The application of parameter estimation to flight measurements to obtain lateral-directional stability derivatives of an augmented jet-flap STOL airplane

Flight experiments with an augmented jet flap STOL aircraft provided data from which the lateral directional stability and control derivatives were calculated by applying a linear regression parameter estimation procedure. The tests, which were conducted with the jet flaps set at a 65 deg deflection, covered a large range of angles of attack and engine power settings. The effect of changing the angle of the jet thrust vector was also investigated. Test results are compared with stability derivatives that had been predicted. The roll damping derived from the tests was significantly larger than had been predicted, whereas the other derivatives were generally in agreement with the predictions. Results obtained using a maximum likelihood estimation procedure are compared with those from the linear regression solutions

N-SAP and G-SAP neutron and gamma ray albedo model scatter shield analysis program

Computer program calculates neutron or gamma ray first order scattering from a plane or cylindrical surface to a detector point. The SAP Codes, G-SAP and N-SAP, constitute a multiple scatter albedo model shield analysis

Boron enrichment in Martian clay

We have detected a concentration of boron in martian clay far in excess of that in any previously reported extra-terrestrial object. This enrichment indicates that the chemistry necessary for the formation of ribose, a key component of RNA, could have existed on Mars since the formation of early clay deposits, contemporary to the emergence of life on Earth. Given the greater similarity of Earth and Mars early in their geological history, and the extensive disruption of Earth's earliest mineralogy by plate tectonics, we suggest that the conditions for prebiotic ribose synthesis may be better understood by further Mars exploration

A Shell of Thermal X-ray Emission Associated with the Young Crab-like Remnant 3C58

Deep X-ray imaging spectroscopy of the bright pulsar wind nebula 3C58 confirms the existence of an embedded thermal X-ray shell surrounding the pulsar PSR J0205+6449. Radially resolved spectra obtained with the XMM-Newton telescope are well-characterized by a power-law model with the addition of a soft thermal emission component in varying proportions. These fits reproduce the well-studied increase in the spectral index with radius attributed to synchrotron burn-off of high energy electrons. Most interestingly, a radially resolved thermal component is shown to map out a shell-like structure ~6' in diameter. The presence of a strong emission line corresponding to the Ne IX He-like transition requires an overabundance of ~3 x [Ne/Ne(sun)] in the Raymond-Smith plasma model. The best-fit temperature kT ~ 0.23 keV is essentially independent of radius for the derived column density of N_H = (4.2 +/- 0.1)E21 per cm squared. Our result suggests that thermal shells can be obscured in the early evolution of a supernova remnant by non-thermal pulsar wind nebulae emission; the luminosity of the 3C58 shell is more than an order of magnitude below the upper limit on a similar shell in the Crab Nebula. We find the shell centroid to be offset from the pulsar location. If this neutron star has a velocity similar to that of the Crab pulsar, we derive an age of 3700 yr and a velocity vector aligned with the long axis of the PWN. The shell parameters and pulsar offset add to the accumulating evidence that 3C58 is not the remnant of the supernova of CE 1181.Comment: 7 pages, 8 figures, 2 tables, Latex emulateapj style. To appear in the Astrophysical Journa

The influence of hamstring extensibility on preselected saddle height within experienced competitive cyclists

Background: Contemporary studies have investigated the effects of bicycle saddle height for optimal performance and injury prevention. A recent review established a dynamic knee flexion angle of 25˚-30˚ for optimal economy, anaerobic power, and knee tracking (Bini et al., 2011: Sports Medicine, 41, 463-476). Muyor et al, (2011: Journal of Human Kinetics, 29, 15-23), investigated hamstring extensibility within 96 highly trained cyclists. They concluded that shortened hamstrings had a negative influence over thoracic spinal curvature, yet no influence over saddle height. Whereas, Ferrer-Roca et al (2012: Journal of Strength and Conditioning Research, 26, 3025- 3029) examined 23 high level competitive male road cyclists and concluded that a lack of flexibility may have an influence over lower preselected saddle heights (> 40˚ knee flexion angle). Consequently, there remains uncertainty whether preselected saddle height may be dependent on hamstring extensibility. Purpose: The purpose of the study was to investigate the influence of hamstring extensibility on preselected saddle height within experienced competitive cyclists. It was suggested that preselected saddle height may be dependent on hamstring extensibility to enable a 25˚-30˚ knee flexion angle. Methods: Participants consisted of 32 moderate to high level male and female road cyclists (35.8 ± 8.4 years; 178.22 ± 11.0 cm; 77.7 ± 13.4 kg). They used their own individually set-up road bicycle, which was placed on an indoor wind trainer. Hamstring extensibility was measured using the passive knee extension test. Dynamic 2D analysis was used to measure bicycle knee flexion and passive knee extension angles. A cycling questionnaire was also used to determine experience, training and competition levels. Results: Pearson’s correlation coefficients revealed bicycle knee flexion angle, years cycling (r = -0.35, p 0.05). Discussion: Results suggest that sustained time period on the bike rather than hamstring extensibility determines preselected saddle height. In particular, being competitive for a longer duration precedes either volume or number of years cycling. However, it is apparent that in agreement with Muyor et al., (2011) a single variable such as hamstring length does not predetermine optimal saddle height. In addition, as suggested by Ferrer-Roca et al., (2012), experienced cyclists are unable to achieve a knee flexion angle of 25˚, unless they have sufficient flexibility. Conclusion: Results reveal that with experience, a competitive cyclist’s subjective and objective interpretation of their preselected saddle height becomes more consistent. Although hamstring extensibility does not appear to influence pre-selected saddle height, an initial 35˚ rather than 25˚ knee flexion angle is recommended. Future research should consider mixed methodologies, to further establish safe and effective recommendations for optimising bicycle fit. References Bini, R., Hume, P.A., & Croft, J.L. (2011). Effects of bicycle saddle height on knee injury risk and cycling performance. Sports Medicine, 41, 463-476. Ferrer-Roca, V., Roig, A., Galilea, P., & Garcia Lopez, J. (2012). Influence of saddle height on lower limb kinematics in well trained cyclists: static vs dynamic evaluation in bike fitting. Journal of Strength and Conditioning Research, 26, 3025- 3029. Muyor, J. M., Alacid, F., & Lopez-Minarro, P.A. (2011). Influence of hamstring muscles extensibility on spinal curvatures and pelvic tilt in highly trained cyclists. Journal of Human Kinetics, 29, 15-23

A basic reference state suitable for anomaly-coupled ocean-atmosphere climate models

AbstractA large class of ocean-atmosphere models exists in which the ocean state is coupled to the model of the atmosphere only through the anomalies of the ocean state. The sea surface temperatures are defined with respect to a mean reference state, i.e., they are the difference between the ocean state and a reference state. Due to coupled model drift, the choice of reference state is important and it can have a large impact on the variability in the model. The reference state can be calculated as an average throughout the coupled simulation and various methods of doing this (moving average, exponentially weighted moving average and accumulated mean) are compared in this note. The accumulated mean method appears to be the sole method of the three which gives both unbiased anomalies and a convergent reference state. It is recommended for use in anomaly-coupled models for improving variability and predictability

Hans-Christoph Lüttgau 20 July 1926-5 November 2017

No abstract available

Understanding The Use Of Social Technologies During A Life Transition: Men's Experience with Fertility Problems

Transition to parenthood is a common experience but one that can be particularly challenging for people who have difficulty in conceiving. Men are reportedly likely to feel isolated and stigmatised when they experience fertility problems and are more likely to turn to sources of social technology for support than approach healthcare services. We share our findings from two studies with data from two different sources; online forum comments and semi-structured qualitative interviews to explore how and why men use technology when they experience fertility problems. We report our findings in relation to the proposed workshop themes

On generalized cluster algorithms for frustrated spin models

Standard Monte Carlo cluster algorithms have proven to be very effective for many different spin models, however they fail for frustrated spin systems. Recently a generalized cluster algorithm was introduced that works extremely well for the fully frustrated Ising model on a square lattice, by placing bonds between sites based on information from plaquettes rather than links of the lattice. Here we study some properties of this algorithm and some variants of it. We introduce a practical methodology for constructing a generalized cluster algorithm for a given spin model, and investigate apply this method to some other frustrated Ising models. We find that such algorithms work well for simple fully frustrated Ising models in two dimensions, but appear to work poorly or not at all for more complex models such as spin glasses.Comment: 34 pages in RevTeX. No figures included. A compressed postscript file for the paper with figures can be obtained via anonymous ftp to minerva.npac.syr.edu in users/paulc/papers/SCCS-527.ps.Z. Syracuse University NPAC technical report SCCS-52