377 research outputs found

    Simulations of HL-LHC Crab Cavity Noise using HEADTAIL

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    The High Luminosity Large Hadron Collider (Hi-Lumi LHC) upgrade -- scheduled to be completed by 2025 -- will improve the existing LHC in many ways. One such upgrade is the addition of Crab Cavities (CCs). The CCs are resonant structures that provide strong transverse kicks to the circulating clouds of particles around each interaction region. As such, the CCs result in a head-on collision of the clouds and a large increase in event rate, leading to reduced statistical uncertainty and potentially faster discoveries. However, the CC field will be modulated by phase and amplitude noise which can have detrimental effects on beam quality. Of utmost concern is the increase in the particle cloud transverse size due to the noise action, which can lead to reduced collision rates or even loss of particles. The relationship between the noise spectrum and the size growth rate has been quantified with a theoretical model. This work presents simulation results using the Python multi-particle tracking package HEADTAIL to validate this model. The evolution of the particle cloud transverse distribution due to the noise is also investigated via HEADTAIL

    Between Mercersburg and Oxford: The Ecclesiology of John Williamson Nevin

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    Abstract This thesis explores the ecclesiology of the American theologian John Williamson Nevin (1803-1886) and its relationship to the wider “church question” of the nineteenth century. It will argue that Nevin’s “high church” theology defended the freedom of the church against both theological and political obstacles. Nevin maintained that the American church must establish an identity separate from modern “Puritanism,” as expressed through revivalism, rationalism and sectarianism. Crucially, Nevin was aided in this struggle by the insights of the Oxford Movement. It is a common misperception that the Oxford Movement never influenced American Protestantism. This thesis will contend that Nevin proves to be an exception to this rule and that his work can only be understood in relation to the theological insights of the Oxford Movement. In this respect Nevin was unique when compared with many nineteenth century American Protestants, and deserves wider recognition for his unique contribution to theology

    A survey of three hundred and fifty-eight seventh and eighth grade pupils in junior high school

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    Thesis (M.A.Ed.)--University of Kansas, Education, 1929

    55 + A Landscape of Intergenerational Living

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    Ontario is experiencing a demographic shift as a significant proportion of its demographic ages. Over the next twenty years it is estimated that the number of seniors aged 65 and above will double. For small urban centres such as Sarnia, a city in Southwestern Ontario, the shift has been increased by the decline in the population of youth. This has led to a change in the city’s urban fabric as multiple schools close and consolidate while proposals of retirement residences across the region begin to proliferate. The closures have left a gap in public infrastructure as places that once facilitated social and community engagement are left vacant and their communal benefit lost. This thesis proposes a plan for the revitalization of a secondary school in the heart of the city that is soon to be vacated. Mixed senior and public units dispersed around a community hub would facilitate social and visual stimulus while offering the potential of intergenerational collaboration and interaction. Age can be subjective; it does not account for the exact mental, physical or emotional state of a human being. Intergenerational mixing in living and community is important to prevent the societal norm of systematically separating generations and benefits all. A typology of living needs to be created to allow for fluid interactions between generations and prevent isolation that can cause quicker degradation of the mind and body. The project creates a landscape in which residents can find agency to view and participate in different aspects of the city’s ecosystem. This is to allow for the embodiment of a life lived, the new possibilities of a societal role and the potential for a rewarding, stimulating and culturally rich relationship between all generations acting within the holarchy

    Solids Accumulation Scouting Studies

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    The objective of Solids Accumulation activities was to perform scaled testing to understand the behavior of remaining solids in a Double Shell Tank (DST), specifically AW-105, at Hanford during multiple fill, mix, and transfer operations. It is important to know if fissionable materials can concentrate when waste is transferred from staging tanks prior to feeding waste treatment plants. Specifically, there is a concern that large, dense particles containing plutonium could accumulate in poorly mixed regions of a blend tank heel for tanks that employ mixing jet pumps. At the request of the DOE Hanford Tank Operations Contractor, Washington River Protection Solutions, the Engineering Development Laboratory of the Savannah River National Laboratory performed a scouting study in a 1/22-scale model of a waste staging tank to investigate this concern and to develop measurement techniques that could be applied in a more extensive study at a larger scale. Simulated waste tank solids: Gibbsite, Zirconia, Sand, and Stainless Steel, with stainless steel particles representing the heavier particles, e.g., plutonium, and supernatant were charged to the test tank and rotating liquid jets were used to mix most of the solids while the simulant was pumped out. Subsequently, the volume and shape of the mounds of residual solids and the spatial concentration profiles for the surrogate for heavier particles were measured. Several techniques were developed and equipment designed to accomplish the measurements needed and they included: 1. Magnetic particle separator to remove simulant stainless steel solids. A device was designed and built to capture these solids, which represent the heavier solids during a waste transfer from a staging tank. 2. Photographic equipment to determine the volume of the solids mounds. The mounds were photographed as they were exposed at different tank waste levels to develop a composite of topographical areas. 3. Laser rangefinders to determine the volume of the solids mounds. The mounds were scanned after tank supernatant was removed. 4. Core sampler to determine the stainless steel solids distribution within the solids mounds. This sampler was designed and built to remove small sections of the mounds to evaluate concentrations of the stainless steel solids at different special locations. 5. Computer driven positioner that placed the laser rangefinders and the core sampler in appropriate locations over solids mounds that accumulated on the bottom of a scaled staging tank where mixing is poor. These devices and techniques were effective to estimate the movement, location, and concentrations of the solids representing heavier particles and could perform well at a larger scale The experiment contained two campaigns with each comprised of ten cycles to fill and empty the scaled staging tank. The tank was filled without mixing, but emptied, while mixing, in seven batches; the first six were of equal volumes of 13.1 gallons each to represent the planned fullscale batches of 145,000 gallons, and the last, partial, batch of 6.9 gallons represented a full-scale partial batch of 76,000 gallons that will leave a 72-inch heel in the staging tank for the next cycle. The sole difference between the two campaigns was the energy to mix the scaled staging tank, i.e., the nozzle velocity and jet rotational speed of the two jet pumps. Campaign 1 used 22.9 ft/s, at 1.54 rpm based on past testing and Campaign 2 used 23.9 ft/s at 1.75 rpm, based on visual observation of minimum velocity that allowed fast settling solids, i.e., sand and stainless steel, to accumulate on the scaled tank bottom

    DEMONSTRATION OF SIMULATED WASTE TRANSFERS FROM TANK AY-102 TO THE HANFORD WASTE TREATMENT FACILITY

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    In support of Hanford's AY-102 Tank waste certification and delivery of the waste to the Waste Treatment and Immobilization Plant (WTP), Savannah River National Laboratory (SRNL) was tasked by the Washington River Protection Solutions (WRPS) to evaluate the effectiveness of mixing and transferring the waste in the Double Shell Tank (DST) to the WTP Receipt Tank. This work is a follow-on to the previous 'Demonstration of Internal Structures Impacts on Double Shell Tank Mixing Effectiveness' task conducted at SRNL 1. The objective of these transfers was to qualitatively demonstrate how well waste can be transferred out of a mixed DST tank and to provide insights into the consistency between the batches being transferred. Twelve (12) different transfer demonstrations were performed, varying one parameter at a time, in the Batch Transfer Demonstration System. The work focused on visual comparisons of the results from transferring six batches of slurry from a 1/22nd scale (geometric by diameter) Mixing Demonstration Tank (MDT) to six Receipt Tanks, where the consistency of solids in each batch could be compared. The simulant used in this demonstration was composed of simulated Hanford Tank AZ-101 supernate, gibbsite particles, and silicon carbide particles, the same simulant/solid particles used in the previous mixing demonstration. Changing a test parameter may have had a small impact on total solids transferred from the MDT on a given test, but the data indicates that there is essentially no impact on the consistency of solids transferred batch to batch. Of the multiple parameters varied during testing, it was found that changing the nozzle velocity of the Mixer Jet Pumps (MJPs) had the biggest impact on the amount of solids transferred. When the MJPs were operating at 8.0 gpm (22.4 ft/s nozzle velocity, U{sub o}D=0.504 ft{sup 2}/s), the solid particles were more effectively suspended, thus producing a higher volume of solids transferred. When the MJP flow rate was reduced to 5 gpm (14 ft/s nozzle velocity, U{sub o}D = 0.315 ft{sup 2}/s) to each pump, dead zones formed in the tank, resulting in fewer solids being transferred in each batch to the Receipt Tanks. The larger, denser particles were displaced (preferentially to the smaller particles) to one of the two dead zones and not re-suspended for the duration of the test. As the liquid level dropped in the MDT, re-suspending the particles became less effective (6th batch). The poor consistency of the solids transferred in the 6th batch was due to low liquid level in the MDT, thus poor mixing by the MJPs. Of the twelve tests conducted the best transfer of solids occurred during Test 6 and 8 where the MJP rotation was reduced to 1.0 rpm

    Aggressive Angiomyxoma: an Unusual Presentation

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    Aggressive angiomyxoma is an uncommon mesenchymal myxoid tumor that is characterized by slow growth and frequent local recurrence. It is currently regarded as a nonmetastasizing tumor. We describe a case of recurrent aggressive angiomyxoma with invasion into the veins including the inferior vena cava and the right atrium and with pulmonary metastases. Our case, together with those unusual cases documented in previous reports, may lead to a reappraisal of the nature of aggressive angiomyxoma
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