Characterization and durability testing of plasma-sprayed zirconia-yttria and hafnia-yttria thermal barrier coatings. Part 1: Effect of spray parameters on the performance of several lots of partially stabilized zirconia-yttria powder

Initial experiments conducted on thermal barrier coatings prepared in the newly upgraded research plasma spray facility and the burner rig test facilities are discussed. Part 1 discusses experiments which establish the spray parameters for three baseline zirconia-yttria coatings. The quality of five similar coating lots was judged primarily by their response to burner rig exposure supplemented by data from other sources such as specimen characterizations and thermal diffusivity measurements. After allowing for burner rig variability, although there appears to be an optimum density (i.e., optimum microstructure) for maximum burner rig life, the distribution tends to be rather broad about the maximum. In Part 2, new hafnia-yttria-based coatings were evaluated against both baseline and alternate zirconia-yttria coatings. The hafnia-yttria coatings and the zirconia-yttria coatings that were prepared by an alternate powder vendor were very sensitive to plasma spray parameters, in that high-quality coatings were only obtained when certain parameters were employed. The reasons for this important observation are not understood. Also not understood is that the first of two replicate specimens sprayed for Part 1 consistently performed better than the second specimen. Subsequent experiments did not display this spray order affect, possibly because a chiller was installed in the torch cooling water circuit. Also, large changes in coating density were observed after switching to a new lot of electrodes. Analyses of these findings were made possible, in part, because of the development of a sensitive density measurement technique described herein in detail. The measured thermal diffusivities did not display the expected strong relationship with porosity. This surprising result was believed to have been caused by increased microcracking of the denser coatings on the stainless steel substrates

Advanced Placement American History in 3-D

The purpose of this project is to create an online collection of visual works that will enable high school teachers to supplement their instruction of AP American history as well as local history in Spartanburg, SC. We are grateful for this grant from the Arthur Vining Davis Foundation and believe that this project will be a credit to their generosity. It is a commonly acknowledge fact in pedagogy today that visual stimulation enhances learning and makes it more enjoyable. Art can introduce social studies, literature, civics, and even science and math in an immediate, tangible way. In AP American History, students can develop a deeper understanding of history and our shared human through visual works of art. As more and more teachers are now utilizing visual technology in the classroom, there is exponentially greater demand for visual illustrations of historical themes. Yet, the supply of such material has not kept up with the demand. Teachers often complain that they must scavenge the Internet for works of art, political cartoons, or other media in order to prepare for class. The advantage of this project is to collect this kind of material in a single website complete with lesson plans and an historical narrative. We therefore hope that our project will not only prove to be of great benefit to AP American history teachers, but a model for the development of similar sites for other academic fields

Action Research

Action research is a common journey for graduate students in education and other human science fields. This book attempts to meet the needs of graduate students, in-service teachers, and any other educators interested in action research and/or self-study. The chapters of this book draw on our collective experiences as educators in a variety of educational contexts, and our roles guiding educator/researchers in various settings. All of our experiences have enabled us to question and refine our own understanding of action research as a process and means for pedagogical improvement. The primary purpose of this book is to offer clear steps and practical guidance to those who intend to carry out action research for the first time. As educators begin their action research journey, we feel it is vital to pose four questions: 1) What is action research, and how is it distinct from other educational research?; 2) When is it appropriate for an educator to conduct an action research project in their context?; 3) How does an educator conduct an action research project?; 4) What does an educator do with the data once the action research project has been conducted? We have attempted to address all four questions in the chapters of this book.https://newprairiepress.org/ebooks/1034/thumbnail.jp

Does Installation Method Affect Snake Entanglement in Erosion Control Blankets?

Erosion control blankets (ECBs) are installed at construction sites to mitigate against soil loss and promote plant growth. Wildlife, particularly snakes, are prone to becoming entangled in ECBs that contain fixed‐intersection, small‐diameter polypropylene mesh with multiple layers (Ebert et al. 2019 Wildl. Soc. Bull.; Fig. 1). The majority of ECBs on the Texas Department of Transportation’s Approved Product List contain fixed-intersection mesh, which pose a risk to snakes. Snake entanglements often occur at the edge of an ECB where the snake often passes between the multiple mesh layers (Ebert et al. 2019 Wildl. Soc. Bull.) Burying the edge of an ECB may decrease the risk of snake entanglement by allowing them to pass over the ECB edge reducing their encounters with the multiple layers of mesh netting. We hypothesized burying the ECB edge would reduce snakes attempting to pass through the mesh and reducing their risk of entanglement and that there will be a positive correlation between circumference and entanglement

Surfactant phosphatidylcholine half-life and pool size measurements in premature baboons developing bronchopulmonary dysplasia

Because minimal information is available about surfactant metabolism in bronchopulmonary dysplasia, we measured half-lives and pool sizes of surfactant phosphatidylcholine in very preterm baboons recovering from respiratory distress syndrome and developing bronchopulmonary dysplasia, using stable isotopes, radioactive isotopes, and direct pool size measurements. Eight ventilated premature baboons received (2)H-DPPC (dipalmitoyl phosphatidylcholine) on d 5 of life, and radioactive (14)C-DPPC with a treatment dose of surfactant on d 8. After 14 d, lung pool sizes of saturated phosphatidylcholine were measured. Half-life of (2)H-DPPC (d 5) in tracheal aspirates was 28 +/- 4 h (mean +/- SEM). Half-life of radioactive DPPC (d 8) was 35 +/- 4 h. Saturated phosphatidylcholine pool size measured with stable isotopes on d 5 was 129 +/- 14 micro mol/kg, and 123 +/- 11 micro mol/kg on d 14 at autopsy. Half-lives were comparable to those obtained at d 0 and d 6 in our previous baboon studies. We conclude that surfactant metabolism does not change during the early development of bronchopulmonary dysplasia, more specifically, the metabolism of exogenous surfactant on d 8 is similar to that on the day of birth. Surfactant pool size is low at birth, increases after surfactant therapy, and is kept constant during the first 2 wk of life by endogenous surfactant synthesis. Measurements with stable isotopes are comparable to measurements with radioactive tracers and measurements at autopsy

High blood pressure and associated risk factors as indicator of preclinical hypertension in rural West Africa: A focus on children and adolescents in The Gambia.

Hypertension is fast becoming a major public health problem across sub-Saharan Africa. We sought to determine the prevalence of high blood pressure (BP) and associated risk factors as indicator of preclinical hypertension in a rural Gambian population.We analyzed data on 6160 healthy Gambians cross-sectionally. Attention was given to 5 to <18-year olds (N = 3637), as data from sub-Saharan Africa on this young age group are scarce. High BP was defined as systolic blood pressure (SBP) above the 95th percentile for age-sex specific height z scores in <18-year olds employing population-specific reference values. Standard high BP categories were applied to ≥18-year olds.In <18-year olds, the multivariable analysis gave an adjusted high BP prevalence ratio of 0.95 (95% confidence interval [CI] 0.92-0.98; P = 0.002) for age and 1.13 (95% CI 1.06-1.19; P < 0.0001) for weight-for-height z score (zWT-HT); sex and hemoglobin were not shown to affect high BP. In adults age 1.05 (95% CI 1.04-1.05; P < 0.0001), body mass index z score 1.28 (95% CI 1.16-1.40; P < 0.0001), hemoglobin 0.90 (95% CI 0.85-0.96; P < 0.0001) and high fasting glucose 2.60 (95% CI 2.02-3.36; P < 0.0001, though the number was very low) were confirmed as risk factors for high BP prevalence; sex was not associated.The reported high BP prevalence and associated risk factors in adults are comparable to other studies conducted in the region. The observed high BP prevalence of 8.2% (95% CI 7.4-9.2) in our generally lean young Gambians (<18 years) is alarming, given that high BP tracks from childhood to adulthood. Hence there is an urgent need for further investigation into risk factors of pediatric high BP/hypertension even in rural African settings

Work-out und Servicing von notleidenden Krediten: Berichte und Referate des HfB-NPL Servicing Forums 2006

The report deals with the current questions relating to the work-out, outsourcing and servicing of non-performing-loans. After a brief market description the paper addresses the specific problems, which arise when servicing real estate and corporate loans. Within these framework issues, which include banking secrecy rules, the risk of civil liability for banks in respect to non-performing-loans, banking regulation law, are explained and practical suggestions for a proposed line of action are made. The main objective is to identify the basic lines taken in the discussion so far and to define different approaches to the topic for the purposes of research and legal practice. --Non-performing-loans,distressed debt,portfolio-management,work-out,outsourcing,servicing, banking regulation law, banker´s duty of secrecy,civil liability risks,corporate loans, real estate loans

Picosecond timing of Microwave Cherenkov Impulses from High-Energy Particle Showers Using Dielectric-loaded Waveguides

We report on the first measurements of coherent microwave impulses from high-energy particle-induced electromagnetic showers generated via the Askaryan effect in a dielectric-loaded waveguide. Bunches of 12.16 GeV electrons with total bunch energy of $\sim 10^3-10^4$ GeV were pre-showered in tungsten, and then measured with WR-51 rectangular (12.6 mm by 6.3 mm) waveguide elements loaded with solid alumina ($Al_2 O_3$) bars. In the 5-8 GHz $TE_{10}$ single-mode band determined by the presence of the dielectric in the waveguide, we observed band-limited microwave impulses with amplitude proportional to bunch energy. Signals in different waveguide elements measuring the same shower were used to estimate relative time differences with 2.3 picosecond precision. These measurements establish a basis for using arrays of alumina-loaded waveguide elements, with exceptional radiation hardness, as very high precision timing planes for high-energy physics detectors.Comment: 16 pages, 15 figure