195,991 research outputs found
Fatigue life assessment for a welded detail: advantages of a local energetic approach and experimental validation
No full textIn modern civil buildings, as well as in mechanical and naval constructions, welding is a widely diffused technological process. The fatigue assessment, as design or verification procedure, of a welded joint to evaluate his endurance with respect to a load spectrum is a challenging but of paramount importance procedure. Several techniques have been proposed in the literature, constantly researching efficient, cost effective and reliable methods to predict the behavior of a complex welded structures. Some of them are part of norms and standards which any design engineer must respect. The aim of the present work is to compare the results provided by some of the principal fatigue life assessment procedures for welded joints, focusing the attention on the stress intensity factor evaluation by the use of numerical methods. Finally the proposed numerical method has been experimentally validated.publishedVersion© 2018 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Influence of hot-dip galvanization on the fatigue performance of high-strength bolted connections
No full textIn the present work, the influence of hot-dip galvanization (HDG) on the fatigue behaviour of high-strength bolted details is investigated through a set of 15 constant-amplitude tests. Cyclic behaviour of coated specimens is hence compared against results for unprotected samples drawn from literature, i.e., both with reference to neutral and aggressive exposure conditions. Namely, while behaviour of coated samples is moderately inferior as respect to uncoated ones in dry air (–6 % in terms of characteristic fatigue strength, probability of failure PF = 5 %, confidence interval CI = 75 %), their performance still complies with European normative requirements for double covered joints, and galvanization proves to be highly effective when corrosion is likely to occur (with a characteristic strength increase of [+12 %; +52 %]). Finally, fractography analyses on both uncoated and coated specimens were performed, suggesting that hydrogen embrittlement may play a role in reducing fatigue strength of coated joints, that is, especially within the high-cycle fatigue regime
Tape winding angle influence on subsea cable sheathing fatigue performance
No full textA fundamental component of subsea power cables is the thin galvanized steel tape winded around the dielectric and sheathing layer in order to prevent permanent thermal cycling induced deformation. The pressure state induced by the resistance offered by such tapes against radial reformation reduces the triaxiality ratio of the stress state of the lead sheathing layer. It is known that a reduced triaxiality has a beneficial effect on ductility and fatigue life of metals. In the present work a series of finite element simulations are performed in presence of galvanized steel tapes at three different winding angles and without such reinforcement at all, obtaining a qualitative indication of its effect on the stress state induced in the sheathing layer. Loading conditions as internal pressure related to thermal dielectric expansion and cable bending are modelled. The numerical qualitative results are discussed in connection to a series of full-scale fatigue tests performed on subsea power cables with and without the support of steel tapes
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
Search superiority in autism within, but not outside the crowding regime
No full textAutosomal recessive spastic paraplegia with thinning of corpus callosum
(ARHSP-TCC) is a complex form of HSP initially described in Japan but
subsequently reported to have a worldwide distribution with a particular high
frequency in multiple families from the Mediterranean basin. We recently showed
that ARHSP-TCC is commonly associated with mutations in SPG11/KIAA1840 on
chromosome 15q. We have now screened a collection of new patients mainly
originating from Italy and Brazil, in order to further ascertain the spectrum of
mutations in SPG11, enlarge the ethnic origin of SPG11 patients, determine the
relative frequency at the level of single Countries (i.e., Italy), and establish
whether there is one or more common mutation. In 25 index cases we identified 32
mutations; 22 are novel, including 9 nonsense, 3 small deletions, 4 insertions, 1
in/del, 1 small duplication, 1 missense, 2 splice-site, and for the first time a
large genomic rearrangement. This brings the total number of SPG11 mutated
patients in the SPATAX collection to 111 cases in 44 families and in 17 isolated
cases, from 16 Countries, all assessed using homogeneous clinical criteria. While
expanding the spectrum of mutations in SPG11, this larger series also
corroborated the notion that even within apparently homogeneous population a
molecular diagnosis cannot be achieved without full gene sequencing
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
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
- …
