Sample records for offers concrete examples

  1. Interfaith Leaders as Social Entrepreneurs

    ERIC Educational Resources Information Center

    Patel, Eboo; Meyer, Cassie

    2012-01-01

    Social entrepreneurs work to find concrete solutions to large-scale problems that are scalable and sustainable. In this article, the authors explore what the framework of social entrepreneurship might offer those seeking to positively engage religious diversity on college campuses, and highlight two programs that offer examples of what such…

  2. Evaluation Practice and Theory: Up and down the Ladder of Abstraction

    ERIC Educational Resources Information Center

    Leviton, Laura C.

    2015-01-01

    Debra Rog presented the 2014 Eleanor Chelimsky Forum address, offering ways to integrate evaluation theory and practice by abundant use of practice examples. These examples illustrate the effective use of the Ladder of Abstraction from semantics, working from the concrete to the abstract and back again.

  3. Coming of Age: The Advanced Writing Curriculum [and CD-ROM]. CrossCurrents.

    ERIC Educational Resources Information Center

    Shamoon, Linda K., Ed.; Howard, Rebecca Moore, Ed.; Jamieson, Sandra, Ed.; Schwegler, Robert A., Ed.

    Part book, part CD-ROM, this publication offers new ideas for transforming advanced writing courses. The 33 essays in the publication describe and offer concrete examples of curriculum that incorporates discipline-based theory and history, that situates writers in public discourse, and that fully prepares students for careers as writers. The…

  4. Utah Marbles and Mars Blueberries: Comparitive Terrestrial Analogs for Hematite Concretions on Mars

    NASA Astrophysics Data System (ADS)

    Chan, M. A.; Beitler, B.; Parry, W. T.; Ormö, J.; Komatsu, G.

    2005-03-01

    Compelling comparisons show why Utah iron oxide-cemented "marbles" are a good analog for Mars hematite "blueberries". Terrestrial examples offer valuable models for interpreting the diagenetic history and importance of water on Mars.

  5. How to Teach Yourself Physical Skills: An Audio Tape for College Students with Some Introductory Comments and a Detailed Outline.

    ERIC Educational Resources Information Center

    Hodges, Daniel L.

    This guide provides a detailed summary of the information, techniques, and examples offered in an audiotape developed to help students teach themselves physical skills. After section I introduces the topic and the objectives of the tape, section II provides concrete examples of adults learning motor skills. Section III presents and discusses nine…

  6. 30 CFR 56.2 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... anticipated, will ignite, burn, support combustion, or release flammable vapors when subjected to fire or heat... covering is one means for making the conductor insulated. Insulation means a dielectric substance offering... flammable vapors when subjected to fire or heat. Concrete, masonry block, brick, and steel are examples of...

  7. Integrating Asian Film into Film Studies and Film Production Courses Using Examples from Yasujiro Ozu (Japan) and Zhang Yimou (China). Asian Studies Module, 1997.

    ERIC Educational Resources Information Center

    Carson, Diane

    This curriculum module offers concrete and specific examples for instructors who wish to integrate the films of Yasujiro Ozu of Japan and Zhang Yimou from China into film studies courses. Through this module, students should learn to compare and contrast conventional screen space, color, and editing to alternative forms. By becoming more familiar…

  8. Active Learning Strategies in Face-to-Face Courses. IDEA Paper #53

    ERIC Educational Resources Information Center

    Millis, Barbara J.

    2012-01-01

    As numerous research studies suggest, teachers who desire increased student learning should adopt active learning. This article explores the research, defines active learning, discusses its value, offers suggestions for implementing it, and provides six concrete examples of active learning approaches: Thinking-Aloud Pair Problem-Solving;…

  9. Concrete images of the sugar content in sugar-sweetened beverages reduces attraction to and selection of these beverages.

    PubMed

    Adams, John Milton; Hart, William; Gilmer, Lauren; Lloyd-Richardson, Elizabeth E; Burton, K Alex

    2014-12-01

    In the present research, we offer a novel method for informing consumers about the sugar content in sugar-sweetened beverages (SSBs). With a series of experiments, we present evidence that this method curbs preference for SSBs and leads to more negative attitudes toward SSBs. We propose that people view SSBs more negatively and show less preference for SSBs when they are able to concretely visualize the quantity of sugar in SSBs. For example, we suggest that people might have more negative views toward the idea of consuming 28 sugar cubes (concrete information), compared to consuming "70g" of sugar (abstract information). Indeed, we found that, without any intervention, people struggle to convert sugar grams into a concrete, physical sugar representation (Experiment 1). But, when people are provided ways to convert abstract sugar-nutrition information into a concrete representation, they find SSBs less attractive (Experiment 2) and are less likely to select SSBs in favor of sugar-free beverage options (Experiments 3 and 4). These findings offer direct applications to the design of public-health messages and nutrition-education interventions. Such applications might benefit society in its battle with the obesity epidemic. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Beyond Standards: Excellence in the High School English Classroom.

    ERIC Educational Resources Information Center

    Jago, Carol

    Each student is capable of achieving excellence, but it requires a nurturing, vigorous classroom environment. To help current and future high school English teachers create and maintain this kind of environment, this book offers concrete ways to reconceive what it means to foster excellent performance in the classroom and vivid examples of student…

  11. WWW Motivation Mining: Finding Treasures for Teaching Evaluation Skills, Grades 1-6. Professional Growth Series.

    ERIC Educational Resources Information Center

    Arnone, Marilyn P.; Small, Ruth V.

    Designed for elementary or middle school teachers and library media specialists, this book provides educators with practical, easy-to-use ways of applying motivation assessment techniques when selecting World Wide Web sites for inclusion in their lessons and offers concrete examples of how to use Web evaluation with young learners. WebMAC…

  12. For the Article Writer...How to Win Acceptances by Psychology Journals: 21 Tips for Better Writing.

    ERIC Educational Resources Information Center

    Sternberg, Robert J.

    1993-01-01

    Twenty-one suggestions are offered for successful writing for psychology journals. Suggestions include tell readers why they should be interested, consider alternative interpretations of the data, give concrete examples, write for a somewhat broader and technically less skilled audience than you expect to read the article, and don't take…

  13. "Reflexivity Is Kicking Our Asses": Tensions in Foregrounding Photographs in a Multimodal Ethnographic Analysis of Participation

    ERIC Educational Resources Information Center

    Chaffee, Rachel; Luehmann, April Lynn; Henderson, Joseph

    2016-01-01

    Bringing multimodal and ethnographic approaches together, this paper seeks to identify key considerations, limitations, and implications of using photographs as primary data. We offer a concrete example of an approach that capitalizes on a systematic look at how different modes work together to foreground unique aspects of participation, while…

  14. Patient Storytelling in the Classroom: A Memorable Way to Teach Spiritual Care.

    PubMed

    Garner, Shelby L

    2016-01-01

    Storytelling is an evidence-based teaching and learning strategy that engages students and promotes critical thinking. Although most nursing textbooks incorporate spiritual nursing care, the texts lack examples of how to tie evidence-based spiritual interventions to specific medical-suigical content. Stories told from the patient's perspective can communicate insights that nurses and students can use when planning spiritual carefor patients. Stories shared by patients with undergraduate nursing students were effective in promoting learning and offered concrete examples of supportive spiritual resources for patients.

  15. Accelerated Learning and Retention: Literature Review and Workshop Review

    DTIC Science & Technology

    2011-03-01

    effectiveness, and the committee found that neurolinguistic programming (NLP) had promise, but had not been shown to be effective. They also...Meier, 2000) have used accelerated learning in training programs . Table 3 provides concrete examples of some of the results offered by approaches...minute counts (as is the case in accelerated programs ), motivation is of critical importance. This is one reason why training interventions aimed to

  16. Reading the World's Classics Critically: A Keyword-Based Approach to Literary Analysis in Foreign Language Studies

    ERIC Educational Resources Information Center

    García, Nuria Alonso; Caplan, Alison

    2014-01-01

    While there are a number of important critical pedagogies being proposed in the field of foreign language study, more attention should be given to providing concrete examples of how to apply these ideas in the classroom. This article offers a new approach to the textual analysis of literary classics through the keyword-based methodology originally…

  17. Comment faire de la grammaire sans trahir le discours: Le cas des exercices grammaticaux (How to Teach Grammar without Betraying Discourse: The Case of Grammatical Exercises).

    ERIC Educational Resources Information Center

    Calve, Pierre

    1994-01-01

    Discusses the various functions of grammar in second-language (SL) education, and examines the relationship between discourse and grammar in SL education. Two problems are then examined concerning the relationship between discourse and grammar within grammatical exercises, and with the help of concrete examples, suggestions are offered to better…

  18. When Science is Not Enough: A Framework Towards More Customer-Focused Drug Development.

    PubMed

    Oraiopoulos, Nektarios; Dunlop, William C N

    2017-07-01

    The purpose of this study was to identify the key barriers to a customer-focused drug development process and develop a comprehensive framework to overcome them. The paper draws on existing literature, both academic and practitioner, across a range of disciplines (innovation management, marketing, organizational behavior, behavioral economics, health economics, industry reports). On the basis of this extensive review, a conceptual framework is developed that offers concrete suggestions on how organizations can overcome the barriers and enable a more customer-focused development process. The barriers to collaboration are organized into three distinct categories (economic, behavioral, organizational), and within each category, a one-to-one mapping between barriers and solutions is developed. The framework is specifically designed with the objective of offering actionable and practical advice to executives who face these challenges in their organizations. The paper provides a unique theoretical contribution by synthesizing findings from several academic disciplines with concrete examples from the pharmaceutical industry. Mundipharma International Limited.

  19. The Ascent of the Concrete: Grammatical Reification in Science Teaching Exchanges and Episodes

    ERIC Educational Resources Information Center

    Lim, Eunsook; Kellogg, David

    2008-01-01

    Foreign language learning and science teaching can both be seen as examples of Davydov's "ascent to the concrete", because they begin from abstract definitions and proceed in the direction of concrete use. The microgenetic lessons that enable these ontogenetic processes can also be seen as examples of "ascent of the concrete" because they involve,…

  20. View of Flume Tunnel #5 showing an example of concrete ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of Flume Tunnel #5 showing an example of concrete flume covered with concrete slabs as it enters a tunnel under the road (FS 502). Looking southwest - Childs-Irving Hydroelectric Project, Childs System, Flume Tunnel No. 5, Forest Service Road 708/502, Camp Verde, Yavapai County, AZ

  1. Estimation in SEM: A Concrete Example

    ERIC Educational Resources Information Center

    Ferron, John M.; Hess, Melinda R.

    2007-01-01

    A concrete example is used to illustrate maximum likelihood estimation of a structural equation model with two unknown parameters. The fitting function is found for the example, as are the vector of first-order partial derivatives, the matrix of second-order partial derivatives, and the estimates obtained from each iteration of the Newton-Raphson…

  2. Evaluation of Consideration and Incorporation of Green and Sustainable Remediation (GSR) Practices in Army Environmental Remediation. Volume 1

    DTIC Science & Technology

    2012-08-27

    materials Examples: - Cheese whey , molasses, compost, or off-spec food products for inducing anaerobic conditions - Crushed concrete for use as...place of refined chemicals or materials Examples: - Cheese whey , molasses, compost, or off-spec food products for inducing anaerobic conditions... whey , molasses, compost, or off-spec food products for inducing anaerobic conditions - Crushed concrete for use as fill - Concrete from coal

  3. How Concrete Is Concrete?

    ERIC Educational Resources Information Center

    Gravemeijer, Koeno

    2011-01-01

    If we want to make something concrete in mathematics education, we are inclined introduce, what we call, "manipulatives", in the form of tactile objects or visual representations. If we want to make something concrete in a everyday-life conversation, we look for an example. In the former, we try to make a concrete model of our own,…

  4. MDOT aims for lower-cost ultra-high performance concrete : research spotlight.

    DOT National Transportation Integrated Search

    2016-08-01

    In recent years, several vendors have developed ultra-high performance : concrete (UHPC) that surpasses traditional concrete mixes by offering : exceptional freeze-thaw resistance, reduced susceptibility to cracking : and far less reinforcement corro...

  5. APPLICATION OF FLOW SIMULATION FOR EVALUATION OF FILLING-ABILITY OF SELF-COMPACTING CONCRETE

    NASA Astrophysics Data System (ADS)

    Urano, Shinji; Nemoto, Hiroshi; Sakihara, Kohei

    In this paper, MPS method was applied to fluid an alysis of self-compacting concrete. MPS method is one of the particle method, and it is suitable for the simulation of moving boundary or free surface problems and large deformation problems. The constitutive equation of self-compacting concrete is assumed as bingham model. In order to investigate flow Stoppage and flow speed of self-compacting concrete, numerical analysis examples of slump flow and L-flow test were performed. In addition, to evaluate verification of compactability of self-compacting concrete, numerical analys is examples of compaction at the part of CFT diaphragm were performed. As a result, it was found that the MPS method was suitable for the simulation of compaction of self-compacting concrete, and a just appraisal was obtained by setting shear strain rate of flow-limit πc and limitation point of segregation.

  6. Patio Stone Project Gives Students a Concrete Learning Experience

    ERIC Educational Resources Information Center

    Fitzgerald, Mike

    2005-01-01

    In this article, the author presents an overview of concrete as a building material and as an example of a particle composite, and discusses the origins of concrete in ancient Rome. He then describes an activity in which students can cast a concrete patio stone. Students can apply the technological design process, as well as the elements of…

  7. Design of ultra high performance concrete as an overlay in pavements and bridge decks.

    DOT National Transportation Integrated Search

    2014-08-01

    The main objective of this research was to develop ultra-high performance concrete (UHPC) as a reliable, economic, low carbon foot : print and durable concrete overlay material that can offer shorter traffic closures due to faster construction. The U...

  8. Feasibility study of two-lift concrete paving : technical report.

    DOT National Transportation Integrated Search

    2014-04-01

    Two-lift concrete paving (2LCP) involves placing two layers of concrete (wet-on-wet) instead of a single : homogeneous layer, as is typically done in the United States. 2LCP offers the opportunity to optimize the use of local : aggregates, recycled m...

  9. Project 0-6749 : feasibility study of two-lift concrete paving : [project summary].

    DOT National Transportation Integrated Search

    2013-08-01

    Two-lift concrete paving (2LCP) involves placing two layers of : concrete (wet-on-wet) instead of a single homogeneous layer, as is : typically done in the United States. 2LCP offers the opportunity to optimize the use of local aggregates and : recyc...

  10. Using Physical Models to Explain a Division Algorithm.

    ERIC Educational Resources Information Center

    Vest, Floyd

    1985-01-01

    Develops a division algorithm in terms of familiar manipulations of concrete objects and presents it with a series of questions for diagnosis of students' understanding of the algorithm in terms of the concrete model utilized. Also offers general guidelines for using concrete illustrations to explain algorithms and other mathematical principles.…

  11. 64. Paynes Creek Culvert. This concrete box culvert is a ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    64. Paynes Creek Culvert. This concrete box culvert is a typical example of a concrete box culvert finished with rusticated stone. Its arches reflect the rigid frame structures. Looking west. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  12. Cement and Concrete Nanoscience and Nanotechnology

    PubMed Central

    Raki, Laila; Beaudoin, James; Alizadeh, Rouhollah; Makar, Jon; Sato, Taijiro

    2010-01-01

    Concrete science is a multidisciplinary area of research where nanotechnology potentially offers the opportunity to enhance the understanding of concrete behavior, to engineer its properties and to lower production and ecological cost of construction materials. Recent work at the National Research Council Canada in the area of concrete materials research has shown the potential of improving concrete properties by modifying the structure of cement hydrates, addition of nanoparticles and nanotubes and controlling the delivery of admixtures. This article will focus on a review of these innovative achievements.

  13. Dynamic Structural Flexible-Beam Response to a Moving Barge Train Impact Force Time-History Using Impact_Beam

    DTIC Science & Technology

    2011-08-01

    concrete box beams . Each pier is constructed of two drilled shafts with cast-in-place concrete cap beams to support the precast concrete wall beams ...and nose cell. The hollow, rectangular beams have an outside dimension of 10 feet by 10 feet. The weight of each of the precast beams is...a concrete-filled sheet-pile nose cell, which support five precast concrete beams . An example of this flexible impact beam is shown in Figures 1.5

  14. Piecewise polynomial representations of genomic tracks.

    PubMed

    Tarabichi, Maxime; Detours, Vincent; Konopka, Tomasz

    2012-01-01

    Genomic data from micro-array and sequencing projects consist of associations of measured values to chromosomal coordinates. These associations can be thought of as functions in one dimension and can thus be stored, analyzed, and interpreted as piecewise-polynomial curves. We present a general framework for building piecewise polynomial representations of genome-scale signals and illustrate some of its applications via examples. We show that piecewise constant segmentation, a typical step in copy-number analyses, can be carried out within this framework for both array and (DNA) sequencing data offering advantages over existing methods in each case. Higher-order polynomial curves can be used, for example, to detect trends and/or discontinuities in transcription levels from RNA-seq data. We give a concrete application of piecewise linear functions to diagnose and quantify alignment quality at exon borders (splice sites). Our software (source and object code) for building piecewise polynomial models is available at http://sourceforge.net/projects/locsmoc/.

  15. Joint forensics and watermarking approach for video authentication

    NASA Astrophysics Data System (ADS)

    Thiemert, Stefan; Liu, Huajian; Steinebach, Martin; Croce-Ferri, Lucilla

    2007-02-01

    In our paper we discuss and compare the possibilities and shortcomings of both content-fragile watermarking and digital forensics and analyze if the combination of both techniques allows the identification of more than the sum of all manipulations identified by both techniques on their own due to synergetic effects. The first part of the paper discusses the theoretical possibilities offered by a combined approach, in which forensics and watermarking are considered as complementary tools for data authentication or deeply combined together, in order to reduce their error rate and to enhance the detection efficiency. After this conceptual discussion the paper proposes some concrete examples in which the joint approach is applied to video authentication. Some specific forensics techniques are analyzed and expanded to handle efficiently video data. The examples show possible extensions of passive-blind image forgery detection to video data, where the motion and time related characteristics of video are efficiently exploited.

  16. Research notes : shear capacity of corrosion-damaged RC beams.

    DOT National Transportation Integrated Search

    2004-01-01

    Bridges on Oregons coast must withstand a corrosive marine environment. Concrete in reinforced concrete structures offers temporary protection to the reinforcing steel against the environment; but eventually the embedded steel succumbs to the inex...

  17. Bi-directional evolutionary structural optimization for strut-and-tie modelling of three-dimensional structural concrete

    NASA Astrophysics Data System (ADS)

    Shobeiri, Vahid; Ahmadi-Nedushan, Behrouz

    2017-12-01

    This article presents a method for the automatic generation of optimal strut-and-tie models in reinforced concrete structures using a bi-directional evolutionary structural optimization method. The methodology presented is developed for compliance minimization relying on the Abaqus finite element software package. The proposed approach deals with the generation of truss-like designs in a three-dimensional environment, addressing the design of corbels and joints as well as bridge piers and pile caps. Several three-dimensional examples are provided to show the capabilities of the proposed framework in finding optimal strut-and-tie models in reinforced concrete structures and verifying its efficiency to cope with torsional actions. Several issues relating to the use of the topology optimization for strut-and-tie modelling of structural concrete, such as chequerboard patterns, mesh-dependency and multiple load cases, are studied. In the last example, a design procedure for detailing and dimensioning of the strut-and-tie models is given according to the American Concrete Institute (ACI) 318-08 provisions.

  18. Identifying incompatible combinations of concrete materials: volume II, test protocol.

    DOT National Transportation Integrated Search

    2006-08-01

    Unexpected interactions between otherwise acceptable ingredients in portland cement : concrete are becoming increasingly common as cementitious systems become more complex : and demands on the systems are more rigorous. Examples of incompatibilities ...

  19. Handout of the Month: Creating and Understanding Concrete Poetry.

    ERIC Educational Resources Information Center

    Notes Plus, 1983

    1983-01-01

    Teaching suggestions and questions on which to build a class discussion are presented regarding concrete poetry. An example of a poem about a bird's feather in which the words are arranged in the shape of a feather is included and is intended as a student handout. In addition to suggestions for student assignments, five sources of concrete poetry…

  20. Surface and microstructural properties of photocatalytic cements for pavement applications.

    DOT National Transportation Integrated Search

    2016-10-01

    Thin concrete inlays incorporating flowable fibrous concrete (FFC) mix designs as well as titanium dioxide (TiO2)- containing photocatalytic cements are a promising pavement preservation solution. These multi-functional inlays offer enhanced construc...

  1. Steel-free hybrid reinforcement system for concrete bridge decks, phase 1

    DOT National Transportation Integrated Search

    2006-05-01

    Use of nonferrous fiber-reinforced polymer (FRP) reinforcement bars (rebars) offers one promising alternative to mitigating the corrosion problem in steel reinforced concrete bridge decks. Resistance to chloride ion driven corrosion, high tensile str...

  2. Phase I development of an aesthetic, precast concrete bridge rail.

    DOT National Transportation Integrated Search

    2012-02-01

    Precast concrete bridge rail systems offer several advantages over traditional cast-in-place rail designs, including reduced construction : time and costs, installation in a wide range of environmental conditions, easier maintenance and repair, impro...

  3. Dynamic Eigenvalue Problem of Concrete Slab Road Surface

    NASA Astrophysics Data System (ADS)

    Pawlak, Urszula; Szczecina, Michał

    2017-10-01

    The paper presents an analysis of the dynamic eigenvalue problem of concrete slab road surface. A sample concrete slab was modelled using Autodesk Robot Structural Analysis software and calculated with Finite Element Method. The slab was set on a one-parameter elastic subsoil, for which the modulus of elasticity was separately calculated. The eigen frequencies and eigenvectors (as maximal vertical nodal displacements) were presented. On the basis of the results of calculations, some basic recommendations for designers of concrete road surfaces were offered.

  4. Random functions via Dyson Brownian Motion: progress and problems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wang, Gaoyuan; Battefeld, Thorsten

    2016-09-05

    We develope a computationally efficient extension of the Dyson Brownian Motion (DBM) algorithm to generate random function in C{sup 2} locally. We further explain that random functions generated via DBM show an unstable growth as the traversed distance increases. This feature restricts the use of such functions considerably if they are to be used to model globally defined ones. The latter is the case if one uses random functions to model landscapes in string theory. We provide a concrete example, based on a simple axionic potential often used in cosmology, to highlight this problem and also offer an ad hocmore » modification of DBM that suppresses this growth to some degree.« less

  5. Possibilities of Use of UAVS for Technical Inspection of Buildings and Constructions

    NASA Astrophysics Data System (ADS)

    Banaszek, Anna; Banaszek, Sebastian; Cellmer, Anna

    2017-12-01

    In recent years, Unmanned Aerial Vehicles (UAVs) have been used in various sectors of the economy. This is due to the development of new technologies for acquiring and processing geospatial data. The paper presents the results of experiments using UAV, equipped with a high resolution digital camera, for a visual assessment of the technical condition of the building roof and for the inventory of energy infrastructure and its surroundings. The usefulness of digital images obtained from the UAV deck is presented in concrete examples. The use of UAV offers new opportunities in the area of technical inspection due to the detail and accuracy of the data, low operating costs and fast data acquisition.

  6. Guidelines for Evaluating the Thermal Environment of Enclosed Spaces

    DTIC Science & Technology

    2009-09-01

    space. Three studies of concrete tanks and metal containers, the High Mobility Multipurpose Wheeled Vehicle; and the Bradley Fighting Vehicle, are...24 13 The initial CST-WMD training site was a concrete casting site. The teams practiced entry and evacuation...Environmental Medicine (USARIEM) studies. Examples are presented from three case studies: one that involved monitoring large concrete septic tanks

  7. Analysis of "D" regions of RC structures based on example of frame corners

    NASA Astrophysics Data System (ADS)

    Michał, Szczecina; Andrzej, Winnicki

    2018-01-01

    Calculations of reinforcement of "D" regions of reinforced concrete structures is much difficult than for "B" regions and demands some specific approaches. Authors of the paper suggest to use both Strut-and-Tie (S&T) and Finite Element Method (FEM). The first of those methods allows to calculate required reinforcement and efficiency factor. In turn FEM can not only confirm S&T results but also gives information about crack width and pattern, strains and nodal displacement. Sample calculations were performed on example of frame corners under opening bending moment. Parameters of Concrete Damaged Plasticity model of concrete implemented in Abaqus were calibrated in tension and compressions test.

  8. A visual approach to efficient analysis and quantification of ductile iron and reinforced sprayed concrete.

    PubMed

    Fritz, Laura; Hadwiger, Markus; Geier, Georg; Pittino, Gerhard; Gröller, M Eduard

    2009-01-01

    This paper describes advanced volume visualization and quantification for applications in non-destructive testing (NDT), which results in novel and highly effective interactive workflows for NDT practitioners. We employ a visual approach to explore and quantify the features of interest, based on transfer functions in the parameter spaces of specific application scenarios. Examples are the orientations of fibres or the roundness of particles. The applicability and effectiveness of our approach is illustrated using two specific scenarios of high practical relevance. First, we discuss the analysis of Steel Fibre Reinforced Sprayed Concrete (SFRSpC). We investigate the orientations of the enclosed steel fibres and their distribution, depending on the concrete's application direction. This is a crucial step in assessing the material's behavior under mechanical stress, which is still in its infancy and therefore a hot topic in the building industry. The second application scenario is the designation of the microstructure of ductile cast irons with respect to the contained graphite. This corresponds to the requirements of the ISO standard 945-1, which deals with 2D metallographic samples. We illustrate how the necessary analysis steps can be carried out much more efficiently using our system for 3D volumes. Overall, we show that a visual approach with custom transfer functions in specific application domains offers significant benefits and has the potential of greatly improving and optimizing the workflows of domain scientists and engineers.

  9. Lessons to be learned from rehabilitation of concrete structures in bleach plants in pulp and paper mills

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nixon, R.

    The deterioration of concrete structures due to chloride induced reinforcing steel corrosion such as in elevated concrete floor slabs, columns, and beams in bleach plants is a constant and growing problem within the pulp and paper industry. In general, the condition analysis methods used for assessing the extent of bleach plant concrete degradation include physical testing of drilled concrete core samples, chloride ion concentration testing, half-cell potential measurements, and physical sounding of concrete surfaces, i.e. chain drag for topside surfaces and hammer sounding of soffit surfaces. While this paper does not promote any vastly different evaluative methods, it does sharemore » learnings relative to interpreting the data provided by these typical test methods. It further offers some recommendations on how to improve the use of these typical evaluation techniques and offers some other test methods which should be considered as valuable additions for such evaluations. One of the most common methods which has been used in the past for large scale bleach plant concrete restoration has been the application of site dry mixed shotcrete for rebuilding the soffits of floor slabs and the faces of columns and beams. More often than not, bulk mixed dry shotcrete repairs have not been cost-effective because they prematurely failed due to excessive hydration related shrinkage cracking, lack of sufficient adhesion to the parent concrete substrate or other problems related to poor durability or construction practice.« less

  10. Health monitoring of post-tension tendons in bridges.

    DOT National Transportation Integrated Search

    2003-01-01

    Post-tensioned concrete has been used in a number of bridge structures and is expected to be used more in future construction in Virginia. This type of detail offers unique advantages for improving the performance of concrete members. Recent problems...

  11. Quality control of fireproof coatings for reinforced concrete structures

    NASA Astrophysics Data System (ADS)

    Gravit, Marina; Dmitriev, Ivan; Ishkov, Alexander

    2017-10-01

    The article analyzes methods of quality inspection of fireproof coatings (work flow, measuring, laboratory, etc.). In modern construction there is a problem of lack of distinct monitoring for the fire protection testing. There is a description of this testing for reinforced concrete structures. The article shows the results of calculation quality control of hatches as an example of fireproof coating for reinforced concrete structures.

  12. Sift like Eratosthenes

    ERIC Educational Resources Information Center

    Buczynski, Sandy; Gorsky, Jennifer; McGrath, Lynn; Myers, Perla

    2011-01-01

    The concrete, pictorial, and abstract methods of this lesson give students access to investigate, isolate, define, and use prime numbers. In this article, the authors describe an enrichment lesson that offers opportunities to investigate prime numbers in concrete, pictorial, and abstract ways. Originally introduced by Jerome Bruner in 1960, the…

  13. Evaluation of dowel bar inserter practices in PCC pavements with magnetic tomography technology : final report.

    DOT National Transportation Integrated Search

    2016-12-01

    Dowel Bar Inserters (DBI) are automated mechanical equipment that position dowel bars in Portland Cement Concrete (PCC) after concrete is placed. Compared to the alternative approach, which is using dowel baskets, DBIs offer advantages in cost and sp...

  14. Study on Detailing Design of Precast Concrete Frame Structure

    NASA Astrophysics Data System (ADS)

    Lida, Tian; Liming, Li; Kang, Liu; Jiao, Geng; Ming, Li

    2018-03-01

    Taking a certain precast concrete frame structure as an example, this paper introduces the general procedures and key points in detailing design of emulative cast-in-place prefabricated structure from the aspects of structural scheme, precast element layout, shop drawing design and BIM 3D modelling. This paper gives a practical solution for the detailing design of precast concrete frame structure under structural design codes in China.

  15. A Bayesian approach to estimating variance components within a multivariate generalizability theory framework.

    PubMed

    Jiang, Zhehan; Skorupski, William

    2017-12-12

    In many behavioral research areas, multivariate generalizability theory (mG theory) has been typically used to investigate the reliability of certain multidimensional assessments. However, traditional mG-theory estimation-namely, using frequentist approaches-has limits, leading researchers to fail to take full advantage of the information that mG theory can offer regarding the reliability of measurements. Alternatively, Bayesian methods provide more information than frequentist approaches can offer. This article presents instructional guidelines on how to implement mG-theory analyses in a Bayesian framework; in particular, BUGS code is presented to fit commonly seen designs from mG theory, including single-facet designs, two-facet crossed designs, and two-facet nested designs. In addition to concrete examples that are closely related to the selected designs and the corresponding BUGS code, a simulated dataset is provided to demonstrate the utility and advantages of the Bayesian approach. This article is intended to serve as a tutorial reference for applied researchers and methodologists conducting mG-theory studies.

  16. Use of the impact-echo method in nondestructive measurements of the thickness of new concrete pavements.

    DOT National Transportation Integrated Search

    1995-01-01

    The nondestructive impact-echo (IE) method offers a simple means for introducing compressional stress waves into a concrete element or slab and measuring the resonance frequencies associated with the reflections of the waves from any internal voids a...

  17. Participant Anonymity in the Internet Age: From Theory to Practice

    PubMed Central

    Saunders, Benjamin; Kitzinger, Jenny; Kitzinger, Celia

    2015-01-01

    Qualitative researchers attempting to protect the identities of their research participants now face a multitude of new challenges due to the wealth of information once considered private but now readily accessible online. We will draw on our research with family members of people with severe brain injury to discuss these challenges in relation to three areas: participant engagement with the mass media, the availability of court transcripts online, and participants’ use of social media. We suggest strategies for managing these challenges via disguise, refining informed consent, and discussion with interviewees. In the context of a largely theoretical literature on anonymization, this article offers concrete examples of the dilemmas we faced and will be of illustrative use to other researchers confronting similar challenges. PMID:25866484

  18. Geopolymer concrete for structural use: Recent findings and limitations

    NASA Astrophysics Data System (ADS)

    Nuruddin, M. F.; Malkawi, A. B.; Fauzi, A.; Mohammed, B. S.; Almattarneh, H. M.

    2016-06-01

    Geopolymer binders offer a possible solution for several problems that facing the current cement industry. These binders exhibit similar or better engineering properties compared to cement and can utilize several types of waste materials. This paper presents the recent research progress regarding the structural behaviour of reinforced geopolymer concrete members including beams, columns and slabs. The reported results showed that the structural behaviour of the reinforced geopolymer concrete members is similar to the known behaviour of the ordinary reinforced concrete members. In addition, the currently available standards have been conservatively used for analysis and designing of reinforced geopolymer concrete structures. On the other hand, the main hurdles facing the spread of geopolymer concrete was the absence of standards and the concerns about the long-term properties. Other issues included the safety, cost and liability.

  19. Emergent spacetime according to effective field theory: From top-down and bottom-up

    NASA Astrophysics Data System (ADS)

    Crowther, Karen

    2013-08-01

    The framework of effective field theory (EFT) is a natural one in which to understand the claim that the spacetime of general relativity (GR) is an emergent low-energy phenomenon. I argue for a pragmatic understanding of EFT, given that the appropriate conception of emergence it suggests is necessarily epistemological in a sense. Analogue models of spacetime are examples of the top-down approach to EFT. They offer concrete illustrations of spacetime emergent within an EFT, and lure us toward a strong analogy between condensed matter physics and GR. I argue that we should be wary of this strong analogy, not least because the pragmatic view of EFT places limits on how much we can legitimately draw from it. On the other hand, programs that treat GR as an EFT and calculate quantum corrections are an example of the bottom-up approach and are explicitly pragmatic in character. I explore what we may learn about the nature of emergent spacetime by comparing these two approaches.

  20. Field application of a thermal-sprayed titanium anode for cathodic protection of reinforcing steel in concrete : final report

    DOT National Transportation Integrated Search

    1999-01-01

    This study provided the first field trial of a catalyzed, thermal-sprayed titanium anode for cathodic protection of steel reinforced concrete structures. Catalyzed titanium as an anode material offers the advantage of long life due to the inherent no...

  1. Determination of the neutralization depth of concrete under the aggressive environment influence

    NASA Astrophysics Data System (ADS)

    Morzhukhina, Anastasia; Nikitin, Stanislav; Akimova, Elena

    2018-03-01

    Aggressive environments have a significant impact on destruction of many reinforced concrete structures, such as high-rise constructions or chemical plants. For example, some high-rise constructions are equipped with a swimming pool, so they are exposed to chloride ions in the air. Penetration of aggressive chemical substances into the body of concrete contributes to acceleration of reinforced concrete structure corrosion that in turn leads to load bearing capacity loss and destruction of the building. The article considers and analyzes the main technologies for calculating penetration depth of various aggressive substances into the body of concrete. The calculation of corrosion depth was made for 50-year service life.

  2. Selecting Tools to Model Integer and Binomial Multiplication

    ERIC Educational Resources Information Center

    Pratt, Sarah Smitherman; Eddy, Colleen M.

    2017-01-01

    Mathematics teachers frequently provide concrete manipulatives to students during instruction; however, the rationale for using certain manipulatives in conjunction with concepts may not be explored. This article focuses on area models that are currently used in classrooms to provide concrete examples of integer and binomial multiplication. The…

  3. The Behaviour of Palm Oil Fibre Block Masonry Prism under Eccentric Compressive Loading

    NASA Astrophysics Data System (ADS)

    Mokhtar, Mardiha; Kolop, Roslan; Baizura Hamid, Nor; Kaamin, Masiri; Farhan Rosdi, Mohd; Ngadiman, Norhayati; Sahat, Suhaila

    2017-08-01

    Dry-stacked masonry offers great benefits in constructing masonry buildings. Several examples from previous research show that dry masonry is reasonable alternative to the traditional building system. By addition of fibre, the ductility and the propagation of cracking will be improved. This study investigates the dry stack oil palm fibre block prisms which were subjected to eccentricity compression loads. These concrete blocks were cast using a single mould with suitable fibre-cement composition namely 1:4 (cement: sand) and 0.40 water to the cement ratio based on cement weight. Prisms test using 400 (length) × 150 (width) × 510 (height) mm specimen was carried under eccentric load. There were forty eight (48) prisms built with different configurations based on their volume of fibre. In this study, one types of grout were used namely the fine grout of mix 1:3:2 (cement: sand: aggregate (5mm maximum). Based on the test performed, the failure mechanism and influencing parameters were discussed. From compressive strength test result, it shows that the strength of concrete block decreased with the increase of fibre used. Although the control sample has the higher strength compared to concrete with EFB, it can be seen from mode failure of masonry prism that fibre could extend the cracking time. These results show that the oil palm fibre blocks can improve the failure behaviour and suitable to be used as load bearing wall construction in Malaysia.

  4. Numerical Investigation on Detection of Prestress Losses in a Prestressed Concrete Slab by Modal Analysis

    NASA Astrophysics Data System (ADS)

    Kovalovs, A.; Rucevskis, S.; Akishin, P.; Kolupajevs, J.

    2017-10-01

    The paper presents numerical results of loss of prestress in the reinforced prestressed precast hollow core slabs by modal analysis. Loss of prestress is investigated by the 3D finite element method, using ANSYS software. In the numerical examples, variables initial stresses were introduced into seven-wire stress-relieved strands of the concrete slabs. The effects of span and material properties of concrete on the modal frequencies of the concrete structure under initial stress were studied. Modal parameters computed from the finite element models were compared. Applicability and effectiveness of the proposed method was investigated.

  5. Assessment of concrete damage and strength degradation caused by reinforcement corrosion

    NASA Astrophysics Data System (ADS)

    Nepal, Jaya; Chen, Hua-Peng

    2015-07-01

    Structural performance deterioration of reinforced concrete structures has been extensively investigated, but very limited studies have been carried out to investigate the effect of reinforcement corrosion on time-dependent reliability with consideration of the influence of mechanical characteristics of the bond interface due to corrosion. This paper deals with how corrosion in reinforcement creates different types of defects in concrete structure and how they are responsible for the structural capacity deterioration of corrosion affected reinforced concrete structures during their service life. Cracking in cover concrete due to reinforcement corrosion is investigated by using rebar-concrete model and realistic concrete properties. The flexural strength deterioration is analytically predicted on the basis of bond strength evolution due to reinforcement corrosion, which is examined by the experimental data available. The time-dependent reliability analysis is undertaken to calculate the life time structural reliability of corrosion damaged concrete structures by stochastic deterioration modelling of reinforced concrete. The results from the numerical example show that the proposed approach is capable of evaluating the damage caused by reinforcement corrosion and also predicting the structural reliability of concrete structures during their lifecycle.

  6. Exploring Childhood Memories with Adult Survivors of Sexual Abuse: Concrete Reconstruction and Visualization Techniques.

    ERIC Educational Resources Information Center

    Roland, Catherine B.

    1993-01-01

    Describes two memory-enhancing techniques, visualization and concrete reconstruction, that have been successful in counseling adult survivors of sexual abuse. Includes suggested implementations, case examples, and implications for incorporating memory techniques into counseling process. Describes various risk factors involved in using these…

  7. BUSINESS, INDUSTRIAL ARTS, AND GENERAL CONSUMER MATHEMATICS GUIDE, TENTATIVE.

    ERIC Educational Resources Information Center

    WINGET, LERUE

    THIS "CONSUMER MATHEMATICS GUIDE" IS DESIGNED TO GIVE CONCRETE HELP TO TEACHERS OF NON-ACADEMIC MATHEMATICS STUDENTS IN THE PRACTICAL AREAS OF BUSINESS AND INDUSTRIAL ARTS. THE COURSE, WHICH IS RECOMMENDED FOR JUNIOR AND SENIOR HIGH SCHOOL STUDENTS, PLACES EMPHASIS ON CONCRETE EXAMPLES, APPLICATIONS, AND VISUAL MATERIALS. SOME UNITS OF…

  8. Recommended practice for accepting new concrete pavement surfaces for tire/pavement noise : designation CPSCP PP 1-11 (rev 3/1/2011).

    DOT National Transportation Integrated Search

    2011-03-01

    This practice provides guidance and example specification language intended for use by Owner- : Agencies in development of specific contract language when requiring the evaluation of : tire/pavement noise for new concrete pavement surfaces. The overa...

  9. Math & the Dyslexic: Making the Abstract Concrete.

    ERIC Educational Resources Information Center

    Kitzen, Kay

    1983-01-01

    Math historian Morris Kline suggests that math instruction should be made concrete and that teachers should not turn kids off by making intuitively understood concepts complex through the use of fancy language. He advocates using pictorial representations and examples of actual physical occurrences. The dyslexic student has special difficulties in…

  10. A Qualitative Research on Example Generation Capabilities of University Students

    ERIC Educational Resources Information Center

    Saglam, Yasemin; Dost, Senol

    2016-01-01

    Examples which are used in exploring a procedure or comprehending/concretizing a mathematical concept are powerful teaching tools. Generating examples other than conventional ones is both a means for research and a pedagogical method. The aim of this study is to determine the transition process between example generation strategies, and the…

  11. Asphalt concrete modified by rubber crumbs in transport construction.

    NASA Astrophysics Data System (ADS)

    Duhovny, G. S.; Karpenko, AV

    2018-03-01

    High-temperature and low-temperature characteristics of the rubber-bitumen binder and rubber asphalt concrete based on it are researched. The determination method of binder’s low-temperature characteristics is offered. The estimation of binder’s and pavement’s stability against technological and operational aging is evaluated. Estimation of environmental and economic aspects of using rubber crumbs is made. The possibility of using rubber crumbs as modifier of organic binder for production of asphalt concrete on its base is justified.

  12. Durability of coconut shell powder (CSP) concrete

    NASA Astrophysics Data System (ADS)

    Leman, A. S.; Shahidan, S.; Senin, M. S.; Shamsuddin, S. M.; Anak Guntor, N. A.; Zuki, S. S. Mohd; Khalid, F. S.; Azhar, A. T. S.; Razak, N. H. S.

    2017-11-01

    The rising cost of construction in developing countries like Malaysia has led concrete experts to explore alternative materials such as coconut shells which are renewable and possess high potential to be used as construction material. Coconut shell powder in varying percentages of1%, 3% and 5% was used as filler material in concrete grade 30 and evaluated after a curing period of 7 days and 28days respectively. Compressive strength, water absorption and carbonation tests were conducted to evaluate the strength and durability of CSP concrete in comparison with normal concrete. The test results revealed that 1%, 3% and 5% of CSP concrete achieved a compressive strength of 47.65 MPa, 45.6 MPa and 40.55% respectively. The rate of water absorption of CSP concrete was recorded as 3.21%, 2.47%, and 2.73% for 1%, 3% and 5% of CSP concrete respectively. Although CSP contained a carbon composition of 47%, the carbonation test showed that CSP no signs of carbon were detected inside the concrete. To conclude, CSP offers great prospects as it demonstrated relatively high durability as a construction material.

  13. Active hematite concretion formation in modern acid saline lake sediments, Lake Brown, Western Australia

    NASA Astrophysics Data System (ADS)

    Bowen, Brenda Beitler; Benison, K. C.; Oboh-Ikuenobe, F. E.; Story, S.; Mormile, M. R.

    2008-04-01

    Concretions can provide valuable records of diagenesis and fluid-sediment interactions, however, reconstruction of ancient concretion-forming conditions can be difficult. Observation of modern hematite concretion growth in a natural sedimentary setting provides a rare glimpse of conditions at the time of formation. Spheroidal hematite-cemented concretions are actively precipitating in shallow subsurface sediments at Lake Brown in Western Australia. Lake Brown is a hypersaline (total dissolved solids up to 23%) and acidic (pH ˜ 4) ephemeral lake. The concretion host sediments were deposited between ˜ 1 and 3 ka, based on dating of stratigraphically higher and lower beds. These age constraints indicate that the diagenetic concretions formed < 3 ka, and field observations suggest that some are currently forming. These modern concretions from Lake Brown provide an example of very early diagenetic formation in acid and saline conditions that may be analogous to past conditions on Mars. Previously, the hematite concretions in the Burns formation on Mars have been interpreted as late stage diagenetic products, requiring long geologic time scales and multiple fluid flow events to form. In contrast, the Lake Brown concretions support the possibility of similar syndepositional to very early diagenetic concretion precipitation on Mars.

  14. Workability enhancement of geopolymer concrete through the use of retarder

    NASA Astrophysics Data System (ADS)

    Umniati, B. Sri; Risdanareni, Puput; Zein, Fahmi Tarmizi Zulfikar

    2017-09-01

    Geopolymer concrete is a type of concrete manufactured without the addition of cement. In geopolymer concrete, along with an activator, cement as the concrete binder can be replaced by the fly ash. This will reduce global demand on cement, and therefore will reduce CO2 emission due to cement production. Thus, geopolymer concrete is commonly known as an eco-friendly concrete. Geopolymer concrete also offers a solution concerning with the utilization of the fly ash waste. However, despite of its environmental advantages, geopolymer concrete has a drawback, namelygeopolymer concrete set quickly, thus reducing its workability. This research aimed to increase the workability of geopolymer concrete by using retarder admixture (Plastocrete RT6 Plus). Retarder used varies within 0.2%, 0.4% and 0.6% of fly ash mass. As a control, geopolymer concrete without retarder (0%) were also made. Activator used in this research was Na2SiO3 mixed with NaOH 10 M solution, with ratio of 1:5. The results showed an optimum composition of geopolymer concrete with 0.6% retarder, where initial setting time occured after 6.75 hours, and the final setting time reached after 9.5 hours. Moreover, the slump of the geopolymer concrete was 8.8 cm, and the slump flow was 24 cm. The compressive strength of the geopolymer concrete at 28 days was 47.21 MPa. The experiment showed that the more retarder added, the setting time of the geopolymer concrete will be increased, thus increasing its workability.

  15. Foregrounding Sociomaterial Practice in Our Understanding of Affordances: The Skilled Intentionality Framework.

    PubMed

    van Dijk, Ludger; Rietveld, Erik

    2016-01-01

    Social coordination and affordance perception always take part in concrete situations in real life. Nonetheless, the different fields of ecological psychology studying these phenomena do not seem to make this situated nature an object of study. To integrate both fields and extend the reach of the ecological approach, we introduce the Skilled Intentionality Framework that situates both social coordination and affordance perception within the human form of life and its rich landscape of affordances. We argue that in the human form of life the social and the material are intertwined and best understood as sociomateriality. Taking the form of life as our starting point foregrounds sociomateriality in each perspective we take on engaging with affordances. Using ethnographical examples we show how sociomateriality shows up from three different perspectives we take on affordances in a real-life situation. One perspective shows us a landscape of affordances that the sociomaterial environment offers. Zooming in on this landscape to the perspective of a local observer, we can focus on an individual coordinating with affordances offered by things and other people situated in this landscape. Finally, viewed from within this unfolding activity, we arrive at the person's lived perspective: a field of relevant affordances solicits activity. The Skilled Intentionality Framework offers a way of integrating social coordination and affordance theory by drawing attention to these complementary perspectives. We end by showing a real-life example from the practice of architecture that suggests how this situated view that foregrounds sociomateriality can extend the scope of ecological psychology to forms of so-called "higher" cognition.

  16. Foregrounding Sociomaterial Practice in Our Understanding of Affordances: The Skilled Intentionality Framework

    PubMed Central

    van Dijk, Ludger; Rietveld, Erik

    2017-01-01

    Social coordination and affordance perception always take part in concrete situations in real life. Nonetheless, the different fields of ecological psychology studying these phenomena do not seem to make this situated nature an object of study. To integrate both fields and extend the reach of the ecological approach, we introduce the Skilled Intentionality Framework that situates both social coordination and affordance perception within the human form of life and its rich landscape of affordances. We argue that in the human form of life the social and the material are intertwined and best understood as sociomateriality. Taking the form of life as our starting point foregrounds sociomateriality in each perspective we take on engaging with affordances. Using ethnographical examples we show how sociomateriality shows up from three different perspectives we take on affordances in a real-life situation. One perspective shows us a landscape of affordances that the sociomaterial environment offers. Zooming in on this landscape to the perspective of a local observer, we can focus on an individual coordinating with affordances offered by things and other people situated in this landscape. Finally, viewed from within this unfolding activity, we arrive at the person’s lived perspective: a field of relevant affordances solicits activity. The Skilled Intentionality Framework offers a way of integrating social coordination and affordance theory by drawing attention to these complementary perspectives. We end by showing a real-life example from the practice of architecture that suggests how this situated view that foregrounds sociomateriality can extend the scope of ecological psychology to forms of so-called “higher” cognition. PMID:28119638

  17. The Cognitive Costs of Context: The Effects of Concreteness and Immersiveness in Instructional Examples

    PubMed Central

    Day, Samuel B.; Motz, Benjamin A.; Goldstone, Robert L.

    2015-01-01

    Prior research has established that while the use of concrete, familiar examples can provide many important benefits for learning, it is also associated with some serious disadvantages, particularly in learners’ ability to recognize and transfer their knowledge to new analogous situations. However, it is not immediately clear whether this pattern would hold in real world educational contexts, in which the role of such examples in student engagement and ease of processing might be of enough importance to overshadow any potential negative impact. We conducted two experiments in which curriculum-relevant material was presented in natural classroom environments, first with college undergraduates and then with middle-school students. All students in each study received the same relevant content, but the degree of contextualization in these materials was varied between students. In both studies, we found that greater contextualization was associated with poorer transfer performance. We interpret these results as reflecting a greater degree of embeddedness for the knowledge acquired from richer, more concrete materials, such that the underlying principles are represented in a less abstract and generalizable form. PMID:26648905

  18. Experience-based training of students on concretes reinforced by recycled carbon fibers

    NASA Astrophysics Data System (ADS)

    Cosgun, Cumhur; Patlolla, Vamsidhar R.; Alzahrani, Naif; Zeineddine, Hatim F.; Asmatulu, Eylem

    2017-04-01

    Fiber reinforcement increases many properties of the concretes, such as toughness, strength, abrasion, and resistance to corrosion. Use of recycled carbon fibers from industrial waste offers many advantages because it will reduce the waste, contribute the economy, protect natural resources and improve the property of structural units. The City of Wichita, KS is known to be "Air Capital of the World" where many aircraft companies have been producing aircraft, parts and components. Due to the superior properties of composites (e.g., light weight, low density, high impact resistance), they have been highly used by aircraft industry. Prepreg is the most preferred combination of the fiber and resin due to the easy application, but it has a limited shelf life (e.g., three months to one year at most) and scrap has no use after all in the same industry. Every year tons of un-used prepreg or after use scrap are being collected in Wichita, KS. Recycling prepreg from the post-consumer waste offers great advantages of waste reduction and resource conservation in the city. Reusing the carbon fibers obtained from outdated prepreg composites for concrete reinforcement will offer double advantages for our environment and concrete structures. In this study, recycled carbon fibers of the outdated prepreg composites were collected, and then incorporated with concretes at different ratios prior to the molding and mechanical testing. An undergraduate student was involved in the project and observed all the process during the laboratory studies, as well as data collection, analysis and presentation. We believe that experience based learning will enhance the students' skills and interest into the scientific and engineering studies.

  19. Applications of Piagetian Theory to the Teaching of Elementary Number Concepts: A Theory-into-Practice Approach.

    ERIC Educational Resources Information Center

    Irmen, Anne

    After a brief description of three Piagetian stages (pre-operational, transition to concrete operations, and concrete operations), the author identifies 12 key statements from Piaget's writings. These statements, together with related implications for teaching elementary school mathematics, methods of diagnosing stage acquisition, and examples are…

  20. Fleet DNA (Presentation)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Walkokwicz, K.; Duran, A.

    2014-06-01

    The Fleet DNA project objectives include capturing and quantifying drive cycle and technology variation for the multitude of medium- and heavy-duty vocations; providing a common data storage warehouse for medium- and heavy-duty vehicle fleet data across DOE activities and laboratories; and integrating existing DOE tools, models, and analyses to provide data-driven decision making capabilities. Fleet DNA advantages include: for Government - providing in-use data for standard drive cycle development, R&D, tech targets, and rule making; for OEMs - real-world usage datasets provide concrete examples of customer use profiles; for fleets - vocational datasets help illustrate how to maximize return onmore » technology investments; for Funding Agencies - ways are revealed to optimize the impact of financial incentive offers; and for researchers -a data source is provided for modeling and simulation.« less

  1. Problem solving in the borderland between mathematics and physics

    NASA Astrophysics Data System (ADS)

    Jensen, Jens Højgaard; Niss, Martin; Jankvist, Uffe Thomas

    2017-01-01

    The article addresses the problématique of where mathematization is taught in the educational system, and who teaches it. Mathematization is usually not a part of mathematics programs at the upper secondary level, but we argue that physics teaching has something to offer in this respect, if it focuses on solving so-called unformalized problems, where a major challenge is to formalize the problems in mathematics and physics terms. We analyse four concrete examples of unformalized problems for which the formalization involves different order of mathematization and applying physics to the problem, but all require mathematization. The analysis leads to the formulation of a model by which we attempt to capture the important steps of the process of solving unformalized problems by means of mathematization and physicalization.

  2. Measures to reduce construction time of high-rise buildings

    NASA Astrophysics Data System (ADS)

    Kolchedantsev, Leonid; Adamtsevich, Aleksey; Stupakova, Olga; Drozdov, Alexander

    2018-03-01

    The organizational and technological solutions for high-rise buildings construction efficiency increase are considered, primarily - decrease of typical floor construction time and improvement of bearing structures concrete quality. The essence of offered technology is: a concrete mixing station and a polygon mainly for load-bearing wall panels with starter bars casting are located on the building site; for reinforced concrete components manufacturing and butt joints grouting the warmed-up concrete mixtures are used. The results of researches and elaborations carried out by the SPSUACE in area of a preliminary warming-up of concrete mixtures are presented. The possibility and feasibility of their usage in high-rise buildings and of excess height buildings construction including cast-in-place and precast execution are shown. The essence of heat-vibro treating of concrete mixture is revealed as a kind of prior electroresistive curing, and the achieved results are: accelerated concrete strength gain, power inputs decrease, concrete quality improvement. It is shown that the location of a concrete mixing station on the building site enables to broaden possibilities of the "thermos" method use and to avoid concrete mixtures warming up in medium-mass structures erection (columns, girders) during the high-rise buildings construction. It is experimentally proved that the splice between precast elements encased with warmed-up concrete mixture is equal with conjugated elements in strength.

  3. General Shop Competencies in Vocational Agriculture for 9th and 10th Grade Classes.

    ERIC Educational Resources Information Center

    Novotny, Ronald; And Others

    The document presents unit plans which offer list of experiences and competencies to be learned for general shop occupations in vocational agriculture. The units include: (1) arc welding, (2) oxy-acetylene welding, (3) flat concrete, (4) concrete block, (5) lumber patterns and wood building materials, (6) metal fasteners, (7) wood adhesives, (8)…

  4. Influence of increasing amount of recycled concrete powder on mechanical properties of cement paste

    NASA Astrophysics Data System (ADS)

    Topič, Jaroslav; Prošek, Zdeněk; Plachý, Tomáš

    2017-09-01

    This paper deals with using fine recycled concrete powder in cement composites as micro-filler and partial cement replacement. Binder properties of recycled concrete powder are given by exposed non-hydrated cement grains, which can hydrate again and in small amount replace cement or improve some mechanical properties. Concrete powder used in the experiments was obtained from old railway sleepers. Infrastructure offer more sources of old concrete and they can be recycled directly on building site and used again. Experimental part of this paper focuses on influence of increasing amount of concrete powder on mechanical properties of cement paste. Bulk density, shrinkage, dynamic Young’s modulus, compression and flexural strength are observed during research. This will help to determine limiting amount of concrete powder when decrease of mechanical properties outweighs the benefits of cement replacement. The shrinkage, dynamic Young’s modulus and flexural strength of samples with 20 to 30 wt. % of concrete powder are comparable with reference cement paste or even better. Negative effect of concrete powder mainly influenced the compression strength. Only a 10 % cement replacement reduced compression strength by about 25 % and further decrease was almost linear.

  5. Reuse of waste iron as a partial replacement of sand in concrete.

    PubMed

    Ismail, Zainab Z; Al-Hashmi, Enas A

    2008-11-01

    One of the major environmental issues in Iraq is the large quantity of waste iron resulting from the industrial sector which is deposited in domestic waste and in landfills. A series of 109 experiments and 586 tests were carried out in this study to examine the feasibility of reusing this waste iron in concrete. Overall, 130 kg of waste iron were reused to partially replace sand at 10%, 15%, and 20% in a total of 1703 kg concrete mixtures. The tests performed to evaluate waste-iron concrete quality included slump, fresh density, dry density, compressive strength, and flexural strength tests: 115 cubes of concrete were molded for the compressive strength and dry density tests, and 87 prisms were cast for the flexural strength tests. This work applied 3, 7, 14, and 28 days curing ages for the concrete mixes. The results confirm that reuse of solid waste material offers an approach to solving the pollution problems that arise from an accumulation of waste in a production site; in the meantime modified properties are added to the concrete. The results show that the concrete mixes made with waste iron had higher compressive strengths and flexural strengths than the plain concrete mixes.

  6. The Impact of a Staff Development Offering on Nursing Practice.

    ERIC Educational Resources Information Center

    Foglesong, Dianne H.

    1983-01-01

    Describes a problem-focused audit used to measure the impact of a staff development offering on pain relief. Concludes that the audit provided concrete evidence that the class on pain did influence nursing practice and affected patients directly. (NRJ)

  7. Clustering, hierarchical organization, and the topography of abstract and concrete nouns.

    PubMed

    Troche, Joshua; Crutch, Sebastian; Reilly, Jamie

    2014-01-01

    The empirical study of language has historically relied heavily upon concrete word stimuli. By definition, concrete words evoke salient perceptual associations that fit well within feature-based, sensorimotor models of word meaning. In contrast, many theorists argue that abstract words are "disembodied" in that their meaning is mediated through language. We investigated word meaning as distributed in multidimensional space using hierarchical cluster analysis. Participants (N = 365) rated target words (n = 400 English nouns) across 12 cognitive dimensions (e.g., polarity, ease of teaching, emotional valence). Factor reduction revealed three latent factors, corresponding roughly to perceptual salience, affective association, and magnitude. We plotted the original 400 words for the three latent factors. Abstract and concrete words showed overlap in their topography but also differentiated themselves in semantic space. This topographic approach to word meaning offers a unique perspective to word concreteness.

  8. 71. Meadow Creek Culvert. This is an example of a ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    71. Meadow Creek Culvert. This is an example of a triple arch concrete box culvert with stone facing mimicking rigid frame structures. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  9. Precast, Prestressed Concrete Bent Caps : Volume 2, Design Recommendations and Design Examples

    DOT National Transportation Integrated Search

    2018-04-01

    Recommendations for design of pretensioned bent caps are developed based on the findings of full-scale experimental tests of bent cap subassemblages. Companion examples are provided to demonstrate implementation of the design recommendations. First, ...

  10. Corrosion Behavior of Steel Reinforcement in Concrete with Recycled Aggregates, Fly Ash and Spent Cracking Catalyst.

    PubMed

    Gurdián, Hebé; García-Alcocel, Eva; Baeza-Brotons, Francisco; Garcés, Pedro; Zornoza, Emilio

    2014-04-21

    The main strategy to reduce the environmental impact of the concrete industry is to reuse the waste materials. This research has considered the combination of cement replacement by industrial by-products, and natural coarse aggregate substitution by recycled aggregate. The aim is to evaluate the behavior of concretes with a reduced impact on the environment by replacing a 50% of cement by industrial by-products (15% of spent fluid catalytic cracking catalyst and 35% of fly ash) and a 100% of natural coarse aggregate by recycled aggregate. The concretes prepared according to these considerations have been tested in terms of mechanical strengths and the protection offered against steel reinforcement corrosion under carbonation attack and chloride-contaminated environments. The proposed concrete combinations reduced the mechanical performance of concretes in terms of elastic modulus, compressive strength, and flexural strength. In addition, an increase in open porosity due to the presence of recycled aggregate was observed, which is coherent with the changes observed in mechanical tests. Regarding corrosion tests, no significant differences were observed in the case of the resistance of these types of concretes under a natural chloride attack. In the case of carbonation attack, although all concretes did not stand the highly aggressive conditions, those concretes with cement replacement behaved worse than Portland cement concretes.

  11. 78 FR 61227 - Public Assistance Cost Estimating Format for Large Projects

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-03

    ... itemized breakdown of construction costs for completing the project. For example, a typical project will... percentage factors. For example, if a Part B percentage factor is 2 percent, the estimator adds 2 percent of... specific to the project scope of work. Examples include concrete strength testing, water quality testing...

  12. Quantum Decision Theory in Simple Risky Choices.

    PubMed

    Favre, Maroussia; Wittwer, Amrei; Heinimann, Hans Rudolf; Yukalov, Vyacheslav I; Sornette, Didier

    2016-01-01

    Quantum decision theory (QDT) is a recently developed theory of decision making based on the mathematics of Hilbert spaces, a framework known in physics for its application to quantum mechanics. This framework formalizes the concept of uncertainty and other effects that are particularly manifest in cognitive processes, which makes it well suited for the study of decision making. QDT describes a decision maker's choice as a stochastic event occurring with a probability that is the sum of an objective utility factor and a subjective attraction factor. QDT offers a prediction for the average effect of subjectivity on decision makers, the quarter law. We examine individual and aggregated (group) data, and find that the results are in good agreement with the quarter law at the level of groups. At the individual level, it appears that the quarter law could be refined in order to reflect individual characteristics. This article revisits the formalism of QDT along a concrete example and offers a practical guide to researchers who are interested in applying QDT to a dataset of binary lotteries in the domain of gains.

  13. Quantum Decision Theory in Simple Risky Choices

    PubMed Central

    Favre, Maroussia; Wittwer, Amrei; Heinimann, Hans Rudolf; Yukalov, Vyacheslav I.; Sornette, Didier

    2016-01-01

    Quantum decision theory (QDT) is a recently developed theory of decision making based on the mathematics of Hilbert spaces, a framework known in physics for its application to quantum mechanics. This framework formalizes the concept of uncertainty and other effects that are particularly manifest in cognitive processes, which makes it well suited for the study of decision making. QDT describes a decision maker’s choice as a stochastic event occurring with a probability that is the sum of an objective utility factor and a subjective attraction factor. QDT offers a prediction for the average effect of subjectivity on decision makers, the quarter law. We examine individual and aggregated (group) data, and find that the results are in good agreement with the quarter law at the level of groups. At the individual level, it appears that the quarter law could be refined in order to reflect individual characteristics. This article revisits the formalism of QDT along a concrete example and offers a practical guide to researchers who are interested in applying QDT to a dataset of binary lotteries in the domain of gains. PMID:27936217

  14. Life Cycle Assessment of concrete manufacturing in small isolated states: the case of Cyprus

    NASA Astrophysics Data System (ADS)

    Chrysostomou, Chrystalla; Kylili, Angeliki; Nicolaides, Demetris; Fokaides, Paris A.

    2017-10-01

    Life Cycle Assessment (LCA) is an effective and valuable methodology for identifying the holistic sustainable behaviour of materials and products. It is also useful in analysing the impact a structure has over the course of its life cycle. Currently, there is no sufficient knowhow regarding the life cycle performance of building materials used in the case of small isolated states. This study focuses on the LCA of the production of concrete for the investigation of its environmental impact in isolated island states, using the case of Cyprus as an example. Four different scenarios for the production of 1 tonne of concrete are examined: (i) manufacturing of concrete by transporting raw materials from different locations around the island, (ii) manufacturing of concrete using alternative energy resources, (iii) manufacturing of concrete with reduced transportation needs, and (iv) on-site manufacturing of concrete. The results, in terms of environmental impacts of concrete produced, indicated that the use of renewable electricity instead of fossil-fuelled electricity in isolated states can drastically improve the environmental performance of the end product. Also, the minimisation of transportation distances and the use of locally available resources can also affect, to a degree, the environmental impact of concrete production.

  15. Seismic performance evaluation of an infilled rocking wall frame structure through quasi-static cyclic testing

    NASA Astrophysics Data System (ADS)

    Pan, Peng; Wu, Shoujun; Wang, Haishen; Nie, Xin

    2018-04-01

    Earthquake investigations have illustrated that even code-compliant reinforced concrete frames may suffer from soft-story mechanism. This damage mode results in poor ductility and limited energy dissipation. Continuous components offer alternatives that may avoid such failures. A novel infilled rocking wall frame system is proposed that takes advantage of continuous component and rocking characteristics. Previous studies have investigated similar systems that combine a reinforced concrete frame and a wall with rocking behavior used. However, a large-scale experimental study of a reinforced concrete frame combined with a rocking wall has not been reported. In this study, a seismic performance evaluation of the newly proposed infilled rocking wall frame structure was conducted through quasi-static cyclic testing. Critical joints were designed and verified. Numerical models were established and calibrated to estimate frame shear forces. The results evaluation demonstrate that an infilled rocking wall frame can effectively avoid soft-story mechanisms. Capacity and initial stiffness are greatly improved and self-centering behavior is achieved with the help of the infilled rocking wall. Drift distribution becomes more uniform with height. Concrete cracks and damage occurs in desired areas. The infilled rocking wall frame offers a promising approach to achieving seismic resilience.

  16. Structural Applications of Fibre Reinforced Concrete in the Czech Republic

    NASA Astrophysics Data System (ADS)

    Kohoutková, A.; Broukalová, I.

    2017-09-01

    The paper presents improvement of function and performance of the precast structural members by using fibre reinforced concrete (FRC) instead of ordinary reinforced concrete and attempts to transfer innovative technologies from laboratory in academic sphere into real industrial production which is cost-effective and brings about savings of labour and material. Three examples of successful technology transfer are shown - application of FRC in an element without common rebar reinforcement, in the element with steel rebar reinforcement and SFRC pre-tensioned structural element. Benefits of FRC utilization are discussed.

  17. Probabilistic design of fibre concrete structures

    NASA Astrophysics Data System (ADS)

    Pukl, R.; Novák, D.; Sajdlová, T.; Lehký, D.; Červenka, J.; Červenka, V.

    2017-09-01

    Advanced computer simulation is recently well-established methodology for evaluation of resistance of concrete engineering structures. The nonlinear finite element analysis enables to realistically predict structural damage, peak load, failure, post-peak response, development of cracks in concrete, yielding of reinforcement, concrete crushing or shear failure. The nonlinear material models can cover various types of concrete and reinforced concrete: ordinary concrete, plain or reinforced, without or with prestressing, fibre concrete, (ultra) high performance concrete, lightweight concrete, etc. Advanced material models taking into account fibre concrete properties such as shape of tensile softening branch, high toughness and ductility are described in the paper. Since the variability of the fibre concrete material properties is rather high, the probabilistic analysis seems to be the most appropriate format for structural design and evaluation of structural performance, reliability and safety. The presented combination of the nonlinear analysis with advanced probabilistic methods allows evaluation of structural safety characterized by failure probability or by reliability index respectively. Authors offer a methodology and computer tools for realistic safety assessment of concrete structures; the utilized approach is based on randomization of the nonlinear finite element analysis of the structural model. Uncertainty of the material properties or their randomness obtained from material tests are accounted in the random distribution. Furthermore, degradation of the reinforced concrete materials such as carbonation of concrete, corrosion of reinforcement, etc. can be accounted in order to analyze life-cycle structural performance and to enable prediction of the structural reliability and safety in time development. The results can serve as a rational basis for design of fibre concrete engineering structures based on advanced nonlinear computer analysis. The presented methodology is illustrated on results from two probabilistic studies with different types of concrete structures related to practical applications and made from various materials (with the parameters obtained from real material tests).

  18. Evaluation of concrete cover by surface wave technique: Identification procedure

    NASA Astrophysics Data System (ADS)

    Piwakowski, Bogdan; Kaczmarek, Mariusz; Safinowski, Paweł

    2012-05-01

    Concrete cover degradation is induced by aggressive agents in ambiance, such as moisture, chemicals or temperature variations. Due to degradation usually a thin (a few millimeters thick) surface layer has porosity slightly higher than the deeper sound material. The non destructive evaluation of concrete cover is vital to monitor the integrity of concrete structures and prevent their irreversible damage. In this paper the methodology applied by the classical technique used for ground structure recovery called Multichanel Analysis of Surface Waves is discussed as the NDT tool in civil engineering domain to characterize the concrete cover. In order to obtain the velocity as a function of sample depth the dispersion of surface waves is used as an input for solving inverse problem. The paper describes the inversion procedure and provides the practical example of use of developed system.

  19. Compressive strength of concrete and mortar containing fly ash

    DOEpatents

    Liskowitz, J.W.; Wecharatana, M.; Jaturapitakkul, C.; Cerkanowicz, A.E.

    1997-04-29

    The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction. The invention includes a method for predicting the compressive strength of such a hardenable mixture, which is very important for planning a project. The invention also relates to hardenable mixtures comprising cement and fly ash which can achieve greater compressive strength than hardenable mixtures containing only concrete over the time period relevant for construction. In a specific embodiment, a formula is provided that accurately predicts compressive strength of concrete containing fly ash out to 180 days. In other specific examples, concrete and mortar containing about 15% to 25% fly ash as a replacement for cement, which are capable of meeting design specifications required for building and highway construction, are provided. Such materials can thus significantly reduce construction costs. 33 figs.

  20. Compressive strength of concrete and mortar containing fly ash

    DOEpatents

    Liskowitz, J.W.; Wecharatana, M.; Jaturapitakkul, C.; Cerkanowicz, A.E.

    1998-12-29

    The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction. The invention includes a method for predicting the compressive strength of such a hardenable mixture, which is very important for planning a project. The invention also relates to hardenable mixtures comprising cement and fly ash which can achieve greater compressive strength than hardenable mixtures containing only concrete over the time period relevant for construction. In a specific embodiment, a formula is provided that accurately predicts compressive strength of concrete containing fly ash out to 180 days. In other specific examples, concrete and mortar containing about 15% to 25% fly ash as a replacement for cement, which are capable of meeting design specification required for building and highway construction, are provided. Such materials can thus significantly reduce construction costs. 33 figs.

  1. Compressive strength of concrete and mortar containing fly ash

    DOEpatents

    Liskowitz, John W.; Wecharatana, Methi; Jaturapitakkul, Chai; Cerkanowicz, deceased, Anthony E.

    1997-01-01

    The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction. The invention includes a method for predicting the compressive strength of such a hardenable mixture, which is very important for planning a project. The invention also relates to hardenable mixtures comprising cement and fly ash which can achieve greater compressive strength than hardenable mixtures containing only concrete over the time period relevant for construction. In a specific embodiment, a formula is provided that accurately predicts compressive strength of concrete containing fly ash out to 180 days. In other specific examples, concrete and mortar containing about 15% to 25% fly ash as a replacement for cement, which are capable of meeting design specifications required for building and highway construction, are provided. Such materials can thus significantly reduce construction costs.

  2. Compressive strength of concrete and mortar containing fly ash

    DOEpatents

    Liskowitz, John W.; Wecharatana, Methi; Jaturapitakkul, Chai; Cerkanowicz, deceased, Anthony E.

    1998-01-01

    The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction. The invention includes a method for predicting the compressive strength of such a hardenable mixture, which is very important for planning a project. The invention also relates to hardenable mixtures comprising cement and fly ash which can achieve greater compressive strength than hardenable mixtures containing only concrete over the time period relevant for construction. In a specific embodiment, a formula is provided that accurately predicts compressive strength of concrete containing fly ash out to 180 days. In other specific examples, concrete and mortar containing about 15% to 25% fly ash as a replacement for cement, which are capable of meeting design specification required for building and highway construction, are provided. Such materials can thus significantly reduce construction costs.

  3. Enhancing Learning in Statistics Classes Through The Use of Concrete Historical Examples: The Space Shuttle Challenger, Pearl Harbor, and the RMS Titanic.

    ERIC Educational Resources Information Center

    Schumm, Walter R.; Webb, Farrell J.; Castelo, Carlos S.; Akagi, Cynthia G.; Jensen, Erick J.; Ditto, Rose M.; Spencer Carver, Elaine; Brown, Beverlyn F.

    2002-01-01

    Discusses the use of historical events as examples for teaching college level statistics courses. Focuses on examples of the space shuttle Challenger, Pearl Harbor (Hawaii), and the RMS Titanic. Finds real life examples can bridge a link to short term experiential learning and provide a means for long term understanding of statistics. (KDR)

  4. Comparative testing of nondestructive examination techniques for concrete structures

    NASA Astrophysics Data System (ADS)

    Clayton, Dwight A.; Smith, Cyrus M.

    2014-03-01

    A multitude of concrete-based structures are typically part of a light water reactor (LWR) plant to provide foundation, support, shielding, and containment functions. Concrete has been used in the construction of nuclear power plants (NPPs) because of three primary properties, its inexpensiveness, its structural strength, and its ability to shield radiation. Examples of concrete structures important to the safety of LWR plants include containment building, spent fuel pool, and cooling towers. Comparative testing of the various NDE concrete measurement techniques requires concrete samples with known material properties, voids, internal microstructure flaws, and reinforcement locations. These samples can be artificially created under laboratory conditions where the various properties can be controlled. Other than NPPs, there are not many applications where critical concrete structures are as thick and reinforced. Therefore, there are not many industries other than the nuclear power plant or power plant industry that are interested in performing NDE on thick and reinforced concrete structures. This leads to the lack of readily available samples of thick and heavily reinforced concrete for performing NDE evaluations, research, and training. The industry that typically performs the most NDE on concrete structures is the bridge and roadway industry. While bridge and roadway structures are thinner and less reinforced, they have a good base of NDE research to support their field NDE programs to detect, identify, and repair concrete failures. This paper will summarize the initial comparative testing of two concrete samples with an emphasis on how these techniques could perform on NPP concrete structures.

  5. For Example? A Philosophical Case Study of Some Problems When Abstract Educational Theory Ignores Concrete Practice

    ERIC Educational Resources Information Center

    Golding, Clinton

    2017-01-01

    In Philosophy of Education we frequently argue for or against different educational theories. Yet, as I illustrate in this analysis of two articles, in order to maintain the abstract theoretical distinctions, we are liable to ignore the concrete details of practice, caricature the theories we reject and make false distinctions. The two articles…

  6. DOE Office of Scientific and Technical Information (OSTI.GOV)

    None, None

    The LEDS Global Partnership (LEDS GP) strives to advance climate-resilient, low-emission development through catalyzing collaboration, information exchange, and action on the ground. The Government of Kenya is a key LEDS GP member and offers an inspiring example of how LEDS GP is having an impact globally. The 2012 LEDS Collaboration in Action workshop in London provided an interactive space for members to share experiences on cross-ministerial LEDS leadership and to learn about concrete development impacts of LEDS around the world. Inspired by these stories, the Kenya's Ministry of State for Planning, National Development and Vision 2030 (MPND) began to collaboratemore » closely with the Ministry of Environment and Mineral Resources to create strong links between climate change action and development in the country, culminating in the integration of Kenya's National Climate Change Action Plan and the country's Medium Term Development Plan.« less

  7. Knowledge acquisition for case-based reasoning systems

    NASA Technical Reports Server (NTRS)

    Riesbeck, Christopher K.

    1988-01-01

    Case-based reasoning (CBR) is a simple idea: solve new problems by adapting old solutions to similar problems. The CBR approach offers several potential advantages over rule-based reasoning: rules are not combined blindly in a search for solutions, solutions can be explained in terms of concrete examples, and performance can improve automatically as new problems are solved and added to the case library. Moving CBR for the university research environment to the real world requires smooth interfaces for getting knowledge from experts. Described are the basic elements of an interface for acquiring three basic bodies of knowledge that any case-based reasoner requires: the case library of problems and their solutions, the analysis rules that flesh out input problem specifications so that relevant cases can be retrieved, and the adaptation rules that adjust old solutions to fit new problems.

  8. The Power of Examples: Illustrative Examples Enhance Conceptual Learning of Declarative Concepts

    ERIC Educational Resources Information Center

    Rawson, Katherine A.; Thomas, Ruthann C.; Jacoby, Larry L.

    2015-01-01

    Declarative concepts (i.e., key terms with short definitions of the abstract concepts denoted by those terms) are a common kind of information that students are expected to learn in many domains. A common pedagogical approach for supporting learning of declarative concepts involves presenting students with concrete examples that illustrate how the…

  9. Worry, problem elaboration and suppression of imagery: the role of concreteness.

    PubMed

    Stöber, J

    1998-01-01

    Both lay concept and scientific theory claim that worry may be helpful for defining and analyzing problems. Recent studies, however, indicate that worrisome problem elaborations are less concrete than worry-free problem elaborations. This challenges the problem solving view of worry because abstract problem analyses are unlikely to lead to concrete problem solutions. Instead the findings support the avoidance theory of worry which claims that worry suppresses aversive imagery. Following research findings in the dual-coding framework [Paivio, A. (1971). Imagery and verbal processes. New York: Holt, Rhinehart and Winston; Paivio, A. (1986). Mental representations: a dual coding approach. New York: Oxford University Press.], the present article proposes that reduced concreteness may play a central role in the understanding of worry. First, reduced concreteness can explain how worry reduces imagery. Second, it offers an explanation why worrisome problem analyses are unlikely to arrive at solutions. Third, it provides a key for the understanding of worry maintenance.

  10. Lattice Modeling of Early-Age Behavior of Structural Concrete.

    PubMed

    Pan, Yaming; Prado, Armando; Porras, Rocío; Hafez, Omar M; Bolander, John E

    2017-02-25

    The susceptibility of structural concrete to early-age cracking depends on material composition, methods of processing, structural boundary conditions, and a variety of environmental factors. Computational modeling offers a means for identifying primary factors and strategies for reducing cracking potential. Herein, lattice models are shown to be adept at simulating the thermal-hygral-mechanical phenomena that influence early-age cracking. In particular, this paper presents a lattice-based approach that utilizes a model of cementitious materials hydration to control the development of concrete properties, including stiffness, strength, and creep resistance. The approach is validated and used to simulate early-age cracking in concrete bridge decks. Structural configuration plays a key role in determining the magnitude and distribution of stresses caused by volume instabilities of the concrete material. Under restrained conditions, both thermal and hygral effects are found to be primary contributors to cracking potential.

  11. Studies on the corrosion resistance of reinforced steel in concrete with ground granulated blast-furnace slag--An overview.

    PubMed

    Song, Ha-Won; Saraswathy, Velu

    2006-11-16

    The partial replacement of clinker, the main constituent of ordinary Portland cement by pozzolanic or latent hydraulic industrial by-products such as ground granulated blast furnace slag (GGBFS), effectively lowers the cost of cement by saving energy in the production process. It also reduces CO2 emissions from the cement plant and offers a low priced solution to the environmental problem of depositing industrial wastes. The utilization of GGBFS as partial replacement of Portland cement takes advantage of economic, technical and environmental benefits of this material. Recently offshore, coastal and marine concrete structures were constructed using GGBFS concrete because high volume of GGBFS can contribute to the reduction of chloride ingress. In this paper, the influence of using GGBFS in reinforced concrete structures from the durability aspects such as chloride ingress and corrosion resistance, long term durability, microstructure and porosity of GGBFS concrete has been reviewed and discussed.

  12. Lattice Modeling of Early-Age Behavior of Structural Concrete

    PubMed Central

    Pan, Yaming; Prado, Armando; Porras, Rocío; Hafez, Omar M.; Bolander, John E.

    2017-01-01

    The susceptibility of structural concrete to early-age cracking depends on material composition, methods of processing, structural boundary conditions, and a variety of environmental factors. Computational modeling offers a means for identifying primary factors and strategies for reducing cracking potential. Herein, lattice models are shown to be adept at simulating the thermal-hygral-mechanical phenomena that influence early-age cracking. In particular, this paper presents a lattice-based approach that utilizes a model of cementitious materials hydration to control the development of concrete properties, including stiffness, strength, and creep resistance. The approach is validated and used to simulate early-age cracking in concrete bridge decks. Structural configuration plays a key role in determining the magnitude and distribution of stresses caused by volume instabilities of the concrete material. Under restrained conditions, both thermal and hygral effects are found to be primary contributors to cracking potential. PMID:28772590

  13. Shrinkage modeling of concrete reinforced by palm fibres in hot dry environments

    NASA Astrophysics Data System (ADS)

    Akchiche, Hamida; Kriker, Abdelouahed

    2017-02-01

    The cement materials, such as concrete and conventional mortar present very little resistance to traction and cracking, these hydraulic materials which induces large withdrawals on materials and cracks in structures. The hot dry environments such as: the Saharan regions of Algeria, Indeed, concrete structures in these regions are very fragile, and present high shrinkage. Strengthening of these materials by fibers can provide technical solutions for improving the mechanical performance. The aim of this study is firstly, to reduce the shrinkage of conventional concrete with its reinforcement with date palm fibers. In fact, Algeria has an extraordinary resources in natural fibers (from Palm, Abaca, Hemp) but without valorization in practical areas, especially in building materials. Secondly, to model the shrinkage behavior of concrete was reinforced by date palm fibers. In the literature, several models for still fiber concrete were founded but few are offers for natural fiber concretes. To do so, a still fiber concretes model of YOUNG - CHERN was used. According to the results, a reduction of shrinkage with reinforcement by date palm fibers was showed. A good ability of molding of shrinkage of date palm reinforced concrete with YOUNG - CHERN Modified model was obtained. In fact, a good correlation between experimental data and the model data was recorded.

  14. Timber - Material of the Future - Examples of Small Wooden Architectural Structures

    NASA Astrophysics Data System (ADS)

    Żmijewki, Tomasz; Wojtowicz-Jankowska, Dorota

    2017-10-01

    The aim of this article is to present various types of wood-based products, classified as engineered timber, while specifying the implications of their structural properties for their forms. Timber is used as a construction material due to its fire resistance, good structural characteristics and insulating properties. The advent of new technologies of wood processing and wood-based materials production has converted timber into a high-tech material, thus encouraging the architects to consider it ever more often in their projects. As wooden technologies overcome constraints, timber begins to compete with steel and concrete. The design characteristics of new wood-based products allow wooden structures to be higher, have larger spans, and more diverse forms than ever. Wood-based materials include materials made of solid wood, veneers, strand, and wood which, due to its inferior quality, would otherwise be unfit for constructions. Elements and layers of these products are glued using different kinds of strong and water-resistant adhesives. The article presents the history of development of new wood technologies, discussing increasingly popular wood-based materials such as glued laminated timber, cross-laminated timber, or structural composite lumber. The paper analyses their technical and fire-resistance properties, and points to ecological aspect, as factors contributing to the growing popularity of these materials. Finally, the timber’s characteristics are contrasted with those of steel and concrete. The article lists examples of wooden objects representing the so-called small architecture structures from across Europe. They illustrate the potential, the uniqueness and the versatility that wood-based materials offer for constructors and architects. All these features form sufficient grounds for stating that timber truly is a construction material of the 21st century.

  15. Word type effects in false recall: concrete, abstract, and emotion word critical lures.

    PubMed

    Bauer, Lisa M; Olheiser, Erik L; Altarriba, Jeanette; Landi, Nicole

    2009-01-01

    Previous research has demonstrated that definable qualities of verbal stimuli have implications for memory. For example, the distinction between concrete and abstract words has led to the finding that concrete words have an advantage in memory tasks (i.e., the concreteness effect). However, other word types, such as words that label specific human emotions, may also affect memory processes. This study examined the effects of word type on the production of false memories by using a list-learning false memory paradigm. Participants heard lists of words that were highly associated to nonpresented concrete, abstract, or emotion words (i.e., the critical lures) and then engaged in list recall. Emotion word critical lures were falsely recalled at a significantly higher rate (with the effect carried by the positively valenced critical lures) than concrete and abstract critical lures. These findings suggest that the word type variable has implications for our understanding of the mechanisms that underlie recall and false recall.

  16. Development of Fast Fourier Transform (FFT) micro-mechanical simulations of concrete specimens characterized by micro-X-ray fluorescence

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Giorla, Alain B.

    Concrete in Nuclear Power Plants (NPPs) can be exposed to a wide range of degradation phenomena. In the past years, the Light Water Reactor Sustainability (LWRS) program has investigated Radiation-Induced Volumetric Expansion (RIVE) as a potential degradation mechanism for concrete biological shields [Graves et al., 2014, Rosseel et al., 2016]. RIVE causes swelling and micro-mechanical damage in concrete due to the amorphization of mineral phases contained in the aggregates under neutron irradiation [Hilsdorf et al., 1978, Rosseel et al., 2016]. For long-term operations, it is critical to assess the durability of concrete after 60 or 80 years of exposure tomore » NPP operating conditions against this phenomenon. RIVE is dependent on the composition of the aggregates used in concrete. Quartz-bearing aggregates are more sensitive to RIVE than calcite-bearing aggregates, for example. However, the aggregate composition of a specific plant is generally not explicitly given in the concrete formulation, which makes it nearly impossible to predict the resistance of that concrete to RIVE. Additional characterization is needed to identify the radiation-sensitive mineral phases contained in the aggregates.« less

  17. Corrosion Behavior of Steel Reinforcement in Concrete with Recycled Aggregates, Fly Ash and Spent Cracking Catalyst

    PubMed Central

    Gurdián, Hebé; García-Alcocel, Eva; Baeza-Brotons, Francisco; Garcés, Pedro; Zornoza, Emilio

    2014-01-01

    The main strategy to reduce the environmental impact of the concrete industry is to reuse the waste materials. This research has considered the combination of cement replacement by industrial by-products, and natural coarse aggregate substitution by recycled aggregate. The aim is to evaluate the behavior of concretes with a reduced impact on the environment by replacing a 50% of cement by industrial by-products (15% of spent fluid catalytic cracking catalyst and 35% of fly ash) and a 100% of natural coarse aggregate by recycled aggregate. The concretes prepared according to these considerations have been tested in terms of mechanical strengths and the protection offered against steel reinforcement corrosion under carbonation attack and chloride-contaminated environments. The proposed concrete combinations reduced the mechanical performance of concretes in terms of elastic modulus, compressive strength, and flexural strength. In addition, an increase in open porosity due to the presence of recycled aggregate was observed, which is coherent with the changes observed in mechanical tests. Regarding corrosion tests, no significant differences were observed in the case of the resistance of these types of concretes under a natural chloride attack. In the case of carbonation attack, although all concretes did not stand the highly aggressive conditions, those concretes with cement replacement behaved worse than Portland cement concretes. PMID:28788613

  18. Static and dynamic behaviours of railway prestressed concrete sleepers with longitudinal through hole

    NASA Astrophysics Data System (ADS)

    Ngamkhanong, C.; Kaewunruen, S.; Remennikov, A. M.

    2017-10-01

    As the crosstie beam in railway track systems, the prestressed concrete sleepers (or railroad ties) are principally designed in order to carry wheel loads from the rails to the ground. Their design takes into account static and dynamic loading conditions. It is evident that prestressed concrete has played a significant role as to maintain the high endurance of the sleepers under low to moderate repeated impact loads. In spite of the most common use of the prestressed concrete sleepers in railway tracks, there have always been many demands from rail engineers to improve serviceability and functionality of concrete sleepers. For example, signalling, fibre optic, equipment cables are often damaged either by ballast corners or by tamping machine. There has been a need to re-design concrete sleeper to cater cables internally so that they would not experience detrimental or harsh environments. Accordingly, this study will investigate the effects of through hole or longitudinal hole on static and dynamic behaviours of concrete sleepers under rail shock loading. The modified compression field theory for ultimate strength design of concrete sleepers will be highlighted in this study. The outcome of this study will enable the new design and calculation methods for prestressed concrete sleepers with holes and web opening that practically benefits civil, track and structural engineers in railway industry.

  19. Heat transfer in hybrid fibre reinforced concrete-steel composite column exposed to a gas-fired radiant heater

    NASA Astrophysics Data System (ADS)

    Štefan, R.; Procházka, J.; Novák, J.; Fládr, J.; Wald, F.; Kohoutková, A.; Scheinherrová, L.; Čáchová, M.

    2017-09-01

    In the paper, a gas-fired radiant heater system for testing of structural elements and materials at elevated temperatures is described. The applicability of the system is illustrated on an example of the heat transfer experiment on a hybrid fibre reinforced concrete-steel composite column specimen. The results obtained during the test are closely analysed by common data visualization techniques. The experiment is simulated by a mathematical model of heat transfer, assuming the material data of the concrete determined by in-house measurements. The measured and calculated data are compared and discussed.

  20. Embedded Ultrasonic Transducers for Active and Passive Concrete Monitoring

    PubMed Central

    Niederleithinger, Ernst; Wolf, Julia; Mielentz, Frank; Wiggenhauser, Herbert; Pirskawetz, Stephan

    2015-01-01

    Recently developed new transducers for ultrasonic transmission, which can be embedded right into concrete, are now used for non-destructive permanent monitoring of concrete. They can be installed during construction or thereafter. Large volumes of concrete can be monitored for changes of material properties by a limited number of transducers. The transducer design, the main properties as well as installation procedures are presented. It is shown that compressional waves with a central frequency of 62 kHz are mainly generated around the transducer’s axis. The transducer can be used as a transmitter or receiver. Application examples demonstrate that the transducers can be used to monitor concrete conditions parameters (stress, temperature, …) as well as damages in an early state or the detection of acoustic events (e.g., crack opening). Besides application in civil engineering our setups can also be used for model studies in geosciences. PMID:25923928

  1. Evaluation of conductive concrete for anti-static flooring applications

    NASA Astrophysics Data System (ADS)

    Yehia, Sherif; Qaddoumi, Nasser; Hassan, Mohamed; Swaked, Bassam

    2015-04-01

    Static electricity, exchange of electrons, and retention of charge between any two materials due to contact and separation are affected by the condition of the materials being nonconductive or insulated from ground. Several work environments, such as electronics industry, hospitals, offices, and computer rooms all require electro-static discharge (ESD) mitigation. Carpet Tile, Carpet Broadloom, Vinyl Tile, Vinyl sheet, Epoxy and Rubber are examples of existing flooring systems in the market. However, each system has its advantages and limitations. Conductive concrete is a relatively new material technology developed to achieve high electrical conductivity and high mechanical strength. The conductive concrete material can be an economical alternative for these ESD flooring systems. In this paper, the effectiveness of conductive concrete as an anti-static flooring system was evaluated. The initial results indicated that the proposed conductive concrete flooring and ground system met the acceptance criteria stated by ASTM F150.

  2. Quality Assurance Plan for Placement of Cold-Cap Grout, Demonstration Vault, Hanford Grout Vault Program

    DTIC Science & Technology

    1992-08-01

    recommend that representatives of the WES Concrete Technology Division be onsite during the placement and postplacement phases to offer technical...written before field placement. PREFACE The work described in this report is part of an ongoing research effort accomplished in the Concrete Technology ... Division (CTD), Structures Laboratory (SL), U.S. Army Engineer Waterways Experiment Station (WES), under Interagency Agreement from the Department of

  3. Balanced improvement of high performance concrete material properties with modified graphite nanomaterials

    NASA Astrophysics Data System (ADS)

    Peyvandi, Amirpasha

    Graphite nanomaterials offer distinct features for effective reinforcement of cementitious matrices in the pre-crack and post-crack ranges of behavior. Thoroughly dispersed and well-bonded nanomaterials provide for effective control of the size and propagation of defects (microcracks) in matrix, and also act as closely spaced barriers against diffusion of moisture and aggressive solutions into concrete. Modified graphite nanomaterials can play multi-faceted roles towards enhancing the mechanical, physical and functional attributes of concrete materials. Graphite nanoplatelets (GP) and carbon nanofibers (CNF) were chosen for use in cementitious materials. Experimental results highlighted the balanced gains in diverse engineering properties of high-performance concrete realized by introduction of graphite nanomaterials. Nuclear Magnetic Resonance (NMR) spectroscopy was used in order to gain further insight into the effects of nanomaterials on the hydration process and structure of cement hydrates. NMR exploits the magnetic properties of certain atomic nuclei, and the sensitivity of these properties to local environments to generate data which enables determination of the internal structure, reaction state, and chemical environment of molecules and bulk materials. 27 Al and 29Si NMR spectroscopy techniques were employed in order to evaluate the effects of graphite nanoplatelets on the structure of cement hydrates, and their resistance to alkali-silica reaction (ASR), chloride ion diffusion, and sulfate attack. Results of 29Si NMR spectroscopy indicated that the percent condensation of C-S-H in cementitious paste was lowered in the presence of nanoplatelets at the same age. The extent of chloride diffusion was assessed indirectly by detecting Friedel's salt as a reaction product of chloride ions with aluminum-bearing cement hydrates. Graphite nanoplatelets were found to significantly reduce the concentration of Friedel's salt at different depths after various periods of exposure to chloride solutions, pointing at the benefits of nanoplatelets towards enhancement of concrete resistance to chloride ion diffusion. It was also found that the intensity of Thaumasite, a key species marking sulfate attack on cement hydrates, was lowered with the addition of graphite nanoplatelets in concrete exposed to sulfate solutions. Experimental evaluations were conducted on scaled-up production of concrete nanocomposite in precast concrete plants. Full-scale reinforced concrete pipes and beams were produced using concrete nanocomposites. Durability and structural tests indicated that the use of graphite nanoplatelets, alone or in combination with synthetic (PVA) fibers, produced significant gains in the durability characteristics, and also benefited the structural performance of precast reinforced concrete products. The material and scaled-up structural investigations conducted in the project concluded that lower-cost graphite nanomaterials (e.g., graphite nanoplatelets) offer significant potentials as multi-functional additives capable of enhancing the barrier, durability and mechanical performance of concrete materials. The benefits of graphite nanomaterials tend to be more pronounced in higher-performance concrete materials.

  4. Differential forms for scientists and engineers

    NASA Astrophysics Data System (ADS)

    Blair Perot, J.; Zusi, Christopher J.

    2014-01-01

    This paper is a review of a number of mathematical concepts from differential geometry and exterior calculus that are finding increasing application in the numerical solution of partial differential equations. The objective of the paper is to introduce the scientist/ engineer to some of these ideas via a number of concrete examples in 2, 3, and 4 dimensions. The goal is not to explain these ideas with mathematical precision but to present concrete examples and enable a physical intuition of these concepts for those who are not mathematicians. The objective of this paper is to provide enough context so that scientist/engineers can interpret, implement, and understand other works which use these elegant mathematical concepts.

  5. Effects of Variation and Prior Knowledge on Abstract Concept Learning

    ERIC Educational Resources Information Center

    Braithwaite, David W.; Goldstone, Robert L.

    2015-01-01

    Learning abstract concepts through concrete examples may promote learning at the cost of inhibiting transfer. The present study investigated one approach to solving this problem: systematically varying superficial features of the examples. Participants learned to solve problems involving a mathematical concept by studying either superficially…

  6. Operational Art Requirements in the Korean War

    DTIC Science & Technology

    2012-05-17

    Historical case studies can provide concrete examples to test the validity of theory and doctrine. A critical analysis of the examples provided by...war into a global conflagration .45 However, as early as 13 July 1950, MacArthur developed his plan to do more than reestablish the territorial

  7. Psychology of Learning for Instruction.

    ERIC Educational Resources Information Center

    Driscoll, Marcy P.

    This cognitively-oriented book focuses on learning and instruction. Specific applications and implications of learning theories are discussed and examples are drawn from educational situations and educational problems. Theoretical concepts are illustrated in concrete terms and a wide variety of examples are provided. The text embodies a theme of…

  8. Acoustic Emission Analysis of Prestressed Concrete Structures

    NASA Astrophysics Data System (ADS)

    Elfergani, H. A.; Pullin, R.; Holford, K. M.

    2011-07-01

    Corrosion is a substantial problem in numerous structures and in particular corrosion is very serious in reinforced and prestressed concrete and must, in certain applications, be given special consideration because failure may result in loss of life and high financial cost. Furthermore corrosion cannot only be considered a long term problem with many studies reporting failure of bridges and concrete pipes due to corrosion within a short period after they were constructed. The concrete pipes which transport water are examples of structures that have suffered from corrosion; for example, the pipes of The Great Man-Made River Project of Libya. Five pipe failures due to corrosion have occurred since their installation. The main reason for the damage is corrosion of prestressed wires in the pipes due to the attack of chloride ions from the surrounding soil. Detection of the corrosion in initial stages has been very important to avoid other failures and the interruption of water flow. Even though most non-destructive methods which are used in the project are able to detect wire breaks, they cannot detect the presence of corrosion. Hence in areas where no excavation has been completed, areas of serious damage can go undetected. Therefore, the major problem which faces engineers is to find the best way to detect the corrosion and prevent the pipes from deteriorating. This paper reports on the use of the Acoustic Emission (AE) technique to detect the early stages of corrosion prior to deterioration of concrete structures.

  9. Laboratory simulation of high-frequency GPR responses of damaged tunnel liners

    NASA Astrophysics Data System (ADS)

    Siggins, A. F.; Whiteley, Robert J.

    2000-04-01

    Concrete lined tunnels and pipelines commonly suffer from damage due to subsidence or poor drainage in the surrounding soils, corrosion of reinforcement if present, and acid vapor leaching of the lining. There is a need to conduct tunnel condition monitoring using non-destructive testing methods (NDT) on a regular basis in many buried installations, for example sewers and storm water drains. A wide variety of NDT methods have been employed in the past to monitor these linings including closed circuit TV (CCTV) inspection, magnetic and various electromagnetic and seismic methods. Ground penetrating radar, GPR, is a promising technique for this application, however there are few systems currently available that can provide the high resolution imaging needed to test the lining. A recently developed Australian GPR system operating at 1400 MHz offers the potential to overcome many of these limitations while maintaining adequate resolution to the rear of the linings which are typically less than 0.5 meters thick. The new high frequency GPR has a nominal resolution of 0.03 m at the center of the pulse band-width. This is a significant improvement over existing radars with the possible exception of some horn based systems. This paper describes the results of a laboratory study on a model tunnel lining using the new 1.4 GHz radar. The model simulated a concrete lining with various degrees of damage including, heavily leached sections, voids and corroded reinforcing. The test results established that the new GPR was capable of imaging subtle variations in the concrete structure and that simulated damage could be detected throughout the liner depth. Furthermore, resolution was found to exceed 0.02 m which was significantly better than expected.

  10. Numerical simulations and experimental measurements of steel and ice impacts on concrete for acoustic interrogation of delaminations in bridge decks

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mazzeo, Brian A.; Patil, Anjali N.; Klis, Jeffrey M.

    2014-02-18

    Delaminations in bridge decks typically result from corrosion of the top mat of reinforcing steel, which leads to a localized separation of the concrete cover from the underlying concrete. Because delaminations cannot be detected using visual inspection, rapid, large-area interrogation methods are desired to characterize bridge decks without disruption to traffic, without the subjectivity inherent in existing methods, and with increased inspector safety. To this end, disposable impactors such as water droplets or ice chips can be dropped using automatic dispensers onto concrete surfaces to excite mechanical vibrations while acoustic responses can be recorded using air-coupled microphones. In this work,more » numerical simulations are used to characterize the flexural response of a model concrete bridge deck subject to both steel and ice impactors, and the results are compared with similar experiments performed in the laboratory on a partially delaminated concrete bridge deck slab. The simulations offer greater understanding of the kinetics of impacts and the responses of materials.« less

  11. Modeling Unidirectional Composite Laminates Using XFEM

    DTIC Science & Technology

    2015-06-30

    evaluated. For example, Benvenuti et al.22 applied XFEM concepts to modeling FRP-reinforced concrete and Sosa and Karapurath23 used XFEM to model...shows the translucent final configurations with = 0.5, 1, 5, and 10 ksi, respectively. When fracture occurs, denoted in red, it is located...REFERENCES (Cont’d) 22. E. Benvenuti, O. Vitarelli, A. Tralli, “Delamination of FRP-Reinforced Concrete by Means of an eXtended Finite Element

  12. No Light at the End of Tunnel Vision: Steps for Improving Lesson Plans

    ERIC Educational Resources Information Center

    Dunn, Rita; Craig, Martin; Favre, Lois; Markus, Doron; Pedota, Paul; Sookdeo, Gale; Stock, Jessica; Terry, Brian

    2010-01-01

    The authors of this article believe that the current structure of lesson plans impede differentiation, individualization, and innovation and offer little in assessing the quality of teaching and learning. Concrete steps will be offered for planning to better respond to student diversity in meeting lesson objectives. (Contains 1 figure.)

  13. [Archaeology and criminology--Strengths and weaknesses of interdisciplinary cooperation].

    PubMed

    Bachhiesl, Christian

    2015-01-01

    Interdisciplinary cooperation of archaeology and criminology is often focussed on the scientific methods applied in both fields of knowledge. In combination with the humanistic methods traditionally used in archaeology, the finding of facts can be enormously increased and the subsequent hermeneutic deduction of human behaviour in the past can take place on a more solid basis. Thus, interdisciplinary cooperation offers direct and indirect advantages. But it can also cause epistemological problems, if the weaknesses and limits of one method are to be corrected by applying methods used in other disciplines. This may result in the application of methods unsuitable for the problem to be investigated so that, in a way, the methodological and epistemological weaknesses of two disciplines potentiate each other. An example of this effect is the quantification of qualia. These epistemological reflections are compared with the interdisciplinary approach using the concrete case of the "Eulau Crime Scene".

  14. Finite element analysis of CFRP reinforced silo structure design method

    NASA Astrophysics Data System (ADS)

    Yuan, Long; Xu, Xinsheng

    2017-11-01

    Because of poor construction, there is a serious problem of concrete quality in the silo project, which seriously affects the safe use of the structure. Concrete quality problems are mainly seen in three aspects: concrete strength cannot meet the design requirements, concrete cracking phenomenon is serious, and the unreasonable concrete vibration leads to a lot of honeycombs and surface voids. Silos are usually reinforced by carbon fiber cloth in order to ensure the safe use of silos. By the example of an alumina silo in a fly ash plant in Binzhou, Shandong Province, the alumina silo project was tested and examined on site. According to filed test results, the actual concrete strength was determined, and the damage causes of the silo was analysed. Then, a finite element analysis model of this silo was established, the CFRP cloth reinforcement method was adopted to strengthen the silo, and other technology like additional reinforcement, rebar planting, carbon fiber bonding technology was also expounded. The research of this paper is of great significance to the design and construction of silo structure.

  15. Reliability assessment of slender concrete columns at the stability failure

    NASA Astrophysics Data System (ADS)

    Valašík, Adrián; Benko, Vladimír; Strauss, Alfred; Täubling, Benjamin

    2018-01-01

    The European Standard for designing concrete columns within the use of non-linear methods shows deficiencies in terms of global reliability, in case that the concrete columns fail by the loss of stability. The buckling failure is a brittle failure which occurs without warning and the probability of its formation depends on the columns slenderness. Experiments with slender concrete columns were carried out in cooperation with STRABAG Bratislava LTD in Central Laboratory of Faculty of Civil Engineering SUT in Bratislava. The following article aims to compare the global reliability of slender concrete columns with slenderness of 90 and higher. The columns were designed according to methods offered by EN 1992-1-1 [1]. The mentioned experiments were used as basis for deterministic nonlinear modelling of the columns and subsequent the probabilistic evaluation of structural response variability. Final results may be utilized as thresholds for loading of produced structural elements and they aim to present probabilistic design as less conservative compared to classic partial safety factor based design and alternative ECOV method.

  16. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rashid, A.; Nygaard, C.

    The use of concrete in marine environment has gained tremendous popularity in the past decade and is continued to be a very popular material for marine industry in the world today. It has a very diversified use from large offshore platforms and floating structures in the North Sea, Canada and South America to offshore loading terminals and junction platforms in shallow waters in the marshes of southern Louisiana in the Gulf of Mexico. Also, precast concrete sections are extensively used all over the world in the construction of marine structures. Because of their large variety of shapes and sizes, theymore » can be tailored to fit multiple applications in marine environment. The added quality control in the fabrication yard and the ease of installation by lifting makes them a very attractive option. The use of precast concrete sections is gaining a lot of popularity in South America. A lot of fabrication yards are manufacturing these sections locally. There are hundreds of offshore concrete platforms utilizing these sections in Lake Maracaibo, Venezuela. The paper discusses the use of concrete for offshore structures including floaters. It describes some general concepts and advantages to be gained by the use of concrete (precast and cast-in-place) in marine environment. It also discusses some general design considerations required for the use of different types of precast concrete sections that can be utilized for oil and gas platforms and loading terminals. Lastly the paper describes some typical examples of concrete platforms built out of concrete piles, precast concrete girders and beam sections and concrete decking.« less

  17. Shrinkage stress in concrete under dry-wet cycles: an example with concrete column

    NASA Astrophysics Data System (ADS)

    Gao, Yuan; Zhang, Jun; Luosun, Yiming

    2014-02-01

    This paper focuses on the simulation of shrinkage stress in concrete structures under dry-wet environments. In the modeling, an integrative model for autogenous and drying shrinkage predictions of concrete under dry-wet cycles is introduced first. Second, a model taking both cement hydration and moisture diffusion into account synchronously is used to calculate the distribution of interior humidity in concrete. Using the above two models, the distributions of shrinkage strain and stress in concrete columns made by normal and high strength concrete respectively under dry-wet cycles are calculated. The model results show that shrinkage gradient along the radial direction of the column from the center to outer surface increases with age as the outer circumference suffers to dry. The maximum and minimum shrinkage occur at the outer surface and the center of the column, respectively, under drying condition. As wetting starts, the shrinkage strain decreases with increase of interior humidity. The closer to the wetting face, the higher the humidity and the lower the shrinkage strain, as well as the lower the shrinkage stress. As results of the dry-wet cycles acting on the outer circumference of the column, cyclic stress status is developed within the area close to the outer surface of the column. The depth of the influencing zone of dry-wet cyclic action is influenced by concrete strength and dry-wet regime. For low strength concrete, relatively deeper influencing zone is expected compared with that of high strength concrete. The models are verified by concrete-steel composite ring tests and a good agreement between model and test results is found.

  18. 55. Virginia Route 688 grade separation structure. This structure, built ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    55. Virginia Route 688 grade separation structure. This structure, built in 1960, is an example of several concrete box culverts built primarily in the late 1950's and early 1960's. They are simply plain concrete with now ornamentation. These structures were used only on lesser used secondary paved roads or dirt roads. View is looking south. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  19. The Control of Welding Deformation of the Three-Section Arm of Placing Boom of HB48B Pump Truck

    NASA Astrophysics Data System (ADS)

    Wang, Zhi-ling

    2018-02-01

    The concrete pump truck is the construction equipment of conveying concrete with self contained base plate and distributing boom. It integrates the pump transport mechanism of the concrete pump, and the hydraulic roll-folding type distributing boom used to distribute materials, and the supporting mechanism into the automobile chassis, and it is the concrete conveying equipment with high efficient and the functions of driving, pumping, and distributing materials. The placing boom of the concrete pump truck is the main force member in the pump parts with bearing great pressure, and its stress condition is complex. Taking the HB48B placing boom as an example, this paper analyzes and studies the deformation produced by placing boom of pump truck, and then obtains some main factors affecting the welding deformation. Through the riveter “joint” size, we controlled the process parameters, post-welding processing, and other aspects. These measures had some practical significance to prevent, control, and reduce the deformation of welding.

  20. Numerical analysis of composite STEEL-CONCRETE SECTIONS using integral equation of Volterra

    NASA Astrophysics Data System (ADS)

    Partov, Doncho; Kantchev, Vesselin

    2011-09-01

    The paper presents analysis of the stress and deflections changes due to creep in statically determinate composite steel-concrete beam. The mathematical model involves the equation of equilibrium, compatibility and constitutive relationship, i.e. an elastic law for the steel part and an integral-type creep law of Boltzmann — Volterra for the concrete part. On the basis of the theory of the viscoelastic body of Arutyunian-Trost-Bažant for determining the redistribution of stresses in beam section between concrete plate and steel beam with respect to time "t", two independent Volterra integral equations of the second kind have been derived. Numerical method based on linear approximation of the singular kernal function in the integral equation is presented. Example with the model proposed is investigated. The creep functions is suggested by the model CEB MC90-99 and the "ACI 209R-92 model. The elastic modulus of concrete E c (t) is assumed to be constant in time `t'. The obtained results from the both models are compared.

  1. A Finite Abelian Group of Two-Letter Inversions

    ERIC Educational Resources Information Center

    Balbuena, Sherwin E.

    2015-01-01

    In abstract algebra, the study of concrete groups is fundamentally important to beginners. Most commonly used groups as examples are integer addition modulo n, real number addition and multiplication, permutation groups, and groups of symmetry. The last two examples are finite non-abelian groups and can be investigated with the aid of concrete…

  2. New potentional of high-speed water jet technology for renovating concrete structures

    NASA Astrophysics Data System (ADS)

    Bodnárová, L.; Sitek, L.; Hela, R.; Foldyna, J.

    2011-06-01

    The paper discusses the background and results of research focused on the action of a high-speed water jet on concrete with different qualities. The sufficient and careful removal of degraded concrete layers is very important for the renovation of concrete structures. High-speed water jet technology is one of the most common methods used for removing degraded concrete layers. Different types of high-speed water jets were tested in the experimental part. The classical technology of a single continuous water jet generated with one nozzle was tested as well as the technology of revolving water jets generated by multiple nozzles (used mainly for the renovation of larger areas). A continuous flat water jet and pulsating flat water jet were tested the first time, because the connection of a water jet with the acoustic generator of a pulsating jet offers new possibilities for the use of a water jet (see [1] and [2]). A water jet with such a modification is capable of efficient action and can even be used for cutting solid concrete with a relatively low consumption of energy. A flat pulsating water jet which can be newly used for renovation seems to be a promising technology.

  3. Composite Material from By-products and Its Properties

    NASA Astrophysics Data System (ADS)

    Šeps, K.; Broukalová, I.; Vodička, J.

    2017-09-01

    The paper shows an example of utilization of specific textile admixture - fluffs of torn textiles from waste cars in production of composite with aggregate consisting entirely of unsorted recycled concrete. The admixture in the mixture of recycled concrete and cement binder fills the pores and voids in composite. The elaborated composite has working title STEREDconcrete. In the article, basic mechanical-physical properties of the composite are presented also the fire resistance of STEREDconcrete, which was determined in tests.

  4. New Fiber Reinforced Waterless Concrete for Extraterrestrial Structural Applications

    NASA Technical Reports Server (NTRS)

    Toutanji, H.; Tucker, D.; Ethridge, E.

    2005-01-01

    Commercial use of sulfur concrete on Earth is well established, particularly in corrosive, e.g., acid and salt, environments. Having found troilite (FeS) on the Moon raises the question of using extracted sulfur as a lunar construction mate: iii an attractive alternative to conventional concrete as it does not require water For the purpose of this paper it is assumed that lunar ore is mined, refined, and the raw sulfur processed with appropriate lunar regolith to form, for example, brick and beam elements. Glass fibers produced from regolith were used as a reinforcement to improve the mechanical properties of the sulfur concrete. Glass fibers and glass rebar were produced by melting the lunar regolith simulant. Lunar regolith stimulant was melted in a 25 cc Pt-Rh crucible in a Sybron Thermoline 46100 high temperature MoSi2 furnace at melting temperatures of 1450 to 1600G. The glass melt wets the ceramic rod and long continuous glass fibers were easily hand drawn. The glass fibers were immediately coated with a protective polymer to maintain the mechanical strength. The viability of sulfur concrete as a construction material for extraterrestrial application is presented. The mechanical properties of the glass fiber reinforced sulfur concrete were investigated.

  5. Turning Despondency into Hope: Charting New Paths to Improve Students' Achievement and Participation in Science Education

    ERIC Educational Resources Information Center

    Rodriguez, Alberto J.

    2004-01-01

    This monograph offers a realistic look at current trends in student achievement in science education, the participation of underrepresented populations, and the many factors that serve to sustain them. In addition, it offers new insights and concrete suggestions for change based on the analysis of recent reports and promising field-based studies.…

  6. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bech, H.; Haugsen, P.B.

    The Norwegian Oil Company, Saga Petroleum a.s., is operator on two promising deep water blocks in the Norwegian sector of the North Sea. As a result, the company has introduced a new platform concept designed specifically for hostile and deep water areas. The platform idea is the result of a systematic innovation procedure. The first step was to analyze and describe the functions of the different structural elements on a general basis. Next was to analyze how these elements contributed to the total concept. The final development stage was to create a new solution. The resulting (hybrid platform design conceptmore » appears to offer a number of inherent deck layout and towout deck weight advantages). The concrete substructure is a lower unit consisting of a foundation with concrete skirts that will penetrate the soft soil in the seabed and a high concrete caisson extending up from the foundation, which is made up of seven cells with varying concrete thicknesses, terminating in domes. The upper steel platform section is a lattice-type jacket structure. There is a separate column for internal personnel access between the platform deck and the concrete caisson.« less

  7. Preparation and performance of arsenate (V) adsorbents derived from concrete wastes.

    PubMed

    Sasaki, Takeshi; Iizuka, Atsushi; Watanabe, Masayuki; Hongo, Teruhisa; Yamasaki, Akihiro

    2014-10-01

    Solid adsorbent materials, prepared from waste cement powder and concrete sludge were assessed for removal of arsenic in the form of arsenic (As(V)) from water. All the materials exhibited arsenic removal capacity when added to distilled water containing 10-700 mg/L arsenic. The arsenic removal isotherms were expressed by the Langmuir type equations, and the highest removal capacity was observed for the adsorbent prepared from concrete sludge with heat treatment at 105°C, the maximum removal capacity being 175 mg-As(V)/g. Based on changes in arsenic and calcium ion concentrations, and solution pH, the removal mechanism for arsenic was considered to involve the precipitation of calcium arsenate, Ca3(AsO4)2. The enhanced removal of arsenic for the adsorbent prepared from concrete sludge with heat treatment was thought to reflect ion exchange by ettringite. The prepared adsorbents, derived from waste cement and concrete using simple procedures, may offer a cost effective approach for arsenic removal and clean-up of contaminated waters, especially in developing countries. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Breakthrough thinking from inside the box.

    PubMed

    Coyne, Kevin P; Clifford, Patricia Gorman; Dye, Renée

    2007-12-01

    Companies often begin their search for great ideas either by encouraging wild, outside-the-box thinking or by conducting quantitative analysis of existing market and financial data and customer opinions. Those approaches can produce middling ideas at best, say Coyne, founder of an executive-counseling firm in Atlanta, and Clifford and Dye, strategy experts at McKinsey. The problem with the first method is that few people are very good at unstructured, abstract brainstorming. The problems with the second are that databases are usually compiled to describe current--not future--offerings, and customers rarely can tell you whether they need or want a product if they've never seen it. The secret to getting your organization to regularly generate lots of good ideas, and occasionally some great ones, is deceptively simple: First, create new boxes for people to think within so that they don't get lost in the cosmos and they have a basis for offering ideas and knowing whether they're making progress in the brainstorming session. Second, redesign ideation processes to remove obstacles that interfere with the flow of ideas--such as most people's aversion to speaking in groups larger than ten. This article offers a tested approach that poses concrete questions. For example, what do Rollerblades, Häagen-Dazs ice cream, and Spider-Man movies have in common? The answer: Each is something that adults loved as children and that was reproduced in an expensive form for grown-ups. Asking brainstorming participants to ponder how their childhood passions could be recast as adult offerings might generate some fabulous ideas for new products or services.

  9. Fiber-optic sensor applications in civil and geotechnical engineering

    NASA Astrophysics Data System (ADS)

    Habel, Wolfgang R.; Krebber, Katerina

    2011-09-01

    Different types of fiber-optic sensors based on glass or polymeric fibers are used to evaluate material behavior or to monitor the integrity and long-term stability of load-bearing structure components. Fiber-optic sensors have been established as a new and innovative measurement technology in very different fields, such as material science, civil engineering, light-weight structures, geotechnical areas as well as chemical and high-voltage substations. Very often, mechanical quantities such as deformation, strain or vibration are requested. However, measurement of chemical quantities in materials and structure components, such as pH value in steel reinforced concrete members also provides information about the integrity of concrete structures. A special fiber-optic chemical sensor for monitoring the alkaline state (pH value) of the cementitious matrix in steel-reinforced concrete structures with the purpose of early detection of corrosion-initiating factors is described. The paper presents the use of several fiber-optic sensor technologies in engineering. One example concerns the use of highly resolving concrete-embeddable fiber Fabry-Perot acoustic emission (AE) sensors for the assessment of the bearing behaviour of large concrete piles in existing foundations or during and after its installation. Another example concerns fiber Bragg grating (FBG) sensors attached to anchor steels (micro piles) to measure the strain distribution in loaded soil anchors. Polymer optical fibers (POF) can be — because of their high elasticity and high ultimate strain — well integrated into textiles to monitor their deformation behaviour. Such "intelligent" textiles are capable of monitoring displacement of soil or slopes, critical mechanical deformation in geotechnical structures (dikes, dams, and embankments) as well as in masonry structures during and after earthquakes.

  10. Intercollegiate Athletics Today and Tomorrow: The President's Challenge

    ERIC Educational Resources Information Center

    Hanford, George H.

    1977-01-01

    Colleges and university presidents must come to terms with the challenges posed by intercollegiate athletics. The author offers concrete ideas and suggestions aimed at breaking through the confusion surrounding intercollegiate athletics. (Editor/LBH)

  11. Is Current US Counterinsurgency Doctrine Applicable to Lebanese Hizballah and the Taliban?

    DTIC Science & Technology

    2010-06-11

    credibility of the Afghan government.180 180Griff White, “Taliban Shadow Officials Offer Concrete ...194International Crisis Group, “Egypts Muslim Brothers: Integration or Conflagration ?” Middle East

  12. The cost of concreteness: the effect of nonessential information on analogical transfer.

    PubMed

    Kaminski, Jennifer A; Sloutsky, Vladimir M; Heckler, Andrew F

    2013-03-01

    Most theories of analogical transfer focus on similarities between the learning and transfer domains, where transfer is more likely between domains that share common surface features, similar elements, or common interpretations of structure. We suggest that characteristics of the learning instantiation alone can give rise to different levels of transfer. We propose that concreteness of the learning instantiation can hinder analogical transfer of well-defined structured concepts, such as mathematical concepts. We operationalize the term concreteness as the amount of information communicated through a specific instantiation of a concept. The 5 reported experiments with undergraduate students tested the hypothesis by presenting participants with the concept of a commutative mathematical group of order 3. The experiments varied the level of concreteness of the training instantiation and measured transfer of learning to a new instantiation. The results support the hypothesis, demonstrating better transfer from more generic instantiations (i.e., ones that communicate minimal extraneous information) than from more concrete instantiations. Specifically, concreteness was found to create an obstacle to successful structural alignment across domains, whereas generic instantiations led to spontaneous structural alignment. These findings have important implications for the theory of learning and transfer and practical implications for the design of educational material. Although some concreteness may activate prior knowledge and perhaps offer a leg up in the learning process, this benefit may come at the cost of transfer.

  13. Automatic Control of the Concrete Mixture Homogeneity in Cycling Mixers

    NASA Astrophysics Data System (ADS)

    Anatoly Fedorovich, Tikhonov; Drozdov, Anatoly

    2018-03-01

    The article describes the factors affecting the concrete mixture quality related to the moisture content of aggregates, since the effectiveness of the concrete mixture production is largely determined by the availability of quality management tools at all stages of the technological process. It is established that the unaccounted moisture of aggregates adversely affects the concrete mixture homogeneity and, accordingly, the strength of building structures. A new control method and the automatic control system of the concrete mixture homogeneity in the technological process of mixing components have been proposed, since the tasks of providing a concrete mixture are performed by the automatic control system of processing kneading-and-mixing machinery with operational automatic control of homogeneity. Theoretical underpinnings of the control of the mixture homogeneity are presented, which are related to a change in the frequency of vibrodynamic vibrations of the mixer body. The structure of the technical means of the automatic control system for regulating the supply of water is determined depending on the change in the concrete mixture homogeneity during the continuous mixing of components. The following technical means for establishing automatic control have been chosen: vibro-acoustic sensors, remote terminal units, electropneumatic control actuators, etc. To identify the quality indicator of automatic control, the system offers a structure flowchart with transfer functions that determine the ACS operation in transient dynamic mode.

  14. Hematite ``Blueberry`` Concretion Doublet and Triplets on Mars: Iron Oxide Twin Analogs From Utah

    NASA Astrophysics Data System (ADS)

    Chan, M. A.; Parry, W. T.; Park, A. S.

    2005-12-01

    Spherical concretions on Earth and Mars comprise a record of diagenetic history that may not otherwise be preserved in the more common host rock. Hematite spherules of Meridiani Planum show some joined forms of twos and threes. Joined iron oxide concretions making doublets and triplets also occur in the Jurassic Navajo Sandstone of southern Utah, and can serve as an analog to understanding why joined forms occur on Mars. The geometries of in situ Utah examples suggest two processes for creating connected forms. In one concretion growth mechanism, occasional coalescing of single forms may result from the growth of doublets or triplets in overly close proximity (typically less than 15% of a population). Joined concretions of roughly equal sizes can be aligned in a row; unequal size concretions take on the shapes of ``snowmen``, or attached ``satellites``. Where cementation is pervasive, individual concretions may grow and coalesce into a lumpy layer or cemented mass along preferential flow paths or preferential nucleation sites. In the second mechanism, nearly all (more than 75%) of the concretions form doublets that are conjoined. The occurrence of dominant twins indicates that these concretions are not coincidental as in the first mechanism. Dominant twin concretions occur regularly and evenly throughout fairly homogeneous host rock. More unusual twins show additional small twin warts suggesting duplicated nucleation and precipitation. Normally, iron oxide concretion precipitation begins when the oxide saturation reaches a precipitation threshold. Precipitation produces chemical gradients, and competition between reaction and diffusion rates determines the spacing between concretions. These factors in combination with reactant supply, competitive growth phenomena and a complex self-organizing processes may contribute to development of internal structure with varying layers of iron-depleted zones to resistant iron-cemented shells. The pervasive nature of sandstone coloration and iron concretion formation throughout much of the Navajo Sandstone indicates a favorable environment for iron mobilization and precipitation. However, the spectrum of sedimentologic, hydrologic, chemical, and nucleation parameters involved in producing the varying concretion forms shows the potential diagenetic subtleties that may be involved to precipitate similar joined concretion forms on Mars.

  15. Sulfur 'Concrete' for Lunar Applications - Environmental Considerations

    NASA Technical Reports Server (NTRS)

    Grugel, R. N.

    2008-01-01

    Commercial use of sulfur concrete on Earth is well established, particularly in corrosive, e.g., acid and salt, environments. Having found troilite (FeS) on the Moon raises the question of using extracted sulfur as a lunar construction material, an attractive alternative to conventional concrete as it does not require water. For the purpose of this Technical Memorandum, it is assumed that lunar ore is mined, refined, and the raw sulfur processed with appropriate lunar regolith to form, for example, bricks. With this stipulation, it is then noted that the viability of sulfur concrete in a lunar environment, which is characterized by lack of an atmosphere and extreme temperatures, is not well understood. The work presented here evaluates two sets of small sulfur concrete samples that have been prepared using JSC-1 lunar simulant as an aggregate addition. One set was subjected to extended periods in high vacuum to evaluate sublimation issues, and the other was cycled between room and liquid nitrogen temperatures to investigate their subsequent mechanical integrity. Results are presented from both investigations, discussed, and put into the context of the lunar environment.

  16. Sulfur "Concrete" for Lunar Applications - Sublimation Concerns

    NASA Technical Reports Server (NTRS)

    Grugel, Richard N.; Toutanji, Houssam

    2006-01-01

    Melting sulfur and mixing it with an aggregate to form "concrete" is commercially well established and constitutes a material that is particularly well-suited for use in corrosive environments. Discovery of the mineral troilite (FeS) on the moon poses the question of extracting the sulfur for use as a lunar construction material. This would be an attractive alternative to conventional concrete as it does not require water. However, the viability of sulfur concrete in a lunar environment, which is characterized by lack of an atmosphere and extreme temperatures, is not well understood. Here it is assumed that the lunar ore can be mined, refined, and the raw sulfur melded with appropriate lunar regolith to form, for example, bricks. This study evaluates pure sulfur and two sets of small sulfur concrete samples that have been prepared using JSC-1 lunar stimulant and SiO2 powder as aggregate additions. Each set was subjected to extended periods in a vacuum environment to evaluate sublimation issues. Results from these experiments are presented and discussed within the context of the lunar environment.

  17. Mathematical modeling of vibration processes in reinforced concrete structures for setting up crack initiation monitoring

    NASA Astrophysics Data System (ADS)

    Bykov, A. A.; Matveenko, B. P.; Serovaev, G. S.; Shardakov, I. N.; Shestakov, A. P.

    2015-03-01

    The contemporary construction industry is based on the use of reinforced concrete structures, but emergency situations resulting in fracture can arise in their exploitation. In a majority of cases, reinforced concrete fracture is realized as the process of crack formation and development. As a rule, the appearance of the first cracks does not lead to the complete loss of the carrying capacity but is a fracture precursor. One method for ensuring the safe operation of building structures is based on crack initiation monitoring. A vibration method for the monitoring of reinforced concrete structures is justified in this paper. An example of a reinforced concrete beam is used to consider all stages related to the analysis of the behavior of natural frequencies in the development of a crack-shaped defect and the use of the obtained numerical results for the vibration test method. The efficiency of the method is illustrated by the results of modeling of the physical part of the method related to the analysis of the natural frequency evolution as a response to the impact action in the crack development process.

  18. Concrete Durability in Harsh Environmental Conditions Exposed to Freeze Thaw Cycles

    NASA Astrophysics Data System (ADS)

    Hamze, Youssef

    Under line Pathology of Materials; one of the environmental causes of damage effects on concrete is freeze thaw cycles, which deteriorate the concrete exposed to water in cold weather. An example of old concrete is a dam project that was built in Canada, in the early 1909-1913. This project was reconstructed in 1932, 1934 and 1972, and required renovation due to the ice abrasion with the freeze/thaw cycles. Before completing any renovation, it is required to analyze the structural stability and the concrete failures of this dam. An investigation was conducted to determine the quality of the concrete in the Piers and in the Bridge Deck Slab. It was also required to determine the basic materials' properties that constitute this project. This will improve the analysis of its stability [10]. Core samples were examined and used as test samples, for the Alkali-Silica reactivity test samples, as well as the compressive strength test, the Chloride Ion test, and the freeze thaw testing which was performed on two sets of 12 concrete core samples that were taken from different locations in the project. These locations are the representations of the age of the concrete. Thus, the age difference between the samples' two sets is four decades. Testing was performed on prisms cut from cores. ASTM C-666 procedure (A) was applied using an automatic test system [6]. It was suggested that a plan for renovation of this project should be performed after the analysis is undertaken to assess the conditions estimating the remaining life of the concrete in this project [15].

  19. Coping with Multicollinearity: An Example on Application of Principal Components Regression in Dendroecology

    Treesearch

    B. Desta Fekedulegn; J.J. Colbert; R.R., Jr. Hicks; Michael E. Schuckers

    2002-01-01

    The theory and application of principal components regression, a method for coping with multicollinearity among independent variables in analyzing ecological data, is exhibited in detail. A concrete example of the complex procedures that must be carried out in developing a diagnostic growth-climate model is provided. We use tree radial increment data taken from breast...

  20. Shotcrete for Expedient Structural Repair

    DTIC Science & Technology

    1991-12-01

    pp. 29-44. Selmer - Olsen , R., "Examples of the Behavior of Shotcrete Linings Underground," Proceedings, Shotcrete for Ground Support, The Engineering... Selmer - Olsen , R. PAPER TITLE: Examples of the Behavior of Shotcrete Linings Underground DESCRIPTIVE TITLE NOTE: -0- BOOK/REPORT TITLE: Proceedings...prestressed tanks, thin overlays over structural materials, repair of concrete deteriorated by fire or earthquake, rock slope stabilization, and

  1. Pervious concrete reactive barrier for removal of heavy metals from acid mine drainage - column study.

    PubMed

    Shabalala, Ayanda N; Ekolu, Stephen O; Diop, Souleymane; Solomon, Fitsum

    2017-02-05

    This paper presents a column study conducted to investigate the potential use of pervious concrete as a reactive barrier for treatment of water impacted by mine waste. The study was done using acid mine drainage (AMD) collected from a gold mine (WZ) and a coalfield (TDB). Pervious concrete mixtures consisting of Portland cement CEM I 52.5R with or without 30% fly ash (FA) were prepared at a water-cementitious ratio of 0.27 then used to make cubes which were employed in the reactor columns. It was found that the removal efficiency levels of Al, Fe, Mn, Co and Ni were 75%, 98%, 99%, 94% and 95% for WZ; 87%, 96%, 99%, 98% and 90% for TDB, respectively. The high rate of acid reduction and metal removal by pervious concrete is attributed to dissolution of portlandite which is a typical constituent of concrete. The dominant reaction product in all four columns was gypsum, which also contributed to some removal of sulphate from AMD. Formation of gypsum, goethite, and Glauber's salt were identified. Precipitation of metal hydroxides seems to be the dominant metal removal mechanism. Use of pervious concrete offers a promising alternative treatment method for polluted or acidic mine water. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Flexural behavior of reinforced concrete beam with polymer coated pumice

    NASA Astrophysics Data System (ADS)

    Nainggolan, Christin Remayanti; Wijatmiko, Indradi; Wibowo, Ari

    2017-09-01

    Sustainable development has become an important issue due to the increasing consideration of preserving the nature. Many alternative for coarse aggregate replacement have been investigated ranging from natural and fabricated aggregates. In this study, natural aggregate pumice was investigated since it offers lower density that give paramount benefit in reducing total building weight and hence reducing the earthquake excitation effect and optimizing the structural dimension. However, the characteristic of porous surfaces of pumice causes excessive water absorption during concrete mixing process. Therefore, to reduce the additional water, the pumice aggregates were coated with polymer. The tested specimens consisted of normal concrete beams (NCB), uncoated pumice aggregate concrete beam (UPA) and polymer coated pumice aggregate concrete beam (PCP). The objective of the research was to obtain the effect of coating on the pumice aggregate to the flexural behavior of concrete beams. The lateral load-displacement behavior, ductility and collapse mechanism were studied. The results showed that there were only marginal drop on the load-carrying capacity of the pumice aggregate beam compared to those of normal beam. Additionally, the ductility coefficient of specimens UPA and PCP decreased of 11,97% and 14,03% respectively compared to NCB, and the ultimate load capacity decreased less than 1%. Overall, the pumice aggregate showed good characteristic for replacing normal coarse aggregate.

  3. Smart CFRP systems for the controlled retrofitting of reinforced concrete members

    NASA Astrophysics Data System (ADS)

    Schaller, M.-B.; Käseberg, S.; Kuhne, M.

    2010-09-01

    During the last ten years an increasing amount of Carbon Fiber Reinforced Polymer (CFRP) applications to rehabilitate damaged concrete elements was observed. Thereby some important disadvantages of the brittle materials must be considered, for example the low ductility of the bond between CFRP and concrete and brittle failure of FRP. With embedded sensor systems it is possible to measure crack propagation and strains. In this paper a sensor based CFRP system will be presented, that can be used for strengthening and measuring. The used optical fibers with Fiber Bragg Gratings (FBG) have a large number of advantages in opposite to electrical measuring methods. Examples are small dimensions, low weight as well as high static and dynamic resolution of measured values. The main problem during the investigations was the fixing of the glass fiber and the small FBG at the designated position. In this paper the possibility of setting the glass fiber with embroidery at the reinforcing fiber material will be presented. On the basis of four point bending tests on beams (dimensions of 700 x 150 x 150 mm) and tests on wrapped columns the potential of the Smart CFRP system is introduced.

  4. Evaluation of continuity detail for precast prestressed girders.

    DOT National Transportation Integrated Search

    2011-08-01

    The construction of highway bridges using precast prestressed concrete (PSC) girders is considered one of the most : economical construction alternatives because of the advantages they offer (e.g. reducing formwork and rapid construction). : Construc...

  5. Performance Assessment of Warm Mix Asphalt (WMA) Pavements

    DOT National Transportation Integrated Search

    2009-09-01

    Abstract : Warm Mix Asphalt (WMA) is a new technology that was introduced in Europe in 1995. WMA offers several advantages over : conventional asphalt concrete mixtures, including: reduced energy consumption, reduced emissions, improved or more unifo...

  6. Performance assessment of warm mix asphalt (WMA) pavements.

    DOT National Transportation Integrated Search

    2009-09-01

    Warm Mix Asphalt (WMA) is a new technology that was introduced in Europe in 1995. WMA offers several advantages over : conventional asphalt concrete mixtures, including: reduced energy consumption, reduced emissions, improved or more uniform : binder...

  7. Simple Exploration Apparatus for the Introductory Physics Laboratory

    ERIC Educational Resources Information Center

    Campbell, Thomas C.

    1977-01-01

    Discusses the laboratory portion of a beginning noncalculus physics course that uses concrete examples of abstract concepts. Describes the use of coffee cans to explain oscillations and plastic darts to illustrate collisions. (MLH)

  8. Calcite-forming bacteria for compressive strength improvement in mortar.

    PubMed

    Park, Sung-Jin; Park, Yu-Mi; Chun, Woo-Young; Kim, Wha-Jung; Ghim, Sa-Youl

    2010-04-01

    Microbiological calcium carbonate precipitation (MCP) has been investigated for its ability to improve the compressive strength of concrete mortar. However, very few studies have been conducted on the use of calcite-forming bacteria (CFB) to improve compressive strength. In this study, we discovered new bacterial genera that are capable of improving the compressive strength of concrete mortar. We isolated 4 CFB from 7 environmental concrete structures. Using sequence analysis of the 16S rRNA genes, the CFB could be partially identified as Sporosarcina soli KNUC401, Bacillus massiliensis KNUC402, Arthrobacter crystallopoietes KNUC403, and Lysinibacillus fusiformis KNUC404. Crystal aggregates were apparent in the bacterial colonies grown on an agar medium. Stereomicroscopy, scanning electron microscopy, and x-ray diffraction analyses illustrated both the crystal growth and the crystalline structure of the CaCO3 crystals. We used the isolates to improve the compressive strength of concrete mortar cubes and found that KNUC403 offered the best improvement in compressive strength.

  9. Fiber Bragg gratings for civil engineering applications

    NASA Astrophysics Data System (ADS)

    Maher, Mohamed H.; Tabrizi, Khosrow; Prohaska, John D.; Snitzer, Elias

    1996-04-01

    Fiber Bragg gratings sensors offer a unique opportunity in civil engineering. They can be configured as a low noise distributed sensor network for measuring mechanical deformations and temperature. They are ideally suited for strain measurements of high modulus structural materials such as steel and concrete. There is considerable interest in the use of these sensors for infrastructural nondestructive testing and there have been several papers on the subject. We present some results of our experiments with fiber Bragg sensors as applied to structural engineering. These include the use of fiber gratings to measure strain behavior of steel, reinforced concrete, and some preliminary results on bituminous materials, such as asphalt concrete. In nondestructive testing using fiber Bragg gratings of structural materials the packaging of the sensors is important and is discussed.

  10. ADIEM II end terminal for concrete barrier

    DOT National Transportation Integrated Search

    2001-03-01

    On September 9, 1997, an ADIEM II (Advanced Dynamic Impact Extension Module) was installed on Interstate 5 near Salem, Oregon. The ADIEM II offered a redirecting, energy-absorbing crash cushion and end treatment for portable and permanent protection ...

  11. Utilization of CO2 in High Performance Building and Infrastructure Products

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    DeCristofaro, Nicholas

    The overall objective of DE-FE0004222 was to demonstrate that calcium silicate phases, in the form of either naturally-occuring minerals or synthetic compounds, could replace Portland cement in concrete manufacturing. The calcium silicate phases would be reacted with gaseous CO2 to create a carbonated concrete end-product. If successful, the project would offer a pathway to a significant reduction in the carbon footprint associated with the manufacture of cement and its use in concrete (approximately 816 kg of CO2 is emitted in the production of one tonne of Portland cement). In the initial phases of the Technical Evaluation, Rutgers University teamed withmore » Solidia Technologies to demonstrate that natural wollastonite (CaSiO3), milled to a particle size distribution consistent with that of Portland cement, could indeed fit this bill. The use of mineral wollastonite as a cementitious material would potentially eliminate the CO2 emitted during cement production altogether, and store an additional 250 kg of CO2 during concrete curing. However, it was recognized that mineral wollastonite was not available in volumes that could meaningfully impact the carbon footprint associated with the cement and concrete industries. At this crucial juncture, DE-FE0004222 was redirected to use a synthetic version of wollastonite, hereafter referred to as Solidia Cement™, which could be manufactured in conventional cement making facilities. This approach enables the new cementitious material to be made using existing cement industry raw material supply chains, capital equipment, and distribution channels. It would also offer faster and more complete access to the concrete marketplace. The latter phases of the Technical Evaluation, conducted with Solidia Cement made in research rotary kilns, would demonstrate that industrially viable CO2-curing practices were possible. Prototypes of full-scale precast concrete products such as pavers, concrete masonry units, railroad ties, hollow-core slabs, and aerated concrete were produced to verify the utility of the CO2-curing process. These products exhibited a range of part dimensions and densities that were representative of the precast concrete industry. In the subsequent Demonstration of Commercial Development phase, the characteristics and performance of Solidia Cement made at a LafargeHolcim cement plant were established. This Solidia Cement was then used to demonstrate the CO2-curing process within operating concrete plants. Pavers, concrete masonry units and roofing tiles were produced according to ASTM and manufacturer specifications. A number of attractive manufacturing economies were recognized when Solidia Cement-based concrete parts were compared to their Portland cement based counterparts. These include reduced raw materials waste, reduced dependence on admixtures to control efflorescence, shorter curing time to full concrete strength, faster equipment clean-up, reduced equipment maintenance, and improved inventory management. These economies make the adoption of the Solidia Cement / CO2-curing process attractive even in the absence of environmental incentives. The culminating activity of the Demonstration of Commercial Development phase was the conversion of 10% of the manufacturing capacity at a concrete paver and block company from Portland cement-based products to Solidia Cement-based products. The successful completion of the Demonstration of Commercial Development phase clearly illustrated the environmental benefits associated with Solidia Cement and Solidia Concrete technologies. The industrial production of Solidia Cement, as a low-lime alternative to traditional Portland cement, reduces CO2 emissions at the cement kiln from 816 kg of CO2 per tonne of Portland cement clinker to 570 kg per tonne of Solidia Cement clinker. Industrial scale CO2-curing of Solidia Concrete sequestered a net of 183 kg of CO2 per tonne of Solidia Cement used in concrete pavers. Taken together, these two effects reduced the CO2 footprint associated with the production and use of cement in concrete products by over 50% (a reduction of 430 kg of CO2 per tonne of cement). Applied at the first commercial Solidia Concrete manufacturing site, the two effects will combine to reduce the CO2 footprint associated with the production and use of cement by over 10,000 tonnes per year. When applied across the precast concrete industry in the U.S., it is estimated that the CO2 footprint will be reduced by 8.6 million tonnes per year (20 million tonnes of cement used in precast concrete x 430 kg of CO2 per tonne of cement). Applied across the entire concrete industry in the U.S., it is expected that 43 million tonnes of CO2 will be avoided per year (100 million tonnes of cement used in all concrete x 430 kg of CO2 per tonne of cement).« less

  12. 40 CFR 63.8105 - What definitions apply to this subpart?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... heating value), use, reuse, or for sale for fuel value, use, or reuse. Examples of equipment that may be... nonearthen materials (e.g., wood, concrete, steel, plastic) which provide structural support. Wastewater...

  13. 40 CFR 63.8105 - What definitions apply to this subpart?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... heating value), use, reuse, or for sale for fuel value, use, or reuse. Examples of equipment that may be... nonearthen materials (e.g., wood, concrete, steel, plastic) which provide structural support. Wastewater...

  14. 40 CFR 63.8105 - What definitions apply to this subpart?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... heating value), use, reuse, or for sale for fuel value, use, or reuse. Examples of equipment that may be... nonearthen materials (e.g., wood, concrete, steel, plastic) which provide structural support. Wastewater...

  15. The Effect of Context on Training: Is Learning Situated?

    DTIC Science & Technology

    1994-09-13

    not underlie the central processes of ordinary everyday cognition ? We think not." There are numerous examples where abstract instruction has been shown... instruction , concrete examples, and abstract rules and procedures. Claims made by proponents of Situated Learning Theory suggest that training must be... instruction . This argues against apprenticeship learning during early stages of acquisition for many skills. Further, too much fidelity in simulation may

  16. Predicting the Probability of Failure of Cementitious Sewer Pipes Using Stochastic Finite Element Method

    PubMed Central

    Alani, Amir M.; Faramarzi, Asaad

    2015-01-01

    In this paper, a stochastic finite element method (SFEM) is employed to investigate the probability of failure of cementitious buried sewer pipes subjected to combined effect of corrosion and stresses. A non-linear time-dependant model is used to determine the extent of concrete corrosion. Using the SFEM, the effects of different random variables, including loads, pipe material, and corrosion on the remaining safe life of the cementitious sewer pipes are explored. A numerical example is presented to demonstrate the merit of the proposed SFEM in evaluating the effects of the contributing parameters upon the probability of failure of cementitious sewer pipes. The developed SFEM offers many advantages over traditional probabilistic techniques since it does not use any empirical equations in order to determine failure of pipes. The results of the SFEM can help the concerning industry (e.g., water companies) to better plan their resources by providing accurate prediction for the remaining safe life of cementitious sewer pipes. PMID:26068092

  17. The odd couple: using biomedical and intersectional approaches to address health inequities

    PubMed Central

    Hankivsky, Olena; Doyal, Lesley; Einstein, Gillian; Kelly, Ursula; Shim, Janet; Weber, Lynn; Repta, Robin

    2017-01-01

    ABSTRACT Background: Better understanding and addressing health inequities is a growing global priority. Objective: In this paper, we contribute to the literature examining complex relationships between biological and social dimensions in the field of health inequalities. Specifically, we explore the potential of intersectionality to advance current approaches to socio-biological entwinements. Design: We provide a brief overview of current approaches to combining both biological and social factors in a single study, and then investigate the contributions of an intersectional framework to such work. Results: We offer a number of concrete examples of how intersectionality has been used empirically to bring both biological and social factors together in the areas of HIV, post-traumatic stress disorder, female genital circumcision/mutilation/cutting, and cardiovascular disease. Conclusion: We argue that an intersectional approach can further research that integrates biological and social aspects of human lives and human health and ultimately generate better and more precise evidence for effective policies and practices aimed at tackling health inequities. PMID:28641056

  18. Toward a Personalized Science of Emotion Regulation

    PubMed Central

    Doré, Bruce P.; Silvers, Jennifer A.; Ochsner, Kevin N.

    2018-01-01

    The ability to successfully regulate emotion plays a key role in healthy development and the maintenance of psychological well-being. Although great strides have been made in understanding the nature of regulatory processes and the consequences of deploying them, a comprehensive understanding of emotion regulation that can specify what strategies are most beneficial for a given person in a given situation is still a far-off goal. In this review, we argue that moving toward this goal represents a central challenge for the future of the field. As an initial step, we propose a concrete framework that (i) explicitly considers emotion regulation as an interaction of person, situation, and strategy, (ii) assumes that regulatory effects vary according to these factors, and (iii) sets as a primary scientific goal the identification of person-, situation-, and strategy-based contingencies for successful emotion regulation. Guided by this framework, we review current questions facing the field, discuss examples of contextual variation in emotion regulation success, and offer practical suggestions for continued progress in this area. PMID:29750085

  19. The odd couple: using biomedical and intersectional approaches to address health inequities.

    PubMed

    Hankivsky, Olena; Doyal, Lesley; Einstein, Gillian; Kelly, Ursula; Shim, Janet; Weber, Lynn; Repta, Robin

    Better understanding and addressing health inequities is a growing global priority. In this paper, we contribute to the literature examining complex relationships between biological and social dimensions in the field of health inequalities. Specifically, we explore the potential of intersectionality to advance current approaches to socio-biological entwinements. We provide a brief overview of current approaches to combining both biological and social factors in a single study, and then investigate the contributions of an intersectional framework to such work. We offer a number of concrete examples of how intersectionality has been used empirically to bring both biological and social factors together in the areas of HIV, post-traumatic stress disorder, female genital circumcision/mutilation/cutting, and cardiovascular disease. We argue that an intersectional approach can further research that integrates biological and social aspects of human lives and human health and ultimately generate better and more precise evidence for effective policies and practices aimed at tackling health inequities.

  20. A review on past and present development on the interlocking loadbearing hollow block (ILHB) system

    NASA Astrophysics Data System (ADS)

    Bosro, M. Z. M.; Samad, A. A. A.; Mohamad, N.; Goh, W. I.; Tambichik, M. A.; Iman, M. A.

    2018-04-01

    Massive migration and increasing population in Malaysia has contributed to the increasing demand of quality and affordable housing. Over the past 50 years, the Malaysian housing industry has seen the growth of using conventional construction system such as reinforced concrete frame structures and bricks. The conventional system, as agreed by many researchers, causes delays and other disadvantages in some of the construction projects. Thus, the utilization of interlocking loadbearing hollow block (ILHB) system is needed to address these issues. This system has been identified as an alternative and sustainable building system for the construction industry in Malaysia which the PUTRA block system is the latest example of the ILHB developed. The system offers various advantages in terms of speed and cost in construction, strength, environmentally friendly and aesthetic qualities. Despite these advantages, this system has not been practically applied and develop in Malaysia. Therefore, this paper aims to review the past and present development of the interlocking loadbearing hollow block (ILHB) system that available locally and globally.

  1. Implementation of virtual models from sheet metal forming simulation into physical 3D colour models using 3D printing

    NASA Astrophysics Data System (ADS)

    Junk, S.

    2016-08-01

    Today the methods of numerical simulation of sheet metal forming offer a great diversity of possibilities for optimization in product development and in process design. However, the results from simulation are only available as virtual models. Because there are any forming tools available during the early stages of product development, physical models that could serve to represent the virtual results are therefore lacking. Physical 3D-models can be created using 3D-printing and serve as an illustration and present a better understanding of the simulation results. In this way, the results from the simulation can be made more “comprehensible” within a development team. This paper presents the possibilities of 3D-colour printing with particular consideration of the requirements regarding the implementation of sheet metal forming simulation. Using concrete examples of sheet metal forming, the manufacturing of 3D colour models will be expounded upon on the basis of simulation results.

  2. Calculation of load-bearing capacity of prestressed reinforced concrete trusses by the finite element method

    NASA Astrophysics Data System (ADS)

    Agapov, Vladimir; Golovanov, Roman; Aidemirov, Kurban

    2017-10-01

    The technique of calculation of prestressed reinforced concrete trusses with taking into account geometrical and physical nonlinearity is considered. As a tool for solving the problem, the finite element method has been chosen. Basic design equations and methods for their solution are given. It is assumed that there are both a prestressed and nonprestressed reinforcement in the bars of the trusses. The prestress is modeled by setting the temperature effect on the reinforcement. The ways of taking into account the physical and geometrical nonlinearity for bars of reinforced concrete trusses are considered. An example of the analysis of a flat truss is given and the behavior of the truss on various stages of its loading up to destruction is analyzed. A program for the analysis of flat and spatial concrete trusses taking into account the nonlinear deformation is developed. The program is adapted to the computational complex PRINS. As a part of this complex it is available to a wide range of engineering, scientific and technical workers

  3. Analysis of the influence of dynamic phenomena on the fracture of a reinforced concrete beam under quasistatic loading (computations and experiment)

    NASA Astrophysics Data System (ADS)

    Bykov, A. A.; Matveenko, V. P.; Serovaev, G. S.; Shardakov, I. N.; Shestakov, A. P.

    2015-07-01

    Construction of numerical models which reliably describe the processes of crack formation and development in reinforced concrete permit estimating the bearing capacity and structural strength of any structural element without using expensive full-scale experiments. In the present paper, an example of four-point bending of a rectangular beam is used to consider a finite-element model of concrete fracture. The results obtained by quasistatic calculations and by solving the problem with inertia forces taken into account are compared. The kinetic energy contribution to the total mechanical energy of the system at the crack origination moment, which is greater than 30%, is estimated to justify the expediency of taking the inertia forces into account. The crack distribution characters obtained numerically and observed experimentally are compared. It is shown that the leading role in the evolution of the crack formation process is played by the mechanism of fracture of bonds between the reinforcing elements and the concrete.

  4. Adiem II end terminal for concrete barrier : final report.

    DOT National Transportation Integrated Search

    2001-03-01

    On September 9, 1997, an ADIEM II (Advanced Dynamic Impact Extension Module) was installed on Interstate 5 near Salem, Oregon. The ADIEM II offered a redirecting, energy-absorbing crash cushion and end treatment for portable and permanent protection ...

  5. What If...?

    ERIC Educational Resources Information Center

    Wolff, Bretta Weiss; Werner, Pat

    1999-01-01

    Offers suggestions for creating a prepared environment for teachers, within the context of Montessori practice. Maintains that teachers' status can be ensured by practices such as giving concrete individual acknowledgments, creating social times together, learning together, doing purposeful process work, exhibiting respectful behavior,…

  6. Vertical dynamic deflection measurement in concrete beams with the Microsoft Kinect.

    PubMed

    Qi, Xiaojuan; Lichti, Derek; El-Badry, Mamdouh; Chow, Jacky; Ang, Kathleen

    2014-02-19

    The Microsoft Kinect is arguably the most popular RGB-D camera currently on the market, partially due to its low cost. It offers many advantages for the measurement of dynamic phenomena since it can directly measure three-dimensional coordinates of objects at video frame rate using a single sensor. This paper presents the results of an investigation into the development of a Microsoft Kinect-based system for measuring the deflection of reinforced concrete beams subjected to cyclic loads. New segmentation methods for object extraction from the Kinect's depth imagery and vertical displacement reconstruction algorithms have been developed and implemented to reconstruct the time-dependent displacement of concrete beams tested in laboratory conditions. The results demonstrate that the amplitude and frequency of the vertical displacements can be reconstructed with submillimetre and milliHz-level precision and accuracy, respectively.

  7. Vertical Dynamic Deflection Measurement in Concrete Beams with the Microsoft Kinect

    PubMed Central

    Qi, Xiaojuan; Lichti, Derek; El-Badry, Mamdouh; Chow, Jacky; Ang, Kathleen

    2014-01-01

    The Microsoft Kinect is arguably the most popular RGB-D camera currently on the market, partially due to its low cost. It offers many advantages for the measurement of dynamic phenomena since it can directly measure three-dimensional coordinates of objects at video frame rate using a single sensor. This paper presents the results of an investigation into the development of a Microsoft Kinect-based system for measuring the deflection of reinforced concrete beams subjected to cyclic loads. New segmentation methods for object extraction from the Kinect's depth imagery and vertical displacement reconstruction algorithms have been developed and implemented to reconstruct the time-dependent displacement of concrete beams tested in laboratory conditions. The results demonstrate that the amplitude and frequency of the vertical displacements can be reconstructed with submillimetre and milliHz-level precision and accuracy, respectively. PMID:24556668

  8. Influence of metakaolin on chemical resistance of concrete

    NASA Astrophysics Data System (ADS)

    Mlinárik, L.; Kopecskó, K.

    2013-12-01

    Nowadays the most suitable and widely used construction material is concrete. We could develop concrete for every request in connection with the properties of fresh concrete and the quality of hardened concrete, too. The demand is rising in application of special concretes, like high performance and ultra high performance concretes (HPC, UHPC). These are usable in extreme natural circumstances or in very corrosive surroundings (for example: sewage farm, sewer, cooling tower, biogas factories). The pH value of the commercial sewage is between 7-8, but this value is often around 4 or less. The concrete pipes, which transport the sewage, are under corrosion, because above the liquid level sulphuric acid occurs due to microbes. Acidic surroundings could start the corrosion of concrete. When the pH value reduces, the influence of the acids will increase. The most significant influence has the sulphuric acid. The pH value of sulphuric acid is about 1, or less. Earlier in the cooling towers of coal thermal power stations used special coating on the concrete wall. Recently application of high performance concrete without polymeric coating is more general. Cementitious supplementary materials are widely used to protect the concrete from these corrosive surroundings. Usually used cementitious supplementary materials are ground granulated blastfurnace slag (GGBS), flying ash (FA) or silica fume (SF). In the last years there has been a growing interest in the application of metakaolin. Metakaolin is made by heat treatment, calcinations of a natural clay mineral, kaolinite. In our present research the chemical resistance of mortars in different corrosive surroundings (pH=1 sulphuric acid; pH=3 acetic acid) and the chloride ion migration were studied on series of mortar samples using rapid chloride migration test. Cement paste and mortar samples were made with 17% metakaolin replacement or without metakaolin. The following cements were used: CEM II/A-S 42.5 N, CEM I 42.5 N-S. We concluded that the replacement of cement by metakaolin results in significant increases in compressive and tensile strengths and it prevents the infiltration of harmful substances.

  9. De la Educacion Liberadora: La Educacion en General y la Universidad en Particular (Concerning Liberalizing Education: Education in General and the University in Particular).

    ERIC Educational Resources Information Center

    Fiori, Ernani Maria

    This paper offers some theoretical proposals for a radical re-thinking of educational theory. Rather than offering concrete methods for reform, it seeks to point out the general direction for change if education is to strive toward the liberation of man. The relationship of man to history, culture, and knowledge is considered, as is the role of…

  10. The development of crashworthy rails for fiber reinforced polymer honeycomb bridge deck system.

    DOT National Transportation Integrated Search

    2015-07-01

    Fiber reinforced polymer (FRP) honeycomb panels offer an efficient and rapid replacement to : concrete decks. The system consists of FRP honeycomb sandwich panels with adequate guardrails. Although : FRP bridge deck panels have already been designed ...

  11. The development of crashworthy rails for fiber reinforced polymer honeycomb bridge deck system : [summary].

    DOT National Transportation Integrated Search

    2015-07-01

    Fiber reinforced polymer (FRP) honeycomb panels offer an efficient and rapid : replacement to concrete decks. The system consists of FRP honeycomb sandwich panels : with adequate guardrails. Although FRP bridge deck panels have already been designed ...

  12. Protection of Reinforcement with Corrosion Inhibitors, Phase II

    DOT National Transportation Integrated Search

    2000-12-01

    Costs due to corrosion of reinforcement in concrete caused by deicing salts have been estimated at up to $1 billion per year in the U.S. alone. For most situations, corrosion-inhibiting admixtures offer significant advantages over other protection me...

  13. Neutron and X-ray Tomography (NeXT) system for simultaneous, dual modality tomography.

    PubMed

    LaManna, J M; Hussey, D S; Baltic, E; Jacobson, D L

    2017-11-01

    Dual mode tomography using neutrons and X-rays offers the potential of improved estimation of the composition of a sample from the complementary interaction of the two probes with the sample. We have developed a simultaneous neutron and 90 keV X-ray tomography system that is well suited to the study of porous media systems such as fuel cells, concrete, unconventional reservoir geologies, limestones, and other geological media. We present the characteristic performance of both the neutron and X-ray modalities. We illustrate the use of the simultaneous acquisition through improved phase identification in a concrete core.

  14. Neutron and X-ray Tomography (NeXT) system for simultaneous, dual modality tomography

    NASA Astrophysics Data System (ADS)

    LaManna, J. M.; Hussey, D. S.; Baltic, E.; Jacobson, D. L.

    2017-11-01

    Dual mode tomography using neutrons and X-rays offers the potential of improved estimation of the composition of a sample from the complementary interaction of the two probes with the sample. We have developed a simultaneous neutron and 90 keV X-ray tomography system that is well suited to the study of porous media systems such as fuel cells, concrete, unconventional reservoir geologies, limestones, and other geological media. We present the characteristic performance of both the neutron and X-ray modalities. We illustrate the use of the simultaneous acquisition through improved phase identification in a concrete core.

  15. Development of acoustic model-based iterative reconstruction technique for thick-concrete imaging

    NASA Astrophysics Data System (ADS)

    Almansouri, Hani; Clayton, Dwight; Kisner, Roger; Polsky, Yarom; Bouman, Charles; Santos-Villalobos, Hector

    2016-02-01

    Ultrasound signals have been used extensively for non-destructive evaluation (NDE). However, typical reconstruction techniques, such as the synthetic aperture focusing technique (SAFT), are limited to quasi-homogenous thin media. New ultrasonic systems and reconstruction algorithms are in need for one-sided NDE of non-homogenous thick objects. An application example space is imaging of reinforced concrete structures for commercial nuclear power plants (NPPs). These structures provide important foundation, support, shielding, and containment functions. Identification and management of aging and degradation of concrete structures is fundamental to the proposed long-term operation of NPPs. Another example is geothermal and oil/gas production wells. These multi-layered structures are composed of steel, cement, and several types of soil and rocks. Ultrasound systems with greater penetration range and image quality will allow for better monitoring of the well's health and prediction of high-pressure hydraulic fracturing of the rock. These application challenges need to be addressed with an integrated imaging approach, where the application, hardware, and reconstruction software are highly integrated and optimized. Therefore, we are developing an ultrasonic system with Model-Based Iterative Reconstruction (MBIR) as the image reconstruction backbone. As the first implementation of MBIR for ultrasonic signals, this paper document the first implementation of the algorithm and show reconstruction results for synthetically generated data.1

  16. The Sense-Appeal Approach

    ERIC Educational Resources Information Center

    Shoneman, Anne

    1977-01-01

    Using a classroom discussion of the human digestive system as an example, the article promotes the idea that demonstrating abstractions in concrete experiential terms permits the learning disabled youngster to discover concepts for himself, which is the best possible learning experience. (JYC)

  17. 117. Laurel Fork Viaduct. Elevation view of this 545 1939 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    117. Laurel Fork Viaduct. Elevation view of this 545 1939 steel girder viaduct. Example of structure with plain reinforced concrete arches. Looking northwest. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  18. Piaget and Elementary Science

    ERIC Educational Resources Information Center

    Chittenden, Edward A.

    1970-01-01

    Describes the intellectual development stages ascribed to children by Jean Piaget. Characteristics and examples are given for sensori-motor, preoperational, concrete operational, and formal operational thinking periods. Implications are given for elementary school science education, including (1) formal instruction does not accelerate acquisition…

  19. 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.

  20. Was Jane Addams a Promiscuous Pragmatist?

    ERIC Educational Resources Information Center

    Atkinson, Becky

    2013-01-01

    Contemporary pragmatist and feminist scholars have proposed the possibilities for "changing the theoretical analyses and concrete practices" of both feminism and classical American pragmatism offered by its recuperation through feminism. Particularly, scholarship on Jane Addams has reached back to retrieve her activism, ethics, and…

  1. Develop, Link, Foster, and Encourage

    ERIC Educational Resources Information Center

    Hyslop, Alisha

    2008-01-01

    The third recommendation in ACTE's postsecondary reform position statement is to develop curriculum and instructional offerings that link to careers, foster lifelong learning, and encourage completion. Concrete linkages must be developed between middle and high school, postsecondary education and work, with lifelong postsecondary learning a part…

  2. Performance assessment of warm mix asphalt (WMA) pavements : executive summary report.

    DOT National Transportation Integrated Search

    2009-09-01

    Warm Mix Asphalt (WMA) is a new technology which was : introduced in 1995 in Europe. WMA is gaining attention all : over the world because it offers several advantages over : conventional asphalt concrete mixes. The benefits include: : (1) Reduced en...

  3. Performance Assessment of Warm Mix Asphalt (WMA) Pavements : Executive Summary Report

    DOT National Transportation Integrated Search

    2009-09-01

    Warm Mix Asphalt (WMA) is a new technology which was : introduced in 1995 in Europe. WMA is gaining attention all : over the world because it offers several advantages over : conventional asphalt concrete mixes. The benefits include: : (1) Reduced en...

  4. Deicer-freeze-thaw resistance characteristics of Portland cement concrete for Wisconsin pavements

    DOT National Transportation Integrated Search

    1995-12-01

    The objectives of the study were to identify PCC mixes that offer increased deicer-freeze-thaw durability and to identify mix characteristics that contribute to premature durability distress. PCC mixes covering a range of air contents and water-cemen...

  5. Multicultural Competencies: A Guidebook of Practices.

    ERIC Educational Resources Information Center

    Roysircar, Gargi, Ed.; Sandhu, Daya Singh, Ed.; Bibbins, Victor E., Sr., Ed.

    Intended to benefit the entire counseling community, this guidebook demonstrates current multicultural competencies and successful delivery of services across the various professional counseling disciplines. Leading authorities offer concrete direction for effective multicultural counseling and reflect on what they have found to be the best…

  6. Calculation of Prestressed Pressure Vessel Taking into Account the Concrete Temperature Inhomogeneity

    NASA Astrophysics Data System (ADS)

    Andreev, Vladimir

    2018-03-01

    The paper deals with the problem of determining the stress state of the pressure vessel (PV) with considering the concrete temperature inhomogeneity. Such structures are widely used in heat power engineering, for example, in nuclear power engineering. The structures of such buildings are quite complex and a comprehensive analysis of the stress state in them can be carried out either by numerical or experimental methods. However, a number of fundamental questions can be solved on the basis of simplified models, in particular, studies of the effect on the stressed state of the inhomogeneity caused by the temperature field.

  7. Architecture and Children.

    ERIC Educational Resources Information Center

    Taylor, Anne; Campbell, Leslie

    1988-01-01

    Describes "Architecture and Children," a traveling exhibition which visually involves children in architectural principles and historic styles. States that it teaches children about architecture, and through architecture it instills the basis for aesthetic judgment. Argues that "children learn best by concrete examples of ideas, not…

  8. Awakening the Erotic in Religious Education.

    ERIC Educational Resources Information Center

    Siejk, Cate

    2001-01-01

    Focuses on exploring and understanding the epistemological significance of eros and the place of the erotic in contemporary religious education. Shows, through concrete examples, how a fully human epistemology makes possible an authentic religious education that promotes both personal and communal transformation. (CAJ)

  9. Post-16 Biology--Some Model Approaches?

    ERIC Educational Resources Information Center

    Lock, Roger

    1997-01-01

    Outlines alternative approaches to the teaching of difficult concepts in A-level biology which may help student learning by making abstract ideas more concrete and accessible. Examples include models, posters, and poems for illustrating meiosis, mitosis, genetic mutations, and protein synthesis. (DDR)

  10. Modelling the behaviour of steel fibre reinforced precast beam-to-column connection

    NASA Astrophysics Data System (ADS)

    Chai, C. E.; Sarbini, NN; Ibrahim, I. S.; Ma, C. K.; Tajol Anuar, M. Z.

    2017-11-01

    The numerical behaviour of steel fibre reinforced concrete (SFRC) corbels reinforced with different fibre volume ratio subjected to vertical incremental load is presented in this paper. Precast concrete structures had become popular in the construction field, which offer a faster, neater, safer, easier and cheaper construction work. The construction components are prefabricated in controlled environment under strict supervision before being erected on site. However, precast beam-column connections are prone to failure due to the brittle properties of concrete. Finite element analysis (FEA) is adopted due to the nonlinear behaviour of concrete and SFRC. The key objective of this research is to develop a reliable nonlinear FEA model to represent the behaviour of reinforced concrete corbel. The developed model is validated with experimental data from previous researches. Then, the validated FEA model is used to predict the behaviour of SFRC corbel reinforced with different fibre volume ratio by changing the material parameters. The results show that the addition of steel fibre (SF) increases the load carrying capacity, ductility, stiffness, and changed the failure mode of corbel from brittle bending-shear to flexural ductile. On the other hand, the increasing of SF volume ratio also leads to increased load carrying capacity, ductility, and stiffness of corbel.

  11. The Utilisation of Shredded PET as Aggregate Replacement for Interlocking Concrete Block

    NASA Astrophysics Data System (ADS)

    Mokhtar, M.; Kaamin, M.; Sahat, S.; Hamid, N. B.

    2018-03-01

    The consumption of plastic has grown substantially all over the world in recent years and this has created huge quantities of plastic-based waste. Plastic waste is now a serious environmental threat to the modern way of living, although steps were taken to reduce its consumption. This creates substantial garbage every day, which is much unhealthy. Plastic bottles such as Polyethylene terephthalate (PET) was use as the partially component in this making of interlocking blocks concrete. This project investigates the strength and workability of the interlocking block concrete by replacing course aggregate with % PET. The suitability of recycled plastics (PET) as course aggregate in interlocking block concrete and its advantages are discussed here. Moreover, there were more benefits when using interlocking block than using conventional block such as it easy for construction because they are aligning, easy to place, high speed stacking and they offer more resistance to shear and buildings would be even stronger. Based on the test perform, the failure parameter were discussed .From the compressive strength test result, it shows that the strength of concrete block decreased with increased of PET used. From the results, it shows that higher compressive strength was found with 5% natural course aggregate replaced with PET compared to other percentages.

  12. Neutral axis determination of full size concrete structures using coda wave measurements

    NASA Astrophysics Data System (ADS)

    Jiang, Hanwan; Zhan, Hanyu; Zhuang, Chenxu; Jiang, Ruinian

    2018-03-01

    Coda waves experiencing multiple scattering behaviors are sensitive to weak changes occurring in media. In this paper, a typical four-point bending test with varied external loads is conducted on a 30-meter T-beam that is removed from a bridge after being in service for 15 years, and the coda wave signals are collected with a couple of sources-receivers pairs. Then the observed coda waves at different loads are compared to calculate their relative velocity variations, which are utilized as the parameter to distinct the compression and tensile zones as well as determine the neutral axis position. Without any prior knowledge of the concrete beam, the estimated axis position agrees well with the associated strain gage measurement results, and the zones bearing stress and tension behaviors are indicated. The presented work offers significant potential for Non-Destructive Testing and Evaluation of full-size concrete structures in future work.

  13. Quantitative ultrasonic evaluation of concrete structures using one-sided access

    NASA Astrophysics Data System (ADS)

    Khazanovich, Lev; Hoegh, Kyle

    2016-02-01

    Nondestructive diagnostics of concrete structures is an important and challenging problem. A recent introduction of array ultrasonic dry point contact transducer systems offers opportunities for quantitative assessment of the subsurface condition of concrete structures, including detection of defects and inclusions. The methods described in this paper are developed for signal interpretation of shear wave impulse response time histories from multiple fixed distance transducer pairs in a self-contained ultrasonic linear array. This included generalizing Kirchoff migration-based synthetic aperture focusing technique (SAFT) reconstruction methods to handle the spatially diverse transducer pair locations, creating expanded virtual arrays with associated reconstruction methods, and creating automated reconstruction interpretation methods for reinforcement detection and stochastic flaw detection. Interpretation of the reconstruction techniques developed in this study were validated using the results of laboratory and field forensic studies. Applicability of the developed methods for solving practical engineering problems was demonstrated.

  14. Geotechnical valorisation of large recycling concrete in FezMeknes region (Morocco)

    NASA Astrophysics Data System (ADS)

    Demehati, A.; Abidi, A.; El Qandil, M.

    2018-05-01

    The growing and accelerated development of agglomerations is resulting in increasing pressure on deposits of materials as natural resources. This results in shortages of aggregates including sand. Situation in the different regions of Morocco, including that of FezMeknes. In addition, the threat to the stability or durability of buildings in general and road works and their annexes in particular is often started either from the surface of the grounds or from areas vulnerable to their geotechnical contact as seating materials surrounding them. The large concrete with recycles aggregates filling or protective mask provides adequate solutions. According to the results of our research, it offers a well-adapted physical and mechanical characterization in transition between conventional concretes, whether or not they are armed, and their support. Its use of protection against the effects of erosion or scouring and against the seismic movements further strengthens its potential field employment.

  15. 48 CFR 25.504 - Evaluation Examples.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... PROGRAMS FOREIGN ACQUISITION Evaluating Foreign Offers-Supply Contracts 25.504 Evaluation Examples. The... examples assume that the contracting officer has eliminated all offers that are unacceptable for reasons... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Evaluation Examples. 25...

  16. Towards the next generation of simplified Dark Matter models

    NASA Astrophysics Data System (ADS)

    Albert, Andreas; Bauer, Martin; Brooke, Jim; Buchmueller, Oliver; Cerdeño, David G.; Citron, Matthew; Davies, Gavin; de Cosa, Annapaola; De Roeck, Albert; De Simone, Andrea; Du Pree, Tristan; Flaecher, Henning; Fairbairn, Malcolm; Ellis, John; Grohsjean, Alexander; Hahn, Kristian; Haisch, Ulrich; Harris, Philip C.; Khoze, Valentin V.; Landsberg, Greg; McCabe, Christopher; Penning, Bjoern; Sanz, Veronica; Schwanenberger, Christian; Scott, Pat; Wardle, Nicholas

    2017-06-01

    This White Paper is an input to the ongoing discussion about the extension and refinement of simplified Dark Matter (DM) models. It is not intended as a comprehensive review of the discussed subjects, but instead summarises ideas and concepts arising from a brainstorming workshop that can be useful when defining the next generation of simplified DM models (SDMM). In this spirit, based on two concrete examples, we show how existing SDMM can be extended to provide a more accurate and comprehensive framework to interpret and characterise collider searches. In the first example we extend the canonical SDMM with a scalar mediator to include mixing with the Higgs boson. We show that this approach not only provides a better description of the underlying kinematic properties that a complete model would possess, but also offers the option of using this more realistic class of scalar mixing models to compare and combine consistently searches based on different experimental signatures. The second example outlines how a new physics signal observed in a visible channel can be connected to DM by extending a simplified model including effective couplings. In the next part of the White Paper we outline other interesting options for SDMM that could be studied in more detail in the future. Finally, we review important aspects of supersymmetric models for DM and use them to propose how to develop more complete SDMMs. This White Paper is a summary of the brainstorming meeting "Next generation of simplified Dark Matter models" that took place at Imperial College, London on May 6, 2016, and corresponding follow-up studies on selected subjects.

  17. Numerical Study on Deflection Behaviour of Concrete Beams Reinforced with GFRP Bars

    NASA Astrophysics Data System (ADS)

    Mohamed, Osama A.; Khattab, Rania; Hawat, Waddah Al

    2017-10-01

    Fiber-Reinforced Polymer (FRP) bars are gaining popularity as sustainable alternatives to conventional reinforcing steel bars in reinforced concrete applications. The production of FRP bars has lower environmental impact compared to steel reinforcing bars. In addition, the non-corroding FRP materials can potentially decrease the cost or need for maintenance of reinforced concrete structural elements, especially in harsh environmental conditions that can impact both concrete and reinforcement. FRP bars offer additional favourable properties including high tensile strength and low unit weight. However, the mechanical properties of FRP bars can lead to large crack widths and deflections. The objective of this study is to investigate the deflection behaviour of concrete beams reinforced with Glass FRP (GFRP) bars as a longitudinal main reinforcement. Six concrete beams reinforced with GFRP bars were modelled using the finite element computer program ANSYS. The main variable considered in the study is the reinforcement ratio. The deflection equations in current North American codes including ACI 440.1R-06, ACI 440.1R-15 and CSA S806-12 are used to compute deflections, and these are compared to numerical results. It was concluded in this paper that deflections predicted by ACI 440.1R-06 equations are lower than the numerical analysis results while ACI 440.1R-15 is in agreement with numerical analysis with tendency to be conservative. The values of deflections estimated by CSA S806-12 formulas are consistent with results of numerical analysis.

  18. Ethnofederalism and the Accommodation of Ethnic Minorities in Burma: United They Stand

    DTIC Science & Technology

    2013-06-01

    perform that role. The two defining criteria are thus met, but with significant limitations. 3. Stepan’s Variables Stepan offers more concrete ...rights book, Suffering in Silence, published in 2000. Rape, burnt villages, confiscated food stores, mutilated livestock, and indiscriminate

  19. Assessing ConnDOT's portland cement concrete testing methods phase II : field trials and implementation.

    DOT National Transportation Integrated Search

    2012-04-01

    This paper presents a description of efforts to disseminate findings from the Phase I study (SPR-2244), provides examples of applied maturity testing and temperature monitoring in Connecticut, reviews several State Highway Agency protocols for using ...

  20. Keep It in Proportion.

    ERIC Educational Resources Information Center

    Snider, Richard G.

    1985-01-01

    The ratio factors approach involves recognizing a given fraction, then multiplying so that units cancel. This approach, which is grounded in concrete operational thinking patterns, provides a standard for science ratio and proportion problems. Examples are included for unit conversions, mole problems, molarity, speed/density problems, and…

  1. Metaphors as Nudges toward Understanding in Mental Health Counseling.

    ERIC Educational Resources Information Center

    Hendrix, Dennis H.

    1992-01-01

    Discusses use of metaphors in mental health counseling. Presents examples of metaphors that are concrete and that use objects and situations familiar to clients so that the properties of the metaphorical items are known. Elaborations of metaphors are provided for readers. (NB)

  2. Brain Friendly School Libraries

    ERIC Educational Resources Information Center

    Sykes, Judith Anne

    2006-01-01

    This title gives concrete practical examples of how to align school library programs and instructional practice with the six key concepts of brain-compatible learning: increasing input to the brain; increasing experiential data; multiple source feedback; reducing threat; involving students in learning decision making; and interdisciplinary unit…

  3. Contextualization in Perspective

    ERIC Educational Resources Information Center

    Son, Ji Y.; Goldstone, Robert L.

    2009-01-01

    Instruction abstracted from specific and concrete examples is frequently criticized for ignoring the context-dependent and perspectival nature of learning (e.g., Bruner, 1962, 1966; Greeno, 1997). Yet, in the effort to create personally interesting learning contexts, cognitive consequences have often been ignored. To examine what kinds of…

  4. A gradient enhanced plasticity-damage microplane model for concrete

    NASA Astrophysics Data System (ADS)

    Zreid, Imadeddin; Kaliske, Michael

    2018-03-01

    Computational modeling of concrete poses two main types of challenges. The first is the mathematical description of local response for such a heterogeneous material under all stress states, and the second is the stability and efficiency of the numerical implementation in finite element codes. The paper at hand presents a comprehensive approach addressing both issues. Adopting the microplane theory, a combined plasticity-damage model is formulated and regularized by an implicit gradient enhancement. The plasticity part introduces a new microplane smooth 3-surface cap yield function, which provides a stable numerical solution within an implicit finite element algorithm. The damage part utilizes a split, which can describe the transition of loading between tension and compression. Regularization of the model by the implicit gradient approach eliminates the mesh sensitivity and numerical instabilities. Identification methods for model parameters are proposed and several numerical examples of plain and reinforced concrete are carried out for illustration.

  5. When Does an Argument Use a Generic Example?

    ERIC Educational Resources Information Center

    Yopp, David A.; Ely, Rob

    2016-01-01

    We offer criteria that an observer can use to determine whether an argument that uses an example to argue for a general claim appeals to that example generically. We review existing literature on generic example and note the strengths of each contribution, as well as inconsistencies among uses of the term. We offer several examples from the…

  6. Meso-Mechanics and Meso-Structures: A Matter of Scale

    NASA Technical Reports Server (NTRS)

    Chamis, Christos C.; Gotsis, P. K.; Mital, S. K.

    1998-01-01

    Meso-mechanics and meso-structures are described in terms of the scales at which they are observed and formulated. Select composite examples are presented to illustrate that meso-mechanics and/or meso-structures are meaningful only when they refer to a specific scale in a hierarchical scale observation/simulation. These examples include different types of composite unit cells, woven fabric unit cells, and progressive fracture as a composite enhanced infrastructure made from reinforced concrete. The results from the select examples indicate that meso-mechanics and meso-structures are elusive terms and depend mainly on the investigators' knowledge and available information.

  7. Peacebuilding with Games and Simulations

    ERIC Educational Resources Information Center

    Brynen, Rex; Milante, Gary

    2013-01-01

    Simulations and games can offer valuable insight into the management of conflict and the achievement of peace. This special symposium issue of "Simulation & Gaming" examines several such approaches, used in both educational settings and to prepare practitioners to deal with the concrete challenges of peacebuilding. In the introduction, the authors…

  8. Incorporating Experimental Technologies in the Middle Level Technology Education Classroom

    ERIC Educational Resources Information Center

    Shields, C. J.; Rogers, George E.

    2005-01-01

    This paper offers some concrete ideas and suggestions for incorporating discussions of experimental technologies in the middle level technology education classroom. Technology education students should be aware of experimental technologies. They should understand the ramifications of items such as hybrid vehicles, photovoltaic solar panels,…

  9. No Disposable Kids.

    ERIC Educational Resources Information Center

    Brendtro, Larry K.; Ness, Arlin; Mitchell, Martin

    Current educational and juvenile justice systems rely greatly on punishment and power over strategies-- especially when faced with youth whose severe behaviors escalate to violence. This book attempts to go beyond the typical problem-focused book, offering field-tested, concrete prevention and intervention strategies that can be used to help even…

  10. The Inferences We Make: Children and Literature.

    ERIC Educational Resources Information Center

    Petrosky, Anthony R.

    1980-01-01

    Discusses classroom literary practices related to teacher questioning, retelling, literalism, and figurative language for children in the concrete operational stage; concludes that recent research on response to literature may say as much about what children are taught to do as what they do developmentally. Offers suggestions about teaching…

  11. Magnetic-Based NDE of Prestressed and Post-Tensioned Concrete Members: The MFL System.

    DOT National Transportation Integrated Search

    1997-07-01

    Many metropolitan areas have begun or are planning to implement traffic monitoring programs to meet the many demands for traffic data. The purpose of this project is to document a series of examples of urban traffic monitoring data collection program...

  12. Structural Behavior Under Precision Impact Tests

    DTIC Science & Technology

    1996-08-01

    ASPECTS OF IMPACT TESTING The problem of impact between two bodies has been studied extensively (for example, Eibl 1987, Feyerabend 1988, Krauthammer...Concrete for Hazard Protection, Edinburgh, Scotland, pp. 175-186. Feyerabend , M., 1988, "Der harte Querstoss auf Stützen aus Stahl und Stahlbeton

  13. Ausgerechnet "Rumpelstilzchen?" Grimms Marchen im DaF-Unterricht (Really Rumpelstilskin? Grimm's Fairy Tales in German as a Foreign Language Instruction).

    ERIC Educational Resources Information Center

    Weber, Hans

    2000-01-01

    Suggests the use of fairy tales in German foreign language instruction at the intermediate level. This suggestion is established using features of the Grimm genre and clarified using concrete examples. (Author/DMK)

  14. MSE wall void repair effect on corrosion of reinforcement - phase 2 : specialty fill materials, [summary].

    DOT National Transportation Integrated Search

    2015-06-01

    Ramps leading, for example, to overpasses or bridges are usually constructed using : mechanically stabilized earth (MSE) walls, earthworks retained by concrete walls. Because : MSE walls are reinforced with steel embedded in the fill, their fill is c...

  15. Development of Acoustic Model-Based Iterative Reconstruction Technique for Thick-Concrete Imaging

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Almansouri, Hani; Clayton, Dwight A; Kisner, Roger A

    Ultrasound signals have been used extensively for non-destructive evaluation (NDE). However, typical reconstruction techniques, such as the synthetic aperture focusing technique (SAFT), are limited to quasi-homogenous thin media. New ultrasonic systems and reconstruction algorithms are in need for one-sided NDE of non-homogenous thick objects. An application example space is imaging of reinforced concrete structures for commercial nuclear power plants (NPPs). These structures provide important foundation, support, shielding, and containment functions. Identification and management of aging and degradation of concrete structures is fundamental to the proposed long-term operation of NPPs. Another example is geothermal and oil/gas production wells. These multi-layered structuresmore » are composed of steel, cement, and several types of soil and rocks. Ultrasound systems with greater penetration range and image quality will allow for better monitoring of the well's health and prediction of high-pressure hydraulic fracturing of the rock. These application challenges need to be addressed with an integrated imaging approach, where the application, hardware, and reconstruction software are highly integrated and optimized. Therefore, we are developing an ultrasonic system with Model-Based Iterative Reconstruction (MBIR) as the image reconstruction backbone. As the first implementation of MBIR for ultrasonic signals, this paper document the first implementation of the algorithm and show reconstruction results for synthetically generated data.« less

  16. Evaluating the uncertainty of input quantities in measurement models

    NASA Astrophysics Data System (ADS)

    Possolo, Antonio; Elster, Clemens

    2014-06-01

    The Guide to the Expression of Uncertainty in Measurement (GUM) gives guidance about how values and uncertainties should be assigned to the input quantities that appear in measurement models. This contribution offers a concrete proposal for how that guidance may be updated in light of the advances in the evaluation and expression of measurement uncertainty that were made in the course of the twenty years that have elapsed since the publication of the GUM, and also considering situations that the GUM does not yet contemplate. Our motivation is the ongoing conversation about a new edition of the GUM. While generally we favour a Bayesian approach to uncertainty evaluation, we also recognize the value that other approaches may bring to the problems considered here, and focus on methods for uncertainty evaluation and propagation that are widely applicable, including to cases that the GUM has not yet addressed. In addition to Bayesian methods, we discuss maximum-likelihood estimation, robust statistical methods, and measurement models where values of nominal properties play the same role that input quantities play in traditional models. We illustrate these general-purpose techniques in concrete examples, employing data sets that are realistic but that also are of conveniently small sizes. The supplementary material available online lists the R computer code that we have used to produce these examples (stacks.iop.org/Met/51/3/339/mmedia). Although we strive to stay close to clause 4 of the GUM, which addresses the evaluation of uncertainty for input quantities, we depart from it as we review the classes of measurement models that we believe are generally useful in contemporary measurement science. We also considerably expand and update the treatment that the GUM gives to Type B evaluations of uncertainty: reviewing the state-of-the-art, disciplined approach to the elicitation of expert knowledge, and its encapsulation in probability distributions that are usable in uncertainty propagation exercises. In this we deviate markedly and emphatically from the GUM Supplement 1, which gives pride of place to the Principle of Maximum Entropy as a means to assign probability distributions to input quantities.

  17. Experimental Study on Welded Headed Studs Used In Steel Plate-Concrete Composite Structures Compared with Contactless Method of Measuring Displacement

    NASA Astrophysics Data System (ADS)

    Kisała, Dawid; Tekieli, Marcin

    2017-10-01

    Steel plate-concrete composite structures are a new innovative design concept in which a thin steel plate is attached to the reinforced concrete beam by means of welded headed studs. The comparison between experimental studies and theoretical analysis of this type of structures shows that their behaviour is dependent on the load-slip relationship of the shear connectors used to ensure sufficient bond between the concrete and steel parts of the structure. The aim of this paper is to describe an experimental study on headed studs used in steel plate-concrete composite structures. Push-out tests were carried out to investigate the behaviour of shear connectors. The test specimens were prepared according to standard push-out tests, however, instead of I-beam, a steel plate 16 mm thick was used to better reflect the conditions in the real structure. The test specimens were produced in two batches using concrete with significantly different compressive strength. The experimental study was carried out on twelve specimens. Besides the traditional measurements based on LVDT sensors, optical measurements based on the digital image correlation method (DIC) and pattern tracking methods were used. DIC is a full-field contactless optical method for measuring displacements in experimental testing, based on the correlation of the digital images taken during test execution. With respect to conventional methods, optical measurements offer a wider scope of results and can give more information about the material or construction behaviour during the test. The ultimate load capacity and load-slip curves obtained from the experiments were compared with the values calculated based on Eurocodes, American and Chinese design specifications. It was observed that the use of the relationships developed for the traditional steel-concrete composite structures is justified in the case of ultimate load capacity of shear connectors in steel plate-concrete composite structures.

  18. Concrete Materials with Ultra-High Damage Resistance and Self- Sensing Capacity for Extended Nuclear Fuel Storage Systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Li, Mo; Nakshatrala, Kalyana; William, Kasper

    The objective of this project is to develop a new class of multifunctional concrete materials (MSCs) for extended spent nuclear fuel (SNF) storage systems, which combine ultra-high damage resistance through strain-hardening behavior with distributed multi-dimensional damage self-sensing capacity. The beauty of multifunctional concrete materials is two-fold: First, it serves as a major material component for the SNF pool, dry cask shielding and foundation pad with greatly improved resistance to cracking, reinforcement corrosion, and other common deterioration mechanisms under service conditions, and prevention from fracture failure under extreme events (e.g. impact, earthquake). This will be achieved by designing multiple levels ofmore » protection mechanisms into the material (i.e., ultrahigh ductility that provides thousands of times greater fracture energy than concrete and normal fiber reinforced concrete; intrinsic cracking control, electrochemical properties modification, reduced chemical and radionuclide transport properties, and crack-healing properties). Second, it offers capacity for distributed and direct sensing of cracking, strain, and corrosion wherever the material is located. This will be achieved by establishing the changes in electrical properties due to mechanical and electrochemical stimulus. The project will combine nano-, micro- and composite technologies, computational mechanics, durability characterization, and structural health monitoring methods, to realize new MSCs for very long-term (greater than 120 years) SNF storage systems.« less

  19. Acoustic emission signatures of damage modes in concrete

    NASA Astrophysics Data System (ADS)

    Aggelis, D. G.; Mpalaskas, A. C.; Matikas, T. E.; Van Hemelrijck, D.

    2014-03-01

    The characterization of the dominant fracture mode may assist in the prediction of the remaining life of a concrete structure due to the sequence between successive tensile and shear mechanisms. Acoustic emission sensors record the elastic responses after any fracture event converting them into electric waveforms. The characteristics of the waveforms vary according to the movement of the crack tips, enabling characterization of the original mode. In this study fracture experiments on concrete beams are conducted. The aim is to examine the typical acoustic signals emitted by different fracture modes (namely tension due to bending and shear) in a concrete matrix. This is an advancement of a recent study focusing on smaller scale mortar and marble specimens. The dominant stress field and ultimate fracture mode is controlled by modification of the four-point bending setup while acoustic emission is monitored by six sensors at fixed locations. Conclusions about how to distinguish the sources based on waveform parameters of time domain (duration, rise time) and frequency are drawn. Specifically, emissions during the shear loading exhibit lower frequencies and longer duration than tensile. Results show that, combination of AE features may help to characterize the shift between dominant fracture modes and contribute to the structural health monitoring of concrete. This offers the basis for in-situ application provided that the distortion of the signal due to heterogeneous wave path is accounted for.

  20. Characterization of steel rebar spacing using synthetic aperture radar imaging

    NASA Astrophysics Data System (ADS)

    Hu, Jie; Tang, Qixiang; Twumasi, Jones Owusu; Yu, Tzuyang

    2018-03-01

    Steel rebars is a vital component in reinforced concrete (RC) and prestressed concrete structures since they provide mechanical functions to those structures. Damages occurred to steel rebars can lead to the premature failure of concrete structures. Characterization of steel rebars using nondestructive evaluation (NDE) offers engineers and decision makers important information for effective/good repair of aging concrete structures. Among existing NDE techniques, microwave/radar NDE has been proven to be a promising technique for surface and subsurface sensing of concrete structures. The objective of this paper is to use microwave/radar NDE to characterize steel rebar grids in free space, as a basis for the subsurface sensing of steel rebars inside RC structures. A portable 10-GHz radar system based on synthetic aperture radar (SAR) imaging was used in this paper. Effect of rebar grid spacing was considered and used to define subsurface steel rebar grids. Five rebar grid spacings were used; 12.7 cm (5 in.), 17.78 cm (7 in.), 22.86 cm (9 in.), 27.94 cm (11 in.), and 33.02 cm (13 in.) # 3 rebars were used in all grid specimens. All SAR images were collected inside an anechoic chamber. It was found that SAR images can successfully capture the change of rebar grid spacing and used for quantifying the spacing of rebar grids. Empirical models were proposed to estimate actual rebar spacing and contour area using SAR images.

  1. Manticore and CS mode : parallelizable encryption with joint cipher-state authentication.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Torgerson, Mark Dolan; Draelos, Timothy John; Schroeppel, Richard Crabtree

    2004-10-01

    We describe a new mode of encryption with inexpensive authentication, which uses information from the internal state of the cipher to provide the authentication. Our algorithms have a number of benefits: (1) the encryption has properties similar to CBC mode, yet the encipherment and authentication can be parallelized and/or pipelined, (2) the authentication overhead is minimal, and (3) the authentication process remains resistant against some IV reuse. We offer a Manticore class of authenticated encryption algorithms based on cryptographic hash functions, which support variable block sizes up to twice the hash output length and variable key lengths. A proof ofmore » security is presented for the MTC4 and Pepper algorithms. We then generalize the construction to create the Cipher-State (CS) mode of encryption that uses the internal state of any round-based block cipher as an authenticator. We provide hardware and software performance estimates for all of our constructions and give a concrete example of the CS mode of encryption that uses AES as the encryption primitive and adds a small speed overhead (10-15%) compared to AES alone.« less

  2. A group matrix representation relevant to scales of measurement of clinical disease states via stratified vectors.

    PubMed

    Sawamura, Jitsuki; Morishita, Shigeru; Ishigooka, Jun

    2016-02-09

    Previously, we applied basic group theory and related concepts to scales of measurement of clinical disease states and clinical findings (including laboratory data). To gain a more concrete comprehension, we here apply the concept of matrix representation, which was not explicitly exploited in our previous work. Starting with a set of orthonormal vectors, called the basis, an operator Rj (an N-tuple patient disease state at the j-th session) was expressed as a set of stratified vectors representing plural operations on individual components, so as to satisfy the group matrix representation. The stratified vectors containing individual unit operations were combined into one-dimensional square matrices [Rj]s. The [Rj]s meet the matrix representation of a group (ring) as a K-algebra. Using the same-sized matrix of stratified vectors, we can also express changes in the plural set of [Rj]s. The method is demonstrated on simple examples. Despite the incompleteness of our model, the group matrix representation of stratified vectors offers a formal mathematical approach to clinical medicine, aligning it with other branches of natural science.

  3. Skilled interaction among professional carers in special accommodations for adult people with learning disabilities.

    PubMed

    Antonsson, H; Aström, S; Lundström, M; Graneheim, U H

    2013-09-01

    Communicative difficulties affect interactions between people with learning disabilities and their carers. Despite such difficulties, however, some carers seem to interact successfully with people who have limited ability to communicate verbally and exhibit challenging behaviour. This study aims to illuminate skilled interaction among carers working in special accommodations for people with learning disabilities. Interactions between 16 caregivers and 11 residents with learning disabilities were recorded on video. Verbal and non-verbal interaction skills among the carers were identified. Four caring situations with people with learning disabilities were chosen to illuminate skilled interaction. The transcribed text was subjected to qualitative content analysis and core stories were created. The results show that skilled interaction between the carers and the people with learning disabilities is based upon being confirming, sharing daily life experience, giving time and space, and using congruent and distinct language. In this paper we present examples that offer concrete suggestions of how to promote successful interaction and create meaning in the shared day-to-day life in special accommodations for people with learning disabilities. © 2012 John Wiley & Sons Ltd.

  4. On Grandmother Neurons and Grandfather Clocks

    ERIC Educational Resources Information Center

    Perkins, David

    2009-01-01

    What does contemporary neuroscience offer educational practice? The promise seems immense, as we come to understand better how the brain learns. However, critics caution that only a few concrete implications for practice have emerged, nowhere near a rewrite of the craft of teaching and learning. How then can we understand better the relationship…

  5. The Learner-Directed Classroom: Developing Creative Thinking Skills through Art

    ERIC Educational Resources Information Center

    Jaquith, Diane B., Ed.; Hathaway, Nan E., Ed.

    2012-01-01

    Educators at all levels want their students to develop habits of self-directed learning and critical problem-solving skills that encourage ownership and growth. In "The Learner-Directed Classroom," practicing art educators (PreK-16) offer both a comprehensive framework for understanding student-directed learning and concrete pedagogical strategies…

  6. Second Language Teaching and Learning in the Net Generation

    ERIC Educational Resources Information Center

    Oxford, Raquel, Ed.; Oxford, Jeffrey, Ed.

    2009-01-01

    Today's young people--the Net Generation--have grown up with technology all around them. However, teachers cannot assume that students' familiarity with technology in general transfers successfully to pedagogical settings. This volume examines various technologies and offers concrete advice on how each can be successfully implemented in the second…

  7. Your Most Essential Audiovisual Aid--Yourself!

    ERIC Educational Resources Information Center

    Hamp-Lyons, Elizabeth

    2012-01-01

    Acknowledging that an interested and enthusiastic teacher can create excitement for students and promote learning, the author discusses how teachers can improve their appearance, and, consequently, how their students perceive them. She offers concrete suggestions on how a teacher can be both a "visual aid" and an "audio aid" in the classroom.…

  8. A Pedagogy for Global Understanding--Intercultural Dialogue: From Theory to Practice

    ERIC Educational Resources Information Center

    Dulabaum, Nina L.

    2011-01-01

    Given the current tensions and animosities between people of varying cultural and ethnic groups, intercultural dialogue, rooted in Europe's humanist tradition, offers a concrete strategy for fostering understanding, promoting tolerance and breaking down barriers based on stereotypes and xenophobic violence. As the world's population increases each…

  9. Laser decontamination and decomposition of PCB-containing paint

    NASA Astrophysics Data System (ADS)

    Anthofer, A.; Kögler, P.; Friedrich, C.; Lippmann, W.; Hurtado, A.

    2017-01-01

    Decontamination of concrete surfaces contaminated with paint containing polychlorinated biphenyls is an elaborate and complex task that must be performed within the scope of nuclear power plant dismantling as well as conventional pollutant cleanup in buildings. The state of the art is mechanical decontamination, which generates dust as well as secondary waste and is both dangerous and physically demanding. Moreover, the ablated PCB-containing paint has to be treated in a separate process step. Laser technology offers a multitude of possibilities for contactless surface treatment with no restoring forces and a high potential for automation. An advanced experimental setup was developed for performing standard laser decontamination investigations on PCB-painted concrete surfaces. As tested with epoxy paints, a high-power diode laser with a laser power of 10 kW in continuous wave (CW) mode was implemented and resulted in decontamination of the concrete surfaces as well as significant PCB decomposition. The experimental results showed PCB removal of 96.8% from the concrete surface and PCB decomposition of 88.8% in the laser decontamination process. Significant PCDD/F formation was thereby avoided. A surface ablation rate of approx. 7.2 m2/h was realized.

  10. Biogenic concrete protection driven by the formate oxidation by Methylocystis parvus OBBP.

    PubMed

    Ganendra, Giovanni; Wang, Jianyun; Ramos, Jose A; Derluyn, Hannelore; Rahier, Hubert; Cnudde, Veerle; Ho, Adrian; Boon, Nico

    2015-01-01

    The effectiveness of Microbiologically Induced Carbonate Precipitation (MICP) from the formate oxidation by Methylocystis parvus OBBP as an alternative process for concrete protection was investigated. MICP was induced on Autoclaved Aerated Concrete (AAC), the model material, by immersing the material in 10(9) M. parvus cells mL(-1) containing 5 g L(-1) of calcium formate. A 2 days immersion of the material gave the maximum weight increase of the specimens (38 ± 19 mg) and this was likely due to the deposition of calcium carbonate, biomass, and unconverted calcium formate. The solid deposition mainly occurred in the micropores of the specimen, close to the outer surface. A significantly lower water absorption was observed in the bacterially treated specimens compared to the non-treated ones (up to 2.92 ± 0.91 kg m(-2)) and this could be attributed to the solid deposition. However, the sonication test demonstrated that the bacterial treatment did not give a consolidating effect to the material. Overall, compared to the currently employed urea hydrolysis process, the formate-based MICP by M. parvus offers a more environmentally friendly approach for the biotechnological application to protect concrete.

  11. Biogenic concrete protection driven by the formate oxidation by Methylocystis parvus OBBP

    PubMed Central

    Ganendra, Giovanni; Wang, Jianyun; Ramos, Jose A.; Derluyn, Hannelore; Rahier, Hubert; Cnudde, Veerle; Ho, Adrian; Boon, Nico

    2015-01-01

    The effectiveness of Microbiologically Induced Carbonate Precipitation (MICP) from the formate oxidation by Methylocystis parvus OBBP as an alternative process for concrete protection was investigated. MICP was induced on Autoclaved Aerated Concrete (AAC), the model material, by immersing the material in 109 M. parvus cells mL−1 containing 5 g L−1 of calcium formate. A 2 days immersion of the material gave the maximum weight increase of the specimens (38 ± 19 mg) and this was likely due to the deposition of calcium carbonate, biomass, and unconverted calcium formate. The solid deposition mainly occurred in the micropores of the specimen, close to the outer surface. A significantly lower water absorption was observed in the bacterially treated specimens compared to the non-treated ones (up to 2.92 ± 0.91 kg m−2) and this could be attributed to the solid deposition. However, the sonication test demonstrated that the bacterial treatment did not give a consolidating effect to the material. Overall, compared to the currently employed urea hydrolysis process, the formate-based MICP by M. parvus offers a more environmentally friendly approach for the biotechnological application to protect concrete. PMID:26284061

  12. Diversity Digest. Volume 9, Number 1

    ERIC Educational Resources Information Center

    Musil, Caryn McTighe, Ed.; Hovland, Kevin, Ed.

    2005-01-01

    Civic engagement is the focus of this issue of "Diversity Digest." Concrete examples of institutions that have linked diversity and civic engagement in powerful, effective, and educationally transforming ways are presented. What is seen in the field is encouraging. Articles feature new conceptual frameworks for civic learning, curricular…

  13. Research Paradigms, Television, and Social Behavior.

    ERIC Educational Resources Information Center

    Asamen, Joy Keiko, Ed.; Berry, Gordon L., Ed.

    Straightforward and engaging in style, this book presents 10 essays that provide concrete, step-by-step examples of how to conduct studies of the impact of television on behavior from quantitative perspectives, qualitative perspectives, and an integrated approach, making the volume useful for both undergraduate and graduate students. Its…

  14. Persuasion = Stating and Arguing Claims Well

    ERIC Educational Resources Information Center

    Lapp, Diane; Fisher, Douglas

    2012-01-01

    Inside a ninth-grade classroom, we witness one teacher's very intentional instructional attempts that resulted in her students being able to convey well-crafted reasoning and text-supported evidence to mount persuasive arguments. Through personal examples and Internet resources, the teacher concretized pathos, logos, and ethos. The teacher and…

  15. Arithmetic Procedures are Induced from Examples.

    DTIC Science & Technology

    1985-08-13

    concrete numerals (eg. coins. Dienes blocks, poker chips. Montessori rods etc Analogy is included as a third hypothesis even though it is not particularly...collections of coins. Diennes blocks. Montessori rods and so forth. This is a mapping between two kinds of numerals. and not two procedures Later. this

  16. Analysis of reinforced concrete structures with occurrence of discrete cracks at arbitrary positions

    NASA Technical Reports Server (NTRS)

    Blaauwendraad, J.; Grootenboer, H. J.; Bouma, A. L.; Reinhardt, H. W.

    1980-01-01

    A nonlinear analysis of in-plane loaded plates is presented, which eliminates the disadvantages of the smeared crack approach. The elements used and the computational method are discussed. An example is shown in which one or more discrete cracks are dominant.

  17. Precious Cargo-Handle with Care.

    ERIC Educational Resources Information Center

    Coleman, Diane J.; Monger, Joyce R.

    1992-01-01

    Learning activities that expose students to the concepts of economics are presented, using concrete examples involving the daily activities of zoos and their visitors. The activities call for students to identify zoo expenses, evaluate decisions about zoo spending, and consider the financial and moral costs of treating animals humanely. (JDD)

  18. 29 CFR 1926.1400 - Scope.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... loads. (3) Automotive wreckers and tow trucks when used to clear wrecks and haul vehicles. (4) Digger... not limited to: Precast concrete members or panels, roof trusses (wooden, cold-formed metal, steel, or... structural steel member (for example, steel joists, beams, columns, steel decking (bundled or unbundled) or a...

  19. The Thermodynamics of Interior Ballistics and Propellant Performance

    DTIC Science & Technology

    2013-11-01

    constant volume and energy. This is referred to as the “chamber” condition, where the propellant is all burnt . IB codes typically use the...for the remainder of this work are performed using BLAKE and illustrated using BLAKE commands as concrete examples of the required computations. It

  20. Elements of Warfare in the Sixth- and Seventh-Grade Physics Course

    ERIC Educational Resources Information Center

    Enokhovich, A. S.

    1973-01-01

    Mechanical movement, pressure, floating bodies, heat phenomena, electrical phenomena, when applied to military problems "for the patriotic edification and military instruction of the children" excite interest and place theory on concrete foundations. Examples of applied physical concepts follow in this article. (Author/JH)

  1. Making Rainforests Relevant.

    ERIC Educational Resources Information Center

    Lustbader, Sara

    1995-01-01

    Describes a program for teaching about tropical rainforests in a concrete way using what's outside the door. This activity uses an eastern deciduous hardwood forest as an example. Step-by-step instructions include introductory activities, plus descriptions of stations in the forest to be visited. Resources include books, audio-visual materials,…

  2. Dual Treatments as Starting Point for Integrative Perceptions in Teaching Mathematics

    ERIC Educational Resources Information Center

    Kërënxhi, Svjetllana; Gjoci, Pranvera

    2015-01-01

    In this paper, we recommend mathematical teaching through dual treatments. The dual treatments notion, classified in dual interpretations, dual analyses, dual solutions, and dual formulations, is explained through concrete examples taken from mathematical textbooks of elementary education. Dual treatments provide opportunities for creating…

  3. Two Decades of Enhancing Children’s Environmental Health Protection at the U.S. Environmental Protection Agency

    PubMed Central

    Firestone, Michael; Berger, Martha; Foos, Brenda; Etzel, Ruth

    2016-01-01

    Summary: This article provides an overview of public health efforts by the U.S. Environmental Protection Agency (EPA) during the past two decades to protect children’s health from environmental hazards. It highlights examples of concrete steps and accomplishments toward improving environmental protection and health outcomes achieved through public policy, rules and regulations, increased scientific understanding, and public health messaging. Additionally, examples of future challenges for better understanding and improving children’s environmental health are discussed. PMID:27905272

  4. Assessment of optimum threshold and particle shape parameter for the image analysis of aggregate size distribution of concrete sections

    NASA Astrophysics Data System (ADS)

    Ozen, Murat; Guler, Murat

    2014-02-01

    Aggregate gradation is one of the key design parameters affecting the workability and strength properties of concrete mixtures. Estimating aggregate gradation from hardened concrete samples can offer valuable insights into the quality of mixtures in terms of the degree of segregation and the amount of deviation from the specified gradation limits. In this study, a methodology is introduced to determine the particle size distribution of aggregates from 2D cross sectional images of concrete samples. The samples used in the study were fabricated from six mix designs by varying the aggregate gradation, aggregate source and maximum aggregate size with five replicates of each design combination. Each sample was cut into three pieces using a diamond saw and then scanned to obtain the cross sectional images using a desktop flatbed scanner. An algorithm is proposed to determine the optimum threshold for the image analysis of the cross sections. A procedure was also suggested to determine a suitable particle shape parameter to be used in the analysis of aggregate size distribution within each cross section. Results of analyses indicated that the optimum threshold hence the pixel distribution functions may be different even for the cross sections of an identical concrete sample. Besides, the maximum ferret diameter is the most suitable shape parameter to estimate the size distribution of aggregates when computed based on the diagonal sieve opening. The outcome of this study can be of practical value for the practitioners to evaluate concrete in terms of the degree of segregation and the bounds of mixture's gradation achieved during manufacturing.

  5. Stable carbon isotopes and lipid biomarkers provide new insight into the formation of calcite and siderite concretions in organic-matter rich deposits

    NASA Astrophysics Data System (ADS)

    Baumann, Lydia; Birgel, Daniel; Wagreich, Michael; Peckmann, Jörn

    2015-04-01

    Carbonate concretions from two distinct settings have been studied for their petrography, stable carbon and oxygen isotopes, and lipid biomarker content. Carbonate concretions are in large part products of microbial degradation of organic matter, as for example by sulfate-reducing bacteria, iron-reducing bacteria, and methanogenic archaea. For these prokaryotes certain lipid biomarkers such as hopanoids, terminally-branched fatty acids (bacteria) and isoprenoids (archaea) are characteristic. Two different types of concretions were studied: a) Upper Miocene septarian calcite concretions of the southern Vienna Basin embedded in brackish sediments represented by partly bituminous calcareous sands, silts and clays; b) Paleocene-Eocene siderite concretions enclosed in marine, sandy to silty turbidites with varying carbonate contents and marl layers from the Upper Gosau Subgroup in northern Styria. Calcite concretions consist of abundant calcite microspar (80-90 vol.%), as well as detrital minerals and iron oxyhydroxides. The septarian cracks show beginning cementation with dog-tooth calcite to varying degrees. Framboidal pyrite occurs in some of the calcite concretions, pointing to bacterial sulfate reduction. Siderite concretions consist of even finer carbonate crystals, mainly siderite (40-70 vol.%) but also abundant ferroan calcite, accompanied by iron oxyhydroxides and detrital minerals. The δ13C values of the calcite concretions (-6.8 to -4.1o ) most likely reflect a combination of bacterial organic matter oxidation and input of marine biodetrital carbonate. The δ18O values range from -8.9 to -7.8o agreeing with a formation within a meteoric environment. The surrounding host sediment shows about 1-2o higher δ13C and δ18O values. The siderite δ13C values (-11.1 to -7.5o ) point to microbial respiration of organic carbon and the δ18O values (-3.5 to +2.2o ) agree with a marine depositional environment. In contrast to the calcite concretions, the stable isotope composition of the host sediment differs significantly from the siderite concretions. The δ13C values of the Gosau host sediment reflect marine conditions, whereas the oxygen isotope values are best explained by meteoric overprint. Lipid biomarkers have been extracted before and after dissolution of the concretions in order to assess their authenticity and to exclude recent surface contamination. In the following, only the biomarkers extracted after dissolution are discussed, since they are thought to be related to concretion formation. The calcite concretions comprise abundant plant wax derived long-chain n-alkanes, reflecting high terrestrial input. Bacterial, terminally-branched fatty acids were found, but in overall low abundance. The siderite concretions did not yield biomarkers due to their high maturity. No archaeal biomarkers were found in any of the concretions. Considering the presence of framboidal pyrite, the moderately low δ13C values, and the biomarker inventory, bacterial sulfate reduction apparently contributed to the formation of the calcite concretions in a brackish environment. In contrast, ongoing sulfate reduction and resultant hydrogen sulfide production inhibit siderite precipitation. Therefore, the low δ13C values of the siderite concretions are best explained by bacterial iron reduction.

  6. Application of Crushed Concrete in Geotechnical Engineering - Selected Issues

    NASA Astrophysics Data System (ADS)

    Kawalec, Jacek; Kwiecien, Slawomir; Pilipenko, Anton; Rybak, Jarosław

    2017-12-01

    The reuse of building materials becomes an important issue in sustainable engineering. As the technical requirements for civil engineering structures changes with time and the life time is limited, the need of building new objects meets the necessity of recycling of the existing ones. In the case of steel structures, the possibility of recycling is obvious, also in the case of wooden constructions, the possibility of “burning” solves the problem. The concrete waste is generated mainly as a result of the demolition and reconstruction of residential and industrial buildings. These types of waste are basically made from crushed rocks and cement minerals and contain non-hydrated cement particles in its composition. Concrete poses a lot of problems mainly for two reasons. It is difficult to crush, heavy and hard to transport and demanding in reuse. Different fractions (particle sizes) may be used for different purposes. Starting from very fine particles which can be used in concrete production, through regular 16-300 mm fractions used to form new fills and fill the mats, up to very irregular mixtures used to form stone columns by means of Impulse Compaction or in Dynamic Replacement. The presented study juxtaposes authors experience with crushed concrete used in civil engineering, mainly in geotechnical projects. Authors’ experiences comprise the application of crushed concrete in the new concrete production in Russia, changing pulverized bridge into the fill of mesh sacks, or mattresses used as an effective way to protect the shoreline and the New Orleans East land bridge after Katrina storm (forming a new shoreline better able to withstand wave actions), and finally the use of very irregular concrete fractions to form stone columns in week soils on the example of railway and road projects in Poland. Selected case studies are presented and summarized with regard to social, technical and economic issues including energy consumption needed for proposed technologies and dynamic impact of ground transmitted vibrations and noise.

  7. Workability of glass reinforced concrete (GRC) with granite and silica sand aggregates

    NASA Astrophysics Data System (ADS)

    Moceikis, R.; Kičaitė, A.; Keturakis, E.

    2017-10-01

    Glass fiber reinforced concrete (GRC) opens the door for lightweight and complex shaped innovative construction, adding architectural value to buildings. With panel thickness down to 15 mm, considerable amount of total loads and materials per square meter of facade can be saved, if compared to conventionally used 80 mm thickness outer layer in insulated precast concrete wall elements. Even though GRC is used for over 50 years in such countries as Great Britain, USA and Japan, there are very few examples and little research done in Eastern Europe with this building material. European Commission propagates sustainable design as commitment to energy efficiency, environmental stewardship and conservation. For this reason, GRC plays important role in mowing toward these goals. In this paper, GRC premix recipes including fine granite and silica sands, reinforced with 13mm length alkali resistant glass fibers are investigated. Two CEM I 52,5R cements with different particle sizes were used and severe water dissociation noticed in one of concrete mixes. Cement particle size distribution determined with laser diffraction particle analyser Cilas 1090LD. To determine modulus of rupture (M.O.R.) and limit of proportionality (L.O.P), plates thickness 15 and 20 mm were produced and tested for flexural resistance according to 4-point bending scheme. Concrete workability tests were made according EN 1170-1.

  8. Effects of Interlocking and Supporting Conditions on Concrete Block Pavements

    NASA Astrophysics Data System (ADS)

    Mahapatra, Geetimukta; Kalita, Kuldeep

    2018-02-01

    Concrete Block Paving (CBP) is widely used as wearing course in flexible pavements, preferably under light and medium vehicular loadings. Construction of CBP at site is quick and easy in quality control. Usually, flexible pavement design philosophy is followed in CBP construction, though it is structurally different in terms of small block elements with high strength concrete and their interlocking aspects, frequent joints and discontinuity, restrained edge etc. Analytical solution for such group action of concrete blocks under loading in a three dimensional multilayer structure is complex and thus, the need of conducting experimental studies is necessitated for extensive understanding of the load—deformation characteristics and behavior of concrete blocks in pavement. The present paper focuses on the experimental studies for load transfer characteristics of CBP under different interlocking and supporting conditions. It is observed that both interlocking and supporting conditions affect significantly on the load transfer behavior in CBP structures. Coro-lock block exhibits better performance in terms of load carrying capacity and distortion behavior under static loads. Plate load tests are performed over subgrade, granular sub-base (GSB), CBP with and without GSB using different block shapes. For an example case, the comparison of CBP with conventional flexible pavement section is also presented and it is found that CBP provides considerable benefit in terms of construction cost of the road structure.

  9. Examples of Solutions for Steel-Concrete Composite Structures in Bridge Engineering / Przykłady Konstrukcji Zespolonych W Budownictwie Mostowym

    NASA Astrophysics Data System (ADS)

    Flaga, Kazimierz; Furtak, Kazimierz

    2015-03-01

    The aim of the article [1] was to discuss the application of steel-concrete composite structures in bridge engineering in the aspect of structural design, analysis and execution. It was pointed out that the concept of steel-concrete structural composition is far from exhausted and new solutions interesting from the engineering, scientific and aesthetic points of view of are constantly emerging. These latest trends are presented against the background of the solutions executed in Poland and abroad. Particular attention is focused on structures of double composition and steel-concrete structures. Concrete filled steel tubular (CFST) structures are highlighted. W artykule [1] omówiono problemy konstrukcyjne, obliczeniowe i realizacyjne, związane z zastosowaniem konstrukcji zespolonych stal-beton w mostownictwie. Wskazano tam, że idea konstrukcyjnego zespolenia stali z betonem jest jeszcze daleka do wyczerpania i że wciąż pojawiają się nowe rozwiązania interesujące z inżynierskiego, naukowego i estetycznego punktu widzenia. W artykule niniejszym pokazano te nowoczesne trendy na tle rozwiązań zrealizowanych w Polsce i na świecie. Szczególną uwagę poświęcono konstrukcjom podwójnie zespolonym oraz konstrukcjom stalowobetonowym. Wyeksponowano tu szczególnie konstrukcje z rur stalowych wypełnionych betonem, typu CFST. Dają one nadzieję na ich szersze zastosowanie w warunkach polskich.

  10. An assessment of the CORCON-MOD3 code. Part 1: Thermal-hydraulic calculations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Strizhov, V.; Kanukova, V.; Vinogradova, T.

    1996-09-01

    This report deals with the subject of CORCON-Mod3 code validation (thermal-hydraulic modeling capability only) based on MCCI (molten core concrete interaction) experiments conducted under different programs in the past decade. Thermal-hydraulic calculations (i.e., concrete ablation, melt temperature, melt energy, concrete temperature, and condensible and non-condensible gas generation) were performed with the code, and compared with the data from 15 experiments, conducted at different scales using both simulant (metallic and oxidic) and prototypic melt materials, using different concrete types, and with and without an overlying water pool. Sensitivity studies were performed in a few cases involving, for example, heat transfer frommore » melt to concrete, condensed phase chemistry, etc. Further, special analysis was performed using the ACE L8 experimental data to illustrate the differences between the experimental and the reactor conditions, and to demonstrate that with proper corrections made to the code, the calculated results were in better agreement with the experimental data. Generally, in the case of dry cavity and metallic melts, CORCON-Mod3 thermal-hydraulic calculations were in good agreement with the test data. For oxidic melts in a dry cavity, uncertainties in heat transfer models played an important role for two melt configurations--a stratified geometry with segregated metal and oxide layers, and a heterogeneous mixture. Some discrepancies in the gas release data were noted in a few cases.« less

  11. Fast Lamb wave energy shift approach using fully contactless ultrasonic system to characterize concrete structures

    NASA Astrophysics Data System (ADS)

    Ham, Suyun; Popovics, John S.

    2015-03-01

    Ultrasonic techniques provide an effective non-destructive evaluation (NDE) method to monitor concrete structures, but the need to perform rapid and accurate structural assessment requires evaluation of hundreds, or even thousands, of measurement datasets. Use of a fully contactless ultrasonic system can save time and labor through rapid implementation, and can enable automated and controlled data acquisition, for example through robotic scanning. Here we present results using a fully contactless ultrasonic system. This paper describes our efforts to develop a contactless ultrasonic guided wave NDE approach to detect and characterize delamination defects in concrete structures. The developed contactless sensors, controlled scanning system, and employed Multi-channel Analysis of Surface Waves (MASW) signal processing scheme are reviewed. Then a guided wave interpretation approach for MASW data is described. The presence of delamination is interpreted by guided plate wave (Lamb wave) behavior, where a shift in excited Lamb mode phase velocity, is monitored. Numerically simulated and experimental ultrasonic data collected from a concrete sample with simulated delamination defects are presented, where the occurrence of delamination is shown to be associated with a mode shift in Lamb wave energy.

  12. Connecting the Interpersonal, Instructional, and Institutional Contexts

    ERIC Educational Resources Information Center

    Nieto, Sonia; Rivera, Melissa; Quinones, Sandra

    2012-01-01

    As discussed throughout this paper, many institutional and instructional strategies can facilitate higher achievement among Latino/a students. Many of these are effective partly because of the relationships they foster. But we also want to point out a few concrete examples of supportive constructive relationships. The common thread in these…

  13. Helping Students to Write Well-Developed and Detailed Paragraphs and Essays Using "QUEEN FRANCIS."

    ERIC Educational Resources Information Center

    Backman, Brian

    1996-01-01

    Explains how to get middle school through college students to write detailed paragraphs with the QUEEN FRANCIS method--an acronym that stands for "Qu"otes, "E"xamples, "E"xperts, "N"ames, "F"acts, "R"easons, "A"necdotes, "N"umbers, "C"oncrete words,…

  14. Developing Intercultural Communication Skills through Intergroup Interaction

    ERIC Educational Resources Information Center

    Eisenchlas, Susana; Trevaskes, Sue

    2007-01-01

    The call to internationalise the curriculum has become firmly ensconced in Australian educational discourse and university mission statements. Yet, scholars in this area agree that there are few concrete examples of how educators actually set about internationalising the curriculum in a tangible and easily replicable way. This paper adopts a…

  15. Students as Doers: Examples of Successful E-Learning Activities

    ERIC Educational Resources Information Center

    Tammelin, Maija; Peltonen, Berit; Puranen, Pasi; Auvinen, Lis

    2012-01-01

    This paper discusses learning language and communication activities that focus on students' concrete involvement in their learning process. The activities first deal with student-produced blogs and digital videos in business Spanish. They then present student-produced podcasts for Swedish business communication learners that are meant for speakers…

  16. Scaffolding Assignments and Activities for Undergraduate Research Methods

    ERIC Educational Resources Information Center

    Fisher, Sarah; Justwan, Florian

    2018-01-01

    This article details assignments and lessons created for and tested in research methods courses at two different universities, a large state school and a small liberal arts college. Each assignment or activity utilized scaffolding. Students were asked to push beyond their comfort zone while utilizing concrete and/or creative examples,…

  17. Random Fill Cache Architecture (Preprint)

    DTIC Science & Technology

    2014-10-01

    a concrete example, we show how the cache collision attack works to extract the AES encryption keys (e.g., in the OpenSSL implementation of AES). AES...each round are implemented as table lookups for performance reasons. OpenSSL uses ten 1-KB lookup tables, five for encryption and five for decryption

  18. How Science Fairs Foster Inquiry Skills and Enrich Learning

    ERIC Educational Resources Information Center

    Paul, Jürgen; Groß, Jorge

    2017-01-01

    Science competitions have continuing relevance for schools. The aim of the German youth science fair "Jugend forscht" is to encourage scientific thinking and inquiry methods such as experimentation. Three concrete examples of participating projects are given. We summarise the current state of research related to science competitions,…

  19. Explorations with 142857: Connecting the Elementary with the Advanced

    ERIC Educational Resources Information Center

    Flores, Alfinio

    2008-01-01

    University mathematics education courses do not always provide the opportunity to make connections between advanced topics and the mathematics taught in middle school or high school. Activities like the ones described in this article invite such connections. Analyzing concrete or particular examples provides a better grasp of abstract concepts.…

  20. A Business Casebook for Young Decision Makers.

    ERIC Educational Resources Information Center

    Tedesco, Paul H., Ed.; And Others

    Ten case studies taken from the business world are presented to help secondary school students develop a realistic understanding of economic problems. Discussion of the cases can be integrated into economics or social studies programs. By studying concrete examples of business reacting to changing economic conditions, students should learn to…

  1. Using Games to Teach Markov Chains

    ERIC Educational Resources Information Center

    Johnson, Roger W.

    2003-01-01

    Games are promoted as examples for classroom discussion of stationary Markov chains. In a game context Markov chain terminology and results are made concrete, interesting, and entertaining. Game length for several-player games such as "Hi Ho! Cherry-O" and "Chutes and Ladders" is investigated and new, simple formulas are given. Slight…

  2. Using Matlab in a Multivariable Calculus Course.

    ERIC Educational Resources Information Center

    Schlatter, Mark D.

    The benefits of high-level mathematics packages such as Matlab include both a computer algebra system and the ability to provide students with concrete visual examples. This paper discusses how both capabilities of Matlab were used in a multivariate calculus class. Graphical user interfaces which display three-dimensional surfaces, contour plots,…

  3. 86. Round Meadow Creek Viaduct. This steel girder bridge, built ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    86. Round Meadow Creek Viaduct. This steel girder bridge, built in 1939, has a reinforced concrete deck and piers. It is an example of a major in-line, or straight, viaduct over a deep ravine. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  4. Sustainability of Higher Education Institutions in Taiwan

    ERIC Educational Resources Information Center

    Su, H. Jenny; Chang, Tzu-chau

    2010-01-01

    Purpose: The purpose of this paper is to provide the rationale and context for recent national policy and funded initiatives to support sustainability developments within higher education in Taiwan, including practical and educational aspects. Concrete examples and specific outcomes are reviewed, to produce a profile across the higher education…

  5. Before the Outline--The Writing Wheel.

    ERIC Educational Resources Information Center

    Rae, Colleen

    1986-01-01

    To help students write more effectively, a technique for writing from thesis statements is described that requires students to create a picture of a wheel. The hub is a word that is the essence of the topic; the spokes are concrete examples; and the tire is the thesis statement. (MLW)

  6. Sulfate resistance of high calcium fly ash concrete

    NASA Astrophysics Data System (ADS)

    Dhole, Rajaram

    Sulfate attack is one of the mechanisms which can cause deterioration of concrete. In general, Class C fly ash mixtures are reported to provide poor sulfate resistance. Fly ashes, mainly those belonging to the Class C, were tested as per the ASTM C 1012 procedure to evaluate chemical sulfate resistance. Overall the Class C fly ashes showed poor resistance in the sulfate environment. Different strategies were used in this research work to improve the sulfate resistance of Class C fly ash mixes. The study revealed that some of the strategies such as use of low W/CM (water to cementing materials by mass ratio), silica fume or ultra fine fly ash, high volumes of fly ash and, ternary or quaternary mixes with suitable supplementary cementing materials, can successfully improve the sulfate resistance of the Class C fly ash mixes. Combined sulfate attack, involving physical and chemical action, was studied using sodium sulfate and calcium sulfate solutions. The specimens were subjected to wetting-drying cycles and temperature changes. These conditions were found to accelerate the rate of degradation of concrete placed in a sodium sulfate environment. W/CM was found to be the main governing factor in providing sulfate resistance to mixes. Calcium sulfate did not reveal damage as a result of mainly physical action. Characterization of the selected fly ashes was undertaken by using SEM, XRD and the Rietveld analysis techniques, to determine the relation between the composition of fly ashes and resistance to sulfate attack. The chemical composition of glass represented on the ternary diagram was the main factor which had a significant influence on the sulfate resistance of fly ash mixtures. Mixes prepared with fly ashes containing significant amounts of vulnerable crystalline phases offered poor sulfate resistance. Comparatively, fly ash mixes containing inert crystalline phases such as quartz, mullite and hematite offered good sulfate resistance. The analysis of hydrated lime-fly ash pastes confirmed that fly ash mortar or concrete mixes forming more monosulfate than ettringite before exposure to sulfates would offer poor sulfate resistance and vice versa. During quantitative Rietveld analysis carried out for determining ettringite, monosulfate and gypsum formed in the fly ash pastes, it was observed that fly ash mixtures showing more ettringite after exposures to sulfates, give poor sulfate resistance. A good relationship between the amounts of ettringite formed and expansions of mortar specimens in the ASTM C 1012 test was found.

  7. Patient-centered innovation in health care organizations: a conceptual framework and case study application.

    PubMed

    Hernandez, Susan E; Conrad, Douglas A; Marcus-Smith, Miriam S; Reed, Peter; Watts, Carolyn

    2013-01-01

    Patient-centered innovation is spreading at the federal and state levels. A conceptual framework can help frame real-world examples and extract systematic learning from an array of innovative applications currently underway. The statutory, economic, and political environment in Washington State offers a special contextual laboratory for observing the interplay of these factors. We propose a framework for understanding the process of initiating patient-centered innovations-particularly innovations addressing patient-centered goals of improved access, continuity, communication and coordination, cultural competency, and family- and person-focused care over time. The framework to a case study of a provider organization in Washington State actively engaged in such innovations was applied in this article. We conducted a selective review of peer-reviewed evidence and theory regarding determinants of organizational change. On the basis of the literature review and the particular examples of patient-centric innovation, we developed a conceptual framework. Semistructured key informant interviews were conducted to illustrate the framework with concrete examples of patient-centered innovation. The primary determinants of initiating patient-centered innovation are (a) effective leadership, with the necessary technical and professional expertise and creative skills; (b) strong internal and external motivation to change; (c) clear and internally consistent organizational mission; (d) aligned organizational strategy; (e) robust organizational capability; and (f) continuous feedback and organizational learning. The internal hierarchy of actors is important in shaping patient-centered innovation. External financial incentives and government regulations also significantly shape innovation. Patient-centered care innovation is a complex process. A general framework that could help managers and executives organize their thoughts around innovation within their organization is presented.

  8. What Google Maps can do for biomedical data dissemination: examples and a design study.

    PubMed

    Jianu, Radu; Laidlaw, David H

    2013-05-04

    Biologists often need to assess whether unfamiliar datasets warrant the time investment required for more detailed exploration. Basing such assessments on brief descriptions provided by data publishers is unwieldy for large datasets that contain insights dependent on specific scientific questions. Alternatively, using complex software systems for a preliminary analysis may be deemed as too time consuming in itself, especially for unfamiliar data types and formats. This may lead to wasted analysis time and discarding of potentially useful data. We present an exploration of design opportunities that the Google Maps interface offers to biomedical data visualization. In particular, we focus on synergies between visualization techniques and Google Maps that facilitate the development of biological visualizations which have both low-overhead and sufficient expressivity to support the exploration of data at multiple scales. The methods we explore rely on displaying pre-rendered visualizations of biological data in browsers, with sparse yet powerful interactions, by using the Google Maps API. We structure our discussion around five visualizations: a gene co-regulation visualization, a heatmap viewer, a genome browser, a protein interaction network, and a planar visualization of white matter in the brain. Feedback from collaborative work with domain experts suggests that our Google Maps visualizations offer multiple, scale-dependent perspectives and can be particularly helpful for unfamiliar datasets due to their accessibility. We also find that users, particularly those less experienced with computer use, are attracted by the familiarity of the Google Maps API. Our five implementations introduce design elements that can benefit visualization developers. We describe a low-overhead approach that lets biologists access readily analyzed views of unfamiliar scientific datasets. We rely on pre-computed visualizations prepared by data experts, accompanied by sparse and intuitive interactions, and distributed via the familiar Google Maps framework. Our contributions are an evaluation demonstrating the validity and opportunities of this approach, a set of design guidelines benefiting those wanting to create such visualizations, and five concrete example visualizations.

  9. What google maps can do for biomedical data dissemination: examples and a design study

    PubMed Central

    2013-01-01

    Background Biologists often need to assess whether unfamiliar datasets warrant the time investment required for more detailed exploration. Basing such assessments on brief descriptions provided by data publishers is unwieldy for large datasets that contain insights dependent on specific scientific questions. Alternatively, using complex software systems for a preliminary analysis may be deemed as too time consuming in itself, especially for unfamiliar data types and formats. This may lead to wasted analysis time and discarding of potentially useful data. Results We present an exploration of design opportunities that the Google Maps interface offers to biomedical data visualization. In particular, we focus on synergies between visualization techniques and Google Maps that facilitate the development of biological visualizations which have both low-overhead and sufficient expressivity to support the exploration of data at multiple scales. The methods we explore rely on displaying pre-rendered visualizations of biological data in browsers, with sparse yet powerful interactions, by using the Google Maps API. We structure our discussion around five visualizations: a gene co-regulation visualization, a heatmap viewer, a genome browser, a protein interaction network, and a planar visualization of white matter in the brain. Feedback from collaborative work with domain experts suggests that our Google Maps visualizations offer multiple, scale-dependent perspectives and can be particularly helpful for unfamiliar datasets due to their accessibility. We also find that users, particularly those less experienced with computer use, are attracted by the familiarity of the Google Maps API. Our five implementations introduce design elements that can benefit visualization developers. Conclusions We describe a low-overhead approach that lets biologists access readily analyzed views of unfamiliar scientific datasets. We rely on pre-computed visualizations prepared by data experts, accompanied by sparse and intuitive interactions, and distributed via the familiar Google Maps framework. Our contributions are an evaluation demonstrating the validity and opportunities of this approach, a set of design guidelines benefiting those wanting to create such visualizations, and five concrete example visualizations. PMID:23642009

  10. Develop Strong and Serviceable Details for Precast, Prestressed Concrete Bent Cap Standards That Can Be Implemented on Everyday Bridge Construction Projects, Project Summary

    DOT National Transportation Integrated Search

    2018-01-01

    Pretensioned bent caps are an attractive substructure component because they offer contractors an option for fabrication by prestressing plants and can be used to eliminate or reduce cracks. Two sets of design recommendations were developed to enable...

  11. Four Training Activities to Help You Forecast the Future.

    ERIC Educational Resources Information Center

    Stolovitch, Harold D.

    1979-01-01

    To avoid meeting the future unprepared, the article offers four training activities that can be used by small groups, in-house, to begin examining and preparing for whatever the future holds. Activities include (1) future headlines, (2) mini-delphi, (3) alternative futures analysis and review, and (4) strategies for concretizing identified future…

  12. Baby Basics: Children's Activities in How Life Begins. Children's Activity Series.

    ERIC Educational Resources Information Center

    Picco, Elizabeth Raptis

    These supplemental teaching resources promote awareness about health, family life, and cultural diversity for children in kindergarten through third grade, and offer a variety of concrete, visual activities to help young children understand how life begins for all living things. The format of each lesson is designed to help classroom and daycare…

  13. Vernaculars in the Classroom: Paradoxes, Pedagogy, Possibilities. Routledge Research in Education

    ERIC Educational Resources Information Center

    Nero, Shondel; Ahmad, Dohra

    2014-01-01

    This book draws on applied linguistics and literary studies to offer concrete means of engaging with vernacular language and literature in secondary and college classrooms. The authors embrace a language-as-resource orientation, countering the popular narrative of vernaculars as problems in schools. The book is divided into two parts, with the…

  14. The Changing World of Higher Education: Where Do Language Centres Fit in?

    ERIC Educational Resources Information Center

    Dijk, Anje; Engelen, Christine; Korebrits, Liesbet

    2014-01-01

    This article assesses the current trends in language centre (LC) management in the Netherlands and Dutch-speaking Belgium. Twenty-five LCs are united under the umbrella of NUT, which offers its members the possibility to meet and discuss concrete professional subjects. Solutions, strategies and decisions emphasise the importance of national…

  15. From the One-Hour Field Trip to a Nature Preschool: Partnering with Environmental Organizations

    ERIC Educational Resources Information Center

    Bailie, Patti Ensel

    2010-01-01

    Nature education is an important part of early childhood education. As young children develop, the natural world offers concrete and authentic learning experiences. Activities focused on nature support learning in all developmental domains. Children develop physically through hiking in natural terrain, climbing hills and trees, balancing on logs,…

  16. Making the Most of College: Students Speak Their Minds.

    ERIC Educational Resources Information Center

    Light, Richard J.

    Based on 10 years of interviews with 1,600 Harvard students, this book offers concrete advice on choosing classes, talking productively with advisors, improving writing and study skills, maximizing the value of research assignments, and connecting learning inside the classroom with the rest of life. The chapters are: (1) "Introduction";…

  17. Composing Science: A Facilitator's Guide to Writing in the Science Classroom

    ERIC Educational Resources Information Center

    Elliott, Leslie Atkins; Jaxon, Kim; Salter, Irene

    2016-01-01

    Offering expertise in the teaching of writing (Kim Jaxon) and the teaching of science (Leslie Atkins Elliott and Irene Salter), this book will help instructors create classrooms in which students use writing to learn and think scientifically. The authors provide concrete approaches for engaging students in practices that mirror the work that…

  18. Youth at Risk: A Prevention Resource for Counselors, Teachers, and Parents. Fourth Edition.

    ERIC Educational Resources Information Center

    Capuzzi, David, Ed.; Gross, Douglas R., Ed.

    The fourth revision of this text offers both tested prevention strategies for work with diverse at-risk populations and counseling techniques that address the complexities of destructive behavior from individual, family, school, and community perspectives. Drawing on the wisdom of 24 experts, this book provides concrete advice for creating and…

  19. Using a Faith Development Model in College Counseling

    ERIC Educational Resources Information Center

    Stanard, Rebecca Powell; Painter, Linda C.

    2004-01-01

    The impact of faith on counseling outcomes has been a topic of interest in recent years, however many counselors are not familiar with faith development theory and little practical information on how to integrate that theory into practice is available. This article reviews Fowler's (1981) theory of faith development and offers concrete suggestions…

  20. Cost optimization of reinforced concrete cantilever retaining walls under seismic loading using a biogeography-based optimization algorithm with Levy flights

    NASA Astrophysics Data System (ADS)

    Aydogdu, Ibrahim

    2017-03-01

    In this article, a new version of a biogeography-based optimization algorithm with Levy flight distribution (LFBBO) is introduced and used for the optimum design of reinforced concrete cantilever retaining walls under seismic loading. The cost of the wall is taken as an objective function, which is minimized under the constraints implemented by the American Concrete Institute (ACI 318-05) design code and geometric limitations. The influence of peak ground acceleration (PGA) on optimal cost is also investigated. The solution of the problem is attained by the LFBBO algorithm, which is developed by adding Levy flight distribution to the mutation part of the biogeography-based optimization (BBO) algorithm. Five design examples, of which two are used in literature studies, are optimized in the study. The results are compared to test the performance of the LFBBO and BBO algorithms, to determine the influence of the seismic load and PGA on the optimal cost of the wall.

  1. Water-Rock Interaction Simulations of Iron Oxide Mobilization and Precipitation: Implications of Cross-diffusion Reactions for Terrestrial and Mars 'Blueberry' Hematite Concretions

    NASA Astrophysics Data System (ADS)

    Park, A. J.; Chan, M. A.; Parry, W. T.

    2005-12-01

    Modeling of how terrestrial concretions form can provide valuable insights into understanding water-rock interactions that led to the formation of hematite concretions at Meridiani Planum, Mars. Numerical simulations of iron oxide concretions in the Jurassic Navajo Sandstone of southern Utah provide physical and chemical input parameters for emulating conditions that may have prevailed on Mars. In the terrestrial example, iron oxide coatings on eolian sand grains are reduced and mobilized by methane or petroleum. Precipitation of goethite or hematite occurs as Fe interacts with oxygen. Conditions that produced Navajo Sandstone concretions can range from a regional scale that is strongly affected by advection of large pore volumes of water, to small sub-meter scale features that are dominantly controlled by diffusive processes. Hematite concretions are results of a small-scale cross-diffusional process, where Fe and oxygen are supplied from two opposite sides from the 'middle' zone of mixing where concretions precipitate. This is an ideal natural system where Liesegang banding and other self-organized patterns can evolve. A complicating variable here is the sedimentologic (both mineralogic and textural) heterogeneity that, in reality, may be the key factor controlling the nucleation and precipitation habits (including possible competitive growth) of hematite concretions. Sym.8 water-rock interaction simulator program was used for the Navajo Sandstone concretions. Sym.8 is a water-rock simulator that accounts for advective and diffusive mass-transfer, and equilibrium and kinetic reactions. The program uses a dynamic composite media texture model to address changing sediment composition and texture to be consistent with the reaction progress. Initial one-dimensional simulation results indicate precipitation heterogeneity in the range of sub-meters, e.g., possible banding and distribution of iron oxide nodules may be centimeters apart for published diffusivities and water chemistries of the solutes involved. This modeling effort underscores the importance of coupled reactions and mass-transfer in formation of iron oxide concretions in both terrestrial and Mars sediments. Methane is interpreted to be the reactive agent that mobilizes iron in Navajo Sandstone. On Mars volatile volcanic gases may be the reactive agents that mobilize iron from volcanic sediments. In both cases, subsequent diffusive and advective mass-transfer coupled to nonlinear chemical reactions produces localized precipitates.

  2. Elasticity Modulus and Flexural Strength Assessment of Foam Concrete Layer of Poroflow

    NASA Astrophysics Data System (ADS)

    Hajek, Matej; Decky, Martin; Drusa, Marian; Orininová, Lucia; Scherfel, Walter

    2016-10-01

    Nowadays, it is necessary to develop new building materials, which are in accordance to the principles of the following provisions of the Roads Act: The design of road is a subject that follows national technical standards, technical regulations and objectively established results of research and development for road infrastructure. Foam concrete, as a type of lightweight concrete, offers advantages such as low bulk density, thermal insulation and disadvantages that will be reduced by future development. The contribution focuses on identifying the major material characteristics of foam concrete named Poroflow 17-5, in order to replace cement-bound granular mixtures. The experimental measurements performed on test specimens were the subject of diploma thesis in 2015 and continuously of the dissertation thesis and grant research project. At the beginning of the contribution, an overview of the current use of foam concrete abroad is elaborated. Moreover, it aims to determine the flexural strength of test specimens Poroflow 17-5 in combination with various basis weights of the underlying geotextile. Another part of the article is devoted to back-calculation of indicative design modulus of Poroflow based layers based on the results of static plate load tests provided at in situ experimental stand of Faculty of Civil Engineering, University of Žilina (FCE Uniza). Testing stand has been created in order to solve problems related to research of road and railway structures. Concern to building construction presents a physical homomorphic model that is identical with the corresponding theory in all structural features. Based on the achieved material characteristics, the tensile strength in bending of previously used road construction materials was compared with innovative alternative of foam concrete and the suitability for the base layers of pavement roads was determined.

  3. The Morality of University Decision-Makers

    ERIC Educational Resources Information Center

    Hatier, Cécile

    2014-01-01

    Ethical failures in UK higher education have recently made the news but are not a recent development. University decision-makers can, in order to adopt an ethical way of reasoning, resort to several ethical traditions. This article focuses, through the use of concrete examples, on three which have had a significant impact in recent higher…

  4. Cultura, Identidad y Aprendizaje en la Edad Pre-escolar.

    ERIC Educational Resources Information Center

    Engelbrecht, Guillermina; Moyer, Joan

    1987-01-01

    Maintains that it is not the volume of information about diverse groups that will help children develop attitudes of respect and appreciation of differences; rather, it is the skill of processing such information in a positive manner. Concrete examples illustrate the different process skills which should be introduced in school. (Author/BB)

  5. Using the Music Industry To Teach Economic Principles.

    ERIC Educational Resources Information Center

    Stamm, K. Brad

    The key purpose of this paper is to provide economics and business professors, particularly those teaching principles courses, with concrete examples of economic theory applied to the music industry. A second objective is to further the interest in economic theory among business majors and expose non-majors to economic principles via real world…

  6. Assessing Institutional Frameworks of Inter- and Transdisciplinary Research and Education

    ERIC Educational Resources Information Center

    Weiss, Gerhard; Steiner, Regina; Eckmullner, Otto

    2011-01-01

    This paper presents a concept for analysing the bearing of institutional settings on inter- and transdisciplinary research and education for sustainable development and applies it to a concrete case example. It asks in how far the funding programme requirements and the institutional project arrangements impacted on the research process and project…

  7. Functions of Japanese Exemplifying Particles in Spoken and Written Discourse

    ERIC Educational Resources Information Center

    Taylor, Yuki Io

    2010-01-01

    This dissertation examines how the Japanese particles "nado", "toka", and "tari" which all may be translated as "such as", "etc.", or "like" behave differently in written and spoken discourse. According to traditional analyses (e.g. Martin, 1987), these particles are assumed to be Exemplifying Particles (EP) used to provide concrete examples to…

  8. Using the Concept Attainment Strategy to Enhance Reading Comprehension

    ERIC Educational Resources Information Center

    Boulware, Beverly J.; Crow, Mary Lynn

    2008-01-01

    The Concept Attainment Strategy is an instructional technique proposed by Jerome Bruner that targets the "big idea" or concept underlining concrete or abstract examples. This strategy focuses on the developing comprehension of words and ideas associated with a concept rather than on its name or what the concept is called. Specifically it develops…

  9. (abstract) Cross with Your Spectra? Cross-Correlate Instead!

    NASA Technical Reports Server (NTRS)

    Beer, Reinhard

    1994-01-01

    The use of cross-correlation for certain types of spectral analysis is discussed. Under certain circumstances, the use of cross-correlation between a real spectrum and either a model or another spectrum can provide a very powerful tool for spectral analysis. The method (and its limitations) will be described with concrete examples using ATMOS data.

  10. Bridging the Gap between Theory and Practice in Educational Research: Methods at the Margins

    ERIC Educational Resources Information Center

    Winkle-Wagner, Rachelle, Ed.; Hunter, Cheryl A., Ed.; Ortloff, Debora Hinderliter, Ed.

    2009-01-01

    This book provides new ways of thinking about educational processes, using quantitative and qualitative methodologies. Concrete examples of research techniques are provided for those conducting research with marginalized populations or about marginalized ideas. This volume asserts theoretical models related to research methods and the study of…

  11. Case study #3 -- severe scaling of an interstate bridge deck, and Potentially reactive carbonate aggregates, progress report #6 (partial): an example of bridge deterioration promoted by alkali-carbonate reaction.

    DOT National Transportation Integrated Search

    1971-01-01

    The project designated "Concrete Durability Studies" comprises case studies of unusual durability, either in kind or extent. These case studies are directed toward situations in which appearances suggest materials or construction rather than structur...

  12. On the Concrete Nature of Human Thinking: Content and Context in Analogical Transfer.

    ERIC Educational Resources Information Center

    Reeves, Lauretta M.; Weisberg, Robert W.

    1993-01-01

    Asserts that the development of abstract knowledge and critical thinking skills has been extolled as a primary goal of education. Reviews research in problem solving and other educational endeavors. Maintains that learning abstract solution principles is enhanced when instruction is accompanied by examples illustrating those principles. (ACM)

  13. Promoting Learning of Instructional Design via Overlay Design Tools

    ERIC Educational Resources Information Center

    Carle, Andrew Jacob

    2012-01-01

    I begin by introducing Virtual Design Apprenticeship (VDA), a learning model--built on a solid foundation of education principles and theories--that promotes learning of design skills via overlay design tools. In VDA, when an individual needs to learn a new design skill or paradigm she is provided accessible, concrete examples that have been…

  14. The Symmetry Group of the Permutahedron

    ERIC Educational Resources Information Center

    Crisman, Karl-Dieter

    2011-01-01

    Although it can be visualized fairly easily and its symmetry group is easy to calculate, the permutahedron is a somewhat neglected combinatorial object. We propose it as a useful case study in abstract algebra. It supplies concrete examples of group actions, the difference between right and left actions, and how geometry and algebra can work…

  15. Computational Literacy and "The Big Picture" Concerning Computers in Mathematics Education

    ERIC Educational Resources Information Center

    diSessa, Andrea A.

    2018-01-01

    This article develops some ideas concerning the "big picture" of how using computers might fundamentally change learning, with an emphasis on mathematics (and, more generally, STEM education). I develop the big-picture model of "computation as a new literacy" in some detail and with concrete examples of sixth grade students…

  16. Organization Development: Its Nature, Origins, and Prospects.

    ERIC Educational Resources Information Center

    Bennis, Warren G.

    A primer on organization development (OD), this book presents a basic statement for people in organizations and for practitioners and students of OD. Many concrete examples are included. After a definition of OD, the basic conditions which create the need for OD are discussed: rapid change, growth in size, increasing diversity, change in…

  17. Cultivating Preservice Secondary Teachers for Project-Based Learning: A Four-Step Model

    ERIC Educational Resources Information Center

    Zhang, Gaoming; Ridgway, Angelia J.; Sachs, Deb

    2015-01-01

    This article describes four different mechanisms for preparing teacher candidates from a liberal arts institution to teach in project based learning (PBL) classrooms: Observe it, Experience it, Create it, and Become it. For each of the four mechanisms, the authors also provide concrete examples of candidates' PBL experiences and candidates'…

  18. The Case Method in Teacher Education: Alaskan Models. ERIC Digest.

    ERIC Educational Resources Information Center

    Kleinfeld, Judith

    This ERIC digest discusses the theoretical basis of case teaching and examines its strengths and limitations as a tool for teacher education. Case teaching presents authentic, concrete teaching problems for students to analyze. The study of a classroom fight, for example, might draw discussion of racial, ethical, political, and other community…

  19. A Conceptual Systems Model to Facilitate Hypothesis-driven Ecotoxicogenomics Research on the Teleost Brain-pituitary-gonadal Axis

    EPA Science Inventory

    This provides an overview of a novel open-source conceptuial model of molecular and biochemical pathways involved in the regulation of fish reproduction. Further, it provides concrete examples of how such models can be used to design and conduct hypothesis-driven "omics" experim...

  20. Emotion and Rhythm in Critical Learning Incidents

    ERIC Educational Resources Information Center

    Soini, Hannu; Flynn, Mark

    2005-01-01

    In this paper, we analyzed the descriptions of learning provided by 234 College of Education students from Finland and Canada and compared them with Whitehead's (1932/1962) epistemological theory of the rhythm of mental growth. The students were asked to "Give a concrete example of a situation in which you really learned something." The…

  1. [Who is interested in quick and intentional death--reflections of a public health economist].

    PubMed

    Oggier, W

    2001-12-06

    Healthcare economics deals with the concepts of direct, indirect and intangible costs and the interrelated timeframes. Using two concrete examples, the author will examine the utilization patterns of direct and indirect costs and take a look at the participants who might be interested in a quick and intentional death.

  2. Lithography of Polymer Nanostructures on Glass for Teaching Polymer Chemistry and Physics

    ERIC Educational Resources Information Center

    Sahar-Halbany, Adi; Vance, Jennifer M.; Drain, Charles Michael

    2011-01-01

    As nanolithography becomes increasingly important in technology and daily life, a variety of inexpensive and creative methods toward communicating the concepts underpinning these processes in the classroom are necessary. An experiment is described that uses simple CD-Rs, C-clamps, an oven, and a freezer to provide concrete examples and insights…

  3. The Interpersonal Conflict Episode: A Systems Model.

    ERIC Educational Resources Information Center

    Slawski, Carl

    A detailed systems diagram elaborates the process of dealing with a single conflict episode between two parties or persons. Hypotheses are fully stated to lead the reader through the flow diagram. A concrete example illustrates its use. Detail is provided in an accounting scheme of virtually all possible variables to consider in analyzing a…

  4. Teaching Conversations with the XDS Sigma 7.

    ERIC Educational Resources Information Center

    Bork, Alfred M.; And Others

    A manual describes the use of graphic commands in student-computer dialogues. How to construct axes, windows, boxes and various other computer displays is explained, in particular reference to the ARDS 100 and TEKTRONIX 4002 and 4010 computer terminals. Concrete examples of displays are included. The appendix contains an explanation of the use of…

  5. Integrating the Performing Arts in Grades K-5

    ERIC Educational Resources Information Center

    Rajan, Rekha S.

    2012-01-01

    Research documents that the arts boost learning, build confidence, and motivate students to participate in class. How do we keep the performing arts alive in this era of increased accountability and decreased funding? Rekha S. Rajan sets the stage for a creative and practical solution with detailed, concrete examples of how to integrate the…

  6. Career Management for Scientists and Engineers

    NASA Astrophysics Data System (ADS)

    Borchardt, John K.

    2000-05-01

    This book will be an important resource for both new graduates and mid-career scientists, engineers, and technicians. Through taking stock of existing or desired skills and goals, it provides both general advice and concrete examples to help asses a current job situation or prospect, and to effectively pursue and attain new ones. Many examples of properly adapted resumes and interview techniques, as well as plenty of practical advice about adaptation to new workplace cultural paradigms, such as team-based management, make this book an invaluable reference for the professional scientist in today's volatile job market.

  7. Teaching the science of learning.

    PubMed

    Weinstein, Yana; Madan, Christopher R; Sumeracki, Megan A

    2018-01-01

    The science of learning has made a considerable contribution to our understanding of effective teaching and learning strategies. However, few instructors outside of the field are privy to this research. In this tutorial review, we focus on six specific cognitive strategies that have received robust support from decades of research: spaced practice, interleaving, retrieval practice, elaboration, concrete examples, and dual coding. We describe the basic research behind each strategy and relevant applied research, present examples of existing and suggested implementation, and make recommendations for further research that would broaden the reach of these strategies.

  8. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Li, Mo; Nakshatrala, Kalyana; William, Kasper

    The objective of this project is to develop a new class of multifunctional concrete materials (MSCs) for extended spent nuclear fuel (SNF) storage systems, which combine ultra-high damage resistance through strain-hardening behavior with distributed multi-dimensional damage self-sensing capacity. The beauty of multifunctional concrete materials is two-fold: First, it serves as a major material component for the SNF pool, dry cask shielding and foundation pad with greatly improved resistance to cracking, reinforcement corrosion, and other common deterioration mechanisms under service conditions, and prevention from fracture failure under extreme events (e.g. impact, earthquake). This will be achieved by designing multiple levels ofmore » protection mechanisms into the material (i.e., ultrahigh ductility that provides thousands of times greater fracture energy than concrete and normal fiber reinforced concrete; intrinsic cracking control, electrochemical properties modification, reduced chemical and radionuclide transport properties, and crack-healing properties). Second, it offers capacity for distributed and direct sensing of cracking, strain, and corrosion wherever the material is located. This will be achieved by establishing the changes in electrical properties due to mechanical and electrochemical stimulus. The project will combine nano-, micro- and composite technologies, computational mechanics, durability characterization, and structural health monitoring methods, to realize new MSCs for very long-term (greater than 120 years) SNF storage systems.« less

  9. Final Technical Report HFC Concrete: A Low­Energy, Carbon-Dioxide­Negative Solution for reducing Industrial Greenhouse Gas Emissions

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dr. Larry McCandlish, Principal Investigator; Dr. Richard Riman, Co-Principal Investigator

    2012-05-14

    Solidia/CCSM received funding for further research and development of its Low Temperature Solidification Process (LTS), which is used to create hydrate-free concrete (HFC). LTS/HFC is a technology/materials platform that offers wide applicability in the built infrastructure. Most importantly, it provides a means of making concrete without Portland cement. Cement and concrete production is a major consumer of energy and source of industrial greenhouse gas (GHG) emissions. The primary goal of this project was to develop and commercialize a novel material, HFC, which by replacing traditional concrete and cement, reduces both energy use and GHG emissions in the built infrastructure. Traditionalmore » concrete uses Portland Cement (PC) as a binder. PC production involves calcination of limestone at {approx}1450 C, which releases significant amounts of CO{sub 2} gas to the atmosphere and consumes a large amount of energy due to the high temperature required. In contrast, HFC is a carbonate-based hydrate-free concrete (HFC) that consumes CO{sub 2} gas in its production. HFC is made by reaction of silicate minerals with CO{sub 2} at temperatures below 100 C, more than an order-of-magnitude below the temperature required to make PC. Because of this significant difference in temperature, it is estimated that we will be able to reduce energy use in the cement and concrete industry by up to 30 trillion Btu by 2020. Because of the insulating properties of HFC, we believe we will also be able to significantly reduce energy use in the Building sector, though the extent of this saving is not yet quantified. It is estimated that production of a tonne of PC-based concrete requires about 6.2 million Btu of energy and produces over 1 tonne of CO{sub 2} emissions (Choate, 2003). These can be reduced to 1.9 million Btu and 0.025 tonnes of CO{sub 2} emissions per tonne of HFC (with overall CO{sub 2}-negativity possible by increasing carbonation yield). In this way, by replacing PC-based concrete with HFC in infrastructure we can reduce energy use in concrete production by 70%, and reduce CO{sub 2} emissions by 98%; thus the potential to reduce the impact of building materials on global warming and climate change is highly significant. Low Temperature Solidification (LTS) is a breakthrough technology that enables the densification of inorganic materials via a hydrothermal process. The resulting product exhibits excellent control of chemistry and microstructure, to provide durability and mechanical performance that exceeds that of concrete or natural stone. The technology can be used in a wide range of applications including facade panels, interior tiles, roof tiles, countertops, and pre-cast concrete. Replacing traditional building materials and concrete in these applications will result in significant reduction in both energy consumption and CO{sub 2} emissions.« less

  10. A Simple Demonstration of Concrete Structural Health Monitoring Framework

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mahadevan, Sankaran; Agarwal, Vivek; Cai, Guowei

    Assessment and management of aging concrete structures in nuclear power plants require a more systematic approach than simple reliance on existing code margins of safety. Structural health monitoring of concrete structures aims to understand the current health condition of a structure based on heterogeneous measurements to produce high confidence actionable information regarding structural integrity that supports operational and maintenance decisions. This ongoing research project is seeking to develop a probabilistic framework for health diagnosis and prognosis of aging concrete structures in a nuclear power plant subjected to physical, chemical, environment, and mechanical degradation. The proposed framework consists of four elements—damagemore » modeling, monitoring, data analytics, and uncertainty quantification. This report describes a proof-of-concept example on a small concrete slab subjected to a freeze-thaw experiment that explores techniques in each of the four elements of the framework and their integration. An experimental set-up at Vanderbilt University’s Laboratory for Systems Integrity and Reliability is used to research effective combination of full-field techniques that include infrared thermography, digital image correlation, and ultrasonic measurement. The measured data are linked to the probabilistic framework: the thermography, digital image correlation data, and ultrasonic measurement data are used for Bayesian calibration of model parameters, for diagnosis of damage, and for prognosis of future damage. The proof-of-concept demonstration presented in this report highlights the significance of each element of the framework and their integration.« less

  11. Socratic Circles in World History: Reflections on a Year in Dialogue

    ERIC Educational Resources Information Center

    Thomas, Corey; Goering, Christian Z.

    2018-01-01

    This article examines and offers insights to a year of Socratic circles in the context of a world history classroom. Grounding this practice in relevant research before offering examples from the classroom and providing advice to practitioners, this discussion strategy offers an antidote to the often divisive and destructive examples of…

  12. Training Skills: A Rating Scale. National Project on Career Education.

    ERIC Educational Resources Information Center

    Egelston-Dodd, Judy

    This manual describes a system for assessing training readiness of state National Project on Career Education (NPCE) trainers who will deliver inservice training to educators of the deaf in career education and planning skills. Each of three sections offers an explanation and concrete scenario for one of the three skill areas included on the…

  13. Learning Gardens: New York's GreenBranches Program Links the Library to the Street

    ERIC Educational Resources Information Center

    Kuzyk, Raya

    2007-01-01

    To the individual, garden areas link to the natural world, offering solace, refuge, inspiration, and purpose. To a low-income neighborhood, where often the only greenery sprouts from between cracks in concrete, their impact can be monumental, signaling sustainability, beautifying, attesting to value and worth--even prompting civic change. A 2000…

  14. The Grieving Process in Children: Strategies for Understanding, Educating, and Reconciling Children's Perceptions of Death.

    ERIC Educational Resources Information Center

    Willis, Clarissa A.

    2002-01-01

    Provides an overview of how young children understand death, and offers concrete strategies for talking to children about death and suggestions for teachers about how to help children of various ages through grief and mourning. Highlights developmental differences in four components of children's understanding of death: irreversibility, finality,…

  15. Understanding the Youngest Children: How to Build a Deep Awareness of the Toddler with Parents and Caregivers

    ERIC Educational Resources Information Center

    Holtvluwer, Nichole

    2015-01-01

    Nichole Holtvluwer writes for fellow guides who work in the toddler community. Recognizing that communication with parents is the most important path to serving the child, Holtvluwer offers concrete advice beginning with the guide's most important stance: withholding judgment. She details four steps to working with parents or caregivers: building…

  16. Interactive Learning with Java Applets: Using Interactive, Web-Based Java Applets to Present Science in a Concrete, Meaningful Manner

    ERIC Educational Resources Information Center

    Corder, Greg

    2005-01-01

    Science teachers face challenges that affect the quality of instruction. Tight budgets, limited resources, school schedules, and other obstacles limit students' opportunities to experience science that is visual and interactive. Incorporating web-based Java applets into science instruction offers a practical solution to these challenges. The…

  17. Strategies for Addressing Asthma within a Coordinated School Health Program, with Updated Resources. Revised

    ERIC Educational Resources Information Center

    Centers for Disease Control and Prevention, 2006

    2006-01-01

    This publication offers concrete suggestions for schools working to improve the health and school attendance of students with asthma. The Centers for Disease Control and Prevention (CDC) has identified six strategies for schools and districts to consider when addressing asthma within a coordinated school health program. The six strategies detailed…

  18. Effects of short-term repeated exposure to different flooring surfaces on the behavior and physiology of dairy cattle.

    PubMed

    Schütz, K E; Cox, N R

    2014-05-01

    Dairy cattle managed in some pasture-based systems such as in New Zealand are predominantly kept outdoors all year around, but are often taken off pasture for periods of time in wet weather to avoid soil damage. It is common to keep cattle on concrete surfaces during such "stand-off" practices and we investigated whether the addition of rubber matting onto concrete areas improves the welfare of dairy cattle. Sixteen groups of 5 cows (4 groups/treatment, 5 cows/group) were allocated to 1 of 4 treatments (concrete, 12-mm-thick rubber mat, 24-mm-thick rubber mat, or deep-bedded wood chips) and kept on these surfaces for 18 h/24h for 4 consecutive days (6h on pasture/24h). Each 4-d stand-off period was repeated 4 times (with 7 d of recovery between periods) to study the accumulated effects of repeated stand-off. Lying behavior was recorded continuously during the experiment. Gait score, stride length, hygiene score, live weight, and blood samples for cortisol analysis were recorded immediately before and after each stand-off period. Cows on wood chips spent the most time lying, and cows on concrete spent the least time lying compared with those on other surfaces [wood chips: 10.8h, 24-mm rubber mat: 7.3h, 12-mm rubber mat: 6.0 h, and concrete: 2.8h/18 h, standard error of the difference (SED): 0.71 h]. Cows on concrete spent more time lying during the 6h on pasture, likely compensating for the reduced lying during the stand-off period. Similarly, cows on concrete spent more time lying on pasture between stand-off periods (concrete: 12.1h, 12-mm rubber mat: 11.1h, 24-mm rubber mat: 11.2h, and wood chips: 10.7h/24h, SED: 0.28 h). Cows on concrete had higher gait score and shorter stride length after the 4-d stand-off period compared with cows on the other surface types, suggesting a change in gait pattern caused by discomfort. Cows on rubber mats were almost 3 times dirtier than cows on concrete or wood chips. Cortisol and live weight decreased for all treatment groups during the stand-off period. We observed no major effect of the repeated stand-off exposure. In summary, adding rubber matting onto concrete surfaces for stand-off purposes is beneficial for animal welfare. A well-managed wood chip surface offered the best welfare for dairy cows removed from pasture, and the findings of this study confirm that a concrete surface decreases the welfare of cows removed from pasture. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  19. 12 CFR Appendix A to Part 610 - Examples of Mortgage Loan Originator Activities

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... mechanism function for a specific loan product is communicated without authority to negotiate the rate. (ii... details of that offer. (c) Offering or negotiating a loan for compensation or gain. The following examples illustrate when an employee does or does not offer or negotiate terms of a loan “for compensation or gain...

  20. 12 CFR Appendix A to Subpart F of... - Examples of Mortgage Loan Originator Activities

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... mechanism function for a specific loan product is communicated without authority to negotiate the rate. (ii...) Offering or negotiating a loan for compensation or gain. The following examples illustrate when an employee does or does not offer or negotiate terms of a loan “for compensation or gain.” (1) Offering or...

  1. 12 CFR Appendix A to Part 610 - Examples of Mortgage Loan Originator Activities

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... mechanism function for a specific loan product is communicated without authority to negotiate the rate. (ii... details of that offer. (c) Offering or negotiating a loan for compensation or gain. The following examples illustrate when an employee does or does not offer or negotiate terms of a loan “for compensation or gain...

  2. 12 CFR Appendix A to Subpart B of... - Examples of Mortgage Loan Originator Activities

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... by the bank's loan approval mechanism function for a specific loan product is communicated without... details of that offer. (c) Offering or negotiating a loan for compensation or gain. The following examples illustrate when an employee does or does not offer or negotiate terms of a loan “for compensation or gain...

  3. 12 CFR Appendix A to Subpart F of... - Examples of Mortgage Loan Originator Activities

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... mechanism function for a specific loan product is communicated without authority to negotiate the rate. (ii...) Offering or negotiating a loan for compensation or gain. The following examples illustrate when an employee does or does not offer or negotiate terms of a loan “for compensation or gain.” (1) Offering or...

  4. 12 CFR Appendix A to Subpart F of... - Examples of Mortgage Loan Originator Activities

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... mechanism function for a specific loan product is communicated without authority to negotiate the rate. (ii...) Offering or negotiating a loan for compensation or gain. The following examples illustrate when an employee does or does not offer or negotiate terms of a loan “for compensation or gain.” (1) Offering or...

  5. 12 CFR Appendix A to Subpart B of... - Examples of Mortgage Loan Originator Activities

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... by the bank's loan approval mechanism function for a specific loan product is communicated without... details of that offer. (c) Offering or negotiating a loan for compensation or gain. The following examples illustrate when an employee does or does not offer or negotiate terms of a loan “for compensation or gain...

  6. 12 CFR Appendix A to Subpart B of... - Examples of Mortgage Loan Originator Activities

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... by the bank's loan approval mechanism function for a specific loan product is communicated without... details of that offer. (c) Offering or negotiating a loan for compensation or gain. The following examples illustrate when an employee does or does not offer or negotiate terms of a loan “for compensation or gain...

  7. 12 CFR Appendix A to Part 610 - Examples of Mortgage Loan Originator Activities

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... mechanism function for a specific loan product is communicated without authority to negotiate the rate. (ii... details of that offer. (c) Offering or negotiating a loan for compensation or gain. The following examples illustrate when an employee does or does not offer or negotiate terms of a loan “for compensation or gain...

  8. 12 CFR Appendix A to Subpart F of... - Examples of Mortgage Loan Originator Activities

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... mechanism function for a specific loan product is communicated without authority to negotiate the rate. (ii...) Offering or negotiating a loan for compensation or gain. The following examples illustrate when an employee does or does not offer or negotiate terms of a loan “for compensation or gain.” (1) Offering or...

  9. 12 CFR Appendix A to Subpart B of... - Examples of Mortgage Loan Originator Activities

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... by the bank's loan approval mechanism function for a specific loan product is communicated without... details of that offer. (c) Offering or negotiating a loan for compensation or gain. The following examples illustrate when an employee does or does not offer or negotiate terms of a loan “for compensation or gain...

  10. Phosphorylation of serine residues is fundamental for the calcium-binding ability of Orchestin, a soluble matrix protein from crustacean calcium storage structures.

    PubMed

    Hecker, Arnaud; Testenière, Olivier; Marin, Frédéric; Luquet, Gilles

    2003-01-30

    Orchestia cavimana is a terrestrial crustacean, which cyclically stores calcium in diverticula of the midgut, in the form of calcified amorphous concretions. These concretions are associated with a proteinaceous matrix, the main constituent of the soluble matrix is Orchestin, an acidic calcium-binding protein [Testenière et al., Biochem. J. 361 (2002) 327-335]. In the present paper, we clearly demonstrate that Orchestin is phosphorylated on serine and tyrosine residues, but that calcium binding only occurs via the phosphoserine residues. To our knowledge, this is the first example of an invertebrate mineralization for which a post-translational modification is clearly related to an important function of a calcifying protein.

  11. Strengthening Clean Energy Technology Cooperation under the UNFCCC: Steps toward Implementation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Benioff, R.; de Coninck, H.; Dhar, S.

    2010-08-01

    Development of a comprehensive and effective global clean technology cooperation framework will require years of experimenting and evaluation with new instruments and institutional arrangements before it is clear what works on which scale and in which region or country. In presenting concrete examples, this paper aims to set the first step in that process by highlighting successful models and innovative approaches that can inform efforts to ramp up clean energy technology cooperation. This paper reviews current mechanisms and international frameworks for global cooperation on clean energy technologies, both within and outside of the UNFCCC, and provides selected concrete options formore » scaling up global cooperation on clean energy technology RD&D, enabling environment, and financing.« less

  12. The Contribution of Stuart Hall to Analyzing Educational Policy and Reform

    ERIC Educational Resources Information Center

    Gandin, Luis Armando

    2015-01-01

    This article focuses on the contribution of Stuart Hall to the study of educational policy and reform, using the experience of the Citizen School initiative in Porto Alegre, Brazil as a concrete example. This experience was a participatory educational reform implemented during the 16 years of the Workers' Party tenure in Porto Alegre's municipal…

  13. Scale-Free Nonparametric Factor Analysis: A User-Friendly Introduction with Concrete Heuristic Examples.

    ERIC Educational Resources Information Center

    Mittag, Kathleen Cage

    Most researchers using factor analysis extract factors from a matrix of Pearson product-moment correlation coefficients. A method is presented for extracting factors in a non-parametric way, by extracting factors from a matrix of Spearman rho (rank correlation) coefficients. It is possible to factor analyze a matrix of association such that…

  14. Building Resiliency: How To Thrive in Times of Change. An Ideas into Action Guidebook.

    ERIC Educational Resources Information Center

    Pulley, Mary Lynn; Wakefield, Michael

    This is a practicing managers' guide for gaining the ability to thrive during change, for leaders of any kind of organization. Resiliency is defined, its components described, and its importance explained. Concrete examples of resiliency and questions that can determine degree of resiliency are provided. Resiliency is not described as being…

  15. Potholes and (In) Geography: Studying State Shapes in the Neighborhood

    ERIC Educational Resources Information Center

    Albert, Donald

    2015-01-01

    This activity is an amusing, but serious exploration into the idea of shapes for grades 4-8. Its purpose is to encourage students to begin thinking about shapes using concrete (and asphalt) examples from their immediate surroundings (i.e., street, block, neighborhood) while enhancing their mental image of world geography. Rather than allowing all…

  16. Using Explicit C-R-A Instruction to Teach Fraction Word Problem Solving to Low-Performing Asian English Learners

    ERIC Educational Resources Information Center

    Kim, Sun A.; Wang, Peishi; Michaels, Craig A.

    2015-01-01

    This article investigates the effects of fraction word problem-solving instruction involving explicit teaching of the concrete-representational-abstract sequence with culturally relevant teaching examples for 3 low-performing Asian immigrant English learners who spoke a language other than English at home. We used a multiple probe design across…

  17. Thinking outside the Box Office: Using Movies to Build Shared Experiences and Student Engagement in Online or Hybrid Learning

    ERIC Educational Resources Information Center

    Kresse, William; Watland, Kathleen Hanold

    2016-01-01

    Movies and films are widely recognized as valuable pedagogical tools. Motion pictures provide concrete and illustrative examples of important concepts and can improve students' understanding of course material as well as increase their satisfaction with courses. Online learning is becoming an increasing dominant facet of higher education. Online…

  18. The Use of PBL in an Interprofessional Education Course for Health Care Professional Students

    ERIC Educational Resources Information Center

    L'Ecuyer, Kristine; Pole, David; Leander, Sheila A.

    2015-01-01

    A problem-based learning (PBL) framework was utilized in a series of six interprofessional team seminars (IPTS) for postbaccalaureate students from seven health professions. The goal of IPTS was to develop a collaborative practice-ready workforce prepared to respond to patient care needs through use of concrete examples, skills development,…

  19. Is Educational Equity Being Addressed in Proposed Standards for Students, Teachers and Schools?

    ERIC Educational Resources Information Center

    Malcom, Shirley M.

    Equity was an invisible issue in the recent reports calling for higher pre-college standards and increased Federal spending on education. Although usually mentioned, equity was part of the (political) rhetoric, not a concrete goal. In "A Nation at Risk," for example, minority and handicapped students are discussed, but with the implication that…

  20. Reduce, Reuse, Recycle: Resources and Strategies for the Use of Writing Projects in Mathematics

    ERIC Educational Resources Information Center

    Latulippe, Joe; Latulippe, Christine

    2014-01-01

    As an often recommended but under-utilized pedagogical strategy, writing in mathematics has many benefits for students. However, creating and grading worthwhile writing projects can be more time-consuming than utilizing more traditional forms of assessment. This paper provides a concrete example of a writing project prompt, questions, directions,…

  1. The Physics of a Walking Robot

    ERIC Educational Resources Information Center

    Guemez, J.; Fiolhais, M.

    2013-01-01

    The physics of walking is explored, using a toy as a concrete example and a "toy model" applied to it. Besides using Newton's second law, the problem is also discussed from the thermodynamical perspective. Once the steady state (constant velocity) is achieved, we show that the internal energy of the toy is dissipated as heat in the…

  2. Non-equilibrium dog-flea model

    NASA Astrophysics Data System (ADS)

    Ackerson, Bruce J.

    2017-11-01

    We develop the open dog-flea model to serve as a check of proposed non-equilibrium theories of statistical mechanics. The model is developed in detail. Then it is applied to four recent models for non-equilibrium statistical mechanics. Comparison of the dog-flea solution with these different models allows checking claims and giving a concrete example of the theoretical models.

  3. Using biological and physico-chemical test methods to assess the role of concrete mixture design in resistance to microbially induced corrosion

    NASA Astrophysics Data System (ADS)

    House, Mitchell Wayne

    Concrete is the most widely used material for construction of wastewater collection, storage, and treatment infrastructure. The chemical and physical characteristics of hydrated portland cement make it susceptible to degradation under highly acidic conditions. As a result, some concrete wastewater infrastructure may be susceptible to a multi-stage degradation process known as microbially induced corrosion, or MIC. MIC begins with the production of aqueous hydrogen sulfide (H2S(aq)) by anaerobic sulfate reducing bacteria present below the waterline. H2S(aq) partitions to the gas phase where it is oxidized to sulfuric acid by the aerobic sulfur oxidizing bacteria Thiobacillus that resides on concrete surfaces above the waterline. Sulfuric acid then attacks the cement paste portion of the concrete matrix through decalcification of calcium hydroxide and calcium silica hydrate coupled with the formation of expansive corrosion products. The attack proceeds inward resulting in reduced service life and potential failure of the concrete structure. There are several challenges associated with assessing a concrete's susceptibility to MIC. First, no standard laboratory tests exist to assess concrete resistance to MIC. Straightforward reproduction of MIC in the laboratory is complicated by the use of microorganisms and hydrogen sulfide gas. Physico-chemical tests simulating MIC by immersing concrete specimens in sulfuric acid offer a convenient alternative, but do not accurately capture the damage mechanisms associated with biological corrosion. Comparison of results between research studies is difficult due to discrepancies that can arise in experimental methods even if current ASTM standards are followed. This thesis presents two experimental methods to evaluate concrete resistance to MIC: one biological and one physico-chemical. Efforts are made to address the critical aspects of each testing method currently absent in the literature. The first method presented is a new test to evaluate performance of concrete specimens under conditions designed to accelerate MIC. Concrete specimens representing 12 mixture designs were inoculated with 5 species of Thiobacillus bacteria and placed in a biological growth chamber designed to encourage bacterial growth and sulfuric acid production by optimizing temperature, delivering necessary nutrients, and providing hydrogen sulfide gas. Results indicate that using supplementary cementitious materials, limestone aggregates, and sulfate resistant cement can improve resistance to MIC. It is interesting to note that this study showed that unlike many other durability problems the role of water to cement ratio was unclear. The second method presented is a sulfuric acid immersion study designed to evaluate the resistance of 12 concrete mixture designs to 5 concentrations of sulfuric acid. Experimental protocols (like those in ASTM) previously considered trivial were found to have a dramatic effect on experimental results. It was found that using supplementary cementitious materials, limestone coarse aggregate, and sulfate resistant cement can increase concrete resistance to moderate sulfuric acid concentrations. The primary damage mechanism was observed to change depending on sulfuric acid concentration. Rapid deterioration of specimens exposed to aggressive sulfuric acid solutions indicates that degradation of concrete under the most severe MIC conditions (i.e., a pH < 1.0) cannot be prevented by strictly manipulating concrete mixture proportions. A holistic approach is needed for these situations that considers environmental conditions as well.

  4. The influence of loading on the corrosion of steel in cracked ordinary Portland cement and high performance concretes

    NASA Astrophysics Data System (ADS)

    Jaffer, Shahzma Jafferali

    Most studies that have examined chloride-induced corrosion of steel in concrete have focused on sound concrete. However, reinforced concrete is seldom uncracked and very few studies have investigated the influence of cracked concrete on rebar corrosion. Furthermore, the studies that have examined the relationship between cracks and corrosion have focused on unloaded or statically loaded cracks. However, in practice, reinforced concrete structures (e.g. bridges) are often dynamically loaded. Hence, the cracks in such structures open and close which could influence the corrosion of the reinforcing steel. Consequently, the objectives of this project were (i) to examine the effect of different types of loading on the corrosion of reinforcing steel, (ii) the influence of concrete mixture design on the corrosion behaviour and (iii) to provide data that can be used in service-life modelling of cracked reinforced concretes. In this project, cracked reinforced concrete beams made with ordinary Portland cement concrete (OPCC) and high performance concrete (HPC) were subjected to no load, static loading and dynamic loading. They were immersed in salt solution to just above the crack level at their mid-point for two weeks out of every four (wet cycle) and, for the remaining two weeks, were left in ambient laboratory conditions to dry (dry cycle). The wet cycle led to three conditions of exposure for each beam: (i) the non-submerged region, (ii) the sound, submerged region and (iii) the cracked mid-section, which was also immersed in the solution. Linear polarization resistance and galvanostatic pulse techniques were used to monitor the corrosion in the three regions. Potentiodynamic polarization, electrochemical current noise and concrete electrical resistance measurements were also performed. These measurements illustrated that (i) rebar corroded faster at cracks than in sound concrete, (ii) HPC was more protective towards the rebar than OPCC even at cracks and (iii) there was a minor effect of the type of loading on rebar corrosion within the period of the project. These measurements also highlighted the problems associated with corrosion measurements, for example, identifying the actual corroding area and the influence of the length of rebar. The numbers of cracks and crack-widths in each beam were measured after the beam's initial exposure to salt solution and, again, after the final corrosion measurements. HPC beams had more cracks than the OPCC. Also, final measurements illustrated increased crack-widths in dynamically loaded beams, regardless of the concrete type. The cracks in both statically and dynamically loaded OPCC and HPC beams bifurcated at the rebar level and propagated parallel to the rebar. This project also examined the extent of corrosion on the rebars and the distribution of corrosion products in the concrete and on the concrete walls of the cracks. Corrosion occurred only at cracks in the concrete and was spread over a larger area on the rebars in HPC than those in OPCC. The damage due to corrosion was superficial in HPC and crater-like in OPCC. Regardless of the concrete type, there was a larger distribution of corrosion products on the crack walls of the dynamically loaded beams. Corrosion products diffused into the cement paste and the paste-aggregate interface in OPCC but remained in the crack in HPC. The most voluminous corrosion product identified was ferric hydroxide. Elemental analysis of mill-scale on rebar which was not embedded in concrete or exposed to chlorides was compared to that of the bars that had been embedded in uncontaminated concrete and in cracked concrete exposed to chlorides. In uncontaminated concrete, mill-scale absorbed calcium and silicon. At a crack, a layer, composed of a mixture of cement paste and corrosion products, developed between the mill-scale and the substrate steel. Based on the results, it was concluded that (i) corrosion occurred on the rebar only at cracks in the concrete, (ii) corrosion was initiated at the cracks immediately upon exposure to salt solution, (ii) the type of loading had a minor influence on the corrosion rates of reinforcing steel and (iv) the use of polarized area led to a significant underestimation of the current density at the crack. It is recommended that the effect of cover-depth on (i) the time to initiation of corrosion and (ii) the corrosion current density in cracked concrete be investigated.

  5. Colour and toxic characteristics of metakaolinite–hematite pigment for integrally coloured concrete, prepared from iron oxide recovered from a water treatment plant of an abandoned coal mine

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sadasivam, Sivachidambaram, E-mail: sadasivams@cardiff.ac.uk; Thomas, Hywel Rhys

    A metakaolinite-hematite (KH) red pigment was prepared using an ocherous iron oxide sludge recovered from a water treatment plant of an abandoned coal mine. The KH pigment was prepared by heating the kaolinite and the iron oxide sludge at kaolinite's dehydroxylation temperature. Both the raw sludge and the KH specimen were characterised for their colour properties and toxic characteristics. The KH specimen could serve as a pigment for integrally coloured concrete and offers a potential use for the large volumes of the iron oxide sludge collected from mine water treatment plants. - Graphical abstract: A kaolinite based red pigment wasmore » prepared using an ocherous iron oxide sludge recovered from an abandoned coal mine water treatment plant. Display Omitted - Highlights: • A red pigment was prepared by heating a kaolinite and an iron oxide sludge. • The iron oxide and the pigment were characterised for their colour properties. • The red pigment can be a potential element for integrally coloured concrete.« less

  6. High temperature thermal energy storage in steel and sand

    NASA Technical Reports Server (NTRS)

    Turner, R. H.

    1979-01-01

    The technical and economic potential for high temperature (343 C, 650 F) thermal energy storage in hollow steel ingots, pipes embedded in concrete, and for pipes buried in sand was evaluated. Because it was determined that concrete would separate from pipes due to thermal stresses, concrete was replaced by sand, which is free from thermal stresses. Variations of the steel ingot concept were not cost effective compared to the sand-pipe approach, therefore, the sand-pipe thermal storage unit (TSU) was evaluated in depth to assess the approximate tube spacing requirements consistent with different system performance characteristics and also attendant system costs. For large TSUs which do not require fast response times, the sand-pipe approach offers attractive possibilities. A pipe diameter about 9 cm (3.5 in) and pipe spacing of approximately 25 cm (10 in), with sand filling the interspaces, appears appropriate. Such a TSU system designed for 8 hours charge/discharge cycle has an energy unit storage cost (CE) of $2.63/kWhr-t and a power unit storage cost (Cp) of $42/kW-t (in 1977 dollars).

  7. 12 CFR Appendix A to Subpart I of... - Examples of Mortgage Loan Originator Activities

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... loan process; or (D) Only the rate approved by the bank's loan approval mechanism function for a... details of that offer. (c) Offering or negotiating a loan for compensation or gain. The following examples illustrate when an employee does or does not offer or negotiate terms of a loan “for compensation or gain...

  8. 12 CFR Appendix A to Subpart I of... - Examples of Mortgage Loan Originator Activities

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... loan process; or (D) Only the rate approved by the bank's loan approval mechanism function for a... details of that offer. (c) Offering or negotiating a loan for compensation or gain. The following examples illustrate when an employee does or does not offer or negotiate terms of a loan “for compensation or gain...

  9. 12 CFR Appendix A to Subpart I of... - Examples of Mortgage Loan Originator Activities

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... loan process; or (D) Only the rate approved by the bank's loan approval mechanism function for a... details of that offer. (c) Offering or negotiating a loan for compensation or gain. The following examples illustrate when an employee does or does not offer or negotiate terms of a loan “for compensation or gain...

  10. 12 CFR Appendix A to Subpart I of... - Examples of Mortgage Loan Originator Activities

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... loan process; or (D) Only the rate approved by the bank's loan approval mechanism function for a... details of that offer. (c) Offering or negotiating a loan for compensation or gain. The following examples illustrate when an employee does or does not offer or negotiate terms of a loan “for compensation or gain...

  11. Temporality and the torments of time.

    PubMed

    Hinton, Ladson

    2015-06-01

    Immersion in time gives birth to consciousness, as well as conflict and torment. When human beings developed a sense of future, they also gained the ability to anticipate threats from nature or their fellow beings. They thereby created cultures that are bastions of survival, as well as places of poetry, art and religion where they could band together and reflect upon their common plight. The practice of psychoanalysis is in many ways a temporal process, a process of remembering, for owning and elaborating a past that gives us substance, thereby providing a basis for reflective consciousness. Stimulated by Freud's early writings, Lacan, Laplanche and their successors in particular have focussed extensively on time and psychoanalysis, and their views are a central point of this discussion. A substantial case study is offered that provides concrete examples of these perspectives. A multi-faceted view of temporality emerges, one that is more syncopated than linear or teleological. In conclusion, I will briefly discuss recent findings in the neuroscience of memory and 'time travel' that underpin contemporary psychoanalytic ideas in surprising ways. It is important to remember that acceptance of the contradictory nature of temporal experience can open space for increased freedom and playfulness. © 2015, The Society of Analytical Psychology.

  12. How Intersectoral Health Promotion Changes Professional Practices: A Case Study From Denmark.

    PubMed

    Christensen, Mads; Burau, Viola; Ledderer, Loni

    2018-05-01

    Intersectoral health promotion (IHP) has pushed health professions to engage in new tasks and interprofessional ways of working. We studied how care assistants from a nursing home and school teachers implemented a cookery project targeted at children ("Cool Beans") as an example of an IHP project in Denmark. Our aim was to examine the impact of the IHP project on the practices of the professions involved. We used a qualitative case study to investigate joint care and teaching situations with the two professions and their users. Our data consisted of documents, participatory observations, and informal interviews (17 hours) as well as semistructured interviews with professionals (n = 4). We used a sociological institutional framework to analyze the professional practices emerging in joint care and teaching situations and identified three themes of new professional activities: (1) "interplay" related to making different generations collaborate on the tasks involved in the cookery session; (2) "care" concerned with caregiving activities; and (3) "learning" focused on schooling on healthy food and cooking. We conclude that changes in professional practices occurred informally and were induced by the concrete activities in the cookery project. The specific, practical tasks of the IHP project thus offered an important leverage for future interprofessional collaborations.

  13. Religious leaders' opinions and guidance towards oral health maintenance and promotion: a qualitative study.

    PubMed

    Zini, Avraham; Sgan-Cohen, Harold D; Feder-Bubis, Paula

    2015-04-01

    Religions emphasize the supreme value of life. However, potential or concrete conflicts of perception between dictates of faith and science often present an inescapable dilemma. The aim of this qualitative research was to examine the views of spiritual and religious leaders towards general and oral health issues. A total of 11 eminent Jewish spiritual and religious community leaders were purposively chosen. They were interviewed using a semi-structured questionnaire. The verbatim transcriptions of the interviews were analysed in the spirit of grounded theory, using qualitative data analysis software. Open, axial, and thematic coding served to build categories and themes. Analysis of participants' perspectives reflected that they, based upon Jewish theology, attributed high importance to primary prevention at both personal and community levels. Religious and orthodox people were depicted as being motivated towards maintaining oral health behaviours due to a sense of obligation to follow religious edicts, strong social support, and elevated perceived spiritual levels. We offer a theoretical model that can explain the potential high motivation among these communities towards implementing positive general and oral health behaviours. Religiosity may be regarded as an example of a psycho-social health determinant, encompassing spiritual belief ("psycho") and social support ("social") components.

  14. Predictive Analytics for City Agencies: Lessons from Children's Services.

    PubMed

    Shroff, Ravi

    2017-09-01

    Many municipal agencies maintain detailed and comprehensive electronic records of their interactions with citizens. These data, in combination with machine learning and statistical techniques, offer the promise of better decision making, and more efficient and equitable service delivery. However, a data scientist employed by an agency to implement these techniques faces numerous and varied choices that cumulatively can have significant real-world consequences. The data scientist, who may be the only person at an agency equipped to understand the technical complexity of a predictive algorithm, therefore, bears a good deal of responsibility in making judgments. In this perspective, I use a concrete example from my experience of working with New York City's Administration for Children's Services to illustrate the social and technical tradeoffs that can result from choices made in each step of data analysis. Three themes underlie these tradeoffs: the importance of frequent communication between the data scientist, agency leadership, and domain experts; the agency's resources and organizational constraints; and the necessity of an ethical framework to evaluate salient costs and benefits. These themes inform specific recommendations that I provide to guide agencies that employ data scientists and rely on their work in designing, testing, and implementing predictive algorithms.

  15. Letter to Secretary of Education Arne Duncan Concerning Evaluation of Teachers and Principals. NEPC Policy Memo

    ERIC Educational Resources Information Center

    Burris, Carol Corbett; Welner, Kevin G.

    2011-01-01

    This NEPC Policy Memo presents the text of a letter from Drs. Burris and Welner to Secretary of Education Arne Duncan. The letter was invited by Secretary Duncan during a phone conversation with Dr. Burris. It offers concrete guiding principles for evaluation of educators and suggestions for a way forward. (Contains 11 notes.)

  16. Education and Community: The Collaborative Solution. Proceedings of the International Conference Linking Research and Practice (Toronto, Ontario, Canada, March 3-5, 1994).

    ERIC Educational Resources Information Center

    Lawton, Stephen B., Ed.; Tanenzapt, Elaine, Ed.; Townsend, Richard G., Ed.

    These proceedings are divided into two sections that explore collaboration between schools and communities. In Part I, the first four papers, analytic frameworks are described that provide different perspectives on collaboration. In Part II, descriptions of concrete programs and advice for developing better school-community relations are offered.…

  17. Our Bodies, Our Cells: Children's Activities in Body Systems. Children's Activity Series.

    ERIC Educational Resources Information Center

    Cahn, Marilyn

    The supplemental teaching resources provided in this book offer a variety of concrete, visual activities designed to help classroom and daycare center teachers introduce children to the human body and the way it is organized. An analogy comparing human body parts to house parts is used throughout the book to make lessons clear and age-appropriate.…

  18. "We Shall Not Speak of It": Nazism and the Holocaust in the Elementary College German Course.

    ERIC Educational Resources Information Center

    Donahue, William Collins

    1994-01-01

    This article surveys the failure on the part of introductory textbooks, as well as some instructors, to treat Nazism and the Holocaust adequately in the elementary German course. Concrete proposals are made to remedy the situation: three documentary texts are offered that provide an often overlooked perspective on the Third Reich. (Contains 17…

  19. Writing for Change: Research as Public Pedagogy and Arts-Based Activism. Critical Qualitative Research. Volume 8

    ERIC Educational Resources Information Center

    Robson, Claire

    2012-01-01

    In its analysis of the potential and realities of narrative inquiry, "Writing for Change" is both theoretical and highly practical, offering a way to conceptualize this kind of research and providing concrete suggestions as to how it might be conducted. With its emphasis on arts-based activist education, the book also contributes to current…

  20. Finding a Concrete Utopia in the Dystopia of a "Sub-City"

    ERIC Educational Resources Information Center

    Busby, Selina

    2017-01-01

    This article examines a 10-year long series of annual short-term interventions with young people living in Dharavi (India) that has led to a number of public theatre events. The partnership offers a unique training experience to students from the UK in theatre facilitation, and a regular opportunity to participate in theatre for young people in…

  1. Sex and Sensibility: A Parent's Guide to Talking Sense about Sex.

    ERIC Educational Resources Information Center

    Roffman, Deborah M.

    Children who grow up in an atmosphere of openness about sexuality grow up more slowly and more responsibly. This book offers parents a new framework for talking honestly about sex and sexuality with their children. The first part of the book examines new ways of thinking and talking, while the second part addresses concrete ways of raising…

  2. Feeling and Thinking about Studio Practices: Exploring Dissonance in Semi-Structured Interviews with Students in Higher Education Music

    ERIC Educational Resources Information Center

    Burwell, Kim

    2017-01-01

    While studio-based instrumental and vocal learning is widely regarded as both important and effective in higher education music, research to date has offered little concrete information about studio practices that students have regarded as ineffective. Two recent case studies investigated what appear to be exceptional instances in which students…

  3. Changing College Classrooms: New Teaching and Learning Strategies for an Increasingly Complex World. Jossey-Bass Higher and Adult Education Series.

    ERIC Educational Resources Information Center

    Halpern, Diane F., Ed.; And Others

    This volume offers 19 papers by college faculty on concrete information and suggestions for the improvement of college teaching, student learning, and the whole education process. The titles and authors are: (1) "Rethinking College Instruction for a Changing World" (Diane F. Halpern); (2) "Inquiry as a Tool in Critical…

  4. Practical physics behind growing crystals of biological macromolecules.

    PubMed

    Candoni, Nadine; Grossier, Romain; Hammadi, Zoubida; Morin, Roger; Veesler, Stéphane

    2012-07-01

    The aim of this review is to provide biocrystallographers who intend to tackle protein-crystallization with theory and practical examples. Crystallization involves two separate processes, nucleation and growth, which are rarely completely unconnected. Here we give theoretical background and concrete examples illustrating protein crystallization. We describe the nucleation of a new phase, solid or liquid, and the growth and transformation of existing crystals obtained by primary or secondary nucleation or by seeding. Above all, we believe that a thorough knowledge of the phase diagram is vital to the selection of starting position and path for any crystallization experiment.

  5. Multiscale Concrete Modeling of Aging Degradation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hammi, Yousseff; Gullett, Philipp; Horstemeyer, Mark F.

    In this work a numerical finite element framework is implemented to enable the integration of coupled multiscale and multiphysics transport processes. A User Element subroutine (UEL) in Abaqus is used to simultaneously solve stress equilibrium, heat conduction, and multiple diffusion equations for 2D and 3D linear and quadratic elements. Transport processes in concrete structures and their degradation mechanisms are presented along with the discretization of the governing equations. The multiphysics modeling framework is theoretically extended to the linear elastic fracture mechanics (LEFM) by introducing the eXtended Finite Element Method (XFEM) and based on the XFEM user element implementation of Ginermore » et al. [2009]. A damage model that takes into account the damage contribution from the different degradation mechanisms is theoretically developed. The total contribution of damage is forwarded to a Multi-Stage Fatigue (MSF) model to enable the assessment of the fatigue life and the deterioration of reinforced concrete structures in a nuclear power plant. Finally, two examples are presented to illustrate the developed multiphysics user element implementation and the XFEM implementation of Giner et al. [2009].« less

  6. A 3D Lattice Modelling Study of Drying Shrinkage Damage in Concrete Repair Systems

    PubMed Central

    Luković, Mladena; Šavija, Branko; Schlangen, Erik; Ye, Guang; van Breugel, Klaas

    2016-01-01

    Differential shrinkage between repair material and concrete substrate is considered to be the main cause of premature failure of repair systems. The magnitude of induced stresses depends on many factors, for example the degree of restraint, moisture gradients caused by curing and drying conditions, type of repair material, etc. Numerical simulations combined with experimental observations can be of great use when determining the influence of these parameters on the performance of repair systems. In this work, a lattice type model was used to simulate first the moisture transport inside a repair system and then the resulting damage as a function of time. 3D simulations were performed, and damage patterns were qualitatively verified with experimental results and cracking tendencies in different brittle and ductile materials. The influence of substrate surface preparation, bond strength between the two materials, and thickness of the repair material were investigated. Benefits of using a specially tailored fibre reinforced material, namely strain hardening cementitious composite (SHCC), for controlling the damage development due to drying shrinkage in concrete repairs was also examined. PMID:28773696

  7. A 3D Lattice Modelling Study of Drying Shrinkage Damage in Concrete Repair Systems.

    PubMed

    Luković, Mladena; Šavija, Branko; Schlangen, Erik; Ye, Guang; van Breugel, Klaas

    2016-07-14

    Differential shrinkage between repair material and concrete substrate is considered to be the main cause of premature failure of repair systems. The magnitude of induced stresses depends on many factors, for example the degree of restraint, moisture gradients caused by curing and drying conditions, type of repair material, etc. Numerical simulations combined with experimental observations can be of great use when determining the influence of these parameters on the performance of repair systems. In this work, a lattice type model was used to simulate first the moisture transport inside a repair system and then the resulting damage as a function of time. 3D simulations were performed, and damage patterns were qualitatively verified with experimental results and cracking tendencies in different brittle and ductile materials. The influence of substrate surface preparation, bond strength between the two materials, and thickness of the repair material were investigated. Benefits of using a specially tailored fibre reinforced material, namely strain hardening cementitious composite (SHCC), for controlling the damage development due to drying shrinkage in concrete repairs was also examined.

  8. Continuous relaxation and retardation spectrum method for viscoelastic characterization of asphalt concrete

    NASA Astrophysics Data System (ADS)

    Bhattacharjee, Sudip; Swamy, Aravind Krishna; Daniel, Jo S.

    2012-08-01

    This paper presents a simple and practical approach to obtain the continuous relaxation and retardation spectra of asphalt concrete directly from the complex (dynamic) modulus test data. The spectra thus obtained are continuous functions of relaxation and retardation time. The major advantage of this method is that the continuous form is directly obtained from the master curves which are readily available from the standard characterization tests of linearly viscoelastic behavior of asphalt concrete. The continuous spectrum method offers efficient alternative to the numerical computation of discrete spectra and can be easily used for modeling viscoelastic behavior. In this research, asphalt concrete specimens have been tested for linearly viscoelastic characterization. The linearly viscoelastic test data have been used to develop storage modulus and storage compliance master curves. The continuous spectra are obtained from the fitted sigmoid function of the master curves via the inverse integral transform. The continuous spectra are shown to be the limiting case of the discrete distributions. The continuous spectra and the time-domain viscoelastic functions (relaxation modulus and creep compliance) computed from the spectra matched very well with the approximate solutions. It is observed that the shape of the spectra is dependent on the master curve parameters. The continuous spectra thus obtained can easily be implemented in material mix design process. Prony-series coefficients can be easily obtained from the continuous spectra and used in numerical analysis such as finite element analysis.

  9. Development of New Generation of Ceramics for Environmentally Focused Chemical Separations

    NASA Astrophysics Data System (ADS)

    Ramakrishnan, Girish

    This dissertation focuses on the use of composite materials for environmental applications. For the first time, applications of both fresh and aged concrete as inexpensive adsorbents for nitrogen dioxide (NO2) removal is demonstrated. Concrete is the most widely used composite material of the modern era. Cement manufacturing (a major component of concrete) is considered to be one of the leading contributors to air pollution, resulting in 7% of the global carbon dioxide emissions along with a number of other harmful pollutants such as oxides, mercury and particulates. These emissions aide in the formation of acid rain, smog, and toxic ground level ozone, causing detrimental effects such as respiratory illnesses, visibility reduction, eutrification and global warming. This thesis offers a novel and sustainable solution in mitigating NOX emissions, by introducing the significant adsorption potential of recycled concrete. The work is based on both commercially available cement paste and already aged concrete samples, providing truly scalable solutions. The concrete samples aged for different periods of time were exposed to NO2 to measure their adsorption capacity. The results show that all of the concrete samples (fresh and aged) exhibited excellent NO2 adsorption capacity, with the fresh concrete samples removing almost 100% of the NO2. Furthermore, to compare the effects of long term aging, 12 year-old recently demolished concrete samples were obtained and its NOX removal was shown to be almost 60%. The experimental results provide evidence of nitrate and nitrite species formation from chemical reactions occurring between NO2 and surface alkaline species. This important discovery can be utilized for NO2 removal and subsequent NOX sequestered demolished concrete (NSDC) recycling in new concrete, either as a set accelerating admixture or as a corrosion inhibitor, a big leap towards better sustainability and longevity of the new reinforced concrete structures. The rest of this thesis focuses on development of a new generation of ceramic membranes utilizing thermal spray techniques to produce highly scalable and extremely cost effective filtration membranes. Thermal spray method of membrane manufacturing has the advantage of economic scalability (up to tens of square meters) along with performance enhancement as compared to conventional wet casting process. In addition to developing a proof of concept for this approach, several strategies on how to improve ceramic membranes' performance via spraying process optimization are also described. Specifically, several thermal sprayed Alumina membrane samples were prepared by varying different process parameters. These samples were characterized using known techniques and subjected to permeability and size exclusion tests to correlate spraying parameters with membranes' performance. The membrane samples showed excellent clean water flux comparable to commercially available membranes and had rejection rates up to 96%. These results show that the membranes produced in this research achieve outstanding performance at a fraction of the cost of commercially produced membrane, enabling the use of membrane filtrations units in developing countries.

  10. 26 CFR 48.4041-7 - Dual use of taxable liquid fuel.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... or boat. For example, tax applies to diesel fuel sold to operate the mixing unit on a concrete mixer truck if the mixing unit is operated by means of a power take-off from the motor of the vehicle... a preliminary determination of the number of gallons of fuel used to propel the vehicle. In order to...

  11. Discovery Lab in the Chemistry Lecture Room: Design and Evaluation of Audio-Visual Constructivist Methodology of Teaching Descriptive Inorganic Chemistry.

    ERIC Educational Resources Information Center

    Young, Barbara N.; Hoffman, Lyubov

    Demonstration of chemical reactions is a tool used in the teaching of inorganic descriptive chemistry to enable students to understand the fundamental concepts of chemistry through the use of concrete examples. For maximum benefit, students need to learn through discovery to observe, interpret, hypothesize, and draw conclusions; however, chemical…

  12. Fixed Point Theorems for Hybrid Mappings

    PubMed Central

    Kamran, Tayyab; Karapinar, Erdal

    2015-01-01

    We obtain some fixed point theorems for two pairs of hybrid mappings using hybrid tangential property and quadratic type contractive condition. Our results generalize some results by Babu and Alemayehu and those contained therein. In the sequel, we introduce a new notion to generalize occasionally weak compatibility. Moreover, two concrete examples are established to illuminate the generality of our results. PMID:25629089

  13. Virtual Ray Tracing as a Conceptual Tool for Image Formation in Mirrors and Lenses

    ERIC Educational Resources Information Center

    Heikkinen, Lasse; Savinainen, Antti; Saarelainen, Markku

    2016-01-01

    The ray tracing method is widely used in teaching geometrical optics at the upper secondary and university levels. However, using simple and straightforward examples may lead to a situation in which students use the model of ray tracing too narrowly. Previous studies show that students seem to use the ray tracing method too concretely instead of…

  14. Teachers and Students "In the Field": What We Have (re-)Learned from Anthropology.

    ERIC Educational Resources Information Center

    Tinberg, Howard

    Strange as it may seem, the classroom is not, by and large, accepted within the composition discipline as a scene for genuine knowledge-making and theory-building. Teachers should go back to the "concrete materials" from which knowledge and theory are made. An example of what can be learned in the classroom comes from an effort to…

  15. Survey of Experience Using Reinforced Concrete in Floating Marine Structures.

    DTIC Science & Technology

    1983-01-01

    organizations involved in materials research and testing . The second largest group consists of those involved in design, consulting, and construction...This distribution is consistent with the open literature where the majority of articles are concerned with materials research, testing , and design. Only...example, organizations involved in materials research, design, testing , and certification were visited in the Netherlands, France, Norway, Scotland, and

  16. A "Paperclip" Approach to Curvature, Torsion, and the Frenet-Serret Formulas

    ERIC Educational Resources Information Center

    Hoensch, Ulrich A.

    2009-01-01

    We explore how curvature and torsion determine the shape of a curve via the Frenet-Serret formulas. The connection is made explicit using the existence of solutions to ordinary differential equations. We use a paperclip as a concrete, visual example and generate its graph in 3-space using a CAS. We also show how certain physical deformations to…

  17. Stochastic nonlinear dynamics pattern formation and growth models

    PubMed Central

    Yaroslavsky, Leonid P

    2007-01-01

    Stochastic evolutionary growth and pattern formation models are treated in a unified way in terms of algorithmic models of nonlinear dynamic systems with feedback built of a standard set of signal processing units. A number of concrete models is described and illustrated by numerous examples of artificially generated patterns that closely imitate wide variety of patterns found in the nature. PMID:17908341

  18. The state of water in living systems: from the liquid to the jellyfish.

    PubMed

    Henry, M

    2005-12-14

    The status of water in living systems is reviewed both from philosophical and scientific viewpoints. Starting from antique Mediterranean civilizations (Sumerian, Egyptian, Hebrew, Greek), a world trip is proposed through Norse myths, Siberian Shamanism, Hinduism, Taoism, Buddhism, Shinto, Mayan, Aztec, Inca, Aboriginal and African philosophies in order to convince that all humans share the same qualitative idea that water was a pre-requisite for life apparition. The quantitative aspect of the problem is further analyzed at the light of the scientific contributions from two leading scientists: R.A. Gortner and E.T. Jaynes. With Gortner's work it is demonstrated using the concrete example of the Jellyfish submitted at a Faraday discussion held in London in 1930, how a paradigm shift has occurred in the thirties concerning the status of bound water in the living cell. With Jaynes' work, the disastrous consequences of the entrenchment of diffusion theory in biology are critically examined and the exact meaning of the second law of thermodynamics for biological systems is given using the concrete example of muscle contraction. In conclusion, the importance of distinguishing between an ontological and epistemological level of knowledge is stressed and suggestions for reconciling scientific and philosophical approaches are given.

  19. Examples of cooler reflective streets for urban heat-island mitigation : Portland cement concrete and chip seals

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pomerantz, M.; Akbari, H.; Chang, S.-C.

    Part of the urban heat island effect can be attributed to dark pavements that are commonly used on streets and parking lots. In this paper we consider two light colored, hence cooler, alternative paving materials that are in actual use in cities today. These are Portland cement concrete (PCC) pavements and chip seals. We report measurements of the albedos of some PCC and chip sealed pavements in the San Francisco Bay Area. The albedos of the PCC pavements ranged from about 0.18 to 0.35. The temperatures of some PCC pavements are also measured and calculated. We then consider how themore » albedos of the constituent materials of the PCC (stone, sand and cement) contribute to the albedos of the resulting finished concrete. The albedos of a set of chip sealed pavements in San Jose, CA, were measured and correlated with the times of their placement. It is found that the albedos decrease with age (and use) but remain higher than that of standard asphalt concrete (AC) for about five years. After t hat, the albedos of the chip seals are about 0.12, similar to aged AC. The fact that many PCC pavements have albedos at least twice as high as aged AC suggests that it is possible to have pavement albedos that remain high for many years.« less

  20. CONTRIBUTION TO THE RADIO-CHRONOLOGY OF SOME NATURAL DEPOSITS (in Rumanian)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Atanasiu, G.

    1962-01-01

    The results obtained for the dating of some natural deposits several thousand years old are reported. It was shown that some deposits of mineral waters contain only Ra and its descendants without any U which gives birth to the Ra. The U remains at some depth, fixed by physicochemical processes. By determinng the Ra of recent deposits of a similar source of mineral water and by determining the Ra of old deposits of the same source, the age of these deposits can be calculated. For example, for old deposits of chalky bedrock of the sources of Singeroz mineral water, anmore » age of approximately 7900 years was found. Deeper beds of the same deposits have a greater age. Another method studied is based on the disintegration of C/sup 14/. It is shown how the radiocarbon of the atmosphere passes into stalactites and stalagmites of a cave where it produces a weak BETA activity of these concretions and, at the same time. an ionization of the air of the caves which contain chalky concretions during their formation. This method permits the dating of the cave concretions and an evaluation of the ionization of the air. It was found that the formation of a gram-mole of concretion produces in the air of the caves a quantity of 3 x 10/sup 5/ ions/min approximately. (tr-auth)« less

  1. A seismic optimization procedure for reinforced concrete framed buildings based on eigenfrequency optimization

    NASA Astrophysics Data System (ADS)

    Arroyo, Orlando; Gutiérrez, Sergio

    2017-07-01

    Several seismic optimization methods have been proposed to improve the performance of reinforced concrete framed (RCF) buildings; however, they have not been widely adopted among practising engineers because they require complex nonlinear models and are computationally expensive. This article presents a procedure to improve the seismic performance of RCF buildings based on eigenfrequency optimization, which is effective, simple to implement and efficient. The method is used to optimize a 10-storey regular building, and its effectiveness is demonstrated by nonlinear time history analyses, which show important reductions in storey drifts and lateral displacements compared to a non-optimized building. A second example for an irregular six-storey building demonstrates that the method provides benefits to a wide range of RCF structures and supports the applicability of the proposed method.

  2. Research on durability of a concrete continuous rigid frame bridge

    NASA Astrophysics Data System (ADS)

    Shi, Jing-xian; Ran, Zhi-hong

    2018-05-01

    The research on the durability of concrete structures has also become one of the most important topics for discussion at international academic institutions and conferences. This paper summarizes and reviews the current research on the durability of bridge structure of the bridge at the index relationship between state lifetime and structure durability. According to the actual situation in this paper on a continuous rigid frame bridge China of Yunnan as an example, this bridge was completed and opened to traffic during the first half of the year, a series of tests are carried out for the durability problem. It is found that all the indicators are good within six months after the bridge opened to traffic, but durability issues should be further studied in future monitoring efforts.

  3. Facing sexual violence in a rape emergency room: identification, projective identification, and the myth of nemesis.

    PubMed

    Orlandini, Alvise

    2002-01-01

    This article focuses on the relationship between identification and sexual abuse. Three subsequent levels are considered, namely, the relationship between (1) the abuser and the victim, (2) the gynecologist or social worker of the Rape Emergency Room (RER) and the victim, and (3) the gynecologist or social worker and the entire RER staff. In the relationship with a rape victim, the gynecologist and the social worker may perceive unexpected negative feelings such as fear, horror, impotence, despair, or even anger which can interfere in the identification with the victim. Rape can be considered also as a concrete form of devaluation through concrete penetration of the victim. As an example, a myth of sexual abuse will be presented: the rape of Nemesis by Zeus.

  4. Shakedown Analysis of Composite Steel-Concrete Frame Systems with Plastic and Brittle Elements Under Seismic Action

    NASA Astrophysics Data System (ADS)

    Alawdin, Piotr; Bulanov, George

    2017-06-01

    In this paper the earthquake analysis of composite steel-concrete frames is performed by finding solution of the optimization problem of shakedown analysis, which takes into account the nonlinear properties of materials. The constructions are equipped with systems bearing structures of various elastic-plastic and brittle elements absorbing energy of seismic actions. A mathematical model of this problem is presented on the base of limit analysis theory with partial redistribution of self-stressed internal forces. It is assumed that the load varies randomly within the specified limits. These limits are determined by the possible direction and magnitude of seismic loads. The illustrative example of such analysis of system is introduced. Some attention has been paid to the practical application of the proposed mathematical model.

  5. Direct to consumer genetic testing-law and policy concerns in Ireland.

    PubMed

    de Paor, Aisling

    2017-11-25

    With rapid scientific and technological advances, the past few years has witnessed the emergence of a new genetic era and a growing understanding of the genetic make-up of human beings. These advances have propelled the introduction of companies offering direct to consumer (DTC) genetic testing, which facilitates the direct provision of such tests to consumers, (for example, via the internet). Although DTC genetic testing offers benefits by enhancing consumer accessibility to such technology, promoting proactive healthcare and increasing genetic awareness, it presents a myriad of challenges, from an ethical, legal and regulatory perspective. As DTC genetic testing usually eliminates the need for a medical professional in accessing genetic tests, this lack of professional guidance and counselling may result in misinterpretation and confusion regarding results. In addition, an evident concern relates to the scientific validity and quality of these tests. A further problem arising is the lack or inadequacy of regulation in this field. Despite the increasing accessibility of DTC genetic testing, this legislative vacuum is apparent in Ireland, where there is no concrete legislation. This article explores the main ethical, legal and regulatory issues arising with the advent of rapid advances in DTC genetic testing in Ireland. Further, with inevitable future advances in genetic science, as well as increasing internet accessibility, the challenges presented are likely to become more amplified. In consideration of the ethical and legal challenges, this paper highlights the regulation of DTC genetic testing as a growing concern in Ireland, recognising its importance to both the scientific community as well as in respect of enhancing consumer confidence in such technologies.

  6. GRIZZLY Model of Multi-Reactive Species Diffusion, Moisture/Heat Transfer and Alkali-Silica Reaction for Simulating Concrete Aging and Degradation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Huang, Hai; Spencer, Benjamin W.; Cai, Guowei

    Concrete is widely used in the construction of nuclear facilities because of its structural strength and its ability to shield radiation. The use of concrete in nuclear power plants for containment and shielding of radiation and radioactive materials has made its performance crucial for the safe operation of the facility. As such, when life extension is considered for nuclear power plants, it is critical to have accurate and reliable predictive tools to address concerns related to various aging processes of concrete structures and the capacity of structures subjected to age-related degradation. The goal of this report is to document themore » progress of the development and implementation of a fully coupled thermo-hydro-mechanical-chemical model in GRIZZLY code with the ultimate goal to reliably simulate and predict long-term performance and response of aged NPP concrete structures subjected to a number of aging mechanisms including external chemical attacks and volume-changing chemical reactions within concrete structures induced by alkali-silica reactions and long-term exposure to irradiation. Based on a number of survey reports of concrete aging mechanisms relevant to nuclear power plants and recommendations from researchers in concrete community, we’ve implemented three modules during FY15 in GRIZZLY code, (1) multi-species reactive diffusion model within cement materials; (2) coupled moisture and heat transfer model in concrete; and (3) anisotropic, stress-dependent, alkali-silica reaction induced swelling model. The multi-species reactive diffusion model was implemented with the objective to model aging of concrete structures subjected to aggressive external chemical attacks (e.g., chloride attack, sulfate attack, etc.). It considers multiple processes relevant to external chemical attacks such as diffusion of ions in aqueous phase within pore spaces, equilibrium chemical speciation reactions and kinetic mineral dissolution/precipitation. The moisture/heat transfer module was implemented to simulate long-term spatial and temporal evolutions of the moisture and temperature fields within concrete structures at both room and elevated temperatures. The ASR swelling model implemented in GRIZZLY code can simulate anisotropic expansions of ASR gel under either uniaxial, biaxial and triaxial stress states, and can be run simultaneously with the moisture/heat transfer model and coupled with various elastic/inelastic solid mechanics models that were implemented in GRIZZLY code previously. This report provides detailed descriptions of the governing equations, constitutive equations and numerical algorithms of the three modules implemented in GRIZZLY during FY15, simulation results of example problems and model validation results by comparing simulations with available experimental data reported in the literature. The close match between the experiments and simulations clearly demonstrate the potential of GRIZZLY code for reliable evaluation and prediction of long-term performance and response of aged concrete structures in nuclear power plants.« less

  7. Corrosion initiation and propagation behavior of corrosion resistant concrete reinforcing materials

    NASA Astrophysics Data System (ADS)

    Hurley, Michael F.

    The life of a concrete structure exposed to deicing compounds or seawater is often limited by chloride induced corrosion of the steel reinforcement. In this study, the key material attributes that affect the corrosion initiation and propagation periods were studied. These included material composition, surface condition, ageing time, propagation behavior during active corrosion, morphology of attack, and type of corrosion products generated by each rebar material. The threshold chloride concentrations for solid 316LN stainless steel, 316L stainless steel clad over carbon steel, 2101 LDX, MMFX-2, and carbon steel rebar were investigated using electrochemical techniques in saturated calcium hydroxide solutions. Surface preparation, test method, duration of period exposed to a passivating condition prior to introduction of chloride, and presence of cladding defects all affected the threshold chloride concentration obtained. A model was implemented to predict the extension of time until corrosion initiation would be expected. 8 years was the predicted time to corrosion initiation for carbon steel. However, model results confirmed that use of 316LN may increase the time until onset of corrosion to 100 years or more. To assess the potential benefits afforded by new corrosion resistant rebar alloys from a corrosion resistance standpoint the corrosion propagation behavior and other factors that might affect the risk of corrosion-induced concrete cracking must also be considered. Radial pit growth was found to be ohmically controlled but repassivation occurred more readily at high potentials in the case of 316LN and 2101 stainless steels. The discovery of ohmically controlled propagation enabled transformation of propagation rates from simulated concrete pore solution to less conductive concrete by accounting for resistance changes in the surrounding medium. The corrosion propagation behavior as well as the morphology of attack directly affects the propensity for concrete cracking. Experimental results were used in conjunction with an existing model to predict the time until concrete cracking occurs for new rebar materials. The results suggest that corrosion resistant materials offer a significant extension to the corrosion propagation stage over carbon steel, even in very aggressive conditions because small, localized anodes develop when initiated.

  8. Talk with Your Kids...before Everyone Else Does: Talking with Kids about Tough Issues.

    ERIC Educational Resources Information Center

    Children Now, Oakland, CA.

    Parents are challenged daily with a wide range of disturbing issues that are difficult for children to understand and for adults to explain. This booklet offers practical, concrete tips and techniques for talking easily and openly with 8- to 12-year-olds about sex, HIV/AIDS, violence, drugs, and alcohol. The book is divided into five parts. Part 1…

  9. Fatigue Response of Pretensioned Concrete Beams

    DTIC Science & Technology

    2003-08-01

    Dedication To my beautiful wife and children, whose love and support motivate my life’s endeavors. Acknowledgements I first offer appreciation to the Texas...7,058,000 Straight PS3 27.6 2,069,000 Straight PS4 27.6 4,173,000 Straight VP2 36.3 1,510,000 Straight VP3 27.6 2,926,000 Straight VP4 27.6 2,890,000 Straight

  10. Summary Report of the Title VI-G Network Third Annual Conference. (Minneapolis, Minnesota, December 5-8, 1977).

    ERIC Educational Resources Information Center

    Network of Innovative Schools, Inc., Andover, MA.

    Presented is the summary report of the Third Annual Conference of the Title VI-G Network which was designed to update learning disability (LD) professionals on pertinent program and education developments, to inform them of future trends and plans, and to offer concrete help in their present work. Introductory sections provide a schedule of the…

  11. Positive Classroom Management. A Step-by-Step Guide to Successfully Running the Show Without Destroying Student Dignity. 2nd Edition.

    ERIC Educational Resources Information Center

    DiGiulio, Robert

    This book provides K-12 teachers with concrete, step-by-step guidance on how to improve student behavior through positive classroom management. It explains how to take control of the classroom, offering an alternative to threats, rewards, and punishments. The book is divided into an introduction and three sections with seven chapters. The…

  12. The solution of proofing pie for the waste sorting plant

    NASA Astrophysics Data System (ADS)

    Braila, Natalya; Kirilkina, Anna; Barinov, Sergey

    2017-10-01

    The modern way of establishment of a flat roof is considered in the article. The standard project of the waste sorting plant was adapted under the conditions of the Republic of Karelia. Instead of the traditional roof with a slope from the concrete coupler, provided by the project, the option with the use of heater in the form of wedge-shaped plates was offered.

  13. Aktiver und passiver Wortschatz im Englischunterricht und in Lehrwerken der Hauptschule (Active and Passive Vocabulary in Teaching English and in Textbooks Used in Hauptschulen ["Terminal" Junior High Schools])

    ERIC Educational Resources Information Center

    Kerschgens, Edda

    1975-01-01

    Discusses the extent to which five popular English teaching texts distinguish between active and passive vocabulary in learning English, and pleads (offering concrete suggestions) for more attention to the vocabulary aspect in constructing teaching textbooks for junior high schools. (Text is in German.) (IFS/WGA)

  14. Environmental control on concretion-forming processes: Examples from Paleozoic terrigenous sediments of the North Gondwana margin, Armorican Massif (Middle Ordovician and Middle Devonian) and SW Sardinia (Late Ordovician)

    NASA Astrophysics Data System (ADS)

    Dabard, Marie-Pierre; Loi, Alfredo

    2012-08-01

    Concretions of various compositions are common in the Paleozoic terrigenous successions of the north Gondwana margin. This study focuses on phosphatic (P) and siliceous (Si) concretions present in some successions of the Armorican Massif (NW France) and SW Sardinia (W Italy). It shows that they consist of mudstones, fine- to very fine-grained sandstones or shellbeds with a more or less abundant P-cement and form a continuum between a phosphatic end-member and a siliceous biogenic end-member. The P2O5 contents are ranging from 0.26% to 21.5% and are related to apatite. The SiO2 contents vary from 25% to 82% and are linked both to a terrigenous phase and to a biogenic silica phase. Concretions showing the lower P-contents (P2O5 < 1.5%) are often enriched in biogenic silica (SiO2/Al2O3 > 5). Comparison with the surrounding sediments shows that all the concretions are enriched in chlorite and in Middle Rare Earth Elements (Las/Gds: 0.12-0.72) and some of them in Y (up to 974 ppm), Rare Earth Elements (more than 300 ppm) and Sr (260-880 ppm). The concretions with highest biogenic silica concentrations are contained in the outer shelf sediments whereas the other concretions are present from the proximal part of the inner shelf to the outer shelf. A genetic model in two stages is proposed. During early diagenesis, the dissolution of shells and degradation of organic matter progressively enrich the pore water in dissolved Si, Ca and P. When the suboxic zone is reached, P-precipitation begins, leading to the formation of protoconcretions. In shallow environments, the relative permeability of sediments and the winnowing or reworking of the upper few centimetres by bottom currents allow for suboxic conditions to be maintained, leading to P-rich concretion formation. In deeper environments, the anoxic zone is reached more rapidly, thereby preventing extensive phosphogenesis. Nevertheless in the protoconcretions the early P-cement preserves pore spaces from compaction. In the presence of biogenic siliceous particles, the fluids are enriched in dissolved silica and diffuse towards the protoconcretions. Silica precipitation can thus occur later in the intergranular spaces.

  15. Galvanic Liquid Applied Coating System for Protection of Embedded Steel Surfaces from Corrosion

    NASA Technical Reports Server (NTRS)

    Curran, Joseph; MacDowell, Louis; Voska, N. (Technical Monitor)

    2002-01-01

    The corrosion of reinforcing steel in concrete is an insidious problem for the Kennedy Space Center, government agencies, and the general public. Existing corrosion protection systems on the market are costly, complex, and time-consuming to install, require continuous maintenance and monitoring, and require specialized skills for installation. NASA's galvanic liquid-applied coating offers companies the ability to conveniently protect embedded steel rebar surfaces from corrosion. Liquid-applied inorganic galvanic coating contains one ore more of the following metallic particles: magnesium, zinc, or indium and may contain moisture attracting compounds that facilitate the protection process. The coating is applied to the outer surface of reinforced concrete so that electrical current is established between metallic particles and surfaces of embedded steel rebar; and electric (ionic) current is responsible for providing the necessary cathodic protection for embedded rebar surfaces.

  16. Toward a Framework for Linking Linguistic Knowledge and Writing Expertise: Interplay between SFL-Based Genre Pedagogy and Task-Based Language Teaching

    ERIC Educational Resources Information Center

    Yasuda, Sachiko

    2017-01-01

    This article attempts to apply some systemic functional linguistic (SFL) concepts to task-based language teaching (TBLT) as a means of enriching the fields of learning, teaching, and evaluating writing in an additional language. The purposes are twofold. First, this article presents a concrete example concerning SFL-initiated genre-based tasks,…

  17. Practical scheme for optimal measurement in quantum interferometric devices

    NASA Astrophysics Data System (ADS)

    Takeoka, Masahiro; Ban, Masashi; Sasaki, Masahide

    2003-06-01

    We apply a Kennedy-type detection scheme, which was originally proposed for a binary communications system, to interferometric sensing devices. We show that the minimum detectable perturbation of the proposed system reaches the ultimate precision bound which is predicted by quantum Neyman-Pearson hypothesis testing. To provide concrete examples, we apply our interferometric scheme to phase shift detection by using coherent and squeezed probe fields.

  18. Why "What Works" Still Doesn't Work: How to Improve Research Syntheses at the What Works Clearinghouse

    ERIC Educational Resources Information Center

    Lykins, Chad

    2012-01-01

    The What Works Clearinghouse (WWC) aims to synthesize and disseminate the results of high-quality education research on areas of significant public interest. The WWC has come to serve as a concrete example of the growing willingness of the federal government to shape both the topic and methods chosen by researchers. However, the scope of research…

  19. The Application of Reciprocal Teaching on the Subject of Straight Line Equation in Second Grade of Junior High School

    ERIC Educational Resources Information Center

    Darsono

    2015-01-01

    Mathematics as an abstract science can be easily understood by a junior high school student when it is accompanied by concrete examples which is appropriate to the situation and conditions encountered. At the level of cognitive development, children actually very much based on the movements and actions. In this case, the children will learn at…

  20. The uncertainty principle in resonant gravitational wave antennae and quantum non-demolition measurement schemes

    NASA Technical Reports Server (NTRS)

    Fortini, Pierluigi; Onofrio, Roberto; Rioli, Alessandro

    1993-01-01

    A review of current efforts to approach and to surpass the fundamental limit in the sensitivity of the Weber type gravitational wave antennae is reported. Applications of quantum non-demolition techniques to the concrete example of an antenna resonant with the transducer are discussed in detail. Analogies and differences from the framework of the squeezed states in quantum optics are discussed.

  1. Toy models and stylized realities

    NASA Astrophysics Data System (ADS)

    Marsili, M.

    2007-01-01

    I discuss the role of toy models as theoretical tools for understanding complex systems of interacting agents. I review some concrete examples, in order to illustrate how this approach is able to capture, though in an admittedly stylized way, the interactions and non-linearities which are responsible for the rich phenomenology observed in reality. This allows one to interpret the system's behavior in terms of phase transitions and critical phenomena.

  2. 52. Virginia Route 666. This single span structure, built in ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    52. Virginia Route 666. This single span structure, built in 1962, is an example of a spandrel arch grade separation structure with a roman arch over a state secondary road. The bridge is constructed of reinforced concrete, backfilled with earth and has a thick stone veneer. Looking east-northeast at elevation. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  3. Enhancing Student Learning with Case-Based Teaching and Audience Response Systems in an Interdisciplinary Food Science Course

    ERIC Educational Resources Information Center

    Giacalone, Davide

    2016-01-01

    The purpose of this article is to discuss the implementation of case-based teaching and use of response technologies to graduate students in a food science course. The article focuses on teaching sensory science and sensometrics, presents several concrete examples used during the course, and discusses in each case some of the observed outcomes.…

  4. Using Standards and High-Stakes Testing for Students: Exploiting Power with Critical Pedagogy. Counterpoints: Studies in the Postmodern Theory of Education. Volume 425

    ERIC Educational Resources Information Center

    Gorlewski, Julie A., Ed.; Porfilio, Brad J., Ed.; Gorlewski, David A., Ed.

    2012-01-01

    This book overturns the typical conception of standards, empowering educators by providing concrete examples of how top-down models of assessment can be embraced and used in ways that are consistent with critical pedagogies. Although standards, as broad frameworks for setting learning targets, are not necessarily problematic, when they are…

  5. Guiding White Pre-Service and In-Service Teachers toward Critical Pedagogy: Utilizing Counter-Cultures in Teacher Education

    ERIC Educational Resources Information Center

    Porfilio, Brad J.; Malott, Curry S.

    2011-01-01

    This essay documents a few key examples of the critical pedagogy and curriculum that the authors employ to challenge pre-service and in-service teachers to consider the concrete and theoretical contexts of taking on a social-activist-teacher persona. Their vision of social justice is rooted firmly in the critical tradition, as it is anchored in…

  6. Experimenting with string musical instruments

    NASA Astrophysics Data System (ADS)

    LoPresto, Michael C.

    2012-03-01

    What follows are several investigations involving string musical instruments developed for and used in a Science of Sound & Light course. The experiments make use of a guitar, orchestral string instruments and data collection and graphing software. They are designed to provide students with concrete examples of how mathematical formulae, when used in physics, represent reality that can actually be observed, in this case, the operation of string musical instruments.

  7. Structural health monitoring for DOT using magnetic shape memory alloy cables in concrete

    NASA Astrophysics Data System (ADS)

    Davis, Allen; Mirsayar, Mirmilad; Sheahan, Emery; Hartl, Darren

    2018-03-01

    Embedding shape memory alloy (SMA) wires in concrete components offers the potential to monitor their structural health via external magnetic field sensing. Currently, structural health monitoring (SHM) is dominated by acoustic emission and vibration-based methods. Thus, it is attractive to pursue alternative damage sensing techniques that may lower the cost or increase the accuracy of SHM. In this work, SHM via magnetic field detection applied to embedded magnetic shape memory alloy (MSMA) is demonstrated both experimentally and using computational models. A concrete beam containing iron-based MSMA wire is subjected to a 3-point bend test where structural damage is induced, thereby resulting in a localized phase change of the MSMA wire. Magnetic field lines passing through the embedded MSMA domain are altered by this phase change and can thus be used to detect damage within the structure. A good correlation is observed between the computational and experimental results. Additionally, the implementation of stranded MSMA cables in place of the MSMA wire is assessed through similar computational models. The combination of these computational models and their subsequent experimental validation provide sufficient support for the feasibility of SHM using magnetic field sensing via MSMA embedded components.

  8. Experimental characterization of thermal and hygric properties of hemp concrete with consideration of the material age evolution

    NASA Astrophysics Data System (ADS)

    Bennai, F.; Issaadi, N.; Abahri, K.; Belarbi, R.; Tahakourt, A.

    2018-04-01

    The incorporation of plant crops in construction materials offers very good hygrothermal performance to the building, ensuring substantial environmental and ecological benefits. This paper focuses on studying the evolution of hygrothermal properties of hemp concrete over age (7, 30 and 60 days). The analysis is done with respect to two main hygric and thermal properties, respectively: sorption isotherms, water vapor permeability, thermal conductivity and heat capacity. In fact, most of these parameters are very susceptible to change function of the age of the material. This influence of the aging is mainly due to the evolution of the microstructure with the binder hydration over time and the creation of new hydrates which can reduces the porosity of the material and consequently modify its properties. All the tested hemp concrete samples presented high moisture storage capacity and high-water vapor permeability whatever the age of such hygroscopic material. These hygric parameters increase significantly for high relative humidity requiring more consideration of such variability during the modeling of coupled heat and mass transfer within the material. By the same, the thermal conductivity and heat capacity tests highlighted the impact of the temperature and hygric state of the studied material.

  9. Data Mining for Web-Based Support Systems: A Case Study in e-Custom Systems

    NASA Astrophysics Data System (ADS)

    Razmerita, Liana; Kirchner, Kathrin

    This chapter provides an example of a Web-based support system (WSS) used to streamline trade procedures, prevent potential security threats, and reduce tax-related fraud in cross-border trade. The architecture is based on a service-oriented architecture that includes smart seals and Web services. We discuss the implications and suggest further enhancements to demonstrate how such systems can move toward a Web-based decision support system with the support of data mining methods. We provide a concrete example of how data mining can help to analyze the vast amount of data collected while monitoring the container movements along its supply chain.

  10. The right frame of reference makes it simple: an example of introductory mechanics supported by video analysis of motion

    NASA Astrophysics Data System (ADS)

    Klein, P.; Gröber, S.; Kuhn, J.; Fleischhauer, A.; Müller, A.

    2015-01-01

    The selection and application of coordinate systems is an important issue in physics. However, considering different frames of references in a given problem sometimes seems un-intuitive and is difficult for students. We present a concrete problem of projectile motion which vividly demonstrates the value of considering different frames of references. We use this example to explore the effectiveness of video-based motion analysis (VBMA) as an instructional technique at university level in enhancing students’ understanding of the abstract concept of coordinate systems. A pilot study with 47 undergraduate students indicates that VBMA instruction improves conceptual understanding of this issue.

  11. In situ alkali-silica reaction observed by x-ray microscopy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kurtis, K.E.; Monteiro, P.J.M.; Brown, J.T.

    1997-04-01

    In concrete, alkali metal ions and hydroxyl ions contributed by the cement and reactive silicates present in aggregate can participate in a destructive alkali-silica reaction (ASR). This reaction of the alkalis with the silicates produces a gel that tends to imbibe water found in the concrete pores, leading to swelling of the gel and eventual cracking of the affected concrete member. Over 104 cases of alkali-aggregate reaction in dams and spillways have been reported around the world. At present, no method exists to arrest the expansive chemical reaction which generates significant distress in the affected structures. Most existing techniques availablemore » for the examination of concrete microstructure, including ASR products, demand that samples be dried and exposed to high pressure during the observation period. These sample preparation requirements present a major disadvantage for the study of alkali-silica reaction. Given the nature of the reaction and the affect of water on its products, it is likely that the removal of water will affect the morphology, creating artifacts in the sample. The purpose of this research is to observe and characterize the alkali-silica reaction, including each of the specific reactions identified previously, in situ without introducing sample artifacts. For observation of unconditioned samples, x-ray microscopy offers an opportunity for such an examination of the alkali-silica reaction. Currently, this investigation is focusing on the effect of calcium ions on the alkali-silica reaction.« less

  12. Structural health monitoring and damage evaluation for steel confined reinforced concrete column using the acoustic emission technique

    NASA Astrophysics Data System (ADS)

    Du, Fangzhu; Li, Dongsheng

    2018-03-01

    As a new kind of composite structures, the using of steel confined reinforced concrete column attract increasing attention in civil engineer. During the damage process, this new structure offers highly complex and invisible failure mechanism due to the combination effects of steel tubes, concrete, and steel rebar. Acoustic emission (AE) technique has been extensively studied in nondestructive testing (NDT) and is currently applied in civil engineering for structural health monitoring (SHM) and damage evaluation. In the present study, damage property and failure evolution of steel confined and unconfined reinforced concrete (RC) columns are investigated under quasi-static loading through (AE) signal. Significantly improved loading capacity and excellent energy dissipation characteristic demonstrated the practicality of that proposed structure. AE monitoring results indicated that the progressive deformation of the test specimens occur in three stages representing different damage conditions. Sentry function compares the logarithm ratio between the stored strain energy (Es) and the released acoustic energy (Ea); explicitly disclose the damage growth and failure mechanism of the test specimens. Other extended AE features including index of damage (ID), and relax ratio are calculated to quantitatively evaluate the damage severity and critical point. Complicated temporal evolution of different AE features confirms the potential importance of integrated analysis of two or more parameters. The proposed multi-indicators analysis is capable of revealing the damage growth and failure mechanism for steel confined RC columns, and providing critical warning information for structure failure.

  13. Stress Wave Scattering: Friend or Enemy of Non Destructive Testing of Concrete?

    NASA Astrophysics Data System (ADS)

    Aggelis, Dimitrios G.; Shiotani, Tomoki; Philippidis, Theodore P.; Polyzos, Demosthenes

    Cementitious materials are by definition inhomogeneous containing cement paste, sand, aggregates as well as air voids. Wave propagation in such a material is characterized by scattering phenomena. Damage in the form of micro or macro cracks certainly enhances scattering influence. Its most obvious manifestation is the velocity variation with frequency and excessive attenuation. The influence becomes stronger with increased mis-match of elastic properties of constituent materials and higher crack content. Therefore, in many cases of large concrete structures, field application of stress waves is hindered since attenuation makes the acquisition of reliable signals troublesome. However, measured wave parameters, combined with investigation with scattering theory can reveal much about the internal condition and supply information that cannot be obtained in any other way. The size and properties of the scatterers leave their signature on the dispersion and attenuation curves making thus the characterization more accurate in case of damage assessment, repair evaluation as well as composition inspection. In this paper, three indicative cases of scattering influence are presented. Namely, the interaction of actual distributed damage, as well as the repair material injected in an old concrete structure with the wave parameters. Other cases are the influence of light plastic inclusions in hardened mortar and the influence of sand and water content in the examination of fresh concrete. In all the above cases, scattering seems to complicate the propagation behavior but also offers the way for a more accurate characterization of the quality of the material.

  14. "I Just bought my residents iPads… now what?" The integration of mobile devices into radiology resident education.

    PubMed

    Bedi, Harprit S; Yucel, Edgar K

    2013-10-01

    This article describes how mobile technologies can improve the way we teach radiology and offers ideas to bridge the clinical gap with technology. Radiology programs across the country are purchasing iPads and other mobile devices for their residents. Many programs, however, do not have a concrete vision for how a mobile device can enhance the learning environment.

  15. Developing Emotion-Based Case Formulations: A Research-Informed Method.

    PubMed

    Pascual-Leone, Antonio; Kramer, Ueli

    2017-01-01

    New research-informed methods for case conceptualization that cut across traditional therapy approaches are increasingly popular. This paper presents a trans-theoretical approach to case formulation based on the research observations of emotion. The sequential model of emotional processing (Pascual-Leone & Greenberg, 2007) is a process research model that provides concrete markers for therapists to observe the emerging emotional development of their clients. We illustrate how this model can be used by clinicians to track change and provides a 'clinical map,' by which therapist may orient themselves in-session and plan treatment interventions. Emotional processing offers as a trans-theoretical framework for therapists who wish to conduct emotion-based case formulations. First, we present criteria for why this research model translates well into practice. Second, two contrasting case studies are presented to demonstrate the method. The model bridges research with practice by using client emotion as an axis of integration. Key Practitioner Message Process research on emotion can offer a template for therapists to make case formulations while using a range of treatment approaches. The sequential model of emotional processing provides a 'process map' of concrete markers for therapists to (1) observe the emerging emotional development of their clients, and (2) help therapists develop a treatment plan. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  16. Bidirectional Transfer between Metaphorical Related Domains in Implicit Learning of Form-Meaning Connections

    PubMed Central

    Yang, Zhiliang; Dienes, Zoltan

    2013-01-01

    People can implicitly learn a connection between linguistic forms and meanings, for example between specific determiners (e.g. this, that…) and the type of nouns to which they apply. Li et al (2013) recently found that transfer of form-meaning connections from a concrete domain (height) to an abstract domain (power) was achieved in a metaphor-consistent way without awareness, showing that unconscious knowledge can be abstract and flexibly deployed. The current study aims to determine whether people transfer knowledge of form-meaning connections not only from a concrete domain to an abstract one, but also vice versa, consistent with metaphor representation being bi-directional. With a similar paradigm as used by Li et al, participants learnt form- meaning connections of different domains (concrete vs. abstract) and then were tested on two kinds of generalizations (same and different domain generalization). As predicted, transfer of form-meaning connections occurred bidirectionally when structural knowledge was unconscious. Moreover, the present study also revealed that more transfer occurred between metaphorically related domains when judgment knowledge was conscious (intuition) rather than unconscious (guess). Conscious and unconscious judgment knowledge may have different functional properties. PMID:23844159

  17. Interface through Cooperative Agreements: Eleven Examples of How It Can Work.

    ERIC Educational Resources Information Center

    Jellison, Holly M., Ed.

    Designed as a resource for community colleges wishing to initiate a cooperative agreement with a local agency to offer community education programs, this publication offers 11 representative examples of such agreements. After explaining that the Center for Community Education collected the agreements as part of a 1981 study of community education…

  18. 12 CFR Appendix A to Part 761 - Examples of Mortgage Loan Originator Activities

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... by the credit union's loan approval mechanism function for a specific loan product is communicated.... (c) Offering or negotiating a loan for compensation or gain. The following examples illustrate when an employee does or does not offer or negotiate terms of a loan “for compensation or gain.” (1...

  19. 12 CFR Appendix A to Part 761 - Examples of Mortgage Loan Originator Activities

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... by the credit union's loan approval mechanism function for a specific loan product is communicated.... (c) Offering or negotiating a loan for compensation or gain. The following examples illustrate when an employee does or does not offer or negotiate terms of a loan “for compensation or gain.” (1...

  20. 12 CFR Appendix A to Part 1007 - Examples of Mortgage Loan Originator Activities

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... approved by the covered financial institution's loan approval mechanism function for a specific loan.... (c) Offering or negotiating a loan for compensation or gain. The following examples illustrate when an employee does or does not offer or negotiate terms of a loan “for compensation or gain.” (1...

  1. 12 CFR Appendix A to Part 1007 - Examples of Mortgage Loan Originator Activities

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... approved by the covered financial institution's loan approval mechanism function for a specific loan.... (c) Offering or negotiating a loan for compensation or gain. The following examples illustrate when an employee does or does not offer or negotiate terms of a loan “for compensation or gain.” (1...

  2. 12 CFR Appendix A to Part 1007 - Examples of Mortgage Loan Originator Activities

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... approved by the covered financial institution's loan approval mechanism function for a specific loan.... (c) Offering or negotiating a loan for compensation or gain. The following examples illustrate when an employee does or does not offer or negotiate terms of a loan “for compensation or gain.” (1...

  3. 12 CFR Appendix A to Part 761 - Examples of Mortgage Loan Originator Activities

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... by the credit union's loan approval mechanism function for a specific loan product is communicated.... (c) Offering or negotiating a loan for compensation or gain. The following examples illustrate when an employee does or does not offer or negotiate terms of a loan “for compensation or gain.” (1...

  4. Assessment of technical condition of concrete pavement by the example of district road

    NASA Astrophysics Data System (ADS)

    Linek, M.; Nita, P.; Żebrowski, W.; Wolka, P.

    2018-05-01

    The article presents the comprehensive assessment of concrete pavement condition. Analyses included the district road located in the swietokrzyskie province, used for 11 years. Comparative analyses were conducted twice. The first analysis was carried out after 9 years of pavement operation, in 2015. In order to assess the extent of pavement degradation, the tests were repeated in 2017. Within the scope of field research, the traffic intensity within the analysed road section was determined. Visual assessment of pavement condition was conducted, according to the guidelines included in SOSN-B. Visual assessment can be extended by ground-penetrating radar measurements which allow to provide comprehensive assessment of the occurred structure changes within its entire thickness and length. The assessment included also performance parameters, i.e. pavement regularity, surface roughness and texture. Extension of test results by the assessment of changes in internal structure of concrete composite and structure observations by means of Scanning Electron Microscope allow for the assessment of parameters of internal structure of hardened concrete. Supplementing the observations of internal structure by means of computed tomography scan provides comprehensive information of possible discontinuities and composite structure. According to the analysis of the obtained results, conclusions concerning the analysed pavement condition were reached. It was determined that the pavement is distinguished by high performance parameters, its condition is good and it does not require any repairs. Maintenance treatment was suggested in order to extend the period of proper operation of the analysed pavement.

  5. Army Synthetic Validity Project Report of Phase 2 Results. Volume 3. Research Instruments

    DTIC Science & Technology

    1990-10-01

    Areas 7. The type of secondary arms room lock shown at A in the diagram below requires rotation A. monthly B. quarterly C. semiannually D. annually E...building concrete, stone, or other structures (for example, roads, fortifications , buildings, etc.). 16. Operate wheeled vehicles - drive wheeled...for cover and concealment and to place weapons, fortifications , mines, and detectors. 64. Translate foreign languages - translate written or spoken

  6. The uncertainty principle in resonant gravitational wave antennae and quantum non-demolition measurement schemes

    NASA Technical Reports Server (NTRS)

    Fortini, Pierluigi; Onofrio, Roberto; Rioli, Alessandro

    1993-01-01

    A review on the current efforts to approach and to surpass the fundamental limit in the sensitivity of the Weber type gravitational wave antennae is reported. Applications of quantum non-demolition techniques to the concrete example of an antenna resonant with the transducer are discussed in detail. Analogies and differences from the framework of the squeezed states in quantum optics are discussed.

  7. Environmental Sense Box: A Strategy for Helping Elementary School Students Understand Abstract Environments through Concrete Learning Activities.

    ERIC Educational Resources Information Center

    Sesow, F. Wm.

    This paper suggests a technique for the development, collection, and organization of materials that will aid learning through the use of the senses by building an environmental sense box. England is used as an example of a place that provides many sensory experiences which can be duplicated in such a box. The box can be made from a cardboard…

  8. Executive Functioning in Three Groups of Pupils in D-KEFSs: Selected Issues in Adapting the Test Battery for Slovakia

    ERIC Educational Resources Information Center

    Ferjencík, Ján; Slavkovská, Miriam; Kresila, Juraj

    2015-01-01

    The paper reports on the adaptation of a D-KEFS test battery for Slovakia. Drawing on concrete examples, it describes and illustrates the key issues relating to the transfer of test items from one socio-cultural environment to another. The standardisation sample of the population of Slovak pupils in the fourth year of primary school included 250…

  9. A class of minimally modified gravity theories

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lin, Chunshan; Mukohyama, Shinji, E-mail: chunshan.lin@yukawa.kyoto-u.ac.jp, E-mail: shinji.mukohyama@yukawa.kyoto-u.ac.jp

    We investigate the Hamiltonian structure of a class of gravitational theories whose actions are linear in the lapse function. We derive the necessary and sufficient condition for a theory in this class to have two or less local physical degrees of freedom. As an application we then find several concrete examples of modified gravity theories in which the total number of local physical degrees of freedom in the gravity sector is two.

  10. Standards for the Mobility Common Operational Picture (M-COP): Elements of Ground Vehicle Maneuver

    DTIC Science & Technology

    2007-07-01

    saturated 0009 waterlogged 0010 wet Surface_Slippery Indication that a surface is slippery . Examples: wet grass, and wet clay soil. 1 boolean...Enumeration Values or Units† 0022 cypress 0023 deciduous_unspecified 0024 dry_crops 0025 elm 0026 eucalyptus 0027 evergreen_unspecified 0028 filao...internal structural material. 1 integer 0024 concrete_steel 0137 steel 0155 wood Surface_Slippery Indication that a surface is slippery

  11. Torsional Shear Device for Testing the Dynamic Properties of Recycled Material

    NASA Astrophysics Data System (ADS)

    Gabryś, Katarzyna; Sas, Wojciech; Soból, Emil; Głuchowski, Andrzej

    2016-12-01

    From the viewpoint of environmental preservation and effective utilization of resources, it is beneficial and necessary to reuse wastes, for example, concrete, as the recycled aggregates for new materials. In this work, the dynamic behavior of such aggregates under low frequency torsional loading is studied. Results show that the properties of such artificial soils match with those reported in the literature for specific natural soils.

  12. Bennett clocking of quantum-dot cellular automata and the limits to binary logic scaling.

    PubMed

    Lent, Craig S; Liu, Mo; Lu, Yuhui

    2006-08-28

    We examine power dissipation in different clocking schemes for molecular quantum-dot cellular automata (QCA) circuits. 'Landauer clocking' involves the adiabatic transition of a molecular cell from the null state to an active state carrying data. Cell layout creates devices which allow data in cells to interact and thereby perform useful computation. We perform direct solutions of the equation of motion for the system in contact with the thermal environment and see that Landauer's Principle applies: one must dissipate an energy of at least k(B)T per bit only when the information is erased. The ideas of Bennett can be applied to keep copies of the bit information by echoing inputs to outputs, thus embedding any logically irreversible circuit in a logically reversible circuit, at the cost of added circuit complexity. A promising alternative which we term 'Bennett clocking' requires only altering the timing of the clocking signals so that bit information is simply held in place by the clock until a computational block is complete, then erased in the reverse order of computation. This approach results in ultralow power dissipation without additional circuit complexity. These results offer a concrete example in which to consider recent claims regarding the fundamental limits of binary logic scaling.

  13. Examining the potential impacts of climate change on international security: EU-Africa partnership on climate change.

    PubMed

    Dodo, Mahamat K

    2014-01-01

    Climate Change like many global problems nowadays is recognized as a threat to the international security and cooperation. In theoretical terms, it is being securitized and included in the traditional security studies. Climate change and its accompanying environmental degradation are perceived to be a threat that can have incalculable consequences on the international community. The consequences are said to have more effects in small island developing nations and Africa where many States are fragile and overwhelmed with mounting challenges. In recent years, the security implications of the climate change are being addressed from national, regional and multilateral level. Against this backdrop, this paper intends to contribute to the debate on climate change and international security and present a broader perspective on the discussion. The paper will draw from the EU-Africa partnership on climate change and is structured as follows: the first part introduces the background of the international climate change policy and its securitization, the second part covers the EU-Africa relations and EU-Africa partnership on climate change, and the third part discusses the Congo Basin Forest Partnership as a concrete example of EU-Africa Partnership on Climate Change. Lastly, the paper concludes by drawing some conclusions and offers some policy perspectives and recommendations. Q54; 055; 052; 01;

  14. Teaching virtue: pedagogical implications of moral psychology.

    PubMed

    Frey, William J

    2010-09-01

    Moral exemplar studies of computer and engineering professionals have led ethics teachers to expand their pedagogical aims beyond moral reasoning to include the skills of moral expertise. This paper frames this expanded moral curriculum in a psychologically informed virtue ethics. Moral psychology provides a description of character distributed across personality traits, integration of moral value into the self system, and moral skill sets. All of these elements play out on the stage of a social surround called a moral ecology. Expanding the practical and professional curriculum to cover the skills and competencies of moral expertise converts the classroom into a laboratory where students practice moral expertise under the guidance of their teachers. The good news is that this expanded pedagogical approach can be realized without revolutionizing existing methods of teaching ethics. What is required, instead, is a redeployment of existing pedagogical tools such as cases, professional codes, decision-making frameworks, and ethics tests. This essay begins with a summary of virtue ethics and informs this with recent research in moral psychology. After identifying pedagogical means for teaching ethics, it shows how these can be redeployed to meet a broader, skills based agenda. Finally, short module profiles offer concrete examples of the shape this redeployed pedagogical agenda would take in the practical and professional ethics classroom.

  15. Bennett clocking of quantum-dot cellular automata and the limits to binary logic scaling

    NASA Astrophysics Data System (ADS)

    Lent, Craig S.; Liu, Mo; Lu, Yuhui

    2006-08-01

    We examine power dissipation in different clocking schemes for molecular quantum-dot cellular automata (QCA) circuits. 'Landauer clocking' involves the adiabatic transition of a molecular cell from the null state to an active state carrying data. Cell layout creates devices which allow data in cells to interact and thereby perform useful computation. We perform direct solutions of the equation of motion for the system in contact with the thermal environment and see that Landauer's Principle applies: one must dissipate an energy of at least kBT per bit only when the information is erased. The ideas of Bennett can be applied to keep copies of the bit information by echoing inputs to outputs, thus embedding any logically irreversible circuit in a logically reversible circuit, at the cost of added circuit complexity. A promising alternative which we term 'Bennett clocking' requires only altering the timing of the clocking signals so that bit information is simply held in place by the clock until a computational block is complete, then erased in the reverse order of computation. This approach results in ultralow power dissipation without additional circuit complexity. These results offer a concrete example in which to consider recent claims regarding the fundamental limits of binary logic scaling.

  16. The complementary medicine (CAM) for the treatment of chronic pain: scientific evidence regarding the effects of healing touch massage.

    PubMed

    Marletta, Giuseppe; Canfora, Angela; Roscani, Francesco; Cernicchiaro, Lucia; Cutrera, Maria; Russo, Marianna; Artioli, Giovanna; Sarli, Leopoldo

    2015-09-09

    Evidence-based medicine offers effective pathways of pharmacological treatment for chronic pain that may compromise the quality of life of patients; this is one of the main reasons why more and more people resort to traditional and complementary approaches, to try to maintain or regain their health. The effectiveness of the various forms of complementary treatments often cannot be proven objectively, which is why, given the need to find more concrete evidence of the effectiveness of complementary therapies with particular reference to the method of healing touch massage, a review of the literature was conducted in order to gather evidence of the efficacy of the specific method regarding pain and other health outcomes of patients with malignant disease to support a proposal for improvement, based on the practice of healing touch massage conducted by nurses. Systematic review. There are several examples (in some cases specifically regarding patients with tumors) of the positive effects of healing touch massage on pain, anxiety and fatigue, and also on biochemical parameters. The way to full recognition by both the institutional and the scientific community seems to promise fairly well, although it should be noted that the achievement of this goal will require further research avoiding the limitations of previous studies.

  17. Concrete volute pumps: technology review and improvement

    NASA Astrophysics Data System (ADS)

    Prunières, R.; Longatte, F.; Catelan, F. X.; Philippot, J. M.

    2012-11-01

    When pumps need to deliver large water flow rates (typically more than 5 m3.s-1), concrete volute pumps (CVP) offer an interesting alternative to standard vertical wet-pit pumps. One of the major advantages of CVP is its simplicity in terms of design, manufacturability and maintainability. In addition, CVP geometrical arrangement allows to reach high performances in terms of hydraulic and mechanical behaviour. These advantages can be specifically appreciated when such pumps are used in the energy field for Power Plants which need high flow rate and reliability, and can lead to important financial savings over the Plant lifetime compared to vertical wet-pit pumps. Finally, as CVP was for a long time limited to total head rise lower than 30 mWC, it was established through CFD analysis that the addition of guide vanes between the impeller and the volute allows to achieve higher head rise without risk.

  18. The Extraterrestrial Materials Simulation Laboratory

    NASA Technical Reports Server (NTRS)

    Green, J. R.

    2001-01-01

    In contrast to fly-by and orbital missions, in situ missions face an incredible array of challenges in near-target navigation, landing site selection, descent, landing, science operations, sample collection and handling, drilling, anchoring, subsurface descent, communications, and contamination. The wide range of materials characteristics and environments threaten mission safety and success. For example, many physical properties are poorly characterized, including strength, composition, heterogeneity, phase change, texture, thermal properties, terrain features, atmospheric interaction, and stratigraphy. Examples of the range of materials properties include, for example: (1) Comets, with a possible compressive strength ranging from a light fluff to harder than concrete: 10(exp 2) to 10 (exp 8) Pa; (2) Europa, including a possible phase change at the surface, unknown strength and terrain roughness; and (3) Titan, with a completely unknown surface and possible liquid ocean. Additional information is contained in the original extended abstract.

  19. Precast concrete unit assessment through GPR survey and FDTD modelling

    NASA Astrophysics Data System (ADS)

    Campo, Davide

    2017-04-01

    Precast concrete elements are widely used within United Kingdom house building offering ease in assembly and added values as structural integrity, sound and thermal insulation; most common concrete components include walls, beams, floors, panels, lintels, stairs, etc. The lack of respect of the manufacturer instruction during assembling, however, may induce cracking and short/long term loss of bearing capacity. GPR is a well-established not destructive technique employed in the assessment of structural elements because of real-time imaging, quickness of data collecting and ability to discriminate finest structural details. In this work, GPR has been used to investigate two different precast elements: precast reinforced concrete planks constituting the roof slab of a school and precast wood-cement blocks with insulation material pre-fitted used to build a perimeter wall of a private building. Visible cracks affected both constructions. For the assessment surveys, a GSSI 2.0 GHz GPR antenna has been used because of the high resolution required and the small size of the antenna case (155 by 90 by 105mm) enabling scanning up to 45mm from any obstruction. Finite Difference Time Domain (FDTD) numerical modelling was also performed to build a scenario of the expected GPR signal response for a preliminary real-time interpretation and to help solve uncertainties due to complex reflection patterns: simulated radargrams were built using Reflex Software v. 8.2, reproducing the same GPR pulse used for the surveys in terms of wavelet, nominal frequency, sample frequency and time window. Model geometries were derived from the design projects available both for the planks and the blocks; the electromagnetic properties of the materials (concrete, reinforcing bars, air-filled void, insulation and wooden concrete) were inferred from both values reported in literature and a preliminary interpretation of radargrams where internal layer interfaces were clearly recognizable and univocally interpretable. Simulated and real radargrams comparison demonstrated that, in both cases, manufacturer instructions were not fully respected and confirmed GPR as a fast and effective structural assessment technique with the support of FDTD modelling as data interpretation validating method when complex reflection patterns are observed. GPR findings will be then used to address the intrusive coring necessary to evaluate the compressive strength of the concrete and, in synergy with the intrusive survey results, to plan properly corrective actions to ensure the stability of the structures and guarantee the usability.

  20. 12 CFR Appendix A to Subpart D of... - Examples of Mortgage Loan Originator Activities

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... by the savings association's loan approval mechanism function for a specific loan product is... compensation or gain. The following examples illustrate when an employee does or does not offer or negotiate terms of a loan “for compensation or gain.” (1) Offering or negotiating terms of a loan for compensation...

  1. 12 CFR Appendix A to Subpart D of... - Examples of Mortgage Loan Originator Activities

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... by the savings association's loan approval mechanism function for a specific loan product is... compensation or gain. The following examples illustrate when an employee does or does not offer or negotiate terms of a loan “for compensation or gain.” (1) Offering or negotiating terms of a loan for compensation...

  2. 12 CFR Appendix A to Subpart D of... - Examples of Mortgage Loan Originator Activities

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... by the savings association's loan approval mechanism function for a specific loan product is... compensation or gain. The following examples illustrate when an employee does or does not offer or negotiate terms of a loan “for compensation or gain.” (1) Offering or negotiating terms of a loan for compensation...

  3. 12 CFR Appendix A to Subpart D of... - Examples of Mortgage Loan Originator Activities

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... by the savings association's loan approval mechanism function for a specific loan product is... compensation or gain. The following examples illustrate when an employee does or does not offer or negotiate terms of a loan “for compensation or gain.” (1) Offering or negotiating terms of a loan for compensation...

  4. Hable con sus hijos: Antes de que lo hagan todos los demas (Talk with Your Kids...before Everyone Else Does: Talking with Kids about Tough Issues).

    ERIC Educational Resources Information Center

    Children Now, Oakland, CA.

    Parents are challenged daily with a wide range of disturbing issues that are difficult for children to understand and for adults to explain. This Spanish-language booklet offers practical, concrete tips and techniques for talking easily and openly with 8- to 12-year-olds about sex, HIV/AIDS, violence, drugs, and alcohol. The book is divided into…

  5. Making Democracy Work and Grow: Practical Suggestions for Students, Teachers, Administrators, and Other Community Leaders. Bulletin, 1948, No. 10

    ERIC Educational Resources Information Center

    Boie, Mildred Louise, Comp.

    1948-01-01

    Democracy is more than a creed or a doctrine. It must be a continuing force in the daily thinking, working, and living of all our citizens. American schools and colleges can strengthen democracy by practicing it--by showing concretely the basic advantages it offers to human beings. It is in the homes and in the schools, in home towns and local…

  6. PubMed Central

    Simoes, Elisabeth; Gostomzyk, Johannes; Brucker, Sara Yvonne; Graf, Joachim

    2017-01-01

    Introduction There has been very little medical research into pregnancies which occur in the context of prostitution, even though the associated health risks for mother and child, e.g. violence or maternal drug abuse, are well known. The aim of this study was to compile and summarize what is known (inter-)nationally about this topic and identify key points of support as part of a uniform standard of healthcare in pregnancy. Material and Methods A selective search of the literature was done in Pubmed and Livivo/Medpilot and in the databases NIH, Cochrane, DARE, NHSEED and HTA on the factors influencing preterm delivery. Results There are no systematic studies on pregnancy risks in the context of sexual services. But there is data available on specific risk factors, for example the increased risk of prematurity associated with sexual/physical violence (OR = 1.28–4.7). The Prostitute Protection Act provides only limited protection for affected women, and statutory maternity protection regulations also have little impact as they require a formal contract of employment which rarely exists even in the context of legal prostitution. Conclusion Approximately 400 000 women are currently working as prostitutes in the Federal Republic of Germany. The number of unreported cases is high. Nevertheless, there is little concrete data available on the probable health risks if these women become pregnant. The existing laws that should offer protection fall short of the mark. There is a need for more research into the future implementation of the Prostitute Protection Act which should focus on health counselling, health promotion and additional protective legislation. Low-threshold healthcare services offered in the context of prenatal care could be an opportunity to improve care. PMID:28553000

  7. Environmental and technical assessments of the potential utilization of sewage sludge ashes (SSAs) as secondary raw materials in construction

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chen, Maozhe; Blanc, Denise, E-mail: denise.blanc-biscarat@insa-lyon.fr; Gautier, Mathieu

    2013-05-15

    Highlights: ► We used sewage sludge ashes in ready-mix concrete recipe. ► SSAs were used as a substitution of cement. ► Compressive strength of ready-mix concrete incorporating SSAs were similar as blank one. ► Contaminants leaching from concrete monoliths were above threshold limits. - Abstract: Ashes produced by thermal treatments of sewage sludge exhibit common properties with cement. For example, major elements present in SSA are the same of major elements of cement. Hydraulic properties of SSA are quite the same of cement ones. They may therefore be used to substitute part of cement in concrete or other cementitious materials,more » provided that technical prescriptions are satisfied and that environmental risks are not significantly increased. The objective of the present study was to determine the appropriate substitution ratios to satisfy both technical and environmental criteria. In a first step, the elemental composition and particle size distribution of the ashes were measured. Then the ashes were used along with Portland cement and sand at different ratios of substitution to produce mortar and concrete which were cured for up to 90 days into parallelepipedic or cylindrical monoliths. The mechanical properties of the monoliths were measured using standard procedures for flexural and compressive strengths, and compared to blanks containing no ashes. The environmental criteria were assessed using leaching tests conducted according to standard protocols both on the ashes and the monoliths, and compared to the blanks. Results showed that the characteristics of the ashes ranged between those of cement and sand because of their larger particle size and higher content in SiO{sub 2} as compared to cement. The monoliths made with the highest substitution ratios exhibited a significant decrease in flexural and compressive strengths. However, when the ashes were used in partial substitution of cement at appropriate ratios, the concrete monoliths exhibited similar compressive strengths as the blank samples. The most appropriate ratios were found to be 10% substitution of cement and 2% substitution of sand. The leaching tests conducted on the ashes in their powdery form revealed that amongst the potential contaminants analyzed only Mo and Se were leached at concentrations above the threshold limits considered. The leaching tests conducted on concrete monoliths showed however that none of the contaminants monitored, including Mo and Se, were leached above the limits. In addition, whether concrete recipe incorporated ashes or not, similar concentrations were measured for each potential contaminant in the leachates. This result indicated that mixing ash with cement and sand to produce mortar or concrete induced a stabilization of Mo and Se and thereby constituted in itself a good treatment of the ashes.« less

  8. The tale wagged by the DAG: broadening the scope of causal inference and explanation for epidemiology.

    PubMed

    Krieger, Nancy; Davey Smith, George

    2016-12-01

    'Causal inference', in 21st century epidemiology, has notably come to stand for a specific approach, one focused primarily on counterfactual and potential outcome reasoning and using particular representations, such as directed acyclic graphs (DAGs) and Bayesian causal nets. In this essay, we suggest that in epidemiology no one causal approach should drive the questions asked or delimit what counts as useful evidence. Robust causal inference instead comprises a complex narrative, created by scientists appraising, from diverse perspectives, different strands of evidence produced by myriad methods. DAGs can of course be useful, but should not alone wag the causal tale. To make our case, we first address key conceptual issues, after which we offer several concrete examples illustrating how the newly favoured methods, despite their strengths, can also: (i) limit who and what may be deemed a 'cause', thereby narrowing the scope of the field; and (ii) lead to erroneous causal inference, especially if key biological and social assumptions about parameters are poorly conceived, thereby potentially causing harm. As an alternative, we propose that the field of epidemiology consider judicious use of the broad and flexible framework of 'inference to the best explanation', an approach perhaps best developed by Peter Lipton, a philosopher of science who frequently employed epidemiologically relevant examples. This stance requires not only that we be open to being pluralists about both causation and evidence but also that we rise to the challenge of forging explanations that, in Lipton's words, aspire to 'scope, precision, mechanism, unification and simplicity'. © The Author 2016; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.

  9. Axial compression behavior and partial composite action of SC walls in safety-related nuclear facilities

    NASA Astrophysics Data System (ADS)

    Zhang, Kai

    Steel-plate reinforced concrete (SC) composite walls typically consist of thick concrete walls with two exterior steel faceplates. The concrete core is sandwiched between the two steel faceplates, and the faceplates are attached to the concrete core using shear connectors, for example, ASTM A108 steel headed shear studs. The shear connectors and the concrete infill enhance the stability of the steel faceplates, and the faceplates serve as permanent formwork for concrete placement. SC composite walls were first introduced in the 1980's in Japan for nuclear power plant (NPP) structures. They are used in the new generation of nuclear power plants (GIII+) and being considered for small modular reactors (SMR) due to their structural efficiency, economy, safety, and construction speed. Steel faceplates can potentially undergo local buckling at certain locations of NPP structures where compressive forces are significant. The steel faceplates are usually thin (0.25 to 1.50 inches in Customary units, or 6.5 to 38 mm in SI units) to maintain economical and constructional efficiency, the geometric imperfections and locked-in stresses induced during construction make them more vulnerable to local buckling. Accidental thermal loading may also reduce the compressive strength and exacerbate the local buckling potential of SC composite walls. This dissertation presents the results from experimental and numerical investigations of the compressive behavior of SC composite walls at ambient and elevated temperatures. The results are used to establish a slenderness limit to prevent local buckling before yielding of the steel faceplates and to develop a design approach for calculating the compressive strength of SC composite walls with non-slender and slender steel faceplates at ambient and elevated temperatures. Composite action in SC walls is achieved by the embedment of shear connectors into the concrete core. The strength and stiffness of shear connectors govern the level of composite action. This level of partial composite action can influence the behavior and stiffness of SC composite walls. This dissertation presents numerical investigations of the level of partial composite action and its influence on the flexural stiffness of SC walls. The results are used to propose design criteria for steel headed shear studs, such as their size, spacing, and strength.

  10. Measurement in Service Businesses: Challenges and Future Directions

    NASA Astrophysics Data System (ADS)

    Tyagi, Rajesh Kumar

    This chapter presents challenges faced by service businesses while implementing a measurement system. A review of existing frameworks is presented and a new framework, the Service Scorecard, is introduced. The Service Scorecard is an adaptation of the Six Sigma Business Scorecard for the service sector. The framework has also been influenced by existing frameworks such as the Malcom Baldrige award criteria, the Balanced Scorecard, the European Quality award and the Service Profit Chain model. The seven elements of the Service Scorecard are Growth, Leadership, Acceleration, Collaboration, Innovation, Execution, and Retention. The examples of measurement systems are presented with concrete real-world case examples. Final thoughts and the challenges faced are also presented.

  11. Current Technologies and its Trends of Machine Vision in the Field of Security and Disaster Prevention

    NASA Astrophysics Data System (ADS)

    Hashimoto, Manabu; Fujino, Yozo

    Image sensing technologies are expected as useful and effective way to suppress damages by criminals and disasters in highly safe and relieved society. In this paper, we describe current important subjects, required functions, technical trends, and a couple of real examples of developed system. As for the video surveillance, recognition of human trajectory and human behavior using image processing techniques are introduced with real examples about the violence detection for elevators. In the field of facility monitoring technologies as civil engineering, useful machine vision applications such as automatic detection of concrete cracks on walls of a building or recognition of crowded people on bridge for effective guidance in emergency are shown.

  12. Security and Dependability Solutions for Networks and Devices

    NASA Astrophysics Data System (ADS)

    Gücrgens, Sigrid; Fuchs, Andreas

    In this chapter we give an overview over the denotation of the SERENITY artefacts S&D Classes, Patterns and Implementations in the context of networks and devices. In order to demonstrate their necessity we sketch an example for confidential and authentic communication and storage that utilizes a trusted platform module, and model the relevant pattern. We then dissociate solutions for network and device related S&D requirements from those targeting the context of organizational or workflow and web services based solutions. Then we give a summary of the broad field of application for network and device solutions. Finally we clarify the meaning and interaction between classes, patterns and implementations by giving some concrete examples.

  13. Contingency Management and Deliberative Decision-Making Processes.

    PubMed

    Regier, Paul S; Redish, A David

    2015-01-01

    Contingency management is an effective treatment for drug addiction. The current explanation for its success is rooted in alternative reinforcement theory. We suggest that alternative reinforcement theory is inadequate to explain the success of contingency management and produce a model based on demand curves that show how little the monetary rewards offered in this treatment would affect drug use. Instead, we offer an explanation of its success based on the concept that it accesses deliberative decision-making processes. We suggest that contingency management is effective because it offers a concrete and immediate alternative to using drugs, which engages deliberative processes, improves the ability of those deliberative processes to attend to non-drug options, and offsets more automatic action-selection systems. This theory makes explicit predictions that can be tested, suggests which users will be most helped by contingency management, and suggests improvements in its implementation.

  14. Contingency Management and Deliberative Decision-Making Processes

    PubMed Central

    Regier, Paul S.; Redish, A. David

    2015-01-01

    Contingency management is an effective treatment for drug addiction. The current explanation for its success is rooted in alternative reinforcement theory. We suggest that alternative reinforcement theory is inadequate to explain the success of contingency management and produce a model based on demand curves that show how little the monetary rewards offered in this treatment would affect drug use. Instead, we offer an explanation of its success based on the concept that it accesses deliberative decision-making processes. We suggest that contingency management is effective because it offers a concrete and immediate alternative to using drugs, which engages deliberative processes, improves the ability of those deliberative processes to attend to non-drug options, and offsets more automatic action-selection systems. This theory makes explicit predictions that can be tested, suggests which users will be most helped by contingency management, and suggests improvements in its implementation. PMID:26082725

  15. Sulfate and acid resistant concrete and mortar

    DOEpatents

    Liskowitz, John W.; Wecharatana, Methi; Jaturapitakkul, Chai; Cerkanowicz, deceased, Anthony E.

    1998-01-01

    The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction and other applications, which hardenable mixtures demonstrate significant levels of acid and sulfate resistance while maintaining acceptable compressive strength properties. The acid and sulfate hardenable mixtures of the invention containing fly ash comprise cementitious materials and a fine aggregate. The cementitous materials may comprise fly ash as well as cement. The fine aggregate may comprise fly ash as well as sand. The total amount of fly ash in the hardenable mixture ranges from about 60% to about 120% of the total amount of cement, by weight, whether the fly ash is included as a cementious material, fine aggregate, or an additive, or any combination of the foregoing. In specific examples, mortar containing 50% fly ash and 50% cement in cementitious materials demonstrated superior properties of corrosion resistance.

  16. Sulfate and acid resistant concrete and mortar

    DOEpatents

    Liskowitz, J.W.; Wecharatana, M.; Jaturapitakkul, C.; Cerkanowicz, A.E.

    1998-06-30

    The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction and other applications, which hardenable mixtures demonstrate significant levels of acid and sulfate resistance while maintaining acceptable compressive strength properties. The acid and sulfate hardenable mixtures of the invention containing fly ash comprise cementitious materials and a fine aggregate. The cementitous materials may comprise fly ash as well as cement. The fine aggregate may comprise fly ash as well as sand. The total amount of fly ash in the hardenable mixture ranges from about 60% to about 120% of the total amount of cement, by weight, whether the fly ash is included as a cementious material, fine aggregate, or an additive, or any combination of the foregoing. In specific examples, mortar containing 50% fly ash and 50% cement in cementitious materials demonstrated superior properties of corrosion resistance. 6 figs.

  17. Behavior of a PCM at Varying Heating Rates: Experimental and Theoretical Study with an Aim at Temperature Moderation in Radionuclide Concrete Encasements

    NASA Astrophysics Data System (ADS)

    Medved', Igor; Trník, Anton

    2018-07-01

    Phase-change materials (PCMs) can store/release thermal energy within a small temperature range. This is of interest in various industrial applications, for example, in civil engineering (heating/cooling of buildings) or cold storage applications. Another application may be the moderation of temperature increases in concrete encasements of radionuclides during their decay. The phase-change behavior of a material is determined by its heat capacity and the peak it exhibits near a phase change. We analyze the behavior of such peaks for a selected PCM at heating rates varying between 0.1°C\\cdot min^{-1} and 1°C\\cdot min^{-1}, corresponding in real situations to different decay rates of radionuclides. We show that experimentally measured peaks can be plausibly described by an equilibrium theory that enables us to calculate the latent heat and phase-change temperature from experimental data.

  18. Structural violence: a barrier to achieving the millennium development goals for women.

    PubMed

    Mukherjee, Joia S; Barry, Donna J; Satti, Hind; Raymonville, Maxi; Marsh, Sarah; Smith-Fawzi, Mary Kay

    2011-04-01

    In 2000, all 191 United Nations member states agreed to work toward the achievement of a set of health and development goals by 2015. The achievement of these eight goals, the Millennium Development goals (MDGs) is highly dependent on improving the status of women, who play a key role in health and education in families and communities around the world. Yet structural violence, defined as the systematic exclusion of a group from the resources needed to develop their full human potential, remains a significant barrier against women's development and threatens the achievement of the MDGs. Although sound evidence has long existed for improving women's survival, the will to address women's health concretely and holistically is only recently gaining the advocacy needed to change policy. Concrete examples of the integration of approaches to mitigate structural violence within the delivery of health services do exist and should be incorporated into global advocacy for women's health.

  19. 48 CFR 25.504 - Evaluation Examples.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Evaluation Examples. 25... PROGRAMS FOREIGN ACQUISITION Evaluating Foreign Offers-Supply Contracts 25.504 Evaluation Examples. The following examples illustrate the application of the evaluation procedures in 25.502 and 25.503. The...

  20. 48 CFR 225.504 - Evaluation examples.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Evaluation examples. 225..., DEPARTMENT OF DEFENSE SOCIOECONOMIC PROGRAMS FOREIGN ACQUISITION Evaluating Foreign Offers-Supply Contracts 225.504 Evaluation examples. For examples that illustrate the evaluation procedures in 225.502(c)(ii...

  1. From Concrete Examples to Abstract Relations: The Rostrolateral Prefrontal Cortex Integrates Novel Examples into Relational Categories.

    PubMed

    Davis, Tyler; Goldwater, Micah; Giron, Josue

    2017-04-01

    The ability to form relational categories for objects that share few features in common is a hallmark of human cognition. For example, anything that can play a preventative role, from a boulder to poverty, can be a "barrier." However, neurobiological research has focused solely on how people acquire categories defined by features. The present functional magnetic resonance imaging study examines how relational and feature-based category learning compare in well-matched learning tasks. Using a computational model-based approach, we observed a cluster in left rostrolateral prefrontal cortex (rlPFC) that tracked quantitative predictions for the representational distance between test and training examples during relational categorization. Contrastingly, medial and dorsal PFC exhibited graded activation that tracked decision evidence during both feature-based and relational categorization. The results suggest that rlPFC computes an alignment signal that is critical for integrating novel examples during relational categorization whereas other PFC regions support more general decision functions. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  2. Lower and upper bounds for entanglement of Rényi-α entropy.

    PubMed

    Song, Wei; Chen, Lin; Cao, Zhuo-Liang

    2016-12-23

    Entanglement Rényi-α entropy is an entanglement measure. It reduces to the standard entanglement of formation when α tends to 1. We derive analytical lower and upper bounds for the entanglement Rényi-α entropy of arbitrary dimensional bipartite quantum systems. We also demonstrate the application our bound for some concrete examples. Moreover, we establish the relation between entanglement Rényi-α entropy and some other entanglement measures.

  3. Anisotropic adaptive mesh generation in two dimensions for CFD

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Borouchaki, H.; Castro-Diaz, M.J.; George, P.L.

    This paper describes the extension of the classical Delaunay method in the case where anisotropic meshes are required such as in CFD when the modelized physic is strongly directional. The way in which such a mesh generation method can be incorporated in an adaptative loop of CFD as well as the case of multicriterium adaptation are discussed. Several concrete application examples are provided to illustrate the capabilities of the proposed method.

  4. Constrained field theories on spherically symmetric spacetimes with horizons

    NASA Astrophysics Data System (ADS)

    Fernandes, Karan; Lahiri, Amitabha; Ghosh, Suman

    2017-02-01

    We apply the Dirac-Bergmann algorithm for the analysis of constraints to gauge theories defined on spherically symmetric black hole backgrounds. We find that the constraints for a given theory are modified on such spacetimes through the presence of additional contributions from the horizon. As a concrete example, we consider the Maxwell field on a black hole background, and determine the role of the horizon contributions on the dynamics of the theory.

  5. JView Visualization for Next Generation Air Transportation System

    DTIC Science & Technology

    2011-01-01

    hardware graphics acceleration. JView relies on concrete Object Oriented Design (OOD) and programming techniques to provide a robust and venue non...visibility priority of a texture set. A good example of this is you have translucent images that should always be visible over the other textures...elements present in the scene. • Capture Alpha. Allows the alpha color channel ( translucency ) to be saved when capturing images or movies of a 3D scene

  6. Computational Modeling of Multi-Scale Material Features in Cement Paste - An Overview

    DTIC Science & Technology

    2015-05-25

    and concrete ; though commonly used are one of the most complex in terms of material morphology and structure than most materials, for example...across the multiple scales are required. In this paper, recent work from our research group on the nano to continuum level modeling of cementitious...of our research work consisting of, • Molecular Dynamics (MD) modeling for the nano scale features of the cementitious material chemistry. • Micro

  7. Structural Design and Economic Evaluation of Roller Compacted Concrete Pavement with Recycled Aggregates

    NASA Astrophysics Data System (ADS)

    Abut, Yavuz; Taner Yildirim, Salih

    2017-10-01

    Using recycled aggregates in the concrete offers advantages in many areas such as waste management, energy save and natural resources, conservation of ecological balance, low CO2 emissions, and users are encouraged in this regard to use these materials. In this study, the profit / loss account arising in the structural design phase was investigated when Reclaimed Asphalt Pavement (RAP), which is limited to use in Roller Compacted Concrete (RCC) pavements, was used as coarse aggregate. RAP materials were used as coarse aggregates by the levels of 0%, 15% and 20% and mechanical properties such as compressive strength, flexural strength, splitting tensile strength and modulus of elasticity were investigated. In the last stage, the mechanical properties obtained from these experimental studies were entered into KENSLABS software as input, and the slab layer thicknesses were determined according to three different subgrade conditions and a certain fatigue criterion. According to the results, it has been determined that the use of RAP at a level of 20% is a serious reducing effect on mechanical properties and and the use of RAP at a level of 15% does not bring a great economic benefit but it is reasonable to use it as coarse aggregate in RCC mixes in consideration of environmental effects.

  8. A brain-based account of “basic-level” concepts

    PubMed Central

    Bauer, Andrew James; Just, Marcel Adam

    2017-01-01

    This study provides a brain-based account of how object concepts at an intermediate (basic) level of specificity are represented, offering an enriched view of what it means for a concept to be a basic-level concept, a research topic pioneered by Rosch and others (Rosch et al., 1976). Applying machine learning techniques to fMRI data, it was possible to determine the semantic content encoded in the neural representations of object concepts at basic and subordinate levels of abstraction. The representation of basic-level concepts (e.g. bird) was spatially broad, encompassing sensorimotor brain areas that encode concrete object properties, and also language and heteromodal integrative areas that encode abstract semantic content. The representation of subordinate-level concepts (robin) was less widely distributed, concentrated in perceptual areas that underlie concrete content. Furthermore, basic-level concepts were representative of their subordinates in that they were neurally similar to their typical but not atypical subordinates (bird was neurally similar to robin but not woodpecker). The findings provide a brain-based account of the advantages that basic-level concepts enjoy in everyday life over subordinate-level concepts: the basic level is a broad topographical representation that encompasses both concrete and abstract semantic content, reflecting the multifaceted yet intuitive meaning of basic-level concepts. PMID:28826947

  9. Utilisation of steel furnace slag coarse aggregate in a low calcium fly ash geopolymer concrete

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Khan, M. S.H.,; Castel, Arnaud; Akbarnezhad, A.

    This paper evaluates the performance of steel furnace slag (SFS) coarse aggregate in blended slag and low calcium fly ash geopolymer concrete (GPC). The geopolymer binder is composed of 90% of low calcium fly ash and 10% of ground granulated blast furnace slag (GGBFS). Mechanical and physical properties, shrinkage, and detailed microstructure analysis were carried out. The results showed that geopolymer concrete with SFS aggregate offered higher compressive strength, surface resistivity and pulse velocity than that of GPC with traditional aggregate. The shrinkage results showed no expansion or swelling due to delayed calcium oxide (CaO) hydration after 320 days. Nomore » traditional porous interfacial transition zone (ITZ) was detected using scanning electron microscopy, indicating a better bond between SFS aggregate and geopolymer matrix. Energy dispersive spectroscopy results further revealed calcium (Ca) diffusion at the vicinity of ITZ. Raman spectroscopy results showed no new crystalline phase formed due to Ca diffusion. X-ray fluorescence result showed Mg diffusion from SFS aggregate towards geopolymer matrix. The incorporation of Ca and Mg into the geopolymer structure and better bond between SFS aggregate and geopolymer matrix are the most likely reasons for the higher compressive strength observed in GPC with SFS aggregate.« less

  10. A brain-based account of "basic-level" concepts.

    PubMed

    Bauer, Andrew James; Just, Marcel Adam

    2017-11-01

    This study provides a brain-based account of how object concepts at an intermediate (basic) level of specificity are represented, offering an enriched view of what it means for a concept to be a basic-level concept, a research topic pioneered by Rosch and others (Rosch et al., 1976). Applying machine learning techniques to fMRI data, it was possible to determine the semantic content encoded in the neural representations of object concepts at basic and subordinate levels of abstraction. The representation of basic-level concepts (e.g. bird) was spatially broad, encompassing sensorimotor brain areas that encode concrete object properties, and also language and heteromodal integrative areas that encode abstract semantic content. The representation of subordinate-level concepts (robin) was less widely distributed, concentrated in perceptual areas that underlie concrete content. Furthermore, basic-level concepts were representative of their subordinates in that they were neurally similar to their typical but not atypical subordinates (bird was neurally similar to robin but not woodpecker). The findings provide a brain-based account of the advantages that basic-level concepts enjoy in everyday life over subordinate-level concepts: the basic level is a broad topographical representation that encompasses both concrete and abstract semantic content, reflecting the multifaceted yet intuitive meaning of basic-level concepts. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Use of formwork systems in high-rise construction

    NASA Astrophysics Data System (ADS)

    Kurakova, Oksana

    2018-03-01

    Erection of high quality buildings and structures within a reasonable time frame is the crucial factor for the competitiveness of any construction organization. The main material used in high-rise construction is insitu reinforced concrete. The technology of its use is directly related to the use of formwork systems. Formwork systems and formwork technologies basically determine the speed of construction and labor intensity of concreting operations. Therefore, it is also possible to achieve the goal of reducing the construction time and labor intensity of works performed by improving the technology of formwork systems use. Currently there are unresolved issues in the area of implementation of monolithic technology projects, and problems related to the selection of a formwork technology, high labor intensity of works, poor quality of materials and structures, etc. are the main ones. The article presents organizational and technological measures, by means of which introduction it is possible to shorten the duration of construction. A comparison of operations performed during formwork installation according to the conventional technology and taking into account the implemented organizational and technological measures is presented. The results of a comparative analysis of economic efficiency assessments are also presented on the example of a specific construction project before and after the implementation of the above mentioned measures. The study showed that introduction of the proposed organizational and technological model taking into account optimization of reinforcing and concreting works significantly improves the efficiency of a high-rise construction project. And further improvement of technologies for the use of insitu reinforced concrete is a promising direction in the construction of high-rise buildings.

  12. High spatial resolution analysis of ferromanganese concretions by LA-ICP-MS†

    PubMed Central

    Axelsson, Mikael D; Rodushkin, Ilia; Baxter, Douglas C; Ingri, Johan; Öhlander, Björn

    2002-01-01

    A procedure was developed for the determination of element distributions in cross-sections of ferromanganese concretions using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The effects of carrier flow rates, rf forward power, ablation energy, ablation spot size, repetition rate and number of shots per point on analyte intensity were studied. It is shown that different carrier gas flow rates are required in order to obtain maximum sensitivities for different groups of elements, thus complicating the optimisation of ICP parameters. On the contrary, LA parameters have very similar effects on almost all elements studied, thus providing a common optimum parameter set for the entire mass range. However, for selected LA parameters, the use of compromise conditions was necessary in order to compensate for relatively slow data acquisition by ICP-MS and maintain high spatial resolution without sacrificing the multielemental capabilities of the technique. Possible variations in ablation efficiency were corrected for mathematically using the sum of Fe and Mn intensities. Quantification by external calibration against matrix-matched standards was successfully used for more than 50 elements. These standards, in the form of pressed pellets (no binder), were prepared in-house using ferromanganese concentrates from a deep-sea nodule reference material as well as from shallow-marine concretions varying in size and having different proportions of three major phases: aluminosilicates, Fe- and Mn-oxyhydroxides. Element concentrations in each standard were determined by means of conventional solution nebulisation ICP-MS following acid digestion. Examples of selected inter-element correlations in distribution patterns along the cross-section of a concretion are given.

  13. Study of the structure of concrete with C-14-PMMA method

    NASA Astrophysics Data System (ADS)

    Muuri, E.; Tikkanen, O.; Ikonen, J.; Siitari-Kauppi, M.; Autio, M.

    2017-12-01

    Cement is used widely in the construction industry and, additionally, in the waste management industry for the stabilization of hazardous materials because of its capacity for both physical and chemical immobilization of contaminants. Cementitious materials have also been suggested as the backfilling materials, for example, in deep geological repositories for the final disposal of spent nuclear fuel. As a result, it is necessary to study the structure of the materials in different conditions. In this study, the structure of concrete was studied with the polymethylmetacrylate (PMMA) method in samples from the construction industry. The spatial distribution of porosity was characterized using this autoradiography method that involves the impregnation of a dried rock sample of hand specimen size with 14C-labelled methyl methacrylate (MMA) in vacuum, thermally initiated polymerization, film and digital autoradiography, and porosity calculation routines relying on digital image processing techniques [1]. Three main components are clearly visible on the PMMA autoradiographs of the studied concrete samples, because of their contrasted porosity (Fig 1.). Ground matrix cement shows even porosity; 27.0±4.7 %. The other two phases are mineral grains and bubbles, which are classified into four categories against their size and quantity. Fig 1. The scanned surface of the concrete sample (left) and the corresponding autoradiograph (right), where the darkest areas are caused by larger activity, and thus, larger porosity. The exposure time used for the autoradiogram was three days. J. Sammaljärvi, L. Jokelainen, J. Ikonen, M. Siitari-Kauppi, Eng. Geol. 135-136, 52-59 (2012).

  14. Treatment of complicated grief using virtual reality: a case report.

    PubMed

    Botella, C; Osma, J; Palacios, A García; Guillén, V; Baños, R

    2008-01-01

    This is the first work exploring the application of new technologies, concretely virtual reality, to facilitate emotional processing in the treatment of Complicated Grief. Our research team has designed a virtual reality environment (EMMA's World) to foster the expression and processing of emotions. In this study the authors present a description of EMMA's World, the clinical protocol, and a case report. The treatment program was applied in eight sessions. We present a brief description of the session agendas including the techniques used. We offer short-term (from pre-test to post-test) and long-term (2-, 6- and 12-month follow-ups) efficacy data. Our results offer preliminary support of the use of EMMA's World for the treatment of Complicated Grief.

  15. Enhanced definition and required examples of common datum imposed by ISO standard

    NASA Astrophysics Data System (ADS)

    Yan, Yiqing; Bohn, Martin

    2017-12-01

    According to the ISO Geometrical Product Specifications (GPS), the establishment and definition of common datum for geometrical components are not fully defined. There are two main limitations of this standard. Firstly: the explications of ISO examples of common datums are not matched with their corresponding definitions, and secondly: a full definition of common datum is missing. This paper suggests a new approach for an enhanced definition and concrete examples of common datum and proposes a holistic methodology for establishment of common datum for each geometrical component. This research is based on the analysis of physical behaviour of geometrical components, orientation constraints and invariance classes of datums. This approach fills the definition gaps of common datum based on ISO GPS, thereby eliminating those deficits. As a result, an improved methodology for a fully functional defined definition of common datum was formulated.

  16. New Finsler package

    NASA Astrophysics Data System (ADS)

    Youssef, Nabil L.; Elgendi, S. G.

    2014-03-01

    The book “Handbook of Finsler geometry” has been included with a CD containing an elegant Maple package, FINSLER, for calculations in Finsler geometry. Using this package, an example concerning a Finsler generalization of Einstein’s vacuum field equations was treated. In this example, the calculation of the components of the hv-curvature of Cartan connection leads to wrong expressions. On the other hand, the FINSLER package works only in dimension four. We introduce a new Finsler package in which we fix the two problems and solve them. Moreover, we extend this package to compute not only the geometric objects associated with Cartan connection but also those associated with Berwald, Chern and Hashiguchi connections in any dimension. These improvements have been illustrated by a concrete example. Furthermore, the problem of simplifying tensor expressions is treated. This paper is intended to make calculations in Finsler geometry more easier and simpler.

  17. Evolution of an Interfacial Crack on the Concrete Embankment Boundary

    NASA Astrophysics Data System (ADS)

    Smith, J.; Ezzedine, S. M.; Lomov, I.; Kanarska, Y.; Antoun, T.; Glascoe, L. G.; Hall, R. L.; Woodson, S. C.

    2013-12-01

    Failure of a dam can have subtle beginnings: a small crack or dislocation at the interface of the concrete dam and the surrounding embankment soil initiated by a seismic event, for example, can: a) result in creating gaps between the concrete dam and the lateral embankments; b) initiate internal erosion of embankment; and c) lead to a catastrophic failure of the dam. The dam may ';self-rehabilitate' if a properly designed granular filter is engineered around the embankment. Currently, the design criteria for such filters have only been based on experimental studies. We demonstrate the numerical prediction of filter effectiveness at the soil grain scale and relate it to the larger dam scale. Validated computer predictions highlight that a resilient (or durable) filter is consistent with the current design specifications for dam filters. These predictive simulations, unlike the design specifications, can be used to assess filter success or failure under different soil or loading conditions and can lead to meaningful estimates of the timing and nature of full-scale dam failure. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 and was sponsored by the Department of Homeland Security (DHS), Science and Technology Directorate, Homeland Security Advanced Research Projects Agency (HSARPA).

  18. Illustrated Examples of the Effects of Risk Preferences and Expectations on Bargaining Outcomes.

    ERIC Educational Resources Information Center

    Dickinson, David L.

    2003-01-01

    Describes bargaining examples that use expected utility theory. Provides example results that are intuitive, shown graphically and algebraically, and offer upper-level student samples that illustrate the usefulness of the expected utility theory. (JEH)

  19. Australian Medical Students' Association Global Health Essay Competition - Global climate change, geo-engineering and human health.

    PubMed

    Boyages, Costa S

    2013-10-07

    Rio+20's proposed Sustainable Development Goals have the potential to redefine the course of international action on climate change. They recognise that environmental health is inextricably linked with human health, and that environmental sustainability is of paramount importance in safeguarding global health. Competition entrants were asked to discuss ways of making global health a central component of international sustainable development initiatives and environmental policy, using one or two concrete examples

  20. Time evolution of the eddy viscosity in two-dimensional navier-stokes flow

    PubMed

    Chaves; Gama

    2000-02-01

    The time evolution of the eddy viscosity associated with an unforced two-dimensional incompressible Navier-Stokes flow is analyzed by direct numerical simulation. The initial condition is such that the eddy viscosity is isotropic and negative. It is shown by concrete examples that the Navier-Stokes dynamics stabilizes negative eddy viscosity effects. In other words, this dynamics moves monotonically the initial negative eddy viscosity to positive values before relaxation due to viscous term occurs.

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