1,142 research outputs found
Optimizacion of planform and cruise conditions of a transport flying wing
The flying wing is a promising concept for the mid long-term commercial aviation. After the previously published conceptual design of a 300-seat class flying wing, the present article carries out a parametric analysis to optimize its planform and analyse the suitable cruise conditions to achieve the highest efficiency of such configuration. The figures of merit chosen for the optimization are the direct operating cost and the maximum take-off weight per passenger, for a specified constant range of 10 000 km. The design has to respect five relevant constraints: wingspan (limited to 80 m), cabin width, wing tip chord, number of passengers, and cruise lift coefficient. The optimum aircraft fulfilling all constraints cruises at 45 000–47 000 ft and M = 0.82, has an aspect ratio of 6.3 and taper ratio of 0.10, and carries about 280 passengers in three-class seating. This aircraft is about 20 per cent more efficient than conventional wide bodies of similar size, in terms of trip fuel
Higgs boson decay into 2 photons in the type~II Seesaw Model
We study the two photon decay channel of the Standard Model-like component of
the CP-even Higgs bosons present in the type II Seesaw Model. The corresponding
cross-section is found to be significantly enhanced in parts of the parameter
space, due to the (doubly-)charged Higgs bosons' virtual
contributions, while all the other Higgs decay channels remain Standard
Model(SM)-like. In other parts of the parameter space (and
) interfere destructively, reducing the two photon branching ratio
tremendously below the SM prediction. Such properties allow to account for any
excess such as the one reported by ATLAS/CMS at GeV if confirmed
by future data; if not, for the fact that a SM-like Higgs exclusion in the
diphoton channel around 114-115 GeV as reported by ATLAS, does not contradict a
SM-like Higgs at LEP(!), and at any rate, for the fact that ATLAS/CMS exclusion
limits put stringent lower bounds on the mass, particularly in
the parameter space regions where the direct limits from same-sign leptonic
decays of do not apply.Comment: 26 pages, 7 figure
Seguridad de la sedación profunda con propofol controlada por el endoscopista en la colangiopancreatografía retrógrada endoscópica (CPRE). Estudio prospectivo en un hospital terciario
Introducción: el propofol, administrado por el endoscopista con una enfermera entrenada, ha evolucionado como alternativa a la monitorización anestésica y es cada vez más frecuente en la práctica clínica habitual, incluso en endoscopia avanzada.
Objetivo: evaluar la seguridad de la sedación profunda con propofol controlada por el endoscopista en pacientes sometidos a colangiopancreatografía retrógrada endoscópica (CPRE).
Material y métodos: estudio prospectivo en los pacientes a los que se les realizó CPRE bajo sedación profunda con propofol. Se incluyeron diferentes variables relacionadas con el paciente y se registraron los datos iniciales y finales de la saturación de oxígeno (SatO2), la tensión arterial (TA), y la frecuencia cardiaca (FC) para determinar la presencia de eventos adversos a la sedación (hipoxemia, hipotensión o bradicardia).
Resultados: un total de 661 pacientes fueron sometidos a CPRE bajo sedación con propofol durante un periodo de 24 meses. La tasa de eventos adversos registrada fue del 9, 7%. La más frecuente fue la hipoxemia (5, 7%), seguida de la bradicardia (2, 4%) y de la hipotensión (1, 6%). En el análisis univariante, la aparición de eventos adversos a la sedación (EAS) se asoció a una clasificación de ASA = III (p = 0, 026), a pacientes de edad más avanzada (p = 0, 009), mayor IMC (p = 0, 002) y a un tiempo de exploración más prolongado (p = 0, 034). La dosis de inducción de propofol también se relacionó con mayor probabilidad de eventos adversos (p = 0, 045), pero no la dosis total de propofol administrado (p = 0, 153). En el análisis de regresión logística multivariante, la edad, el índice de masa corporal (IMC) y la duración de la exploración se registran como predictores independientes de EAS (p < 0, 05).
Conclusión: la sedación profunda con propofol controlada por personal de endoscopia entrenado es un método seguro en procedimientos endoscópicos complejos como la CPRE.
Introduction: propofol administered by an endoscopist with a trained nurse has evolved as an alternative to anesthesia monitoring and is increasingly common in the routine clinical practice, even in advanced endoscopy.
Objective: to evaluate the safety of deep sedation with endoscopist-controlled propofol in patients undergoing endoscopic retrograde cholangiopancreatography (ERCP).
Material and methods: this was a prospective study in patients undergoing ERCP under deep sedation with propofol. Different patient-related variables were included and the initial and final data on oxygen saturation (SatO(2)) blood pressure (BP) and heart rate (HR) were recorded in order to determine the presence of adverse events due to sedation (hypoxemia, hypotension, or bradycardia).
Results: a total of 661 patients underwent ERCP under sedation with propofol over a 24-month period. The rate of recorded adverse events was 9.7%. The most frequent adverse event was hypoxemia (5.7%), followed by bradycardia (2.4%) and hypotension (1.6%). According to the univariate analysis, the occurrence of adverse events due to sedation (AES) was associated with an ASA score >= III (p = 0.026), older patients (p = 0.009), higher body mass index (BMI) (p = 0.002) and a longer exploration time (p = 0.034). The induction dose of propofol was also associated with a greater likelihood of adverse events (p = 0.045) but not the total dose of propofol administered (p = 0.153). According to the multivariate logistic regression analysis, age, body mass index (BMI) and the duration of the exploration were independent predictors of SAE (p < 0.05).
Conclusion: deep sedation with propofol controlled by trained endoscopy staff is a safe method in complex endoscopic procedures such as ERCP
Innovative downhole geophysical methods for high frequency seawater intrusion dynamics monitoring
The detailed characterization of salt water intrusion is a key to understand both submarine groundwater discharge and
manage often intensively exploited groundwater resources in coastal areas. With the objective to study the response of
a coastal aquifer to a series of boundary conditions, a new experimental site has been developed through a clastic aquifer
located north of Barcelona (Spain). This hectometer scale site is located 50 m from the seashore and equipped with
17 nearby shallow holes, with depths ranging from 15 to 28 m.
In order to study not only the sedimentary structure but also the response of the aquifer to a set of natural boundary
conditions, downhole geophysical measurements have been deployed over the past 3 years in an innovative manner,
either in a time-lapse or stationary manner. The downhole measurements are complicated by the unconsolidated nature
of the sediment, obliging to perform all measurements through PVC. Also, the granitic nature of the sediment prevents
clays identification from a direct use of gamma ray profiles. For this, constituting minerals (quartz, albite, feldspar,
microcline, illite) were identified from X-ray diffraction on cores, and spectral gamma logs used to determine the illite
fractions from Th/K ratios.
In time lapse, high frequency electrical resistivity induction measurements show that preferential flow paths through the
aquifer can be identified in a fast and reliable manner. Also, changes in depth of the fresh to salt water interface (FSWI)
are precisely described, either in response to marine tides, or to a short but intense mediterranean rain event. Changes
on the order of than 1.70 m are obtain in less than a day of heavy rain. Overnight as well as seasonal changes such as
months of dryness are also illustrated due to the variability of pore fluid salinity and temperature, even over short
periods of time such as tens of minutes.
In stationary mode, the spectral natural gamma sensor located in front of the FSWI fluctuation zones records changes
in front of all radioactive peaks (from K, Tl, Bi, but also Ra with Rn) during intense rain events such as that of October
18-19, 2017. This places constraints on Ra and Rn production rate during such an event, leading to trace fresh water
outpour into the sea.Peer reviewe
Hydrodynamics and hydrogeochemical changes in the mixing zone of a coastal aquifer during a heavy rain event
The coastal aquifers are the place where meet fresh water and seawater. This confluence
between both of them is called mixing zone which is in equilibrium due to the different
density of the two masses and where various biogeochemical reactions takes place. We
know that this equilibrium can be canceled during an important recharge event. Within the
aquifer, such events displace the mixing zone over a short time period.
This study is aims at the identification and description at high frequency of spatial and
temporal response of the mixing zone and its impact on geochemical processes during one
such fast water inflow event.
We choose the experimental site of Argentona as the place of this study. Located in the
northeast of Spain this site is subjected to a Mediterranean climate characterized by heavy
rainfall amount recorded during Fall and early Spring period, concentrated during a few
hours. Furthermore, this site is located on an alluvial aquifer, equipped with 16 shallow
boreholes over a 100 m scale (Fig.1). The geological cross section presented in Fig.2 shows
that the aquifer is multilayered and we suspect an effect of a clay/silt layer located at
around 12 m.This work was funded by the projects CGL2013-48869-C2-1 y
CGL2013-48869-C2-2-R of the Spanish Government.
We would like to thank SIMMAR (Serveis Integrals de
Manteniment del Maresme) and the Consell
Comarcal del Maresme in the construction of the research site.Peer reviewe
Search for direct stau production in events with two hadronic tau-leptons in root s=13 TeV pp collisions with the ATLAS detector
A search for the direct production of the supersymmetric partners ofτ-leptons (staus) in final stateswith two hadronically decayingτ-leptons is presented. The analysis uses a dataset of pp collisions corresponding to an integrated luminosity of139fb−1, recorded with the ATLAS detector at the LargeHadron Collider at a center-of-mass energy of 13 TeV. No significant deviation from the expected StandardModel background is observed. Limits are derived in scenarios of direct production of stau pairs with eachstau decaying into the stable lightest neutralino and oneτ-lepton in simplified models where the two staumass eigenstates are degenerate. Stau masses from 120 GeV to 390 GeV are excluded at 95% confidencelevel for a massless lightest neutralino
Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial
Background
Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy
Immunostaining of modified histones defines high-level features of the human metaphase epigenome
Analysis of genetic diversity of Tunisian caprifig (Ficus carica L.) accessions using simple sequence repeat (SSR) markers
Beyond the crisis: building back better mental health care in 10 emergency-affected areas using a longer-term perspective
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