Weldability evaluation of thick sections of Hastelloy X with varying aluminum content. NERVA program

Weldability evaluation of thick sections of Hastelloy X with varying aluminum content, for NERVA nozzle

Prevention of rust in the ID weld and heat affected zone of CRES 347 NERVA lines. NERVA program

Rust prevention in stainless steel fluid transmission lines of nuclear engine for rocket vehicle

Heat flow calorimeter

Heat flow calorimeter devices are used to measure heat liberated from or absorbed by an object. This device is capable of measuring the thermal output of sealed nickel-cadmium batteries or cells during charge-discharge cycles. An elongated metal heat conducting rod is coupled between the calorimeter vessel and a heat sink, thus providing the only heat exchange path from the calorimeter vessel itself

Sense of agency, associative learning, and schizotypy

Despite the fact that the role of learning is recognised in empirical and theoretical work on sense of agency (SoA), the nature of this learning has, rather surprisingly, received little attention. In the present study we consider the contribution of associative mechanisms to SoA. SoA can be measured quantitatively as a temporal linkage between voluntary actions and their external effects. Using an outcome blocking procedure, it was shown that training action-outcome associations under conditions of increased surprise augmented this temporal linkage. Moreover, these effects of surprise were correlated with schizotypy scores, suggesting that individual differences in higher level experiences are related to associative learning and to its impact on SoA. These results are discussed in terms of models of SoA, and our understanding of disrupted SoA in certain disorders

Weld procedure produces quality welds for thick sections of Hastelloy-X

Welding program produces premium quality, multipass welds in heavy tube sections of Hastelloy-X. It develops semiautomatic tungsten/inert gas procedures, weld wire procurement specifications material weld properties, welder-operator training, and nondestructive testing inspection techniques and procedures

Attribution of intentional causation influences the perception of observed movements: behavioral evidence and neural correlates

Recent research on human agency suggests that intentional causation is associated with a subjective compression in the temporal interval between actions and their effects. That is, intentional movements and their causal effects are perceived as closer together in time than equivalent unintentional movements and their causal effects. This so-called intentional binding effect is consistently found for one's own self-generated actions. It has also been suggested that intentional binding occurs when observing intentional movements of others. However, this evidence is undermined by limitations of the paradigm used. In the current study we aimed to overcome these limitations using a more rigorous design in combination with functional Magnetic Resonance Imaging (fMRI) to explore the neural underpinnings of intentional binding of observed movements. In particular, we aimed to identify brain areas sensitive to the interaction between intentionality and causality attributed to the observed action. Our behavioral results confirmed the occurrence of intentional binding for observed movements using this more rigorous paradigm. Our fMRI results highlighted a collection of brain regions whose activity was sensitive to the interaction between intentionality and causation. Intriguingly, these brain regions have previously been implicated in the sense of agency over one's own movements. We discuss the implications of these results for intentional binding specifically, and the sense of agency more generally

Evaluation of consumable weld inserts for NERVA line welds. Program NERVA

Weldability characteristics of consumable inserts for tungsten arc welding of NERVA line

Geometric approach to Fletcher's ideal penalty function

Original article can be found at: www.springerlink.com Copyright Springer. [Originally produced as UH Technical Report 280, 1993]In this note, we derive a geometric formulation of an ideal penalty function for equality constrained problems. This differentiable penalty function requires no parameter estimation or adjustment, has numerical conditioning similar to that of the target function from which it is constructed, and also has the desirable property that the strict second-order constrained minima of the target function are precisely those strict second-order unconstrained minima of the penalty function which satisfy the constraints. Such a penalty function can be used to establish termination properties for algorithms which avoid ill-conditioned steps. Numerical values for the penalty function and its derivatives can be calculated efficiently using automatic differentiation techniques.Peer reviewe

The NASA/MSFC global reference atmospheric model: MOD 3 (with spherical harmonic wind model)

Improvements to the global reference atmospheric model are described. The basic model includes monthly mean values of pressure, density, temperature, and geostrophic winds, as well as quasi-biennial and small and large scale random perturbations. A spherical harmonic wind model for the 25 to 90 km height range is included. Below 25 km and above 90 km, the GRAM program uses the geostrophic wind equations and pressure data to compute the mean wind. In the altitudes where the geostrophic wind relations are used, an interpolation scheme is employed for estimating winds at low latitudes where the geostrophic wind relations being to mesh down. Several sample wind profiles are given, as computed by the spherical harmonic model. User and programmer manuals are presented

Evaluation of the NEI visual functioning questionnaire as an interval measure of visual ability in low vision

AbstractThe National Eye Institute developed a visual functioning questionnaire (NEI-VFQ) designed to assess health-related quality of life of patients with visual impairments. The developers of the NEI-VFQ distributed the original 52 items into 13 different domains. The recommended method for scoring the NEI-VFQ is to linearly transform the sum of the ordinal ratings to each item within each domain to produce 13 scores. The major shortcoming of this scoring method is that sums of ordinal numbers do not necessarily generate valid measurement scales. However, Rasch models can be used to estimate interval measurement scales from ordinal responses to items. We administered 27 items from the 52-item NEI-VFQ to 341 patients with low vision. Rasch analysis was used to estimate the ‘visual ability’ required by each item for a particular response (item measures) and to estimate the ‘visual ability’ of each patient (person measures). The validity of the model was evaluated by examining the distributions of residuals for item and person measures. We observed that the 17 items we tested from the NEI-VFQ that require difficulty ratings produce a valid interval scale for low-vision patients. The estimated person measures of visual ability are linear with log MAR acuity. The ten items that require frequency or level of agreement ratings do not work together to produce a valid interval scale. Rather, these items appear to be confounded by other variables distributed in the patient sample (e.g. psychological state). The visual ability scale estimated from the 17 NEI-VFQ items is proportional to the visual ability scales estimated from two earlier studies that also elicited difficulty ratings from low-vision patients