12,012 research outputs found

    Instrumentation for hydrogen slush storage containers

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    Hydrogen liquid and slush tank continuous inventory during ground storag

    Hydrogen slush density reference system

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    A hydrogen slush density reference system was designed for calibration of field-type instruments and/or transfer standards. The device is based on the buoyancy principle of Archimedes. The solids are weighed in a low-mass container so arranged that solids and container are buoyed by triple-point liquid hydrogen during the weighing process. Several types of hydrogen slush density transducers were developed and tested for possible use as transfer standards. The most successful transducers found were those which depend on change in dielectric constant, after which the Clausius-Mossotti function is used to relate dielectric constant and density

    An enzymatic Finkelstein reaction : fluorinase catalyses direct halogen exchange

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    We thank the Engineering and Physical Sciences Research Council, UK, for a research grant.The fluorinase enzyme from Streptomyces cattleya is shown to catalyse a direct displacement of bromide and iodide by fluoride ion from 5′-bromodeoxyadenosine (5′-BrDA) and 5′-iododeoxyadenosine (5′-IDA) respectively to form 5′-fluorodeoxyadenosine (5′-FDA) in the absence of L-methionine (L-Met) or S-adenosyl-L-methionine (SAM). 5′-BrDA is the most efficient substrate for this enzyme catalysed Finkelstein reaction.PostprintPeer reviewe

    The Role of Genetic Polymorphism of IL-4 (C-589T) and TNfa (G-308A) and Regular Passive Smoking in Clinical Manifestations of Pneumonia in Infants

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    Objective: This study set out to investigate the relationship between molecular-genetic mechanisms that modulate cytokine in infants whose parents expose them to cigarette smoke and those that do not expose their infants to cigarette smoke with the possible effects on the severity of pneumonia at presentation to hospital. Exposure to cigarette smoke in infants changed the likelihood of the severity of pneumonia. The results suggest a possible link between the duration of clinical manifestation of pneumonia within infants that are exposed to cigarette smoke. Infants who are exposed to cigarette smoke had higher plasma concentrates in both IgE and CRP. Among infants with the mutant variant of the TNF-α (G-308A) gene, infants from households where both parents smoked or had a father who smoked had longer duration of clinical signs of pneumonia than did infants with no exposure to tobacco smoke. The plasma concentration of IgE in infants in families where one or both parents smoke was significantly higher than in infants with no smoke exposure. The study begins to develop evidence that if the newborn infant is exposed to tobacco smoke either directly from their mother or from others in the household including automobiles, the severity of pneumonia is increased. Both nurses and pediatricians should reinforce the consequences of smoke around the baby to all parents at every opportunity

    Remote sensing in Michigan for land resource management

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    The utilization of NASA earth resource survey technology as an important aid in the solution of current problems in resource management and environmental protection in Michigan is discussed. Remote sensing techniques to aid Michigan government agencies were used to achieve the following results: (1) provide data on Great Lakes beach recession rates to establish shoreline zoning ordinances; (2) supply technical justification for public acquisition of land to establish the St. John's Marshland Recreation Area; (3) establish economical and effective methods for performing a statewide wetlands survey; (4) accomplish a variety of regional resource management actions in the Upper Peninsula; and (5) demonstrate improved soil survey methods. The project disseminated information on remote sensing technology and provided advice and assistance to a number of users in Michigan

    AdS/CFT and the Information Paradox

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    The information paradox in the quantum evolution of black holes is studied within the framework of the AdS/CFT correspondence. The unitarity of the CFT strongly suggests that all information about an initial state that forms a black hole is returned in the Hawking radiation. The CFT dynamics implies an information retention time of order the black hole lifetime. This fact determines many qualitative properties of the non-local effects that must show up in a semi-classical effective theory in the bulk. We argue that no violations of causality are apparent to local observers, but the semi-classical theory in the bulk duplicates degrees of freedom inside and outside the event horizon. Non-local quantum effects are required to eliminate this redundancy. This leads to a breakdown of the usual classical-quantum correspondence principle in Lorentzian black hole spacetimes.Comment: 16 pages, harvmac, reference added, minor correction

    Black Hole Complementarity vs. Locality

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    The evaporation of a large mass black hole can be described throughout most of its lifetime by a low-energy effective theory defined on a suitably chosen set of smooth spacelike hypersurfaces. The conventional argument for information loss rests on the assumption that the effective theory is a local quantum field theory. We present evidence that this assumption fails in the context of string theory. The commutator of operators in light-front string theory, corresponding to certain low-energy observers on opposite sides of the event horizon, remains large even when these observers are spacelike separated by a macroscopic distance. This suggests that degrees of freedom inside a black hole should not be viewed as independent from those outside the event horizon. These nonlocal effects are only significant under extreme kinematic circumstances, such as in the high-redshift geometry of a black hole. Commutators of space-like separated operators corresponding to ordinary low-energy observers in Minkowski space are strongly suppressed in string theory.Comment: 32 pages, harvmac, 3 figure

    Modifying the Einstein Equations off the Constraint Hypersuface

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    A new technique is presented for modifying the Einstein evolution equations off the constraint hypersurface. With this approach the evolution equations for the constraints can be specified freely. The equations of motion for the gravitational field variables are modified by the addition of terms that are linear and nonlocal in the constraints. These terms are obtained from solutions of the linearized Einstein constraints.Comment: 4 pages, 1 figure, uses REVTe

    Remote sensing in Michigan for land resource management

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    The application of NASA earth resource survey technology to resource management and environmental protection in Michigan was investigated. Remote sensing techniques to aid Michigan government agencies were applied in the following activities: (1) land use inventory and management, (2) great lakes shorelands protection and management, (3) wetlands protection and management, and (4) soil survey. In addition, information was disseminated on remote sensing technology, and advice and assistance was provided to a number of users
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