Trees of Iowa

Trees, of all nature’s creations, are probably our closest friends. They enter every aspect of our lives and contribute to most of our necessities and luxuries. Economically, they are indispensable. Without them our whole way of life would be greatly changed. That is why an acquaintanceship with the trees of our state goes beyond a pleasant experience to an obligation. To be able to recognize them by name and to know something of the many uses to which they are put is a worthy achievement. Man’s dependence on wood is as old as man himself. Since man first learned that a tree branch picked up from the forest floor made it easier to obtain a better dinner, win arguments with a neighbor or protect himself against attack in the deep forests, he has used wood throughout his life. When he discovered that a stone tied to the end of this stick made a more effective weapon, he took a long stride toward the solution of such problems as food, shelter, clothing and defense

Racial Disparities in Breast Cancer Survival: The Mediating Effects of Macro-Social Context and Social Network Factors

ABSTRACT This study attempts to clarify the associations between macro-social and social network factors and continuing racial disparities in breast cancer survival. The study improves on prior methodologies by using a neighborhood disadvantage measure that assesses both economic and social disadvantage and an ego-network measurement tool that assesses key social network characteristics. Our population-based sample included 786 breast cancer patients (nHWhite=388; nHBlack=398) diagnosed during 2005-2008 in Chicago, IL. The data included census-derived macro-social context, self-reported social network, self-reported demographic and medically abstracted health measures. Mortality data from the National Death Index (NDI) were used to determine 5-year survival. Based on our findings, neighborhood concentrated disadvantage was negatively associated with survival among nHBlack and nHWhite breast cancer patients. In unadjusted models, social network size, network density, practical support, and financial support were positively associated with 5-year survival. However, in adjusted models only practical support was associated with 5-year survival. Our findings suggest that the association between network size and breast cancer survival is sensitive to scaling of the network measure, which helps to explain inconsistencies in past findings. Social networks of nHWhites and nHBlacks differed in size, social support dimensions, network density, and geographic proximity. Among social factors, residence in disadvantaged neighborhoods and unmet practical support explained some of the racial disparity in survival. Differences in late stage diagnosis and comorbidities between nHWhites and nHBlacks also explained some of the racial disparity in survival. Our findings highlight the relevance of social factors, both macro and inter-personal in the racial disparity in breast cancer survival. Findings suggest that reduced survival of nHBlack women is in part due to low social network resources and residence in socially and economically deprived neighborhoods. Our findings indicate that, to improve survival among breast cancer patients, policies need to focus on continued improvement of access to care and reduction of racially patterned social and economic hardship. Additionally, our findings support the need for health care providers to assess social support resources of breast cancer patients at the time of diagnosis

Efficient instruction level simulation of computers

Journal ArticleA technique for creating efficient, yet highly accurate, instruction level simulation models of computers is described. In contrast to traditional approaches that use a software interpreter, this technique employs direct execution of application programs on the host computer. An assembly language program for the machine to be modeled is decompiled to a high level language, instrumented, and then recompiled and executed on the host computer. A prototype implementation modeling the Motorola MC68010 microprocessor is described, and the efficiency and accuracy of this prototype is reported. It is demonstrated that the direct execution technique can be used to produce accurate simulation models which are orders of magnitude faster than traditional, register transfer level simulators

Experimental Investigation of the NASA Common Research Model with a Natural Laminar Flow Wing in the NASA Langley National Transonic Facility

A test of the new NASA Common Research Model with a Natural Laminar Flow (CRMNLF) semispan wing in the NASA Langley National Transonic Facility (NTF) was completed in October 2018. The main focus of this test was the evaluation of the extent of laminar flow on the CRM-NLF wing at various Reynolds numbers and test conditions. During this test, data were acquired at chord Reynolds numbers from 10 to 30 million and at Mach numbers ranging from 0.84 to 0.86. This investigation provided valuable insight into the necessary procedures for laminar flow testing in the NTF. It also significantly advanced the new carbonbased heating layer technique to improve the quality of transition visualization data from temperature sensitive paint (TSP) in a cryogenic wind tunnel

USM3D Analysis of Low Boom Configuration

In the past few years considerable improvement was made in NASA's in house boom prediction capability. As part of this improved capability, the USM3D Navier-Stokes flow solver, when combined with a suitable unstructured grid, went from accurately predicting boom signatures at 1 body length to 10 body lengths. Since that time, the research emphasis has shifted from analysis to the design of supersonic configurations with boom signature mitigation In order to design an aircraft, the techniques for accurately predicting boom and drag need to be determined. This paper compares CFD results with the wind tunnel experimental results conducted on a Gulfstream reduced boom and drag configuration. Two different wind-tunnel models were designed and tested for drag and boom data. The goal of this study was to assess USM3D capability for predicting both boom and drag characteristics. Overall, USM3D coupled with a grid that was sheared and stretched was able to reasonably predict boom signature. The computational drag polar matched the experimental results for a lift coefficient above 0.1 despite some mismatch in the predicted lift-curve slope

The He abundance in the metal-deficient blue compact dwarf galaxies Tol 1214-277 and Tol 65

We present high-quality Keck telescope spectroscopic observations of the two metal-deficient blue compact dwarf (BCD) galaxies Tol 1214-277 and Tol 65. These data are used to derive the heavy-element and helium abundances. We find that the oxygen abundances in Tol 1214-277 and Tol 65 are the same, 12+logO/H=7.54+/-0.01, or Zsun/24, despite the different ionization conditions in these galaxies. The nitrogen-to-oxygen abundance ratio in both galaxies is logN/O=-1.64+/-0.02 and lies in the narrow range found for the other most metal-deficient BCDs. We use the five strongest HeI emission lines 3889, 4471, 5876, 6678 and 7065, to correct self-consistently their intensities for collisional and fluorescent enhancement mechanisms and to derive the He abundance. Underlying stellar absorption is found to be important for the HeI 4471 emission line in both galaxies, being larger in Tol 65. The weighted He mass fractions in Tol 1214-277 and Tol 65 are respectively Y=0.2458+/-0.0039 and 0.2410+/-0.0050 when the three HeI emission lines, 4471, 5876 and 6678, are used, and are, respectively, 0.2466+/-0.0043 and 0.2463+/-0.0057 when the HeI 4471 emission line is excluded. These values are in very good agreement with recent measurements of the He mass fraction in others of the most metal-deficient BCDs by Izotov and coworkers. We find that the combined effect of the systematic uncertainties due to the underlying HeI stellar absorption lines, ionization and temperature structure of the HII region and collisional excitation of the hydrogen emission lines is likely small, not exceeding ~2% (the error is 2sigma). Our results support the validity of the standard big bang model of nucleosynthesis.Comment: 22 pages, 3 Postscript figures, accepted for publication in the Astrophysical Journa

Preliminary Results from an Experimental Assessment of a Natural Laminar Flow Design Method

A 5.2% scale semispan model of the new Common Research Model with Natural Laminar Flow (CRM-NLF) was tested in the National Transonic Facility (NTF) at the NASA Langley Research Center. The model was tested at transonic cruise flight conditions with Reynolds numbers based on mean aerodynamic chord ranging from 10 to 30 million. The goal of the test was to experimentally validate a new design method, referred to as Crossflow Attenuated NLF (CATNLF), which shapes airfoils to have pressure distributions that delay transition on wings with high sweep and Reynolds numbers. Additionally, the test aimed to characterize the NTF laminar flow testing capabilities, as well as establish best practices for laminar flow wind tunnel testing. Preliminary results regarding the first goal of validating the new design method are presented in this paper. Experimental data analyzed in this assessment include surface pressure data and transition images. The surface pressure data acquired during the test agree well with computational fluid dynamics (CFD) results. Transition images at a variety of Reynolds numbers and angles of attack are presented and compared to computational transition predictions. The experimental data are used to assess transition due to a turbulent attachment line, as well as crossflow and Tollmien-Schlichting modal instabilities. Preliminary results suggest the CATNLF design method is successful at delaying transition on wings with high sweep. Initial analysis of the transition front images showed transition Reynolds numbers that exceed historic experimental values at similar sweep angles. , section lif

Microwave telemetry for sensing conditions in enclosed rotating and/or reciprocating machinery

An apparatus for measuring the pressure within the torque converter of an automatic transmission. The apparatus includes a sensor to sense the interior pressure of the torque converter and generate an electrical signal representative of that pressure. That signal is converted to microwave energy which is radiated into the interior of the torque converter housing from a microwave transmitter located within the torque converter. Receiving microwave antennae exposed to the housing interior receive the microwaves and transmit an electrical signal corresponding to the microwave energy to a remote readout external of the torque converter. The receiving antenna are preferably in the form of resonant slots in the torque converter housing and the slots have a length related to the wavelength of the generated microwaves.https://digitalcommons.mtu.edu/patents/1069/thumbnail.jp

Inventaire printanier d'une frayère multispécifique : l'ichtyofaune des rapides de la rivière Gatineau, Québec

Un inventaire ichtyologique printanier a été réalisé dans la rivière Gatineau, dans le premier rapide à l’amont de son embouchure dans la rivière des Outaouais, pour établir la chronoséquence d’utilisation du site par les espèces s’y reproduisant, dont trois espèces de chevaliers. L’échantillonnage des rapides a permis de capturer 2388 poissons répartis en 13 familles et 39 espèces, dont six ayant fait l’objet d’une évaluation par le COSEPAC. Seize espèces étaient en état de se reproduire lors de l’échantillonnage. Nous avons observé une reproduction plus ou moins simultanée pour le Chevalier blanc et le Chevalier rouge, suivie de celle du Chevalier de rivière. Également, pour ces trois espèces, nous avons observé la capture des mâles de stade V plus tôt que les femelles, et nous les retrouvons en plus grand nombre. Ceci pourrait s’expliquer du fait que les mâles précèdent les femelles sur les frayères, que celles-ci sont reconnues pour rester très peu de temps sur les sites de fraie et qu’un minimum de deux mâles par femelle est requis pour la reproduction. Cette étude démontre que les rapides de la rivière Gatineau doivent être protégés puisqu’ils sont habités par trois espèces qui ont obtenu un statut spécial du COSEPAC (Menacée: Fouille-roche gris; situation préoccupante : Lamproie du nord et Chevalier de rivière) en plus de constituer une frayère multispécifique importante