Turbulence measurements in high-speed flows by resonant fluoresence

Both mean flow and turbulence measurements were investigated using the resonant Doppler velocimeter in a Mach 3.2 nitrogen flow. Data are presented showing velocity, temperature and pressure measured point by point across the flow field. This data is compared with conventional pitot and temperature surveys. Turbulence was induced by a small metal tab in the flow and observed by both hot wire and RDV techniques. Photographs of the flow field demonstrate the utility of the RDV for quantitative flow field visualization

Photocatalytic generation of hydrogen from water

A concept designed to overcome the problems encountered when using photodissociation for the generation of hydrogen is discussed. The problems limiting the efficiency of photodissociation of water are the separation of the photolysis products and the high energy photons necessary for the reaction. It is shown that the dissociation energy of a large number of molecules is catalytically reduced when these molecules are in intimate contact with the surface of certain metals. It is proposed to develop a surface which will take advantage of this catalytic shift in dissociation energies to reduce the photon energy required to produce hydrogen. This same catalytic surface can be used to separate the reaction products if it is made so that one of the dissociations products is soluble in the metal and others are not. This condition is met by many metal systems such as platinum group metals which have been used commercially to separate hydrogen from other gases and liquids

A study of the thermoregulatory characteristics of a liquid-cooled garment with automatic temperature control based on sweat rate: Experimental investigation and biothermal man-model development

Experimental results for three subjects walking on a treadmill at exercise rates of up to 590 watts showed that thermal comfort could be maintained in a liquid cooled garment by using an automatic temperature controller based on sweat rate. The addition of head- and neck-cooling to an Apollo type liquid cooled garment increased its effectiveness and resulted in greater subjective comfort. The biothermal model of man developed in the second portion of the study utilized heat rates and exchange coefficients based on the experimental data, and included the cooling provisions of a liquid-cooled garment with automatic temperature control based on sweat rate. Simulation results were good approximations of the experimental results

Evaluation of non-intrusive flow measurement techniques for a re-entry flight experiment

This study evaluates various non-intrusive techniques for the measurement of the flow field on the windward side of the Space Shuttle orbiter or a similar reentry vehicle. Included are linear (Rayleigh, Raman, Mie, Laser Doppler Velocimetry, Resonant Doppler Velocimetry) and nonlinear (Coherent Anti-Stokes Raman, Laser-Induced Fluorescence) light scattering, electron-beam fluorescence, thermal emission, and mass spectroscopy. Flow-field properties were taken from a nonequilibrium flow model by Shinn, Moss, and Simmonds at the NASA Langley Research Center. Conclusions are, when possible, based on quantitative scaling of known laboratory results to the conditions projected. Detailed discussion with researchers in the field contributed further to these conclusions and provided valuable insights regarding the experimental feasibility of each of the techniques

Effects of forward velocity on noise for a J85 turbojet engine with multitube suppressor from wind tunnel and flight tests

Flight and wind tunnel noise tests were conducted using a J85 turbojet engine as a part of comprehensive programs to obtain an understanding of forward velocity effects on jet exhaust noise. Nozzle configurations of primary interest were a 104-tube suppressor with and without an acoustically-treated shroud. The installed configuration of the engine was as similar as possible in the flight and wind tunnel tests. Exact simultaneous matching of engine speed, exhaust velocity, and exhaust temperature was not possible, and the wind tunnel maximum Mach number was approximately 0.27, while the flight Mach number was approximately 0.37. The nominal jet velocity range was 450 to 640 m/sec. For both experiments, background noise limited the jet velocity range for which significant data could be obtained. In the present tests the observed directivity and forward velocity effects for the suppressor are more similar to predicted trends for internally-generated noise than unsuppressed jet noise

Non-intrusive flow measurements on a reentry vehicle

This study evaluates the utility of various non-intrusive techniques for the measurement of the flow field on the windward side of the Space Shuttle or a similar re-entry vehicle. Included are linear (Rayleigh, Raman, Mie, Laser Doppler Velocimetry, Resonant Doppler Velocimetry) and nonlinear (Coherent Anti-Stokes Raman, Laser Induced Fluorescence) light scattering, electron beam fluorescence, thermal emission and mass spectroscopy. Flow field properties are taken from a nonequilibrium flow model by Shinn, Moss and Simmonds at NASA Langley. Conclusions are, when possible, based on quantitative scaling of known laboratory results to the conditions projected. Detailed discussion with researchers in the field contributed further to these conclusions and provided valuable insights regarding the experimental feasibility of each of the techniques

Pump linewidth requirement for optical parametric oscillators

Pumping laser bandwidth requirement for optical parametric oscillator

State-of-the-Art: the quality of case study research in innovation management

The practice of innovation management is developing fast. As new concepts emerge, exploratory studies are needed and case study research is often appropriate. To investigate the usage and quality of case study research in innovation management, all of the articles published in five top journals over 20 years (1997–2016) were reviewed. Case study research accounted for 818 of the published articles in this period (12%) and an evaluation template (termed case study evaluation template: CASET) was developed to objectively assess these articles against 10 quality criteria. It was found that the quality of case study research has often been low, although it has improved over time. Similarly, quality was found to fluctuate both within and between the different innovation journals. This indicates that the peer review process for case study research is not as robust as it should be. The assessment of individual articles using the evaluation template found significant deficiencies. Many articles: did not justify why case study research was appropriate; did not apply theoretical sampling criteria; were not transparent on how conclusions were drawn from the data; did not consider validity and reliability adequately; and did not go beyond description in their interpretation. However, the evaluation template also identified 23 “exemplary studies,” which clearly addressed nearly every criterion. Such exemplary studies provide innovation management researchers with “benchmark” reading, which can help shape their own research. This article makes four contributions to the innovation management discipline. First, the evaluation template and exemplary studies can help innovation researchers improve the quality of their case study research. Second, clear recommendations are given for how reviewers can use the template to make the peer review process more consistent and robust. Third, journal editors are encouraged to consider the implications of the findings for their particular journal. Fourth, the article should stimulate a long overdue debate on methodology in innovation management research, including the use of case study research

Unsolicited written narratives as a methodological genre in terminal illness: challenges and limitations

Stories about illness have proven invaluable in helping health professionals understand illness experiences. Such narratives have traditionally been solicited by researchers through interviews and the collection of personal writings, including diaries. These approaches are, however, researcher driven; the impetus for the creation of the story comes from the researcher and not the narrator. In recent years there has been exponential growth in illness narratives created by individuals, of their own volition, and made available for others to read in print or as Internet accounts. We sought to determine whether it was possible to identify such material for use as research data to explore the subject of living with the terminal illness amyotrophic lateral sclerosis/motor neuron disease—the contention being that these accounts are narrator driven and therefore focus on issues of greatest importance to the affected person. We encountered and sought to overcome a number of methodological and ethical challenges, which is our focus here

Testing the existence of optical linear polarization in young brown dwarfs

Linear polarization can be used as a probe of the existence of atmospheric condensates in ultracool dwarfs. Models predict that the observed linear polarization increases withthe degree of oblateness, which is inversely proportional to the surface gravity. We aimed to test the existence of optical linear polarization in a sample of bright young brown dwarfs, with spectral types between M6 and L2, observable from the Calar Alto Observatory, and cataloged previously as low gravity objects using spectroscopy. Linear polarimetric images were collected in I and R-band using CAFOS at the 2.2 m telescope in Calar Alto Observatory (Spain). The flux ratio method was employed to determine the linear polarization degrees. With a confidence of 3$\sigma$, our data indicate that all targets have a linear polarimetry degree in average below 0.69% in the I-band, and below 1.0% in the R-band, at the time they were observed. We detected significant (i.e. P/$\sigma$ $\le$ 3) linear polarization for the young M6 dwarf 2MASS J04221413+1530525 in the R-band, with a degree of $\mathrm{p^{*}}$ = 0.81 $\pm$ 0.17 %.Comment: Accepted for publication in MNRA