Simulations of HL-LHC Crab Cavity Noise using HEADTAIL

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

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

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

Methane and methanol oxidation in supercritical water: Chemical kinetics and hydrothermal flame studies

Supercritical water oxidation (SCWO) is an emerging technology for the treatment of wastes in the presence of a large concentration of water at conditions above water`s thermodynamic critical point. A high-pressure, optically accessible reaction cell was constructed to investigate the oxidation of methane and methanol in this environment. Experiments were conducted to examine both flame and non-flame oxidation regimes. Optical access enabled the use of normal and shadowgraphy video systems for visualization, and Raman spectroscopy for in situ measurement of species concentrations. Flame experiments were performed by steadily injecting pure oxygen into supercritical mixtures of water and methane or methanol at 270 bar and at temperatures from 390 to 510{degrees}C. The experiments mapped conditions leading to the spontaneous ignition of diffusion flames in supercritical water. Above 470{degrees}C, flames spontaneously ignite in mixtures containing only 6 mole% methane or methanol. This data is relevant to the design and operation of commercial SCWO processes that may be susceptible to inadvertent flame formation. Non-flame oxidation kinetics experiments measured rates of methane oxidation in supercritical water at 270 bar and at temperatures from 390 to 442{degrees}C. The initial methane concentration was nominally 0.15 gmol/L, a level representative of commercial SCWO processes. The observed methane concentration histories were fit to a one-step reaction rate expression indicating a reaction order close to two for methane and zero for oxygen. Experiments were also conducted with varying water concentrations (0 to 8 gmol/L) while temperature and initial reactant concentrations were held constant. The rate of methane oxidation rises steadily with water concentration up to about 5 gmol/L and then abruptly falls off at higher concentrations

55 + A Landscape of Intergenerational Living

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

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

PHASE I SINGLE CELL ELECTROLYZER TEST RESULTS

This document reports the results of Phase I Single Cell testing of an SO{sub 2}-Depolarized Water Electrolyzer. Testing was performed primarily during the first quarter of FY 2008 at the Savannah River National Laboratory (SRNL) using an electrolyzer cell designed and built at SRNL. Other facility hardware were also designed and built at SRNL. This test further advances this technology for which work began at SRNL in 2005. This research is valuable in achieving the ultimate goal of an economical hydrogen production process based on the Hybrid Sulfur (HyS) Cycle. The focus of this work was to conduct single cell electrolyzer tests to further develop the technology of SO{sub 2}-depolarized electrolysis as part of the HyS Cycle. The HyS Cycle is a hybrid thermochemical cycle that may be used in conjunction with advanced nuclear reactors or centralized solar receivers to produce hydrogen by water-splitting. Like all other sulfur-based cycles, HyS utilizes the high temperature thermal decomposition of sulfuric acid to produce oxygen and regenerate sulfur dioxide. The unique aspect of HyS is the generation of hydrogen in a water electrolyzer that is operated under conditions where dissolved sulfur dioxide depolarizes the anodic reaction, resulting in substantial voltage reduction. Low cell voltage is essential for both thermodynamic efficiency and hydrogen cost. Sulfur dioxide is oxidized at the anode, producing sulfuric acid that is sent to the high temperature acid decomposition portion of the cycle. The electrolyzer cell uses the membrane electrode assembly (MEA) concept. The anode and cathode are formed by spraying platinum containing catalyst on both sides of a Proton Exchange Membrane (PEM). In most testing the material of the PEM was NafionR. The electrolyzer cell active area can be as large as 54.8 cm{sup 2}. Feed to the anode of the electrolyzer is a sulfuric acid solution containing sulfur dioxide. The partial pressure of sulfur dioxide could be varied in the range of 1 to 6 atm (15 to 90 psia). Temperatures could be controlled in the range from ambient to 80 C. Hydrogen generated at the cathode of the cell was collected for the purpose of flow measurement and composition analysis. The test facility proved to be easy to operate, versatile, and reliable

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

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

Design and Experimental Test Plan for Hybrid Sulfur Single Cell Pressurized Electrolyzer

The Hybrid Sulfur (HyS) process is one of the leading thermochemical cycles being studied as part of the DOE Nuclear Hydrogen Initiative (NHI). SRNL is conducting analyses and research and development for the Department of Energy on the HyS process. A conceptual design report and development plan for the HyS process was issued on April 1, 2005 [Buckner, et. al., 2005] , and a report on atmospheric testing of a sulfur dioxide depolarized electrolyzer (SDE), a major component of the HyS process, was issued on August 1, 2005 [Steimke, 2005]. The purpose of this report is to document work related to the design and experimental test plan for a pressurized SDE. Pressurized operation of the SDE is a key requirement for development of an efficient and cost-effective HyS process. The HyS process, a hybrid thermochemical cycle proposed and investigated in the 1970s and early 1980s by Westinghouse Electric Corporation, is a high priority candidate for NHI due to the potential for high efficiency and its relatively high level of technical maturity. It was demonstrated in laboratory experiments by Westinghouse in 1978. Process improvements and component advancements that build on that work are being pursued. One of the objectives of the current work is to develop the SDE in order to permit the demonstration of a closed-loop laboratory model of the HyS process. The heart of the HyS process for generating hydrogen is a bank of electrolyzers incorporating sulfur dioxide depolarized anodes. SRNL planned, designed, built and operated a facility for testing single cell electrolyzers at ambient temperature and near atmospheric pressure during the spring and summer of 2005. The major contribution of the SRNL work was the establishment of the proof-of-concept for utilizing the proton-exchange-membrane (PEM) cell design for the SDE operation. Since PEM cells are being extensively developed for automotive fuel cell use, they offer significant potential for cost-effective application for the HyS Process. This report discusses the modifications necessary to the existing SRNL sulfur dioxide depolarized electrolyzer test facility to allow testing at up to 80 C and 90 psig. Because of the need for significant additional equipment and the ability to infer performance results to higher pressures, it recommends delaying further modifications to support testing at up to 300 psig (the commercial goal) until other, higher priority technical issues are addressed. These issues include membrane material selection, component designs, catalyst type and loading, etc. The factors and rationale that should be considered in developing and executing a detailed test matrix for pressurized operation are also discussed. In addition, an electrolyzer assembly design has been developed to allow the testing of different Membrane Electrode Assemblies (MEA's) as part of the planned FY06 HyS Development Program to complete selection of component design specifications for the HyS electrolyzer. MEA's are used in PEM cells to allow intimate contact and minimal resistance between the electrodes and the electrolyte layer. The pressurized electrolyzer assembly presented in this report will facilitate rapid change-out and testing of various MEA designs as part of the electrolyzer development effort