Researching Environmental Justice: A Conversation

The U.S. Environmental Protection Agency defines environmental justice as “the fair treatment and meaningful involvement of all people regardless of race, color, national origin, or income with respect to the development, implementation, and enforcement of environmental laws, regulations, and policies.” The concerns that arise in this complex environmental context extend beyond the scope of traditional legal research resources to include historical, social, scientific, and governmental documents that reside in unique archival collections. Through the conversation that follows, senior archivist William LeFevre of the Walter P. Reuther Library shares his experience and insights on how archival resources can provide essential support for legal researchers seeking to discover the foundations, background, and motivation underlying environmental justice concerns

Generalized Sagnac Effect

Experiments were conducted to study light propagation in a light waveguide loop consisting of linearly and circularly moving segments. We found that any segment of the loop contributes to the total phase difference between two counterpropagating light beams in the loop. The contribution is proportional to a product of the moving velocity v and the projection of the segment length Deltal on the moving direction, Deltaphi=4pivDeltal/clambda. It is independent of the type of motion and the refractive index of waveguides. The finding includes the Sagnac effect of rotation as a special case and suggests a new fiber optic sensor for measuring linear motion with nanoscale sensitivity.Comment: 3 pages (including 3 figures

2-Dust : a Dust Radiative Transfer Code for an Axisymmetric System

We have developed a general purpose dust radiative transfer code for an axisymmetric system, 2-Dust, motivated by the recent increasing availability of high-resolution images of circumstellar dust shells at various wavelengths. This code solves the equation of radiative transfer following the principle of long characteristic in a 2-D polar grid while considering a 3-D radiation field at each grid point. A solution is sought through an iterative scheme in which self-consistency of the solution is achieved by requiring a global luminosity constancy throughout the shell. The dust opacities are calculated through Mie theory from the given size distribution and optical properties of the dust grains. The main focus of the code is to obtain insights on (1) the global energetics of dust grains in the shell (2) the 2-D projected morphologies that are strongly dependent on the mixed effects of the axisymmetric dust distribution and inclination angle of the shell. Here, test models are presented with discussion of the results. The code can be supplied with a user-defined density distribution function, and thus, is applicable to a variety of dusty astronomical objects possessing the axisymmetric geometry.Comment: To be published in ApJ, April 2003 issue; 13 pages, 4 tables, 17 figures, 5-page appendix (no figures for the main text included in this preprint). For the complete preprint and code distribution, contact the author

Scanning Transmission Ion Microscopy as it Complements Particle Induced X-Ray Emission Microanalysis

The early uses of Scanning Transmission Ion Microscopy (STIM) with MeV ions are reviewed. The transformation of STIM energy-loss images into maps of areal density is discussed, and is illustrated with images of a fruit fly head (Drosophila melanogaster). Freeze-dried male heads are transparent to 4-MeV protons in the dorsal and frontal directions, but in the sagittal direction the brain is opaque. STIM with molecular ions is shown to be useful for increasing contrast in low density areas. For recording registered STIM and PIXE images without changing accelerator parameters, apertures are used to accomplish the required change in beam intensity (a factor of 105). Molecular ions are used to assess contamination of the microbeam by scattered ions. Pixel by pixel ratios of x-ray intensity to areal density are taken to obtain maps of element concentrations. Calcium and iron maps are shown. Inner parts of the fly head are clearly seen in the concentration maps. The PIXE exposure caused differential displacements of inner parts of the head by 15 μm or less. Weight loss during the PIXE exposure was measured to be 3%

Modelling up to 45 GHz of coupling between microvias and PCB cavities considering several boundary conditions

International audienceModeling up to 45 GHz of coupling between microvias and PCB cavities considering several boundary conditions thierry le gouguec 1 , najib mahdi 1 , ste ' phane cadiou 1 , ce ' dric quendo 1 , erich schlaffer 2 , walter pessl 2 and alain lefevre 3 The recent developments in electronic cards such as the network equipment are characterized by the miniaturization of the board size and the increasing complexity of the layout. Because of these requirements, multi-layered printed circuit boards are commonly used and vias connecting signal lines on different layers, or integrated circuit devices to power and ground planes, are frequently used and often essential. However, a via is not an ideal transmission line. Besides, it creates discontinuities at high frequencies leading to high insertion loss degradation of signal which limits the performances of integrated circuit and systems. In this paper, the impacts of coupling between via and parallel-plates cavity on the response of microwave integrated devices are highlighted in the first part. Then, to describe the intrinsic interaction between the via transition and parallel-plate modes, the notion of parallel-plates matrix impedances is presented and new boundary conditions like open or plated through holes shielded boundaries of the cavities are introduced. Then, using this physics-based model, an intuitive equivalent circuit has been developed. Finally, the proposed approach and the equivalent circuits were validated by using comparisons with electromagnetic simulations and measurements in different scenarios. Three-dimensional (3D) multi-layer technologies such as low temperature co-fired ceramics (LTCC) [1] or high-density multi-layers printed circuit board (HD-PCB) [2] are currently being strongly developed because they offer considerable size reduction as well as the embedded function possibilities. For microwave applications such as filters, couplers, diplexers, etc. [3, 4], these 3D structures offer new design possibilities for frequencies up to 100 GHz. HD-PCB structures consist of several metal layers separated by dielectric substrates. The vias and microvias used in multilayer PCBs allow connecting lines of different metallic levels together or connecting devices to the power and ground plane [5]. The different metal planes can also be connected together with metallic plated through holes (PTHs). With the rise of working frequencies, the stacked multilayer PCB structures are subjected to electromagnetic phenomena like standing waves in cavities or like coupling and interaction between neighboring components. As example of HD-PCB technology, the AT&S TM (PCB manufacturer) technology used during MIDIMU-HD project funded by the Euripides council is presented in Fig. 1. This HD multilayer consists of eight metallic layers (30 mm thickness) separated by Megtron6 (Panasonic TM) sub-strate of 95 mm thickness (depending on the metal densities of each level) and with a relative permittivity 1 r ¼ 3.3 and loss tangent tan(d) ¼ 0.0065 at 40 GHz. A single microvia hole consists of a central cylinder with a diameter of 140 mm, a conductor pad with a diameter of 240 mm, and when this via passes through a metallic plane it will also have a clearance hole called anti-pad of diameter of 350 mm. AT&S is able to stack more than three microvias and to realize buried via with diameter of 200 mm. The PTHs connecting the metal level M1 to the metal level M8 are 200 mm of diameter. Obviously, these multilayer structures which involve parallel planes, dielectric layers, pads, and anti-pads are not ideal transmission components at high frequencies. The electrical behavior of a microvia can be modeled by serial inductance and resistance like is done for a metallic wire [6, 7]. The vias and microvias may cause mismatch [7], crosstalk, reflections, some additional signal delays, and consequently the degradation of signal performance. On the other hand, the coupling between vias, microvias, and parallel plates also plays an important role in the electrical performances of the via transition [8, 9]. The excitation of the parallel plate modes results in conversion of energy between propagation on line and propagation on guided plated structures which imply some transmission zeros

Preliminary Analysis of Male and Female Size Differences of the Achilles Tendon in Active Aging Adults

Achilles tendinopathy impacts athletes of all ages. The Achilles tendon plays a key role in most athletic movements and is vital in the gait cycle. The prevalence of Achilles tendinopathy is associated with increasing age, which causes problems with gait and decreases quality of life. PURPOSE: We investigated factors associated with differences in Achilles size — cross sectional area (CSA) and thickness — in active maturing adults. METHODS: Participants were chosen from volunteers competing in the Huntsman World Senior Games in St. George, UT, October 2021. Participants rested prone on a treatment table with the ankle in a neutral position. A strap connected to the end of the table was placed around each foot to create a 90-degree angle at the ankle. Ultrasound (US) transmission gel was applied to the head of the probe to collect transverse and longitudinal images using a ML 6-15 Probe. The midportion of the Achilles tendon CSA was measured at the intersection of a line between the medial and lateral malleoli. The probe was then rotated 90 at this point to capture thickness measurements. Random selection of 20 males (age=68.050, weight=181.780 lbs., height=67.925 in., body fat=13.875%) and 20 females (age=63.391, weight=147.409 lbs., height=65.543 in., body fat=33.500%) were chosen from a larger data set and analyzed by a single researcher in this preliminary study. RESULTS: There was a significant difference between the CSA of males and females (p=0.046), with an average of 0.747 cm2 and 0.565 cm2 respectively. Achilles thickness also had a significant difference when comparing males and females (p=0.029), with an average of 0.601 cm and 0.491 cm respectively. Weight, body fat, and age were significant independent variables for both CSA and thickness. There was not a significant relationship between left and right Achilles tendons (p0.23). Large effect sizes (1.07 and 0.97) were found for CSA and thickness between groups indicative of a meaningful clinical difference. CONCLUSION: Males and females have a quantifiable size difference of the midportion of the Achilles tendon in an active older adult population. These values are important for interpreting images within this population and may also be important in determining pathologic tendons

Assessing the Impact of the Concrete Canoe and Steel Bridge Competitions on Civil Engineering Technology Students

The new accreditation criteria (TC2K) of the Technology Accreditation Commission of ABET require an assessment of Program Intended Learning Outcomes. Some of the learning outcomes required by the “a” through “k” and the Civil criteria of TC2K include leadership skills, teamwork skills, project management skills, communication skills, and design and construction skills. The American Society of Civil Engineers (ASCE) and the American Institute for Steel Construction (AISC) sponsors regional and national concrete canoe and steel bridge competitions on an annual basis. The Civil Engineering Technology (CET) students at the Rochester Institute of Technology (RIT) have participated in these competitions for the past nine years. These competitions give students a chance to apply what they have learned in the classroom. To assess the impact of the concrete canoe and steel bridge competitions on student learning and development, the authors carried out a survey of current students and graduates of the CET program at RIT who have been members of the concrete canoe and steel bridge teams. The issues addressed in our survey include the following: impact of these activities on leadership skills, communication skills, teamwork skills, design and construction skills, project management skills, confidence levels, students’ enthusiasm for the profession, and a positive image and exposure for students and CET programs. In this paper, we discuss the results of this survey and some of the challenges to student participation in these non-credit activities at RIT, and present some suggestions for enhancing the level of student participation