Repeatability Analysis of 304L Deposition by the LENS® Process

Sandia National Laboratories is currently engaging in an effort to qualify Laser Engineered Net Shaping™ (LENS®) as a repair and modification process for high rigor metal components. As part of that effort, the LENS team has conducted a process repeatability test to help identify variation within the system. This test utilized 304L stainless steel which is a commonly used material at Sandia. Over the course of 12 weeks, 3/8”x3/8”x2” towers were built in sets of 3 with a total of 30 towers completed. A random sampling of 10 of these towers (1 from each set of 3) had been identified before depositing the towers, and these towers were used for tensile testing and metallographic testing. The testing showed the ultimate and yield strengths of all samples to be well above those of annealed 304L. This is expected because of the rapid melt pool solidification present in the LENS process and the resulting grain refinement. The ductility, which usually remains on par with annealed 304L, was found to be lower. The final cause of this loss of ductility was determined to be inter-layer separation due to loose wires in the closed loop melt pool control system.Englis

An engineering study of hybrid adaptation of wind tunnel walls for three-dimensional testing

Solid wall tunnels having only upper and lower walls flexing are described. An algorithm for selecting the wall contours for both 2 and 3 dimensional wall flexure is presented and numerical experiments are used to validate its applicability to the general test case of 3 dimensional lifting aircraft models in rectangular cross section wind tunnels. The method requires an initial approximate representation of the model flow field at a given lift with wallls absent. The numerical methods utilized are derived by use of Green's source solutions obtained using the method of images; first order linearized flow theory is employed with Prandtl-Glauert compressibility transformations. Equations are derived for the flexed shape of a simple constant thickness plate wall under the influence of a finite number of jacks in an axial row along the plate centerline. The Green's source methods are developed to provide estimations of residual flow distortion (interferences) with measured wall pressures and wall flow inclinations as inputs

FLOWERS FROM THE DEVIL: AN AMERICAN OPIATE CRISIS, THE CRIMINALIZATION OF MARIJUANA, AND THE TRIUMPH OF THE PROHIBITION STATE, 1840-1940

This dissertation focuses on historic changes in public perception of narcotic use and abuse from the mid-nineteenth century to the mid-twentieth. From the 1840s to the outbreak of Civil War, politicians, physicians, the general public, and state and federal government remained largely ambivalent on the topic of drug use. Opium, morphine, and cannabis were legal, widely available in American pharmacies, and touted as essential medicines. Within the Bohemian community, artists and writers experimented with the recreational use of cannabis and their accounts of that style of consumption filled the pages of Harper’s, The New Yorker, and a host of other literary-minded publications. By the 1880s, that seemingly permissive environment seemed to suddenly give way to a government increasingly focused on the regulation and prohibition of drugs. This work argues that a late-nineteenth century opiate epidemic radically transformed the country’s relationship with drugs and placed cannabis on a historical trajectory that led to its criminalization in the late-1930s. As newspapers blamed the perceived narcotic crisis that emerged in post-bellum America on the medical community, public opinion turned, to a large extent, against doctors and pharmacists. This erosion in public trust in the practice of medicine— a direct byproduct of an American opiate crisis—instigated a transfer of control over the nation’s approach to drug management. Once entirely the occupation of a relatively decentralized medical community, crucial choices over the dispensation of narcotics and their general management shifted to the arena of popular politics. This dissertation argues that transference of power aided the formation of a prohibition-minded state that rapidly banned smokable opium, non-medicinal opiates, cocaine, alcohol, heroin, and—eventually—marijuana

A Home at the End of the World: Eritrean and Sudanese Asylum Seekers in Tel Aviv, Israel

This paper explores the ways in which national culture intersects with urban environs to produce multinational subjectivity. Specifically, this paper shows the activity of Eritrean and Sudanese asylum seekers in Tel Aviv, Israel, as particularly generative of the life world building of Southern Tel Aviv (known as Little Africa). Juxtaposing these spaces of urban life, this paper also looks at the Holot Detention Facility as a space of life as well, situating the asylum seeker along various, migratory paths towards citizenship. With the near-total recreation of African life, this paper examines the Neve Sha’anan neighborhood as supportive of the LGBT and migrant communities, evidencing the flourishing of national culture outside of traditional boundaries. Particularly, this paper looks at “The Prevention of Infiltration Law” to discuss ideas of “infiltrators” using frameworks from Foucault, Merleau-Ponty, Levinas, Jean-Luc Nancy and Achille Mbembe. Examining ideas of space, place, ethics, embodiment, law, the body, street art, border fences, architecture, and minimalism, this paper juxtaposes BLM (Black Lives Matter) and BDS (Boycott, Divestment, Sanctions) from a transnational perspective of world-building, asking the question of where can one call a place, home

Investigation of transonic region of high dynamic response encountered on an elastic supercritical wing

Unsteady aerodynamic data were measured on an aspect ratio 10.3 elastic supercritical wing while undergoing high dynamic response above a Mach number of 0.90. These tests were conducted in the NASA Langley Transonic Dynamics Tunnel. A previous test of this wing predicted an unusual instability boundary based on subcritical response data. During the present test no instability was found, but an angle of attack dependent narrow Mach number region of high dynamic wing response was observed over a wide range of dynamic pressures. The effect on dynamic wing response of wing angle of attack, static outbound control surface deflection and a lower surface spanwise fence located near the 60 percent local chordline was investigated. The driving mechanism of the dynamic wing response appears to be related to chordwise shock movement in conjunction with flow separation and reattachment on both the upper and lower surfaces

Unsteady pressure and structural response measurements of an elastic supercritical wing

Results are presented which define unsteady flow conditions associated with high dynamic response experienced on a high aspect ratio elastic supercritical wing at transonic test conditions while being tested in the NASA Langley Transonic Dynamics Tunnel. The supercritical wing, designed for a cruise Mach number of 0.80, experienced the high dynamic response in the Mach number range from 0.90 to 0.94 with the maximum response occurring at a Mach number of approximately 0.92. At the maximum wing response condition the forcing function appears to be the oscillatory chordwise movement of strong shocks located on both the wing upper and lower surfaces in conjunction with the flow separating and reattaching in the trailing edge region

Foreign investment in Australia

New research reveals the companies profiting from the $62.5 billion LNG industry exporting Australian gas – a key driver of shock domestic gas prices for households and business – are on average 95.7% foreign owned. The research also reveals that the top 20 ASX listed companies in Australia are, on average, 80% foreign owned, with US ownership alone almost triple Australian ownership. The top 30 companies in Australia by sales value (listed plus unlisted) are 79% foreign owned, including many companies with 100% foreign ownership. The research report comes amid growing calls for a windfall profits tax on gas

Environmental justice in the context of sustainable urban renewal / regeneration: the case for heritage at Constitution Hill

Since the birth of democracy in South Africa, Urban Geography has experienced many paradigmatic and epistemological shifts; within Human Geography 'planning' faces various challenges in the new Millennium. Environmental management, in light of the emphasis on sustainable development, sees many urban planners and politicians strive to reconcile environmentalism with development that is equitable. The emergence of the environmental justice discourse is significant, since inter-generational justice (as enshrined in sustainable development) is a key issue, this research report used heritage as a lens to explore this complex relationship in regard to urban regeneration. Using a case study approach this report shows the nature and context of postmodern urban environmental management. Special reference to the significance and impact of environmental justice on the cityscape of Johannesburg is made, as this report suggests that environmental justice is a useful conceptual framework to give depth and meaning to sustainable development, in urban regeneration as a policy objective. The use of Constitution Hill as a case study placed the project in a post-apartheid South African context

Tourist guides' perceptions of cultural heritage tourism in South Africa

Heritage tourism is a fast growing niche of cultural tourism worldwide. In Africa, several countries, including South Africa, place great emphasis on the growth of heritage tourism because of its potential for local economic development. Cultural and heritage tourism are being advocated as an important niche within the South African economy. This paper explores the perceptions of cultural heritage tourist guides in South Africa towards heritage tourism, it is argued that the country's National Department of Tourism must improve the poor governance and poor management of South African heritage assets, and enhance the preservation, transformation and segmented marketing of South Africa's cultural assets (at all levels of government) in order to sustain and grow cultural tourism in the future