Wave drag as the objective function in transonic fighter wing optimization

The original computational method for determining wave drag in a three dimensional transonic analysis method was replaced by a wave drag formula based on the loss in momentum across an isentropic shock. This formula was used as the objective function in a numerical optimization procedure to reduce the wave drag of a fighter wing at transonic maneuver conditions. The optimization procedure minimized wave drag through modifications to the wing section contours defined by a wing profile shape function. A significant reduction in wave drag was achieved while maintaining a high lift coefficient. Comparisons of the pressure distributions for the initial and optimized wing geometries showed significant reductions in the leading-edge peaks and shock strength across the span

Pressure distribution in a hydrostatic bearing of multi-wells

Pressure distribution in hydrostatic bearing of multi-wells obtained by use of Navier-Stokes equation

Breakdown of Strong-Coupling Perturbation Theory in Doped Mott Insulators

We show that doped Mott insulators, such as the copper-oxide superconductors, are asymptotically slaved in that the quasiparticle weight, $Z$, near half-filling depends critically on the existence of the high energy scale set by the upper Hubbard band. In particular, near half filling, the following dichotomy arises: $Z\ne 0$ when the high energy scale is integrated out but Z=0 in the thermodynamic limit when it is retained. Slavery to the high energy scale arises from quantum interference between electronic excitations across the Mott gap. Broad spectral features seen in photoemission in the normal state of the cuprates are argued to arise from high energy slavery.Comment: Published versio

Towards standardisation of no fault found taxonomy

There is a phenomenon which exists in complex engineered systems, most notably those which are electrical or electronic which is the inability to diagnose faults reported during operation. This includes difficulties in detecting the same reported symptoms with standard testing, the inability to correctly localise the suspected fault and the failure to diagnose the problem which has resulted in maintenance work. However an inconsistent terminology is used in connection with this phenomenon within both scientific communities and industry. It has become evident that ambiguity, misuse and misunderstanding have directly compounded the issue. The purpose of this paper is to work towards standardisation of the taxonomy surrounding the phenomena popularly termed No Fault Found, Retest Okay, Cannot Duplicate or Fault Not Found amongst many others. This includes discussion on how consistent terminology is essential to the experts within organisation committees and, to the larger group of users, who do not have specialised knowledge of the field

Electro-optic bunch diagnostics on ALICE

An electro-optic longitudinal bunch profile monitor has been implemented on ALICE (Accelerators and Lasers in Combined Experiments) at the Daresbury Laboratories and will be used both to characterise the electron bunch and to provide a testbed for electro-optic techniques. The electro-optic station is located immediately after the bunch compressor, within the FEL cavity; its location allows nearby OTR, beam profile monitors and Coherent Synchrontron Radiation (CSR) diagnostics to be used for calibration and benchmarking. We discuss the implementation and the planned studies on electro-optic diagnostics using this diagnostic station

Excitation of the molecular gas in the nuclear region of M82

We present high-resolution HIFI spectroscopy of the nucleus of the archetypical starburst galaxy M 82. Six ^(12)CO lines, 2 ^(13)CO lines and 4 fine-structure lines have been detected. Besides showing the effects of the overall velocity structure of the nuclear region, the line profiles also indicate the presence of multiple components with different optical depths, temperatures, and densities in the observing beam. The data have been interpreted using a grid of PDR models. It is found that the majority of the molecular gas is in low density (n = 10^(3.5) cm^(-3)) clouds, with column densities of N_H = 10^(21.5) cm^(-2) and a relatively low UV radiation field (G_0 = 10^2). The remaining gas is predominantly found in clouds with higher densities (n = 10^5 cm^(-3)) and radiation fields (G_0 = 10^(2.75)), but somewhat lower column densities (N_H = 10^(21.2) cm^(-2)). The highest J CO lines are dominated by a small (1% relative surface filling) component, with an even higher density (n = 10^6 cm^(-3)) and UV field (G_0 = 10^(3.25)). These results show the strength of multi-component modelling for interpretating the integrated properties of galaxies

Apnea, bradycardia and desaturation spells in premature infants: impact of a protocol for the duration of 'spell-free' observation on interprovider variability and readmission rates.

ObjectiveTo study the impact of implementing a protocol to standardize the duration of observation in preterm infants with apnea/bradycardia/desaturation spells before hospital discharge on length of stay (LOS) and readmission rates.Study designA protocol to standardize the duration of in-hospital observation for preterm infants with apnea, bradycardia and desaturation spells who were otherwise ready for discharge was implemented in December 2013. We evaluated the impact of this protocol on the LOS and readmission rates of very low birth weight infants (VLBW). Data on readmission for apnea and an apparent life-threatening event (ALTE) within 30 days of discharge were collected. The pre-implementation epoch (2011 to 2013) was compared to the post-implementation period (2014 to 2016).ResultsThere were 426 and 368 VLBW discharges before and after initiation of the protocol during 2011 to 2013 and 2014 to 2016, respectively. The LOS did not change with protocol implementation (66±42 vs 64±42 days before and after implementation of the protocol, respectively). Interprovider variability on the duration of observation for apneic spells (F-8.8, P=0.04) and bradycardia spells (F-17.4, P<0.001) decreased after implementation of the protocol. The readmission rate for apnea/ALTE after the protocol decreased from 12.1 to 3.4% (P=0.01).ConclusionImplementing an institutional protocol for VLBW infants to determine the duration of apnea/bradycardia/ desaturation spell-free observation period as recommended by the American Academy of Pediatrics clinical report did not prolong the LOS but effectively reduced interprovider variability and readmission rates

On the wake of a Darrieus turbine

The theory and experimental measurements on the aerodynamic decay of a wake from high performance vertical axis wind turbine are discussed. In the initial experimental study, the wake downstream of a model Darrieus rotor, 28 cm diameter and a height of 45.5 cm, was measured in a Boundary Layer Wind Tunnel. The wind turbine was run at the design tip speed ratio of 5.5. It was found that the wake decayed at a slower rate with distance downstream of the turbine, than a wake from a screen with similar troposkein shape and drag force characteristics as the Darrieus rotor. The initial wind tunnel results indicated that the vertical axis wind turbines should be spaced at least forty diameters apart to avoid mutual power depreciation greater than ten per cent

ICT as learning media and research instrument: What eResearch can offer for those who research eLearning?

Students‘ interactions in digital learning environments are distributed over time and space, and many aspects of eLearning phenomenon cannot be investigated using traditional research approaches. At the same time, the possibility to collect digital data about students‘ online interactions and learning opens a range of new opportunities to use ICT as research tool and apply new research approaches. This symposium brings together some of the recent advancements in the area of ICT-enhanced research and aims to discuss future directions for methodological innovation in this area. The session will include four presentations that will explore different directions of ICT use for eLearning research