Development of deployable structures for large space platforms. Volume 2: Design development
NASA Technical Reports Server (NTRS)
Greenberg, H. S.
1983-01-01
Design evolution, test article design, test article mass properties, and structural analysis of deployable platform systems are discussed. Orbit transfer vehicle (OTV) hangar development, OTV hangar concept selection, and manned module development are discussed. Deployable platform systems requirements, material data base, technology development needs, concept selection and deployable volume enclosures are also discussed.
Commercial transport aircraft composite structures
NASA Technical Reports Server (NTRS)
Mccarty, J. E.
1983-01-01
The role that analysis plays in the development, production, and substantiation of aircraft structures is discussed. The types, elements, and applications of failure that are used and needed; the current application of analysis methods to commercial aircraft advanced composite structures, along with a projection of future needs; and some personal thoughts on analysis development goals and the elements of an approach to analysis development are discussed.
Preliminary shuttle structural dynamics modeling design study
NASA Technical Reports Server (NTRS)
1972-01-01
The design and development of a structural dynamics model of the space shuttle are discussed. The model provides for early study of structural dynamics problems, permits evaluation of the accuracy of the structural and hydroelastic analysis methods used on test vehicles, and provides for efficiently evaluating potential cost savings in structural dynamic testing techniques. The discussion is developed around the modes in which major input forces and responses occur and the significant structural details in these modes.
Recent developments in large-scale structural optimization
NASA Technical Reports Server (NTRS)
Venkayya, Vipperla B.
1989-01-01
A brief discussion is given of mathematical optimization and the motivation for the development of more recent numerical search procedures. A review of recent developments and issues in multidisciplinary optimization is also presented. These developments are discussed in the context of the preliminary design of aircraft structures. A capability description of programs FASTOP, TSO, STARS, LAGRANGE, ELFINI and ASTROS is included.
Structural analysis and design for the development of floating photovoltaic energy generation system
NASA Astrophysics Data System (ADS)
Yoon, S. J.; Joo, H. J.; Kim, S. H.
2018-06-01
In this paper, we discussed the structural analysis and design for the development of floating photovoltaic energy generation system. Series of research conducted to develop the system from the analysis and design of the structural system to the installation of the system discussed. In the structural system supporting solar panels PFRP materials and SMC FRP materials used. A unit module structure is fabricated and then the unit module structures are connected each other to assemble whole PV energy generation complex. This system connected directly to the power grid system. In addition, extensive monitoring for the efficiency of electricity generation and the soundness of the structural system is in progress for the further system enhancement.
NASA Technical Reports Server (NTRS)
Frost, R. K.; Jones, J. S.; Dynes, P. J.; Wykes, D. H.
1981-01-01
The development and demonstration of manufacturing technologies for the structural application of Celion graphite/LARC-160 polyimide composite material is discussed. Process development and fabrication of demonstration components are discussed. Process development included establishing quality assurance of the basic composite material and processing, nondestructive inspection of fabricated components, developing processes for specific structural forms, and qualification of processes through mechanical testing. Demonstration components were fabricated. The demonstration components consisted of flat laminates, skin/stringer panels, honeycomb panels, chopped fiber compression moldings, and a technology demonstrator segment (TDS) representative of the space shuttle aft body flap.
Overview of an Advanced Hypersonic Structural Concept Test Program
NASA Technical Reports Server (NTRS)
Stephens, Craig A.; Hudson, Larry D.; Piazza, Anthony
2007-01-01
This viewgraph presentation provides an overview of hypersonics M&S advanced structural concepts development and experimental methods. The discussion on concepts development includes the background, task objectives, test plan, and current status of the C/SiC Ruddervator Subcomponent Test Article (RSTA). The discussion of experimental methods examines instrumentation needs, sensors of interest, and examples of ongoing efforts in the development of extreme environment sensors.
Fostering Leadership through Organizational Structure
ERIC Educational Resources Information Center
Willett, Brantley P.
2012-01-01
This case study discusses the postindustrial paradigm of leadership and its influence on the field of leadership and also the higher education leadership literature. Furthermore, this case study examines the structure of one university honor society to discuss how the structure allows for the development of multiple leaders within the…
Power Structures and Rural Development.
ERIC Educational Resources Information Center
Beal, George M.
Some of the assumptions, conditions, and parameters which deal with power structures and rural development are briefly specified in this paper. The definitions (conceptual and operational) for power, social power, authority, influence, power structure, development, and rural are discussed. The ideological orientation under which development…
Structural dynamics payload loads estimates
NASA Technical Reports Server (NTRS)
Engels, R. C.
1982-01-01
Methods for the prediction of loads on large space structures are discussed. Existing approaches to the problem of loads calculation are surveyed. A full scale version of an alternate numerical integration technique to solve the response part of a load cycle is presented, and a set of short cut versions of the algorithm developed. The implementation of these techniques using the software package developed is discussed.
Piezoceramic devices and artificial intelligence time varying concepts in smart structures
NASA Technical Reports Server (NTRS)
Hanagud, S.; Calise, A. J.; Glass, B. J.
1990-01-01
The problem of development of smart structures and their vibration control by the use of piezoceramic sensors and actuators have been discussed. In particular, these structures are assumed to have time varying model form and parameters. The model form may change significantly and suddenly. Combined identification of the model from parameters of these structures and model adaptive control of these structures are discussed in this paper.
Developing an Approach for Teaching and Learning about Lewis Structures
ERIC Educational Resources Information Center
Kaufmann, Ilana; Hamza, Karim M.; Rundgren, Carl-Johan; Eriksson, Lars
2017-01-01
This study explores first-year university students' reasoning as they learn to draw Lewis structures. We also present a theoretical account of the formal procedure commonly taught for drawing these structures. Students' discussions during problem-solving activities were video recorded and detailed analyses of the discussions were made through the…
Structures Technology for Future Aerospace Systems
NASA Technical Reports Server (NTRS)
Noor, Ahmed K.; Venneri, Samuel L.; Paul, Donald B.; Hopkins, Mark A.
2000-01-01
An overview of structures technology for future aerospace systems is given. Discussion focuses on developments in component technologies that will improve the vehicle performance, advance the technology exploitation process, and reduce system life-cycle costs. The component technologies described are smart materials and structures, multifunctional materials and structures, affordable composite structures, extreme environment structures, flexible load bearing structures, and computational methods and simulation-based design. The trends in each of the component technologies are discussed and the applicability of these technologies to future aerospace vehicles is described.
Quantifying the Workload of Subject Bibliographers in Collection Development.
ERIC Educational Resources Information Center
Metz, Paul
1991-01-01
Discussion of the role of subject bibliographers in collection development activities focuses on an approach developed at Virginia Polytechnic and State Institute to provide a formula for estimating the collection development workload of subject bibliographers. Workload standards and matrix models of organizational structures are discussed, and…
New Parenting Challenges in Europe Today.
ERIC Educational Resources Information Center
Fthenakis, Wassilios E.
This article discusses factors affecting parents in contemporary Europe. The focus is on family development, mechanisms conditioning social and family interactions, and the historical processes that are resulting in changes in family structure. Family changes discussed include the declining birthrate, structural conditions for parenthood, changing…
NASA Workshop on Computational Structural Mechanics 1987, part 2
NASA Technical Reports Server (NTRS)
Sykes, Nancy P. (Editor)
1989-01-01
Advanced methods and testbed/simulator development topics are discussed. Computational Structural Mechanics (CSM) testbed architecture, engine structures simulation, applications to laminate structures, and a generic element processor are among the topics covered.
Self-Learning through Programmed Learning in Distance Mode.
ERIC Educational Resources Information Center
Rao, D. Prakasa; Reddy, B. Sudhakar
2002-01-01
Presents the characteristics and development of self-learning material (SLM) in distance education. Discusses teaching with programmed learning; structure of SLM; and how SLM helps in self-study. Discusses the advantages of print materials as accompanying programmed instruction, because they are portable, well-structured, compact, and easily…
Biomimetic multifunctional surfaces inspired from animals.
Han, Zhiwu; Mu, Zhengzhi; Yin, Wei; Li, Wen; Niu, Shichao; Zhang, Junqiu; Ren, Luquan
2016-08-01
Over millions of years, animals have evolved to a higher intelligent level for their environment. A large number of diverse surface structures on their bodies have been formed to adapt to the extremely harsh environment. Just like the structural diversity existed in plants, the same also applies true in animals. Firstly, this article provides an overview and discussion of the most common functional surface structures inspired from animals, such as drag reduction, noise reduction, anti-adhesion, anti-wear, anti-erosion, anti-fog, water capture, and optical surfaces. Then, some typical characteristics of morphologies, structures, and materials of the animal multifunctional surfaces were discussed. The adaptation of these surfaces to environmental conditions was also analyzed. It mainly focuses on the relationship between their surface functions and their surface structural characteristics. Afterwards, the multifunctional mechanisms or principles of these surfaces were discussed. Models of these structures were provided for the development of structure materials and machinery surfaces. At last, fabrication techniques and existing or potential technical applications inspired from biomimetic multifunctional surfaces in animals were also discussed. The application prospects of the biomimetic functional surfaces are very broad, such as civil field of self-cleaning textile fabrics and non-stick pots, ocean field of oil-water separation, sports field of swimming suits, space development field of lens arrays. Copyright © 2016 Elsevier B.V. All rights reserved.
Development of Textile Reinforced Composites for Aircraft Structures
NASA Technical Reports Server (NTRS)
Dexter, H. Benson
1998-01-01
NASA has been a leader in development of composite materials for aircraft applications during the past 25 years. In the early 1980's NASA and others conducted research to improve damage tolerance of composite structures through the use of toughened resins but these resins were not cost-effective. The aircraft industry wanted affordable, robust structures that could withstand the rigors of flight service with minimal damage. The cost and damage tolerance barriers of conventional laminated composites led NASA to focus on new concepts in composites which would incorporate the automated manufacturing methods of the textiles industry and which would incorporate through-the-thickness reinforcements. The NASA Advanced Composites Technology (ACT) Program provided the resources to extensively investigate the application of textile processes to next generation aircraft wing and fuselage structures. This paper discusses advanced textile material forms that have been developed, innovative machine concepts and key technology advancements required for future application of textile reinforced composites in commercial transport aircraft. Multiaxial warp knitting, triaxial braiding and through-the-thickness stitching are the three textile processes that have surfaced as the most promising for further development. Textile reinforced composite structural elements that have been developed in the NASA ACT Program are discussed. Included are braided fuselage frames and window-belt reinforcements, woven/stitched lower fuselage side panels, stitched multiaxial warp knit wing skins, and braided wing stiffeners. In addition, low-cost processing concepts such as resin transfer molding (RTM), resin film infusion (RFI), and vacuum-assisted resin transfer molding (VARTM) are discussed. Process modeling concepts to predict resin flow and cure in textile preforms are also discussed.
ERIC Educational Resources Information Center
Winschel, Grace A.; Everett, Renata K.; Coppola, Brian P.; Shultz, Ginger V.
2015-01-01
Cooperative learning was employed as an instructional approach to facilitate student development of spectroscopy problem solving skills. An interactive online environment was used as a framework to structure weekly discussions around spectroscopy problems outside of class. Weekly discussions consisted of modified jigsaw-style problem solving…
Models in the Teaching of Playwriting.
ERIC Educational Resources Information Center
Delgado, Ramon
One of the best means to create student awareness of play structure is through assigned reading and classroom discussion of successful plays used as models. Various plays from the 1982 edition of "Best Short Plays" are appropriate for discussion of the following structures and techniques: (1) development of conflict and action, suspense,…
NASA Astrophysics Data System (ADS)
Tokizane, Soichi
At the historical meeting of the ACS CINF Division, the 1990 Herman Skolnik Award was presented to Dr. Ernst Meyer, who at BASF in Germany had developed a computer storage and retrieval system of chemical structures in 1960s. His and his colleagues' speeches in the award symposium were about the history of the development of chemical structure information in Germany. In the symposium of the Markush structure system, a hottest topic in this field, CAS's MARPAT and Markush-DARC co-developed by Questel, INPI, and Derwent were discussed by many papers. Other topics of this meeting were discussed, too.
NASA Technical Reports Server (NTRS)
Figueroa, Fernando; Tomizuka, Masayoshi; Bergman, Lawrence; Carpenter, Bernie; Salzano, Carmine; Bairrao, rogerio; Deraemaker, Arnaud; Magonette, Georges; Rodellar, Jose; Kadirkamanathan, Visaken
2005-01-01
This document is a result of discussions that took place during the workshop. It describes current state of research and development (R&D) in the areas of structural actuation and adaptation in the context of smart structures and advanced sensors (SS&AS), and provides an outlook to guide future R&D efforts to develop technologies needed to build SS&AS. The discussions took place among the members of the Structural Actuation and Adaptation Working Group, as well as in general sessions including all four working groups. Participants included members of academia, industry, and government from the US and Europe, and representatives from China, Japan, and Korea.
NASA Astrophysics Data System (ADS)
Trachtenberg, I.
How a reliability model might be developed with new data from accelerated stress testing, failure mechanisms, process control monitoring, and test structure evaluations is illustrated. The effects of the acceleration of temperature on operating life is discussed. Test structures that will further accelerate the failure rate are discussed. Corrosion testing is addressed. The uncoated structure is encapsulated in a variety of mold compounds and subjected to pressure-cooker testing.
Space station structures development
NASA Technical Reports Server (NTRS)
Teller, V. B.
1986-01-01
A study of three interrelated tasks focusing on deployable Space Station truss structures is discussed. Task 1, the development of an alternate deployment system for linear truss, resulted in the preliminary design of an in-space reloadable linear motor deployer. Task 2, advanced composites deployable truss development, resulted in the testing and evaluation of composite materials for struts used in a deployable linear truss. Task 3, assembly of structures in space/erectable structures, resulted in the preliminary design of Space Station pressurized module support structures. An independent, redundant support system was developed for the common United States modules.
Toward a More Holistic Evaluation Approach for Rural Development
ERIC Educational Resources Information Center
Miyoshi, Koichi
2013-01-01
The discussion on and development of a holistic evaluation approach for rural development will be indispensable to improving and enriching the lives of rural people. This approach can be developed by considering the conceptualization of community policy structure in rural areas, the localization of policy structure in the rural community, and the…
Application of neural nets in structural optimization
NASA Technical Reports Server (NTRS)
Berke, Laszlo; Hajela, Prabhat
1993-01-01
The biological motivation for Artificial Neural Net developments is briefly discussed, and the most popular paradigm, the feedforward supervised learning net with error back propagation training algorithm, is introduced. Possible approaches for utilization in structural optimization is illustrated through simple examples. Other currently ongoing developments for application in structural mechanics are also mentioned.
ERIC Educational Resources Information Center
Journal of Child Language, 1998
1998-01-01
Presents the responses of 12 authors to Michael Tomasello's essay, which comments on Adele Goldberg's recent book, "Constructions: A Construction Grammar Approach to Argument Structure." Goldberg's book develops the theory of construction grammar for a set of problems associated with verb-argument structure. (SM)
Advertising Agencies: An Analysis of Industry Structure.
ERIC Educational Resources Information Center
Smith, Sandra J.
Noting that advertising agencies have not been examined as a collective industry, this paper looks at the development and structure of the advertising agency industry. The first portion of the paper discusses the development of the agency. The remaining two sections deal with trends in and the structure of the industry including: (1) the growth of…
The Development of Metal Oxide Chemical Sensing Nanostructures
NASA Technical Reports Server (NTRS)
Hunter, G. W.; VanderWal,R. L.; Xu, J. C.; Evans, L. J.; Berger, G. M.; Kulis, M. J.
2008-01-01
This paper discusses sensor development based on metal oxide nanostructures and microsystems technology. While nanostructures such as nanowires show significant potential as enabling materials for chemical sensors, a number of significant technical challenges remain. This paper discusses development to address each of these technical barriers: 1) Improved contact and integration of the nanostructured materials with microsystems in a sensor structure; 2) Control of nanostructure crystallinity to allow control of the detection mechanism; and 3) Widening the range of gases that can be detected by fabricating multiple nanostructured materials. A sensor structure composed of three nanostructured oxides aligned on a single microsensor has been fabricated and tested. Results of this testing are discussed and future development approaches are suggested. It is concluded that while this work lays the foundation for further development, these are the beginning steps towards realization of repeatable, controlled sensor systems using oxide based nanostructures.
Contribution of Neuroimaging Studies to Understanding Development of Human Cognitive Brain Functions
Morita, Tomoyo; Asada, Minoru; Naito, Eiichi
2016-01-01
Humans experience significant physical and mental changes from birth to adulthood, and a variety of perceptual, cognitive and motor functions mature over the course of approximately 20 years following birth. To deeply understand such developmental processes, merely studying behavioral changes is not sufficient; simultaneous investigation of the development of the brain may lead us to a more comprehensive understanding. Recent advances in noninvasive neuroimaging technologies largely contribute to this understanding. Here, it is very important to consider the development of the brain from the perspectives of “structure” and “function” because both structure and function of the human brain mature slowly. In this review, we first discuss the process of structural brain development, i.e., how the structure of the brain, which is crucial when discussing functional brain development, changes with age. Second, we introduce some representative studies and the latest studies related to the functional development of the brain, particularly for visual, facial recognition, and social cognition functions, all of which are important for humans. Finally, we summarize how brain science can contribute to developmental study and discuss the challenges that neuroimaging should address in the future. PMID:27695409
Prischi, Filippo; Pastore, Annalisa
2016-01-01
The current main challenge of Structural Biology is to undertake the structure determination of increasingly complex systems in the attempt to better understand their biological function. As systems become more challenging, however, there is an increasing demand for the parallel use of more than one independent technique to allow pushing the frontiers of structure determination and, at the same time, obtaining independent structural validation. The combination of different Structural Biology methods has been named hybrid approaches. The aim of this review is to critically discuss the most recent examples and new developments that have allowed structure determination or experimentally-based modelling of various molecular complexes selecting them among those that combine the use of nuclear magnetic resonance and small angle scattering techniques. We provide a selective but focused account of some of the most exciting recent approaches and discuss their possible further developments.
Thermal management and mechanical structures for silicon detector systems
NASA Astrophysics Data System (ADS)
Viehhauser, G.
2015-09-01
Due to the size of current silicon tracking systems system aspects have become a major design driver. This article discusses requirements for the engineering of the mechanical structures and thermal management of such systems and reviews solutions developed to satisfy them. Modern materials and fabrication techniques have been instrumental in constructing these devices and will be discussed here. Finally, this paper will describe current and potential future developments in the engineering of silicon tracking systems which will shape the silicon tracking systems of the future.
Structural and compositional features of high-rise buildings: experimental design in Yekaterinburg
NASA Astrophysics Data System (ADS)
Yankovskaya, Yulia; Lobanov, Yuriy; Temnov, Vladimir
2018-03-01
The study looks at the specifics of high-rise development in Yekaterinburg. High-rise buildings are considered in the context of their historical development, structural features, compositional and imaginative design techniques. Experience of Yekaterinburg architects in experimental design is considered and analyzed. Main issues and prospects of high-rise development within the Yekaterinburg structure are studied. The most interesting and significant conceptual approaches to the structural and compositional arrangement of high-rise buildings are discussed.
Biomaterials Made from Coiled-Coil Peptides.
Conticello, Vincent; Hughes, Spencer; Modlin, Charles
The development of biomaterials designed for specific applications is an important objective in personalized medicine. While the breadth and prominence of biomaterials have increased exponentially over the past decades, critical challenges remain to be addressed, particularly in the development of biomaterials that exhibit highly specific functions. These functional properties are often encoded within the molecular structure of the component molecules. Proteins, as a consequence of their structural specificity, represent useful substrates for the construction of functional biomaterials through rational design. This chapter provides an in-depth survey of biomaterials constructed from coiled-coils, one of the best-understood protein structural motifs. We discuss the utility of this structurally diverse and functionally tunable class of proteins for the creation of novel biomaterials. This discussion illustrates the progress that has been made in the development of coiled-coil biomaterials by showcasing studies that bridge the gap between the academic science and potential technological impact.
Nealon, John Oliver; Philomina, Limcy Seby
2017-01-01
The elucidation of protein–protein interactions is vital for determining the function and action of quaternary protein structures. Here, we discuss the difficulty and importance of establishing protein quaternary structure and review in vitro and in silico methods for doing so. Determining the interacting partner proteins of predicted protein structures is very time-consuming when using in vitro methods, this can be somewhat alleviated by use of predictive methods. However, developing reliably accurate predictive tools has proved to be difficult. We review the current state of the art in predictive protein interaction software and discuss the problem of scoring and therefore ranking predictions. Current community-based predictive exercises are discussed in relation to the growth of protein interaction prediction as an area within these exercises. We suggest a fusion of experimental and predictive methods that make use of sparse experimental data to determine higher resolution predicted protein interactions as being necessary to drive forward development. PMID:29206185
Computerized management information systems and organizational structures
NASA Technical Reports Server (NTRS)
Zannetos, Z. S.; Sertel, M. R.
1970-01-01
The computerized management of information systems and organizational structures is discussed. The subjects presented are: (1) critical factors favoring centralization and decentralization of organizations, (2) classification of organizations by relative structure, (3) attempts to measure change in organization structure, and (4) impact of information technology developments on organizational structure changes.
Search and rescue in collapsed structures: engineering and social science aspects.
El-Tawil, Sherif; Aguirre, Benigno
2010-10-01
This paper discusses the social science and engineering dimensions of search and rescue (SAR) in collapsed buildings. First, existing information is presented on factors that influence the behaviour of trapped victims, particularly human, physical, socioeconomic and circumstantial factors. Trapped victims are most often discussed in the context of structural collapse and injuries sustained. Most studies in this area focus on earthquakes as the type of disaster that produces the most extensive structural damage. Second, information is set out on the engineering aspects of urban search and rescue (USAR) in the United States, including the role of structural engineers in USAR operations, training and certification of structural specialists, and safety and general procedures. The use of computational simulation to link the engineering and social science aspects of USAR is discussed. This could supplement training of local SAR groups and USAR teams, allowing them to understand better the collapse process and how voids form in a rubble pile. A preliminary simulation tool developed for this purpose is described. © 2010 The Author(s). Journal compilation © Overseas Development Institute, 2010.
Permanent magnet design methodology
NASA Technical Reports Server (NTRS)
Leupold, Herbert A.
1991-01-01
Design techniques developed for the exploitation of high energy magnetically rigid materials such as Sm-Co and Nd-Fe-B have resulted in a revolution in kind rather than in degree in the design of a variety of electron guidance structures for ballistic and aerospace applications. Salient examples are listed. Several prototype models were developed. These structures are discussed in some detail: permanent magnet solenoids, transverse field sources, periodic structures, and very high field structures.
Recent Developments of Graphene Oxide-Based Membranes: A Review
Ma, Jinxia; Ping, Dan; Dong, Xinfa
2017-01-01
Membrane-based separation technology has attracted great interest in many separation fields due to its advantages of easy-operation, energy-efficiency, easy scale-up, and environmental friendliness. The development of novel membrane materials and membrane structures is an urgent demand to promote membrane-based separation technology. Graphene oxide (GO), as an emerging star nano-building material, has showed great potential in the membrane-based separation field. In this review paper, the latest research progress in GO-based membranes focused on adjusting membrane structure and enhancing their mechanical strength as well as structural stability in aqueous environment is highlighted and discussed in detail. First, we briefly reviewed the preparation and characterization of GO. Then, the preparation method, characterization, and type of GO-based membrane are summarized. Finally, the advancements of GO-based membrane in adjusting membrane structure and enhancing their mechanical strength, as well as structural stability in aqueous environment, are particularly discussed. This review hopefully provides a new avenue for the innovative developments of GO-based membrane in various membrane applications. PMID:28895877
Recent Developments of Graphene Oxide-Based Membranes: A Review.
Ma, Jinxia; Ping, Dan; Dong, Xinfa
2017-09-12
Membrane-based separation technology has attracted great interest in many separation fields due to its advantages of easy-operation, energy-efficiency, easy scale-up, and environmental friendliness. The development of novel membrane materials and membrane structures is an urgent demand to promote membrane-based separation technology. Graphene oxide (GO), as an emerging star nano-building material, has showed great potential in the membrane-based separation field. In this review paper, the latest research progress in GO-based membranes focused on adjusting membrane structure and enhancing their mechanical strength as well as structural stability in aqueous environment is highlighted and discussed in detail. First, we briefly reviewed the preparation and characterization of GO. Then, the preparation method, characterization, and type of GO-based membrane are summarized. Finally, the advancements of GO-based membrane in adjusting membrane structure and enhancing their mechanical strength, as well as structural stability in aqueous environment, are particularly discussed. This review hopefully provides a new avenue for the innovative developments of GO-based membrane in various membrane applications.
NASA Astrophysics Data System (ADS)
Casten, R. F.; Cakirli, R. B.
2009-03-01
Understanding the development of configuration mixing, coherence, collectivity, and deformation in nuclei is one of the crucial challenges in nuclear structure physics, and one which has become all the more important with the advent of next generation facilities for the study of exotic nuclei. We will discuss recent work on phase/shape transitional behavior in nuclei, and the role of changes in sub-shell structure in mediating such transitional regions. We will also discuss a newly found, much deeper, link between nuclear structure and nuclear binding energies.
ERIC Educational Resources Information Center
Vassileva, Julita
1990-01-01
Discusses the structure of intelligent tutoring systems (ITSs) and describes the development of a new structure for ITSs that is not domain dependent and is more readily adaptable by individual teachers. Pedagogical rules that help decide how much student control versus how much teacher control is present in the system are discussed. (14…
NASA Technical Reports Server (NTRS)
1977-01-01
The development of a framework and structure for shuttle era unmanned spacecraft projects and the development of a commonality evaluation model is documented. The methodology developed for model utilization in performing cost trades and comparative evaluations for commonality studies is discussed. The model framework consists of categories of activities associated with the spacecraft system's development process. The model structure describes the physical elements to be treated as separate identifiable entities. Cost estimating relationships for subsystem and program-level components were calculated.
Erbium-doped fiber amplifier elements for structural analysis sensors
NASA Technical Reports Server (NTRS)
Hanna-Hawver, P.; Kamdar, K. D.; Mehta, S.; Nagarajan, S.; Nasta, M. H.; Claus, R. O.
1992-01-01
The use of erbium-doped fiber amplifiers (EDFA's) in optical fiber sensor systems for structural analysis is described. EDFA's were developed for primary applications as periodic regenerator amplifiers in long-distance fiber-based communication systems. Their in-line amplification performance also makes them attractive for optical fiber sensor systems which require long effective lengths or the synthesis of special length-dependent signal processing functions. Sensor geometries incorporating EDFA's in recirculating and multiple loop sensors are discussed. Noise and polarization birefringence are also considered, and the experimental development of system components is discussed.
An Exchange Structure Analysis of the Development of Online Intercultural Activity
ERIC Educational Resources Information Center
Kitade, Keiko
2012-01-01
Internet-mediated intercultural discussions have been adopted for intercultural and second-language learning. However, the notion of community development in this context has received less attention. This study employs exchange structure (ES) analysis (Stubbs, M. (1983). "Discourse analysis." Oxford: Basil Blackwell) to investigate the…
Structural Analysis of Communication Development.
ERIC Educational Resources Information Center
Conville, Richard L.
This paper discusses the question of the legitimacy of applying structural analysis to actual human behavior and illustrates its legitimacy by using the reasoning in an essay by Paul Ricoeur. It then asks if the principles of communication development (obliqueness, exchange, and dying) derived from Helen Keller's experience of communication…
Polymer and ceramic nanocomposites for aerospace applications
NASA Astrophysics Data System (ADS)
Rathod, Vivek T.; Kumar, Jayanth S.; Jain, Anjana
2017-11-01
This paper reviews the potential of polymer and ceramic matrix composites for aerospace/space vehicle applications. Special, unique and multifunctional properties arising due to the dispersion of nanoparticles in ceramic and metal matrix are briefly discussed followed by a classification of resulting aerospace applications. The paper presents polymer matrix composites comprising majority of aerospace applications in structures, coating, tribology, structural health monitoring, electromagnetic shielding and shape memory applications. The capabilities of the ceramic matrix nanocomposites to providing the electromagnetic shielding for aircrafts and better tribological properties to suit space environments are discussed. Structural health monitoring capability of ceramic matrix nanocomposite is also discussed. The properties of resulting nanocomposite material with its disadvantages like cost and processing difficulties are discussed. The paper concludes after the discussion of the possible future perspectives and challenges in implementation and further development of polymer and ceramic nanocomposite materials.
Comparison of two matrix data structures for advanced CSM testbed applications
NASA Technical Reports Server (NTRS)
Regelbrugge, M. E.; Brogan, F. A.; Nour-Omid, B.; Rankin, C. C.; Wright, M. A.
1989-01-01
The first section describes data storage schemes presently used by the Computational Structural Mechanics (CSM) testbed sparse matrix facilities and similar skyline (profile) matrix facilities. The second section contains a discussion of certain features required for the implementation of particular advanced CSM algorithms, and how these features might be incorporated into the data storage schemes described previously. The third section presents recommendations, based on the discussions of the prior sections, for directing future CSM testbed development to provide necessary matrix facilities for advanced algorithm implementation and use. The objective is to lend insight into the matrix structures discussed and to help explain the process of evaluating alternative matrix data structures and utilities for subsequent use in the CSM testbed.
NASA Astrophysics Data System (ADS)
Godinez-Azcuaga, Valery F.; Farmer, Justin; Ziehl, Paul H.; Giurgiutiu, Victor; Nanni, Antonio; Inman, Daniel J.
2012-04-01
This paper discusses the development status of a self-powered wireless sensor node for steel and concrete bridges monitoring and prognosis. By the end of the third year in this four-year cross-disciplinary project, the 4-channel acoustic emission wireless node, developed by Mistras Group Inc, has already been deployed in concrete structures by the University of Miami. Also, extensive testing is underway with the node powered by structural vibration and wind energy harvesting modules developed by Virginia Tech. The development of diagnosis tools and models for bridge prognosis, which will be discussed in the paper, continues and the diagnosis tools are expected to be programmed in the node's AVR during the 4th year of the project. The impact of this development extends beyond the area of bridge health monitoring into several fields, such as offshore oil platforms, composite components on military ships and race boats, combat deployable bridges and wind turbine blades. Some of these applications will also be discussed. This project was awarded to a joint venture formed by Mistras Group Inc, Virginia Tech, University of South Carolina and University of Miami by the National Institute of Standards and Technology through its Technology Innovation Program Grant #70NANB9H007.
Kwakwa, Kristin A; Vanderburgh, Joseph P; Guelcher, Scott A; Sterling, Julie A
2017-08-01
Bone is a structurally unique microenvironment that presents many challenges for the development of 3D models for studying bone physiology and diseases, including cancer. As researchers continue to investigate the interactions within the bone microenvironment, the development of 3D models of bone has become critical. 3D models have been developed that replicate some properties of bone, but have not fully reproduced the complex structural and cellular composition of the bone microenvironment. This review will discuss 3D models including polyurethane, silk, and collagen scaffolds that have been developed to study tumor-induced bone disease. In addition, we discuss 3D printing techniques used to better replicate the structure of bone. 3D models that better replicate the bone microenvironment will help researchers better understand the dynamic interactions between tumors and the bone microenvironment, ultimately leading to better models for testing therapeutics and predicting patient outcomes.
Temporomandibular Joint Imaging.
Tamimi, Dania; Jalali, Elnaz; Hatcher, David
2018-01-01
The temporomandibular joint (TMJ) is an anatomically and biomechanically complex structure. Understanding how this structure grows and functions is essential to accurate radiographic evaluation. This article discusses the anatomy, function, and growth and development of the TMJ and how growth changes can affect the morphology of the craniofacial structures. Accordingly, the radiographic appearance of the entities that may alter the TMJ are discussed, including developmental, degenerative, inflammatory, and traumatic changes. Both osseous imaging and soft tissue imaging are shown. Copyright © 2017 Elsevier Inc. All rights reserved.
Functional Dissection: The Nemesis of Coexistence.
ERIC Educational Resources Information Center
Alloway, James A.
A former New Jersey local official discusses the complex organizational structures in universities, government, and businesses that have developed to serve the needs of citizens. Each of these specialized structures developed a rather high level of efficiency, and each set its own priorities, criteria, and cost factors. Now this functional…
Unified control/structure design and modeling research
NASA Technical Reports Server (NTRS)
Mingori, D. L.; Gibson, J. S.; Blelloch, P. A.; Adamian, A.
1986-01-01
To demonstrate the applicability of the control theory for distributed systems to large flexible space structures, research was focused on a model of a space antenna which consists of a rigid hub, flexible ribs, and a mesh reflecting surface. The space antenna model used is discussed along with the finite element approximation of the distributed model. The basic control problem is to design an optimal or near-optimal compensator to suppress the linear vibrations and rigid-body displacements of the structure. The application of an infinite dimensional Linear Quadratic Gaussian (LQG) control theory to flexible structure is discussed. Two basic approaches for robustness enhancement were investigated: loop transfer recovery and sensitivity optimization. A third approach synthesized from elements of these two basic approaches is currently under development. The control driven finite element approximation of flexible structures is discussed. Three sets of finite element basic vectors for computing functional control gains are compared. The possibility of constructing a finite element scheme to approximate the infinite dimensional Hamiltonian system directly, instead of indirectly is discussed.
Cosbey, Simon; Elliott, Simon; Paterson, Sue
2017-01-01
The current status of forensic toxicology in the United Kingdom is discussed with an emphasis on professional training and development. Best practice is proposed using a blend of modular foundation knowledge training, continuing professional development, academic study, research & development and ongoing analytical practice. The need for establishing a professional career structure is also discussed along with a suggested example of a suitable model. The issues discussed in this paper are intended to provoke discussion within the forensic toxicology community, industry regulators and other government bodies responsible for the administration of justice. Copyright © 2016 The Chartered Society of Forensic Sciences. Published by Elsevier Ireland Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Yang, Peilu
2013-03-01
In the first place, the article discusses the theory, content, development, and questions about structured programming design. The further extension on this basement provides the cycle structure in computer language is the sequence structure, branch structure, and the cycle structure with independence. Through the deeply research by the writer, we find the non-independence and reach the final simplification about the computer language design. In the first, the writer provides the language structure of linear structure (I structure) and curvilinear structure (Y structure). This makes the computer language has high proficiency with simplification during the program exploration. The research in this article is corresponding with the widely used dualistic structure in the computer field. Moreover, it is greatly promote the evolution of computer language.
The NASA High Speed ASE Project: Computational Analyses of a Low-Boom Supersonic Configuration
NASA Technical Reports Server (NTRS)
Silva, Walter A.; DeLaGarza, Antonio; Zink, Scott; Bounajem, Elias G.; Johnson, Christopher; Buonanno, Michael; Sanetrik, Mark D.; Yoo, Seung Y.; Kopasakis, George; Christhilf, David M.;
2014-01-01
A summary of NASA's High Speed Aeroservoelasticity (ASE) project is provided with a focus on a low-boom supersonic configuration developed by Lockheed-Martin and referred to as the N+2 configuration. The summary includes details of the computational models developed to date including a linear finite element model (FEM), linear unsteady aerodynamic models, structured and unstructured CFD grids, and discussion of the FEM development including sizing and structural constraints applied to the N+2 configuration. Linear results obtained to date include linear mode shapes and linear flutter boundaries. In addition to the tasks associated with the N+2 configuration, a summary of the work involving the development of AeroPropulsoServoElasticity (APSE) models is also discussed.
[Structural Study in the Platform for Drug Discovery, Informatics, and Structural Life Science].
Senda, Toshiya
2016-01-01
The Platform for Drug Discovery, Informatics, and Structural Life Science (PDIS), which has been launched since FY2012, is a national project in the field of structural biology. The PDIS consists of three cores - structural analysis, control, and informatics - and aims to support life science researchers who are not familiar with structural biology. The PDIS project is able to provide full-scale support for structural biology research. The support provided by the PDIS project includes protein purification with various expression systems, large scale protein crystallization, crystal structure determination, small angle scattering (SAXS), NMR, electron microscopy, bioinformatics, etc. In order to utilize these methods of support, PDIS users need to submit an application form to the one-stop service office. Submitted applications will be reviewed by three referees. It is strongly encouraged that PDIS users have sufficient discussion with researchers in the PDIS project before submitting the application. This discussion is very useful in the process of project design, particularly for beginners in structural biology. In addition to this user support, the PDIS project has conducted R&D, which includes the development of synchrotron beamlines. In the PDIS project, PF and SPring-8 have developed beamlines for micro-crystallography, high-throughput data collection, supramolecular assembly, and native single anomalous dispersion (SAD) phasing. The newly developed beamlines have been open to all users, and have accelerated structural biology research. Beamlines for SAXS have also been developed, which has dramatically increased bio-SAXS users.
ERIC Educational Resources Information Center
Wilson, Michael
The report summarizes the various job analysis techniques that have been developed, discusses their applications to selected human resource management activities, and suggests priorities for further research and developmental work. The introduction defines job analysis and discusses the applications of job analysis data, and the structure of the…
ERIC Educational Resources Information Center
Jones, Joseph R.
2015-01-01
Homophobia is an incredible problem within educational settings. Therefore, we must begin examining how we can address the challenge in an effective manner. Researchers postulate professional development (PD) discussing homophobia is an appropriate method to address the problem. To date, there is little published literature that discusses how a PD…
Systemic Perspectives on Beginning Teacher Programs.
ERIC Educational Resources Information Center
Schlechty, Phillip C.; Whitford, Betty Lou
1989-01-01
Discusses the importance of basing beginning teacher programs in schools where roles are structured to support induction and provide exemplary education for students. Addresses structural and political issues, human resource development, and symbolism. (RJC)
Buckling Imperfection Sensitivity of Axially Compressed Orthotropic Cylinders
NASA Technical Reports Server (NTRS)
Schultz, Marc R.; Nemeth, Michael P.
2010-01-01
Structural stability is a major consideration in the design of lightweight shell structures. However, the theoretical predictions of geometrically perfect structures often considerably over predict the buckling loads of inherently imperfect real structures. It is reasonably well understood how the shell geometry affects the imperfection sensitivity of axially compressed cylindrical shells; however, the effects of shell anisotropy on the imperfection sensitivity is less well understood. In the present paper, the development of an analytical model for assessing the imperfection sensitivity of axially compressed orthotropic cylinders is discussed. Results from the analytical model for four shell designs are compared with those from a general-purpose finite-element code, and good qualitative agreement is found. Reasons for discrepancies are discussed, and potential design implications of this line of research are discussed.
Direct and inverted nematic dispersions for soft matter photonics.
Muševič, I; Skarabot, M; Humar, M
2011-07-20
General properties and recent developments in the field of nematic colloids and emulsions are discussed. The origin and nature of pair colloidal interactions in the nematic colloids are explained and an overview of the stable colloidal 2D crystalline structures and superstructures discovered so far is given. The nature and role of topological defects in the nematic colloids is discussed, with an emphasis on recently discovered entangled colloidal structures. Applications of inverted nematic emulsions and binding force mechanisms in nematic colloids for soft matter photonic devices are discussed.
Advanced InSb monolithic Charge Coupled Infrared Imaging Devices (CCIRID)
NASA Technical Reports Server (NTRS)
Koch, T. L.; Thom, R. D.; Parrish, W. D.
1981-01-01
The continued development of monolithic InSb charge coupled infrared imaging devices (CCIRIDs) is discussed. The processing sequence and structural design of 20-element linear arrays are discussed. Also, results obtained from radiometric testing of the 20-element arrays using a clamped sample-and-hold output circuit are reported. The design and layout of a next-generation CCIRID chip are discussed. The major devices on this chip are a 20 by 16 time-delay-and-integration (TDI) area array and a 100-element linear imaging array. The development of a process for incorporating an ion implanted S(+) planar channel stop into the CCIRID structure and the development of a thin film transparent photogate are also addressed. The transparent photogates will increase quantum efficiency to greater than 70% across the 2.5 to 5.4 micrometer spectral region in future front-side illuminated CCIRIDs.
Integrated design of structures, controls, and materials
NASA Technical Reports Server (NTRS)
Blankenship, G. L.
1994-01-01
In this talk we shall discuss algorithms and CAD tools for the design and analysis of structures for high performance applications using advanced composite materials. An extensive mathematical theory for optimal structural (e.g., shape) design was developed over the past thirty years. Aspects of this theory have been used in the design of components for hypersonic vehicles and thermal diffusion systems based on homogeneous materials. Enhancement of the design methods to include optimization of the microstructure of the component is a significant innovation which can lead to major enhancements in component performance. Our work is focused on the adaptation of existing theories of optimal structural design (e.g., optimal shape design) to treat the design of structures using advanced composite materials (e.g., fiber reinforced, resin matrix materials). In this talk we shall discuss models and algorithms for the design of simple structures from composite materials, focussing on a problem in thermal management. We shall also discuss methods for the integration of active structural controls into the design process.
Factor Structure of the Piagetian Stage of Concrete Operations.
ERIC Educational Resources Information Center
Klausmeier, Herbert J.; Sipple, Thomas S.
1982-01-01
The Piagetian developmental stage of concrete operational thought and the theoretical groupement structures underlying children's performance of 12 concrete operations tasks are discussed. Tasks were shown to develop in five related sets. Three factor structures were found in this longitudinal study. (Author/CM)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Miller, M.; Kempner, L. Jr.; Mueller, W. III
The concept of an Expert System is not new. It has been around since the days of the early computers when scientists had dreams of robot automation to do everything from washing windows to automobile design. This paper discusses an application of an expert system and addresses software development issues and various levels of expert system development form a structural engineering viewpoint. An expert system designed to aid the structural engineer in first order inelastic analysis of latticed steel transmission powers is presented. The utilization of expert systems with large numerical analysis programs is discussed along with the software developmentmore » of such a system.« less
The balloon and the airship technological heritage
NASA Technical Reports Server (NTRS)
Mayer, N. J.
1981-01-01
The balloon and the airship are discussed with emphasis on the identification of commonalities and distinctions. The aerostat technology behind the shape and structure of the vehicles is reviewed, including a discussion of structural weight, internal pressure, buckling, and the development of a stable tethered balloon system. Proper materials for the envelope are considered, taking elongation and stress into account, and flight operation and future developments are reviewed. Airships and tethered balloons which are designed to carry high operating pressure with low gas loss characteristics are found to share similar problems in low speed flight operations, while possessing interchangeable technologies.
Chemical calculations on Cray computers
NASA Technical Reports Server (NTRS)
Taylor, Peter R.; Bauschlicher, Charles W., Jr.; Schwenke, David W.
1989-01-01
The influence of recent developments in supercomputing on computational chemistry is discussed with particular reference to Cray computers and their pipelined vector/limited parallel architectures. After reviewing Cray hardware and software the performance of different elementary program structures are examined, and effective methods for improving program performance are outlined. The computational strategies appropriate for obtaining optimum performance in applications to quantum chemistry and dynamics are discussed. Finally, some discussion is given of new developments and future hardware and software improvements.
The Shock and Vibration Digest. Volume 8, Number 2, February 1976
1976-02-01
B. The procedure for applying this technique to a structure com- posed of many substructures is discussed , 22 CURRENT LITERATURE 76-162 76-164... a more complete listing of during the period t April 1974 to 31 March software developed for structural problems see 1975. Subjects discussed are...programs, acoustic pressure levels, A -weighted noise levels, signatures perceived noise levels, and effective perceived noise levels are calculated
A software package for the data-independent management of multidimensional data
NASA Technical Reports Server (NTRS)
Treinish, Lloyd A.; Gough, Michel L.
1987-01-01
The Common Data Format (CDF), a structure which provides true data independence for applications software and has been developed at the National Space Science Data Center, is discussed. The background to the CDF is reviewed, and the CDF is described. The conceptual organization of the CDF is discussed, and a sample CDF structure is shown and described. The implementation of CDF, its status, and its applications are examined.
Managing the Drafting Process: Creating a New Model for the Workplace.
ERIC Educational Resources Information Center
Shwom, Barbara L.; Hirsch, Penny L.
1994-01-01
Discusses the development of a pragmatic model of the writing process in the workplace, focusing on the importance of "drafting" as part of that process. Discusses writers' attitudes about drafting and the structures of the workplace that drafting has to accommodate. Introduces a drafting model and discusses results of using this model…
ERIC Educational Resources Information Center
Dong, Ting
2009-01-01
The assessment and structure of personality traits and small group learning during classroom discussions are both research fields that have undergone fast development in the past few decades. However, very few studies have investigated the relationship between individual personality characteristics and performance in discussions, especially with…
Progress in materials and structures at Lewis Research Center
NASA Technical Reports Server (NTRS)
Glasgow, T. K.; Lauver, R. W.; Halford, G. R.; Davies, R. L.
1980-01-01
The development of power and propulsion system technology is discussed. Specific emphasis is placed on the following: high temperature materials; composite materials; advanced design and life prediction; and nondestructive evaluation. Future areas of research are also discussed.
NASA Technical Reports Server (NTRS)
Thomas, J. M.; Hanagud, S.
1974-01-01
The design criteria and test options for aerospace structural reliability were investigated. A decision methodology was developed for selecting a combination of structural tests and structural design factors. The decision method involves the use of Bayesian statistics and statistical decision theory. Procedures are discussed for obtaining and updating data-based probabilistic strength distributions for aerospace structures when test information is available and for obtaining subjective distributions when data are not available. The techniques used in developing the distributions are explained.
NASA Technical Reports Server (NTRS)
Seshadri, B. R.; Smith, S. W.; Johnston, W. M.
2008-01-01
This viewgraph presentation describes residual strength analysis of integral structures fabricated using different manufacturing procedures. The topics include: 1) Built-up and Integral Structures; 2) Development of Prediction Methodology for Integral Structures Fabricated using different Manufacturing Procedures; 3) Testing Facility; 4) Fracture Parameters Definition; 5) Crack Branching in Integral Structures; 6) Results and Discussion; and 7) Concluding Remarks.
ERIC Educational Resources Information Center
Saito, Eisuke; Atencio, Matthew
2013-01-01
Lesson study has been implemented as a viable approach to support teachers' professional development. Yet, this approach has not been thoroughly examined in relation to key micro-political power relations that are arguably endemic to the use of this collaborative learning model. Accordingly, this paper discusses post-structural concepts that might…
Manufacturing of Smart Structures Using Fiber Placement Manufacturing Processes
NASA Technical Reports Server (NTRS)
Thomas, Matthew M.; Glowasky, Robert A.; McIlroy, Bruce E.; Story, Todd A.
1996-01-01
Smart structures research and development, with the ultimate aim of rapid commercial and military production of these structures, are at the forefront of the Synthesis and Processing of Intelligent Cost-Effective Structures (SPICES) program. As part of this ARPA-sponsored program, MDA-E is using fiber placement processes to manufacture integrated smart structure systems. These systems comprise advanced composite structures with embedded fiber optic sensors, shape memory alloys, piezoelectric actuators, and miniature accelerometers. Cost-effective approaches and solutions to smart material synthesis in the fiber-placement process, based upon integrated product development, are discussed herein.
Nonlocal continuum-based modeling of mechanical characteristics of nanoscopic structures
NASA Astrophysics Data System (ADS)
Rafii-Tabar, Hashem; Ghavanloo, Esmaeal; Fazelzadeh, S. Ahmad
2016-06-01
Insight into the mechanical characteristics of nanoscopic structures is of fundamental interest and indeed poses a great challenge to the research communities around the world. These structures are ultra fine in size and consequently performing standard experiments to measure their various properties is an extremely difficult and expensive endeavor. Hence, to predict the mechanical characteristics of the nanoscopic structures, different theoretical models, numerical modeling techniques, and computer-based simulation methods have been developed. Among several proposed approaches, the nonlocal continuum-based modeling is of particular significance because the results obtained from this modeling for different nanoscopic structures are in very good agreement with the data obtained from both experimental and atomistic-based studies. A review of the essentials of this model together with its applications is presented here. Our paper is a self contained presentation of the nonlocal elasticity theory and contains the analysis of the recent works employing this model within the field of nanoscopic structures. In this review, the concepts from both the classical (local) and the nonlocal elasticity theories are presented and their applications to static and dynamic behavior of nanoscopic structures with various morphologies are discussed. We first introduce the various nanoscopic structures, both carbon-based and non carbon-based types, and then after a brief review of the definitions and concepts from classical elasticity theory, and the basic assumptions underlying size-dependent continuum theories, the mathematical details of the nonlocal elasticity theory are presented. A comprehensive discussion on the nonlocal version of the beam, the plate and the shell theories that are employed in modeling of the mechanical properties and behavior of nanoscopic structures is then provided. Next, an overview of the current literature discussing the application of the nonlocal models of nanoscopic carbon allotropes is presented. We then discuss the application of the models to the investigation of the properties of nanoscopic structures from different materials and with different types of morphologies. Furthermore, we also present recent developments in the application of the nonlocal models. Finally, conclusions and discussions regarding the potentiality of these models for future research are provided.
Kwakwa, Kristin A.; Vanderburgh, Joseph P.; Guelcher, Scott A.
2018-01-01
Purpose of Review Bone is a structurally unique microenvironment that presents many challenges for the development of 3D models for studying bone physiology and diseases, including cancer. As researchers continue to investigate the interactions within the bone microenvironment, the development of 3D models of bone has become critical. Recent Findings 3D models have been developed that replicate some properties of bone, but have not fully reproduced the complex structural and cellular composition of the bone microenvironment. This review will discuss 3D models including polyurethane, silk, and collagen scaffolds that have been developed to study tumor-induced bone disease. In addition, we discuss 3D printing techniques used to better replicate the structure of bone. Summary 3D models that better replicate the bone microenvironment will help researchers better understand the dynamic interactions between tumors and the bone microenvironment, ultimately leading to better models for testing therapeutics and predicting patient outcomes. PMID:28646444
Cellular commitment in the developing cerebellum
Marzban, Hassan; Del Bigio, Marc R.; Alizadeh, Javad; Ghavami, Saeid; Zachariah, Robby M.; Rastegar, Mojgan
2014-01-01
The mammalian cerebellum is located in the posterior cranial fossa and is critical for motor coordination and non-motor functions including cognitive and emotional processes. The anatomical structure of cerebellum is distinct with a three-layered cortex. During development, neurogenesis and fate decisions of cerebellar primordium cells are orchestrated through tightly controlled molecular events involving multiple genetic pathways. In this review, we will highlight the anatomical structure of human and mouse cerebellum, the cellular composition of developing cerebellum, and the underlying gene expression programs involved in cell fate commitments in the cerebellum. A critical evaluation of the cell death literature suggests that apoptosis occurs in ~5% of cerebellar cells, most shortly after mitosis. Apoptosis and cellular autophagy likely play significant roles in cerebellar development, we provide a comprehensive discussion of their role in cerebellar development and organization. We also address the possible function of unfolded protein response in regulation of cerebellar neurogenesis. We discuss recent advancements in understanding the epigenetic signature of cerebellar compartments and possible connections between DNA methylation, microRNAs and cerebellar neurodegeneration. Finally, we discuss genetic diseases associated with cerebellar dysfunction and their role in the aging cerebellum. PMID:25628535
Development of Robotics Applications in a Solid Propellant Mixing Laboratory
1988-06-01
implementation of robotic hardware and software into a laboratory environment requires a carefully structured series of phases which examines, in...strategy. The general methodology utilized in this project is discussed in Appendix A. The proposed laboratory robotics development program was structured ...Accessibility - Potential modifications - Safety precautions e) Robot Transport - Slider mechanisms - Linear tracks - Gantry configuration - Mobility f
In Search of Speedier Searches.
ERIC Educational Resources Information Center
Peterson, Ivars
1984-01-01
Methods to make computer searching as simple and efficient as possible have led to the development of various data structures. Data structures specify the items involved in searching and what can be done to them. The nature and advantages of using "self-adjusting" data structures (self-adjusting binary search trees) are discussed. (JN)
NASA Technical Reports Server (NTRS)
Houbolt, J. C.
1972-01-01
Criteria and guidelines are presented for combining loads that develop during the ascent phase of a space flight. The primary load-caring structure is discussed including the basic tank and interconnecting members, engine support mounts and connections to tank structure, transition structures between stages, payload shrouds, and the basic support points at separation planes.
Structural mechanics research at the Langley Research Center
NASA Technical Reports Server (NTRS)
Stephens, W. B.
1976-01-01
The contributions of NASA's Langley Research Center in areas of structural mechanics were traced from its NACA origins in 1917 to the present. The developments in structural mechanics technology since 1940 were emphasized. A brief review of some current research topics were discussed as well as anticipated near-term research projects.
Structural Identification and Comparison of Intelligent Mobile Learning Environment
ERIC Educational Resources Information Center
Upadhyay, Nitin; Agarwal, Vishnu Prakash
2007-01-01
This paper proposes a methodology using graph theory, matrix algebra and permanent function to compare different architecture (structure) design of intelligent mobile learning environment. The current work deals with the development/selection of optimum architecture (structural) model of iMLE. This can be done using the criterion as discussed in…
NASA Technical Reports Server (NTRS)
1979-01-01
The development of large space structure technology is discussed, with emphasis on space fabricated structures which are automatically manufactured in space from sheet-strip materials and assembled on-orbit. Definition of a flight demonstration involving an Automated Beam Builder and the building and assembling of large structures is presented.
Composite Structures Repair Development at Kennedy Space Center
NASA Technical Reports Server (NTRS)
Cox, Sarah B.
2015-01-01
This presentation discusses the development and results of composite patch repair perfromed at Kennedy Space Center. This includes impact damage, patch repair methods, nondestructive evaluation, and edgewise compression testing.
UNICOS Kernel Internals Application Development
NASA Technical Reports Server (NTRS)
Caredo, Nicholas; Craw, James M. (Technical Monitor)
1995-01-01
Having an understanding of UNICOS Kernel Internals is valuable information. However, having the knowledge is only half the value. The second half comes with knowing how to use this information and apply it to the development of tools. The kernel contains vast amounts of useful information that can be utilized. This paper discusses the intricacies of developing utilities that utilize kernel information. In addition, algorithms, logic, and code will be discussed for accessing kernel information. Code segments will be provided that demonstrate how to locate and read kernel structures. Types of applications that can utilize kernel information will also be discussed.
Structural Design and Sizing of a Metallic Cryotank Concept
NASA Technical Reports Server (NTRS)
Sleight, David W.; Martin, Robert A.; Johnson, Theodore F.
2013-01-01
This paper presents the structural design and sizing details of a 33-foot (10 m) metallic cryotank concept used as the reference design to compare with the composite cryotank concepts developed by industry as part of NASA s Composite Cryotank Technology Development (CCTD) Project. The structural design methodology and analysis results for the metallic cryotank concept are reported in the paper. The paper describes the details of the metallic cryotank sizing assumptions for the baseline and reference tank designs. In particular, the paper discusses the details of the cryotank weld land design and analyses performed to obtain a reduced weight metallic cryotank design using current materials and manufacturing techniques. The paper also discusses advanced manufacturing techniques to spin-form the cryotank domes and compares the potential mass savings to current friction stir-welded technology.
Engine System Loads Development for the Fastrac 60K Flight Engine
NASA Technical Reports Server (NTRS)
Frady, Greg; Christensen, Eric R.; Mims, Katherine; Harris, Don; Parks, Russell; Brunty, Joseph
2000-01-01
Early implementation of structural dynamics finite element analyses for calculation of design loads is considered common design practice for high volume manufacturing industries such as automotive and aeronautical industries. However, with the rarity of rocket engine development programs starts, these tools are relatively new to the design of rocket engines. In the new Fastrac engine program, the focus has been to reduce the cost to weight ratio; current structural dynamics analysis practices were tailored in order to meet both production and structural design goals. Perturbation of rocket engine design parameters resulted in a number of Fastrac load cycles necessary to characterize the impact due to mass and stiffness changes. Evolution of loads and load extraction methodologies, parametric considerations and a discussion of load path sensitivities are discussed.
Population structure in the Arab world and its impact on integration and development trends.
El-hallak, M N
1986-12-01
The author examines three issues: "population structure in the Arab world; trends making for integration and unity among the Arab countries; and economic and social development trends." Data from the United Nations for 1985 and from recent censuses are used to discuss population size, growth, and spatial distribution; the labor force; age and sex distribution; and fertility, mortality, and natural increase. Figures are presented separately for 22 Arab countries. Attention is then given to the relationships between population structure and economic and social development and between development and Arab unity and integration. excerpt
Promoting quality: the health-care organization from a management perspective.
Glickman, Seth W; Baggett, Kelvin A; Krubert, Christopher G; Peterson, Eric D; Schulman, Kevin A
2007-12-01
Although agreement about the need for quality improvement in health care is almost universal, the means of achieving effective improvement in overall care is not well understood. Avedis Donabedian developed the structure-process-outcome framework in which to think about quality-improvement efforts. There is now a robust evidence-base in the quality-improvement literature on process and outcomes, but structure has received considerably less attention. The health-care field would benefit from expanding the current interpretation of structure to include broader perspectives on organizational attributes as primary determinants of process change and quality improvement. We highlight and discuss the following key elements of organizational attributes from a management perspective: (i) executive management, including senior leadership and board responsibilities (ii) culture, (iii) organizational design, (iv) incentive structures and (v) information management and technology. We discuss the relevant contributions from the business and medical literature for each element, and provide this framework as a roadmap for future research in an effort to develop the optimal definition of 'structure' for transforming quality-improvement initiatives.
Experimental approaches to identify cellular G-quadruplex structures and functions.
Di Antonio, Marco; Rodriguez, Raphaël; Balasubramanian, Shankar
2012-05-01
Guanine-rich nucleic acids can fold into non-canonical DNA secondary structures called G-quadruplexes. The formation of these structures can interfere with the biology that is crucial to sustain cellular homeostases and metabolism via mechanisms that include transcription, translation, splicing, telomere maintenance and DNA recombination. Thus, due to their implication in several biological processes and possible role promoting genomic instability, G-quadruplex forming sequences have emerged as potential therapeutic targets. There has been a growing interest in the development of synthetic molecules and biomolecules for sensing G-quadruplex structures in cellular DNA. In this review, we summarise and discuss recent methods developed for cellular imaging of G-quadruplexes, and the application of experimental genomic approaches to detect G-quadruplexes throughout genomic DNA. In particular, we will discuss the use of engineered small molecules and natural proteins to enable pull-down, ChIP-Seq, ChIP-chip and fluorescence imaging of G-quadruplex structures in cellular DNA. Copyright © 2012 Elsevier Inc. All rights reserved.
Conceptual design and analysis of a large antenna utilizing electrostatic membrane management
NASA Technical Reports Server (NTRS)
Brooks, A. L.; Coyner, J. V.; Gardner, W. J.; Mihora, D. J.
1982-01-01
Conceptual designs and associated technologies for deployment 100 m class radiometer antennas were developed. An electrostatically suspended and controlled membrane mirror and the supporting structure are discussed. The integrated spacecraft including STS cargo bay stowage and development were analyzed. An antenna performance evaluation was performed as a measure of the quality of the membrane/spacecraft when used as a radiometer in the 1 GHz to 5 GHz region. Several related LSS structural dynamic models differing by their stiffness property (and therefore, lowest modal frequencies) are reported. Control system whose complexity varies inversely with increasing modal frequency regimes are also reported. Interactive computer-aided-design software is discussed.
IN SILICO MODELLING OF HAZARDOUS ENDPOINTS: CURRENT PROBLEMS AND PROSPECTIVES
The primary hurdles for Quantitative Structure-Activity Relationships (QSARs) to overcome their acceptance for regulatory purposes will be discussed. They include (a) the development of more mechanistic representations of chemical structure, (b) the classification of toxicity pa...
Microcomputer design and analysis of the cable catenary large space antenna system
NASA Technical Reports Server (NTRS)
Akle, W.
1984-01-01
The use of microcomputers in the design of a cable catenary large space antenna system is discussed. The development of a system design capability, data base utilization, systems integration, program structure and logic, and integrated graphics output are discussed.
Recent Developments in Radioastronomy--Part 2.
ERIC Educational Resources Information Center
Booth, R. S.
1980-01-01
Described are recent developments and discoveries in radioastronomy. Topics discussed include galactic structures, stellar evolution, the binary pulsar and general relativity, extragalactic radioastronomy, model of the source of radioactive emission and quasars. (DS)
Molecular Analysis of Protein Assembly in Muscle Development.
ERIC Educational Resources Information Center
Epstein, Henry F.; Fischman, Donald A.
1991-01-01
Advances in the genetics and cell biology of muscle development are discussed. In-vitro analysis of the renaturation, polymerization, and three-dimensional structure of the purified proteins involved is described. (CW)
DOE Office of Scientific and Technical Information (OSTI.GOV)
McDonald, J.R.; Minor, J.E.; Mehta, K.C.
1975-06-01
In order to evaluate the ability of critical facilities at the Nevada Test Site to withstand the possible damaging effects of extreme winds and tornadoes, parameters for the effects of tornadoes and extreme winds and structural design criteria for the design and evaluation of structures were developed. The meteorological investigations conducted are summarized, and techniques used for developing the combined tornado and extreme wind risk model are discussed. The guidelines for structural design include methods for calculating pressure distributions on walls and roofs of structures and methods for accommodating impact loads from wind-driven missiles. Calculations for determining the design loadsmore » for an example structure are included. (LCL)« less
Development of Advanced Computational Aeroelasticity Tools at NASA Langley Research Center
NASA Technical Reports Server (NTRS)
Bartels, R. E.
2008-01-01
NASA Langley Research Center has continued to develop its long standing computational tools to address new challenges in aircraft and launch vehicle design. This paper discusses the application and development of those computational aeroelastic tools. Four topic areas will be discussed: 1) Modeling structural and flow field nonlinearities; 2) Integrated and modular approaches to nonlinear multidisciplinary analysis; 3) Simulating flight dynamics of flexible vehicles; and 4) Applications that support both aeronautics and space exploration.
STRUCTURAL SCALE LIFE PREDICTION OF AERO STRUCTURES EXPERIENCING COMBINED EXTREME ENVIRONMENTS
2017-07-01
representation is converted into a tetrahedral FE mesh using the software DREAM .3D. Due to a special voxel-identification scheme the FE mesh includes...research team met with DREAM .3D developers at AFRL (Drs. Mike Groeber and Sean Donegan) to discuss possible solutions. Together, the group proposed the...development of a DREAM .3D extension that can leverage the topological data structure within DREAM .3D instead of relying on an image-based
Application of numerical methods to heat transfer and thermal stress analysis of aerospace vehicles
NASA Technical Reports Server (NTRS)
Wieting, A. R.
1979-01-01
The paper describes a thermal-structural design analysis study of a fuel-injection strut for a hydrogen-cooled scramjet engine for a supersonic transport, utilizing finite-element methodology. Applications of finite-element and finite-difference codes to the thermal-structural design-analysis of space transports and structures are discussed. The interaction between the thermal and structural analyses has led to development of finite-element thermal methodology to improve the integration between these two disciplines. The integrated thermal-structural analysis capability developed within the framework of a computer code is outlined.
Advances in Fabrication Materials of Honeycomb Structure Films by the Breath-Figure Method
Heng, Liping; Wang, Bin; Li, Muchen; Zhang, Yuqi; Jiang, Lei
2013-01-01
Creatures in nature possess almost perfect structures and properties, and exhibit harmonization and unification between structure and function. Biomimetics, mimicking nature for engineering solutions, provides a model for the development of functional surfaces with special properties. Recently, honeycomb structure materials have attracted wide attention for both fundamental research and practical applications and have become an increasingly hot research topic. Though progress in the field of breath-figure formation has been reviewed, the advance in the fabrication materials of bio-inspired honeycomb structure films has not been discussed. Here we review the recent progress of honeycomb structure fabrication materials which were prepared by the breath-figure method. The application of breath figures for the generation of all kinds of honeycomb is discussed. PMID:28809319
NASA experiments on the B-720 structure and seats
NASA Astrophysics Data System (ADS)
Alfaro-Bou, E.
1986-01-01
Two experiments onboard a remotely piloted transport aircraft that was crashed on landing are discussed. The structural experiment deals with the location and distribution of the instrumentation throughout the airplane structure. In the seat experiment, the development and testing of an energy absorbing seat are discussed. The objective of the structural experiment was to obtain a data base of structural crash loads for use in the advancement of crashworthy technology of materials (such as composites) in structural design and for use in the comparison between computer and experimental results. The objective of the seat experiment was to compare the performance of an energy absorbing transport seat and a standard seat when subjected to similar crash pulses. Details are given on the location of instrumentation, on the dynamic seat test pulse and headward acceleration limits.
ERIC Educational Resources Information Center
Einsiedler, Wolfgang
1996-01-01
Asks whether theories of knowledge representation provide a basis for the development of theories of knowledge structuring in instruction. Discusses codes of knowledge, surface versus deep structures, semantic networks, and multiple memory systems. Reviews research on teaching, external representation of cognitive structures, hierarchical…
Resin transfer molding for advanced composite primary aircraft structures
NASA Technical Reports Server (NTRS)
Markus, Alan; Palmer, Ray
1991-01-01
Resin Transfer Molding (RTM) has been identified by Douglas Aircraft Company (DAC) and industry to be one of the promising processes being developed today which can break the cost barrier of implementing composite primary structures into a commercial aircraft production environment. The RTM process developments and scale-up plans Douglas Aircrart will be conducting under the NASA ACT contract are discussed.
The Move-Me Project: Reflecting on xMOOC and cMOOC Structure and Pedagogical Implementation
ERIC Educational Resources Information Center
McLoughlin, Laura; Magnoni, Francesca
2017-01-01
This paper discusses the rationale and structure of two Massive Open Online Courses (MOOCs) created as part of the EU-funded Move-Me project, which aims to develop two MOOCs and open educational resources for university learners participating in mobility programmes in Europe. The MOOCs are designed to help learners develop the skills necessary to…
Resin transfer molding for advanced composite primary wing and fuselage structures
NASA Technical Reports Server (NTRS)
Markus, Alan
1992-01-01
The stitching and resin transfer molding (RTM) processes developed at Douglas Aircraft Co. are successfully demonstrating significant cost reductions with good damage tolerance properties. These attributes were identified as critical to application of advanced composite materials to commercial aircraft primary structures. The RTM/stitching developments, cost analyses, and test results are discussed of the NASA Advanced Composites Technology program.
Tarka, Piotr
2018-01-01
This paper is a tribute to researchers who have significantly contributed to improving and advancing structural equation modeling (SEM). It is, therefore, a brief overview of SEM and presents its beginnings, historical development, its usefulness in the social sciences and the statistical and philosophical (theoretical) controversies which have often appeared in the literature pertaining to SEM. Having described the essence of SEM in the context of causal analysis, the author discusses the years of the development of structural modeling as the consequence of many researchers' systematically growing needs (in particular in the social sciences) who strove to effectively understand the structure and interactions of latent phenomena. The early beginnings of SEM models were related to the work of Spearman and Wright, and to that of other prominent researchers who contributed to SEM development. The importance and predominance of theoretical assumptions over technical issues for the successful construction of SEM models are also described. Then, controversies regarding the use of SEM in the social sciences are presented. Finally, the opportunities and threats of this type of analytical strategy as well as selected areas of SEM applications in the social sciences are discussed.
Product Development as a Fuzzy Interface between Technical and Non-technical Education.
ERIC Educational Resources Information Center
Masarnau, Juan
1988-01-01
Discusses a product development structure, including marketing, design, technology, industrial manufacturing, reasoning, and objects. Describes needs of the interface in terms of marketing, industrial design, technology, and industry. (YP)
Piezoceramic devices and PVDF films as sensors and actuators for intelligent structures
NASA Astrophysics Data System (ADS)
Hanagud, S.; Obal, M. W.; Calise, A. G.
The use of bonded piezoceramic sensors and piezoceramic actuators to control vibrations in structural dynamic systems is discussed. Equations for developing optimum control strategies are derived. An example of a cantilever beam is considered to illustrate the development procedure for optimal vibration control of structures by the use of piezoceramic sensors, actuators, and rate feedbacks with appropriate gains. Research areas and future directions are outlined, including dynamic coupling and constitutive equations; load and energy transfer; composite structures; optimal dynamic compensation; estimation and identification; and distributed control.
Building bridges between cellular and molecular structural biology.
Patwardhan, Ardan; Brandt, Robert; Butcher, Sarah J; Collinson, Lucy; Gault, David; Grünewald, Kay; Hecksel, Corey; Huiskonen, Juha T; Iudin, Andrii; Jones, Martin L; Korir, Paul K; Koster, Abraham J; Lagerstedt, Ingvar; Lawson, Catherine L; Mastronarde, David; McCormick, Matthew; Parkinson, Helen; Rosenthal, Peter B; Saalfeld, Stephan; Saibil, Helen R; Sarntivijai, Sirarat; Solanes Valero, Irene; Subramaniam, Sriram; Swedlow, Jason R; Tudose, Ilinca; Winn, Martyn; Kleywegt, Gerard J
2017-07-06
The integration of cellular and molecular structural data is key to understanding the function of macromolecular assemblies and complexes in their in vivo context. Here we report on the outcomes of a workshop that discussed how to integrate structural data from a range of public archives. The workshop identified two main priorities: the development of tools and file formats to support segmentation (that is, the decomposition of a three-dimensional volume into regions that can be associated with defined objects), and the development of tools to support the annotation of biological structures.
OpenMx: An Open Source Extended Structural Equation Modeling Framework
ERIC Educational Resources Information Center
Boker, Steven; Neale, Michael; Maes, Hermine; Wilde, Michael; Spiegel, Michael; Brick, Timothy; Spies, Jeffrey; Estabrook, Ryne; Kenny, Sarah; Bates, Timothy; Mehta, Paras; Fox, John
2011-01-01
OpenMx is free, full-featured, open source, structural equation modeling (SEM) software. OpenMx runs within the "R" statistical programming environment on Windows, Mac OS-X, and Linux computers. The rationale for developing OpenMx is discussed along with the philosophy behind the user interface. The OpenMx data structures are…
The Continued Development of the Structural Approach.
ERIC Educational Resources Information Center
Sweet, Waldo E.
1967-01-01
A brief discussion of traditional Latin textbooks is followed by a survey of the first attempts at new materials (emphasizing integration of audiovisual aids and texts) at the William Penn Charter School and at the University of Michigan. The body of the article considers the structural approach, using "Latin: A Structural Approach"…
Online Monitoring of Concrete Structures in Nuclear Power Plants: Interim Report
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mahadevan, Sankaran; Cai, Guowei; Agarwal, Vivek
The existing fleet of nuclear power plants in the United States have initial operating licenses of 40 years, and many of these plants have applied for and received license extensions. As plant structures, systems, and components age, their useful life—considering both structural integrity and performance—is reduced as a result of deterioration of the materials. Assessment and management of aging concrete structures in nuclear plants require a more systematic approach than simple reliance on existing code-based design margins of safety. Structural health monitoring is required to produce actionable information regarding structural integrity that supports operational and maintenance decisions. The online monitoringmore » of concrete structures project conducted under the Advanced Instrumentation, Information, and Control Technologies Pathway of the Light Water Reactor Sustainability program at Idaho National Laboratory is seeking to develop and demonstrate capabilities for concrete structures health monitoring. Through this research project, several national laboratories and Vanderbilt University propose to develop a framework of research activities for the health monitoring of nuclear power plant concrete structures that includes the integration of four elements—damage modeling, monitoring, data analytics, and uncertainty quantification. This report briefly discusses activities in this project during October-December, 2014. The most significant activity during this period was the organizing of a two-day workshop on research needs in online monitoring of concrete structures, hosted by Vanderbilt University in November 2014. Thirty invitees from academia, industry and government participated in the workshop. The presentations and discussions at the workshop surveyed current activities related to concrete structures deterioration modeling and monitoring, and identified the challenges, knowledge gaps, and opportunities for advancing the state of the art; these discussions are summarized in this report« less
The evolutionary and ecological consequences of animal social networks: emerging issues.
Kurvers, Ralf H J M; Krause, Jens; Croft, Darren P; Wilson, Alexander D M; Wolf, Max
2014-06-01
The first generation of research on animal social networks was primarily aimed at introducing the concept of social networks to the fields of animal behaviour and behavioural ecology. More recently, a diverse body of evidence has shown that social fine structure matters on a broader scale than initially expected, affecting many key ecological and evolutionary processes. Here, we review this development. We discuss the effects of social network structure on evolutionary dynamics (genetic drift, fixation probabilities, and frequency-dependent selection) and social evolution (cooperation and between-individual behavioural differences). We discuss how social network structure can affect important coevolutionary processes (host-pathogen interactions and mutualisms) and population stability. We also discuss the potentially important, but poorly studied, role of social network structure on dispersal and invasion. Throughout, we highlight important areas for future research. Copyright © 2014 Elsevier Ltd. All rights reserved.
Teacher Training in Family Involvement: An Interpersonal Approach.
ERIC Educational Resources Information Center
Coleman, Mick; Wallinga, Charlotte
2000-01-01
Discusses ways to develop family-school-community involvement, based on an early childhood teacher training course in family involvement. Discusses strategies for using Maslow's Hierarchy of Needs to facilitate family involvement interactions, and using student teachers' experiences for structuring reflective thought about family involvement…
Functional 5' UTR mRNA structures in eukaryotic translation regulation and how to find them.
Leppek, Kathrin; Das, Rhiju; Barna, Maria
2018-03-01
RNA molecules can fold into intricate shapes that can provide an additional layer of control of gene expression beyond that of their sequence. In this Review, we discuss the current mechanistic understanding of structures in 5' untranslated regions (UTRs) of eukaryotic mRNAs and the emerging methodologies used to explore them. These structures may regulate cap-dependent translation initiation through helicase-mediated remodelling of RNA structures and higher-order RNA interactions, as well as cap-independent translation initiation through internal ribosome entry sites (IRESs), mRNA modifications and other specialized translation pathways. We discuss known 5' UTR RNA structures and how new structure probing technologies coupled with prospective validation, particularly compensatory mutagenesis, are likely to identify classes of structured RNA elements that shape post-transcriptional control of gene expression and the development of multicellular organisms.
Library-Information Education in Algeria.
ERIC Educational Resources Information Center
Boumarafi, B. B.; Haythornthwaite, J.
1988-01-01
Reviews the development of educational programs for library technicians, librarians, and information professionals in Algeria and describes the current educational structure. Topics discussed include the need for improvements in curriculum development, teaching staff development, library facilities, and the use of information technologies. (CLB)
GaN based nanorods for solid state lighting
NASA Astrophysics Data System (ADS)
Li, Shunfeng; Waag, Andreas
2012-04-01
In recent years, GaN nanorods are emerging as a very promising novel route toward devices for nano-optoelectronics and nano-photonics. In particular, core-shell light emitting devices are thought to be a breakthrough development in solid state lighting, nanorod based LEDs have many potential advantages as compared to their 2 D thin film counterparts. In this paper, we review the recent developments of GaN nanorod growth, characterization, and related device applications based on GaN nanorods. The initial work on GaN nanorod growth focused on catalyst-assisted and catalyst-free statistical growth. The growth condition and growth mechanisms were extensively investigated and discussed. Doping of GaN nanorods, especially p-doping, was found to significantly influence the morphology of GaN nanorods. The large surface of 3 D GaN nanorods induces new optical and electrical properties, which normally can be neglected in layered structures. Recently, more controlled selective area growth of GaN nanorods was realized using patterned substrates both by metalorganic chemical vapor deposition (MOCVD) and by molecular beam epitaxy (MBE). Advanced structures, for example, photonic crystals and DBRs are meanwhile integrated in GaN nanorod structures. Based on the work of growth and characterization of GaN nanorods, GaN nanoLEDs were reported by several groups with different growth and processing methods. Core/shell nanoLED structures were also demonstrated, which could be potentially useful for future high efficient LED structures. In this paper, we will discuss recent developments in GaN nanorod technology, focusing on the potential advantages, but also discussing problems and open questions, which may impose obstacles during the future development of a GaN nanorod based LED technology.
Computational Methods in Drug Discovery
Sliwoski, Gregory; Kothiwale, Sandeepkumar; Meiler, Jens
2014-01-01
Computer-aided drug discovery/design methods have played a major role in the development of therapeutically important small molecules for over three decades. These methods are broadly classified as either structure-based or ligand-based methods. Structure-based methods are in principle analogous to high-throughput screening in that both target and ligand structure information is imperative. Structure-based approaches include ligand docking, pharmacophore, and ligand design methods. The article discusses theory behind the most important methods and recent successful applications. Ligand-based methods use only ligand information for predicting activity depending on its similarity/dissimilarity to previously known active ligands. We review widely used ligand-based methods such as ligand-based pharmacophores, molecular descriptors, and quantitative structure-activity relationships. In addition, important tools such as target/ligand data bases, homology modeling, ligand fingerprint methods, etc., necessary for successful implementation of various computer-aided drug discovery/design methods in a drug discovery campaign are discussed. Finally, computational methods for toxicity prediction and optimization for favorable physiologic properties are discussed with successful examples from literature. PMID:24381236
Thienoacene-based organic semiconductors.
Takimiya, Kazuo; Shinamura, Shoji; Osaka, Itaru; Miyazaki, Eigo
2011-10-11
Thienoacenes consist of fused thiophene rings in a ladder-type molecular structure and have been intensively studied as potential organic semiconductors for organic field-effect transistors (OFETs) in the last decade. They are reviewed here. Despite their simple and similar molecular structures, the hitherto reported properties of thienoacene-based OFETs are rather diverse. This Review focuses on four classes of thienoacenes, which are classified in terms of their chemical structures, and elucidates the molecular electronic structure of each class. The packing structures of thienoacenes and the thus-estimated solid-state electronic structures are correlated to their carrier transport properties in OFET devices. With this perspective of the molecular structures of thienoacenes and their carrier transport properties in OFET devices, the structure-property relationships in thienoacene-based organic semiconductors are discussed. The discussion provides insight into new molecular design strategies for the development of superior organic semiconductors. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
NASA Astrophysics Data System (ADS)
Piyadasa, Adimali; Wang, Sibo; Gao, Pu-Xian
2017-07-01
The electronic band structure of a solid state semiconductor determines many of its physical and chemical characteristics such as electrical, optical, physicochemical, and catalytic activity. Alteration or modification of the band structure could lead to significant changes in these physical and chemical characteristics, therefore we introduce new mechanisms of creating novel solid state materials with interesting properties. Over the past three decades, research on band structure engineering has allowed development of various methods to modify the band structure of engineered materials. Compared to bulk counterparts, nanostructures generally exhibit higher band structure modulation capabilities due to the quantum confinement effect, prominent surface effect, and higher strain limit. In this review we will discuss various band structure engineering strategies in semiconductor nanowires and other related nanostructures, mostly focusing on metal oxide systems. Several important strategies of band structure modulation are discussed in detail, such as doping, alloying, straining, interface and core-shell nanostructuring.
Development Committee. AGB Standing Committee Series.
ERIC Educational Resources Information Center
Kinnison, William
1984-01-01
The structure and functions of college development committees are discussed. The development committee of a board of trustees, also known as "the institutional advancement" committee, is responsible for ensuring the operation of the fund-raising program. Whether the development committee works through a foundation or directly for the…
McDonnell Douglas Helicopter Company independent research and development: Preparing for the future
NASA Technical Reports Server (NTRS)
Haggerty, Allen C.
1988-01-01
During the 1970's and 80's, research has produced the technology that is seen in aircraft such as the LHX and future models. The technology is discussed that is reaching maturity and moving into the application stage of future programs. Technology is discussed in six major areas: advanced concepts, analysis techniques, structures, systems, simulation, and research and development facilities. The partnership of McDonnell Douglas Helicopter Co. and the government in developing these technologies is illustrated in several programs.
FY-79 - development of fiber optics connector technology for large space systems
NASA Technical Reports Server (NTRS)
Campbell, T. G.
1980-01-01
The development of physical concepts for integrating fiber optic connectors and cables with structural concepts proposed for the LSST is discussed. Emphasis is placed on remote connections using integrated cables.
Guidelines for development structured FORTRAN programs
NASA Technical Reports Server (NTRS)
Earnest, B. M.
1984-01-01
Computer programming and coding standards were compiled to serve as guidelines for the uniform writing of FORTRAN 77 programs at NASA Langley. Software development philosophy, documentation, general coding conventions, and specific FORTRAN coding constraints are discussed.
Chromogenic switchable glazing: Towards the development of the smart window
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lampert, C.M.
1995-06-01
The science and technology of chromogenic materials for switchable glazings in building applications is discussed. These glazings can be used for dynamic control of solar and visible energy. Currently many researchers and engineers are involved with the development of products in this field. A summary of activities in Japan, Europe, Australia, USA and Canada is made. The activities of the International Energy Agency are included. Both non-electrically activated and electrically activated glazings are discussed. Technologies covered in the first category are photochromics, and thermochromics and thermotropics. A discussion of electrically activated chromogenic glazings includes dispersed liquid crystals, dispersed particles andmore » electrochromics. A selection of device structures and performance characteristics are compared. A discussion of transparent conductors is presented. Technical issues concerning large-area development of smart windows are discussed.« less
Investigation of empirical damping laws for the space shuttle
NASA Technical Reports Server (NTRS)
Bernstein, E. L.
1973-01-01
An analysis of dynamic test data from vibration testing of a number of aerospace vehicles was made to develop an empirical structural damping law. A systematic attempt was made to fit dissipated energy/cycle to combinations of all dynamic variables. The best-fit laws for bending, torsion, and longitudinal motion are given, with error bounds. A discussion and estimate are made of error sources. Programs are developed for predicting equivalent linear structural damping coefficients and finding the response of nonlinearly damped structures.
Brain Structure and Development.
ERIC Educational Resources Information Center
Teyler, T.J.; Chiaia, N.
1983-01-01
Considers basic biology of brain, what is known of how it operates, and something of how it develops. Discusses properties of neurons and specialized regions of the brain in linguistic and higher order processing skills, as well as genetic and environmental influences on brain development. (CMG)
ERIC Educational Resources Information Center
Eliot, Lise
2001-01-01
Discusses the connection between brain development and human educational needs based on neuroscience research. Considers brain development from conception, including cell structure, myelination, and regional development of the brain, stressing the importance of a child's early environment and the prenatal vulnerability of the brain. (JPB)
Fire retardancy with structural materials
NASA Technical Reports Server (NTRS)
Gardner, R. E.
1971-01-01
Impregnating wood with chemicals to reduce or prevent combustion is discussed. Basic types of materials for fireproofing purposes and methods of applications are described. It is concluded that effective fireproofing materials have been developed and their application to wooden structures represents acceptable safety management procedures.
Management Information Systems and Organizational Structure.
ERIC Educational Resources Information Center
Cox, Bruce B.
1987-01-01
Discusses the context within which office automation takes place by using the models of the Science of Creative Intelligence and Transcendental Meditation. Organizational structures are compared to the phenomenon of the "collective consciousness" and the development of automated information systems from manual methods of organizational…
Structural Molecular Biology-A Personal Reflection on the Occasion of John Kendrew's 100th Birthday.
Cramer, Patrick
2017-08-18
Here, I discuss the development and future of structural molecular biology, concentrating on the eukaryotic transcription machinery and reflecting on John Kendrew's legacy from a personal perspective. Copyright © 2017 Elsevier Ltd. All rights reserved.
Formal Specification of Information Systems Requirements.
ERIC Educational Resources Information Center
Kampfner, Roberto R.
1985-01-01
Presents a formal model for specification of logical requirements of computer-based information systems that incorporates structural and dynamic aspects based on two separate models: the Logical Information Processing Structure and the Logical Information Processing Network. The model's role in systems development is discussed. (MBR)
NASA Technical Reports Server (NTRS)
Buchanan, H. J.
1983-01-01
Work performed in Large Space Structures Controls research and development program at Marshall Space Flight Center is described. Studies to develop a multilevel control approach which supports a modular or building block approach to the buildup of space platforms are discussed. A concept has been developed and tested in three-axis computer simulation utilizing a five-body model of a basic space platform module. Analytical efforts have continued to focus on extension of the basic theory and subsequent application. Consideration is also given to specifications to evaluate several algorithms for controlling the shape of Large Space Structures.
Anomalies of the middle and inner ear.
Rodriguez, Kimsey; Shah, Rahul K; Kenna, Margaret
2007-02-01
The development of the middle and inner ear highlights the intricacy of embryology. As early as 3 weeks after fertilization, the inner ear begins taking form. This process, along with development of the middle ear, continues throughout gestation. At birth, the middle ear, inner ear, and associated structures are almost adult size. An understanding of the embryologic development of the ear serves as a foundation for evaluating and managing congenital malformations of these structures. The focus of this article is the normal, abnormal, and arrested development of the middle and inner ear, with a clinical emphasis on malformed middle and inner ear structures and a discussion of associated syndromes.
Space construction base control system
NASA Technical Reports Server (NTRS)
1978-01-01
Aspects of an attitude control system were studied and developed for a large space base that is structurally flexible and whose mass properties change rather dramatically during its orbital lifetime. Topics of discussion include the following: (1) space base orbital pointing and maneuvering; (2) angular momentum sizing of actuators; (3) momentum desaturation selection and sizing; (4) multilevel control technique applied to configuration one; (5) one-dimensional model simulation; (6) N-body discrete coordinate simulation; (7) structural analysis math model formulation; and (8) discussion of control problems and control methods.
A program for the investigation of the Multibody Modeling, Verification, and Control Laboratory
NASA Technical Reports Server (NTRS)
Tobbe, Patrick A.; Christian, Paul M.; Rakoczy, John M.; Bulter, Marlon L.
1993-01-01
The Multibody Modeling, Verification, and Control (MMVC) Laboratory is under development at NASA MSFC in Huntsville, Alabama. The laboratory will provide a facility in which dynamic tests and analyses of multibody flexible structures representative of future space systems can be conducted. The purpose of the tests are to acquire dynamic measurements of the flexible structures undergoing large angle motions and use the data to validate the multibody modeling code, TREETOPS, developed under sponsorship of NASA. Advanced control systems design and system identification methodologies will also be implemented in the MMVC laboratory. This paper describes the ground test facility, the real-time control system, and the experiments. A top-level description of the TREETOPS code is also included along with the validation plan for the MMVC program. Dynamic test results from component testing are also presented and discussed. A detailed discussion of the test articles, which manifest the properties of large flexible space structures, is included along with a discussion of the various candidate control methodologies to be applied in the laboratory.
ERIC Educational Resources Information Center
Hansen, Linda; Monk, Martin
2002-01-01
Reviews evidence of the way the maturation of the brain may structure the plasticity that is available for the construction of the mind. Presents evidence taken from non-invasive imaging techniques that makes use of electrode potentials, magnetic resonance, or positron emission. Discusses the development of the brain in terms of grey and white…
The origin of biological macromolecules on the earth. The hypothesis of inorganic template
NASA Technical Reports Server (NTRS)
Lu, T. S.
1977-01-01
Studies about the origin of life are reviewed. The nonrandom organization of organelles is discussed from a structural and functional point of view. After postulating that the origin of biomacromolecules was not a random event, the paper develops the hypothesis that polypeptides and polynucleotides were formed on an inorganic template. Only information-containing structures can pass natural selection and develop through evolution.
Developing Army Leaders through Increased Rigor in Professional Military Training and Education
2017-06-09
leadership. Research Methodology An applied, exploratory, qualitative research methodology via a structured and focused case study comparison was...research methodology via a structured and focused case study comparison. Finally, it will discuss how the methodology will be conducted to make...development models; it serves as the base data for case study comparison. 48 Research Methodology and Data Analysis A qualitative research
NASA Astrophysics Data System (ADS)
Engmann, Jan
2008-07-01
We discuss which rheological material functions of wheat flour dough are most relevant for structure development in baked products under common processing conditions. We consider the growth of gas cells during dough proofing (driven by yeast) and during baking, where the growth is driven by a combination of CO2 desorption, water and ethanol evaporation, and thermal expansion of gas. Attention is given to upper limits on biaxial extension rate and stress and the consequences for the required rheological material functions. The applicability of the "Considère criterion" to predict the probability of coalescence between gas cells and its effect on loaf aeration is briefly discussed.
Schnick, Rosalie A.; Morton, John M.; Mochalski, Jeffrey C.; Beall, Jonathan T.
1982-01-01
Extensive information is provided on techniques that can reduce or eliminate the negative impact of man's activities (particularly those related to navigation) on large river systems, with special reference to the Upper Mississippi River. These techniques should help resource managers who are concerned with such river systems to establish sound environmental programs. Discussion of each technique or group of techniques include (1) situation to be mitigated or enhanced; (2) description of technique; (3) impacts on the environment; (4) costs; and (5) evaluation for use on the Upper Mississippi River Systems. The techniques are divided into four primary categories: Bank Stabilization Techniques, Dredging and Disposal of Dredged Material, Fishery Management Techniques, and Wildlife Management Techniques. Because techniques have been grouped by function, rather than by structure, some structures are discussed in several contexts. For example, gabions are discussed for use in revetments, river training structures, and breakwaters. The measures covered under Bank Stabilization Techniques include the use of riprap revetments, other revetments, bulkheads, river training structures, breakwater structures, chemical soil stabilizers, erosion-control mattings, and filter fabrics; the planting of vegetation; the creation of islands; the creation of berms or enrichment of beaches; and the control of water level and boat traffic. The discussions of Dredging and the Disposal of Dredged Material consider dredges, dredging methods, and disposal of dredged material. The following subjects are considered under Fishery Management Techniques: fish attractors; spawning structures; nursery ponds, coves, and marshes; fish screens and barriers; fish passage; water control structures; management of water levels and flows; wing dam modification; side channel modification; aeration techniques; control of nuisance aquatic plants; and manipulated of fish populations. Wildlife Management Techniques include treatments of artificial nest structures, island creation or development, marsh creation or development, greentree reservoirs and mast management, vegetation control, water level control, and revegetation.
ERIC Educational Resources Information Center
Norsworthy, Kathryn L.
An analysis of structural and institutional violence against women in three cultures in Southeast Asia, Thailand, Cambodia, and among refugees of Burma, was generated by groups of women and men from these countries. Group members also discussed strategies for transforming systems supporting gender-based violence into structures of peace and…
Lee, Joonkoo; Gereffi, Gary; Beauvais, Janet
2012-01-01
The rise of private food standards has brought forth an ongoing debate about whether they work as a barrier for smallholders and hinder poverty reduction in developing countries. This paper uses a global value chain approach to explain the relationship between value chain structure and agrifood safety and quality standards and to discuss the challenges and possibilities this entails for the upgrading of smallholders. It maps four potential value chain scenarios depending on the degree of concentration in the markets for agrifood supply (farmers and manufacturers) and demand (supermarkets and other food retailers) and discusses the impact of lead firms and key intermediaries on smallholders in different chain situations. Each scenario is illustrated with case examples. Theoretical and policy issues are discussed, along with proposals for future research in terms of industry structure, private governance, and sustainable value chains. PMID:21149723
Revolting Developments in Our Understanding of the Organization of the Eukaryotic Genome.
ERIC Educational Resources Information Center
Krider, Hallie M.
1984-01-01
Various typs of DNA are discussed. Areas considered include highly repetitive and satellite sequences, genes encoding, ribosomal RNA, histone protein genes, and dispersed repeated genes that jump. Regulated genetic misbehavior, structure and use of unique genes, and higher order complexities of chromosomes are also discussed. (JN)
Impact of Automation on Technical Services.
ERIC Educational Resources Information Center
Rooks, Dana C.; Thompson, Linda L.
1988-01-01
Discusses the impact of automation on library technical services, and the need for library managers to be aware of the issues involved and to plan for future developments. The discussion focuses on the areas of job related concerns of technical staff, organizational structures, recruitment and training, and ergonomic considerations. (CLB)
Genetic conservation in applied tree breeding programs.
R. Johnson; B. St. Clair; S. Lipow
2001-01-01
This paper reviews how population size and structure impacts the maintenance of genetic variation in breeding and gene resource populations. We discuss appropriate population sizes for low frequency alleles and point out some examples of low frequency alleles in the literature. Development of appropriate breeding populations and gene resource populations are discussed...
Functional 5′ UTR mRNA structures in eukaryotic translation regulation and how to find them
Leppek, Kathrin; Das, Rhiju; Barna, Maria
2017-01-01
RNA molecules can fold into intricate shapes that can provide an additional layer of control of gene expression beyond that of their sequence. In this Review, we discuss the current mechanistic understanding of structures in 5′ untranslated regions (UTRs) of eukaryotic mRNAs and the emerging methodologies used to explore them. These structures may regulate cap-dependent translation initiation through helicase-mediated remodelling of RNA structures and higher-order RNA interactions, as well as cap-independent translation initiation through internal ribosome entry sites (IRESs), mRNA modifications and other specialized translation pathways. We discuss known 5′ UTR RNA structures and how new structure probing technologies coupled with prospective validation, particularly compensatory mutagenesis, are likely to identify classes of structured RNA elements that shape post-transcriptional control of gene expression and the development of multicellular organisms. PMID:29165424
European Directions for Hypersonic Thermal Protection Systems and Hot Structures
NASA Technical Reports Server (NTRS)
Glass, David E.
2007-01-01
This presentation will overview European Thermal Protection Systems (TPS) and Hot Structures activities in Europe. The Europeans have a lot of very good work going on in the area. The presentation will discuss their emphasis on focused technology development for their flight vehicles.
Web-based OPACs: Between Tradition and Innovation.
ERIC Educational Resources Information Center
Moscoso, Purificacion; Ortiz-Repiso, Virginia
1999-01-01
Analyzes the change that Internet-based OPACs (Online Public Access Catalogs) have represented to the structure, administration, and maintenance of the catalogs, retrieval systems, and user interfaces. Examines the structure of databases and traditional principles that have governed systems development. Discusses repercussions of the application…
The Topology of a Discussion: The #Occupy Case.
Gargiulo, Floriana; Bindi, Jacopo; Apolloni, Andrea
2015-01-01
We analyse a large sample of the Twitter activity that developed around the social movement 'Occupy Wall Street', to study the complex interactions between the human communication activity and the semantic content of a debate. We use a network approach based on the analysis of the bipartite graph @Users-#Hashtags and of its projections: the 'semantic network', whose nodes are hashtags, and the 'users interest network', whose nodes are users. In the first instance, we find out that discussion topics (#hashtags) present a high structural heterogeneity, with a relevant role played by the semantic hubs that are responsible to guarantee the continuity of the debate. In the users' case, the self-organisation process of users' activity, leads to the emergence of two classes of communicators: the 'professionals' and the 'amateurs'. Both the networks present a strong community structure, based on the differentiation of the semantic topics, and a high level of structural robustness when certain sets of topics are censored and/or accounts are removed. By analysing the characteristics of the dynamical networks we can distinguish three phases of the discussion about the movement. Each phase corresponds to a specific moment of the movement: from declaration of intent, organisation and development and the final phase of political reactions. Each phase is characterised by the presence of prototypical #hashtags in the discussion.
NASA Astrophysics Data System (ADS)
Wang, Pei-Xi; MacLachlan, Mark J.
2017-12-01
Tactoids are liquid crystalline microdroplets that spontaneously nucleate from isotropic dispersions, and transform into macroscopic anisotropic phases. These intermediate structures have been found in a range of molecular, polymeric and colloidal liquid crystals. Typically only studied by polarized optical microscopy, these ordered but easily deformable microdroplets are now emerging as interesting components for structural investigations and developing new materials. In this review, we highlight the structure, property and transformation of tactoids in different compositions, but especially cellulose nanocrystals. We have selected references that illustrate the diversity and most exciting developments in tactoid research, while capturing the historical development of this field. This article is part of a discussion meeting issue `New horizons for cellulose nanotechnology'.
Research, development and application of noncombustible Beta fiber structures. [for Apollo
NASA Technical Reports Server (NTRS)
Dillon, J. J.; Cobb, E. S.
1975-01-01
Beta fiber was selected as the primary material for flexible fibrous structures used in spacecraft and crew systems applications in the Apollo program because it was noncombustible in a 100 percent oxygen atmosphere up to 16.5 psia. It met NASA criteria for outgassing, toxicity, odor, and crew comfort, and possessed sufficient durability to last through the mission. Topics discussed include: study of spacecraft applications; design of Beta fiber textile structures to meet the requirements; selection of surface treatments (finishes, coatings, and printing systems) to impart the required durability and special functional use to the textile structures; development of sewing and fabrication techniques; and testing and evaluation programs, and development of production sources.
Intricate Hollow Structures: Controlled Synthesis and Applications in Energy Storage and Conversion.
Zhou, Liang; Zhuang, Zechao; Zhao, Huihui; Lin, Mengting; Zhao, Dongyuan; Mai, Liqiang
2017-05-01
Intricate hollow structures garner tremendous interest due to their aesthetic beauty, unique structural features, fascinating physicochemical properties, and widespread applications. Here, the recent advances in the controlled synthesis are discussed, as well as applications of intricate hollow structures with regard to energy storage and conversion. The synthetic strategies toward complex multishelled hollow structures are classified into six categories, including well-established hard- and soft-templating methods, as well as newly emerging approaches based on selective etching of "soft@hard" particles, Ostwald ripening, ion exchange, and thermally induced mass relocation. Strategies for constructing structures beyond multishelled hollow structures, such as bubble-within-bubble, tube-in-tube, and wire-in-tube structures, are also covered. Niche applications of intricate hollow structures in lithium-ion batteries, Li-S batteries, supercapacitors, Li-O 2 batteries, dye-sensitized solar cells, photocatalysis, and fuel cells are discussed in detail. Some perspectives on the future research and development of intricate hollow structures are also provided. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Structural considerations in design of lightweight glass-fiber composite pressure vessels
NASA Technical Reports Server (NTRS)
Faddoul, J. R.
1973-01-01
The development of structurally efficient, metal-lined, glass-fiber composite pressure vessels. Both the current state-of-the-art and current problems are discussed along with fracture mechanics considerations for the metal liner. The design concepts used for metal-lined, glass-fiber, composite pressure vessels are described and the structural characteristics of the composite designs are compared with each other and with homogeneous metal pressure vessels. Specific design techniques and available design data are identified. Results of a current program to evaluate flaw growth and fracture characteristics of the metal liners are reviewed and the impact of these results on composite pressure vessel designs is discussed.
STRCMACS: An extensive set of Macros for structured programming in OS/360 assembly language
NASA Technical Reports Server (NTRS)
Barth, C. W.
1974-01-01
Two techniques are discussed that have been most often referred to as structured programming. One is that of programming with high level control structures (such as the if and while) replacing the branch instruction (goto-less programming); the other is the process of developing a program by progressively refining descriptions of components in terms of more primitive components (called stepwise refinement or top-down programming). In addition to discussing what these techniques are, it is shown why their use is advised and how both can be implemented in OS assembly language by the use of a special macro instruction package.
Materials, Structures and Manufacturing: An Integrated Approach to Develop Expandable Structures
NASA Technical Reports Server (NTRS)
Belvin, W. Keith; Zander, Martin E.; Sleight, Daid W.; Connell, John; Holloway, Nancy; Palmieri, Frank
2012-01-01
Membrane dominated space structures are lightweight and package efficiently for launch; however, they must be expanded (deployed) in-orbit to achieve the desired geometry. These expandable structural systems include solar sails, solar power arrays, antennas, and numerous other large aperture devices that are used to collect, reflect and/or transmit electromagnetic radiation. In this work, an integrated approach to development of thin-film damage tolerant membranes is explored using advanced manufacturing. Bio-inspired hierarchical structures were printed on films using additive manufacturing to achieve improved tear resistance and to facilitate membrane deployment. High precision, robust expandable structures can be realized using materials that are both space durable and processable using additive manufacturing. Test results show this initial work produced higher tear resistance than neat film of equivalent mass. Future research and development opportunities for expandable structural systems designed using an integrated approach to structural design, manufacturing, and materials selection are discussed.
Development of the field of structural physiology
FUJIYOSHI, Yoshinori
2015-01-01
Electron crystallography is especially useful for studying the structure and function of membrane proteins — key molecules with important functions in neural and other cells. Electron crystallography is now an established technique for analyzing the structures of membrane proteins in lipid bilayers that closely simulate their natural biological environment. Utilizing cryo-electron microscopes with helium-cooled specimen stages that were developed through a personal motivation to understand the functions of neural systems from a structural point of view, the structures of membrane proteins can be analyzed at a higher than 3 Å resolution. This review covers four objectives. First, I introduce the new research field of structural physiology. Second, I recount some of the struggles involved in developing cryo-electron microscopes. Third, I review the structural and functional analyses of membrane proteins mainly by electron crystallography using cryo-electron microscopes. Finally, I discuss multifunctional channels named “adhennels” based on structures analyzed using electron and X-ray crystallography. PMID:26560835
Structures for the 3rd Generation Reusable Concept Vehicle
NASA Technical Reports Server (NTRS)
Hrinda, Glenn A.
2001-01-01
A major goal of NASA is to create an advance space transportation system that provides a safe, affordable highway through the air and into space. The long-term plans are to reduce the risk of crew loss to 1 in 1,000,000 missions and reduce the cost of Low-Earth Orbit by a factor of 100 from today's costs. A third generation reusable concept vehicle (RCV) was developed to assess technologies required to meet NASA's space access goals. The vehicle will launch from Cape Kennedy carrying a 25,000 lb. payload to the International Space Station (ISS). The system is an air breathing launch vehicle (ABLV) hypersonic lifting body with rockets and uses triple point hydrogen and liquid oxygen propellant. The focus of this paper is on the structural concepts and analysis methods used in developing the third generation reusable launch vehicle (RLV). Member sizes, concepts and material selections will be discussed as well as analysis methods used in optimizing the structure. Analysis based on the HyperSizer structural sizing software will be discussed. Design trades required to optimize structural weight will be presented.
Development and Comparison of Mechanical Structures for FNAL 15 T Nb$$_3$$Sn Dipole Demonstrator
DOE Office of Scientific and Technical Information (OSTI.GOV)
Novitski, I.; Zlobin, A. V.
2016-11-08
Main design challenges for 15 T accelerator magnets are large Lorentz forces at this field level. The large Lorentz forces generate high stresses in the coil and mechanical structure and, thus, need stress control to maintain them at the acceptable level for brittle Nb3Sn coils and other elements of magnet mechanical structure. To provide these conditions and achieve the design field in the FNAL 15 T dipole demonstrator, several mechanical structures have been developed and analysed. The possibilities and limitations of these designs are discussed in this paper
NASA Technical Reports Server (NTRS)
Bryan, W. B.; Adams, M.
1973-01-01
Relationships between volcanic and structural features along the southern edge of Mare Serenitatis as determined from low angle lighting in Apollo 17 photographs are discussed. Observational summaries are given of: (1) contact relations between the dark border material and the central mare fill, (2) a late stage lava flow with associated cinder cones, and (3) certain structural features related to the development of the mare basin and its associated volcanic landforms. A chronologic summary is given of volcanic and structural events believed to be critical to understanding the development of Mare Serenitatis.
NASA Subsonic Rotary Wing Project - Structures and Materials Discipline
NASA Technical Reports Server (NTRS)
Halbig, Michael C.; Johnson, Susan M.
2008-01-01
The Structures & Materials Discipline within the NASA Subsonic Rotary Wing Project is focused on developing rotorcraft technologies. The technologies being developed are within the task areas of: 5.1.1 Life Prediction Methods for Engine Structures & Components 5.1.2 Erosion Resistant Coatings for Improved Turbine Blade Life 5.2.1 Crashworthiness 5.2.2 Methods for Prediction of Fatigue Damage & Self Healing 5.3.1 Propulsion High Temperature Materials 5.3.2 Lightweight Structures and Noise Integration The presentation will discuss rotorcraft specific technical challenges and needs as well as details of the work being conducted in the six task areas.
Automated procedures for sizing aerospace vehicle structures /SAVES/
NASA Technical Reports Server (NTRS)
Giles, G. L.; Blackburn, C. L.; Dixon, S. C.
1972-01-01
Results from a continuing effort to develop automated methods for structural design are described. A system of computer programs presently under development called SAVES is intended to automate the preliminary structural design of a complete aerospace vehicle. Each step in the automated design process of the SAVES system of programs is discussed, with emphasis placed on use of automated routines for generation of finite-element models. The versatility of these routines is demonstrated by structural models generated for a space shuttle orbiter, an advanced technology transport,n hydrogen fueled Mach 3 transport. Illustrative numerical results are presented for the Mach 3 transport wing.
[Effects of globalization of structure and function of public health service in Germany].
Bauch, J
1999-01-01
This essay discusses the effects of globalization on the German health care system. Globalization is regarded as a process to a "One-World-Society" without limits or borders to communication. Especially the economic effects of globalization are discussed, and the reduction of working places and wage levels in developed industrial societies, caused by globalization. Considering this development, it will not be possible to uphold present health care standards.
Advanced design for lightweight structures: Review and prospects
NASA Astrophysics Data System (ADS)
Braga, Daniel F. O.; Tavares, S. M. O.; da Silva, Lucas F. M.; Moreira, P. M. G. P.; de Castro, Paulo M. S. T.
2014-08-01
Current demand for fuel efficient aircraft has been pushing the aeronautical sector to develop ever more lightweight designs while keeping safe operation and required structural strength. Along with light-weighting, new structural design concepts have also been established in order to maintain the aircraft in service for longer periods of time, with high reliability levels. All these innovations and requirements have led to deeply optimized aeronautical structures contributing to more sustainable air transport. This article reviews the major design philosophies which have been employed in aircraft structures, including safe-life, fail-safe and damage tolerance taking into account their impact on the structural design. A brief historical review is performed in order to analyse what led to the development of each philosophy. Material properties are related to each of the design philosophies. Damage tolerant design has emerged as the main structural design philosophy in aeronautics, requiring deep knowledge on materials fatigue and corrosion strength, as well as potential failure modes and non-destructive inspection techniques, particularly minimum detectable defect and scan times. A discussion on the implementation of structural health monitoring and self-healing structures within the current panorama of structures designed according to the damage tolerant philosophy is presented. This discussion is aided by a review of research on these two subjects. These two concepts show potential for further improving safety and durability of aircraft structures.
Cheng, Yuhua; Deng, Yiming; Cao, Jing; Xiong, Xin; Bai, Libing; Li, Zhaojun
2013-01-01
In this article, the state-of-the-art multi-wave and hybrid imaging techniques in the field of nondestructive evaluation and structural health monitoring were comprehensively reviewed. A new direction for assessment and health monitoring of various structures by capitalizing the advantages of those imaging methods was discussed. Although sharing similar system configurations, the imaging physics and principles of multi-wave phenomena and hybrid imaging methods are inherently different. After a brief introduction of nondestructive evaluation (NDE), structure health monitoring (SHM) and their related challenges, several recent advances that have significantly extended imaging methods from laboratory development into practical applications were summarized, followed by conclusions and discussion on future directions. PMID:24287536
Reproductive tourism and the quest for global gender justice.
Donchin, Anne
2010-09-01
Reproductive tourism is a manifestation of a larger, more inclusive trend toward globalization of capitalist cultural and material economies. This paper discusses the development of cross-border assisted reproduction within the globalized economy, transnational and local structural processes that influence the trade, social relations intersecting it, and implications for the healthcare systems affected. I focus on prevailing gender structures embedded in the cross-border trade and their intersection with other social and economic structures that reflect and impact globalization. I apply a social connection model of responsibility for unjust outcomes and consider strategies to counter structural injustices embedded in this industry. The concluding section discusses policy reforms and proposals for collaborative action to preclude further injustices and extend full human rights to all.
Analysis of structural dynamic data from Skylab. Volume 1: Technical discussion
NASA Technical Reports Server (NTRS)
Demchak, L.; Harcrow, H.
1976-01-01
A compendium of Skylab structural dynamics analytical and test programs is presented. These programs are assessed to identify lessons learned from the structural dynamic prediction effort and to provide guidelines for future analysts and program managers of complex spacecraft systems. It is a synopsis of the structural dynamic effort performed under the Skylab Integration contract and specifically covers the development, utilization, and correlation of Skylab Dynamic Orbital Models.
Recent advances in convectively cooled engine and airframe structures for hypersonic flight
NASA Technical Reports Server (NTRS)
Kelly, H. N.; Wieting, A. R.; Shore, C. P.; Nowak, R. J.
1978-01-01
A hydrogen-cooled structure for a fixed-geometry, airframe-integrated scramjet is described. The thermal/structural problems, concepts, design features, and technological advances are applicable to a broad range of engines. Convectively cooled airframe structural concepts that have evolved from an extensive series of investigations, the technology developments that have led to these concepts, and the benefits that accrue from their use are discussed.
Using Organization Development To Improve School Climate. Report No. 17.
ERIC Educational Resources Information Center
Gottfredson, Gary D.; Gottfredson, Denise C.
This paper presents and illustrates some principles for organizational development approaches to improving school climate. It discusses a specific structure for facilitating school improvement entitled Program Development Evaluation, and it illustrates the use of school climate assessments for school diagnosis and the evaluation of improvement…
SSME structural dynamic model development
NASA Technical Reports Server (NTRS)
Foley, M. J.; Tilley, D. M.; Welch, C. T.
1983-01-01
A mathematical model of the Space Shuttle Main Engine (SSME) as a complete assembly, with detailed emphasis on LOX and High Fuel Turbopumps is developed. The advantages of both complete engine dynamics, and high fidelity modeling are incorporated. Development of this model, some results, and projected applications are discussed.
Composite structural materials. [aircraft applications
NASA Technical Reports Server (NTRS)
Ansell, G. S.; Loewy, R. G.; Wiberley, S. E.
1981-01-01
The development of composite materials for aircraft applications is addressed with specific consideration of physical properties, structural concepts and analysis, manufacturing, reliability, and life prediction. The design and flight testing of composite ultralight gliders is documented. Advances in computer aided design and methods for nondestructive testing are also discussed.
A Structure for Creating Quality Software.
ERIC Educational Resources Information Center
Christensen, Larry C.; Bodey, Michael R.
1990-01-01
Addresses the issue of assuring quality software for use in computer-aided instruction and presents a structure by which developers can create quality courseware. Differences between courseware and computer-aided instruction software are discussed, methods for testing software are described, and human factors issues as well as instructional design…
IVS Working Group 4: VLBI Data Structures
NASA Technical Reports Server (NTRS)
Gipson, John
2010-01-01
In 2007 the IVS Directing Board established IVS Working Group 4 on VLBI Data Structures. This note discusses the current VLBI data format, goals for a new format, the history and formation of the Working Group, and a timeline for the development of a new VLBI data format.
Structured Analysis and the Data Flow Diagram: Tools for Library Analysis.
ERIC Educational Resources Information Center
Carlson, David H.
1986-01-01
This article discusses tools developed to aid the systems analysis process (program evaluation and review technique, Gantt charts, organizational charts, decision tables, flowcharts, hierarchy plus input-process-output). Similarities and differences among techniques, library applications of analysis, structured systems analysis, and the data flow…
Technology Alignment and Portfolio Prioritization (TAPP)
NASA Technical Reports Server (NTRS)
Funaro, Gregory V.; Alexander, Reginald A.
2015-01-01
Technology Alignment and Portfolio Prioritization (TAPP) is a method being developed by the Advanced Concepts Office, at NASA Marshall Space Flight Center. The TAPP method expands on current technology assessment methods by incorporating the technological structure underlying technology development, e.g., organizational structures and resources, institutional policy and strategy, and the factors that motivate technological change. This paper discusses the methods ACO is currently developing to better perform technology assessments while taking into consideration Strategic Alignment, Technology Forecasting, and Long Term Planning.
Application of Soft Computing in Coherent Communications Phase Synchronization
NASA Technical Reports Server (NTRS)
Drake, Jeffrey T.; Prasad, Nadipuram R.
2000-01-01
The use of soft computing techniques in coherent communications phase synchronization provides an alternative to analytical or hard computing methods. This paper discusses a novel use of Adaptive Neuro-Fuzzy Inference Systems (ANFIS) for phase synchronization in coherent communications systems utilizing Multiple Phase Shift Keying (MPSK) modulation. A brief overview of the M-PSK digital communications bandpass modulation technique is presented and it's requisite need for phase synchronization is discussed. We briefly describe the hybrid platform developed by Jang that incorporates fuzzy/neural structures namely the, Adaptive Neuro-Fuzzy Interference Systems (ANFIS). We then discuss application of ANFIS to phase estimation for M-PSK. The modeling of both explicit, and implicit phase estimation schemes for M-PSK symbols with unknown structure are discussed. Performance results from simulation of the above scheme is presented.
An Analysis of Conceptual Flow Patterns and Structures in the Physics Classroom
NASA Astrophysics Data System (ADS)
Eshach, Haim
2010-03-01
The aim of the current research is to characterize the conceptual flow processes occurring in whole-class dialogic discussions with a high level of interanimation; in the present case, of a high-school class learning about image creation on plane mirrors. Using detailed chains of interaction and conceptual flow discourse maps-both developed for the purpose of this research-the classroom discourse, audio-taped and transcribed verbatim, was analyzed and three discussion structures were revealed: accumulation around budding foci concepts, zigzag between foci concepts, and concept tower. These structures as well as two additional factors, suggest the Two-Space Model of the whole class discussion proposed in the present article. The two additional factors are: (1) the teacher intervention; and (2) the conceptual barriers observed among the students, namely, materialistic thinking, and the tendency to attribute "unique characteristics" to optical devices. This model might help teachers to prepare and conduct efficient whole-class discussions which accord with the social constructivist perspective of learning.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Thornton, E.A.
1992-01-01
The present conference discusses aerobrake-maneuver vehicle aerothermodynamics, aerothermal issues in the structural design of high speed vehicles, laser surface-alloying of superlight metals with ceramic surfaces, high-temperature Al alloys for supersonic and hypersonic vehicles, advanced metallics for high temperature airframes, novel materials for engine applications, and the development status of computational methods for high temperature structural design. Also discussed are a transient thermal-structural analysis using adaptive unstructured remeshing and mesh movement, the FEM thermoviscoplastic analysis of aerospace structures, hot-structures testing techniques, a thermal-structural analysis of a carbon-carbon/refractory metal heat pipe-cooled leading edge, dynamic effects in thermoviscoplastic structures, microlevel thermal effects inmore » metal-matrix composites (MMCs), thermomechanical effects in the plasma spray manufacture of MMC monotapes, and intelligent HIP processing. Most of the presentations at this conference were abstracted previously (see A91-16027 to A91-16047).« less
Globalization and identity development: a Chinese perspective.
Cheng, Min; Berman, Steven L
2012-01-01
This chapter begins with a discussion of the unique experience of adolescents and emerging adults who grew up with globalization in China and how it has affected their sense of self. We then discuss the effects of globalization on identity development in general, with a special focus on the sociohistorical context of China. We also review and critique the psychological literature that has been conducted on identity within Chinese and Chinese American populations. Finally, we discuss the applicability of Western concepts of identity on a culture that does not necessarily share the same value structure. Copyright © 2012 Wiley Periodicals, Inc., A Wiley Company.
The notochord: structure and functions.
Corallo, Diana; Trapani, Valeria; Bonaldo, Paolo
2015-08-01
The notochord is an embryonic midline structure common to all members of the phylum Chordata, providing both mechanical and signaling cues to the developing embryo. In vertebrates, the notochord arises from the dorsal organizer and it is critical for proper vertebrate development. This evolutionary conserved structure located at the developing midline defines the primitive axis of embryos and represents the structural element essential for locomotion. Besides its primary structural function, the notochord is also a source of developmental signals that patterns surrounding tissues. Among the signals secreted by the notochord, Hedgehog proteins play key roles during embryogenesis. The Hedgehog signaling pathway is a central regulator of embryonic development, controlling the patterning and proliferation of a wide variety of organs. In this review, we summarize the current knowledge on notochord structure and functions, with a particular emphasis on the key developmental events that take place in vertebrates. Moreover, we discuss some genetic studies highlighting the phenotypic consequences of impaired notochord development, which enabled to understand the molecular basis of different human congenital defects and diseases.
Population and National Development--The Dilemma of Developing Countries. Occasional Essay Number 2.
ERIC Educational Resources Information Center
Sai, Fred T.
This essay describes the relationship of population to the overall development process and is based on a special university lecture given at the London School of Hygiene in February, 1974. The contents include discussions of population trends, reasons for the population explosion, the structure of populations, development inequalities,…
Bragge, P; Piccenna, L; Middleton, J; Williams, S; Creasey, G; Dunlop, S; Brown, D; Gruen, R
2015-10-01
Literature review/semi-structured interviews. To develop a spinal cord injury (SCI) research strategy for Australia and New Zealand. Australia. The National Trauma Research Institute Forum approach of structured evidence review and stakeholder consultation was employed. This involved gathering from published literature and stakeholder consultation the information necessary to properly consider the challenge, and synthesising this into a briefing document. A research strategy 'roadmap' was developed to define the major steps and key planning questions to consider; next, evidence from published SCI research strategy initiatives was synthesised with information from four one-on-one semi-structured interviews with key SCI research stakeholders to create a research strategy framework, articulating six key themes and associated activities for consideration. These resources, combined with a review of SCI prioritisation literature, were used to generate a list of draft principles for discussion in a structured stakeholder dialogue meeting. The research strategy roadmap and framework informed discussion at a structured stakeholder dialogue meeting of 23 participants representing key SCI research constituencies, results of which are published in a companion paper. These resources could also be of value in other research strategy or planning exercises. This project was funded by the Victorian Transport Accident Commission and the Australian and New Zealand Spinal Cord Injury Network.
Methodologies for Quantitative Systems Pharmacology (QSP) Models: Design and Estimation.
Ribba, B; Grimm, H P; Agoram, B; Davies, M R; Gadkar, K; Niederer, S; van Riel, N; Timmis, J; van der Graaf, P H
2017-08-01
With the increased interest in the application of quantitative systems pharmacology (QSP) models within medicine research and development, there is an increasing need to formalize model development and verification aspects. In February 2016, a workshop was held at Roche Pharma Research and Early Development to focus discussions on two critical methodological aspects of QSP model development: optimal structural granularity and parameter estimation. We here report in a perspective article a summary of presentations and discussions. © 2017 The Authors CPT: Pharmacometrics & Systems Pharmacology published by Wiley Periodicals, Inc. on behalf of American Society for Clinical Pharmacology and Therapeutics.
The pediatric mandible: I. A primer on growth and development.
Smartt, James M; Low, David W; Bartlett, Scott P
2005-07-01
After studying this article, the participant should be able to: 1. Describe embryonic and fetal mandibular development. 2. Summarize the aggregate changes in mandibular form from birth to puberty. 3. Describe the eruption and maturation of the deciduous and permanent mandibular dentition. In this, the first of two articles addressing the surgical management of pediatric mandibular fractures, the authors provide a detailed discussion of mandibular development and anatomy during the fetal period, infancy, and childhood. A review of the pertinent literature was performed. The changing structure of the developing mandible is discussed, with particular attention to surgically relevant anatomical structures. Throughout development, key anatomical structures with relevance to surgical therapy change markedly in position. The mandible undergoes significant change in its bony structure and the composition of its surrounding soft tissues. The mandible's bony structure becomes more robust, with an increasingly acute gonial angle and enlargement of the ramus and body. Furthermore, the mandible provides the bony structure from which tooth buds erupt as the deciduous and permanent dentition--a process that generates significant growth of the alveolar process. As a consequence, the distance between the developing dentition and the inferior mandibular border increases. While the canal of the inferior alveolar nerve undergoes significant superior displacement, the mental foramen becomes positioned more posteriorly over time. In addition, the ligamentous and muscular attachments that surround the temporomandibular joint become increasingly robust. Throughout childhood and adolescence, the blood supply of the mandibular body changes little, with the buccal periosteal plexus and inferior dental artery making significant contributions. Mandibular growth provides the basis for normal occlusal relations and the generation of increasingly large masticatory force. Although the exact mechanisms of bone remodeling during mandibular development remain unclear, the process likely receives contributions from primary growth centers and the response to local alterations in biomechanical force produced by surrounding soft-tissue structures. A working knowledge of the changing mandibular anatomy is a prerequisite for effective clinical management of traumatic injury.
NASA Technical Reports Server (NTRS)
Harris, Charles E. (Editor)
1994-01-01
International technical experts in durability and damage tolerance of metallic airframe structures were assembled to present and discuss recent research findings and the development of advanced design and analysis methods, structural concepts, and advanced materials. The symposium focused on the dissemination of new knowledge and the peer-review of progress on the development of advanced methodologies. Papers were presented on: structural concepts for enhanced durability, damage tolerance, and maintainability; new metallic alloys and processing technology; fatigue crack initiation and small crack effects; fatigue crack growth models; fracture mechanics failure, criteria for ductile materials; structural mechanics methodology for residual strength and life prediction; development of flight load spectra for design and testing; and advanced approaches to resist corrosion and environmentally assisted fatigue.
NASA Technical Reports Server (NTRS)
Harris, Charles E. (Editor)
1994-01-01
The international technical experts in the areas of durability and damage tolerance of metallic airframe structures were assembled to present and discuss recent research findings and the development of advanced design and analysis methods, structural concepts, and advanced materials. The principal focus of the symposium was on the dissemination of new knowledge and the peer-review of progress on the development of advanced methodologies. Papers were presented on the following topics: structural concepts for enhanced durability, damage tolerance, and maintainability; new metallic alloys and processing technology; fatigue crack initiation and small crack effects; fatigue crack growth models; fracture mechanics failure criteria for ductile materials; structural mechanics methodology for residual strength and life prediction; development of flight load spectra for design and testing; and corrosion resistance.
Linking Neural and Symbolic Representation and Processing of Conceptual Structures
van der Velde, Frank; Forth, Jamie; Nazareth, Deniece S.; Wiggins, Geraint A.
2017-01-01
We compare and discuss representations in two cognitive architectures aimed at representing and processing complex conceptual (sentence-like) structures. First is the Neural Blackboard Architecture (NBA), which aims to account for representation and processing of complex and combinatorial conceptual structures in the brain. Second is IDyOT (Information Dynamics of Thinking), which derives sentence-like structures by learning statistical sequential regularities over a suitable corpus. Although IDyOT is designed at a level more abstract than the neural, so it is a model of cognitive function, rather than neural processing, there are strong similarities between the composite structures developed in IDyOT and the NBA. We hypothesize that these similarities form the basis of a combined architecture in which the individual strengths of each architecture are integrated. We outline and discuss the characteristics of this combined architecture, emphasizing the representation and processing of conceptual structures. PMID:28848460
ERIC Educational Resources Information Center
Kang, Hye-Kyung; O'Neill, Peggy
2018-01-01
Discussions of power and privilege, oppression, and structural inequities in classrooms can produce complex understanding and critical analysis when facilitated effectively. In this article we present the critical conversations model for facilitating conversations that open up space for discussing such issues and encourage the development of…
Dialogue for Change. Options for Re-Structuring K-12 Education. 3rd Edition, 1988.
ERIC Educational Resources Information Center
Metropolitan Affairs Corp., Detroit, MI.
This Third Edition of the 1985 report, "Dialogue for Change," discusses options and examples of educational choice and teacher empowerment and summarizes developments between 1985 and 1987. The following key options are discussed in Chapter 1, "Proposed Options for Change": (1) magnet schools; (2) open enrollment; (3) purchase…
Development of structural ceramic components for automobile applications
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kawamoto, H.
1995-12-01
Development efforts have been made in automobile technologies on heat engines to improve the power performance, the fuel economy, and so on. It is well recognized that ceramic applications are keys to succeed in such advanced heat engines, because of their good mechanical and thermal properties. This paper discusses present automobile applications of structural ceramic components and the expectations in automobile uses. The strength and reliability of mass-produced components for the engines are described with the manufacturing processes. The future R&D directions are recommended for structural ceramics.
A structural analysis of an ocean going patrol boat subjected to planning loads
NASA Technical Reports Server (NTRS)
Clark, James H.; Lafreniere, Robert; Stoodt, Robert; Wiedenheft, John
1987-01-01
A static structural analysis of an ocean going patrol vessel subjected to hydrodynamic planning loads is discussed. The analysis required the development of a detailed model that included hull plating, five structural bulkheads, longitudinal and transverse stiffners, and a coarse representation of the superstructure. The finite element model was developed from fabrication drawings using the Navy computer aided design system. Various stress and displacement contours are shown for the entire hull. Because several critical areas appeared to be overstressed, these areas were remeshed for detail and are presented for completeness.
ES12; The 24th Annual Workshop on Recent Developments in Electronic Structure Theory
DOE Office of Scientific and Technical Information (OSTI.GOV)
Holzwarth, Natalie; Thonhauser, Timo; Salam, Akbar
ES12: The 24th Annual Workshop on Recent Developments in Electronic Structure Theory was held June 5-8, 2012 at Wake Forest University in Winston-Salem, NC 27109. The program consisted of 24 oral presentations, 70 posters, and 2 panel discussions. The attendance of the Workshop was comparable to or larger than previous workshops and participation was impressively diverse. The 136 participants came from all over the world and included undergraduate students, graduate students, postdoctoral researchers, and senior scientists. The general assessment of the Workshop was extremely positive in terms of the high level of scientific presentations and discussions, and in terms ofmore » the schedule, accommodations, and affordability of the meeting.« less
Doped graphene supercapacitors.
Kumar, Nanjundan Ashok; Baek, Jong-Beom
2015-12-11
Heteroatom-doped graphitic frameworks have received great attention in energy research, since doping endows graphitic structures with a wide spectrum of properties, especially critical for electrochemical supercapacitors, which tend to complement or compete with the current lithium-ion battery technology/devices. This article reviews the latest developments in the chemical modification/doping strategies of graphene and highlights the versatility of such heteroatom-doped graphitic structures. Their role as supercapacitor electrodes is discussed in detail. This review is specifically focused on the concept of material synthesis, techniques for electrode fabrication and metrics of performance, predominantly covering the last four years. Challenges and insights into the future research and perspectives on the development of novel electrode architectures for electrochemical supercapacitors based on doped graphene are also discussed.
Doped graphene supercapacitors
NASA Astrophysics Data System (ADS)
Ashok Kumar, Nanjundan; Baek, Jong-Beom
2015-12-01
Heteroatom-doped graphitic frameworks have received great attention in energy research, since doping endows graphitic structures with a wide spectrum of properties, especially critical for electrochemical supercapacitors, which tend to complement or compete with the current lithium-ion battery technology/devices. This article reviews the latest developments in the chemical modification/doping strategies of graphene and highlights the versatility of such heteroatom-doped graphitic structures. Their role as supercapacitor electrodes is discussed in detail. This review is specifically focused on the concept of material synthesis, techniques for electrode fabrication and metrics of performance, predominantly covering the last four years. Challenges and insights into the future research and perspectives on the development of novel electrode architectures for electrochemical supercapacitors based on doped graphene are also discussed.
The Four Levels of Web Site Development Expertise.
ERIC Educational Resources Information Center
Ingram, Albert L.
2000-01-01
Discusses the design of Web pages and sites and proposes a four-level model of Web development expertise that can serve as a curriculum overview or as a plan for an individual's professional development. Highlights include page design, media use, client-side processing, server-side processing, and site structure. (LRW)
ERIC Educational Resources Information Center
McIlwaine, I. C.
1997-01-01
Discusses the history and development of the Universal Decimal Classification (UDC). Topics include the relationship with Dewey Decimal Classification; revision process; structure; facet analysis; lack of standard rules for application; application in automated systems; influence of UDC on classification development; links with thesauri; and use…
Managing Risk in Systems Development.
ERIC Educational Resources Information Center
DePaoli, Marilyn M.; And Others
Stanford University's use of a risk assessment methodology to improve the management of systems development projects is discussed. After examining the concepts of hazard, peril, and risk as they relate to the system development process, three ways to assess risk are covered: size, structure, and technology. The overall objective for Stanford…
ERIC Educational Resources Information Center
Farmer, D. W.
1983-01-01
An effective collegial and relatively noncompetitive approach to integrated planning developed at King's College is discussed. The development of a structured system of intensive oral communication; an organizational design integrating planning, budgeting, marketing, and evaluation, and a modified matrix management system are described. (MLW)
Factors Underlying the Need for In-Service Development Programs in Student Personnel Work.
ERIC Educational Resources Information Center
Truitt, John W.
Definitions, objectives, and concepts of in-service development programs in student personnel work are discussed. A structured, in-service development program p"ovides: (1) continuity for constantly changing staff; (2) enhances orientation and upgrading of new staff; (3) increases staff morale through shared responsibility; (4) encourages…
Biomimetic photonic materials with tunable structural colors.
Xu, Jun; Guo, Zhiguang
2013-09-15
Nature is a huge gallery of art involving nearly perfect structures and forms over the millions of years developing. Inspiration from natural structures exhibiting structural colors is first discussed. We give some examples of natural one-, two-, and three-dimensional photonic structures. This review article presents a brief summary of recent progress on bio-inspired photonic materials with variable structural colors, including the different facile and efficient routes to construct the nano-architectures, and the development of the artificial variable structural color photonic materials. Besides the superior optical properties, the excellent functions such as robust mechanical strength, good wettability are also mentioned, as well as the technical importance in various applications. This review will provide significant insight into the fabrication, design and application of the structural color materials. Copyright © 2013 Elsevier Inc. All rights reserved.
Preparing Women for the Profession: A Course Using Structured Role-Model Analysis.
ERIC Educational Resources Information Center
Sauer, Barbara L.; Koda-Kimble, Mary Anne
1989-01-01
A course was developed at the University of California, San Francisco, School of Pharmacy, addressing issues facing women. Female students discussed career planning and management, the complexities of balancing career and family life, and career commitment. The technique of structured role-model analysis was used. (Author/MLW)
Understanding the Nature of Structures in Education: Recent Developments
ERIC Educational Resources Information Center
Van der Walt, Johannes L.
2015-01-01
In this paper the author discusses how 21st century education researchers could and in his opinion, should approach the scientific description of the various entities that they might encounter. The word "entities" in pedagogical context refers to phenomena and structures such as "an education system", "education",…
NASA Technical Reports Server (NTRS)
1979-01-01
the development of large space structure technology is discussed. A detailed thermal analysis of a model space fabricated 1 meter beam is presented. Alternative thermal coatings are evaluated, and deflections, stresses, and stiffness variations resulting from flight orientations and solar conditions are predicted.
Household and Structural Pests. MEP 307.
ERIC Educational Resources Information Center
Wood, F. E.
This pamphlet is a non-technical description of common household arthropod pests in Maryland. Since most of the pests can be found in houses throughout North America, this publication has a wide geographic range of use. General discussions of arthropod structure, growth and development, and metamorphosis are given before the pages on specific…
Structuring a Clinical Learning Environment for a Hybrid-PBL Dental Curriculum.
ERIC Educational Resources Information Center
MacNeil, M. A. J.; Walton, Joanne N.; Clark, D. Christopher; Tobias, David L.; Harrison, Rosamund L.
1998-01-01
Describes the evolution and implementation of a joint medical-dental problem-based learning (PBL) curriculum at the University of British Columbia's medical and dental schools, featuring development of an integrated care clinic. Issues in structuring the new curriculum are discussed, including management of the clinic's group practices, affective…
Structural and Multilingual Approaches to Subject Access on the Web.
ERIC Educational Resources Information Center
Chan, Lois Mai; Lin, Xia; Zeng, Marcia
This paper presents some of the efforts currently being made to develop mechanisms that can organize World Wide Web resources for efficient and effective retrieval, as well as programs that can accommodate multiple languages. Part 1 discusses structural approaches to organizing Web resources, including the use of hierarchical or…
Modular shipbuilding and its relevance to construction of nuclear power plants. Master's thesis
DOE Office of Scientific and Technical Information (OSTI.GOV)
Seubert, T.W.
1988-05-01
The modern techniques of modular shipbuilding based on the Product Work Breakdown Structure as developed at the Ishikawajima-Harima Heavy Industries Co., Ltd. of Japan are examined and compared to conventional shipbuilding methods. The application of the Product Work Breakdown Structure in the building of the U.S. Navy's DDG-51 class ship at Bath Iron Works is described and compared to Japanese shipbuilding practices. Implementation of the Product Work Breakdown Structure at Avondale Shipyards, Incorporated is discussed and compared to Bath Iron Works shipbuilding practices. A proposed generic implementation of the Product Work Breakdown Structure to the modular construction of nuclear powermore » plants is described. Specific conclusions for the application of Product Work Breakdown Structure to the construction of a light water reactor nuclear power plant are discussed.« less
Developing an Information Resources Management Curriculum.
ERIC Educational Resources Information Center
Montie, Irene C.
1983-01-01
Discusses the development of an Information Resources Management (IRM) curriculum by the IRM Curriculum Advisory Committee established by the Graduate School, United States Department of Agriculture. Initial activities, models proposed for the program (standards, skills, users, operational), course selection, and structural proposals considered…
Positron-annihilation 2D-ACAR studies of disordered and defected alloys
NASA Astrophysics Data System (ADS)
Bansil, A.; Prasad, R.; Smedskjaer, L. C.; Benedek, R.; Mijnarends, P. E.
1987-09-01
Theoretical and experimental progess in connection with 2D-ACAR positron annihilation studies of ordered, disordered, and defected alloys is discussed. We present, in particular, some of the recent developments concerning the electronic structure of disordered alloys, and the work in the area of annihilation from positrons trapped at vacancy-type defects in metals and alloys. The electronic structure and properties of a number of compounds are also discussed briefly; we comment specifically on high T sub c ceramic superconductors, Heusler alloys, and transition-metal aluminides.
General Council should remain CMA's ultimate authority, Committee on Structure told
Rafuse, Jill
1995-01-01
A lively discussion during an information session at the annual meeting about the governance and policy-making authority within the CMA will help the Committee on Structure develop a discussion paper for delivery by early next year. Physicians were concerned about representation within the CMA and supported efforts to find ways to give a voice to affiliate societies, women and young physicians. However, they also made it clear that they want policy-making authority to rest with General Council, not the Board of Directors. Imagesp979-a
A preliminary damage tolerance methodology for composite structures
NASA Technical Reports Server (NTRS)
Wilkins, D. J.
1983-01-01
The certification experience for the primary, safety-of-flight composite structure applications on the F-16 is discussed. The rationale for the selection of delamination as the major issue for damage tolerance is discussed, as well as the modeling approach selected. The development of the necessary coupon-level data base is briefly summarized. The major emphasis is on the description of a full-scale fatigue test where delamination growth was obtained to demonstrate the validity of the selected approach. A summary is used to review the generic features of the methodology.
The European Spacelab structural design evolution
NASA Technical Reports Server (NTRS)
Thirkettle, A. J.
1982-01-01
Spacelab is a manned, reusable laboratory which is being developed for the European Space Agency (ESA). In its working mode it will fly in low earth orbit in the cargo bay of the Shuttle Transportation System (STS) Orbiter. A description is presented of the structural development of the various features of Spacelab. System requirements are considered along with structural requirements, quasi-static loads, acoustic loads, pressure loads, crash loads, ground loads, and the fatigue profile. Aspects of thermal environment generation are discussed, and questions regarding the design evolution of the pallet structure are examined. Details of pallet structure testing are reported, taking into account static strength tests, acoustic tests, the modal survey test, crash tests, and fatigue/fracture mechanics testing.
Crystal Structure Predictions Using Adaptive Genetic Algorithm and Motif Search methods
NASA Astrophysics Data System (ADS)
Ho, K. M.; Wang, C. Z.; Zhao, X.; Wu, S.; Lyu, X.; Zhu, Z.; Nguyen, M. C.; Umemoto, K.; Wentzcovitch, R. M. M.
2017-12-01
Material informatics is a new initiative which has attracted a lot of attention in recent scientific research. The basic strategy is to construct comprehensive data sets and use machine learning to solve a wide variety of problems in material design and discovery. In pursuit of this goal, a key element is the quality and completeness of the databases used. Recent advance in the development of crystal structure prediction algorithms has made it a complementary and more efficient approach to explore the structure/phase space in materials using computers. In this talk, we discuss the importance of the structural motifs and motif-networks in crystal structure predictions. Correspondingly, powerful methods are developed to improve the sampling of the low-energy structure landscape.
NASA Technical Reports Server (NTRS)
Kenigsberg, I. J.; Dean, M. W.; Malatino, R.
1974-01-01
The correlation achieved with each program provides the material for a discussion of modeling techniques developed for general application to finite-element dynamic analyses of helicopter airframes. Included are the selection of static and dynamic degrees of freedom, cockpit structural modeling, and the extent of flexible-frame modeling in the transmission support region and in the vicinity of large cut-outs. The sensitivity of predicted results to these modeling assumptions are discussed. Both the Sikorsky Finite-Element Airframe Vibration analysis Program (FRAN/Vibration Analysis) and the NASA Structural Analysis Program (NASTRAN) have been correlated with data taken in full-scale vibration tests of a modified CH-53A helicopter.
NASA Technical Reports Server (NTRS)
Murthy, T. Sreekanta
1988-01-01
Several key issues involved in the application of formal optimization technique to helicopter airframe structures for vibration reduction are addressed. Considerations which are important in the optimization of real airframe structures are discussed. Considerations necessary to establish relevant set of design variables, constraints and objectives which are appropriate to conceptual, preliminary, detailed design, ground and flight test phases of airframe design are discussed. A methodology is suggested for optimization of airframes in various phases of design. Optimization formulations that are unique to helicopter airframes are described and expressions for vibration related functions are derived. Using a recently developed computer code, the optimization of a Bell AH-1G helicopter airframe is demonstrated.
Experiments In Characterizing Vibrations Of A Structure
NASA Technical Reports Server (NTRS)
Yam, Yeung; Hadaegh, Fred Y.; Bayard, David S.
1993-01-01
Report discusses experiments conducted to test methods of identification of vibrational and coupled rotational/vibrational modes of flexible structure. Report one in series that chronicle development of integrated system of methods, sensors, actuators, analog and digital signal-processing equipment, and algorithms to suppress vibrations in large, flexible structure even when dynamics of structure partly unknown and/or changing. Two prior articles describing aspects of research, "Autonomous Frequency-Domain Indentification" (NPO-18099), and "Automated Characterization Of Vibrations Of A Structure" (NPO-18141).
Poly-symplectic Groupoids and Poly-Poisson Structures
NASA Astrophysics Data System (ADS)
Martinez, Nicolas
2015-05-01
We introduce poly-symplectic groupoids, which are natural extensions of symplectic groupoids to the context of poly-symplectic geometry, and define poly-Poisson structures as their infinitesimal counterparts. We present equivalent descriptions of poly-Poisson structures, including one related with AV-Dirac structures. We also discuss symmetries and reduction in the setting of poly-symplectic groupoids and poly-Poisson structures, and use our viewpoint to revisit results and develop new aspects of the theory initiated in Iglesias et al. (Lett Math Phys 103:1103-1133, 2013).
2016 Summer Series - Kenneth Cheung: Building Blocks for Aerospace Structures
2016-06-16
Strong, ultra-lightweight materials are expected to play a key role in the design of future aircraft and space vehicles. Lower structural mass leads to improved performance, maneuverability, efficiency, range and payload capacity. Dr. Kenneth Cheung is developing cellular composite building blocks, or digital materials, to create transformable aerostructures. In his presentation, Dr. Cheung will discuss the implications of the digital materials and morphing structures.
Structural Rheology of the Smectic Phase
Fujii, Shuji; Komura, Shigeyuki; Lu, Chun-Yi David
2014-01-01
In this review article, we discuss the rheological properties of the thermotropic smectic liquid crystal 8CB with focal conic domains (FCDs) from the viewpoint of structural rheology. It is known that the unbinding of the dislocation loops in the smectic phase drives the smectic-nematic transition. Here we discuss how the unbinding of the dislocation loops affects the evolution of the FCD size, linear and nonlinear rheological behaviors of the smectic phase. By studying the FCD formation from the perpendicularly oriented smectic layers, we also argue that dislocations play a key role in the structural development in layered systems. Furthermore, similarities in the rheological behavior between the FCDs in the smectic phase and the onion structures in the lyotropic lamellar phase suggest that these systems share a common physical origin for the elasticity. PMID:28788123
NASA Technical Reports Server (NTRS)
Schenk, P. M.
1984-01-01
An evaluation of surface features and structures on the Galilean moon Europa is made using the available high resolution Voyager imagery, low resolution support imaging, and what understanding of ice structure and mechanical behavior science has that is applicable to the problem. A general discussion of the history of Europa studies and the fundamental global morphology is undertaken. The visible lineament and terrain patterns are described, and possible origins discussed. Observations of faulting and block rotation previously described are amplified. A comparison of Europa's structures to terrestrial sea ice and lava lake crust features is also included. Finally, an attempt is made at synthesizing a unified model for the evolution of Europa's crust is presented which is compared with models developed by others.
NASA Astrophysics Data System (ADS)
Gryzunova, N. N.; Vikarchuk, A. A.; Tyur'kov, M. N.
2016-10-01
The defect structure of the electrolytic copper coatings formed upon mechanical activation of a cathode is described. These coatings are shown to have a fragmented structure containing disclination-type defects, namely, terminating dislocation, disclination and twin boundaries; partial disclinations, misorientation bands; and twin layers. They have both growth and deformation origins. The mechanisms of formation of the structural defects are discussed. It is experimentally proved that part of the elastic energy stored in the crystal volume during electrocrystallization can be converted into surface energy. As a result, catalytically active materials with a large developed surface can be synthesized.
New natural products of interest under development at the National Cancer Institute.
Douros, J; Suffness, M
1978-01-01
Fourteen new agents of natural products origin which are under development as antitumor agents at the National Cancer Institute are discussed with reference to their sources, structures, antitumor activity, current status, and future prospects as clinically effective agents.
Matching Preservation Decisions with Collection Development Policy.
ERIC Educational Resources Information Center
Khislovskaya, Galina
Based on communication with librarians from Russia, Mongolia, the Baltic States, Bulgaria, Slovenia, the Czech Republic, and Romania, this paper discusses library collection development and preservation policies. Highlights include: mission statements of national and regional libraries; availability of a formal structure responsible for collection…
ERIC Educational Resources Information Center
Weiss, Rick
1991-01-01
Research on the structure, growth, development, and loss of hair in humans is reviewed. Studies designed to investigate methods of hair restoration using minoxidil and other compounds and treatments are discussed. (CW)
Small Scaffolds, Big Potential: Developing Miniature Proteins as Therapeutic Agents.
Holub, Justin M
2017-09-01
Preclinical Research Miniature proteins are a class of oligopeptide characterized by their short sequence lengths and ability to adopt well-folded, three-dimensional structures. Because of their biomimetic nature and synthetic tractability, miniature proteins have been used to study a range of biochemical processes including fast protein folding, signal transduction, catalysis and molecular transport. Recently, miniature proteins have been gaining traction as potential therapeutic agents because their small size and ability to fold into defined tertiary structures facilitates their development as protein-based drugs. This research overview discusses emerging developments involving the use of miniature proteins as scaffolds to design novel therapeutics for the treatment and study of human disease. Specifically, this review will explore strategies to: (i) stabilize miniature protein tertiary structure; (ii) optimize biomolecular recognition by grafting functional epitopes onto miniature protein scaffolds; and (iii) enhance cytosolic delivery of miniature proteins through the use of cationic motifs that facilitate endosomal escape. These objectives are discussed not only to address challenges in developing effective miniature protein-based drugs, but also to highlight the tremendous potential miniature proteins hold for combating and understanding human disease. Drug Dev Res 78 : 268-282, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Heberle, Frederick A; Pan, Jianjun; Standaert, Robert F
2012-01-01
Some of our recent work has resulted in the detailed structures of fully hydrated, fluid phase phosphatidylcholine (PC) and phosphatidylglycerol (PG) bilayers. These structures were obtained from the joint refinement of small-angle neutron and X-ray data using the scattering density profile (SDP) models developed by Ku erka et al. (Ku erka et al. 2012; Ku erka et al. 2008). In this review, we first discuss models for the standalone analysis of neutron or X-ray scattering data from bilayers, and assess the strengths and weaknesses inherent in these models. In particular, it is recognized that standalone data do not contain enoughmore » information to fully resolve the structure of inherently disordered fluid bilayers, and therefore may not provide a robust determination of bilayer structural parameters, including the much sought after area per lipid. We then discuss the development of matter density-based models (including the SDP model) that allow for the joint refinement of different contrast neutron and X-ray data sets, as well as the implementation of local volume conservation in the unit cell (i.e., ideal packing). Such models provide natural definitions of bilayer thicknesses (most importantly the hydrophobic and Luzzati thicknesses) in terms of Gibbs dividing surfaces, and thus allow for the robust determination of lipid areas through equivalent slab relationships between bilayer thickness and lipid volume. In the final section of this review, we discuss some of the significant findings/features pertaining to structures of PC and PG bilayers as determined from SDP model analyses.« less
Advanced composite rudders for DC-10 aircraft: Design, manufacturing, and ground tests
NASA Technical Reports Server (NTRS)
Lehman, G. M.; Purdy, D. M.; Cominsky, A.; Hawley, A. V.; Amason, M. P.; Kung, J. T.; Palmer, R. J.; Purves, N. B.; Marra, P. J.; Hancock, G. R.
1976-01-01
Design synthesis, tooling and process development, manufacturing, and ground testing of a graphite epoxy rudder for the DC-10 commercial transport are discussed. The composite structure was fabricated using a unique processing method in which the thermal expansion characteristics of rubber tooling mandrels were used to generate curing pressures during an oven cure cycle. The ground test program resulted in certification of the rudder for passenger-carrying flights. Results of the structural and environmental tests are interpreted and detailed development of the rubber tooling and manufacturing process is described. Processing, tooling, and manufacturing problems encountered during fabrication of four development rudders and ten flight-service rudders are discussed and the results of corrective actions are described. Non-recurring and recurring manufacturing labor man-hours are tabulated at the detailed operation level. A weight reduction of 13.58 kg (33 percent) was attained in the composite rudder.
Nonlinear Constitutive Relations for High Temperature Application, 1984
NASA Technical Reports Server (NTRS)
1985-01-01
Nonlinear constitutive relations for high temperature applications were discussed. The state of the art in nonlinear constitutive modeling of high temperature materials was reviewed and the need for future research and development efforts in this area was identified. Considerable research efforts are urgently needed in the development of nonlinear constitutive relations for high temperature applications prompted by recent advances in high temperature materials technology and new demands on material and component performance. Topics discussed include: constitutive modeling, numerical methods, material testing, and structural applications.
NASA's supercomputing experience
NASA Technical Reports Server (NTRS)
Bailey, F. Ron
1990-01-01
A brief overview of NASA's recent experience in supercomputing is presented from two perspectives: early systems development and advanced supercomputing applications. NASA's role in supercomputing systems development is illustrated by discussion of activities carried out by the Numerical Aerodynamical Simulation Program. Current capabilities in advanced technology applications are illustrated with examples in turbulence physics, aerodynamics, aerothermodynamics, chemistry, and structural mechanics. Capabilities in science applications are illustrated by examples in astrophysics and atmospheric modeling. Future directions and NASA's new High Performance Computing Program are briefly discussed.
NASA Technical Reports Server (NTRS)
Thorp, Scott A.
1992-01-01
This presentation will discuss the development of a NASA Geometry Exchange Specification for transferring aerodynamic surface geometry between LeRC systems and grid generation software used for computational fluid dynamics research. The proposed specification is based on a subset of the Initial Graphics Exchange Specification (IGES). The presentation will include discussion of how the NASA-IGES standard will accommodate improved computer aided design inspection methods and reverse engineering techniques currently being developed. The presentation is in viewgraph format.
Chemical Bonding in Sulfide Minerals
DOE Office of Scientific and Technical Information (OSTI.GOV)
Vaughan, David J.; Rosso, Kevin M.
An understanding of chemical bonding and electronic structure in sulfide minerals is central to any attempt at understanding their crystal structures, stabilities and physical properties. It is also an essential precursor to understanding reactivity through modeling surface structure at the molecular scale. In recent decades, there have been remarkable advances in first principles (ab initio) methods for the quantitative calculation of electronic structure. These advances have been made possible by the very rapid development of high performance computers. Several review volumes that chart the applications of these developments in mineralogy and geochemistry are available (Tossell and Vaughan, 1992; Cygan andmore » Kubicki, 2001). An important feature of the sulfide minerals is the diversity of their electronic structures, as evidenced by their electrical and magnetic properties (see Pearce et al. 2006, this volume). Thus, sulfide minerals range from insulators through semiconductors to metals, and exhibit every type of magnetic behavior. This has presented problems for those attempting to develop bonding models for sulfides, and also led to certain misconceptions regarding the kinds of models that may be appropriate. In this chapter, chemical bonding and electronic structure models for sulfides are reviewed with emphasis on more recent developments. Although the fully ab initio quantitative methods are now capable of a remarkable degree of sophistication in terms of agreement with experiment and potential to interpret and predict behavior with varying conditions, both qualitative and more simplistic quantitative approaches will also be briefly discussed. This is because we believe that the insights which they provide are still helpful to those studying sulfide minerals. In addition to the application of electronic structure models and calculations to solid sulfides, work on sulfide mineral surfaces (Rosso and Vaughan 2006a,b) and solution complexes and clusters (Rickard and Luther, 2006) are discussed in detail later in this volume.« less
Aerospace technology as a source of new ideas.
NASA Technical Reports Server (NTRS)
Hamilton, J. T.
1972-01-01
It is shown that technological products and processes resulting from aeronautical and space research and development can be a significant source of new product or product improvement ideas. The problems associated with technology transfer are discussed. As an example, the commercialization of NASTRAN, NASA's structural analysis computer program, is discussed. Some other current application projects are also outlined.
Data Mining of Macromolecular Structures.
van Beusekom, Bart; Perrakis, Anastassis; Joosten, Robbie P
2016-01-01
The use of macromolecular structures is widespread for a variety of applications, from teaching protein structure principles all the way to ligand optimization in drug development. Applying data mining techniques on these experimentally determined structures requires a highly uniform, standardized structural data source. The Protein Data Bank (PDB) has evolved over the years toward becoming the standard resource for macromolecular structures. However, the process selecting the data most suitable for specific applications is still very much based on personal preferences and understanding of the experimental techniques used to obtain these models. In this chapter, we will first explain the challenges with data standardization, annotation, and uniformity in the PDB entries determined by X-ray crystallography. We then discuss the specific effect that crystallographic data quality and model optimization methods have on structural models and how validation tools can be used to make informed choices. We also discuss specific advantages of using the PDB_REDO databank as a resource for structural data. Finally, we will provide guidelines on how to select the most suitable protein structure models for detailed analysis and how to select a set of structure models suitable for data mining.
2013-01-01
Background The axial skeleton is one of the defining evolutionary landmarks of vertebrates. How this structure develops and how it has evolved in the different vertebrate lineages is, however, a matter of debate. Vertebrae and vertebral structures are derived from the embryonic somites, although the mechanisms of development are different between lineages. Discussion Using the anecdotal description of a teratological newt (Triturus dobrogicus) with an unusual malformation in its axial skeleton, we review, compare, and discuss the development of vertebral structures and, in particular, the development of centra from somitic cellular domains in different vertebrate groups. Vertebrae development through re-segmentation of the somitic sclerotomal cells is considered the general mechanism among vertebrates, which has been generalized from studies in amniotic model organisms. The prevalence of this mechanism among anamniotes is, however, controversial. We propose alternative developmental mechanisms for vertebrae formation that should be experimentally tested. Summary Research in model organisms, especially amniotes, is laying the foundations for a thorough understanding of the mechanisms of development of the axial skeleton in vertebrates, foundations that should expand the extent of future comparative studies. Although immersed in the ‘-omics’ era, we emphasize the need for an integrative and organismal approach in evolutionary developmental biology for a better understanding of the causal role of development in the evolution of morphological diversity in nature. PMID:23577917
An Efficient Analysis Methodology for Fluted-Core Composite Structures
NASA Technical Reports Server (NTRS)
Oremont, Leonard; Schultz, Marc R.
2012-01-01
The primary loading condition in launch-vehicle barrel sections is axial compression, and it is therefore important to understand the compression behavior of any structures, structural concepts, and materials considered in launch-vehicle designs. This understanding will necessarily come from a combination of test and analysis. However, certain potentially beneficial structures and structural concepts do not lend themselves to commonly used simplified analysis methods, and therefore innovative analysis methodologies must be developed if these structures and structural concepts are to be considered. This paper discusses such an analysis technique for the fluted-core sandwich composite structural concept. The presented technique is based on commercially available finite-element codes, and uses shell elements to capture behavior that would normally require solid elements to capture the detailed mechanical response of the structure. The shell thicknesses and offsets using this analysis technique are parameterized, and the parameters are adjusted through a heuristic procedure until this model matches the mechanical behavior of a more detailed shell-and-solid model. Additionally, the detailed shell-and-solid model can be strategically placed in a larger, global shell-only model to capture important local behavior. Comparisons between shell-only models, experiments, and more detailed shell-and-solid models show excellent agreement. The discussed analysis methodology, though only discussed in the context of fluted-core composites, is widely applicable to other concepts.
Lipases as biocatalysts for the synthesis of structured lipids.
Jala, Ram Chandra Reddy; Hu, Peng; Yang, Tiankui; Jiang, Yuanrong; Zheng, Yan; Xu, Xuebing
2012-01-01
Structured lipids (SL) are broadly referred to as modified or synthetic oils and fats or lipids with functional or pharmaceutical applications. Some structured lipids, such as triglycerides that contain both long-chain (mainly essential) fatty acids and medium- or short-chain fatty acids and also artificial products that mimic the structure of natural materials, namely human milk fat substitutes and cocoa butter equivalents, have been discussed. Further, other modified or synthetic lipids, such as structured phospholipids and synthetic phenolic lipids are also included in this chapter. For all the products described in this chapter, enzymatic production in industry has been already conducted in one way or another. Cocoa butter equivalents, healthy oil containing medium-chain fatty acids, phosphatidyl serine, and phenol lipids from enzyme technology have been reported for commercial operation. As the demand for better quality functional lipids is increasing, the production of structured lipids becomes an interesting area. Thus, in this chapter we have discussed latest developments as well as present industrial situation of all commercially important structured lipids.
Intellectual, Psychosocial, and Moral Development in College: Four Major Theories. Revised.
ERIC Educational Resources Information Center
Kurfiss, Joanne
Four models are discussed with which to view students, educational goals, and learning environments. Each of the four theories emphasizes a unique aspect of the total development process. Piaget's model describes the development of structures and processes which characterize mature logical thinking. Perry provides a closer look at students'…
A Career Practitioner's Response to the National Career Development Strategy Green Paper
ERIC Educational Resources Information Center
Athanasou, James A.
2012-01-01
The National Career Development Strategy Green Paper is a discussion paper issued by the Department of Employment, Education and Workplace Relations. It is aimed at the formulation of a coherent and structured career development strategy throughout Australia. The Green Paper seeks to lay the foundation for policy change through establishing the…
Bifilar analysis users manual, volume 2
NASA Technical Reports Server (NTRS)
Cassarino, S. J.
1980-01-01
The digital computer program developed to study the vibration response of a coupled rotor/bifilar/airframe coupled system is described. The theoretical development of the rotor/airframe system equations of motion is provided. The fuselage and bifilar absorber equations of motion are discussed. The modular block approach used in the make-up of this computer program is described. The input data needed to run the rotor and bifilar absorber analyses is described. Sample output formats are presented and discussed. The results for four test cases, which use the major logic paths of the computer program, are presented. The overall program structure is discussed in detail. The FORTRAN subroutines are described in detail.
School Governance Structures that Foster Friendship in the Elementary School.
ERIC Educational Resources Information Center
Kuhmerker, Lisa
1989-01-01
Uses examples from the Schaefer School in Tappan (New York) to illustrate how an elementary school can develop an educational climate that fosters friendship, the key to student socialization. Discusses the following areas: (1) classroom activities; (2) school-wide democratic governance structures; (3) support staff roles; and (4) time scheduling.…
Supporting Teachers' Reflection and Learning through Structured Digital Teaching Portfolios
ERIC Educational Resources Information Center
Sung, Y. -T.; Chang, K. -E.; Yu, W. -C.; Chang, T. -H.
2009-01-01
Digital teaching portfolios have been proposed as an effective tool for teacher learning and professional development, but there is a lack of empirical evidence supporting their effectiveness. This study proposed the design of a structured digital portfolio equipped with multiple aids (e.g. self-assessment, peer assessment, discussion and journal…
ERIC Educational Resources Information Center
Jones, Earl I., Ed.
This five-section symposium report includes 22 papers assessing the state-of-the-art in occupational research. Section 1, Occupational Analysis, Structure, and Methods, contains four papers that discuss: the Air Force Occupational Research project, methodologies in job analysis, evaluation, structures and requirements, career development,…
The Application of Morpho-Syntactic Language Processing to Effective Phrase Matching.
ERIC Educational Resources Information Center
Sheridan, Paraic; Smeaton, Alan F.
1992-01-01
Describes a process of morpho-syntactic language analysis for information retrieval. Tree Structured Analytics (TSA) used for text representation is summarized; the matching process developed for such structures is outlined with an example appended; and experiments carried out to evaluate the effectiveness of TSA matching are discussed. (26…
Learning to Cook: Production Learning Environment in Kitchens
ERIC Educational Resources Information Center
James, Susan
2006-01-01
Learning in workplaces is neither ad hoc nor informal. Such labels are a misnomer and do not do justice to the highly-structured nature and complexity of many workplaces where learning takes place. This article discusses the organisational and structural framework developed from a three-year doctoral study into how apprentice chefs construct their…
NASA Technical Reports Server (NTRS)
Mishler, H. W.
1974-01-01
The fabrication of prototype titanium alloy primary and secondary mirror support structures for a proposed experimental three-meter space telescope is discussed. The structure was fabricated entirely of Ti-6Al-4V tubing and plate. Fabrication included the development of procedures including welding, forming, and machining. Most of the structures was fabricated by gas-shielding tungsten-arc (GTA) welding with several major components fabricated by high frequency resistance (HFR) welding.
Development of hydrogen resistant structural alloy NASA-23
NASA Technical Reports Server (NTRS)
Bhat, B. N.; Mcpherson, W. B.; Kuruvilla, A. K.; Chen, P. S.; Panda, B.
1993-01-01
Hydrogen-resistant alloy NASA-23 was developed specifically as a structural alloy for application in liquid propulsion systems that use hydrogen fuel. NASA-23 was designed to be similar to Alloy 718 in strength, ductility, and corrosion resistance, but with superior resistance to hydrogen environment embrittlement. The alloy is readily processed; it can be both hot and cold worked and is castable and weldable. A material property data base is being generated for both cast and wrought NASA-23. This paper will present the status of alloy development and discuss potential applications in propulsion systems.
Automated fiber placement: Evolution and current demonstrations
NASA Technical Reports Server (NTRS)
Grant, Carroll G.; Benson, Vernon M.
1993-01-01
The automated fiber placement process has been in development at Hercules since 1980. Fiber placement is being developed specifically for aircraft and other high performance structural applications. Several major milestones have been achieved during process development. These milestones are discussed in this paper. The automated fiber placement process is currently being demonstrated on the NASA ACT program. All demonstration projects to date have focused on fiber placement of transport aircraft fuselage structures. Hercules has worked closely with Boeing and Douglas on these demonstration projects. This paper gives a description of demonstration projects and results achieved.
Development and Use of Diagnostic Tests to Evaluate Students' Misconceptions in Science.
ERIC Educational Resources Information Center
Treagust, David F.
1988-01-01
Describes 10 steps for developing a diagnostic test of students' misconceptions and the use of two tests in chemistry (covalent bonding and structure) and in biology (photosynthesis and respiration in plants). Discusses the results and some implications for teaching science. (YP)
Strategies for the Internal Development of Summer Sessions.
ERIC Educational Resources Information Center
Seagren, Alan T.; And Others
Organizational matters and strategies useful in developing more effective collegiate summer sessions are discussed, and examples of some productive strategies at the University of Nebraska-Lincoln are reported. Four elements of organizational structure in higher education considered are organizational environment, mission and goals, governance…
Lexical Morphology: Structure, Process, and Development
ERIC Educational Resources Information Center
Jarmulowicz, Linda; Taran, Valentina L.
2013-01-01
Recent work has demonstrated the importance of derivational morphology to later language development and has led to a consensus that derivation is a lexical process. In this review, derivational morphology is discussed in terms of lexical representation models from both linguistic and psycholinguistic perspectives. Input characteristics, including…
The Development of Sport Expertise: Mapping the Tactical Domain.
ERIC Educational Resources Information Center
McPherson, Sue L.
1994-01-01
Explores issues and research relevant to sport tactical knowledge development and expertise. The paper discusses controversies concerning methodological tools, possible levels of analysis in sport research, sport tactical knowledge and expertise, a protocol structure model for sport, and expert-novice sport research. (SM)
ERIC Educational Resources Information Center
Department of the Secretary of State, Ottawa (Ontario).
This report on the state of education in Canada is comprised of two parts. Part I deals with the administration and organization of education within the ten provinces, and lists developments and trends from 1974-76. Structure, curricula, teacher education, and certification are discussed. Educational developments include public involvement,…
"Out of the box" professional development
NASA Astrophysics Data System (ADS)
2015-04-01
At a recent AAPT meeting, I was part of a conversation about professional development that focused on conferences. We discussed the current meeting structure used by AAPT and some alternative formats. This discussion added greatly to my own understanding of new ways for teachers to receive their professional development. This conversation also began my friendship with Kelly O'Shea, a physics teacher from New York. She is also a blogger (check her out at https://kellyoshea.wordpress.com) and an innovative educator. Through my relationship with Kelly, I have grown in my own knowledge of two "out of the box" ways teachers are getting their professional development.
NASTRAN users' experience of Avco Aerostructures Division
NASA Technical Reports Server (NTRS)
Blackburn, C. L.; Wilhelm, C. A.
1973-01-01
The NASTRAN experiences of a major structural design and fabrication subcontractor that has less engineering personnel and computer facilities than those available to large prime contractors are discussed. Efforts to obtain sufficient computer capacity and the development and implementation of auxiliary programs to reduce manpower requirements are described. Applications of the NASTRAN program for training users, checking out auxiliary programs, performing in-house research and development, and structurally analyzing an Avco designed and manufactured missile case are presented.
A reliability-based cost effective fail-safe design procedure
NASA Technical Reports Server (NTRS)
Hanagud, S.; Uppaluri, B.
1976-01-01
The authors have developed a methodology for cost-effective fatigue design of structures subject to random fatigue loading. A stochastic model for fatigue crack propagation under random loading has been discussed. Fracture mechanics is then used to estimate the parameters of the model and the residual strength of structures with cracks. The stochastic model and residual strength variations have been used to develop procedures for estimating the probability of failure and its changes with inspection frequency. This information on reliability is then used to construct an objective function in terms of either a total weight function or cost function. A procedure for selecting the design variables, subject to constraints, by optimizing the objective function has been illustrated by examples. In particular, optimum design of stiffened panel has been discussed.
Clay-based polymer nanocomposites: research and commercial development.
Zeng, Q H; Yu, A B; Lu, G Q; Paul, D R
2005-10-01
This paper reviews the recent research and development of clay-based polymer nanocomposites. Clay minerals, due to their unique layered structure, rich intercalation chemistry and availability at low cost, are promising nanoparticle reinforcements for polymers to manufacture low-cost, lightweight and high performance nanocomposites. We introduce briefly the structure, properties and surface modification of clay minerals, followed by the processing and characterization techniques of polymer nanocomposites. The enhanced and novel properties of such nanocomposites are then discussed, including mechanical, thermal, barrier, electrical conductivity, biodegradability among others. In addition, their available commercial and potential applications in automotive, packaging, coating and pigment, electrical materials, and in particular biomedical fields are highlighted. Finally, the challenges for the future are discussed in terms of processing, characterization and the mechanisms governing the behaviour of these advanced materials.
Malfolded Protein Structure and Proteostasis in Lung Diseases
Balch, William E.; Sznajder, Jacob I.; Budinger, Scott; Finley, Daniel; Laposky, Aaron D.; Cuervo, Ana Maria; Benjamin, Ivor J.; Barreiro, Esther; Morimoto, Richard I.; Postow, Lisa; Weissman, Allan M.; Gail, Dorothy; Banks-Schlegel, Susan; Croxton, Thomas
2014-01-01
Recent discoveries indicate that disorders of protein folding and degradation play a particularly important role in the development of lung diseases and their associated complications. The overarching purpose of the National Heart, Lung, and Blood Institute workshop on “Malformed Protein Structure and Proteostasis in Lung Diseases” was to identify mechanistic and clinical research opportunities indicated by these recent discoveries in proteostasis science that will advance our molecular understanding of lung pathobiology and facilitate the development of new diagnostic and therapeutic strategies for the prevention and treatment of lung disease. The workshop's discussion focused on identifying gaps in scientific knowledge with respect to proteostasis and lung disease, discussing new research advances and opportunities in protein folding science, and highlighting novel technologies with potential therapeutic applications for diagnosis and treatment. PMID:24033344
Malfolded protein structure and proteostasis in lung diseases.
Balch, William E; Sznajder, Jacob I; Budinger, Scott; Finley, Daniel; Laposky, Aaron D; Cuervo, Ana Maria; Benjamin, Ivor J; Barreiro, Esther; Morimoto, Richard I; Postow, Lisa; Weissman, Allan M; Gail, Dorothy; Banks-Schlegel, Susan; Croxton, Thomas; Gan, Weiniu
2014-01-01
Recent discoveries indicate that disorders of protein folding and degradation play a particularly important role in the development of lung diseases and their associated complications. The overarching purpose of the National Heart, Lung, and Blood Institute workshop on "Malformed Protein Structure and Proteostasis in Lung Diseases" was to identify mechanistic and clinical research opportunities indicated by these recent discoveries in proteostasis science that will advance our molecular understanding of lung pathobiology and facilitate the development of new diagnostic and therapeutic strategies for the prevention and treatment of lung disease. The workshop's discussion focused on identifying gaps in scientific knowledge with respect to proteostasis and lung disease, discussing new research advances and opportunities in protein folding science, and highlighting novel technologies with potential therapeutic applications for diagnosis and treatment.
Unternehmen in der Verantwortung. Regionaler Strukturwandel anders
NASA Astrophysics Data System (ADS)
Kost, Klaus; Weingarten, Jörg
2016-03-01
Factory closures, relocations and extensive measures to reduce personnel have consequences far beyond the affected employees - the social and economic coherence of the location and region are often negatively affected, too. This presents an interesting and important field for economic and applied geography. Apart from the development and evaluation of concepts of instruments of regional development, geographers can discuss and conceive options and obstacles for compensation and replacement measures after corporate restructuring. This text discusses structural and individual opportunities and obstacles in implementing company-induced economic development measures in the wider context of the corporate responsibility debate.
Klika, Václav; Gaffney, Eamonn A; Chen, Ying-Chun; Brown, Cameron P
2016-09-01
There is a long history of mathematical and computational modelling with the objective of understanding the mechanisms governing cartilage׳s remarkable mechanical performance. Nonetheless, despite sophisticated modelling development, simulations of cartilage have consistently lagged behind structural knowledge and thus the relationship between structure and function in cartilage is not fully understood. However, in the most recent generation of studies, there is an emerging confluence between our structural knowledge and the structure represented in cartilage modelling. This raises the prospect of further refinement in our understanding of cartilage function and also the initiation of an engineering-level understanding for how structural degradation and ageing relates to cartilage dysfunction and pathology, as well as informing the potential design of prospective interventions. Aimed at researchers entering the field of cartilage modelling, we thus review the basic principles of cartilage models, discussing the underlying physics and assumptions in relatively simple settings, whilst presenting the derivation of relatively parsimonious multiphase cartilage models consistent with our discussions. We proceed to consider modern developments that start aligning the structure captured in the models with observed complexities. This emphasises the challenges associated with constitutive relations, boundary conditions, parameter estimation and validation in cartilage modelling programmes. Consequently, we further detail how both experimental interrogations and modelling developments can be utilised to investigate and reduce such difficulties before summarising how cartilage modelling initiatives may improve our understanding of cartilage ageing, pathology and intervention. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.
ERIC Educational Resources Information Center
Salmah, Ummy; Putri, Ratu Ilma Indra; Somakim
2015-01-01
The aim of this study is to design learning activities that can support students to develop strategies for the addition of number 1 to 20 in the first grade by involving students' spatial structuring ability. This study was conducted in Indonesia by involving 27 students. In this paper, one of three activities is discussed namely ten-box activity.…
Liu, Lingyun; Li, Wenchen; Liu, Qingsheng
2014-01-01
Antifouling polymers have been proven to be vital to many biomedical applications such as medical implants, drug delivery, and biosensing. This review covers the major development of antifouling polymers in the last 2 decades, including the material chemistry, structural factors important to antifouling properties, and how to challenge or evaluate the antifouling performances. We then discuss the applications of antifouling polymers in nano/micro-biomedical applications in the form of nanoparticles, thin coatings for medical devices (e.g., artificial joint, catheter, wound dressing), and nano/microscale fibers. © 2014 Wiley Periodicals, Inc.
Gavin, David P; Grayson, Dennis R; Varghese, Sajoy P; Guizzetti, Marina
2017-05-11
Prenatal alcohol exposure causes persistent neuropsychiatric deficits included under the term fetal alcohol spectrum disorders (FASD). Cellular identity emerges from a cascade of intrinsic and extrinsic (involving cell-cell interactions and signaling) processes that are partially initiated and maintained through changes in chromatin structure. Prenatal alcohol exposure influences neuronal and astrocyte development, permanently altering brain connectivity. Prenatal alcohol exposure also alters chromatin structure through histone and DNA modifications. However, the data linking alcohol-induced differentiation changes with developmental alterations in chromatin structure remain to be elucidated. In the first part of this review, we discuss the sequence of chromatin structural changes involved in neural cell differentiation during normal development. We then discuss the effects of prenatal alcohol on developmental histone modifications and DNA methylation in the context of neurogenesis and astrogliogenesis. We attempt to synthesize the developmental literature with the FASD literature, proposing that alcohol-induced changes to chromatin structure account for altered neurogenesis and astrogliogenesis as well as altered neuron and astrocyte differentiation. Together these changes may contribute to the cognitive and behavioral abnormalities in FASD. Future studies using standardized alcohol exposure paradigms at specific developmental stages will advance the understanding of how chromatin structural changes impact neural cell fate and maturation in FASD.
Gavin, David P.; Grayson, Dennis R.; Varghese, Sajoy P.; Guizzetti, Marina
2017-01-01
Prenatal alcohol exposure causes persistent neuropsychiatric deficits included under the term fetal alcohol spectrum disorders (FASD). Cellular identity emerges from a cascade of intrinsic and extrinsic (involving cell-cell interactions and signaling) processes that are partially initiated and maintained through changes in chromatin structure. Prenatal alcohol exposure influences neuronal and astrocyte development, permanently altering brain connectivity. Prenatal alcohol exposure also alters chromatin structure through histone and DNA modifications. However, the data linking alcohol-induced differentiation changes with developmental alterations in chromatin structure remain to be elucidated. In the first part of this review, we discuss the sequence of chromatin structural changes involved in neural cell differentiation during normal development. We then discuss the effects of prenatal alcohol on developmental histone modifications and DNA methylation in the context of neurogenesis and astrogliogenesis. We attempt to synthesize the developmental literature with the FASD literature, proposing that alcohol-induced changes to chromatin structure account for altered neurogenesis and astrogliogenesis as well as altered neuron and astrocyte differentiation. Together these changes may contribute to the cognitive and behavioral abnormalities in FASD. Future studies using standardized alcohol exposure paradigms at specific developmental stages will advance the understanding of how chromatin structural changes impact neural cell fate and maturation in FASD. PMID:28492482
Tenth NASTRAN User's Colloquium
NASA Technical Reports Server (NTRS)
1982-01-01
The development of the NASTRAN computer program, a general purpose finite element computer code for structural analysis, was discussed. The application and development of NASTRAN is presented in the following topics: improvements and enhancements; developments of pre and postprocessors; interactive review system; the use of harmonic expansions in magnetic field problems; improving a dynamic model with test data using Linwood; solution of axisymmetric fluid structure interaction problems; large displacements and stability analysis of nonlinear propeller structures; prediction of bead area contact load at the tire wheel interface; elastic plastic analysis of an overloaded breech ring; finite element solution of torsion and other 2-D Poisson equations; new capability for elastic aircraft airloads; usage of substructuring analysis in the get away special program; solving symmetric structures with nonsymmetric loads; evaluation and reduction of errors induced by Guyan transformation.
Penn, Alexandra S.; Knight, Christopher J. K.; Lloyd, David J. B.; Avitabile, Daniele; Kok, Kasper; Schiller, Frank; Woodward, Amy; Druckman, Angela; Basson, Lauren
2013-01-01
Fuzzy Cognitive Mapping (FCM) is a widely used participatory modelling methodology in which stakeholders collaboratively develop a ‘cognitive map’ (a weighted, directed graph), representing the perceived causal structure of their system. This can be directly transformed by a workshop facilitator into simple mathematical models to be interrogated by participants by the end of the session. Such simple models provide thinking tools which can be used for discussion and exploration of complex issues, as well as sense checking the implications of suggested causal links. They increase stakeholder motivation and understanding of whole systems approaches, but cannot be separated from an intersubjective participatory context. Standard FCM methodologies make simplifying assumptions, which may strongly influence results, presenting particular challenges and opportunities. We report on a participatory process, involving local companies and organisations, focussing on the development of a bio-based economy in the Humber region. The initial cognitive map generated consisted of factors considered key for the development of the regional bio-based economy and their directional, weighted, causal interconnections. A verification and scenario generation procedure, to check the structure of the map and suggest modifications, was carried out with a second session. Participants agreed on updates to the original map and described two alternate potential causal structures. In a novel analysis all map structures were tested using two standard methodologies usually used independently: linear and sigmoidal FCMs, demonstrating some significantly different results alongside some broad similarities. We suggest a development of FCM methodology involving a sensitivity analysis with different mappings and discuss the use of this technique in the context of our case study. Using the results and analysis of our process, we discuss the limitations and benefits of the FCM methodology in this case and in general. We conclude by proposing an extended FCM methodology, including multiple functional mappings within one participant-constructed graph. PMID:24244303
Recent development in the design, testing and impact-damage tolerance of stiffened composite panels
NASA Technical Reports Server (NTRS)
Williams, J. G.; Anderson, M. S.; Rhodes, M. D.; Starnes, J. H., Jr.; Stroud, W. J.
1979-01-01
Structural technology of laminated filamentary-composite stiffened-panel structures under combined inplane and lateral loadings is discussed. Attention is focused on: (1) methods for analyzing the behavior of these structures under load and for determining appropriate structural proportions for weight-efficient configurations; and (2) effects of impact damage and geometric imperfections on structural performance. Recent improvements in buckling analysis involving combined inplane compression and shear loadings and transverse shear deformations are presented. A computer code is described for proportioning or sizing laminate layers and cross-sectional dimensions, and the code is used to develop structural efficiency data for a variety of configurations, loading conditions, and constraint conditions. Experimental data on buckling of panels under inplane compression is presented. Mechanisms of impact damage initiation and propagation are described.
Mechanical features of the shuttle rotating service structure
NASA Technical Reports Server (NTRS)
Crump, J. M.
1985-01-01
With the development of the space shuttle launching facilities, it became mandatory to develop a shuttle rotating service structure to provide for the insertion and/or removal of payloads at the launch pads. The rotating service structure is a welded tubular steel space frame 189 feet high, 65 feet wide, and weighing 2100 tons. At the pivot column the structure is supported on a 30 inch diameter hemispherical bearing. At the opposite terminus the structure is supported on two truck assemblies each having eight 36 inch diameter double flanged wheels. The following features of the rotating service structure are discussed: (1) thermal expansion and contraction; (2) hurricane tie downs; (3) payload changeout room; (4) payload ground handling mechanism; (5) payload and orbiter access platforms; and (6) orbiter cargo bay access.
Managing NASA in the Apollo era
NASA Technical Reports Server (NTRS)
Levine, A. S.
1982-01-01
The administration and organization are described and analyzed. Policies on manpower and the budgetary process for contracting for research development, the structure of NASA-DOD relations, and program planning are discussed.
Mathematical geophysics: A survey of recent developments in seismology and geodynamics
DOE Office of Scientific and Technical Information (OSTI.GOV)
Vlaar, N.J.
1988-01-01
This survey deals with modern methods for the determination of the structure of the Earth and for the analysis and modeling of the dynamic processes in the Earth's interior. Seismology and the three-dimensional structure of the Earth are covered in chapters devoted to waves in the three-dimensional Earth and large-scale inversion, while the discussion of convection and lithospheric processes focuses on geomagnetism, mantle convection, post-glacial rebound, and thermomechanical processes in the lithosphere. The emphasis of the work is theoretical, but the reader will find a discussion of the pertinent observational evidence.
DOE Office of Scientific and Technical Information (OSTI.GOV)
NONE
1996-07-01
The module discusses the regulatory and statutory requirements and authorities governing the Resource Conservation and Recovery Act (RCRA) corrective action process. There are minimal regulatory requirements at present, but the Agency has issued a proposed rule (55 FR 30798; July 27, 1990) that would establish a comprehensive regulatory framework for implementing the corrective action program. This proposed rule and other guidance developed pursuant to statutory authorities are used to structure corrective action requirements in facility permits and orders. This module describes the current statutory and regulatory structure and discusses the future of the proposed rule.
ERIC Educational Resources Information Center
Lehmann, Martin; Fryd, Ole
2008-01-01
Purpose: The purpose of this paper is to describe and discuss the development and the structure of a new international master on the subject of urban quality development and management (UQDM), and explore the potential of the process and the outcome in serving as models adoptable by faculty at other universities. Design/methodology/approach: The…
Parabolic Dish Concentrator (PDC-2) Development
NASA Technical Reports Server (NTRS)
Rafinejad, D.
1984-01-01
The design of the Parabolic Dish Concentrator (PDC-2) is described. The following five subsystems of the concentrator are discussed: (1) reflective surface subsystem, (2) support structure subsystem, (3) foundation, (4) drive subsystem, and (5) electrical and control subsystem. The status of the PDC-2 development project is assessed.
ERIC Educational Resources Information Center
McFarland, E. L.; And Others
1978-01-01
Describes the development and operation of a college biophysics course as well as the educational materials used, the structure of the modules and the performance of the students. Also discusses the economics of such a flexible system of instruction. (GA)
Understanding the Structure of Children's Emotion-Regulation Strategies
ERIC Educational Resources Information Center
Callear, Angela; Harvey, Shane Trevor; Bimler, David
2017-01-01
Emotion regulation is a central feature in human emotional development. However, measures based on children's observable emotion regulation behaviors are largely absent. An inventory of children's emotion regulation strategies was developed from current measures and four focus group discussions with experts in child behavior and emotion. From…
Trends of Educational Policy in Socialist Countries.
ERIC Educational Resources Information Center
Kluczynski, J.
Education in Eastern Europe's socialist countries is closely related to national development, emphasizes this report on the structure and goals of education in seven nations and two Soviet federated states. The author discusses the relationship of educational development to technical and organizational progress, changes in socioeconomic and…
Optically Tunable Magnetoresistance Effect: From Mechanism to Novel Device Application.
Liu, Pan; Lin, Xiaoyang; Xu, Yong; Zhang, Boyu; Si, Zhizhong; Cao, Kaihua; Wei, Jiaqi; Zhao, Weisheng
2017-12-28
The magnetoresistance effect in sandwiched structure describes the appreciable magnetoresistance effect of a device with a stacking of two ferromagnetic layers separated by a non-magnetic layer (i.e., a sandwiched structure). The development of this effect has led to the revolution of memory applications during the past decades. In this review, we revisited the magnetoresistance effect and the interlayer exchange coupling (IEC) effect in magnetic sandwiched structures with a spacer layer of non-magnetic metal, semiconductor or organic thin film. We then discussed the optical modulation of this effect via different methods. Finally, we discuss various applications of these effects and present a perspective to realize ultralow-power, high-speed data writing and inter-chip connection based on this tunable magnetoresistance effect.
Enhancing instruction scheduling with a block-structured ISA
DOE Office of Scientific and Technical Information (OSTI.GOV)
Melvin, S.; Patt, Y.
It is now generally recognized that not enough parallelism exists within the small basic blocks of most general purpose programs to satisfy high performance processors. Thus, a wide variety of techniques have been developed to exploit instruction level parallelism across basic block boundaries. In this paper we discuss some previous techniques along with their hardware and software requirements. Then we propose a new paradigm for an instruction set architecture (ISA): block-structuring. This new paradigm is presented, its hardware and software requirements are discussed and the results from a simulation study are presented. We show that a block-structured ISA utilizes bothmore » dynamic and compile-time mechanisms for exploiting instruction level parallelism and has significant performance advantages over a conventional ISA.« less
The Protein Data Bank in Europe (PDBe): bringing structure to biology
DOE Office of Scientific and Technical Information (OSTI.GOV)
Velankar, Sameer; Kleywegt, Gerard J., E-mail: gerard@ebi.ac.uk
2011-04-01
Some future challenges for the PDB and its guardians are discussed and current and future activities in structural bioinformatics at the Protein Data Bank in Europe (PDBe) are described. The Protein Data Bank in Europe (PDBe) is the European partner in the Worldwide PDB and as such handles depositions of X-ray, NMR and EM data and structure models. PDBe also provides advanced bioinformatics services based on data from the PDB and related resources. Some of the challenges facing the PDB and its guardians are discussed, as well as some of the areas on which PDBe activities will focus in themore » future (advanced services, ligands, integration, validation and experimental data). Finally, some recent developments at PDBe are described.« less
Cheng, Xin; Jiang, Shunxing; Wang, Xiaolin; Kellner, Alexander W A
2017-01-01
Cranial crests show considerable variation within the Pterosauria, a group of flying reptiles that developed powered flight. This includes the Wukongopteridae, a clade of non-pterodactyloids, where the presence or absence of such head structures, allied with variation in the pelvic canal, have been regarded as evidence for sexual dimorphism. Here we discuss the cranial crest variation within wukongopterids and briefly report on a new specimen (IVPP V 17957). We also show that there is no significant variation in the anatomy of the pelvis of crested and crestless specimens. We further revisit the discussion regarding the function of cranial structures in pterosaurs and argue that they cannot be dismissed a priori as a valuable tool for species recognition.
Advanced composite vertical stabilizer for DC-10 transport aircraft
NASA Technical Reports Server (NTRS)
Stephens, C. O.
1979-01-01
Structural design, tooling, fabrication, and test activities are reported for a program to develop an advanced composite vertical stabilizer (CVS) for the DC 10 Commercial Transport Aircraft. Structural design details are described and the status of structural and weight analyses are reported. A structural weight reduction of 21.7% is currently predicted. Test results are discussed for sine wave stiffened shear webs containing representative of the CVS spar webs and for lightning current transfer and tests on a panel representative of the CVS skins.
Fatigue tests on big structure assemblies of concorde aircraft
NASA Technical Reports Server (NTRS)
Nguyen, V. P.; Perrais, J. P.
1972-01-01
Fatigue tests on structural assemblies of the Concorde supersonic transport aircraft are reported. Two main sections of the aircraft were subjected to pressure, mechanical load, and thermal static tests. The types of fatigue tests conducted and the results obtained are discussed. It was concluded that on a supersonic aircraft whose structural weight is a significant part of the weight analysis, many fatigue and static strength development tests should be made and fatigue and thermal tests of the structures are absolutely necessary.
NASA Technical Reports Server (NTRS)
Aniversario, R. B.; Harvey, S. T.; Mccarty, J. E.; Parsons, J. T.; Peterson, D. C.; Pritchett, L. D.; Wilson, D. R.; Wogulis, E. R.
1982-01-01
Results of tests conducted to demonstrate that composite structures save weight, possess long term durability, and can be fabricated at costs competitive with conventional metal structures are presented with focus on the use of graphite-epoxy in the design of a stabilizer for the Boeing 737 aircraft. Component definition, materials evaluation, material design properties, and structural elements tests are discussed. Fabrication development, as well as structural repair and inspection are also examined.
[Discussion on knowledge structural system of modern acupuncture professionals].
Wang, Qin-Yu; Li, Su-He
2012-02-01
To explore the knowledge structural system that the modern acupuncture professionals should have. The current situation of personnel training for modern acupuncture professionals was multi-dimensionally and comprehensively analyzed from course offering of higher education, laws of famous physicians growth, and discipline development features of the acupuncture and moxibustion subject, and suggestions were made to the shortages. The reasonable knowledge structural system that the modern acupuncture professionals should have included establishment of good Chinese medicine thoughts, mastery of complete Chinese medicine therapy, and ability of followup of dynamic development of subject. The reformation of course design is imperative in order to promote the reasonable knowledge structural system formation of modern acupuncture professionals.
The XFV-12A Thrust-Augmented Wing (TAW) prototype aircraft
NASA Technical Reports Server (NTRS)
Murphy, R.; Lewis, E. L.
1979-01-01
The XFV-12A, a unique V/STOL technology prototype aircraft being developed for the Navy, is described. The innovative design features a thrust augmented wing and a canard ejector. Structural, functional, and control test performances are discussed. Static tether test results are also discussed. Assessment of test results are given along with projections for future modification areas.
The Loci Multidisciplinary Simulation System Overview and Status
NASA Technical Reports Server (NTRS)
Luke, Edward A.; Tong, Xiao-Ling; Tang, Lin
2002-01-01
This paper will discuss the Loci system, an innovative tool for developing tightly coupled multidisciplinary three dimensional simulations. This presentation will overview some of the unique capabilities of the Loci system to automate the assembly of numerical simulations from libraries of fundamental computational components. We will discuss the demonstration of the Loci system on coupled fluid-structure problems related to RBCC propulsion systems.
Behavioral Science Design for Audio-Visual Software Development
ERIC Educational Resources Information Center
Foster, Dennis L.
1974-01-01
A discussion of the basic structure of the behavioral audio-visual production which consists of objectives analysis, approach determination, technical production, fulfillment evaluation, program refinement, implementation, and follow-up. (Author)
Development of compact slip detection sensor using dielectric elastomer
NASA Astrophysics Data System (ADS)
Choi, Jae-young; Hwang, Do-Yeon; Kim, Baek-chul; Moon, Hyungpil; Choi, Hyouk Ryeol; Koo, Ja Choon
2015-04-01
In this paper, we developed a resistance tactile sensor that can detect a slip on the surface of sensor structure. The presented sensor device has fingerprint-like structures that are similar with the role of the humans finger print. The resistance slip sensor that the novel developed uses acrylo-nitrile butadiene rubber (NBR) as a dielectric substrate and graphene as an electrode material. We can measure the slip as the structure of sensor makes a deformation and it changes the resistance through forming a new conductive route. To manufacture our sensor, we developed a new imprint process. By using this process, we can produce sensor with micro unit structure. To verify effectiveness of the proposed slip detection, experiment using prototype of resistance slip sensor is conducted with an algorithm to detect slip and slip is successfully detected. We will discuss the slip detection properties.
The impact of distributed computing on education
NASA Technical Reports Server (NTRS)
Utku, S.; Lestingi, J.; Salama, M.
1982-01-01
In this paper, developments in digital computer technology since the early Fifties are reviewed briefly, and the parallelism which exists between these developments and developments in analysis and design procedures of structural engineering is identified. The recent trends in digital computer technology are examined in order to establish the fact that distributed processing is now an accepted philosophy for further developments. The impact of this on the analysis and design practices of structural engineering is assessed by first examining these practices from a data processing standpoint to identify the key operations and data bases, and then fitting them to the characteristics of distributed processing. The merits and drawbacks of the present philosophy in educating structural engineers are discussed and projections are made for the industry-academia relations in the distributed processing environment of structural analysis and design. An ongoing experiment of distributed computing in a university environment is described.
Regulation of Mitochondrial Structure and Dynamics by the Cytoskeleton and Mechanical Factors.
Bartolák-Suki, Erzsébet; Imsirovic, Jasmin; Nishibori, Yuichiro; Krishnan, Ramaswamy; Suki, Béla
2017-08-21
Mitochondria supply cells with energy in the form of ATP, guide apoptosis, and contribute to calcium buffering and reactive oxygen species production. To support these diverse functions, mitochondria form an extensive network with smaller clusters that are able to move along microtubules aided by motor proteins. Mitochondria are also associated with the actin network, which is involved in cellular responses to various mechanical factors. In this review, we discuss mitochondrial structure and function in relation to the cytoskeleton and various mechanical factors influencing cell functions. We first summarize the morphological features of mitochondria with an emphasis on fission and fusion as well as how network properties govern function. We then review the relationship between the mitochondria and the cytoskeletal structures, including mechanical interactions. We also discuss how stretch and its dynamic pattern affect mitochondrial structure and function. Finally, we present preliminary data on how extracellular matrix stiffness influences mitochondrial morphology and ATP generation. We conclude by discussing the more general role that mitochondria may play in mechanobiology and how the mechanosensitivity of mitochondria may contribute to the development of several diseases and aging.
Regulation of Mitochondrial Structure and Dynamics by the Cytoskeleton and Mechanical Factors
Bartolák-Suki, Erzsébet; Imsirovic, Jasmin; Nishibori, Yuichiro; Krishnan, Ramaswamy; Suki, Béla
2017-01-01
Mitochondria supply cells with energy in the form of ATP, guide apoptosis, and contribute to calcium buffering and reactive oxygen species production. To support these diverse functions, mitochondria form an extensive network with smaller clusters that are able to move along microtubules aided by motor proteins. Mitochondria are also associated with the actin network, which is involved in cellular responses to various mechanical factors. In this review, we discuss mitochondrial structure and function in relation to the cytoskeleton and various mechanical factors influencing cell functions. We first summarize the morphological features of mitochondria with an emphasis on fission and fusion as well as how network properties govern function. We then review the relationship between the mitochondria and the cytoskeletal structures, including mechanical interactions. We also discuss how stretch and its dynamic pattern affect mitochondrial structure and function. Finally, we present preliminary data on how extracellular matrix stiffness influences mitochondrial morphology and ATP generation. We conclude by discussing the more general role that mitochondria may play in mechanobiology and how the mechanosensitivity of mitochondria may contribute to the development of several diseases and aging. PMID:28825689
NASA Technical Reports Server (NTRS)
1974-01-01
A monograph is presented which establishes structural design criteria and recommends practices to ensure the design of sound composite structures, including composite-reinforced metal structures. (It does not discuss design criteria for fiber-glass composites and such advanced composite materials as beryllium wire or sapphire whiskers in a matrix material.) Although the criteria were developed for aircraft applications, they are general enough to be applicable to space vehicles and missiles as well. The monograph covers four broad areas: (1) materials, (2) design, (3) fracture control, and (4) design verification. The materials portion deals with such subjects as material system design, material design levels, and material characterization. The design portion includes panel, shell, and joint design, applied loads, internal loads, design factors, reliability, and maintainability. Fracture control includes such items as stress concentrations, service-life philosophy, and the management plan for control of fracture-related aspects of structural design using composite materials. Design verification discusses ways to prove flightworthiness.
ERIC Educational Resources Information Center
Hale, Enoch; Bessette, Lee Skallerup
2016-01-01
In the spirit of exploration, this paper discusses the what, why and how of unconferencing and explores its implications as a transformative approach to faculty development in higher education. The authors define an unconference faculty development experience as: a less-structured opportunity for participants to learn and grow by sharing…
ERIC Educational Resources Information Center
Bermant, M.; And Others
This study provides a tool for describing, analyzing, and evaluating the effectiveness of human resources development (HRD) systems and their components. It is intended for policy makers, planners, and senior officials from government, employers', and workers' organizations who have responsibilities in human resources development. The first part…
NASA Technical Reports Server (NTRS)
Cassenti, B. N.
1983-01-01
The results of a 10-month research and development program for nonlinear structural modeling with advanced time-temperature constitutive relationships are presented. The implementation of the theory in the MARC nonlinear finite element code is discussed, and instructions for the computational application of the theory are provided.
Probing Protein Structure and Folding in the Gas Phase by Electron Capture Dissociation
NASA Astrophysics Data System (ADS)
Schennach, Moritz; Breuker, Kathrin
2015-07-01
The established methods for the study of atom-detailed protein structure in the condensed phases, X-ray crystallography and nuclear magnetic resonance spectroscopy, have recently been complemented by new techniques by which nearly or fully desolvated protein structures are probed in gas-phase experiments. Electron capture dissociation (ECD) is unique among these as it provides residue-specific, although indirect, structural information. In this Critical Insight article, we discuss the development of ECD for the structural probing of gaseous protein ions, its potential, and limitations.
Mayanovic, Robert A.; Jayanetti, Sumedha; Anderson, Alan J.; Bassett, William A.; Chou, I.-Ming
2003-01-01
Recently x-ray absorption fine structure (XAFS) studies of various ions in aqueous solutions showed a variation of cation-ligand bond lengths, often coupled with other structure changes, with increasing temperatures. Thus, the variations of the structure of several metal ion complexes with temperature based on observations from the X-ray absorption fine structure (XAFS) studies in the hope that it will stimulate the development of either first- principles theory or molecular dynamics simulations that might adequately describes these results are discussed.
Ford, Dee W; Downey, Lois; Engelberg, Ruth; Back, Anthony L; Curtis, J Randall
2012-01-01
Communication about religious and spiritual issues is fundamental to palliative care, yet little empirical data exist to guide curricula in this area. The goal of this study was to develop an improved understanding of physicians' perspectives on their communication competence about religious and spiritual issues. We examined surveys of physician trainees (n=297) enrolled in an ongoing communication skills study at two medical centers in the northwestern and southeastern United States. Our primary outcome was self-assessed competence in discussing religion and spirituality. We used exploratory structural equation modeling (SEM) to develop measurement and full models for acquisition of self-assessed communication competencies. Our measurement SEM identified two latent constructs that we label Basic and Intermediate Competence, composed of five self-assessed communication skills. The Basic Competence construct included overall satisfaction with palliative care skills and with discussing do not resuscitate (DNR) status. The Intermediate Competence construct included responding to inappropriate treatment requests, maintaining hope, and addressing fears about the end-of-life. Our full SEM model found that Basic Competence predicted Intermediate Competence and that Intermediate Competence predicted competence in religious and spiritual discussions. Years of clinical training directly influenced Basic Competence. Increased end-of-life discussions positively influenced Basic Competence and had a complex association with Intermediate Competence. Southeastern trainees perceived more competence in religious and spiritual discussions than northwestern trainees. This study suggests that discussion of religious and spiritual issues is a communication skill that trainees consider more advanced than other commonly taught communication skills, such as discussing DNR orders.
ERIC Educational Resources Information Center
Kretschmer, Hildrun
2002-01-01
Based on Gestalt theory, the author assumes the existence of a field-force equilibrium to explain how, according to the conciseness principle, mathematically precise gestalts could exist in coauthorship networks. Develops a mathematical function to describe these gestalts in scientific literature and discusses structural characteristics of…
Introduction to session on materials and structures
NASA Technical Reports Server (NTRS)
Vosteen, L. F.
1978-01-01
A review was given of the development of composites for aircraft. Supporting base technology and the Aircraft Energy Efficiency Composites Program are included. Specific topics discussed include: (1) environmental effects on materials; (2) material quality and chemical characterization; (3) design and analysis methods; (4) structural durability; (5) impact sensitivity; (6) carbon fiber electrical effects; and (7) composite components.
NASA Technical Reports Server (NTRS)
Spencer, F. A.
1980-01-01
The development and implementation of aircraft noise control regulations in various European states are described. The countries include the United Kingdom, France, Switzerland, Federal Republic of Germany, Sweden, Denmark, and the Netherlands. Topics discussed include noise monitoring, airport curfews, land use planning, and the government structure for noise regulation.
Ideology and Linguistic Theory: Noam Chomsky and the Deep Structure Debates.
ERIC Educational Resources Information Center
Huck, Geoffrey J.; Goldsmith, John A.
A revisionist account of the development of ideas about semantics in modern theories of language is presented, focusing on the rift between Noam Chomsky and Generative Semanticists about the concept of deep structure, or the role of meaning in grammar. The discussion re-appraises the paradigm that has dominated American linguistics since the…
Do General Physics Textbooks Discuss Scientists' Ideas about Atomic Structure? A Case in Korea
ERIC Educational Resources Information Center
Niaz, Mansoor; Kwon, Sangwoon; Kim, Nahyun; Lee, Gyoungho
2013-01-01
Research in science education has recognized the importance of teaching atomic structure within a history and philosophy of science perspective. The objective of this study is to evaluate general physics textbooks published in Korea based on the eight criteria developed in previous research. The result of this study shows that Korean general…
Developing an Environment for Exploring Distributed Operations: A Wargaming Example
2005-05-01
a basis for performance standards. At the same time, the design tried to provide an acceptable mix of structured versus free - play activity in...participants’ free - play discussion and collaboration during Counteraction. Scripting allowed the research team to embed potential problems or measurement...Learned - Structured Exercises ......................................................................... 24 Scripted and Free - Play Wargaming Phases
Individuals' Life Structures in the Early Adulthood Period Based on Levinson's Theory
ERIC Educational Resources Information Center
Aktu, Yahya; Ilhan, Tahsin
2017-01-01
Early adulthood is one of the important milestones considered within lifelong development in the relevant literature. Adulthood is examined through various theories; however, universality of many of these is still being discussed. One of these theories is Levinson's theory of life structure. Thus, the current research aims to examine the extent to…
NiCd battery electrodes, C-150
NASA Technical Reports Server (NTRS)
Holleck, G.; Turchan, M.; Hopkins, J.
1972-01-01
Electrodes for a nongassing negative limited nickel-cadmium cell are discussed. The key element is the development of cadmium electrodes with high hydrogen overvoltage. For this, the following electrode structures were manufactured and their physical and electrochemical characteristics were evaluated: (1) silver-sinter-based Cd electrodes, (2) Teflon-bonded Cd electrodes, (3) electrodeposited Cd sponge, and (4) Cd-sinter structures.
ERIC Educational Resources Information Center
Campbell-Barr, Verity
2017-01-01
The early childhood workforce is routinely demonstrated as being central to the quality of early childhood education and care (ECEC). Frequently, discussions of quality focus on structural features of training, such as level and duration. However, the literature demonstrates that quality extends beyond the structural and that early childhood…
The performance of lightweight plastic foams developed for fire safety
NASA Technical Reports Server (NTRS)
Fish, R. H.
1971-01-01
The use of a low density, polyurethane based foam to suppress a fire and to provide protection for the structure of an aircraft or spacecraft is discussed. The mechanism by which foams provide protection from heat and create a nonflammable surface is described. Various materials and their application to specific types of structures are examined.
Interval Estimation of Revision Effect on Scale Reliability via Covariance Structure Modeling
ERIC Educational Resources Information Center
Raykov, Tenko
2009-01-01
A didactic discussion of a procedure for interval estimation of change in scale reliability due to revision is provided, which is developed within the framework of covariance structure modeling. The method yields ranges of plausible values for the population gain or loss in reliability of unidimensional composites, which results from deletion or…
Overview of NASA/OAST efforts related to manufacturing technology
NASA Technical Reports Server (NTRS)
Saunders, N. T.
1976-01-01
Activities of the Office of Aeronautics and Space Technology (OAST) in a number of areas related to manufacturing technology are considered. In the computer-aided design area improved approaches are developed for the design of specific classes of components or structural subsystems. A generalized approach for the design of a complete aerospace vehicle is also developed. Efforts directed toward an increased use of composite materials in aerospace structures are also discussed and attention is given to projects concerned with the manufacture of turbine engine components.
Goal Structuring Notation in a Radiation Hardening Assurance Case for COTS-Based Spacecraft
NASA Technical Reports Server (NTRS)
Witulski, A.; Austin, R.; Evans, J.; Mahadevan, N.; Karsai, G.; Sierawski, B.; LaBel, K.; Reed, R.; Schrimpf, R.
2016-01-01
A systematic approach is presented to constructing a radiation assurance case using Goal Structuring Notation (GSN) for spacecraft containing COTS parts. The GSN paradigm is applied to an SRAM single-event upset experiment board designed to fly on a CubeSat in January 2017. A custom software language for development of a GSN assurance case is under development at Vanderbilt. Construction of a radiation assurance case without use of hardened parts or extensive radiation testing is discussed.
Learning about Children Learning about Squirrels
ERIC Educational Resources Information Center
Diamond, Julie
2007-01-01
This article describes a curriculum developed by the author and the children in her public school kindergarten class. Teaching practices that foster children's intellectual--and overall human--development are documented. The goals and purposes of schooling are discussed as well as issues pertaining to the role of the teacher, structures that…
An Audiovisual Program in Cell Biology
ERIC Educational Resources Information Center
Fedoroff, Sergey; Opel, William
1978-01-01
A subtopic of cell biology, the structure and function of cell membranes, has been developed as a series of seven self-instructional slide-tape units and tested in five medical schools. Organization of advisers, analysis and definition of objectives and content, and development and evaluation of scripts and storyboards are discussed. (Author/LBH)
From Noise to Order: The Psychological Development of Knowledge and Phenocopy in Biology
ERIC Educational Resources Information Center
Piaget, Jean
1975-01-01
Shows that one of the most general processes in the development of cognitive structures consists in replacing exogenous knowledge by endogenous reconstructions that reconstitute the same forms but incorporate them into systems whose internal composition is a pre-requisite. Biologically equivalent process is discussed. (Author/AM)
Some Instructional Implications from a Mathematical Model of Cognitive Development.
ERIC Educational Resources Information Center
Mierkiewicz, Diane B.
Cognitive development and various educational implications are discussed in terms of Donald Saari's model of the interaction of a learner and the enviroment and the constraints imposed by the inefficiency of the learner's cognitive system. Saari proposed a hierarchical system of cognitive structures such that the relationships between structures…
ERIC Educational Resources Information Center
Sillince, J. A. A.; Sillince, M.
1993-01-01
Discusses molecular databases and the role that government and private companies play in their administration and development. Highlights include copyright and patent issues relating to public databases and the information contained in them; data quality; data structures and technological questions; the international organization of molecular…
CPD: Support Strategies for Professional Learning, National Initiatives and Major Curriculum Reform
ERIC Educational Resources Information Center
Cumming, Carol
2011-01-01
This article outlines developments in continuous professional development (CPD) for teachers, within the Scottish context. It discusses some examples of both bottom-up and top-down structures, approaches to, and opportunities for CPD within Scotland, contextualizing the importance of professional learning within global issues of educational…
Modeling the Development of Vocational Competence: A Psychometric Model for Economic Domains
ERIC Educational Resources Information Center
Klotz, Viola Katharina; Winther, Esther; Festner, Dagmar
2015-01-01
This article discusses the development of vocational competence through economic vocational educational training (VET) from a theoretical and psychometric perspective. Most assessment and competence models tend to adopt a state perspective toward assessments of competence and carve out different structures of competence for diverse vocational…
Towards Mass Higher Education. Issues and Dilemmas.
ERIC Educational Resources Information Center
Organisation for Economic Cooperation and Development, Paris (France).
To discuss a number of major issues related to policies for the future development of higher education systems, the Organisation for Economic Cooperation and Development (OECD) organized a Conference on Future Structures of Post-Secondary Education, which took place in Paris in June 1973. High officials responsible for education policy in OECD…
Recent Trends in Human Resource Development. Japanese Industrial Relations Series 17.
ERIC Educational Resources Information Center
Amaya, Tadashi
This paper discusses human resources development (HRD) in Japanese industry. Chapter I addresses changing industrial and occupational structures as a foundation for planning and constructing management strategy, especially for business restructuring. The actual situation regarding business diversification is considered, and an attempt is made to…
ERIC Educational Resources Information Center
Donnellan, Anne M.
The paper addresses the history and current status of educational provisions for autistic students, discusses the requirements for effective education for this population, and analyzes the implications for teacher education practices. A status report cites lack of structure in programs, non-functional and age-inappropriate curricula, largely…
A Reflection on a Collaborative Process of Courseware Development.
ERIC Educational Resources Information Center
Joyes, Gordon; Scott, Rachael
2000-01-01
Discusses the collaborative development of technology-based teaching materials for use within civil and structural engineering departments in higher education. Describes a project funded by the European Union called SteelCAL that is based on a partnership between the European steel industry and universities to involve faculty in curriculum…
Design, analysis, and test verification of advanced encapsulation systems
NASA Technical Reports Server (NTRS)
Mardesich, N.; Minning, C.
1982-01-01
Design sensitivities are established for the development of photovoltaic module criteria and the definition of needed research tasks. The program consists of three phases. In Phase I, analytical models were developed to perform optical, thermal, electrical, and structural analyses on candidate encapsulation systems. From these analyses several candidate systems will be selected for qualification testing during Phase II. Additionally, during Phase II, test specimens of various types will be constructed and tested to determine the validity of the analysis methodology developed in Phase I. In Phse III, a finalized optimum design based on knowledge gained in Phase I and II will be developed. All verification testing was completed during this period. Preliminary results and observations are discussed. Descriptions of the thermal, thermal structural, and structural deflection test setups are included.
Distributed multifunctional sensor network for composite structural state sensing
NASA Astrophysics Data System (ADS)
Qing, Xinlin P.; Wang, Yishou; Gao, Limin; Kumar, Amrita
2012-04-01
Advanced fiber reinforced composite materials are becoming the main structural materials of next generation of aircraft because of their high strength and stiffness to weight ratios, and strong designability. In order to take full advantages of composite materials, there is a need to develop an embeddable multifunctional sensing system to allow a structure to "feel" and "think" its structural state. In this paper, the concept of multifunctional sensor network integrated with a structure, similar to the human nervous system, has been developed. Different types of network sensors are permanently integrated within a composite structure to sense structural strain, temperature, moisture, aerodynamic pressure; monitor external impact on the structure; and detect structural damages. Utilizing this revolutionary concept, future composite structures can be designed and manufactured to provide multiple modes of information, so that the structures have the capabilities for intelligent sensing, environmental adaptation and multi-functionality. The challenges for building such a structural state sensing system and some solutions to address the challenges are also discussed in the paper.
Leaving the structural ivory tower, assisted by interactive 3D PDF.
Kumar, Pravin; Ziegler, Alexander; Grahn, Alexander; Hee, Chee Seng; Ziegler, Andreas
2010-08-01
The ability to embed interactive three-dimensional (3D) models into electronic publications in portable document format (PDF) greatly enhances the accessibility of molecular structures. Here, we report advances in this procedure and discuss what is needed to develop this format into a truly useful tool for the structural biology community as well as for readers who are less well trained in molecular visualization. Copyright 2010 Elsevier Ltd. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sonzogni, A.A.
2005-05-24
A package of computer codes has been developed to process and display nuclear structure and decay data stored in the ENSDF (Evaluated Nuclear Structure Data File) library. The codes were written in an object-oriented fashion using the java language. This allows for an easy implementation across multiple platforms as well as deployment on web pages. The structure of the different java classes that make up the package is discussed as well as several different implementations.
Recent Advances in the Inverted Planar Structure of Perovskite Solar Cells.
Meng, Lei; You, Jingbi; Guo, Tzung-Fang; Yang, Yang
2016-01-19
Inorganic-organic hybrid perovskite solar cells research could be traced back to 2009, and initially showed 3.8% efficiency. After 6 years of efforts, the efficiency has been pushed to 20.1%. The pace of development was much faster than that of any type of solar cell technology. In addition to high efficiency, the device fabrication is a low-cost solution process. Due to these advantages, a large number of scientists have been immersed into this promising area. In the past 6 years, much of the research on perovskite solar cells has been focused on planar and mesoporous device structures employing an n-type TiO2 layer as the bottom electron transport layer. These architectures have achieved champion device efficiencies. However, they still possess unwanted features. Mesoporous structures require a high temperature (>450 °C) sintering process for the TiO2 scaffold, which will increase the cost and also not be compatible with flexible substrates. While the planar structures based on TiO2 (regular structure) usually suffer from a large degree of J-V hysteresis. Recently, another emerging structure, referred to as an "inverted" planar device structure (i.e., p-i-n), uses p-type and n-type materials as bottom and top charge transport layers, respectively. This structure derived from organic solar cells, and the charge transport layers used in organic photovoltaics were successfully transferred into perovskite solar cells. The p-i-n structure of perovskite solar cells has shown efficiencies as high as 18%, lower temperature processing, flexibility, and, furthermore, negligible J-V hysteresis effects. In this Account, we will provide a comprehensive comparison of the mesoporous and planar structures, and also the regular and inverted of planar structures. Later, we will focus the discussion on the development of the inverted planar structure of perovskite solar cells, including film growth, band alignment, stability, and hysteresis. In the film growth part, several methods for obtaining high quality perovskite films are reviewed. In the interface engineering parts, the effect of hole transport layer on subsequent perovskite film growth and their interface band alignment, and also the effect of electron transport layers on charge transport and interface contact will be discussed. As concerns stability, the role of charge transport layers especially the top electron transport layer in the devices stability will be concluded. In the hysteresis part, possible reasons for hysteresis free in inverted planar structure are provided. At the end of this Account, future development and possible solutions to the remaining challenges facing the commercialization of perovskite solar cells are discussed.
Qian, Xiaoqin; Han, Xiaoxia; Chen, Yu
2017-10-01
The clinical ultrasound (US)-based theranostic biomedicine suffers from the critical issue that traditional microbubbles (MBs) have lots of drawbacks such as low stability, large particle size, difficult structural control, etc. The unique composition, structure and functionality of inorganic micro/nanoplatforms have shown their great prospect for solving these critical issues and drawbacks of traditional organic MBs. This review summarizes and discusses the state-of-art development on exploring inorganic micro/nanoparticles for versatile US-based biomedical applications, ranging from US imaging, photoacoustic imaging, sonodynamic therapy, high intensity-focused US ablation and US-triggered chemotherapy. These inorganic micro/nanoplatforms include silica-based particles, Au, carbon nanotubes, TiO 2 , manganese oxide, iron oxide, Prussian blue, inorganic gas-generating nanoparticles and their versatile composite micro/nanosystems. Especially, their unique structure/composition-functionality relationships and biocompatibility/biosafety in US-based theranostics have been discussed and revealed in detail. Their facing challenges and future developments are finally discussed to promote their further clinical translations. It is highly expected that these inorganic micro/nanoplatforms will enter the clinical stage to benefit the personalized theranostics biomedicine based on their unique functionalities and high performance as necessarily required in US-based theranostics. Copyright © 2017 Elsevier Ltd. All rights reserved.
Local numerical modelling of ultrasonic guided waves in linear and nonlinear media
NASA Astrophysics Data System (ADS)
Packo, Pawel; Radecki, Rafal; Kijanka, Piotr; Staszewski, Wieslaw J.; Uhl, Tadeusz; Leamy, Michael J.
2017-04-01
Nonlinear ultrasonic techniques provide improved damage sensitivity compared to linear approaches. The combination of attractive properties of guided waves, such as Lamb waves, with unique features of higher harmonic generation provides great potential for characterization of incipient damage, particularly in plate-like structures. Nonlinear ultrasonic structural health monitoring techniques use interrogation signals at frequencies other than the excitation frequency to detect changes in structural integrity. Signal processing techniques used in non-destructive evaluation are frequently supported by modeling and numerical simulations in order to facilitate problem solution. This paper discusses known and newly-developed local computational strategies for simulating elastic waves, and attempts characterization of their numerical properties in the context of linear and nonlinear media. A hybrid numerical approach combining advantages of the Local Interaction Simulation Approach (LISA) and Cellular Automata for Elastodynamics (CAFE) is proposed for unique treatment of arbitrary strain-stress relations. The iteration equations of the method are derived directly from physical principles employing stress and displacement continuity, leading to an accurate description of the propagation in arbitrarily complex media. Numerical analysis of guided wave propagation, based on the newly developed hybrid approach, is presented and discussed in the paper for linear and nonlinear media. Comparisons to Finite Elements (FE) are also discussed.
AGT 100 automotive gas turbine system development
NASA Technical Reports Server (NTRS)
Helms, H. E. G.
1982-01-01
General Motors is developing an automotive gas turbine system that can be an alternate powerplant for future automobiles. Work sponsored by DOE and administered by NASA Lewis Research Center is emphasizing small component aerodynamics and high-temperature structural ceramics. Reliability requirements of the AGT 100 turbine system include chemical and structural ceramic component stability in the gas turbine environment. The power train system, its configuration and schedule are presented, and its performance tested. The aerodynamic component development is reviewed with discussions on the compressor, turbine, regenerator, interturbine duct and scroll, and combustor. Ceramic component development is also reviewed, and production cost and required capital investment are taken into consideration.
ERIC Educational Resources Information Center
Roxå, Torgny; Mårtensson, Katarina
2017-01-01
This text taps into an ongoing discussion about academic development. It challenges an image of academic development as precarious and liminal and explores academic development as powerful. Sources of power are described and put into the context of values, ideologies, and policies governing higher education of today. It is our hope that readers…
NASA's Platform for Cross-Disciplinary Microchannel Research
NASA Technical Reports Server (NTRS)
Son, Sang Young; Spearing, Scott; Allen, Jeffrey; Monaco, Lisa A.
2003-01-01
A team from the Structural Biology group located at the NASA Marshall Space Flight Center in Huntsville, Alabama is developing a platform suitable for cross-disciplinary microchannel research. The original objective of this engineering development effort was to deliver a multi-user flight-certified facility for iterative investigations of protein crystal growth; that is, Iterative Biological Crystallization (IBC). However, the unique capabilities of this facility are not limited to the low-gravity structural biology research community. Microchannel-based research in a number of other areas may be greatly accelerated through use of this facility. In particular, the potential for gas-liquid flow investigations and cellular biological research utilizing the exceptional pressure control and simplified coupling to macroscale diagnostics inherent in the IBC facility will be discussed. In conclusion, the opportunities for research-specific modifications to the microchannel configuration, control, and diagnostics will be discussed.
Royal Society, Discussion on New Coal Chemistry, London, England, May 21, 22, 1980, Proceedings
NASA Astrophysics Data System (ADS)
1981-03-01
A discussion of new coal chemistry is presented. The chemical and physical structure of coal is examined in the first section, including structural studies of coal extracts, metal and metal complexes in coal and coal microporosity. The second section presents new advances in applied coal technology. The development of liquid fuels and chemicals from coal is given especial emphasis, with papers on the Sasol Synthol process, the Shell-Koppers gasification process, liquefaction and gasification in Germany, the Solvent Refined Coal process, the Exxon Donor Solvent liquefaction process and the Mobil Methanol-to-Gasoline process. Finally, some developments that will be part of the future of coal chemistry in the year 2000 are examined in the third section, including coal-based chemical complexes and the use of coal as an alternative source to oil for chemical feedstocks.
Overview of Heatshield for Extreme Entry Environment Technology (HEEET)
NASA Technical Reports Server (NTRS)
Driver, David M.; Ellerby, Donald T.; Gasch, Matthew J.; Mahzari, Milad; Milos, Frank S.; Nishioka, Owen S.; Stackpoole, Margaret M.; Venkatapathy, Ethiraj; Young, Zion W.; Gage, Peter J.;
2018-01-01
The Heatshield for Extreme Entry Environment Technology (HEEET) projects objective is to mature a 3-D Woven Thermal Protection System (TPS) to Technical Readiness Level (TRL) 6 to support future NASA missions to destinations such as Venus and Saturn. The scope of the project, status of which will be discussed, encompasses development of manufacturing and integration processes, fabrication of a prototype 1m diameter engineering test unit (ETU) that will undergo a series of structural tests, characterizing material aerothermal performance including development of a material response model, and structural testing and analysis to develop tools to support design and establish system capability.
Keller, Robert T
2006-01-01
Transformational leadership, initiating structure, and selected substitutes for leadership were studied as longitudinal predictors of performance in 118 research and development (R&D) project teams from 5 firms. As hypothesized, transformational leadership predicted 1-year-later technical quality, schedule performance, and cost performance and 5-year-later profitability and speed to market. Initiating structure predicted all the performance measures. The substitutes of subordinate ability and an intrinsically satisfying task each predicted technical quality and profitability, and ability predicted speed to market. Moderator effects for type of R&D work were hypothesized and found whereby transformational leadership was a stronger predictor of technical quality in research projects, whereas initiating structure was a stronger predictor of technical quality in development projects. Implications for leadership theory and research are discussed. (c) 2006 APA, all rights reserved.
Novel cost controlled materials and processing for primary structures
NASA Technical Reports Server (NTRS)
Dastin, S. J.
1993-01-01
Textile laminates, developed a number of years ago, have recently been shown to be applicable to primary aircraft structures for both small and large components. Such structures have the potential to reduce acquisition costs but require advanced automated processing to keep costs controlled while verifying product reliability and assuring structural integrity, durability and affordable life-cycle costs. Recently, resin systems and graphite-reinforced woven shapes have been developed that have the potential for improved RTM processes for aircraft structures. Ciba-Geigy, Brochier Division has registered an RTM prepreg reinforcement called 'Injectex' that has shown effectivity for aircraft components. Other novel approaches discussed are thermotropic resins producing components by injection molding and ceramic polymers for long-duration hot structures. The potential of such materials and processing will be reviewed along with initial information/data available to date.
Space Shuttle Orbiter - Leading edge structural design/analysis and material allowables
NASA Technical Reports Server (NTRS)
Johnson, D. W.; Curry, D. M.; Kelly, R. E.
1986-01-01
Reinforced Carbon-Carbon (RCC), a structural composite whose development was targeted for the high temperature reentry environments of reusable space vehicles, has successfully demonstrated that capability on the Space Shuttle Orbiter. Unique mechanical properties, particularly at elevated temperatures up to 3000 F, make this material ideally suited for the 'hot' regions of multimission space vehicles. Design allowable characterization testing, full-scale development and qualification testing, and structural analysis techniques will be presented herein that briefly chart the history of the RCC material from infancy to eventual multimission certification for the Orbiter. Included are discussions pertaining to the development of the design allowable data base, manipulation of the test data into usable forms, and the analytical verification process.
Han, Ning-Xu; Xing, Feng
2016-01-01
A review of the research activities and achievements at Shenzhen University is conducted in this paper concerning the creation and further development of novel microcapsule based self-resilience systems for their application in concrete structures. After a brief description of pioneering works in the field starting about 10 years ago, the principles raised in the relevant research are examined, where fundamental terms related to the concept of resilience are discussed. Several breakthrough points are highlighted concerning the three adopted comprehensive self-resilience systems, namely physical, chemical and microbial systems. The major challenges regarding evaluation are emphasized and further development concerning self-resilience in concrete structures will be addressed. PMID:28772362
Han, Ning-Xu; Xing, Feng
2016-12-22
A review of the research activities and achievements at Shenzhen University is conducted in this paper concerning the creation and further development of novel microcapsule based self-resilience systems for their application in concrete structures. After a brief description of pioneering works in the field starting about 10 years ago, the principles raised in the relevant research are examined, where fundamental terms related to the concept of resilience are discussed. Several breakthrough points are highlighted concerning the three adopted comprehensive self-resilience systems, namely physical, chemical and microbial systems. The major challenges regarding evaluation are emphasized and further development concerning self-resilience in concrete structures will be addressed.
Case report: Improvement in dissociative symptoms with mixed amphetamine salts.
Scarella, Timothy M; Franzen, Jamie R
2017-01-01
Symptoms of dissociation, including dissociative amnesia, depersonalization, and derealization, commonly develop in individuals subject to chronic and repeated trauma during development. This includes the trauma of environmental inability to facilitate development of adequate cognitive strategies for coping with strong negative emotions. Dissociation likely involves dysregulated balance of prefrontal inhibition of limbic structures and inadequate regulation of attentional bias by both prefrontal and limbic systems. There is currently no established psychopharmacologic treatment for dissociative symptoms. Here the case of a woman with severe dissociative symptoms that were markedly improved with the administration of mixed amphetamine salts is discussed. Potential neurobiologic mechanisms for dissociative symptom improvement with psychostimulants are discussed.
A view of software management issues
NASA Technical Reports Server (NTRS)
Manley, J. H.
1985-01-01
The Software Development Environment (SDE) Panel addressed key programmatic, scope, and structural issues raised by its members and the general audience regarding the proposed software development environment for the Space Station program. The general team approach taken by this group led to a consensus on 18 recommendations to NASA mangament regarding the acquisition and definition of the SDE. This approach was keyed by the initial issues presentation given to the general audience. Additional issues (for a total of 23) were developed by the panelists in their first closed session from which key areas were selected and discussed in open session. These discussions led to key recommendations which are summarized and described.
ERIC Educational Resources Information Center
Barry, Ursula
This report concerns the training requirements of women workers arising from the introduction of new technology in the services sector of the Irish economy. Section 1 discusses the importance of the services sector as a source of employment for women workers. In Section 2, the structure of female employment in the services sector is explored with…
Large space systems technology electronics: Data and power distribution
NASA Technical Reports Server (NTRS)
Dunbar, W. G.
1980-01-01
The development of hardware technology and manufacturing techniques required to meet space platform and antenna system needs in the 1980s is discussed. Preliminary designs for manned and automatically assembled space power system cables, connectors, and grounding and bonding materials and techniques are reviewed. Connector concepts, grounding design requirements, and bonding requirements are discussed. The problem of particulate debris contamination for large structure spacecraft is addressed.
NASA Technical Reports Server (NTRS)
Baker, C. E.
1977-01-01
The program structure is presented. The activities of the thermochemical cycles program are grouped according to the following categories: (1) specific cycle development, (2) support research and technology, (3) cycle evaluation. Specific objectives and status of on-going activities are discussed. Chemical reaction series for the production of hydrogen are presented. Efficiency and economic evaluations are also discussed.
ERIC Educational Resources Information Center
Troy, Warwick G.; And Others
Three types of workshops dealing with racism and sexism were conducted for 1900 incoming university freshmen as part of their orientation program. The methods were a structured discussion model developed by Sedlacek and Brooks (1976), a Starpower simulation workshop, and a movie discussion group. Students were randomly assigned to one of the three…
NASA Technical Reports Server (NTRS)
Sen, S.; Bhattacharya, M.; Schofield, E.; Carranza, S.; O'Dell, S.
2007-01-01
One of the major challenges for long duration human exploration beyond the low Earth orbit and sustained human presence on planetary surfaces would be development of materials that would help minimize the radiation exposure to crew and equipment from the interplanetary radiation environment, This radiation environment consists primarily of a continuous flux of galactic cosmic rays (GCR) and transient but intense fluxes of solar energetic particles (SEP). The potential for biological damage by the relatively low percentage of high-energy heavy-ions in the GCR spectrum far outweigh that due to lighter particles because of their ionizing-power and the quality of the resulting biological damage. Although the SEP spectrum does not contain heavy ions and their energy range is much lower than that for GCRs, they however pose serious risks to astronaut health particularly in the event of a bad solar storm The primary purpose of this paper is to discuss our recent efforts in development and evaluation of materials for minimizing the hazards from the interplanetary radiation environment. Traditionally, addition of shielding materials to spacecrafts has invariably resulted in paying a penalty in terms of additional weight. It would therefore be of great benefit if materials could be developed not only with superior shielding effectiveness but also sufficient structural integrity. Such a multifunctional material could then be considered as an integral part of spacecraft structures. Any proposed radiation shielding material for use in outer space should be composed of nuclei that maximize the likelihood of projectile fragmentation while producing the minimum number of target fragments. A modeling based approach will be presented to show that composite materials using hydrogen-rich epoxy matrices reinforced with polyethylene fibers and/or fabrics could effectively meet this requirement. This paper will discuss the fabrication of such a material for a crewed vehicle. Ln addition, the capability of synthesizing radiation shielding materials for habitat structures primarily from Lunar or Martian in-situ resources will also be presented. Such an approach would significantly _reduce the cost associated with transportation of such materials and structures from earth. Results from radiation exposure measurements will be presented demonstrating the shielding effectiveness of the developed materials. Mechanical testing data will be discussed to illustrate that the specific mechanical properties of the developed composites are comparable to structural aluminum based alloys currently used for the space shuttle and space station.
Active vibration control activities at the LaRC - Present and future
NASA Technical Reports Server (NTRS)
Newsom, J. R.
1990-01-01
The NASA Controls-Structures-Interaction (CSI) program is presented with a description of the ground testing element objectives and approach. The goal of the CSI program is to develop and validate the technology required to design, verify and operate space systems in which the structure and the controls interact beneficially to meet the needs of future NASA missions. The operational Mini-Mast ground testbed and some sample active vibration control experimental results are discussed along with a description of the CSI Evolutionary Model testbed presently under development. Initial results indicate that embedded sensors and actuators are effective in controlling a large truss/reflector structure.
Repair techniques for celion/LARC-160 graphite/polyimide composite structures
NASA Technical Reports Server (NTRS)
Jones, J. S.; Graves, S. R.
1984-01-01
The large stiffness-to-weight and strength-to-weight ratios of graphite composite in combination with the 600 F structural capability of the polyimide matrix can reduce the total structure/TPS weight of reusable space vehicles by 20-30 percent. It is inevitable that with planned usage of GR/PI structural components, damage will occur either in the form of intrinsic flaw growth or mechanical damage. Research and development programs were initiated to develop repair processes and techniques specific to Celion/LARC-160 GR/PI structure with emphasis on highly loaded and lightly loaded compression critical structures for factory type repair. Repair processes include cocure and secondary bonding techniques applied under vacuum plus positive autoclave pressure. Viable repair designs and processes are discussed for flat laminates, honeycomb sandwich panels, and hat-stiffened skin-stringer panels. The repair methodology was verified through structural element compression tests at room temperature and 315 C (600 F).
Ceramic Nanocomposites from Tailor-Made Preceramic Polymers
Mera, Gabriela; Gallei, Markus; Bernard, Samuel; Ionescu, Emanuel
2015-01-01
The present Review addresses current developments related to polymer-derived ceramic nanocomposites (PDC-NCs). Different classes of preceramic polymers are briefly introduced and their conversion into ceramic materials with adjustable phase compositions and microstructures is presented. Emphasis is set on discussing the intimate relationship between the chemistry and structural architecture of the precursor and the structural features and properties of the resulting ceramic nanocomposites. Various structural and functional properties of silicon-containing ceramic nanocomposites as well as different preparative strategies to achieve nano-scaled PDC-NC-based ordered structures are highlighted, based on selected ceramic nanocomposite systems. Furthermore, prospective applications of the PDC-NCs such as high-temperature stable materials for thermal protection systems, membranes for hot gas separation purposes, materials for heterogeneous catalysis, nano-confinement materials for hydrogen storage applications as well as anode materials for secondary ion batteries are introduced and discussed in detail. PMID:28347023
HIV-1 reverse transcriptase and antiviral drug resistance. Part 2.
Das, Kalyan; Arnold, Eddy
2013-04-01
Structures of RT and its complexes combined with biochemical and clinical data help in illuminating the molecular mechanisms of different drug-resistance mutations. The NRTI drugs that are used in combinations have different primary mutation sites. RT mutations that confer resistance to one drug can be hypersensitive to another RT drug. Structure of an RT-DNA-nevirapine complex revealed how NNRTI binding forbids RT from forming a polymerase competent complex. Collective knowledge about various mechanisms of drug resistance by RT has broader implications for understanding and targeting drug resistance in general. In Part 1, we discussed the role of RT in developing HIV-1 drug resistance, structural and functional states of RT, and the nucleoside/nucleotide analog (NRTI) and non-nucleoside (NNRTI) drugs used in treating HIV-1 infections. In this part, we discuss structural understanding of various mechanisms by which RT confers antiviral drug resistance. Copyright © 2013 Elsevier B.V. All rights reserved.
[On the approaches enhancing the structural effectiveness of regional public health system].
Uahakova, E I
2009-01-01
The particular technique of assessment of total extent of population consumption of medical care is discussed. The approach is based on the calculation of the sum of monetary equivalent units of rendering of medical care to population. The additional analysis of its structure according to the forms of medical care is specified. The approaches to the comparison between the existing structure of financing and factual cost criteria of unit of medical care provision on a particular territory are discussed. The example is given of calculation of possible economic benefit in the process of bring the ratio of medical care forms to conformity with the structure of its consumption recommended in the federal program of state guarantees of medical care in Russia. The recommendations are proposed how to reallocate the volumes of financing according the forms of medical care which will become the foundation of more balanced development of regional health care system.
Chemodiversity in Freshwater and Terrestrial Cyanobacteria – a Source for Drug Discovery
Chlipala, George E.; Mo, Shunyan; Orjala, Jimmy
2011-01-01
Cyanobacteria are considered a promising source for new pharmaceutical lead compounds and a large number of chemically diverse and bioactive metabolites have been obtained from cyanobacteria over the last few decades. This review highlights the structural diversity of natural products from freshwater and terrestrial cyanobacteria. The review is divided into three areas: cytotoxic metabolites, protease inhibitors, and antimicrobial metabolites. The first section discusses the potent cytotoxins cryptophycin and tolytoxin. The second section covers protease inhibitors from freshwater and terrestrial cyanobacteria and is divided in five subsections according to structural class: aeruginosins, cyanopeptolins, microviridins, anabaenopeptins, and microginins. Structure activity relationships are discussed within each protease inhibitor class. The third section, antimicrobial metabolites from freshwater and terrestrial cyanobacteria, is divided by chemical class in three subsections: alkaloids, peptides and terpenoids. These examples emphasize the structural diversity and drug development potential of natural products from freshwater and terrestrial cyanobacteria. PMID:21561419
Structural Concepts and Materials for Lunar Exploration Habitats
NASA Technical Reports Server (NTRS)
Belvin, W. Keith; Watson, Judith J.; Singhal, Surendra N.
2006-01-01
A new project within the Exploration Systems Mission Directorate s Technology Development Program at NASA involves development of lightweight structures and low temperature mechanisms for Lunar and Mars missions. The Structures and Mechanisms project is to develop advanced structure technology for the primary structure of various pressurized elements needed to implement the Vision for Space Exploration. The goals are to significantly enhance structural systems for man-rated pressurized structures by 1) lowering mass and/or improving efficient volume for reduced launch costs, 2) improving performance to reduce risk and extend life, and 3) improving manufacturing and processing to reduce costs. The targeted application of the technology is to provide for the primary structure of the pressurized elements of the lunar lander for both sortie and outpost missions, and surface habitats for the outpost missions. The paper presents concepts for habitats that support six month (and longer) lunar outpost missions. Both rigid and flexible habitat wall systems are discussed. The challenges of achieving a multi-functional habitat that provides micro-meteoroid, radiation, and thermal protection for explorers are identified.
The Use of Games in Teaching a Second Language in the Classroom: A Workshop.
ERIC Educational Resources Information Center
Pluto, Joseph A.
Using games in the classroom is discussed as a means of promoting the learning of second language structure, fluency, and culture, and complementing concept development and learning. Attention is directed to the development or adaptation of games to the English as a second language curriculum and the development of games to meet specific needs. It…
NASA Operational Environment Team (NOET) - NASA's key to environmental technology
NASA Technical Reports Server (NTRS)
Cook, Beth
1993-01-01
NOET is a NASA-wide team which supports the research and development community by sharing information both in person and via a computerized network, assisting in specification and standard revisions, developing cleaner propulsion systems, and exploring environmentally compliant alternatives to current processes. NOET's structure, dissemination of materials, electronic information, EPA compliance, specifications and standards, and environmental research and development are discussed.
Designing organizational structures: Key thoughts for development.
Killingsworth, Patricia; Eschenbacher, Lynn
2018-04-01
Current strategies and concepts to consider in developing a system-level organizational structure for the pharmacy enterprise are discussed. There are many different ways to design an organizational structure for the pharmacy enterprise within a health system. The size of the organization, the number of states in which it operates, and the geographic spread and complexity of the pharmacy business lines should be among the key considerations in determining the optimal organizational and decision-making structures for the pharmacy enterprise. The structure needs to support incorporation of the pharmacy leadership (both system-level executives and local leaders) into all strategic planning and discussions at the hospital and health-system levels so that they can directly represent the pharmacy enterprise instead of relying on others to develop strategy on their behalf. It is important that leaders of all aspects of the pharmacy enterprise report through the system's top pharmacy executive, who should be a pharmacist and have a title consistent with those of other leaders reporting at the same organizational level (e.g., chief pharmacy officer). Pharmacy leaders need to be well positioned within an organization to advocate for the pharmacy enterprise and use all resources to the best of their ability. As the scope and complexity of pharmacy services grow, it is critical to ensure that leadership of the pharmacy enterprise is unified under a single pharmacy executive team. Copyright © 2018 by the American Society of Health-System Pharmacists, Inc. All rights reserved.
Elements of Regolith Simulant's Cost Structure
NASA Technical Reports Server (NTRS)
Rickman, Douglas L.
2009-01-01
The cost of lunar regolith simulants is much higher than many users anticipate. After all, it is nothing more than broken rock. This class will discuss the elements which make up the cost structure for simulants. It will also consider which elements can be avoided under certain circumstances and which elements might be altered by the application of additional research and development.
Application of a hierarchical structure stochastic learning automation
NASA Technical Reports Server (NTRS)
Neville, R. G.; Chrystall, M. S.; Mars, P.
1979-01-01
A hierarchical structure automaton was developed using a two state stochastic learning automato (SLA) in a time shared model. Application of the hierarchical SLA to systems with multidimensional, multimodal performance criteria is described. Results of experiments performed with the hierarchical SLA using a performance index with a superimposed noise component of ? or - delta distributed uniformly over the surface are discussed.
Large-scale configuration interaction description of the structure of nuclei around 100Sn and 208Pb
NASA Astrophysics Data System (ADS)
Qi, Chong
2016-08-01
In this contribution I would like to discuss briefly the recent developments of the nuclear configuration interaction shell model approach. As examples, we apply the model to calculate the structure and decay properties of low-lying states in neutron-deficient nuclei around 100Sn and 208Pb that are of great experimental and theoretical interests.
Two different flavours of complexity in financial data
NASA Astrophysics Data System (ADS)
Buonocore, R. J.; Musmeci, N.; Aste, T.; Matteo, T. Di
2016-12-01
We discuss two elements that define the complexity of financial time series: one is the multiscaling property, which is linked to how the statistics of a single time-series changes with the time horizon; the second is the structure of dependency between time-series, which accounts for the collective behaviour, i.e. the market structure. Financial time-series have statistical properties which change with the time horizon and the quantification of such multiscaling property has been successful to distinguish among different degrees of development of markets, monitor the stability of firms and estimate risk. The study of the structure of dependency between time-series with the use of information filtering graphs can reveal important insight on the market structure highlighting risks, stress and portfolio management strategies. In this contribution we highlight achievements, major successes and discuss major challenges and open problems in the study of these two elements of complexity, hoping to attract the interest of more researchers in this research area. We indeed believe that with the advent of the Big Data era, the need and the further development of such approaches, designed to deal with systems with many degrees of freedom, have become more urgent.
Pipelines subject to slow landslide movements: Structural modeling vs field measurement
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bruschi, R.; Glavina, S.; Spinazze, M.
1996-12-01
In recent years finite element techniques have been increasingly used to investigate the behavior of buried pipelines subject to soil movements. The use of these tools provides a rational basis for the definition of minimum wall thickness requirements in landslide crossings. Furthermore the design of mitigation measures or monitoring systems which control the development of undesirable strains in the pipe wall over time, requires a detailed structural modeling. The scope of this paper is to discuss the use of dedicated structural modeling with relevant calibration to field measurements. The strain measurements used were regularly gathered from pipe sections, in twomore » different sites over a period of time long enough to record changes of axial strain due to soil movement. Detailed structural modeling of pipeline layout in both sites and for operating conditions, is applied. Numerical simulations show the influence of the distribution of soil movement acting on the pipeline with regards to the state of strain which can be developed in certain locations. The role of soil nature and direction of relative movements in the definition of loads transferred to the pipeline, is also discussed.« less
Haan, Claude; Behrmann, Iris; Haan, Serge
2010-01-01
Abstract Gain-of-function mutations in the genes encoding Janus kinases have been discovered in various haematologic diseases. Jaks are composed of a FERM domain, an SH2 domain, a pseudokinase domain and a kinase domain, and a complex interplay of the Jak domains is involved in regulation of catalytic activity and association to cytokine receptors. Most activating mutations are found in the pseudokinase domain. Here we present recently discovered mutations in the context of our structural models of the respective domains. We describe two structural hotspots in the pseudokinase domain of Jak2 that seem to be associated either to myeloproliferation or to lymphoblastic leukaemia, pointing at the involvement of distinct signalling complexes in these disease settings. The different domains of Jaks are discussed as potential drug targets. We present currently available inhibitors targeting Jaks and indicate structural differences in the kinase domains of the different Jaks that may be exploited in the development of specific inhibitors. Moreover, we discuss recent chemical genetic approaches which can be applied to Jaks to better understand the role of these kinases in their biological settings and as drug targets. PMID:20132407
Segmentation of human brain using structural MRI.
Helms, Gunther
2016-04-01
Segmentation of human brain using structural MRI is a key step of processing in imaging neuroscience. The methods have undergone a rapid development in the past two decades and are now widely available. This non-technical review aims at providing an overview and basic understanding of the most common software. Starting with the basis of structural MRI contrast in brain and imaging protocols, the concepts of voxel-based and surface-based segmentation are discussed. Special emphasis is given to the typical contrast features and morphological constraints of cortical and sub-cortical grey matter. In addition to the use for voxel-based morphometry, basic applications in quantitative MRI, cortical thickness estimations, and atrophy measurements as well as assignment of cortical regions and deep brain nuclei are briefly discussed. Finally, some fields for clinical applications are given.
Hypersonic airframe structures: Technology needs and flight test requirements
NASA Technical Reports Server (NTRS)
Stone, J. E.; Koch, L. C.
1979-01-01
Hypersonic vehicles, that may be produced by the year 2000, were identified. Candidate thermal/structural concepts that merit consideration for these vehicles were described. The current status of analytical methods, materials, manufacturing techniques, and conceptual developments pertaining to these concepts were reviewed. Guidelines establishing meaningful technology goals were defined and twenty-eight specific technology needs were identified. The extent to which these technology needs can be satisfied, using existing capabilities and facilities without the benefit of a hypersonic research aircraft, was assessed. The role that a research aircraft can fill in advancing this technology was discussed and a flight test program was outlined. Research aircraft thermal/structural design philosophy was also discussed. Programs, integrating technology advancements with the projected vehicle needs, were presented. Program options were provided to reflect various scheduling and cost possibilities.
Application of Various Types of Liposomes in Drug Delivery Systems
Alavi, Mehran; Karimi, Naser; Safaei, Mohsen
2017-01-01
Liposomes, due to their various forms, require further exploration. These structures can deliver both hydrophilic and hydrophobic drugs for cancer, antibacterial, antifungal, immunomodulation, diagnostics, ophtalmica, vaccines, enzymes and genetic elements. Preparation of liposomes results in different properties for these systems. In addition, based on preparation methods, liposomes types can be unilamellar, multilamellar and giant unilamellar; however, there are many factors and difficulties that affect the development of liposome drug delivery structure. In the present review, we discuss some problems that impact drug delivery by liposomes. In addition, we discuss a new generation of liposomes, which is utilized for decreasing the limitation of the conventional liposomes. PMID:28507932
Porosity in Ocean Racing Yacht Composites: a Review
NASA Astrophysics Data System (ADS)
Baley, Christophe; Lan, Marine; Davies, Peter; Cartié, Denis
2015-02-01
Ocean racing yachts are mainly manufactured from carbon/epoxy composites similar to those used by the aeronautical industry but, with some exceptions such as masts, these structures are not produced in autoclaves. This leads to the presence of higher porosity levels. This paper will first present the different types of porosity found in traditional racing yacht structures. Difficulties in evaluating defect levels will then be discussed and published work characterizing the influence of defects will be reviewed. Current developments to improve racing yacht composite quality such as thin ply technology, out-of-autoclave processing and automated fibre placement will then be described, and their implications for porosity will be discussed.
Acoustical, morphological and optical properties of oral rehydration salts (ORS)
NASA Astrophysics Data System (ADS)
George, Preetha Mary; Jayakumar, S.; Divya, P.; Subhashree, N. S.; Ahmed, M. Anees
2015-06-01
Ultrasonic velocity, density and viscosity were measured in different concentrations of oral rehydration salts (ORS) at room temperature 303 k. From the experimental data other related thermodynamic parameters, viz adiabatic compressibility, intermolecular free length, acoustic impedence, relaxation time are calculated. The experimental data were discussed in the light of molecular interaction existing in the liquid mixtures. The results have been discussed in terms of solute-solvent interaction between the components. Structural characterization is important for development of new material. The morphology, structure and grain size of the samples are investigated by SEM. The optical properties of the sample have been studied using UV Visible spectroscopy.
Analysis of multicrystal pump–probe data sets. I. Expressions for the RATIO model
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fournier, Bertrand; Coppens, Philip
2014-08-30
The RATIO method in time-resolved crystallography [Coppenset al.(2009).J. Synchrotron Rad.16, 226–230] was developed for use with Laue pump–probe diffraction data to avoid complex corrections due to wavelength dependence of the intensities. The application of the RATIO method in processing/analysis prior to structure refinement requires an appropriate ratio model for modeling the light response. The assessment of the accuracy of pump–probe time-resolved structure refinements based on the observed ratios was discussed in a previous paper. In the current paper, a detailed ratio model is discussed, taking into account both geometric and thermal light-induced changes.
ERIC Educational Resources Information Center
Michigan Univ., Ann Arbor.
The organization of knowledge related to the development of the environment and the building industry is provided in this index which provides a framework or classification system for a broad range of information. Man's development in terms of environmental structuring and control is discussed as development goals, development cycle, and…
Two Growth Modes of Graphitic Carbon Nanofibers with Herring-Bone Structure
DOE Office of Scientific and Technical Information (OSTI.GOV)
Merkulov, Igor A; Melechko, Anatoli Vasilievich; Wells, Jack C
2005-01-01
A simple mathematical model of the carbon nanofiber catalytic growth process is presented. Two major types of the fiber-catalyst interface shapes have been identified and described having qualitatively different structure in the center of a nanofiber. Presently, we discuss that the appearance of the irregular structure in the nanofiber central area is a result of curved-interface-growth kinematics. We suggest the method to determine the phenomenological parameters of the developed model from experimental data.
Two growth modes of graphitic carbon nanofibers with herring-bone structure
NASA Astrophysics Data System (ADS)
Merkulov, I. A.; Meleshko, A. V.; Wells, J. C.; Cui, H.; Merkulov, V. I.; Simpson, M. L.; Lowndes, D. H.
2005-07-01
A simple mathematical model of the carbon nanofiber catalytic growth process is presented. Two major types of the fiber-catalyst interface shapes have been identified and described having qualitatively different structure in the center of a nanofiber. Presently, we discuss that the appearance of the irregular structure in the nanofiber central area is a result of curved-interface-growth kinematics. We suggest the method to determine the phenomenological parameters of the developed model from experimental data.
Characterisation of pore structures of pharmaceutical tablets: A review.
Markl, Daniel; Strobel, Alexa; Schlossnikl, Rüdiger; Bøtker, Johan; Bawuah, Prince; Ridgway, Cathy; Rantanen, Jukka; Rades, Thomas; Gane, Patrick; Peiponen, Kai-Erik; Zeitler, J Axel
2018-03-01
Traditionally, the development of a new solid dosage form is formulation-driven and less focus is put on the design of a specific microstructure for the drug delivery system. However, the compaction process particularly impacts the microstructure, or more precisely, the pore architecture in a pharmaceutical tablet. Besides the formulation, the pore structure is a major contributor to the overall performance of oral solid dosage forms as it directly affects the liquid uptake rate, which is the very first step of the dissolution process. In future, additive manufacturing is a potential game changer to design the inner structures and realise a tailor-made pore structure. In pharmaceutical development the pore structure is most commonly only described by the total porosity of the tablet matrix. Yet it is of great importance to consider other parameters to fully resolve the interplay between microstructure and dosage form performance. Specifically, tortuosity, connectivity, as well as pore shape, size and orientation all impact the flow paths and play an important role in describing the fluid flow in a pharmaceutical tablet. This review presents the key properties of the pore structures in solid dosage forms and it discusses how to measure these properties. In particular, the principles, advantages and limitations of helium pycnometry, mercury porosimetry, terahertz time-domain spectroscopy, nuclear magnetic resonance and X-ray computed microtomography are discussed. Copyright © 2018 Elsevier B.V. All rights reserved.
A four-panel enclosure protects from explosion
NASA Technical Reports Server (NTRS)
King, P. V.
1972-01-01
Development of multi-layered baffle as enclosure to protect personnel from effects of explosion during production of ammunition is discussed. Advantages of new system over previous systems are described. Illustration of typical panel structure is provided.
Plasma Desorption Mass Spectrometry: Coming of Age.
ERIC Educational Resources Information Center
Cotter, Robert J.
1988-01-01
Discusses the history and development of Plasma Desorption Mass Spectrometry to determine molecular weights and structures of proteins and polymers. Outlines theory, instrumentation, and sample preparation commonly used. Gives several examples of resulting spectra. (ML)
DOT National Transportation Integrated Search
1982-08-01
This report discusses the level and nature of world motor vehicle demand for the period 1980-1990. A general understanding of the structure of motor vehicle demand is developed. Published demand forecasts, varying widely, are gathered and their discr...
Evolution of an Aggregate-Based Community Health Curriculum.
ERIC Educational Resources Information Center
Segall, Mary; McKay, Rose
1984-01-01
Discusses the graduate program in community health nursing at the University of Colorado that is structured according to the aggregate/family and group model. Describes the development of the program and its evaluation. (JOW)
Using an Instructional LAN to Teach a Statistics Course.
ERIC Educational Resources Information Center
Barnes, J. Wesley; And Others
1988-01-01
Discusses a computer assisted learning system for engineering statistics based on personalized system of instruction methods. Describes the system's network, development, course structure, programing, and security. Lists the benefits of the system. (MVL)
Advances in Lithium-Sulfur Rechargeable Batteries Powering the Electronic Future
NASA Technical Reports Server (NTRS)
Skotheim, Terje; Akridge, Jim; Hyland, Bob
2001-01-01
This viewgraph presentation discusses the Moltech Corporation's history and structure, power systems development, product attributes, Li-S adapted products, cell construction, specific energy comparisons, and product requirements necessary for use in spacecraft applications.
NASA Technical Reports Server (NTRS)
1992-01-01
Daniel S. Goldin (NASA Administrator) announces the reconstruction of several NASA programs and management structural changes. The upcoming developments for Space Station Freedom, the Office of Space Science Applications (OSSA), and the field of Aeronautics are discussed.
Research and Development in a Department of Education.
ERIC Educational Resources Information Center
Hawley, Willis D.; Sheekey, Arthur
1979-01-01
This outline of the organizational structure for the new department of education lists propositions to guide the reorganization of educational research and innovation activities and discusses the potential functions of several new department offices. (RLV)
DOE Office of Scientific and Technical Information (OSTI.GOV)
McDonald, J.R.; Minor, J.E.; Mehta, K.C.
1975-11-01
Criteria are prescribed and guidance is provided for professional personnel who are involved with the evaluation of existing buildings and facilities at Site 300 near Livermore, California to resist the possible effects of extreme winds and tornadoes. The development of parameters for the effects of tornadoes and extreme winds and guidelines for evaluation and design of structures are presented. The investigations conducted are summarized and the techniques used for arriving at the combined tornado and extreme wind risk model are discussed. The guidelines for structural design methods for calculating pressure distributions on walls and roofs of structures and methods formore » accommodating impact loads from missiles are also presented. (auth)« less
Maximum Likelihood Estimation with Emphasis on Aircraft Flight Data
NASA Technical Reports Server (NTRS)
Iliff, K. W.; Maine, R. E.
1985-01-01
Accurate modeling of flexible space structures is an important field that is currently under investigation. Parameter estimation, using methods such as maximum likelihood, is one of the ways that the model can be improved. The maximum likelihood estimator has been used to extract stability and control derivatives from flight data for many years. Most of the literature on aircraft estimation concentrates on new developments and applications, assuming familiarity with basic estimation concepts. Some of these basic concepts are presented. The maximum likelihood estimator and the aircraft equations of motion that the estimator uses are briefly discussed. The basic concepts of minimization and estimation are examined for a simple computed aircraft example. The cost functions that are to be minimized during estimation are defined and discussed. Graphic representations of the cost functions are given to help illustrate the minimization process. Finally, the basic concepts are generalized, and estimation from flight data is discussed. Specific examples of estimation of structural dynamics are included. Some of the major conclusions for the computed example are also developed for the analysis of flight data.
Development of advanced acreage estimation methods
NASA Technical Reports Server (NTRS)
Guseman, L. F., Jr. (Principal Investigator)
1982-01-01
The development of an accurate and efficient algorithm for analyzing the structure of MSS data, the application of the Akaiki information criterion to mixture models, and a research plan to delineate some of the technical issues and associated tasks in the area of rice scene radiation characterization are discussed. The AMOEBA clustering algorithm is refined and documented.
Studies for the 3-Dimensional Structure, Composition, and Dynamic of Io's Atmosphere
NASA Technical Reports Server (NTRS)
Smyth, William H.
2001-01-01
Research work is discussed for the following: (1) the exploration of new H and Cl chemistry in Io's atmosphere using the already developed two-dimensional multi-species hydrodynamic model of Wong and Smyth; and (2) for the development of a new three-dimensional multi-species hydrodynamic model for Io's atmosphere.
Naturalism and Educational Administration: New Directions
ERIC Educational Resources Information Center
Evers, Colin W.; Lakomski, Gabriele
2015-01-01
The purpose of this paper is to outline some new developments in a mature research program that sees administrative theory as cohering with natural science and uses a coherence theory of epistemic justification to shape the content and structure of administrative theory. Three main developments are discussed. First, the paper shows how to deal…
Integrated and Early Childhood Education: Preparation for Social Development.
ERIC Educational Resources Information Center
Chitepo, Victoria
This keynote address first briefly reviews the historical nature and structure of education in Zimbabwe prior to independence. Then, the theme of the seminar (integrated education as a preparation for social development), as well as related policy issues are stated. Educational goals of the government of Zimbabwe are discussed. Concluding remarks…
ERIC Educational Resources Information Center
Allen, Heather Willis; Negueruela-Azarola, Eduardo
2010-01-01
Although the professional development of graduate students in foreign language (FL) departments is of critical importance, discussion of its significance and evolution was all but absent in the 2007 Modern Language Association report "Foreign Languages and Higher Education: New Structures for a Changed World," a document advocating curricular and…
ERIC Educational Resources Information Center
Crowell, Doris
This report describes a curriculum, based on stated performance objectives, which was developed and implemented by the Kamehameha Early Education Program (KEEP). The structure of the mathematics and reading curriculum is described briefly and the use of performance objectives in evaluating student progress is discussed. Advantages of the…
Organisational Conditions to Boost or Limit Professional Development in the Cypriot Primary School
ERIC Educational Resources Information Center
Loizou, Florentia
2014-01-01
In this article, I examine which organisational conditions can promote or limit the professional development of teachers in the Cypriot primary school. The discussion builds on findings from a study I conducted about Cypriot primary school teachers' reflective practices (Loizou 2011). The study was qualitative and used semi-structured interviews…
Teacher Education: Privileges and Problems Associated with Reading Programs in Developing Countries.
ERIC Educational Resources Information Center
Robertson, Jean E.
The problems of teacher education in developing nations are discussed. Blending new knowledge with cultural heritage so that the personal cultural synthesis demanded of new literates is effected without disrupting social structures is complicated by the language problem. The impact of the written word on a society dependent on oral communication…
[Development of an Atypical Response Scale.
ERIC Educational Resources Information Center
Mendelsohn, Mark; Linden, James
The development of an objective diagnostic scale to measure atypical behavior is discussed. The Atypical Response Scale (ARS) is a structured projective test consisting of 17 items, each weighted 1, 2, or 3, that were tested for convergence and reliability. ARS may be individually or group administered in 10-15 minutes; hand scoring requires 90…
An Evaluation Model for Competency Based Teacher Preparatory Programs.
ERIC Educational Resources Information Center
Denton, Jon J.
This discussion describes an evaluation model designed to complement a curriculum development project, the primary goal of which is to structure a performance based program for preservice teachers. Data collected from the implementation of this four-phase model can be used to make decisions for developing and changing performance objectives and…
ACTEX flight experiment: development issues and lessons learned
NASA Astrophysics Data System (ADS)
Schubert, S. R.
1993-09-01
The ACTEX flight experiment is scheduled for launch and to begin its on orbit operations in early 1994. The objective of the ACTEX experiment is to demonstrate active vibration control in space, using the smart structure technology. This paper discusses primarily the hardware development and program management issues associated with delivering low cost flight experiments.
ERIC Educational Resources Information Center
Lionberger, Herbert F.
The need for an information development system for farmers is discussed in this paper. Issues and alternatives are described in terms of the research-extension-teaching trinity, extension services, role combinations, specialist advisor issues, innovations, research orientation, reward structures, and information services. Information gathered in…
Research and Clinical Center for Child Development Annual Report, 1997-1998, No. 21.
ERIC Educational Resources Information Center
Chen, Shing-Jen, Ed.; Furutsuka, Takashi, Ed.; Shirotani, Yukari, Ed.
This annual report discusses several topics related to the work of the Clinical Center for Child Development at Hokkaido University in Sapporo, Japan. The articles are: (1) "The Study of Mothers' Parenting Practices with Child's Withdrawn Behaviors and Temperament" (Sueko Toda); (2) "Structure, Developmental Change, and Sex…
Gender Issues in Youth Development Programs.
ERIC Educational Resources Information Center
Nicholson, Heather Johnston; And Others
This document discusses the question of gender in youth development programs, those structured activities and opportunities sponsored by organizations other than schools and offered outside of school hours. Many of these organizations offer programs for people of all ages but the clear focus of this paper is early adolescence, about ages 10 to 15.…
NASA Technical Reports Server (NTRS)
Oconnell, R. F.; Hassig, H. J.; Radovcich, N. A.
1976-01-01
Results of a study of the development of flutter modules applicable to automated structural design of advanced aircraft configurations, such as a supersonic transport, are presented. Automated structural design is restricted to automated sizing of the elements of a given structural model. It includes a flutter optimization procedure; i.e., a procedure for arriving at a structure with minimum mass for satisfying flutter constraints. Methods of solving the flutter equation and computing the generalized aerodynamic force coefficients in the repetitive analysis environment of a flutter optimization procedure are studied, and recommended approaches are presented. Five approaches to flutter optimization are explained in detail and compared. An approach to flutter optimization incorporating some of the methods discussed is presented. Problems related to flutter optimization in a realistic design environment are discussed and an integrated approach to the entire flutter task is presented. Recommendations for further investigations are made. Results of numerical evaluations, applying the five methods of flutter optimization to the same design task, are presented.
Cost-efficient manufacturing of composite structures
NASA Technical Reports Server (NTRS)
Freeman, W. Tom; Davis, John G.; Johnston, Norman J.
1991-01-01
The Advanced Composites Technology (ACT) program is seeking research breakthroughs that will allow structures made of graphite epoxy materials to replace metals in the wings and fuselages of future aircrafts. NASA's goals are to reduce acquisition cost by 20 to 25 percent, structural weight for a resized aircraft by 40 to 50 percent, and the number of parts by half compared to current production aluminum aircraft. The innovative structural concepts, materials, and fabrication techniques emerging from the ACT program are described, and the relationship between aerospace developments and industrial, commercial, and sporting goods applications are discussed.
Dynamic and structural control utilizing smart materials and structures
NASA Technical Reports Server (NTRS)
Rogers, C. A.; Robertshaw, H. H.
1989-01-01
An account is given of several novel 'smart material' structural control concepts that are currently under development. The thrust of these investigations is the evolution of intelligent materials and structures superceding the recently defined variable-geometry trusses and shape memory alloy-reinforced composites; the substances envisioned will be able to autonomously evaluate emergent environmental conditions and adapt to them, and even change their operational objectives. While until now the primary objective of the developmental efforts presently discussed has been materials that mimic biological functions, entirely novel concepts may be formulated in due course.
Tong, Allison; Lopez-Vargas, Pamela; Howell, Martin; Phoon, Richard; Johnson, David; Campbell, Denise; Walker, Rowan G; Craig, Jonathan C
2012-12-01
Consumer involvement in guideline development is advocated, but minimal participation, such as a nominated consumer representative on a guideline working group, can inhibit their decision-making power and contribution. Little is known about how to involve consumers more effectively in guideline development. To describe a targeted approach for involving consumers actively in guideline development, by focusing on topic and outcome selection, and to discuss the impact on content and structure of the final guideline. Descriptive study. Patients and carers (n = 24) from a tertiary hospital in Sydney attended three structured peer-facilitated workshops to complete group-based exercises on topic and outcome selection for guidelines for early stage chronic kidney disease. These workshops were run in parallel with the guideline-writing group. For each exercise, participants formed small groups and facilitated their own discussion, recorded their responses and presented them to the wider group. The topics and outcomes identified were fed back to the guideline writers. The participants actively engaged in the workshop discussions and articulated topics and outcomes they perceived should be included in clinical guidelines. Four main changes to guideline-related outputs were observed. A new guideline subtopic was introduced, guidelines were consumer-endorsed, guideline recommendations and suggestions for clinical care were augmented with consumer-focused issues, and plain English guidelines were developed. Consumer workshops in parallel and feeding into guideline development can be a feasible and effective approach for active consumer contribution. This process can inform the development of both consumer-focused guidelines for clinicians and specific versions for consumers. © 2011 Blackwell Publishing Ltd.
Mechanical forces as information: an integrated approach to plant and animal development
Hernández-Hernández, Valeria; Rueda, Denisse; Caballero, Lorena; Alvarez-Buylla, Elena R.; Benítez, Mariana
2014-01-01
Mechanical forces such as tension and compression act throughout growth and development of multicellular organisms. These forces not only affect the size and shape of the cells and tissues but are capable of modifying the expression of genes and the localization of molecular components within the cell, in the plasma membrane, and in the plant cell wall. The magnitude and direction of these physical forces change with cellular and tissue properties such as elasticity. Thus, mechanical forces and the mesoscopic fields that emerge from their local action constitute important sources of positional information. Moreover, physical and biochemical processes interact in non-linear ways during tissue and organ growth in plants and animals. In this review we discuss how such mechanical forces are generated, transmitted, and sensed in these two lineages of multicellular organisms to yield long-range positional information. In order to do so we first outline a potentially common basis for studying patterning and mechanosensing that relies on the structural principle of tensegrity, and discuss how tensegral structures might arise in plants and animals. We then provide some examples of morphogenesis in which mechanical forces appear to act as positional information during development, offering a possible explanation for ubiquitous processes, such as the formation of periodic structures. Such examples, we argue, can be interpreted in terms of tensegral phenomena. Finally, we discuss the hypothesis of mechanically isotropic points as a potentially generic mechanism for the localization and maintenance of stem-cell niches in multicellular organisms. This comparative approach aims to help uncovering generic mechanisms of morphogenesis and thus reach a better understanding of the evolution and development of multicellular phenotypes, focusing on the role of physical forces in these processes. PMID:24959170
Mechanical forces as information: an integrated approach to plant and animal development.
Hernández-Hernández, Valeria; Rueda, Denisse; Caballero, Lorena; Alvarez-Buylla, Elena R; Benítez, Mariana
2014-01-01
Mechanical forces such as tension and compression act throughout growth and development of multicellular organisms. These forces not only affect the size and shape of the cells and tissues but are capable of modifying the expression of genes and the localization of molecular components within the cell, in the plasma membrane, and in the plant cell wall. The magnitude and direction of these physical forces change with cellular and tissue properties such as elasticity. Thus, mechanical forces and the mesoscopic fields that emerge from their local action constitute important sources of positional information. Moreover, physical and biochemical processes interact in non-linear ways during tissue and organ growth in plants and animals. In this review we discuss how such mechanical forces are generated, transmitted, and sensed in these two lineages of multicellular organisms to yield long-range positional information. In order to do so we first outline a potentially common basis for studying patterning and mechanosensing that relies on the structural principle of tensegrity, and discuss how tensegral structures might arise in plants and animals. We then provide some examples of morphogenesis in which mechanical forces appear to act as positional information during development, offering a possible explanation for ubiquitous processes, such as the formation of periodic structures. Such examples, we argue, can be interpreted in terms of tensegral phenomena. Finally, we discuss the hypothesis of mechanically isotropic points as a potentially generic mechanism for the localization and maintenance of stem-cell niches in multicellular organisms. This comparative approach aims to help uncovering generic mechanisms of morphogenesis and thus reach a better understanding of the evolution and development of multicellular phenotypes, focusing on the role of physical forces in these processes.
Recent progress in the structure control of Pd–Ru bimetallic nanomaterials
Wu, Dongshuang; Kusada, Kohei; Kitagawa, Hiroshi
2016-01-01
Abstract Pd and Ru are two key elements of the platinum-group metals that are invaluable to areas such as catalysis and energy storage/transfer. To maximize the potential of the Pd and Ru elements, significant effort has been devoted to synthesizing Pd–Ru bimetallic materials. However, most of the reports dealing with this subject describe phase-separated structures such as near-surface alloys and physical mixtures of monometallic nanoparticles (NPs). Pd–Ru alloys with homogenous structure and arbitrary metallic ratio are highly desired for basic scientific research and commercial material design. In the past several years, with the development of nanoscience, Pd–Ru bimetallic alloys with different architectures including heterostructure, core-shell structure and solid-solution alloy were successfully synthesized. In particular, we have now reached the stage of being able to obtain Pd–Ru solid-solution alloy NPs over the whole composition range. These Pd–Ru bimetallic alloys are better catalysts than their parent metal NPs in many catalytic reactions, because the electronic structures of Pd and Ru are modified by alloying. In this review, we describe the recent development in the structure control of Pd–Ru bimetallic nanomaterials. Aiming for a better understanding of the synthesis strategies, some fundamental details including fabrication methods and formation mechanisms are discussed. We stress that the modification of electronic structure, originating from different nanoscale geometry and chemical composition, profoundly affects material properties. Finally, we discuss open issues in this field. PMID:27877905
A Review of Wind Project Financing Structures in the USA
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bolinger, Mark A; Harper, John; Karcher, Matthew
2008-09-24
The rapid pace of wind power development in the U.S. over the last decade has outstripped the ability of most project developers to provide adequate equity capital and make efficient use of project-related tax benefits. In response, the sector has created novel project financing structures that feature varying combinations of equity capital from project developers and third-party tax-oriented investors, and in some cases commercial debt. While their origins stem from variations in the financial capacity and business objectives of wind project developers, as well as the risk tolerances and objectives of equity and debt providers, each structure is, at itsmore » core, designed to manage project risk and allocate federal tax incentives to those entities that can use them most efficiently. This article surveys the six principal financing structures through which most new utility-scale wind projects (excluding utility-owned projects) in the U.S. have been financed from 1999 to the present. These structures include simple balance-sheet finance, several varieties of all-equity special allocation partnership 'flip' structures, and two leveraged structures. In addition to describing each structure's mechanics, the article also discusses its rationale for use, the types of investors that find it appealing and why, and its relative frequency of use in the market. The article concludes with a generalized summary of how a developer might choose one structure over another.« less
In Situ Resource-Based Lunar and Martian Habitat Structures Development at NASA/MSFC
NASA Technical Reports Server (NTRS)
Bodiford, Melanie P.; Fiske, Michael R.; McGregory, Walter; Pope, Regina D.
2005-01-01
As the nation prepares to return to the Moon and subsequently to Mars, it is apparent that the viability of long duration visits with appropriate radiation shielding/crew protection, hinges on the development of habitat structures, preferably in advance of a manned landing, and preferably utilizing in-situ resources. A relatively large number of habitat structure configurations can be developed from a relatively small set of in-situ resource-based construction products, including, blocks, raw regolith, reinforced concrete, and glass products. A much larger group of habitat designs can be developed when "imported" material are brought from Earth, including thin films and liners, and foldable, or expandable metal structures. These, and other technologies have been identified, and subjected to a rigorous trade study evaluation with respect to exploration and other performance criteria. In this paper, results of this trade study will be presented, as well as various habitat structure design concepts and concepts for construction automation. Results of initial tests aimed at concrete, block and glass production using Lunar regolith simulants will also be presented. Key issues and concerns will be discussed, as well as design concepts for a Lunar environment testbed to be developed at MSFC's Microgravity Development Laboratory. (MDL).
In-situ Resource-based Lunar and Martian Habitat Structures Development at NASA/MSFC
NASA Technical Reports Server (NTRS)
Bodiford, Melanie P.; Burks, Kevin H.; Fiske, Michael R.; Strong, Janet D.; McGregor, Walter
2005-01-01
As the nation prepares to return to the Moon and subsequently to Mars, it is apparent that the viability of long duration visits with appropriate radiation shielding/crew protection, hinges on the development of habitat structures, preferably in advance of a manned landing, and preferably utilizing in-situ resources. A relatively large number of habitat structure configurations can be developed from a relatively small set of in-situ resource-based construction products, including, blocks, raw regolith, reinforced concrete, and glass products. A much larger group of habitat designs can be developed when "imported" material are brought from Earth, including thin films and liners, and foldable, or expandable metal structures. These, and other technologies have been identified, and subjected to a rigorous trade study evaluation with respect to exploration and other performance criteria. In this paper, results of this trade study will be presented, as well as various habitat structure design concepts and concepts for construction automation. Results of initial tests aimed at concrete, block and glass production using Lunar regolith simulants will also be presented. Key issues and concerns will be discussed, as well as design concepts for a Lunar environment testbed to be developed at MSFC's Microgravity Development Laboratory (MDL).
Proceedings of the Conference Arctic '85; Civil Engineering in the Artic offshore
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bennett, F.L.; Machemehl, J.L.
1985-01-01
Topics of the 1985 Conference included: Arctic construction, Arctic foundation, Arctic structures, and ocean effects. Arctic terminals and coastal offshore bases, protecting the Arctic environment, and probabilistic methods in Arctic offshore engineering were also discussed. Ice mechanics, marine pipelines in the Arctic, and the role of universities in training civil engineers for Arctic offshore development were highlighted. Sessions on remote sensing, surveying, and mapping were included, and offshore installations in the Bering Sea were discussed. Another topic of discussion was research in Civil Engineering for development of the Arctic offshore. The overall thrust of the conference was the application ofmore » Arctic offshore engineering principles and research in the field of oil and gas exploration and exploitation activity.« less
Tuned grid generation with ICEM CFD
NASA Technical Reports Server (NTRS)
Wulf, Armin; Akdag, Vedat
1995-01-01
ICEM CFD is a CAD based grid generation package that supports multiblock structured, unstructured tetrahedral and unstructured hexahedral grids. Major development efforts have been spent to extend ICEM CFD's multiblock structured and hexahedral unstructured grid generation capabilities. The modules added are: a parametric grid generation module and a semi-automatic hexahedral grid generation module. A fully automatic version of the hexahedral grid generation module for around a set of predefined objects in rectilinear enclosures has been developed. These modules will be presented and the procedures used will be described, and examples will be discussed.
Test method development for structural characterization of fiber composites at high temperatures
NASA Technical Reports Server (NTRS)
Mandell, J. F.; Grande, D. H.; Edwards, B.
1985-01-01
Test methods used for structural characterization of polymer matrix composites can be applied to glass and ceramic matrix composites only at low temperatures. New test methods are required for tensile, compressive, and shear properties of fiber composites at high temperatures. A tensile test which should be useful to at least 1000 C has been developed and used to characterize the properties of a Nicalon/glass composite up to the matrix limiting temperature of 600 C. Longitudinal and transverse unidirectional composite data are presented and discussed.
NASA Astrophysics Data System (ADS)
Conboy, Kieran; Lang, Michael
This chapter outlines the alternative perspectives of "rationalism" and "improvisation" within information systems development and describes the major shortcomings of each. It then discusses how these shortcomings manifested themselves within an e-government case study where a "structured" requirements management method was employed. Although this method was very prescriptive and firmly rooted in the "rational" paradigm, it was observed that users often resorted to improvised behaviour, such as privately making decisions on how certain aspects of the method should or should not be implemented.
A cognitive developmental approach to variability in the psychotherapeutic process with adolescents.
Gunning, C; Verheij, F
1990-01-01
Formulated from a cognitive frame of reference, psychodynamic therapy can be viewed as acting on one of the three aspects (feeling, thought, action) in order to influence or change the client's action and thought schemes. In this paper the consequences of the interaction of cognition and emotion for psychotherapeutic practice with adolescents are explored. Knowledge of cognitive development is supposed to be important for the therapist because, from Piaget's viewpoint, the structures of affect are cognitive structures. Moreover a great variability exists in cognitive development between adolescents. This variability is due to individual, family and social variables. The cognitive structural developmental model, the relation between emotional and cognitive development and the afore-mentioned variables are discussed. Consequences are psychotherapeutic practice with adolescents are described and short case histories are given. The authors conclude that in psychotherapeutic practice psychodynamic theory and cognitive structural theory can complete each other.
Development of a composite geodetic structure for space construction, phase 1A
NASA Technical Reports Server (NTRS)
1980-01-01
The development of a geodetic beam and beam builder for on orbit construction of large truss type space structures is discussed. The geodetic beam is a lightweight, open lattice structure composed of an equilateral gridwork of crisscrossing rods. The beam provides a high degree of stiffness and minimizes structural distortion, due to temperature gradients, through the incorporation of a new graphite and glass reinforced thermoplastic composite material with a low coefficient of thermal expansion. A low power consuming, high production rate, beam builder automatically fabricates the geodetic beams in space using rods preprocessed on Earth. Three areas of the development are focused upon; (1) geodetic beam designs for local attachment of equipment or beam to beam joining in a parallel or crossing configurations, (2) evaluation of long life pultruded rods capable of service temperatures higher than possible with the HMS/P1700 rod material, and (3) evalaution of high temperature joint encapsulant materials.
NASA Astrophysics Data System (ADS)
Adams, L. R.; Vonroos, A.
1985-04-01
An investigation being conducted by Astro Aerospace Corporation (Astro) for Jet Propulsion Laboratory in which efficient structures for geosynchronous spacecraft solar arrays are being developed is discussed. Recent developments in solar blanket technology, including the introduction of ultrathin (50 micrometer) silicon solar cells with conversion efficiencies approaching 15 percent, have resulted in a significant increase in blanket specific power. System specific power depends not only on blanket mass but also on the masses of the support structure and deployment mechanism. These masses must clearly be reduced, not only to minimize launch weight, but also to increase array natural frequency. The solar array system natural frequency should be kept high in order to reduce the demands on the attitude control system. This goal is approached by decreasing system mass, by increasing structural stiffness, and by partitioning the blanket. As a result of this work, a highly efficient structure for deploying a solar array was developed.
National and Local Economic Structures: Conflicting Views of Rural Education.
ERIC Educational Resources Information Center
Howley, Craig B.
1992-01-01
Compares and contrasts two economic views, political economy and neoclassical economics, as they pertain to the development of human capital and education in rural areas. The concluding discussion draws implications for rural educators. (Author/KS)
Synthesis of temperature and solvent-resistant polymers
NASA Technical Reports Server (NTRS)
Webster, J. A.; Patterson, W. J.; Moffett, R. L.; Morris, D. E.
1972-01-01
Development of silicone polymers, polyimides, and polyisocyanurates for use as insulation, coatings, or adhesives under adverse environmental conditions is discussed. Chemical structure of the organic compounds is presented. Physical and mechanical properties of the compounds are analyzed.
WLN's Database: New Directions.
ERIC Educational Resources Information Center
Ziegman, Bruce N.
1988-01-01
Describes features of the Western Library Network's database, including the database structure, authority control, contents, quality control, and distribution methods. The discussion covers changes in distribution necessitated by increasing telecommunications costs and the development of optical data disk products. (CLB)
Multiple Approaches to Design Education
ERIC Educational Resources Information Center
Fox, Richard L.; And Others
1974-01-01
Discusses implementation of Sloan Foundation projects at the Case Western School of Engineering, including the development of a computer assisted mechanical structural design course, the establishment of a complex systems laboratory, and personnel views of industry-university design projects. (CC)
User's Guide for a Computerized Track Maintenance Simulation Cost Methodology
DOT National Transportation Integrated Search
1982-02-01
This User's Guide describes the simulation cost modeling technique developed for costing of maintenance operations of track and its component structures. The procedure discussed provides for separate maintenance cost entries to be associated with def...
Icosahedrons: A Multifaceted Project.
ERIC Educational Resources Information Center
Strazdin, Ray
2000-01-01
Discusses a project focusing on icosahedrons that combines geometry, structure, graphic design, animation, motion, and mechanical and freehand drawing with ancient Greek catapult mechanics. Includes directions on how to both construct a template and develop the pattern for the icosahedrons. (CMK)
Jenders, Robert A.; Osheroff, Jerome A.; Sittig, Dean F.; Pifer, Eric A.; Teich, Jonathan M
2007-01-01
Background: Ample evidence exists that clinical decision support (CDS) can improve clinician performance. Nevertheless, additional evidence demonstrates that clinicians still do not perform adequately in many instances. This suggests an ongoing need for implementation of CDS, in turn prompting development of a roadmap for national action regarding CDS. Objective: Develop practical advice to aid CDS implementation in order to improve clinician performance. Method: Structured group interview during a roundtable discussion by medical directors of information systems (N = 30), with subsequent review by participants and synthesis. Results: Participant consensus was that CDS should be comprehensive and should involve techniques such as order sets and facilitated documentation as well as alerts; should be subject to ongoing feedback; and should flow from and be governed by an organization’s clinical goals. Conclusion: A structured roundtable discussion of clinicians experienced in health information technology can yield practical, consensus advice for implementation of CDS. PMID:18693858
TOPICS IN THEORY OF GENERALIZED PARTON DISTRIBUTIONS
DOE Office of Scientific and Technical Information (OSTI.GOV)
Radyushkin, Anatoly V.
Several topics in the theory of generalized parton distributions (GPDs) are reviewed. First, we give a brief overview of the basics of the theory of generalized parton distributions and their relationship with simpler phenomenological functions, viz. form factors, parton densities and distribution amplitudes. Then, we discuss recent developments in building models for GPDs that are based on the formalism of double distributions (DDs). A special attention is given to a careful analysis of the singularity structure of DDs. The DD formalism is applied to construction of a model GPDs with a singular Regge behavior. Within the developed DD-based approach, wemore » discuss the structure of GPD sum rules. It is shown that separation of DDs into the so-called ``plus'' part and the $D$-term part may be treated as a renormalization procedure for the GPD sum rules. This approach is compared with an alternative prescription based on analytic regularization.« less
A Mobile Satellite Experiment (MSAT-X) network definition
NASA Technical Reports Server (NTRS)
Wang, Charles C.; Yan, Tsun-Yee
1990-01-01
The network architecture development of the Mobile Satellite Experiment (MSAT-X) project for the past few years is described. The results and findings of the network research activities carried out under the MSAT-X project are summarized. A framework is presented upon which the Mobile Satellite Systems (MSSs) operator can design a commercial network. A sample network configuration and its capability are also included under the projected scenario. The Communication Interconnection aspect of the MSAT-X network is discussed. In the MSAT-X network structure two basic protocols are presented: the channel access protocol, and the link connection protocol. The error-control techniques used in the MSAT-X project and the packet structure are also discussed. A description of two testbeds developed for experimentally simulating the channel access protocol and link control protocol, respectively, is presented. A sample network configuration and some future network activities of the MSAT-X project are also presented.
Protein Crystallography in Vaccine Research and Development.
Malito, Enrico; Carfi, Andrea; Bottomley, Matthew J
2015-06-09
The use of protein X-ray crystallography for structure-based design of small-molecule drugs is well-documented and includes several notable success stories. However, it is less well-known that structural biology has emerged as a major tool for the design of novel vaccine antigens. Here, we review the important contributions that protein crystallography has made so far to vaccine research and development. We discuss several examples of the crystallographic characterization of vaccine antigen structures, alone or in complexes with ligands or receptors. We cover the critical role of high-resolution epitope mapping by reviewing structures of complexes between antigens and their cognate neutralizing, or protective, antibody fragments. Most importantly, we provide recent examples where structural insights obtained via protein crystallography have been used to design novel optimized vaccine antigens. This review aims to illustrate the value of protein crystallography in the emerging discipline of structural vaccinology and its impact on the rational design of vaccines.
Protein Crystallography in Vaccine Research and Development
Malito, Enrico; Carfi, Andrea; Bottomley, Matthew J.
2015-01-01
The use of protein X-ray crystallography for structure-based design of small-molecule drugs is well-documented and includes several notable success stories. However, it is less well-known that structural biology has emerged as a major tool for the design of novel vaccine antigens. Here, we review the important contributions that protein crystallography has made so far to vaccine research and development. We discuss several examples of the crystallographic characterization of vaccine antigen structures, alone or in complexes with ligands or receptors. We cover the critical role of high-resolution epitope mapping by reviewing structures of complexes between antigens and their cognate neutralizing, or protective, antibody fragments. Most importantly, we provide recent examples where structural insights obtained via protein crystallography have been used to design novel optimized vaccine antigens. This review aims to illustrate the value of protein crystallography in the emerging discipline of structural vaccinology and its impact on the rational design of vaccines. PMID:26068237
Electron crystallography and aquaporins.
Schenk, Andreas D; Hite, Richard K; Engel, Andreas; Fujiyoshi, Yoshinori; Walz, Thomas
2010-01-01
Electron crystallography of two-dimensional (2D) crystals can provide information on the structure of membrane proteins at near-atomic resolution. Originally developed and used to determine the structure of bacteriorhodopsin (bR), electron crystallography has recently been applied to elucidate the structure of aquaporins (AQPs), a family of membrane proteins that form pores mostly for water but also other solutes. While electron crystallography has made major contributions to our understanding of the structure and function of AQPs, structural studies on AQPs, in turn, have fostered a number of technical developments in electron crystallography. In this contribution, we summarize the insights electron crystallography has provided into the biology of AQPs, and describe technical advancements in electron crystallography that were driven by structural studies on AQP 2D crystals. In addition, we discuss some of the lessons that were learned from electron crystallographic work on AQPs. Copyright © 2010 Elsevier Inc. All rights reserved.
A Framework for Preliminary Design of Aircraft Structures Based on Process Information. Part 1
NASA Technical Reports Server (NTRS)
Rais-Rohani, Masoud
1998-01-01
This report discusses the general framework and development of a computational tool for preliminary design of aircraft structures based on process information. The described methodology is suitable for multidisciplinary design optimization (MDO) activities associated with integrated product and process development (IPPD). The framework consists of three parts: (1) product and process definitions; (2) engineering synthesis, and (3) optimization. The product and process definitions are part of input information provided by the design team. The backbone of the system is its ability to analyze a given structural design for performance as well as manufacturability and cost assessment. The system uses a database on material systems and manufacturing processes. Based on the identified set of design variables and an objective function, the system is capable of performing optimization subject to manufacturability, cost, and performance constraints. The accuracy of the manufacturability measures and cost models discussed here depend largely on the available data on specific methods of manufacture and assembly and associated labor requirements. As such, our focus in this research has been on the methodology itself and not so much on its accurate implementation in an industrial setting. A three-tier approach is presented for an IPPD-MDO based design of aircraft structures. The variable-complexity cost estimation methodology and an approach for integrating manufacturing cost assessment into design process are also discussed. This report is presented in two parts. In the first part, the design methodology is presented, and the computational design tool is described. In the second part, a prototype model of the preliminary design Tool for Aircraft Structures based on Process Information (TASPI) is described. Part two also contains an example problem that applies the methodology described here for evaluation of six different design concepts for a wing spar.
Nano-particle modified stationary phases for high-performance liquid chromatography.
Nesterenko, Ekaterina P; Nesterenko, Pavel N; Connolly, Damian; He, Xiaoyun; Floris, Patrick; Duffy, Emer; Paull, Brett
2013-08-07
This review covers the latest developments and applications of nano-materials in stationary phase development for various modes of high-performance liquid chromatography. Specific attention is placed upon the development of new composite phases, including the synthetic and immobilisation strategies used, to produce either encapsulated nano-particles, or surface attached nano-particles, layers, coatings and other structures. The resultant chromatographic applications, where applicable, are discussed with comment upon enhanced selectivity and/or efficiency of the nano-particle modified phases, where such effects have been identified. In the main this review covers developments over the past five years and is structured according to the nature of the nano-particles themselves, including carbonaceous, metallic, inorganic, and organopolymer based materials.
Applications of Parallel Computation in Micro-Mechanics and Finite Element Method
NASA Technical Reports Server (NTRS)
Tan, Hui-Qian
1996-01-01
This project discusses the application of parallel computations related with respect to material analyses. Briefly speaking, we analyze some kind of material by elements computations. We call an element a cell here. A cell is divided into a number of subelements called subcells and all subcells in a cell have the identical structure. The detailed structure will be given later in this paper. It is obvious that the problem is "well-structured". SIMD machine would be a better choice. In this paper we try to look into the potentials of SIMD machine in dealing with finite element computation by developing appropriate algorithms on MasPar, a SIMD parallel machine. In section 2, the architecture of MasPar will be discussed. A brief review of the parallel programming language MPL also is given in that section. In section 3, some general parallel algorithms which might be useful to the project will be proposed. And, combining with the algorithms, some features of MPL will be discussed in more detail. In section 4, the computational structure of cell/subcell model will be given. The idea of designing the parallel algorithm for the model will be demonstrated. Finally in section 5, a summary will be given.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Deka, Deepjyoti; Backhaus, Scott N.; Chertkov, Michael
Traditionally power distribution networks are either not observable or only partially observable. This complicates development and implementation of new smart grid technologies, such as those related to demand response, outage detection and management, and improved load-monitoring. In this two part paper, inspired by proliferation of the metering technology, we discuss estimation problems in structurally loopy but operationally radial distribution grids from measurements, e.g. voltage data, which are either already available or can be made available with a relatively minor investment. In Part I, the objective is to learn the operational layout of the grid. Part II of this paper presentsmore » algorithms that estimate load statistics or line parameters in addition to learning the grid structure. Further, Part II discusses the problem of structure estimation for systems with incomplete measurement sets. Our newly suggested algorithms apply to a wide range of realistic scenarios. The algorithms are also computationally efficient – polynomial in time– which is proven theoretically and illustrated computationally on a number of test cases. The technique developed can be applied to detect line failures in real time as well as to understand the scope of possible adversarial attacks on the grid.« less
NASA Astrophysics Data System (ADS)
Gutzwiller, David; Gontier, Mathieu; Demeulenaere, Alain
2014-11-01
Multi-Block structured solvers hold many advantages over their unstructured counterparts, such as a smaller memory footprint and efficient serial performance. Historically, multi-block structured solvers have not been easily adapted for use in a High Performance Computing (HPC) environment, and the recent trend towards hybrid GPU/CPU architectures has further complicated the situation. This paper will elaborate on developments and innovations applied to the NUMECA FINE/Turbo solver that have allowed near-linear scalability with real-world problems on over 250 hybrid GPU/GPU cluster nodes. Discussion will focus on the implementation of virtual partitioning and load balancing algorithms using a novel meta-block concept. This implementation is transparent to the user, allowing all pre- and post-processing steps to be performed using a simple, unpartitioned grid topology. Additional discussion will elaborate on developments that have improved parallel performance, including fully parallel I/O with the ADIOS API and the GPU porting of the computationally heavy CPUBooster convergence acceleration module. Head of HPC and Release Management, Numeca International.
Faculty verbal evaluations reveal strategies used to promote medical student performance
Hauer, Karen E.; Mazotti, Lindsay; O'Brien, Bridget; Hemmer, Paul A.; Tong, Lowell
2011-01-01
Background Preceptors rarely follow medical students' developing clinical performance over time and across disciplines. This study analyzes preceptors' descriptions of longitudinal integrated clerkship (LIC) students' clinical development and their identification of strategies to guide students' progress. Methods We used a common evaluation framework, reporter-interpreter-manager-educator, to guide multidisciplinary LIC preceptors' discussions of students' progress. We conducted thematic analysis of transcripts from preceptors' (seven longitudinal ambulatory preceptors per student) quarterly group discussions of 15 students' performance over one year. Results All students' clinical development progressed, although most experienced obstacles. Lack of structure in the history and physical exam commonly obstructed progression. Preceptors used templates for data gathering, and modeling or experiences in the inpatient setting to provide time and solidify structure. To advance students' knowledge acquisition, many preceptors identified focused learning topics with their students; to promote application of knowledge, preceptors used reasoning strategies to teach the steps involved in synthesizing clinical data. Preceptors shared accountability for helping students advance as the LIC allowed them to follow students' response to teaching strategies. Discussion These results depict preceptors' perceptions of LIC students' developmental continuum and illustrate how multidisciplinary preceptors can use a common evaluation framework to identify strategies to improve performance and follow students' performance longitudinally. PMID:21629669
Development of a tool to assess past food insecurity of immigrant latino mothers.
Kuyper, Edith M; Espinosa-Hall, Gloria; Lamp, Catherine L; Martin, Anna C; Metz, Diane L; Smith, Dorothy; Townsend, Marilyn S; Kaiser, Lucia L
2006-01-01
The purpose is to describe the development and validation of a tool to measure the degree of past food insecurity in an immigrant US population. Focus group discussions and a structured interview. As a first step, focus group discussions were conducted among immigrant Latino mothers. Based on these discussions, an 8-item tool was developed and pilot-tested in a convenience sample of mothers. California. Twenty-two low-income Latino mothers with children, ages 4 to 5 years, in the focus groups and 85 low-income Latino and white mothers of young children in the structured interviews. Constant comparative analysis, Cronbach alpha, Spearman correlations, Chi-square, and Kruskal-Wallis test. Internal consistency of the remaining 7 items was good (Cronbach alpha = 0.84). Evidence of convergent validity included significant correlations between past food insecurity and maternal education (r = -0.45, p < .0001), crowding in the mother's childhood household (r = +0.30, p < .006), and past food insufficiency (r = +0.74, p < .0001). Foreign-born Latino mothers reported significantly greater levels of past food insecurity than US-born mothers, demonstrating discriminant validity (p < .01). This tool may be useful to determine how past deprivation influences current food choices and other nutrition-related behaviors in low-income Latino immigrants.
Pursuit tracking and higher levels of skill development in the human pilot
NASA Technical Reports Server (NTRS)
Hess, R. A.
1981-01-01
A model of the human pilot is offered for pursuit tracking tasks; the model encompasses an existing model for compensatory tracking. The central hypothesis in the development of this model states that those primary structural elements in the compensatory model responsible for the pilot's equalization capabilities remain intact in the pursuit model. In this latter case, effective low-frequency inversion of the controlled-element dynamics occurs by feeding-forward derived input rate through the equalization dynamics, with low-frequency phase droop minimized. The sharp reduction in low-frequency phase lag beyond that associated with the disappearance of phase droop is seen to accompany relatively low-gain feedback of vehicle output. The results of some recent motion cue research are discussed and interpreted in terms of the compensatory-pursuit display dichotomy. Tracking with input preview is discussed in a qualitative way. In terms of the model, preview is shown to demand no fundamental changes in structure or equalization and to allow the pilot to eliminate the effective time delays that accrue in the inversion of the controlled-element dynamics. Precognitive behavior is discussed, and a model that encompasses all the levels of skill development outlined in the successive organizations of perception theory is finally proposed.
The major bioactive components of seaweeds and their mosquitocidal potential.
Yu, Ke-Xin; Jantan, Ibrahim; Ahmad, Rohani; Wong, Ching-Lee
2014-09-01
Seaweeds are one of the most widely studied natural resources for their biological activities. Novel seaweed compounds with unique chemical structures have been reported for their pharmacological properties. The urge to search for novel insecticidal compound with a new mode of action for development of botanical insecticides supports the relevant scientific research on discovering the bioactive compounds in seaweeds. The mosquitocidal potential of seaweed extracts and their isolated compounds are documented in this review paper, along with the discussion on bioactivities of the major components of seaweeds such as polysaccharides, phenolics, proteins, terpenes, lipids, and halogenated compounds. The effects of seaweed extracts and compounds toward different life stages of mosquito (egg, larva, pupa, and adult), its growth, development, and reproduction are elaborated. The structure-activity relationships of mosquitocidal compounds are discussed to extrapolate the possible chemical characteristics of seaweed compounds responsible for insecticidal properties. Furthermore, the possible target sites and mode of actions of the mosquitocidal seaweed compounds are included in this paper. The potential synergistic effects between seaweeds and commercial insecticides as well as the toxic effects of seaweed extracts and compounds toward other insects and non-target organisms in the same habitat are also described. On top of that, various factors that influence the mosquitocidal potential of seaweeds, such as abiotic and biotic variables, sample preparation, test procedures, and considerations for a precise experimental design are discussed. The potential of active seaweed extracts and compounds in the development of effective bioinsecticide are also discussed.
The Use of the STAGS Finite Element Code in Stitched Structures Development
NASA Technical Reports Server (NTRS)
Jegley, Dawn C.; Lovejoy, Andrew E.
2014-01-01
In the last 30 years NASA has worked in collaboration with industry to develop enabling technologies needed to make aircraft more fuel-efficient and more affordable. The focus on the airframe has been to reduce weight, improve damage tolerance and better understand structural behavior under realistic flight and ground loading conditions. Stitched structure is a technology that can address the weight savings, cost reduction, and damage tolerance goals, but only if it is supported by accurate analytical techniques. Development of stitched technology began in the 1990's as a partnership between NASA and Boeing (McDonnell Douglas at the time) under the Advanced Composites Technology Program and has continued under various titles and programs and into the Environmentally Responsible Aviation Project today. These programs contained development efforts involving manufacturing development, design, detailed analysis, and testing. Each phase of development, from coupons to large aircraft components was supported by detailed analysis to prove that the behavior of these structures was well-understood and predictable. The Structural Analysis of General Shells (STAGS) computer code was a critical tool used in the development of many stitched structures. As a key developer of STAGS, Charles Rankin's contribution to the programs was quite significant. Key features of STAGS used in these analyses and discussed in this paper include its accurate nonlinear and post-buckling capabilities, its ability to predict damage growth, and the use of Lagrange constraints and follower forces.
Developing an approach for teaching and learning about Lewis structures
NASA Astrophysics Data System (ADS)
Kaufmann, Ilana; Hamza, Karim M.; Rundgren, Carl-Johan; Eriksson, Lars
2017-08-01
This study explores first-year university students' reasoning as they learn to draw Lewis structures. We also present a theoretical account of the formal procedure commonly taught for drawing these structures. Students' discussions during problem-solving activities were video recorded and detailed analyses of the discussions were made through the use of practical epistemology analysis (PEA). Our results show that the formal procedure was central for drawing Lewis structures, but its use varied depending on situational aspects. Commonly, the use of individual steps of the formal procedure was contingent on experiences of chemical structures, and other information such as the characteristics of the problem given. The analysis revealed a number of patterns in how students constructed, checked and modified the structure in relation to the formal procedure and the situational aspects. We suggest that explicitly teaching the formal procedure as a process of constructing, checking and modifying might be helpful for students learning to draw Lewis structures. By doing so, the students may learn to check the accuracy of the generated structure not only in relation to the octet rule and formal charge, but also to other experiences that are not explicitly included in the formal procedure.
Structure and Computation in Immunoreagent Design: From Diagnostics to Vaccines.
Gourlay, Louise; Peri, Claudio; Bolognesi, Martino; Colombo, Giorgio
2017-12-01
Novel immunological tools for efficient diagnosis and treatment of emerging infections are urgently required. Advances in the diagnostic and vaccine development fields are continuously progressing, with reverse vaccinology and structural vaccinology (SV) methods for antigen identification and structure-based antigen (re)design playing increasingly relevant roles. SV, in particular, is predicted to be the front-runner in the future development of diagnostics and vaccines targeting challenging diseases such as AIDS and cancer. We review state-of-the-art methodologies for structure-based epitope identification and antigen design, with specific applicative examples. We highlight the implications of such methods for the engineering of biomolecules with improved immunological properties, potential diagnostic and/or therapeutic uses, and discuss the perspectives of structure-based rational design for the production of advanced immunoreagents. Copyright © 2017 Elsevier Ltd. All rights reserved.
The biomedical disciplines and the structure of biomedical and clinical knowledge.
Nederbragt, H
2000-11-01
The relation between biomedical knowledge and clinical knowledge is discussed by comparing their respective structures. The knowledge of a disease as a biological phenomenon is constructed by the interaction of facts and theories from the main biomedical disciplines: epidemiology, diagnostics, clinical trial, therapy development and pathogenesis. Although these facts and theories are based on probabilities and extrapolations, the interaction provides a reliable and coherent structure, comparable to a Kuhnian paradigma. In the structure of clinical knowledge, i.e. knowledge of the patient with the disease, not only biomedical knowledge contributes to the structure but also economic and social relations, ethics and personal experience. However, the interaction between each of the participating "knowledges" in clinical knowledge is not based on mutual dependency and accumulation of different arguments from each, as in biomedical knowledge, but on competition and partial exclusion. Therefore, the structure of biomedical knowledge is different from that of clinical knowledge. This difference is used as the basis for a discussion in which the place of technology, evidence-based medicine and the gap between scientific and clinical knowledge are evaluated.
Principles of disaster management lesson. 12: structuring organizations.
Cuny, F C
2001-01-01
This lesson discusses various structures for organizations that have functional roles in disaster responses, relief, and/or management activities. It distinguishes between pyramidal and matrix structures, and notes the advantages and disadvantages of each in relation to disasters. Span of control issues are dissected including the impact of the "P" factor on the performance of disaster managers and workers including its relationship to the coordination and control function. The development of a Table of Organization and how it relates to departmentalization within an organization also is provided.
An overview of the EASE/ACCESS space construction demonstration
NASA Technical Reports Server (NTRS)
Levin, George M.; Ross, Jerry L.; Spring, Sherwood C.
1988-01-01
Consideration is given to the development of the Experimental Assembly of Structures in EVA/Assembly Concept for Construction of Erectable Space Structures (EASE/ACCESS) space construction demonstration, which was performed during Space Shuttle mission 61-B. The mission equipment is described and illustrated and the EASE/ACCESS mission management structure is outlined. Simulations of the assembly and disassembly in the NASA neutral buoyancy simulators were used to test the mission plans. In addition, EVA training and crew performance for the mission are discussed.
Cambrian potential indicated in Kentucky Rome trough
DOE Office of Scientific and Technical Information (OSTI.GOV)
Harris, D.C.; Drahovzal, J.A.
1996-02-19
This paper reviews recent gas discoveries in the Kentucky Rome trough and the implications for future developments. It reviews the geology and stratigraphy of this structure and identifies the potential zones of production and trapping mechanisms. It provides results from geologic logs and seismic data to provide cross sectional and structural interpretations. Finally it discusses the gas composition of natural gas recovered from the basin.
Elements of Regolith Simulant's Cost Structure--Why Rock Is NOT Cheap
NASA Technical Reports Server (NTRS)
Rickman, Douglas L.
2009-01-01
The cost of lunar regolith simulants is much higher than many users anticipate. After all, it is nothing more than broken rock. This class will discuss the elements which make up the cost structure for simulants. It will also consider which elements can be avoided under certain circumstances and which elements might be altered by the application of additional research and development.
Closed-loop carrier phase synchronization techniques motivated by likelihood functions
NASA Technical Reports Server (NTRS)
Tsou, H.; Hinedi, S.; Simon, M.
1994-01-01
This article reexamines the notion of closed-loop carrier phase synchronization motivated by the theory of maximum a posteriori phase estimation with emphasis on the development of new structures based on both maximum-likelihood and average-likelihood functions. The criterion of performance used for comparison of all the closed-loop structures discussed is the mean-squared phase error for a fixed-loop bandwidth.
Composite structural materials
NASA Technical Reports Server (NTRS)
Loewy, Robert G.; Wiberley, Stephen E.
1988-01-01
A decade long program to develop critical advanced composite technology in the areas of physical properties, structural concept and analysis, manufacturing, reliability, and life predictions is reviewed. Specific goals are discussed. The status of the chemical vapor deposition effects on carbon fiber properties; inelastic deformation of metal matrix laminates; fatigue damage in fibrous MMC laminates; delamination fracture toughness in thermoplastic matrix composites; and numerical analysis of composite micromechanical behavior are presented.
Research in nonlinear structural and solid mechanics
NASA Technical Reports Server (NTRS)
Mccomb, H. G., Jr. (Compiler); Noor, A. K. (Compiler)
1981-01-01
Recent and projected advances in applied mechanics, numerical analysis, computer hardware and engineering software, and their impact on modeling and solution techniques in nonlinear structural and solid mechanics are discussed. The fields covered are rapidly changing and are strongly impacted by current and projected advances in computer hardware. To foster effective development of the technology perceptions on computing systems and nonlinear analysis software systems are presented.
Reliability-based criteria for load and resistance factor design code for wood bridges
Chris Eamon; Andrzej S. Nowak; Michael A. Ritter; Joe Murphy
2000-01-01
Recently AASHTO adopted a load and resistance factor design code for highway bridges. The new code provides a rational basis for the design of steel and concrete structures. However, the calibration was not done for wood bridges. Therefore, there is a need to fill this gap. The development of statistical models for wood bridge structures is discussed. Recent test...
2014 Trans-Atlantic Research and Development Interchange ...
The Trans-Atlantic Research and Development Interchange on Sustainability (TARDIS) has been bringing together a select group of scientists and engineers for in-depth discussions on sustainability on a bi-annual basis since 2004. TARDIS 2014 included twenty eight individuals from across the globe discussing issues related to progress towards sustainability. The discussion included policies, technologies, societal structure and norms, business practices and culture, and time-frames. As discussed later, the focus was on four questions: (1) what progress has been accomplished in sustainability? (2) why has there not been more progress in moving societies towards sustainability? (3) what are the road-blocks to progress towards sustainability? (4) what are the policies, technologies, and other changes that are needed to make further progress towards sustainability? One salient conclusion from TARDIS 2014 is that while sustainability has entered mainstream thinking, significant social, economic, technological, and business barriers remain to further progress towards a sustainable path as discussed throughout this report. The Trans-Atlantic Research and Development Interchange on Sustainability is a bi-annual workshop alternatively held in the United States and Austria. The purpose is to bring the best thinkers from across the globe to discuss, explore, and clarify major issues related to sustainability. A report summarizing teh finding and discussions is prepared and d
A manned-machine space station construction concept
NASA Technical Reports Server (NTRS)
Mikulas, M. M., Jr.; Bush, H. G.; Wallsom, R. E.; Dorsey, J. T.; Rhodes, M. D.
1984-01-01
A design concept for the construction of a permanent manned space station is developed and discussed. The main considerations examined in developing the design concept are: (1) the support structure of the station be stiff enough to preclude the need for an elaborate on-orbit system to control structural response, (2) the station support structure and solar power system be compatible with existing technology, and (3) the station be capable of growing in a systematic modular fashion. The concept is developed around the assembly of truss platforms by pressure-suited astronauts operating in extravehicular activity (EVA), assisted by a machine (Assembly and Transport Vehicle, ATV) to position the astronauts at joint locations where they latch truss members in place. The ATV is a mobile platform that is attached to and moves on the station support structure using pegs attached to each truss joint. The operation of the ATV is described and a number of conceptual configurations for potential space stations are developed.
Developments in Nano-Satellite Structural Subsystem Design at NASA-GSFC
NASA Technical Reports Server (NTRS)
Rossoni, Peter; Panetta, Peter V.
1999-01-01
The NASA-GSFC Nano-satellite Technology Development Program will enable flying constellations of tens to hundreds of nano-satellites for future NASA Space and Earth Science missions. Advanced technology components must be developed to make these future spacecraft compact, lightweight, low-power, low-cost, and survivable to a radiation environment over a two-year mission lifetime. This paper describes the efforts underway to develop lightweight, low cost, and multi-functional structures, serviceable designs, and robust mechanisms. As designs shrink, the integration of various subsystems becomes a vital necessity. This paper also addresses structurally integrated electrical power, attitude control, and thermal systems. These innovations bring associated fabrication, integration, and test challenges. Candidate structural materials and processes are examined and the merits of each are discussed. Design and fabrication processes include flat stock composite construction, cast aluminum-beryllium alloy, and an injection molded fiber-reinforced plastic. A viable constellation deployment scenario is described as well as a Phase-A Nano-satellite Pathfinder study.
A nonlinear viscoelastic approach to durability predictions for polymer based composite structures
NASA Technical Reports Server (NTRS)
Brinson, Hal F.
1991-01-01
Current industry approaches for the durability assessment of metallic structures are briefly reviewed. For polymer based composite structures, it is suggested that new approaches must be adopted to include memory or viscoelastic effects which could lead to delayed failures that might not be predicted using current techniques. A durability or accelerated life assessment plan for fiber reinforced plastics (FRP) developed and documented over the last decade or so is reviewed and discussed. Limitations to the plan are outlined and suggestions to remove the limitations are given. These include the development of a finite element code to replace the previously used lamination theory code and the development of new specimen geometries to evaluate delamination failures. The new DCB model is reviewed and results are presented. Finally, it is pointed out that new procedures are needed to determine interfacial properties and current efforts underway to determine such properties are reviewed. Suggestions for additional efforts to develop a consistent and accurate durability predictive approach for FRP structures are outlined.
A nonlinear viscoelastic approach to durability predictions for polymer based composite structures
NASA Technical Reports Server (NTRS)
Brinson, Hal F.; Hiel, C. C.
1990-01-01
Current industry approaches for the durability assessment of metallic structures are briefly reviewed. For polymer based composite structures, it is suggested that new approaches must be adopted to include memory or viscoelastic effects which could lead to delayed failures that might not be predicted using current techniques. A durability or accelerated life assessment plan for fiber reinforced plastics (FRP) developed and documented over the last decade or so is reviewed and discussed. Limitations to the plan are outlined and suggestions to remove the limitations are given. These include the development of a finite element code to replace the previously used lamination theory code and the development of new specimen geometries to evaluate delamination failures. The new DCB model is reviewed and results are presented. Finally, it is pointed out that new procedures are needed to determine interfacial properties and current efforts underway to determine such properties are reviewed. Suggestions for additional efforts to develop a consistent and accurate durability predictive approach for FRP structures is outlined.
Postnatal brain development: Structural imaging of dynamic neurodevelopmental processes
Jernigan, Terry L.; Baaré, William F. C.; Stiles, Joan; Madsen, Kathrine Skak
2013-01-01
After birth, there is striking biological and functional development of the brain’s fiber tracts as well as remodeling of cortical and subcortical structures. Behavioral development in children involves a complex and dynamic set of genetically guided processes by which neural structures interact constantly with the environment. This is a protracted process, beginning in the third week of gestation and continuing into early adulthood. Reviewed here are studies using structural imaging techniques, with a special focus on diffusion weighted imaging, describing age-related brain maturational changes in children and adolescents, as well as studies that link these changes to behavioral differences. Finally, we discuss evidence for effects on the brain of several factors that may play a role in mediating these brain–behavior associations in children, including genetic variation, behavioral interventions, and hormonal variation associated with puberty. At present longitudinal studies are few, and we do not yet know how variability in individual trajectories of biological development in specific neural systems map onto similar variability in behavioral trajectories. PMID:21489384
NASA Technical Reports Server (NTRS)
Stanley, A. G.
1975-01-01
Development, fabrication and applications of CdS solar cells are reviewed in detail. The suitability of CdS cells for large solar panels and microcircuitry, and their low cost, are emphasized. Developments are reviewed by manufacturer-developer. Vapor phase deposition of thin-film solar cells, doping and co-evaporation, sputtering, chemical spray, and sintered layers are reviewed, in addition to spray deposition, monograin layer structures, and silk screening. Formation of junctions by electroplating, evaporation, brushing, CuCl dip, and chemiplating are discussed, along with counterelectrode fabrication, VPD film structures, the Cu2S barrier layer, and various photovoltaic effects (contact photovoltage, light intensity variation, optical enhancement), and various other CdS topics.
Elbert, Donald L.
2011-01-01
Recapitulating the elegant structures formed during development is an extreme synthetic and biological challenge. Great progress has been made in developing materials to support transplanted cells, yet the complexity of tissues is far beyond that found in even the most advanced scaffolds. Self-assembly is a motif used in development and a route for the production of complex materials. Self-assembly of peptides, proteins and other molecules at the nanoscale is promising, but in addition, intriguing ideas are emerging for self-assembly of micron-scale structures. In this brief review, very recent advances in the assembly of micron-scale cell aggregates and microgels will be described and discussed. PMID:21524904
NASA Space Engineering Research Center for Utilization of Local Planetary Resources
NASA Technical Reports Server (NTRS)
Ramohalli, Kumar; Lewis, John S.
1991-01-01
In the processing of propellants, volatiles, and metals subject area, the following topics are discussed: reduction of lunar regolith; reduction of carbon dioxide; and reduction of carbonaceous materials. Other areas addressed include: (1) production of structural and refractory materials; (2) resource discovery and characterization; (3) system automation and optimization; and (4) database development. The majority of these topics are discussed with respect to the development of lunar and mars bases. Some main topics of interest include: asteroid resources, lunar resources, mars resources, materials processing, construction materials, propellant production, oxygen production, and space-based oxygen production plants.
The new applications of sputtering and ion plating
NASA Technical Reports Server (NTRS)
Spalvins, T.
1977-01-01
The potential industrial applications of sputtering and ion plating are strictly governed by the unique features these methods possess. The outstanding features of each method, the resultant coating characteristics and the various sputtering modes and configurations are discussed. New, more complex coatings and deposits can be developed such as graded composition structures (metal-ceramic seals), laminated and dispersion strengthened composites which improve the mechanical properties and high temperature stability. Specific industrial areas where future effort of sputtering and ion plating will concentrate to develop intricate alloy or compound coatings and solve difficult problem areas are discussed.
Heitt, Michael C; Tamburo, Melissa Back
2005-01-01
The creation and development of a Risk Assessment Team at a large urban university is presented as a case study, with particular focus on the role the Employee Assistance Program (EAP) plays in the multidisciplinary team. The structure of the team and differing roles and responsibilities of members will be discussed. A specific protocol for addressing incidents will be introduced, along with changes in the team ' response over time. Major lessons learned will be presented, as well as the challenges the team faces today, and discussion of areas for future research and evaluation.
Chemical Markup, XML and the World-Wide Web. 8. Polymer Markup Language.
Adams, Nico; Winter, Jerry; Murray-Rust, Peter; Rzepa, Henry S
2008-11-01
Polymers are among the most important classes of materials but are only inadequately supported by modern informatics. The paper discusses the reasons why polymer informatics is considerably more challenging than small molecule informatics and develops a vision for the computer-aided design of polymers, based on modern semantic web technologies. The paper then discusses the development of Polymer Markup Language (PML). PML is an extensible language, designed to support the (structural) representation of polymers and polymer-related information. PML closely interoperates with Chemical Markup Language (CML) and overcomes a number of the previously identified challenges.
Frequency Response Function Based Damage Identification for Aerospace Structures
NASA Astrophysics Data System (ADS)
Oliver, Joseph Acton
Structural health monitoring technologies continue to be pursued for aerospace structures in the interests of increased safety and, when combined with health prognosis, efficiency in life-cycle management. The current dissertation develops and validates damage identification technology as a critical component for structural health monitoring of aerospace structures and, in particular, composite unmanned aerial vehicles. The primary innovation is a statistical least-squares damage identification algorithm based in concepts of parameter estimation and model update. The algorithm uses frequency response function based residual force vectors derived from distributed vibration measurements to update a structural finite element model through statistically weighted least-squares minimization producing location and quantification of the damage, estimation uncertainty, and an updated model. Advantages compared to other approaches include robust applicability to systems which are heavily damped, large, and noisy, with a relatively low number of distributed measurement points compared to the number of analytical degrees-of-freedom of an associated analytical structural model (e.g., modal finite element model). Motivation, research objectives, and a dissertation summary are discussed in Chapter 1 followed by a literature review in Chapter 2. Chapter 3 gives background theory and the damage identification algorithm derivation followed by a study of fundamental algorithm behavior on a two degree-of-freedom mass-spring system with generalized damping. Chapter 4 investigates the impact of noise then successfully proves the algorithm against competing methods using an analytical eight degree-of-freedom mass-spring system with non-proportional structural damping. Chapter 5 extends use of the algorithm to finite element models, including solutions for numerical issues, approaches for modeling damping approximately in reduced coordinates, and analytical validation using a composite sandwich plate model. Chapter 6 presents the final extension to experimental systems-including methods for initial baseline correlation and data reduction-and validates the algorithm on an experimental composite plate with impact damage. The final chapter deviates from development and validation of the primary algorithm to discuss development of an experimental scaled-wing test bed as part of a collaborative effort for developing structural health monitoring and prognosis technology. The dissertation concludes with an overview of technical conclusions and recommendations for future work.
NASA Astrophysics Data System (ADS)
Demirci, İsmail; Dikmen, Ünal; Candansayar, M. Emin
2018-02-01
Joint inversion of data sets collected by using several geophysical exploration methods has gained importance and associated algorithms have been developed. To explore the deep subsurface structures, Magnetotelluric and local earthquake tomography algorithms are generally used individually. Due to the usage of natural resources in both methods, it is not possible to increase data quality and resolution of model parameters. For this reason, the solution of the deep structures with the individual usage of the methods cannot be fully attained. In this paper, we firstly focused on the effects of both Magnetotelluric and local earthquake data sets on the solution of deep structures and discussed the results on the basis of the resolving power of the methods. The presence of deep-focus seismic sources increase the resolution of deep structures. Moreover, conductivity distribution of relatively shallow structures can be solved with high resolution by using MT algorithm. Therefore, we developed a new joint inversion algorithm based on the cross gradient function in order to jointly invert Magnetotelluric and local earthquake data sets. In the study, we added a new regularization parameter into the second term of the parameter correction vector of Gallardo and Meju (2003). The new regularization parameter is enhancing the stability of the algorithm and controls the contribution of the cross gradient term in the solution. The results show that even in cases where resistivity and velocity boundaries are different, both methods influence each other positively. In addition, the region of common structural boundaries of the models are clearly mapped compared with original models. Furthermore, deep structures are identified satisfactorily even with using the minimum number of seismic sources. In this paper, in order to understand the future studies, we discussed joint inversion of Magnetotelluric and local earthquake data sets only in two-dimensional space. In the light of these results and by means of the acceleration on the three-dimensional modelling and inversion algorithms, it is thought that it may be easier to identify underground structures with high resolution.
NASA Technical Reports Server (NTRS)
Hanagud, S.; Uppaluri, B.
1975-01-01
This paper describes a methodology for making cost effective fatigue design decisions. The methodology is based on a probabilistic model for the stochastic process of fatigue crack growth with time. The development of a particular model for the stochastic process is also discussed in the paper. The model is based on the assumption of continuous time and discrete space of crack lengths. Statistical decision theory and the developed probabilistic model are used to develop the procedure for making fatigue design decisions on the basis of minimum expected cost or risk function and reliability bounds. Selections of initial flaw size distribution, NDT, repair threshold crack lengths, and inspection intervals are discussed.
Recent Developments in Antimicrobial Polymers: A Review
Santos, Madson R. E.; Fonseca, Ana C.; Mendonça, Patrícia V.; Branco, Rita; Serra, Arménio C.; Morais, Paula V.; Coelho, Jorge F. J.
2016-01-01
Antimicrobial polymers represent a very promising class of therapeutics with unique characteristics for fighting microbial infections. As the classic antibiotics exhibit an increasingly low capacity to effectively act on microorganisms, new solutions must be developed. The importance of this class of materials emerged from the uncontrolled use of antibiotics, which led to the advent of multidrug-resistant microbes, being nowadays one of the most serious public health problems. This review presents a critical discussion of the latest developments involving the use of different classes of antimicrobial polymers. The synthesis pathways used to afford macromolecules with antimicrobial properties, as well as the relationship between the structure and performance of these materials are discussed. PMID:28773721
NASA Technical Reports Server (NTRS)
Cross, James H., II
1990-01-01
The study, formulation, and generation of structures for Ada (GRASP/Ada) are discussed in this second phase report of a three phase effort. Various graphical representations that can be extracted or generated from source code are described and categorized with focus on reverse engineering. The overall goal is to provide the foundation for a CASE (computer-aided software design) environment in which reverse engineering and forward engineering (development) are tightly coupled. Emphasis is on a subset of architectural diagrams that can be generated automatically from source code with the control structure diagram (CSD) included for completeness.
Dynamic soft variable structure control of singular systems
NASA Astrophysics Data System (ADS)
Liu, Yunlong; Zhang, Caihong; Gao, Cunchen
2012-08-01
The dynamic soft variable structure control (VSC) of singular systems is discussed in this paper. The definition of soft VSC and the design of its controller modes are given. The stability of singular systems with the dynamic soft VSC is proposed. The dynamic soft variable structure controller is designed, and the concrete algorithm on the dynamic soft VSC is given. The dynamic soft VSC of singular systems which was developed for the purpose of intentionally precluding chattering, achieving high regulation rates and shortening settling times enhanced the dynamic quality of the systems. It is illustrated the feasibility and validity of the proposed strategy by a simulation example, and an outlook on its auspicious further development is presented.
Precambrian organic geochemistry - Preservation of the record
NASA Technical Reports Server (NTRS)
Hayes, J. M.; Wedeking, K. W.; Kaplan, I. R.
1983-01-01
A review of earlier studies is presented, and new results in Precambrian organic geochemistry are discussed. It is pointed out that two lines of evidence can be developed. One is based on structural organic chemistry, while the other is based on isotopic analyses. In the present investigation, the results of both structural and isotopic investigations of Precambrian organic matter are discussed. Processes and products related to organic geochemistry are examined, taking into account the carbon cycle, an approximate view of the principal pathways of carbon cycling associated with organic matter in the present global ecosystem, processes affecting sedimentary organic matter, and distribution and types of organic matter. Attention is given to chemical fossils in Precambrian sediments, kerogen analyses, the determination of the structural characteristics of kerogen, and data concerning the preservation of the Precambrian organic geochemical record.
The African American Women's Summit: A Student Affairs Professional Development Program
ERIC Educational Resources Information Center
West, Nicole M.
2017-01-01
The African American Women's Summit (AAWS) is a professional development program in the United States created by and for African American women in student affairs. This article reviews the evolution and structure of the AAWS. A discussion, grounded in Black feminist thought, is included relative to the impact of the AAWS on African American women…
ERIC Educational Resources Information Center
Theobald, Neil D.
The purpose of this paper is to: (1) discuss the requisite financial and organizational components of partner schools or professional development schools; and (2) identify structures and processes which will allow these schools to contribute to the simultaneous reconstruction and renewal of the public schools in which teachers work and the…
A Calendar of Activities for Parents of Handicapped Students, 1983-1984. Developmentally Young.
ERIC Educational Resources Information Center
District of Columbia Public Schools, Washington, DC. Div. of Special Education and Pupil Personnel Services.
These activities for handicapped preschool children in the Washington, D.C. school district can be used by all parents interested in developing a structured home development program for their children. A calendar format offers daily activities ranging from brief discussions and exercises to day-long family excursions. Each month's activities cover…
Community Schools in Developing Countries. International Studies in Education 23.
ERIC Educational Resources Information Center
Houghton, Harold, Ed.; Tregear, Peter, Ed.
This book is a synthesis of the work and discussions of a Unesco conference that examined the problems concerning the structure and functioning of community schools in developing countries. Participants worked in four groups studying respectively the position of the teacher in relation to the community, the means he should employ to obtain the…
ERIC Educational Resources Information Center
Rikoon, Samuel H.; Liebtag, Travis; Olivera-Aguilar, Margarita; Steinberg, Jonathan; Robbins, Steven B.
2015-01-01
In this report, we describe the development of an extension of the "SuccessNavigator"® assessment for late high school settings. We discuss the assessment's conceptualization and support its application with psychometric studies detailing scale development in terms of structural analyses, reliability, and several other aspects of…
ERIC Educational Resources Information Center
Dahm, Kevin; Newell, James; Newell, Heidi; Harvey, Roberta
2009-01-01
This paper discusses efforts to develop metacognition in teams of engineering students by: first, exploring personal learning patterns, and second, ongoing biweekly journaling exercises. Thirty-three junior and senior engineering students (30 chemical engineer, one each from mechanical, civil and electrical) working on semester-long projects in…
Project CAD as of July 1978: CAD support project, situation in July 1978
NASA Technical Reports Server (NTRS)
Boesch, L.; Lang-Lendorff, G.; Rothenberg, R.; Stelzer, V.
1979-01-01
The structure of Computer Aided Design (CAD) and the requirements for program developments in past and future are described. The actual standard and the future aims of CAD programs are presented. The developed programs in: (1) civil engineering; (2) mechanical engineering; (3) chemical engineering/shipbuilding; (4) electrical engineering; and (5) general programs are discussed.
Renewing and Developing the Partnership: Federal/State/Campus Cooperation in Student Financial Aid.
ERIC Educational Resources Information Center
Fenske, Robert H., Ed.; Clark, Patricia L., Ed.
The proceedings of the conference are summarized, including a symposium discussion following the formal conference. Contents include: two views of the present advisory structure for student aid (The Case for Maintaining and Expanding the Coalition for the Coordination of Student Financial Aid, by Robert H. Atwell, and The Need for Developing a…
ERIC Educational Resources Information Center
Thomas, Keith; McNaught, Carmel; Wong, Kin-Chi; Li, Yi-Ching
2011-01-01
This paper discusses early-career academics' development at a university in Hong Kong. Reflecting the impact of local context, the paper explores cultural and structural influences that can impinge on teaching and learning strategies for new academics. Barriers such as student learning behaviour and publication pressure may discourage new…
Solid-state Distributed Temperature Control for International Space Station
NASA Technical Reports Server (NTRS)
Holladay, Jon B.; Reagan, Shawn E.; Day, Greg
2004-01-01
A newly developed solid-state temperature controller will offer greater flexibility in the thermal control of aerospace vehicle structures. A status of the hardware development along with its implementation on the Multi- Purpose Logistics Module will be provided. Numerous advantages of the device will also be discussed with regards to current and future flight vehicle implementations.
Mediation with Families in Separation and Divorce in the United Kingdom: Links with Family Therapy.
ERIC Educational Resources Information Center
Robinson, Margaret
1988-01-01
Gives a brief account of recent developments in matrimonial law related to divorce, custody, and visitation to the children of divorcing couples. Discusses the development of mediation, its organizational structure, and its place within the context of the legal system of the United Kingdom. Outlines the principles of conciliation. (Author/ABL)
Fetal Alcohol Effects in Children: Cognitive, Educational, and Behavioral Considerations.
ERIC Educational Resources Information Center
Horowitz, Sheldon
The effects of alcohol on the developing fetus are examined. Noted is the existence of both structural problems (such as microcephaly and cardiac anomalies) and behavioral problems (such as mental retardation and speech and language deficits). The potential damage of alcohol at a very early stage of fetal development is discussed. It is thought…
Towards an "International Forum for Teacher Educator Development": An Agenda for Research and Action
ERIC Educational Resources Information Center
Kelchtermans, Geert; Smith, Kari; Vanderlinde, Ruben
2018-01-01
The outcomes of an international collaborative project are presented, involving experienced teacher educators and researchers from eight different countries, who engaged in a series of structured discussions on the professional development of teacher educators. We start with an overview of the needs in practice and policy, as well as the research…
ERIC Educational Resources Information Center
Johnson, Matthew
2015-01-01
The development of college students' civic identity is understudied, but worthy of attention because of its salience to many students and higher education's commitment to fostering an engaged citizenry. Using 45,271 participants from the 2009 Multi-Institutional Study of Leadership, this study uses structural equation modeling to explore…
Telescope technology for space-borne submillimeter astronomy
NASA Technical Reports Server (NTRS)
Lehman, David H.; Helou, George
1990-01-01
The Precision Segmented Reflector (PSR) project which is developing telescope technology needed for future spaceborne submillimeter astronomy missions is described. Four major technical areas are under development. Lighweight composite mirrors and associated materials, precision structures and segmented reflector figure sensing and control are discussed. The objectives of the PSR project, approaches, and project technology status, are reported.
Developmental regulation of fear learning and anxiety behavior by endocannabinoids
Lee, Tiffany T.-Y.; Hill, Matthew N.; Lee, Francis S.
2015-01-01
The developing brain undergoes substantial maturation into adulthood and the development of specific neural structures occurs on differing timelines. Transient imbalances between developmental trajectories of corticolimbic structures, which are known to contribute to regulation over fear learning and anxiety, can leave an individual susceptible to mental illness, particularly anxiety disorders. There is a substantial body of literature indicating that the endocannabinoid system critically regulates stress responsivity and emotional behavior throughout the life span, making this system a novel therapeutic target for stress- and anxiety-related disorders. During early life and adolescence, corticolimbic endocannabinoid signaling changes dynamically and coincides with different sensitive periods of fear learning, suggesting that endocannabinoid signaling underlies age-specific fear learning responses. Moreover, perturbations to these normative fluctuations in corticolimbic endocannabinoid signaling, such as stress or cannabinoid exposure, could serve as a neural substrate contributing to alterations to the normative developmental trajectory of neural structures governing emotional behavior and fear learning. In this review, we first introduce the components of the endocannabinoid system and discuss clinical and rodent models demonstrating endocannabinoid regulation of fear learning and anxiety in adulthood. Next, we highlight distinct fear learning and regulation profiles throughout development and discuss the ontogeny of the endocannabinoid system in the central nervous system, and models of pharmacological augmentation of endocannabinoid signaling during development in the context of fear learning and anxiety. PMID:26419643
NASA Technical Reports Server (NTRS)
Brewer, W. V.; Rasis, E. P.; Shih, H. R.
1993-01-01
Results from NASA/HBCU Grant No. NAG-1-1125 are summarized. Designs developed for model fabrication, exploratory concepts drafted, interface of computer with robot and end-effector, and capability enhancement are discussed.
The Architectural and Interior Design Planning Process.
ERIC Educational Resources Information Center
Cohen, Elaine
1994-01-01
Explains the planning process in designing effective library facilities and discusses library building requirements that result from electronic information technologies. Highlights include historical structures; Americans with Disabilities Act; resource allocation; electrical power; interior spaces; lighting; design development; the roles of…
ERIC Educational Resources Information Center
Olsen, Deborah
2000-01-01
Discusses institutional research (IR) in higher education, which is designed to generate information that serves planning, policy development, resource allocation, and management or evaluation decisions in all functional areas. Addresses its history, the skills and training needed by researchers, structure and staffing, and professional…
Cybernetics and Education (Special Issue)
ERIC Educational Resources Information Center
Kopstein, Felix F., Ed.
1977-01-01
This is a special issue examining the potential of cybernetics in educational technology. Articles discuss: cybernetic methods, algorithms, feedback learning theory, a structural approach to behavioral objectives and criterion-referenced testing, task specifications and diagnosis, teacher-child interaction, educational development, teaching…
Structural Test and Analysis of a Hybrid Inflatable Antenna
NASA Technical Reports Server (NTRS)
Gaspar, James L.; Mann, Troy; Sreekantamurthy, Tham; Behun, Vaughn
2007-01-01
NASA is developing ultra-lightweight structures technology for communication antennas for space missions. One of the research goals is to evaluate the structural characteristics of inflatable and rigidizable antennas through test and analysis. Being able to test and analyze the structural characteristics of a full scale antenna is important to enable the simulation of various mission scenarios to determine system performance in space. Recent work completed to evaluate a Hybrid Inflatable Antenna concept will be discussed. Tests were completed on a 2-m prototype to optimize its static shape and identify its modal dynamics that are important for analytical model validation. These test results were used to evaluate a preliminary finite element model of the antenna, and this model development and correlation activity is also described in the paper.
Trends in Mobile Application Development
NASA Astrophysics Data System (ADS)
Holzer, Adrian; Ondrus, Jan
Major software companies, such as Apple and Google, are disturbing the relatively safe and established actors of the mobile application business. These newcomers have caused significant structural changes by imposing and enforcing their own rules for the future of mobile application development. The implications of these changes do not only concern the mobile network operators and mobile phone manufacturers. This changed environment also brings additional opportunities and constraints for current mobile application developers. Therefore, developers need to assess what their options are and how they can take advantages of these current trends. In this paper, we take a developer’s perspective in order to explore how the structural changes will influence the mobile application development markets. Moreover, we discuss what aspects developers need to take into account in order to position themselves within the current trends.
Low-Cost Quality Control and Nondestructive Evaluation Technologies for General Aviation Structures
NASA Technical Reports Server (NTRS)
Cramer, K. Elliott; Gavinsky, Bob; Semanskee, Grant
1998-01-01
NASA's Advanced General Aviation Transport Experiments (AGATE) Program has as a goal to reduce the overall cost of producing private aviation aircraft while maintaining the safety of these aircraft. In order to successfully meet this goal, it is necessary to develop nondestructive inspection techniques which will facilitate the production of the materials used in these aircraft and assure the quality necessary to maintain airworthiness. This paper will discuss a particular class of general aviation materials and several nondestructive inspection techniques that have proven effective for making these inspections. Additionally, this paper will discuss the investigation and application of other commercially available quality control techniques applicable to these structures.
Layered Composite Analysis Capability
NASA Technical Reports Server (NTRS)
Narayanaswami, R.; Cole, J. G.
1985-01-01
Laminated composite material construction is gaining popularity within industry as an attractive alternative to metallic designs where high strength at reduced weights is of prime consideration. This has necessitated the development of an effective analysis capability for the static, dynamic and buckling analyses of structural components constructed of layered composites. Theoretical and user aspects of layered composite analysis and its incorporation into CSA/NASTRAN are discussed. The availability of stress and strain based failure criteria is described which aids the user in reviewing the voluminous output normally produced in such analyses. Simple strategies to obtain minimum weight designs of composite structures are discussed. Several example problems are presented to demonstrate the accuracy and user convenient features of the capability.
Acoustical, morphological and optical properties of oral rehydration salts (ORS)
DOE Office of Scientific and Technical Information (OSTI.GOV)
George, Preetha Mary, E-mail: preethageoti@gmail.com, E-mail: jayakumars030@gmail.com; Divya, P.; Jayakumar, S., E-mail: preethageoti@gmail.com, E-mail: jayakumars030@gmail.com
Ultrasonic velocity, density and viscosity were measured in different concentrations of oral rehydration salts (ORS) at room temperature 303 k. From the experimental data other related thermodynamic parameters, viz adiabatic compressibility, intermolecular free length, acoustic impedence, relaxation time are calculated. The experimental data were discussed in the light of molecular interaction existing in the liquid mixtures. The results have been discussed in terms of solute-solvent interaction between the components. Structural characterization is important for development of new material. The morphology, structure and grain size of the samples are investigated by SEM. The optical properties of the sample have been studied usingmore » UV Visible spectroscopy.« less
Proteoglycomics: Recent Progress and Future Challenges
Ly, Mellisa; Laremore, Tatiana N.
2010-01-01
Abstract Proteoglycomics is a systematic study of structure, expression, and function of proteoglycans, a posttranslationally modified subset of a proteome. Although relying on the established technologies of proteomics and glycomics, proteoglycomics research requires unique approaches for elucidating structure–function relationships of both proteoglycan components, glycosaminoglycan chain, and core protein. This review discusses our current understanding of structure and function of proteoglycans, major players in the development, normal physiology, and disease. A brief outline of the proteoglycomic sample preparation and analysis is provided along with examples of several recent proteoglycomic studies. Unique challenges in the characterization of glycosaminoglycan component of proteoglycans are discussed, with emphasis on the many analytical tools used and the types of information they provide. PMID:20450439
Plasticity - Theory and finite element applications.
NASA Technical Reports Server (NTRS)
Armen, H., Jr.; Levine, H. S.
1972-01-01
A unified presentation is given of the development and distinctions associated with various incremental solution procedures used to solve the equations governing the nonlinear behavior of structures, and this is discussed within the framework of the finite-element method. Although the primary emphasis here is on material nonlinearities, consideration is also given to geometric nonlinearities acting separately or in combination with nonlinear material behavior. The methods discussed here are applicable to a broad spectrum of structures, ranging from simple beams to general three-dimensional bodies. The finite-element analysis methods for material nonlinearity are general in the sense that any of the available plasticity theories can be incorporated to treat strain hardening or ideally plastic behavior.
Zhou, Jie-Bin; Luo, Rong; Zheng, Ying-Lin; Pang, Ji-Yan
2018-01-01
Numerous studies have indicated that marine natural products are one of the most important sources of the lead compounds in drug discovery for their unique structures, various bioactivities and less side effects. In this review, the marine natural products with cardiovascular pharmacological effects reported after 2000 will be presented. Their structural types, relevant biological activities, origin of isolation and information of strain species will be discussed in detail. Finally, by describing our studies as an example, we also discuss the chances and challenges for translating marine-derived compounds into preclinical or clinical trials. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.
Action of ionizing radiation on epoxy resins
DOE Office of Scientific and Technical Information (OSTI.GOV)
Van de Voorde, M. E.
1970-12-01
The resistance of classical and experimental epoxy resins to irradiation was studied. The resistance to irradiation of epoxy resins of diverse compositions as well as the development of resins having a radioresistance that approaches that of certain ceramics are discussed. Sources of irradiation and the techniques of dosimetry used are described. The structures of certain epoxy resins and of hardeners are given. The preparation of these resins and their physical properties is described. The effects of radiation on epoxy resins, as well as conditions of irradiation, and suggested mechanisms for degradation of the irradiated resins are discussed. The relationship betweenmore » chemical structure of the resins and their physical properties is evaluated. (115 references) (JCB)« less
NASA Technical Reports Server (NTRS)
Lin, C. C.
1971-01-01
The question whether the galactic spiral arms are material objects or wave patterns is discussed. A semiempirical approach is adopted in presenting the concept of density waves. The theory of density waves is considered, giving attention to a survey of theoretical developments by analytical methods, the implication of a spiral pattern of density waves, spirals with moderately small pitch angle, and the origin and permanence of galactic spirals. The theoretical aspects discussed are tested against more detailed observations in the Milky Way system. It is pointed out that the density wave concept introduced by Lindblad, including the material concentration of both gas and stars, is the essential basis for the spiral structure of disk-shaped galaxies.
A New Approach in Force-Limited Vibration Testing of Flight Hardware
NASA Technical Reports Server (NTRS)
Kolaini, Ali R.; Kern, Dennis L.
2012-01-01
The force-limited vibration test approaches discussed in NASA-7004C were developed to reduce overtesting associated with base shake vibration tests of aerospace hardware where the interface responses are excited coherently. This handbook outlines several different methods of specifying the force limits. The rationale for force limiting is based on the disparity between the impedances of typical aerospace mounting structures and the large impedances of vibration test shakers when the interfaces in general are coherently excited. Among these approaches, the semi-empirical method is presently the most widely used method to derive the force limits. The inclusion of the incoherent excitation of the aerospace structures at mounting interfaces has not been accounted for in the past and provides the basis for more realistic force limits for qualifying the hardware using shaker testing. In this paper current methods for defining the force limiting specifications discussed in the NASA handbook are reviewed using data from a series of acoustic and vibration tests. A new approach based on considering the incoherent excitation of the structural mounting interfaces using acoustic test data is also discussed. It is believed that the new approach provides much more realistic force limits that may further remove conservatism inherent in shaker vibration testing not accounted for by methods discussed in the NASA handbook. A discussion on using FEM/BEM analysis to obtain realistic force limits for flight hardware is provided.