63,979 research outputs found
Analysis and interpretation of Viking inorganic chemistry data (Mars data analysis program)
Soil samples gathered by the Viking Lander from the surface of Mars were analyzed. The Martian fines were lower in aluminum, iron, sulfur, and chlorine than typical terrestrial continental soils or lunar mare fines. Sample variabilities were as great within a few meters as between lander locations (4500 km apart) implying the existence of a universal Martian regolith component of constant average composition
Final-state interactions and superscaling in the semi-relativistic approach to quasielastic electron and neutrino scattering
The semi-relativistic approach to electron and neutrino quasielastic
scattering from nuclei is extended to include final-state interactions.
Starting with the usual non-relativistic continuum shell model, the problem is
relativized by using the semi-relativistic expansion of the current in powers
of the initial nucleon momentum and relativistic kinematics. Two different
approaches are considered for the final-state interactions: the Smith-Wambach
2p-2h damping model and the Dirac-equation-based potential extracted from a
relativistic mean-field plus the Darwin factor. Using the latter the scaling
properties of and cross sections for intermediate
momentum transfers are investigated.Comment: 36 pages, 17 figure
Helmet weight simulator
A device for providing acceleration cues to the helmet of a simulator pilot is described. Pulleys are attached to both shoulders of the pilot. A cable is attached to both sides of the helmet and extends through the pulleys to a takeup reel that is controlled by a torque motor. Control signals are applied to a servo system including the torque motor, the takeup reel and a force transducer which supplies the feedback signal. In one embodiment of the invention the force transducer is in the cable and in another it is in the takeup reel
Inflatable stretcher to transport patients
Inflatable plastic bag inside strong, inflexible outer bag facilitates emergency transport of seriously burned or disabled patients. When the bag is inflated the patient is completely immobilized and cushioned from external shock. Air for breathing, temperature controls and communications may be provided by appropriate plug-in connections
Study of sampling systems for comets and Mars
Several aspects of the techniques that can be applied to acquisition and preservation of samples from Mars and a cometary nucleus were examined. Scientific approaches to sampling, grounded in proven engineering methods are the key to achieving the maximum science value from the sample return mission. If development of these approaches for collecting and preserving does not preceed mission definition, it is likely that only suboptimal techniques will be available because of the constraints of formal schedule timelines and the normal pressure to select only the most conservative and least sophisticated approaches when development has lagged the mission milestones. With a reasonable investment now, before the final mission definition, the sampling approach can become highly developed, ready for implementation, and mature enough to help set the requirements for the mission hardware and its performance
PIA update: Correlation analyses of mass spectra
The PIA instrument aboard the Giotto spacecraft (a time of flight spectrometer) has been presented elsewhere. The mass spectra used in this analysis were decoded and mass numbers assigned according to the presence of carbon and silver, using the global values for these elements in their spectral absence. The results presented here were obtained using a frequency of occurrence based on analysis which correlated how often mass numbers appear in the mass spectra and which mass numbers tend to occur together in the same spectra; no amplitude information is utilized. The data are presented as plots of mass vs coincident mass for different subsets of the PIA data set, with both axes having units of atomic mass. Frequency contours are plotted at approximately five percent contour intervals, relative to the maximum AMU occurrence in that plot. The plots presented are symmetrical about the matrix diagonal, i.e., every mass is coincident with itself in a given spectra
Can pictures have explicatures?
This paper considers the question of whether pictures can be understood to give rise to explicit meanings. In relevance-theoretic terms, this means asking whether pictures give rise to ‘explicatures’. The definition of the term ‘explicature’ seems to rule out this possibility except in cases where pictures include or are accompanied by material with coded meanings. The paper considers a range of non-verbal phenomena with coded meanings, including pictograms (Forceville 2011, Forceville et al 2014). It then considers whether the explicature-implicature distinction could be relevant to pictures without such elements. Some assumptions communicated by pictures seem to be more ‘explicature-like’ than others, so it is possible that the distinction will be useful. The question is not merely terminological as the discussion leads to a fuller understanding of ways in which pictures communicate
BMI-for-age graphs with severe obesity percentile curves: Tools for plotting cross-sectional and longitudinal youth BMI data
Abstract Background Severe obesity is an important and distinct weight status classification that is associated with disease risk and is increasing in prevalence among youth. The ability to graphically present population weight status data, ranging from underweight through severe obesity class 3, is novel and applicable to epidemiologic research, intervention studies, case reports, and clinical care. Methods The aim was to create body mass index (BMI) graphing tools to generate sex-specific BMI-for-age graphs that include severe obesity percentile curves. We used the Centers for Disease Control and Prevention youth reference data sets and weight status criteria to generate the percentile curves. The statistical software environments SAS and R were used to create two different graphing options. Results This article provides graphing tools for creating sex-specific BMI-for-age graphs for males and females ages 2 to <20 years. The novel aspects of these graphing tools are an expanded BMI range to accommodate BMI values ˃35 kg/m2, inclusion of percentile curves for severe obesity classes 2 and 3, the ability to plot individual data for thousands of children and adolescents on a single graph, and the ability to generate cross-sectional and longitudinal graphs. Conclusions These new BMI graphing tools will enable investigators, public health professionals, and clinicians to view and present youth weight status data in novel and meaningful ways
Advanced dosimetry systems for the space transport and space station
Advanced dosimetry system concepts are described that will provide automated and instantaneous measurement of dose and particle spectra. Systems are proposed for measuring dose rate from cosmic radiation background to greater than 3600 rads/hr. Charged particle spectrometers, both internal and external to the spacecraft, are described for determining mixed field energy spectra and particle fluxes for both real time onboard and ground-based computer evaluation of the radiation hazard. Automated passive dosimetry systems consisting of thermoluminescent dosimeters and activation techniques are proposed for recording the dose levels for twelve or more crew members. This system will allow automatic onboard readout and data storage of the accumulated dose and can be transmitted to ground after readout or data records recovered with each crew rotation
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