Rhetorical Structure of Research Articles in Agricultural Science
ERIC Educational Resources Information Center
Shi, Huimin; Wannaruk, Anchalee
2014-01-01
Although the rhetorical structure of research articles (RA) has been extensively examined from individual sections to complete IMRD sections regarding different disciplines, no research has been addressed to the overall rhetorical structure of RAs as a whole entity in the field of agricultural science. In this study, we analyzed 45 agricultural…
Science and Institutional Research: The Links. AIR 1991 Annual Forum Paper.
ERIC Educational Resources Information Center
McKinney, E. Bernadette; Hindera, John J.
This paper compares the process and structure of institutional research with three ways of conceptualizing science. The first section examines the scientific method as a process of disciplined inquiry, then compares institutional research to that process. The second section compares the logical structure of institutional research with the logical…
ERIC Educational Resources Information Center
Jones, Earl I., Ed.
This five-section symposium report includes 22 papers assessing the state-of-the-art in occupational research. Section 1, Occupational Analysis, Structure, and Methods, contains four papers that discuss: the Air Force Occupational Research project, methodologies in job analysis, evaluation, structures and requirements, career development,…
Strang, David; Siler, Kyle
2017-08-01
This paper analyzes the surface structure of research articles published in Administrative Science Quarterly between 1956 and 2008. The period is marked by a shift from essays that interweave theory, methods and results to experimental reports that separate them. There is dramatic growth in the size of theory, methods and discussion sections, accompanied by a shrinking results section. Bibliographic references and hypotheses expand in number and become concentrated in theory sections. Article structure varies primarily with historical time and also with research design (broadly, quantitative vs. qualitative) and the author's background. We link trends in article structure to the disciplinary development of organization studies and consider its distinctive trajectory relative to physical science.
Research and technology highlights of the Lewis Research Center
NASA Technical Reports Server (NTRS)
1984-01-01
Highlights of research accomplishments of the Lewis Research Center for fiscal year 1984 are presented. The report is divided into four major sections covering aeronautics, space communications, space technology, and materials and structures. Six articles on energy are included in the space technology section.
ERIC Educational Resources Information Center
Overmyer, Jerry
2015-01-01
This quantitative research compares five sections of College Algebra using flipped classroom methods with six sections using the traditional lecture/homework structure and its effect on student achievement as measured through a common final exam. Common final exam scores were the dependent variables. Instructors of flipped sections who had…
Move Analysis of the Conclusion Sections of Research Papers in Persian and English
ERIC Educational Resources Information Center
Zamani, Gerannaz; Ebadi, Saman
2016-01-01
The structure of the conclusion sections in Research Papers (RPs) is of significance in academic writing. The conclusion section in spite of providing an outline of the article, states other essential components, such as recommendations, implications and statements of possible lines of future research. This paper analyses the conclusion parts of…
Turbine Engine Hot Section Technology 1986
NASA Technical Reports Server (NTRS)
1986-01-01
The Turbine Engine Hot Section Technology (HOST) Project of the NASA Lewis Research Center sponsored a workshop to discuss current research pertinent to turbine engine durability problems. Presentations were made concerning the hot section environment and the behavior of combustion liners, turbine blades, and turbine vanes. The presentations were divided into six sessions: Instrumentation, Combustion, Turbine Heat Transfer, Structural Analysis, Fatigue and Fracture, and Surface Protection. Topics discussed included modeling of thermal and fluid-flow phenomena, structural analysis, fatigue and fracture, surface protective coatings, constitutive behavior of materials, stress-strain response, and life-prediction methods. Researchers from industry, academia, and government presented results of their work sponsored by the HOST project.
Rhetorical Structure of Education Research Article Methods Sections
ERIC Educational Resources Information Center
Zhang, Baoya; Wannaruk, Anchalee
2016-01-01
This study investigated the rhetorical move structure of the education research article genre within the framework of Swales' (1981, 1990, 2004) move analysis. A corpus of 120 systematically sampled empirical education research articles served as data input for the analysis. The results indicate that the education research article methods section…
[Research progress and trend on grassland agroecology].
Ren, Jizhou; Li, Xianglin; Hou, Fujiang
2002-08-01
The connotation, progress, research frontiers and developmental trend of grassland agroecology are discussed in this paper. The interface theory, structure and function, coupling and discordance, and health assessment of grassland agroecosystems were recognized as the four research frontiers of the discipline. There exist three primary interfaces in a grassland agroecosystem, i.e., vegetation-site, grassland-animal and production-management. Research into a series of the ecological processes that occurred at these interfaces is the key to revealing the features of the system behavior. There are four sections in a grassland agroecosystem, i.e., pre-plant, plant, animal and post-biotic sections. System coupling and discordance are the two important concepts to describe interactions among the production sections. System coupling among the sections can lead to system improvement by exerting the potential of system capacity. Health of an ecosystem is a reflection of its structure and function, and health assessment is a measurement of its orderliness and service value.
Research Associate | Center for Cancer Research
PROGRAM DESCRIPTION The Basic Science Program (BSP) pursues independent, multidisciplinary research in basic and applied molecular biology, immunology, retrovirology, cancer biology, and human genetics. Research efforts and support are an integral part of the Center for Cancer Research (CCR) at the Frederick National Laboratory for Cancer Research (FNLCR). KEY ROLES/RESPONSIBILITIES - Research Associate III Dr. Zbigniew Dauter is the head investigator of the Synchrotron Radiation Research Section (SRRS) of CCR’s Macromolecular Crystallography Laboratory. The Synchrotron Radiation Research Section is located at Argonne National Laboratory, Argonne, Illinois; this is the site of the largest U.S. synchrotron facility. The SRRS uses X-ray diffraction technique to solve crystal structures of various proteins and nucleic acids of biological and medical relevance. The section is also specializing in analyzing crystal structures at extremely high resolution and accuracy and in developing methods of effective diffraction data collection and in using weak anomalous dispersion effects to solve structures of macromolecules. The areas of expertise are: Structural and molecular biology Macromolecular crystallography Diffraction data collection Dr. Dauter requires research support in these areas, and the individual will engage in the purification and preparation of samples, crystallize proteins using various techniques, and derivatize them with heavy atoms/anomalous scatterers, and establish conditions for cryogenic freezing. Individual will also participate in diffraction data collection at the Advanced Photon Source. In addition, the candidate will perform spectroscopic and chromatographic analyses of protein and nucleic acid samples in the context of their purity, oligomeric state and photophysical properties.
Suggestions for Structuring a Research Article
ERIC Educational Resources Information Center
Klein, James D.; Reiser, Robert A.
2014-01-01
Researchers often experience difficulty as they attempt to prepare journal articles that describe their work. The purpose of this article is to provide researchers in the field of education with a series of suggestions as to how to clearly structure each section of a research manuscript that they intend to submit for publication in a scholarly…
ERIC Educational Resources Information Center
Basturkmen, Helen
2012-01-01
Outwardly the rhetorical organisation of sections of research reports in different disciplines can appear similar. Close examination, however, may reveal subtle differences. Numerous studies have drawn on the genre-based approach developed by Swales (1990, 2004) to investigate the schematic structure of sections of articles in a range of…
Collaborators | Center for Cancer Research
Collaborators Structural Biophysics Laboratory, CCR Macromolecular NMR Section (R. Andrew Byrd, Ph.D.) Protein-Nucleic Acid Interactions Section (Yun-Xing Wang, Ph.D.) Protein Processing Section (Kylie J. Walters, Ph.D.) Kinase Complexes Section (Ping Zhang, Ph.D.) Macromolecular Crystallography Laboratory, CCR
Using Research To Inform Business and Strategic Decisions.
ERIC Educational Resources Information Center
Young, Graeme
This paper examines and reviews research techniques used to support business and strategic planning at a large metropolitan technical and further education (TAFE) college. Section 1 is an outline of the structure of Chisholm Institute's planning and research processes. It discusses the management structure, strategic plan, and departments within…
Lewis Structures Technology, 1988. Volume 1: Structural Dynamics
NASA Technical Reports Server (NTRS)
1988-01-01
The specific purpose of the symposium was to familiarize the engineering structures community with the depth and range of research performed by the Structures Division of the Lewis Research Center and its academic and industrial partners. Sessions covered vibration control, fracture mechanics, ceramic component reliability, parallel computing, nondestructive testing, dynamical systems, fatigue and damage, wind turbines, hot section technology, structural mechanics codes, computational methods for dynamics, structural optimization, and applications of structural dynamics.
Modeling and Negotiating Service Quality
NASA Astrophysics Data System (ADS)
Benbernou, Salima; Brandic, Ivona; Cappiello, Cinzia; Carro, Manuel; Comuzzi, Marco; Kertész, Attila; Kritikos, Kyriakos; Parkin, Michael; Pernici, Barbara; Plebani, Pierluigi
In this chapter the research problems of specifying and negotiating QoS and its corresponding quality documents are analyzed. For this reason, this chapter is separated into two main sections, Section 6.1 and 6.2, with each dedicated to one of the two problems, i.e., QoS specification and negotiation, respectively. Each section has a similar structure: they first introduce the problem and then, in the remaining subsections, review related work. Finally, the chapter ends with Section 6.3, which identifies research gaps and presents potential research challenges in QoS modelling, specification and negotiation.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
1994-02-02
This report consists of three separate but related reports. They are (1) Human Resource Development, (2) Carbon-based Structural Materials Research Cluster, and (3) Data Parallel Algorithms for Scientific Computing. To meet the objectives of the Human Resource Development plan, the plan includes K--12 enrichment activities, undergraduate research opportunities for students at the state`s two Historically Black Colleges and Universities, graduate research through cluster assistantships and through a traineeship program targeted specifically to minorities, women and the disabled, and faculty development through participation in research clusters. One research cluster is the chemistry and physics of carbon-based materials. The objective of thismore » cluster is to develop a self-sustaining group of researchers in carbon-based materials research within the institutions of higher education in the state of West Virginia. The projects will involve analysis of cokes, graphites and other carbons in order to understand the properties that provide desirable structural characteristics including resistance to oxidation, levels of anisotropy and structural characteristics of the carbons themselves. In the proposed cluster on parallel algorithms, research by four WVU faculty and three state liberal arts college faculty are: (1) modeling of self-organized critical systems by cellular automata; (2) multiprefix algorithms and fat-free embeddings; (3) offline and online partitioning of data computation; and (4) manipulating and rendering three dimensional objects. This cluster furthers the state Experimental Program to Stimulate Competitive Research plan by building on existing strengths at WVU in parallel algorithms.« less
Compression member response of double steel angles on truss structure with member length variation
NASA Astrophysics Data System (ADS)
Hasibuan, Purwandy; Panjaitan, Arief; Haiqal, Muhammad
2018-05-01
One type of structures that implements steel angles as its members is truss system of telecommunication tower. For this structure, reinforcements on tower legs are also needed when antennas and microwaves installation placed on the peak of tower increases in quantity. One type of reinforcement methods commonly used is by increasing areas section capacity, where tower leg consisted of single angle section will be reinforced to be double angle sections. Regarding this case, this research discussed behavior two types of double angle steel section 2L 30.30.3 that were designed identically in area section but vary in length: 103 cm and 83 cm. At the first step, compression member together with tension member was formed to be a truss system, where compression and tension member were met at the joint plate. Schematic loading was implemented by giving tension loading on the joint plate, and this loading was terminated when each specimen reached its failure. Research findings showed that implementing shorter double angle (83 cm) sections, increased compression strength of steel angle section up to 13 %. Significant deformation occurring only on the flange for both of specimens indicated that implementing double angle is effective to prevent lateral-torsional buckling.
NASA Astrophysics Data System (ADS)
Serugendo, Giovanna Di Marzo; Risoldi, Matteo; Solemayni, Mohammad
The following sections are included: * Introduction * Problem and Research Questions * State of the Art * TSC Structure and Computational Awareness * Methodology and Research Directions * Case Study: Democracy * Conclusions
Technical report on the surface reconstruction of stacked contours by using the commercial software
NASA Astrophysics Data System (ADS)
Shin, Dong Sun; Chung, Min Suk; Hwang, Sung Bae; Park, Jin Seo
2007-03-01
After drawing and stacking contours of a structure, which is identified in the serially sectioned images, three-dimensional (3D) image can be made by surface reconstruction. Usually, software is composed for the surface reconstruction. In order to compose the software, medical doctors have to acquire the help of computer engineers. So in this research, surface reconstruction of stacked contours was tried by using commercial software. The purpose of this research is to enable medical doctors to perform surface reconstruction to make 3D images by themselves. The materials of this research were 996 anatomic images (1 mm intervals) of left lower limb, which were made by serial sectioning of a cadaver. On the Adobe Photoshop, contours of 114 anatomic structures were drawn, which were exported to Adobe Illustrator files. On the Maya, contours of each anatomic structure were stacked. On the Rhino, superoinferior lines were drawn along all stacked contours to fill quadrangular surfaces between contours. On the Maya, the contours were deleted. 3D images of 114 anatomic structures were assembled with their original locations preserved. With the surface reconstruction technique, developed in this research, medical doctors themselves could make 3D images of the serially sectioned images such as CTs and MRIs.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
1978-06-01
The OSTP Working Group was commissioned to advise on the scope and quality of basic research conducted by and on behalf of DOE. The Group formed Subgroups in these areas: large-scale solar, fossil, fusion, small technology, and geothermal, environment and life sciences, social sciences, transportation, and fission. Work of the Subgroups forms the basis of much of this report, which has five sections. Following the introduction, preface, and executive summary (Section II), there is discussion of broad problem areas as they pertain to research (Section III). Section IV consists of general recommendations regarding policies for, as well as management andmore » scope of, research within the DOE: this section has four parts: Part A pertains to research in programmatic areas under the aegis of the Assistant Secretaries; Part B deals with the role and structure of the Office of Energy Research; Part C is concerned with broad research issues; and Part D addresses DOE Laboratories and Energy Research Centers. In Section V, research needs and opportunities for selected programs are discussed.« less
Asian- and Pacific-American Perspectives in Bilingual Education: Comparative Research.
ERIC Educational Resources Information Center
Chu-Chang, Mae, Ed.; Rodriguez, Victor, Ed.
The articles in this book together provide a state-of-the-art review of bilingual education research specifically dealing with Asian and Pacific Americans. Following an introduction by Mae Chu-Chang, chapters are grouped into 3 sections. In Section I, "Bilingual and Biliteracy Acquisition," works include (1) "The Basic Grammatical Structures of…
Writing a qualitative research report.
Burnard, Philip
2004-04-01
A research project in nursing or nursing education is probably only complete once the findings have been published. This paper offers a format for writing a qualitative research report for publication. It suggests, at least, the following sections: introduction, aims of the study, review of the literature, sample, data collection methods, data analysis methods, findings, discussion, conclusion, abstract. Each of these sections is addressed along with many written-out examples. In some sections, alternative approaches are suggested. The aim of the paper is to help the neophyte researcher to structure his or her report and for the experienced researcher to reflect on his or her current practice. References to other source material on qualitative research are given.
Writing a qualitative research report.
Burnard, Philip
2004-07-01
A research project in nursing or nursing education is probably only complete once the findings have been published. This paper offers a format for writing a qualitative research report for publication. It suggests, at least, the following sections: introduction, aims of the study, review of the literature, sample, data collection methods, data analysis methods, findings, discussion, conclusion, abstract. Each of these sections is addressed along with many written-out examples. In some sections, alternative approaches are suggested. The aim of the paper is to help the neophyte researcher to structure his or her report and for the experienced researcher to reflect on his or her current practice. References to other source material on qualitative research are given.
Khalil, Mohammed K; Paas, Fred; Johnson, Tristan E; Su, Yung K; Payer, Andrew F
2008-01-01
This research is an effort to best utilize the interactive anatomical images for instructional purposes based on cognitive load theory. Three studies explored the differential effects of three computer-based instructional strategies that use anatomical cross-sections to enhance the interpretation of radiological images. These strategies include: (1) cross-sectional images of the head that can be superimposed on radiological images, (2) transparent highlighting of anatomical structures in radiological images, and (3) cross-sectional images of the head with radiological images presented side-by-side. Data collected included: (1) time spent on instruction and on solving test questions, (2) mental effort during instruction and test, and (3) students' performance to identify anatomical structures in radiological images. Participants were 28 freshmen medical students (15 males and 13 females) and 208 biology students (190 females and 18 males). All studies used posttest-only control group design, and the collected data were analyzed by either t test or ANOVA. In self-directed computer-based environments, the strategies that used cross sections to improve students' ability to recognize anatomic structures in radiological images showed no significant positive effects. However, when increasing the complexity of the instructional materials, cross-sectional images imposed a higher cognitive load, as indicated by higher investment of mental effort. There is not enough evidence to claim that the simultaneous combination of cross sections and radiological images has no effect on the identification of anatomical structures in radiological images for novices. Further research that control for students' learning and cognitive style is needed to reach an informative conclusion.
Preface: Special Topic Section on Advanced Electronic Structure Methods for Solids and Surfaces.
Michaelides, Angelos; Martinez, Todd J; Alavi, Ali; Kresse, Georg; Manby, Frederick R
2015-09-14
This Special Topic section on Advanced Electronic Structure Methods for Solids and Surfaces contains a collection of research papers that showcase recent advances in the high accuracy prediction of materials and surface properties. It provides a timely snapshot of a growing field that is of broad importance to chemistry, physics, and materials science.
Nuclear Structure Research at Richmond
DOE Office of Scientific and Technical Information (OSTI.GOV)
Beausang, Cornelius W.
The goals for the final year were; (1) to continue ongoing efforts to develop and enhance GRETINA and work towards GRETA; (2) to investigate the structure of non-yrast states in shape transitional Sm and Gd nuclei; (3) to investigate the structure of selected light Cd nuclei; (4) to exploit the surrogate reaction technique to extract (n,f) cross sections for actinide nuclei, particularly the first measurement of the 236Pu and 237Pu(n,f) cross sections.
Simulating the Impact Response of Full-Scale Composite Airframe Structures
NASA Technical Reports Server (NTRS)
Fasanella, Edwin L.; Jackson, Karen E.; Littell, Justin D.; Seal, Michael D.
2012-01-01
NASA Langley Research Center obtained a composite helicopter cabin structure in 2010 from the US Army's Survivable Affordable Repairable Airframe Program (SARAP) that was fabricated by Sikorsky Aircraft Corporation. The cabin had been subjected to a vertical drop test in 2008 to evaluate a tilting roof concept to limit the intrusion of overhead masses into the fuselage cabin. Damage to the cabin test article was limited primarily to the roof. Consequently, the roof area was removed and the remaining structure was cut into test specimens including a large subfloor section and a forward framed fuselage section. In 2011, NASA and Sikorsky entered into a cooperative research agreement to study the impact responses of composite airframe structures and to evaluate the capabilities of the explicit transient dynamic finite element code, LS-DYNA®, to simulate these responses including damage initiation and progressive failure. Most of the test articles were manufactured of graphite unidirectional tape composite with a thermoplastic resin system. However, the framed fuselage section was constructed primarily of a plain weave graphite fabric material with a thermoset resin system. Test data were collected from accelerometers and full-field photogrammetry. The focus of this paper will be to document impact testing and simulation results for the longitudinal impact of the subfloor section and the vertical drop test of the forward framed fuselage section.
46 CFR 190.01-10 - Structural standards.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 7 2010-10-01 2010-10-01 false Structural standards. 190.01-10 Section 190.01-10 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS CONSTRUCTION AND ARRANGEMENT Hull Structure § 190.01-10 Structural standards. (a) In general, compliance with...
PHIRE (Public Health Innovation and Research in Europe): methods, structures and evaluation.
Barnhoorn, Floris; McCarthy, Mark; Devillé, Walter; Alexanderson, Kristina; Voss, Margaretha; Conceição, Claudia
2013-11-01
Public Health Innovation and Research in Europe (PHIRE), building on previous European collaborative projects, was developed to assess national uptake and impacts of European public health innovations, to describe national public health research programmes, strategies and structures and to develop participation of researchers through the organizational structures of the European Public Health Association (EUPHA). This article describes the methods used. PHIRE was led by EUPHA with seven partner organisations over 30 months. It was conceived to engage the organisation of EUPHA--working through its thematic Sections, and through its national public health associations--and assess innovation and research across 30 European countries. Public health research was defined broadly as health research at population and organisational level. There were seven Work Packages (three covering coordination and four for technical aspects) led by partners and coordinated through management meetings. Seven EUPHA Sections identified eight innovations within the projects funded by the Public Health Programme of the European Commission Directorate for Health and Consumers. Country informants, identified through EUPHA thematic Sections, reported on national uptake of the innovations in eight public health projects supported by the European Union Public Health Programme. Four PHIRE partners, each taking a regional sector of Europe, worked with the public health associations and other informants to describe public health research programmes, calls and systems. A classification was created for the national public health research programmes and calls in 2010. The internal and external evaluations were supportive. PHIRE described public health innovations and research across Europe through national experts. More work is needed to conceptualize and define public health 'innovations' and to develop theories and methods for the assessment of their uptake and impacts at country and cross-country levels. More attention to methods to describe and assess national public health research programmes, strategies and structures--contributing to development of the European Research Area.
ERIC Educational Resources Information Center
Clayton, Berwyn; Fisher, Thea; Harris, Roger; Bateman, Andrea; Brown, Mike
2008-01-01
This document supports the report "A Study in Difference: Structures and Cultures in Registered Training Organisations." The first section outlines the methodology used to undertake the research and covers the design of the research, sample details, the data collection process and the strategy for data analysis and reporting. The…
Structural Patterns in Empirical Research Articles: A Cross-Disciplinary Study
ERIC Educational Resources Information Center
Lin, Ling; Evans, Stephen
2012-01-01
This paper presents an analysis of the major generic structures of empirical research articles (RAs), with a particular focus on disciplinary variation and the relationship between the adjacent sections in the introductory and concluding parts. The findings were derived from a close "manual" analysis of 433 recent empirical RAs from high-impact…
Tax-exempt bonds and sponsored research.
Ballard, Frederic L
2003-01-01
"Sponsored research," wherein a business corporation or the government pays a portion of the cost of research activities carried out by a university or hospital, is increasingly important both for state institutions and for Section 510(c)(3) organizations. Sponsored research arrangements that are not properly structured can jeopardize the status of tax-exempt bonds issued to finance the facility at which the sponsored research occurs. While these rules have been difficult to apply in practice, properly structured agreements can provide funding for research without undue risk. This Article discusses the multiple pieces of guidance put forth by the Internal Revenue Service to clarify the many issues and tiers of analysis necessary to ensure a properly-structured sponsored research agreement.
Introduction to the Wetland Book 1: Wetland structure and function, management, and nethods
Davidson, Nick C.; Middleton, Beth A.; McInnes, Robert J.; Everard, Mark; Irvine, Kenneth; Van Dam, Anne A.; Finlayson, C. Max; Finlayson, C. Max; Everard, Mark; Irvine, Kenneth; McInnes, Robert J.; Middleton, Beth A.; Van Dam, Anne A.; Davidson, Nick C.
2016-01-01
The Wetland Book 1 is designed as a ‘first port-of-call’ reference work for information on the structure and functions of wetlands, current approaches to wetland management, and methods for researching and understanding wetlands. Contributions by experts summarize key concepts, orient the reader to the major issues, and support further research on such issues by individuals and multidisciplinary teams. The Wetland Book 1 is organized in three parts - Wetland structure and function; Wetland management; and Wetland methods - each of which is divided into a number of thematic Sections. Each Section starts with one or more overview chapters, supported by chapters providing further information and case studies on different aspects of the theme.
Lewis Structures Technology, 1988. Volume 2: Structural Mechanics
NASA Technical Reports Server (NTRS)
1988-01-01
Lewis Structures Div. performs and disseminates results of research conducted in support of aerospace engine structures. These results have a wide range of applicability to practitioners of structural engineering mechanics beyond the aerospace arena. The engineering community was familiarized with the depth and range of research performed by the division and its academic and industrial partners. Sessions covered vibration control, fracture mechanics, ceramic component reliability, parallel computing, nondestructive evaluation, constitutive models and experimental capabilities, dynamic systems, fatigue and damage, wind turbines, hot section technology (HOST), aeroelasticity, structural mechanics codes, computational methods for dynamics, structural optimization, and applications of structural dynamics, and structural mechanics computer codes.
Pacific Northwest Laboratory annual report for 1990 to the DOE Office of Energy Research
DOE Office of Scientific and Technical Information (OSTI.GOV)
Park, J.F.
This report summarizes progress on OHER human health, biological, and general life sciences research programs conducted at PNL in FY 1990. The research develops the knowledge and scientific principles necessary to identify understand, and anticipate the long-term health consequences of energy-related radiation and chemicals. Our continuing emphasis is to decrease the uncertainty of health risk estimates from existing and developing energy-related technologies through an increased of understanding of how radiation and chemicals cause biological damage. The sequence of this report of PNL research reflects the OHER programmatic structure. The first section, on human health research, concerns epidemiological and statistical studiesmore » for assessing health risks. The next section contains reports of biological research in laboratory animals and in vitro cell systems, including research with radionuclides and chemicals. The general life sciences research section reports research conducted for the OHER human genome research program.« less
Drop test analysis of fuselage section of R80 commuter aircraft by using finite element method
NASA Astrophysics Data System (ADS)
Anggono, Agus Dwi; Ardianto, Adik Nofa Rochma Wahyu
2017-04-01
In commercial aerospace development, feasibility accidents design or crashworthiness is a major concern in aviation safety. Fuselage structure plays an important role in absorbing energy during an accident. The research aims are to determine drop test phenomenon on the fuselage, to investigate deformation occurred in the structure of the fuselage, and to know the influence of the airframe falls position to the stress strain which occurred in the structure of the fuselage. This research was conducted by varying the fall angle of the fuselage in a vertical position or 0° and 15°. Fuselage design was modeled by using SolidWorks. Then the model is imported to the Abaqus for drop test simulation. From the simulation results, it can be obtained the phenomenon of deformation on the structure of the fuselage when it comes in contact with the rigid ground. The high deformation occurs shows the structure capabilities in order to absorb the impact. It could be happened because the deformation is influenced by internal energy and strain energy. The various positions shows the structure capability in order to withstand impact loads during periods of 4-8 seconds and the maximum deformation was reached in 12 seconds. The experiment on the vertical position and the position falls of 15° angle was delivered the highest stress strain. The stress was 483 MPa in struts section, 400.78 MPa in skin section, 358.28 MPa in the floor and 483 MPa in the cargo frame section.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Park, J.F.
This report summarizes progress on OHER human health, biological, general life sciences, and medical applications research programs conducted at PNL in FY 1989. The research develops the knowledge and scientific principles necessary to identify, understand, and anticipate the long-term health consequences of energy-related radiation and chemicals. Our continuing emphasis is to decrease the uncertainty of health risk estimates from existing and developing energy-related technologies through an increased understanding of how radiation and chemicals cause biological damage. The sequence of this report of PNL research reflects the OHER programmatic structure. The first section, on human health research, concerns statistical and epidemiologicalmore » studies for assessing health risks. The next section contains reports of biological research in laboratory animals and in vitro cell systems, including research with radionuclides and chemicals. The general life sciences research section reports research conducted for the OHER human genome research program, and the medical applications section summarizes commercial radioisotope production and distribution activities at DOE facilities. 6 refs., 50 figs., 35 tabs.« less
Metals and Ceramics Division progress report for period ending June 30, 1984
DOE Office of Scientific and Technical Information (OSTI.GOV)
Brogden, I.
1984-09-01
This progress report covers the research and development activities of the Metals and Ceramics Division from January 1, 1983, through June 30, 1984. The format of the report follows the organizational structure of the division. Short summaries of technical work in progress in the various experimental groups are presented in six parts. Chapter 1 deals with the research and development activities of the Engineering Materials Section, Chapter 2 with the Processing Science and Technology Section, Chapter 3 with the Materials Science Section, Chapter 4 with Project Activities, Chapter 5 with Specialized Research Facilities and Equipment, and Chapter 6 with Miscellaneousmore » Activities.« less
40 CFR 725.239 - Use of specific microorganisms in activities conducted outside a structure.
Code of Federal Regulations, 2010 CFR
2010-07-01
... activities conducted outside a structure. 725.239 Section 725.239 Protection of Environment ENVIRONMENTAL... MICROORGANISMS Exemptions for Research and Development Activities § 725.239 Use of specific microorganisms in activities conducted outside a structure. (a) Bradyrhizobium japonicum. To qualify for an exemption under...
40 CFR 725.239 - Use of specific microorganisms in activities conducted outside a structure.
Code of Federal Regulations, 2011 CFR
2011-07-01
... activities conducted outside a structure. 725.239 Section 725.239 Protection of Environment ENVIRONMENTAL... MICROORGANISMS Exemptions for Research and Development Activities § 725.239 Use of specific microorganisms in activities conducted outside a structure. (a) Bradyrhizobium japonicum. To qualify for an exemption under...
ERIC Educational Resources Information Center
Pinto, Rogério M.; Wall, Melanie M.; Spector, Anya Y.
2014-01-01
Partnerships between HIV researchers and service providers are essential for reducing the gap between research and practice. Community-Based Participatory Research principles guided this cross-sectional study, combining 40 in-depth interviews with surveys of 141 providers in 24 social service agencies in New York City. We generated the…
Aspects of Theme in the Method and Discussion Sections of Biology Journal Articles in English.
ERIC Educational Resources Information Center
Martinez, Iliana A.
2003-01-01
Analyzes the thematic structure of the method and Discussion section of biology research articles. A corpus of 30 journal articles was analyzed using the categories of systematic functional linguistics and a semantic categorization for unmarked themes realized by subject. Revealed differences in the semantic construction of the sections. (VWL)
NASA Astrophysics Data System (ADS)
Sarpün, Ismail Hakki; n, Abdullah Aydı; Tel, Eyyup
2017-09-01
In fusion reactors, neutron induced radioactivity strongly depends on the irradiated material. So, a proper selection of structural materials will have been limited the radioactive inventory in a fusion reactor. First-wall and blanket components have high radioactivity concentration due to being the most flux-exposed structures. The main objective of fusion structural material research is the development and selection of materials for reactor components with good thermo-mechanical and physical properties, coupled with low-activation characteristics. Double differential light charged particle emission cross section, which is a fundamental data to determine nuclear heating and material damages in structural fusion material research, for some elements target nuclei have been calculated by the TALYS 1.8 nuclear reaction code at 14-15 MeV neutron incident energy and compared with available experimental data in EXFOR library. Direct, compound and pre-equilibrium reaction contribution have been theoretically calculated and dominant contribution have been determined for each emission of proton, deuteron and alpha particle.
NASA Astrophysics Data System (ADS)
Panjaitan, Arief; Hasibuan, Purwandy
2018-05-01
Implementation of an axial compression load on the steel angle can be found at the various structure such as truss system on telecommunication tower. For telecommunication tower, steel angle section can be suggested as an alternative solution due to its assembling easiness as well as its strength. But, antennas and microwaves installation that keep increases every time on this structure demand reinforcement on each leg of the tower structure. One solution suggested is reinforcement with increasing areas section capacity, where tower leg consisted of single angle section will be reinforced to be double angle section. Regarding this case, this research discussed the behavior of two types of steel angle section: single angle of L.30.30.3 and double angles of 2L.30.30.3. These two sections were designed identically in length (103 cm) and tested by axial compression load. At the first step, compression member together with tension member was formed to be a truss system, where compression and tension member were met at a joint plate. Schematic loading was implemented by giving tension loading on the joint plate until failure of specimens. Experimental work findings showed that implementing double angle sections (103 cm) significantly increased compression capacity of steel angle section up to 118 %.
48 CFR 227.7107-2 - Contracts for construction supplies and research and development work.
Code of Federal Regulations, 2010 CFR
2010-10-01
... supplies and research and development work. 227.7107-2 Section 227.7107-2 Federal Acquisition Regulations... research and development work. Use the provisions and clauses required by 227-7103-6 and 227.7203-6 when..., or research work, or test and evaluation studies of structures, equipment, processes, or materials...
Accessible and informative sectioned images, color-coded images, and surface models of the ear.
Park, Hyo Seok; Chung, Min Suk; Shin, Dong Sun; Jung, Yong Wook; Park, Jin Seo
2013-08-01
In our previous research, we created state-of-the-art sectioned images, color-coded images, and surface models of the human ear. Our ear data would be more beneficial and informative if they were more easily accessible. Therefore, the purpose of this study was to distribute the browsing software and the PDF file in which ear images are to be readily obtainable and freely explored. Another goal was to inform other researchers of our methods for establishing the browsing software and the PDF file. To achieve this, sectioned images and color-coded images of ear were prepared (voxel size 0.1 mm). In the color-coded images, structures related to hearing, equilibrium, and structures originated from the first and second pharyngeal arches were segmented supplementarily. The sectioned and color-coded images of right ear were added to the browsing software, which displayed the images serially along with structure names. The surface models were reconstructed to be combined into the PDF file where they could be freely manipulated. Using the browsing software and PDF file, sectional and three-dimensional shapes of ear structures could be comprehended in detail. Furthermore, using the PDF file, clinical knowledge could be identified through virtual otoscopy. Therefore, the presented educational tools will be helpful to medical students and otologists by improving their knowledge of ear anatomy. The browsing software and PDF file can be downloaded without charge and registration at our homepage (http://anatomy.dongguk.ac.kr/ear/). Copyright © 2013 Wiley Periodicals, Inc.
Toward improved durability in advanced aircraft engine hot sections
NASA Technical Reports Server (NTRS)
Sokolowski, Daniel E. (Editor)
1989-01-01
The conference on durability improvement methods for advanced aircraft gas turbine hot-section components discussed NASA's Hot Section Technology (HOST) project, advanced high-temperature instrumentation for hot-section research, the development and application of combustor aerothermal models, and the evaluation of a data base and numerical model for turbine heat transfer. Also discussed are structural analysis methods for gas turbine hot section components, fatigue life-prediction modeling for turbine hot section materials, and the service life modeling of thermal barrier coatings for aircraft gas turbine engines.
NASA Technical Reports Server (NTRS)
1988-01-01
The charter of the Structures Division is to perform and disseminate results of research conducted in support of aerospace engine structures. These results have a wide range of applicability to practioners of structural engineering mechanics beyond the aerospace arena. The specific purpose of the symposium was to familiarize the engineering structures community with the depth and range of research performed by the division and its academic and industrial partners. Sessions covered vibration control, fracture mechanics, ceramic component reliability, parallel computing, nondestructive evaluation, constitutive models and experimental capabilities, dynamic systems, fatigue and damage, wind turbines, hot section technology (HOST), aeroelasticity, structural mechanics codes, computational methods for dynamics, structural optimization, and applications of structural dynamics, and structural mechanics computer codes.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jubin, R.T.
This report summarizes the major activities conducted in the Chemical and Energy Research Section of the Chemical Technology Division at Oak Ridge National Laboratory (ORNL) during the period July--September 1997. The section conducts basic and applied research and development in chemical engineering, applied chemistry, and bioprocessing, with an emphasis on energy-driven technologies and advanced chemical separations for nuclear and waste applications. The report describes the various tasks performed within nine major areas of research: Hot Cell Operations, Process Chemistry and Thermodynamics, Molten Salt Reactor Experiment (MSRE) Remediation Studies, Chemistry Research, Biotechnology, Separations and Materials Synthesis, Fluid Structure and Properties, Biotechnologymore » Research, and Molecular Studies. The name of a technical contact is included with each task described, and readers are encouraged to contact these individuals if they need additional information.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Park, J.F.
1988-02-01
This report summarizes progress on OHER biomedical and health-effects research conducted at Pacific Northwest Laboratory in FY 1987. The research develops the knowledge and scientific principles necessary to identify, understand, and anticipate the long-term health consequences of energy-related radiation and chemicals. Our continuing emphasis is to decrease the uncertainty of health-effects risk estimates from existing and/or developing energy-related technologies through an increased understanding of how radiation and chemicals cause health effects. The report is arranged to reflect PNL research relative to OHER programmatic structure. The first section, on human health effects, concerns statistical and epidemiological studies for assessing health risks.more » The next section, which contains reports of health-effects research in biological systems, includes research with radiation and chemicals. The last section is related to medical applications of nuclear technology.« less
Turbine Engine Hot Section Technology, 1984
NASA Technical Reports Server (NTRS)
1984-01-01
Presentations were made concerning the hot section environment and behavior of combustion liners, turbine blades, and waves. The presentations were divided into six sessions: instrumentation, combustion, turbine heat transfer, structural analysis, fatigue and fracture, and surface properties. The principal objective of each session was to disseminate research results to date, along with future plans. Topics discussed included modeling of thermal and fluid flow phenomena, structural analysis, fatigue and fracture, surface protective coatings, constitutive behavior, stress-strain response, and life prediction methods.
Finite Element Analysis of an Energy Absorbing Sub-floor Structure
NASA Technical Reports Server (NTRS)
Moore, Scott C.
1995-01-01
As part of the Advanced General Aviation Transportation Experiments program, the National Aeronautics and Space Administration's Langley Research Center is conducting tests to design energy absorbing structures to improve occupant survivability in aircraft crashes. An effort is currently underway to design an Energy Absorbing (EA) sub-floor structure which will reduce occupant loads in an aircraft crash. However, a recent drop test of a fuselage specimen with a proposed EA sub-floor structure demonstrated that the effects of sectioning the fuselage on both the fuselage section's stiffness and the performance of the EA structure were not fully understood. Therefore, attempts are underway to model the proposed sub-floor structure on computers using the DYCAST finite element code to provide a better understanding of the structure's behavior in testing, and in an actual crash.
The flows structure in unsteady gas flow in pipes with different cross-sections
NASA Astrophysics Data System (ADS)
Plotnikov, Leonid; Nevolin, Alexandr; Nikolaev, Dmitrij
2017-10-01
The results of numerical simulation and experimental study of the structure of unsteady flows in pipes with different cross sections are presented in the article. It is shown that the unsteady gas flow in a circular pipe is axisymmetric without secondary currents. Steady vortex structures (secondary flows) are observed in pipes with cross sections in the form of a square and an equilateral triangle. It was found that these secondary flows have a significant impact on gas flows in pipes of complex configuration. On the basis of experimental researches it is established that the strong oscillatory phenomena exist in the inlet pipe of the piston engine arising after the closing of the intake valve. The placement of the profiled plots (with a cross section of a square or an equilateral triangle) in the intake pipe leads to the damping of the oscillatory phenomena and a more rapid stabilization of pulsating flow. This is due to the stabilizing effect of the vortex structures formed in the corners of this configuration.
A Genre Analysis of Preface Sections of Textbook
ERIC Educational Resources Information Center
Asghar, Samina Ali; Asghar, Zobina Muhammad; Mahmood, Muhammad Asim
2015-01-01
This study aims to analyze the preface section of the fifteen English academic text book related to the field of linguistics. Researcher adapted the move structure pattern proposed by Abdollahzadeh & Salarvan (2013) on the notion of Swales (1990) and Bhatia (1993). Fourteen moves were identified employed by preface authors to indicate…
Impediments to the Employment of Young People. Review of Research.
ERIC Educational Resources Information Center
Wooden, Mark
This study provides a review of research, especially Australian research, concerned with youth employment and the impediments to the expansion of youth employment. Following the introduction, the report is divided into nine main sections. First, a demand and supply framework, which is used to structure this review, is introduced. The next four…
Best Practices for Young Children's Music Education: Guidance from Brain Research
ERIC Educational Resources Information Center
Flohr, John W.
2010-01-01
This article reviews best practices for young children's music experiences in light of developments in brain research. The first section reviews research music and brain topics including neuromyths, effect of music on structural brain changes and general intelligence, plasticity, critical and optimal periods, and at-risk student populations. The…
Nonlinear analyses of composite aerospace structures in sonic fatigue
NASA Technical Reports Server (NTRS)
Mei, Chuh
1993-01-01
This report summarizes the semiannual research progress, accomplishments, and future plans performed under the NASA Langley Research Center Grant No. NAG-1-1358. The primary research effort of this project is the development of analytical methods for the prediction of nonlinear random response of composite aerospace structures subjected to combined acoustic and thermal loads. The progress, accomplishments, and future plates on four sonic fatigue research topics are described. The sonic fatigue design and passive control of random response of shape memory alloy hybrid composites presented in section 4, which is suited especially for HSCT, is a new initiative.
Nonlinear analyses of composite aerospace structures in sonic fatigue
NASA Astrophysics Data System (ADS)
Mei, Chuh
1993-06-01
This report summarizes the semiannual research progress, accomplishments, and future plans performed under the NASA Langley Research Center Grant No. NAG-1-1358. The primary research effort of this project is the development of analytical methods for the prediction of nonlinear random response of composite aerospace structures subjected to combined acoustic and thermal loads. The progress, accomplishments, and future plates on four sonic fatigue research topics are described. The sonic fatigue design and passive control of random response of shape memory alloy hybrid composites presented in section 4, which is suited especially for HSCT, is a new initiative.
Farr, Deeonna E; Brandt, Heather M; Comer, Kimberly D; Jackson, Dawnyéa D; Pandya, Kinjal; Friedman, Daniela B; Ureda, John R; Williams, Deloris G; Scott, Dolores B; Green, Wanda; Hébert, James R
2015-09-01
Increasing the participation of Blacks in cancer research is a vital component of a strategy to reduce racial inequities in cancer burden. Community-based participatory research (CBPR) is especially well-suited to advancing our knowledge of factors that influence research participation to ultimately address cancer-related health inequities. A paucity of literature focuses on the role of structural factors limiting participation in cancer research. As part of a larger CBPR project, we used survey data from a statewide cancer needs assessment of a Black faith community to examine the influence of structural factors on attitudes toward research and the contributions of both structural and attitudinal factors on whether individuals participate in research. Regression analyses and non-parametric statistics were conducted on data from 727 adult survey respondents. Structural factors, such as having health insurance coverage, experiencing discrimination during health care encounters, and locale, predicted belief in the benefits, but not the risks, of research participation. Positive attitudes toward research predicted intention to participate in cancer research. Significant differences in structural and attitudinal factors were found between cancer research participants and non-participants; however, directionality is confounded by the cross-sectional survey design and causality cannot be determined. This study points to complex interplay of structural and attitudinal factors on research participation as well as need for additional quantitative examinations of the various types of factors that influence research participation in Black communities.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yao, Wenlong
2006-01-01
This thesis consists of six sections. The first section gives the basic research background on the ionic conduction mechanism in glass, polarization in the glass, and the method of determining the mobile carrier density in glass. The proposed work is also included in this section. The second section is a paper that characterizes the structure of MI + M 2S + (0.1 Ga 2S 3 + 0.9 GeS 2) (M = Li, Na, K and Cs) glasses using Raman and IR spectroscopy. Since the ionic radius plays an important role in determining the ionic conductivity in glasses, the glass formingmore » range for the addition of different alkalis into the basic glass forming system 0.1 Ga 2S 3 + 0.9 GeS 2 was studied. The study found that the change of the alkali radius for the same nominal composition causes significant structure change to the glasses. The third section is a paper that investigates the ionic conductivity of MI + M 2S + (0.1Ga 2S 3 + 0.9 GeS 2) (M = Li, Na, K and Cs) glasses system. Corresponding to the compositional changes in these fast ionic conducting glasses, the ionic conductivity shows changes due to the induced structural changes. The ionic radius effect on the ionic conductivity in these glasses was investigated. The fourth section is a paper that examines the mobile carrier density based upon the measurements of space charge polarization. For the first time, the charge carrier number density in fast ionic conducting chalcogenide glasses was determined. The experimental impedance data were fitted using equivalent circuits and the obtained parameters were used to determine the mobile carrier density. The influence of mobile carrier density and mobility on the ionic conductivity was separated. The fifth section is a paper that studies the structures of low-alkali-content Na 2S + B 2S 3 (x ≤ 0.2) glasses by neutron and synchrotron x-ray diffraction. Similar results were obtained both in neutron and synchrotron x-ray diffraction experiments. The results provide direct structural evidence that doping B 2S 3 with Na 2S creates a large fraction of tetrahedrally coordinated boron in the glass. The final section is the general conclusion of this thesis and the suggested future work that could be conducted to expand upon this research.« less
ERIC Educational Resources Information Center
Ntunja, A.; Gabriel, L.
The South African Library of Parliament and Research unit has devoted considerable time and money to improving its research and library services for members, committees, and management of Parliament. The Library and Research Units have recently re-structured and re-designed services and information products, engaging in collection development…
Catering Education and Training in Germany--A Comparative Study. Research Report.
ERIC Educational Resources Information Center
Rutter, Duncan
This report updates 1979 studies of European practice in catering training and education. Section 1 provides background. Section 2 describes the structure of West German federal and state government and their respective responsibilities for vocational education and training, including the dual system of apprentice training and the role played in…
Experimental investigations of aeration efficiency in high-head gated circular conduits.
Cihat Tuna, M; Ozkan, Fahri; Baylar, Ahmet
2014-01-01
The primary purpose of water aeration is to increase the oxygen saturation of the water. This can be achieved by using hydraulic structures because of substantial air bubble entrainment at these structures. Closed conduit aeration is a particular instance of this. While there has been a great deal of research on air-demand ratio within closed conduit, very little research has specifically addressed aeration efficiency of closed conduit. In the present work an experimental study was conducted to investigate the aeration efficiency of high-head gated circular conduits. Results showed that high-head gated circular conduits were effective for oxygen transfer. The effects of Froude number and ratio of the water cross-sectional flow area to the conduit cross-sectional area on aeration efficiency were particularly significant, whereas the effect of conduit length was only moderate. Further, a design formula for the aeration efficiency was presented relating the aeration efficiency to ratio of water cross-sectional flow area to conduit cross-sectional area and Froude number. The obtained results will be useful in future modeling processes and aid the practicing engineer in predicting aeration efficiency for design purposes.
Cultural Landscape Analysis of Existing Historic Districts: Picatinny Arsenal, New Jersey
2016-03-01
district, site, building, structure , or object. Especially relevant is Section 110 of the National Historic Preservation Act, which re- quires federal...82 Figure 79. Noncontributing structures in the Administrative and Research Historic District Boundary (ERDC-CERL, 2012...East side of Cannon Gate structure (ERDC-CERL, 2012). ............................. 142 ERDC/CERL TR-16-4 xii Figure 150. Stone wall that extends
A Review of Crashworthiness of Composite Aircraft Structures
1990-02-01
proprietary, or other reaons . Details on the availability of these publications may be obtained from: Graphics Section, National Research Council Canada...bottoming out, good energy-absorbing and load-limiting ability, good post-crushing structural integrity and no significant load rate sensitivity. In a... good energy absorption capability under compressive loadings. However, under tensile or bending conditions, structural integrity may be lost at initial
Impact of Academic and Nonacademic Support Structures on Third Grade Reading Achievement
ERIC Educational Resources Information Center
Peugeot, Megan A.
2017-01-01
Through a Whole Child lens a cross-sectional quantitative research design evaluated the impact of academic and nonacademic support structures on student reading achievement per the third grade Ohio Achievement Assessment (OAA). Two demographically similar public school districts within geographical proximity in Ohio were involved utilizing…
Structural requirements of research tissue banks derived from standardized project surveillance.
Herpel, E; Koleganova, N; Schreiber, B; Walter, B; Kalle, C V; Schirmacher, P
2012-07-01
Tissue banks constitute decisive and rate-limiting resource and technology platforms for basic and translational biomedical research, notably in the area of cancer. Thus, it is essential to plan and structure tissue banking and allocate resources according to research needs, but essential requirements are still incompletely defined. The tissue bank of the National Center of Tumor Diseases Heidelberg (NCT) was founded with the intention to provide tissues of optimal quality and to prioritize the realization of research projects. We analysed its structure and prospective project management registration as well as tracking records for all projects of the NCT tissue bank as of its start in 2005 in order to obtain information that may be relevant for tissue bank planning. All project proposals submitted to the NCT tissue bank (n = 681) were included in the study. For a detailed evaluation of provided services, only projects that were completed until July 2011 (n = 605) were analysed. For these 605 projects, NCT tissue bank provided 769 specific services. In all projects/services, we recorded project leader, type and amount of material provided, type of research (basic/translational), work load of project and project completion. Furthermore, all completed projects were tracked after 90 days according to a standard protocol to determine principal investigators' (PI) satisfaction and quality of the provided material. Until July 2011, 605 projects had been successfully completed as documented by material transfer agreement. Of the projects, 72.7 % addressed basic research, 22.3 % were translational research projects and 3 % concerned epidemiological research; 91 % (n = 546) concerned a single PI and the NTC tissue bank. For these projects, 769 specific services were provided. Of these services, 288 concerned providing formalin-fixed and paraffin-embedded (FFPE) tissue (extracts, full size sections), 126 providing fresh frozen materials (including fresh frozen sections), 137 providing tissue micro-array (TMA)-based sections and 199 providing immunohistochemical services. Project tracking demonstrated that all projects had started within 90 days after reception of the material by the PIs, and PI satisfaction with provided material exceeded 97 %. Standardized registration and tracking provides valuable structural information for planning and financing of tissue banks and allocation of resources. The high number of completed projects as well as high user satisfaction demonstrates that structuring of tissue banks should be preferably research-oriented and highly efficient. The comparable number of requests for FFPE and fresh frozen tissue as well as TMA-based services underpins the need for a broad approach in terms of methods and material types in order to fulfil research needs.
Facilitating Coherence across Qualitative Research Papers
ERIC Educational Resources Information Center
Chenail, Ronald J.; Duffy, Maureen; St. George, Sally; Wulff, Dan
2011-01-01
Bringing the various elements of qualitative research papers into coherent textual patterns presents challenges for authors and editors alike. Although individual sections such as presentation of the problem, review of the literature, methodology, results, and discussion may each be constructed in a sound logical and structural sense, the…
Quantitative Research in Written Composition.
ERIC Educational Resources Information Center
Gebhard, Ann O.
Offered as an introductory guide to teachers interested in approaching written English as a "second dialect" that students must master, this review covers quantitative investigations of written language. The first section deals with developmental studies, describing how a variety of researchers have related written structure to writer maturity.…
Inflatable Tubular Structures Rigidized with Foams
NASA Technical Reports Server (NTRS)
Tinker, Michael L.; Schnell, Andrew R.
2010-01-01
Inflatable tubular structures that have annular cross sections rigidized with foams, and the means of erecting such structures in the field, are undergoing development. Although the development effort has focused on lightweight structural booms to be transported in compact form and deployed in outer space, the principles of design and fabrication are also potentially applicable to terrestrial structures, including components of ultralightweight aircraft, lightweight storage buildings and shelters, lightweight insulation, and sales displays. The use of foams to deploy and harden inflatable structures was first proposed as early as the 1960s, and has been investigated in recent years by NASA, the U.S. Air Force Research Laboratory, industry, and academia. In cases of deployable booms, most of the investigation in recent years has focused on solid cross sections, because they can be constructed relatively easily. However, solid-section foam-filled booms can be much too heavy for some applications. In contrast, booms with annular cross sections according to the present innovation can be tailored to obtain desired combinations of stiffness and weight through choice of diameters, wall thicknesses, and foam densities. By far the most compelling advantage afforded by this innovation is the possibility of drastically reducing weights while retaining or increasing the stiffnesses, relative to comparable booms that have solid foamfilled cross sections. A typical boom according to this innovation includes inner and outer polyimide film sleeves to contain foam that is injected between them during deployment.
Environmental Sciences Division: Summaries of research in FY 1996
DOE Office of Scientific and Technical Information (OSTI.GOV)
NONE
This document describes the Fiscal Year 1996 activities and products of the Environmental Sciences Division, Office of Biological and Environmental Research, Office of Energy Research. The report is organized into four main sections. The introduction identifies the basic program structure, describes the programs of the Environmental Sciences Division, and provides the level of effort for each program area. The research areas and project descriptions section gives program contact information, and provides descriptions of individual research projects including: three-year funding history, research objective and approach used in each project, and results to date. Appendixes provide postal and e-mail addresses for principalmore » investigators and define acronyms used in the text. The indexes provide indexes of principal investigators, research institutions, and keywords for easy reference. Research projects are related to climatic change and remedial action.« less
Browsing software of the Visible Korean data used for teaching sectional anatomy.
Shin, Dong Sun; Chung, Min Suk; Park, Hyo Seok; Park, Jin Seo; Hwang, Sung Bae
2011-01-01
The interpretation of computed tomographs (CTs) and magnetic resonance images (MRIs) to diagnose clinical conditions requires basic knowledge of sectional anatomy. Sectional anatomy has traditionally been taught using sectioned cadavers, atlases, and/or computer software. The computer software commonly used for this subject is practical and efficient for students but could be more advanced. The objective of this research was to present browsing software developed from the Visible Korean images that can be used for teaching sectional anatomy. One thousand seven hundred and two sets of MRIs, CTs, and sectioned images (intervals, one millimeter) of a whole male cadaver were prepared. Over 900 structures in the sectioned images were outlined and then filled with different colors to elaborate each structure. Software was developed where four corresponding images could be displayed simultaneously; in addition, the structures in the image data could be readily recognized with the aid of the color-filled outlines. The software, distributed free of charge, could be a valuable tool to teach medical students. For example, sectional anatomy could be taught by showing the sectioned images with real color and high resolution. Students could then review the lecture by using the sectioned and color-filled images on their own computers. Students could also be evaluated using the same software. Furthermore, other investigators would be able to replace the images for more comprehensive sectional anatomy. Copyright © 2011 Wiley-Liss, Inc.
Turbine Engine Hot Section Technology (HOST)
NASA Technical Reports Server (NTRS)
1983-01-01
A two-day workshop on the research and plans for turbine engine hot section durability problems was held on October 25 and 26, 1983, at the NASA Lewis Research Center. Presentations were made during six sessions, including structural analysis, fatigue and fracture, surface protective coatings, combustion, turbine heat transfer, and instrumentation, that dealt with the thermal and fluid environment around liners, blades, and vanes, and with material coatings, constitutive behavior, stress-strain response, and life prediction methods for the three components. The principal objective of each session was to disseminate the research results to date, along with future plans, in each of the six areas. Contract and government researchers presented results of their work.
An Overview: NASA LeRC Structures Programs
NASA Technical Reports Server (NTRS)
Zaretsky, Erwin V.
1998-01-01
A workshop on National Structures Programs was held, jointly sponsored by the AIAA Structures Technical Committee, the University of Virginia's Center for Advanced Computational Technology and NASA. The Objectives of the Workshop were to: provide a forum for discussion of current Government-sponsored programs in the structures area; identify high potential research areas for future aerospace systems; and initiate suitable interaction mechanisms with the managers of structures programs. The presentations covered structures programs at NASA, DOD (AFOSR, ONR, ARO and DARPA), and DOE. This publication is the presentation of the Structures and Acoustics Division of the NASA Lewis Research Center. The Structures and Acoustics Division has its genesis dating back to 1943. It is responsible for NASA research related to rotating structures and structural hot sections of both airbreathing and rocket engines. The work of the division encompasses but is not limited to aeroelasticity, structural life prediction and reliability, fatigue and fracture, mechanical components such as bearings, gears, and seals, and aeroacoustics. These programs are discussed and the names of responsible individuals are provided for future reference.
Review on cold-formed steel connections.
Lee, Yeong Huei; Tan, Cher Siang; Mohammad, Shahrin; Tahir, Mahmood Md; Shek, Poi Ngian
2014-01-01
The concept of cold-formed light steel framing construction has been widespread after understanding its structural characteristics with massive research works over the years. Connection serves as one of the important elements for light steel framing in order to achieve its structural stability. Compared to hot-rolled steel sections, cold-formed steel connections perform dissimilarity due to the thin-walled behaviour. This paper aims to review current researches on cold-formed steel connections, particularly for screw connections, storage rack connections, welded connections, and bolted connections. The performance of these connections in the design of cold-formed steel structures is discussed.
Review on Cold-Formed Steel Connections
Tan, Cher Siang; Mohammad, Shahrin; Md Tahir, Mahmood; Shek, Poi Ngian
2014-01-01
The concept of cold-formed light steel framing construction has been widespread after understanding its structural characteristics with massive research works over the years. Connection serves as one of the important elements for light steel framing in order to achieve its structural stability. Compared to hot-rolled steel sections, cold-formed steel connections perform dissimilarity due to the thin-walled behaviour. This paper aims to review current researches on cold-formed steel connections, particularly for screw connections, storage rack connections, welded connections, and bolted connections. The performance of these connections in the design of cold-formed steel structures is discussed. PMID:24688448
NASA Astrophysics Data System (ADS)
RóŻyło, Patryk; Debski, Hubert; Kral, Jan
2018-01-01
The subject of the research was a short thin-walled top-hat cross-section composite profile. The tested structure was subjected to axial compression. As part of the critical state research, critical load and the corresponding buckling mode was determined. Later in the study laminate damage areas were determined throughout numerical analysis. It was assumed that the profile is simply supported on the cross sections ends. Experimental tests were carried out on a universal testing machine Zwick Z100 and the results were compared with the results of numerical calculations. The eigenvalue problem and a non-linear problem of stability of thin-walled structures were carried out by the use of commercial software ABAQUS®. In the presented cases, it was assumed that the material is linear-elastic and non-linearity of the model results from the large displacements. Solution to the geometrically nonlinear problem was conducted by the use of the incremental-iterative Newton-Raphson method.
Composite structure of helicopter rotor blades studied by neutron- and X-ray radiography
NASA Astrophysics Data System (ADS)
Balaskó, M.; Veres, I.; Molnár, Gy.; Balaskó, Zs.; Sváb, E.
2004-07-01
In order to inspect the possible defects in the composite structure of helicopter rotor blades combined neutron- and X-ray radiography investigations were performed at the Budapest Research Reactor. Imperfections in the honeycomb structure, resin rich or starved areas at the core-honeycomb surfaces, inhomogeneities at the adhesive filling and water percolation at the sealing interfaces of the honeycomb sections were discovered.
Impact Testing and Simulation of Composite Airframe Structures
NASA Technical Reports Server (NTRS)
Jackson, Karen E.; Littell, Justin D.; Horta, Lucas G.; Annett, Martin S.; Fasanella, Edwin L.; Seal, Michael D., II
2014-01-01
Dynamic tests were performed at NASA Langley Research Center on composite airframe structural components of increasing complexity to evaluate their energy absorption behavior when subjected to impact loading. A second objective was to assess the capabilities of predicting the dynamic response of composite airframe structures, including damage initiation and progression, using a state-of-the-art nonlinear, explicit transient dynamic finite element code, LS-DYNA. The test specimens were extracted from a previously tested composite prototype fuselage section developed and manufactured by Sikorsky Aircraft Corporation under the US Army's Survivable Affordable Repairable Airframe Program (SARAP). Laminate characterization testing was conducted in tension and compression. In addition, dynamic impact tests were performed on several components, including I-beams, T-sections, and cruciform sections. Finally, tests were conducted on two full-scale components including a subfloor section and a framed fuselage section. These tests included a modal vibration and longitudinal impact test of the subfloor section and a quasi-static, modal vibration, and vertical drop test of the framed fuselage section. Most of the test articles were manufactured of graphite unidirectional tape composite with a thermoplastic resin system. However, the framed fuselage section was constructed primarily of a plain weave graphite fabric material with a thermoset resin system. Test data were collected from instrumentation such as accelerometers and strain gages and from full-field photogrammetry.
Turbine Engine Hot Section Technology (HOST)
NASA Technical Reports Server (NTRS)
1982-01-01
Research and plans concerning aircraft gas turbine engine hot section durability problems were discussed. Under the topics of structural analysis, fatigue and fracture, surface protective coatings, combustion, turbine heat transfer, and instrumentation specific points addressed were the thermal and fluid environment around liners, blades, and vanes, material coatings, constitutive behavior, stress-strain response, and life prediction methods for the three components.
ERIC Educational Resources Information Center
Khalil, Mohammed K.; Paas, Fred; Johnson, Tristan E.; Su, Yung K.; Payer, Andrew F.
2008-01-01
This research is an effort to best utilize the interactive anatomical images for instructional purposes based on cognitive load theory. Three studies explored the differential effects of three computer-based instructional strategies that use anatomical cross-sections to enhance the interpretation of radiological images. These strategies include:…
33 CFR Appendix A to Part 325 - Permit Form and Special Conditions
Code of Federal Regulations, 2010 CFR
2010-07-01
...). () Section 404 of the Clean Water Act (33 U.S.C. 1344). () Section 103 of the Marine Protection, Research and... unpermitted activities or structures caused by the activity authorized by this permit. d. Design or... Ocean Service, Office of Coast Survey, N/CS261, 1315 East West Highway, Silver Spring, Maryland 20910...
33 CFR Appendix A to Part 325 - Permit Form and Special Conditions
Code of Federal Regulations, 2011 CFR
2011-07-01
...). () Section 404 of the Clean Water Act (33 U.S.C. 1344). () Section 103 of the Marine Protection, Research and... unpermitted activities or structures caused by the activity authorized by this permit. d. Design or... Ocean Service, Office of Coast Survey, N/CS261, 1315 East West Highway, Silver Spring, Maryland 20910...
33 CFR Appendix A to Part 325 - Permit Form and Special Conditions
Code of Federal Regulations, 2013 CFR
2013-07-01
...). () Section 404 of the Clean Water Act (33 U.S.C. 1344). () Section 103 of the Marine Protection, Research and... unpermitted activities or structures caused by the activity authorized by this permit. d. Design or... Ocean Service, Office of Coast Survey, N/CS261, 1315 East West Highway, Silver Spring, Maryland 20910...
33 CFR Appendix A to Part 325 - Permit Form and Special Conditions
Code of Federal Regulations, 2012 CFR
2012-07-01
...). () Section 404 of the Clean Water Act (33 U.S.C. 1344). () Section 103 of the Marine Protection, Research and... unpermitted activities or structures caused by the activity authorized by this permit. d. Design or... Ocean Service, Office of Coast Survey, N/CS261, 1315 East West Highway, Silver Spring, Maryland 20910...
NASA Astrophysics Data System (ADS)
Nugroho, B.; Pranantya, P. A.; Witjahjati, R.; Rofinus
2018-01-01
This study aims to estimate the potential collapse in the Seropan cave, based on the existing geological structure conditions in the cave. This is very necessary because in the Seropan cave will be built Microhydro installation for power plants. The electricity will be used to raise the underground river water in the cave to a barren soil surface, which can be used for surface irrigation. The method used is analysis the quality of rock mass along the cave. Analysis of rock mass quality using Geomechanical Classification or Rock Mass Rating (RMR), to determine the magnitude of the effect of geological structure on rock mass stability. The research path is divided into several sections and quality analysis is performed on each section. The results show that the influence of geological structure is very large and along the cave where the research there are several places that have the potential to collapse, so need to get serious attention in handling it. Nevertheless, the construction of this Microhydro installation can still be carried out by making a reinforcement on potentially collapsing parts
Advanced Computation Dynamics Simulation of Protective Structures Research
2013-02-01
additional load with increased cracking and deflection. Eventually, the walls failed in flexure due to self-weight and did not indicate any signs of shear...overall volume of the FEM block to be 432.2 in3, instead of 415.1 in3; the overall volume increased of area is 1.041%. This additional material is...sections in addition to the summary. Section 2 consists of an introduction, objectives, scope and methodology, and organization of the report. Section 2
Vertical drop test of a transport fuselage section located forward of the wing
NASA Technical Reports Server (NTRS)
Williams, M. S.; Hayduk, R. J.
1983-01-01
A Boeing 707 fuselage section was drop tested at the NASA Langley Research Center to measure structural, seat, and occupant response to vertical crack loads. Post-test inspection showed that the section bottom collapsed inward approximately 2 ft. Preliminary data traces indicated maximum normal accelerations of 20 g on the fuselage bottom, 10 to 12 g on the cabin floor, and 6.5 to 8 g in the pelvises of the anthropomorphic dummies.
NASA Astrophysics Data System (ADS)
Abdel-Jaber, H.; Glisic, B.
2014-07-01
Structural health monitoring (SHM) consists of the continuous or periodic measurement of structural parameters and their analysis with the aim of deducing information about the performance and health condition of a structure. The significant increase in the construction of prestressed concrete bridges motivated this research on an SHM method for the on-site determination of the distribution of prestressing forces along prestressed concrete beam structures. The estimation of the distribution of forces is important as it can give information regarding the overall performance and structural integrity of the bridge. An inadequate transfer of the designed prestressing forces to the concrete cross-section can lead to a reduced capacity of the bridge and consequently malfunction or failure at lower loads than predicted by design. This paper researches a universal method for the determination of the distribution of prestressing forces along concrete beam structures at the time of transfer of the prestressing force (e.g., at the time of prestressing or post-tensioning). The method is based on the use of long-gauge fiber optic sensors, and the sensor network is similar (practically identical) to the one used for damage identification. The method encompasses the determination of prestressing forces at both healthy and cracked cross-sections, and for the latter it can yield information about the condition of the cracks. The method is validated on-site by comparison to design forces through the application to two structures: (1) a deck-stiffened arch and (2) a curved continuous girder. The uncertainty in the determination of prestressing forces was calculated and the comparison with the design forces has shown very good agreement in most of the structures’ cross-sections, but also helped identify some unusual behaviors. The method and its validation are presented in this paper.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nguyen, Ba Nghiep; Jin, Xiaoshi; Wang, Jin
2012-02-23
This report describes the work conducted under the CRADA Nr. PNNL/304 between Battelle PNNL and Autodesk whose objective is to validate the new process models developed under the previous CRADA for large injection-molded LFT composite structures. To this end, the ARD-RSC and fiber length attrition models implemented in the 2013 research version of Moldflow was used to simulate the injection molding of 600-mm x 600-mm x 3-mm plaques from 40% glass/polypropylene (Dow Chemical DLGF9411.00) and 40% glass/polyamide 6,6 (DuPont Zytel 75LG40HSL BK031) materials. The injection molding was performed by Injection Technologies, Inc. at Windsor, Ontario (under a subcontract by Oakmore » Ridge National Laboratory, ORNL) using the mold offered by the Automotive Composite Consortium (ACC). Two fill speeds under the same back pressure were used to produce plaques under slow-fill and fast-fill conditions. Also, two gating options were used to achieve the following desired flow patterns: flows in edge-gated plaques and in center-gated plaques. After molding, ORNL performed measurements of fiber orientation and length distributions for process model validations. The structure of this report is as follows. After the Introduction (Section 1), Section 2 provides a summary of the ARD-RSC and fiber length attrition models. A summary of model implementations in the latest research version of Moldflow is given in Section 3. Section 4 provides the key processing conditions and parameters for molding of the ACC plaques. The validations of the ARD-RSC and fiber length attrition models are presented and discussed in Section 5. The conclusions will be drawn in Section 6.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Park, J.F.
1989-06-01
This report summarizes progress on OHER biomedical and health-effects research conducted at PNL in FY 1988. The research develops the knowledge and scientific principles necessary to identify, understand, and anticipate the long-term health consequences of energy-related radiation and chemicals. Our continuing emphasis is to decrease the uncertainty of health-effects risk estimates from existing and/or developing energy-related technologies through an increased understanding of how radiation and chemicals cause health effects. The report is arranged to reflect PNL research relative to OHER programmatic structure. The first section, on human health effects, concerns statistical and epidemiological studies for assessing health risks. The nextmore » section, which contains reports of health-effects research in biological systems, includes research with radiation and chemicals.« less
2005-10-01
I found Sarantakos's book to be a clear and straightforward guide to social research methods. The book is aimed at undergraduate level, and I am sure will appeal to students from a range of disciplines. The structure of the book reflects the different stages of the research process and as such it is easy to locate all the required sections. It introduces qualitative and quantitative approaches in a balanced way and includes sufficient detail of the philosophical roots of each of these research traditions. It was good to find simple and easy to follow accounts of the complex underpinning of a number of research approach that are popular in nursing research. Included are topics such as interpretivism, symbolic interactionism and phenomenology as well the more usually found hallmarks of positivistic-type research. While feminism and feministic research in nursing is an important subject area I did wonder if the amount of attention they received were perhaps a little unbalanced when related to the other subject areas covered. There are, however, useful sections on data collection and analysis. I found, for example, the section on grounded theory approaches to data analysis particularly good.
New Directions in NASA's Materials Science Program
NASA Technical Reports Server (NTRS)
Gillies, Donald C.; Whitaker, Ann F. (Technical Monitor)
2001-01-01
Recently, NASA's Microgravity Research Division was re-aligned to match the Agency's increasing awareness of the importance of biological and nano-structural sciences. The Division has become the Physical Sciences Research section within the newly created Office of Biological and Physical Research. Within materials science and in the last few years, new programs aimed at biomaterials have been initiated. Results from these programs and also new research pertaining to materials for radiation protection will be discussed.
Novel Thin Film Sensor Technology for Turbine Engine Hot Section Components
NASA Technical Reports Server (NTRS)
Wrbanek, John D.; Fralick, Gustave C.
2007-01-01
Degradation and damage that develops over time in hot section components can lead to catastrophic failure of the turbine section of aircraft engines. A range of thin film sensor technology has been demonstrated enabling on-component measurement of multiple parameters either individually or in sensor arrays including temperature, strain, heat flux, and flow. Conductive ceramics are beginning to be investigated as new materials for use as thin film sensors in the hot section, leveraging expertise in thin films and high temperature materials. The current challenges are to develop new sensor and insulation materials capable of withstanding the extreme hot section environment, and to develop techniques for applying sensors onto complex high temperature structures for aging studies of hot propulsion materials. The technology research and development ongoing at NASA Glenn Research Center for applications to future aircraft, launch vehicles, space vehicles, and ground systems is outlined.
Physics through the 1990s: Atomic, molecular and optical physics
NASA Technical Reports Server (NTRS)
1986-01-01
The volume presents a program of research initiatives in atomic, molecular, and optical physics. The current state of atomic, molecular, and optical physics in the US is examined with respect to demographics, education patterns, applications, and the US economy. Recommendations are made for each field, with discussions of their histories and the relevance of the research to government agencies. The section on atomic physics includes atomic theory, structure, and dynamics; accelerator-based atomic physics; and large facilities. The section on molecular physics includes spectroscopy, scattering theory and experiment, and the dynamics of chemical reactions. The section on optical physics discusses lasers, laser spectroscopy, and quantum optics and coherence. A section elucidates interfaces between the three fields and astrophysics, condensed matter physics, surface science, plasma physics, atmospheric physics, and nuclear physics. Another section shows applications of the three fields in ultra-precise measurements, fusion, national security, materials, medicine, and other topics.
Civil society engagement in innovation and research through the European Public Health Association.
Zeegers Paget, Dineke; Barnhoorn, Floris; McCarthy, Mark; Alexanderson, Kristina; Conceição, Claudia; Devillé, Walter; Grimaud, Olivier; Katreniakova, Zuzana; Narkauskaité, Laura; Saliba, Amanda; Sammut, Marvic; Voss, Margaretha
2013-11-01
The European Public Health Association (EUPHA) proposed and led PHIRE (Public Health Innovation and Research in Europe), with co-financing by the European Commission, to assess public health innovation and research at national level in Europe. PHIRE was also designed to promote organizational development and capacity building of EUPHA. We assess the success and limitations of using EUPHA's participative structures. In total, 30 European countries were included-27 EU countries, Iceland, Norway and Switzerland. EUPHA thematic section presidents were asked to identify country informants to report, through a web-based questionnaire, on eight public health innovations. National public health associations (EUPHA member organizations) were requested to identify their national public health research programmes and calls, review the health research system, coordinate a stakeholder workshop and provide a national report. The section and national reports were assessed for responses and completeness. Half of the final responding CIs were members of EUPHA sections and the other half gained from other sources. Experts declined to respond for reasons including lack of time, knowledge of the innovation or funding. National public health associations held PHIRE workshops with Ministries of Health in 14 countries; information for 10 countries was gained through discussions within the national association, or country visits by PHIRE partners. Six countries provided no response. Some national associations had too weak organizational structures for the work or insufficient financial resources or criticism of the project. EUPHA is the leading civil society organization giving support to public health research in Europe. PHIRE created new knowledge and supported organizational development. EUPHA sections gained expert reports on public health innovations in European countries and national public health associations reported on national public health research systems. Significant advances could be made if the European Commission worked more directly with EUPHA's expert members and with the national public health associations.
Research on Darrieus-type hydraulic turbine for extra-low head hydropower utilization
NASA Astrophysics Data System (ADS)
Furukawa, A.; Watanabe, S.; Okuma, K.
2012-11-01
A Darrieus-type turbine has been investigated for extra-low head hydropower utilization. In the present paper, authors'research on Darrieus-type hydraulic turbine is briefly reviewed. The working principle of Darrieus turbine is explained with advantage of its simple structure, at first. Then the fluid-dynamic difference between rotating and linear motions of a blade in a uniform flow is clarified with guiding principle of high performance design of Darrieus turbine. Cavitation problem is also described. Next, effects of duct-casing, consisting of an intake, runner section and draft tube, are discussed and a simplified structure of Darrieus turbine is shown by installing the inlet nozzle. Finally, in the practical use, an adjustment of inlet nozzle section by lowering the inlet nozzle height is proposed when flow rate is varied temporally and seasonally.
[Histo-anatomical researches of two subspecies of Lavandula angustifolia Mill].
Robu, Silvia; Galeş, Ramona; Toma, C; Stănescu, Ursula
2011-01-01
The structure of the inflorescences of two subspecies of Lavandula angustifolia sL. angustifolia ssp. angustifolia and. L. angustifolia ssp. pyrenaica (D.C.) Guineaţ was studied to determine the range of variation in certain histo-anatomical characters. The flower and leaf structure has been analysed on cross and superficial section using the usual techniques and methods applied in plant histo-anatomical research. In cross-section, inflorescence axis has a squared-shape contour, with four proeminent ribs. On the epiderme of inflorescence axis there are present stomata, trichoms and secretory hairs. The trichoms are pluricelullar and T-branched. The secretory hairs have a short pedicel and a uni-or bicellular head. The study revealed that there are only quantitative differences, referring to the degree of sclerification and lignification of mechanical elements and the size of the vascular bundles.
Scottish Schools Science Equipment Research Centre, Bulletin No. 56, June 1972.
ERIC Educational Resources Information Center
1972
A model demonstrating the relationship between the structure of blood vessels and the flow of blood is described and illustrated in the biology section of the newsletter. The apparatus also contains a functional (but not structural) model of the heart. Suggestions for the preparation of a relatively permanent dialysis bag from visking tubing are…
A combined histological and MRI brain atlas of the common marmoset monkey, Callithrix jacchus.
Newman, John D; Kenkel, William M; Aronoff, Emily C; Bock, Nicholas A; Zametkin, Molly R; Silva, Afonso C
2009-12-11
The common marmoset, Callithrix jacchus, is of growing importance for research in neuroscience and related fields. In the present work, we describe a combined histological and magnetic resonance imaging (MRI) atlas constructed from the brains of two adult female marmosets. Histological sections were processed from Nissl staining and digitized to produce an atlas in a large format that facilitates visualization of structures with significant detail. Naming of identifiable brain structures was performed utilizing current terminology. The histological sections and a simplified schematic atlas are available online at http://udn.nichd.nih.gov/brainatlas_home.html.
Robust control of accelerators
NASA Astrophysics Data System (ADS)
Joel, W.; Johnson, D.; Chaouki, Abdallah T.
1991-07-01
The problem of controlling the variations in the rf power system can be effectively cast as an application of modern control theory. Two components of this theory are obtaining a model and a feedback structure. The model inaccuracies influence the choice of a particular controller structure. Because of the modelling uncertainty, one has to design either a variable, adaptive controller or a fixed, robust controller to achieve the desired objective. The adaptive control scheme usually results in very complex hardware; and, therefore, shall not be pursued in this research. In contrast, the robust control method leads to simpler hardware. However, robust control requires a more accurate mathematical model of the physical process than is required by adaptive control. Our research at the Los Alamos National Laboratory (LANL) and the University of New Mexico (UNM) has led to the development and implementation of a new robust rf power feedback system. In this article, we report on our research progress. In section 1, the robust control problem for the rf power system and the philosophy adopted for the beginning phase of our research is presented. In section 2, the results of our proof-of-principle experiments are presented. In section 3, we describe the actual controller configuration that is used in LANL FEL physics experiments. The novelty of our approach is that the control hardware is implemented directly in rf. without demodulating, compensating, and then remodulating.
Simulating the Impact Response of Composite Airframe Components
NASA Technical Reports Server (NTRS)
Jackson, Karen E.; Littell, Justin D.; Fasanella, Edwin L.
2014-01-01
In 2010, NASA Langley Research Center obtained residual hardware from the US Army's Survivable Affordable Repairable Airframe Program (SARAP). The hardware consisted of a composite fuselage section that was representative of the center section of a Black Hawk helicopter. The section was fabricated by Sikorsky Aircraft Corporation and designated the Test Validation Article (TVA). The TVA was subjected to a vertical drop test in 2008 to evaluate a tilting roof concept to limit the intrusion of overhead mass items, such as the rotor transmission, into the fuselage cabin. As a result of the 2008 test, damage to the hardware was limited primarily to the roof. Consequently, when the post-test article was obtained in 2010, the roof area was removed and the remaining structure was cut into six different types of test specimens including: (1) tension and compression coupons for material property characterization, (2) I-beam sections, (3) T-sections, (4) cruciform sections, (5) a large subfloor section, and (6) a forward framed fuselage section. In 2011, NASA and Sikorsky entered into a cooperative research agreement to study the impact responses of composite airframe structures and to evaluate the capabilities of the explicit transient dynamic finite element code, LS-DYNA®, to simulate these responses including damage initiation and progressive failure. Finite element models of the composite specimens were developed and impact simulations were performed. The properties of the composite material were represented using both a progressive in-plane damage model (Mat 54) and a continuum damage mechanics model (Mat 58) in LS-DYNA. This paper provides test-analysis comparisons of time history responses and the location and type of damage for representative I-beam, T-section, and cruciform section components.
The Earth Science Research Network as Seen Through Network Analysis of the AGU
NASA Astrophysics Data System (ADS)
Narock, T.; Hasnain, S.; Stephan, R.
2017-12-01
Scientometrics is the science of science. Scientometric research includes measurements of impact, mapping of scientific fields, and the production of indicators for use in policy and management. We have leveraged network analysis in a scientometric study of the American Geophysical Union (AGU). Data from the AGU's Linked Data Abstract Browser was used to create a visualization and analytics tools to explore the Earth science's research network. Our application applies network theory to look at network structure within the various AGU sections, identify key individuals and communities related to Earth science topics, and examine multi-disciplinary collaboration across sections. Opportunities to optimize Earth science output, as well as policy and outreach applications, are discussed.
Open Architecture Data System for NASA Langley Combined Loads Test System
NASA Technical Reports Server (NTRS)
Lightfoot, Michael C.; Ambur, Damodar R.
1998-01-01
The Combined Loads Test System (COLTS) is a new structures test complex that is being developed at NASA Langley Research Center (LaRC) to test large curved panels and cylindrical shell structures. These structural components are representative of aircraft fuselage sections of subsonic and supersonic transport aircraft and cryogenic tank structures of reusable launch vehicles. Test structures are subjected to combined loading conditions that simulate realistic flight load conditions. The facility consists of two pressure-box test machines and one combined loads test machine. Each test machine possesses a unique set of requirements or research data acquisition and real-time data display. Given the complex nature of the mechanical and thermal loads to be applied to the various research test articles, each data system has been designed with connectivity attributes that support both data acquisition and data management functions. This paper addresses the research driven data acquisition requirements for each test machine and demonstrates how an open architecture data system design not only meets those needs but provides robust data sharing between data systems including the various control systems which apply spectra of mechanical and thermal loading profiles.
Rhetorical Organisation of the Subsections of Research Article Introductions in Applied Linguistics
ERIC Educational Resources Information Center
Öztürk, Ismet
2018-01-01
Since the publication of the book Genre Analysis (CUP) by Swales (1990), many studies have focused on the study of the rhetorical organisation of different sections of research articles (RAs). The organisation of RA introductions has received most of the attention. However, the focus has generally been on the structure of introductions without…
AFRL Research in Plasma-Assisted Combustion
2013-10-23
Scramjet propulsion Non-equilibrium flows Diagnostics for scramjet controls Boundary-layer transition Structural sciences for...hypersonic vehicles Computational sciences for hypersonic flight 3 DISTRIBUTION STATEMENT A – Unclassified, Unlimited Distribution Overview Research...within My Division HIFiRE-5 Vehicle Launched 23 April 2012 can payload transition section Orion S-30 Focus on hypersonic flight: scalability
Introduction to the special section on mixture modeling in personality assessment.
Wright, Aidan G C; Hallquist, Michael N
2014-01-01
Latent variable models offer a conceptual and statistical framework for evaluating the underlying structure of psychological constructs, including personality and psychopathology. Complex structures that combine or compare categorical and dimensional latent variables can be accommodated using mixture modeling approaches, which provide a powerful framework for testing nuanced theories about psychological structure. This special series includes introductory primers on cross-sectional and longitudinal mixture modeling, in addition to empirical examples applying these techniques to real-world data collected in clinical settings. This group of articles is designed to introduce personality assessment scientists and practitioners to a general latent variable framework that we hope will stimulate new research and application of mixture models to the assessment of personality and its pathology.
NASA Technical Reports Server (NTRS)
Smith, Russell W.; Langford, William M.
2012-01-01
In support of NASA s Habitat Demonstration Unit - Deep Space Habitat Prototype, a number of evolved structural sections were designed, fabricated, analyzed and installed in the 5 meter diameter prototype. The hardware consisted of three principal structural sections, and included the development of novel fastener insert concepts. The articles developed consisted of: 1) 1/8th of the primary flooring section, 2) an inner radius floor beam support which interfaced with, and supported (1), 3) two upper hatch section prototypes, and 4) novel insert designs for mechanical fastener attachments. Advanced manufacturing approaches were utilized in the fabrication of the components. The structural components were developed using current commercial aircraft constructions as a baseline (for both the flooring components and their associated mechanical fastener inserts). The structural sections utilized honeycomb sandwich panels. The core section consisted of 1/8th inch cell size Nomex, at 9 lbs/cu ft, and which was 0.66 inches thick. The facesheets had 3 plys each, with a thickness of 0.010 inches per ply, made from woven E-glass with epoxy reinforcement. Analysis activities consisted of both analytical models, as well as initial closed form calculations. Testing was conducted to help verify analysis model inputs, as well as to facilitate correlation between testing and analysis. Test activities consisted of both 4 point bending tests as well as compressive core crush sequences. This paper presents an overview of this activity, and discusses issues encountered during the various phases of the applied research effort, and its relevance to future space based habitats.
NASA Technical Reports Server (NTRS)
2002-01-01
The purpose of this document is to present the strategic plan and associated organizational structure that the National Space Biomedical Research Institute (NSBRI) will utilize to achieve the defined mission and objectives provided by NASA. Much of the information regarding the background and establishment of the NSBRI by NASA has been provided in other documentation and will not be repeated in this Strategic Plan. This Strategic Plan is presented in two volumes. Volume I (this volume) begins with an Introduction (Section 2) that provides the Institute's NASA-defined mission and objectives, and the organizational structure adopted to implement these through three Strategic Programs: Countermeasure Research; Education, Training and Outreach; and Cooperative Research and Development. These programs are described in Sections 3 to 5. Each program is presented in a similar way, using four subsections: Goals and Objectives; Current Strategies; Gaps and Modifications; and Resource Requirements. Section 6 provides the administrative infrastructure and total budget required to implement the Strategic Programs and assures that they form a single cohesive plan. This plan will ensure continued success of the Institute for the next five years. Volume II of the Strategic Plan provides an in-depth analysis of the current and future strategic programs of the 12 current NSBRI teams, including their goals, objectives, mutual interactions and schedules.
Development of improved overlay thickness design alternatives for local roads.
DOT National Transportation Integrated Search
2015-07-01
In this research study, 20 pavement sections were selected from six counties in Illinois, with varying : structural and traffic characteristics. Falling weight deflectometer (FWD) tests were conducted on these : road segments to determine and monitor...
NASA Astrophysics Data System (ADS)
Polskoy, Petr; Mailyan, Dmitry; Georgiev, Sergey; Muradyan, Viktor
2018-03-01
The increase of high-rise construction volume or «High-Rise Construction» requires the use of high-strength concrete and that leads to the reduction in section size of structures and to the decrease in material consumption. First of all, it refers to the compressed elements for which, when the transverse dimensions are reduced, their flexibility and deformation increase but the load bearing capacity decreases. Growth in construction also leads to the increase of repair and restoration works or to the strengthening of structures. The most effective method of their strengthening in buildings of «High-Rise Construction» is the use of composite materials which reduces the weight of reinforcement elements and labour costs on execution of works. In this article the results of experimental research on strength and deformation of short compressed reinforced concrete structures, reinforced with external carbon fiber reinforcement, are presented. Their flexibility is λh=10, and the cross-section dimensions ratio b/h is 2, that is 1,5 times more, than recommended by standards in Russia. The following research was being done for three kinds of strained and deformed conditions with different variants of composite reinforcement. The results of the experiment proved the real efficiency of composite reinforcement of the compressed elements with sides ratio equal to 2, increasing the bearing capacity of pillars till 1,5 times. These results can be used for designing the buildings of different number of storeys.
1979-08-01
0 Blue staff modules will operate under a manual staff system only. The section begins with the fundamental structure of the design concept. This...engagements, etc. Hard wired elements, like the steel and concrete in a building under construction, represent the underlying structural framework of... structure of this file is illustrated in Figure 4-10. The file will consist of 300 records of approximately 300 bytes or characters each. The records
Finite Element Simulations of Two Vertical Drop Tests of F-28 Fuselage Sections
NASA Technical Reports Server (NTRS)
Jackson, Karen E.; Littell, Justin D.; Annett, Martin S.; Haskin, Ian M.
2018-01-01
In March 2017, a vertical drop test of a forward fuselage section of a Fokker F-28 MK4000 aircraft was conducted as part of a joint NASA/FAA project to investigate the performance of transport aircraft under realistic crash conditions. In June 2017, a vertical drop test was conducted of a wing-box fuselage section of the same aircraft. Both sections were configured with two rows of aircraft seats, in a triple-double configuration. A total of ten Anthropomorphic Test Devices (ATDs) were secured in seats using standard lap belt restraints. The forward fuselage section was also configured with luggage in the cargo hold. Both sections were outfitted with two hat racks, each with added ballast mass. The drop tests were performed at the Landing and Impact Research facility located at NASA Langley Research Center in Hampton, Virginia. The measured impact velocity for the forward fuselage section was 346.8-in/s onto soil. The wing-box section was dropped with a downward facing pitch angle onto a sloping soil surface in order to create an induced forward acceleration in the airframe. The vertical impact velocity of the wing-box section was 349.2-in/s. A second objective of this project was to assess the capabilities of finite element simulations to predict the test responses. Finite element models of both fuselage sections were developed for execution in LS-DYNA(Registered Trademark), a commercial explicit nonlinear transient dynamic code. The models contained accurate representations of the airframe structure, the hat racks and hat rack masses, the floor and seat tracks, the luggage in the cargo hold for the forward section, and the detailed under-floor structure in the wing-box section. Initially, concentrated masses were used to represent the inertial properties of the seats, restraints, and ATD occupants. However, later simulations were performed that included finite element representations of the seats, restraints, and ATD occupants. These models were developed to more accurately replicate the seat loading of the floor and to enable prediction of occupant impact responses. Models were executed to generate analytical predictions of airframe responses, which were compared with test data to validate the model. Comparisons of predicted and experimental structural deformation and failures were made. Finally, predicted and experimental soil deformation and crater depths were also compared for both drop test configurations.
NASA Astrophysics Data System (ADS)
Brawn, A. D.; Wheal, H. V.
1986-07-01
A system is described which can be used to create a three-dimensional model of a neurone from the central nervous system. This model can then be used to obtain quantitative data on the physical and electrical pro, perties of the neurone. Living neurones are either raised in culture, or taken from in vitro preparations of brain tissue and optically sectioned. These two-dimensional sections are digitised, and input to a 68008-based microcomputer. The system reconstructs the three-dimensional structure of the neurone, both geanetrically and electrically. The user can a) View the structure fran any point at any angle b) "Move through" the structure along any given vector c) Nave through" the structure following a neurone process d) Fire the neurone at any point, and "watch" the action potentials propagate e) Vary the parameters of the electrical model of a process element. The system is targeted to a research programme on epilepsy, which makes frequent use of both geometric and electrical neurone modelling. Current techniques which may involve crude histology and two-dimensional drawings have considerable short camings.
Preparation for Testing a Multi-Bay Box Subjected to Combined Loads
NASA Technical Reports Server (NTRS)
Rouse, Marshall; Jegley, Dawn
2015-01-01
The COmbined Loads Test System (COLTS) facility at NASA Langley Research Center provides a test capability to help develop validated structures technologies. The test machine was design to accommodate a range of fuselage structures and wing sections and subject them to both quasistatic and cyclic loading conditions. The COLTS facility is capable of testing fuselage barrels up to 4.6 m in diameter and 13.7 m long with combined mechanical, internal pressure, and thermal loads. The COLTS facility is currently being prepared to conduct a combined mechanical and pressure loading for a multi-bay pressure box to experimentally verify the structural performance of a composite structure which is 9.1 meters long and representative of a section of a hybrid wing body fuselage section in support of the Environmentally Responsible Aviation Project at NASA. This paper describes development of the multi-bay pressure box test using the COLTS facility. The multi-bay test article will be subjected to mechanical loads and internal pressure loads up to design ultimate load. Mechanical and pressure loads will be applied independently in some tests and simultaneously in others.
Effect of cavitation on flow structure of a tip vortex
NASA Astrophysics Data System (ADS)
Matthieu, Dreyer; Reclari, Martino; Farhat, Mohamed
2013-11-01
Tip vortices, which may develop in axial turbines and marine propellers, are often associated with the occurrence of cavitation because of the low pressure in their core. Although this issue has received a great deal of attention, it is still unclear how the phase transition affects the flow structure of such a vortex. In the present work, we investigate the change of the vortex structure due to cavitation incipience. The measurement of the velocity field is performed in the case of a tip vortex generated by an elliptical hydrofoil placed in the test section of EPFL high speed cavitation tunnel. To this end, a 3D stereo PIV is used with fluorescent seeding particles. A cost effective method is developed to produce in-house fluorescent seeding material, based on polyamide particles and Rhodamine-B dye. The amount of cavitation in the vortex core is controlled by the inlet pressure in the test section, starting with the non-cavitating case. We present an extensive analysis of the vorticity distribution, the vortex intensity and core size for various cavitation developments. This research is supported by CCEM and swisselectric research.
Materials sciences programs: Fiscal year 1994
NASA Astrophysics Data System (ADS)
1995-04-01
The Division of Materials Sciences is located within the DOE in the Office of Basic Energy Sciences. The Division of Materials Sciences is responsible for basic research and research facilities in strategic materials science topics of critical importance to the mission of the Department and its Strategic Plan. Materials Science is an enabling technology. The performance parameters, economics, environmental acceptability and safety of all energy generation, conversion, transmission and conservation technologies are limited by the properties and behavior of materials. The Materials Sciences programs develop scientific understanding of the synergistic relationship amongst the synthesis, processing, structure, properties, behavior, performance and other characteristics of materials. Emphasis is placed on the development of the capability to discover technologically, economically, and environmentally desirable new materials and processes, and the instruments and national user facilities necessary for achieving such progress. Materials Sciences sub-fields include physical metallurgy, ceramics, polymers, solid state and condensed matter physics, materials chemistry, surface science and related disciplines where the emphasis is on the science of materials. This report includes program descriptions for 458 research programs including 216 at 14 DOE National Laboratories, 242 research grants (233 for universities), and 9 Small Business Innovation Research (SBIR) Grants. The report is divided into eight sections. Section A contains all Laboratory projects, Section B has all contract research projects, Section C has projects funded under the SBIR Program, Section D describes the Center of Excellence for the Synthesis and Processing of Advanced Materials and E has information on major user facilities. F contains descriptions of other user facilities; G, a summary of funding levels; and H, indices characterizing research projects.
Materials sciences programs, fiscal year 1994
DOE Office of Scientific and Technical Information (OSTI.GOV)
NONE
1995-04-01
The Division of Materials Sciences is located within the DOE in the Office of Basic Energy Sciences. The Division of Materials Sciences is responsible for basic research and research facilities in strategic materials science topics of critical importance to the mission of the Department and its Strategic Plan. Materials Science is an enabling technology. The performance parameters, economics, environmental acceptability and safety of all energy generation, conversion, transmission and conservation technologies are limited by the properties and behavior of materials. The Materials Sciences programs develop scientific understanding of the synergistic relationship amongst the synthesis, processing, structure, properties, behavior, performance andmore » other characteristics of materials. Emphasis is placed on the development of the capability to discover technologically, economically, and environmentally desirable new materials and processes, and the instruments and national user facilities necessary for achieving such progress. Materials Sciences sub-fields include physical metallurgy, ceramics, polymers, solid state and condensed matter physics, materials chemistry, surface science and related disciplines where the emphasis is on the science of materials. This report includes program descriptions for 458 research programs including 216 at 14 DOE National Laboratories, 242 research grants (233 for universities), and 9 Small Business Innovation Research (SBIR) Grants. The report is divided into eight sections. Section A contains all Laboratory projects, Section B has all contract research projects, Section C has projects funded under the SBIR Program, Section D describes the Center of Excellence for the Synthesis and Processing of Advanced Materials and E has information on major user facilities. F contains descriptions of other user facilities; G, a summary of funding levels; and H, indices characterizing research projects.« less
Military efforts in nanosensors, 3D printing, and imaging detection
NASA Astrophysics Data System (ADS)
Edwards, Eugene; Booth, Janice C.; Roberts, J. Keith; Brantley, Christina L.; Crutcher, Sihon H.; Whitley, Michael; Kranz, Michael; Seif, Mohamed; Ruffin, Paul
2017-04-01
A team of researchers and support organizations, affiliated with the Army Aviation and Missile Research, Development, and Engineering Center (AMRDEC), has initiated multidiscipline efforts to develop nano-based structures and components for advanced weaponry, aviation, and autonomous air/ground systems applications. The main objective of this research is to exploit unique phenomena for the development of novel technology to enhance warfighter capabilities and produce precision weaponry. The key technology areas that the authors are exploring include nano-based sensors, analysis of 3D printing constituents, and nano-based components for imaging detection. By integrating nano-based devices, structures, and materials into weaponry, the Army can revolutionize existing (and future) weaponry systems by significantly reducing the size, weight, and cost. The major research thrust areas include the development of carbon nanotube sensors to detect rocket motor off-gassing; the application of current methodologies to assess materials used for 3D printing; and the assessment of components to improve imaging seekers. The status of current activities, associated with these key areas and their implementation into AMRDEC's research, is outlined in this paper. Section #2 outlines output data, graphs, and overall evaluations of carbon nanotube sensors placed on a 16 element chip and exposed to various environmental conditions. Section #3 summarizes the experimental results of testing various materials and resulting components that are supplementary to additive manufacturing/fused deposition modeling (FDM). Section #4 recapitulates a preliminary assessment of the optical and electromechanical components of seekers in an effort to propose components and materials that can work more effectively.
Survey of NASA research on crash dynamics
NASA Technical Reports Server (NTRS)
Thomson, R. G.; Carden, H. D.; Hayduk, R. J.
1984-01-01
Ten years of structural crash dynamics research activities conducted on general aviation aircraft by the National Aeronautics and Space Administration (NASA) are described. Thirty-two full-scale crash tests were performed at Langley Research Center, and pertinent data on airframe and seat behavior were obtained. Concurrent with the experimental program, analytical methods were developed to help predict structural behavior during impact. The effects of flight parameters at impact on cabin deceleration pulses at the seat/occupant interface, experimental and analytical correlation of data on load-limiting subfloor and seat configurations, airplane section test results for computer modeling validation, and data from emergency-locator-transmitter (ELT) investigations to determine probable cause of false alarms and nonactivations are assessed. Computer programs which provide designers with analytical methods for predicting accelerations, velocities, and displacements of collapsing structures are also discussed.
EDDIX--a database of ionisation double differential cross sections.
MacGibbon, J H; Emerson, S; Liamsuwan, T; Nikjoo, H
2011-02-01
The use of Monte Carlo track structure is a choice method in biophysical modelling and calculations. To precisely model 3D and 4D tracks, the cross section for the ionisation by an incoming ion, double differential in the outgoing electron energy and angle, is required. However, the double differential cross section cannot be theoretically modelled over the full range of parameters. To address this issue, a database of all available experimental data has been constructed. Currently, the database of Experimental Double Differential Ionisation Cross sections (EDDIX) contains over 1200 digitalised experimentally measured datasets from the 1960s to present date, covering all available ion species (hydrogen to uranium) and all available target species. Double differential cross sections are also presented with the aid of an eight parameter functions fitted to the cross sections. The parameters include projectile species and charge, target nuclear charge and atomic mass, projectile atomic mass and energy, electron energy and deflection angle. It is planned to freely distribute EDDIX and make it available to the radiation research community for use in the analytical and numerical modelling of track structure.
Hubbard, Katharine E; Dunbar, Sonja D
2017-01-01
Reading primary research literature is an essential skill for all scientists and students on science degree programmes, however little is known about how researchers at different career stages interact with and interpret scientific papers. To explore this, we conducted a survey of 260 undergraduate students and researchers in Biological Sciences at a research intensive UK university. Responses to Likert scale questions demonstrated increases in confidence and skill with reading the literature between individuals at each career stage, including between postdoctoral researchers and faculty academics. The survey indicated that individuals at different career stages valued different sections of scientific papers, and skill in reading the results section develops slowly over the course of an academic career. Inexperienced readers found the methods and results sections of research papers the most difficult to read, and undervalued the importance of the results section and critical interpretation of data. These data highlight a need for structured support with reading scientific literature at multiple career stages, and for senior academics to be aware that junior colleagues may prioritise their reading differently. We propose a model for the development of literature processing skills, and consider the need for training strategies to help inexperienced readers engage with primary literature, and therefore develop important skills that underpin scientific careers. We also encourage researchers to be mindful of language used when writing papers, and to be more inclusive of diverse audiences when disseminating their work.
Dunbar, Sonja D.
2017-01-01
Reading primary research literature is an essential skill for all scientists and students on science degree programmes, however little is known about how researchers at different career stages interact with and interpret scientific papers. To explore this, we conducted a survey of 260 undergraduate students and researchers in Biological Sciences at a research intensive UK university. Responses to Likert scale questions demonstrated increases in confidence and skill with reading the literature between individuals at each career stage, including between postdoctoral researchers and faculty academics. The survey indicated that individuals at different career stages valued different sections of scientific papers, and skill in reading the results section develops slowly over the course of an academic career. Inexperienced readers found the methods and results sections of research papers the most difficult to read, and undervalued the importance of the results section and critical interpretation of data. These data highlight a need for structured support with reading scientific literature at multiple career stages, and for senior academics to be aware that junior colleagues may prioritise their reading differently. We propose a model for the development of literature processing skills, and consider the need for training strategies to help inexperienced readers engage with primary literature, and therefore develop important skills that underpin scientific careers. We also encourage researchers to be mindful of language used when writing papers, and to be more inclusive of diverse audiences when disseminating their work. PMID:29284031
Whatever Happened to Economic Geography?
ERIC Educational Resources Information Center
Fagan, Robert
1985-01-01
Maintains that economic geography is alive and well. Describes some of the challenges facing research in economic geography and highlights the changing approaches being applied to economic geography. Includes sections on structural change, economic reorganization, and internationalization of manufacturing and finances. (JDH)
On Some Interesting Trends in Research of Steel and Composite Structures
NASA Astrophysics Data System (ADS)
Marcinowski, Jakub
2017-06-01
This paper is a kind of introduction to the special issue of CEER devoted to metal and composite structures. Papers collected in this issue were ordered from Authors who took part in International Conference on Metal Structures which was held in Zielona Góra in 2016. Selection of Authors and theme of ordered papers were done in cooperation with Metal Structures Section of the Civil Engineering Committee of the Polish Academy of Sciences. Selected papers included in this special issue of CEER were shortly presented in this editorial.
DOE Office of Scientific and Technical Information (OSTI.GOV)
de la Rubia, T D; Shang, S P; Rennie, G
2005-07-29
Glance at the articles in this report, and you will sense the transformation that is reshaping the landscape of materials science and chemistry. This transformation is bridging the gaps among chemistry, materials science, and biology--ushering in a wealth of innovative technologies with broad scientific impact. The emergence of this intersection is reinvigorating our strategic investment into areas that build on our strength of interdisciplinary science. It is at the intersection that we position our strategic vision into a future where we will provide radical materials innovations and solutions to our national-security programs and other sponsors. Our 2004 Annual Report describesmore » how our successes and breakthroughs follow a path set forward by our strategic plan and four organizing research themes, each with key scientific accomplishments by our staff and collaborators. We have organized this report into two major sections: research themes and our dynamic teams. The research-theme sections focus on achievements arising from earlier investments while addressing future challenges. The dynamic teams section illustrates the directorate's organizational structure of divisions, centers, and institutes that support a team environment across disciplinary and institutional boundaries. The research presented in this annual report gives substantive examples of how we are proceeding in each of these four theme areas and how they are aligned with our national-security mission. By maintaining an organizational structure that offers an environment of collaborative problem-solving opportunities, we are able to nurture the discoveries and breakthroughs required for future successes.« less
Computed tomographic and cross-sectional anatomy of the normal pacu (Colossoma macroponum).
Carr, Alaina; Weber, E P Scott; Murphy, Chris J; Zwingenberger, Alison
2014-03-01
The purpose of this study was to compare and define the normal cross-sectional gross and computed tomographic (CT) anatomy for a species of boney fish to better gain insight into the use of advanced diagnostic imaging for future clinical cases. The pacu (Colossoma macropomum) was used because of its widespread presence in the aquarium trade, its relatively large body size, and its importance in the research and aquaculture settings. Transverse 0.6-mm CT images of three cadaver fish were obtained and compared to corresponding frozen cross sections of the fish. Relevant anatomic structures were identified and labeled at each level; the Hounsfield unit density of major organs was established. The images presented good anatomic detail and provide a reference for future research and clinical investigation.
Multidisciplinary aerospace design optimization: Survey of recent developments
NASA Technical Reports Server (NTRS)
Sobieszczanski-Sobieski, Jaroslaw; Haftka, Raphael T.
1995-01-01
The increasing complexity of engineering systems has sparked increasing interest in multidisciplinary optimization (MDO). This paper presents a survey of recent publications in the field of aerospace where interest in MDO has been particularly intense. The two main challenges of MDO are computational expense and organizational complexity. Accordingly the survey is focussed on various ways different researchers use to deal with these challenges. The survey is organized by a breakdown of MDO into its conceptual components. Accordingly, the survey includes sections on Mathematical Modeling, Design-oriented Analysis, Approximation Concepts, Optimization Procedures, System Sensitivity, and Human Interface. With the authors' main expertise being in the structures area, the bulk of the references focus on the interaction of the structures discipline with other disciplines. In particular, two sections at the end focus on two such interactions that have recently been pursued with a particular vigor: Simultaneous Optimization of Structures and Aerodynamics, and Simultaneous Optimization of Structures Combined With Active Control.
NASA Technical Reports Server (NTRS)
Naffin, Richard K.; Ulun, Umut; Garmel, Charles D.; McManus, Nika; Hu, Zhenning; Ohlerking, Westin B.; Myers, David E.
2017-01-01
This report investigates the practical usage of hybrid structures for rotorcraft gearing. The primary driver for utilizing hybrid structures for rotorcraft gearing is to reduce the drive system weight. The hybrid structure concept featured in this study for rotorcraft gearing consists of a metallic gear tooth-rim, a web section manufactured from composite materials, and a metallic hub. The metallic gear tooth-rim is manufactured from conventional gear steel alloys, such as AISI 9310. The gear tooth-rim attaches to the outer diameter of the web section made from composite materials. The inner diameter of the composite web can then attach to a metallic hub, completing the assembly. It is assumed that areas of the shafting or hub where rolling element bearings may ride must remain as gear steel alloys for this study.
Zero-gravity atmospheric Cloud Physics Experiment Laboratory; Programmatics report
NASA Technical Reports Server (NTRS)
1974-01-01
The programmatics effort included comprehensive analyses in four major areas: (1) work breakdown structure, (2) schedules, (3) costs, and (4) supporting research and technology. These analyses are discussed in detail in the following sections which identify and define the laboratory project development schedule, cost estimates, funding distributions and supporting research and technology requirements. All programmatics analyses are correlated among themselves and with the technical analyses by means of the work breakdown structure which serves as a common framework for program definition. In addition, the programmatic analyses reflect the results of analyses and plans for reliability, safety, test, and maintenance and refurbishment.
DOE Office of Scientific and Technical Information (OSTI.GOV)
NONE
1998-12-31
Research in the initial grant period focused on computational studies relevant to the selective activation of methane, the prime component of natural gas. Reaction coordinates for methane activation by experimental models were delineated, as well as the bonding and structure of complexes that effect this important reaction. This research, highlighted in the following sections, also provided the impetus for further development, and application of methods for modeling metal-containing catalysts. Sections of the report describe the following: methane activation by multiple-bonded transition metal complexes; computational lanthanide chemistry; and methane activation by non-imido, multiple-bonded ligands.
Laboratory directed research and development program FY 1997
DOE Office of Scientific and Technical Information (OSTI.GOV)
NONE
1998-03-01
This report compiles the annual reports of Laboratory Directed Research and Development projects supported by the Berkeley Lab. Projects are arranged under the following topical sections: (1) Accelerator and fusion research division; (2) Chemical sciences division; (3) Computing Sciences; (4) Earth sciences division; (5) Environmental energy technologies division; (6) life sciences division; (7) Materials sciences division; (8) Nuclear science division; (9) Physics division; (10) Structural biology division; and (11) Cross-divisional. A total of 66 projects are summarized.
2017-02-27
Quiet Supersonic Technology (QueSST) X-plane in the 8x6 Supersonic Wind Tunnel at NASA Glenn Research Center. This time-lapse shows the model support structure buildup and balance checkout as well as the installation of the model in the test section.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
This eighth annual report of the Division covers work done during FY 1981 (October 1, 1980, through September 30, 1981). As with these documents in the past, the format follows approximately the organizational structure of the Energy Division. Chapters 2 through 6 summarize the activities of the sections of the Division: Environmental Impact Section, headed by H.E. Zittel; Regional and Urban Studies Section, R.M. Davis; Economic Analysis Section, R.B. Shelton; Data and Analysis Section, A.S. Loebl; and Efficiency and Renewables Research Section, J.W. Michel. In addition, work on a variety of projects which cut across section lines is reported inmore » Chapter 7, Integrated Programs. These activities are under the supervision of T.J. Wilbanks, Associate Director for the Division. Separate abstracts are included for individual projects.« less
The development of a center cell structure in bonded aluminum for the Ferrari 408 research vehicle
DOE Office of Scientific and Technical Information (OSTI.GOV)
Seeds, A.; Nardini, D.; Cassese, F.
1989-01-01
In F408 research vehicle has enabled Ferrari Engineering to evaluate new forms of transmission, suspension, bodywork and structure for future production vehicles. As Alcan worked with Ferrari Engineering to adapt its Aluminum Structured Vehicle Technology (ASVT) to develop a bonded version of a central section of the structure (center cell). This paper begins with an outline of the major F408 project objectives and indicates the performance and manufacturing advantages for the features of interest, particularly the center cell structure. The paper describes the development stages of the bonded aluminum center cell. It shows that the performance and manufacturing objectives weremore » met with a substantial weight-saving and improvement in stiffness compared to laser-welded stainless steel. The paper concludes with a summary of the other technical innovations and developments in the F408 vehicle.« less
Active Control of Panel Vibrations Induced by a Boundary Layer Flow
NASA Technical Reports Server (NTRS)
Chow, Pao-Liu
1998-01-01
In recent years, active and passive control of sound and vibration in aeroelastic structures have received a great deal of attention due to many potential applications to aerospace and other industries. There exists a great deal of research work done in this area. Recent advances in the control of sound and vibration can be found in the several conference proceedings. In this report we will summarize our research findings supported by the NASA grant NAG-1-1175. The problems of active and passive control of sound and vibration has been investigated by many researchers for a number of years. However, few of the articles are concerned with the sound and vibration with flow-structure interaction. Experimental and numerical studies on the coupling between panel vibration and acoustic radiation due to flow excitation have been done by Maestrello and his associates at NASA/Langley Research Center. Since the coupled system of nonlinear partial differential equations is formidable, an analytical solution to the full problem seems impossible. For this reason, we have to simplify the problem to that of the nonlinear panel vibration induced by a uniform flow or a boundary-layer flow with a given wall pressure distribution. Based on this simplified model, we have been able to study the control and stabilization of the nonlinear panel vibration, which have not been treated satisfactorily by other authors. The vibration suppression will clearly reduce the sound radiation power from the panel. The major research findings will be presented in the next three sections. In Section II we shall describe our results on the boundary control of nonlinear panel vibration, with or without flow excitation. Section III is concerned with active control of the vibration and sound radiation from a nonlinear elastic panel. A detailed description of our work on the parametric vibrational control of nonlinear elastic panel will be presented in Section IV. This paper will be submitted to the Journal of Acoustic Society of America for publication.
ERIC Educational Resources Information Center
Sandler, Martin E.
Researchers used cross-sectional survey research to reexamine the problem of adult persistence within undergraduate degree programs. They identified a variable--perceived stress--that permitted a richer explanation of the process of student persistence. A model was presented that examined the attitudinal and behavioral impacts of unmet need,…
ERIC Educational Resources Information Center
National Academy of Sciences - National Research Council, Washington, DC.
Four aspects of preassembled building components are discussed--(1) attitudes on preassembled components, (2) principles of preassembled components construction, (3) structural component case studies, and (4) mechanical component case studies. In section 1, various views on preassembled components are discussed including--(1) the architect's view,…
NASA Astrophysics Data System (ADS)
Beech, M.
1989-02-01
The author discusses some of the more recent research on fractal astronomy and results presented in several astronomical studies. First, the large-scale structure of the universe is considered, while in another section one drops in scale to examine some of the smallest bodies in our solar system; the comets and meteoroids. The final section presents some thoughts on what influence the fractal ideology might have on astronomy, focusing particularly on the question recently raised by Kadanoff, "Fractals: where's the physics?"
NASA Technical Reports Server (NTRS)
1979-01-01
The accompanying photos show two types of offshore oil platforms used by Exxon Corporation. In the upper photo is a leg-supported gravity platform; the other structure is a "jackettype" platform, built in sections, towed to sea and assembled on-site. In construction of platforms like these, Exxon Production Research Company, Houston, Texas, conducts extensive structural investigations of decks, supporting members and other platform components, making use of the NASTRAN @ (NASA Structural Analysis) computer program. NASTRAN is a predictive tool which analyzes a computerized design and reports how the structure will react to a great many conditions it will encounter in its operational environment; in this case, NASTRAN studies the effects of waves, winds, ocean storms and other stress-inducing factors. NASTRAN allows Exxon Production Research to perform more complex and more detailed analysis than was possible with previous programs. The same program has also been used by Exxon Research and Engineering Company, Florham Park, New Jersey, in analysis of pressure vessels, turbine components and composite building boards.
Using databases in medical education research: AMEE Guide No. 77.
Cleland, Jennifer; Scott, Neil; Harrild, Kirsten; Moffat, Mandy
2013-05-01
This AMEE Guide offers an introduction to the use of databases in medical education research. It is intended for those who are contemplating conducting research in medical education but are new to the field. The Guide is structured around the process of planning your research so that data collection, management and analysis are appropriate for the research question. Throughout we consider contextual possibilities and constraints to educational research using databases, such as the resources available, and provide concrete examples of medical education research to illustrate many points. The first section of the Guide explains the difference between different types of data and classifying data, and addresses the rationale for research using databases in medical education. We explain the difference between qualitative research and qualitative data, the difference between categorical and quantitative data, and the difference types of data which fall into these categories. The Guide reviews the strengths and weaknesses of qualitative and quantitative research. The next section is structured around how to work with quantitative and qualitative databases and provides guidance on the many practicalities of setting up a database. This includes how to organise your database, including anonymising data and coding, as well as preparing and describing your data so it is ready for analysis. The critical matter of the ethics of using databases in medical educational research, including using routinely collected data versus data collected for research purposes, and issues of confidentiality, is discussed. Core to the Guide is drawing out the similarities and differences in working with different types of data and different types of databases. Future AMEE Guides in the research series will address statistical analysis of data in more detail.
Providing structural modules with self-integrity monitoring software user's manual
NASA Technical Reports Server (NTRS)
1990-01-01
National Aeronautics and Space Administration (NASA) Contract NAS7-961 (A Small Business Innovation and Research (SBIR) contract from NASA) involved research dealing with remote structural damage detection using the concept of substructures. Several approaches were developed. The main two were: (1) the module (substructure) transfer function matrix (MTFM) approach; and (2) modal strain energy distribution method (MSEDM). Either method can be used with a global structure; however, the focus was on substructures. As part of the research contract, computer software was to be developed which would implement the developed methods. This was done and it was used to process all the finite element generated numerical data for the research. The software was written for the IBM AT personal computer. Copies of it were placed on floppy disks. This report serves as a user's manual for the two sets of damage detection software. Sections 2.0 and 3.0 discuss the use of the MTFM and MSEDM software, respectively.
[The SGO Health Research Promotion Program. XIII. Evaluation of the section 'Addiction Research'].
van Rees-Wortelboer, M M
1999-01-02
As a part of the SGO Health Research Promotion Programme a research programme on addiction research was realized. Aim of the programme was to strengthen and concentrate the Dutch research into addiction. Within the Amsterdam Institute for Addiction Research (AIAR), a structural collaboration between the Jellinek Treatment Centre for Addiction, the University of Amsterdam and the Academic Hospital of the University of Amsterdam, strategic research programmes were developed on the borderland of addiction and psychiatry, notably 'Clinical epidemiology addiction' and 'Developmental disorders, addiction and psychotraumas'. The institution of a co-ordinating platform of research groups conducting socio-epidemiological addiction research improved the co-ordination of research lines in this field.
NASA Technical Reports Server (NTRS)
Collette, J. G. R.
1984-01-01
A test was conducted in the NASA/Ames Research Center 9x7-foot Supersonic Wind Tunnel to help resolve an anomaly that developed during the STS-6 orbiter flight wherein sections of the Advanced Flexible Reusable Surface Insulation (AFRSI) covering the OMS pods suffered some damage. A one-third scale two-dimensional shell structure model of an OMS pod cross-section was employed to support the test articles. These consisted of 15 AFRSI blanket panels form-fitted over the shell structures for exposure to simulated flight conditions. Of six baseline blankets, two were treated with special surface coatings. Two other panels were configured with AFRSI sections removed from the OV099 orbiter vehicle after the STS-6 flight. Seven additional specimens incorporated alternative designs and repairs. Following a series of surface pressure calibration runs, the specimens were exposed to simulated ascent and entry dynamic pressure profiles. Entry conditions included the use of a vortex generator to evaluate the effect of shed vortices on the AFRSI located in the area of concern.
Factor structure of the Shoulder Pain and Disability Index in patients with adhesive capsulitis.
Tveitå, Einar Kristian; Sandvik, Leiv; Ekeberg, Ole Marius; Juel, Niels Gunnar; Bautz-Holter, Erik
2008-07-17
The Shoulder Pain and Disability Index (SPADI) is a self-administered questionnaire that aims to measure pain and disability associated with shoulder disease. It consists of a pain section and a disability section with 13 items being responded to on visual analogue scales. Few researchers have investigated SPADI validity in specified diagnostic groups, although the selection of an evaluative instrument should be based on evidence of validity in the target patient group. The aim of the present study was to investigate factor structure of the SPADI in a study population of patients with adhesive capsulitis. The questionnaire was administered to 191 patients with adhesive capsulitis. Descriptive statistics for items and a comparison of scores for the two subscales were produced. Internal consistency was analyzed by use of the Cronbach alpha and a principal components analysis with varimax rotation was conducted. Study design was cross-sectional. Two factors were extracted, but the factor structure failed to support the original division of items into separate pain and disability sections. We found minimal evidence to justify the use of separate subscales for pain and disability. It is our impression that the SPADI should be viewed as essentially unidimensional in patients with adhesive capsulitis.
Mansyur, Carol Leler; Amick, Benjamin C; Harrist, Ronald B; Franzini, Luisa; Roberts, Robert E
2009-01-01
In a 2001 report, the U.S. National Institutes of Health called for more integration of the social sciences into health-related research, including research guided by theories and methods that take social and cultural systems into consideration. Based on a theoretical framework that integrates Hofstede's cultural dimensions with sociological theory, the authors used multilevel modeling to explore the association of culture with structural inequality and health disparities. Their results support the idea that cultural dimensions and social structure, along with economic development, may account for much of the cross-national variation in the distribution of health inequalities. Sensitivity tests also suggest that an interaction between culture and social structure may confound the relationship between income inequality and health. It is necessary to identify important cultural and social structural characteristics before we can achieve an understanding of the complex, dynamic systems that affect health, and develop culturally sensitive interventions and policies. This study takes a step toward identifying some of the relevant cultural and structural influences. More research is needed to explore the pathways leading from the sociocultural environment to health inequalities.
Lee, Seungjae; Park, Jaeseong; Kwak, Euishin; Shon, Sudeok; Kang, Changhoon; Choi, Hosoon
2017-03-06
Modular systems have been mostly researched in relatively low-rise structures but, lately, their applications to mid- to high-rise structures began to be reviewed, and research interest in new modularization subjects has increased. The application of modular systems to mid- to high-rise structures requires the structural stability of the frame and connections that consist of units, and the evaluation of the stiffness of structures that are combined in units. However, the combination of general units causes loss of the cross-section of columns or beams, resulting in low seismic performance and hindering installation works in the field. In addition, the evaluation of a frame considering such a cross-sectional loss is not easy. Therefore, it is necessary to develop a joint that is stable and easy to install. In the study, a rigidly connected modular system was proposed as a moment-resisting frame for a unit modular system, and their joints were developed and their performances were compared. The proposed system changed the ceiling beam into a bracket type to fasten bolts. It can be merged with other seismic force-resisting systems. To verify the seismic performance of the proposed system, a cyclic loading test was conducted, and the rigidly connected joint performance and integrated behavior at the joint of modular units were investigated. From the experimental results, the maximum resisting force of the proposed connection exceeded the theoretical parameters, indicating that a rigid joint structural performance could be secured.
Physics Division annual review, 1 April 1980-31 March 1981
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
1982-06-01
Progress in nuclear physics research is reported in the following areas: medium-energy physics (pion reaction mechanisms, high-resolution studies and nuclear structure, and two-nucleon physics with pions and electrons); heavy-ion research at the tandem and superconducting linear accelerator (resonant structure in heavy-ion reactions, fusion cross sections, high angular momentum states in nuclei, and reaction mechanisms and distributions of reaction strengths); charged-particle research; neutron and photonuclear physics; theoretical physics (heavy-ion direct-reaction theory, nuclear shell theory and nuclear structure, nuclear matter and nuclear forces, intermediate-energy physics, microscopic calculations of high-energy collisions of heavy ions, and light ion direct reactions); the superconducting linac; acceleratormore » operations; and GeV electron linac. Progress in atomic and molecular physics research is reported in the following areas: dissociation and other interactions of energetic molecular ions in solid and gaseous targets, beam-foil research and collision dynamics of heavy ions, photoionization- photoelectron research, high-resolution laser rf spectroscopy with atomic and molecular beams, moessbauer effect research, and theoretical atomic physics. Studies on interactions of energetic particles with solids are also described. Publications are listed. (WHK)« less
1995-07-27
The Pathfinder research aircraft's wing structure was clearly defined as it soared under a clear blue sky during a test flight July 27, 1995, from Dryden Flight Research Center, Edwards, California. The center section and outer wing panels of the aircraft had ribs constructed of thin plastic foam, while the ribs in the inner wing panels are fabricated from lightweight composite material. Developed by AeroVironment, Inc., the Pathfinder was one of several unmanned aircraft being evaluated under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program.
Extracting Cross-Sectional Clinical Images Based on Their Principal Axes of Inertia
Fan, Yuzhou; Djuric, Marija; Li, Zhiyu; Antonijevic, Djordje; Milenkovic, Petar; Sun, Yueyang; Li, Ruining
2017-01-01
Cross-sectional imaging is considered the gold standard in diagnosing a range of diseases. However, despite its widespread use in clinical practice and research, no widely accepted method is available to reliably match cross-sectional planes in several consecutive scans. This deficiency can impede comparison between cross-sectional images and ultimately lead to misdiagnosis. Here, we propose and demonstrate a method for finding the same imaging plane in images obtained during separate scanning sessions. Our method is based on the reconstruction of a “virtual organ” from which arbitrary cross-sectional images can be extracted, independent of the axis orientation in the original scan or cut; the key is to establish unique body coordinates of the organ from its principal axes of inertia. To verify our method a series of tests were performed, and the same cross-sectional plane was successfully extracted. This new approach offers clinicians access, after just a single scanning session, to the morphology and structure of a lesion through cross-sectional images reconstructed along arbitrary axes. It also aids comparable detection of morphological and structural changes in the same imaging plane from scans of the same patient taken at different times—thus potentially reducing the misdiagnosis rate when cross-sectional images are interpreted. PMID:29410714
Extracting Cross-Sectional Clinical Images Based on Their Principal Axes of Inertia.
Fan, Yuzhou; Luo, Liangping; Djuric, Marija; Li, Zhiyu; Antonijevic, Djordje; Milenkovic, Petar; Sun, Yueyang; Li, Ruining; Fan, Yifang
2017-01-01
Cross-sectional imaging is considered the gold standard in diagnosing a range of diseases. However, despite its widespread use in clinical practice and research, no widely accepted method is available to reliably match cross-sectional planes in several consecutive scans. This deficiency can impede comparison between cross-sectional images and ultimately lead to misdiagnosis. Here, we propose and demonstrate a method for finding the same imaging plane in images obtained during separate scanning sessions. Our method is based on the reconstruction of a "virtual organ" from which arbitrary cross-sectional images can be extracted, independent of the axis orientation in the original scan or cut; the key is to establish unique body coordinates of the organ from its principal axes of inertia. To verify our method a series of tests were performed, and the same cross-sectional plane was successfully extracted. This new approach offers clinicians access, after just a single scanning session, to the morphology and structure of a lesion through cross-sectional images reconstructed along arbitrary axes. It also aids comparable detection of morphological and structural changes in the same imaging plane from scans of the same patient taken at different times-thus potentially reducing the misdiagnosis rate when cross-sectional images are interpreted.
NASA Astrophysics Data System (ADS)
Abdel-Jaber, H.; Glisic, B.
2015-02-01
Prestressed structures experience limited tensile stresses in concrete, which limits or completely eliminates the occurrence of cracks. However, in some cases, large tensile stresses can develop during the early age of the concrete due to thermal gradients and shrinkage effects. Such stresses can cause early-age cracks, termed ‘pre-release cracks’, which occur prior to the transfer of the prestressing force. When the prestressing force is applied to the cross-section, it is assumed that partial or full closure of the cracks occurs by virtue of the force transfer through the cracked cross-section. Verification of the closure of the cracks after the application of the prestressing force is important as it can either confirm continued structural integrity or indicate and approximate reduced structural capacity. Structural health monitoring (SHM) can be used for this purpose. This paper researches an SHM method that can be applied to prestressed beam structures to assess the condition of pre-release cracks. The sensor network used in this method consists of parallel long-gauge fiber optic strain sensors embedded in the concrete cross-sections at various locations. The same network is used for damage detection, i.e. detection and characterization of the pre-release cracks, and for monitoring the prestress force transfer. The method is validated on a real structure, a curved continuous girder. Results from the analysis confirm the safety and integrity of the structure. The method and its application are presented in this paper.
NASA Technical Reports Server (NTRS)
Esgar, J. B.; Sokolowski, Daniel E.
1989-01-01
The Hot Section Technology (HOST) Project, which was initiated by NASA Lewis Research Center in 1980 and concluded in 1987, was aimed at improving advanced aircraft engine hot section durability through better technical understanding and more accurate design analysis capability. The project was a multidisciplinary, multiorganizational, focused research effort that involved 21 organizations and 70 research and technology activities and generated approximately 250 research reports. No major hardware was developed. To evaluate whether HOST had a significant impact on the overall aircraft engine industry in the development of new engines, interviews were conducted with 41 participants in the project to obtain their views. The summarized results of these interviews are presented. Emphasis is placed on results relative to three-dimensional inelastic structural analysis, thermomechanical fatigue testing, constitutive modeling, combustor aerothermal modeling, turbine heat transfer, protective coatings, computer codes, improved engine design capability, reduced engine development costs, and the impacts on technology transfer and the industry-government partnership.
D'Atri, Valentina; Porrini, Massimiliano; Rosu, Frédéric; Gabelica, Valérie
2015-01-01
Ion mobility spectrometry experiments allow the mass spectrometrist to determine an ion's rotationally averaged collision cross section ΩEXP. Molecular modelling is used to visualize what ion three-dimensional structure(s) is(are) compatible with the experiment. The collision cross sections of candidate molecular models have to be calculated, and the resulting ΩCALC are compared with the experimental data. Researchers who want to apply this strategy to a new type of molecule face many questions: (1) What experimental error is associated with ΩEXP determination, and how to estimate it (in particular when using a calibration for traveling wave ion guides)? (2) How to generate plausible 3D models in the gas phase? (3) Different collision cross section calculation models exist, which have been developed for other analytes than mine. Which one(s) can I apply to my systems? To apply ion mobility spectrometry to nucleic acid structural characterization, we explored each of these questions using a rigid structure which we know is preserved in the gas phase: the tetramolecular G-quadruplex [dTGGGGT]4, and we will present these detailed investigation in this tutorial. © 2015 The Authors. Journal of Mass Spectrometry published by John Wiley & Sons Ltd. PMID:26259654
NASA Technical Reports Server (NTRS)
Schwartz, Susan K.
1992-01-01
The Solid Modeling Aerospace Research Tool (SMART) is a computer aided design tool used in aerospace vehicle design. Modeling of structural components using SMART includes the representation of the transverse or cross-wise elements of a vehicle's fuselage, ringframes, and bulkheads. Ringframes are placed along a vehicle's fuselage to provide structural support and maintain the shape of the fuselage. Bulkheads are also used to maintain shape, but are placed at locations where substantial structural support is required. Given a Bezier curve representation of a cross sectional cut through a vehicle's fuselage and/or an internal tank, this project produces a first-guess Bezier patch representation of a ringframe or bulkhead at the cross-sectional position. The grid produced is later used in the structural analysis of the vehicle. The graphical display of the generated patches allows the user to edit patch control points in real time. Constraints considered in the patch generation include maintaining 'square-like' patches and placement of longitudinal, or lengthwise along the fuselage, structural elements called longerons.
Cross section for the subthreshold fission of 236U
NASA Astrophysics Data System (ADS)
Alekseev, A. A.; Bergman, A. A.; Berlev, A. I.; Koptelov, E. A.; Samylin, B. F.; Trufanov, A. M.; Fursov, B. I.; Shorin, V. S.
2008-08-01
The cross section for 236U fission in the neutron-energy range E n = 0.001 20 keV was measured by using the INR RAS (Institute of Nuclear Research, Russian Academy of Sciences, Moscow) LSDS-100 neutron spectrometer of the lead slowing-down spectrometer type. The resonance fission areas of the resonances at 5.45 eV and 1.28 keV were found, and the fission widths of these resonances were evaluated. The cross section for the 238U( n, f) fission process was measured, and the threshold sensitivity of the LSDS-100 to small values of fission cross sections was estimated. The well-known intermediate structure in the cross section for the neutron-induced subbarrier fission of 236U was confirmed.
Hybrid Wing-Body Pressurized Fuselage and Bulkhead, Design and Optimization
NASA Technical Reports Server (NTRS)
Mukhopadhyay, Vivek
2013-01-01
The structural weight reduction of a pressurized Hybrid Wing-Body (HWB) fuselage is a serious challenge. Hence, research and development are presently being continued at NASA under the Environmentally Responsible Aviation (ERA) and Subsonic Fixed Wing (SFW) projects in collaboration with the Boeing Company, Huntington Beach and Air Force Research Laboratory (AFRL). In this paper, a structural analysis of the HWB fuselage and bulkhead panels is presented, with the objectives of design improvement and structural weight reduction. First, orthotropic plate theories for sizing, and equivalent plate analysis with appropriate simplification are considered. Then parametric finite-element analysis of a fuselage section and bulkhead are conducted using advanced stitched composite structural concepts, which are presently being developed at Boeing for pressurized HWB flight vehicles. With this advanced stiffened-shell design, structural weights are computed and compared to the thick sandwich, vaulted-ribbed-shell, and multi-bubble stiffened-shell structural concepts that had been studied previously. The analytical and numerical results are discussed to assess the overall weight/strength advantages.
Telecommunications Policy Research Conference. International Comparisons I (Europe) Section. Papers.
ERIC Educational Resources Information Center
Telecommunications Policy Research Conference, Inc., Washington, DC.
Three papers consider telecommunications policy in Great Britain and Germany specifically, and the nations of the European Economic Community generally. The first paper, "German Telecommunications Law and Policies" (Ernst-Joachim Mestamacker) outlines the present structure of telecommunications in West Germany, and discusses deregulation…
DOE Office of Scientific and Technical Information (OSTI.GOV)
Michaelides, Angelos, E-mail: angelos.michaelides@ucl.ac.uk; Martinez, Todd J.; Alavi, Ali
This Special Topic section on Advanced Electronic Structure Methods for Solids and Surfaces contains a collection of research papers that showcase recent advances in the high accuracy prediction of materials and surface properties. It provides a timely snapshot of a growing field that is of broad importance to chemistry, physics, and materials science.
NASA Technical Reports Server (NTRS)
Wong, Douglas T.
2010-01-01
Topics in this student project report include: biography, NASA history and structure, overview of Johnson Space Center facilities and major projects, and an overview of the Usability Testing and Analysis Facility (UTAF). The UTAF section slides include space habitat evaluations with mockups, crew space vehicle evaluations, and human factors research.
76 FR 13412 - Agency Information Collection Activities: Proposed Collection; Comment Request
Federal Register 2010, 2011, 2012, 2013, 2014
2011-03-11
...) Screening questionnaire--used to recruit research participants for the needs assessment interviews...) Needs assessment interviews--consisting of semi-structured interviews with non-users of the Health IT... those persons that ``screen-in'' will complete the demographics section). The needs assessment will be...
46 CFR 190.01-15 - Special consideration.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 7 2010-10-01 2010-10-01 false Special consideration. 190.01-15 Section 190.01-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS CONSTRUCTION AND ARRANGEMENT Hull Structure § 190.01-15 Special consideration. (a) Special consideration will...
Ultimate strength capacity of a square hollow section filled with fibrous foamed concrete
NASA Astrophysics Data System (ADS)
Amirah Azra Khairuddin, Siti; Rahman, Norashidah Abd; Jamaluddin, Norwati; Jaini, Zainorizuan Mohd; Ali, Noorwirdawati
2017-11-01
Concrete-filled sections used as building columns have become popular due to their architectural and structural elements. In recent years, there has been a renewed call for the improvement of materials used as concrete to fill the composite columns. Among these materials, foamed concrete has received great attention due to its structural characteristics and its potential as a construction material used in hollow sections. However, its behaviors as infill material in a hollow section, such as its strength and failure mode, should be investigated. In this study, experimental research was conducted to compare the experimental and theoretical values of its ultimate strength capacity. Eight specimens of hollow steel sections with two different thicknesses were filled with fibrous foamed concrete and then subjected to compression load. The obtained results were compared with those obtained from a hollow section with the same thicknesses, but were filled with normal foamed concrete. Results show that the ultimate strength capacity of the experimental value is the same as that of the theoretical value based on Eurocode 4. The largest percentage values between theoretical and experimental results for thicknesses of 2 and 4 mm are 58% and 55%, respectively.
NASA Astrophysics Data System (ADS)
Provo, Judy; Lamar, Carlton; Newby, Timothy
2002-01-01
A cross section was used to enhance three-dimensional knowledge of anatomy of the canine head. All veterinary students in two successive classes (n = 124) dissected the head; experimental groups also identified structures on a cross section of the head. A test assessing spatial knowledge of the head generated 10 dependent variables from two administrations. The test had content validity and statistically significant interrater and test-retest reliability. A live-dog examination generated one additional dependent variable. Analysis of covariance controlling for performance on course examinations and quizzes revealed no treatment effect. Including spatial skill as a third covariate revealed a statistically significant effect of spatial skill on three dependent variables. Men initially had greater spatial skill than women, but spatial skills were equal after 8 months. A qualitative analysis showed the positive impact of this experience on participants. Suggestions for improvement and future research are discussed.
Guidelines for Preparation of a Scientific Paper
Kosiba, Margaret M.
1988-01-01
Even the experienced scientific writer may have difficulty transferring research results to clear, concise, publishable words. To assist the beginning scientific writer, guidelines are proposed that will provide direction for determining a topic, developing protocols, collecting data, using computers for analysis and word processing, incorporating copyediting notations, consulting scientific writing manuals, and developing sound writing habits. Guidelines for writing each section of a research paper are described to help the writer prepare the title page, introduction, materials and methods, results, and discussion sections of the paper, as well as the acknowledgments and references. Procedures for writing the first draft and subsequent revisions include a checklist of structural and stylistic problems and common errors in English usage. PMID:3339646
Perception of emotional prosody: moving toward a model that incorporates sex-related differences.
Everhart, D Erik; Demaree, Heath A; Shipley, Amy J
2006-06-01
The overall purpose of this article is to review the literature that addresses the theoretical models, neuroanatomical mechanisms, and sex-related differences in the perception of emotional prosody. Specifically, the article focuses on the right-hemisphere model of emotion processing as it pertains to the perception of emotional prosody. This article also reviews more recent research that implicates a role for the left hemisphere and subcortical structures in the perception of emotional prosody. The last major section of this article addresses sex-related differences and the potential influence of hormones on the perception of emotional prosody. The article concludes with a section that offers directions for future research.
Buytaert, Jan A N; Salih, Wasil H M; Dierick, Manual; Jacobs, Patric; Dirckx, Joris J J
2011-12-01
In order to improve realism in middle ear (ME) finite-element modeling (FEM), comprehensive and precise morphological data are needed. To date, micro-scale X-ray computed tomography (μCT) recordings have been used as geometric input data for FEM models of the ME ossicles. Previously, attempts were made to obtain these data on ME soft tissue structures as well. However, due to low X-ray absorption of soft tissue, quality of these images is limited. Another popular approach is using histological sections as data for 3D models, delivering high in-plane resolution for the sections, but the technique is destructive in nature and registration of the sections is difficult. We combine data from high-resolution μCT recordings with data from high-resolution orthogonal-plane fluorescence optical-sectioning microscopy (OPFOS), both obtained on the same gerbil specimen. State-of-the-art μCT delivers high-resolution data on the 3D shape of ossicles and other ME bony structures, while the OPFOS setup generates data of unprecedented quality both on bone and soft tissue ME structures. Each of these techniques is tomographic and non-destructive and delivers sets of automatically aligned virtual sections. The datasets coming from different techniques need to be registered with respect to each other. By combining both datasets, we obtain a complete high-resolution morphological model of all functional components in the gerbil ME. The resulting 3D model can be readily imported in FEM software and is made freely available to the research community. In this paper, we discuss the methods used, present the resulting merged model, and discuss the morphological properties of the soft tissue structures, such as muscles and ligaments.
Practical Formal Verification of Diagnosability of Large Models via Symbolic Model Checking
NASA Technical Reports Server (NTRS)
Cavada, Roberto; Pecheur, Charles
2003-01-01
This document reports on the activities carried out during a four-week visit of Roberto Cavada at the NASA Ames Research Center. The main goal was to test the practical applicability of the framework proposed, where a diagnosability problem is reduced to a Symbolic Model Checking problem. Section 2 contains a brief explanation of major techniques currently used in Symbolic Model Checking, and how these techniques can be tuned in order to obtain good performances when using Model Checking tools. Diagnosability is performed on large and structured models of real plants. Section 3 describes how these plants are modeled, and how models can be simplified to improve the performance of Symbolic Model Checkers. Section 4 reports scalability results. Three test cases are briefly presented, and several parameters and techniques have been applied on those test cases in order to produce comparison tables. Furthermore, comparison between several Model Checkers is reported. Section 5 summarizes the application of diagnosability verification to a real application. Several properties have been tested, and results have been highlighted. Finally, section 6 draws some conclusions, and outlines future lines of research.
46 CFR 190.01-1 - Application.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 7 2010-10-01 2010-10-01 false Application. 190.01-1 Section 190.01-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS CONSTRUCTION AND ARRANGEMENT Hull Structure § 190.01-1 Application. (a) The provisions of this subpart, with the exception of...
46 CFR 190.07-1 - Application.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 7 2010-10-01 2010-10-01 false Application. 190.07-1 Section 190.07-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS CONSTRUCTION AND ARRANGEMENT Structural Fire Protection § 190.07-1 Application. (a) The provisions of this subpart, with the...
Chen, Jinxiang; Xie, Juan; Wu, Zhishen; Elbashiry, Elsafi Mohamed Adam; Lu, Yun
2015-10-01
This paper discusses the progress made in China in terms of the structural colors, microstructure and mechanical properties of the beetle forewing. 1) The forewing microstructures can be classified into six phases, the first three of which are characterized by sandwich, multilayer and fiber layer structures, respectively. The fracture behaviors resulting from these three phases suggest that different scale microstructures or coupled adjacent scale microstructures can determine the macroscopic mechanical behavior of the forewing. 2) The forewing colors are derived from three features: regulation of the structural parameters of the internal optical structures, i.e., a sculpted multilayer composite two-dimensional nanopillar structure grating system; scattering on the three-dimensional surface of the bowl-shaped structure; and reversible color changes due to changes in the physical microstructure of fluffs. Their formation mechanisms were clarified, and fibers with ecological biomimetic structural colors have been developed. 3) Beetles exhibit a lightweight sectional frame structure with a trabecular core structure. Both of the joints on the left and right are concave-convex butt-joint structures with burrs, which provide an efficient docking mechanism with high intensity. The forewing of dichotoma exhibits a non-equiangular layered structure, which results in anisotropy in its tensile strength. Finally, the authors propose potential new research directions for the next 20 years. Copyright © 2015 Elsevier B.V. All rights reserved.
Morphosyntactic annotation of CHILDES transcripts*
SAGAE, KENJI; DAVIS, ERIC; LAVIE, ALON; MACWHINNEY, BRIAN; WINTNER, SHULY
2014-01-01
Corpora of child language are essential for research in child language acquisition and psycholinguistics. Linguistic annotation of the corpora provides researchers with better means for exploring the development of grammatical constructions and their usage. We describe a project whose goal is to annotate the English section of the CHILDES database with grammatical relations in the form of labeled dependency structures. We have produced a corpus of over 18,800 utterances (approximately 65,000 words) with manually curated gold-standard grammatical relation annotations. Using this corpus, we have developed a highly accurate data-driven parser for the English CHILDES data, which we used to automatically annotate the remainder of the English section of CHILDES. We have also extended the parser to Spanish, and are currently working on supporting more languages. The parser and the manually and automatically annotated data are freely available for research purposes. PMID:20334720
Structural damping results from vibration tests of straight piping sections
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ware, A.G.; Thinnes, G.L.
EG and G Idaho is assisting the USNRC and the Pressure Vessel Research Committee in supporting a final position on revised damping values for structural analyses of nuclear piping systems. As part of this program, a series of vibrational tests on 76-mm and 203-mm (3-in. amd 8-in.) Schedule 40 carbon steel piping was conducted to determine the changes in structural damping due to various parametric effects. The 10-m (33-ft) straight sections of piping were rigidly supported at the ends. Spring, rod, and constant force hangers, as well as a sway brace and snubbers were included as intermediate supports. Excitation wasmore » provided by low-force level hammer inpacts, a hydraulic shaker, and a 445-kN (50-ton) overhead crane. Data was recorded using acceleration, strain, and displacement time histories. This paper presents results from the testing showing the effect of stress level and type of supports on structural damping in piping.« less
Development of thermoplastic composite aircraft structures
NASA Technical Reports Server (NTRS)
Renieri, Michael P.; Burpo, Steven J.; Roundy, Lance M.; Todd, Stephanie A.; Kim, H. J.
1992-01-01
Efforts focused on the use of thermoplastic composite materials in the development of structural details associated with an advanced fighter fuselage section with applicability to transport design. In support of these designs, mechanics developments were conducted in two areas. First, a dissipative strain energy approach to material characterization and failure prediction, developed at the Naval Research Laboratory, was evaluated as a design/analysis tool. Second, a finite element formulation for thick composites was developed and incorporated into a lug analysis method which incorporates pin bending effects. Manufacturing concepts were developed for an upper fuel cell cover. A detailed trade study produced two promising concepts: fiber placement and single-step diaphragm forming. Based on the innovative design/manufacturing concepts for the fuselage section primary structure, elements were designed, fabricated, and structurally tested. These elements focused on key issues such as thick composite lugs and low cost forming of fastenerless, stiffener/moldine concepts. Manufacturing techniques included autoclave consolidation, single diaphragm consolidation (SDCC) and roll-forming.
Structural Design and Analysis of the Upper Pressure Shell Section of a Composite Crew Module
NASA Technical Reports Server (NTRS)
Sleight, David W.; Paddock, David; Jeans, Jim W.; Hudeck, John D.
2008-01-01
This paper presents the results of the structural design and analysis of the upper pressure shell section of a carbon composite demonstration structure for the Composite Crew Module (CCM) Project. The project is managed by the NASA Engineering and Safety Center with participants from eight NASA Centers, the Air Force Research Laboratory, and multiple aerospace contractors including ATK/Swales, Northrop Grumman, Lockheed Martin, Collier Research Corporation, Genesis Engineering, and Janicki Industries. The paper discusses details of the upper pressure shell section design of the CCM and presents the structural analysis results using the HyperSizer structural sizing software and the MSC Nastran finite element analysis software. The HyperSizer results showed that the controlling load case driving most of the sizing in the upper pressure shell section was the internal pressure load case. The regions around the cutouts were controlled by internal pressure and the main parachute load cases. The global finite element analysis results showed that the majority of the elements of the CCM had a positive margin of safety with the exception of a few hot spots around the cutouts. These hot spots are currently being investigated with a more detailed analysis. Local finite element models of the Low Impact Docking System (LIDS) interface ring and the forward bay gussets with greater mesh fidelity were created for local sizing and analysis. The sizing of the LIDS interface ring was driven by the drogue parachute loads, Trans-Lunar Insertion (TLI) loads, and internal pressure. The drogue parachute loads controlled the sizing of the gusset cap on the drogue gusset and TLI loads controlled the sizing of the other five gusset caps. The main parachute loads controlled the sizing of the lower ends of the gusset caps on the main parachute fittings. The results showed that the gusset web/pressure shell and gusset web/gusset cap interfaces bonded using Pi-preform joints had local hot spots in the Pi-preform termination regions. These regions require a detailed three-dimensional analysis, which is currently being performed, to accurately address the load distribution near the Pi-preform termination in the upper and lower gusset caps.
Design, analysis, and testing of the Phase 1 CSI Evolutionary Model erectable truss
NASA Technical Reports Server (NTRS)
Gronet, M. J.; Davis, D. A.; Kintis, D. H.; Brillhart, R. D.; Atkins, E. M.
1992-01-01
This report addressed the design, analysis, and testing of the erectable truss structure for the Phase 1 CSI Evolutionary Model (CEM) testbed. The Phase 1 CEM testbed is the second testbed to form part of an ongoing program of focused research at NASA/LaRC in the development of Controls-Structures Integration (CSI) technology. The Phase 1 CEM contains the same overall geometry, weight, and sensor locations as the Phase 0 CEM, but is based in an integrated controller and structure design, whereby both structure and controller design variables are sized simultaneously. The Phase 1 CEM design features seven truss sections composed of struts with tailored mass and stiffness properties. A common erectable joint is used and the strut stiffness is tailored by varying the cross-sectional area. To characterize the structure, static tests were conducted on individual struts and 10-bay truss assemblies. Dynamic tests were conducted on 10-bay truss assemblies as well as the fully-assembled CEM truss. The results indicate that the static and dynamic properties of the structure are predictable, well-characterized, and within the performance requirements established during the Phase 1 CEM integrated controller/structure design analysis.
Topology synthesis and size optimization of morphing wing structures
NASA Astrophysics Data System (ADS)
Inoyama, Daisaku
This research demonstrates a novel topology and size optimization methodology for synthesis of distributed actuation systems with specific applications to morphing air vehicle structures. The main emphasis is placed on the topology and size optimization problem formulations and the development of computational modeling concepts. The analysis model is developed to meet several important criteria: It must allow a rigid-body displacement, as well as a variation in planform area, with minimum strain on structural members while retaining acceptable numerical stability for finite element analysis. Topology optimization is performed on a semi-ground structure with design variables that control the system configuration. In effect, the optimization process assigns morphing members as "soft" elements, non-morphing load-bearing members as "stiff' elements, and non-existent members as "voids." The optimization process also determines the optimum actuator placement, where each actuator is represented computationally by equal and opposite nodal forces with soft axial stiffness. In addition, the configuration of attachments that connect the morphing structure to a non-morphing structure is determined simultaneously. Several different optimization problem formulations are investigated to understand their potential benefits in solution quality, as well as meaningfulness of the formulations. Extensions and enhancements to the initial concept and problem formulations are made to accommodate multiple-configuration definitions. In addition, the principal issues on the external-load dependency and the reversibility of a design, as well as the appropriate selection of a reference configuration, are addressed in the research. The methodology to control actuator distributions and concentrations is also discussed. Finally, the strategy to transfer the topology solution to the sizing optimization is developed and cross-sectional areas of existent structural members are optimized under applied aerodynamic loads. That is, the optimization process is implemented in sequential order: The actuation system layout is first determined through multi-disciplinary topology optimization process, and then the thickness or cross-sectional area of each existent member is optimized under given constraints and boundary conditions. Sample problems are solved to demonstrate the potential capabilities of the presented methodology. The research demonstrates an innovative structural design procedure from a computational perspective and opens new insights into the potential design requirements and characteristics of morphing structures.
NASA Astrophysics Data System (ADS)
Lei, Mingfeng; Lin, Dayong; Liu, Jianwen; Shi, Chenghua; Ma, Jianjun; Yang, Weichao; Yu, Xiaoniu
2018-03-01
For the purpose of investigating lining concrete durability, this study derives a modified chloride diffusion model for concrete based on the odd continuation of boundary conditions and Fourier transform. In order to achieve this, the linear stress distribution on a sectional structure is considered, detailed procedures and methods are presented for model verification and parametric analysis. Simulation results show that the chloride diffusion model can reflect the effects of linear stress distribution of the sectional structure on the chloride diffusivity with reliable accuracy. Along with the natural environmental characteristics of practical engineering structures, reference value ranges of model parameters are provided. Furthermore, a chloride diffusion model is extended for the consideration of multi-factor coupling of linear stress distribution, chloride concentration and diffusion time. Comparison between model simulation and typical current research results shows that the presented model can produce better considerations with a greater universality.
Magnetic resonance imaging of the normal bovine digit.
Raji, A R; Sardari, K; Mirmahmoob, P
2009-08-01
The purpose of this study was defining the normal structures of the digits and hoof in Holstein dairy cattle using Magnetic Resonance Image (MRI). Transverse, Sagital and Dorsoplantar MRI images of three isolated cattle cadaver digits were obtained using Gyroscan T5-NT a magnet of 0.5 Tesla and T1 Weighted sequence. The MRI images were compared to corresponding frozen cross-sections and dissect specimens of the cadaver digits. Relevant anatomical structures were identified and labeled at each level. The MRI images provided anatomical detail of the digits and hoof in Holstein dairy cattle. Transversal images provided excellent depiction of anatomical structures when compared to corresponding frozen cross-sections. The information presented in this paper would serve as an initial reference to the evaluation of MRI images of the digits and hoof in Holstein dairy cattle, that can be used by radiologist, clinicians, surgeon or for research propose in bovine lameness.
Briukhanov, A F; Zaĭtsev, A A; Babenyshev, B V; Protsenko, S L; Abgarian, G P; Solodovnikov, B V; Lebedev, K K; Maevskiĭ, M P; Antonov, A V; Sukhov, V V; Grizhebovskiĭ, G M; Evchenko, Iu M
2001-01-01
The experience of use of efforts and resources by the bacteriological section of the specialized antiepidemic brigade of the Stavropol Research Institute for Plague Control in the Chechen Republic during the period of 1999-2000 under the conditions of the emergency situation, formed as the consequence of carrying out the antiterrorist operation, is summarized. The work load falling of the bacteriological section in different shifts, the structure of bacteriological investigations, as well as some problems arising in the process of work, were analyzed. The experience showed the necessity of the complete accommodation of the bacteriological laboratory in specialized motor-vehicle modules having all necessary equipment for investigation works, disinfection, sterilization. The brigade sent to its mission should be given concrete tasks with a view to ensure the adequate supply of the bacteriological section with diagnostic preparations, materials and equipment.
RATFOR user's guide version 2.0
NASA Technical Reports Server (NTRS)
Helmle, L. C.
1985-01-01
This document is a user's guide for RATFOR at Ames Research Center. The main part of the document is a general description of RATFOR, and the appendix is devoted to a machine specific implementation for the Cray X-MP. The general stylistic features of RATFOR are discussed, including the block structure, keywords, source code, format, and the notion of tokens. There is a section on the basic control structures (IF-ELSE, ELSE IF, WHILE, FOR, DO, REPEAT-UNTIL, BREAK, NEXT), and there is a section on the statements that extend FORTRAN's capabilities (DEFINE, MACRO, INCLUDE, STRING). THE appendix discusses everything needed to compile and run a basic job, the preprocessor options, the supported character sets, the generated listings, fatal errors, and program limitations and the differences from standard FORTRAN.
NASA Technical Reports Server (NTRS)
1997-01-01
The NASA Lewis Research Center Structures Division is an international leader and pioneer in developing new structural analysis, life prediction, and failure analysis related to rotating machinery and more specifically to hot section components in air-breathing aircraft engines and spacecraft propulsion systems. The research consists of both deterministic and probabilistic methodology. Studies include, but are not limited to, high-cycle and low-cycle fatigue as well as material creep. Studies of structural failure are at both the micro- and macrolevels. Nondestructive evaluation methods related to structural reliability are developed, applied, and evaluated. Materials from which structural components are made, studied, and tested are monolithics and metal-matrix, polymer-matrix, and ceramic-matrix composites. Aeroelastic models are developed and used to determine the cyclic loading and life of fan and turbine blades. Life models are developed and tested for bearings, seals, and other mechanical components, such as magnetic suspensions. Results of these studies are published in NASA technical papers and reference publication as well as in technical society journal articles. The results of the work of the Structures Division and the bibliography of its publications for calendar year 1995 are presented.
Structures Division 1994 Annual Report
NASA Technical Reports Server (NTRS)
1996-01-01
The NASA Lewis Research Center Structures Division is an international leader and pioneer in developing new structural analysis, life prediction, and failure analysis related to rotating machinery and more specifically to hot section components in air-breathing aircraft engines and spacecraft propulsion systems. The research consists of both deterministic and probabilistic methodology. Studies include, but are not limited to, high-cycle and low-cycle fatigue as well as material creep. Studies of structural failure are at both the micro- and macrolevels. Nondestructive evaluation methods related to structural reliability are developed, applied, and evaluated. Materials from which structural components are made, studied, and tested are monolithics and metal-matrix, polymer-matrix, and ceramic-matrix composites. Aeroelastic models are developed and used to determine the cyclic loading and life of fan and turbine blades. Life models are developed and tested for bearings, seals, and other mechanical components, such as magnetic suspensions. Results of these studies are published in NASA technical papers and reference publication as well as in technical society journal articles. The results of the work of the Structures Division and the bibliography of its publications for calendar year 1994 are presented.
Lee, Seungjae; Park, Jaeseong; Kwak, Euishin; Shon, Sudeok; Kang, Changhoon; Choi, Hosoon
2017-01-01
Modular systems have been mostly researched in relatively low-rise structures but, lately, their applications to mid- to high-rise structures began to be reviewed, and research interest in new modularization subjects has increased. The application of modular systems to mid- to high-rise structures requires the structural stability of the frame and connections that consist of units, and the evaluation of the stiffness of structures that are combined in units. However, the combination of general units causes loss of the cross-section of columns or beams, resulting in low seismic performance and hindering installation works in the field. In addition, the evaluation of a frame considering such a cross-sectional loss is not easy. Therefore, it is necessary to develop a joint that is stable and easy to install. In the study, a rigidly connected modular system was proposed as a moment-resisting frame for a unit modular system, and their joints were developed and their performances were compared. The proposed system changed the ceiling beam into a bracket type to fasten bolts. It can be merged with other seismic force-resisting systems. To verify the seismic performance of the proposed system, a cyclic loading test was conducted, and the rigidly connected joint performance and integrated behavior at the joint of modular units were investigated. From the experimental results, the maximum resisting force of the proposed connection exceeded the theoretical parameters, indicating that a rigid joint structural performance could be secured. PMID:28772622
Physics Structure Analysis of Parallel Waves Concept of Physics Teacher Candidate
NASA Astrophysics Data System (ADS)
Sarwi, S.; Supardi, K. I.; Linuwih, S.
2017-04-01
The aim of this research was to find a parallel structure concept of wave physics and the factors that influence on the formation of parallel conceptions of physics teacher candidates. The method used qualitative research which types of cross-sectional design. These subjects were five of the third semester of basic physics and six of the fifth semester of wave course students. Data collection techniques used think aloud and written tests. Quantitative data were analysed with descriptive technique-percentage. The data analysis technique for belief and be aware of answers uses an explanatory analysis. Results of the research include: 1) the structure of the concept can be displayed through the illustration of a map containing the theoretical core, supplements the theory and phenomena that occur daily; 2) the trend of parallel conception of wave physics have been identified on the stationary waves, resonance of the sound and the propagation of transverse electromagnetic waves; 3) the influence on the parallel conception that reading textbooks less comprehensive and knowledge is partial understanding as forming the structure of the theory.
Impact Damage to Composite Structures
1986-02-01
Sections Through the Gasbubble A sudden incompre causes i pedo sho So loadi has to e Eulerian me t r i c b pressure mot ssib mmed t th ng a...KINGDOM Defence Research Information Centre Kentigern House 65 Brown Street Glasgow G2 SEX UNITED STATES National Aeronautics and Space
Urban Men's Knowledge and Perceptions regarding Sexually Transmitted Infections in Pakistan
ERIC Educational Resources Information Center
Mohammad Mir, Ali; Reichenbach, Laura; Wajid, Abdul
2009-01-01
In a pioneering study undertaken in Pakistan, urban men's sexual behaviors, perceptions and knowledge regarding sexually transmitted infections including HIV/AIDS were determined by employing both qualitative and quantitative research methods. Focus group discussions were carried out initially and followed by a structured cross sectional survey…
Space architecture monograph series. Volume 4: Genesis 2: Advanced lunar outpost
NASA Technical Reports Server (NTRS)
Fieber, Joseph P.; Huebner-Moths, Janis; Paruleski, Kerry L.; Moore, Gary T. (Editor)
1991-01-01
This research and design study investigated advanced lunar habitats for astronauts and mission specialists on the Earth's moon. Design recommendations are based on environmental response to the lunar environment, human habitability (human factors and environmental behavior research), transportability (structural and materials system with least mass), constructability (minimizing extravehicular time), construction dependability and resilience, and suitability for NASA launch research missions in the 21st century. The recommended design uses lunar lava tubes, with construction being a combination of Space Station Freedom derived hard modules and light weight Kevlar laminate inflatable structures. The proposed habitat includes research labs and a biotron, crew quarters and crew support facility, mission control, health maintenance facility, maintenance work areas for psychological retreat, privacy, and comtemplation. Furniture, specialized equipment, and lighting are included in the analysis and design. Drawings include base master plans, construction sequencing, overall architectural configuration, detailed floor plans, sections and axonometrics, with interior perspectives.
Innovative Structural Materials and Sections with Strain Hardening Cementitious Composites
NASA Astrophysics Data System (ADS)
Dey, Vikram
The motivation of this work is based on development of new construction products with strain hardening cementitious composites (SHCC) geared towards sustainable residential applications. The proposed research has three main objectives: automation of existing manufacturing systems for SHCC laminates; multi-level characterization of mechanical properties of fiber, matrix, interface and composites phases using servo-hydraulic and digital image correlation techniques. Structural behavior of these systems were predicted using ductility based design procedures using classical laminate theory and structural mechanics. SHCC sections are made up of thin sections of matrix with Portland cement based binder and fine aggregates impregnating continuous one-dimensional fibers in individual or bundle form or two/three dimensional woven, bonded or knitted textiles. Traditional fiber reinforced concrete (FRC) use random dispersed chopped fibers in the matrix at a low volume fractions, typically 1-2% to avoid to avoid fiber agglomeration and balling. In conventional FRC, fracture localization occurs immediately after the first crack, resulting in only minor improvement in toughness and tensile strength. However in SHCC systems, distribution of cracking throughout the specimen is facilitated by the fiber bridging mechanism. Influence of material properties of yarn, composition, geometry and weave patterns of textile in the behavior of laminated SHCC skin composites were investigated. Contribution of the cementitious matrix in the early age and long-term performance of laminated composites was studied with supplementary cementitious materials such as fly ash, silica fume, and wollastonite. A closed form model with classical laminate theory and ply discount method, coupled with a damage evolution model was utilized to simulate the non-linear tensile response of these composite materials. A constitutive material model developed earlier in the group was utilized to characterize and correlate the behavior of these structural composites under uniaxial tension and flexural loading responses. Development and use of analytical models enables optimal design for application of these materials in structural applications. Another area of immediate focus is the development of new construction products from SHCC laminates such as angles, channels, hat sections, closed sections with optimized cross sections. Sandwich composites with stress skin-cellular core concept were also developed to utilize strength and ductility of fabric reinforced skin in addition to thickness, ductility, and thermal benefits of cellular core materials. The proposed structurally efficient and durable sections promise to compete with wood and light gage steel based sections for lightweight construction and panel application.
2011-08-01
investigated. Implementation of this technology into the maintenance framework depends on several factors, including safety of the structural system, cost... Maintenance Parameters The F-15 Program has indicated that, in practice , maintenance actions are generally performed on flight hour multiples of 200...Risk Analysis or the Perform Cost Benefit Analysis sections of the flowchart. 4.6. Determine System Configurations The current maintenance practice
African Primary Care Research: Performing surveys using questionnaires
Mabuza, Langalibalele H.; Ogunbanjo, Gboyega A.; Mash, Bob
2014-01-01
The aim of this article is to provide practical guidance on conducting surveys and the use of questionnaires for postgraduate students at a Masters level who are undertaking primary care research. The article is intended to assist with writing the methods section of the research proposal and thinking through the relevant issues that apply to sample size calculation, sampling strategy, design of a questionnaire and administration of a questionnaire. The article is part of a larger series on primary care research, with other articles in the series focusing on the structure of the research proposal and the literature review, as well as quantitative data analysis. PMID:26245434
African primary care research: performing surveys using questionnaires.
Govender, Indiran; Mabuza, Langalibalele H; Ogunbanjo, Gboyega A; Mash, Bob
2014-04-25
The aim of this article is to provide practical guidance on conducting surveys and the use of questionnaires for postgraduate students at a Masters level who are undertaking primary care research. The article is intended to assist with writing the methods section of the research proposal and thinking through the relevant issues that apply to sample size calculation, sampling strategy, design of a questionnaire and administration of a questionnaire. The articleis part of a larger series on primary care research, with other articles in the series focusing on the structure of the research proposal and the literature review, as well as quantitative data analysis.
NASA Astrophysics Data System (ADS)
Chiu, Ya-Ping; Huang, Bo-Chao; Shih, Min-Chuan; Huang, Po-Cheng; Chen, Chun-Wei
2015-09-01
Interfacial science has received much attention recently based on the development of state-of-the-art analytical tools that can create and manipulate the charge, spin, orbital, and lattice degrees of freedom at interfaces. Motivated by the importance of nanoscale interfacial science that governs device operation, we present a technique to probe the electronic characteristics of heterointerfaces with atomic resolution. In this work, the interfacial characteristics of heteroepitaxial structures are investigated and the fundamental mechanisms that pertain in these systems are elucidated through cross-sectional scanning tunneling microscopy (XSTM). The XSTM technique is employed here to directly observe epitaxial interfacial structures and probe local electronic properties with atomic-level capability. Scanning tunneling microscopy and spectroscopy experiments with atomic precision provide insight into the origin and spatial distribution of electronic properties across heterointerfaces. The first part of this report provides a brief description of the cleavage technique and spectroscopy analysis in XSTM measurements. The second part addresses interfacial electronic structures of several model heterostructures in current condensed matter research using XSTM. Topics to be discussed include high-κ‘s/III-V’s semiconductors, polymer heterojunctions, and complex oxide heterostructures, which are all material systems whose investigation using this technique is expected to benefit the research community. Finally, practical aspects and perspectives of using XSTM in interface science are presented.
NASA Technical Reports Server (NTRS)
Riddlebaugh, Stephen M. (Editor)
2008-01-01
The NASA Glenn Research Center is pushing the envelope of research and technology in aeronautics, space exploration, science, and space operations. Our research in aeropropulsion, structures and materials, and instrumentation and controls is enabling next-generation transportation systems that are faster, more environmentally friendly, more fuel efficient, and safer. Our research and development of space flight systems is enabling advanced power, propulsion, communications, and human health systems that will advance the exploration of our solar system. This report selectively summarizes NASA Glenn Research Center s research and technology accomplishments for fiscal year 2007. Comprising 104 short articles submitted by the staff scientists and engineers, the report is organized into six major sections: Aeropropulsion, Power and Space Propulsion, Communications, Space Processes and Experiments, Instrumentation and Controls, and Structures and Materials. It is not intended to be a comprehensive summary of all the research and technology work done over the past fiscal year; most of the work is reported in Glenn-published technical reports, journal articles, and presentations. For each article in this report, a Glenn contact person has been identified, and where possible, a reference document is listed so that additional information can be easily obtained.
The qualitative research proposal.
Klopper, H
2008-12-01
Qualitative research in the health sciences has had to overcome many prejudices and a number of misunderstandings, but today qualitative research is as acceptable as quantitative research designs and is widely funded and published. Writing the proposal of a qualitative study, however, can be a challenging feat, due to the emergent nature of the qualitative research design and the description of the methodology as a process. Even today, many sub-standard proposals at post-graduate evaluation committees and application proposals to be considered for funding are still seen. This problem has led the researcher to develop a framework to guide the qualitative researcher in writing the proposal of a qualitative study based on the following research questions: (i) What is the process of writing a qualitative research proposal? and (ii) What does the structure and layout of a qualitative proposal look like? The purpose of this article is to discuss the process of writing the qualitative research proposal, as well as describe the structure and layout of a qualitative research proposal. The process of writing a qualitative research proposal is discussed with regards to the most important questions that need to be answered in your research proposal with consideration of the guidelines of being practical, being persuasive, making broader links, aiming for crystal clarity and planning before you write. While the structure of the qualitative research proposal is discussed with regards to the key sections of the proposal, namely the cover page, abstract, introduction, review of the literature, research problem and research questions, research purpose and objectives, research paradigm, research design, research method, ethical considerations, dissemination plan, budget and appendices.
One-dimensional analysis of filamentary composite beam columns with thin-walled open sections
NASA Technical Reports Server (NTRS)
Lo, Patrick K.-L.; Johnson, Eric R.
1986-01-01
Vlasov's one-dimensional structural theory for thin-walled open section bars was originally developed and used for metallic elements. The theory was recently extended to laminated bars fabricated from advanced composite materials. The purpose of this research is to provide a study and assessment of the extended theory. The focus is on flexural and torsional-flexural buckling of thin-walled, open section, laminated composite columns. Buckling loads are computed from the theory using a linear bifurcation analysis and a geometrically nonlinear beam column analysis by the finite element method. Results from the analyses are compared to available test data.
[A review of mixed gas detection system based on infrared spectroscopic technique].
Dang, Jing-Min; Fu, Li; Yan, Zi-Hui; Zheng, Chuan-Tao; Chang, Yu-Chun; Chen, Chen; Wang, Yi-Din
2014-10-01
In order to provide the experiences and references to the researchers who are working on infrared (IR) mixed gas detection field. The proposed manuscript reviews two sections of the aforementioned field, including optical multiplexing structure and detection method. At present, the coherent light sources whose representative are quantum cascade laser (QCL) and inter-band cascade laser(ICL) become the mainstream light source in IR mixed gas detection, which replace the traditional non-coherent light source, such as IR radiation source and IR light emitting diode. In addition, the photon detector which has a super high detectivity and very short response time is gradually beyond thermal infrared detector, dominant in the field of infrared detector. The optical multiplexing structure is the key factor of IR mixed gas detection system, which consists of single light source multi-plexing detection structure and multi light source multiplexing detection structure. Particularly, single light source multiplexing detection structure is advantages of small volume and high integration, which make it a plausible candidate for the portable mixed gas detection system; Meanwhile, multi light source multiplexing detection structure is embodiment of time division multiplex, frequency division multiplexing and wavelength division multiplexing, and become the leading structure of the mixed gas detection system because of its wider spectral range, higher spectral resolution, etc. The detection method applied to IR mixed gas detection includes non-dispersive infrared (NDIR) spectroscopy, wavelength and frequency-modulation spectroscopy, cavity-enhanced spectroscopy and photoacoustic spectroscopy, etc. The IR mixed gas detection system designed by researchers after recognizing the whole sections of the proposed system, which play a significant role in industrial and agricultural production, environmental monitoring, and life science, etc.
Software for browsing sectioned images of a dog body and generating a 3D model.
Park, Jin Seo; Jung, Yong Wook
2016-01-01
The goals of this study were (1) to provide accessible and instructive browsing software for sectioned images and a portable document format (PDF) file that includes three-dimensional (3D) models of an entire dog body and (2) to develop techniques for segmentation and 3D modeling that would enable an investigator to perform these tasks without the aid of a computer engineer. To achieve these goals, relatively important or large structures in the sectioned images were outlined to generate segmented images. The sectioned and segmented images were then packaged into browsing software. In this software, structures in the sectioned images are shown in detail and in real color. After 3D models were made from the segmented images, the 3D models were exported into a PDF file. In this format, the 3D models could be manipulated freely. The browsing software and PDF file are available for study by students, for lecture for teachers, and for training for clinicians. These files will be helpful for anatomical study by and clinical training of veterinary students and clinicians. Furthermore, these techniques will be useful for researchers who study two-dimensional images and 3D models. © 2015 Wiley Periodicals, Inc.
Systematic review of Kinect applications in elderly care and stroke rehabilitation
2014-01-01
In this paper we present a review of the most current avenues of research into Kinect-based elderly care and stroke rehabilitation systems to provide an overview of the state of the art, limitations, and issues of concern as well as suggestions for future work in this direction. The central purpose of this review was to collect all relevant study information into one place in order to support and guide current research as well as inform researchers planning to embark on similar studies or applications. The paper is structured into three main sections, each one presenting a review of the literature for a specific topic. Elderly Care section is comprised of two subsections: Fall detection and Fall risk reduction. Stroke Rehabilitation section contains studies grouped under Evaluation of Kinect’s spatial accuracy, and Kinect-based rehabilitation methods. The third section, Serious and exercise games, contains studies that are indirectly related to the first two sections and present a complete system for elderly care or stroke rehabilitation in a Kinect-based game format. Each of the three main sections conclude with a discussion of limitations of Kinect in its respective applications. The paper concludes with overall remarks regarding use of Kinect in elderly care and stroke rehabilitation applications and suggestions for future work. A concise summary with significant findings and subject demographics (when applicable) of each study included in the review is also provided in table format. PMID:24996956
NASA Astrophysics Data System (ADS)
Hight Walker, Angela Renee
1995-01-01
With the use of a Fourier transform microwave (FTM) spectrometer, structural determinations of two types of species; multiconformational molecules and van der Waals complexes, have been performed. Presented in this thesis are three sections summarizing this research effort. The first section contains a detailed explanation of the FTM instrument. In Section II, the study of three multiconformational molecules is presented as two chapters. Finally, three chapters in Section III outline the work still in progress on many van der Waals complexes. Section I was written to be a "manual" for the FTM spectrometer and to aid new additions to the group in their understanding of the instrument. An instruction guide is necessary for home-built instruments such as this one due to their unique design and application. Vital techniques and theories are discussed and machine operation is outlined. A brief explanation of general microwave spectroscopy as performed on an FTM spectrometer is also given. Section II is composed of two chapters pertaining to multiconformational molecules. In Chapter 2, a complete structural analysis of dipropyl ether is reported. The only conformer assigned had C_{rm s} symmetry. Many transitions are yet unassigned. Chapter 3 summarizes an investigation of two nitrosamines; methyl ethyl and methyl propyl nitrosamine. Only one conformer was observed for methyl ethyl nitrosamine, but two were assigned to methyl propyl nitrosamine. Nuclear hyperfine structure and internal methyl rotation complicated the spectra. The final section, Section III, contains the ongoing progress on weakly bound van der Waals complexes. The analysis of the OCS--HBr complex identified the structure as quasi-linear with large amplitude bending motions. Five separate isotopomers were assigned. Transitions originating from the HBr--DBr complex were measured and presented in Chapter 5. Although early in the analysis, the structure was determined to be bent and deuterium bonded. The final chapter of this section is meant to be a permanent record of transition frequencies whose molecular carrier is still in question. Two different groups of transitions from two different samples are listed. Further work is needed to unambiguously assign the frequencies with a carrier and quantum numbers, however the complexes (H_2 O)--(HCl)_2 and NO--H _2O are considered possible suspects.
Sectoral risk research about input-output structure of the United States
NASA Astrophysics Data System (ADS)
Zhang, Mao
2018-02-01
There exist rare researches about economic risk in sectoral level, which is significantly important for risk prewarning. This paper employed status coefficient to measure the symmetry of economic subnetwork, which is negatively correlated with sectoral risk. Then, we do empirical research in both cross section and time series dimensions. In cross section dimension, we study the correlation between sectoral status coefficient and sectoral volatility, earning rate and Sharpe ratio respectively in the year 2015. Next, in the perspective of time series, we first investigate the correlation change between sectoral status coefficient and annual total output from 1997 to 2015. Then, we divide the 71 sectors in America into agriculture, manufacturing, services and government, compare the trend terms of average sectoral status coefficients of the four industries and illustrate the causes behind it. We also find obvious abnormality in the sector of housing. At last, this paper puts forward some suggestions for the federal government.
Research of low cost wind generator rotors
NASA Technical Reports Server (NTRS)
Fertis, D. G.; Ross, R. S.
1978-01-01
A feasibility program determined that it would be possible to significantly reduce the cost of manufacturing wind generator rotors by making them of cast urethane. Several high modulus urethanes which were structurally tested were developed. A section of rotor was also cast and tested showing the excellent aerodynamic surface which results. A design analysis indicated that a cost reduction of almost ten to one can be achieved with a small weight increase to achieve the same structural integrity as expected of current rotor systems.
NASA Technical Reports Server (NTRS)
Chattopadhyay, Aditi
1996-01-01
The objective of this research is to develop analysis procedures to investigate the coupling of composite and smart materials to improve aeroelastic and vibratory response of aerospace structures. The structural modeling must account for arbitrarily thick geometries, embedded and surface bonded sensors and actuators and imperfections, such as delamination. Changes in the dynamic response due to the presence of smart materials and delaminations is investigated. Experiments are to be performed to validate the proposed mathematical model.
Avionics Technology Contract Project Report Phase I with Research Findings.
ERIC Educational Resources Information Center
Sappe', Hoyt; Squires, Shiela S.
This document reports on Phase I of a project that examined the occupation of avionics technician, established appropriate committees, and conducted task verification. Results of this phase provide the basic information required to develop the program standards and to guide and set up the committee structure to guide the project. Section 1…
Family Transmission of Work Affectivity and Experiences to Children
ERIC Educational Resources Information Center
Porfeli, Erik J.; Wang, Chuang; Hartung, Paul J.
2008-01-01
Theory and research suggest that children develop orientations toward work appreciably influenced by their family members' own expressed work experiences and emotions. Cross-sectional data from 100 children (53 girls, 47 boys; mean age = 11.1 years) and structural equation modeling were used to assess measures of work affectivity and experiences…
ERIC Educational Resources Information Center
Bulunuz, Mizrap
2012-01-01
This research studied the development of preservice teachers' understandings and attitudes about teaching science through playful experiences. Subjects were 94 senior preservice teachers in two sections of a science methods class on teaching preschool children. Data sources were semi-structured interviews and open-ended questionnaire at the…
Code of Federal Regulations, 2014 CFR
2014-10-01
..., cargo tank internal examination, and underwater survey intervals. 189.40-3 Section 189.40-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS INSPECTION AND... examination, and underwater survey intervals. (a) Except as provided for in paragraphs (b) through (g) of this...
Code of Federal Regulations, 2010 CFR
2010-10-01
..., cargo tank internal examination, and underwater survey intervals. 189.40-3 Section 189.40-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS INSPECTION AND... examination, and underwater survey intervals. (a) Except as provided for in paragraphs (b) through (g) of this...
Code of Federal Regulations, 2011 CFR
2011-10-01
..., cargo tank internal examination, and underwater survey intervals. 189.40-3 Section 189.40-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS INSPECTION AND... examination, and underwater survey intervals. (a) Except as provided for in paragraphs (b) through (g) of this...
Code of Federal Regulations, 2013 CFR
2013-10-01
..., cargo tank internal examination, and underwater survey intervals. 189.40-3 Section 189.40-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS INSPECTION AND... examination, and underwater survey intervals. (a) Except as provided for in paragraphs (b) through (g) of this...
Code of Federal Regulations, 2012 CFR
2012-10-01
..., cargo tank internal examination, and underwater survey intervals. 189.40-3 Section 189.40-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS INSPECTION AND... examination, and underwater survey intervals. (a) Except as provided for in paragraphs (b) through (g) of this...
An Investigation of Motivation to Transfer Second Language Learning
ERIC Educational Resources Information Center
James, Mark Andrew
2012-01-01
Research on motivation in second language (L2) education has tended to focus on learning; this study took an alternative perspective, examining students' motivation to transfer L2 learning. Data were gathered through semi-structured interviews with 40 students who were enrolled in several sections of a university English-for-academic-purposes…
75 FR 51082 - Center for Scientific Review; Notice of Closed Meetings
Federal Register 2010, 2011, 2012, 2013, 2014
2010-08-18
...: Muscle Biology. Date: September 8, 2010. Time: 11 a.m. to 3 p.m. Agenda: To review and evaluate grant...: Technology Development for High-Throughput Structural Biology Research Review. Date: September 14-15, 2010...: Biology of Development and Aging Integrated Review Group; Development--1 Study Section. Date: September 30...
46 CFR 190.01-90 - Vessels contracted for prior to March 1, 1968.
Code of Federal Regulations, 2010 CFR
2010-10-01
... Section 190.01-90 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS CONSTRUCTION AND ARRANGEMENT Hull Structure § 190.01-90 Vessels contracted for prior to March 1... and alterations may be made to the same standards as the original construction. (b) Conversions, major...
46 CFR 190.01-5 - Vessels subject to load line.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 7 2010-10-01 2010-10-01 false Vessels subject to load line. 190.01-5 Section 190.01-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS CONSTRUCTION AND ARRANGEMENT Hull Structure § 190.01-5 Vessels subject to load line. (a) For vessels assigned a...
Piloting a European Employer Survey on Skill Needs: Illustrative Findings. Research Paper No 36
ERIC Educational Resources Information Center
Sofroniou, Nicholas, Ed.; Zukersteinova, Alena, Ed.
2013-01-01
Today, information and data on skills development come mainly from household and employees surveys: trends in the labour market, demand and supply of skills, data on skill mismatch and skills obsolescence. Recurrent analysis of individual cross-sectional data and their extrapolation into the future indicates significant structural changes over…
West, Stephen G.
2016-01-01
Psychologists have long had interest in the processes through which antecedent variables produce their effects on the outcomes of ultimate interest (e.g., Wood-worth's Stimulus-Organism-Response model). Models involving such meditational processes have characterized many of the important psychological theories of the 20th century and continue to the present day. However, it was not until Judd and Kenny (1981) and Baron and Kenny (1986) combined ideas from experimental design and structural equation modeling that statistical methods for directly testing such models, now known as mediation analysis, began to be developed. Methodologists have improved these statistical methods, developing new, more efficient estimators for mediated effects. They have also extended mediation analysis to multilevel data structures, models involving multiple mediators, models in which interactions occur, and an array of noncontinuous outcome measures (see MacKinnon, 2008). This work nicely maps on to key questions of applied researchers and has led to an outpouring of research testing meditational models (As of August, 2011, Baron and Kenny's article has had over 24,000 citations according to Google Scholar). PMID:26736046
An overview of the crash dynamics failure behavior of metal and composite aircraft structures
NASA Technical Reports Server (NTRS)
Carden, Huey D.; Boitnott, Richard L.; Fasanella, Edwin L.; Jones, Lisa E.
1991-01-01
An overview of failure behavior results is presented from some of the crash dynamics research conducted with concepts of aircraft elements and substructure not necessarily designed or optimized for energy absorption or crash loading considerations. Experimental and analytical data are presented that indicate some general trends in the failure behavior of a class of composite structures that includes fuselage panels, individual fuselage sections, fuselage frames, skeleton subfloors with stringers and floor beams without skin covering, and subfloors with skin added to the frame stringer structure. Although the behavior is complex, a strong similarity in the static/dynamic failure behavior among these structures is illustrated through photographs of the experimental results and through analytical data of generic composite structural models.
Okereke, Olivia I; Copeland, Maura; Hyman, Bradley T; Wanggaard, Taylor; Albert, Marilyn S; Blacker, Deborah
2011-03-01
The Clinical Dementia Rating (CDR) and CDR Sum-of-Boxes can be used to grade mild but clinically important cognitive symptoms of Alzheimer disease. However, sensitive clinical interview formats are lengthy. To develop a brief instrument for obtaining CDR scores and to assess its reliability and cross-sectional validity. Using legacy data from expanded interviews conducted among 347 community-dwelling older adults in a longitudinal study, we identified 60 questions (from a possible 131) about cognitive functioning in daily life using clinical judgment, inter-item correlations, and principal components analysis. Items were selected in 1 cohort (n=147), and a computer algorithm for generating CDR scores was developed in this same cohort and re-run in a replication cohort (n=200) to evaluate how well the 60 items retained information from the original 131 items. Short interviews based on the 60 items were then administered to 50 consecutively recruited older individuals, with no symptoms or mild cognitive symptoms, at an Alzheimer's Disease Research Center. Clinical Dementia Rating scores based on short interviews were compared with those from independent long interviews. In the replication cohort, agreement between short and long CDR interviews ranged from κ=0.65 to 0.79, with κ=0.76 for Memory, κ=0.77 for global CDR, and intraclass correlation coefficient for CDR Sum-of-Boxes=0.89. In the cross-sectional validation, short interview scores were slightly lower than those from long interviews, but good agreement was observed for global CDR and Memory (κ≥0.70) as well as for CDR Sum-of-Boxes (intraclass correlation coefficient=0.73). The Structured Interview & Scoring Tool-Massachusetts Alzheimer's Disease Research Center is a brief, reliable, and sensitive instrument for obtaining CDR scores in persons with symptoms along the spectrum of mild cognitive change.
A novel hybrid joining methodology for composite to steel joints
NASA Astrophysics Data System (ADS)
Sarh, Bastian
This research has established a novel approach for designing, analyzing, and fabricating load bearing structural connections between resin infused composite materials and components made of steel or other metals or alloys. A design philosophy is proposed wherein overlapping joint sections comprised of fiber reinforced plastics (FRP's) and steel members are connected via a combination of adhesive bonding and integrally placed composite pins. A film adhesive is utilized, placed into the dry stack prior to resin infusion and is cured after infusion through either local heat elements or by placing the structure into an oven. The novel manner in which the composite pins are introduced consists of perforating the steel member with holes and placing pre-formed composite pins through them, also prior to resin infusion of the composite section. In this manner joints are co-molded structures such that secondary processing is eliminated. It is shown that such joints blend the structural benefits of adhesive and mechanically connected joints, and that the fabrication process is feasible for low-cost, large-scale production as applicable to the shipbuilding industry. Analysis procedures used for designing such joints are presented consisting of an adhesive joint design theory and a pin placement theory. These analysis tools are used in the design of specimens, specific designs are fabricated, and these evaluated through structural tests. Structural tests include quasi-static loading and low cycle fatigue evaluation. This research has thereby invented a novel philosophy on joints, created the manufacturing technique for fabricating such joints, established simple to apply analysis procedures used in the design of such joints (consisting of both an adhesive and a pin placement analysis), and has validated the methodology through specimen fabrication and testing.
NASA Astrophysics Data System (ADS)
Kagawa, T.; Petukhin, A.; Koketsu, K.; Miyake, H.; Murotani, S.; Tsurugi, M.
2010-12-01
Three dimensional velocity structure model of southwest Japan is provided to simulate long-period ground motions due to the hypothetical subduction earthquakes. The model is constructed from numerous physical explorations conducted in land and offshore areas and observational study of natural earthquakes. Any available information is involved to explain crustal structure and sedimentary structure. Figure 1 shows an example of cross section with P wave velocities. The model has been revised through numbers of simulations of small to middle earthquakes as to have good agreement with observed arrival times, amplitudes, and also waveforms including surface waves. Figure 2 shows a comparison between Observed (dash line) and simulated (solid line) waveforms. Low velocity layers have added on seismological basement to reproduce observed records. The thickness of the layer has been adjusted through iterative analysis. The final result is found to have good agreement with the results from other physical explorations; e.g. gravity anomaly. We are planning to make long-period (about 2 to 10 sec or longer) simulations of ground motion due to the hypothetical Nankai Earthquake with the 3-D velocity structure model. As the first step, we will simulate the observed ground motions of the latest event occurred in 1946 to check the source model and newly developed velocity structure model. This project is partly supported by Integrated Research Project for Long-Period Ground Motion Hazard Maps by Ministry of Education, Culture, Sports, Science and Technology (MEXT). The ground motion data used in this study were provided by National Research Institute for Earth Science and Disaster Prevention Disaster (NIED). Figure 1 An example of cross section with P wave velocities Figure 2 Observed (dash line) and simulated (solid line) waveforms due to a small earthquake
1992-12-28
Chief, Cloud Physics Section at the Phillips Laboratory Geophysics Directorate, for his assistance both in my research, and in preparing this paper; Lisa...American soccerball . Due to their hollow closed structure, the buckyballs can be used to "cage" other molecules. This potential has created a great deal of...forming a symmetrical sphere. 12-3 Physically modeling the fullerene on the computer began with the formation of a single pentagon. This pentagon was
1984-11-15
Coupling to Surface Plasma Waves 20 2.3 Theory of the Effect of Traps on the Spectral Charac- teristics of Diode Lasers 23 3 . MATERIALS RESEARCH 27...Page 1-1(a) Schematic Cross Section of InGaAs PSIN Structure. Gap Spac- ing (d) Is 3 , 5, 10, or 20 pm. 2 1-1(b) Curve Tracer I-V Characteristics of a...20-pim PSIN Device in Dark and Under Illumination 2 1-2 Pulse Response of a 3 -#Am PSIN Device, Under Forward and Reverse Bias. to a Comb-Generator
Solid Modeling Aerospace Research Tool (SMART) user's guide, version 2.0
NASA Technical Reports Server (NTRS)
Mcmillin, Mark L.; Spangler, Jan L.; Dahmen, Stephen M.; Rehder, John J.
1993-01-01
The Solid Modeling Aerospace Research Tool (SMART) software package is used in the conceptual design of aerospace vehicles. It provides a highly interactive and dynamic capability for generating geometries with Bezier cubic patches. Features include automatic generation of commonly used aerospace constructs (e.g., wings and multilobed tanks); cross-section skinning; wireframe and shaded presentation; area, volume, inertia, and center-of-gravity calculations; and interfaces to various aerodynamic and structural analysis programs. A comprehensive description of SMART and how to use it is provided.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nguyen, Ba Nghiep; Jin, Xiaoshi; Wang, Jin
2010-02-23
This report describes the work conducted under the Cooperative Research and Development Agreement (CRADA) (Nr. 260) between the Pacific Northwest National Laboratory (PNNL) and Autodesk, Inc. to develop and implement process models for injection-molded long-fiber thermoplastics (LFTs) in processing software packages. The structure of this report is organized as follows. After the Introduction Section (Section 1), Section 2 summarizes the current fiber orientation models developed for injection-molded short-fiber thermoplastics (SFTs). Section 3 provides an assessment of these models to determine their capabilities and limitations, and the developments needed for injection-molded LFTs. Section 4 then focuses on the development of amore » new fiber orientation model for LFTs. This model is termed the anisotropic rotary diffusion - reduced strain closure (ARD-RSC) model as it explores the concept of anisotropic rotary diffusion to capture the fiber-fiber interaction in long-fiber suspensions and uses the reduced strain closure method of Wang et al. to slow down the orientation kinetics in concentrated suspensions. In contrast to fiber orientation modeling, before this project, no standard model was developed to predict the fiber length distribution in molded fiber composites. Section 5 is therefore devoted to the development of a fiber length attrition model in the mold. Sections 6 and 7 address the implementations of the models in AMI, and the conclusions drawn from this work is presented in Section 8.« less
Carmona, Jesús; Climent, Miguel-Ángel; Antón, Carlos; de Vera, Guillem; Garcés, Pedro
2015-01-01
This article shows the research carried out by the authors focused on how the shape of structural reinforced concrete elements treated with electrochemical chloride extraction can affect the efficiency of this process. Assuming the current use of different anode systems, the present study considers the comparison of results between conventional anodes based on Ti-RuO2 wire mesh and a cement-based anodic system such as a paste of graphite-cement. Reinforced concrete elements of a meter length were molded to serve as laboratory specimens, to closely represent authentic structural supports, with circular and rectangular sections. Results confirm almost equal performances for both types of anode systems when electrochemical chloride extraction is applied to isotropic structural elements. In the case of anisotropic ones, such as rectangular sections with no uniformly distributed rebar, differences in electrical flow density were detected during the treatment. Those differences were more extreme for Ti-RuO2 mesh anode system. This particular shape effect is evidenced by obtaining the efficiencies of electrochemical chloride extraction in different points of specimens.
Large image microscope array for the compilation of multimodality whole organ image databases.
Namati, Eman; De Ryk, Jessica; Thiesse, Jacqueline; Towfic, Zaid; Hoffman, Eric; Mclennan, Geoffrey
2007-11-01
Three-dimensional, structural and functional digital image databases have many applications in education, research, and clinical medicine. However, to date, apart from cryosectioning, there have been no reliable means to obtain whole-organ, spatially conserving histology. Our aim was to generate a system capable of acquiring high-resolution images, featuring microscopic detail that could still be spatially correlated to the whole organ. To fulfill these objectives required the construction of a system physically capable of creating very fine whole-organ sections and collecting high-magnification and resolution digital images. We therefore designed a large image microscope array (LIMA) to serially section and image entire unembedded organs while maintaining the structural integrity of the tissue. The LIMA consists of several integrated components: a novel large-blade vibrating microtome, a 1.3 megapixel peltier cooled charge-coupled device camera, a high-magnification microscope, and a three axis gantry above the microtome. A custom control program was developed to automate the entire sectioning and automated raster-scan imaging sequence. The system is capable of sectioning unembedded soft tissue down to a thickness of 40 microm at specimen dimensions of 200 x 300 mm to a total depth of 350 mm. The LIMA system has been tested on fixed lung from sheep and mice, resulting in large high-quality image data sets, with minimal distinguishable disturbance in the delicate alveolar structures. Copyright 2007 Wiley-Liss, Inc.
A Review of Recent Aeroelastic Analysis Methods for Propulsion at NASA Lewis Research Center
NASA Technical Reports Server (NTRS)
Reddy, T. S. R.; Bakhle, Milind A.; Srivastava, R.; Mehmed, Oral; Stefko, George L.
1993-01-01
This report reviews aeroelastic analyses for propulsion components (propfans, compressors and turbines) being developed and used at NASA LeRC. These aeroelastic analyses include both structural and aerodynamic models. The structural models include a typical section, a beam (with and without disk flexibility), and a finite-element blade model (with plate bending elements). The aerodynamic models are based on the solution of equations ranging from the two-dimensional linear potential equation to the three-dimensional Euler equations for multibladed configurations. Typical calculated results are presented for each aeroelastic model. Suggestions for further research are made. Many of the currently available aeroelastic models and analysis methods are being incorporated in a unified computer program, APPLE (Aeroelasticity Program for Propulsion at LEwis).
Compositional and structural analysis of nitrogen incorporated and ion implanted diamond thin films
NASA Astrophysics Data System (ADS)
Garratt, Elias James
Significant progress in area of nano-structured thin film systems has taken place in recent decades. In particular, diamond thin film systems are being widely studied for their wear resistant, optical and electronic properties. Of the various methods researchers use to modify the structure of such films, three techniques in particular are of interest due to their versatility: modification of the growth atmosphere, growth on metalized substrates, providing an interfacial layer, and modification through post-growth ion implantation. The aim of this study is to investigate the effects each has to the structure and composition of elements. Different techniques are applied in each section; nitrogen gas dilution in a microwave plasma CVD system, diamond deposition on a metal interfacial layer and ion implantation in thin nanocrystalline diamond film. The forms of nanocrystalline diamond film resulting from such modifications are investigated using advanced spectroscopic and spectrometric techniques, as well as mechanical testing and surface mapping. The impact of these characterizations will provide valuable perspective to researchers in materials science. Understanding the changes to the structure and properties of this class of thin films, which can be induced through various mechanisms, will allow future researchers to refine these films towards technological applications in areas of hard coatings, electronics and photonics.
Quantitative Characterization of Nanostructured Materials
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dr. Frank
The two-and-a-half day symposium on the "Quantitative Characterization of Nanostructured Materials" will be the first comprehensive meeting on this topic held under the auspices of a major U.S. professional society. Spring MRS Meetings provide a natural venue for this symposium as they attract a broad audience of researchers that represents a cross-section of the state-of-the-art regarding synthesis, structure-property relations, and applications of nanostructured materials. Close interactions among the experts in local structure measurements and materials researchers will help both to identify measurement needs pertinent to real-world materials problems and to familiarize the materials research community with the state-of-the-art local structuremore » measurement techniques. We have chosen invited speakers that reflect the multidisciplinary and international nature of this topic and the need to continually nurture productive interfaces among university, government and industrial laboratories. The intent of the symposium is to provide an interdisciplinary forum for discussion and exchange of ideas on the recent progress in quantitative characterization of structural order in nanomaterials using different experimental techniques and theory. The symposium is expected to facilitate discussions on optimal approaches for determining atomic structure at the nanoscale using combined inputs from multiple measurement techniques.« less
Fontelo, Paul; Gavino, Alex; Sarmiento, Raymond Francis
2013-12-01
The abstract is the most frequently read section of a research article. The use of 'Consensus Abstracts', a clinician-oriented web application formatted for mobile devices to search MEDLINE/PubMed, for informing clinical decisions was proposed recently; however, inaccuracies between abstracts and the full-text article have been shown. Efforts have been made to improve quality. We compared data in 60 recent-structured abstracts and full-text articles from six highly read medical journals. Data inaccuracies were identified and then classified as either clinically significant or not significant. Data inaccuracies were observed in 53.33% of articles ranging from 3.33% to 45% based on the IMRAD format sections. The Results section showed the highest discrepancies (45%) although these were deemed to be mostly not significant clinically except in one. The two most common discrepancies were mismatched numbers or percentages (11.67%) and numerical data or calculations found in structured abstracts but not mentioned in the full text (40%). There was no significant relationship between journals and the presence of discrepancies (Fisher's exact p value =0.3405). Although we found a high percentage of inaccuracy between structured abstracts and full-text articles, these were not significant clinically. The inaccuracies do not seem to affect the conclusion and interpretation overall. Structured abstracts appear to be informative and may be useful to practitioners as a resource for guiding clinical decisions.
Active control of panel vibrations induced by a boundary layer flow
NASA Technical Reports Server (NTRS)
Chow, Pao-Liu
1995-01-01
The problems of active and passive control of sound and vibration has been investigated by many researchers for a number of years. However, few of the articles are concerned with the sound and vibration with flow-structure interaction. Experimental and numerical studies on the coupling between panel vibration and acoustic radiation due to flow excitation have been done by Maestrello and his associates at NASA/Langley Research Center. Since the coupled system of nonlinear partial differential equations is formidable, an analytical solution to the full problem seems impossible. For this reason, we have to simplify the problem to that of the nonlinear panel vibration induced by a uniform flow or a boundary-layer flow with a given wall pressure distribution. Based on this simplified model, we have been able to consider the control and stabilization of the nonlinear panel vibration, which have not been treated satisfactorily by other authors. Although the sound radiation has not been included, the vibration suppression will clearly reduce the sound radiation power from the panel. The major research findings are presented in three sections. In section two we describe results on the boundary control of nonlinear panel vibration, with or without flow excitation. Sections three and four are concerned with some analytical and numerical results in the optimal control of the linear and nonlinear panel vibrations, respectively, excited by the flow pressure fluctuations. Finally, in section five, we draw some conclusions from research findings.
The Future of Qualitative Research in Psychology: Accentuating the Positive.
Gough, Brendan; Lyons, Antonia
2016-06-01
In this paper we reflect on current trends and anticipate future prospects regarding qualitative research in Psychology. We highlight various institutional and disciplinary obstacles to qualitative research diversity, complexity and quality. At the same time, we note some causes for optimism, including publication breakthroughs and vitality within the field. The paper is structured into three main sections which consider: 1) the positioning of qualitative research within Psychology; 2) celebrating the different kinds of knowledge produced by qualitative research; and 3) implementing high quality qualitative research. In general we accentuate the positive, recognising and illustrating innovative qualitative research practices which generate new insights and propel the field forward. We conclude by emphasising the importance of research training: for qualitative research to flourish within Psychology (and beyond), students and early career researchers require more sophisticated, in-depth instruction than is currently offered.
Conceptual Design and Structural Analysis of an Open Rotor Hybrid Wing Body Aircraft
NASA Technical Reports Server (NTRS)
Gern, Frank H.
2013-01-01
Through a recent NASA contract, Boeing Research and Technology in Huntington Beach, CA developed and optimized a conceptual design of an open rotor hybrid wing body aircraft (HWB). Open rotor engines offer a significant potential for fuel burn savings over turbofan engines, while the HWB configuration potentially allows to offset noise penalties through possible engine shielding. Researchers at NASA Langley converted the Boeing design to a FLOPS model which will be used to develop take-off and landing trajectories for community noise analyses. The FLOPS model was calibrated using Boeing data and shows good agreement with the original Boeing design. To complement Boeing s detailed aerodynamics and propulsion airframe integration work, a newly developed and validated conceptual structural analysis and optimization tool was used for a conceptual loads analysis and structural weights estimate. Structural optimization and weight calculation are based on a Nastran finite element model of the primary HWB structure, featuring centerbody, mid section, outboard wing, and aft body. Results for flight loads, deformations, wing weight, and centerbody weight are presented and compared to Boeing and FLOPS analyses.
Evolutionary Optimization of a Geometrically Refined Truss
NASA Technical Reports Server (NTRS)
Hull, P. V.; Tinker, M. L.; Dozier, G. V.
2007-01-01
Structural optimization is a field of research that has experienced noteworthy growth for many years. Researchers in this area have developed optimization tools to successfully design and model structures, typically minimizing mass while maintaining certain deflection and stress constraints. Numerous optimization studies have been performed to minimize mass, deflection, and stress on a benchmark cantilever truss problem. Predominantly traditional optimization theory is applied to this problem. The cross-sectional area of each member is optimized to minimize the aforementioned objectives. This Technical Publication (TP) presents a structural optimization technique that has been previously applied to compliant mechanism design. This technique demonstrates a method that combines topology optimization, geometric refinement, finite element analysis, and two forms of evolutionary computation: genetic algorithms and differential evolution to successfully optimize a benchmark structural optimization problem. A nontraditional solution to the benchmark problem is presented in this TP, specifically a geometrically refined topological solution. The design process begins with an alternate control mesh formulation, multilevel geometric smoothing operation, and an elastostatic structural analysis. The design process is wrapped in an evolutionary computing optimization toolset.
Classification of defects in honeycomb composite structure of helicopter rotor blades
NASA Astrophysics Data System (ADS)
Balaskó, M.; Sváb, E.; Molnár, Gy.; Veres, I.
2005-04-01
The use of non-destructive testing methods to qualify the state of rotor blades with respect to their expected flight hours, with the aim to extend their lifetime without any risk of breakdown, is an important financial demand. In order to detect the possible defects in the composite structure of Mi-8 and Mi-24 type helicopter rotor blades used by the Hungarian Army, we have performed combined neutron- and X-ray radiography measurements at the Budapest Research Reactor. Several types of defects were detected, analysed and typified. Among the most frequent and important defects observed were cavities, holes and/or cracks in the sealing elements on the interface of the honeycomb structure and the section boarders. Inhomogeneities of the resin materials (resin-rich or starved areas) at the core-honeycomb surfaces proved to be an other important point. Defects were detected at the adhesive filling, and water percolation was visualized at the sealing interfaces of the honeycomb sections. Corrosion effects, and metal inclusions have also been detected.
Is the ultimobranchial body a reality or myth: a study using serial sections of human embryos.
Honkura, Yohei; Yamamoto, Masahito; Yoshimoto, Toshihito; Rodriguez-Vazquez, Jose Francisco; Murakami, Gen; Katori, Yukio; Abe, Shin-Ichi
2016-01-01
Reported morphologies of the ultimobranchial body had varied between researchers: a cluster of mitotic cells, a duct-like structure and a rosette-like cell mass. To clarify the true morphology, we studied tilted horizontal sections of 20 human embryos (crown-rump length 5-18 mm; 4-6 weeks). The sections displayed a ladder-like arrangement of the second to fourth endodermal pouches and, in 5 early embryos we found the fifth pouch attached to the fifth ectodermal groove near the fourth pharyngeal arch artery. The bilateral fifth pharyngeal pouches protruded anterolaterally to form a U-shaped lumen surrounding the arytenoid swelling. The third to fifth pouches were each characterized by a pedal-shaped inferior end. We identified several types of cell clusters as candidates for the ultimobranchial body, but morphologically most of them were, to various degrees, likely to correspond to the blind end of the lower pouch when cut tangentially. Because of the topographical relation to the common carotid artery, a cyst-like structure with a cell cluster seemed to be the most likely candidate of the ultimobranchial body (a common anlage of the thymus and parathyroid). However, we were not able to deny a possibility that a certain plane cutting the pouch end incidentally provided such a cyst-like structure in sections. At any stage, the ultimobranchial body might not appear as a definite structure that is discriminated from others with routine staining. A concept of the ultimobranchial body might be biased by comparative anatomy that shows the ultimobranchial gland in adult birds and reptiles.
ERIC Educational Resources Information Center
Leiva, Alicia; Andrés, Pilar; Servera, Mateu; Verbruggen, Frederick; Parmentier, Fabrice B. R.
2016-01-01
Sounds deviating from an otherwise repeated or structured sequence capture attention and affect performance in an ongoing visual task negatively, testament to the balance between selective attention and change detection. Although deviance distraction has been the object of much research, its modulation across the life span has been more scarcely…
Education and Development: The Issues and the Evidence. Education Research. Serial No. 6.
ERIC Educational Resources Information Center
Lewin, Keith M.
This literature review is divided into two main sections. The first part identifies key dimensions of the policy debate that will condition future patterns of investment in education. The themes chosen are the impact of recession, the effects of debt and structural adjustment programs on the resources available for education; the implications of…
Parental Experiences of Support for Pupils with Dyslexia: Ignoring the Effect on Parents
ERIC Educational Resources Information Center
Earey, Alison
2013-01-01
This article reports on research that was carried out with parents in order to understand the education system in England from their viewpoint through in-depth, semi-structured interviews with seven parents, who were largely sourced through a local dyslexia specialist tutor. The data were analysed by using cross-sectional analysis in order to…
ERIC Educational Resources Information Center
Telecommunications Policy Research Conference, Inc., Washington, DC.
This document consist of the abstracts for two papers which considered the impact of information technologies on political and economic systems. The first paper, "The Political Repercussions of Transnational Corporate Information Systems" (Terry Curtis), argued that information technologies are the most recent in a series of…
Multiscale Analysis of Nanocomposites and Their Use in Structural Level Applications
NASA Astrophysics Data System (ADS)
Hasan, Zeaid
This research focuses on the benefits of using nanocomposites in aerospace structural components to prevent or delay the onset of unique composite failure modes, such as delamination. Analytical, numerical, and experimental analyses were conducted to provide a comprehensive understanding of how carbon nanotubes (CNTs) can provide additional structural integrity when they are used in specific hot spots within a structure. A multiscale approach was implemented to determine the mechanical and thermal properties of the nanocomposites, which were used in detailed finite element models (FEMs) to analyze interlaminar failures in T and Hat section stringers. The delamination that first occurs between the tow filler and the bondline between the stringer and skin was of particular interest. Both locations are considered to be hot spots in such structural components, and failures tend to initiate from these areas. In this research, nanocomposite use was investigated as an alternative to traditional methods of suppressing delamination. The stringer was analyzed under different loading conditions and assuming different structural defects. Initial damage, defined as the first drop in the load displacement curve was considered to be a useful variable to compare the different behaviors in this study and was detected via the virtual crack closure technique (VCCT) implemented in the FE analysis. Experiments were conducted to test T section skin/stringer specimens under pull-off loading, replicating those used in composite panels as stiffeners. Two types of designs were considered: one using pure epoxy to fill the tow region and another that used nanocomposite with 5 wt. % CNTs. The response variable in the tests was the initial damage. Detailed analyses were conducted using FEMs to correlate with the experimental data. The correlation between both the experiment and model was satisfactory. Finally, the effects of thermal cure and temperature variation on nanocomposite structure behavior were studied, and both variables were determined to influence the nanocomposite structure performance.
Yong-Ki Kim — His Life and Recent Work
NASA Astrophysics Data System (ADS)
Stone, Philip M.
2007-08-01
Dr. Kim made internationally recognized contributions in many areas of atomic physics research and applications, and was still very active when he was killed in an automobile accident. He joined NIST in 1983 after 17 years at the Argonne National Laboratory following his Ph.D. work at the University of Chicago. Much of his early work at Argonne and especially at NIST was the elucidation and detailed analysis of the structure of highly charged ions. He developed a sophisticated, fully relativistic atomic structure theory that accurately predicts atomic energy levels, transition wavelengths, lifetimes, and transition probabilities for a large number of ions. This information has been vital to model the properties of the hot interior of fusion research plasmas, where atomic ions must be described with relativistic atomic structure calculations. In recent years, Dr. Kim worked on the precise calculation of ionization and excitation cross sections of numerous atoms, ions, and molecules that are important in fusion research and in plasma processing for manufacturing semiconductor chips. Dr. Kim greatly advanced the state-of-the-art of calculations for these cross sections through development and implementation of highly innovative methods, including his Binary-Encounter-Bethe (BEB) theory and a scaled plane wave Born (scaled PWB) theory. His methods, using closed quantum mechanical formulas and no adjustable parameters, avoid tedious large-scale computations with main-frame computers. His calculations closely reproduce the results of benchmark experiments as well as large-scale calculations requiring hours of computer time. This recent work on BEB and scaled PWB is reviewed and examples of its capabilities are shown.
Sora, Mircea-Constantin; Jilavu, Radu; Matusz, Petru
2012-10-01
The aim of this study was to describe a method of developing a computerized model of the human female pelvis using plastinated slices. Computerized reconstruction of anatomical structures is becoming very useful for developing anatomical teaching, research modules and animations. Although databases consisting of serial sections derived from frozen cadaver material exist, plastination represents an alternative method for developing anatomical data useful for computerized reconstruction. A slice anatomy study, using plastinated transparent pelvis cross sections, was performed to obtain a 3D reconstruction. One female human pelvis used for this study, first plastinated as a block, then sliced into thin slices and in the end subjected to 3D computerized reconstruction using WinSURF modeling system (SURFdriver Software). To facilitate the understanding of the complex pelvic floor anatomy on sectional images obtained through MR imaging, and to make the representation more vivid, a female pelvis computer-aided 3D model was created. Qualitative observations revealed that the morphological features of the model were consistent with those displayed by typical cadaveric specimens. The quality of the reconstructed images appeared distinct, especially the spatial positions and complicated relationships of contiguous structures of the female pelvis. All reconstructed structures can be displayed in groups or as a whole and interactively rotated in 3D space. The utilization of plastinates for generating tissue sections is useful for 3D computerized modeling. The 3D model of the female pelvis presented in this paper provides a stereoscopic view to study the adjacent relationship and arrangement of respective pelvis sections. A better understanding of the pelvic floor anatomy is relevant to gynaecologists, radiologists, surgeons, urologists, physical therapists and all professionals who take care of women with pelvic floor dysfunction.
Report of the panel on earth structure and dynamics, section 6
NASA Technical Reports Server (NTRS)
Dziewonski, Adam M.; Mcadoo, David C.; Oconnell, Richard J.; Smylie, Douglas E.; Yoder, Charles F.
1991-01-01
The panel identified problems related to the dynamics of the core and mantle that should be addressed by NASA programs. They include investigating the geodynamo based on observations of the Earth's magnetic field, determining the rheology of the mantle from geodetic observations of post-glacial vertical motions and changes in the gravity field, and determining the coupling between plate motions and mantle flow from geodetic observations of plate deformation. Also emphasized is the importance of support for interdisciplinary research to combine various data sets with models which couple rheology, structure and dynamics.
Aeroelastic Response of the Adaptive Compliant Trailing Edge Transtition Section
NASA Technical Reports Server (NTRS)
Herrera, Claudia Y.; Spivey, Natalie D.; Lung, Shun-fat
2016-01-01
The Adaptive Compliant Trailing Edge demonstrator was a joint task under the Environmentally Responsible Aviation Project in partnership with the Air Force Research Laboratory and FlexSys, Inc. (Ann Arbor, Michigan), chartered by the National Aeronautics and Space Administration to develop advanced technologies that enable environmentally friendly aircraft, such as continuous mold-line technologies. The Adaptive Compliant Trailing Edge demonstrator encompassed replacing the Fowler flaps on the SubsoniC Aircraft Testbed, a Gulfstream III (Gulfstream Aerospace, Savannah, Georgia) aircraft, with control surfaces developed by FlexSys, Inc., a pair of uniquely-designed, unconventional flaps to be used as lifting surfaces during flight-testing to substantiate their structural effectiveness. The unconventional flaps consisted of a main flap section and two transition sections, inboard and outboard, which demonstrated the continuous mold-line technology. Unique characteristics of the transition sections provided a challenge to the airworthiness assessment for this part of the structure. A series of build-up tests and analyses were conducted to ensure the data required to support the airworthiness assessment were acquired and applied accurately. The transition sections were analyzed both as individual components and as part of the flight-test article assembly. Instrumentation was installed in the transition sections based on the analysis to best capture the in-flight aeroelastic response. Flight-testing was conducted and flight data were acquired to validate the analyses. This paper documents the details of the aeroelastic assessment and in-flight response of the transition sections of the unconventional Adaptive Compliant Trailing Edge flaps.
Artificial Hip Simulator with Crystal Models
1966-06-21
Robert Johnson, top, sets the lubricant flow while Donald Buckley adjusts the bearing specimen on an artificial hip simulator at the National Aeronautics and Space Administration (NASA) Lewis Research Center. The simulator was supplemented by large crystal lattice models to demonstrate the composition of different bearing alloys. This this image by NASA photographer Paul Riedel was used for the cover of the August 15, 1966 edition of McGraw-Hill Product Engineering. Johnson was chief of Lubrication Branch and Buckley head of the Space Environment Lubrication Section in the Fluid System Components Division. In 1962 they began studying the molecular structure of metals. Their friction and wear testing revealed that the optimal structure for metal bearings was a hexagonal crystal structure with proper molecular space. Bearing manufacturers traditionally preferred cubic structures over hexagonal arrangements. Buckley and Johnson found that even though the hexagonal structural was not as inherently strong as its cubic counterpart, it was less likely to cause a catastrophic failure. The Lewis researchers concentrated their efforts on cobalt-molybdenum and titanium alloys for high temperatures applications. The alloys had a number of possible uses, included prosthetics. The alloys were similar in composition to the commercial alloys used for prosthetics, but employed the longer lasting hexagonal structure.
Generation of a three-dimensional ultrastructural model of human respiratory cilia.
Burgoyne, Thomas; Dixon, Mellisa; Luther, Pradeep; Hogg, Claire; Shoemark, Amelia
2012-12-01
The ultrastructures of cilia and flagella are highly similar and well conserved through evolution. Consequently, Chlamydomonas is commonly used as a model organism for the study of human respiratory cilia. Since detailed models of Chlamydomonas axonemes were generated using cryoelectron tomography, disparities among some of the ultrastructural features have become apparent when compared with human cilia. Extrapolating information on human disease from the Chlamydomonas model may lead to discrepancies in translational research. This study aimed to establish the first three-dimensional ultrastructural model of human cilia. Tomograms of transverse sections (n = 6) and longitudinal sections (n = 9) of human nasal respiratory cilia were generated from three healthy volunteers. Key features of the cilium were resolved using subatomic averaging, and were measured. For validation of the method, a model of the well characterized structure of Chlamydomonas reinhardtii was simultaneously generated. Data were combined to create a fully quantified three-dimensional reconstruction of human nasal respiratory cilia. We highlight key differences in the axonemal sheath, microtubular doublets, radial spokes, and dynein arms between the two structures. We show a decreased axial periodicity of the radial spokes, inner dynein arms, and central pair protrusions in the human model. We propose that this first human model will provide a basis for research into the function and structure of human respiratory cilia in health and in disease.
Preliminary Multiphysics Analyses of HFIR LEU Fuel Conversion using COMSOL
DOE Office of Scientific and Technical Information (OSTI.GOV)
Freels, James D; Bodey, Isaac T; Arimilli, Rao V
The research documented herein was performed by several individuals across multiple organizations. We have previously acknowledged our funding for the project, but another common thread among the authors of this document, and hence the research performed, is the analysis tool COMSOL. The research has been divided into categories to allow the COMSOL analysis to be performed independently to the extent possible. As will be seen herein, the research has progressed to the point where it is expected that next year (2011) a large fraction of the research will require collaboration of our efforts as we progress almost exclusively into three-dimensionalmore » (3D) analysis. To the extent possible, we have tried to segregate the development effort into two-dimensional (2D) analysis in order to arrive at techniques and methodology that can be extended to 3D models in a timely manner. The Research Reactors Division (RRD) of ORNL has contracted with the University of Tennessee, Knoxville (UTK) Mechanical, Aerospace and Biomedical Engineering Department (MABE) to perform a significant fraction of this research. This group has been chosen due to their expertise and long-term commitment in using COMSOL and also because the participating students are able to work onsite on a part-time basis due to the close proximity of UTK with the ORNL campus. The UTK research has been governed by a statement of work (SOW) which clearly defines the specific tasks reported herein on the perspective areas of research. Ph.D. student Isaac T. Bodey has focused on heat transfer, fluid flow, modeling, and meshing issues and has been aided by his major professor Dr. Rao V. Arimilli and is the primary contributor to Section 2 of this report. Ph.D student Franklin G. Curtis has been focusing exclusively on fluid-structure interaction (FSI) due to the mechanical forces acting on the plate caused by the flow and has also been aided by his major professor Dr. Kivanc Ekici and is the primary contributor to Section 4 of this report. The HFIR LEU conversion project has also obtained the services of Dr. Prashant K. Jain of the Reactor & Nuclear Systems Division (RNSD) of ORNL. Prashant has quickly adapted to the COMSOL tools and has been focusing on thermal-structure interaction (TSI) issues and development of alternative 3D model approaches that could yield faster-running solutions. Prashant is the primary contributor to Section 5 of the report. And finally, while incorporating findings from all members of the COMSOL team (i.e., the team) and contributing as the senior COMSOL leader and advocate, Dr. James D. Freels has focused on the 3D model development, cluster deployment, and has contributed primarily to Section 3 and overall integration of this report. The team has migrated to the current release of COMSOL at version 4.1 for all the work described in this report, except where stated otherwise. Just as in the performance of the research, each of the respective sections has been originally authored by the respective authors. Therefore, the reader will observe a contrast in writing style throughout this document.« less
Vertical drop test of a transport fuselage section located aft of the wing
NASA Technical Reports Server (NTRS)
Fasanella, E. L.; Alfaro-Bou, E.
1986-01-01
A 12-foot long Boeing 707 aft fuselage section with a tapering cross section was drop tested at the NASA Langley Research Center to measure structural, seat, and occupant response to vertical crash laods and to provide data for nonlinear finite element modeling. This was the final test in a series of three different transport fuselage sections tested under identical conditions. The test parameters at impact were: 20 ft/s velocity, and zero pitch, roll, and yaw. In addition, the test was an operational shock test of the data acquisition system used for the Controlled Impact Demonstration (CID) of a remotely piloted Boeing 720 that was crash tested at NASA Ames Dryden Flight Research Facility on December 1, 1984. Post-test measurements of the crush showed that the front of the section (with larger diameter) crushed vertically approximately 14 inches while the rear crushed 18 inches. Analysis of the data traces indicate the maximum peak normal (vertical) accelerations at the bottom of the frames were approximately 109 G at body station 1040 and 64 G at body station 1120. The peak floor acceleration varied from 14 G near the wall to 25 G near the center where high frequency oscillations of the floor were evident. The peak anthropomorphic dummy pelvis normal (vertical) acceleration was 19 G's.
Jikijela, Thobeka P; James, Sindiwe; Sonti, Balandeli S I
2018-01-30
The rate of caesarean section deliveries has increased globally and mothers are faced with challenges of postoperative recovery and caring thereof. Midwives have a duty to assist these mothers to self-care. The objective was to explore and describe experiences of post-caesarean section delivered mothers of midwifery care at a public hospital in Nelson Mandela Bay. A qualitative, descriptive and explorative research design was used in the study. Data were collected from 11 purposively criterion-selected mothers who had a caesarean section delivery. One-on-one semi-structured interviews were conducted in the post-natal wards. Research ethics, namely autonomy, beneficence, justice and informed consent, were adopted in the study. All participants were informed of their right to withdraw from the study at any stage without penalties. Interviews were analysed using Tesch's method of data analysis. Three main themes were identified as experiences of: diverse pain, physical limitation and frustration and health care services as different. Experiences of mothers following a caesarean section delivery with midwifery services at a public hospital in Nelson Mandela Bay were explored and described as diverse. A need for adequate pain management as well as assistance and breastfeeding support to mothers following caesarean delivery was identified as crucial to promote a good mother-to-child relationship.
Research support of the WETNET Program
NASA Technical Reports Server (NTRS)
Estes, John E.; Mcgwire, Kenneth C.; Scepan, Joseph; Henderson, SY; Lawless, Michael
1995-01-01
This study examines various aspects of the Microwave Vegetation Index (MVI). MVI is a derived signal created by differencing the spectral response of the 37 GHz horizontally and vertically polarized passive microwave signals. The microwave signal employed to derive this index is thought to be primarily influenced by vegetation structure, vegetation growth, standing water, and precipitation. The state of California is the study site for this research. Imagery from the Special Sensor Microwave/Imager (SSM/I) is used for the creation of MVI datasets analyzed in this research. The object of this research is to determine whether MVI corresponds with some quantifiable vegetation parameter (such as vegetation density) or whether the index is more affected by known biogeophysical parameters such antecedent precipitation. A secondary question associated with the above is whether the vegetation attributes that MVI is employed to determine can be more easily and accurately evaluated by other remote sensing means. An important associated question to be addressed in the study is the effect of different multi-temporal composting techniques on the derived MVI dataset. This work advances our understanding of the fundamental nature of MVI by studying vegetation as a mixture of structural types, such as forest and grassland. The study further advances our understanding by creating multitemporal precipitation datasets to compare the affects of precipitation upon MVI. This work will help to lay the groundwork for the use of passive microwave spectral information either as an adjunct to visible and near infrared imagery in areas where that is feasible or for the use of passive microwave alone in areas of moderate cloud coverage. In this research, an MVI dataset, spanning the period February 15, 1989 through April 25, 1990, has been created using National Aeronautic and Space Administration (NASA) supplied brightness temperature data. Information from the DMSP satellite 37 GHz wavelength SSM/I sensor in both horizontal and vertical polarization has been processed using the MVI algorithm. In conjunction with the MVI algorithm a multitemporal compositing technique was used to create datasets that correspond to 14 day periods. In this technical report, Section Two contains background information on the State of California and the three MVI study sites. Section Three describes the methods used to create the MVI and independent variables datasets. Section Four presents the results of the experiment. Section Five summarizes and concludes the work.
CFD based aerodynamic modeling to study flight dynamics of a flapping wing micro air vehicle
NASA Astrophysics Data System (ADS)
Rege, Alok Ashok
The demand for small unmanned air vehicles, commonly termed micro air vehicles or MAV's, is rapidly increasing. Driven by applications ranging from civil search-and-rescue missions to military surveillance missions, there is a rising level of interest and investment in better vehicle designs, and miniaturized components are enabling many rapid advances. The need to better understand fundamental aspects of flight for small vehicles has spawned a surge in high quality research in the area of micro air vehicles. These aircraft have a set of constraints which are, in many ways, considerably different from that of traditional aircraft and are often best addressed by a multidisciplinary approach. Fast-response non-linear controls, nano-structures, integrated propulsion and lift mechanisms, highly flexible structures, and low Reynolds aerodynamics are just a few of the important considerations which may be combined in the execution of MAV research. The main objective of this thesis is to derive a consistent nonlinear dynamic model to study the flight dynamics of micro air vehicles with a reasonably accurate representation of aerodynamic forces and moments. The research is divided into two sections. In the first section, derivation of the nonlinear dynamics of flapping wing micro air vehicles is presented. The flapping wing micro air vehicle (MAV) used in this research is modeled as a system of three rigid bodies: a body and two wings. The design is based on an insect called Drosophila Melanogaster, commonly known as fruit-fly. The mass and inertial effects of the wing on the body are neglected for the present work. The nonlinear dynamics is simulated with the aerodynamic data published in the open literature. The flapping frequency is used as the control input. Simulations are run for different cases of wing positions and the chosen parameters are studied for boundedness. Results show a qualitative inconsistency in boundedness for some cases, and demand a better aerodynamic data. The second part of research involves preliminary work required to generate new aerodynamic data for the nonlinear model. First, a computational mesh is created over a 2-D wing section of the MAV model. A finite volume based computational flow solver is used to test different flapping trajectories of the wing section. Finally, a parametric study of the results obtained from the tests is performed.
Optical-fiber strain sensors with asymmetric etched structures.
Vaziri, M; Chen, C L
1993-11-01
Optical-fiber strain gauges with asymmetric etched structures have been analyzed, fabricated, and tested. These sensors are very sensitive with a gauge factor as high as 170 and a flat frequency response to at least 2.7 kHz. The gauge factor depends on the asymmetry of the etched structures and the number of etched sections. To understand the physical principles involved, researchers have used structural analysis programs based on a finite-element method to analyze fibers with asymmetric etched structures under tensile stress. The results show that lateral bends are induced on the etched fibers when they are stretched axially. To relate the lateral bending to the optical attenuation, we have also employed a ray-tracing technique to investigate the dependence of the attenuation on the structural deformation. Based on the structural analysis and the ray-tracing study parameters affecting the sensitivity have been studied. These results agree with the results of experimental investigations.
Subsurface multidisciplinary research results at ICTJA-CSIC downhole lab and test site
NASA Astrophysics Data System (ADS)
Jurado, Maria Jose; Crespo, Jose; Salvany, Josep Maria; Teixidó, Teresa
2017-04-01
Two scientific boreholes, Almera-1 and Almera-2 were drilled in the Barcelona University campus area in 2011. The main purpose for this drilling was to create a new geophysical logging and downhole monitoring research facility and infrastructure. We present results obtained in the frame of multidisciplinary studies and experiments carried out since 2011 at the ICTJA "Borehole Geophysical Logging Lab - Scientific Boreholes Almera" downhole lab facilities. First results obtained from the scientific drilling, coring and logging allowed us to characterize the urban subsurface geology and hydrology adjacent to the Institute of Earth Sciences Jaume Almera (ICTJA-CSIC) in Barcelona. The subsurface geology and structural picture has been completed with recent geophysical studies and monitoring results. The upper section of Almera-1 214m deep hole was cased with PVC after drilling and after the logging operations. An open hole interval was left from 112m to TD (Paleozoic section). Almera-2 drilling reached 46m and was cased also with PVC to 44m. Since completion of the drilling in 2011, both Almera-1 and Almera-2 have been extensively used for research purposes, tests, training, hydrological and geophysical monitoring. A complete set of geophysical logging measurements and borehole oriented images were acquired in open hole mode of the entire Almera-1 section. Open hole measurements included acoustic and optical imaging, spectral natural gamma ray, full wave acoustic logging, magnetic susceptibility, hydrochemical-temperature logs and fluid sampling. Through casing (PVC casing) measurements included spectral gamma ray logging, full wave sonic and acoustic televiewer. A Quaternary to Paleozoic section was characterized based on the geophysical logging and borehole images interpretation and also on the complete set of (wireline) cores of the entire section. Sample availability was intended for geological macro and micro-facies detailed characterization, mineralogical and petrophysical tests and analyses. The interpretation of the geophysical logging data and borehole oriented images, and core data allowed us to define the stratigraphy, structures and petrophysical properties in the subsurface. Quaternary sediments overlie unconformably weathered, deformed and partially metamorphosed Paleozoic rocks. A gap of the Tertiary rocks at the drillsite was detected. Structures at intensely fractured and faulted sections were measured and have yielded valuable data to understand the subsurface geology, hydrology and geological evolution in that area. Logging, borehole imaging and monitoring carried out in the scientific boreholes Almera-1 and Almera-2 has allowed also to identify three preferential groundwater flow paths in the subsurface. Geophysical logging data combined with groundwater monitoring allowed us to identify three zones of high permeability in the subsurface. Logging data combined with core analysis were used to characterize the aquifers lithology and their respective petrophysical properties. We also analyzed the aquifer dynamics and potential relationships between the variations in groundwater levels and the rainfalls by comparing the groundwater monitoring results and the rainfall. A seismic survey was carried out to outline the geological structures beyond Almera-1 borehole, a vertical reverse pseudo-3D (2.5D) seismic tomography experiment. The results allowed us to define the geological structure beyond the borehole wall and also a correlation between the different geological units in the borehole and their geometry and spatial geophysical and seismic image.
Environmental Sciences Division annual progress report for period ending September 30, 1994
DOE Office of Scientific and Technical Information (OSTI.GOV)
NONE
1994-12-31
This progress report summarizes the research and development activities conducted in the Environmental Sciences Division (ESD) of Oak Ridge National Laboratory during fiscal year (FY) 1994, which extended from October 1, 1993, through September 30, 1994. The report is structured to provide descriptions of current activities and accomplishments in each of the division`s major organizational units. Following the sections describing the organizational units are sections highlighting ESD Scientific, Technical, and Administrative Achievement awards and listing information necessary to covey the scope of the work in the division. An organizational chart of staff and long-term guests who wee in ESD atmore » the end of FY 1994 is located in the final section of the report.« less
NASA Astrophysics Data System (ADS)
Ryzhkov, V.; Morozov, I.
2018-01-01
The paper presents the calculating results of the combustion products parameters in the tract of the low thrust rocket engine with thrust P ∼ 100 N. The article contains the following data: streamlines, distribution of total temperature parameter in the longitudinal section of the engine chamber, static temperature distribution in the cross section of the engine chamber, velocity distribution of the combustion products in the outlet section of the engine nozzle, static temperature near the inner wall of the engine. The presented parameters allow to estimate the efficiency of the mixture formation processes, flow of combustion products in the engine chamber and to estimate the thermal state of the structure.
NASA Technical Reports Server (NTRS)
Mukkamala, Ravi; Sundaram, P.
2001-01-01
HUMS systems have been an area of increased research in the recent times due to two main reasons: (a) increase in the occurrences of accidents in the aerospace, and (b) stricter FAA regulations on aircrafts maintenance [2]. There are several problems associated with the maintenance of aircrafts that the HUMS systems can solve through the use of several monitoring technologies.This paper documents our methodology of employing scenarios in the specification and evaluation of architecture for HUMS. Section 2 investigates related works that use scenarios in software development. Section 3 describes how we use scenarios in our work, which is followed by a demonstration of our methods in the development of KUMS in section 4. Conclusion summarizes results.
APPLE - An aeroelastic analysis system for turbomachines and propfans
NASA Technical Reports Server (NTRS)
Reddy, T. S. R.; Bakhle, Milind A.; Srivastava, R.; Mehmed, Oral
1992-01-01
This paper reviews aeroelastic analysis methods for propulsion elements (advanced propellers, compressors and turbines) being developed and used at NASA Lewis Research Center. These aeroelastic models include both structural and aerodynamic components. The structural models include the typical section model, the beam model with and without disk flexibility, and the finite element blade model with plate bending elements. The aerodynamic models are based on the solution of equations ranging from the two-dimensional linear potential equation for a cascade to the three-dimensional Euler equations for multi-blade configurations. Typical results are presented for each aeroelastic model. Suggestions for further research are indicated. All the available aeroelastic models and analysis methods are being incorporated into a unified computer program named APPLE (Aeroelasticity Program for Propulsion at LEwis).
Draftsmen at Work during Construction of the Aircraft Engine Research Laboratory
1942-09-21
The National Advisory Committee for Aeronautics (NACA) Aircraft Engine Research Laboratory was designed by a group of engineers at the Langley Memorial Aeronautical Laboratory in late 1940 and 1941. Under the guidance of Ernest Whitney, the men worked on drawings and calculations in a room above Langley’s Structural Research Laboratory. The main Aircraft Engine Research Laboratory design group originally consisted of approximately 30 engineers and draftsmen, but there were smaller groups working separately on specific facilities. The new engine lab would have six principal buildings: the Engine Research Building, hangar, Fuels and Lubricants Building, Administration Building, Propeller Test Stand, and Altitude Wind Tunnel. In December 1941 most of those working on the project transferred to Cleveland from Langley. Harrison Underwood and Charles Egan led 18 architectural, 26 machine equipment, 3 structural and 10 mechanical draftsmen. Initially these staff members were housed in temporary offices in the hangar. As sections of the four-acre Engine Research Building were completed in the summer of 1942, the design team began relocating there. The Engine Research Building contained a variety of test cells and laboratories to address virtually every aspect of piston engine research. It also contained a two-story office wing, seen in this photograph that would later house many of the powerplant research engineers.
Factors Shaping the Evolution of Electronic Documentation Systems. Research Activity No. IM.4.
ERIC Educational Resources Information Center
Dede, C. J.; And Others
The first of 10 sections in this report focuses on factors that will affect the evolution of Space Station Project (SSP) documentation systems. The goal of this project is to prepare the space station technical and managerial structure for likely changes in the creation, capture, transfer, and utilization of knowledge about the space station which…
International Workshop on Gamma Aluminide Alloy Technology. Section Three
1997-04-18
Structure / Property Relationships General Mechanical Behavior Tensile Fracture Toughness Creep Fatigue; FCG, Inverse Ductility/FT Relationship...Workshop on Gamma Titanium Aluminide Alloy Technology. 1 May 1996-3 May 1996 The Topics covered include: Fundamental research issues for...understanding the emerging class of Gamma Titanium Aluminide Alloy Technologies 14. SUBJECT TERMS 15. NUMBER OF PAGES 16. PRICE CODE N/A 17. SECURITY
Weaving a Virtual Web: Practical Approaches to New Information Technologies.
ERIC Educational Resources Information Center
Gruber, Sibylle, Ed.
With sections on using the Web to plan and structure courses, conduct research, and publish student work, as well as a reference essay that reviews Web sites for educators and students, this book reveals the rich variety of ways in which this technology can be used by English and language arts teachers at all levels. The 20 essays in the book…
Finite element simulation of core inspection in helicopter rotor blades using guided waves.
Chakrapani, Sunil Kishore; Barnard, Daniel; Dayal, Vinay
2015-09-01
This paper extends the work presented earlier on inspection of helicopter rotor blades using guided Lamb modes by focusing on inspecting the spar-core bond. In particular, this research focuses on structures which employ high stiffness, high density core materials. Wave propagation in such structures deviate from the generic Lamb wave propagation in sandwich panels. To understand the various mode conversions, finite element models of a generalized helicopter rotor blade were created and subjected to transient analysis using a commercial finite element code; ANSYS. Numerical simulations showed that a Lamb wave excited in the spar section of the blade gets converted into Rayleigh wave which travels across the spar-core section and mode converts back into Lamb wave. Dispersion of Rayleigh waves in multi-layered half-space was also explored. Damage was modeled in the form of a notch in the core section to simulate a cracked core, and delamination was modeled between the spar and core material to simulate spar-core disbond. Mode conversions under these damaged conditions were examined numerically. The numerical models help in assessing the difficulty of using nondestructive evaluation for complex structures and also highlight the physics behind the mode conversions which occur at various discontinuities. Copyright © 2015 Elsevier B.V. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jubin, R.T.
This report summarizes the major activities conducted in the Chemical and Energy Research Section of the Chemical Technology Division at Oak Ridge National Laboratory (ORNL) during the period October--December 1997. The section conducts basic and applied research and development in chemical engineering, applied chemistry, and bioprocessing, with an emphasis on energy-driven technologies and advanced chemical separations for nuclear and waste applications. The report describes the various tasks performed within six major areas of research: Hot Cell Operations, Process Chemistry and Thermodynamics, Separations and Materials Synthesis, Fluid Structure and Properties, Biotechnology Research, and Molecular Studies. The name of a technical contactmore » is included with each task described, and readers are encouraged to contact these individuals if they need additional information. Activities conducted within the area of Hot Cell Operations included efforts to optimize the processing conditions for Enhanced Sludge Washing of Hanford tank sludge, the testing of candidate absorbers and ion exchangers under continuous-flow conditions using actual supernatant from the Melton Valley Storage Tanks, and attempts to develop a cesium-specific spherical inorganic sorbent for the treatment of acidic high-salt waste solutions. Within the area of Process Chemistry and Thermodynamics, the problem of solids formation in process solutions from caustic treatment of Hanford sludge was addressed and experimental collaborative efforts with Russian scientists to determine the solidification conditions of yttrium barium, and copper oxides from their melts were completed.« less
Goubert, Dorien; De Pauw, Robby; Meeus, Mira; Willems, Tine; Cagnie, Barbara; Schouppe, Stijn; Van Oosterwijck, Jessica; Dhondt, Evy; Danneels, Lieven
2017-09-01
Heterogeneity exists within the low back pain (LBP) population. Some patients recover after every pain episode, whereas others suffer daily from LBP complaints. Until now, studies rarely make a distinction between recurrent low back pain (RLBP) and chronic low back pain (CLBP), although both are characterized by a different clinical picture. Clinical experiences also indicate that heterogeneity exists within the CLBP population. Muscle degeneration, like atrophy, fat infiltration, alterations in muscle fiber type, and altered muscle activity, compromises proper biomechanics and motion of the spinal units in LBP patients. The amount of alterations in muscle structure and muscle function of the paraspinal muscles might be related to the recurrence or chronicity of LBP. The aim of this experimental study is to evaluate differences in muscle structure (cross-sectional area and lean muscle fat index) and muscle activity of the multifidus (MF) and erector spinae (ES) during trunk extension, in patients with RLBP, non-continuous CLBP, and continuous CLBP. This cross-sectional study took place in the university hospital of Ghent, Belgium. Muscle structure characteristics and muscle activity were assessed by magnetic resonance imaging (MRI). Fifty-five adults with non-specific LBP (24 RLBP in remission, 15 non-continuous CLBP, 16 continuous CLBP) participated in this study. Total cross-sectional area, muscle cross-sectional area, fat cross-sectional area, lean muscle fat index, T2-rest and T2-shift were assessed. A T1-weighted Dixon MRI scan was used to evaluate spinal muscle cross-sectional area and fat infiltration in the lumbar MF and ES. Muscle functional MRI was used to evaluate the muscle activity of the lumbar MF and ES during a lumbar extension exercise. Before and after the exercise, a pain assessment was performed. This study was supported by grants from the Special Research Fund of Ghent University (DEF12/AOP/022) without potential conflict of interest-associated biases in the text of the paper. Fat cross-sectional area and lean muscle fat index were significantly higher in MF and ES in continuous CLBP compared with non-continuous CLBP and RLBP (p<.05). No differencesbetween groups were found for total cross-sectional area and muscle cross-sectional area in MF or ES (p>.05). Also, no significant differences between groups for T2-rest were established. T2-shift, however, was significantly lower in MF and ES in RLBP compared with, respectively, non-continuous CLBP and continuous CLBP (p<.05). These results indicate a higher amount of fat infiltration in the lumbar muscles, in the absence of clear atrophy, in continuous CLBP compared with RLBP. A lower metabolic activity of the lumbar muscles was seen in RLBP replicating a relative lower intensity in contractions performed by the lumbar muscles in RLBP compared with non-continuous and continuous CLBP. In conclusion, RLBP differs from continuous CLBP for both muscle structure and muscle function, whereas non-continuous CLBP seems comparable with RLBP for lumbar muscle structure and with continuous CLBP for lumbar muscle function. These results underline the differences in muscle structure and muscle function between different LBP populations. Copyright © 2017 Elsevier Inc. All rights reserved.
NASA Astrophysics Data System (ADS)
Jaffal, Mohammed; Kchikach, Azzouz; Lefort, Jean-Pierre; Hanich, Lahoucine
A large number of seismic reflection lines and boreholes have been carried out in the Essaouira Basin by the oil industry. The present study concentrates on the reinterpretation of these data in the restricted area of Khemis Meskala, in order to better characterise the structure of the Cretaceous aquiferous system. The reflector corresponding to the bottom of the Vraconian formation has been identified on the different seismic sections. This horizon, which marks the base of the aquiferous system, was first digitised on time migration sections and then converted to depth sections using a suitable linear velocity law. The isobath map of the bottom of the Vraconian resulting from this study images the 3D geometrical structure of this horizon and shows that it is slightly folded in domes and basins. This document will be useful for rationalising the future hydrogeological researches that will be undertaken in the Khemis Meskala area. To cite this article: M. Jaffal et al., C. R. Geoscience 334 (2002) 229-234.
Leonard, Annemarie K; Loughran, Elizabeth A; Klymenko, Yuliya; Liu, Yueying; Kim, Oleg; Asem, Marwa; McAbee, Kevin; Ravosa, Matthew J; Stack, M Sharon
2018-01-01
This chapter highlights methods for visualization and analysis of extracellular matrix (ECM) proteins, with particular emphasis on collagen type I, the most abundant protein in mammals. Protocols described range from advanced imaging of complex in vivo matrices to simple biochemical analysis of individual ECM proteins. The first section of this chapter describes common methods to image ECM components and includes protocols for second harmonic generation, scanning electron microscopy, and several histological methods of ECM localization and degradation analysis, including immunohistochemistry, Trichrome staining, and in situ zymography. The second section of this chapter details both a common transwell invasion assay and a novel live imaging method to investigate cellular behavior with respect to collagen and other ECM proteins of interest. The final section consists of common electrophoresis-based biochemical methods that are used in analysis of ECM proteins. Use of the methods described herein will enable researchers to gain a greater understanding of the role of ECM structure and degradation in development and matrix-related diseases such as cancer and connective tissue disorders. © 2018 Elsevier Inc. All rights reserved.
Design and Experimental Verification of Deployable/Inflatable Ultra-Lightweight Structures
NASA Technical Reports Server (NTRS)
Pai, P. Frank
2004-01-01
Because launch cost of a space structural system is often proportional to the launch volume and mass and there is no significant gravity in space, NASA's space exploration programs and various science missions have stimulated extensive use of ultra-lightweight deployable/inflatable structures. These structures are named here as Highly Flexible Structures (HFSs) because they are designed to undergo large displacements, rotations, and/or buckling without plastic deformation under normal operation conditions. Except recent applications to space structural systems, HFSs have been used in many mechanical systems, civil structures, aerospace vehicles, home appliances, and medical devices to satisfy space limitations, provide special mechanisms, and/or reduce structural weight. The extensive use of HFSs in today's structural engineering reveals the need of a design and analysis software and a database system with design guidelines for practicing engineers to perform computer-aided design and rapid prototyping of HFSs. Also to prepare engineering students for future structural engineering requires a new and easy-to- understand method of presenting the complex mathematics of the modeling and analysis of HFSs. However, because of the high flexibility of HFSs, many unique challenging problems in the modeling, design and analysis of HFSs need to be studied. The current state of research on HFSs needs advances in the following areas: (1) modeling of large rotations using appropriate strain measures, (2) modeling of cross-section warpings of structures, (3) how to account for both large rotations and cross- section warpings in 2D (two-dimensional) and 1D structural theories, (4) modeling of thickness thinning of membranes due to inflation pressure, pretension, and temperature change, (5) prediction of inflated shapes and wrinkles of inflatable structures, (6) development of efficient numerical methods for nonlinear static and dynamic analyses, and (7) filling the gap between geometrically exact elastic analysis and elastoplastic analysis. The objectives of this research project were: (1) to study the modeling, design, and analysis of deployable/inflatable ultra-lightweight structures, (2) to perform numerical and experimental studies on the static and dynamic characteristics and deployability of HFSs, (3) to derive guidelines for designing HFSs, (4) to develop a MATLAB toolbox for the design, analysis, and dynamic animation of HFSs, and (5) to perform experiments and establish an adequate database of post-buckling characteristics of HFSs.
Road safety forecasts in five European countries using structural time series models.
Antoniou, Constantinos; Papadimitriou, Eleonora; Yannis, George
2014-01-01
Modeling road safety development is a complex task and needs to consider both the quantifiable impact of specific parameters as well as the underlying trends that cannot always be measured or observed. The objective of this research is to apply structural time series models for obtaining reliable medium- to long-term forecasts of road traffic fatality risk using data from 5 countries with different characteristics from all over Europe (Cyprus, Greece, Hungary, Norway, and Switzerland). Two structural time series models are considered: (1) the local linear trend model and the (2) latent risk time series model. Furthermore, a structured decision tree for the selection of the applicable model for each situation (developed within the Road Safety Data, Collection, Transfer and Analysis [DaCoTA] research project, cofunded by the European Commission) is outlined. First, the fatality and exposure data that are used for the development of the models are presented and explored. Then, the modeling process is presented, including the model selection process, introduction of intervention variables, and development of mobility scenarios. The forecasts using the developed models appear to be realistic and within acceptable confidence intervals. The proposed methodology is proved to be very efficient for handling different cases of data availability and quality, providing an appropriate alternative from the family of structural time series models in each country. A concluding section providing perspectives and directions for future research is presented.
Hip Structural Analysis in Adolescent Boys With Anorexia Nervosa and Controls
Katzman, Debra K.; Clarke, Hannah; Snelgrove, Deirdre; Brigham, Kathryn; Miller, Karen K.; Klibanski, Anne
2013-01-01
Context: We have reported lower hip bone mineral density (BMD) in adolescent boys with anorexia nervosa (AN) compared with controls. Although studies have described bone structure in girls with AN, these data are not available for boys. Hip structural analysis (HSA) using dual-energy x-ray absorptiometry is a validated technique to assess hip geometry and strength while avoiding radiation associated with quantitative computed tomography. Objective: We hypothesized that boys with AN would have impaired hip structure/strength (assessed by HSA) compared with controls. Design and Setting: We conducted a cross-sectional study at a clinical research center. Subjects and Intervention: We used HSA techniques on hip dual-energy x-ray absorptiometry scans in 31 previously enrolled boys, 15 with AN and 16 normal-weight controls, 12 to 19 years old. Results: AN boys had lower body mass index SD score (P < .0001), testosterone (P = .0005), and estradiol (P = .006) than controls. A larger proportion of AN boys had BMD Z-scores <−1 at the femoral neck (60% vs 12.5%, P = 0008). Using HSA, at the narrow neck and trochanter region, boys with AN had lower cross-sectional area (P = .03, 0.02) and cortical thickness (P = .02, 0.03). Buckling ratio at the trochanter region was higher in AN (P = .008). After controlling for age and height, subperiosteal width at the femoral shaft, cross-sectional moment of inertia (narrow neck and femoral shaft), and section modulus (all sites) were lower in AN. The strongest associations of HSA measures were observed with lean mass, testosterone, and estradiol. On multivariate analysis, lean mass remained associated with most HSA measures. Conclusions: Boys with AN have impaired hip geometric parameters, associated with lower lean mass. PMID:23653430
Development of explosive welding procedures to fabricate channeled nozzle structures
NASA Technical Reports Server (NTRS)
Pattee, H. E.; Linse, V. D.
1976-01-01
Research was conducted to demonstrate the feasibility of fabricating a large contoured structure with complex internal channeling by explosive welding procedures. Structures or nozzles of this nature for wind tunnel applications were designed. Such nozzles vary widely in their complexity. However, in their simplest form, they consist of a grooved base section to which a cover sheet is attached to form a series of internal cooling passages. The cover sheet attachment can be accomplished in various ways: fusion welding, brazing, and diffusion welding. The cover sheet has also been electroformed in place. Of these fabrication methods, brazing has proved most successful in producing nozzles with complex contoured surfaces and a multiplicity of internal channels.
Ground/Flight Correlation of Aerodynamic Loads with Structural Response
NASA Technical Reports Server (NTRS)
Mangalam, Arun S.; Davis, Mark C.
2009-01-01
United States Air Force Research Laboratory (AFRL) ground tests at the NASA Transonic Dynamics Tunnel (TDT) and NASA flight tests provide a basis and methodology for in-flight characterization of the aeroelastic performance through the monitoring of the fluid-structure interaction using surface flow sensors. NASA NF-15B flight tests provided a unique opportunity to test the correlation of aerodynamic loads with sectional flow attachment/detachment points, also known as flow bifurcation points (FBPs), as observed in previous wind tunnel tests. The NF-15B tail was instrumented with hot-film sensors and strain gages for measuring root-bending strains. These data were gathered via selected sideslip maneuvers performed at level flight and subsonic speeds. The aerodynamic loads generated by the sideslip maneuver resulted in root-bending strains and hot-film sensor signals near the stagnation region that were highly correlated. For the TDT tests, a flexible wing section developed under the AFRL SensorCraft program was instrumented with strain gages, accelerometers, and hot-film sensors at multiple span stations. The TDT tests provided data showing a gradual phase change between the FBP and the structural mode occurred during a resonant condition as the wings structural modes were excited by the tunnel-generated gusts.
A Java application for tissue section image analysis.
Kamalov, R; Guillaud, M; Haskins, D; Harrison, A; Kemp, R; Chiu, D; Follen, M; MacAulay, C
2005-02-01
The medical industry has taken advantage of Java and Java technologies over the past few years, in large part due to the language's platform-independence and object-oriented structure. As such, Java provides powerful and effective tools for developing tissue section analysis software. The background and execution of this development are discussed in this publication. Object-oriented structure allows for the creation of "Slide", "Unit", and "Cell" objects to simulate the corresponding real-world objects. Different functions may then be created to perform various tasks on these objects, thus facilitating the development of the software package as a whole. At the current time, substantial parts of the initially planned functionality have been implemented. Getafics 1.0 is fully operational and currently supports a variety of research projects; however, there are certain features of the software that currently introduce unnecessary complexity and inefficiency. In the future, we hope to include features that obviate these problems.
Laser printed interconnects for flexible electronics
NASA Astrophysics Data System (ADS)
Pique, Alberto; Beniam, Iyoel; Mathews, Scott; Charipar, Nicholas
Laser-induced forward transfer (LIFT) can be used to generate microscale 3D structures for interconnect applications non-lithographically. The laser printing of these interconnects takes place through aggregation of voxels of either molten metal or dispersed metallic nanoparticles. However, the resulting 3D structures do not achieve the bulk conductivity of metal interconnects of the same cross-section and length as those formed by wire bonding or tab welding. It is possible, however, to laser transfer entire structures using a LIFT technique known as lase-and-place. Lase-and-place allows whole components and parts to be transferred from a donor substrate onto a desired location with one single laser pulse. This talk will present the use of LIFT to laser print freestanding solid metal interconnects to connect individual devices into functional circuits. Furthermore, the same laser can bend or fold the thin metal foils prior to transfer, thus forming compliant 3D structures able to provide strain relief due to flexing or thermal mismatch. Examples of these laser printed 3D metallic bridges and their role in the development of next generation flexible electronics by additive manufacturing will be presented. This work was funded by the Office of Naval Research (ONR) through the Naval Research Laboratory Basic Research Program.
Thermo-mechanical cyclic testing of carbon-carbon primary structure for an SSTO vehicle
NASA Astrophysics Data System (ADS)
Croop, Harold C.; Leger, Kenneth B.; Lowndes, Holland B.; Hahn, Steven E.; Barthel, Chris A.
1999-01-01
An advanced carbon-carbon structural component is being experimentally evaluated for use as primary load carrying structure for future single-stage-to-orbit (SSTO) vehicles. The component is a wing torque box section featuring an advanced, three-spar design. This design features 3D-woven, angle-interlock skins, 3D integrally woven spar webs and caps, oxidation inhibited matrix, chemical vapor deposited (CVD) oxidation protection coating, and ceramic matrix composite fasteners. The box spar caps are nested into the skins which, when processed together through the carbon-carbon processing cycle, resulted in monolithic box halves. The box half sections were then joined at the spar web intersections using ceramic matrix composite fasteners. This method of fabrication eliminated fasteners through both the upper and lower skins. Development of the carbon-carbon wing box structure was accomplished in a four phase design and fabrication effort, conducted by Boeing, Information, Space and Defense Systems, Seattle, WA, under contract to the Air Force Research Laboratory (AFRL). The box is now set up for testing and will soon begin cyclic loads testing in the AFRL Structural Test Facility at Wright-Patterson Air Force Base (WPAFB), OH. This paper discusses the latest test setup accomplishments and the results of the pre-cyclic loads testing performed to date.
Zhao, Qilin; Chen, Li; Shao, Guojian
2014-01-01
The axial compressive strength of unidirectional FRP made by pultrusion is generally quite lower than its axial tensile strength. This fact decreases the advantages of FRP as main load bearing member in engineering structure. A theoretical iterative calculation approach was suggested to predict the ultimate axial compressive stress of the combined structure and analyze the influences of geometrical parameters on the ultimate axial compressive stress of the combined structure. In this paper, the experimental and theoretical research on the CFRP sheet confined GFRP short pole was extended to the CFRP sheet confined GFRP short pipe, namely, a hollow section pole. Experiment shows that the bearing capacity of the GFRP short pipe can also be heightened obviously by confining CFRP sheet. The theoretical iterative calculation approach in the previous paper is amended to predict the ultimate axial compressive stress of the CFRP sheet confined GFRP short pipe, of which the results agree with the experiment. Lastly the influences of geometrical parameters on the new combined structure are analyzed. PMID:24672288
Wang, Jun; Xie, Xiaomei; Peng, Huasheng
2012-06-01
To elucidate the composition structure of "annual rings" and the formation process of anomalous structures in Sophora flavescens, and further discuss the medicinal parts of S. flavescens. Based on investigation on S. flavescens in its producing areas, the morphology of root systems was observed, and the developmental anatomy of roots was researched. Creeping underground rhizomes of S. flavescen existed in some parts of the north place, there were many differences in appearance characters and microscopic features between these roots and rhizomes. Parenchyma cells in secondary xylem regained meristematic ability, became into anomalous cambia, and then developed into anomalous structures. "Annual rings" in transverse section of S. flavescens were not actually growth rings, they were made up of anomalous parenchyma girdle in secondary xylem and normal secondary structure. Roots are the medicinal parts of S. flavescens. This paper suggests that "annual rings" in the decoction pieces of S. flavescens should be called "annular structure".
Vibroacoustic Response Data of Stiffened Panels and Cylinders
NASA Technical Reports Server (NTRS)
Cabell, Randolph; Klos, Jake; Buehrle, Ralph; Schiller, Noah
2008-01-01
NASA has collected vibroacoustic response data on a variety of complex, aerospace structures to support research into numerical modeling of such structures. This data is being made available to the modeling community to promote the development and validation of analysis methods for these types of structures. Existing data from two structures is described, as well as plans for a data set from a third structure. The first structure is a 1.22 m by 1.22 m stiffened aluminum panel, typical of a commercial aircraft sidewall section. The second is an enclosed, stiffened aluminum cylinder, approximately 3.66 m long and 1.22 m in diameter, constructed to resemble a small aircraft fuselage with no windows and a periodic structure. The third structure is a filament-wound composite cylinder with composite stiffeners. Numerous combinations of excitation and response variables were measured on the structures, including: shaker excitation; diffuse acoustic field; velocity response from a laser vibrometer; intensity scans; and point acceleration.
Tensoral for post-processing users and simulation authors
NASA Technical Reports Server (NTRS)
Dresselhaus, Eliot
1993-01-01
The CTR post-processing effort aims to make turbulence simulations and data more readily and usefully available to the research and industrial communities. The Tensoral language, which provides the foundation for this effort, is introduced here in the form of a user's guide. The Tensoral user's guide is presented in two main sections. Section one acts as a general introduction and guides database users who wish to post-process simulation databases. Section two gives a brief description of how database authors and other advanced users can make simulation codes and/or the databases they generate available to the user community via Tensoral database back ends. The two-part structure of this document conforms to the two-level design structure of the Tensoral language. Tensoral has been designed to be a general computer language for performing tensor calculus and statistics on numerical data. Tensoral's generality allows it to be used for stand-alone native coding of high-level post-processing tasks (as described in section one of this guide). At the same time, Tensoral's specialization to a minute task (namely, to numerical tensor calculus and statistics) allows it to be easily embedded into applications written partly in Tensoral and partly in other computer languages (here, C and Vectoral). Embedded Tensoral, aimed at advanced users for more general coding (e.g. of efficient simulations, for interfacing with pre-existing software, for visualization, etc.), is described in section two of this guide.
Harry Mergler with His Modified Differential Analyzer
1951-06-21
Harry Mergler stands at the control board of a differential analyzer in the new Instrument Research Laboratory at the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory. The differential analyzer was a multi-variable analog computation machine devised in 1931 by Massachusetts Institute of Technology researcher and future NACA Committee member Vannevar Bush. The mechanical device could solve computations up to the sixth order, but had to be rewired before each new computation. Mergler modified Bush’s differential analyzer in the late 1940s to calculate droplet trajectories for Lewis’ icing research program. In four days Mergler’s machine could calculate what previously required weeks. NACA Lewis built the Instrument Research Laboratory in 1950 and 1951 to house the large analog computer equipment. The two-story structure also provided offices for the Mechanical Computational Analysis, and Flow Physics sections of the Physics Division. The division had previously operated from the lab’s hangar because of its icing research and flight operations activities. Mergler joined the Instrument Research Section of the Physics Division in 1948 after earning an undergraduate degree in Physics from the Case Institute of Technology. Mergler’s focus was on the synthesis of analog computers with the machine tools used to create compressor and turbine blades for jet engines.
Baseline Fracture Toughness and CGR testing of alloys X-750 and XM-19 (EPRI Phase I)
DOE Office of Scientific and Technical Information (OSTI.GOV)
J. H. Jackson; S. P. Teysseyre
2012-10-01
The Advanced Test Reactor National Scientific User Facility (ATR NSUF) and Electric Power Research Institute (EPRI) formed an agreement to test representative alloys used as reactor structural materials as a pilot program toward establishing guidelines for future ATR NSUF research programs. This report contains results from the portion of this program established as Phase I (of three phases) that entails baseline fracture toughness, stress corrosion cracking (SCC), and tensile testing of selected materials for comparison to similar tests conducted at GE Global Research. The intent of this Phase I research program is to determine baseline properties for the materials ofmore » interest prior to irradiation, and to ensure comparability between laboratories using similar testing techniques, prior to applying these techniques to the same materials after having been irradiated at the Advanced Test Reactor (ATR). The materials chosen for this research are the nickel based super alloy X-750, and nitrogen strengthened austenitic stainless steel XM-19. A spare core shroud upper support bracket of alloy X-750 was purchased by EPRI from Southern Co. and a section of XM-19 plate was purchased by EPRI from GE-Hitachi. These materials were sectioned at GE Global Research and provided to INL.« less
Baseline Fracture Toughness and CGR testing of alloys X-750 and XM-19 (EPRI Phase I)
DOE Office of Scientific and Technical Information (OSTI.GOV)
J. H. Jackson; S. P. Teysseyre
2012-02-01
The Advanced Test Reactor National Scientific User Facility (ATR NSUF) and Electric Power Research Institute (EPRI) formed an agreement to test representative alloys used as reactor structural materials as a pilot program toward establishing guidelines for future ATR NSUF research programs. This report contains results from the portion of this program established as Phase I (of three phases) that entails baseline fracture toughness, stress corrosion cracking (SCC), and tensile testing of selected materials for comparison to similar tests conducted at GE Global Research. The intent of this Phase I research program is to determine baseline properties for the materials ofmore » interest prior to irradiation, and to ensure comparability between laboratories using similar testing techniques, prior to applying these techniques to the same materials after having been irradiated at the Advanced Test Reactor (ATR). The materials chosen for this research are the nickel based super alloy X-750, and nitrogen strengthened austenitic stainless steel XM-19. A spare core shroud upper support bracket of alloy X-750 was purchased by EPRI from Southern Co. and a section of XM-19 plate was purchased by EPRI from GE-Hitachi. These materials were sectioned at GE Global Research and provided to INL.« less
Radio stimulation and diagnostics of space plasmas
NASA Technical Reports Server (NTRS)
Lee, Min-Chang
1993-01-01
We have investigated the small-scale topside ionospheric plasma structures first observed at Millstone Hill, Massachusetts with the 440 MHz incoherent scatter radar. These small-scale obliquely propagating plasma modes occurring in the vicinity of the midlatitude ionospheric trough, have large radar cross-sections and narrow spectral widths. They have, until recently, been dismissed solely as hard target contamination of the incoherent scatter radar. The geophysical conditions associated with the ionospheric trough, such as the field-aligned current activity and steep plasma density gradients, suggest that these recently discovered small-scale topside ionospheric plasmas may also appear in the auroral and polar ionosphere. In fact, this speculation has been corroborated by the preliminary experiments and data analyses at Tromso, Norway and Sondrestromfjord, Greenland. The primary research results are highlighted. Described in Section 3 are the experiments conducted at Arecibo, Puerto Rico in the past summer for simulating the geophysical conditions of generating these topside ionospheric plasma structures. Recommendation for the future research is finally given. Attached as the appendix of this report are several chapters which present the detailed results of research in the concerned topside ionospheric clutter. Highlights of the research results include: (1) causes of the enhanced radar backscatter (ERB) phenomenon; (2) occurrence of the ERB phenomenon; (3) altitudes of the ERB phenomenon; (4) strength of the ERB returns; (5) range of altitudes of the ERB returns; (6) occurrence frequency of the ERB phenomenon; (7) Doppler effect of the ERB phenomenon; (8) persistency of the ERB; and (9) distinction between ERB phenomenon and space object signatures.
Wind Tunnel Complex at the Aircraft Engine Research Laboratory
1945-09-21
This aerial photograph shows the entire original wind tunnel complex at the National Advisory Committee for Aeronautics (NACA) Aircraft Engine Research Laboratory. The large Altitude Wind Tunnel (AWT) at the center of the photograph dominates the area. The Icing Research Tunnel to the right was incorporated into the lab’s design to take advantage of the AWT’s powerful infrastructure. The laboratory’s first supersonic wind tunnel was added to this complex just prior to this September 1945 photograph. The AWT was the nation’s only wind tunnel capable of studying full-scale engines in simulated flight conditions. The AWT’s test section and control room were within the two-story building near the top of the photograph. The exhauster equipment used to thin the airflow and the drive motor for the fan were in the building to the right of the tunnel. The unique refrigeration equipment was housed in the structure to the left of the tunnel. The Icing Research Tunnel was an atmospheric tunnel that used the AWT’s refrigeration equipment to simulate freezing rain inside its test section. A spray bar system inside the tunnel was originally used to create the droplets. The 18- by 18-inch supersonic wind tunnel was built in the summer of 1945 to take advantage of the AWT’s powerful exhaust system. It was the lab’s first supersonic tunnel and could reach Mach 1.91. Eventually the building would house three small supersonic tunnels, referred to as the “stack tunnels” because of the vertical alignment. The two other tunnels were added to this structure in 1949 and 1951.
Radio stimulation and diagnostics of space plasmas
NASA Astrophysics Data System (ADS)
Lee, Min-Chang
1993-02-01
We have investigated the small-scale topside ionospheric plasma structures first observed at Millstone Hill, Massachusetts with the 440 MHz incoherent scatter radar. These small-scale obliquely propagating plasma modes occurring in the vicinity of the midlatitude ionospheric trough, have large radar cross-sections and narrow spectral widths. They have, until recently, been dismissed solely as hard target contamination of the incoherent scatter radar. The geophysical conditions associated with the ionospheric trough, such as the field-aligned current activity and steep plasma density gradients, suggest that these recently discovered small-scale topside ionospheric plasmas may also appear in the auroral and polar ionosphere. In fact, this speculation has been corroborated by the preliminary experiments and data analyses at Tromso, Norway and Sondrestromfjord, Greenland. The primary research results are highlighted. Described in Section 3 are the experiments conducted at Arecibo, Puerto Rico in the past summer for simulating the geophysical conditions of generating these topside ionospheric plasma structures. Recommendation for the future research is finally given. Attached as the appendix of this report are several chapters which present the detailed results of research in the concerned topside ionospheric clutter. Highlights of the research results include: (1) causes of the enhanced radar backscatter (ERB) phenomenon; (2) occurrence of the ERB phenomenon; (3) altitudes of the ERB phenomenon; (4) strength of the ERB returns; (5) range of altitudes of the ERB returns; (6) occurrence frequency of the ERB phenomenon; (7) Doppler effect of the ERB phenomenon; (8) persistency of the ERB; and (9) distinction between ERB phenomenon and space object signatures.
Sandwich Panels Evaluated With Ultrasonic Spectroscopy
NASA Technical Reports Server (NTRS)
Cosgriff, Laura M.
2004-01-01
Enhanced, lightweight material systems, such as 17-4PH stainless steel sandwich panels are being developed for use as fan blades and fan containment systems for next-generation engines. The bond strength between the core and face sheets is critical in maintaining the structural integrity of the sandwich structure. To improve the inspection and production of these systems, researchers at the NASA Glenn Research Center are using nondestructive evaluation (NDE) techniques, such as ultrasonic spectroscopy, to evaluate the brazing quality between the face plates and the metallic foam core. The capabilities and limitations of a swept-frequency approach to ultrasonic spectroscopy were evaluated with respect to these sandwich structures. This report discusses results from three regions of a sandwich panel representing different levels of brazing quality between the outer face plates and a metallic foam core. Each region was investigated with ultrasonic spectroscopy. Then, on the basis of the NDE results, three shear specimens sectioned from the sandwich panel to contain each of these regions were mechanically tested.
Structural interpretation from horizontal seismic sections
DOE Office of Scientific and Technical Information (OSTI.GOV)
Brown, A.R.
1983-03-01
The interpreter of a 3D survey must use a data volume. Horizontal slices through a data volume, called Seiscrop sections, have unique properties and structural interpretation from them is fast, convenient, and effective. An event on a Seiscrop section displays local strike, a property which permits direct contouring of a structural surface without any timing and posting. The width of an event on a Seiscrop section is a composition of the frequency of the data and the structural dip. Event terminations indicate faults or other discontinuities when they are transverse to structural strike. Faults parallel to structural strike are muchmore » less evident on a single Seiscrop section but become apparent with the relative movement of events from section to section. In practical mapping, we normally contour one fault block before proceeding to the next with the correlation between them being established from the vertical sections. With dual polarity variable area displays, the interpreter can perceive five amplitude levels and normally picks the edge of a trough. With color amplitude Seiscrop sections, it is possible to pick on the crest of any event. With color phase sections the interpreter can pick at any arbitrary but consistent point on the seismic waveform. Subtle structural features are commonly revealed on horizontal sections which may never have been noticed if working from vertical sections alone.« less
Students' perceptions of the flipped classroom model in an engineering course: a case study
NASA Astrophysics Data System (ADS)
Baytiyeh, Hoda; Naja, Mohamad K.
2017-11-01
The flipped classroom model is an innovative educational trend that has been widely adopted in the social sciences but not engineering education. In this model, an active instructional approach shifts the educational strategy from a teacher- to a student-centred approach. The purpose of this study is to compare the learning outcomes of engineering students attending a flipped-model section of the Dynamics of Structures course with students attending a traditional, lecture-based section of the same course taught by the same instructor. The results confirm previous research showing that test scores in the flipped course sections were slightly higher than traditional sections. Although the improvement in test scores was statistically insignificant, student statements indicated that the flipped model promoted a deeper, broader perspective on learning, facilitated problem-solving strategies and improved critical-thinking abilities, self-confidence and teamwork skills, which are needed for a successful engineering career.
Development of SMA Actuated Morphing Airfoil for Wind Turbine Load Alleviation
NASA Astrophysics Data System (ADS)
Karakalas, A.; Machairas, T.; Solomou, A.; Riziotis, V.; Saravanos, D.
Wind turbine rotor upscaling has entered a range of rotor diameters where the blade structure cannot sustain the increased aerodynamic loads without novel load alleviation concepts. Research on load alleviation using morphing blade sections is presented. Antagonistic shape memory alloy (SMA) actuators are implemented to deflect the section trailing edge (TE) to target shapes and target time-series relating TE movement with changes in lift coefficient. Challenges encountered by the complex thermomechanical response of morphing section and the enhancement of SMA transient response to achieve frequencies meaningful for aerodynamic load alleviation are addressed. Using a recently developed finite element for SMA actuators [1], actuator configurations are considered for fast cooling and heating cycles. Numerical results quantify the attained ranges of TE angle movement, the moving time period and the developed stresses. Estimations of the attained variations of lift coefficient vs. time are also presented to assess the performance of the morphing section.
Life prediction and constitutive behavior
NASA Technical Reports Server (NTRS)
Halford, G. R.
1983-01-01
One of the primary drivers that prompted the initiation of the hot section technology (HOST) program was the recognized need for improved cyclic durability of costly hot section components. All too frequently, fatigue in one form or another was directly responsible for the less than desired durability, and prospects for the future weren't going to improve unless a significant effort was mounted to increase our knowledge and understanding of the elements governing cyclic crack initiation and propagation lifetime. Certainly one of the important factors is the ability to perform accurate structural stress-strain analyses on a routine basis to determine the magnitudes of the localized stresses and strains since it is these localized conditions that govern the initiation and crack growth processes. Developing the ability to more accurately predict crack initiation lifetimes and cyclic crack growth rates for the complex loading conditions found in turbine engine hot sections is of course the ultimate goal of the life prediction research efforts. It has been found convenient to divide the research efforts into those dealing with nominally isotropic and anisotropic alloys; the latter for application to directionally solidified and single crystal turbine blades.
Simulation and analysis of tape spring for deployed space structures
NASA Astrophysics Data System (ADS)
Chang, Wei; Cao, DongJing; Lian, MinLong
2018-03-01
The tape spring belongs to the configuration of ringent cylinder shell, and the mechanical properties of the structure are significantly affected by the change of geometrical parameters. There are few studies on the influence of geometrical parameters on the mechanical properties of the tape spring. The bending process of the single tape spring was simulated based on simulation software. The variations of critical moment, unfolding moment, and maximum strain energy in the bending process were investigated, and the effects of different radius angles of section and thickness and length on driving capability of the simple tape spring was studied by using these parameters. Results show that the driving capability and resisting disturbance capacity grow with the increase of radius angle of section in the bending process of the single tape spring. On the other hand, these capabilities decrease with increasing length of the single tape spring. In the end, the driving capability and resisting disturbance capacity grow with the increase of thickness in the bending process of the single tape spring. The research has a certain reference value for improving the kinematic accuracy and reliability of deployable structures.
3D visualization of sheath folds in Ancient Roman marble wall coverings from Ephesos, Turkey
NASA Astrophysics Data System (ADS)
Wex, Sebastian; Passchier, Cees W.; de Kemp, Eric A.; İlhan, Sinan
2014-10-01
Archaeological excavations and restoration of a palatial Roman housing complex in Ephesos, Turkey yielded 40 wall-decorating plates of folded mylonitic marble (Cipollino verde), derived from the internal Hellenides near Karystos, Greece. Cipollino verde was commonly used for decoration purposes in Roman buildings. The plates were serial-sectioned from a single quarried block of 1,25 m3 and provided a research opportunity for detailed reconstruction of the 3D geometry of meterscale folds in mylonitized marble. A GOCAD model is used to visualize the internal fold structures of the marble, comprising curtain folds and multilayered sheath folds. The sheath folds are unusual in that they have their intermediate axis normal to the parent layering. This agrees with regional tectonic studies, which suggest that Cipollino verde structures formed by local constrictional non-coaxial flow. Sheath fold cross-section geometry, exposed on the surface of a plate or outcrop, is found to be independent of the intersection angle of the fold structure with the studied plane. Consequently, a single surface cannot be used as an indicator of the three-dimensional geometry of transected sheath folds.
NASA Astrophysics Data System (ADS)
Albus, J.; Oery, H.
1993-04-01
One of the main problems associated with the structural design of a hypersonic aircraft is the conception of the cryogenic tank. Therefore two essential questions, in consideration of structural weight, volumetric efficiency and the aspects as well of inspection, maintenance and repair, as of exchangeability in case of leakage (leak before burst) and safety in operation, have to be answered. These questions concern the choice of the tank integration concept and the tank cross section. To get an idea how much the take-off weight depends on the tank integration concept, at the Institut fuer Leichtbau of the RWTH Aachen a program for weight estimation of hypersonic aircraft has been developed. Herewith the goal was to define well suited substitute models which allow the performance of parametric studies within a wide range of parameters in a tolerable amount of time. In the following the mass model and calculation methods used will be shortly introduced and finally the results achieved will be presented and discussed. On this occasion also comments on structural efficiency of different tank cross sections will be given.
Research in Pressure Broadening.
1986-08-01
is to provide some discussion of the structure and functioning of the molecular-electromag- netic correlation formalism ( MECF ) which is applicable to...the comprehensiveness of the MECF for- alism, Section IV outlines several past applications of the method and points out some potential areas for...or mist. It is hoped that this discussion will stimulate interest in the capabilities of the MECF approach. 1C. A. Coulter and D. W. Howgate
ERIC Educational Resources Information Center
Frese, Wolfgang, Ed.
A total of 47 papers representing the broad research and extension interests related to rural areas are included in this volume. The 13 sessions are entitled Rural Structure and Process, Industrialization, Migration, Health and Alcohol, Quality of Life, Occupations and Work, Applied Sociology, Education, Network Analysis, Poverty, Status…
ERIC Educational Resources Information Center
Woodward, John
2016-01-01
In this commentary, John Woodward observes that, when judged collectively, the pre-K to Grade 4 research in this special section not only exemplifies the effects of the Institute of Education Sciences' emphasis on large-scale empirical studies over the last decade, but it also demonstrates how the field of special education has moved away from a…
2013-01-01
Background In biomedical research, a huge variety of different techniques is currently available for the structural examination of small specimens, including conventional light microscopy (LM), transmission electron microscopy (TEM), confocal laser scanning microscopy (CLSM), microscopic X-ray computed tomography (microCT), and many others. Since every imaging method is physically limited by certain parameters, a correlative use of complementary methods often yields a significant broader range of information. Here we demonstrate the advantages of the correlative use of microCT, light microscopy, and transmission electron microscopy for the analysis of small biological samples. Results We used a small juvenile bivalve mollusc (Mytilus galloprovincialis, approximately 0.8 mm length) to demonstrate the workflow of a correlative examination by microCT, LM serial section analysis, and TEM-re-sectioning. Initially these three datasets were analyzed separately, and subsequently they were fused in one 3D scene. This workflow is very straightforward. The specimen was processed as usual for transmission electron microscopy including post-fixation in osmium tetroxide and embedding in epoxy resin. Subsequently it was imaged with microCT. Post-fixation in osmium tetroxide yielded sufficient X-ray contrast for microCT imaging, since the X-ray absorption of epoxy resin is low. Thereafter, the same specimen was serially sectioned for LM investigation. The serial section images were aligned and specific organ systems were reconstructed based on manual segmentation and surface rendering. According to the region of interest (ROI), specific LM sections were detached from the slides, re-mounted on resin blocks and re-sectioned (ultrathin) for TEM. For analysis, image data from the three different modalities was co-registered into a single 3D scene using the software AMIRA®. We were able to register both the LM section series volume and TEM slices neatly to the microCT dataset, with small geometric deviations occurring only in the peripheral areas of the specimen. Based on co-registered datasets the excretory organs, which were chosen as ROI for this study, could be investigated regarding both their ultrastructure as well as their position in the organism and their spatial relationship to adjacent tissues. We found structures typical for mollusc excretory systems, including ultrafiltration sites at the pericardial wall, and ducts leading from the pericardium towards the kidneys, which exhibit a typical basal infolding system. Conclusions The presented approach allows a comprehensive analysis and presentation of small objects regarding both the overall organization as well as cellular and subcellular details. Although our protocol involves a variety of different equipment and procedures, we maintain that it offers savings in both effort and cost. Co-registration of datasets from different imaging modalities can be accomplished with high-end desktop computers and offers new opportunities for understanding and communicating structural relationships within organisms and tissues. In general, the correlative use of different microscopic imaging techniques will continue to become more widespread in morphological and structural research in zoology. Classical TEM serial section investigations are extremely time consuming, and modern methods for 3D analysis of ultrastructure such as SBF-SEM and FIB-SEM are limited to very small volumes for examination. Thus the re-sectioning of LM sections is suitable for speeding up TEM examination substantially, while microCT could become a key-method for complementing ultrastructural examinations. PMID:23915384
Distribution-free Inference of Zero-inated Binomial Data for Longitudinal Studies.
He, H; Wang, W J; Hu, J; Gallop, R; Crits-Christoph, P; Xia, Y L
2015-10-01
Count reponses with structural zeros are very common in medical and psychosocial research, especially in alcohol and HIV research, and the zero-inflated poisson (ZIP) and zero-inflated negative binomial (ZINB) models are widely used for modeling such outcomes. However, as alcohol drinking outcomes such as days of drinkings are counts within a given period, their distributions are bounded above by an upper limit (total days in the period) and thus inherently follow a binomial or zero-inflated binomial (ZIB) distribution, rather than a Poisson or zero-inflated Poisson (ZIP) distribution, in the presence of structural zeros. In this paper, we develop a new semiparametric approach for modeling zero-inflated binomial (ZIB)-like count responses for cross-sectional as well as longitudinal data. We illustrate this approach with both simulated and real study data.
Ardestani, M S; Niknami, S; Hidarnia, A; Hajizadeh, E
2016-08-18
This research examined the validity and reliability of a researcher-developed questionnaire based on Social Cognitive Theory (SCT) to assess the physical activity behaviour of Iranian adolescent girls (SCT-PAIAGS). Psychometric properties of the SCT-PAIAGS were assessed by determining its face validity, content and construct validity as well as its reliability. In order to evaluate factor structure, cross-sectional research was conducted on 400 high-school girls in Tehran. Content validity index, content validity ratio and impact score for the SCT-PAIAGS varied between 0.97-1, 0.91-1 and 4.6-4.9 respectively. Confirmatory factor analysis approved a six-factor structure comprising self-efficacy, self-regulation, family support, friend support, outcome expectancy and self-efficacy to overcoming impediments. Factor loadings, t-values and fit indices showed that the SCT model was fitted to the data. Cronbach's α-coefficient ranged from 0.78 to 0.85 and intraclass correlation coefficient from 0.73 to 0.90.
Forest ecosystems in the Alaskan taiga
DOE Office of Scientific and Technical Information (OSTI.GOV)
Van Cleve, K.; Chapin, F.S. III; Flanagan, P.W.
1986-01-01
This volume in the series ''Ecological Studies'' provides an overview and synthesis of research on the structure and function of taiga forest ecosystems of interior Alaska. The first section discusses the nature of the taiga environment and covers climate, forest ecosystem distribution, natural regeneration of vegetation, and the role of fire. The second edition focuses on environmental controls over organism activity with discussions on growth and nutrient use, nitrogen fixation, physiological ecology of mosses, and microbial activity and element availability. The final section considers environmental controls over ecosystem processes with discussions of processes, plant-animal interactions, and a model of forestmore » growth and yield.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Carter, J. M.
The Concrete and Materials Branch (CMB) of the Geotechnical and Structures Laboratory was requested to perform an analysis on concrete cores collected from the north and south walls of the H-Canyon Section 3 Personnel Tunel, Savannah River Site, Aiken, South Carolina to determine the cause of the lower than expected compressive strength. This study examined five cores provided to the ERDC by the Department of Energy. The cores were logged in as CMB No. 170051-1 to 170051-5 and subjected to petrographic examination, air void analysis, chemical sprays, scanning electron microscopy, and x-ray diffraction.
NASA Astrophysics Data System (ADS)
Boichuk, T. M.; Bachinskiy, V. T.; Vanchuliak, O. Ya.; Minzer, O. P.; Garazdiuk, M.; Motrich, A. V.
2014-08-01
This research presents the results of investigation of laser polarization fluorescence of biological layers (histological sections of the myocardium). The polarized structure of autofluorescence imaging layers of biological tissues was detected and investigated. Proposed the model of describing the formation of polarization inhomogeneous of autofluorescence imaging biological optically anisotropic layers. On this basis, analytically and experimentally tested to justify the method of laser polarimetry autofluorescent. Analyzed the effectiveness of this method in the postmortem diagnosis of infarction. The objective criteria (statistical moments) of differentiation of autofluorescent images of histological sections myocardium were defined. The operational characteristics (sensitivity, specificity, accuracy) of these technique were determined.
1981-06-26
of the Ministry of Inland Water Transportation of the RSFSR with participation of the Central Scientific Research Institute and the Construction... Articles . General Indicators" I-V.5.2-62, "Reinforced-Concrete Articles for Structures" and the regulations of this chapter which supplement them. 9.2...Department of Scientific and Technical Literature at SOYUZKNIG. 58 Ct R.C’lTI : NOR’,IS AND RIGULATrONS I\\. I. Pal ’ch ikov, S . P. Antonov , Editors
Complex Intelligent Systems: Juxtaposition of Foundational Notions and a Research Agenda
NASA Astrophysics Data System (ADS)
Gelepithis, Petros A.
2001-11-01
The cardinality of the class, C , of complex intelligent systems, i.e., systems of intelligent systems and their resources, is steadily increasing. Such an increase, whether designed, sometimes changes significantly and fundamentally, the structure of C . Recently,the study of members of C and its structure comes under a variety of multidisciplinary headings the most prominent of which include General Systems Theory, Complexity Science, Artificial Life, and Cybernetics. Their common characteristic is the quest for a unified theory of a certain class of systems like a living system or an organisation. So far, the only candidate for a general theory of intelligent systems is Newell's Soar. To my knowledge there is presently no candidate theory of C except Newell's claimed extensibility of Soar. This paper juxtaposes the elements of Newell's conceptual basis with those of an alternative conceptual framework based on the thesis that communication and understanding are the primary processes shaping the structure of C and its members. It is patently obvious that a research agenda for the study of C can be extremely varied and long. The third section of this paper presents a highly selective research agenda that aims to provoke discussion among complexity theory scientists.
NASA Astrophysics Data System (ADS)
Bulusu, Kartik V.; Hussain, Shadman; Plesniak, Michael W.
2014-11-01
Secondary flow vortical patterns in arterial curvatures have the potential to affect several cardiovascular phenomena, e.g., progression of atherosclerosis by altering wall shear stresses, carotid atheromatous disease, thoracic aortic aneurysms and Marfan's syndrome. Temporal characteristics of secondary flow structures vis-à-vis physiological (pulsatile) inflow waveform were explored by continuous wavelet transform (CWT) analysis of phase-locked, two-component, two-dimensional particle image velocimeter data. Measurements were made in a 180° curved artery test section upstream of the curvature and at the 90° cross-sectional plane. Streamwise, upstream flow rate measurements were analyzed using a one-dimensional antisymmetric wavelet. Cross-stream measurements at the 90° location of the curved artery revealed interesting multi-scale, multi-strength coherent secondary flow structures. An automated process for coherent structure detection and vortical feature quantification was applied to large ensembles of PIV data. Metrics such as the number of secondary flow structures, their sizes and strengths were generated at every discrete time instance of the physiological inflow waveform. An autonomous data post-processing method incorporating two-dimensional CWT for coherent structure detection was implemented. Loss of coherence in secondary flow structures during the systolic deceleration phase is observed in accordance with previous research. The algorithmic approach presented herein further elucidated the sensitivity and dependence of morphological changes in secondary flow structures on quasiperiodicity and magnitude of temporal gradients in physiological inflow conditions.
How to Write Your First Research Paper
Kallestinova, Elena D.
2011-01-01
Writing a research manuscript is an intimidating process for many novice writers in the sciences. One of the stumbling blocks is the beginning of the process and creating the first draft. This paper presents guidelines on how to initiate the writing process and draft each section of a research manuscript. The paper discusses seven rules that allow the writer to prepare a well-structured and comprehensive manuscript for a publication submission. In addition, the author lists different strategies for successful revision. Each of those strategies represents a step in the revision process and should help the writer improve the quality of the manuscript. The paper could be considered a brief manual for publication. PMID:21966034
How to write your first research paper.
Kallestinova, Elena D
2011-09-01
Writing a research manuscript is an intimidating process for many novice writers in the sciences. One of the stumbling blocks is the beginning of the process and creating the first draft. This paper presents guidelines on how to initiate the writing process and draft each section of a research manuscript. The paper discusses seven rules that allow the writer to prepare a well-structured and comprehensive manuscript for a publication submission. In addition, the author lists different strategies for successful revision. Each of those strategies represents a step in the revision process and should help the writer improve the quality of the manuscript. The paper could be considered a brief manual for publication. Copyright © 2011.
The business of addiction treatment: A research agenda.
Kimberly, John R; McLellan, A Thomas
2006-10-01
The social and economic costs of addiction are substantial and of great concern to society. Research in the past decade has led to promising therapies that appear to be highly effective but not widely diffused. This leads one to wonder if there is something about the structure, dynamics, or structure and dynamics of the addiction treatment industry that is getting in the way. However, there has been very little research in the areas of organization, finance, or management practices within the substance abuse treatment field-the kinds of issues that reduce the potential impact of addiction treatment industrywide. With this as background, this article introduces the Center for Organization and Management in Addiction Treatment (COMAT) and a special section on research in the "business of addiction treatment." Many other industries have experienced significant problems that are similar, in many respects, to those seen in substance abuse treatment, but research in leadership, innovation, investment, organization, and consolidation strategies has helped to overcome those problems. COMAT is dedicated to implementing and testing evidence-based methods from other industries to improve the outcomes performance and, ultimately, the clinical effectiveness of service providers in the addiction treatment field.
Kostelnik, Kevin M.; Kawamura, Hideki; Richardson, John G.; Noda, Masaru
2005-02-08
An advanced containment system for containing buried waste and associated leachate. The advanced containment system comprises a plurality of casing sections with each casing section interlocked to an adjacent casing section. Each casing section includes a complementary interlocking structure that interlocks with the complementary interlocking structure on an adjacent casing section. A barrier filler substantially fills the casing sections and may substantially fill the spaces of the complementary interlocking structure to form a substantially impermeable barrier. Some of the casing sections may include sensors so that the casing sections and the zone of interest may be remotely monitored after the casing sections are emplaced in the ground.
Landscape moderation of biodiversity patterns and processes - eight hypotheses.
Tscharntke, Teja; Tylianakis, Jason M; Rand, Tatyana A; Didham, Raphael K; Fahrig, Lenore; Batáry, Péter; Bengtsson, Janne; Clough, Yann; Crist, Thomas O; Dormann, Carsten F; Ewers, Robert M; Fründ, Jochen; Holt, Robert D; Holzschuh, Andrea; Klein, Alexandra M; Kleijn, David; Kremen, Claire; Landis, Doug A; Laurance, William; Lindenmayer, David; Scherber, Christoph; Sodhi, Navjot; Steffan-Dewenter, Ingolf; Thies, Carsten; van der Putten, Wim H; Westphal, Catrin
2012-08-01
Understanding how landscape characteristics affect biodiversity patterns and ecological processes at local and landscape scales is critical for mitigating effects of global environmental change. In this review, we use knowledge gained from human-modified landscapes to suggest eight hypotheses, which we hope will encourage more systematic research on the role of landscape composition and configuration in determining the structure of ecological communities, ecosystem functioning and services. We organize the eight hypotheses under four overarching themes. Section A: 'landscape moderation of biodiversity patterns' includes (1) the landscape species pool hypothesis-the size of the landscape-wide species pool moderates local (alpha) biodiversity, and (2) the dominance of beta diversity hypothesis-landscape-moderated dissimilarity of local communities determines landscape-wide biodiversity and overrides negative local effects of habitat fragmentation on biodiversity. Section B: 'landscape moderation of population dynamics' includes (3) the cross-habitat spillover hypothesis-landscape-moderated spillover of energy, resources and organisms across habitats, including between managed and natural ecosystems, influences landscape-wide community structure and associated processes and (4) the landscape-moderated concentration and dilution hypothesis-spatial and temporal changes in landscape composition can cause transient concentration or dilution of populations with functional consequences. Section C: 'landscape moderation of functional trait selection' includes (5) the landscape-moderated functional trait selection hypothesis-landscape moderation of species trait selection shapes the functional role and trajectory of community assembly, and (6) the landscape-moderated insurance hypothesis-landscape complexity provides spatial and temporal insurance, i.e. high resilience and stability of ecological processes in changing environments. Section D: 'landscape constraints on conservation management' includes (7) the intermediate landscape-complexity hypothesis-landscape-moderated effectiveness of local conservation management is highest in structurally simple, rather than in cleared (i.e. extremely simplified) or in complex landscapes, and (8) the landscape-moderated biodiversity versus ecosystem service management hypothesis-landscape-moderated biodiversity conservation to optimize functional diversity and related ecosystem services will not protect endangered species. Shifting our research focus from local to landscape-moderated effects on biodiversity will be critical to developing solutions for future biodiversity and ecosystem service management. © 2012 The Authors. Biological Reviews © 2012 Cambridge Philosophical Society.
Research and technology, 1993. Salute to Skylab and Spacelab: Two decades of discovery
NASA Technical Reports Server (NTRS)
1993-01-01
A summary description of Skylab and Spacelab is presented. The section on Advanced Studies includes projects in space science, space systems, commercial use of space, and transportation systems. Within the Research Programs area, programs are listed under earth systems science, space physics, astrophysics, and microgravity science and applications. Technology Programs include avionics, materials and manufacturing processes, mission operations, propellant and fluid management, structures and dynamics, and systems analysis and integration. Technology transfer opportunities and success are briefly described. A glossary of abbreviations and acronyms is appended as is a list of contract personnel within the program areas.
Background of the completed research; relevances to solar physics
NASA Technical Reports Server (NTRS)
Sellin, I. A.
1973-01-01
Research activities reported consider the atomic structures of highly stripped heavy ions and their modes of formation and destruction in collisions. The lifetime of the metastable 2 3p1 state of the two electron ion F-7(+) was determined by measuring the radiative decay of an excited helium-like fluorine beam, Metastable state quenching measurements were performed on a helium-like ion to obtain the 1 1S0 to 2 3p2 transition probability. Exponential exchange state dependence of X-ray production cross sections was studied in heavy target atoms during collisions with light charged particles.
Database structure for the Laser Accident and Incident Registry (LAIR)
NASA Astrophysics Data System (ADS)
Ness, James W.; Hoxie, Stephen W.; Zwick, Harry; Stuck, Bruce E.; Lund, David J.; Schmeisser, Elmar T.
1997-05-01
The ubiquity of laser radiation in military, medical, entertainment, telecommunications and research industries and the significant risk, of eye injury from this radiation are firmly established. While important advances have been made in understanding laser bioeffects using animal analogues and clinical data, the relationships among patient characteristics, exposure conditions, severity of the resulting injury, and visual function are fragmented, complex and varied. Although accident cases are minimized through laser safety regulations and control procedures, accumulated accident case information by the laser eye injury evaluation center warranted the development of a laser accident and incident registry. The registry includes clinical data for validating and refining hypotheses on injury and recovery mechanisms; a means for analyzing mechanisms unique to human injury; and a means for identifying future areas of investigation. The relational database supports three major sections: (1) the physics section defines exposure circumstances, (2) the clinical/ophthalmologic section includes fundus and scanning laser ophthalmoscope images, and (3) the visual functions section contains specialized visual function exam results. Tools are available for subject-matter experts to estimate parameters like total intraocular energy, ophthalmic lesion grade, and exposure probability. The database is research oriented to provide a means for generating empirical relationships to identify symptoms for definitive diagnosis and treatment of laser induced eye injuries.
NASA Astrophysics Data System (ADS)
Su, Lilan; Liu, Yanfang; Gao, Xiaoyong
2009-10-01
During the process of economic growth, the industry structure transforms at different developing sections and that industrial composition as well as each department interior demand for land resources would reflect on land-use structure reform. This paper takes Hubei as the research zone, through a consecutive time sequence of 10 years period (1996-2005) just before and after the 1 plus 8 Eastern Hubei Metropolitan Area project, a quantitative study of the correlation between the industry structure and land-use structure is made based on the entropy theory. According to the classification of industrial composition, the land-use structure here is also redefined into four types as Land Use for Primary Industry, Land Use for Secondary Industry, Land Use for Tertiary Industry, and Land Use for Potential Reserve, in the aim that it should model new methods for researching the relationship of industry structure and land-use structure, and the instinct driving force would be presented more evidently at the same time. The outcomes indicate that the change of land-use structure has close relationship with the structure of industry composition; the trend of information entropy in Hubei mostly keeps increasing during the past 10 years which predicating the symmetrical degree of land-use structure is gradually built; and Eastern Hubei Metropolitan Area is of favorable power far superiority other units within province in promoting regional development, yet land-use structure adjustments are still not stable and a optimal mode of land use needs further approach.
Validating metal binding sites in macromolecule structures using the CheckMyMetal web server
Zheng, Heping; Chordia, Mahendra D.; Cooper, David R.; Chruszcz, Maksymilian; Müller, Peter; Sheldrick, George M.
2015-01-01
Metals play vital roles in both the mechanism and architecture of biological macromolecules. Yet structures of metal-containing macromolecules where metals are misidentified and/or suboptimally modeled are abundant in the Protein Data Bank (PDB). This shows the need for a diagnostic tool to identify and correct such modeling problems with metal binding environments. The "CheckMyMetal" (CMM) web server (http://csgid.org/csgid/metal_sites/) is a sophisticated, user-friendly web-based method to evaluate metal binding sites in macromolecular structures in respect to 7350 metal binding sites observed in a benchmark dataset of 2304 high resolution crystal structures. The protocol outlines how the CMM server can be used to detect geometric and other irregularities in the structures of metal binding sites and alert researchers to potential errors in metal assignment. The protocol also gives practical guidelines for correcting problematic sites by modifying the metal binding environment and/or redefining metal identity in the PDB file. Several examples where this has led to meaningful results are described in the anticipated results section. CMM was designed for a broad audience—biomedical researchers studying metal-containing proteins and nucleic acids—but is equally well suited for structural biologists to validate new structures during modeling or refinement. The CMM server takes the coordinates of a metal-containing macromolecule structure in the PDB format as input and responds within a few seconds for a typical protein structure modeled with a few hundred amino acids. PMID:24356774
1981-12-01
instability are several among which some readily identifiable ones are phase trans- formation, relief of residual stresses, and microplastic deformation...selection procedures. ideally, advanced generations of inertial instruments require that induced long-term microplastic strains be maintained at levels...SECTION 2 OBJECTIVES The present objectives of this program are as follows: (1) To survey the literature on microplastic properties of materials and
1980-06-01
instrument. The most common sources of such dimensional instability in instruments are: phase trans- formation, relief of resiiual stress, and microplastic ...the stress or by increasing the resistance of the material to microplastic deformation. Section 3 of this report is concerned with an investigation of...hot isostatically pressed (HIP) beryllium as a material with potentially greater resistance to microplastic deformation than the grades of beryllium
Aerospace Vehicle Design, Spacecraft Section. Volume 3
NASA Technical Reports Server (NTRS)
1988-01-01
Research results are presented for the following groups: Project Mars Airplane Vehicle and Reconnaissance Instrument Carrier (MAVRIC), ACME, ARES, Project ACRONYM, Mars Aircraft Recepticle with Technical Instruments, Aerobraking, and Navigation (MARTIAN), and NOMADS. Each project is described by the following areas of focus: mission planning and costs; aerobraking systems; structures and thermal control systems; attitude and articulation control systems; comman and data control systems; science instrumentation; and power and propulsion systems.
Research on Radiation Effects in Support of the Defense Nuclear Agency
1993-01-01
relationships between pertinent parameters,------------ n. which can guide device design and optimization, aid the inter - CColleclor pretation of results from...Handbook for Stopping Cross Sections for of the parasiti ( npn-structure is the most effective measure to Energetic Ions in all Elements, Vol. 5, Pergamon... inter - actions between collector current, electric field distribution, 35 2262 and avalanche multiplication in the collector depletion region N are
Negotiation Support System’s Impact on the Socio-Emotional Environment: A Research Design Framework
1992-03-01
conflict environment and develop some proposed effects that Negotiation Support Systems (NSS) have on the socio- emotional climate. This introduction of...assessment of current NSS structure, processes and capabilities. Section IV provides a theoretical discussion of conflict and the socio- emotional environment ...model. First, strict economic rationalization does not take into account social/normative issues present --n the negotiation environment . Thus, in an
Naval Research Reviews. Volume XXXIII. Number 2,
1981-01-01
and filler metal addition. ratio weld is a characteristic of a keyhole -produced The most distinctive feature of LB welding , weld . T /h III laser Ii...evolved from these radiation for precision operation, such as hole-drill- efforts include a 3kW CO. laser /workstation system ing, trimming, and welding ...asso- Laser Surface Modifications ciated with thick-section welding of naval structure and surface modification for improved corrosion and The high
Measuring nuclear reaction cross sections to extract information on neutrinoless double beta decay
NASA Astrophysics Data System (ADS)
Cavallaro, M.; Cappuzzello, F.; Agodi, C.; Acosta, L.; Auerbach, N.; Bellone, J.; Bijker, R.; Bonanno, D.; Bongiovanni, D.; Borello-Lewin, T.; Boztosun, I.; Branchina, V.; Bussa, M. P.; Calabrese, S.; Calabretta, L.; Calanna, A.; Calvo, D.; Carbone, D.; Chávez Lomelí, E. R.; Coban, A.; Colonna, M.; D'Agostino, G.; De Geronimo, G.; Delaunay, F.; Deshmukh, N.; de Faria, P. N.; Ferraresi, C.; Ferreira, J. L.; Finocchiaro, P.; Fisichella, M.; Foti, A.; Gallo, G.; Garcia, U.; Giraudo, G.; Greco, V.; Hacisalihoglu, A.; Kotila, J.; Iazzi, F.; Introzzi, R.; Lanzalone, G.; Lavagno, A.; La Via, F.; Lay, J. A.; Lenske, H.; Linares, R.; Litrico, G.; Longhitano, F.; Lo Presti, D.; Lubian, J.; Medina, N.; Mendes, D. R.; Muoio, A.; Oliveira, J. R. B.; Pakou, A.; Pandola, L.; Petrascu, H.; Pinna, F.; Reito, S.; Rifuggiato, D.; Rodrigues, M. R. D.; Russo, A. D.; Russo, G.; Santagati, G.; Santopinto, E.; Sgouros, O.; Solakci, S. O.; Souliotis, G.; Soukeras, V.; Spatafora, A.; Torresi, D.; Tudisco, S.; Vsevolodovna, R. I. M.; Wheadon, R. J.; Yildirin, A.; Zagatto, V. A. B.
2018-02-01
Neutrinoless double beta decay (0vββ) is considered the best potential resource to access the absolute neutrino mass scale. Moreover, if observed, it will signal that neutrinos are their own anti-particles (Majorana particles). Presently, this physics case is one of the most important research “beyond Standard Model” and might guide the way towards a Grand Unified Theory of fundamental interactions. Since the 0vββ decay process involves nuclei, its analysis necessarily implies nuclear structure issues. In the NURE project, supported by a Starting Grant of the European Research Council (ERC), nuclear reactions of double charge-exchange (DCE) are used as a tool to extract information on the 0vββ Nuclear Matrix Elements. In DCE reactions and ββ decay indeed the initial and final nuclear states are the same and the transition operators have similar structure. Thus the measurement of the DCE absolute cross-sections can give crucial information on ββ matrix elements. In a wider view, the NUMEN international collaboration plans a major upgrade of the INFN-LNS facilities in the next years in order to increase the experimental production of nuclei of at least two orders of magnitude, thus making feasible a systematic study of all the cases of interest as candidates for 0vββ.
Peck, Ronald F.; Colton, Shannon; Morris, Jennifer; Chaibub Neto, Elias; Kallio, Julie
2009-01-01
We conducted a controlled investigation to examine whether a combination of computer imagery and tactile tools helps introductory cell biology laboratory undergraduate students better learn about protein structure/function relationships as compared with computer imagery alone. In all five laboratory sections, students used the molecular imaging program, Protein Explorer (PE). In the three experimental sections, three-dimensional physical models were made available to the students, in addition to PE. Student learning was assessed via oral and written research summaries and videotaped interviews. Differences between the experimental and control group students were not found in our typical course assessments such as research papers, but rather were revealed during one-on-one interviews with students at the end of the semester. A subset of students in the experimental group produced superior answers to some higher-order interview questions as compared with students in the control group. During the interview, students in both groups preferred to use either the hand-held models alone or in combination with the PE imaging program. Students typically did not use any tools when answering knowledge (lower-level thinking) questions, but when challenged with higher-level thinking questions, students in both the control and experimental groups elected to use the models. PMID:19255134
Visual memory, the long and the short of it: A review of visual working memory and long-term memory.
Schurgin, Mark W
2018-04-23
The majority of research on visual memory has taken a compartmentalized approach, focusing exclusively on memory over shorter or longer durations, that is, visual working memory (VWM) or visual episodic long-term memory (VLTM), respectively. This tutorial provides a review spanning the two areas, with readers in mind who may only be familiar with one or the other. The review is divided into six sections. It starts by distinguishing VWM and VLTM from one another, in terms of how they are generally defined and their relative functions. This is followed by a review of the major theories and methods guiding VLTM and VWM research. The final section is devoted toward identifying points of overlap and distinction across the two literatures to provide a synthesis that will inform future research in both fields. By more intimately relating methods and theories from VWM and VLTM to one another, new advances can be made that may shed light on the kinds of representational content and structure supporting human visual memory.
Physics of magnetospheric boundary layers
NASA Technical Reports Server (NTRS)
Cairns, I. H.
1993-01-01
The central ideas of this grant are that the magnetospheric boundary layers link disparate regions of the magnetosphere together, and the global behavior of the magnetosphere can be understood only by understanding the linking mechanisms. Accordingly the present grant includes simultaneous research on the global, meso-, and micro-scale physics of the magnetosphere and its boundary layers. These boundary layers include the bow shock, magnetosheath, the plasma sheet boundary layer, and the ionosphere. Analytic, numerical and simulation projects have been performed on these subjects, as well as comparison of theoretical results with observational data. Very good progress has been made, with four papers published or in press and two additional papers submitted for publication during the six month period 1 June - 30 November 1993. At least two projects are currently being written up. In addition, members of the group have given papers at scientific meetings. The further structure of this report is as follows: section two contains brief accounts of research completed during the last six months, while section three describes the research projects intended for the grant's final period.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Roach, Dennis Patrick; Jauregui, David Villegas; Daumueller, Andrew Nicholas
2012-02-01
Recent structural failures such as the I-35W Mississippi River Bridge in Minnesota have underscored the urgent need for improved methods and procedures for evaluating our aging transportation infrastructure. This research seeks to develop a basis for a Structural Health Monitoring (SHM) system to provide quantitative information related to the structural integrity of metallic structures to make appropriate management decisions and ensuring public safety. This research employs advanced structural analysis and nondestructive testing (NDT) methods for an accurate fatigue analysis. Metal railroad bridges in New Mexico will be the focus since many of these structures are over 100 years old andmore » classified as fracture-critical. The term fracture-critical indicates that failure of a single component may result in complete collapse of the structure such as the one experienced by the I-35W Bridge. Failure may originate from sources such as loss of section due to corrosion or cracking caused by fatigue loading. Because standard inspection practice is primarily visual, these types of defects can go undetected due to oversight, lack of access to critical areas, or, in riveted members, hidden defects that are beneath fasteners or connection angles. Another issue is that it is difficult to determine the fatigue damage that a structure has experienced and the rate at which damage is accumulating due to uncertain history and load distribution in supporting members. A SHM system has several advantages that can overcome these limitations. SHM allows critical areas of the structure to be monitored more quantitatively under actual loading. The research needed to apply SHM to metallic structures was performed and a case study was carried out to show the potential of SHM-driven fatigue evaluation to assess the condition of critical transportation infrastructure and to guide inspectors to potential problem areas. This project combines the expertise in transportation infrastructure at New Mexico State University with the expertise at Sandia National Laboratories in the emerging field of SHM.« less
Lewis-Fernández, Roberto; Raggio, Greer A.; Gorritz, Magdaliz; Duan, Naihua; Marcus, Sue; Cabassa, Leopoldo J.; Humensky, Jennifer; Becker, Anne E.; Alarcón, Renato D.; Oquendo, María A.; Hansen, Helena; Like, Robert C.; Weiss, Mitchell; Desai, Prakash N.; Jacobsen, Frederick M.; Foulks, Edward F.; Primm, Annelle; Lu, Francis; Kopelowicz, Alex; Hinton, Ladson; Hinton, Devon E.
2015-01-01
Growing awareness of health and health care disparities highlights the importance of including information about race, ethnicity, and culture (REC) in health research. Reporting of REC factors in research publications, however, is notoriously imprecise and unsystematic. This article describes the development of a checklist to assess the comprehensiveness and the applicability of REC factor reporting in psychiatric research publications. The 16-itemGAP-REACH© checklist was developed through a rigorous process of expert consensus, empirical content analysis in a sample of publications (N = 1205), and interrater reliability (IRR) assessment (N = 30). The items assess each section in the conventional structure of a health research article. Data from the assessment may be considered on an item-by-item basis or as a total score ranging from 0% to 100%. The final checklist has excellent IRR (κ = 0.91). The GAP-REACH may be used by multiple research stakeholders to assess the scope of REC reporting in a research article. PMID:24080673
NASA Astrophysics Data System (ADS)
Štaffenová, Daniela; Rybárik, Ján; Jakubčík, Miroslav
2017-06-01
The aim of experimental research in the area of exterior walls and windows suitable for wooden buildings was to build special pavilion laboratories. These laboratories are ideally isolated from the surrounding environment, airtight and controlled by the constant internal climate. The principle of experimental research is measuring and recording of required physical parameters (e.g. temperature or relative humidity). This is done in layers of experimental fragment sections in the direction from exterior to interior, as well as in critical places by stable interior and real exterior climatic conditions. The outputs are evaluations of experimental structures behaviour during the specified time period, possibly during the whole year by stable interior and real exterior boundary conditions. The main aim of this experimental research is processing of long-term measurements of experimental structures and the subsequent analysis. The next part of the research consists of collecting measurements obtained with assistance of the experimental detached weather station, analysis, evaluation for later setting up of reference data set for the research locality, from the point of view of its comparison to the data sets from Slovak Hydrometeorological Institute (SHMU) and to localities with similar climate conditions. Later on, the data sets could lead to recommendations for design of wooden buildings.
Warming of Monolithic Structures in Winter
NASA Astrophysics Data System (ADS)
Pikus, G. A.; Lebed, A. R.
2017-11-01
The present work attempts to develop a mathematical model for calculating the heat transfer coefficient of the fence of monolithic structures erected in winter. The urgency and, at the same time, the practical significance of the research lies in the fact that to date no simple, effective tool has been developed to ensure the elimination of the unfavorable thermally stressed state of a structure’s concrete from maximum equalization of temperatures across its cross-section. The main problem for concrete is a high temperature which leads to a sharp decrease in the quality of erected structures due to developing cracks. This paper based on the well-known Newton’s law and its differential equation demonstrates the formula of concrete cooling and the analysis of its proportionality coefficient. Based on the literature analysis, it is established that the proportionality coefficient is determined by the thermophysical properties of concrete, the size and shape of the structure, and the intensity of its heat exchange with the surrounding medium. A limitation was used on the temperature gradient over the section of the monolithic structure to derive a formula for calculating the reduced heat transfer coefficient of a concrete fence. All mathematical calculations are given for cooling monolithic constructions in the form of plates. At the end of the work an example is given for the calculation of the required reduced heat transfer coefficient for the fence ensuring compliance with the permissible concrete temperature gradient.
The intrinsic fluorescence of FAD and its application in analytical chemistry: a review
NASA Astrophysics Data System (ADS)
Galbán, Javier; Sanz-Vicente, Isabel; Navarro, Jesús; de Marcos, Susana
2016-12-01
This review (with 106 references) mainly deals with the analytical applications of flavin-adenine dinucleotide (FAD) fluorescence. In the first section, the spectroscopic properties of this compound are reviewed at the light of his different acid-base, oxidation and structural forms; the chemical and spectroscopic properties of flavin mononucleotide (FMN) and other flavins will be also briefly discussed. The second section discusses how the properties of FAD fluorescence changes in flavoenzymes (FvEs), again considering the different chemical and structural forms; the glucose oxidase (GOx) and the choline oxidase (ChOx) cases will be commented. Since almost certainly the most reported analytical application of FAD fluorescence is as an auto-indicator in enzymatic methods catalysed by FvE oxidoreductases, it is important to know how the concentrations of the different forms of FAD changes along the reaction and, consequently, the fluorescence and the analytical signals. An approach to do this will be presented in section 3. The fourth part of the paper compiles the analytical applications which have been reported until now based in these fluorescence properties. Finally, some suggestions about tentative future research are also given.
The intrinsic fluorescence of FAD and its application in analytical chemistry: a review.
Galbán, Javier; Sanz-Vicente, Isabel; Navarro, Jesús; de Marcos, Susana
2016-12-19
This review (with 106 references) mainly deals with the analytical applications of flavin-adenine dinucleotide (FAD) fluorescence. In the first section, the spectroscopic properties of this compound are reviewed at the light of his different acid-base, oxidation and structural forms; the chemical and spectroscopic properties of flavin mononucleotide (FMN) and other flavins will be also briefly discussed. The second section discusses how the properties of FAD fluorescence changes in flavoenzymes (FvEs), again considering the different chemical and structural forms; the glucose oxidase (GOx) and the choline oxidase (ChOx) cases will be commented. Since almost certainly the most reported analytical application of FAD fluorescence is as an auto-indicator in enzymatic methods catalysed by FvE oxidoreductases, it is important to know how the concentrations of the different forms of FAD changes along the reaction and, consequently, the fluorescence and the analytical signals. An approach to do this will be presented in section 3. The fourth part of the paper compiles the analytical applications which have been reported until now based in these fluorescence properties. Finally, some suggestions about tentative future research are also given.
Bagby, R Michael; Widiger, Thomas A
2018-01-01
The Five-Factor Model (FFM) is a dimensional model of general personality structure, consisting of the domains of neuroticism (or emotional instability), extraversion versus introversion, openness (or unconventionality), agreeableness versus antagonism, and conscientiousness (or constraint). The FFM is arguably the most commonly researched dimensional model of general personality structure. However, a notable limitation of existing measures of the FFM has been a lack of coverage of its maladaptive variants. A series of self-report inventories has been developed to assess for the maladaptive personality traits that define Diagnostic and Statistical Manual of Mental Disorders (fifth edition; DSM-5) Section II personality disorders (American Psychiatric Association [APA], 2013) from the perspective of the FFM. In this paper, we provide an introduction to this Special Section, presenting the rationale and empirical support for these measures and placing them in the historical context of the recent revision to the APA diagnostic manual. This introduction is followed by 5 papers that provide further empirical support for these measures and address current issues within the personality assessment literature. (PsycINFO Database Record (c) 2018 APA, all rights reserved).
Half a Century of Hawaiian Marine Natural Products.
Hagiwara, Kehau A; Wright, Anthony D
2016-06-01
The following review covers the primary literature concerning marine natural products isolated for the first time from organisms collected around the islands of Hawaii published in the 51-year period 1964 to July 2015. The review is divided into seven main sections based on major taxonomic groupings; algae, sponges, mollusks, miscellaneous invertebrates, cyanobacteria, bacteria, and fungi. The aim of the review is to discuss the compounds and information concerning their original biological activity and other potentially interesting properties. The majority of the 320 structures of isolated compounds are not shown directly in the review but are contained in the Supporting Information section in 22 figures, Figs. 1 S-22 S. The Supporting Information section also contains Table 1 S that has information relating to the taxonomic identification of the source organism of each compound, collection location of the source organism, a trivial or semi-systematic name for each compound, as well as its general structural class. The authors hope that this review will be the spawning ground for other reviews and the basis for a great deal more research into the marine life found in Hawaiian waters. Georg Thieme Verlag KG Stuttgart · New York.
Liu, Wenbin; Shi, Lizheng; Pong, Raymond W; Dong, Hengjin; Mao, Yiwei; Tang, Meng; Chen, Yingyao
2014-12-01
The aim of this study was to examine the gaps between researchers and policy makers in perceptions and influencing factors of knowledge translation (KT) of health technology assessment (HTA) in China. A sample of 382 HTA researchers and 112 policy makers in China were surveyed using structured questionnaires. The questionnaires contained two sections: perceptions of HTA research and assessments of six-stage KT activities. Wilcoxon rank sum test was applied to compare the differences in these two sections between HTA researchers and policy makers. Multivariate linear regression was performed to explore KT determinants of HTA for researchers and policy makers separately. Policy makers and researchers differed in their perceptions of HTA research in all items except collaboration in research development and presentation of evidence in easy-to-understand language. Significant differences in KT activities existed in all the six stages except academic translation. Regarding KT determinants, close contact between research unit and policy-making department, relevance of HTA to policy making, and importance of HTA on policy making were considered facilitators by both groups. For researchers, practicality of HTA report and presentation of evidence in easy-to-understand language can facilitate KT. Policy makers, on the other hand, considered an overly pedantic nature of HTA research as an obstacle to effective KT. Substantial gaps existed between HTA researchers and policy makers regarding the perceptions of HTA research and KT activities. There are also some differences in KT determinants by these two groups. Enhancing collaboration, promoting practicality and policy relevance of HTA research, and making HTA findings easily understood are likely to further the KT of HTA evidence.
Analysis of a Hybrid Wing Body Center Section Test Article
NASA Technical Reports Server (NTRS)
Wu, Hsi-Yung T.; Shaw, Peter; Przekop, Adam
2013-01-01
The hybrid wing body center section test article is an all-composite structure made of crown, floor, keel, bulkhead, and rib panels utilizing the Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) design concept. The primary goal of this test article is to prove that PRSEUS components are capable of carrying combined loads that are representative of a hybrid wing body pressure cabin design regime. This paper summarizes the analytical approach, analysis results, and failure predictions of the test article. A global finite element model of composite panels, metallic fittings, mechanical fasteners, and the Combined Loads Test System (COLTS) test fixture was used to conduct linear structural strength and stability analyses to validate the specimen under the most critical combination of bending and pressure loading conditions found in the hybrid wing body pressure cabin. Local detail analyses were also performed at locations with high stress concentrations, at Tee-cap noodle interfaces with surrounding laminates, and at fastener locations with high bearing/bypass loads. Failure predictions for different composite and metallic failure modes were made, and nonlinear analyses were also performed to study the structural response of the test article under combined bending and pressure loading. This large-scale specimen test will be conducted at the COLTS facility at the NASA Langley Research Center.
Experimental Research on the Dense CFB's Riser and the Simulation Based on the EMMS Model
NASA Astrophysics Data System (ADS)
Wang, X. Y.; Wang, S. D.; Fan, B. G.; Liao, L. L.; Jiang, F.; Xu, X.; Wu, X. Z.; Xiao, Y. H.
2010-03-01
The flow structure in the CFB (circulating fluidized bed) riser has been investigated. Experimental studies were performed in a cold square section unit with 270 mm×270 mm×10 m. Since the drag force model based on homogeneous two-phase flow such as the Gidaspow drag model could not depict the heterogeneous structures of the gas-solid flow, the structure-dependent energy-minimization multi-scale (EMMS) model based on the heterogenerity was applied in the paper and a revised drag force model based on the EMMS model was proposed. A 2D two-fluid model was used to simulate a bench-scale square cross-section riser of a cold CFB. The typical core-annulus structure and the back-mixing near the wall of the riser were observed and the assembly and fragmentation processes of clusters were captured. By comparing with the Gidaspow drag model, the results obtained by the revised drag model based on EMMS shows better consistency with the experimental data. The model can also depict the difference from the two exit configurations. This study once again proves the key role of drag force in CFD (Computational Fluid Dynamics) simulation and also shows the availability of the revised drag model to describe the gas-solid flow in CFB risers.
Imaging of dental material by polarization-sensitive optical coherence tomography
NASA Astrophysics Data System (ADS)
Dichtl, Sabine; Baumgartner, Angela; Hitzenberger, Christoph K.; Moritz, Andreas; Wernisch, Johann; Robl, Barbara; Sattmann, Harald; Leitgeb, Rainer; Sperr, Wolfgang; Fercher, Adolf F.
1999-05-01
Partial coherence interferometry (PCI) and optical coherence tomography (OCT) are noninvasive and noncontact techniques for high precision biometry and for obtaining cross- sectional images of biologic structures. OCT was initially introduced to depict the transparent tissue of the eye. It is based on interferometry employing the partial coherence properties of a light source with high spatial coherence ut short coherence length to image structures with a resolution of the order of a few microns. Recently this technique has been modified for cross section al imaging of dental and periodontal tissues. In vitro and in vivo OCT images have been recorded, which distinguish enamel, cemento and dentin structures and provide detailed structural information on clinical abnormalities. In contrast to convention OCT, where the magnitude of backscattered light as a function of depth is imaged, polarization sensitive OCT uses backscattered light to image the magnitude of the birefringence in the sample as a function of depth. First polarization sensitive OCT recordings show, that changes in the mineralization status of enamel or dentin caused by caries or non-caries lesions can result in changes of the polarization state of the light backscattered by dental material. Therefore polarization sensitive OCT might provide a new diagnostic imaging modality in clinical and research dentistry.
Photodetachment dynamics in a time-dependent oscillating electric field
NASA Astrophysics Data System (ADS)
Wang, De-hua; Xu, Qin-feng; Du, Jie
2017-03-01
Using the time-dependent form of closed orbit theory, as developed by Haggerty and Delos [M.R. Haggerty, J.B. Delos, Phys. Rev. A 61, 053406 (2000)], and by Yang and Robicheaux [B.C. Yang, F. Robicheaux, Phys. Rev. A 93, 053413 (2016)], we study the photodetachment dynamics of a hydrogen negative ion in a time-dependent oscillating electric field. Compared to the photodetachment in a static electric field, the photodetachment dynamics of a negative ion in the time-dependent oscillating electric field become much more complicated but more interesting. Since the applied electric field is oscillating with time, the photodetachment cross section of the negative ion in the oscillating electric field is time-dependent. In a time-dependent framework, we put forward an analytical formula for calculating the instantaneous photodetachment cross section of this system. Our study suggests that the instantaneous photodetachment cross section exhibits oscillatory structure, which depends sensitively on the frequency of the oscillating electric field. With increasing frequency of the oscillating electric field, the number of closed orbits increases and the oscillatory structure in the photodetachment cross section becomes much more complicated. The connection between the detached electron's closed orbit with the oscillating cross section is analyzed quantitatively. This study provides a clear and intuitive picture for the photodetachment processes of a negative ion in the presence of an oscillating electric field. We hope that our work will be useful in guiding future experimental research.
NASA Technical Reports Server (NTRS)
Soderman, Paul T.; Olsen, Larry E.
1990-01-01
An engineering feasibility study was made of aeroacoustic inserts designed for large-scale acoustic research on aircraft models in the 80 by 120 foot Wind Tunnel at NASA Ames Research Center. The advantages and disadvantages of likely designs were analyzed. Results indicate that the required maximum airspeed leads to the design of a particular insert. Using goals of 200, 150, and 100 knots airspeed, the analysis indicated a 30 x 60 ft open-jet test section, a 40 x 80 ft open jet test section, and a 70 x 100 ft closed test section with enhanced wall lining, respectively. The open-jet inserts would be composed of a nozzle, collector, diffuser, and acoutic wedges incorporated in the existing 80 x 120 test section. The closed test section would be composed of approximately 5 ft acoustic wedges covered by a porous plate attached to the test section walls of the existing 80 x 120. All designs would require a double row of acoustic vanes between the test section and fan drive to attenuate fan noise and, in the case of the open-jet designs, to control flow separation at the diffuser downstream end. The inserts would allow virtually anechoic acoustic studies of large helicopter models, jets, and V/STOL aircraft models in simulated flight. Model scale studies would be necessary to optimize the aerodynamic and acoustic performance of any of the designs. In all designs studied, the existing structure would have to be reinforced. Successful development of acoustically transparent walls, though not strictly necessary to the project, would lead to a porous-wall test section that could be substituted for any of the open-jet designs, and thereby eliminate many aerodynamic and acoustic problems characteristic of open-jet shear layers. The larger size of the facility would make installation and removal of the insert components difficult. Consequently, scheduling of the existing 80 x 120 aerodynamic test section and scheduling of the open-jet test section would likely be made on an annual or longer basis. The enhanced wall-lining insert would likely be permanent. Although the modifications are technically feasible, the economic practicality of the project was not evaluated.
Contribution to the anatomical nomenclature concerning upper limb anatomy.
Kachlik, David; Musil, Vladimir; Baca, Vaclav
2017-04-01
The aim of this article is to revise and extend the existing sections of Terminologia Anatomica dealing with the upper limb structures, which nomenclature belongs to its most neglected and not developing parts, and to justify the use of the proposed anatomical terms in the clinical practice, research, and education. A sample collected from own educational and research experience was matched in the main anatomical textbooks as well as old and recent anatomical journals and compared with four versions of the official Latin anatomical nomenclatures. The authors summarize here 145 terms, completed with their definitions or explanations, concerning both constant and variable (inconstant) morphological structures (bones, joints, muscles, vessels, and nerves) of the pectoral girdle, arm, cubital region, forearm, wrist, and hand, completed with some grammar remarks and several general terms. After a broad discussion on this topic, the Terminologia Anatomica should be revised and extend with the listed terms (or their equivalents).
NASA Technical Reports Server (NTRS)
Siegel, W. H.
1978-01-01
As part of NASA's continuing research into hypersonics and 85 square foot hypersonic wing test section of a proposed hypersonic research airplane was laboratory tested. The project reported on in this paper has carried the hypersonic wing test structure project one step further by testing a single beaded panel to failure. The primary interest was focused upon the buckling characteristics of the panel under pure compression with boundary conditions similar to those found in a wing mounted condition. Three primary phases of analysis are included in the report. These phases include: experimental testing of the beaded panel to failure; finite element structural analysis of the beaded panel with the computer program NASTRAN; a summary of the semiclassical buckling equations for the beaded panel under purely compressive loads. Comparisons between each of the analysis methods are also included.
Jian Receives 2009 F. L. Scarf Award
NASA Astrophysics Data System (ADS)
2010-03-01
Lan Jian has been awarded the AGU F. L. Scarf Award, given annually to recent Ph.D recipients for outstanding dissertation research that contributes directly to solar planetary sciences. Jian's thesis is entitled “Radial evolution of large-scale solar wind structures.” She was formally presented with the award at the Space Physics and Aeronomy section dinner during the 2009 AGU Fall Meeting, held 14-18 December in San Francisco, Calif. Lan Jian received her B.S. in geophysics from University of Science and Technology of China in 2003. She received her M.S. and Ph.D. degrees in geophysics and space physics, under the supervision of Christopher T. Russell, at University of California, Los Angeles in 2006 and 2008, respectively. Her research interests include various structures in the solar wind, their origin and evolution, and their effect on the space environment of planets.
In-plane free vibration analysis of cable arch structure
NASA Astrophysics Data System (ADS)
Zhao, Yueyu; Kang, Houjun
2008-05-01
Cable-stayed arch bridge is a new type of composite bridge, which utilizes the mechanical characters of cable and arch. Based on the supporting members of cable-stayed arch bridge and of erection of arch bridge using of the cantilever construction method with tiebacks, we propose a novel mechanical model of cable-arch structure. In this model, the equations governing vibrations of the cable-arch are derived according to Hamilton's principle for dynamic problems in elastic body under equilibrium state. Then, the program of solving the dynamic governing equations is ultimately established by the transfer matrix method for free vibration of uniform and variable cross-section, and the internal characteristics of the cable-arch are investigated. After analyzing step by step, the research results approve that the program is accurate; meanwhile, the mechanical model and method are both valuable and significant not only in theoretical research and calculation but also in design of engineering.
Cross-Sectional Analysis of Longitudinal Mediation Processes.
O'Laughlin, Kristine D; Martin, Monica J; Ferrer, Emilio
2018-01-01
Statistical mediation analysis can help to identify and explain the mechanisms behind psychological processes. Examining a set of variables for mediation effects is a ubiquitous process in the social sciences literature; however, despite evidence suggesting that cross-sectional data can misrepresent the mediation of longitudinal processes, cross-sectional analyses continue to be used in this manner. Alternative longitudinal mediation models, including those rooted in a structural equation modeling framework (cross-lagged panel, latent growth curve, and latent difference score models) are currently available and may provide a better representation of mediation processes for longitudinal data. The purpose of this paper is twofold: first, we provide a comparison of cross-sectional and longitudinal mediation models; second, we advocate using models to evaluate mediation effects that capture the temporal sequence of the process under study. Two separate empirical examples are presented to illustrate differences in the conclusions drawn from cross-sectional and longitudinal mediation analyses. Findings from these examples yielded substantial differences in interpretations between the cross-sectional and longitudinal mediation models considered here. Based on these observations, researchers should use caution when attempting to use cross-sectional data in place of longitudinal data for mediation analyses.
Structural Test Documentation and Results for the McDonnell Douglas All-Composite Wing Stub Box
NASA Technical Reports Server (NTRS)
Jegley, Dawn C.; Bush, Harold G.
1997-01-01
The results of a series of tests conducted at the NASA Langley Research Center to evaluate the behavior of an all-composite full-scale wing box are presented. The wing stub box is representative of a section of a commercial transport aircraft wing box and was designed and constructed by McDonnell Douglas Aerospace Company as part of the NASA Advanced Composites Technology (ACT) program. Tests were conducted with and without low-speed impact damage and repairs. The structure with nonvisible impact damage carried 140 percent of Design Limit Load prior to failure through an impact site.
Possibilities of the fish pass restoration
NASA Astrophysics Data System (ADS)
Čubanová, Lea
2018-03-01
According to the new elaborated methodology of the Ministry of Environment of the Slovak Republic: Identification of the appropriate fish pass types according to water body typology (2015) each barrier on the river must be passable. On the barriers or structures without fish passes new ones should be design and built and on some water structures with existed but nonfunctional fish passes must be realized reconstruction or restoration of such objects. Assessment should be done in terms of the existing migratory fish fauna and hydraulic conditions. Fish fauna requirements resulting from the ichthyological research of the river section with barrier. Hydraulic conditions must than fulfil these requirements inside the fish pass body.
Detection of lobular structures in normal breast tissue.
Apou, Grégory; Schaadt, Nadine S; Naegel, Benoît; Forestier, Germain; Schönmeyer, Ralf; Feuerhake, Friedrich; Wemmert, Cédric; Grote, Anne
2016-07-01
Ongoing research into inflammatory conditions raises an increasing need to evaluate immune cells in histological sections in biologically relevant regions of interest (ROIs). Herein, we compare different approaches to automatically detect lobular structures in human normal breast tissue in digitized whole slide images (WSIs). This automation is required to perform objective and consistent quantitative studies on large data sets. In normal breast tissue from nine healthy patients immunohistochemically stained for different markers, we evaluated and compared three different image analysis methods to automatically detect lobular structures in WSIs: (1) a bottom-up approach using the cell-based data for subsequent tissue level classification, (2) a top-down method starting with texture classification at tissue level analysis of cell densities in specific ROIs, and (3) a direct texture classification using deep learning technology. All three methods result in comparable overall quality allowing automated detection of lobular structures with minor advantage in sensitivity (approach 3), specificity (approach 2), or processing time (approach 1). Combining the outputs of the approaches further improved the precision. Different approaches of automated ROI detection are feasible and should be selected according to the individual needs of biomarker research. Additionally, detected ROIs could be used as a basis for quantification of immune infiltration in lobular structures. Copyright © 2016 Elsevier Ltd. All rights reserved.
Frontiers, Opportunities, and Challenges in Biochemical and Chemical Catalysis of CO2
DOE Office of Scientific and Technical Information (OSTI.GOV)
Appel, Aaron M.; Bercaw, John E.; Bocarsly, Andrew B.
2013-08-14
Our central premise is that catalytic scientists can learn by studying how these important metabolic processes occur in nature. Complementarily, biochemists can learn by studying how catalytic scientists view these same chemical transformations promoted by synthetic catalysts. From these studies, hypotheses can be developed and tested through manipulation of enzyme structure and by synthesizing simple molecular catalysts to incorporate different structural features of the enzymes. It is hoped that these studies will lead to new and useful concepts in catalyst design for fuel production and utilization. This paper describes the results of a workshop held to explore these concepts inmore » regard to the development of new and more efficient catalytic processes for the conversion of CO2 to a variety of carbon-based fuels. The organization of this overview/review is as follows: 1) The first section briefly explores how interactions between the catalysis and biological communities have been fruitful in developing new catalysts for the reduction of protons to hydrogen, the simplest fuel generation reaction. 2) The second section assesses the state of the art in both biological and chemical reduction of CO2 by two electrons to form either carbon monoxide (CO) or formate (HCOO-). It also attempts to identify common principles between biological and synthetic catalysts and productive areas for future research. 3) The third section explores both biological and chemical processes that result in the reduction of CO2 beyond the level of CO and formate, again seeking to identify common principles and productive areas of future research. 4) The fourth section explores the formation of carbon-carbon bonds in biological and chemical systems in the same vein as the other sections. 5) A fifth section addresses the role of non-redox reactions of CO2 in biological systems and their role in carbon metabolism, with a parallel discussion of chemical systems. 6) In section 6, the topics of electrode modification, photochemical systems, and tandem catalysis are briefly discussed. These areas may be important for developing practical systems for CO2 reduction, and they share the common theme of coupling chemical reactions. 7) Section 7 describes some of the crosscutting activities that are critical for advancing the science underpinning catalyst development. 8) The last section attempts to summarize common issues in biological and chemical catalysis and to identify challenges that must be addressed to achieve practical catalysts that are suitable for the reduction of CO2 to fuels.« less
Nanoscale insights on one- and two-dimensional material structures
NASA Astrophysics Data System (ADS)
Floresca, Herman Carlo
The race for smaller, faster and more efficient devices has led researchers to explore the possibilities of utilizing nanostructures for scaling. These one-dimensional and two-dimensional materials have properties that are attractive for this purpose but are still not well controlled. Control comes with a complete understanding of the materials' electrical, thermal, optical and structural characteristics but is difficult to obtain due to their small scale. This work is intended to help researchers overcome the difficulty in studying nanostructures by providing techniques for analysis and insights of nanostructures that have not been previously available. Two nanostructures were studied: silicon nanowires and graphene. The nanowires were prepared for cross-section transmission electron microscopy (TEM) to discover the effects that controlled oxidation has on the dimensions and shape of the nanowires. Since cross-section TEM is not able to provide information about surface structure, a method for manipulating the wires with orientation control was developed. With this ability, all three orthogonal views of the nanowire were compiled for a comprehensive study on its structure in terms of shape and surface roughness. Graphene was used for a two-dimensional analytical technique that took advantage of customized computer programs for data acquisition, measurement and display. With the information provided, distinctions between grain boundary types in polycrystalline graphene were made and supported by statistical information from the software's output. It was also applied to a growth series of graphene samples in conjunction with scanning electron microscopy (SEM) images and electron backscatter diffraction (EBSD) maps. The results help point to origins of graphene's polycrystalline nature. This dissertation concludes with a thought towards the future by highlighting a method that can help analyze nanostructures, which may become incorporated into the structures of large devices. The fold-out method is a TEM sample preparation technique utilizing a focused ion beam (FIB) for site specific thinning across a large sample area. Its process is demonstrated along with advantages over conventional methods.
Methodologies for Combined Loads Tests Using a Multi-Actuator Test Machine
NASA Technical Reports Server (NTRS)
Rouse, Marshall
2013-01-01
The NASA Langley COmbined Loads Test System (COLTS) Facility was designed to accommodate a range of fuselage structures and wing sections and subject them to both quasistatic and cyclic loading conditions. Structural tests have been conducted in COLTS that address structural integrity issues of metallic and fiber reinforced composite aerospace structures in support of NASA Programs (i.e. the Aircraft Structural Integrity (ASIP) Program, High-Speed-Research program and the Supersonic Project, NASA Engineering and Safety Center (NESC) Composite Crew Module Project, and the Environmentally Responsible Aviation Program),. This paper presents experimental results for curved panels subjected to mechanical and internal pressure loads using a D-box test fixture. Also, results are presented that describe use of a checkout beam for development of testing procedures for a combined mechanical and pressure loading test of a Multi-bay box. The Multi-bay box test will be used to experimentally verify the structural performance of the Multi-bay box in support of the Environmentally Responsible Aviation Project at NASA Langley.
Determining the Mechanical Properties of Lattice Block Structures
NASA Technical Reports Server (NTRS)
Wilmoth, Nathan
2013-01-01
Lattice block structures and shape memory alloys possess several traits ideal for solving intriguing new engineering problems in industries such as aerospace, military, and transportation. Recent testing at the NASA Glenn Research Center has investigated the material properties of lattice block structures cast from a conventional aerospace titanium alloy as well as lattice block structures cast from nickel-titanium shape memory alloy. The lattice block structures for both materials were sectioned into smaller subelements for tension and compression testing. The results from the cast conventional titanium material showed that the expected mechanical properties were maintained. The shape memory alloy material was found to be extremely brittle from the casting process and only compression testing was completed. Future shape memory alloy lattice block structures will utilize an adjusted material composition that will provide a better quality casting. The testing effort resulted in baseline mechanical property data from the conventional titanium material for comparison to shape memory alloy materials once suitable castings are available.
CESAR5.3: Isotopic depletion for Research and Testing Reactor decommissioning
NASA Astrophysics Data System (ADS)
Ritter, Guillaume; Eschbach, Romain; Girieud, Richard; Soulard, Maxime
2018-05-01
CESAR stands in French for "simplified depletion applied to reprocessing". The current version is now number 5.3 as it started 30 years ago from a long lasting cooperation with ORANO, co-owner of the code with CEA. This computer code can characterize several types of nuclear fuel assemblies, from the most regular PWR power plants to the most unexpected gas cooled and graphite moderated old timer research facility. Each type of fuel can also include numerous ranges of compositions like UOX, MOX, LEU or HEU. Such versatility comes from a broad catalog of cross section libraries, each corresponding to a specific reactor and fuel matrix design. CESAR goes beyond fuel characterization and can also provide an evaluation of structural materials activation. The cross-sections libraries are generated using the most refined assembly or core level transport code calculation schemes (CEA APOLLO2 or ERANOS), based on the European JEFF3.1.1 nuclear data base. Each new CESAR self shielded cross section library benefits all most recent CEA recommendations as for deterministic physics options. Resulting cross sections are organized as a function of burn up and initial fuel enrichment which allows to condensate this costly process into a series of Legendre polynomials. The final outcome is a fast, accurate and compact CESAR cross section library. Each library is fully validated, against a stochastic transport code (CEA TRIPOLI 4) if needed and against a reference depletion code (CEA DARWIN). Using CESAR does not require any of the neutron physics expertise implemented into cross section libraries generation. It is based on top quality nuclear data (JEFF3.1.1 for ˜400 isotopes) and includes up to date Bateman equation solving algorithms. However, defining a CESAR computation case can be very straightforward. Most results are only 3 steps away from any beginner's ambition: Initial composition, in core depletion and pool decay scenario. On top of a simple utilization architecture, CESAR includes a portable Graphical User Interface which can be broadly deployed in R&D or industrial facilities. Aging facilities currently face decommissioning and dismantling issues. This way to the end of the nuclear fuel cycle requires a careful assessment of source terms in the fuel, core structures and all parts of a facility that must be disposed of with "industrial nuclear" constraints. In that perspective, several CESAR cross section libraries were constructed for early CEA Research and Testing Reactors (RTR's). The aim of this paper is to describe how CESAR operates and how it can be used to help these facilities care for waste disposal, nuclear materials transport or basic safety cases. The test case will be based on the PHEBUS Facility located at CEA - Cadarache.
Application of Composite Mechanics to Composites Enhanced Concrete Structures
NASA Technical Reports Server (NTRS)
Chamis, Christos C.; Gotsis, Pascal K.
2006-01-01
A new and effective method is described to design composites to repair damage or enhance the overload strength of concrete infrastructures. The method is based on composite mechanics which is available in computer codes. It is used to simulate structural sections made from reinforced concrete which are typical in infrastructure as well as select reinforced concrete structures. The structural sections are represented by a number of layers through the thickness where different layers are used in concrete, and for the composite. The reinforced concrete structures are represented with finite elements where the element stiffness parameters are from the structural sections which are represented by composite mechanics. The load carrying capability of the structure is determined by progressive structural fracture. Results show up to 40 percent improvements for damage and for overload enhancement with relatively small laminate thickness for the structural sections and up to three times for the composite enhanced select structures (arches and domes).
A Microwave Blade Tip Clearance Sensor for Propulsion Health Monitoring
NASA Technical Reports Server (NTRS)
Woike, Mark R.; Abdul-Aziz, Ali; Bencic, Timothy J.
2010-01-01
Microwave sensor technology is being investigated by the NASA Glenn Research Center as a means of making non-contact structural health measurements in the hot sections of gas turbine engines. This type of sensor technology is beneficial in that it is accurate, it has the ability to operate at extremely high temperatures, and is unaffected by contaminants that are present in turbine engines. It is specifically being targeted for use in the High Pressure Turbine (HPT) and High Pressure Compressor (HPC) sections to monitor the structural health of the rotating components. It is intended to use blade tip clearance to monitor blade growth and wear and blade tip timing to monitor blade vibration and deflection. The use of microwave sensors for this application is an emerging concept. Techniques on their use and calibration needed to be developed. As a means of better understanding the issues associated with the microwave sensors, a series of experiments have been conducted to evaluate their performance for aero engine applications. This paper presents the results of these experiments.
A Downloadable Three-Dimensional Virtual Model of the Visible Ear
Wang, Haobing; Merchant, Saumil N.; Sorensen, Mads S.
2008-01-01
Purpose To develop a three-dimensional (3-D) virtual model of a human temporal bone and surrounding structures. Methods A fresh-frozen human temporal bone was serially sectioned and digital images of the surface of the tissue block were recorded (the ‘Visible Ear’). The image stack was resampled at a final resolution of 50 × 50 × 50/100 µm/voxel, registered in custom software and segmented in PhotoShop® 7.0. The segmented image layers were imported into Amira® 3.1 to generate smooth polygonal surface models. Results The 3-D virtual model presents the structures of the middle, inner and outer ears in their surgically relevant surroundings. It is packaged within a cross-platform freeware, which allows for full rotation, visibility and transparency control, as well as the ability to slice the 3-D model open at any section. The appropriate raw image can be superimposed on the cleavage plane. The model can be downloaded at https://research.meei.harvard.edu/Otopathology/3dmodels/ PMID:17124433
Super-resolution structured illumination in optically thick specimens without fluorescent tagging
NASA Astrophysics Data System (ADS)
Hoffman, Zachary R.; DiMarzio, Charles A.
2017-11-01
This research extends the work of Hoffman et al. to provide both sectioning and super-resolution using random patterns within thick specimens. Two methods of processing structured illumination in reflectance have been developed without the need for a priori knowledge of either the optical system or the modulation patterns. We explore the use of two deconvolution algorithms that assume either Gaussian or sparse priors. This paper will show that while both methods accomplish their intended objective, the sparse priors method provides superior resolution and contrast against all tested targets, providing anywhere from ˜1.6× to ˜2× resolution enhancement. The methods developed here can reasonably be implemented to work without a priori knowledge about the patterns or point spread function. Further, all experiments are run using an incoherent light source, unknown random modulation patterns, and without the use of fluorescent tagging. These additional modifications are challenging, but the generalization of these methods makes them prime candidates for clinical application, providing super-resolved noninvasive sectioning in vivo.
Axial Crushing Behaviors of Thin-Walled Corrugated and Circular Tubes - A Comparative Study
NASA Astrophysics Data System (ADS)
Reyaz-Ur-Rahim, Mohd.; Bharti, P. K.; Umer, Afaque
2017-10-01
With the help of finite element analysis, this research paper deals with the energy absorption and collapse behavior with different corrugated section geometries of hollow tubes made of aluminum alloy 6060-T4. Literature available experimental data were used to validate the numerical models of the structures investigated. Based on the results available for symmetric crushing of circular tubes, models were developed to investigate corrugated thin-walled structures behavior. To study the collapse mechanism and energy absorbing ability in axial compression, the simulation was carried in ABAQUS /EXPLICIT code. In the simulation part, specimens were prepared and axially crushed to one-fourth length of the tube and the energy diagram of crushing force versus axial displacement is shown. The effect of various parameters such as pitch, mean diameter, corrugation, amplitude, the thickness is demonstrated with the help of diagrams. The overall result shows that the corrugated section geometry could be a good alternative to the conventional tubes.
Numerical and experimental research on pentagonal cross-section of the averaging Pitot tube
NASA Astrophysics Data System (ADS)
Zhang, Jili; Li, Wei; Liang, Ruobing; Zhao, Tianyi; Liu, Yacheng; Liu, Mingsheng
2017-07-01
Averaging Pitot tubes have been widely used in many fields because of their simple structure and stable performance. This paper introduces a new shape of the cross-section of an averaging Pitot tube. Firstly, the structure of the averaging Pitot tube and the distribution of pressure taps are given. Then, a mathematical model of the airflow around it is formulated. After that, a series of numerical simulations are carried out to optimize the geometry of the tube. The distribution of the streamline and pressures around the tube are given. To test its performance, a test platform was constructed in accordance with the relevant national standards and is described in this paper. Curves are provided, linking the values of flow coefficient with the values of Reynolds number. With a maximum deviation of only ±3%, the results of the flow coefficient obtained from the numerical simulations were in agreement with those obtained from experimental methods. The proposed tube has a stable flow coefficient and favorable metrological characteristics.
Reconsideration of Natural Monuments No. 413 (Mungokri Stromatolite) of Chosun Supergroup, Korea
NASA Astrophysics Data System (ADS)
KONG, Dal Yong; LEE, Seong Joo
2014-05-01
Stromatolite-like structures, so-called "Mungokri Stromatolite", which is located along the cliff of creeks in the vicinity of Oman bridge, Mungok-ri, Yeongwol, Kangweondo was designated as Natural Monument No. 413 in March, 2000. The Mungokri Stromatolite resembles LLH(laterally-linked hemispheroid) type stromatolite, each dome of which is laterally connected forming a stromatolite bed. The Mungokri Stromatolite, however, cannot be regarded as stromatolite because domal structure and fine lamination (the most diagnostic character) cannot be observed both in the field and through the petrological thin section. The smooth surface structure and very thin, irregular cracks characterized in the surface of the Mungokri Stromatolite also differ from those of a normal stromatolite. Such differences strongly suggest that the Mungokri Stromatolite is not a stromatolite but an algal mound. If we take considerations: 1) general lithology and sedimentary structures of Socheong island, 2) observation that angles of columns' inclination are not consistent throughout the stromatolite beds, and that vertical columns are also found in stromatolite beds, 3) igneous intrusion that would have caused structural deformation of sedimentary rocks of Socheong island, the inclination of Socheong stromatolites could be better interpreted as a secondary structural deformation probably after formation of stromatolite columns, rather than as a result of heliotropism. Consequently, renaming of the Mungokri Stromatolite, Natural Monument No. 413, is necessary. [Acknowledgments] This research was financially supported by the National Research Institute of Cultural Heritage.
1982-12-01
generations of inertial instruments require that induced q long-term microplastic strains be maintained at levels substantially lower than 10-6 to 10-7 inch...instability are several, azong which some readily identifiable ones are phase transformation, relief of residual stresses, and microplastic deformation...numbered items in the List of Refprpnces. 2 SECTION 2 OBJECTIVES The present objectives of this program are -Alows: (1) To study the microplastic
1980-12-01
residual stresses, and microplastic deformation from applied stresses. Although effects related to phase transformations and residual stresses can...measuring devices, microplastic strains on the order of 10-6 and 10-7 become significant sources of instrument error. Strains of this order of magnitude...have been possible. 2 SECTION 2 OBJECTIVES The principal objectives of this program have been as follows: (1) To survey the literature on microplastic
2000-11-03
On the Space Shuttle Orbiter Atlantis' middeck, Astronaut Joseph R. Tarner, mission specialist, works at an area amidst several lockers which support the Protein Crystal Growth (PCG) experiment during the STS-66 mission. This particular section is called the Crystal Observation System, housed in the Thermal Enclosure System (COS/TES). Together with the Vapor Diffusion Apparatus (VDA), housed in Single Locker Thermal Enclosure (SLTES), the COS/TES represents the continuing research into the structure of proteins and other macromolecules such as viruses.
The Structure and Dynamics of the Solar Corona
NASA Technical Reports Server (NTRS)
Mikic, Zoran
1998-01-01
Under this contract SAIC, the University of California, Irvine (UCI), and the Jet Propulsion Laboratory (JPL), have conducted research into theoretical modeling of active regions, the solar corona, and the inner heliosphere, using the MHD model. During the period covered by this report we have published 17 articles in the scientific literature. These publications are listed in Section 4 of this report. In the Appendix we have attached reprints of selected articles.
Development of a Dielectric-Loaded Accelerator Test Facility Based on an X-Band Magnicon Amplifier
NASA Astrophysics Data System (ADS)
Gold, S. H.; Kinkead, A. K.; Gai, W.; Power, J. G.; Konecny, R.; Jing, C.; Tantawi, S. G.; Nantista, C. D.; Hu, Y.; Du, X.; Tang, C.; Lin, Y.; Bruce, R. W.; Bruce, R. L.; Fliflet, A. W.; Lewis, D.
2006-01-01
The Naval Research Laboratory (NRL) and Argonne National Laboratory (ANL), in collaboration with the Stanford Linear Accelerator Center (SLAC), are developing a dielectric-loaded accelerator (DLA) test facility powered by the 11.424-GHz magnicon amplifier that was developed jointly by NRL and Omega-P, Inc. Thus far, DLA structures developed by ANL have been tested at the NRL Magnicon Facility without injected electrons, including tests of alumina and magnesium calcium titanate structures at gradients up to ˜8 MV/m. The next step is to inject electrons in order to build a compact DLA test accelerator. The Accelerator Laboratory of Tsinghua University in Beijing, China has developed a 5-MeV electron injector for the accelerator, and SLAC is developing a means to combine the two magnicon output arms, and to drive the injector and an accelerator section with separate control of the power ratio and relative phase. Also, RWBruce Associates, working with NRL, is developing a means to join ceramic tubes to produce long accelerating sections using a microwave brazing process. The installation and commissioning of the first dielectric-loaded test accelerator, including injector, DLA structure, and spectrometer, should take place within the next year.
Sandwich Core Heat-Pipe Radiator for Power and Propulsion Systems
NASA Technical Reports Server (NTRS)
Gibson, Marc; Sanzi, James; Locci, Ivan
2013-01-01
Next-generation heat-pipe radiator technologies are being developed at the NASA Glenn Research Center to provide advancements in heat-rejection systems for space power and propulsion systems. All spacecraft power and propulsion systems require their waste heat to be rejected to space in order to function at their desired design conditions. The thermal efficiency of these heat-rejection systems, balanced with structural requirements, directly affect the total mass of the system. Terrestrially, this technology could be used for thermal control of structural systems. One potential use is radiant heating systems for residential and commercial applications. The thin cross section and efficient heat transportability could easily be applied to flooring and wall structures that could evenly heat large surface areas. Using this heat-pipe technology, the evaporator of the radiators could be heated using any household heat source (electric, gas, etc.), which would vaporize the internal working fluid and carry the heat to the condenser sections (walls and/or floors). The temperature could be easily controlled, providing a comfortable and affordable living environment. Investigating the appropriate materials and working fluids is needed to determine this application's potential success and usage.
Advanced structural optimization of a heliostat with cantilever arms
NASA Astrophysics Data System (ADS)
Bogdanov, Dimitar; Zlatanov, Hristo
2016-05-01
The weight of the support structure of heliostats, CPV and PV trackers is important cost element of a solar plant and reducing it will improve the economic viability of a solar project. Heliostats with rectangular area (1 to 5 in 1 m² steps; 5 to 150 in 5 m² steps) and aspect ratios (0.5, 1.0, 1.2, 1.5, 2.0) were investigated under various winds speeds (0, 5 to 100 in 5 m/s steps), wind direction (0 to 180° in 15° steps) and elevation positions (0 to 90° in 10° steps). Each load case was run with three different cantilever arms. The inclination angle of the chords and bracings was chosen so as to fulfill the geometrical boundary condition. Stress and buckling validations were performed according to Eurocode. The results of research carried out can be used to determine the specific weight of a heliostat in kg/m² as a function of the wind speed, tracker area and tracker aspect ratio. Future work should investigate the impact of using cold formed structural hollow sections and cross sections with thinner wall thickness which is not part of EN 10210.
Directly connected heat exchanger tube section and coolant-cooled structure
Chainer, Timothy J.; Coico, Patrick A.; Graybill, David P.; Iyengar, Madhusudan K.; Kamath, Vinod; Kochuparambil, Bejoy J.; Schmidt, Roger R.; Steinke, Mark E.
2015-09-15
A method is provided for fabricating a cooling apparatus for cooling an electronics rack, which includes an air-to-liquid heat exchanger, one or more coolant-cooled structures, and a tube. The heat exchanger is associated with the electronics rack and disposed to cool air passing through the rack, includes a plurality of coolant-carrying tube sections, each tube section having a coolant inlet and outlet, one of which is coupled in fluid communication with a coolant loop to facilitate flow of coolant through the tube section. The coolant-cooled structure(s) is in thermal contact with an electronic component(s) of the rack, and facilitates transfer of heat from the component(s) to the coolant. The tube connects in fluid communication one coolant-cooled structure and the other of the coolant inlet or outlet of the one tube section, and facilitates flow of coolant directly between that coolant-carrying tube section of the heat exchanger and the coolant-cooled structure.
Directly connected heat exchanger tube section and coolant-cooled structure
Chainer, Timothy J; Coico, Patrick A; Graybill, David P; Iyengar, Madhusudan K; Kamath, Vinod; Kochuparambil, Bejoy J; Schmidt, Roger R; Steinke, Mark E
2014-04-01
A cooling apparatus for an electronics rack is provided which includes an air-to-liquid heat exchanger, one or more coolant-cooled structures and a tube. The heat exchanger, which is associated with the electronics rack and disposed to cool air passing through the rack, includes a plurality of distinct, coolant-carrying tube sections, each tube section having a coolant inlet and a coolant outlet, one of which is coupled in fluid communication with a coolant loop to facilitate flow of coolant through the tube section. The coolant-cooled structure(s) is in thermal contact with an electronic component(s) of the rack, and facilitates transfer of heat from the component(s) to the coolant. The tube connects in fluid communication one coolant-cooled structure and the other of the coolant inlet or outlet of the one tube section, and facilitates flow of coolant directly between that coolant-carrying tube section of the heat exchanger and the coolant-cooled structure.
NASA Technical Reports Server (NTRS)
Ko, William L.; Gong, Leslie
2001-01-01
Heat transfer, thermal stresses, and thermal buckling analyses were performed on the unconventional wing structures of a Hyper-X hypersonic flight research vehicle (designated as X-43) subjected to nominal Mach 7 aerodynamic heating. A wing midspan cross section was selected for the heat transfer and thermal stress analyses. Thermal buckling analysis was performed on three regions of the wing skin (lower or upper); 1) a fore wing panel, 2) an aft wing panel, and 3) a unit panel at the middle of the aft wing panel. A fourth thermal buckling analysis was performed on a midspan wing segment. The unit panel region is identified as the potential thermal buckling initiation zone. Therefore, thermal buckling analysis of the Hyper-X wing panels could be reduced to the thermal buckling analysis of that unit panel. "Buckling temperature magnification factors" were established. Structural temperature-time histories are presented. The results show that the concerns of shear failure at wing and spar welded sites, and of thermal buckling of Hyper-X wing panels, may not arise under Mach 7 conditions.
Shi, Bitao; Bourne, Jennifer; Harris, Kristen M
2011-03-01
Serial section electron microscopy (ssEM) is rapidly expanding as a primary tool to investigate synaptic circuitry and plasticity. The ultrastructural images collected through ssEM are content rich and their comprehensive analysis is beyond the capacity of an individual laboratory. Hence, sharing ultrastructural data is becoming crucial to visualize, analyze, and discover the structural basis of synaptic circuitry and function in the brain. We devised a web-based management system called SynapticDB (http://synapses.clm.utexas.edu/synapticdb/) that catalogues, extracts, analyzes, and shares experimental data from ssEM. The management strategy involves a library with check-in, checkout and experimental tracking mechanisms. We developed a series of spreadsheet templates (MS Excel, Open Office spreadsheet, etc) that guide users in methods of data collection, structural identification, and quantitative analysis through ssEM. SynapticDB provides flexible access to complete templates, or to individual columns with instructional headers that can be selected to create user-defined templates. New templates can also be generated and uploaded. Research progress is tracked via experimental note management and dynamic PDF forms that allow new investigators to follow standard protocols and experienced researchers to expand the range of data collected and shared. The combined use of templates and tracking notes ensures that the supporting experimental information is populated into the database and associated with the appropriate ssEM images and analyses. We anticipate that SynapticDB will serve future meta-analyses towards new discoveries about the composition and circuitry of neurons and glia, and new understanding about structural plasticity during development, behavior, learning, memory, and neuropathology.
NASA Astrophysics Data System (ADS)
Gomez-Diaz, Juan Sebastian
This PhD. dissertation presents a multidisciplinary work, which involves the development of different novel formulations applied to the accurate and efficient analysis of a wide variety of new structures, devices, and phenomena at themicrowave frequency region. The objectives of the present work can be divided into three main research lines: (1) The first research line is devoted to the Green's function analysis of multilayered enclosures with convex arbitrarily-shaped cross section. For this purpose, three accurate spatial-domain formulations are developed at the Green's functions level. These techniques are then efficiently incorporated into a mixed-potential integral equation framework, which allows the fast and accurate analysis of multilayered printed circuits in shielded enclosures. The study of multilayered shielded circuits has lead to the development of the novel hybridwaveguide-microstrip filter technology, which is light, compact, low-loss and presents important advantages for the space industry. (2) The second research line is related to the impulse-regime study ofmetamaterial-based composite right/left-handed (CRLH) structures and the subsequent theoretical and practical demonstration of several novel optically-inspired phenomena and applications at microwaves, in both, the guided and the radiative region. This study allows the development of new devices for ultra wide band and high data-rate communications systems. Besides, this research line also deals with the simple and accurate characterization of CRLH leaky-wave antennas using transmission line theory. (3) The third and last research line presents a novel CRLH parallel-plate waveguide leaky-wave antenna structure, and a rigorous iterative modal-based technique for its fast and complete characterization, including a systematic calculation of the antenna physical dimensions. It is important to point out that all the theoretical developments and novel structures presented in thiswork have been numerically confirmed, by the use of both, home-made software and commercial full-wave simulations, and experimentally verified, by the use of measurements from fabricated prototypes.
Research progress at the Slow Positron Facility in the Institute of Materials Structure Science, KEK
NASA Astrophysics Data System (ADS)
Hyodo, T.; Wada, K.; Mochizuki, I.; Kimura, M.; Toge, N.; Shidara, T.; Fukaya, Y.; Maekawa, M.; Kawasuso, A.; Iida, S.; Michishio, K.; Nagashima, Y.
2017-01-01
Recent results at the Slow Positron Facility (SPF), Institute of Materials Structure Science (IMSS), KEK are reported. Studies using the total-reflection high-energy positron diffraction (TRHEPD) station revealed the structures of rutile-TiO2(110) (1×2), graphene on Cu (111) and Co (0001), and germanene on Al (111). First observations of the shape resonance in the Ps- photodetachment process were made using the positronium negative ion (Ps-) station. Experiments using the positronium time-of-flight (Ps-TOF) station showed significant enhancement of the Ps formation efficiency and the energy loss in the Ps formation-emission process. A pulse-stretching section has been implemented, which stretches the positron pulse width from 1.2 μs up to almost 20 ms.
Micromirror structured illumination microscope for high-speed in vivo drosophila brain imaging.
Masson, A; Pedrazzani, M; Benrezzak, S; Tchenio, P; Preat, T; Nutarelli, D
2014-01-27
Genetic tools and especially genetically encoded fluorescent reporters have given a special place to optical microscopy in drosophila neurobiology research. In order to monitor neural networks activity, high speed and sensitive techniques, with high spatial resolution are required. Structured illumination microscopies are wide-field approaches with optical sectioning ability. Despite the large progress made with the introduction of the HiLo principle, they did not meet the criteria of speed and/or spatial resolution for drosophila brain imaging. We report on a new implementation that took advantage of micromirror matrix technology to structure the illumination. Thus, we showed that the developed instrument exhibits a spatial resolution close to that of confocal microscopy but it can record physiological responses with a speed improved by more than an order a magnitude.
Synthesis of energy-efficient FSMs implemented in PLD circuits
NASA Astrophysics Data System (ADS)
Nawrot, Radosław; Kulisz, Józef; Kania, Dariusz
2017-11-01
The paper presents an outline of a simple synthesis method of energy-efficient FSMs. The idea consists in using local clock gating to selectively block the clock signal, if no transition of a state of a memory element is required. The research was dedicated to logic circuits using Programmable Logic Devices as the implementation platform, but the conclusions can be applied to any synchronous circuit. The experimental section reports a comparison of three methods of implementing sequential circuits in PLDs with respect to clock distribution: the classical fully synchronous structure, the structure exploiting the Enable Clock inputs of memory elements, and the structure using clock gating. The results show that the approach based on clock gating is the most efficient one, and it leads to significant reduction of dynamic power consumed by the FSM.
AAPG-SEPM Gulf of Mexico type-well project
DOE Office of Scientific and Technical Information (OSTI.GOV)
Slatt, R.M.; Christopher, R.C.; Katz, B.J.
1992-12-01
In 1991, The American Association of Petroleum Geologists (AAPG) published a regional stratigraphic cross section and accompanying seismic line that extends from the south flank of the Ouachita tectonic belt in southern Arkansas (lat. 34.15'N) to south of the 28th parallel in the High Island area, South Addition Block of offshore Gulf of Mexico. The cross section shows chronostratigraphic correlations, lithostratigraphy, and generalized structural relations common to the central Gulf Coast and mid-continent region. The section has been published in three large sheets, each representing approximately 425 statue mi of geographic coverage. As an outgrowth of this project, AAPG, jointlymore » with the Society of Sedimentary Geology (SEPM), organized and sponsored a project through their respective Research Committees on biostratigraphic, lithostratigraphic, and organic geochemical analyses of cuttings from key wells tied to the cross section. Separate splits of samples were sent to volunteers for the following analyses: (1) binocular microscope lithology analysis, (2) detailed biostratigraphy, (3) organic geochemistry, and (4) clay mineralogy by x-ray diffraction (XRD).« less
Initial Assessment of X-Ray Computer Tomography image analysis for material defect microstructure
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kane, Joshua James; Windes, William Enoch
2016-06-01
The original development work leading to this report was focused on the non destructive three-dimensional (3-D) characterization of nuclear graphite as a means to better understand the nature of the inherent pore structure. The pore structure of graphite and its evolution under various environmental factors such as irradiation, mechanical stress, and oxidation plays an important role in their observed properties and characteristics. If we are to transition from an empirical understanding of graphite behavior to a truly predictive mechanistic understanding the pore structure must be well characterized and understood. As the pore structure within nuclear graphite is highly interconnected andmore » truly 3-D in nature, 3-D characterization techniques are critical. While 3-D characterization has been an excellent tool for graphite pore characterization, it is applicable to a broad number of materials systems over many length scales. Given the wide range of applications and the highly quantitative nature of the tool, it is quite surprising to discover how few materials researchers understand and how valuable of a tool 3-D image processing and analysis can be. Ultimately, this report is intended to encourage broader use of 3 D image processing and analysis in materials science and engineering applications, more specifically nuclear-related materials applications, by providing interested readers with enough familiarity to explore its vast potential in identifying microstructure changes. To encourage this broader use, the report is divided into two main sections. Section 2 provides an overview of some of the key principals and concepts needed to extract a wide variety of quantitative metrics from a 3-D representation of a material microstructure. The discussion includes a brief overview of segmentation methods, connective components, morphological operations, distance transforms, and skeletonization. Section 3 focuses on the application of concepts from Section 2 to relevant materials at Idaho National Laboratory. In this section, image analysis examples featuring nuclear graphite will be discussed in detail. Additionally, example analyses from Transient Reactor Test Facility low-enriched uranium conversion, Advanced Gas Reactor like compacts, and tristructural isotopic particles are shown to give a broader perspective of the applicability to relevant materials of interest.« less
A Modular Hierarchical Approach to 3D Electron Microscopy Image Segmentation
Liu, Ting; Jones, Cory; Seyedhosseini, Mojtaba; Tasdizen, Tolga
2014-01-01
The study of neural circuit reconstruction, i.e., connectomics, is a challenging problem in neuroscience. Automated and semi-automated electron microscopy (EM) image analysis can be tremendously helpful for connectomics research. In this paper, we propose a fully automatic approach for intra-section segmentation and inter-section reconstruction of neurons using EM images. A hierarchical merge tree structure is built to represent multiple region hypotheses and supervised classification techniques are used to evaluate their potentials, based on which we resolve the merge tree with consistency constraints to acquire final intra-section segmentation. Then, we use a supervised learning based linking procedure for the inter-section neuron reconstruction. Also, we develop a semi-automatic method that utilizes the intermediate outputs of our automatic algorithm and achieves intra-segmentation with minimal user intervention. The experimental results show that our automatic method can achieve close-to-human intra-segmentation accuracy and state-of-the-art inter-section reconstruction accuracy. We also show that our semi-automatic method can further improve the intra-segmentation accuracy. PMID:24491638
24 CFR 3285.802 - Structural interconnection of multi-section homes.
Code of Federal Regulations, 2011 CFR
2011-04-01
...-section homes. 3285.802 Section 3285.802 Housing and Urban Development Regulations Relating to Housing and..., DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT MODEL MANUFACTURED HOME INSTALLATION STANDARDS Exterior and Interior Close-Up § 3285.802 Structural interconnection of multi-section homes. (a) For multi-section homes...
24 CFR 3285.802 - Structural interconnection of multi-section homes.
Code of Federal Regulations, 2010 CFR
2010-04-01
...-section homes. 3285.802 Section 3285.802 Housing and Urban Development Regulations Relating to Housing and..., DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT MODEL MANUFACTURED HOME INSTALLATION STANDARDS Exterior and Interior Close-Up § 3285.802 Structural interconnection of multi-section homes. (a) For multi-section homes...
24 CFR 3285.802 - Structural interconnection of multi-section homes.
Code of Federal Regulations, 2013 CFR
2013-04-01
...-section homes. 3285.802 Section 3285.802 Housing and Urban Development Regulations Relating to Housing and..., DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT MODEL MANUFACTURED HOME INSTALLATION STANDARDS Exterior and Interior Close-Up § 3285.802 Structural interconnection of multi-section homes. (a) For multi-section homes...
NASA Astrophysics Data System (ADS)
Abdelatty, M. Y.; Badr, M. M.; Swillam, M. A.
2018-03-01
Using transparent conducting oxides (TCOs), like indium-tin-oxide (ITO), for optical modulation attracted research interest because of their epsilon-near-zero (ENZ) characteristics at telecom wavelengths. Utilizing indium-tin-oxide (ITO) in multilayer structure modulators, optical absorption of the active ITO layer can be electrically modulated over a large spectrum range. Although they show advances over common silicon electro-optical modulators (EOMs), they suffer from high insertion losses. To reduce insertion losses and device footprints without sacrificing bandwidth and modulation strength, slot waveguides are promising options because of their high optical confinement. In this paper, we present the study and the design of an electro-optical absorption modulator based on electrically tuning ITO carrier density inside a MOS structure. The device structure is based on dielectric slot waveguide with an ITO plasmonic waveguide modulation section. By changing the dimensions, the effective refractive indices for the slot mode and the off-sate mode of the plasmonic section can be matched. When applying electric field to the plasmonic section (on-state), carriers are generated at the ITO-dielectric interface that result in changing the layer where the electric field is confined from a transparent layer into a lossy layer. A finite difference time domain method with perfect matching layer (PML) absorbing boundary conditions is taken up to simulate and analyze this design. An extinction ratio of 2.3 dB is achieved for a 1-μm-short modulation section, at the telecommunications wavelength (1.55 μm). This EOM has advantages of simple design, easy fabrication, compact size, compatibility with existing silicon photonics platforms, as well as broadband performance.
Ultrasonic guided waves in eccentric annular pipes
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pattanayak, Roson Kumar; Balasubramaniam, Krishnan; Rajagopal, Prabhu
2014-02-18
This paper studies the feasibility of using ultrasonic guided waves to rapidly inspect tubes and pipes for possible eccentricity. While guided waves are well established in the long range inspection of structures such as pipes and plates, studies for more complex cross sections are limited and analytical solutions are often difficult to obtain. Recent developments have made the Semi Analytical Finite Element (SAFE) method widely accessible for researchers to study guided wave properties in complex structures. Here the SAFE method is used to study the effect of eccentricity on the modal structures and velocities of lower order guided wave modesmore » in thin pipes of diameters typically of interest to the industry. Results are validated using experiments. The paper demonstrates that even a small eccentricity in the pipe can strongly affect guided wave mode structures and velocities and hence shows potential for pipe eccentricity inspection.« less
DiBartolo, Patricia Marten; Rendón, María José
2012-04-01
Although the bulk of the research literature on the construct of perfectionism and its relationship to mental health in the last 20 years has focused predominantly on Caucasian American samples, researchers are paying increasing attention to understanding perfectionism's dimensions across ethnicities. Given this momentum, the purpose of this paper is to use a cross-cultural framework to review published studies assessing perfectionism in members of an ethnic minority group living in the United States. Research to date has focused exclusively on Asian and African American samples and we organize our review by separating this literature into those studies that use level and structure-oriented cross-cultural approaches. Structure-oriented approaches empirically explore the phenomenology and/or correlates of perfectionism within each ethnic group whereas level-oriented approaches examine the relative magnitude of perfectionism's levels across groups. The last section of the review critically examines the strength of the evidence in support of researchers' arguments that certain sociocultural factors, such as collectivism and parenting style, influence perfectionism's expression and implications for ethnic minorities. Throughout the review, we offer a series of steps researchers can take to foster our understanding of perfectionism and its impacts using a cross-cultural perspective. Copyright © 2011 Elsevier Ltd. All rights reserved.
Structural Configuration Systems Analysis for Advanced Aircraft Fuselage Concepts
NASA Technical Reports Server (NTRS)
Mukhopadhyay, Vivek; Welstead, Jason R.; Quinlan, Jesse R.; Guynn, Mark D.
2016-01-01
Structural configuration analysis of an advanced aircraft fuselage concept is investigated. This concept is characterized by a double-bubble section fuselage with rear mounted engines. Based on lessons learned from structural systems analysis of unconventional aircraft, high-fidelity finite-element models (FEM) are developed for evaluating structural performance of three double-bubble section configurations. Structural sizing and stress analysis are applied for design improvement and weight reduction. Among the three double-bubble configurations, the double-D cross-section fuselage design was found to have a relatively lower structural weight. The structural FEM weights of these three double-bubble fuselage section concepts are also compared with several cylindrical fuselage models. Since these fuselage concepts are different in size, shape and material, the fuselage structural FEM weights are normalized by the corresponding passenger floor area for a relative comparison. This structural systems analysis indicates that an advanced composite double-D section fuselage may have a relative structural weight ratio advantage over a conventional aluminum fuselage. Ten commercial and conceptual aircraft fuselage structural weight estimates, which are empirically derived from the corresponding maximum takeoff gross weight, are also presented and compared with the FEM- based estimates for possible correlation. A conceptual full vehicle FEM model with a double-D fuselage is also developed for preliminary structural analysis and weight estimation.
Seismic Structural Setting of Western Farallon Basin, Southern Gulf of California, Mexico.
NASA Astrophysics Data System (ADS)
Pinero-Lajas, D.; Gonzalez-Fernandez, A.; Lopez-Martinez, M.; Lonsdale, P.
2007-05-01
Data from a number of high resolution 2D multichannel seismic (MCS) lines were used to investigate the structure and stratigraphy of the western Farallon basin in the southern Gulf of California. A Generator-Injector air gun provided a clean seismic source shooting each 12 s at a velocity of 6 kts. Each signal was recorded during 6- 8 s, at a sampling interval of 1 ms, by a 600 m long digital streamer with 48 channels and a spacing of 12.5 m. The MCS system was installed aboard CICESE's (Centro de Investigacion Cientifica y de Educacion Superior de Ensenada) 28 m research vessel Francisco de Ulloa. MCS data were conventionally processed, to obtain post- stack time-migrated seismic sections. The MCS seismic sections show a very detailed image of the sub-bottom structure up to 2-3 s two-way travel time (aprox. 2 km). We present detailed images of faulting based on the high resolution and quality of these data. Our results show distributed faulting with many active and inactive faults. Our study also constrains the depth to basement near the southern Baja California eastern coast. The acoustic basement appears as a continuous feature in the western part of the study area and can be correlated with some granite outcrops located in the southern Gulf of California islands. To the East, near the center of the Farallon basin, the acoustic basement changes, it is more discontinuous, and the seismic sections show a number of diffracted waves.
Examining non-structural retrofitting status of teaching hospitals in Kerman against disasters.
Moghadam, Mahmood Nekooi; Moradi, Seyed Mobin; Amiresmaili, Mohammadreza
2017-05-01
Continuous services provision of a hospital before and after a disaster is one of the most prominent issues that all people, especially the authorities must take into huge consideration. Concerning the experiences of previous earthquakes, the role and importance of nonstructural components becomes increasingly clear in the uninterrupted services of hospitals. In this study, non-structural retrofitting status of Kerman teaching hospitals was evaluated against natural disasters. This cross-sectional study was carried out in the second half of 2014 on the teaching hospitals in Kerman (Iran). The study population consisted of all Kerman teaching hospitals. The research instrument was World Health Organization/Pan American Health Organization (WHO/PAHO) standard checklist. Data analysis was carried out using descriptive statistics through SPSS 19. One hospital had a low retrofitting level, two hospitals had an average level and one had a high level. In the examined hospitals in this study, the medical gas section had the lowest preparedness against natural disasters, while the office, warehouse and furniture section had the highest resistance. Generally, the non-structural retrofitting status was 50% in one hospital and was between 65% and 85% in other hospitals. Generally, the retrofitting status of hospitals was not at the ideal condition, most hospitals were in average condition. Concerning the high risk of hospitals in disasters, it is necessary that senior executives and managers of Kerman Province and Kerman University of Medical Sciences take some measures to retrofit these buildings and to reduce the risk of vulnerability.
Becker, Stephen P; Marshall, Stephen A; McBurnett, Keith
2014-01-01
There has recently been a resurgence of interest in Sluggish Cognitive Tempo (SCT) as an important construct in the field of abnormal child psychology. Characterized by drowsiness, daydreaming, lethargy, mental confusion, and slowed thinking/behavior, SCT has primarily been studied as a feature of Attention-Deficit/Hyperactivity Disorder (ADHD), and namely the predominately inattentive subtype/presentation. Although SCT is strongly associated with ADHD inattention, research increasingly supports the possibility that SCT is distinct from ADHD or perhaps a different mental health condition altogether, with unique relations to child and adolescent psychosocial adjustment. This introductory article to the Special Section on SCT provides an historical overview of the SCT construct and briefly describes the contributions of the eight empirical papers included in the Special Section. Given the emerging importance of SCT for abnormal psychology and clinical science, there is a clear need for additional studies that examine (1) the measurement, structure, and multidimensional nature of SCT, (2) SCT as statistically distinct from not only ADHD-inattention but also other psychopathologies (particularly depression and anxiety), (3) genetic and environmental contributions to the development of SCT symptoms, and (4) functional impairments associated with SCT. This Special Section brings together papers to advance the current knowledge related to these issues as well as to spur research in this exciting and expanding area of abnormal psychology.
NASA Astrophysics Data System (ADS)
Liu, Dongrun; Lu, Zhaijun; Zhong, Mu; Cao, Tianpei; Chen, Dong; Xiong, Yupu
2018-02-01
Assessment of the vibration of high-speed trains negotiating complex sections of terrain under strong wind conditions is very important for research into the operation safety and comfort of passengers on high-speed trains. To assess the vibration of high-speed trains negotiating complex sections of terrain under strong wind conditions, we performed a field measurement when the train passes through typical sections of complex terrain along the Lanzhou-Xinjiang high-speed railway in China. We selected the lateral vibration conditions, including the roll angle and lateral displacement of car-body gravity centre through two typical representative sections (embankment-tunnel-embankment and embankment-rectangular transition-cutting) for analysis. The results show that the severe car-swaying phenomenon occurs when the high-speed train moves through the test section, and the car-body lateral vibration characteristic is related significantly to the state of the terrain and topography along the railway. The main causes for this car-swaying phenomenon may be the transitions between different windproof structures, and the greater the scale of the transition region between different windproof structures or landform changes, the more obvious the car-swaying phenomenon becomes. The lateral vibration of the car-body is relatively steady when the train is running through terrain with minor changes in topography, such as the windbreak installed on the bridge and embankment, but the tail car sways more violently than the head car. When the vehicle runs from the windbreak installed on the embankment into the tunnel (or in the opposite direction), the tail car sways more intensely than the head car, and the head car runs relatively stable in the tunnel.
Industry liaison section implementation plan
NASA Technical Reports Server (NTRS)
Lakowske, Stephen
1990-01-01
The Industry Liaison Section is a new function of the Army/NASA Aircrew-Aircraft Integration (AAAI) Program that is intended to bridge an existing gap between Government developers (including contractors) and outside organizations who are potential users of products and services developed by the AAAI Program. Currently in its sixth year, the Program is experiencing considerable pull from industry and other government organizations to disseminate products. Since the AAAI Program's charter is exploratory and research in nature, and satisfying proper dissemination requirements is in conflict with the rapid prototyping approach utilized by the design team, the AAAI Program has elected to create an Industry Liaison Section (ILS) to serve as the Program's technology transfer focal point. The process by which the ILS may be established, organized and managed is described, including the baseline organizational structure, duties, functions, authority, responsibilities, relations and policies and procedures relevant to the conduct of the ILS.
Behaviour of thin-walled cold-formed steel members in eccentric compression
NASA Astrophysics Data System (ADS)
Ungureanu, Viorel; Kotełko, Maria; Borkowski, Łukasz; Grudziecki, Jan
2018-01-01
Thin-walled cold-formed steel structures are usually made of members of class 4 cross-sections. Since these sections are prematurely prone to local or distortional buckling and due to the fact they do not have a real post-elastic capacity, the failure at ultimate stage of those members, either in compression or bending, always occurs by forming a local plastic mechanism. The present paper investigates the evolution of the plastic mechanisms and the possibility to use them to characterise the ultimate strength of short thin-walled cold-formed steel members subjected to eccentric compression about minor axis, particularly for members with lipped channel cross-section. Five different types of plastic mechanisms for members in compression with different eccentricities are identified and examined on the basis of FE numerical simulations. Preliminary results of experimental validation of numerical results are presented. The research is based on previous studies and some new investigations of the authors.
Microstructures and mechanical properties of Ti5553 alloy processed by high-pressure torsion
NASA Astrophysics Data System (ADS)
Jiang, B. Z.; Emura, S.; Tsuchiya, K.
2014-08-01
In the present research, the effects of high-pressure torsion (HPT) processing on the microstructure and mechanical properties of Ti-5Al-5Mo-5V-3Cr (Ti5553) alloy were studied. HPT processing produced a white etching layer (WEL) in the middle section of the cross-section and numerous shear bands in the surface region of the cross-section. And the thickness of the WEL increased with increasing the HPT revolutions. TEM observation of the WEL revealed an ultrafine-grained structure with high degree of lattice distortions. The mechanical properties measurements showed that the hardness and ultimate tensile strength increased by HPT processing, accompanied with a decrease in the elongation to failure. It is considered that the mechanical properties of HPT processed Ti5553 alloy are mostly dominated by the shear banded region and the WEL where have the finest grain size and high density of dislocations.
Finite element analysis of composite beam-to-column connection with cold-formed steel section
NASA Astrophysics Data System (ADS)
Firdaus, Muhammad; Saggaff, Anis; Tahir, Mahmood Md
2017-11-01
Cold-formed steel (CFS) sections are well known due to its lightweight and high structural performance which is very popular for building construction. Conventionally, they are used as purlins and side rails in the building envelopes of the industrial buildings. Recent research development on cold-formed steel has shown that the usage is expanded to the use in composite construction. This paper presents the modelling of the proposed composite connection of beam-to-column connection where cold-formed steel of lipped steel section is positioned back-to-back to perform as beam. Reinforcement bars is used to perform the composite action anchoring to the column and part of it is embedded into a slab. The results of the finite element and numerical analysis has showed good agreement. The results show that the proposed composite connection contributes to significant increase to the moment capacity.
Present state of knowledge of the upper atmosphere1993: An assessment report, part 2
NASA Technical Reports Server (NTRS)
Kurylo, Michael J.; Kaye, Jack A.; Hampson, Robert F.; Schmoltner, Anne-Marie
1994-01-01
This document is issued in response to the Clean Air Act Amendment of 1990, Public Law 101-549, which mandates that the National Aeronautics and Space Administration (NASA) and other key agencies submit triennial reports to Congress and the Environmental Protection Agency. NASA is charged with the responsibility to report on the state of our knowledge of the earth's upper atmosphere, particularly the stratosphere. Part 2 (this document) presents summaries of several scientific assessments of our current understanding of the chemical composition and physical structure of the stratosphere, in particular how the abundance and distribution of ozone is predicted to change in the future. These reviews include: (Section B) 'Scientific Assessment of Ozone Depletion: 1991'; (Section C) 'Methyl bromide and the Ozone Layer: A Summary of Current Understanding', published in 1992; (Section D) 'Concentrations, Lifetimes, and Trends of Chlorofluorocarbons (CFC's), Halons, and Related Molecules in the Atmosphere'; (Section E) 'The Atmospheric Effects of Stratospheric Aircraft: Interim Assessment Report of the NASA High-Speed Research Program'; (Section F) 'Chemical Kinetics and Photochemical Data for Use in Stratospheric Modeling'; and (Section G) a list of the contributors to this report.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jubin, R.T.
2001-04-16
This report summarizes the major activities conducted in the Chemical and Energy Research Section of the Chemical Technology Division at Oak Ridge National Laboratory (ORNL) during the period July-September 1999. The section conducts basic and applied research and development in chemical engineering, applied chemistry, and bioprocessing, with an emphasis on energy-driven technologies and advanced chemical separations for nuclear and waste applications. The report describes the various tasks performed within ten major areas of research: Hot Cell Operations, Process Chemistry, Molten Salt Reactor Experiment (MSRE) Remediation Studies, Chemistry Research, Physical Properties Research, Biochemical Engineering, Separations and Materials Synthesis, Fluid Structures andmore » Properties, Biotechnology Research, and Molecular Studies. The name of a technical contact is included with each task described, and readers are encouraged to contact these individuals if they need additional information. Activities conducted within the area of the Cell Operations involved the testing of two continuously stirred tank reactors in series to evaluate the Savannah River-developed process of small-tank tetraphenylborate precipitation to remove cesium, strontium and transuranics from supernatant. Within the area of Process Chemistry, various topics related to solids formation in process solutions from caustic treatment of Hanford sludge were addressed. Saltcake dissolution efforts continued, including the development of a predictive algorithm. New initiatives for the section included modeling activities centered on detection of hydrogen in {sup 233}U storage wells and wax formation in petroleum mixtures, as well as support for the Spallation Neutron Source (investigation of transmutation products formed during operation). Other activities involved in situ grouting and evaluation of options for use (i.e., as castable shapes) of depleted uranium. In a continuation of activities of the preceding quarter, MSRE Remediation Studies focused on recovery of {sup 233}U and its conversion to a stable oxide and radiolysis experiments to permit remediation of MSRE fuel salt. Investigation of options for final disposition of the {sup 233}U inventory represents a new initiative within this area. In the area of Chemistry Research, activities included studies relative to molecular imprinting for use in areas such as selective sorption, chemical sensing, and catalysis, as well as spectroscopic investigation into the fundamental interaction between ionic solvents and solutes in both low- and high-temperature ionic liquids.« less
Environmental Sciences Division annual progress report for period ending September 30, 1991
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
1992-04-01
This progress report summarizes the research and development activities conducted in the Environmental Sciences Division of Oak Ridge National Laboratory during the period October 1, 1990, through September 30, 1991. The report is structured to provide descriptions of current activities and accomplishments in each of the division's major organizational units. Following the sections describing the organizational units is a section devoted to lists of information necessary to convey the scope of the work in the division. The Environmental Sciences Division (ESD) at Oak Ridge National Laboratory (ORNL) conducts environmental research and analyses associated with both energy technology development and themore » interactions between people and the environment. The division engages in basic and applied research for a diverse list of sponsors. While the US Department of Energy (DOE) is the primary sponsor ESD staff also perform research for other federal agencies, state agencies, and private industry. The division works collaboratively with federal agencies, universities, and private organizations in achieving its research objectives and hosts a large number of visiting investigators from these organizations. Given the diverse interdisciplinary specialization of its staff, ESD provides technical expertise on complex environmental problems and renders technical leadership for major environmental issues of national and local concern. This progress report highlights many of ESD's accomplishment in these and other areas in FY 1991.« less
Environmental Sciences Division annual progress report for period ending September 30, 1991
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
1992-04-01
This progress report summarizes the research and development activities conducted in the Environmental Sciences Division of Oak Ridge National Laboratory during the period October 1, 1990, through September 30, 1991. The report is structured to provide descriptions of current activities and accomplishments in each of the division`s major organizational units. Following the sections describing the organizational units is a section devoted to lists of information necessary to convey the scope of the work in the division. The Environmental Sciences Division (ESD) at Oak Ridge National Laboratory (ORNL) conducts environmental research and analyses associated with both energy technology development and themore » interactions between people and the environment. The division engages in basic and applied research for a diverse list of sponsors. While the US Department of Energy (DOE) is the primary sponsor ESD staff also perform research for other federal agencies, state agencies, and private industry. The division works collaboratively with federal agencies, universities, and private organizations in achieving its research objectives and hosts a large number of visiting investigators from these organizations. Given the diverse interdisciplinary specialization of its staff, ESD provides technical expertise on complex environmental problems and renders technical leadership for major environmental issues of national and local concern. This progress report highlights many of ESD`s accomplishment in these and other areas in FY 1991.« less
Materials sciences programs: Fiscal Year 1987
NASA Astrophysics Data System (ADS)
1987-09-01
Purpose of this report is to provide a convenient compilation and index of the DOE Materials Sciences Division programs. This compilation is primarily intended for use by administrators, managers, and scientists to help coordinate research. The report is divided into seven sections. Section A contains all Laboratory projects, Section B has all contract research projects, Section C has projects funded under the Small Business Innovation Research Program, Sections D and E have information on DOE collaborative research centers, gives distribution of funding, and Section G has various indexes.
Vibration-response due to thickness loss on steel plate excited by resonance frequency
NASA Astrophysics Data System (ADS)
Kudus, S. A.; Suzuki, Y.; Matsumura, M.; Sugiura, K.
2018-04-01
The degradation of steel structure due to corrosion is a common problem found especially in the marine structure due to exposure to the harsh marine environment. In order to ensure safety and reliability of marine structure, the damage assessment is an indispensable prerequisite for plan of remedial action on damaged structure. The main goal of this paper is to discuss simple vibration measurement on plated structure to give image on overview condition of the monitored structure. The changes of vibration response when damage was introduced in the plate structure were investigated. The damage on plate was simulated in finite element method as loss of thickness section. The size of damage and depth of loss of thickness were varied for different damage cases. The plate was excited with lower order of resonance frequency in accordance estimate the average remaining thickness based on displacement response obtain in the dynamic analysis. Significant reduction of natural frequency and increasing amplitude of vibration can be observed in the presence of severe damage. The vibration analysis summarized in this study can serve as benchmark and reference for researcher and design engineer.
EDITORIAL: TaCoNa-Photonics 2008 TaCoNa-Photonics 2008
NASA Astrophysics Data System (ADS)
Chigrin, Dmitry N.; Busch, Kurt; Lavrinenko, Andrei V.
2009-11-01
This special section on theoretical and computational nano-photonics features papers presented at the first International Workshop on Theoretical and Computational Nano-Photonics (TaCoNa-Photonics 2008) held in Bad Honnef, Germany, 3-5 December 2008. The workshop covered a broad range of topics related to current developments and achievements in this interdisciplinary area of research. Since the late 1960s, the word `photonics' has been understood as the science of generating, controlling, and detecting light. Nowadays, a routine fabrication of complex structures with micro- and nano-scale dimensions opens up many new and exciting possibilities in photonics. The science of generating, routing and detecting light in micro- and nano-structured matter, `nano-photonics', is becoming more important both in research and technology and offers many promising applications. The inherently sub-wavelength character of the structures that nano-photonics deals with challenges modern theoretical and computational physics and engineering with many nontrivial questions: Up to what length-scale can one use a macroscopic phenomenological description of matter? Where is the interface between the classical and quantum description of light in nano-scale structures? How can one combine different physical systems, different time- and length-scales in a single computational model? How can one engineer nano-structured materials in order to achieve the desired optical properties for particular applications? Any attempt at answering these kinds of questions is impossible without the joint efforts of physicists, engineers, applied mathematicians and programmers. This is the reason why the major goal of the TaCoNa-Photonics workshops is to provide a forum where theoreticians and specialists in numerical methods from all branches of physics, engineering sciences and mathematics can compare their results, report on novel results and breakthroughs, and discuss new challenges ahead. In order to intensify theoretical discussions and to put them on `solid' ground it was decided to invite world-leading experts in experimental photonics for plenary talks. Over three days, the workshop has brought together more than 70 specialists in theoretical and computational nano-photonics. The workshop took place in the historical `Physikzentrum Bad Honnef', whose unique atmosphere supported a multitude of highly interesting debates and discussions that often lasted until midnight and beyond. Different theoretical and numerical aspects of light generation, control and detection in general inhomogeneous media, photonic crystals, plasmonic structures, metamaterials and integrated optical systems were covered in 15 invited talks and 52 contributed oral and posters presentations. The plenary talks were given by Professor M Wegener (metamaterials) and Professor W Barnes (plasmonics). This special section is a cross-sectional selection of papers which were submitted by the authors of invited and contributed oral presentations. It also includes two papers of the winners of the Best Poster Awards. We hope that these papers will enhance the interest of the scientific community regarding nano-photonics in general and regarding the TaCoNa-Photonics workshop series in particular. It is our distinct pleasure to acknowledge the generous financial support of our sponsors: Karlsruhe School of Optics & Photonics (KSOP) (Germany), U.S. Army International Technology Center-Atlantic, Research Division (USA), and the Office of Naval Research Global (USA). Without the organizational assistance from the International Department of the Universität Karlsruhe GmbH (Germany) this event would simply have been impossible.
Some structures of marine natural products
DOE Office of Scientific and Technical Information (OSTI.GOV)
Finer-Moore, J.S.
1979-07-01
Applications of x-ray crystallographic methods to marine chemistry are discussed. Results of research on a biosynthetic problem: diterpenes from Dictyotaceae are discussed under the following section headings: history of the problem; dictyoxepin; dictyodial; and dictyolactone. Studies on marine ecology are reported under the following headings: symbiosis and antibiosis; metabolites from opisthobranch molluscs, including, dolabelladiene, 9-isocyanopupukeanane and 2-isocyanopupukeanane, and crispatone; metabolites of goronians and soft corals, including zooxanthellae and the metabolism of coelenterates, ophirin, sinularene, and erectene. (JGB)
ERIC Educational Resources Information Center
White, Margaret
2009-01-01
In 2006, there were an estimated 181,000 low-income children in the province, with British Columbia (BC) reporting the highest before-tax child poverty rate (21.9%) in Canada (15.8%) for the fifth year in a row. This was the news in the "2008 Child Poverty Report Card" recently released by the First Call: BC Child and Youth Advocacy…
3-D Cellular Ultrastructure Can Be Resolved by X-ray Microscopy | Center for Cancer Research
X-ray microscopy (XRM) is more rapid than cryoelectron tomography or super-resolution fluorescence microscopy and could fill an important gap in current technologies used to investigate in situ three-dimensional structure of cells. New XRM methods developed by first author Gerd Schneider, Ph.D., working with James McNally. Ph.D., and a team of colleagues, is capable of revealing full cellular ultrastructure without requiring fixation, staining, or sectioning.
ERIC Educational Resources Information Center
DePapae, Marc; Hulstaert, Karen
2013-01-01
This article consists of five sections. First, it briefly describes the results of the authors' previous studies on the history of colonial education in view of the problem introduced by the special issue of which this article is a part. Second, it links these results to such central concepts as the so-called grammars of schooling and…
Poindexter, Erin K; Nazem, Sarra; Forster, Jeri E
2017-01-15
The interpersonal theory of suicide suggests three proximal risk factors for suicide: perceived burdensomeness, thwarted belongingness, and acquired capability. Previous literature indicates that repetitive exposure to painful and provocative events is related to increased acquired capability for suicide. Despite this, research related to the assessment of painful and provocative events has been insufficient. Research has inconsistently administered the Painful and Provocative Events Scale (PPES; a painful and provocative events assessment), and no study has examined the factor structure of the English PPES. This study explored the factor structure of the PPES and the relation between factors and fearlessness about death. The sample was a cross-sectional, self-report study comprised of 119 Veterans (Mage = 46.5, SD = 13.5). Findings from an exploratory factor analysis indicated a four-factor solution for the PPES; however, no factor from the PPES significantly related to fearlessness about death (measured by the Acquired Capability for Suicide Scale - Fearlessness About Death Scale; all p >.21). Cross-sectional, small Veteran sample. Findings suggest that the PPES lacks the psychometric properties necessary to reliably investigate painful and provocative factors. Consequently, this measure may not reliably capture and explain how painful and provocative events relate to fearlessness about death, which is a barrier to improving suicide risk assessment and prediction. Recommendations for the construction of a new PPES are offered. Published by Elsevier B.V.
Altitude Wind Tunnel at the NACA’s Aircraft Engine Research Laboratory
1945-06-21
Two men on top of the Altitude Wind Tunnel (AWT) at the National Advisory Committee for Aeronautics (NACA) Aircraft Engine Research Laboratory. The tunnel was a massive rectangular structure, which for years provided one of the highest vantage points on the laboratory. The tunnel was 263 feet long on the north and south legs and 121 feet long on the east and west sides. The larger west end of the tunnel, seen here, was 51 feet in diameter. The east side of the tunnel was 31 feet in diameter at the southeast corner and 27 feet in diameter at the northeast. The throat section, which connected the northwest corner to the test section, narrowed sharply from 51 to 20 feet in diameter. The AWT’s altitude simulation required temperature and pressure fluctuations that made the design of the shell more difficult than other tunnels. The simultaneous decrease in both pressure and temperature inside the facility produced uneven stress loads, particularly on the support rings. The steel used in the primary tunnel structure was one inch thick to ensure that the shell did not collapse as the internal air pressure was dropped to simulate high altitudes. It was a massive amount of steel considering the World War II shortages. The shell was covered with several inches of fiberglass insulation to retain the refrigerated air and a thinner outer steel layer to protect the insulation against the weather. A unique system of rollers was used between the shell and its support piers. These rollers allowed for movement as the shell expanded or contracted during the altitude simulations. Certain sections would move as much as five inches during operation.
Catalog of databases and reports
DOE Office of Scientific and Technical Information (OSTI.GOV)
Burtis, M.D.
1996-04-01
This document provides information about the many reports and other materials made available by the US Department of Energy`s (DOE`s) Global Change Research Program (GCRP). It is divided into nine sections plus author and title indexes: Section A -- US Department of Energy Global Change Research Program research plans and summaries; Section B -- US Department of Energy Global Change Research Program technical reports; Section C -- US Department of energy Atmospheric Radiation Measurement (ARM) program reports; Section D -- Other US Department of Energy reports; Section E -- CDIAC reports; Section F -- CDIAC numeric data and computer modelmore » distribution; Section G -- other data sets distributed by CDIAC; Section H -- USDA reports on response of vegetation to carbon dioxide; Section I -- other publications.« less
Raschpichler, Matthias; Straatman, Kees; Schroeter, Matthias Leopold; Arelin, Katrin; Schlögl, Haiko; Fritzsch, Dominik; Mende, Meinhard; Pampel, André; Böttcher, Yvonne; Stumvoll, Michael; Villringer, Arno; Mueller, Karsten
2013-01-01
Objectives To investigate whether the metabolically important visceral adipose tissue (VAT) relates differently to structural and functional brain changes in comparison with body weight measured as body mass index (BMI). Moreover, we aimed to investigate whether these effects change with age. Design Cross-sectional, exploratory. Setting University Clinic, Integrative Research and Treatment Centre. Participants We included 100 (mean BMI=26.0 kg/m², 42 women) out of 202 volunteers randomly invited by the city's registration office, subdivided into two age groups: young-to-mid-age (n=51, 20–45 years of age, mean BMI=24.9, 24 women) versus old (n=49, 65–70 years of age, mean BMI=27.0, 18 women). Main outcome measures VAT, BMI, subcutaneous abdominal adipose tissue, brain structure (grey matter density), functional brain architecture (eigenvector centrality, EC). Results We discovered a loss of cerebellar structure with increasing VAT in the younger participants, most significantly in regions involved in motor processing. This negative correlation disappeared in the elderly. Investigating functional brain architecture showed again inverse VAT–cerebellum correlations, whereas now regions involved in cognitive and emotional processing were significant. Although we detected similar results for EC using BMI, significant age interaction for both brain structure and functional architecture was only found using VAT. Conclusions Visceral adiposity is associated with cerebellar changes of both structure and function, whereas the regions involved contribute to motor, cognitive and emotional processes. Furthermore, these associations seem to be age dependent, with younger adults’ brains being adversely affected. PMID:23355665
[Study on shape and structure of calcified cartilage zone in normal human knee joint].
Wang, Fuyou; Yang, Liu; Duan, Xiaojun; Tan, Hongbo; Dai, Gang
2008-05-01
To explore the shape and structure of calcified cartilage zone and its interface between the non-calcified articular cartilage and subchondral bone plate. The normal human condyles of femur (n=20) were obtained from the tissue bank donated by the residents, 10 males and 10 females, aged 17-45 years. The longitudinal and transverse paraffin sections were prepared by the routine method. The shape and structure of calcified cartilage zone were observed with the Safranin O/fast green and von kossa stain method. The interface conjunction among zones of cartilage was researched by SEM and the 3D structural model was established by serial sections and modeling technique. Articular bone-cartilage safranin O/fast green staining showed that cartilage was stained red and subchondral bone was stained blue. The calcified cartilage zone was located between the tidemark and cement line. Von kossa staining showed that calcified cartilage zone was stained black and sharpness of structure border. Upper interface gomphosised tightly with the non-calcified cartilage by the wave shaped tidemark and lower interface anchored tightly with the subchondral bone by the uneven comb shaped cement line. The non-calcified cartilage zone was interlocked tightly in the manner of "ravine-engomphosis" by the calcified cartilage zone as observed under SEM, and the subchondral bone was anchored tightly in the manner of"comb-anchor" by the in the calcified cartilage zone 3D reconstruction model. The calcified cartilage zone is an important structure in the articular cartilage. The articular cartilage is fixed firmly into subchondral bone plate by the distinctive conjunct interfaces of calcified cartilage zone.
Patient satisfaction constructs.
Rahman, Muhammad Sabbir; Osmangani, Aahad M
2015-01-01
The purpose of this paper is to examine the five-factor structure of patients' satisfaction constructs toward private healthcare service providers. This research is a cross-sectional study. A questionnaire-based survey was conducted with previous and current Bangladeshi patients. Exploratory factor analysis was employed to extract the underlying constructs. Five underlying dimensions that play a significant role in structuring the satisfaction perceived by Bangladeshi private healthcare patients are identified in this study. Practical implications - The main contribution of this study is identifying the dimensions of satisfaction perceived by Bangladeshi patients regarding private healthcare service providers. Healthcare managers adopt the five identified underlying construct items in their business practices to improve their respective healthcare efficiency while ensuring overall customer satisfaction.
Vibro-acoustic performance of newly designed tram track structures
NASA Astrophysics Data System (ADS)
Haladin, Ivo; Lakušić, Stjepan; Ahac, Maja
2017-09-01
Rail vehicles in interaction with a railway structure induce vibrations that are propagating to surrounding structures and cause noise disturbance in the surrounding areas. Since tram tracks in urban areas often share the running surface with road vehicles one of top priorities is to achieve low maintenance and long lasting structure. Research conducted in scope of this paper gives an overview of newly designed tram track structures designated for use on Zagreb tram network and their performance in terms of noise and vibration mitigation. Research has been conducted on a 150 m long test section consisted of three tram track types: standard tram track structure commonly used on tram lines in Zagreb, optimized tram structure for better noise and vibration mitigation and a slab track with double sleepers embedded in a concrete slab, which presents an entirely new approach of tram track construction in Zagreb. Track has been instrumented with acceleration sensors, strain gauges and revision shafts for inspection. Relative deformations give an insight into track structure dynamic load distribution through the exploitation period. Further the paper describes vibro-acoustic measurements conducted at the test site. To evaluate the track performance from the vibro-acoustical standpoint, detailed analysis of track decay rate has been analysed. Opposed to measurement technique using impact hammer for track decay rate measurements, newly developed measuring technique using vehicle pass by vibrations as a source of excitation has been proposed and analysed. Paper gives overview of the method, it’s benefits compared to standard method of track decay rate measurements and method evaluation based on noise measurements of the vehicle pass by.
Individuals at high risk for suicide are categorically distinct from those at low risk.
Witte, Tracy K; Holm-Denoma, Jill M; Zuromski, Kelly L; Gauthier, Jami M; Ruscio, John
2017-04-01
Although suicide risk is often thought of as existing on a graded continuum, its latent structure (i.e., whether it is categorical or dimensional) has not been empirically determined. Knowledge about the latent structure of suicide risk holds implications for suicide risk assessments, targeted suicide interventions, and suicide research. Our objectives were to determine whether suicide risk can best be understood as a categorical (i.e., taxonic) or dimensional entity, and to validate the nature of any obtained taxon. We conducted taxometric analyses of cross-sectional, baseline data from 16 independent studies funded by the Military Suicide Research Consortium. Participants (N = 1,773) primarily consisted of military personnel, and most had a history of suicidal behavior. The Comparison Curve Fit Index values for MAMBAC (.85), MAXEIG (.77), and L-Mode (.62) all strongly supported categorical (i.e., taxonic) structure for suicide risk. Follow-up analyses comparing the taxon and complement groups revealed substantially larger effect sizes for the variables most conceptually similar to suicide risk compared with variables indicating general distress. Pending replication and establishment of the predictive validity of the taxon, our results suggest the need for a fundamental shift in suicide risk assessment, treatment, and research. Specifically, suicide risk assessments could be shortened without sacrificing validity, the most potent suicide interventions could be allocated to individuals in the high-risk group, and research should generally be conducted on individuals in the high-risk group. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
Noise Reduction Design of the Volute for a Centrifugal Compressor
NASA Astrophysics Data System (ADS)
Song, Zhen; Wen, Huabing; Hong, Liangxing; Jin, Yudong
2017-08-01
In order to effectively control the aerodynamic noise of a compressor, this paper takes into consideration a marine exhaust turbocharger compressor as a research object. According to the different design concept of volute section, tongue and exit cone, six different volute models were established. The finite volume method is used to calculate the flow field, whiles the finite element method is used for the acoustic calculation. Comparison and analysis of different structure designs from three aspects: noise level, isentropic efficiency and Static pressure recovery coefficient. The results showed that under the concept of volute section model 1 yielded the best result, under the concept of tongue analysis model 3 yielded the best result and finally under exit cone analysis model 6 yielded the best results.
Photogrammetry of a Hypersonic Inflatable Aerodynamic Decelerator
NASA Technical Reports Server (NTRS)
Kushner, Laura Kathryn; Littell, Justin D.; Cassell, Alan M.
2013-01-01
In 2012, two large-scale models of a Hypersonic Inflatable Aerodynamic decelerator were tested in the National Full-Scale Aerodynamic Complex at NASA Ames Research Center. One of the objectives of this test was to measure model deflections under aerodynamic loading that approximated expected flight conditions. The measurements were acquired using stereo photogrammetry. Four pairs of stereo cameras were mounted inside the NFAC test section, each imaging a particular section of the HIAD. The views were then stitched together post-test to create a surface deformation profile. The data from the photogram- metry system will largely be used for comparisons to and refinement of Fluid Structure Interaction models. This paper describes how a commercial photogrammetry system was adapted to make the measurements and presents some preliminary results.
From brittle to ductile: a structure dependent ductility of diamond nanothread.
Zhan, Haifei; Zhang, Gang; Tan, Vincent B C; Cheng, Yuan; Bell, John M; Zhang, Yong-Wei; Gu, Yuantong
2016-06-07
As a potential building block for the next generation of devices/multifunctional materials that are spreading in almost every technology sector, one-dimensional (1D) carbon nanomaterial has received intensive research interests. Recently, a new ultra-thin diamond nanothread (DNT) has joined this palette, which is a 1D structure with poly-benzene sections connected by Stone-Wales (SW) transformation defects. Using large-scale molecular dynamics simulations, we found that this sp(3) bonded DNT can transition from brittle to ductile behaviour by varying the length of the poly-benzene sections, suggesting that DNT possesses entirely different mechanical responses than other 1D carbon allotropes. Analogously, the SW defects behave like a grain boundary that interrupts the consistency of the poly-benzene sections. For a DNT with a fixed length, the yield strength fluctuates in the vicinity of a certain value and is independent of the "grain size". On the other hand, both yield strength and yield strain show a clear dependence on the total length of DNT, which is due to the fact that the failure of the DNT is dominated by the SW defects. Its highly tunable ductility together with its ultra-light density and high Young's modulus makes diamond nanothread ideal for the creation of extremely strong three-dimensional nano-architectures.
Environmental Barrier Coatings for Ceramics and Ceramic Composites
NASA Technical Reports Server (NTRS)
Lee, Kang N.; Fox, Dennis; Eldridge, Jeffrey; Robinson, R. Craig; Bansal, Narottam
2004-01-01
One key factor that limits the performance of current gas turbine engines is the temperature capability of hot section structural components. Silicon-based ceramics, such as SiC/SiC composites and monolithic Si3N4, are leading candidates to replace superalloy hot section components in the next generation gas turbine engines due to their excellent high temperature properties. A major stumbling block to realizing Si-based ceramic hot section components is the recession of Si-based ceramics in combustion environments due to the volatilization of silica scale by water vapor. An external environmental barrier coating (EBC) is the most promising approach to preventing the recession. Current EBCs are based on silicon, mullite (3A12O3-2SiO2) and BSAS (barium strontium aluminum silicate with celsian structure). Volatility of BSAS, BSAS-silica chemical reaction, and low melting point of silicon limit the durability and temperature capability of current EBCs. Research is underway to develop EBCs with longer life and enhanced temperature capability. Understanding key issues affecting the performance of current EBCs is necessary for successful development of advanced EBCs. These issues include stress, chemical compatibility, adherence, and water vapor stability. Factors that affect stress are thermal expansion mismatch, phase stability, chemical stability, elastic modulus, etc. The current understanding on these issues will be discussed.
Overview of the NASA Subsonic Rotary Wing Aeronautics Research Program in Rotorcraft Crashworthiness
NASA Technical Reports Server (NTRS)
Jackson, Karen E.; Kellas, Sotiris; Fuchs, Yvonne T.
2009-01-01
This paper provides an overview of rotorcraft crashworthiness research being conducted at NASA Langley Research Center under sponsorship of the Subsonic Rotary Wing (SRW) Aeronautics Program. The research is focused in two areas: development of an externally deployable energy attenuating concept and improved prediction of rotorcraft crashworthiness. The deployable energy absorber (DEA) is a composite honeycomb structure, with a unique flexible hinge design that allows the honeycomb to be packaged and remain flat until needed for deployment. The capabilities of the DEA have been demonstrated through component crush tests and vertical drop tests of a retrofitted fuselage section onto different surfaces or terrain. The research on improved prediction of rotorcraft crashworthiness is focused in several areas including simulating occupant responses and injury risk assessment, predicting multi-terrain impact, and utilizing probabilistic analysis methods. A final task is to perform a system-integrated simulation of a full-scale helicopter crash test onto a rigid surface. A brief description of each research task is provided along with a summary of recent accomplishments.
Overview of the NASA Subsonic Rotary Wing Aeronautics Research Program in Rotorcraft Crashworthiness
NASA Technical Reports Server (NTRS)
Jackson, Karen E.; Fuchs, Yvonne T.; Kellas, Sotiris
2008-01-01
This paper provides an overview of rotorcraft crashworthiness research being conducted at NASA Langley Research Center under sponsorship of the Subsonic Rotary Wing (SRW) Aeronautics Program. The research is focused in two areas: development of an externally deployable energy attenuating concept and improved prediction of rotorcraft crashworthiness. The deployable energy absorber (DEA) is a composite honeycomb structure, with a unique flexible hinge design that allows the honeycomb to be packaged and remain flat until needed for deployment. The capabilities of the DEA have been demonstrated through component crush tests and vertical drop tests of a retrofitted fuselage section onto different surfaces or terrain. The research on improved prediction of rotorcraft crashworthiness is focused in several areas including simulating occupant responses and injury risk assessment, predicting multi-terrain impact, and utilizing probabilistic analysis methods. A final task is to perform a system-integrated simulation of a full-scale helicopter crash test onto a rigid surface. A brief description of each research task is provided along with a summary of recent accomplishments.
Lewis-Fernández, Roberto; Raggio, Greer A; Gorritz, Magdaliz; Duan, Naihua; Marcus, Sue; Cabassa, Leopoldo J; Humensky, Jennifer; Becker, Anne E; Alarcón, Renato D; Oquendo, María A; Hansen, Helena; Like, Robert C; Weiss, Mitchell; Desai, Prakash N; Jacobsen, Frederick M; Foulks, Edward F; Primm, Annelle; Lu, Francis; Kopelowicz, Alex; Hinton, Ladson; Hinton, Devon E
2013-10-01
Growing awareness of health and health care disparities highlights the importance of including information about race, ethnicity, and culture (REC) in health research. Reporting of REC factors in research publications, however, is notoriously imprecise and unsystematic. This article describes the development of a checklist to assess the comprehensiveness and the applicability of REC factor reporting in psychiatric research publications. The 16-item GAP-REACH checklist was developed through a rigorous process of expert consensus, empirical content analysis in a sample of publications (N = 1205), and interrater reliability (IRR) assessment (N = 30). The items assess each section in the conventional structure of a health research article. Data from the assessment may be considered on an item-by-item basis or as a total score ranging from 0% to 100%. The final checklist has excellent IRR (κ = 0.91). The GAP-REACH may be used by multiple research stakeholders to assess the scope of REC reporting in a research article.
Processing and optimization of functional ceramic coatings and inorganic nanomaterials
NASA Astrophysics Data System (ADS)
Nyutu, Edward Kennedy G.
Processing of functional inorganic materials including zero (0-D) dimensional (e.g. nanoparticles), 1-D (nanorods, nanofibers), and 2-D (films/coating) structures is of fundamental and technological interest. This research will have two major sections. The first part of section one focuses on the deposition of silicon dioxide onto a pre-deposited molybdenum disilicide coating on molybdenum substrates for both high (>1000 °C) and moderate (500-600 °C) temperature oxidation protection. Chemical vapor deposition (CVD/MOCVD) techniques will be utilized to deposit the metal suicide and oxide coatings. The focus of this study will be to establish optimum deposition conditions and evaluate the metal oxide coating as oxidation - thermal barriers for Mo substrates under both isothermal (static) and cyclic oxidation conditions. The second part of this section will involve a systematic evaluation of a boron nitride (BN) interface coating prepared by chemical vapor deposition. Ceramic matrix composites (CMCs) are prospective candidates for high (>1000 °C) temperature applications and fiber- matrix interfaces are the dominant design parameters in ceramic matrix composites (CMCs). An important goal of the study is to determine a set of process parameters, which would define a boron nitride (BN) interface coating by a chemical vapor deposition (CVD) process with respect to coating. In the first part of the second section, we will investigate a new approach to synthesize ultrafine metal oxides that combines microwave heating and an in-situ ultrasonic mixing of two or more liquid precursors with a tubular flow reactor. Different metal oxides such as nickel ferrite and zinc aluminate spinels will be studied. The synthesis of metal oxides were investigated in order to study the effects of the nozzle and microwave (INM process) on the purity, composition, and particle size of the resulting powders. The second part of this research section involves a study of microwave frequency effects on the synthesis of nanocrystalline tetragonal barium titanate. The effects of microwave frequency (fixed and variable), microwave bandwidths sweep time, and aging time on the microstructure, particle sizes, phase purity, surface areas, and porosities of the as-prepared BaTiO3 were systematically investigated. The final part of the research involves a new rapid and facile synthetic route to prepare size-tunable, ultranarrow, high surface area OMS-2 nanomaterials via open-vessel microwave-assisted refluxing preparations without employing templates or surfactants. The particle size control is achieved by varying the concentration or type of non-aqueous co-solvent. The structural, textural, and catalytic application properties of the prepared nanomaterials are investigated.
Federal Register 2010, 2011, 2012, 2013, 2014
2010-06-01
... closely the governance structure of the FINRA Board. Section 4.3--Qualifications The proposed rule change would amend Article IV, section 4.3(a) to reflect FINRA's current governance structure by establishing... to Article IV, section 4.3 as follows: Re-structure the Board to remove the President of NASD Dispute...
Catalog of databases and reports
DOE Office of Scientific and Technical Information (OSTI.GOV)
Burtis, M.D.
1997-04-01
This catalog provides information about the many reports and materials made available by the US Department of Energy`s (DOE`s) Global Change Research Program (GCRP) and the Carbon Dioxide Information Analysis Center (CDIAC). The catalog is divided into nine sections plus the author and title indexes: Section A--US Department of Energy Global Change Research Program Research Plans and Summaries; Section B--US Department of Energy Global Change Research Program Technical Reports; Section C--US Department of Energy Atmospheric Radiation Measurement (ARM) Program Reports; Section D--Other US Department of Energy Reports; Section E--CDIAC Reports; Section F--CDIAC Numeric Data and Computer Model Distribution; Section G--Othermore » Databases Distributed by CDIAC; Section H--US Department of Agriculture Reports on Response of Vegetation to Carbon Dioxide; and Section I--Other Publications.« less
Optimization of rotor blades for combined structural, dynamic, and aerodynamic properties
NASA Technical Reports Server (NTRS)
He, Cheng-Jian; Peters, David A.
1990-01-01
Optimal helicopter blade design with computer-based mathematical programming has received more and more attention in recent years. Most of the research has focused on optimum dynamic characteristics of rotor blades to reduce vehicle vibration. There is also work on optimization of aerodynamic performance and on composite structural design. This research has greatly increased our understanding of helicopter optimum design in each of these aspects. Helicopter design is an inherently multidisciplinary process involving strong interactions among various disciplines which can appropriately include aerodynamics; dynamics, both flight dynamics and structural dynamics; aeroelasticity: vibrations and stability; and even acoustics. Therefore, the helicopter design process must satisfy manifold requirements related to the aforementioned diverse disciplines. In our present work, we attempt to combine several of these important effects in a unified manner. First, we design a blade with optimum aerodynamic performance by proper layout of blade planform and spanwise twist. Second, the blade is designed to have natural frequencies that are placed away from integer multiples of the rotor speed for a good dynamic characteristics. Third, the structure is made as light as possible with sufficient rotational inertia to allow for autorotational landing, with safe stress margins and flight fatigue life at each cross-section, and with aeroelastical stability and low vibrations. Finally, a unified optimization refines the solution.
Characterization of structure and thermophysical properties of three ESR slags
NASA Astrophysics Data System (ADS)
Plotkowski, A.; deBarbadillo, J.; Krane, Matthew J. M.
2016-07-01
The structure and properties of electroslag remelting (ESR) slags were characterized. Slags samples of three compositions were obtained from industrial remelting processes at Special Metals Corporation and from casting in a laboratory vacuum induction melter. The structure of the slag samples was observed using optical and electron microscopy, and phases were identified and their relative amounts quantified using X-ray diffraction. Laser flash thermal diffusivity, density, and differential scanning calorimetry measurements for specific heat were performed to determine the bulk thermal conductivity of the samples. Sample porosity was measured as a function of depth using a serial sectioning technique, and a onedimensional computational model was developed to estimate the thermal conductivity of the fully dense slags. These results are discussed in context with previous studies, and opportunities for future research are identified. AFRL Case Number: 88ABW-2015-1871.
Reliability-based optimization of an active vibration controller using evolutionary algorithms
NASA Astrophysics Data System (ADS)
Saraygord Afshari, Sajad; Pourtakdoust, Seid H.
2017-04-01
Many modern industrialized systems such as aircrafts, rotating turbines, satellite booms, etc. cannot perform their desired tasks accurately if their uninhibited structural vibrations are not controlled properly. Structural health monitoring and online reliability calculations are emerging new means to handle system imposed uncertainties. As stochastic forcing are unavoidable, in most engineering systems, it is often needed to take them into the account for the control design process. In this research, smart material technology is utilized for structural health monitoring and control in order to keep the system in a reliable performance range. In this regard, a reliability-based cost function is assigned for both controller gain optimization as well as sensor placement. The proposed scheme is implemented and verified for a wing section. Comparison of results for the frequency responses is considered to show potential applicability of the presented technique.
Lin, B Y; Wan, T T
1999-12-01
Few empirical analyses have been done in the organizational researches of integrated healthcare networks (IHNs) or integrated healthcare delivery systems. Using a contingency derived contact-process-performance model, this study attempts to explore the relationships among an IHN's strategic direction, structural design, and performance. A cross-sectional analysis of 100 IHNs suggests that certain contextual factors such as market competition and network age and tax status have statistically significant effects on the implementation of an IHN's service differentiation strategy, which addresses coordination and control in the market. An IHN's service differentiation strategy is positively related to its integrated structural design, which is characterized as integration of administration, patient care, and information system across different settings. However, no evidence supports that the development of integrated structural design may benefit an IHN's performance in terms of clinical efficiency and financial viability.
The chaotic set and the cross section for chaotic scattering in three degrees of freedom
NASA Astrophysics Data System (ADS)
Jung, C.; Merlo, O.; Seligman, T. H.; Zapfe, W. P. K.
2010-10-01
This article treats chaotic scattering with three degrees of freedom, where one of them is open and the other two are closed, as a first step towards a more general understanding of chaotic scattering in higher dimensions. Despite the strong restrictions, it breaks the essential simplicity implicit in any two-dimensional time-independent scattering problem. Introducing the third degree of freedom by breaking a continuous symmetry, we first explore the topological structure of the homoclinic/heteroclinic tangle and the structures in the scattering functions. Then we work out the implications of these structures for the doubly differential cross section. The most prominent structures in the cross section are rainbow singularities. They form a fractal pattern that reflects the fractal structure of the chaotic invariant set. This allows us to determine structures in the cross section from the invariant set and, conversely, to obtain information about the topology of the invariant set from the cross section. The latter is a contribution to the inverse scattering problem for chaotic systems.
Park, Jin Seo; Jung, Yong Wook; Choi, Hyung-Do; Lee, Ae-Kyoung
2018-01-01
Abstract The anatomical structures in most phantoms are classified according to tissue properties rather than according to their detailed structures, because the tissue properties, not the detailed structures, are what is considered important. However, if a phantom does not have detailed structures, the phantom will be unreliable because different tissues can be regarded as the same. Thus, we produced the Visible Korean (VK) -phantoms with detailed structures (male, 583 structures; female, 459 structures) based on segmented images of the whole male body (interval, 1.0 mm; pixel size, 1.0 mm2) and the whole female body (interval, 1.0 mm; pixel size, 1.0 mm2), using house-developed software to analyze the text string and voxel information for each of the structures. The density of each structure in the VK-phantom was calculated based on Virtual Population and a publication of the International Commission on Radiological Protection. In the future, we will standardize the size of each structure in the VK-phantoms. If the VK-phantoms are standardized and the mass density of each structure is precisely known, researchers will be able to measure the exact absorption rate of electromagnetic radiation in specific organs and tissues of the whole body. PMID:29659988
Park, Jin Seo; Jung, Yong Wook; Choi, Hyung-Do; Lee, Ae-Kyoung
2018-05-01
The anatomical structures in most phantoms are classified according to tissue properties rather than according to their detailed structures, because the tissue properties, not the detailed structures, are what is considered important. However, if a phantom does not have detailed structures, the phantom will be unreliable because different tissues can be regarded as the same. Thus, we produced the Visible Korean (VK) -phantoms with detailed structures (male, 583 structures; female, 459 structures) based on segmented images of the whole male body (interval, 1.0 mm; pixel size, 1.0 mm2) and the whole female body (interval, 1.0 mm; pixel size, 1.0 mm2), using house-developed software to analyze the text string and voxel information for each of the structures. The density of each structure in the VK-phantom was calculated based on Virtual Population and a publication of the International Commission on Radiological Protection. In the future, we will standardize the size of each structure in the VK-phantoms. If the VK-phantoms are standardized and the mass density of each structure is precisely known, researchers will be able to measure the exact absorption rate of electromagnetic radiation in specific organs and tissues of the whole body.
Unit cell geometry of multiaxial preforms for structural composites
NASA Technical Reports Server (NTRS)
Ko, Frank; Lei, Charles; Rahman, Anisur; Du, G. W.; Cai, Yun-Jia
1993-01-01
The objective of this study is to investigate the yarn geometry of multiaxial preforms. The importance of multiaxial preforms for structural composites is well recognized by the industry but, to exploit their full potential, engineering design rules must be established. This study is a step in that direction. In this work the preform geometry for knitted and braided preforms was studied by making a range of well designed samples and studying them by photo microscopy. The structural geometry of the preforms is related to the processing parameters. Based on solid modeling and B-spline methodology a software package is developed. This computer code enables real time structural representations of complex fiber architecture based on the rule of preform manufacturing. The code has the capability of zooming and section plotting. These capabilities provide a powerful means to study the effect of processing variables on the preform geometry. the code also can be extended to an auto mesh generator for downstream structural analysis using finite element method. This report is organized into six sections. In the first section the scope and background of this work is elaborated. In section two the unit cell geometries of braided and multi-axial warp knitted preforms is discussed. The theoretical frame work of yarn path modeling and solid modeling is presented in section three. The thin section microscopy carried out to observe the structural geometry of the preforms is the subject in section four. The structural geometry is related to the processing parameters in section five. Section six documents the implementation of the modeling techniques into the computer code MP-CAD. A user manual for the software is also presented here. The source codes and published papers are listed in the Appendices.
Valdez-Martinez, E; Garduño-Espinosa, J; Martinez-Salgado, H; Porter, J D H
2004-07-01
To identify the structure, composition and work of the local research ethics committees (LRECs) of the Mexican Institute of Social Security (IMSS) in Mexico. A descriptive cross-sectional study was performed that included all LRECs of the IMSS. A total of 335 questionnaires coded in advance were posted to each LREC secretary. The requested information was from January to December 2001. The response rate was 100%. Two hundred and thirty-eight (71%) LRECs were reported as 'active' during the evaluation period. Although almost all LRECs were composed of diverse professionals, physicians dominated the LRECs' membership. The rejection rate for research projects was lower than 1 per 1000, and less than half of the LRECs held meetings to issue a report of projects' evaluation. LRECs need to foster good ethical research; implementation of an audit system to examine their work might help improve LRECs' performance and accountability.
Advanced materials and concepts for energy storage devices
NASA Astrophysics Data System (ADS)
Teng, Shiang Jen
Over the last decade, technological progress and advances in the miniaturization of electronic devices have increased demands for light-weight, high-efficiency, and carbon-free energy storage devices. These energy storage devices are expected to play important roles in automobiles, the military, power plants, and consumer electronics. Two main types of electrical energy storage systems studied in this research are Li ion batteries and supercapacitors. Several promising solid state electrolytes and supercapacitor electrode materials are investigated in this research. The first section of this dissertation is focused on the novel results on pulsed laser annealing of Li7La3Zr2O12 (LLZO). LLZO powders with a tetragonal structure were prepared by a sol-gel technique, then a pulsed laser annealing process was employed to convert the tetragonal powders to cubic LLZO without any loss of lithium. The second section of the dissertation reports on how Li5La 3Nb2O12 (LLNO) was successfully synthesized via a novel molten salt synthesis (MSS) method at the relatively low temperature of 900°C. The low sintering temperature prevented the loss of lithium that commonly occurs during synthesis using conventional solid state or wet chemical reactions. The second type of energy storage device studied is supercapacitors. Currently, research on supercapacitors is focused on increasing their energy densities and lowering their overall production costs by finding suitable electrode materials. The third section of this dissertation details how carbonized woods electrodes were used as supercapacitor electrode materials. A high energy density of 45.6 Wh/kg and a high power density of 2000 W/kg were obtained from the supercapacitor made from carbonized wood electrodes. The high performance of the supercapacitor was discovered to originate from the hierarchical porous structures of the carbonized wood. Finally, the fourth section of this dissertation is on the electrochemical effects of embedding Cu nanoparticles into a carbonized wood supercapacitor. The nano-composites were fabricated using a solution method. The electrochemical measurements indicated that Cu nanoparticles did enhance the energy density of the supercapacitor by a factor of three. Both cyclic voltammetry and cyclic charge-discharge measurements showed that the electrode has typical reversible pseudocapacitive behavior, with two pairs of redox reaction peaks.
Influence of cross section variations on the structural behaviour of composite rotor blades
NASA Astrophysics Data System (ADS)
Rapp, Helmut; Woerndle, Rudolf
1991-09-01
A highly sophisticated structural analysis is required for helicopter rotor blades with nonhomogeneous cross sections made from nonisotropic material. Combinations of suitable analytical techniques with FEM-based techniques permit a cost effective and sufficiently accurate analysis of these complicated structures. It is determined that in general the 1D engineering theory of bending combined with 2D theories for determining the cross section properties is sufficient to describe the structural blade behavior.
Two-Photon Fluorescence Microscopy Developed for Microgravity Fluid Physics
NASA Technical Reports Server (NTRS)
Fischer, David G.; Zimmerli, Gregory A.; Asipauskas, Marius
2004-01-01
Recent research efforts within the Microgravity Fluid Physics Branch of the NASA Glenn Research Center have necessitated the development of a microscope capable of high-resolution, three-dimensional imaging of intracellular structure and tissue morphology. Standard optical microscopy works well for thin samples, but it does not allow the imaging of thick samples because of severe degradation caused by out-of-focus object structure. Confocal microscopy, which is a laser-based scanning microscopy, provides improved three-dimensional imaging and true optical sectioning by excluding the out-of-focus light. However, in confocal microscopy, out-of-focus object structure is still illuminated by the incoming beam, which can lead to substantial photo-bleaching. In addition, confocal microscopy is plagued by limited penetration depth, signal loss due to the presence of a confocal pinhole, and the possibility of live-cell damage. Two-photon microscopy is a novel form of laser-based scanning microscopy that allows three-dimensional imaging without many of the problems inherent in confocal microscopy. Unlike one-photon microscopy, it utilizes the nonlinear absorption of two near-infrared photons. However, the efficiency of two-photon absorption is much lower than that of one-photon absorption because of the nonlinear (i.e., quadratic) electric field dependence, so an ultrafast pulsed laser source must typically be employed. On the other hand, this stringent energy density requirement effectively localizes fluorophore excitation to the focal volume. Consequently, two-photon microscopy provides optical sectioning and confocal performance without the need for a signal-limiting pinhole. In addition, there is a reduction in photo-damage because of the longer excitation wavelength, a reduction in background fluorescence, and a 4 increase in penetration depth over confocal methods because of the reduction in Rayleigh scattering.
NASA Technical Reports Server (NTRS)
Lee, Kang N.; Fox, Dennis S.; Robinson, R. Craig
2001-01-01
Silicon-based ceramics, such as SiC/SiC composites and Si3N4, are the prime candidates for hot section structural components of next-generation gas turbines. A key barrier to such an application is the rapid recession of silicon-based ceramics in combustion environments because of the volatilization of silica scale by water vapor (refs. 1 and 2). Environmental barrier coatings (EBC's) were developed to prevent recession in the High Speed Research--Enabling Propulsion Materials (HSR-EPM) Program (refs. 3 and 4). An investigation under the Ultra-Efficient Engine Technology Program was undertaken at the NASA Glenn Research Center to establish the upper temperature limit of the EPM EBC.
NASA Astrophysics Data System (ADS)
Liao, Wei-Hsin
2010-12-01
The 20th International Conference on Adaptive Structures and Technologies (ICAST) was held on 20-22 October 2009 in Hong Kong. This special section of Smart Materials and Structures is derived from the research papers presented at the conference. Of the 106 papers presented at the conference, 11 papers were reviewed and accepted for this special section, following the regular review procedures of the journal. This special section is focused on smart materials, multifunctional composites, and applications on morphing structures. Smart materials. Smart materials are the foundation of adaptive structures and intelligent systems. The development of new materials will lead to significant improvement in various applications. Three articles are focused on the fabrication of new materials and investigation of their behaviors: Barium strontium zirconate titanate ((Ba1-xSrx)(ZrxTi1-x)O3; BSZT, x = 0.25 and 0.75) ceramics with a highly crystalline structure were fabricated using the combustion technique. The microstructure of BSZT powders exhibited an almost-spherical morphology and had a porous agglomerated form. Polyaniline (PANI)/clay nanoparticles with unique core-shell structure were synthesized via Pickering emulsion polymerization. By dispersing PANI/clay nanoparticles in silicone oil, the ER fluid was made. Magnetic field effects were investigated on the deposition rate and surface morphology of chromium nitride coatings deposited by magnetron sputtering for superior hardness, excellent wear and oxidation resistance. The surface morphology of chromium nitride films was also examined by a scanning electron microscope (SEM). Multifunctional composites. Composites are made from two or more constituent materials so they can combine the best properties of different materials. Five papers deal with fabrication, testing, and modeling of various multifunctional composites: A new active structural fiber (ASF) was fabricated by coating a single carbon fiber with a concentric PZT (PbZr0.52Ti0.48O3) shell using electrolytic deposition. This new ASF is expected to have broader applications due to the higher piezoelectric coupling effect with the use of carbon fiber and PZT. The sol-gel technique was employed to deposit lead zirconium titanium (PZT) and silica composite film onto a copper (Cu)/polyimide (PI) flexible structure. The fabricated PZT-silica composite films were then used for flexible actuator and sensor applications. Interfacial properties and hydrophobicity of multifunctional Ni-nanopowder/epoxy composites were evaluated for self-sensing and actuation. The effects of water content on the actuation performance of ionic polymer-metal composites (IPMCs) were investigated experimentally. Multiscale modelling of a composite electroactive polymer structure was developed, in particular for tubular actuators. The models were validated with experimental data. Morphing structures. Three papers relate to morphing skins and structures. Several issues including stiffness and energy consumption were explored: Composite corrugated structures were used as morphing skin panels (MSPs) in the trailing edge region of a scaled morphing aerofoil section. Wind tunnel testing was carried out to demonstrate the MSP concept. Optimization of a variable-stiffness skin was performed for morphing high-lift devices. The objective is to design the structure to have high enough stiffness to withstand aerodynamic loading and yet low enough stiffness to enable morphing. The aerodynamic and actuation loads were taken into consideration during the optimization. Two adaptive and morphing structures were proposed for low-energy consumption or even energy-harvesting green buildings with the use of an optimization process. Searching for optimal solutions was done by means of an evolutionary technique while the compatibility of the resulting configurations of the adaptive envelope was ensured by the virtual force density method. We would like to thank all of the authors for their significant contributions to this special section for Smart Materials and Structures. We are also grateful to all of the reviewers and associate editors who handled the reviews for their time and effort. I would like to express my sincere appreciation to Professor E Garcia, Editor-in-Chief, for his encouragement by providing the opportunity to make this special section. I am indebted to IOP Publishing for their strong support and the staff, in particular publisher Natasha Leeper, for their special attention and excellent service.
NASA Technical Reports Server (NTRS)
Moisan, Tiffany A.; Ellisman, M. H.; Sosinsky, G. E.; Gerlach, John C. (Technical Monitor)
2001-01-01
Understanding the light-harvesting properties of algae and higher plants are a fundamental topic in photosynthesis research. Using thick sections obtained from fixed and embedded cultures of colonial P antarctica, we calculate tomographic reconstructions of individual chloroplasts under light-limiting and saturating conditions for net photosynthesis. Our goal is to gain an understanding of the continuity of thylakoid membranes and understand the spatial relationship between the pyrenoid, the starch containing organelle, and thylakoid membranes. We found that Phaeocystis showed considerable morphological and physiological flexibility in response to environmental light levels. We found that the thylakoids generally run parallel to the chloroplast membrane with many junctures and bifurcations, many of which are in contact with the chloroplast membrane itself. The considerable flexibility in the. thylakoid membranes allows for the accommodation of the pyrenoid structure. The arrangement of the thylakoids within these structures resemble those found in new structures of mitochondria cristae. We present a new structural model for algal chloroplasts which greatly revises current concepts of thylakoid membrane structure in relation to photoacclimation.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Khalifa, Hesham
Advanced ceramic materials exhibit properties that enable safety and fuel cycle efficiency improvements in advanced nuclear reactors. In order to fully exploit these desirable properties, new processing techniques are required to produce the complex geometries inherent to nuclear fuel assemblies and support structures. Through this project, the state of complex SiC-SiC composite fabrication for nuclear components has advanced significantly. New methods to produce complex SiC-SiC composite structures have been demonstrated in the form factors needed for in-core structural components in advanced high temperature nuclear reactors. Advanced characterization techniques have been employed to demonstrate that these complex SiC-SiC composite structures providemore » the strength, toughness and hermeticity required for service in harsh reactor conditions. The complex structures produced in this project represent a significant step forward in leveraging the excellent high temperature strength, resistance to neutron induced damage, and low neutron cross section of silicon carbide in nuclear applications.« less
SPF/DB primary structure for supersonic aircraft (T-38 horizontal stabilizer)
NASA Technical Reports Server (NTRS)
Delmundo, A. R.; Mcquilkin, F. T.; Rivas, R. R.
1981-01-01
The structural integrity and potential cost savings of superplastic forming/diffusion bonding (SPF/DB) titanium structure for future Supersonic Cruise Research (SCR) and military aircraft primary structure applications was demonstrated. Using the horizontal stabilizer of the T-38 aircraft as a baseline, the structure was redesigned to the existing criteria and loads, using SPF/DB titanium technology. The general concept of using a full-depth sandwich structure which is attached to a steel spindle, was retained. Trade studies demonstrated that the optimum design should employ double-truss, sinewave core in the deepest section of the surface, making a transition to single-truss core in the thinner areas at the leading and trailing edges and at the tip. At the extreme thin edges of the surface, the single-truss core was changed to dot core to provide for gas passages during the SPF/DB process. The selected SPF/DB horizontal stabilizer design consisted of a one-piece SPF/DB sinewave truss core panel, a trunnion fitting, and reinforcing straps. The fitting and the straps were mechanically fastened to the SPF/DB panel.
Engaging undergraduate students in hadron physics research and instrumentation
NASA Astrophysics Data System (ADS)
Horn, Tanja
2017-09-01
Nuclear physics research is fundamental to our understanding of the visible universe and at the same time intertwined with our daily life. Nuclear physics studies the origin and structure of the atomic nuclei in terms of their basic constituents, the quarks and gluons. Atoms and molecules would not exist without underlying quark-gluon interactions, which build nearly all the mass of the visible universe from an assembly of massless gluons and nearly-massless quarks. The study of hadron structure with electromagnetic probes through exclusive and semi-inclusive scattering experiments carried out at the 12 GeV Jefferson Laboratory plays an important role in this effort. In particular, planned precision measurements of pion and kaon form factors and longitudinal-transverse separated deep exclusive pion and kaon electroproduction cross sections to the highest momentum transfers achievable play an important role in understanding hadron structure and masses and provide essential constraints for 3D hadron imaging. While a growing fraction of nuclear physics research is carried out at large international laboratories, individual university research groups play critical roles in the success of that research. These include data analysis projects and the development of state-of-the-art instrumentation demanded by increasingly sophisticated experiments. These efforts are empowered by the creativity of university faculty, staff, postdocs, and provide students with unique hands-on experience. As an example, an aerogel Cherenkov detector enabling strangeness physics research in Hall C at Jefferson Lab was constructed at the Catholic University of America with the help of 16 undergraduate and high school students. The ''Conference Experience for Undergraduates'' (CEU) provides a venue for these students who have conducted research in nuclear physics. This presentation will present the experiences of one of the participants in the first years of the CEU, her current research program in hadronic physics, and her current and former students who have been participating in more recent CEU events. Supported in part by NSF Grants PHY1714133, PHY1306227 and PHY1306418.
Equilibrium structures and flows of polar and nonpolar liquids in different carbon nanotubes
NASA Astrophysics Data System (ADS)
Abramyan, Andrey K.; Bessonov, Nick M.; Mirantsev, Leonid V.; Chevrychkina, Anastasiia A.
2018-03-01
Molecular dynamics (MD) simulations of equilibrium structures and flows of polar water and nonpolar methane confined by single-walled carbon nanotubes (SWCNTs) with circular and square cross sections and bounding walls with regular graphene structure and random (amorphous) distribution of carbon atoms have been performed. The results of these simulations show that equilibrium structures of both confined liquids depend strongly on the shape of the cross section of SWCNTs, whereas the structure of their bounding walls has a minor influence on these structures. On contrary, the external pressure driven water and methane flows through above mentioned SWCNTs depend significantly on both the shape of their cross sections and the structure of their bounding walls.
1991-06-01
32303, "Application of New Technology to Maintenance and Minor Repair," for which Mr. James E. McDonald (CEWES-SC-R) was Principal Investigator. Dr. Tony...materials, shotcrete, and silica-fume concrete. 6. Section -D contains 710 references-on maintenance and repair tech- niques including bonding new concrote to...sys- -tem. The process problems have been resolved-by introduction of new instrumentation, static mixers, elimination of washers and high density
Protein Crystal Growth (PCG) experiment aboard mission STS-66
NASA Technical Reports Server (NTRS)
2000-01-01
On the Space Shuttle Orbiter Atlantis' middeck, Astronaut Joseph R. Tarner, mission specialist, works at an area amidst several lockers which support the Protein Crystal Growth (PCG) experiment during the STS-66 mission. This particular section is called the Crystal Observation System, housed in the Thermal Enclosure System (COS/TES). Together with the Vapor Diffusion Apparatus (VDA), housed in Single Locker Thermal Enclosure (SLTES), the COS/TES represents the continuing research into the structure of proteins and other macromolecules such as viruses.
Astronaut Joseph R. Tanner works with PCG experiment on middeck
1994-11-14
On the Space Shuttle Atlantis' mid-deck, astronaut Joseph R. Tanner, mission specialist, works at area amidst several lockers onboard the Shuttle which support the Protein Crystal Growth (PCG) experiment. This particular section is called the Crystal Observation System, housed in the Thermal Enclosure System (COS/TES). Together with the Vapor Diffusion Apparatus (VDA), housed in a Single Locker Thermal Enclosure (SLTES) which is out of frame, the Cos/TES represents the continuing research into the structures of proteins and other macromolecules such as viruses.
2014-01-01
airships , was taken into consideration when checking cross section dimensions. The top speed chosen to size the engines was 84 knots. The maximum...paramount to understanding the structural design. Engine choice is also critical since long duration missions, typical for airships , heavily...geometry input pages. This may serve as a starting point for a new airship . • Layout is used to define engine , fin and gondola geometry. • Geometry 1
1993-08-12
Shop for their expert assistance during thze design ard development ur the wind tunnel and experimental apparatus; Drs. Alan L. Kistler, Seth Lichter...vertical wind tunnel was designed and built for this research. I With the test section in a vertical orientation, gravity effects leading to cylinder sag...were eliminated. The overall design and layout of the wind tunnel, as well as specific design features incorporated into the wind tunnel to satisfy
Annual Report on Electronics Research at The University of Texas at Austin.
1982-05-15
Professor, Physics, 471-5747 L. Frommhold, Professor, Physics, 471-5100 J. Keto , Associate Professor, Physics, 471-4151 H.J. Kimble, Assistant Professor...Scattering Cross Section of Argon Diatom," Canad. J. Physics, 59, 1418 (1981). *Michael H. Proffitt, J.W. Keto and Lothar Frommhold, "Col- lision Induced...Elec- tron Diffraction Study of the Structure of Anthraquinone and Anthracene," J. Mol. Struct. 77, 127-138 (1981). J.W. Keto , T.D. Raymond and Chien-Yu
1991-06-01
steps at the Rugby Football Union Ground in Twickenham, England. The deteriorated steps were cut away from the existing steel support beams. Reinforcing...provided in each vol- ume as a guide for users of this -bibliography. 6 SECTION C MAINTENANCE AND--REPAIR MATERIALS and a matching of these needs to a...calculations were correct). 73 Several types- of repair mediums are available. The medium should match -the quality of the-6riginal concrete but with-greater
1979-12-01
Links between processes can be aLlocated strictLy to controL functions. In fact, the degree of separation of control and data is an important research is...delays or Loss of control messages. Cognoscienti agree that message-passing IPC schemes are equivalent in "power" to schemes which employ shared...THEORETICAL WORK Page 55 SECTION 6 THEORETICAL WORK 6.1 WORKING GRUP JIM REP.OR STRUCTURE of Discussion: Distributed system without central (or any) control
Lidar Observations of the Optical Properties and 3-Dimensional Structure of Cirrus Clouds
NASA Technical Reports Server (NTRS)
Eloranta, E. W.
1996-01-01
The scientific research conducted under this grant have been reported in a series of journal articles, dissertations, and conference proceedings. This report consists of a compilation of these publications in the following areas: development and operation of a High Spectral Resolution Lidar, cloud physics and cloud formation, mesoscale observations of cloud phenomena, ground-based and satellite cloud cover observations, impact of volcanic aerosols on cloud formation, visible and infrared radiative relationships as measured by satellites and lidar, and scattering cross sections.
NASA Astrophysics Data System (ADS)
Fritz, Steffen
2017-07-01
The book titled European Landscape Dynamics is a comprehensive compendium on the European CORINE land cover (CLC) and some other aspects such as fragmentation and ecosystem services in Europe. The authors constitute a wide selection of researchers and practitioners from across Europe active in this field. It contains 29 chapters of very different sizes ranging between 2 pages (Chapter 8) to 43 pages (Chapter 20). The book is structured in 5 different sections: 1. Introduction; 2. Methodology; 3. European CORINE data layers; 4. Case studies; and 5. CORINE Land Cover Perspective.
A national facility for biological cryo-electron microscopy
Saibil, Helen R.; Grünewald, Kay; Stuart, David I.
2015-01-01
Three-dimensional electron microscopy is an enormously powerful tool for structural biologists. It is now able to provide an understanding of the molecular machinery of cells, disease processes and the actions of pathogenic organisms from atomic detail through to the cellular context. However, cutting-edge research in this field requires very substantial resources for equipment, infrastructure and expertise. Here, a brief overview is provided of the plans for a UK national three-dimensional electron-microscopy facility for integrated structural biology to enable internationally leading research on the machinery of life. State-of-the-art equipment operated with expert support will be provided, optimized for both atomic-level single-particle analysis of purified macromolecules and complexes and for tomography of cell sections. The access to and organization of the facility will be modelled on the highly successful macromolecular crystallography (MX) synchrotron beamlines, and will be embedded at the Diamond Light Source, facilitating the development of user-friendly workflows providing near-real-time experimental feedback. PMID:25615867
NASA Astrophysics Data System (ADS)
Sinha, Tarkeshwar; Lilhare, Devjyoti; Khare, Ayush
2018-02-01
Zinc sulfide (ZnS) thin films deposited by chemical bath deposition (CBD) technique have proved their capability in a wide area of applications including electroluminescent and display devices, solar cells, sensors, and field emitters. These semiconducting thin films have attracted a much attention from the scientific community for industrial and research purposes. In this article, we provide a comprehensive review on the effect of various parameters on various properties of CBD-grown ZnS films. In the first part, we discuss the historical background of ZnS, its basic properties, and the advantages of the CBD technique. Detailed discussions on the film growth, structural and optical properties of ZnS thin films affected by various parameters, such as bath temperature and concentration, deposition time, stirring speed, complexing agents, pH value, humidity in the environment, and annealing conditions, are also presented. In later sections, brief information about the recent studies and findings is also added to explore the scope of research work in this field.
Benson, Alex J; Eys, Mark
2017-02-01
The ways in which newcomers are integrated into sport teams may have broad consequences for the athletes entering the group, as well as for the existing team members. Drawing from organizational socialization theory, the current research developed a questionnaire to assess athletes' perceptions of how newcomers are socialized into their group. Across four studies, think-aloud interviews (N = 8), an expert panel review (N = 6), cross-sectional tests of the factor structure (N Study 2 = 197; N Study 3 = 460), and a two-wave correlational design (N Study 4 = 194) were used to evaluate the construct validity and the internal consistency of the Sport Team Socialization Tactics Questionnaire (STSTQ). Collectively, these efforts identified a three-factor structure underlying the STSTQ and provided preliminary evidence for its validity. The STSTQ enables researchers to systematically examine the individual- and group-level consequences associated with the socialization tactics implemented in sport teams.
Enhancing regenerative approaches with nanoparticles
Habibovic, Pamela
2017-01-01
In this review, we discuss recent developments in the field of nanoparticles and their use in tissue regeneration approaches. Owing to their unique chemical properties and flexibility in design, nanoparticles can be used as drug delivery systems, to create novel features within materials or as bioimaging agents, or indeed these properties can be combined to create smart multifunctional structures. This review aims to provide an overview of this research field where the focus will be on nanoparticle-based strategies to stimulate bone regeneration; however, the same principles can be applied for other tissue and organ regeneration strategies. In the first section, nanoparticle-based methods for the delivery of drugs, growth factors and genetic material to promote tissue regeneration are discussed. The second section deals with the addition of nanoparticles to materials to create nanocomposites. Such materials can improve several material properties, including mechanical stability, biocompatibility and biological activity. The third section will deal with the emergence of a relatively new field of research using nanoparticles in advanced cell imaging and stem cell tracking approaches. As the development of nanoparticles continues, incorporation of this technology in the field of regenerative medicine will ultimately lead to new tools that can diagnose, track and stimulate the growth of new tissues and organs. PMID:28404870
Enhancing regenerative approaches with nanoparticles.
van Rijt, Sabine; Habibovic, Pamela
2017-04-01
In this review, we discuss recent developments in the field of nanoparticles and their use in tissue regeneration approaches. Owing to their unique chemical properties and flexibility in design, nanoparticles can be used as drug delivery systems, to create novel features within materials or as bioimaging agents, or indeed these properties can be combined to create smart multifunctional structures. This review aims to provide an overview of this research field where the focus will be on nanoparticle-based strategies to stimulate bone regeneration; however, the same principles can be applied for other tissue and organ regeneration strategies. In the first section, nanoparticle-based methods for the delivery of drugs, growth factors and genetic material to promote tissue regeneration are discussed. The second section deals with the addition of nanoparticles to materials to create nanocomposites. Such materials can improve several material properties, including mechanical stability, biocompatibility and biological activity. The third section will deal with the emergence of a relatively new field of research using nanoparticles in advanced cell imaging and stem cell tracking approaches. As the development of nanoparticles continues, incorporation of this technology in the field of regenerative medicine will ultimately lead to new tools that can diagnose, track and stimulate the growth of new tissues and organs. © 2017 The Author(s).
Fernández-Suárez, Xosé M; Rigden, Daniel J; Galperin, Michael Y
2014-01-01
The 2014 Nucleic Acids Research Database Issue includes descriptions of 58 new molecular biology databases and recent updates to 123 databases previously featured in NAR or other journals. For convenience, the issue is now divided into eight sections that reflect major subject categories. Among the highlights of this issue are six databases of the transcription factor binding sites in various organisms and updates on such popular databases as CAZy, Database of Genomic Variants (DGV), dbGaP, DrugBank, KEGG, miRBase, Pfam, Reactome, SEED, TCDB and UniProt. There is a strong block of structural databases, which includes, among others, the new RNA Bricks database, updates on PDBe, PDBsum, ArchDB, Gene3D, ModBase, Nucleic Acid Database and the recently revived iPfam database. An update on the NCBI's MMDB describes VAST+, an improved tool for protein structure comparison. Two articles highlight the development of the Structural Classification of Proteins (SCOP) database: one describes SCOPe, which automates assignment of new structures to the existing SCOP hierarchy; the other one describes the first version of SCOP2, with its more flexible approach to classifying protein structures. This issue also includes a collection of articles on bacterial taxonomy and metagenomics, which includes updates on the List of Prokaryotic Names with Standing in Nomenclature (LPSN), Ribosomal Database Project (RDP), the Silva/LTP project and several new metagenomics resources. The NAR online Molecular Biology Database Collection, http://www.oxfordjournals.org/nar/database/c/, has been expanded to 1552 databases. The entire Database Issue is freely available online on the Nucleic Acids Research website (http://nar.oxfordjournals.org/).
Health and Safety Research Division. Progress report, October 1, 1979-March 31, 1981
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
1981-08-01
Research progress for the period October 1, 1979 through March 31, 1981 is reported. Research conducted by the Office of Integrated Assessments and Policy Analysis, Health Studies Section, Technology Assessments Section, Biological and Radiation Physics Section, and Chemical Physics Section is summarized. (ACR)
A Finite Element Procedure for Calculating Fluid-Structure Interaction Using MSC/NASTRAN
NASA Technical Reports Server (NTRS)
Chargin, Mladen; Gartmeier, Otto
1990-01-01
This report is intended to serve two purposes. The first is to present a survey of the theoretical background of the dynamic interaction between a non-viscid, compressible fluid and an elastic structure is presented. Section one presents a short survey of the application of the finite element method (FEM) to the area of fluid-structure-interaction (FSI). Section two describes the mathematical foundation of the structure and fluid with special emphasis on the fluid. The main steps in establishing the finite element (FE) equations for the fluid structure coupling are discussed in section three. The second purpose is to demonstrate the application of MSC/NASTRAN to the solution of FSI problems. Some specific topics, such as fluid structure analogy, acoustic absorption, and acoustic contribution analysis are described in section four. Section five deals with the organization of the acoustic procedure flowchart. Section six includes the most important information that a user needs for applying the acoustic procedure to practical FSI problems. Beginning with some rules concerning the FE modeling of the coupled system, the NASTRAN USER DECKs for the different steps are described. The goal of section seven is to demonstrate the use of the acoustic procedure with some examples. This demonstration includes an analytic verification of selected FE results. The analytical description considers only some aspects of FSI and is not intended to be mathematically complete. Finally, section 8 presents an application of the acoustic procedure to vehicle interior acoustic analysis with selected results.
Examining non-structural retrofitting status of teaching hospitals in Kerman against disasters
Moghadam, Mahmood Nekooi; Moradi, Seyed Mobin; Amiresmaili, Mohammadreza
2017-01-01
Background and objective Continuous services provision of a hospital before and after a disaster is one of the most prominent issues that all people, especially the authorities must take into huge consideration. Concerning the experiences of previous earthquakes, the role and importance of nonstructural components becomes increasingly clear in the uninterrupted services of hospitals. In this study, non-structural retrofitting status of Kerman teaching hospitals was evaluated against natural disasters. Methods This cross-sectional study was carried out in the second half of 2014 on the teaching hospitals in Kerman (Iran). The study population consisted of all Kerman teaching hospitals. The research instrument was World Health Organization/Pan American Health Organization (WHO/PAHO) standard checklist. Data analysis was carried out using descriptive statistics through SPSS 19. Results One hospital had a low retrofitting level, two hospitals had an average level and one had a high level. In the examined hospitals in this study, the medical gas section had the lowest preparedness against natural disasters, while the office, warehouse and furniture section had the highest resistance. Generally, the non-structural retrofitting status was 50% in one hospital and was between 65% and 85% in other hospitals. Conclusions Generally, the retrofitting status of hospitals was not at the ideal condition, most hospitals were in average condition. Concerning the high risk of hospitals in disasters, it is necessary that senior executives and managers of Kerman Province and Kerman University of Medical Sciences take some measures to retrofit these buildings and to reduce the risk of vulnerability. PMID:28713518
Türker-Kaya, Sevgi; Huck, Christian W
2017-01-20
Plant cells, tissues and organs are composed of various biomolecules arranged as structurally diverse units, which represent heterogeneity at microscopic levels. Molecular knowledge about those constituents with their localization in such complexity is very crucial for both basic and applied plant sciences. In this context, infrared imaging techniques have advantages over conventional methods to investigate heterogeneous plant structures in providing quantitative and qualitative analyses with spatial distribution of the components. Thus, particularly, with the use of proper analytical approaches and sampling methods, these technologies offer significant information for the studies on plant classification, physiology, ecology, genetics, pathology and other related disciplines. This review aims to present a general perspective about near-infrared and mid-infrared imaging/microspectroscopy in plant research. It is addressed to compare potentialities of these methodologies with their advantages and limitations. With regard to the organization of the document, the first section will introduce the respective underlying principles followed by instrumentation, sampling techniques, sample preparations, measurement, and an overview of spectral pre-processing and multivariate analysis. The last section will review selected applications in the literature.
An Experimental Study on Strengthening of Reinforced Concrete Flexural Members using Steel Wire Mesh
NASA Astrophysics Data System (ADS)
Al Saadi, Hamza Salim Mohammed; Mohandas, Hoby P.; Namasivayam, Aravind
2017-01-01
One of the major challenges and contemporary research in the field of structural engineering is strengthening of existing structural elements using readily available materials in the market. Several investigations were conducted on strengthening of various structural components using traditional and advanced materials. Many researchers tried to enhance the reinforced concrete (RC) beams strength using steel plate, Glass and Carbon Fibre Reinforced Polymers (GFRP & CFRP). For the reason that high weight to the strength ratio and compatibility in strength between FRP composites and steel bars, steel plates and GFRP and CFRP composites are not used for strengthening works practically. Hence, in this present work the suitability of using wire mesh for the purpose of strengthening the RC flexural members is studied by conducting experimental works. New technique of strengthening system using wire mesh with a view to improve sectional properties and subsequently flexural strength of RC beams is adopted in this work. The results for experimental and theoretical analysis were compared and found that good correlation exists between them. The experimental results indicate that RC beams strengthened with steel wire mesh are easy technique for strengthening of existing flexural members.
A national facility for biological cryo-electron microscopy
DOE Office of Scientific and Technical Information (OSTI.GOV)
Saibil, Helen R., E-mail: h.saibil@mail.cryst.bbk.ac.uk; Grünewald, Kay; Stuart, David I.
2015-01-01
This review provides a brief update on the use of cryo-electron microscopy for integrated structural biology, along with an overview of the plans for the UK national facility for electron microscopy being built at the Diamond synchrotron. Three-dimensional electron microscopy is an enormously powerful tool for structural biologists. It is now able to provide an understanding of the molecular machinery of cells, disease processes and the actions of pathogenic organisms from atomic detail through to the cellular context. However, cutting-edge research in this field requires very substantial resources for equipment, infrastructure and expertise. Here, a brief overview is provided ofmore » the plans for a UK national three-dimensional electron-microscopy facility for integrated structural biology to enable internationally leading research on the machinery of life. State-of-the-art equipment operated with expert support will be provided, optimized for both atomic-level single-particle analysis of purified macromolecules and complexes and for tomography of cell sections. The access to and organization of the facility will be modelled on the highly successful macromolecular crystallography (MX) synchrotron beamlines, and will be embedded at the Diamond Light Source, facilitating the development of user-friendly workflows providing near-real-time experimental feedback.« less
Manufacturing processes for fabricating graphite/PMR 15 polyimide structural elements
NASA Technical Reports Server (NTRS)
Sheppard, C. H.; Hoggatt, J. T.; Symonds, W. A.
1979-01-01
Investigations were conducted to obtain commercially available graphite/PMR-15 polyimide prepreg, develop an autoclave manufacturing process, and demonstrate the process by manufacturing structural elements. Controls were established on polymer, prepreg, composite fabrication, and quality assurance, Successful material quality control and processes were demonstrated by fabricating major structural elements including flat laminates, hat sections, I beam sections, honeycomb sandwich structures, and molded graphite reinforced fittings. Successful fabrication of structural elements and simulated section of the space shuttle aft body flap shows that the graphite/PMR-15 polyimide system and the developed processes are ready for further evaluation in flight test hardware.
26 CFR 1.1446-5 - Tiered partnership structures.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 26 Internal Revenue 12 2010-04-01 2010-04-01 false Tiered partnership structures. 1.1446-5 Section...-Free Covenant Bonds § 1.1446-5 Tiered partnership structures. (a) In general. The rules of this section... prescribes rules applicable to a publicly traded partnership in a tiered partnership structure. Paragraph (e...
28 CFR 0.191 - Changes which affect the overall structure of the Department.
Code of Federal Regulations, 2010 CFR
2010-07-01
... structure of the Department. 0.191 Section 0.191 Judicial Administration DEPARTMENT OF JUSTICE ORGANIZATION OF THE DEPARTMENT OF JUSTICE Sections and Subunits § 0.191 Changes which affect the overall structure of the Department. Changes to the overall structure of the Department include: The establishment...
40 CFR 92.6 - Regulatory structure.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Regulatory structure. 92.6 Section 92... Regulations for Locomotives and Locomotive Engines § 92.6 Regulatory structure. This section provides an overview of the regulatory structure of this part. (a) The regulations of this part 92 are intended to...
40 CFR 94.6 - Regulatory structure.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Regulatory structure. 94.6 Section 94... for Compression-Ignition Marine Engines § 94.6 Regulatory structure. This section provides an overview of the regulatory structure of this part. (a) The regulations of this Part 94 are intended to control...
Heritage landscape structure analysis in surrounding environment of the Grand Canal Yangzhou section
NASA Astrophysics Data System (ADS)
Xu, Huan
2018-03-01
The Yangzhou section of the Grand Canal is selected for a case study in this paper. The ZY-3 satellite images of 2016 are adopted as the data source. RS and GIS are used to analyze the landscape classification of the surrounding landscape of the Grand Canal, and the classification results are precisely evaluated. Next, the overall features of the landscape pattern are analyzed. The results showed that the overall accuracy is 82.5% and the Kappa coefficient is 78.17% in the Yangzhou section. The producer’s accuracy of the water landscape is the highest, followed by that of the other landscape, farmland landscape, garden and forest landscape, architectural landscape. The user’s accuracy of different landscape types can be ranked in a descending order, as the water landscape, farmland landscape, road landscape, architectural landscape, other landscape, garden and forest landscape. The farmland landscape and the architectural landscape are the top advantageous landscape types of the heritage site. The research findings can provide basic data for landscape protection, management and sustainable development of the Grand Canal Yangzhou section.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Larriba, Carlos, E-mail: clarriba@umn.edu; Hogan, Christopher J.
2013-10-15
The structures of nanoparticles, macromolecules, and molecular clusters in gas phase environments are often studied via measurement of collision cross sections. To directly compare structure models to measurements, it is hence necessary to have computational techniques available to calculate the collision cross sections of structural models under conditions matching measurements. However, presently available collision cross section methods contain the underlying assumption that collision between gas molecules and structures are completely elastic (gas molecule translational energy conserving) and specular, while experimental evidence suggests that in the most commonly used background gases for measurements, air and molecular nitrogen, gas molecule reemission ismore » largely inelastic (with exchange of energy between vibrational, rotational, and translational modes) and should be treated as diffuse in computations with fixed structural models. In this work, we describe computational techniques to predict the free molecular collision cross sections for fixed structural models of gas phase entities where inelastic and non-specular gas molecule reemission rules can be invoked, and the long range ion-induced dipole (polarization) potential between gas molecules and a charged entity can be considered. Specifically, two calculation procedures are described detail: a diffuse hard sphere scattering (DHSS) method, in which structures are modeled as hard spheres and collision cross sections are calculated for rectilinear trajectories of gas molecules, and a diffuse trajectory method (DTM), in which the assumption of rectilinear trajectories is relaxed and the ion-induced dipole potential is considered. Collision cross section calculations using the DHSS and DTM methods are performed on spheres, models of quasifractal aggregates of varying fractal dimension, and fullerene like structures. Techniques to accelerate DTM calculations by assessing the contribution of grazing gas molecule collisions (gas molecules with altered trajectories by the potential interaction) without tracking grazing trajectories are further discussed. The presented calculation techniques should enable more accurate collision cross section predictions under experimentally relevant conditions than pre-existing approaches, and should enhance the ability of collision cross section measurement schemes to discern the structures of gas phase entities.« less
Fish assemblage structure and habitat associations in a large western river system
Smith, C.D.; Quist, Michael C.; Hardy, R. S.
2016-01-01
Longitudinal gradients of fish assemblage and habitat structure were investigated in the Kootenai River of northern Idaho. A total of 43 500-m river reaches was sampled repeatedly with several techniques (boat-mounted electrofishing, hoop nets and benthic trawls) in the summers of 2012 and 2013. Differences in habitat and fish assemblage structure were apparent along the longitudinal gradient of the Kootenai River. Habitat characteristics (e.g. depth, substrate composition and water velocity) were related to fish assemblage structure in three different geomorphic river sections. Upper river sections were characterized by native salmonids (e.g. mountain whitefish Prosopium williamsoni), whereas native cyprinids (peamouth Mylocheilus caurinus, northern pikeminnow Ptychocheilus oregonensis) and non-native fishes (pumpkinseed Lepomis gibbosus, yellow perch Perca flavescens) were common in the downstream section. Overall, a general pattern of species addition from upstream to downstream sections was discovered and is likely related to increased habitat complexity and additions of non-native species in downstream sections. Assemblage structure of the upper sections were similar, but were both dissimilar to the lower section of the Kootenai River. Species-specific hurdle regressions indicated the relationships among habitat characteristics and the predicted probability of occurrence and relative abundance varied by species. Understanding fish assemblage structure in relation to habitat could improve conservation efforts of rare fishes and improve management of coldwater river systems.
Henoch, Ingela; Carlander, Ida; Holm, Maja; James, Inger; Sarenmalm, Elisabeth Kenne; Hagelin, Carina Lundh; Lind, Susanne; Sandgren, Anna; Öhlén, Joakim
2016-03-01
In 2007, a literature review was undertaken of palliative care research from Sweden during the 1970s-2006, paving the way for a follow-up study to explore the recent developments. The aim was to systematically examine palliative care research from Sweden between 2007 and 2012, with special attention to methods, designs and research foci. A literature review was undertaken. The databases Academic search elite, Age line, Ahmed, Cinahl, PsychInfo, PubMed, Scopus, Soc abstracts, Web of science and Libris were reviewed for Swedish palliative care research studies published from 2007 to 2012, applying the search criteria 'palliative care OR palliative medicine OR end-of-life care OR terminal care OR hospice care OR dying OR death'. A total of 263 papers met the inclusion criteria, indicating an increased volume of research compared to the 133 articles identified in the previous review. Common study foci were symptom assessment and management, experiences of illness and care planning. Targeting non-cancer-specific populations and utilisation of population-based register studies were identified as new features. There was continued domination of cross-sectional, qualitative and mono-disciplinary studies, not including ethnic minority groups, nonverbally communicable people or children <18 years of age. The trend is that Swedish palliative care research has expanded in volume from 2007 to 2012 compared to during the 1970s to 2006, with increasing participation of non-cancer-specific populations. A domination of qualitative approaches and small, cross-sectional studies with few interventions is still characteristic. Still more strategies are needed to expand the knowledge development of palliative care to respond to demographical, epidemiological, therapeutic and healthcare structure changes. © 2015 Nordic College of Caring Science.
Cancer Research in the Arab World
Hamadeh, Randah R.; Borgan, Saif M.; Sibai, Abla M.
2017-01-01
This review aimed to examine trends in cancer research in the Arab world and identify existing research gaps. A search of the MEDLINE® database (National Library of Medicine, Bethesda, Maryland, USA) was undertaken for all cancer-related publications published between January 2000 and December 2013 from seven countries, including Bahrain, Kuwait, Iraq, Lebanon, Morocco, Palestine and Sudan. A total of 1,773 articles were identified, with a significant increase in yearly publications over time (P <0.005). Only 30.6% of the publications included subjects over the age of 50 years old. There was a dearth of cross-sectional/correlational studies (8.8%), randomised controlled trials (2.4%) and systematic reviews/meta-analyses (1.3%). Research exploring cancer associations mainly considered social and structural determinants of health (27.1%), followed by behavioural risk factors (14.1%), particularly tobacco use. Overall, more cancer research is needed in the Arab world, particularly analytical studies with high-quality evidence and those focusing on older age groups and associations with physical activity and diet. PMID:28690885
Layer coefficients for NHDOT pavement materials
NASA Astrophysics Data System (ADS)
Janoo, Vincent C.
1994-09-01
In 1992, the New Hampshire Department of Transportation (NHDOT) experimented with the use of reclaimed asphalt concrete as a base course material, identified by NHDOT as reclaimed stabilized base (RSB). The RSB and a control test section were placed on Interstate 93 between exits 18 and 19. The RSB test section was designed to the same structural number (SN) as the control. To evaluate the structural capacity of these test sections, the U.S. Army Cold Regions Research and Engineering Laboratory (CRREL) conducted deflection tests using a Dynatest 8000 falling weight deflectometer (FWD). Preliminary analysis of the results by NHDOT personnel showed higher deflection in the reclaimed asphalt concrete test sections. The explanation was that the layer coefficient used for the RSB layer in the design was probably incorrect. A total of 10 test sections constituting the base course materials used by NHDOT were built near Bow, New Hampshire. CRREL evaluated and estimated the layer coefficients of the base course materials. The test program was developed to characterize the material in more than one way. Tests were conducted with the heavy weight deflectometer (HWD), dynamic cone penetrometer (DCP) and the Clegg hammer. In situ California bearing ratio (CBR) tests were also conducted. The deflection from the HWD were used with the WESDEF back calculation program to determine the layer moduli. The moduli were than used with the AASHTO Design Guide to calculate the layer coefficients. The layer coefficients were also determined with the method proposed by Rohde. The CBR values from the Clegg hammer, in situ CBR and DCP tests were also used in the relationships in the HDM model to determine the layer coefficients.
Structuring Legacy Pathology Reports by openEHR Archetypes to Enable Semantic Querying.
Kropf, Stefan; Krücken, Peter; Mueller, Wolf; Denecke, Kerstin
2017-05-18
Clinical information is often stored as free text, e.g. in discharge summaries or pathology reports. These documents are semi-structured using section headers, numbered lists, items and classification strings. However, it is still challenging to retrieve relevant documents since keyword searches applied on complete unstructured documents result in many false positive retrieval results. We are concentrating on the processing of pathology reports as an example for unstructured clinical documents. The objective is to transform reports semi-automatically into an information structure that enables an improved access and retrieval of relevant data. The data is expected to be stored in a standardized, structured way to make it accessible for queries that are applied to specific sections of a document (section-sensitive queries) and for information reuse. Our processing pipeline comprises information modelling, section boundary detection and section-sensitive queries. For enabling a focused search in unstructured data, documents are automatically structured and transformed into a patient information model specified through openEHR archetypes. The resulting XML-based pathology electronic health records (PEHRs) are queried by XQuery and visualized by XSLT in HTML. Pathology reports (PRs) can be reliably structured into sections by a keyword-based approach. The information modelling using openEHR allows saving time in the modelling process since many archetypes can be reused. The resulting standardized, structured PEHRs allow accessing relevant data by retrieving data matching user queries. Mapping unstructured reports into a standardized information model is a practical solution for a better access to data. Archetype-based XML enables section-sensitive retrieval and visualisation by well-established XML techniques. Focussing the retrieval to particular sections has the potential of saving retrieval time and improving the accuracy of the retrieval.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Burge, S.W.
This report describes the theory and structure of the FORCE2 flow program. The manual describes the governing model equations, solution procedure and their implementation in the computer program. FORCE2 is an extension of an existing B&V multidimensional, two-phase flow program. FORCE2 was developed for application to fluid beds by flow implementing a gas-solids modeling technology derived, in part, during a joint government -- industry research program, ``Erosion of FBC Heat Transfer Tubes,`` coordinated by Argonne National Laboratory. The development of FORCE2 was sponsored by ASEA-Babcock, an industry participant in this program. This manual is the principal documentation for the programmore » theory and organization. Program usage and post-processing of code predictions with the FORCE2 post-processor are described in a companion report, FORCE2 -- A Multidimensional Flow Program for Fluid Beds, User`s Guide. This manual is segmented into sections to facilitate its usage. In section 2.0, the mass and momentum conservation principles, the basis for the code, are presented. In section 3.0, the constitutive relations used in modeling gas-solids hydrodynamics are given. The finite-difference model equations are derived in section 4.0 and the solution procedures described in sections 5.0 and 6.0. Finally, the implementation of the model equations and solution procedure in FORCE2 is described in section 7.0.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
None
Progress is reported on fundamental research in: crystal physics, reactions at metal surfaces, spectroscopy of ionic media, structure of metals, theory of alloying, physical properties, sintering, deformation of crystalline solids, x ray diffraction, metallurgy of superconducting materials, and electron microscope studies. Long-randge applied research studies were conducted for: zirconium metallurgy, materials compatibility, solid reactions, fuel element development, mechanical properties, non-destructive testing, and high-temperature materials. Reactor development support work was carried out for: gas-cooled reactor program, molten-salt reactor, high-flux isotope reactor, space-power program, thorium-utilization program, advanced-test reactor, Army Package Power Reactor, Enrico Fermi fast-breeder reactor, and water desalination program. Other programmore » activities, for which research was conducted, included: thermonuclear project, transuraniunn program, and post-irradiation examination laboratory. Separate abstracts were prepared for 30 sections of the report. (B.O.G.)« less
Attitude Research in Physical Education: A Review
ERIC Educational Resources Information Center
Silverman, Stephen
2017-01-01
This paper provides a comprehensive review of attitude research in physical education. The first section reviews theoretical models that are prevalent in attitude research. Then, the next section describes the methods that were used to locate the research used in the remainder of the paper. The third section discusses measurement issues in…
Engineering derivatives from biological systems for advanced aerospace applications
NASA Technical Reports Server (NTRS)
Winfield, Daniel L.; Hering, Dean H.; Cole, David
1991-01-01
The present study consisted of a literature survey, a survey of researchers, and a workshop on bionics. These tasks produced an extensive annotated bibliography of bionics research (282 citations), a directory of bionics researchers, and a workshop report on specific bionics research topics applicable to space technology. These deliverables are included as Appendix A, Appendix B, and Section 5.0, respectively. To provide organization to this highly interdisciplinary field and to serve as a guide for interested researchers, we have also prepared a taxonomy or classification of the various subelements of natural engineering systems. Finally, we have synthesized the results of the various components of this study into a discussion of the most promising opportunities for accelerated research, seeking solutions which apply engineering principles from natural systems to advanced aerospace problems. A discussion of opportunities within the areas of materials, structures, sensors, information processing, robotics, autonomous systems, life support systems, and aeronautics is given. Following the conclusions are six discipline summaries that highlight the potential benefits of research in these areas for NASA's space technology programs.
Logan, Robert A
2017-01-01
This chapter compares the conceptual foundations of health literacy and health disparities. It details some of the conceptual differences between health literacy and health disparities and explains some similarities that suggest the need for increased research collaboration. The chapter is among the first to address the structural and social determinants of health together and explain that future research needs to assess their interactions. Overall, the chapter creates a conceptual foundation as well as challenges future scholars/practitioners to take more multidimensional approaches to assess health's determinants. The chapter also attempts to demonstrate there is nothing more practical than good theory, or clear conceptual foundations. The chapter is divided into four sections that address the following topics: three conceptual frameworks about the determinants of health; opportunities in health disparities and health literacy research; seeking an expanded, multidimensional conceptual approach to health literacy and health disparities research; as well as a conclusion. The chapter suggests there are vacuums in current research knowledge that need future attention - especially regarding the integration of health literacy and health disparities research.
Middleton, James W; Tran, Yvonne; Lo, Charles; Craig, Ashley
2016-12-01
To improve the clinical utility of the Moorong Self-Efficacy Scale (MSES) by reexamining its factor structure and comparing its performance against a measure of general self-efficacy in persons with spinal cord injury (SCI). Cross-sectional survey design. Community. Adults with SCI (N=161; 118 men and 43 women) recruited from Australia (n=82) and the United States (n=79), including 86 with paraplegia and 75 with tetraplegia. None. Confirmatory factor analysis deriving fit indices on reported 1-, 2-, and 3-factor structures for the MSES. Exploratory factor analysis of MSES using principal component analysis with promax oblique rotation and structure validation, with correlations and multiple regression using cross-sectional data from the Sherer General Self-Efficacy Scale and Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36). The MSES was confirmed to have a 3-factor structure, explaining 61% of variance. Two of the factors, labeled social function self-efficacy and personal function self-efficacy, were SCI condition-specific, whereas the other factor (accounting for 9.7% of variance) represented general self-efficacy, correlating most strongly with the Sherer General Self-Efficacy Scale. Correlations and multiple regression analyses between MSES factors, Sherer General Self-Efficacy Scale total score, SF-36 Physical and Mental Component Summary scores, and SF-36 domain scores support validity of this MSES factor structure. No significant cross-cultural differences existed between Australia and the United States in total MSES or factor scores. The findings support a 3-factor structure encompassing general and SCI domain-specific self-efficacy beliefs and better position the MSES to assist SCI rehabilitation assessment, planning, and research. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.
Taheri, Safoura; Ehsanpour, Soheila; Kohan, Shahnaz
2014-03-01
Organizational and structural obstacles are a group of major obstacles in achievement of appropriate family planning counseling. Detection of these obstacles from the viewpoint of managers, staffs and clients who are key members in health services providing system is a major step toward appropriate planning to modify or delete this group of obstacles. The present study was conducted with the goal of comparing managers', staffs' and clients' viewpoints about organizational and structural obstacles in family planning counseling in health-care centers in Isfahan in 2012. This is a cross-sectional one-step three-group comparative descriptive study conducted on 295 subjects including 59 managers, 110 staffs and 126 clients in medical health-care centers in Isfahan in 2012. Managers and the staffs were selected by census sampling and the clients were recruited through convenient random sampling. The date collection tool was a researcher made questionnaire, which was designed in two sections of fertility and personal characteristics and viewpoint measurement. Descriptive and inferential statistical test were used to analyze the data. The obtained results showed no significant difference between mean scores of viewpoints in three groups of managers, staffs and clients concerning organizational and structural obstacles in family planning counseling (P = 0.677). In addition, most of the managers, staffs and clients reported organizational and structural obstacles as the obstacles in the process of family planning in moderate level. The results showed the necessity of health services managers' planning to modify or delete organizational and structural obstacles especially the agreed obstacles from the viewpoint of managers, staffs and clients.
High gradient linac for proton therapy
NASA Astrophysics Data System (ADS)
Benedetti, S.; Grudiev, A.; Latina, A.
2017-04-01
Proposed for the first time almost 30 years ago, the research on radio frequency linacs for hadron therapy experienced a sparkling interest in the past decade. The different projects found a common ground on a relatively high rf operating frequency of 3 GHz, taking advantage of the availability of affordable and reliable commercial klystrons at this frequency. This article presents for the first time the design of a proton therapy linac, called TULIP all-linac, from the source up to 230 MeV. In the first part, we will review the rationale of linacs for hadron therapy. We then divided this paper in two main sections: first, we will discuss the rf design of the different accelerating structures that compose TULIP; second, we will present the beam dynamics design of the different linac sections.
Aircraft engine hot section technology: An overview of the HOST Project
NASA Technical Reports Server (NTRS)
Sokolowski, Daniel E.; Hirschberg, Marvin H.
1990-01-01
NASA sponsored the Turbine Engine Hot Section (HOST) project to address the need for improved durability in advanced aircraft engine combustors and turbines. Analytical and experimental activities aimed at more accurate prediction of the aerothermal environment, the thermomechanical loads, the material behavior and structural responses to loads, and life predictions for cyclic high temperature operation were conducted from 1980 to 1987. The project involved representatives from six engineering disciplines who are spread across three work disciplines - industry, academia, and NASA. The HOST project not only initiated and sponsored 70 major activities, but also was the keystone in joining the multiple disciplines and work sectors to focus on critical research needs. A broad overview of the project is given along with initial indications of the project's impact.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
The body of this report provides summaries of the aims, scope and progress of the research by groups of investigators in the Division during the period of October 1, 1984, through September 30, 1985. At the end of each summary is a list of publications covering the same period. For convenience, the summaries are assembled under Sections in accordance with the current organizational structure of the Biology Division; each Section begins with an overview. It will be apparent, however, tha crosscurrents run throughout the Division and that the various programs support and interact with each other. In addition, this reportmore » includes information on the Division's educational activities, Advisory Committee, seminar program, and international interactions, as well as extramural activities of staff members, abstracts for technical meetings, and funding and personnel levels.« less
Komori, M; Miura, T; Shiota, K; Minato, K; Takahashi, T
1995-01-01
The volumetric shape of a human embryo and its development is hard to comprehend as they have been viewed as a 2D schemes in a textbook or microscopic sectional image. In this paper, a CAI and research support system for human embryology using multimedia presentation techniques is described. In this system, 3D data is acquired from a series of sliced specimens. Its 3D structure can be viewed interactively by rotating, extracting, and truncating its whole body or organ. Moreover, the development process of embryos can be animated using a morphing technique applied to the specimen in several stages. The system is intended to be used interactively, like a virtual reality system. Hence, the system is called Virtual Embryology.
Biology Division. Progress report, August 1, 1982-September 30, 1983
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
1984-01-01
The Biology Division is the component of the Oak Ridge National Laboratory that investigates the potential adverse health effects of energy-related substances. The body of this report provides summaries of the aims, scope and progress of the research of groups of investigators in the Division during the period of August 1, 1982, through September 30, 1983. At the end of each summary is a list of publications covering the same period (published or accepted for publication). For convenience, the summaries are assembled under Sections in accordance with the current organizational structure of the Biology Division; each Section begins with anmore » overview. It will be apparent, however, that currents run throughout the Division and that the various programs support and interact with each other.« less
Dynamic tests of composite panels of an aircraft wing
NASA Astrophysics Data System (ADS)
Splichal, Jan; Pistek, Antonin; Hlinka, Jiri
2015-10-01
The paper describes the analysis of aerospace composite structures under dynamic loading. Today, it is common to use design procedures based on assumption of static loading only, and dynamic loading is rarely assumed and applied in design and certification of aerospace structures. The paper describes the application of dynamic loading for the design of aircraft structures, and the validation of the procedure on a selected structure. The goal is to verify the possibility of reducing the weight through improved design/modelling processes using dynamic loading instead of static loading. The research activity focuses on the modelling and testing of a composite panel representing a local segment of an aircraft wing section, investigating in particular the buckling behavior under dynamic loading. Finite Elements simulation tools are discussed, as well as the advantages of using a digital optical measurement system for the evaluation of the tests. The comparison of the finite element simulations with the results of the tests is presented.
Displacement Based Multilevel Structural Optimization
NASA Technical Reports Server (NTRS)
Sobieszezanski-Sobieski, J.; Striz, A. G.
1996-01-01
In the complex environment of true multidisciplinary design optimization (MDO), efficiency is one of the most desirable attributes of any approach. In the present research, a new and highly efficient methodology for the MDO subset of structural optimization is proposed and detailed, i.e., for the weight minimization of a given structure under size, strength, and displacement constraints. Specifically, finite element based multilevel optimization of structures is performed. In the system level optimization, the design variables are the coefficients of assumed polynomially based global displacement functions, and the load unbalance resulting from the solution of the global stiffness equations is minimized. In the subsystems level optimizations, the weight of each element is minimized under the action of stress constraints, with the cross sectional dimensions as design variables. The approach is expected to prove very efficient since the design task is broken down into a large number of small and efficient subtasks, each with a small number of variables, which are amenable to parallel computing.
NASA Astrophysics Data System (ADS)
Sun, Li; Wang, Deyu
2011-09-01
A new multi-level analysis method of introducing the super-element modeling method, derived from the multi-level analysis method first proposed by O. F. Hughes, has been proposed in this paper to solve the problem of high time cost in adopting a rational-based optimal design method for ship structural design. Furthermore, the method was verified by its effective application in optimization of the mid-ship section of a container ship. A full 3-D FEM model of a ship, suffering static and quasi-static loads, was used as the analyzing object for evaluating the structural performance of the mid-ship module, including static strength and buckling performance. Research results reveal that this new method could substantially reduce the computational cost of the rational-based optimization problem without decreasing its accuracy, which increases the feasibility and economic efficiency of using a rational-based optimal design method in ship structural design.
Erlandson, Marta C; Runalls, Shonah B; Jackowski, Stefan A; Faulkner, Robert A; Baxter-Jones, Adam D G
2017-11-01
Premenarcheal female gymnasts have been consistently found to have greater bone mass and structural advantages. However, little is known about whether these structural advantages are maintained after the loading stimulus is removed. Therefore, the purpose of this study was to investigate the structural properties at the hip after long-term retirement from gymnastics. Structural properties were derived from dual-energy X-ray absorptiometry scans using the hip structural analysis program for the same 24 gymnasts and 21 nongymnasts both in adolescence (8-15 y) and adulthood (22-30 y). Structural measures were obtained at the narrow neck, intertrochanter, and femoral shaft and included cross-sectional area, section modulus, and buckling ratio. Multivariate analysis of covariance was used to assess differences between groups in bone measures while controlling for size, age, maturity, and physical activity. Gymnasts were found to have structural advantages at the narrow neck in adolescence (16% greater cross-sectional area, 17% greater section modulus, and 25% lower buckling ratio) and 14 years later (13% greater cross-sectional area and 26% lower buckling ratio). Benefits were also found at the intertrochanter and femoral shaft sites in adolescence and adulthood. Ten years after retirement from gymnastics, former gymnasts' maintained significantly better hip bone structure than females who did not participate in gymnastics during growth.
Seismic Modeling of the Alasehir Graben, Western Turkey
NASA Astrophysics Data System (ADS)
Gozde Okut, Nigar; Demirbag, Emin
2014-05-01
The purpose of this study is to develop a depth model to make synthetic seismic reflection sections, such as stacked and migrated sections with different velocity models. The study area is east-west trending Alasehir graben which is one of the most prominent structure in the western Anatolia, proved to have geothermal energy potential by researchers and exploration companies. Geological formations were taken from Alaşehir-1 borehole drilled by Turkish Petroleum Corporation (Çiftçi, 2007) and seismic interval velocities were taken from check-shots in the same borehole (Kolenoǧlu-Demircioǧlu, 2009). The most important structure is the master graben bounding fault (MGBF) in the southern margin of the Alasehir graben. Another main structure is the northern bounding fault called the antithetic fault of the MGBF with high angle normal fault characteristic. MGBF is a crucial contact between sedimentary cover and the metamorphic basement. From basement to the surface, five different stratigraphic units constitute graben fill . All the sedimentary units thicknesses get thinner from the southern margin to the northern margin of the Alasehir graben displaying roll-over geometry. A commercial seismic data software was used during modeling. In the first step, a 2D velocity/depth model was defined. Ray tracing was carried out with diffraction option to produce the reflection travel times. The reflection coefficients were calculated and wavelet shaping was carried out by means of band-pass filtering. Finally synthetic stacked section of the Alasehir graben was obtained. Then, migrated sections were generated with different velocity models. From interval velocities, average and RMS velocities were calculated for the formation entires to test how the general features of the geological model may change against different seismic models after the migration. Post-stack time migration method was used. Pseudo-velocity analysis was applied at selected CDP locations. In theory, seismic migration moves events to their correct spatial locations and collapse energy from diffractions back to their scattering points. This features of migration can be distinguished in the migrated sections. When interval velocities used, all the diffractions are removed and fault planes can be seen clearly. When average velocities used, MGBF plane extends to greater depths. Additionally, slope angles and locations of antithetic faults in the northern margin of the graben changes. When RMS velocities used, a migrated section was obtained for which to make an interpretation was quite hard, especially for the main structures along the northern margin and reflections related to formations.
Innovative forming and fabrication technologies : new opportunities.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Davis, B.; Hryn, J.; Energy Systems
2008-01-31
The advent of light metal alloys and advanced materials (polymer, composites, etc.) have brought the possibility of achieving important energy reductions into the full life cycle of these materials, especially in transportation applications. 1 These materials have gained acceptance in the aerospace industry but use of light metal alloys needs to gain wider acceptance in other commercial transportation areas. Among the main reasons for the relatively low use of these materials are the lack of manufacturability, insufficient mechanical properties, and increased material costs due to processing inefficiencies. Considering the enormous potential energy savings associated with the use of light metalmore » alloys and advanced materials in transportation, there is a need to identify R&D opportunities in the fields of materials fabrication and forming aimed at developing materials with high specific mechanical properties combined with energy efficient processes and good manufacturability. This report presents a literature review of the most recent developments in the areas of fabrication and metal forming focusing principally on aluminum alloys. In the first section of the document, the different sheet manufacturing technologies including direct chill (DC) casting and rolling, spray forming, spray rolling, thin slab, and strip casting are reviewed. The second section of the document presents recent research on advanced forming processes. The various forming processes reviewed are: superplastic forming, electromagnetic forming, age forming, warm forming, hydroforming, and incremental forming. Optimization of conventional forming processes is also discussed. Potentially interesting light metal alloys for high structural efficiency including aluminum-scandium, aluminum-lithium, magnesium, titanium, and amorphous metal alloys are also reviewed. This section concludes with a discussion on alloy development for manufacturability. The third section of the document reviews the latest developments in fiber-reinforced composite materials. Emerging curing processes are presented along with a discussion on the possible developments in biocomposite materials. The fourth section presents recent developments in the fabrication of bulk nanomaterials and nanoparticles reinforced materials. Advanced joining technologies are presented in the fifth section. Future research is proposed in the last section.« less
49 CFR 238.413 - End structures of trailer cars.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 49 Transportation 4 2012-10-01 2012-10-01 false End structures of trailer cars. 238.413 Section... II Passenger Equipment § 238.413 End structures of trailer cars. (a) Except as provided in paragraph (b) of this section, the end structure of a trailer car shall be designed to include the following...
49 CFR 238.413 - End structures of trailer cars.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 49 Transportation 4 2010-10-01 2010-10-01 false End structures of trailer cars. 238.413 Section... II Passenger Equipment § 238.413 End structures of trailer cars. (a) Except as provided in paragraph (b) of this section, the end structure of a trailer car shall be designed to include the following...
49 CFR 238.413 - End structures of trailer cars.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 49 Transportation 4 2013-10-01 2013-10-01 false End structures of trailer cars. 238.413 Section... II Passenger Equipment § 238.413 End structures of trailer cars. (a) Except as provided in paragraph (b) of this section, the end structure of a trailer car shall be designed to include the following...
49 CFR 238.413 - End structures of trailer cars.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 49 Transportation 4 2014-10-01 2014-10-01 false End structures of trailer cars. 238.413 Section... II Passenger Equipment § 238.413 End structures of trailer cars. (a) Except as provided in paragraph (b) of this section, the end structure of a trailer car shall be designed to include the following...
49 CFR 238.413 - End structures of trailer cars.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 4 2011-10-01 2011-10-01 false End structures of trailer cars. 238.413 Section... II Passenger Equipment § 238.413 End structures of trailer cars. (a) Except as provided in paragraph (b) of this section, the end structure of a trailer car shall be designed to include the following...