PROGRAMS ADDRESSING CONSUMER CONCERNS FROM THE OHIO STATE UNIVERSITY

Consumer/Household Economics,

CONSUMER PREFERENCES FOR MAPLE SYRUP GRADE NAMES

Consumer/Household Economics,

Guidelines for the Provision of Garbage Reception Facilities at Ports Under MARPOL Annex V

This report offers guidelines for the provision of adequate port reception facilities for vessel-generated garbage under the requirements of Annex V of the International Convention for the Prevention of Pollution From Ships, 1973 (MARPOL 73/78), Regulations for the Prevention of Pollution by Garbage from Ships. MARPOL Annex V prohibits at-sea disposal of plastic materials from vessels, and specifies the distance from shore at which other materials may be dumped. Annex V also requires the provision of port reception facilities for garbage, but it does not specify these facilities or how they are to be provided. Since the at-sea dumping restrictions apply to all vessels, the reception facility requirement applies to all ports, terminals, and marinas that serve vessels. These guidelines were prepared to assist port owners and operators in meeting their obligation to provide adequate reception facilities for garbage. The report synthesizes available information and draws upon experience from the first years ofimplementation of MARPOL Annex V. (PDF file contains 55 pages.

A new algorithm for modelling photoionising radiation in smoothed particle hydrodynamics

We present a new fast algorithm which allows the simulation of ionising radiation emitted from point sources to be included in high-resolution three-dimensional smoothed particle hydrodynamics simulations of star cluster formation. We employ a Str\"omgren volume technique in which we use the densities of particles near the line-of-sight between the source and a given target particle to locate the ionisation front in the direction of the target. Along with one--dimensional tests, we present fully three--dimensional comparisons of our code with the three--dimensional Monte-Carlo radiative transfer code, MOCASSIN, and show that we achieve good agreement, even in the case of highly complex density fields.Comment: 10 pages, 7 figures, submitted to MNRA

The effects of technology on making conjectures: linking multiple representations in learning iterations

Numerous studies have suggested that different technologies have different effects on students' learning of mathematics, particularly in facilitating students' graphing skills and preferences for representations. For example, there are claims that students who prefer algebraic representations can experience discomfort in learning mathematics concepts using computers (Weigand and Weller, 2001; Villarreal, 2000) whilst students using calculators preferred graphical representation (Keller and Hirsch, 1994). Although, arguably, the teaching of mathematics has traditionally centred more on procedural skills, it is possible that students' understandings, preferences and difficulties in relating different representations might be explained by analysing students' thought processes in terms of the making of conjectures. Within the topic of iteration, this study investigated how using graphical calculators, and PC-based graphing software changed A-level mathematics students' conjectures in relation to: 1) students' understanding of the concepts of iteration, and their discovery of the properties of particular iterations; 2) students' preferences for representations; and 3) the way the students express their conjectures. Students were observed tackling iteration questions using graphical calculators, and, later, graphing software. The students' written inferences were collected using two parallel worksheets and were subsequently analysed using a coding scheme developed based on previous studies in the literature, and focusing on students' conjectures as a unit of analysis. The investigation found similar results to those of previous studies in terms of graphing difficulty, linking different representations and preferences for representations. However, the results also hinted that the computer positively influences students' understanding of iteration and their movement between representations more than the graphical calculator; and this possibility requires further research

Linking multiple representations in exploring iterations: does change in technology change students' conjectures?

This study investigates changes in conjectures of four typical students when they are using different kinds of technologies, particularly in relation to their preferences for representations and the way they express their conjectures in understanding the concept and properties of iteration. The first stage of the research was conducted using pen and paper (PP) with graphical calculator (GC) in a classroom while the second stage used PP with graphical software (GS) in a laboratory. The findings suggest, with important caveats, that different technologies significantly influence the students' preferences for representations. Also, this study shows that students' conjectures can be an effective unit of analysis in researching students' understanding of iteration and preferences for representations

IMPACTS OF MAPLE SYRUP GRADING LAWS ON THE MAPLE PRODUCING REGIONS OF UNITED STATES AND CANADA

Agricultural and Food Policy,

Experimental and analytical studies of flow through a ventral and axial exhaust nozzle system for STOVL aircraft

Flow through a combined ventral and axial exhaust nozzle system was studied experimentally and analytically. The work is part of an ongoing propulsion technology effort at NASA Lewis Research Center for short takeoff, vertical landing (STOVL) aircraft. The experimental investigation was done on the NASA Lewis Powered Lift Facility. The experiment consisted of performance testing over a range of tailpipe pressure ratios from 1 to 3.2 and flow visualization. The analytical investigation consisted of modeling the same configuration and solving for the flow using the PARC3D computational fluid dynamics program. The comparison of experimental and analytical results was very good. The ventral nozzle performance coefficients obtained from both the experimental and analytical studies agreed within 1.2 percent. The net horizontal thrust of the nozzle system contained a significant reverse thrust component created by the flow overturning in the ventral duct. This component resulted in a low net horizontal thrust coefficient. The experimental and analytical studies showed very good agreement in the internal flow patterns

The long-term evolution of photoevaporating transition discs with giant planets

Photo-evaporation and planet formation have both been proposed as mechanisms responsible for the creation of a transition disc. We have studied their combined effect through a suite of 2d simulations of protoplanetary discs undergoing X-ray photoevaporation with an embedded giant planet. In a previous work we explored how the formation of a giant planet triggers the dispersal of the inner disc by photo-evaporation at earlier times than what would have happened otherwise. This is particularly relevant for the observed transition discs with large holes and high mass accretion rates that cannot be explained by photo-evaporation alone. In this work we significantly expand the parameter space investigated by previous simulations. In addition, the updated model includes thermal sweeping, needed for studying the complete dispersal of the disc. After the removal of the inner disc the disc is a non accreting transition disc, an object that is rarely seen in observations. We assess the relative length of this phase, to understand if it is long lived enough to be found observationally. Depending on the parameters, especially on the X-ray luminosity of the star, we find that the fraction of time spent as a non-accretor greatly varies. We build a population synthesis model to compare with observations and find that in general thermal sweeping is not effective enough to destroy the outer disc, leaving many transition discs in a relatively long lived phase with a gas free hole, at odds with observations. We discuss the implications for transition disc evolution. In particular, we highlight the current lack of explanation for the missing non-accreting transition discs with large holes, which is a serious issue in the planet hypothesis.Comment: 11 pages, 5 figures; accepted by MNRA