Structural parameters for globular clusters in M31 and generalizations for the fundamental plane

The structures of globular clusters (GCs) reflect their dynamical states and past histories. High-resolution imaging allows the exploration of morphologies of clusters in other galaxies. Surface brightness profiles from new Hubble Space Telescope observations of 34 globular clusters in M31 are presented, together with fits of several different structural models to each cluster. M31 clusters appear to be adequately fit by standard King models, and do not obviously require alternate descriptions with relatively stronger halos, such as are needed to fit many GCs in other nearby galaxies. The derived structural parameters are combined with corrected versions of those measured in an earlier survey to construct a comprehensive catalog of structural and dynamical parameters for M31 GCs with a sample size similar to that for the Milky Way. Clusters in M31, the Milky Way, Magellanic Clouds, Fornax dwarf spheroidal and NGC 5128 define a very tight fundamental plane with identical slopes. The combined evidence for these widely different galaxies strongly reinforces the view that old globular clusters have near-universal structural properties regardless of host environment.Comment: AJ in press; 59 pages including 16 figure

Vibration effects on heat transfer in cryogenic systems Quarterly progress report no. 1, Jun. 1 - Aug. 31, 1966

Vibration effects on natural convection and fluid transport properties in cryogenic system

Graptolites from the Benton area of west-central New Brunswick and their regional significance

Graptolites In black slate underlying volcanics along Eel River near Benton, 20 km south of Woodstock, New Brunswick belong to the Clonograptus tenellus Zone of the upper Tremadoc Series. They are essentially the same age as graptolites from the Cookson Formation of southern New Brunswick. The Belle Lake Slate overlies the same volcanics, and on Belle Brook, 12 km southwest of Benton, contains graptolites referred to the Nemagraptus gracilis Zone of the Caradoc Series. The Belle Lake Slate correlates with an unnamed sequence of greywacke and slate in the Hayesville area of central New Brunswick. The Ordovician volcanics and overlying sedimentary rocks are the sane general age as a limestone facies found to the east and northeast of Woodstock. The limestones were deposited in shallow-water at varying distances from volcanically active areas. The presence of lithologlcally similar Lower Ordovician and older rocks in the Benton area of west-central New Brunswick and in the Cookson Formation of southern New Brunswick allows both areas to be included in the same suspect terrane. RÉSUMÉ A 20 km au sud de Woodstock (Nouveau-Brunswick) on trouve, dans une ardoise noire recouverte de roches volcaniques, des graptolites qui appartiennent à la zone Clonograptus tenellus de la série du Trémadocien supérieur. Ces graptolites datent essentiellement de la même période que les graptolites de la formation de Cookson du sud du Nouveau-Brunswick. À 12 km au sud-ouest de Benton, le long du ruisseau Belle, les roches volcanlques mentionnées ci-haut sont recouvertes par l 1 ardoise Belle Lake qui contient des graptolites de la zone à Nemagraptus gracilis de la serle du Caradocien. L‘ardoise Belle Lake est correlée avec une séquence de grauwacke et d'ardoise que l'on retrouve dans la région de Hayesville au centre du Nouveau-Brunswick. Les roches volcaniques ordoviciennes et les roches sédimentaires qui les recouvrent ont environ le même âge qu'un faciès de calcaire situe à l'est et au nord-est de Woodstock. Les calcaires ont été déposés en eau peu profonde à des distances variables d'une région volcaniquement active. La présence de roches lithologiquement semblables, certaines datant de l'Ordovicien inférieur, d'autres plus anciennes, dans la région de Benton au centre-ouest du Nouveau-Brunswick et dans la formation de Cookson au sud du Nouveau-Brunswick presuppose une pa renté entre les deux régions. [Tradult par le Journal

Ascertaining the Impact of P–12 Engineering Education Initiatives: Student Impact through Teacher Impact

The widespread need to address both science, technology, engineering, and math (STEM) education and STEM workforce development is persistent. Underscored by the Next Generation Science Standards, demand is high for P–12 engineering-centered curricula. TeachEngineering is a free, standards-aligned NSF-funded digital library of more than 1,500 hands-on, design-rich K–12 engineering lessons and activities. Beyond anonymous site-user counts, the impact of the TeachEngineering collection and outreach initiatives on the education of children and their teachers was previously unknown. Thus, the project team wrestled with the question of how to meaningfully ascertain classroom impacts of the digital engineering education library and—more broadly—how to ascertain the impacts of teacher-focused P–12 engineering education initiatives. In this paper, the authors approach the classroom impact question through probing self-reported differentials in: (1) teachers’ confidence in teaching engineering concepts, and (2) changes in their teaching practices as a result of exposure to (and experiences with) K–12 engineering education resources and outreach opportunities. In 2016, four quantitative and qualitative surveys were implemented to probe the impact of the TeachEngineering digital library and outreach on four populations of K–12 teachers’ confidence and practices, including the frequency with which they integrate engineering into their precollege classrooms. Survey results document the teacher experience and perception of using hands-on K–12 engineering curricular materials in the classroom and help create a data-driven understanding of where to best invest future resources. The results suggest that the TeachEngineering curricular resources and outreach initiatives help teachers build confidence in their use of engineering curriculum and pedagogy in K–12 classrooms, impact their teaching practices, and increase their likelihood of teaching engineering in the classroom in the future

Late Ordovician-Early Silurian trace fossils from the Matapedia Group, Tobique River, western New Brunswick, Canada. II. Additional discoveries with descriptions and comments

Previous recordings of Late Ordovician-Early Silurian flysch trace fossils (13 ichnogenera, 15 ichnospecies) from slope deposits of the Matapedia Basin at a single site on the Tobique River, western New Brunswick, are supplemented by the addition of 9 newly discovered ichnogenera (12 ichnospecies). These are:- Cirrculichnis montanus, Cruziana problematica, Cruziana cf. stromnessa, Dipt'tchnites ichnosp., Megagrapton irregulare, Monocraterion ichnosp., Phycosiphon incertum, Rusophycus didymus, Rusophycus ichnosp. types A and H, Scolicia ichnosp, and Tuberculichnus ichnosp. The traces are poorly preserved and occur only in low numbers compared to previously documented forms. Nevertheless, the meticulous sampling procedures adopted at the site emphasize the need for detailed collecting, before drawing conclusions regarding diversity models, stratigraphic distribution, etc., of trace fossils. Of these new forms only Diplichnites ichnosp. has previously been recorded from die Matapedia Basin in the partially coeval Lower Silurian Siegas Formation. Tuberculichnus ichnosp. is recorded for the first time in North America. The combined total of 22 ichnogenera (27 ichnospecies) from the Tobique River represents the most diverse ichnocoenosis yet reported from a single ancient slope deposit. The occurrence of several more typically shallow-water ichnogenera (e.g., Cruziana, Diplichnites, Monocraterion and Rusophycus) suggests that, at least in the Early Palaeozoic, caution must be exercised in their utilization as distinctive facies or environmental indicators. RÉSUMÉ 9 nouveaux ichnogenres (12 ichnoespeces) s'ajoutent à ceux déjà répertoriés (13 ichnogenrcs, 15 ichnoespcces) en un site unique localise sur la rivière Tobique, dans l’ouest du Nouveau-Brunswick, dans des sédiments tardiordoviciens è éosiluriens accumulés sur le talus continental du Bassin de Matapedia. Ce sont: Cirrculichnis montanus, Cruziana problematica, Cruziana cf. stromnessa, Dipt'tchnites ichnosp., Megagrapton irregulare, Monocraterion ichnosp., Phycosiphon incertum, Rusophycus didymus, Rusophycus ichnosp. types A et H, Scolicia ichnosp, et Tuberculichnus ichnosp. Ces demières sont malconservées et relativement rares par rapport aux formés déjà connues. Néanmoins, le dépouillement méiculeux utilisé à ce site démontre la nécessité d'une collecte détailiée avant de tirer des conclusions quant aux modeèles de diversité, à la distribution stratigraphique, etc., des traces fossiles. De ces nouvelles formés, seule Diplichinites ichnosp. est déjà cormue dans le Bassin de Matapedia, soil dans la Formation sihirienne inférieure et en partie synchrone de Siegas. On recense Tuberculichnus ichnosp. pour la première fois en Amerique du Nord. Le total combine de 22 ichnogenres (27 ichnoespeces) présents sur la rivière Tobique représente l’inchnocoenose la plus diverse jamais répertoriée dans un seul dépôt de talus. La présence de plusieur sichnogenres typiques d'une faible tranche d'eau (e.g., Cruziana, Diplichnites, Monocraterion et Rusophycus) démontre que la prudence est de mise lors de leur utilisation à litre d'indicateurs de faciès on de milieu, tout particuliérement à l'Éopaléozoique. [Traduit par le journal

Non-existence of Skyrmion-Skyrmion and Skyrmion-anti-Skyrmion static equilibria

We consider classical static Skyrmion-anti-Skyrmion and Skyrmion-Skyrmion configurations, symmetric with respect to a reflection plane, or symmetric up to a $G$-parity transformation respectively. We show that the stress tensor component completely normal to the reflection plane, and hence its integral over the plane, is negative definite or positive definite respectively. Classical Skyrmions always repel classical Skyrmions and classical Skyrmions always attract classical anti-Skyrmions and thus no static equilibrium, whether stable or unstable, is possible in either case. No other symmetry assumption is made and so our results also apply to multi-Skyrmion configurations. Our results are consistent with existing analyses of Skyrmion forces at large separation, and with numerical results on Skymion-anti-Skyrmion configurations in the literature which admit a different reflection symmetry. They also hold for the massive Skyrme model. We also point out that reflection symmetric self-gravitating Skyrmions or black holes with Skyrmion hair cannot rest in symmetric equilibrium with self-gravitating anti-Skyrmions.Comment: v2 Typos corrected, refs added. v3 Journal versio