Raise the (Proportion) Bar!

This article, drawing mainly on references to teacher preparation textbooks, proposes proportion bars as a somewhat novel graphical approach to solving simple (direct) proportion problems and to illustrate the advantages of such an approach, which include accessibility with materials at early grade levels, allowance of students to better develop number sense and estimation, facilitation of setting up proportions, allowance for conceptual understanding and motivation of the procedure for solving direct proportions, assistance with part-to-part and part-to whole comparisons, and drawing of connections among mathematical topics. The emphasis is on teaching with understanding, rather than procedural knowledge

Analysis of Additively Manufactured Injectors for Rotating Detonation Engines

This research represents an experimental and computational analysis of additively manufactured injectors for Rotating Detonation Engines (RDEs) for use in rocket propulsion. This research was based on the manufacture and testing of existing injector element designs using additive techniques. The designs were modeled from geometries gathered from Sutton and Biblarz Elements of Rocket Propulsion [23]. The goal of this research was to characterize the viscous losses of each design based on the discharge coefficient. The designs were computationally simulated to gain insight to the flow characteristics using multiple sets of conditions for surface roughness and inlet pressure. The results were then compared to experimental results of similar conditions. Each design was then tested using pressurized water as a simulated propellant. The results show the viscous losses to be highly dependent on design and the relative roughness of the surface. For designs with areas of high relative roughness and L/D such that ow interaction is facilitated the surface roughness was shown to affect the discharge coefficient

NEW DEVELOPMENT IN LEPROSY CONTROL AND THE ISSUES OF INTEGRATION

ABSTRACT Control of leprosy has up till now depended on active case finding, early diagnosu, and lon.&r-term treatment with dapsone monotherapy of all cases, but especially of infectious (lepro matous and bordprline-lepromatousJ patients. Thu strategy u failing because of poor compliance, microbial persistence which causes relapse in patients prematurely stopping dapsone therapy, and relapses associated with a world-wide epidemic of secondary dapsone resutance. Primary dapsone resutance, occurring in any type of leprosy, u increasingly being detected. WHO now recommends that all multibacillary lepro.,.y patients should be treated ulith a three-drug regimen of rifampicin, dapsone, and pither clofazimine or ethionamide prothionamide, in a rhythm especially suitable for field superoision, for a minimal duration of two years and preferably until the patient becomes'smear ne~tive. Paucibacillary patients may be treated with short course therapy consuting of rifampicin monthly for six doses plus six months of daily dapsone. These regimens will cause a steep increase in work load, not least to the skinsmear laboratory. But after about three years, the work load should begin to reduce substantially. Then after about 10 years, it should reach well below the present level. It is suggested that integration with the TB seroices might be possible about three years after the setting-up of multidrug therapy in any area. Full integration into PHC could be possible after about 10 .years. But intewation is likely to fail unless massive health education is undertaken to lessen the stigma of leprosy

Exploring Interfacial Phenomena in Photovoltaic Materials Structures Using First-Principles Calculations and Beyond.

Photovoltaics are a large part of the global strategy to reduce carbon dioxide emissions. The strict processing requirements of silicon are viewed as economic barriers to larger scale deployment of solar energy. Many of these materials have photocurrents limited by dissociation of bound excited states. The separation between the photo-excited electron and the hole at the interface between the donor and acceptor material is at the core of the functional response of an organic photovoltaic (OPV) device. We therefore examine the effects of interfacial electrostatics in a semi-classical manner on these excited states for both an organic interface and a hybrid organic-inorganic interface. We use boron subphtalocyanine chloride and C60 as our organic interface wherein we also simulate the effects of thermal motion on the excited state energetics using ab initio molecular dynamics. For our hybrid interface, we use pentacene and silicon for which the applicability of our model depends on surface termination. We develop a semi-classical model for the description of dissociation between electron and hole, which takes into account the difference of dielectric constants of the materials juxtaposed at the interface, as well as the potentially polar nature of the interfacial termination. Particularly this latter effect can be exploited for device performance optimization. Using ab intio modeling, we explore possible modifications of boron subphthalocyanine chloride derivatives to control the dipole associated with these molecules and their photonic properties. We substitute the axial boron and chlorine atoms for other trivalent and halogen atoms in our derivatives. We explore boron subphthalocyanine chloride derivatives as possible organic photovoltaic materials. Possible crystal structures are predicted and their electronic and photonic properties for the proposed derivatives. We further refine the semi-classical model, leading to a quantum mechanical model based on the effective mass Schrödinger equation, which utilizes a self-consistent approach for the calculation of excited states. This model reveals that at hybrid organic/inorganic interfaces, excited electron-hole configurations transition from a regime where both reside in the donor phase to a regime where they are separated across the interface, which is controlled by the attraction between electron and hole and the band edge offset.PHDMaterials Science and EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/120725/1/mjwaters_1.pd

RelB acts as a molecular switch to drive chronic inflammation in glioblastoma multiforme (GBM).

Inflammation is a homeostatic response to tissue injury or infection, which is normally short- lived and quickly resolves to limit tissue damage. In contrast, chronic inflammation has been linked to a variety of human diseases, including cancers such as glioblastoma multiforme (GBM). GBMs are very aggressive tumors with very low patient survival rates, which have not improved in several decades. GBM tumors are characterized by necrosis and profound inflammation; with cytokines secreted by both GBM cells and the tumor microenvironment. The mechanisms by which chronic inflammation develops and persists in GBM regardless of multiple anti-inflammatory feedback loops remain elusive. This project identifies a molecular switch which promotes chronic inflammation in GBM, but not primary human astrocytes

Annular flow regimes in a novel down-hole gas liquid separator and pump connector

Flow patterns were investigated in a novel dual-use pump connector and down-hole gas-liquid separator. The device was designed by Dr. Paul Bommer with The University of Texas at Austin and is currently on file with the United States Patent and Trademark Office. A detailed description of the pump connector is provided. This includes a discussion of the theory underlying its design and possible applications for its use. Two-phase annular flow occurs throughout this device. This flow has been well documented throughout the literature and is discussed in this report. Following this review are experimental results from testing performed at J.J. Pickle Research Campus at The University of Texas at Austin. Visual observation was used to characterize the upward gas-liquid flow in the prototype’s concentric annulus. The pump connector exhibited flow regimes consistent with those seen in literature in its vertical orientation. Additional flow regime maps were generated at 10, 20 and 45 degrees. Increasing the inclination up to 45 degrees delayed the onset of churn flow and appeared to improve the effectiveness of this device. This is the first study to investigate fluid flow in this apparatus. The results of this research will aid in a better understanding of the pump connector and assist in its improved design.Petroleum and Geosystems Engineerin

The Fishing Optimization Problem: A Tour of Technology in the Teaching of Mathematics Dedicated to Bert Waits and Frank Demana

Relaxation can provide time for reflection. This paper illustrates how relaxation, in the form of fishing, led to reflection involving mathematics and technology – in particular, the calculator technology fostered by Bert Waits and Frank Demana, Ohio's internationally-recognized leaders in the field