The Comstar D/3 gain degradation experiment

The results of gain degradation measurements using the Comstar D/3 19.04 GHz beacon are reported. This experiment utilized 0.6 and 5 m aperture antennas aligned along the same propagation path to examine propagation effects which are related to the antenna aperture size. Sample data for clear air, scintillation in clear air, and precipitation fading are presented. Distributions of the received signal levels and variances for both antennas are also presented

Micro-abrasion-corrosion interactions of Ni-Cr/WC based coatings : approaches to construction of tribo-corrosion maps for the abrasion-corrosion synergism

The process of micro-abrasion-corrosion has been the subject of much research in recent years due to the fact that the action of micron sized particles, typically less than 10 um in diameter, can cause significant degradation of materials in many diverse environments involving aqueous corrosion. Cermet based coatings are often used to combat micro-abrasion-corrosion, but has been little work carried out to characterize the performance of such coatings exposed to micro-abrasion-corrosion or to provide a basis for coating optimisation. In addition, a basis for defining the various micro-abrasion-corrosion interactions has not been suggested to date. In this study the micro-abrasion-corrosion performance of a Ni-Cr/WC coating was assessed and compared to the performance of the steel substrate. The results were used to identify regimes of micro-abrasion as a function of applied load and pH of the solution. In addition, micro-abrasion-corrosion maps were constructed based on the results, showing the variation between micro-abrasion-corrosion regimes, as a function of applied load and pH of the solution

If I Ruled the World: Putting Hip Hop on the Atlas

“If I Ruled the World: Putting Hip Hop on the Atlas” contends for a third wave of Global Hip Hop Studies that builds on the work of the first two waves, identifies Hip Hop as an African diasporic phenomenon, and aligns with Hip Hop where there are no boundaries between Hip Hop inside and outside of the United States. Joanna Daguirane Da Sylva adds to the cipha with her examination of Didier Awadi. Da Sylva\u27s excellent work reveals the ways in which Hip Hoppa Didier Awadi elevates Pan-Africanism and uses Hip Hop as a tool to decolonize the minds of African peoples. The interview by Tasha Iglesias and myself of members of Generation Hip Hop and the Universal Hip Hop Museum provides a primary source and highlights two Hip Hop organizations with chapters around the world. Mich Yonah Nyawalo’s Negotiating French Muslim Identities through Hip Hop details Hip Hop artists Médine and Diam’s, who are both French and Muslim, and whose self-identification can be understood as political strategies in response to the French Republic’s marginalization of Muslims. In “Configurations of Space and Identity in Hip Hop: Performing ’Global South’,” Igor Johannsen adds to this special issue an examination of the spatiality of the Global South and how Hip Hoppas in the Global South oppose global hegemony. The final essay, “‘I Got the Mics On, My People Speak’: On the Rise of Aboriginal Australian Hip Hop,” by Benjamin Kelly and Rhyan Clapham, provides a thorough analysis of Aboriginal Hip Hop and situates it within postcolonialism. Overall, the collection of these essays points to the multiple identities, political economies, cultures, and scholarly fields and disciplines that Hip Hop interacts with around the world

Standardized Consent Forms for Surgical Procedures: An Intervention to Improve the Resident-led Informed Consent Process

Objectives and Goals: To provide high quality, consistent consent forms for common surgical procedures and improve resident workflow by creating and implementing standardized printed consents for common surgical procedures. These consents will be used by residents consenting patients in the ED or inpatient setting. Consents shall include standardized procedure descriptions, risks and benefits of the procedure, and alternative treatment option descriptions, risks and benefitshttps://jdc.jefferson.edu/patientsafetyposters/1057/thumbnail.jp

Commonly Encountered Problems in the Safety-Focused Design of Capital Projects

PresentationThe design and construction of a new building is often a significant investment for capital projects. As a result, there are typically many competing design considerations, such as: land use, interconnectivity, access for operations personnel, building codes, personnel safety, cost, etc. To minimize the number of costly design iterations, it is vital that overall project goals for the building be firmly established, communicated, and implemented effectively. Unfortunately, many projects suffer from a misstep in one or more of these areas. This paper details lessons learned from common building design complications encountered in the process industries, with a focus on personnel safety. The paper contains examples of common building design issues and suggests methods to avoid them. The paper discusses the safety-focused design requirements that are typically chosen for building projects as well as the potential impacts those requirements have on personnel safety and project cost

Landscapes and Fragilities

The concept of fragility provides a possibility to rank different supercooled liquids on the basis of the temperature dependence of dynamic and/or thermodynamic quantities. We recall here the definitions of kinetic and thermodynamic fragility proposed in the last years and discuss their interrelations. At the same time we analyze some recently introduced models for the statistical properties of the potential energy landscape. Building on the Adam-Gibbs relation, which connects structural relaxation times to configurational entropy, we analyze the relation between statistical properties of the landscape and fragility. We call attention to the fact that the knowledge of number, energy depth and shape of the basins of the potential energy landscape may not be sufficient for predicting fragility. Finally, we discuss two different possibilities for generating strong behavior.Comment: 17 pages, 10 figures; accepted version, minor correction

Meteor ablation spheres from deep-sea sediments

Spheres from mid-Pacific abyssal clays (0 to 500,000 yrs old), formed from particles that completely melted and subsequently recrystallized as they separated from their meteoroid bodies, or containing relict grains of parent meteoroids that did not experience any melting were analyzed. The spheres were readily divided into three groups using their dominant mineralogy. The Fe-rich spheres were produced during ablation of Fe and metal-rich silicate meteoroids. The glassy spheres are considerably more Fe-rich than the silicate spheres. They consist of magnetite and an Fe glass which is relatively low in Si. Bulk compositions and relict grains are useful for determining the parent meteoroid types for the silicate spheres. Bulk analyses of recrystallized spheres show that nonvolatile elemental abundances are similar to chondrite abundances. Analysis of relict grains identified high temperature minerals associated with a fine-grained, low temperature, volatile-rich matrix. The obvious candidates for parent meteoroids of this type of silicate sphere is a carbonaceous chondrite