A comprehensive model to determine the effects of temperature and species fluctuations on reaction rates in turbulent reacting flows

The use of probability theory to determine the effects of turbulent fluctuations on reaction rates in turbulent combustion systems is briefly reviewed. Results are presented for the effect of species fluctuations in particular. It is found that turbulent fluctuations of species act to reduce the reaction rates, in contrast with the temperature fluctuations previously determined to increase Arrhenius reaction rate constants. For the temperature fluctuations, a criterion is set forth for determining if, in a given region of a turbulent flow field, the temperature can be expected to exhibit ramp like fluctuations. Using the above results, along with results previously obtained, a model is described for testing the effects of turbulent fluctuations of temperature and species on reaction rates in computer programs dealing with turbulent reacting flows. An alternative model which employs three variable probability density functions (temperature and two species) and is currently being formulated is discussed as well

School-based health centers: A four year experience, with a focus on reducing student exclusion rates

We describe a four year collaborative experience with an on-site, community school-based health center that is staffed by the Vallejo City Unified School District and supervised by the pediatric faculty of the Touro University College of Osteopathic Medicine, with particular attention to first grade student exclusion rates

The case for intervention bias in the practice of medicine.

Bias is an inclination to present or hold a partial perspective at the expense of possibly equal or more valid alternatives. In this paper, we present a series of conditional arguments to prove that intervention bias exists in the practice of medicine. We then explore its potential causes, consequences, and criticisms. We use the term to describe the bias on the part of physicians and the medical community to intervene, whether it is with drugs, diagnostic tests, non-invasive procedures, or surgeries, when not intervening would be a reasonable alternative. The recognition of intervention bias in medicine is critically important given today\u27s emphasis on providing high-value care and reducing unnecessary and potentially harmful interventions

Triaxial Acceleration Analysis Applied to the Evaluation of Pavement Riding Qualities

Traditionally the riding qualities of a pavement are expressed as some function of localized irregularities in the contour of the pavement surface. This is predicated on the fact that the portion of passenger comfort or discomfort imparted by all features of the pavement surface can not be isolated and determined separately from other influences such as vehicle characteristics or psychological and physiological aspects of the passenger himself. Measurements of riding qualities have dealt almost exclusively with vehicle displacements in the vertical direction only, these having been and still being the most prominent and most amenable to measurement. By this procedure displacements in other directions have been ignored, although their relative influence on riding comfort as determined by comfort research is known to be great. During the past few years certain features of highway construction and use have emphasized surface irregularities that cause significant amounts of combined transverse and longitudinal motion. In response to this developing need for determination of riding qualities on the basis of component motions, an instrument for measuring and recording induced accelerations in the three principal directions was developed and adapted to a passenger vehicle. This paper describes the equipment and its use in evaluating riding qualities of various pavements in Kentucky

[Wallace-Hardeman correspondence, May 19, 1945-October 3, 1945]

https://digitalcommons.acu.edu/crs_books/1424/thumbnail.jp

Information requirements for guidance and control systems

Control or guidance system performance dependency on information handling by subsystem

A comprehensive model to determine the effects of temperature and species fluctuations on reaction rates in turbulent reacting flows

A principal element to be derived from modeling turbulent reacting flows is an expression for the reaction rates of the various species involved in any particular combustion process under consideration. A temperature-derived most-likely probability density function (pdf) was used to describe the effects of temperature fluctuations on the Arrhenius reaction rate constant. A most-likely bivariate pdf described the effects of temperature and species concentrations fluctuations on the reaction rate. A criterion is developed for the use of an "appropriate" temperature pdf. The formulation of models to calculate the mean turbulent Arrhenius reaction rate constant and the mean turbulent reaction rate is considered and the results of calculations using these models are presented

Wide-field Magnetic Field and Temperature Imaging using Nanoscale Quantum Sensors

The simultaneous imaging of magnetic fields and temperature (MT) is important in a range of applications, including studies of carrier transport, solid-state material dynamics, and semiconductor device characterization. Techniques exist for separately measuring temperature (e.g., infrared (IR) microscopy, micro-Raman spectroscopy, and thermo-reflectance microscopy) and magnetic fields (e.g., scanning probe magnetic force microscopy and superconducting quantum interference devices). However, these techniques cannot measure magnetic fields and temperature simultaneously. Here, we use the exceptional temperature and magnetic field sensitivity of nitrogen vacancy (NV) spins in conformally-coated nanodiamonds to realize simultaneous wide-field MT imaging. Our "quantum conformally-attached thermo-magnetic" (Q-CAT) imaging enables (i) wide-field, high-frame-rate imaging (100 - 1000 Hz); (ii) high sensitivity; and (iii) compatibility with standard microscopes. We apply this technique to study the industrially important problem of characterizing multifinger gallium nitride high-electron-mobility transistors (GaN HEMTs). We spatially and temporally resolve the electric current distribution and resulting temperature rise, elucidating functional device behavior at the microscopic level. The general applicability of Q-CAT imaging serves as an important tool for understanding complex MT phenomena in material science, device physics, and related fields

Stories from Edzell Lodge Children’s Home in the 1940s and 1950s:Lessons for practice and research

‘Gnatola ma no kpon sia, eyenabe adelan to kpo mi sena’ (‘Until the lion has his or her own storyteller, the hunter will always have the best part of the story’) (Ghanian proverb, available at: http://thelionandthehunter.org/). Historically, both the discipline and profession of social work have been imagined and constructed by those who oversee social work services – ‘the hunters’, according to the aforementioned Ghanaian proverb. Thus, it has been predominantly white, middle-class, non-disabled, mainly female, Global North voices that have determined what social work looks like and how it is carried out across the world. However, this is changing. Today, many more ‘lions’ are telling their stories, as this article demonstrates. Through the curated narratives of Bob, Doug and Rose, as well as that of their storyteller/collaborator, Viv, we learn that growing up in care in Scotland in the 1940s and 1950s was ‘confused and confusing’ for the children at the heart of it. Contradictory discourses competed for dominance, and the children experienced unintended consequences from the ‘care’ they received. While not attempting to universalise on the basis of three people’s stories, we believe that they have much to teach social work