography, with abstracts, consists of 257 citations arranged in chronological order. Selection of the citations was made for their value to researchers working to solve problems associated with reducing wall interference by the design, development, and operation of adaptive wall test sections. Author, source, and subject indexes are included.
Developments in the field of AI are discussed. The components and applications of expert systems, which are computer systems designed to simulate the problem-solving behavior of a person expert in a narrow field, are examined. Two types of expert systems, shallow and deep, are described and examples are given. A logic programming system, rule-based system, and framed-based system are utilized as means of representing the expert system's data base. The limitations of expert systems are considered.
The training performed for flights of the Space Shuttle is intensive and extremely complicated. The training is totally dependent on computer generated training situations in both cockpit simulations and in integrated simulations between the simulators and the Mission Control Center (MCC). These simulations form a complex set of dress rehearsals of the actual spaceflight allowing the participants to address problems in a real world situation and utilize problem solving rationale just as they will be called upon to do during the real flight. The benefits of this type of training have been demonstrated during the flights of the Shuttle as individual flight controllers and whole teams have been tested by various untoward situations. This system of integrated simulation and training, more complex than ever, will be continued in use in the future using even more intricate man-machine interactions required to initialize, control, and operate it.