Reducing the Effect of Transducer Mount Induced Noise on Aeroacoustic Wind Tunnel Testing Data with a New Transducer Mount Design

Flight vehicle aeroacoustic environments induced during transonic and supersonic flight are usually predicted by subscale wind tunnel testing utilizing high frequency miniature pressure transducers. In order to minimize noise induced by the measurement itself, transducer flush mounting with the model surface is very important. The National Aeronautics and Space Administration (NASA) has accomplished flushness in recent testing campaigns via use of a transducer holder that can be machined and sanded. A single hole in the holder allows the flow medium to interact with the transducer diaphragm. Noise is induced by the resulting cavity however, and is a challenge to remove in post-processing. A new holder design has been developed that minimizes the effects of this transducer mount induced noise (XMIN) by reducing the resonance amplitude or increasing its resonance frequency beyond the range of interest. This paper describes a test conducted at the NASA/George C. Marshall Space Flight Center Trisonic Wind Tunnel intended to verify the effectiveness of this design. The results from this test show that this new transducer holder design does significantly reduce the influence of XMIN on measured fluctuating pressure levels without degrading a transducer's ability to accurately measure the noise external to the model

Blue light as a drug?

Treballs Finals de Grau de Farmàcia, Facultat de Farmàcia, Universitat de Barcelona, 2015. Tutora: Trinitat Cambras Riu.[eng] This Final Project is based on bibliographic research and integration of recent scientific articles that contain information related to light and its effects on the body; and aims to raise awareness that humans need light, not only for vision or known functions such as the synthesis of vitamin D, but also for non-visual effects. Light is detected and transformed into information that goes direct to the brain through a small population of intrinsically photosensitive retinal ganglion cells. This information obtained from the environment allows the body to regulate several physiological and behavioural functions that are essential for a good health and quality of life. This set of non-visual functions include the synchronization of circadian and seasonal rhythms and the regulation of sleep, alertness, mood and cognitive performance, which are interconnected with each other and with other physiological and pathophysiological processes such as aging, metabolic processes, development of cancer and cardiovascular consequences, so the alteration of any of these functions can cause damage to other systems and ultimately affect the entire body. It is important therefore to control light exposure at certain times of day, because light in the morning does not affect the same way than light at night. This property allows its use for treating these disorders; therefore, patient lifestyle education and more effective architectural designs for lighting environments like schools and work are potentially beneficial.[cat] Aquest Treball Fi de Grau es basa en la recerca bibliogràfica i la integració d’articles científics recents, que contenen informació relacionada amb la llum i els seus efectes en l’organisme; i pretén donar a conèixer que els humans necessitem la llum, no només per la visió o funcions conegudes, com la síntesi de Vitamina D, sinó també pels seus efectes no visuals. La llum és captada i transformada en informació que va directa al cervell per una petita població de cèl·lules ganglionars de la retina que són intrínsecament fotosensibles. Aquesta informació extreta de l’ambient permet a l’organisme regular diverses funcions fisiològiques i de comportament que són essencials per una bona salut i qualitat de vida. Aquest conjunt de funcions no visuals inclouen la sincronització dels ritmes circadiaris i estacionals, i la regulació del son, l'estat d'alerta, l’humor i el rendiment cognitiu, que estan interconnectades entre elles, i amb altres processos fisiològics i fisiopatològics com l’envelliment, processos metabòlics, desenvolupament de càncer i conseqüències cardiovasculars, per tant, l’alteració d’alguna d’aquestes funcions pot provocar danys en altres sistemes i acabar afectant tot l’organisme. És molt important per això, controlar l’exposició a la llum en certs moments del dia, ja que no afecta de la mateixa manera la llum al matí que a la nit. Aquesta propietat però permet el seu ús per tractar aquests trastorns, per tant, l'educació en l’estil de vida del pacient i la realització de dissenys arquitectònics més eficaços per entorns d'il·luminació com escoles i treballs són potencialment beneficiosos

Aerospace medicine and biology: A continuing bibliography with indexes (supplement 299)

This bibliography lists 96 reports, articles, and other documents introduced into the NASA scientific and technical information system in June, 1987

Viking dynamics experience with application to future payload design

Analytical and test techniques are discussed. Areas in which hindsight indicated erroneous, redundant, or unnecessarily severe design and test specifications are identified. Recommendations are made for improvements in the dynamic design and criteria philosophy, aimed at reducing costs for payloads

Investigation of lightweight designs and materials for LO2 and LH2 propellant tanks for space vehicles, phase 2 and phase 3

Full size Tug LO2 and LH2 tank configurations were defined, based on selected tank geometries. These configurations were then locally modeled for computer stress analysis. A large subscale test tank, representing the selected Tug LO2 tank, was designed and analyzed. This tank was fabricated using procedures which represented production operations. An evaluation test program was outlined and a test procedure defined. The necessary test hardware was also fabricated

Evaluation of Light-Emitting Diode Spectral Output and Photoperiod Duration on Pekin Duck Performance, Stress, and Welfare

As duck production becomes more prevalent on a global scale, modern duck housing systems must maximize duck productivity. The welfare of an animal influences its productivity, and is therefore useful in evaluating which environmental factors, such as artificial lighting, are more favorable in duck production systems. However, limited research has examined the manipulation of photoperiod and light spectrum on Pekin duck welfare and growth. Four experiments were conducted to determine the effects of (i) two photoperiods, (ii) two commercially available LED fixtures, (iii) ultraviolet (UV) light supplementation, and (iv) four experimental monochromatic LED fixtures on Pekin duck growth, stress, and fear responses during a 35 d grow-out period. Ducks reared under a 20L:4D photoperiod had more efficient nutrient metabolism and stronger humoral immune response to Newcastle Disease Virus vaccine due to improved FCR and decreased stress and the effects of stress compared to ducks reared under 16L:8D. Ducks subjected to white/red LED lighting had lower stress susceptibility and fear responses compared to those subjected to white/blue LED lighting, indicating duck welfare may be compromised by blue LED light exposure, even at supplemental levels. Ducks exposed to supplemental UV light had narrower and lighter eyes and lower acute and chronic stress susceptibility compared to ducks not subjected to UV light (control). UV ducks also had a faster latency to first head movement during tonic immobility (TI) and required more attempts to induce TI than in the control ducks. These results indicate supplemental UV lighting can lower stress and fear responses in Pekin ducks and increase duck welfare. Exposing ducks to monochromatic red and blue LED lighting elevated the stress response of ducks and decreased eye weight compared to white and monochromatic green LED light. This indicates blue and red lighting may not be adequate for Pekin duck grow-out, and Pekin ducks may require artificial light sources containing a broad range of wavelengths, as seen with white and green lights. The current findings indicate Pekin duck welfare and performance can be influenced by artificial lighting duration and spectrum and emphasize the importance of choosing correct artificial lighting for Pekin ducks

Precision pollination strategies for advancing horticultural tomato crop production

Global climate change and anthropological activities have led to a decline in insect pollinators worldwide. Agricultural globalisation and intensification have also removed crops from their natural insect pollinators, and sparked research to identify alternate natural insect pollinators and artificial technologies. In certain countries such as Australia the importation of commercial insect pollinators is prohibited, necessitating manual labour to stimulate floral pollination. Artificial pollination technologies are now increasingly essential as the demand for food grown in protected facilities increases worldwide. For tomato fruits, precision pollination has the ability to vastly improve their seed set, size, yield, and quality under optimal environmental conditions and has become financially beneficial. Like many crops from the Solanaceae, tomatoes have a unique self-pollinating mechanism that requires stimulation of the floral organs to release pollen from the poricidal anthers. This review investigates various mechanisms employed to pollinate tomato flowers and discusses emerging precision pollination technologies. The advantages and disadvantages of various pollinating technologies currently available in the protected-cropping industry are described. We provide a buzz perspective on new promising pollination technologies involving robotic air and acoustic devices that are still in their nascency and could provide non-contact techniques to automate pollination for the tomato horticultural industry

Reusable Agena study. Volume 2: Technical

The application of the existing Agena vehicle as a reusable upper stage for the space shuttle is discussed. The primary objective of the study is to define those changes to the Agena required for it to function in the reusable mode in the 100 percent capture of the NASA-DOD mission model. This 100 percent capture is achieved without use of kick motors or stages by simply increasing the Agena propellant load by using optional strap-on-tanks. The required shuttle support equipment, launch and flight operations techniques, development program, and cost package are also defined