66,928 research outputs found

    Ultrasonic scanner for radial and flat panels

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    An ultrasonic scanning mechanism is described that scans panels of honeycomb construction or with welded seams. It incorporates a device which by simple adjustment is adapted to scan either a flat panel or a radial panel. The supporting structure takes the form of a pair of spaced rails. An immersion tank is positioned between the rails and below their level. A work holder is mounted in the tank and is adapted to hold the flat or radial panel. A traveling bridge is movable along the rails and a carriage is mounted on the bridge

    Opportunities for use of exact statistical equations

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    Exact structure function equations are an efficient means of obtaining asymptotic laws such as inertial range laws, as well as all measurable effects of inhomogeneity and anisotropy that cause deviations from such laws. "Exact" means that the equations are obtained from the Navier-Stokes equation or other hydrodynamic equations without any approximation. A pragmatic definition of local homogeneity lies within the exact equations because terms that explicitly depend on the rate of change of measurement location appear within the exact equations; an analogous statement is true for local stationarity. An exact definition of averaging operations is required for the exact equations. Careful derivations of several inertial range laws have appeared in the literature recently in the form of theorems. These theorems give the relationships of the energy dissipation rate to the structure function of acceleration increment multiplied by velocity increment and to both the trace of and the components of the third-order velocity structure functions. These laws are efficiently derived from the exact velocity structure function equations. In some respects, the results obtained herein differ from the previous theorems. The acceleration-velocity structure function is useful for obtaining the energy dissipation rate in particle tracking experiments provided that the effects of inhomogeneity are estimated by means of displacing the measurement location.Comment: accepted by Journal of Turbulenc

    Future Land Use Decisions of North Dakota Conservation Reserve Program Participants

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    Environmental Economics and Policy, Land Economics/Use,

    Probability Distributions of Random Electromagnetic Fields in the Presence of a Semi-Infinite Isotropic Medium

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    Using a TE/TM decomposition for an angular plane-wave spectrum of free random electromagnetic waves and matched boundary conditions, we derive the probability density function for the energy density of the vector electric field in the presence of a semi-infinite isotropic medium. The theoretical analysis is illustrated with calculations and results for good electric conductors and for a lossless dielectric half-space. The influence of the permittivity and conductivity on the intensity, random polarization, statistical distribution and standard deviation of the field is investigated, both for incident plus reflected fields and for refracted fields. External refraction is found to result in compression of the fluctuations of the random field.Comment: 23 pages, 11 figures, accepted for publication in Radio Scienc

    Interacting with digital media at home via a second screen

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    In recent years Interactive Television (iTV) has become a household technology on a global scale. However, iTV is still a new technology in the early stages of its evolution. Our previous research looked at how everyday users of iTV feel about the interactive part of iTV. In a series of studies we investigated how people use iTV services; their likes, dislikes, preferences and opinions. We then developed a second screen-based prototype device in response to these findings and tested it with iTV users in their own homes. This is a work in progress paper that outlines the work carried previously in the area of controlling interactive Television via a second screen. The positive user responses led us to extend the scope of our previous research to look into other related areas such as barriers to digital interactive media and personalisation of digital interactive media at home

    Preferences for Prenatal Tests for Cystic Fibrosis: A Discrete Choice Experiment to Compare the Views of Adult Patients, Carriers of Cystic Fibrosis and Health Professionals

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    As new technologies enable the development of non-invasive prenatal diagnosis (NIPD) for cystic fibrosis (CF), research examining stakeholder views is essential for the preparation of implementation strategies. Here, we compare the views of potential service users with those of health professionals who provide counselling for prenatal tests. A questionnaire incorporating a discrete choice experiment examined preferences for key attributes of NIPD and explored views on NIPD for CF. Adult patients (n = 92) and carriers of CF (n = 50) were recruited from one children’s and one adult NHS specialist CF centre. Health professionals (n = 70) were recruited via an e-mail invitation to relevant professional bodies. The key attribute affecting service user testing preferences was no miscarriage risk, while for health professionals, accuracy and early testing were important. The uptake of NIPD by service users was predicted to be high and includes couples that would currently decline invasive testing. Many service users (47%) and health professionals (55.2%) thought the availability of NIPD for CF would increase the pressure to undergo prenatal testing. Most service users (68.5%) thought NIPD for CF should be offered to all pregnant women, whereas more health professionals (68.2%) thought NIPD should be reserved for known carrier couples. The implications for clinical practice are discussed

    Research and development of a capacity nonaqueous secondary battery Fourth quarterly report, Jul. - Sep. 1965

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    High capacity nonaqueous secondary battery development - lithium deposition and cycling, ionic solvation, cathode construction and discharge efficiency, and solvent purificatio

    Circular No. 66 - Physical Curd Character of Milk and Its Probably Relation to Infant Nutrition

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    A problem which must be met by many mothers is that of obtaining for their infants an adequate substitute for breast milk. The weaning period is a very critical time in the life of every infant. Its ability to properly digest and assimilate the food supplied will largely determine its state of health, provided it is kept free from infection. Milk formulas for the feeding of infants are often made up to conform to certain fat requirements. Some infants apparently have difficulty in properly assimilating a milk with a high fat content. This may be due to a low fat tolerance on the part of the infant or it may be caused by the physical curd character of the milk which has coagulated in the child\u27s stomach. The curd obtained by the coagulation of the milk from some cows is soft and feathery, resembling breast milk in this regard. From the milk of other cows, however, a tough, rubbery curd is obtained which has an entirely different texture from that of breast milk. The physical curd character of the milk can be approximated by the test which is described in this publication. The milk is coagulated by means of a solution of dry-scale pepsin and calcium chloride. The ease with which the curd formed can be wrung thru a fine-meshed cheesecloth is an index to its physical character
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