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Results for “State functions”

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At least 163 records · Page 9

All sources NASA NTRS DOE OSTI

NASA NTRS1980

Effect of immobilization on the EEG of the baboon. Comparison with telemetry results from unrestricted animals

The EEG of the baboon was studied under two very different sets of conditions: 37 were totally immobolized while 12 were studied in their free movements with 4 channel telemetry. For the immobilzed, 3 stages were described: (1) activation, record desynchronized; (2) rest with 13-15 cm/sec rhythm, like the human alpha rhythm stage but with eyes open or closed; (3)relaxation with a decrease in 13-15 rhythm and the appearance of 5-7 cm/sec theta waves, eyelids closed, animal apparently sleeping. For the free animals the rest stage appeared when the animal's attention was not directed anywhere and there was no relaxation stage. It is concluded that the EEG pattern of the immobilized animal that was described as the "relaxation" stage really represents a special functional state which one must distinguish clearly from the physiological stages of sleep.

Bert, J.↗

NASA NTRS1980

Effect of restricted mobility on RNA content and nucleotide composition and on protein content in motoneurons of spinal cord anterior horns

An investigation into the effect of hypokinesia on the ribonucleic acid (RNA) content, the nucleotide composition, and dynamics of protein content in the motoneuron of the rat spinal cord anterior horns is described. Methodology and findings are presented. The study results showed that the nucleotide composition of the total cellular RNA at all the studied periods of hypokinesia remained unchanged and is characteristic for the cytoplasmic, high polymer ribosomal RNA. This means that with a change in the functional state of the neuron the newly formed RNA of the nerve cell has the same composition of bases as the original RNA that belongs to the ribosomal type.

Gorbunova, A. V.↗

NASA NTRS1980

Physiological reactions of a passenger to transportation conditions

The effect of transportation conditions on the performance capacity of a passenger were studied, in order to establish the time for his most rapid inclusion in production activity after the trip. It was concluded that the transportation conditions impair the functional condition of the passenger's organism. The restoration of the functional state to the initial level occurs mainly in the space of one day. It is shown that it is necessary to take into consideration the adaptation of the organism during transfer to another climate zone.

Lakshin, A. M.↗

NASA NTRS1980

Electrostimulation of muscles as a method for the treatment and prophylaxis of hemodynamic disturbances during prolonged hypokinesia

Hemodynamic and periopheral circulation indexes were recorded before, at the end of, and 5 days after 10 days of electrostimulation for 45 min daily, at rest and after a physical loading test. It was found that stroke and minute volume, cardiac output, and regional circulation improved and heart rate and peripheral resistance decreased. The functional state of the cardiac muscle and vascular tone are improved by electrostimulation of selected groups of skeletal muscles.

Dukhin, Y. O.↗

NASA NTRS1981

Existence and uniqueness of solutions to a class of nonlinear-operator-differential equations arising in automated spaceship navigation

A proof is given of the existence and uniqueness of the solution to the automatic control problem with a nonlinear state equation of the form y' = f(t,y,u) and nonlinear operator controls u = U(y) acting onto the state function y which satisfies the initial condition y(t) = x(t) for t or = 0.

Bogdan, V. M.↗

NASA NTRS1981

Experiment K305: Quantitative analysis of selected bone parameters. Supplement 3B: Mineralization in the long bones

Electron microscope and optical birefringent studies of growth plates and metaphyseal trabeculae are described. The type and functional state of bone cells were investigated and the zone of calcification of the cartilagenous growth plate, particularly the presence and condition of matrix vesicles, was characterized. Trabecular number, size, and orientation were assessed. Comparisons with a control group, indicating changes resulting from a zero gravity situation, are presented.

Matthews, J. L.↗

NASA NTRS1983

The dissociation energy of Cu2 - Do we want to perform multi-reference singles and doubles CIs on many-electron systems?

Reference is made to a study by Hay and Dunning (1976), who showed that, for most problems, it is not necessary to perform full FOCI (first order configuration interaction); instead, only that subset of configuration state functions (CSFs) that differ by only one or two spin orbitals from any of a list of reference configurations need be used. This is referred to as POLCI. Calculations of the D(e) of Cu2 using both SDCI (singles and doubles configuration interaction) and POLCI models are presented. It is found that the size-consistency problems associated with SDCI cause an error in D(e), whereas the POLCI results are in excellent agreement with experiment. It is proposed that the orbitals be classified as inactive and active and that the inactive-inactive correlation be eliminated to reduce the size-consistency error. In addition, it is recommended that SDCI treatments be applied with caution to systems having a large number of electrons.

Bauschlicher, C. W., Jr.↗

NASA NTRS1985

Laplace-transform technique for deriving thermodynamic equations from the classical microcanonical ensemble

A direct and convenient method is presented for deriving expressions which equate any thermodynamic state function to averages of specific dynamical functions and their fluctuations over the classical microcanonical distribution. Specific expressions are obtained for a variety of thermodynamic quantities. The effect of various entropy definitions on the results are assessed, and the latter are compared to previous work in the literature. The derived formulas are applied to the analysis of molecular-dynamics computer simulations.

Pearson, E. M.↗

NASA NTRS1986

N(+)-N and O(+)-O interaction energies, dipole transition moments, and transport cross sections

Complete sets of ion-atom interaction energies have been computed for nitrogen and oxygen with accurate large scale structure calculations. The computed energies agree well with the accurate potential curves available from spectroscopic measurement. The state functions from the nitrogen calculations have been applied to determine the transition moment for all allowed dipole transitions. These results can be combined to compute a detailed radiation spectrum such as that required to define the highly nonequilibrium environment of aeroassisted orbital transfer vehicle (AOTV). The long-range interaction energies have been used to determine the ion-atom resonance charge exchange cross sections that are important for transport processes such as diffusion. A calculation to determine reliable transport properties for energies that include the AOTV temperature range from these computed properties is described.

Partridge, H.↗

NASA NTRS1988

Certain aspects of human metabolism during spaceflights of varying duration

A comparative analysis is made of hormone reactions after short and long term spaceflights. Endocrinological indicators from venous blood and daily urine samples of cosmonauts completing flights lasting from 7 to 237 days were examined. No pathological indicators were found in the metabolic shifts in the erythrocytes and disruption of the functional state of their membranes.

Grigoryev, A. I.↗

NASA NTRS1988

Radiation resistance studies of amorphous silicon films

A study of hydrogenated amorphous silicon thin films irradiated with 2.00 MeV helium ions using fluences ranging from 1E11 to 1E15/sq cm is presented. The films were characterized using photothermal deflection spectroscopy, transmission and reflection spectroscopy, and photoconductivity and annealing measurements. Large changes were observed in the subband-gap optical absorption for energies between 0.9 and 1.7 eV. The steady-state photoconductivity showed decreases of almost five orders of magnitude for a fluence of 1E15/sq cm, but the slope of the intensity dependence of the photoconductivity remained almost constant for all fluences. Substantial annealing occurs even at room temperature, and for temperatures greater than 448 K the damage is completely annealed. The data are analyzed to describe the defects and the density of states function.

Payson, J. Scott↗

NASA NTRS1985

Equilibrium thermodynamics and stochastic nonlinear acoustic fields

A crystalline solid is considered to consist of a large number of incoherent nonlinear acoustic radiation sources identified with the vibrating particles of the crystalline lattice. Randomization of the field, together with the assumption of a stochastically independent, fluctuating, radiation field at the absolue zero of temperature, leads to an expression of the temperature-dependent radiation field in terms of the zero-point field. The equation is identified with the Planck distribution formula of quantum mechanics in the linear field limit. The thermodynamic state functions are also obtained in terms of the nonlinear acoustic modal energies per unit mass and reduce to the results of the Debye-Einstein stochastic quantum oscillator model in the linear field limit.

Cantrell, J. H.↗

NASA NTRS2003

Optimization Based Efficiencies in First Order Reliability Analysis

This paper develops a method for updating the gradient vector of the limit state function in reliability analysis using Broyden's rank one updating technique. In problems that use commercial code as a black box, the gradient calculations are usually done using a finite difference approach, which becomes very expensive for large system models. The proposed method replaces the finite difference gradient calculations in a standard first order reliability method (FORM) with Broyden's Quasi-Newton technique. The resulting algorithm of Broyden updates within a FORM framework (BFORM) is used to run several example problems, and the results compared to standard FORM results. It is found that BFORM typically requires fewer functional evaluations that FORM to converge to the same answer.

Peck, Jeffrey A.↗

NASA NTRS2003

Using CASE to Adopt Organizational Learning at NASA

The research direction was articulated in a statement of work created in collaboration between two program colleagues, an outside researcher and an internal user. The researcher was to deliver an implemented CASE tool (CasewiseTM) that was to be used to serve non-traditional (i.e., not software development related) organizational purposes. The explicitly stated functions of the tool were the support of 1) ISO-9000 compliance in the documentation of processes and 2) the management of process improvement. The collaborative team consisted of the researcher (GT), a full-time accompanying student (CRO), and the user (JD). The team originally focused on populating the CASE repository for the purpose of solving the two primary objectives. Consistent with the action research approach, several additional user requirements emerged as the project evolved, needs became apparent in discussions about how the tool would be used to solve organizational problems. These deliverables were contained within the CASE repository: 1) the creation of a paradigm diagram 2) the creation of a context diagram 3) the creation of child diagrams 4) the generation of 73 issues relating to organizational change 5) a compendium of stakeholder interview transcripts All record keeping was done manually and then keyed into the CASE interface. An issue is the difference between an organization s current situation (action) and its collective ideals.

Templeton, Gary F.↗

NASA NTRS2004

RTO Technical Publications: A Quarterly Listing

This is a listing of recent unclassified RTO technical publications for April 1, 2004 through June 30, 2004, processed by the NASA Center for AeroSpace Information. Topics covered include: heat transfer and cooling in propulsion and power systems; assessment of operator functional state; microwaves; aerodynamics in solid rocket propulsion; command, control, communications and intelligence modeling; personal protective equipment against anti-personnel mine blast; and data fusion and visualization.

Source record↗

NASA NTRS2006

Microgravity and Immunity: Changes in Lymphocyte Gene Expression

Earlier studies had shown that modeled and true microgravity (MG) cause multiple direct effects on human lymphocytes. MG inhibits lymphocyte locomotion, suppresses polyclonal and antigen-specific activation, affects signal transduction mechanisms, as well as activation-induced apoptosis. In this study we assessed changes in gene expression associated with lymphocyte exposure to microgravity in an attempt to identify microgravity-sensitive genes (MGSG) in general and specifically those genes that might be responsible for the functional and structural changes observed earlier. Two sets of experiments targeting different goals were conducted. In the first set, T-lymphocytes from normal donors were activated with antiCD3 and IL2 and then cultured in 1g (static) and modeled MG (MMG) conditions (Rotating Wall Vessel bioreactor) for 24 hours. This setting allowed searching for MGSG by comparison of gene expression patterns in zero and 1 g gravity. In the second set - activated T-cells after culturing for 24 hours in 1g and MMG were exposed three hours before harvesting to a secondary activation stimulus (PHA) thus triggering the apoptotic pathway. Total RNA was extracted using the RNeasy isolation kit (Qiagen, Valencia, CA). Affymetrix Gene Chips (U133A), allowing testing for 18,400 human genes, were used for microarray analysis. In the first set of experiments MMG exposure resulted in altered expression of 89 genes, 10 of them were up-regulated and 79 down-regulated. In the second set, changes in expression were revealed in 85 genes, 20 were up-regulated and 65 were down-regulated. The analysis revealed that significant numbers of MGS genes are associated with signal transduction and apoptotic pathways. Interestingly, the majority of genes that responded by up- or down-regulation in the alternative sets of experiments were not the same, possibly reflecting different functional states of the examined T-lymphocyte populations. The responder genes (MGSG) might play an essential role in adaptation to MG and/or be responsible for pathologic changes encountered in Space and thus represent potential targets for molecular-based countermeasures

Risin, D.↗

NASA NTRS2011

Fingerprinted circuits and methods of making and identifying the same

A circuit having a fingerprint for identification of a particular instantiation of the circuit is disclosed. The circuit may include a plurality of digital circuits or gates. Each of the digital circuits or gates is responsive to a configuration voltage applied to its analog input for controlling whether or not the digital circuit or gate performs its intended digital function and each of the digital circuits or gates transitioning between its functional state and its at least one other state when the configuration voltage equals a boundary voltage. The boundary voltage varies between different instantiations of the circuit for a majority of the digital circuits or gates and these differing boundary voltages serving to identify (or fingerprint) different instantiations of the same circuit.

Ferguson, Michael Ian↗

NASA NTRS2012

Fingerprinted circuits and methods of making and identifying the same

Ferguson, Michael Ian↗