27,565 research outputs found
Prospects for Measurement of the Neutrino Mass Hierarchy
The unknown neutrino mass hierarchy -- whether the mass eigenstate is
the heaviest or the lightest -- represents a major gap in our knowledge of
neutrino properties. Determining the hierarchy is a critical step toward
further precision measurements in the neutrino sector. The hierarchy is also
central to interpreting the next generation of neutrinoless double beta decay
results, plays a role in numerous cosmological and astrophysical questions, and
serves as a powerful model discriminant for theories of neutrino mass
generation and unification. Various current and planned experiments claim
sensitivity for establishing the neutrino mass hierarchy. We review the most
promising of these here, paying special attention to points of concern and
consolidating the projected sensitivities into an outlook for the years ahead.Comment: Uploading final version. 13 pages, 7 figure
Library Event Matching event classification algorithm for electron neutrino interactions in the NOvA detectors
We describe the Library Event Matching classification algorithm implemented
for use in the NOvA oscillation measurement.
Library Event Matching, developed in a different form by the earlier MINOS
experiment, is a powerful approach in which input trial events are compared to
a large library of simulated events to find those that best match the input
event. A key feature of the algorithm is that the comparisons are based on all
the information available in the event, as opposed to higher-level derived
quantities. The final event classifier is formed by examining the details of
the best-matched library events. We discuss the concept, definition,
optimization, and broader applications of the algorithm as implemented here.
Library Event Matching is well-suited to the monolithic, segmented detectors of
NOvA and thus provides a powerful technique for event discrimination.Comment: 10 pages, 7 figures. Minor fixe
Legal and professional implications of shared care: a case study in oral anticoagulation stroke prevention therapy.
Policy initiatives and technological advances enable the use of integrated shared care models of healthcare delivery whereby the focus of care is moved from the hospital to the community, and also of models where patients take increasing responsibility for monitoring and treatment. Such shifts may or may be perceived to change professional roles and responsibilities with implications to the delivery of a professionally and legally acceptable standard of care. We focus on oral anticoagulation and stroke prevention therapy to examine some possible professional and legal implications of the increasing use of shared care
Apollo experience report: Guidance and control systems: Command and service module entry monitor subsystem
The conceptual aspects of the command and service module entry monitor subsystem, together with an interpretation of the displays and their associated relationship to entry trajectory control, are presented. The entry monitor subsystem is described, and the problems encountered during the developmental phase and the first five manned Apollo flights are discussed in conjunction with the design improvements implemented
New electrical plethysmograph monitors cardiac output
Four-electrode impedance plethysmograph measures ventricular stroke volume of cardiac output of humans. The instrument is automatic, operates with only one recording channel, and minimizes patient discomfort
Determination of transmitter function by neuronal activity
The role of neuronal activity in the determination of transmitter function was studied in cultures of dissociated sympathetic neurons from newborn rat superior cervical ganglia. Cholinergic and adrenergic differentiation were assayed by incubating the cultures with radioactive choline and tyrosine and determining the rate of synthesis and accumulation of labelled acetylcholine and catecholamines. As in previous studies, pure neuronal cultures grown in control medium displayed much lower ratios of acetylcholine synthesis to catecholamine synthesis than did sister cultures grown in medium previously conditioned by incubation on appropriate nonneuronal cells (conditioned medium). However, here we report that neurons treated with the depolarizing agents elevated K+ or veratridine, or stimulated directly with electrical current, either before or during application of conditioned medium, displayed up to 300-fold lower acetylcholine/catecholamine ratios than they would have without depolarization, and thus remained primarily adrenergic. Elevated K+ and veratridine produced this effect on cholinergic differentiation without significantly altering neuronal survival. Because depolarization causes Ca2+ entry in a number of cell types, the effects of several Ca2+ agonists and antagonists were investigated. In the presence of the Ca2+ antagonists D600 or Mg2+, K+ did not prevent the induction of cholinergic properties by conditioned medium. Thus depolarization, either steady or accompanying activity, is one of the factors determining whether cultured sympathetic neurons become adrenergic or cholinergic, and this effect may be mediated by Ca2+
Process characteristics and design methods for a 300 deg quad OP amp
The results of process characterization, circuit design, and reliability studies for the development of a quad OP amplifier intended for use up to 300 C are presented. A dielectrically isolated complementary vertical bipolar process was chosen to fabricate the amplifier in order to eliminate isolation leakage and the possibility of latch up. Characterization of NPN and PNP junctions showed them to be suitable for use up to 300 C. Interconnect reliability was predicted to be greater than four years mean time between failure. Parasitic MOS formation was eliminated by isolation of each device
Thermal Transients in District Heating Systems
Heat fluxes in a district heating pipeline systems need to be controlled on
the scale from minutes to an hour to adjust to evolving demand. There are two
principal ways to control the heat flux - keep temperature fixed but adjust
velocity of the carrier (typically water) or keep the velocity flow steady but
then adjust temperature at the heat producing source (heat plant). We study the
latter scenario, commonly used for operations in Russia and Nordic countries,
and analyze dynamics of the heat front as it propagates through the system.
Steady velocity flows in the district heating pipelines are typically turbulent
and incompressible. Changes in the heat, on either consumption or production
sides, lead to slow transients which last from tens of minutes to hours. We
classify relevant physical phenomena in a single pipe, e.g. turbulent spread of
the turbulent front. We then explain how to describe dynamics of temperature
and heat flux evolution over a network efficiently and illustrate the network
solution on a simple example involving one producer and one consumer of heat
connected by "hot" and "cold" pipes. We conclude the manuscript motivating
future research directions.Comment: 31 pages, 7 figure
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