Invisible Collisions

This activity relates an elastic collision to the change in a satellite’s or spacecraft’s speed and direction resulting from a planetary fly-by, often called a “gravity assist” maneuver. Both hands-on and online interactive methods are used to explore these topics. Educational levels: High school

Energy densification via hydrothermal carbonization

A process called hydrothermal carbonization (HTC), also known as wet torrefaction involves treatment of raw biomass in hot, pressurized water. HTC of woody biomass has been shown to significantly increase the energy density of the feedstock, producing a biochar, similar to coal, having up to 40% higher calorific energy content. Feedstocks investigated include Tahoe chips, Pinion/Juniper chips, Rice hulls, and Corn Stover pellets pre-treated at 215 °C, 255 °C, and 295 °C. Chemical analyses were conducted on the gaseous, aqueous, and solid HTC products. Energy contents of the solid biochar products were measured by calorimetry, and mass balances were determined

The Effects of Peer Mentoring on Students with Autism Spectrum Disorder

The purpose of this study was to determine the characteristics of students with autism and their peer mentors that may contribute to the success of peer-mediated intervention strategies. Target students and peer mentors were matched based on skill level, age, and preferences; the students participated in a variety of activities throughout a week-long day camp. Peer mentors were taught how to interact with students, and behavior technicians were trained to facilitate these interactions. A qualitative case study was designed to determine patterns across the matched pairs. Findings indicate that peer mentor characteristics and the characteristics of the target student contribute to the success of a peer mentoring intervention

Theory of CP violation in B decays

The study of CP violation in $B$-meson decays has already reached a high level of precision, which will be pushed even higher in the future era of Belle-II and the LHCb upgrade. %Important probes of CP violation are the $B_d^0$ and $B_s^0$ mixing phases and the CKM angle $\gamma$. Here, the theoretical challenge is to control the uncertainties from strong interactions to distinguish between the Standard Model and possible New Physics effects. In this talk, I will present a selected overview of recent theoretical developments in this field. This includes, in particular, the semileptonic asymmetry $a_{\text{sl}}^s$ and extractions of the CKM angle $\gamma$ and the $B_d^0$ and $B_s^0$ mixing phases. I focus on recently proposed strategies in which the theory uncertainties can be controlled through data using flavour symmetries of the strong interaction. A newly found puzzle in the $B \to \pi K$ system is highlighted and a theoretically clean way to determine the underlying electroweak penguin parameters is discussed. Finally, the recent progress to describe three-body $B$ decays in QCD factorization is discussed.Comment: To be published in the proceedings of The International Conference on B-Physics at Frontier Machines - BEAUTY2018, La Biodola, Elba Island, Italy, 6-11 May, 2018 and in the proceedings of the XIV International Conference on Heavy Quarks and Leptons (HQL2018), Yamagata, Japan, May 27- June 1, 201

Earth Matters!

This module features classification activities that will lead students from simple sorting of familiar objects to classifying materials into liquids, gases, and solids. Educational levels: Primary elementary

Lock-free atom garbage collection for multithreaded Prolog

The runtime system of dynamic languages such as Prolog or Lisp and their derivatives contain a symbol table, in Prolog often called the atom table. A simple dynamically resizing hash-table used to be an adequate way to implement this table. As Prolog becomes fashionable for 24x7 server processes we need to deal with atom garbage collection and concurrent access to the atom table. Classical lock-based implementations to ensure consistency of the atom table scale poorly and a stop-the-world approach to implement atom garbage collection quickly becomes a bottle-neck, making Prolog unsuitable for soft real-time applications. In this article we describe a novel implementation for the atom table using lock-free techniques where the atom-table remains accessible even during atom garbage collection. Relying only on CAS (Compare And Swap) and not on external libraries, the implementation is straightforward and portable. Under consideration for acceptance in TPLP.Comment: Paper presented at the 32nd International Conference on Logic Programming (ICLP 2016), New York City, USA, 16-21 October 2016, 14 pages, LaTeX, 4 PDF figure

Interpreting & practicing kaupapa Māori research in a community setting: The in’s and out’s

Pou Tuia Rangahau is a unique community based research unit based within a kaupapa Māori organisation. Kaupapa Māori methodologies are utilised, with the importance of these methodologies being that Māori are defining the process, doing the research for and about Māori, with the eventual outcome being meaningful to Māori. This paper is placed within this wider context of Kaupapa Māori and how it applies to the practice of research in particular. We discuss how we interpret and practice Kaupapa Māori Research (KMR) within an urban community based organisation by highlighting a particular piece of research that was undertaken by Pou Tuia Rangahau, the Research Unit of Te Runanga O Kirikiriroa Trust Inc

On velocity structure functions and the spherical vortex model for isotropic turbulence

We investigate a stochastic model for homogeneous, isotropic turbulence based on Hill's spherical vortex. This is an extension of the method of Synge and Lin [Trans. R. Soc. Can. 37, 45 (1943)], to the calculation of higher even-order velocity structure functions. Isotropic turbulence is represented by a homogeneous distribution of eddies, each modeled by a spherical vortex. The cascade process of eddy breakdown is incorporated into the statistical model through an average over an assumed log-normal distribution of vortex radii. We calculate the statistical properties of the model, in particular order-n velocity structure functions defined by rank-n tensors for the ensemble average of a set of incremental differences in velocity components. We define Di[centered ellipsis]s = , where denotes the ensemble average. Specifically Dij, Dijkl, and the longitudinal component of Dijklmn are calculated directly from the spherical vortex ensemble. Matching the longitudinal components of Dij and Dijkl with experimental results fixes two independent model parameters. The lateral and mixed components of Dijkl and the longitudinal component of Dijklmn are then model predictions