CFD predictions of near-field pressure signatures of a low-boom aircraft

A three dimensional Euler marching code has been utilized to predict near-field pressure signatures of an aircraft with low boom characteristics. Computations were extended to approximately six body lengths aft of the aircraft in order to obtain pressure data at three body lengths below the aircraft for a cruise Mach number of 1.6. The near-field pressure data were extrapolated to the ground using a Whitham based method. The distance below the aircraft where the pressure data are attained is defined in this paper as the 'separation distance.' The influences of separation distances and the still highly three-dimensional flow field on the predicted ground pressure signatures and boom loudness are presented in this paper

Impact of Sewage Sludge Spreading on Soil and Crop quality – Results from a French thorough Survey

The spreading of urban sewage sludge is a constant cause of controversy, in particular as this practice is known to supply amounts of potentially toxic trace metals to the soil, particularly cadmium. In order to clarify some parts of this debate, this article presents a synthesis of the results of many studies carried out in France on the impact of sewage sludge spreading: old experiments as well as more recent trials. This paper deals mainly with cadmium but sometimes some interesting results relating to other trace metals are reported. Presented data are relative to: i) the soil quality such as total trace metal contents and results of partial extraction aimed at determining the most phytoavailable fractions; ii) the composition of cereal grain, chiefly wheat. Depending upon the period, the experiments were completely different as far as the tonnages of sludge applied and the quantities of cadmium involved. Three categories of trials stand out: 1) During the 1970s and 80s, sludges with a high trace metal content, especially cadmium, were spread at one experimental farm on sandy soils and in the Vexin area on silty topsoils. In all cases, a notable long-lasting impact was found on the total Cd content of the topsoil and the composition of cereal grains. The quantities of applied Cd were very high, from 3,600 g ha-1 to 641,000 g ha-1. 2) Sludges containing high amounts of industrial Ca were spread on acid soils in the Limoges region for more than 20 years. Increases of the cadmium content in the topsoil were only measured in fields where the cadmium input was the highest, of 300 to 600 g per ha. A clear increase in the Cd content of cereal grains has been noted as well. 3) During the 1990s and 2000s, numerous experiments with sewage sludge applications compatible with the French regulations were implemented. Local authorities launched many, relatively light, experiments in diverse areas and on diverse soil types. Research institutions carried out other, more exacting, trials. The quantities of Cd input varied from 0.6 to 270 g ha-1. In these cases, no impact was measurable on the composition of cereal grains

Mama’s Got a Brand New Degree: Education and Changing Perceptions of Femininity During the Mexican Revolution (1910-1917)

Bloody struggles, tense political debates, and general unease characterized Mexico in the early twentieth century. Under former president Porfirio Díaz, tensions grew as the lower classes pleaded for labor and land reform, culminating in a violent period of revolution from 1910 to 1917. As with all conflicts of this scale, the Mexican Revolution prompted the challenging of many long standing social conventions, specifically as they pertained to the role of government and the organization of social classes. With the restructuring of society already underway, many activists capitalized on the uncertainty of the era to push against the subjugation of women. Feminist movements were not new to Mexico; however, the revolution presented an opportunity to raise women\u27s stations and make space for them outside of the home. With this campaign to bolster women’s positions in society came critical examinations of the existing gender roles and perceptions of femininity. Class struggles revealed how typical understandings of women’s role in society–specifically remaining confined to the home–derived from upper class customs, and often proved inapplicable or unattainable for those of lower socioeconomic standing. This period also saw immense conflicts between the Mexican state and the Catholic Church on the grounds of political power and land ownership, however the Church provided one of the few opportunities for women to participate in the public sphere. This relationship helped define many aspects of femininity as the revolution approached and became a prominent discussion point in the fight for education as many champions of the anti-clerical movement argued in support of women’s education as a means to decrease their reliance on the institution. Women\u27s suffrage, soldaderas, prostitution, and sex education all played key roles in exposing and morphing how Mexican society conceptualized femininity. The fight for women’s education became a focal point of revolutionary Mexico by embodying the Mexican public’s attempt to integrate changing perceptions of femininity into the emerging modern era as the struggle pushed many women from their previous places in the home into the public sphere

Bernard Williams's Internalism: A New Interpretation

There has been significant and continued debate over the nature and truth of Bernard Williams’s internalism. My aim is to resolve much of the dispute over both of those issues by providing a new interpretation of his internalism--the reasonsH interpretation. To explain the new interpretation I make a distinction between there being a reason to perform an action (a reasonE) and an agent having a reason to perform an action (a reasonH). For an agent to have a reason to perform an action, it must be within the agent’s capacity to perform the action for that reason. According to the reasonsH interpretation, internalism is the claim that in order for an agent to have a reason, it must be within the agent’s capacity to be motivated to perform the action. An important consequence of this interpretation is that externalists with respect to the previous interpretations can consistently accept the truth of internalism on the reasonsH interpretation. To support the accuracy of this new interpretation of Williams’s internalism, in Chapter 1 I argue that the predominant interpretations are problematic because they inconsistent with one of two claims which are most likely essential to a correct interpretation. In Chapter 2 I then provide a detailed explanation of the reasonsH interpretation as well as three considerations which together strongly support the plausibility of it as a correct interpretation. Chapter 3 completes the argument that the reasonsH interpretation is the most charitable interpretation with respect to Williams's argument against external reasons. In Chapter 4 I defend the truth of internalism against various objections that have been raised against the doctrine. Lastly, in Chapter 5 I will show that the same concern which underlies Williams's explanation and defense of internalism is the same concern which is the basis for his rejection of the “morality system”--a particular conception of morality which he addresses in Ethics and the Limits of Philosophy

“So, how real can I get?: opportunities and obstacles for teacher learners enacting culturally responsive pedagogy.

This qualitative study examines the experiences of three alternative certification teachers (teachers who begin teaching as they worked to complete teacher education courses for initial certification) whom I call “teacher learners” (Jacobs & Low, 2017) as they try to enact culturally responsive practices while navigating their first-year of teaching. The teacher learners worked to develop their understanding and capacities to enact a culturally responsive pedagogy (CRP) even as they were faced with the obstacles inherent to shifting teaching practices in K-12 schools. Through these challenges, they still furthered their conceptualization of CRP, as evidenced by, and in some ways guided by, their work with a lesson planning template inspired by Foster et al.’s (2020) The Heuristic for Thinking About Culturally Responsive Teaching (HiTCRiT). This study is situated in Vygotskian sociocultural theory, Freire’s (1970) work on critical consciousness, and leans heavily on Ladson-Billings’s (1995) conceptualization of a “culturally relevant pedagogy” in my analysis of the teacher learners’ interviews and work. I employed qualitative data collection methods of interviewing and the collection and analysis of artifacts from the teacher learners’ coursework in an English teaching methods course. I listen to their depictions of attempts to enact CRP and develop their knowledge of it within the generally unaccommodating cultures of practice in their schools, and using discourse analysis, explore those attempts through their work on the HiTCRiT planning template. The data show that the teacher learners expanded their understanding of culturally responsive pedagogy as a concept (Smagorinsky et al., 2003), an informed theory of practice. Additionally, the data show that the teacher learners lacked the influence of experienced colleagues prepared to mentor them in CRP and that those colleagues often served as obstacles to this goal. While this situation sheds light on challenge teachers face enacting CRP in K-12 schools, the teacher learners showed, through their work teaching online and away from the wider cultures of their schools during the COVID-19 lockdown, that using the HiTCRiT planning tool allowed them to explore and expand their teaching in cultural responsive ways

Towards cheaper control centers

Today, any approach to the design of new space systems must take into consideration an important constraint, namely costs. This approach is our guideline for new missions and also applies to the ground segment, and particularly to the control center. CNES has carried out a study on a recent control center for application satellites in order to take advantage of the experience gained. This analysis, the purpose of which is to determine, a posteriori, the costs of architecture needs and choices, takes hardware and software costs into account and makes a number of recommendations

Probabilities Involving Standard Trirectangular Tetrahedral Dice Rolls

The goal is to be able to calculate probabilities involving irregular shaped dice rolls. Here it is attempted to model the probabilities of rolling standard tri-rectangular tetrahedral dice on a hard surface, such as a table top. The vertices and edges of a tetrahedron were projected onto the surface of a sphere centered at the center of mass of the tetrahedron. By calculating the surface areas bounded by the resultant geodesics, baseline probabilities were achieved. Using a 3D printer, dice were constructed of uniform density and the results of rolling them were recorded. After calculating the corresponding confidence intervals, the results were significantly different from the original calculated probabilities. Possible reasons for the discrepancy are noted, but further research is needed to better understand what is going on

Spectral Polarization Distribution Models (PDMs) for NASA CLARREO Pathfinders Inter-Calibration Applications

Solar radiation scattered by Earth surfaces of various scene types such as oceans, deserts, tree leaves etc and atmospheric molecules and particles is polarized and the amount of polarization depends on the surface composition and particle physical properties. This can be a source of measurement errors in satellite data if a non-polarimetric radiometric sensor is sensitive to the polarization state of light. To obtain highly accurate spectral solar radiation data from the Earth-atmosphere system for the space-borne inter-calibration studies as proposed in NASA's Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission and the CLARREO Pathfinder (CPF) mission, the spectral polarization state of the reflected solar light at the top of atmosphere (TOA) must be known with sufficient accuracy. The degree of polarization (DOP) and the angle of linear polarization (AOLP) of the light at the TOA as functions of incident and viewing geometry and scene type construct the Polarization Distribution Models (PDMs) for correction of polarization-induced error of satellite data. In this work, algorithms for modeling the spectral polarization state of reflected sunlight from various types of Earth, including oceans, deserts, vegetated land surfaces and these scene types with all kinds of clouds, are developed. By comparing the model results with the PARASOL satellite data, our numerical results demonstrate that the model can provide a reliable approach for making the spectral PDMs for wavelengths between 320 and 2300 nm for satellite inter-calibration applications as proposed in the CLARREO and the CLARREO CPF missions

The 1995 NASA High-Speed Research Program Sonic Boom Workshop

The High-Speed Research Program and NASA Langley Research Center sponsored the NASA High-Speed Research Program Sonic Boom Workshop on September 12-13, 1995. The workshop was designed to bring together NASAs scientists and engineers and their counterparts in industry, other Government agencies, and academia working together in the sonic boom element of NASAs High-Speed Research Program. Specific objectives of this workshop were to (1) report the progress and status of research in sonic boom propagation, acceptability, and design; (2) promote and disseminate this technology within the appropriate technical communities; (3) help promote synergy among the scientists working in the Program; and (4) identify technology pacing the development of viable reduced-boom High-Speed Civil Transport concepts. The Workshop included these sessions: Session 1 - Sonic Boom Propagation (Theoretical); Session 2 - Sonic Boom Propagation (Experimental); and Session 3 - Acceptability Studies - Human and Animal