Compensating for pneumatic distortion in pressure sensing devices

A technique of compensating for pneumatic distortion in pressure sensing devices was developed and verified. This compensation allows conventional pressure sensing technology to obtain improved unsteady pressure measurements. Pressure distortion caused by frictional attenuation and pneumatic resonance within the sensing system makes obtaining unsteady pressure measurements by conventional sensors difficult. Most distortion occurs within the pneumatic tubing which transmits pressure impulses from the aircraft's surface to the measurement transducer. To avoid pneumatic distortion, experiment designers mount the pressure sensor at the surface of the aircraft, (called in-situ mounting). In-situ transducers cannot always fit in the available space and sometimes pneumatic tubing must be run from the aircraft's surface to the pressure transducer. A technique to measure unsteady pressure data using conventional pressure sensing technology was developed. A pneumatic distortion model is reduced to a low-order, state-variable model retaining most of the dynamic characteristics of the full model. The reduced-order model is coupled with results from minimum variance estimation theory to develop an algorithm to compensate for the effects of pneumatic distortion. Both postflight and real-time algorithms are developed and evaluated using simulated and flight data

A constraint on a varying proton--electron mass ratio 1.5 billion years after the Big Bang

A molecular hydrogen absorber at a lookback time of 12.4 billion years, corresponding to 10$\%$ of the age of the universe today, is analyzed to put a constraint on a varying proton--electron mass ratio, $\mu$. A high resolution spectrum of the J1443$+$2724 quasar, which was observed with the Very Large Telescope, is used to create an accurate model of 89 Lyman and Werner band transitions whose relative frequencies are sensitive to $\mu$, yielding a limit on the relative deviation from the current laboratory value of $\Delta\mu/\mu=(-9.5\pm5.4_{\textrm{stat}} \pm 5.3_{\textrm{sys}})\times 10^{-6}$.Comment: Accepted for publication in PRL. Includes supplemental materia

Student Perceptions of Academic Advising at Two-Year Colleges

This research project examined students’ perceptions of academic advising through an online survey method at select two-year colleges within the Minnesota State College and University System. The purpose of this research was to build upon scant existing research relating to student satisfaction with academic advising models utilized by individual colleges. The purpose was to also identify the academic advising model preferred by students. The sample for this research consisted of 177 students enrolled at two-year state community and technical colleges. Outcomes indicated a preference for the developmental model of academic advising. Outcomes also indicated that the developmental model of academic advising was reported to be commonly utilized by the colleges participating in the research

Air data position-error calibration using state reconstruction techniques

During the highly maneuverable aircraft technology (HiMAT) flight test program recently completed at NASA Ames Research Center's Dryden Flight Research Facility, numerous problems were experienced in airspeed calibration. This necessitated the use of state reconstruction techniques to arrive at a position-error calibration. For the HiMAT aircraft, most of the calibration effort was expended on flights in which the air data pressure transducers were not performing accurately. Following discovery of this problem, the air data transducers of both aircraft were wrapped in heater blankets to correct the problem. Additional calibration flights were performed, and from the resulting data a satisfactory position-error calibration was obtained. This calibration and data obtained before installation of the heater blankets were used to develop an alternate calibration method. The alternate approach took advantage of high-quality inertial data that was readily available. A linearized Kalman filter (LKF) was used to reconstruct the aircraft's wind-relative trajectory; the trajectory was then used to separate transducer measurement errors from the aircraft position error. This calibration method is accurate and inexpensive. The LKF technique has an inherent advantage of requiring that no flight maneuvers be specially designed for airspeed calibrations. It is of particular use when the measurements of the wind-relative quantities are suspected to have transducer-related errors

The "Lungooty" Bandage.

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Optimal control of organic matter applications

Organic matter amendments appear to increase yield, but need to be sustained, as yield decreases when amendments cease. Here we mathematically devise optimal strategies for organic matter applications that take account of how quickly, in years of application, yields build up with amendments and how long these benefits persist. The empirical idea of a nutrient response curve is used and extended to include more than a single nutrient input as well as the effect of yield-enhancing factors such as organic matter that endure for more than one year. Nonlinear regression is used for the selection and the parameter identification for a reciprocal response curve working with a dataset from Rothamsted’s Woburn organic manuring long term experiment. Such a response curve is then treated analytically to develop economically optimum applications over a period of time. A simple static case is developed first and is shown to be equivalent to the well-known break-even ratio (BER) used in nitrogen fertiliser guidance by the Agricultural and Horticultural Development Board in the UK. The mathematical technique of optimal control is then employed to deduce dynamic strategies where the application of an amendment may change from year to year and for different time frames. Because this empirical modelling methodology can appear complex, we infer a rule-of-thumb for an equilibrium level of yield-enhancement rather like the equilibrium level of organic carbon that builds up over several years. This yield-enhancing power of organic matter is somewhat variable and probably does not persist in soil for as long as the organic matter from which it derives. It appears beneficial to apply amendments at a constant rate for much of the time-frame of interest but to begin with a large application to raise the fertility to the yield-enhancement equilibrium. After a transition year with reduced amendments, applications of organic matter are stopped for the final five years with the example amendment studied, farmyard manure. These conclusions depend on the persistence of the yield-enhancing power of organic matter in soil associated with the soil organic carbon kinetics

Experimental characterization of the effects of pneumatic tubing on unsteady pressure measurements

Advances in aircraft control system designs have, with increasing frequency, required that air data be used as flight control feedback. This condition requires that these data be measured with accuracy and high fidelity. Most air data information is provided by pneumatic pressure measuring sensors. Typically unsteady pressure data provided by pneumatic sensing systems are distorted at high frequencies. The distortion is a result of the pressure being transmitted to the pressure sensor through a length of connective tubing. The pressure is distorted by frictional damping and wave reflection. As a result, air data provided all-flush, pneumatically sensed air data systems may not meet the frequency response requirements necessary for flight control augmentation. Both lab and flight test were performed at NASA-Ames to investigate the effects of this high frequency distortion in remotely located pressure measurement systems. Good qualitative agreement between lab and flight data are demonstrated. Results from these tests are used to describe the effects of pneumatic distortion in terms of a simple parametric model

NOTES ON THE SYSTEMATY OF SOLOMON ISLANDS' PLANTS AND SOME OF THEIR NEW GUINEA RELATIVES. XI

Preliminary to a revision of the Myrsinaceae of the British Solomon Islands, we have found it necessary to name and validate the two large undescribed species of Tapeinosperma Hook.f., diagnoses of which are given in this paper, in order that their names may be available for use in connection with studies of the phytogeography of the Solomon Islands

Exploring the Usefulness of the Dispositional Flow Scale for Outdoor Recreation Activities

The Dispositional Flow Scale (DFS), developed by Jackson et al. (1998), measures an individual’s dispositional tendency to experience flow, a psychological state of optimal experience originally conceptualized by Csikszentmihalyi in 1975. The DFS, developed in the realm of sports psychology, has primarily been used with participants of urban sports settings, such as: football, running, or tennis. This study explores the validity and reliability of applying the DFS to outdoor recreation activities. A stratified sample of 406 visitors to the Bob Marshall Wilderness Complex in Montana was contacted during the summer of 2004. A survey response rate of 74 percent was achieved with on-site contact, mail back questionnaires, follow-up reminder postcards, and replacement mailing. The primary activities reported were hiking, horseback riding, and fishing. Results from confirmatory factor analysis, a special application of structural equation modeling, confirm that the DFS displays a satisfactory level of validity and reliability when applied to these activities

Traumatic myiasis in farmed animals caused by Wohlfahrtia magnifica in southern Italy (Diptera: Sarcophagidae)

Ten herds of sheep and goats (455 heads) were inspected for the presence of traumatic myiasis between May and September 2013 in the province of Cosenza, Calabria, southern Italy. Nine cases were discovered in sheep, goats and a sheepdog. Infested body sites included external genitalia, wounds (sheep and sheepdog) and hooves (goats). Larvae were removed from the infested body areas and reared to adult stage in the laboratory. Both the larvae and the adults were identified as belonging to the Mediterranean screwworm fly Wohlfahrtia magnifica (Schiner, 1862) (Diptera: Sarcophagidae), an obligatory parasite of humans and warm-blooded vertebrates. To our knowledge, these are the first cases of wohlfahrtiosis in sheep and goats to be reported from Calabria. The infested animals were living outdoors in spring and summer, and enclosed in sheds during the autumn and winter months. Observed effects of the myiases included severely impeded walking and tissue damage. Wohlfahrtiosis can cause significant economic loss to farmers. Data about the local distribution, seasonality and types of infestation caused by W. magnifica are useful to farmers and vets to improve control systems, in Calabria as elsewhere within the distributional range of the species.The file attached is the publishes (publishers PDF) version of the article. Open Access journal