Status of linear boundary-layer stability and the e to the nth method, with emphasis on swept-wing applications

The-state-of-the-art for the application of linear stability theory and the e to the nth power method for transition prediction and laminar flow control design are summarized, with analyses of previously published low disturbance, swept wing data presented. For any set of transition data with similar stream distrubance levels and spectra, the e to the nth power method for estimating the beginning of transition works reasonably well; however, the value of n can vary significantly, depending upon variations in disturbance field or receptivity. Where disturbance levels are high, the values of n are appreciably below the usual average value of 9 to 10 obtained for relatively low disturbance levels. It is recommended that the design of laminar flow control systems be based on conservative estimates of n and that, in considering the values of n obtained from different analytical approaches or investigations, the designer explore the various assumptions which entered into the analyses

Cycles in the chamber homology of GL(3)

Let F be a nonarchimedean local field and let GL(N) = GL(N,F). We prove the existence of parahoric types for GL(N). We construct representative cycles in all the homology classes of the chamber homology of GL(3).Comment: 45 pages. v3: minor correction

Downstream influence of swept slot injection in hypersonic turbulent flow

Results of an experimental and numerical investigation of tangential swept slot injection into a thick turbulent boundary layer at Mach 6 are presented. Film cooling effectiveness, skin friction, and flow structure downstream of the swept slot injection were investigated. The data were compared with that for unswept slots, and it was found that cooling effectiveness and skin friction reductions are not significantly affected by sweeping the slot

Distinction of representations via Bruhat-Tits buildings of p-adic groups

Introductory and pedagogical treatmeant of the article : P. Broussous "Distinction of the Steinberg representation", with an appendix by Fran\c{c}ois Court\`es, IMRN 2014, no 11, 3140-3157. To appear in Proceedings of Chaire Jean Morlet, Dipendra Prasad, Volker Heiermann Ed. 2017. Contains modified and simplified proofs of loc. cit. This article is written in memory of Fran\c{c}ois Court\`es who passed away in september 2016.Comment: 33 pages, 4 figure

Combined Effects of Acute Temperature Change and Elevated pCO2 on the Metabolic Rates and Hypoxia Tolerances of Clearnose Skate (Rostaraja eglanteria), Summer Flounder (Paralichthys dentatus), and Thorny Skate (Amblyraja radiata)

Understanding how rising temperatures, ocean acidification, and hypoxia affect the performance of coastal fishes is essential to predicting species-specific responses to climate change. Although a population’s habitat influences physiological performance, little work has explicitly examined the multi-stressor responses of species from habitats differing in natural variability. Here, clearnose skate (Rostaraja eglanteria) and summer flounder (Paralichthys dentatus) from mid-Atlantic estuaries, and thorny skate (Amblyraja radiata) from the Gulf of Maine, were acutely exposed to current and projected temperatures (20, 24, or 28 °C; 22 or 30 °C; and 9, 13, or 15 °C, respectively) and acidification conditions (pH 7.8 or 7.4). We tested metabolic rates and hypoxia tolerance using intermittent-flow respirometry. All three species exhibited increases in standard metabolic rate under an 8 °C temperature increase (Q10 of 1.71, 1.07, and 2.56, respectively), although this was most pronounced in the thorny skate. At the lowest test temperature and under the low pH treatment, all three species exhibited significant increases in standard metabolic rate (44–105%; p \u3c 0.05) and decreases in hypoxia tolerance (60–84% increases in critical oxygen pressure; p \u3c 0.05). This study demonstrates the interactive effects of increasing temperature and changing ocean carbonate chemistry are species-specific, the implications of which should be considered within the context of habitat. Associated dataset: Gail D. Schweiterman, Daniel P. Crear et al. 2019. Metabolic Rates and Hypoxia Tolerences of clearnose skate (Rostaraja eglanteria), summer flounder (Paralichthys dentatus), and thorny skate (Amblyraja radiata) https://doi.org/10.25773/qmew-c18

Metabolic Rates and Hypoxia Tolerences of clearnose skate (Rostaraja eglanteria), summer flounder (Paralichthys dentatus), and thorny skate (Amblyraja radiata)

These data were collected following methods described in the associated publication: LINK “Combined Effects of Acute Temperature Change and Elevated pCO2 on the Metabolic Rates and Hypoxia Tolerances of Clearnose Skate (Rostaraja eglanteria), Summer Flounder (Paralichthys dentatus), and Thorny Skate (Amblyraja radiata)”. Schweiterman, G.D. et al. 2019 Biology, 8(3), 56

Terahertz frequency quantum cascade lasers for use as waveguide-integrated local oscillators

Since their first demonstration in 2002, the performance of terahertz frequency quantum cascade lasers has developed extremely rapidly. We consider the potential use of terahertz frequency quantum cascade lasers as local oscillators in satellite-borne instrumentation for future Earth observation and planetary science missions. A specific focus will be on the development of compact, waveguide-integrated, heterodyne detection systems for the supra-terahertz range

Touch and look: the role of visual-haptic cues for categorical learning in children

Benefits of synchronous presentation of multisensory compared to unisensory cues are well established. However, the generality of such findings to children’s learning with visual and haptic sensory cue pairings is unclear. Children aged six to ten years (N=180) participated in a novel table-top category learning paradigm with visual, haptic or visuo-haptic informative cues. The results indicated that combinations of complimentary visual and haptic cues facilitated learning above unisensory visual cues only in 8-year-old children. Primarily, however, haptic information was found to dominate children’s category learning across ages, particularly in the youngest children (six-year-olds), even with equal discriminability of haptic and visual exemplars. These findings suggest developmental changes in the ability to effectively combine un-related visual and haptic information for categorical learning. Implications for the use of non-pertinent visuohaptic cues in learning tasks within educational settings at different ages, and in particular the dominance of haptic stimuli for children’s learning are discussed