696 research outputs found
Reconstruction and safety assessment of the Hengelo brinefield phase 1 area
No full textSince 1918 AkzoNobel produces salt by means of solution mining from the bedded Triassic Röt Evaporite deposit in the eastern part of the Netherlands. In this technique water is pumped into the rock salt layer through a well and dissolves the halite in situ. Subsequently the brine is pumped to the purification plant at surface level where the NaCl is extracted from the brine after several impurities have been removed. Near the city of Hengelo, the Hengelo Brine field has been exploited by AkzoNobel since 1933 and based on the technological progress during the years it can be divided into five phases:1. 1933-1958, 53 wells, 42 caverns; 2.1959-1975, 226 wells, 94 caverns; 3.1976-2005, 213 wells, 72 caverns; 4.2006-2013, 37 wells, 36 caverns; 5.2014-present day, 31 wells, 31 caverns. The area corresponding to the first phase comprises 42 caverns which have been developed from 50 production wells. The production wells have been drilled between 1933 and 1958 and during later stages 3 appraisal wells have been drilled.Present-day AkzoNobel pursues stable caverns at the end of their production life. This is achieved by leaving a sufficient thickness of salt in the roof above the cavity. The result is a ductile boundary between the void and the overburden material. The directly overlain anhydrite layer is much stiffer and shows brittle behavior. When this anhydrite layer is not supported by a sufficient amount of rock salt underneath it can potentially collapse. This roof failure occurs when the span of the exposed anhydrite is large enough. The fragments of the collapsed roof layer will deposit on the bottom of the cavern leaving the next roof layer exposed. With each roof layer collapsing the cavern top and bottom attain a new depth. This process is called cavern migration, which continues until the cavern reaches a status where the roof layer is stable either by sufficient support or strength. Most of the 42 caverns of the phase 1 area have migrated and in five cases this led to significant surface subsidence. Currently AkzoNobel prepares abandonment of the last open wells in the phase 1 area. In order to proof long term safety after closure, the caverns have been examined, simulated, reconstructed, and modelled. By analyzing the available data and scrutinizing a few caverns where extensive migration did occur, the cavern migration behavior and its influential parameters were identified. This report clarifies how the caverns have been reconstructed and how the maximum migration potential is determined with the model. The phase 1 area comprises the oldest part of the Hengelo Brine field. The wells were drilled between 1933 and 1958. During this phase some of the wells were positioned close to each other, intentionally allowing interconnections. The motive was to complete these wells as doublets, while the rest were setup as single completion caverns. Despite these intentions, the leaching during this phase was performed in a less restrained manner than what is acceptable today. The majority of the caverns in the phase 1 area have established unintentional connections and were completed as series of caverns. Due to this lack of control overmining occurred at some of the caverns and as a result most of the caverns have migrated upwards through the overburden and some induced significant subsidence at the surface. As the amount of data and especially measurements of these phase 1 caverns is scarce, the caverns needed to be reconstructed to enable a comprehensive analysis. In order to reconstruct the cavern development and final dimensions, the caverns have been simulated based on their historical production and on interpretations of the geology and logbooks. After cross-correlating the dimensions with the available data, the dimensions are used in an analytical model. Considering multiple influential parameters the post-production ‘residual’ volume and dimensions of the caverns are deduced. Thereafter the maximum potential migration is determined using a migration model.Applied Earth Sciences | European Mining Cours
OTOH
No full textContains the essay “Unsettled Feelings". Funded by SSHRC Institutional Explore Grant. Design by Chloe Brumwell & Randy Lee Cutler.Unsettle
Coat Cooke & Joe Poole | Coat Cooke & Rainer Wiens: Reviews
No full textCoat Cooke album reviews by Randy Raine-Reusch. Coat Cooke (sax); Joe Poole (drums); Rainer Wiens (guitar)
Interview with Randy Stoecker, author, Liberating Service Learning and the Rest of Higher Education Civic Engagement
No full textIt’s common for colleges in the U.S. to have service learning programs of one kind or another. These are sometimes criticized as being liberal or even radical endeavors — especially if “social justice” language is employed. But what if these are, in fact, conservative programs at their heart, ones that, in the context of the corporatized university, are furthering the neoliberal project and inhibiting the development of better social welfare policies? Listen to our interview with Randy Stoecker as he discusses his book, Liberating Service Learning and the Rest of Higher Education Civic Engagement (Temple University Press, 2016), for a first-hand critique as well as some thoughts on how we might all better serve our students — and the communities they would engage with
Reflections 1979
No full textThe 1979 issue of Reflections is edited by Randy Waters with Michele Barale and Joyce Compton Brown serving as faculty advisers. Cover art and photography is by Les Brown. Author biographies are included on a contributors page at the conclusion of the issue. Award winners of the student literary context include: Randy Waters, Debbie Drayer, and Susan Sheilds.https://digitalcommons.gardner-webb.edu/reflections/1005/thumbnail.jp
Species suitability guide for Colorado
No full textCompiled by Randy Moench, data from the Colorado State Forest Nursery, Fort Collins, Colorado
Reconsidering Randy Shilts: examining the reportage of America's AIDS chronicler
No full text2013 Fall.Includes bibliographical references.The role of openly-gay reporter and author Randy Shilts (1951-1994) is examined related to his use of journalistic practices and places him on a continuum of traditional reporting roles as considered in the context of twentieth century philosophers Walter Lippmann and John Dewey. Reporter functions demonstrated by Shilts are examined, including those dictated by expectations of either strong journalistic influence over society and media consumers, or those more aligned with democratic practices where education and participation emphasize strong roles for society and media consumers. Using a biographical approach including 17 primary source interviews of former colleagues, critics, sources and family/friends, the examination of Shilts work as both a reporter and noted author is presented as being heavily influenced by his forthcoming attitudes about disclosure of his sexual orientation from the start of his career and his desire to explain or unpack aspects of gay culture, and ultimately the AIDS crisis, to heterosexual audiences. Careful examination of the posthumous critique of Shilts' work - including his construction of Patient Zero - is undertaken. The study concludes that Shilts fully engaged a Lippmann-esque approach embodied in an authoritarian role for journalism that sought to change the world in which it was offered, and did so perhaps most influentially during the earliest days of the HIV/AIDS pandemic in America
Sleep as an Occupation: Perceptions and Assessment Behaviors of Practicing Occupational Therapists
No full textAbstract
Date Presented 3/30/2017
People spend a considerable portion of time engaged in a bioneurological state termed sleep. Sleep loss impacts physiological, cognitive, and mood functioning. This study examined whether occupational therapists view sleep as an occupation and the extent to which they assess sleep precursors and sleep dysfunction.
Primary Author and Speaker: Randy P. McCombie
Additional Authors and Speakers: Ralyn Wolfe</jats:p
Global Survey of the Experience and Education of Aviation Maintenance Instructors
No full textThesis presented in partial fulfillment of the requirement for the Master of Education degree in the College of Education and Human Service Professions, University of Minnesota Duluth, 2011Committee names: Randy Hyman (Chair), Cindy Ryan, Diane J. Rauschenfels. This item has been modified from the original to redact the signatures present.Limited research exists regarding the education, experience, and professional opinions of aviation maintenance instructors. The author surveyed a global sample to identify trends in responses related to regulatory agency, type of business, segment of industry, and kind of training. A web-based instrument collected anonymous data for comparative analyses. The responses of researched categories showed patterns of interest for industry regulators, executives, decision-makers, and educators.University of Minnesota, Duluth. College of Education and Human Service ProfessionsLarson, Douglas A. (2011). Global Survey of the Experience and Education of Aviation Maintenance Instructors. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/187477
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