Rectenna system design

The function of the rectenna in the solar power satellite system is described and the basic design choices based on the desired microwave field concentration and ground clearance requirements are given. One important area of concern, from the EMI point of view, harmonic reradiation and scattering from the rectenna is also designed. An optimization of a rectenna system design to minimize costs was performed. The rectenna cost breakdown for a 56 w installation is given as an example

Applications of a Venus thermospheric circulation model

A variety of Pioneer Venus observations suggest a global scale, day-to-night Venus thermospheric circulation. Model studies of the dynamics and energetics of the Venus thermosphere are presented in order to address new driving, mixing and cooling mechanisms for an improved model simulation. The adopted approach was to reexamine the circulation by first using a previous two dimensional code to quantify those physical processes which can be inferred from the Pioneer Venus observations. Specifically, the model was used to perform sensitivity studies to determine the degree to which eddy cooling, eddy or wave drag, eddy diffusion and 15 micrometer radiational cooling are necessary to bring the model temperature and composition fields into agreement with observations. Three EUV heating cases were isolated for study. Global temperature and composition fields in good agreement with Pioneer data were obtained. Large scale horizontal winds 220 m/s were found to be consistent with the observed cold nightside temperatures and dayside bulges of O, CO and CO2. Observed dayside temperatures were obtained by using a 7 to 19% EUV heating efficiency profile. The enhanced 15 micrometer cooling needed for thermal balance is obtained using the best rate coefficient available for atomic O collisional excitation of CO2(0,1,0). Eddy conduction was not found to be a viable cooling mechanism due to the weakened global circulation. The strong 15 micrometer damping and low EUV efficiency imply a very weak dependence of the general circulation to solar cycle variability. The NCAR terrestrial thermospheric general circulation model was adapted for Venus inputs using the above two dimensional model parameters, to give a three dimensional benchmark for future Venus modelling work

Synchrotron emission from molecular clouds

Observations of the properties of dense molecular clouds are critical in understanding the process of star-formation. One of the most important, but least understood, is the role of the magnetic fields. We discuss the possibility of using high-resolution, high-sensitivity radio observations to measure the in-situ synchrotron radiation from these molecular clouds. If the cosmic-ray (CR) particles penetrate clouds as expected, then we can measure the B-field strength directly using radio data. So far, this signature has never been detected from the collapsing clouds themselves and would be a unique probe of the magnetic field. Dense cores are typically ∼ 0.05 pc in size, corresponding to ∼arcsec at ∼kpc distances, and flux density estimates are ∼ mJy at 1 GHz. They should be detectable, for example with the Square Kilometre Array

Inhibition of RNA polymerase II transcription in human cells by synthetic DNA-binding ligands

Sequence-specific DNA-binding small molecules that can permeate human cells potentially could regulate transcription of specific genes. Multiple cellular DNA-binding transcription factors are required by HIV type 1 for RNA synthesis. Two pyrrole-imidazole polyamides were designed to bind DNA sequences immediately adjacent to binding sites for the transcription factors Ets-l, lymphoid-enhancer binding factor 1, and TATA-box binding protein. These synthetic ligands specifically inhibit DNA-binding of each transcription factor and HIV type 1 transcription in cell-free assays. When used in combination, the polyamides inhibit virus replication by >99% in isolated human peripheral blood lymphocytes, with no detectable cell toxicity, The ability of small molecules to target predetermined DNA sequences located within RNA polymerase II promoters suggests a general approach for regulation of gene expression, as well as a mechanism for the inhibition of viral replication

Synchrotron radiation from molecular clouds

Observations of the properties of dense molecular clouds are critical in understanding the process of star-formation. One of the most important, but least understood, is the role of the magnetic fields. We discuss the possibility of using high-resolution, high-sensitivity radio observations to measure the in-situ synchrotron radiation from these molecular clouds. If the cosmic-ray particles penetrate clouds as expected, then we can measure the B-field strength directly using radio data. So far, this signature has never been detected from the collapsing clouds themselves and would be a unique probe of the magnetic field. Dense cores are typically ~0.05 pc in size, corresponding to ~arcsec at ~kpc distances, and flux density estimates are ~mJy at 1 GHz. They should be detectable, for example with the Square Kilometre Array.Comment: Proceedings of Conference "Cosmic Rays and their InterStellar Medium Environment", (CRISM-2014), June 24-27, 2014, Montpellier, France. PoS(CRISM2014)03

Plasma Electron Beam Welder for Space Vehicles Final Report

Feasibility of developing plasma electron beam welding system for earth orbiting vehicl

Gender Diversity Cultural Responsiveness Education in Speech-Language Pathology Graduate Programs: A Pilot Survey

Purpose: Gender-affirming voice therapy aims to align a person’s voice and communication with their gender identity. Historically, transgender and gender-nonconforming (TGNC) individuals have been marginalized and continue to face significant healthcare disparities. The goal of this research was to examine the self-perceived preparedness of recent speech-language pathology (SLP) graduates for working with TGNC clients. A survey was developed to include both multiple choice and open-ended questions. Topics included graduate-level training on working with TGNC individuals, perceived preparedness to work with this client population, educational resources sought by respondents, and suggested improvements for SLP graduate programs. Thirty recent (since 2016) SLP graduates completed the survey anonymously. Although a majority (83%) of respondents reported that working with TGNC clients was addressed in their graduate education, 66% of respondents felt that instruction time spent on this topic was insufficient or slightly insufficient. Those who had clinical experiences with TGNC clients, or who learned from the perspectives of the TGNC community (e.g., from a guest speaker or video), reported that their graduate education better prepared them to work with TGNC clients. One of the most common recommendations to improve graduate education was to invite TGNC speakers to share their experiences. The majority of respondents identified a need for improvement of gender diversity education in SLP graduate programs. Further research is needed to determine the efficacy of different curricula in increasing the knowledge and skills of SLP graduates specific to TGNC clients to ensure clinical competency and equitable care

Detachment force of particles with pinning of contact line from fluid bubbles/droplets

Deformation of a spherical droplet or bubble, containing a pair of particles on its surface is considered when equal but opposite forces are applied to the particles. The particles are placed opposite each other thus providing a symmetrical problem which is more amenable to analytical treatment. We extend our previous calculations, concerning such arrangements with constant contact angles, to situations where now it is the contact line that is pinned on the surface of the particles. The force-displacement curves are calculated as the particles are pulled apart and was found to be linear for small displacements. However, it is also found that the "Hookean constant" for the pinned contact line problem is different to one derived for systems with a constant contact angle, being larger if the pinned line is at the equator of the particles

Dispersity-Driven Melting Transition in Two Dimensional Solids

We perform extensive simulations of $10^4$ Lennard-Jones particles to study the effect of particle size dispersity on the thermodynamic stability of two-dimensional solids. We find a novel phase diagram in the dispersity-density parameter space. We observe that for large values of the density there is a threshold value of the size dispersity above which the solid melts to a liquid along a line of first order phase transitions. For smaller values of density, our results are consistent with the presence of an intermediate hexatic phase. Further, these findings support the possibility of a multicritical point in the dispersity-density parameter space.Comment: In revtex format, 4 pages, 6 postscript figures. Submitted to PR