196,101 research outputs found
Comparison of intraoperative microscopic and endoscopic ICG angiography in aneurysm surgery
No full textBACKGROUND: Indocyanine green (ICG) angiography is used to detect vessel compromise by the clip, residual aneurysms after clipping, or persistent aneurysm filling due to incomplete clipping. For ICG angiography, the microscope must be in a direct line-of-sight with the region of interest, limiting the identification of hidden arteries and dog-ear remnants. OBJECTIVE: To use a prototype endoscope for visualization of ICG fluorescence in hidden regions of the microsurgical field and evaluate its potential usefulness compared with microscopic ICG angiography (m-ICG-A) in a consecutive series of 30 aneurysms in 26 patients. METHODS: In selected cases, before and routinely after microsurgical clip application, m-ICG-A and endoscopic ICG angiography (e-ICG-A) were performed. The information gained by m-ICG-A was compared with that gained by e-ICG-A. RESULTS: E-ICG-A was technically feasible in all operations. Intra-arterial fluorescence could be visualized up to 10 times longer with the endoscope than with the microscope. The endoscope allowed a closer view on the fluorescent artery-aneurysm-complex. e-ICG-A provided more information than m-ICG-A in 11 operations (confirmation of unhindered blood flow in microscopically hidden vessels [n = 6], neck remnant identification [n = 2], neck remnant exclusion [n = 2], blood flow control in 2 distant clipped aneurysms [n = 1]). In 14 operations, identical information was obtained, and in 1 operation e-ICG-A was inferior because of trapped intra-aneurysmal fluorescence. CONCLUSION: In selected cases, e-ICG-A provides the neurosurgeon with information that cannot be obtained by m-ICG-A. e-ICG-A is capable of emerging as a useful adjunct in aneurysm surgery and has the potential to further improve operative results
Influence of inelastic buckling on low-cycle fatigue degradation of reinforcing bars
No full textThe effect of inelastic buckling on low-cycle high amplitude fatigue life of reinforcing bars is investigated experimentally. Ninety low-cycle fatigue tests on reinforcing bars varied in amplitudes and buckling lengths are conducted. Using scanning electron microscope the fractography of fractured surfaces are studied. The results show that the inelastic buckling, bar diameter and surface condition are the main parameters affecting the low-cycle fatigue life of reinforcing bars. Through nonlinear regression analyses of the experimental data a new set of empirical equations for fatigue life prediction of reinforcing bars as a function of the buckling length and yield strength are developed. Finally, these empirical models have been implemented into a new phenomenological hysteretic material model for reinforcing bars. The new material model is able to simulate the nonlinear stress–strain behaviour of reinforcing bars with the effect of inelastic buckling and low-cycle fatigue degradation. The results of simulation using the analytical model show a good agreement with the observed experimental results
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
Impact of Implementing an Elaborated CT Perfusion Protocol for Aneurysmal SAH on Functional Outcome: CTP Protocol for SAH
No full textBACKGROUND AND PURPOSE: The acute phase of aneurysmal SAH is characterized by a plethora of impending complications with the potential to worsen patients’ outcomes. The aim of this study was to evaluate whether an elaborated CTP-based imaging protocol during the acute aneurysmal SAH phase is able to prevent delayed infarctions and contribute to a better outcome. MATERIALS AND METHODS: In 2012, an elaborated CTP-based protocol was implemented for the management of patients with aneurysmal SAH. Retrospective analysis of patients with aneurysmal SAH treated from 2010 to 2013 was performed, comparing the patients treated before (group one, 2010–2011) with those treated after the protocol implementation (group two, 2012–2013) with regard to delayed infarctions and outcome according to the mRS at 3-months’ follow-up. RESULTS: A total of 133 patients were enrolled, of whom 57 were included in group 1, and 76, in group 2. There were no significant differences between the groups concerning baseline characteristics. In the multivariate analysis, independent predictors of a good outcome (mRS ≤ 2) were younger age (P < .001), lower World Federation of Neurosurgical Societies grade (P < .001), absence of delayed infarction (P = .01), and management according to the CTP protocol (P = .01). Larger or multiple infarctions occurred significantly more often in group 1 compared with group 2 (88% versus 33% of all delayed infarctions, P = .03). The outcome in group 2 was significantly better compared with group 1 (P = .005). CONCLUSIONS: The findings suggest that implementation of an elaborated CTP protocol is associated with a better outcome. An earlier initiation of further diagnostics and treatment with prevention of large territorial and/or multiple infarctions might have led to this finding
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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