196,029 research outputs found
Parametric design, simulation, fabrication, and test of an Origami-core based sandwich composite material
No full textSandwich panel structures are widely used for light-weight applications due to their high strength and stiffness to density ratios. They are composed of two main parts: the skins and the core. This paper investigates a Miura-ori structural sandwich core with open cells that can be used as an alternative to the existing honeycomb structures. A fully parametric design approach, starting from drawing to Finite Element Analysis (FEA), is presented to efficiently analyze the effect of different geometries on the resulting structure. The geometric model was built based on the kinematic model, which can represent the folding process of the foldcore using the Matlab script. The obtained coordinates of the vertices of the folding pattern were exported to ANSYS APDL where the surfaces were automatically created and meshed. The created mesh was imported to LS-Dyna where explicit compression analyses were performed to evaluate the compression stiffness and strength of the studied geometries. The developed parametric model aims to find the best configuration for a given application, based on three sets of geometric parameters that define the shape of the Miura Ori folding pattern. Therefore, in the range of the studied geometries, the best parameter combination for specific compression stiffness and specific compression strength was found. To evaluate the performance of the foldcore and to validate the FE model, experimental quasi-static compression tests were undertaken with two kinds of specimens (‘strip’ and “panel”), and the measured force-displacement curves were obtained. The result of the test agrees with that of the FE simulations, with an error of <6.6% in the elastic region
Serum tumor markers in colorectal cancer staging, grading, and follow-up.
No full textEarly diagnosis of colorectal cancer, a frequent neoplasia in industrialized countries, permits curative surgery. In this study we assessed the clinical role of serum tumor markers determination in diagnosing, staging, and grading colorectal cancer; the role of carcinoembryonic antigen (CEA), CA 19-9, tissue polypeptide antigen (TPA) and CA 72-4 in colorectal cancer follow-up was also assessed. In 114 patients with colorectal cancer, the oncofetal antigen CEA was compared with the membrane-associated glycoproteins CA 19-9, CA 242, and CA 72-4 and with the cytokeratins TPA, tissue polypeptide-specific antigen (TPS) and tissue polypeptide monoclonal antigen (TPM). Overall, the most sensitive indices were TPA and TPS (67% and 70%, respectively). Tumor stage influenced the levels of CEA, CA 19-9, and TPA, but not those of TPS, while tumor grade influenced CEA and TPS, but not CA 72-4, TPA, and TPM. TPA was the most sensitive index in identifying early or well-differentiated colorectal cancers. The sensitivity was enhanced when this marker was determined in combination with CEA, in diagnosing both advanced and early colorectal tumors. Seventy-seven patients were followed up after therapy for at least 18 months. CEA was the most sensitive index of recurrence (58%); however, this sensitivity is too low to consider tumor markers useful in colorectal cancer follow-up
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 role of urokinase-type plasminogen activator and its inhibitor PAI-1 in gastric cancer.
No full textBACKGROUND: It has been proposed that the serine protease urokinase-type plasminogen activator (UPA) and its inhibitor type-1 (PAI-1) may play an important part in cancer spread and metastasis.AIMS OF THE STUDY: 1. To determine the UPA, PAI-1 antigen levels in gastric cancer (GC) and in normal gastric mucosa far from the tumor (NORM). 2. To evaluate changes related to the presence of metastasis, tumor differentiation (grading) and histotype.PATIENTS AND METHODS: Samples of tumor and of normal mucosa were obtained from 25 GC patients undergoing surgery (17 males, 8 females, mean age 62, range 31-84). Antigen concentrations were measured using the ELISA method.RESULTS: Significantly higher UPA and PAI-1 antigen levels were found: 1. in GC vs. NORM tissue; 2. in patients with poorly and moderately differentiated GC vs. well-differentiated GC. UPA was significantly higher in GC with vs. without metastasis. PAI-1 was also higher, though not significantly so, in GC with metastasis than in GC without metastasis.CONCLUSION: Our results confirm that the serine protease UPA and its inhibitor PAI-1 play an important role in GC progression. Considering the higher protease levels detected in GC with metastases and poorer differentiation, UPA and PAI-1 might be useful for identifying gastric cancer patients with a poor prognosis
CEA mRNA identification in peripheral blood is feasible for colorectal, but not for gastric or pancreatic cancer staging
No full textOBJECTIVE: It has been suggested that the molecular identification of cancer cells in the circulation may be useful in predicting the presence of micrometastasis in several cancer types. The aim of the present study was therefore to assess the feasibility of CEA mRNA identification in blood for diagnosing and staging colorectal, gastric and pancreatic cancer.
METHODS: We studied 16 control subjects, 69 patients with colorectal (CRC), 30 with gastric (GC), 27 with pancreatic cancer (PC) and 8 with benign diseases of the pancreatobiliary tree. At diagnosis CEA mRNA was identified in peripheral blood by means of a RT-PCR procedure.
RESULTS: The specificity of this test in control subjects was 94%, and its sensitivity in identifying CRC, GC and PC were 34, 37 and 41%, respectively. False-positive findings were recorded in 25% patients with benign diseases. No association was found between CEA mRNA and stage in patients with GC or PC. In CRC patients, positive CEA mRNA findings were correlated with local spread (chi(2) = 14.6, p<0.01), lymph node (chi(2) = 18.95, p<0.001) and distant metastasis (chi(2) = 11.3, p<0.001). In these cases, CEA mRNA, but not CEA, was entered in stepwise discriminant analysis to classify the presence of lymph node metastasis.
CONCLUSIONS: The molecular detection of micrometastasis in the blood by means of CEA mRNA identification is feasible for colorectal, but not for gastric or pancreatic cancer staging. Further studies are needed in order to define the clinical utility of this marker also in follow-up protocols
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
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