Green River Adjudication v. United States, 404 P.2d 251 (Utah 1965)

Green River Adjudication v. United State

Hardware, Software, and Low-Level Control Scheme Development for a Real-Time Autonomous Rover

The objective of this research is to develop a low-cost autonomous rover platform for experiments in autonomous navigation. This thesis describes the design, development, and testing of an autonomous rover platform, based on the commercial, off-the-shelf Tamiya TXT-1 radio controlled vehicle. This vehicle is outfitted with an onboard computer based on the Mini-ITX architecture and an array of sensors for localization and obstacle avoidance, and programmed with Matlab/SimulinkRTM Real-Time Workshop (RTW) utilizing the Linux Real-Time Application Interface (RTAI) operating system.;First, a kinematic model is developed and verified for the rover. Then a proportional-integral-derivative (PID) feedback controller is developed for translational and rotational velocity regulation. Finally, a hybrid navigation controller is developed combining a potential field controller and an obstacle avoidance controller for waypoint tracking.;Experiments are performed to verify the functionality of the kinematic model and the PID velocity controller, and to demonstrate the capabilities of the hybrid navigation controller. These experiments prove that the rover is capable of successfully navigating in an unknown indoor environment. Suggestions for future research include the integration of additional sensors for localization and creation of multiple platforms for autonomous coordination experiments

State-of-the-Art Review of Bibliographic Control of Higher Education in Canada

During the last two decades the quantity and variety of materials providing information on higher education in Canada have increased greatly. Nevertheless, researchers, administrators, instructors and students find it difficult to identify and locate relevant items. The following article reports on a survey of Canadian agencies and institutions collecting higher education materials; identifies four problem areas - definitions, collection policies, accessibility, and collection co- ordination; and recommends further information exchange and the compilation of a more complete directory of collections in higher education.Au cours des deux dernières décennies on a assisté à une augmentation consi-dérable de la quantité et de la variété de l'information ayant trait à l'enseigne-ment supérieur au Canada. Cependant, l'identification et la localisation de ces documents ne sont pas pour autant sans poser des problèmes aux chercheurs, administrateurs, enseignants, et étudiants. L'article suivant signale les résultats d'une enquête portant sur les organismes et établissements canadiens qui recueil-lent des documents relatifs à l'enseignement supérieur. Il identifie quatre caté-gories de problèmes - définitions, politiques de développement des fonds, acces-sibilité des documents, et coordination des collections — et recommande l'inten-sification des échanges d'information ainsi que la compilation d'un répertoire plus complet pour donner accès à ces collections

Capacitance mass sensing of boiling propellants

Capacitance mass sensing of boiling propellant

Neutron Beam Effects on Spin Exchange Polarized He-3

We have observed depolarization effects when high intensity cold neutron beams are incident on alkali-metal-spin-exchange polarized He-3 cells used as neutron spin filters. This was first observed as a reduction of the maximum attainable He-3 polarization and was attributed to a decrease of alkali-metal polarization, which led us to directly measure alkali-metal polarization and spin relaxation over a range of neutron fluxes at LANSCE and ILL. The data reveal a new alkali-metal spin-relaxation mechanism that approximately scales as the square root of the neutron capture-flux density incident on the cell. This is consistent with an effect proportional to the recombination-limited ion concentration, but is much larger than expected from earlier work.Comment: submitted to Physical Review Letter

New measurement of the scattering cross section of slow neutrons on liquid parahydrogen from neutron transmission

Liquid hydrogen is a dense Bose fluid whose equilibrium properties are both calculable from first principles using various theoretical approaches and of interest for the understanding of a wide range of questions in many body physics. Unfortunately, the pair correlation function $g(r)$ inferred from neutron scattering measurements of the differential cross section $d\sigma \over d\Omega$ from different measurements reported in the literature are inconsistent. We have measured the energy dependence of the total cross section and the scattering cross section for slow neutrons with energies between 0.43~meV and 16.1~meV on liquid hydrogen at 15.6~K (which is dominated by the parahydrogen component) using neutron transmission measurements on the hydrogen target of the NPDGamma collaboration at the Spallation Neutron Source at Oak Ridge National Laboratory. The relationship between the neutron transmission measurement we perform and the total cross section is unambiguous, and the energy range accesses length scales where the pair correlation function is rapidly varying. At 1~meV our measurement is a factor of 3 below the data from previous work. We present evidence that these previous measurements of the hydrogen cross section, which assumed that the equilibrium value for the ratio of orthohydrogen and parahydrogen has been reached in the target liquid, were in fact contaminated with an extra non-equilibrium component of orthohydrogen. Liquid parahydrogen is also a widely-used neutron moderator medium, and an accurate knowledge of its slow neutron cross section is essential for the design and optimization of intense slow neutron sources. We describe our measurements and compare them with previous work.Comment: Edited for submission to Physical Review

Adverse Childhood Experiences and Mental Health Conditions Among Multiracial Adolescents

The relationships between adverse childhood experiences (ACEs) and mental health conditions have received much attention in the literature. A particularly well-documented type of ACE is household dysfunction. However, compared to monoracial youth, little is known about the relationship between this type of ACE and mental health outcomes among multiracial adolescents. Objective The objective of this study was to verify the factor structure of the household dysfunction type of ACE using data from the National Survey of Children’s Health (NSCH), and then examine whether household dysfunction (measured as a latent construct) was associated with mental health conditions among multiracial adolescents. Design We used cross-sectional data collected in 2016 from caregivers who completed the NSCH and analyzed data from a subpopulation of adolescents (12–17) who reported more than one race (n = 1,231). Mplus 8.4 was used to conduct confirmatory factor analysis and probit models from a structural equation modeling framework. Results Results from this study indicated that the household dysfunction type of ACE, as a latent construct, had good model fit and was significantly associated with depression [standardized coefficient [B] = .50, 95% confidence interval [CI] .36, .65], anxiety [B = .61, 95% CI .48, .73], behavior problems [B = .58, 95% CI .44, .72], and ADHD [B = .54, 95% CI .38, .69] for multiracial adolescents. Conclusions Household dysfunction may result in adolescents being separated (physically or emotionally) from their caregivers, which may hinder adolescents’ ability to establish or maintain one of the most important relationships needed to promote racial/ethnic identity development and mental health. Implications for advancements in theory and NSCH are presented

Neutron Beta Decay Studies with Nab

Precision measurements in neutron beta decay serve to determine the coupling constants of beta decay and allow for several stringent tests of the standard model. This paper discusses the design and the expected performance of the Nab spectrometer.Comment: Submitted to Proceedings of the Conference CIPANP12, St.Petersburg, Florida, May 201

Qweak: A Precision Measurement of the Proton's Weak Charge

The Qweak experiment at Jefferson Lab aims to make a 4% measurement of the parity-violating asymmetry in elastic scattering at very low $Q^2$ of a longitudinally polarized electron beam on a proton target. The experiment will measure the weak charge of the proton, and thus the weak mixing angle at low energy scale, providing a precision test of the Standard Model. Since the value of the weak mixing angle is approximately 1/4, the weak charge of the proton $Q_w^p = 1-4 \sin^2 \theta_w$ is suppressed in the Standard Model, making it especially sensitive to the value of the mixing angle and also to possible new physics. The experiment is approved to run at JLab, and the construction plan calls for the hardware to be ready to install in Hall C in 2007. The theoretical context of the experiment and the status of its design are discussed.Comment: 5 pages, 2 figures, LaTeX2e, to be published in CIPANP 2003 proceeding

The Nab Experiment: A Precision Measurement of Unpolarized Neutron Beta Decay

Neutron beta decay is one of the most fundamental processes in nuclear physics and provides sensitive means to uncover the details of the weak interaction. Neutron beta decay can evaluate the ratio of axial-vector to vector coupling constants in the standard model, $\lambda = g_A / g_V$, through multiple decay correlations. The Nab experiment will carry out measurements of the electron-neutrino correlation parameter $a$ with a precision of $\delta a / a = 10^{-3}$ and the Fierz interference term $b$ to $\delta b = 3\times10^{-3}$ in unpolarized free neutron beta decay. These results, along with a more precise measurement of the neutron lifetime, aim to deliver an independent determination of the ratio $\lambda$ with a precision of $\delta \lambda / \lambda = 0.03\%$ that will allow an evaluation of $V_{ud}$ and sensitively test CKM unitarity, independent of nuclear models. Nab utilizes a novel, long asymmetric spectrometer that guides the decay electron and proton to two large area silicon detectors in order to precisely determine the electron energy and an estimation of the proton momentum from the proton time of flight. The Nab spectrometer is being commissioned at the Fundamental Neutron Physics Beamline at the Spallation Neutron Source at Oak Ridge National Lab. We present an overview of the Nab experiment and recent updates on the spectrometer, analysis, and systematic effects.Comment: Presented at PPNS201