4,417 research outputs found
NASA metrology information system: A NEMS subsystem
the NASA Metrology Information Systems (NMIS) is being developed as a standardized tool in managing the NASA field Center's instrument calibration programs. This system, as defined by the NASA Metrology and Calibration Workshop, will function as a subsystem of the newly developed NASA Equipment Management System (NEMS). The Metrology Information System is designed to utilize and update applicable NEMS data fields for controlled property and to function as a stand alone system for noncontrolled property. The NMIS provides automatic instrument calibration recall control, instrument historical performance data storage and analysis, calibration and repair labor and parts cost data, and instrument user and location data. Nineteen standardized reports were developed to analyze calibration system operations
How Attitudes of Important Stakeholder Groups Can Influence Effective Water Quality Management
Preliminary results of a survey of Lincoln Lake agricultural and non-agricultural watershed residents as well as water quality regulators/specialists suggests discrepancies exists in different groups perceptions of water quality, the sources of water pollution, and the roles of local, county, state and federal officials in meeting water quality objectives.Resource /Energy Economics and Policy, Q25, Q53, Q59,
Cost and benefits of using best management practices to control non-point sources of pollution under environmental and economic uncertainty
The economy of northwest Arkansas, including the Lincoln Lake watershed (a sub-watershed of the Illinois River), relies greatly upon livestock and poultry production. The supply of production by-products is increasingly under scrutiny as one of the potential sources of water pollution in the region. In light of the recent economic crisis, methodologies that help producers to evaluate the environmental and economic impacts of several practices before implementing them may be a cost-effective means of increasing BMP adoption. This study uses stochastic dominance techniques to evaluate, environmentally and economically, ten best management practices (BMPs) combinations to lessen water pollution in the Lincoln Lake watershed. All BMP combinations analyzed were effective in reducing total phosphorous (TP) losses. However, six combinations also decreased net returns (NR) when compared to a baseline. This suggests that including BMPs in the bermudagrass production systems may lead to increased NR risk. Without additional incentives, producers will not likely implement these BMP combinations regardless of their TP reduction benefits. Although, as expected, rankings of BMP combinations in terms of TP or NR differed from each other, four scenarios established that environmental and economic goals are not necessarily conflicting; they may be complementary. Additionally, this analysis revealed that producers’ risk preferences did not matter when selecting among the top-four BMP combinations but it could be a factor for other less preferred scenarios.nonpoint pollution, watershed, best management practices, risk analysis, stochastic dominance, Environmental Economics and Policy, Risk and Uncertainty, Q25, Q53,
Gravitational Constant and Torsion
Riemann-Cartan space time is considered here. It has been shown that
when we link topological Nieh-Yan density with the gravitational constant then
we get Einstein-Hilbert Lagrangian as a consequence.Comment: 8 page
Analysis of cosmic ray variations observed by the CARPET in association with solar flares in 2011-2012
The CARPET cosmic ray detector was installed on April 2006 at CASLEO (Complejo Astronmico El Leoncito) at the Argentinean Andes (31.8S, 69.3W, 2550 m, Rc=9.65 GV). This instrument was developed within an international cooperation between the Lebedev Physical Institute RAS (LPI; Russia), the Centro de Radio Astronomia e Astrofsica Mackenzie (CRAAM; Brazil) and the Complejo Astronmico el Leoncito (CASLEO; Argentina). In this paper we present results of analysis of cosmic ray variations recorded by the CARPET during increased solar flare activity in 2011-2012. Available solar and interplanetary medium observational data obtained onboard GOES, FERMI, ISS, as well as cosmic ray measurements by ground-based neutron monitor network were also used in the present analysis.Fil: Makhmutov, V.. Lebedev Physical Institute; Rusia. Universidade Presbiteriana Mackenzie; BrasilFil: Raulin, J. P.. Universidade Presbiteriana Mackenzie; BrasilFil: De Mendonca, R. R. S.. National Institute for Space Research; BrasilFil: Bazilevskaya, G. A.. Lebedev Physical Institute; RusiaFil: Correia, E.. Universidade Presbiteriana Mackenzie; Brasil. National Institute for Space Research; BrasilFil: Kaufmann, Pierre. Universidade Presbiteriana Mackenzie; BrasilFil: Marun, Adolfo Hector. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico "El Leoncito". Universidad Nacional de Córdoba. Complejo Astronómico "El Leoncito". Universidad Nacional de la Plata. Complejo Astronómico "El Leoncito". Universidad Nacional de San Juan. Complejo Astronómico "El Leoncito"; ArgentinaFil: Fernandez, German Enzo Leonel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico "El Leoncito". Universidad Nacional de Córdoba. Complejo Astronómico "El Leoncito". Universidad Nacional de la Plata. Complejo Astronómico "El Leoncito". Universidad Nacional de San Juan. Complejo Astronómico "El Leoncito"; ArgentinaFil: Echer, E.. National Institute for Space Research; Brasi
Radio-frequency dressed lattices for ultracold alkali atoms
Ultracold atomic gases in periodic potentials are powerful platforms for exploring quantum physics in regimes dominated by many-body effects as well as for developing applications that benefit from quantum mechanical effects. Further advances face a range of challenges including the realization of potentials with lattice constants smaller than optical wavelengths as well as creating schemes for effective addressing and manipulation of single sites. In this paper we propose a dressed-based scheme for creating periodic potential landscapes for ultracold alkali atoms with the capability of overcoming such difficulties. The dressed approach has the advantage of operating in a low-frequency regime where decoherence and heating effects due to spontaneous emission do not take place. These results highlight the possibilities of atom-chip technology in the future development of quantum simulations and quantum technologies, and provide a realistic scheme for starting such an exploration
Morpholinium perchlorate
In the title salt, C4H10NO+·ClO4
−, which has three independent formula units, the cations are linked into chains along [100] by N—H⋯O hydrogen bonds. Each cation acts both as a donor and as an acceptor, and every cation makes one N—H⋯O hydrogen bond with a ClO4
− anion. The crystal studied was an inversion twin
Expression of neurogenin3 reveals an islet cell precursor population in the pancreas
Differentiation of early gut endoderm cells into the endocrine cells forming the pancreatic islets of Langerhans depends on a cascade of gene activation events controlled by transcription factors including the basic helix-loop-helix (bHLH) proteins. To delineate this cascade, we began by establishing the position of neurogenin3, a bHLH factor found in the pancreas during fetal development. We detect neurogenin3 immunoreactivity transiently in scattered ductal cells in the fetal mouse pancreas, peaking at embryonic day 15.5. Although not detected in cells expressing islet hormones or the islet transcription factors Isl1, Brn4, Pax6 or PDX1, neurogenin3 is detected along with early islet differentiation factors Nkx6.1 and Nkx2.2, establishing that it is expressed in immature cells in the islet lineage. Analysis of transcription factor-deficient mice demonstrates that neurogenin3 expression is not dependent on neuroD1/BETA2, Mash1, Nkx2.2, Nkx6.1, or Pax6. Furthermore, early expression of neurogenin3 under control of the Pdx1 promoter is alone sufficient to drive early and ectopic differentiation of islet cells, a capability shared by the pancreatic bHLH factor, neuroD1/BETA2, but not by the muscle bHLH factor, MyoD. However, the islet cells produced in these transgenic experiments are overwhelmingly α cells, suggesting that factors other than the bHLH factors are required to deviate from a default α cell fate. These data support a model in which neurogenin3 acts upstream of other islet differentiation factors, initiating the differentiation of endocrine cells, but switching off prior to final differentiation. The ability to uniquely identify islet cell precursors by neurogenin3 expression allows us to determine the position of other islet transcription factors in the differentiation cascade and to propose a map for the islet cell differentiation pathway
Separation of suspended particles in microfluidic systems by directional-locking in periodic fields
We investigate the transport and separation of overdamped particles under the
action of a uniform external force in a two-dimensional periodic energy
landscape. Exact results are obtained for the deterministic transport in a
square lattice of parabolic, repulsive centers that correspond to a
piecewise-continuous linear-force model. The trajectories are periodic and
commensurate with the obstacle lattice and exhibit phase-locking behavior in
that the particle moves at the same average migration angle for a range of
orientation of the external force. The migration angle as a function of the
orientation of the external force has a Devil's staircase structure. The first
transition in the migration angle was analyzed in terms of a Poincare map,
showing that it corresponds to a tangent bifurcation. Numerical results show
that the limiting behavior for impenetrable obstacles is equivalent to the high
Peclet number limit in the case of transport of particles in a periodic pattern
of solid obstacles. Finally, we show how separation occurs in these systems
depending on the properties of the particles
Towards the interoperability of computerised guidelines and electronic health records: an experiment with openEHR archetypes and a chronic heart failure guideline
Clinical guidelines contain recommendations based on the best empirical evidence available at the moment. There is a wide consensus about the benefits of guidelines and about the fact that they should be deployed through clinical information systems, making them available during clinical consultations. However, one of the main obstacles to this integration is the interaction with the electronic healthrecord system. With the aim of solving the interoperability problems of guideline systems, we have investigated the utilisation of the openEHR standardisation proposal in the context of one of the existing guideline representation languages. Concretely, we have designed a collection of archetypes to be used within a chronic heart failure guideline. The main contribution of our work is the utilisation of openEHR archetypes in the framework of guideline representation languages. Other contributions include both the concrete set of archetypes that we have selected and the methodological approach that we have followed to obtain itThis work has been supported by Fundaci´o Caixa Castell´o-Bancaixa, through the research project P11B2009-3
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