196,136 research outputs found
Undersjøiske skred i Balsfjorden, Nord-Norge: egenskaper og sammensetning
No full textBatymetridata, høyoppløselige seismisk data samt en sedimentkjerne fra indre Balsfjorden, Troms, nord-Norge, har blitt analysert for å undersøke sedimentasjonsprosesser i løpet av Holocen, med spesiell fokus på undersjøiske rasavsetninger.
Hovedvekt av denne oppgaven ligger på analyse av den 8,67 m lange sedimentkjernen JM11-001-PC. Dette inkluderte beskrivelse av sedimentoverflate og røntgen bilder, måling av fysiske egenskaper (våt-bulk tetthet, P-bølge hastighet, magnetisk susceptibilitet), kjemiske sammensetning (røntgenfluorescensskanning) og kornfordeling.
Basert på resultater av utført multi-proksi analyse, har sedimenter i kjernen blitt inndelt i 5 litologiske enheter og 6 sub-enheter. Disse representerer marin avsetninger og suspensjonutfelling, avbrutt av turbiditter. Tydelige endringer i røntgenfluorescens (XRF) data, det vil si skarpe økninger i Ti/Rb, K/Rb, Si/Al, Fe/Rb og Ca/Fe skiller turbidittavsetninger fra andre sedimenter.
Resultater ble sammenlignet med tidligere seismostratigrafiske studier (Hansen, 1998) og analyser av sedimentkjerner (Forwick, 2001; Forwick & Vorren, 2002). Sistnevnte studie inneholdte blant annet analyser av kjerne JM98-1014-PC, som ble tatt i umiddelbar nærhet av kjerne JM11-001-PC. Denne kjernen inneholdt tre forholdvis store rasavsetninger (debrisstrøm, turbiditter) av tidlig Holocen alder (ca. 9400 – 8825 14 C år før nåtid)
Retarded deglaciation of north-Spitsbergen fjords during the last glacial – an example of bathymetric controls on the dynamics of retreating glaciers
No full textNorth and west Spitsbergen fjords acted as pathways for fast-flowing ice streams during the last glacial (e.g. Ottesen et al., 2005). The deglaciation of west Spitsbergen fjords occurred stepwise and the ice retreat terminated around 11,200 cal. years BP (calendar years before the present; e.g. Forwick & Vorren, 2009, 2011, and references therein; Baeten et al., 2010). However, the deglaciation dynamics and chronology of north Spitsbergen fjords still remain poorly understood.
We present swath-bathymetry, high-resolution seismic data and two sediment cores from the approx. 110 km long, N-S oriented Wijdefjorden-Austfjorden fjord system, the largest fjord system on northern Spitsbergen. The data indicate that – as in the fjords on west Spitsbergen – multiple halts and/or readvances interrupted the retreat of the ice front during the final phase of the last glacial. However, even though the study area and several west Spitsbergen fjords are fed by the same glacier source (the ice field Lomonosovfonna), the final deglaciation of Wijdefjorden-Austfjorden took place after 9300 cal. years BP, i.e. at least approx. 2000 years later than in the west. We assume that the retarded deglaciation in the north is mainly related to the fjord bathymetry, i.e. a more than 35 km wide and up to 60 m high area in the central parts of the study area (approx. 45 km beyond the present fjord head) that acted as pinning point for the grounded glacier. Multiple, relatively large and partly stacked moraine ridges and sediment wedges are suggested to reflected that the ice front retreated slowly across this shallow area and that repeated readvances interrupted this retreat. The absence of larger sediment wedges in the deeper parts between the shallow area and the fjord head may indicate that the final retreat occurred relatively rapid.
References:
Baeten, N.J., Forwick, M., Vogt, C. & Vorren, T.O., 2010. Late Weichselian and Holocene sedimentary environments and glacial activity in Billefjorden, Svalbard. In: Howe, J.A., Austin, W.E.N, Forwick, M. & Paetzel, M. (eds.): Fjord Systems and Archives. Geological Society, London, Special Publication, 344, 207-223.
Forwick, M. & Vorren, T.O., 2009. Late Weichselian and Holocene sedimentary environments and ice rafting in Isfjorden, Spitsbergen. Palaeogeography, Palaeoclimatology, Palaeoecology 280, 258-274.
Forwick, M. & Vorren, T.O., 2011. Stratigraphy and deglaciation of the Isfjorden area, Spitsbergen. Norwegian Journal of Geology 90, 163-179.
Ottesen, D., Dowdeswell, J.A., Rise, L., 2005. Submarine landforms and the reconstruction of fast-flowing ice streams within a large Quaternary ice sheet: The 2500-km-long Norwegian-Svalbard margin (57°-80°N). Geological Society of America Bulletin 117, 1033-1050
Dr. Duane M. Jackson, Morehouse College, July 2011
No full textThis video is a conversation with Dr. Duane M. Jackson. Dr. Jackson talks about his paper, "Recall and the Serial Position Effect: The Role of Primacy and Recency on Accounting Students' Performance." Jackie Daniel, AUC Woodruff Library, is the interviewer
"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States" By M. Carey.
No full text"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States: containing bried sketches of the moral and political character of those states.
By M. Carey, member of the American philosophical, and of the American Antiquarian Society, and author of The Olive Branch, Cindiciae Hibernicae, essays on banking, on political economy, and on internal improvement.
To which are now added the English editor's comments on the subject; together with Important Advice to Emigrants, and Cautions Against Impositions Practiced in the Outports
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Dr. Glendon Swarthout
No full textHosted by Roger M. Busfield, MSU Assistant Professor of Speech and Theater, Meet the Author is designed to introduce a general audience to a contemporary author and their work through in-depth interviews. This episode features a conversation between Dr. Glendon Swarthout, prolific author and English professor at MSU, and assistant professors Sam S. Baskett and Theodore B. Strandness
Simulation of thermal plant optimization and hydraulic aspects of thermal distribution loops for large campuses
No full textFollowing an introduction, the author describes Texas A&M University and its utilities system. After that, the author presents how to construct simulation models for chilled water and heating hot water distribution systems. The simulation model was used in a $2.3 million Ross Street chilled water pipe replacement project at Texas A&M University. A second project conducted at the University of Texas at San Antonio was used as an example to demonstrate how to identify and design an optimal distribution system by using a simulation model. The author found that the minor losses of these closed loop thermal distribution systems are significantly higher than potable water distribution systems. In the second part of the report, the author presents the latest development of software called the Plant Optimization Program, which can simulate cogeneration plant operation, estimate its operation cost and provide optimized operation suggestions. The author also developed detailed simulation models for a gas turbine and heat recovery steam generator and identified significant potential savings. Finally, the author also used a steam turbine as an example to present a multi-regression method on constructing simulation models by using basic statistics and optimization algorithms. This report presents a survey of the author??s working experience at the Energy Systems Laboratory (ESL) at Texas A&M University during the period of January 2002 through March 2004. The purpose of the above work was to allow the author to become familiar with the practice of engineering. The result is that the author knows how to complete a project from start to finish and understands how both technical and nontechnical aspects of a project need to be considered in order to ensure a quality deliverable and bring a project to successful completion. This report concludes that the objectives of the internship were successfully accomplished and that the requirements for the degree of Degree of Engineering have been satisfied
The response of quaternary climatic cycles in the South-East Pacific: development of the opal belt and dynamics behavior of the West Antarctic ice sheet
No full textThe reconstruction of the paleoclimatic and paleoceanographic development of the late Quaternary south polar ocean and adjacent continental areas in high temporal and spatial resolution is the main goal of our long-term study. During this expedition the sedimentary budget of biogenic and terrigenous components and their variability will be investigated. One objective of this leg is to continue the studies of former expeditions to gather more detailed paleoceanographic information on the eastern Pacific sector of the Southern Ocean for reconstruction of the distribution of water masses, frontal systems and sea ice, as well as information on high export productivity areas and their impact on global climate evolution. Thus, it will help us to broaden our understanding of the impact of environmental processes in the Southern Ocean on global climate. The second objective is to investigate the response of the West Antarctic Ice Sheet (WAIS) to Quaternary climatic changes. This ice sheet represents the most instable portion of Antarctic ice. The distribution pattern of the WAIS and its development can be deciphered from the sediment deposition in the study area. Previous investigations indicated that the WAIS collapsed once or multiple times during the past 0.75 million years. However there are also controversial findings. Since marine-geological records of glaciomarine deposition proximal to the WAIS are sparse, the exact timing and boundary conditions for such an event, which would result in a rise of the sea level of 5-6 m, are not yet known. The reconstruction of environmental conditions based on a multiproxy approach (this includes the investigations of sediment composition, microfossil assemblages and isotopic measurement of biogenic components) and its stratigraphic dating should substantially add to the knowledge of the WAIS history and its stability during a possibly warmer climate in the future.ANT XXIII4, ANT XXIII/5info:eu-repo/semantics/publishe
Intern experience at CH���M Hill, Inc.: an internship report
No full textIncludes author's vita"Submitted to the College of Engineering of Texas A&M University in partial
fulfillment of the requirement for the degree of Doctor of Engineering."Includes bibliographical referencesA review of the author's internship experience with CH���M HILL, Inc.
during the period September 1975 through May 1976 is presented. During this nine month
internship the author worked as an Engineer II in the Industrial Processes discipline of this
large consulting engineering firm... The author's prime responsibility was as one of three
lead design engineers on the design of a large wastewater treatment facility for a pulp mill
in Hoquiam, Washington owned by ITT Rayonier Inc. The work generally consisted of the design
of individual treatment units and associated piping and pumping. The purpose of the project
was to provide wastewater treatment capabilities that would satisfy the effluent limitations
(standards) imposed upon the mill by the State of Washington Department of Ecology and the
U.S. Environmental Protection Agency. The author's assignment also entailed necessary
interaction with the project manager and other CH���M HILL design engineers and support staff
members, the client's representatives, and representatives of two other consulting engineering
firms working on the project. Thus, the internship position at CH���M HILL provided considerable
experience coordinating the author's work with the work of other engineers, guiding the design
and administrative efforts of a support staff, and interacting regularly with the client and
other consulting firms. This broad exposure to a variety of engineering and organizational
problems provided a valuable educational experience
Transition to turbulence in a qblique shock-wave/boundary-layer interaction at M=15
No full textDirect numerical simulations are carried out for different forcing techniques to trigger transition during the interaction between an oblique shock-wave and a laminar boundary-layer at M = 1.5. Three forcing methods are used: a) forcing of oblique unstable modes, whose shape and behaviour are determined by the local linear stability theory, b) broadband free-stream acoustic disturbances, and c) a cold plasma flow control device. While the oblique-mode breakdown is dominant for low-amplitude forcing, long streaky structures drive the transition process in a high-amplitude disturbance environment. LES are also performed on the experimental setup by the Institute of Theoretical and Applied Mechanics (ITAM) from Novosibirsk State University with cold plasma actuation. As well as the disturbance type, the effect of Reynolds number and forcing amplitude will be investigated
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