1,144 research outputs found

    "Stay at Home and Live with Integrity": Advice to German Emigrants to the United States from the Journeymen’s Father

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    In recent decades, American historians have asserted that a broad chasm existed between the rhetoric of equality in Jacksonian America and the actual economic reality that existed. Several years ago, Edward Pessen observed that the so-called Era of the Common Man brought no startling social or economic improvements for the common sort of people. More recently, authors like Alan Dawley, Paul E. Johnson, and Sean Wilentz have argued that not only was there no improvement in the conditions for working men, but the universe of options for skilled journeymen was undergoing a radical contraction, which endangered their integrity as an independent productive class.* Furthermore, eroding economic conditions seem to have led to a decline in the commitment to democratic ideology. Michael Holt posits that economic dislocation of the artisan class as a result of the industrial revolution and increased pressure for jobs created by rising immigration led many Americans to support programs which were designed to reduce immigration, or at least to reduce the political influence of incoming immigrants. This support resulted in the rise of such antidemocratic organizations as the nativist societies which eventually formed the American Know-Nothing party.

    Stay at Home and Live with Integrity : Advice to German Emigrants to the United States from the Journeymen’s Father

    Get PDF
    In recent decades, American historians have asserted that a broad chasm existed between the rhetoric of equality in Jacksonian America and the actual economic reality that existed. Several years ago, Edward Pessen observed that the so-called Era of the Common Man brought no startling social or economic improvements for the common sort of people. More recently, authors like Alan Dawley, Paul E. Johnson, and Sean Wilentz have argued that not only was there no improvement in the conditions for working men, but the universe of options for skilled journeymen was undergoing a radical contraction, which endangered their integrity as an independent productive class.* Furthermore, eroding economic conditions seem to have led to a decline in the commitment to democratic ideology. Michael Holt posits that economic dislocation of the artisan class as a result of the industrial revolution and increased pressure for jobs created by rising immigration led many Americans to support programs which were designed to reduce immigration, or at least to reduce the political influence of incoming immigrants. This support resulted in the rise of such antidemocratic organizations as the nativist societies which eventually formed the American Know-Nothing party.

    Archaeological Testing and Monitoring of a Service Drive at Mission San Juan Capistrano, San Antonio, Texas

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    Archaeological testing for the installation of a new service drive and monitoring the removal of the existing service drive at Mission San Juan Capistrano was conducted in November, 1997 and October, 1999 respectively, by the Center for Archaeological Research (CAR) at The University of Texas at San Antonio (UTSA) for the National Park Service (NPS). The results of the testing and monitoring indicated that no intact Colonial midden deposits were observed, and few Colonial artifacts were recovered within the proposed service drive right-ofway. Three post-Colonial trash deposits were documented within the project area; however, due to the disturbed nature of these deposits which contain stratigraphically mixed nineteenth and twentieth century materials the research potential of such deposits is considered minimal and it is recommended that no further archaeological investigations are required prior to the construction of the service drive. Also included as an Appendix to this report is a brief analysis of an isolated burial discovered during a monitoring project at Mission San Juan in 1999. These remains have since been reinterred by NPS

    Archaeological Survey at Rancho de las Cabras, San Antonio Missions National Historic Park, 41WN30, Wilson County, Texas

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    A two-stage archaeological investigation and preliminary geomorphological assessment was conducted at Rancho de las Cabras, San Antonio Missions National Historical Park, by the Center for Archaeological Research (CAR) of The University of Texas at San Antonio for the National Park Service (NPS). The investigation was prompted by NPS plans to construct a parking lot and visitors\u27 center near the Spanish colonial ruins (41WN30). The geomorphological investigations are preliminary, with more fieldwork needed to test the proposed working model; however, the geomorphological conclusions suggest widespread potential for finding buried prehistoric sites in the alluvial terraces. Four newly identified surface lithic scatter sites were recorded and mapped. Sites 41WN90, 41WN92, and 41WN93 are presently on NPS property and 41WN91 is located on private land. These sites are located in the upland Early to Middle Pleistocene Leona Formation. Due to the paucity of surface and subsurface cultural material, and to previous subsurface disturbance in the form of deep root cutting and plowing, the four sites are considered to have minimal research potential. The three sites on NPS property are currently included in the National Register nomination filed in 1977; however, the systematic collection of surface artifacts conducted during the current investigation, has in effect, mitigated these sites by exhausting their research potential. Site 41WN91, located on private property, is not recommended as eligible for inclusion in the National Register. During the course of the archaeological investigation, two important cultural areas were identified near the Las Cabras ruins. Artifacts recovered near the western edge of the ruins demonstrate their association with the Colonial ranch; this area has been identified as culturally sensitive. West of the ruins, the second area is comprised of an isolated dark soil (over-thickened A-horizon) which may have formed from anthropogenic activities related to the Colonial ranch. Therefore, prior to any future ground disturbing activities, it is recommended that additional testing be conducted in the archaeologically sensitive area, the over-thickened A-horizon, and the alluvial terraces

    Multi-wavelength observations and modelling of a canonical solar flare

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    This paper investigates the temporal evolution of temperature, emission measure, energy loss and velocity in a C-class solar flare from both an observational and theoretical perspective. The properties of the flare were derived by following the systematic cooling of the plasma through the response functions of a number of instruments -- RHESSI (>5 MK), GOES-12 (5-30 MK), TRACE 171 A (1 MK) and SOHO/CDS (~0.03-8 MK). These measurements were studied in combination with simulations from the 0-D EBTEL model. At the flare on-set, upflows of ~90 km s-1 and low level emission were observed in Fe XIX, consistent with pre-flare heating and gentle chromospheric evaporation. During the impulsive phase, upflows of ~80 km s-1 in Fe XIX and simultaneous downflows of 20 km s-1 in He I and O V were observed, indicating explosive chromospheric evaporation. The plasma was subsequently found to reach a peak temperature of ~13 MK in approximately 10 minutes. Using EBTEL, conduction was found to be the dominant loss mechanism during the initial ~300s of the decay phase. It was also found to be responsible for driving gentle chromospheric evaporation during this period. As the temperature fell below ~8 MK, and for the next ~4,000s, radiative losses were determined to dominate over conductive losses. The radiative loss phase was accompanied by significant downflows of <40 km s-1 in O V. This is the first extensive study of the evolution of a canonical solar flare using both spectroscopic and broad-band instruments in conjunction with a hydrodynamic model. While our results are in broad agreement with the standard flare model, the simulations suggest that both conductive and non-thermal beam heating play important roles in heating the flare plasma during the impulsive phase of at least this event.Comment: 10 pages, 7 figures, 2 tables. Accepted for publication in A&

    The flaring and quiescent components of the solar corona

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    The solar corona is a template to understand stellar activity. The Sun is a moderately active star, and its corona differs from active stars: active stellar coronae have a double-peaked EM(T) with the hot peak at 8-20 MK, while the non flaring solar corona has one peak at 1-2 MK. We study the average contribution of flares to the solar EM(T) to investigate indirectly the hypothesis that the hot peak of the EM(T) of active stellar coronae is due to a large number of unresolved solar-like flares, and to infer properties on the flare distribution from nano- to macro-flares. We measure the disk-integrated time-averaged emission measure, EM_F(T), of an unbiased sample of solar flares analyzing uninterrupted GOES/XRS light curves over time intervals of one month. We obtain the EM_Q(T) of quiescent corona for the same time intervals from the Yohkoh/SXT data. To investigate how EM_F(T) and EM_Q(T) vary with the solar cycle, we evaluate them at different phases of the cycle (from Dec. 1991 to Apr. 1998). Irrespective of the solar cycle phase, EM_F(T) appears like a peak of the distribution significantly larger than the values of EM_Q(T) for T~5-10 MK. As a result the time-averaged EM(T) of the whole solar corona is double-peaked, with the hot peak, due to time-averaged flares, located at temperature similar of that of active stars, but less enhanced. The EM_F(T) shape supports the hypothesis that the hot EM(T) peak of active coronae is due to unresolved solar-like flares. If this is the case, quiescent and flare components should follow different scaling laws for increasing stellar activity. In the assumption that the heating of the corona is entirely due to flares, from nano- to macro-flares, then either the flare distribution or the confined plasma response to flares, or both, are bimodal.Comment: 8 pages, 7 postscript figures, accepted for publication in Astronomy and Astrophysic

    Engine Component Retirement-For-Cause: A Nondestructive Evaluation (NDE) and Fracture Mechanics Based Maintainance Concep

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    Historically, cyclic life limited gas turbine engine components have been retired when they reach an analytically determined life where the first fatigue crack per 1000 parts could be expected. By definition, 99.9% of these components are being retired prematurely as they have considerable useful life remaining. Retirement for Cause is a procedure which would allow safe utilization of the full life capacity of each individual component. Since gas turbine engine rotor components are prime candidates and are among the most costly of engine components, adoption of a RFC maintenance philosophy could result in substantial engine systems life cycle cost savings. Two major technical disciplines must be developed and integrated to realize those cost savings: Fracture Mechanics and Nondestructive Evaluation. This paper discusses the methodology, and development activity required, to integrate these disciplines to provide a viable RFC system for use on military gas turbine engines, and illustrates potential benefits of its application

    Homogenization of the Equations Governing the Flow Between a Slider and a Rough Spinning Disk

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    We have analyzed the behavior of the flow between a slider bearing and a hard-drive magnetic disk under two types of surface roughness. For both cases the length scale of the roughness along the surface is small as compared to the scale of the slider, so that a homogenization of the governing equations was performed. For the case of longitudinal roughness, we derived a one-dimensional lubrication-type equation for the leading behavior of the pressure in the direction parallel to the velocity of the disk. The coefficients of the equation are determined by solving linear elliptic equations on a domain bounded by the gap height in the vertical direction and the period of the roughness in the span-wise direction. For the case of transverse roughness the unsteady lubrication equations were reduced, following a multiple scale homogenization analysis, to a steady equation for the leading behavior of the pressure in the gap. The reduced equation involves certain averages of the gap height, but retains the same form of the usual steady, compressible lubrication equations. Numerical calculations were performed for both cases, and the solution for the case of transverse roughness was shown be in excellent agreement with a corresponding numerical calculation of the original unsteady equations

    A new approach for modelling chromospheric evaporation in response to enhanced coronal heating : II. Non-uniform heating

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    This project has received funding from the Science and Technology Facilities Council (UK) through the consolidated grant ST/N000609/1 and the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement No 647214).We proposed that the use of an approximate “jump condition” at the solar transition region permits fast and accurate numerical solutions of the one dimensional hydrodynamic equations when the corona undergoes impulsive heating. In particular, it eliminates the need for the very short timesteps imposed by a highly resolved numerical grid. This paper presents further examples of the applicability of the method for cases of non-uniform heating, in particular, nanoflare trains (uniform in space but non-uniform in time) and spatially localised impulsive heating, including at the loop apex and base of the transition region. In all cases the overall behaviour of the coronal density and temperature shows good agreement with a fully resolved one dimensional model and is significantly better than the equivalent results from a 1D code run without using the jump condition but with the same coarse grid. A detailed assessment of the errors introduced by the jump condition is presented showing that the causes of discrepancy with the fully resolved code are (i) the neglect of the terms corresponding to the rate of change of total energy in the unresolved atmosphere; (ii) mass motions at the base of the transition region and (iii) for some cases with footpoint heating, an over-estimation of the radiative losses in the transition region.PostprintPeer reviewe
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