Multiscale Pores in TBCs for Lower Thermal Conductivity

NASA Astrophysics Data System (ADS)

Zhang, Wei-Wei; Li, Guang-Rong; Zhang, Qiang; Yang, Guan-Jun

2017-08-01

The morphology and pattern (including orientation and aspect ratio) of pores in thermal barrier coatings (TBCs) significantly affect their thermal insulation performance. In this work, finite element analysis was used to comprehensively understand the thermal insulation effect of pores and correlate the effective thermal conductivity with the structure. The results indicated that intersplat pores, and in particular their aspect ratio, dominantly affect the heat transfer in the top coat. The effective thermal conductivity decreased as a function of aspect ratio, since a larger aspect ratio often corresponds to a greater proportion of effective length of the pores. However, in conventional plasma-sprayed TBCs, intersplat pores often fail to maximize thermal insulation due to their distinct lower aspect ratios. Therefore, considering this effect of aspect ratio, a new structure design with multiscale pores is proposed and a corresponding structural model developed to correlate the thermal properties with this pore-rich structure. The predictions of the model are well consistent with experimental data. This study provides comprehensive understanding of the effect of pores on the thermal insulation performance, shedding light on the possibility of structural tailoring to obtain advanced TBCs with lower thermal conductivity.

Multidisciplinary Analysis and Optimal Design: As Easy as it Sounds?

NASA Technical Reports Server (NTRS)

Moore, Greg; Chainyk, Mike; Schiermeier, John

2004-01-01

The viewgraph presentation examines optimal design for precision, large aperture structures. Discussion focuses on aspects of design optimization, code architecture and current capabilities, and planned activities and collaborative area suggestions. The discussion of design optimization examines design sensitivity analysis; practical considerations; and new analytical environments including finite element-based capability for high-fidelity multidisciplinary analysis, design sensitivity, and optimization. The discussion of code architecture and current capabilities includes basic thermal and structural elements, nonlinear heat transfer solutions and process, and optical modes generation.

Engineering aspects of the application of structural materials in the 5 MW-ESS-mercury-target

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

Guttek, B.

1996-06-01

A main problem of the ESS-Hg-target development and the design of the components of its primary Hg-circuit is the choice of structural materials. As designing, calculations and experiments with elected materials take time and are very costy, a preview on their successful application has to be done before as detailed as possible. One aspect on this is to have the knowledge of characteristics values of the structural material candidates under the occuring mechanical and thermal loads, irradiation, corrosion and erosion. Another point is the technology of engineering concerning the manufacturing, welding, surface treatment, and quality control of such parts andmore » components under the demand to reach maximum lifetime.« less

Materials and structural aspects of advanced gas-turbine helicopter engines

NASA Technical Reports Server (NTRS)

Freche, J. C.; Acurio, J.

1979-01-01

The key to improved helicopter gas turbine engine performance lies in the development of advanced materials and advanced structural and design concepts. The modification of the low temperature components of helicopter engines (such as the inlet particle separator), the introduction of composites for use in the engine front frame, the development of advanced materials with increased use-temperature capability for the engine hot section, can result in improved performance and/or decreased engine maintenance cost. A major emphasis in helicopter engine design is the ability to design to meet a required lifetime. This, in turn, requires that the interrelated aspects of higher operating temperatures and pressures, cooling concepts, and environmental protection schemes be integrated into component design. The major material advances, coatings, and design life-prediction techniques pertinent to helicopter engines are reviewed; the current state-of-the-art is identified; and when appropriate, progress, problems, and future directions are assessed.

Structural Pain Compensating Flight Control

NASA Technical Reports Server (NTRS)

Miller, Chris J.

2014-01-01

The problem of control command and maneuver induced structural loads is an important aspect of any control system design. Designers must design the aircraft structure and the control architecture to achieve desired piloted control responses while limiting the imparted structural loads. The classical approach is to build the structure with high margins, restrict control surface commands to known good combinations, and train pilots to follow procedural maneuvering limitations. With recent advances in structural sensing and the continued desire to improve safety and vehicle fuel efficiency, it is both possible and desirable to develop control architectures that enable lighter vehicle weights while maintaining and improving protection against structural damage.

Blended Interaction Design: A Spatial Workspace Supporting HCI and Design Practice

NASA Astrophysics Data System (ADS)

Geyer, Florian

This research investigates novel methods and techniques along with tool support that result from a conceptual blend of human-computer interaction with design practice. Using blending theory with material anchors as a theoretical framework, we frame both input spaces and explore emerging structures within technical, cognitive, and social aspects. Based on our results, we will describe a framework of the emerging structures and will design and evaluate tool support within a spatial, studio-like workspace to support collaborative creativity in interaction design.

Damage Tolerance Applied to Design of Mid-Size Aircraft

NASA Astrophysics Data System (ADS)

Chaves, Carlos Eduardo

Most of the mid-size aircraft are certified according to FAA Part 25 requirements, and in order to comply with these requirements the majority of the aircraft structure must be damage tolerant. To assure damage tolerance, despite the overall structural behavior, one should look at the details. There is a great amount of analysis tasks and tests that must be carried out in order to guarantee the aircraft structural integrity. This paper presents an overview of Embraer experience with design and analysis for damage tolerance during the last 30 years. Aspects like DT analysis for metallic and composite structures, selection of appropriate materials, loads, definition of limits of validity and definition of inspection intervals will be addressed along this work. Selected structural tests that have been performed for validation of modeling predictions will be presented. Some aspects to be discussed are related to the design differences between commercial jets, which are usually subjected to high usage conditions, business jets and military aircraft. Further, the application of future technologies, such as structural health monitoring, and also of new materials and manufacturing processes that have been evaluated in order to improve the damage tolerance capability of the aircraft structures will be discussed.

Preliminary design characteristics of a subsonic business jet concept employing an aspect ratio 25 strut braced wing

NASA Technical Reports Server (NTRS)

Turriziani, R. V.; Lovell, W. A.; Martin, G. L.; Price, J. E.; Swanson, E. E.; Washburn, G. F.

1980-01-01

The advantages of replacing the conventional wing on a transatlantic business jet with a larger, strut braced wing of aspect ratio 25 were evaluated. The lifting struts reduce both the induced drag and structural weight of the heavier, high aspect ratio wing. Compared to the conventional airplane, the strut braced wing design offers significantly higher lift to drag ratios achieved at higher lift coefficients and, consequently, a combination of lower speeds and higher altitudes. The strut braced wing airplane provides fuel savings with an attendant increase in construction costs.

Telecom Link--A Competitive Simulated Design Exercise.

ERIC Educational Resources Information Center

Freeman, J.; Allen, J.

1982-01-01

Telecom link is a structured design exercise concerned with building a telecommunications link between London and Amsterdam. Designed for A-level physics, the simulation requires a minimum of 10 hours. Aims of the exercise, design specifications and technical aspects, and summaries of four possible technologies used in the simulation are…

Students-Designers' Professional Competencies Formation by Means of Folk Arts and Crafts

ERIC Educational Resources Information Center

Budkeev, Sergey Mikhailovich; Kiryushina, Julia Vladimirovna; Shokorova, Larisa Vladimirovna

2016-01-01

This article reviewed the structure of design activities, special aspects of the specialists' training in multi-disciplinary design environment, the formation process of their cultural and professional competences, necessary for artistic, creative and research activities in the field of design. It identified the components of the national…

Structured FORTRAN Preprocessor

NASA Technical Reports Server (NTRS)

Flynn, J. A.; Lawson, C. L.; Van Snyder, W.; Tsitsivas, H. N.

1985-01-01

SFTRAN3 supports structured programing in FORTRAN environment. Language intended particularly to support two aspects of structured programing -- nestable single-entry control structures and modularization and top-down organization of code. Code designed and written using these SFTRAN3 facilities have fewer initial errors, easier to understand and less expensive to maintain and modify.

A Cache Design to Exploit Structural Locality

DTIC Science & Technology

1991-12-01

memory and secondary storage. Main memory was used to store the instructions and data of an executing pro- gram, while secondary storage held programs ...efficiency of the CPU and faster turnaround of executing programs . In addition to the well known spatial and temporal aspects of locality, Hobart has...identified a third aspect, which he has called structural locality (9). This type of locality is defined as the tendency of an executing program to

Taking Action--Mathematics Curricular Organization for Effective Teaching and Learning

ERIC Educational Resources Information Center

Appelbaum, Peter

2009-01-01

The curricular structure of Taking Action is described and analyzed as a form of culturally responsive and culturally specific pedagogy. In this design structure, students reconsider what they have done and identify key aspects of their experience. Based on this reflection, they design a way to interact with people outside of their class in order…

Advanced composite structures. [metal matrix composites - structural design criteria for spacecraft construction materials

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.

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.

Structural design optimization with survivability dependent constraints application: Primary wing box of a multi-role fighter

NASA Technical Reports Server (NTRS)

Dolvin, Douglas J.

1992-01-01

The superior survivability of a multirole fighter is dependent upon balanced integration of technologies for reduced vulnerability and susceptability. The objective is to develop a methodology for structural design optimization with survivability dependent constraints. The design criteria for optimization will be survivability in a tactical laser environment. The following analyses are studied to establish a dependent design relationship between structural weight and survivability: (1) develop a physically linked global design model of survivability variables; and (2) apply conventional constraints to quantify survivability dependent design. It was not possible to develop an exact approach which would include all aspects of survivability dependent design, therefore guidelines are offered for solving similar problems.

A review on non-linear aeroelasticity of high aspect-ratio wings

NASA Astrophysics Data System (ADS)

Afonso, Frederico; Vale, José; Oliveira, Éder; Lau, Fernando; Suleman, Afzal

2017-02-01

Current economic constraints and environmental regulations call for design of more efficient aircraft configurations. An observed trend in aircraft design to reduce the lift induced drag and improve fuel consumption and emissions is to increase the wing aspect-ratio. However, a slender wing is more flexible and subject to higher deflections under the same operating conditions. This effect may lead to changes in dynamic behaviour and in aeroelastic response, potentially resulting in instabilities. Therefore, it is important to take into account geometric non-linearities in the design of high aspect-ratio wings, as well as having accurate computational codes that couple the aerodynamic and structural models in the presence of non-linearities. Here, a review on the state-of-the-art on non-linear aeroelasticity of high aspect-ratio wings is presented. The methodologies employed to analyse high aspect-ratio wings are presented and their applications discussed. Important observations from the state-of-the-art studies are drawn and the current challenges in the field are identified.

Configuration design studies and wind tunnel tests of an energy efficient transport with a high-aspect-ratio supercritical wing

NASA Technical Reports Server (NTRS)

Henne, P. A.; Dahlin, J. A.; Peavey, C. C.; Gerren, D. S.

1982-01-01

The results of design studies and wind tunnel tests of high aspect ratio supercritical wings suitable for a medium range, narrow body transport aircraft flying near M=0.80 were presented. The basic characteristics of the wing design were derived from system studies of advanced transport aircraft where detailed structural and aerodynamic tradeoffs were used to determine the most optimum design from the standpoint of fuel usage and direct operating cost. These basic characteristics included wing area, aspect ratio, average thickness, and sweep. The detailed wing design was accomplished through application of previous test results and advanced computational transonic flow procedures. In addition to the basic wing/body development, considerable attention was directed to nacelle/plyon location effects, horizontal tail effects, and boundary layer transition effects. Results of these tests showed that the basic cruise performance objectives were met or exceeded.

Comprehensive Aspectual UML Approach to Support AspectJ

PubMed Central

Magableh, Aws; Shukur, Zarina; Mohd. Ali, Noorazean

2014-01-01

Unified Modeling Language is the most popular and widely used Object-Oriented modelling language in the IT industry. This study focuses on investigating the ability to expand UML to some extent to model crosscutting concerns (Aspects) to support AspectJ. Through a comprehensive literature review, we identify and extensively examine all the available Aspect-Oriented UML modelling approaches and find that the existing Aspect-Oriented Design Modelling approaches using UML cannot be considered to provide a framework for a comprehensive Aspectual UML modelling approach and also that there is a lack of adequate Aspect-Oriented tool support. This study also proposes a set of Aspectual UML semantic rules and attempts to generate AspectJ pseudocode from UML diagrams. The proposed Aspectual UML modelling approach is formally evaluated using a focus group to test six hypotheses regarding performance; a “good design” criteria-based evaluation to assess the quality of the design; and an AspectJ-based evaluation as a reference measurement-based evaluation. The results of the focus group evaluation confirm all the hypotheses put forward regarding the proposed approach. The proposed approach provides a comprehensive set of Aspectual UML structural and behavioral diagrams, which are designed and implemented based on a comprehensive and detailed set of AspectJ programming constructs. PMID:25136656

Canadian Building Digests 1-100 (With Index).

ERIC Educational Resources Information Center

National Research Council of Canada, Ottawa (Ontario). Div. of Building Research.

One hundred different topics related to the technical aspects of building design and construction are discussed. The major areas of discussion are--(1) the effects of climate on building materials, (2) site and soil analysis, (3) acoustical and thermal design considerations, (4) fire and building design, (5) structural analysis and design, and (6)…

Data Banks; Bibliography.

ERIC Educational Resources Information Center

van der Aa, H. J., Comp.; And Others

This 249 item, mostly annotated bibliography cites literature on the general themes of basic principles, hardware, software and application studies of data bases. The broad categories are principles, development possibilities, organizational design, bibliographies, economic aspects, data structure-design, file organization, programing, aviation,…

Structural dynamics technology research in NASA: Perspective on future needs

NASA Technical Reports Server (NTRS)

1979-01-01

The perspective of a NASA ad hoc study group on future research needs in structural dynamics within the aerospace industry is presented. The common aspects of the design process across the industry are identified and the role of structural dynamics is established through a discussion of various design considerations having their basis in structural dynamics. The specific structural dynamics issues involved are identified and assessed as to their current technological status and trends. Projections of future requirements based on this assessment are made and areas of research to meet them are identified.

A Model for Teaching Information Design

ERIC Educational Resources Information Center

Pettersson, Rune

2011-01-01

The author presents his views on the teaching of information design. The starting point includes some general aspects of teaching and learning. The multidisciplinary structure and content of information design as well as the combined practical and theoretical components influence studies of the discipline. Experiences from working with a model for…

Design of Lexicons in Some Natural Language Systems.

ERIC Educational Resources Information Center

Cercone, Nick; Mercer, Robert

1980-01-01

Discusses an investigation of certain problems concerning the structural design of lexicons used in computational approaches to natural language understanding. Emphasizes three aspects of design: retrieval of relevant portions of lexicals items, storage requirements, and representation of meaning in the lexicon. (Available from ALLC, Dr. Rex Last,…

Creating 3D Physical Models to Probe Student Understanding of Macromolecular Structure

ERIC Educational Resources Information Center

Cooper, A. Kat; Oliver-Hoyo, M. T.

2017-01-01

The high degree of complexity of macromolecular structure is extremely difficult for students to process. Students struggle to translate the simplified two-dimensional representations commonly used in biochemistry instruction to three-dimensional aspects crucial in understanding structure-property relationships. We designed four different physical…

Analysis, preliminary design and simulation systems for control-structure interaction problems

NASA Technical Reports Server (NTRS)

Park, K. C.; Alvin, Kenneth F.

1991-01-01

Software aspects of control-structure interaction (CSI) analysis are discussed. The following subject areas are covered: (1) implementation of a partitioned algorithm for simulation of large CSI problems; (2) second-order discrete Kalman filtering equations for CSI simulations; and (3) parallel computations and control of adaptive structures.

Technology of civil usage of composites. [in commercial aircraft structures

NASA Technical Reports Server (NTRS)

Kemp, D. E.

1977-01-01

The paper deals with the use of advanced composites in structural components of commercial aircraft. The need for testing the response of a material system to service environment is discussed along with methods for evaluating design and manufacturing aspects of a built-up structure under environmental conditions and fail-safe (damage-tolerance) evaluation of structures. Crashworthiness aspects, the fire-hazard potential, and electrical damage of composite structures are considered. Practical operational experience with commercial aircraft is reviewed for boron/epoxy foreflaps, Kevlar/epoxy fillets and fairings, graphite/epoxy spoilers, graphite/polysulfone spoilers, graphite/epoxy floor posts, boron/aluminum aft pylon skin panels, graphite/epoxy engine nose cowl outer barrels, and graphite/epoxy upper aft rudder segments.

Teaching Case: Analysis of an Electronic Voting System

ERIC Educational Resources Information Center

Thompson, Nik; Toohey, Danny

2014-01-01

This teaching case discusses the analysis of an electronic voting system. The development of the case was motivated by research into information security and management, but as it includes procedural aspects, organizational structure and personnel, it is a suitable basis for all aspects of systems analysis, planning and design tasks. The material…

Analysis of Work Design in Rubber Processing Plant

NASA Astrophysics Data System (ADS)

Wahyuni, Dini; Nasution, Harmein; Budiman, Irwan; Wijaya, Khairini

2018-02-01

The work design illustrates how structured jobs, tasks, and roles are defined and modified and their impact on individuals, groups, and organizations. If the work is not designed well, the company must pay greater costs for workers' health, longer production processes or even penalties for not being able to meet the delivery schedule. This is visible to the condition in a rubber processing factory in North Sumatra. Work design aspects such as layouts, machinery and equipment, worker's physical working environment, work methods, and organizational policies have not been well-organized. Coagulum grinding machines into sheets are often damaged, resulting in 4 times the delay of product delivery in 2016, the presence of complaints of heat exposure submitted by workers, and workstation that has not been properly arranged is an indication of the need for work design. The research data will be collected through field observation, and distribution of questionnaires related aspects of work design. The result of the analysis depends on the respondent's answer from the distributed questionnaire regarding the 6 aspects studied.

Complexity of Curved Glass Structures

NASA Astrophysics Data System (ADS)

Kosić, T.; Svetel, I.; Cekić, Z.

2017-11-01

Despite the increasing number of research on the architectural structures of curvilinear forms and technological and practical improvement of the glass production observed over recent years, there is still a lack of comprehensive codes and standards, recommendations and experience data linked to real-life curved glass structures applications regarding design, manufacture, use, performance and economy. However, more and more complex buildings and structures with the large areas of glass envelope geometrically complex shape are built every year. The aim of the presented research is to collect data on the existing design philosophy on curved glass structure cases. The investigation includes a survey about how architects and engineers deal with different design aspects of curved glass structures with a special focus on the design and construction process, glass types and structural and fixing systems. The current paper gives a brief overview of the survey findings.

Robotic influence in the conceptual design of mechanical systems in space and vice versa - A survey

NASA Technical Reports Server (NTRS)

Sanger, George F.

1988-01-01

A survey of methods using robotic devices to construct structural elements in space is presented. Two approaches to robotic construction are considered: one in which the structural elements are designed using conventional aerospace techniques which tend to constrain the function aspects of robotics and one in which the structural elements are designed from the conceptual stage with built-in robotic features. Examples are presented of structural building concepts using robotics, including the construction of the SP-100 nuclear reactor power system, a multimirror large aperture IR space telescope concept, retrieval and repair in space, and the Flight Telerobotic Servicer.

Development of a composite repair and the associated inspection intervals for the F-111C stiffener runout region

NASA Technical Reports Server (NTRS)

Jones, R.; Molent, L.; Paul, J.; Saunders, T.; Chiu, W. K.

1994-01-01

This paper presents an overview of the structural aspects of the design and development of a local reinforcement designed to lower the stresses in a region of the F-111C wing fitting which is prone to cracking. The stress analysis, with particular emphasis on the use of a unified constitutive model for the cyclic inelastic response of the structure, representative specimen testing, thermal analysis and full scale static testing of this design are summarized.

Thin-film module circuit design: Practical and reliability aspects

NASA Technical Reports Server (NTRS)

Daiello, R. V.; Twesme, E. N.

1985-01-01

This paper will address several aspects of the design and construction of submodules based on thin film amorphous silicon (a-Si) p i n solar cells. Starting from presently attainable single cell characteristics, and a realistic set of specifications, practical module designs are discussed from the viewpoints of efficient designs, the fabrication requirements, and reliability concerns. The examples center mostly on series interconnected modules of the superstrate type with detailed discussions of each portion of the structure in relation to its influence on module efficiency. Emphasis is placed on engineering topics such as: area coverage, optimal geometries, and cost and reliability. Practical constraints on achieving optimal designs, along with some examples of potential pitfalls in the manufacture and subsequent performance of a-Si modules are discussed.

Science in the liberal arts curriculum - A personal view

NASA Astrophysics Data System (ADS)

Young, A.

1983-12-01

A discussion concerning the character and importance of the epistemological structure of science notes that contemporary textbooks and traditional courses used in the scientific component of the liberal arts curriculum do not communicate that structure. A course, designated 'The Structure of Scientific Thought', is suggested as a vehicle for communicating to nonscientists the fundamental aspects of scientific inquiry, and the shortcommings of traditional textbooks and courses are illustrated by contrast to its contents. Attention is given to such aspects of the structure of science as empiricism, conceptualization, the relationships among science, truth and reality, theoretical hierarchies, the distinction between explanation and understanding, and the centrality of abstraction and mathematical formalism in science.

Pulsed ultrasonic instruments for monitoring the strength of materials

NASA Astrophysics Data System (ADS)

Korolev, Mikhail Viktorovich; Starikov, Boris Pavlovich; Karpel'Son, Arkadii Efimovich

The book is concerned with various aspects of the design of portable instruments for the ultrasonic monitoring of the strength and ductile characteristics of structural materials, including metals, alloys, and ceramics. Particular attention is given to methods for increasing the accuracy of the instruments while reducing their size, which is particularly important in the design of miniature instruments for the real-time monitoring of machines, mechanisms, and structures during operation.

Structural analysis of a ship on global aspect using ANSYS

NASA Astrophysics Data System (ADS)

Rahman, M. Muzibur; Kamol, Rajia Sultana; Islam, Reyana

2017-12-01

Ship is a complex geometry which undergoes a combination of loadings such as hydrostatic, hydrodynamic, wind, wave etc. at sea and thus adequate strength in a ship has always been one of the most challenging tasks for the ship designers. International Maritime Organization (IMO) and classification societies are providing the standards to ensure the adequacy of strength for the ship against all demands throughout its service life. Thus, structural analysis is needed to assess the overall strength of hull, and the means in this regard are based on finite element method which may be applied either local or global aspect of the ship. This paper is an attempt to carry out the structural analysis of a ship in global aspect using ANSYS software to locate the most stress concentration and deformed area, which will have ultimate effect on fatigue fracture.

Three-dimensional Numerical Analysis on Blade Response of Vertical Axis Tidal Current Turbine Under Operational Condition

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

Li, Ye; Karri, Naveen K.; Wang, Qi

Tidal power as a large-scale renewable source of energy has been receiving significant attention recently because of its advantages over the wind and other renewal energy sources. The technology used to harvest energy from tidal current is called a tidal current turbine. Though some of the principles of wind turbine design are applicable to tidal current turbines, the design of latter ones need additional considerations like cavitation damage, corrosion etc. for the long-term reliability of such turbines. Depending up on the orientation of axis, tidal current turbines can be classified as vertical axis turbines or horizontal axis turbines. Existing studiesmore » on the vertical axis tidal current turbine focus more on the hydrodynamic aspects of the turbine rather than the structural aspects. This paper summarizes our recent efforts to study the integrated hydrodynamic and structural aspects of the vertical axis tidal current turbines. After reviewing existing methods in modeling tidal current turbines, we developed a hybrid approach that combines discrete vortex method -finite element method that can simulate the integrated hydrodynamic and structural response of a vertical axis turbine. This hybrid method was initially employed to analyze a typical three-blade vertical axis turbine. The power coefficient was used to evaluate the hydrodynamic performance, and critical deflection was considered to evaluate the structural reliability. A sensitivity analysis was also conducted with various turbine height-to-radius ratios. The results indicate that both the power output and failure probability increase with the turbine height, suggesting a necessity for optimal design. An attempt to optimize a 3-blade vertical axis turbine design with hybrid method yielded a ratio of turbine height to radius (H/R) about 3.0 for reliable maximum power output.« less

Fabrication and characterization of artificial hair cell sensor based on MWCNT-PDMS composite

NASA Astrophysics Data System (ADS)

Kim, Chi Yeon; Lee, Hyun Sup; Cho, Yo Han; Joh, Cheeyoung; Choi, Pyung; Park, Seong Jin

2011-06-01

The aim of this work is to design and fabricate a flow sensor using an artificial hair cell (AHC) inspired by biological hair cells of fish. The sensor consists of a single cilium structure with high aspect ratio and a mechanoreceptor using force sensitive resistor (FSR). The cilium structure is designed for capturing a drag force with direction due to flow field around the sensor and the mechanoreceptor is designed for sensing the drag force with direction from the cilium structure and converting it into an electric signal. The mechanoreceptor has a symmetric four electrodes to sense the drag force and its direction. To fabricate the single cilium structure with high aspect ratio, we have proposed a new design concept using a separated micro mold system (SMS) fabricated by the LIGA process. For a successful replication of the cilium structure, we used the hot embossing process with the help of a double-sided mold system. We used a composite of multiwall carbon nanotube and polydimethylsiloxane (MWCNT-PDMS). The performance of the mechanoreceptors was measured by a computer-controlled nanoindenter. We carried out several experiments with the sensor in the different flow rate and direction using the experimental test apparatus. To calibrate the sensor and calculate the velocity with direction based the signal from the sensor, we analyzed the coupled phenomena between flow field and the cilium structure to calculate the deflection of the cilium structure and the drag force applying to the cilium structure due to the flow field around sensor.

A small perturbation based optimization approach for the frequency placement of high aspect ratio wings

NASA Astrophysics Data System (ADS)

Goltsch, Mandy

Design denotes the transformation of an identified need to its physical embodiment in a traditionally iterative approach of trial and error. Conceptual design plays a prominent role but an almost infinite number of possible solutions at the outset of design necessitates fast evaluations. The corresponding practice of empirical equations and low fidelity analyses becomes obsolete in the light of novel concepts. Ever increasing system complexity and resource scarcity mandate new approaches to adequately capture system characteristics. Contemporary concerns in atmospheric science and homeland security created an operational need for unconventional configurations. Unmanned long endurance flight at high altitudes offers a unique showcase for the exploration of new design spaces and the incidental deficit of conceptual modeling and simulation capabilities. Structural and aerodynamic performance requirements necessitate light weight materials and high aspect ratio wings resulting in distinct structural and aeroelastic response characteristics that stand in close correlation with natural vibration modes. The present research effort evolves around the development of an efficient and accurate optimization algorithm for high aspect ratio wings subject to natural frequency constraints. Foundational corner stones are beam dimensional reduction and modal perturbation redesign. Local and global analyses inherent to the former suggest corresponding levels of local and global optimization. The present approach departs from this suggestion. It introduces local level surrogate models to capacitate a methodology that consists of multi level analyses feeding into a single level optimization. The innovative heart of the new algorithm originates in small perturbation theory. A sequence of small perturbation solutions allows the optimizer to make incremental movements within the design space. It enables a directed search that is free of costly gradients. System matrices are decomposed based on a Timoshenko stiffness effect separation. The formulation of respective linear changes falls back on surrogate models that approximate cross sectional properties. Corresponding functional responses are readily available. Their direct use by the small perturbation based optimizer ensures constitutive laws and eliminates a previously necessary optimization at the local level. The scope of the present work is derived from an existing configuration such as a conceptual baseline or a prototype that experiences aeroelastic instabilities. Due to the lack of respective design studies in the traditional design process it is not uncommon for an initial wing design to have such stability problems. The developed optimization scheme allows the effective redesign of high aspect ratio wings subject to natural frequency objectives. Its successful application is demonstrated by three separate optimization studies. The implementation results of all three studies confirm that the gradient liberation of the new methodology brings about great computational savings. A generic wing study is used to indicate the connection between the proposed methodology and the aeroelastic stability problems outlined in the motivation. It is also used to illustrate an important practical aspect of structural redesign, i.e., a minimum departure from the existing baseline configuration. The proposed optimization scheme is naturally conducive to this practical aspect by using a minimum change optimization criterion. However, only an elemental formulation truly enables a minimum change solution. It accounts for the spanwise significance of a structural modification to the mode of interest. This idea of localized reinforcement greatly benefits the practical realization of structural redesign efforts. The implementation results also highlight the fundamental limitation of the proposed methodology. The exclusive consideration of mass and stiffness effects on modal response characteristics disregards other disciplinary problems such as allowable stresses or buckling loads. Both are of central importance to the structural integrity of an aircraft but are currently not accounted for in the proposed optimization scheme. The concluding discussion thus outlines the need for respective constraints and/or additional analyses to capture all requirements necessary for a comprehensive structural redesign study.

Integrated aerodynamic-structural design of a forward-swept transport wing

NASA Technical Reports Server (NTRS)

Haftka, Raphael T.; Grossman, Bernard; Kao, Pi-Jen; Polen, David M.; Sobieszczanski-Sobieski, Jaroslaw

1989-01-01

The introduction of composite materials is having a profound effect on aircraft design. Since these materials permit the designer to tailor material properties to improve structural, aerodynamic and acoustic performance, they require an integrated multidisciplinary design process. Futhermore, because of the complexity of the design process, numerical optimization methods are required. The utilization of integrated multidisciplinary design procedures for improving aircraft design is not currently feasible because of software coordination problems and the enormous computational burden. Even with the expected rapid growth of supercomputers and parallel architectures, these tasks will not be practical without the development of efficient methods for cross-disciplinary sensitivities and efficient optimization procedures. The present research is part of an on-going effort which is focused on the processes of simultaneous aerodynamic and structural wing design as a prototype for design integration. A sequence of integrated wing design procedures has been developed in order to investigate various aspects of the design process.

A Novel Coupled Resonator Photonic Crystal Design in Lithium Niobate for Electrooptic Applications

DOE PAGES

Ozturk, Birol; Yavuzcetin, Ozgur; Sridhar, Srinivas

2015-01-01

High-aspect-ratio photonic crystal air-hole fabrication on bulk Lithium Niobate (LN) substrates is extremely difficult due to its inherent resistance to etching, resulting in conical structures and high insertion losses. Here, we propose a novel coupled resonator photonic crystal (CRPC) design, combining a coupled resonator approach with that of Bragg gratings. CRPC design parameters were optimized by analytical calculations and FDTD simulations. CRPC structures with optimized parameters were fabricated and electrooptically tested on bulk LN annealed proton exchange waveguides. Low insertion loss and large electrooptic effect were observed with the fabricated devices, making the CRPC design a promising structure for electroopticmore » device applications.« less

Graphic Design in Educational Television.

ERIC Educational Resources Information Center

Clarke, Beverley

To help educational television (ETV) practitioners achieve maximum clarity, economy and purposiveness, the range of techniques of television graphics is explained. Closed-circuit and broadcast ETV are compared. The design process is discussed in terms of aspect ratio, line structure, cut off, screen size, tone scales, studio apparatus, and…

A fundamental study of drag and an assessment of conventional drag-due-to-lift reduction devices

NASA Astrophysics Data System (ADS)

Yates, J. E.; Donald, C. D.

1986-09-01

The integral conservation laws of fluid mechanics are used to assess the drag efficiency of lifting wings, both CTOL and various out-of-plane configurations. The drag-due-to-lift is separated into two major components: (1) the induced drag-due-to-lift that depends on aspect ratio but is relatively independent of Reynolds number; (2) the form drag-due-to-lift that is independent of aspect ratio but dependent on the details of the wing section design, planform and Reynolds number. For each lifting configuration there is an optimal load distribution that yields the minimum value of drag-due-to-lift. For well designed high aspect ratio CTOL wings the two drag components are independent. With modern design technology CTOL wings can be (and usually are) designed with a drag-due-to-lift efficiency close to unity. Wing tip-devices (winglets, feathers, sails, etc.) can improve drag-due-to-lift efficiency by 10 to 15% if they are designed as an integral part of the wing. As add-on devices they can be detrimental. It is estimated that 25% improvements of wing drag-due-to-lift efficiency can be obtained with joined tip configurations and vertically separated lifting elements without considering additional benefits that might be realized by improved structural efficiency. It is strongly recommended that an integrated aerodynamic/structural approach be taken in the design of (or research on) future out-of-plane configurations.

A fundamental study of drag and an assessment of conventional drag-due-to-lift reduction devices

NASA Technical Reports Server (NTRS)

Yates, J. E.; Donald, C. D.

1986-01-01

The integral conservation laws of fluid mechanics are used to assess the drag efficiency of lifting wings, both CTOL and various out-of-plane configurations. The drag-due-to-lift is separated into two major components: (1) the induced drag-due-to-lift that depends on aspect ratio but is relatively independent of Reynolds number; (2) the form drag-due-to-lift that is independent of aspect ratio but dependent on the details of the wing section design, planform and Reynolds number. For each lifting configuration there is an optimal load distribution that yields the minimum value of drag-due-to-lift. For well designed high aspect ratio CTOL wings the two drag components are independent. With modern design technology CTOL wings can be (and usually are) designed with a drag-due-to-lift efficiency close to unity. Wing tip-devices (winglets, feathers, sails, etc.) can improve drag-due-to-lift efficiency by 10 to 15% if they are designed as an integral part of the wing. As add-on devices they can be detrimental. It is estimated that 25% improvements of wing drag-due-to-lift efficiency can be obtained with joined tip configurations and vertically separated lifting elements without considering additional benefits that might be realized by improved structural efficiency. It is strongly recommended that an integrated aerodynamic/structural approach be taken in the design of (or research on) future out-of-plane configurations.

Proceedings of the Workshop on Computational Aspects in the Control of Flexible Systems, part 1

NASA Technical Reports Server (NTRS)

Taylor, Lawrence W., Jr. (Compiler)

1989-01-01

Control/Structures Integration program software needs, computer aided control engineering for flexible spacecraft, computer aided design, computational efficiency and capability, modeling and parameter estimation, and control synthesis and optimization software for flexible structures and robots are among the topics discussed.

SIP Shear Walls: Cyclic Performance of High-Aspect-Ratio Segments and Perforated Walls

Treesearch

Vladimir Kochkin; Douglas R. Rammer; Kevin Kauffman; Thomas Wiliamson; Robert J. Ross

2015-01-01

Increasing stringency of energy codes and the growing market demand for more energy efficient buildings gives structural insulated panel (SIP) construction an opportunity to increase its use in commercial and residential buildings. However, shear wall aspect ratio limitations and lack of knowledge on how to design SIPs with window and door openings are barriers to the...

A Study of Vehicle Structural Layouts in Post-WWII Aircraft

NASA Technical Reports Server (NTRS)

Sensmeier, Mark D.; Samareh, Jamshid A.

2004-01-01

In this paper, results of a study of structural layouts of post-WWII aircraft are presented. This study was undertaken to provide the background information necessary to determine typical layouts, design practices, and industry trends in aircraft structural design. Design decisions are often predicated not on performance-related criteria, but rather on such factors as manufacturability, maintenance access, and of course cost. For this reason, a thorough understanding of current best practices in the industry is required as an input for the design optimization process. To determine these best practices and industry trends, a large number of aircraft structural cutaway illustrations were analyzed for five different aircraft categories (commercial transport jets, business jets, combat jet aircraft, single engine propeller aircraft, and twin-engine propeller aircraft). Several aspects of wing design and fuselage design characteristics are presented here for the commercial transport and combat aircraft categories. A great deal of commonality was observed for transport structure designs over a range of eras and manufacturers. A much higher degree of variability in structural designs was observed for the combat aircraft, though some discernable trends were observed as well.

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

Lazarus, E.A.; Attenberger, S.E.; Baylor, L.R.

The design of the Spherical Torus Experiment (STX) is discussed. The physics of the plasma are given in a magnetohydrodynamic model. The structural aspects and instrumentation of the device are described. 19 refs., 103 figs. (WRF)

AIAA/USAF/NASA/OAI Symposium on Multidisciplinary Analysis and Optimization, 4th, Cleveland, OH, Sept. 21-23, 1992, Technical Papers. Pts. 1 & 2

NASA Technical Reports Server (NTRS)

1992-01-01

The papers presented at the symposium cover aerodynamics, design applications, propulsion systems, high-speed flight, structures, controls, sensitivity analysis, optimization algorithms, and space structures applications. Other topics include helicopter rotor design, artificial intelligence/neural nets, and computational aspects of optimization. Papers are included on flutter calculations for a system with interacting nonlinearities, optimization in solid rocket booster application, improving the efficiency of aerodynamic shape optimization procedures, nonlinear control theory, and probabilistic structural analysis of space truss structures for nonuniform thermal environmental effects.

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

Sandvik, K.; Karal, K.

The paper gives a general description of the Concrete Gravity Base Structure (GBS) for the Draugen platform installed by Norwegian Contractors a.s. The GBS was installed at the Haltenbank area on the Norwegian continental shelf in May 1993 for A/S Norske Shell. Further, the paper describes the following challenging aspects encountered during the design and construction: design for high frequency response to wave loading, so called ringing, discovered during construction of the GBS; impact of the ringing effect discovery on the construction schedule; design to prevent delamination of concrete structural elements; modifications to prevent damages on pipe work caused bymore » deformations of the concrete structure.« less

JOSE, Jupiter orbiting spacecraft: A systems study, volume 1

NASA Technical Reports Server (NTRS)

1971-01-01

A brief summary of the mechanical properties of Jupiter is presented along with an organizational outline of the entire JOSE program. Other aspects of the program described include: spacecraft design, mission trajectories, altitude control, propulsion subsystem, on-board power supply, spacecraft structures and environmental design considerations, and telemetry.

Delivery of Functionality in Complex Food Systems: Physically Inspired Approaches from Nanoscale to Microscale, Wageningen 18–21 October 2009

PubMed Central

Ubbink, Job; Duchateau, Guus

2010-01-01

The Wageningen Delivery of Functionality symposium covered all aspects involved with food structural design to arrive at high-quality foods which meet demanding customer expectations and regulatory requirements. The symposium integrated aspects from the structural organization of foods at molecular and supramolecular scales to dedicated techniques required to describe and visualize such structures, the gastro-intestinal events and how to model these in a laboratory setting, and finally the impact those food structures and ingredients have on the consumer’s physiology and on the human perception. As an interdisciplinary platform, bringing together more than 160 researchers from academia and industry, the symposium meanwhile fulfills an important role in the food science community. PMID:21125000

The Shock and Vibration Bulletin: Proceedings on the Symposium on ShocK and Vibration (52nd) Held in New Orleans, Louisiana on 26-28 October 1981. Part 5. Mathematical Modeling and Structural Dynamics

DTIC Science & Technology

1982-05-01

ment analysis to evaluate viscoelastic damping treatments for HCF control . Steps for analyzing passive damping treatments are presented. Design criteria... design earthquake levels could structures such as piers, drydocks, power result in destruction of such critical strut- plants, control towers, and...and J.R. Curreri, "Some Aspects of 2 Vibration Control Support Designs ," The Shock p m 0.0005161 lb-sec n and vibration Symposium Bulletin, The Shock

Semikinematic mount for spatially constrained high aspect ratio spacecraft fold mirrors

NASA Astrophysics Data System (ADS)

Sahu, Rupali; Arora, Hemant; Munjal, Bhawdeep Singh

2017-12-01

An attempt has been made to propose a passive flexure-based semikinematic optimized mounting design for mirror fixing devices (MFDs) to mount spacecraft mirrors made of brittle materials, especially for high aspect ratio mirrors with low available space for mounting in satellites. The traditionally used tangent cantilever spiders occupy a lot of space and are suitable only for small mirrors. Similarly, the efficiency of flexural bipods is lost if not placed 120 deg apart, which is not possible in high aspect ratio mirrors. Two mounting configurations, one with collinear MFDs and the other with staggered MFDs, have been studied. An optimization problem is set up with dimensions of the proposed design as design variables and constraints imposed on structural performance of the mirror assembly. Investigations indicate that both configurations have potential applications in spacecrafts as they have provided feasible results and have satisfactory optical performance as well.

Design and control considerations for industrial and space manipulators

NASA Technical Reports Server (NTRS)

Whitney, D. E.; Book, W. J.; Lynch, P. M.

1974-01-01

This paper is a progress report summarizing theoretical and practical results concerning integration of design and control aspects of manipulator arms for industrial or space applications. The relationships between task specifications, gross motions, fine motions, actuator type and location, size and strength of structural members, control servos and strategies, and overall design evaluation are briefly discussed, with some technical examples.

High Energy Astronomy Observatory, Mission C, Phase A. Volume 2: Preliminary analyses and conceptual design

NASA Technical Reports Server (NTRS)

1972-01-01

An analysis and conceptual design of a baseline mission and spacecraft are presented. Aspects of the HEAO-C discussed include: baseline experiments with X-ray observations of space, analysis of mission requirements, observatory design, structural analysis, thermal control, attitude sensing and control system, communication and data handling, and space shuttle launch and retrieval of HEAO-C.

Design oriented structural analysis

NASA Technical Reports Server (NTRS)

Giles, Gary L.

1994-01-01

Desirable characteristics and benefits of design oriented analysis methods are described and illustrated by presenting a synoptic description of the development and uses of the Equivalent Laminated Plate Solution (ELAPS) computer code. ELAPS is a design oriented structural analysis method which is intended for use in the early design of aircraft wing structures. Model preparation is minimized by using a few large plate segments to model the wing box structure. Computational efficiency is achieved by using a limited number of global displacement functions that encompass all segments over the wing planform. Coupling with other codes is facilitated since the output quantities such as deflections and stresses are calculated as continuous functions over the plate segments. Various aspects of the ELAPS development are discussed including the analytical formulation, verification of results by comparison with finite element analysis results, coupling with other codes, and calculation of sensitivity derivatives. The effectiveness of ELAPS for multidisciplinary design application is illustrated by describing its use in design studies of high speed civil transport wing structures.

Thermal design of composite materials high temperature attachments

NASA Technical Reports Server (NTRS)

1972-01-01

The thermal aspects of using filamentary composite materials as primary airframe structures on advanced atmospheric entry spacecraft such as the space shuttle vehicle were investigated to identify and evaluate potential design approaches for maintaining composite structures within allowable temperature limits at thermal protection system (TPS) attachments and/or penetrations. The investigation included: (1) definition of thermophysical data for composite material structures; (2) parametric characterization and identification of the influence of the aerodynamic heating and attachment design parameters on composite material temperatures; (3) conceptual design, evaluation, and detailed thermal analyses of temperature limiting design concepts; and (4) the development of experimental data for assessment of the thermal design methodologies and data used for evaluation of the temperature-limiting design concepts. Temperature suppression attachment concepts were examined for relative merit. The simple isolator was identified as the most weight-effective concept and was selected for detail design, thermal analysis, and testing. Tests were performed on TPS standoff attachments to boron/aluminum, boron/polyimide and graphite/epoxy composite structures.

The NASTRAN theoretical manual

NASA Technical Reports Server (NTRS)

1981-01-01

Designed to accommodate additions and modifications, this commentary on NASTRAN describes the problem solving capabilities of the program in a narrative fashion and presents developments of the analytical and numerical procedures that underlie the program. Seventeen major sections and numerous subsections cover; the organizational aspects of the program, utility matrix routines, static structural analysis, heat transfer, dynamic structural analysis, computer graphics, special structural modeling techniques, error analysis, interaction between structures and fluids, and aeroelastic analysis.

Langley's CSI evolutionary model: Phase 2

NASA Technical Reports Server (NTRS)

Horta, Lucas G.; Reaves, Mercedes C.; Elliott, Kenny B.; Belvin, W. Keith; Teter, John E.

1995-01-01

Phase 2 testbed is part of a sequence of laboratory models, developed at NASA Langley Research Center, to enhance our understanding on how to model, control, and design structures for space applications. A key problem with structures that must perform in space is the appearance of unwanted vibrations during operations. Instruments, design independently by different scientists, must share the same vehicle causing them to interact with each other. Once in space, these problems are difficult to correct and therefore, prediction via analysis design, and experiments is very important. Phase 2 laboratory model and its predecessors are designed to fill a gap between theory and practice and to aid in understanding important aspects in modeling, sensor and actuator technology, ground testing techniques, and control design issues. This document provides detailed information on the truss structure and its main components, control computer architecture, and structural models generated along with corresponding experimental results.

Knowledge modeling tool for evidence-based design.

PubMed

Durmisevic, Sanja; Ciftcioglu, Ozer

2010-01-01

The aim of this study is to take evidence-based design (EBD) to the next level by activating available knowledge, integrating new knowledge, and combining them for more efficient use by the planning and design community. This article outlines a framework for a performance-based measurement tool that can provide the necessary decision support during the design or evaluation of a healthcare environment by estimating the overall design performance of multiple variables. New knowledge in EBD adds continuously to complexity (the "information explosion"), and it becomes impossible to consider all aspects (design features) at the same time, much less their impact on final building performance. How can existing knowledge and the information explosion in healthcare-specifically the domain of EBD-be rendered manageable? Is it feasible to create a computational model that considers many design features and deals with them in an integrated way, rather than one at a time? The found evidence is structured and readied for computation through a "fuzzification" process. The weights are calculated using an analytical hierarchy process. Actual knowledge modeling is accomplished through a fuzzy neural tree structure. The impact of all inputs on the outcome-in this case, patient recovery-is calculated using sensitivity analysis. Finally, the added value of the model is discussed using a hypothetical case study of a patient room. The proposed model can deal with the complexities of various aspects and the relationships among variables in a coordinated way, allowing existing and new pieces of evidence to be integrated in a knowledge tree structure that facilitates understanding of the effects of various design interventions on overall design performance.

A Comprehensive Structural Dynamic Analysis Approach for Multi Mission Earth Entry Vehicle (MMEEV) Development

NASA Technical Reports Server (NTRS)

Perino, Scott; Bayandor, Javid; Siddens, Aaron

2012-01-01

The anticipated NASA Mars Sample Return Mission (MSR) requires a simple and reliable method in which to return collected Martian samples back to earth for scientific analysis. The Multi-Mission Earth Entry Vehicle (MMEEV) is NASA's proposed solution to this MSR requirement. Key aspects of the MMEEV are its reliable and passive operation, energy absorbing foam-composite structure, and modular impact sphere (IS) design. To aid in the development of an EEV design that can be modified for various missions requirements, two fully parametric finite element models were developed. The first model was developed in an explicit finite element code and was designed to evaluate the impact response of the vehicle and payload during the final stage of the vehicle's return to earth. The second model was developed in an explicit code and was designed to evaluate the static and dynamic structural response of the vehicle during launch and reentry. In contrast to most other FE models, built through a Graphical User Interface (GUI) pre-processor, the current model was developed using a coding technique that allows the analyst to quickly change nearly all aspects of the model including: geometric dimensions, material properties, load and boundary conditions, mesh properties, and analysis controls. Using the developed design tool, a full range of proposed designs can quickly be analyzed numerically and thus the design trade space for the EEV can be fully understood. An engineer can then quickly reach the best design for a specific mission and also adapt and optimize the general design for different missions.

Phased-array-fed antenna configuration study. Volume 1: Technology assessment

NASA Technical Reports Server (NTRS)

Sorbello, R. M.; Zaghloul, A. I.; Lee, B. S.; Siddiqi, S.; Geller, B. D.; Gerson, H. I.; Srinivas, D. N.

1983-01-01

The status of the technologies for phased-array-fed dual reflector systems is reviewed. The different aspects of these technologies, including optical performances, phased array systems, problems encountered in phased array design, beamforming networks, MMIC design and its incorporation into waveguide systems, reflector antenna structures, and reflector deployment mechanisms are addressed.

A More Powerful Test in Three-Level Cluster Randomized Designs

ERIC Educational Resources Information Center

Konstantopoulos, Spyros

2011-01-01

Field experiments that involve nested structures frequently assign treatment conditions to entire groups (such as schools). A key aspect of the design of such experiments includes knowledge of the clustering effects that are often expressed via intraclass correlation. This study provides methods for constructing a more powerful test for the…

Aircraft wing structural design optimization based on automated finite element modelling and ground structure approach

NASA Astrophysics Data System (ADS)

Yang, Weizhu; Yue, Zhufeng; Li, Lei; Wang, Peiyan

2016-01-01

An optimization procedure combining an automated finite element modelling (AFEM) technique with a ground structure approach (GSA) is proposed for structural layout and sizing design of aircraft wings. The AFEM technique, based on CATIA VBA scripting and PCL programming, is used to generate models automatically considering the arrangement of inner systems. GSA is used for local structural topology optimization. The design procedure is applied to a high-aspect-ratio wing. The arrangement of the integral fuel tank, landing gear and control surfaces is considered. For the landing gear region, a non-conventional initial structural layout is adopted. The positions of components, the number of ribs and local topology in the wing box and landing gear region are optimized to obtain a minimum structural weight. Constraints include tank volume, strength, buckling and aeroelastic parameters. The results show that the combined approach leads to a greater weight saving, i.e. 26.5%, compared with three additional optimizations based on individual design approaches.

Does Inquiry Based Learning Affect Students' Beliefs and Attitudes towards Mathematics?

ERIC Educational Resources Information Center

McGregor, Darren

2014-01-01

Ill-structured tasks presented in an inquiry learning environment have the potential to affect students' beliefs and attitudes towards mathematics. This empirical research followed a Design Experiment approach to explore how aspects of using ill-structured tasks may have affected students' beliefs and attitudes. Results showed this task type and…

Multidisciplinary Computational Aerodynamics

DTIC Science & Technology

2013-10-01

flat plate. These wings exhibit large aspect ratio and a highly corrugated structure. Several wind tunnel studies have shown possible advantages...Advances in Turbines Aero-thermo-mechanical Design and Analysis”, IGT Institute, Vancouver, June 2011 Rizzetta: Invited Seminar, University of...pressure turbines for high- altitude aircraft, distributed-roughness transition, flapping wing aerodynamics and laser turrets. Flow Structure and Unsteady

Agricultural Structures. Volume I. Instructor's Guide. Volume 13, Number 1.

ERIC Educational Resources Information Center

Linhardt, Richard E.; Burhoe, Steve

This document is a curriculum unit in agricultural structures designed to expand the curriculum materials available in vocational agriculture in Missouri. The guide consists of three units on constructing farm buildings, planning farm water systems, and building fences. Each unit contains 10-15 lessons on various aspects of the unit's topic. Each…

Factor Structure of the "Escala de Autoeficacia para la Depresion en Adolescentes" (EADA)

ERIC Educational Resources Information Center

Diaz-Santos, Mirella; Cumba-Aviles, Eduardo; Bernal, Guillermo; Rivera-Medina, Carmen

2011-01-01

The current concept and measures of self-efficacy for depression in adolescents do not consider developmental and cultural aspects essential to understand and assess this construct in Latino youth. We examined the factor structure of the "Escala de Autoeficacia para la Depresion en Adolescentes" (EADA), a Spanish instrument designed to…

Structural and chemical aspects of HPMA copolymers as drug carriers.

PubMed

Ulbrich, Karel; Subr, Vladimír

2010-02-17

Synthetic strategies and chemical and structural aspects of the synthesis of HPMA copolymer conjugates with various drugs and other biologically active molecules are described and discussed in this chapter. The discussion is held from the viewpoint of design and structure of the polymer backbone and biodegradable spacer between a polymer and drug, structure and methods of attachment of the employed drugs to the carrier and structure and methods of conjugation with targeting moieties. Physicochemical properties of the water-soluble polymer-drug conjugates and polymer micelles including mechanisms of drug release are also discussed. Detailed description of biological behavior of the polymer-drug conjugates as well as application of the copolymers for surface modification and targeting of gene delivery vectors are not included, they are presented and discussed in separate chapters of this issue. Copyright 2009 Elsevier B.V. All rights reserved.

A Converter from the Systems Biology Markup Language to the Synthetic Biology Open Language.

PubMed

Nguyen, Tramy; Roehner, Nicholas; Zundel, Zach; Myers, Chris J

2016-06-17

Standards are important to synthetic biology because they enable exchange and reproducibility of genetic designs. This paper describes a procedure for converting between two standards: the Systems Biology Markup Language (SBML) and the Synthetic Biology Open Language (SBOL). SBML is a standard for behavioral models of biological systems at the molecular level. SBOL describes structural and basic qualitative behavioral aspects of a biological design. Converting SBML to SBOL enables a consistent connection between behavioral and structural information for a biological design. The conversion process described in this paper leverages Systems Biology Ontology (SBO) annotations to enable inference of a designs qualitative function.

Extreme Mechanics: Self-Folding Origami

NASA Astrophysics Data System (ADS)

Santangelo, Christian D.

2017-03-01

Origami has emerged as a tool for designing three-dimensional structures from flat films. Because they can be fabricated by lithographic or roll-to-roll processing techniques, they have great potential for the manufacture of complicated geometries and devices. This article discusses the mechanics of origami and kirigami with a view toward understanding how to design self-folding origami structures. Whether an origami structure can be made to fold autonomously depends strongly on the geometry and kinematics of the origami fold pattern. This article collects some of the results on origami rigidity into a single framework, and discusses how these aspects affect the foldability of origami. Despite recent progress, most problems in origami and origami design remain completely open.

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.

High-Fidelity Multidisciplinary Design Optimization of Aircraft Configurations

NASA Technical Reports Server (NTRS)

Martins, Joaquim R. R. A.; Kenway, Gaetan K. W.; Burdette, David; Jonsson, Eirikur; Kennedy, Graeme J.

2017-01-01

To evaluate new airframe technologies we need design tools based on high-fidelity models that consider multidisciplinary interactions early in the design process. The overarching goal of this NRA is to develop tools that enable high-fidelity multidisciplinary design optimization of aircraft configurations, and to apply these tools to the design of high aspect ratio flexible wings. We develop a geometry engine that is capable of quickly generating conventional and unconventional aircraft configurations including the internal structure. This geometry engine features adjoint derivative computation for efficient gradient-based optimization. We also added overset capability to a computational fluid dynamics solver, complete with an adjoint implementation and semiautomatic mesh generation. We also developed an approach to constraining buffet and started the development of an approach for constraining utter. On the applications side, we developed a new common high-fidelity model for aeroelastic studies of high aspect ratio wings. We performed optimal design trade-o s between fuel burn and aircraft weight for metal, conventional composite, and carbon nanotube composite wings. We also assessed a continuous morphing trailing edge technology applied to high aspect ratio wings. This research resulted in the publication of 26 manuscripts so far, and the developed methodologies were used in two other NRAs. 1

Application of fully stressed design procedures to redundant and non-isotropic structures

NASA Technical Reports Server (NTRS)

Adelman, H. M.; Haftka, R. T.; Tsach, U.

1980-01-01

An evaluation is presented of fully stressed design procedures for sizing highly redundant structures including structures made of composite materials. The evaluation is carried out by sizing three structures: a simple box beam of either composite or metal construction; a low aspect ratio titanium wing; and a titanium arrow wing for a conceptual supersonic cruise aircraft. All three structures are sized by ordinary fully-stressed design (FSD) and thermal fully stressed design (TFSD) for combined mechanical and thermal loads. Where possible, designs are checked by applying rigorous mathematical programming techniques to the structures. It is found that FSD and TFSD produce optimum designs for the metal box beam, but produce highly non-optimum designs for the composite box beam. Results from the delta wing and arrow wing indicate that FSD and TFSD exhibits slow convergence for highly redundant metal structures. Further, TFSD exhibits slow oscillatory convergence behavior for the arrow wing for very high temperatures. In all cases where FSD and TFSD perform poorly either in obtaining nonoptimum designs or in converging slowly, the assumptions on which the algorithms are based are grossly violated. The use of scaling, however, is found to be very effective in obtaining fast convergence and efficiently produces safe designs even for those cases when FSD and TFSD alone are ineffective.

Achievements and Challenges in Computational Protein Design.

PubMed

Samish, Ilan

2017-01-01

Computational protein design (CPD), a yet evolving field, includes computer-aided engineering for partial or full de novo designs of proteins of interest. Designs are defined by a requested structure, function, or working environment. This chapter describes the birth and maturation of the field by presenting 101 CPD examples in a chronological order emphasizing achievements and pending challenges. Integrating these aspects presents the plethora of CPD approaches with the hope of providing a "CPD 101". These reflect on the broader structural bioinformatics and computational biophysics field and include: (1) integration of knowledge-based and energy-based methods, (2) hierarchical designated approach towards local, regional, and global motifs and the integration of high- and low-resolution design schemes that fit each such region, (3) systematic differential approaches towards different protein regions, (4) identification of key hot-spot residues and the relative effect of remote regions, (5) assessment of shape-complementarity, electrostatics and solvation effects, (6) integration of thermal plasticity and functional dynamics, (7) negative design, (8) systematic integration of experimental approaches, (9) objective cross-assessment of methods, and (10) successful ranking of potential designs. Future challenges also include dissemination of CPD software to the general use of life-sciences researchers and the emphasis of success within an in vivo milieu. CPD increases our understanding of protein structure and function and the relationships between the two along with the application of such know-how for the benefit of mankind. Applied aspects range from biological drugs, via healthier and tastier food products to nanotechnology and environmentally friendly enzymes replacing toxic chemicals utilized in the industry.

Planar Microstrip Ring Resonators for Microwave-Based Gas Sensing: Design Aspects and Initial Transducers for Humidity and Ammonia Sensing.

PubMed

Bogner, Andreas; Steiner, Carsten; Walter, Stefanie; Kita, Jaroslaw; Hagen, Gunter; Moos, Ralf

2017-10-24

A planar microstrip ring resonator structure on alumina was developed using the commercial FEM software COMSOL. Design parameters were evaluated, eventually leading to an optimized design of a miniaturized microwave gas sensor. The sensor was covered with a zeolite film. The device was successfully operated at around 8.5 GHz at room temperature as a humidity sensor. In the next step, an additional planar heater will be included on the reverse side of the resonator structure to allow for testing of gas-sensitive materials under sensor conditions.

Planar Microstrip Ring Resonators for Microwave-Based Gas Sensing: Design Aspects and Initial Transducers for Humidity and Ammonia Sensing

PubMed Central

Bogner, Andreas; Steiner, Carsten; Walter, Stefanie; Kita, Jaroslaw; Hagen, Gunter; Moos, Ralf

2017-01-01

A planar microstrip ring resonator structure on alumina was developed using the commercial FEM software COMSOL. Design parameters were evaluated, eventually leading to an optimized design of a miniaturized microwave gas sensor. The sensor was covered with a zeolite film. The device was successfully operated at around 8.5 GHz at room temperature as a humidity sensor. In the next step, an additional planar heater will be included on the reverse side of the resonator structure to allow for testing of gas-sensitive materials under sensor conditions. PMID:29064438

[Basis for designing a medical course curriculum].

PubMed

Villarreal, R; Bojalil, L F; Mercer, H

1977-01-01

This article sets forth the reasons for the structure given to the Division of Biology and Health on the Xochimilco campus of Metropolitan Autonomous University in Mexico: to adjust the university to the process of social change going forward in the country and gear the university to the problems of the present by avoiding the rigidity of its structure. The basic aspects of curriculum design are cited against a background of an historical analysis of the socioeconomic structure of education and health. The principles underlying the curriculum and the course work are then described on the basis of that analysis.

Travelling wave effects in large space structures

NASA Technical Reports Server (NTRS)

Vonflotow, A.

1983-01-01

Several aspects of travelling waves in Large Space Structures(LSS) are discussed. The dynamic similarity among LSS's, electric power systems, microwave circuits and communications network is noted. The existence of time lag between actuation and response is illuminated with the aid of simple examples, and their prediction is demonstrated. To prevent echoes, communications lines have matched terminations; this idea is applied to the design of dampers of one dimensional structures. Periodic structures act as mechanical band pass filters. Implications of this behavior are examined on a simple example. It is noted that the implication is twofold; continuum models of periodic lattice structures may err considerably; on the other hand, it is possible to design favorable transmission (and resonance) characteristics into the structure.

Advanced Technology Composite Fuselage - Repair and Damage Assessment Supporting Maintenance

NASA Technical Reports Server (NTRS)

Flynn, B. W.; Bodine, J. B.; Dopker, B.; Finn, S. R.; Griess, K. H.; Hanson, C. T.; Harris, C. G.; Nelson, K. M.; Walker, T. H.; Kennedy, T. C.;

Are We "Experienced Listeners"? A Review of the Musical Capacities that Do Not Depend on Formal Musical Training

ERIC Educational Resources Information Center

Bigand, E.; Poulin-Charronnat, B.

2006-01-01

The present paper reviews a set of studies designed to investigate different aspects of the capacity for processing Western music. This includes perceiving the relationships between a theme and its variations, perceiving musical tensions and relaxations, generating musical expectancies, integrating local structures in large-scale structures,…

Static characteristics design of hydrostatic guide-ways based on fluid-structure interactions

NASA Astrophysics Data System (ADS)

Lin, Shuo; Yin, YueHong

2016-10-01

With the raising requirements in micro optical systems, the available machines become hard to achieve the process dynamic and accuracy in all aspects. This makes compact design based on fluid/structure interactions (FSI) important. However, there is a difficulty in studying FSI with oil film as fluid domain. This paper aims at static characteristic design of a hydrostatic guide-way with capillary restrictors based on FSI. The pressure distribution of the oil film land is calculated by solving the Reynolds-equation with Galerkin technique. The deformation of structure is calculated by commercial FEM software, MSC. Nastran. A matlab program is designed to realize the coupling progress by modifying the load boundary in the submitting file and reading the deformation result. It's obvious that the stiffness of the hydrostatic bearing decreases with the weakening of the bearing structure. This program is proposed to make more precise prediction of bearing stiffness.

High Temperature Advanced Structural Composites. Book 1: Executive Summary and Intermetallic Compounds

DTIC Science & Technology

1993-04-02

Misiolek, W.Z. and German, R.M., "Economical Aspects of Experiment Design for Compaction of High Temperature Composites," Proceedings of the American...ten years, the computational capability should be available. For infiltrated matrix depositions, the research has shown that design fiber... designed for manufacturing, was not completed. However, even with present 2-D fabric composite preforms, a two-step deposition procedure, optimized for the

Modeling and Design Analysis Methodology for Tailoring of Aircraft Structures with Composites

NASA Technical Reports Server (NTRS)

Rehfield, Lawrence W.

2004-01-01

Composite materials provide design flexibility in that fiber placement and orientation can be specified and a variety of material forms and manufacturing processes are available. It is possible, therefore, to 'tailor' the structure to a high degree in order to meet specific design requirements in an optimum manner. Common industrial practices, however, have limited the choices designers make. One of the reasons for this is that there is a dearth of conceptual/preliminary design analysis tools specifically devoted to identifying structural concepts for composite airframe structures. Large scale finite element simulations are not suitable for such purposes. The present project has been devoted to creating modeling and design analysis methodology for use in the tailoring process of aircraft structures. Emphasis has been given to creating bend-twist elastic coupling in high aspect ratio wings or other lifting surfaces. The direction of our work was in concert with the overall NASA effort Twenty- First Century Aircraft Technology (TCAT). A multi-disciplinary team was assembled by Dr. Damodar Ambur to work on wing technology, which included our project.

Multidisciplinary design and optimization (MDO) methodology for the aircraft conceptual design

NASA Astrophysics Data System (ADS)

Iqbal, Liaquat Ullah

An integrated design and optimization methodology has been developed for the conceptual design of an aircraft. The methodology brings higher fidelity Computer Aided Design, Engineering and Manufacturing (CAD, CAE and CAM) Tools such as CATIA, FLUENT, ANSYS and SURFCAM into the conceptual design by utilizing Excel as the integrator and controller. The approach is demonstrated to integrate with many of the existing low to medium fidelity codes such as the aerodynamic panel code called CMARC and sizing and constraint analysis codes, thus providing the multi-fidelity capabilities to the aircraft designer. The higher fidelity design information from the CAD and CAE tools for the geometry, aerodynamics, structural and environmental performance is provided for the application of the structured design methods such as the Quality Function Deployment (QFD) and the Pugh's Method. The higher fidelity tools bring the quantitative aspects of a design such as precise measurements of weight, volume, surface areas, center of gravity (CG) location, lift over drag ratio, and structural weight, as well as the qualitative aspects such as external geometry definition, internal layout, and coloring scheme early in the design process. The performance and safety risks involved with the new technologies can be reduced by modeling and assessing their impact more accurately on the performance of the aircraft. The methodology also enables the design and evaluation of the novel concepts such as the blended (BWB) and the hybrid wing body (HWB) concepts. Higher fidelity computational fluid dynamics (CFD) and finite element analysis (FEA) allow verification of the claims for the performance gains in aerodynamics and ascertain risks of structural failure due to different pressure distribution in the fuselage as compared with the tube and wing design. The higher fidelity aerodynamics and structural models can lead to better cost estimates that help reduce the financial risks as well. This helps in achieving better designs with reduced risk in lesser time and cost. The approach is shown to eliminate the traditional boundary between the conceptual and the preliminary design stages, combining the two into one consolidated preliminary design phase. Several examples for the validation and utilization of the Multidisciplinary Design and Optimization (MDO) Tool are presented using missions for the Medium and High Altitude Long Range/Endurance Unmanned Aerial Vehicles (UAVs).

Comparative analysis of structural concrete Quality Assurance practices on nine nuclear and three fossil fuel power plant construction projects. Final summary report

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

Willenbrock, J.H.; Thomas, H.R. Jr.; Burati, J.J. Jr.

1978-12-01

A summary of two reports, COO/4120-1 and COO/4120-2, is given. A comparative analysis was made of the Quality Assurance practices related to the structural concrete phase on nine nuclear and three fossil fuel power plant projects which are (or have been) under construction in the United States in the past ten years. For the nuclear projects the analysis identified the response of each Quality Assurance program to the applicable criteria of 10 CFR Part 50, Appendix B as well as to the pertinent regulatory requirements and industry standards. For the fossil projects the analysis identified the response of each Qualitymore » Assurance program to criteria similar to those which were applicable in the nuclear situation. The major emphasis was placed on the construction aspects of the structural concrete phase of each project. The engineering and design aspects were examined whenever they interfaced with the construction aspects.« less

The Correction of Myopia Evaluation Trial: lessons from the study design.

PubMed

Hyman, L; Gwiazda, J

2004-01-01

The Correction of Myopia Evaluation Trial (COMET), a multicentre clinical trial based in 4 schools of optometry in the United States, evaluated the effect of progressive addition lenses versus single vision lenses on myopia progression in an ethnically diverse group of 469 myopic children aged 6 to 11 years. Completion of the clinical trial phase of the study provides an opportunity to evaluate aspects of the study design that contribute to its success. This article describes aspects of the study design that were influential in ensuring the smooth conduct of COMET. These include a dedicated team of investigators, an organisational structure with strong leadership and an independent Co-ordinating Centre, regular communication among investigators, flexible and creative approaches to recruitment and retention, sensitivity to concerns for child safety and child participation, and methods for enhancing and monitoring data reliability. The experience with COMET has provided a number of valuable lessons for all aspects of the study design that should benefit the development and implementation of future clinical trials, particularly those done in similar populations of children. The use of a carefully designed protocol using standard methods by dedicated members of the study team is essential in ensuring achievement of the study aims.

Cognitive-ergonomics and instructional aspects of e-learning courses.

PubMed

Rodrigues, Martha; Castello Branco, Iana; Shimioshi, José; Rodrigues, Evaldo; Monteiro, Simone; Quirino, Marcelo

2012-01-01

This paper presents an analysis of cognitive-ergonomic aspects of e-learning courses, offered by an organism from Brazilian Public Administration. The Cognitive Ergonomic studies conductive and cognitive aspects concerning to the relation between human, physics elements and social elements of the work space. From that usability aspects were evaluated by these points: i) visualization; ii) text comprehension lecture; iii) memory; iv) interface; v) instructional design; and vi) attention and learning. That survey is characterized as having been applied using the following techniques: (1) bibliographic survey, (2) field survey and (3) analysis of the documents. It was chosen the semi-structured questionnaire as the main method of data collection. About the interacting with artifacts, the interface of the courses is classified as direct engagement, because it allows the user to get the feeling that acts directly on the objects. Although the courses are well-structured they have flaws that will be discussed below. Even with these problems, the courses have a good degree of usability.

Comparison of Requirements for Composite Structures for Aircraft and Space Applications

NASA Technical Reports Server (NTRS)

Raju, Ivatury S.; Elliott, Kenny B.; Hampton, Roy W.; Knight, Norman F., Jr.; Aggarwal, Pravin; Engelstad, Stephen P.; Chang, James B.

2010-01-01

In this paper, the aircraft and space vehicle requirements for composite structures are compared. It is a valuable exercise to study composite structural design approaches used in the airframe industry, and to adopt methodology that is applicable for space vehicles. The missions, environments, analysis methods, analysis validation approaches, testing programs, build quantities, inspection, and maintenance procedures used by the airframe industry, in general, are not transferable to spaceflight hardware. Therefore, while the application of composite design approaches from other industries is appealing, many aspects cannot be directly utilized. Nevertheless, experiences and research for composite aircraft structures may be of use in unexpected arenas as space exploration technology develops, and so continued technology exchanges are encouraged.

Basic materials and structures aspects for hypersonic transport vehicles (HTV)

NASA Astrophysics Data System (ADS)

Steinheil, E.; Uhse, W.

A Mach 5 transport design is used to illustrate structural concepts and criteria for materials selections and also key technologies that must be followed in the areas of computational methods, materials and construction methods. Aside from the primary criteria of low weight, low costs, and conceivable risks, a number of additional requirements must be met, including stiffness and strength, corrosion resistance, durability, and a construction adequate for inspection, maintenance and repair. Current aircraft construction requirements are significantly extended for hypersonic vehicles. Additional consideration is given to long-duration temperature resistance of the airframe structure, the integration of large-volume cryogenic fuel tanks, computational tools, structural design, polymer matrix composites, and advanced manufacturing technologies.

An Approach to Risk-Based Design Incorporating Damage Tolerance Analyses

NASA Technical Reports Server (NTRS)

Knight, Norman F., Jr.; Glaessgen, Edward H.; Sleight, David W.

2002-01-01

Incorporating risk-based design as an integral part of spacecraft development is becoming more and more common. Assessment of uncertainties associated with design parameters and environmental aspects such as loading provides increased knowledge of the design and its performance. Results of such studies can contribute to mitigating risk through a system-level assessment. Understanding the risk of an event occurring, the probability of its occurrence, and the consequences of its occurrence can lead to robust, reliable designs. This paper describes an approach to risk-based structural design incorporating damage-tolerance analysis. The application of this approach to a candidate Earth-entry vehicle is described. The emphasis of the paper is on describing an approach for establishing damage-tolerant structural response inputs to a system-level probabilistic risk assessment.

Earthquake ground motion: Chapter 3

USGS Publications Warehouse

Luco, Nicolas; Kircher, Charles A.; Crouse, C. B.; Charney, Finley; Haselton, Curt B.; Baker, Jack W.; Zimmerman, Reid; Hooper, John D.; McVitty, William; Taylor, Andy

2016-01-01

Most of the effort in seismic design of buildings and other structures is focused on structural design. This chapter addresses another key aspect of the design process—characterization of earthquake ground motion into parameters for use in design. Section 3.1 describes the basis of the earthquake ground motion maps in the Provisions and in ASCE 7 (the Standard). Section 3.2 has examples for the determination of ground motion parameters and spectra for use in design. Section 3.3 describes site-specific ground motion requirements and provides example site-specific design and MCER response spectra and example values of site-specific ground motion parameters. Section 3.4 discusses and provides an example for the selection and scaling of ground motion records for use in various types of response history analysis permitted in the Standard.

Input-output oriented computation algorithms for the control of large flexible structures

NASA Technical Reports Server (NTRS)

Minto, K. D.

1989-01-01

An overview is given of work in progress aimed at developing computational algorithms addressing two important aspects in the control of large flexible space structures; namely, the selection and placement of sensors and actuators, and the resulting multivariable control law design problem. The issue of sensor/actuator set selection is particularly crucial to obtaining a satisfactory control design, as clearly a poor choice will inherently limit the degree to which good control can be achieved. With regard to control law design, the researchers are driven by concerns stemming from the practical issues associated with eventual implementation of multivariable control laws, such as reliability, limit protection, multimode operation, sampling rate selection, processor throughput, etc. Naturally, the burden imposed by dealing with these aspects of the problem can be reduced by ensuring that the complexity of the compensator is minimized. Our approach to these problems is based on extensions to input/output oriented techniques that have proven useful in the design of multivariable control systems for aircraft engines. In particular, researchers are exploring the use of relative gain analysis and the condition number as a means of quantifying the process of sensor/actuator selection and placement for shape control of a large space platform.

Design verification and fabrication of active control systems for the DAST ARW-2 high aspect ratio wing, part 1

NASA Technical Reports Server (NTRS)

Mcgehee, C. R.

1986-01-01

A study was conducted under Drones for Aerodynamic and Structural Testing (DAST) program to accomplish the final design and hardware fabrication for four active control systems compatible with and ready for installation in the NASA Aeroelastic Research Wing No. 2 (ARW-2) and Firebee II drone flight test vehicle. The wing structure was designed so that Active Control Systems (ACS) are required in the normal flight envelope by integrating control system design with aerodynamics and structure technologies. The DAST ARW-2 configuration uses flutter suppression, relaxed static stability, and gust and maneuver load alleviation ACS systems, and an automatic flight control system. Performance goals and criteria were applied to individual systems and the systems collectively to assure that vehicle stability margins, flutter margins, flying qualities and load reductions are achieved.

Structural Design of a 4-Meter Off-Axis Space Telescope for the Habitable-Zone Exoplanet Direct Imaging Mission

NASA Technical Reports Server (NTRS)

Arnold, William, Sr.; Stahl, H Philip

2017-01-01

This design study was conducted to support the HABEX project. There are a number of companion papers at this conference which go into detail on what all the HABEX goals are. The objective of this paper is to establish a baseline primary mirror design which satisfies the following structural related requirements. The designs in this study have a high TRL (Technology Readiness Level), realistic manufacturing limits and performance in line with the HABEX mission. A secondary goal of the study was to evaluate a number competing criteria for the selection. Questions such as differences in the on axis versus off axis static and dynamic response to disturbances. This study concentrates on the structural behavior, companion papers cover thermal and long term stability aspects of the problem.

Principles of Emergency Department facility design for optimal management of mass-casualty incidents.

PubMed

Halpern, Pinchas; Goldberg, Scott A; Keng, Jimmy G; Koenig, Kristi L

2012-04-01

The Emergency Department (ED) is the triage, stabilization and disposition unit of the hospital during a mass-casualty incident (MCI). With most EDs already functioning at or over capacity, efficient management of an MCI requires optimization of all ED components. While the operational aspects of MCI management have been well described, the architectural/structural principles have not. Further, there are limited reports of the testing of ED design components in actual MCI events. The objective of this study is to outline the important infrastructural design components for optimization of ED response to an MCI, as developed, implemented, and repeatedly tested in one urban medical center. In the authors' experience, the most important aspects of ED design for MCI have included external infrastructure and promoting rapid lockdown of the facility for security purposes; an ambulance bay permitting efficient vehicle flow and casualty discharge; strategic placement of the triage location; patient tracking techniques; planning adequate surge capacity for both patients and staff; sufficient command, control, communications, computers, and information; well-positioned and functional decontamination facilities; adequate, well-located and easily distributed medical supplies; and appropriately built and functioning essential services. Designing the ED to cope well with a large casualty surge during a disaster is not easy, and it may not be feasible for all EDs to implement all the necessary components. However, many of the components of an appropriate infrastructural design add minimal cost to the normal expenditures of building an ED. This study highlights the role of design and infrastructure in MCI preparedness in order to assist planners in improving their ED capabilities. Structural optimization calls for a paradigm shift in the concept of structural and operational ED design, but may be necessary in order to maximize surge capacity, department resilience, and patient and staff safety.

Integrated orbital servicing study follow-on. Volume 2: Technical analysis and system design

NASA Technical Reports Server (NTRS)

1978-01-01

In-orbit service functional and physical requirements to support both low and high Earth orbit servicing/maintenance operations were defined, an optimum servicing system configuration was developed and mockups and early prototype hardware were fabricated to demonstrate and validate the concepts selected. Significant issues addressed include criteria for concept selection; representative mission equipment and approaches to their design for serviceability; significant serviceable spacecraft design aspects; servicer mechanism operation in one-g; approaches for the demonstration/simulation; and service mechanism structure design approach.

RosettaRemodel: A Generalized Framework for Flexible Backbone Protein Design

PubMed Central

Huang, Po-Ssu; Ban, Yih-En Andrew; Richter, Florian; Andre, Ingemar; Vernon, Robert; Schief, William R.; Baker, David

2011-01-01

We describe RosettaRemodel, a generalized framework for flexible protein design that provides a versatile and convenient interface to the Rosetta modeling suite. RosettaRemodel employs a unified interface, called a blueprint, which allows detailed control over many aspects of flexible backbone protein design calculations. RosettaRemodel allows the construction and elaboration of customized protocols for a wide range of design problems ranging from loop insertion and deletion, disulfide engineering, domain assembly, loop remodeling, motif grafting, symmetrical units, to de novo structure modeling. PMID:21909381

Solar power satellite system definition study. Part 2, volume 4: Microwave power transmission systems

NASA Technical Reports Server (NTRS)

1977-01-01

A slotted waveguide planar array was established as the baseline design for the spaceborne transmitter antenna. Key aspects of efficient energy conversion at both ends of the power transfer link were analyzed and optimized alternate approaches in the areas of antenna and tube design are discussed. An integrated design concept was developed which meets design requirements, observes structural and thermal constraints, exhibits good performance and was developed in adequate depth to permit cost estimating at the subsystem/component level.

Research on numerical algorithms for large space structures

NASA Technical Reports Server (NTRS)

Denman, E. D.

1982-01-01

Numerical algorithms for large space structures were investigated with particular emphasis on decoupling method for analysis and design. Numerous aspects of the analysis of large systems ranging from the algebraic theory to lambda matrices to identification algorithms were considered. A general treatment of the algebraic theory of lambda matrices is presented and the theory is applied to second order lambda matrices.

Preparation, Purification, and Secondary Structure Determination of Bacillus Circulans Xylanase. A Molecular Laboratory Incorporating Aspects of Molecular Biology, Biochemistry, and Biophysical Chemistry

ERIC Educational Resources Information Center

Russo, Sal; Gentile, Lisa

2006-01-01

A project module designed for biochemistry or cellular and molecular biology student which involves determining the secondary structure of Bacillus circulans xylanase (BCX) by circular dichroism (CD) spectroscopy under conditions that compromise its stabilizing intramolecular forces is described. The lab model enhanced students knowledge of the…

The high-power iodine laser

NASA Astrophysics Data System (ADS)

Brederlow, G.; Fill, E.; Witte, K. J.

The book provides a description of the present state of the art concerning the iodine laser, giving particular attention to the design and operation of pulsed high-power iodine lasers. The basic features of the laser are examined, taking into account aspects of spontaneous emission lifetime, hyperfine structure, line broadening and line shifts, stimulated emission cross sections, the influence of magnetic fields, sublevel relaxation, the photodissociation of alkyl iodides, flashlamp technology, excitation in a direct discharge, chemical excitation, and questions regarding the chemical kinetics of the photodissociation iodine laser. The principles of high-power operation are considered along with aspects of beam quality and losses, the design and layout of an iodine laser system, the scalability and prospects of the iodine laser, and the design of the single-beam Asterix III laser.

Optimal Control Allocation with Load Sensor Feedback for Active Load Suppression, Experiment Development

NASA Technical Reports Server (NTRS)

Miller, Christopher J.; Goodrick, Dan

2017-01-01

The problem of control command and maneuver induced structural loads is an important aspect of any control system design. The aircraft structure and the control architecture must be designed to achieve desired piloted control responses while limiting the imparted structural loads. The classical approach is to utilize high structural margins, restrict control surface commands to a limited set of analyzed combinations, and train pilots to follow procedural maneuvering limitations. With recent advances in structural sensing and the continued desire to improve safety and vehicle fuel efficiency, it is both possible and desirable to develop control architectures that enable lighter vehicle weights while maintaining and improving protection against structural damage. An optimal control technique has been explored and shown to achieve desirable vehicle control performance while limiting sensed structural loads. The subject of this paper is the design of the optimal control architecture, and provides the reader with some techniques for tailoring the architecture, along with detailed simulation results.

Forest Structure Retrieval From EcoSAR P-Band Single-Pass Interferometry

NASA Technical Reports Server (NTRS)

Osmanoglu, Batuhan; Rincon, Rafael; Lee, Seung Kuk; Fatoyinbo, Temilola; Bollian, Tobias

2017-01-01

EcoSAR is a single-pass (dual antenna) digital beamforming, P-band radar system that is designed for remote sensing of dense forest structure. Forest structure retrievals require the measurement related to the vertical dimension, for which several techniques have been developed over the years. These techniques use polarimetric and interferometric aspects of the SAR data, which can be collected using EcoSAR. In this paper we describe EcoSAR system in light of its interferometric capabilities and investigate forest structure retrieval techniques.

Options in virtual 3D, optical-impression-based planning of dental implants.

PubMed

Reich, Sven; Kern, Thomas; Ritter, Lutz

2014-01-01

If a 3D radiograph, which in today's dentistry often consists of a CBCT dataset, is available for computerized implant planning, the 3D planning should also consider functional prosthetic aspects. In a conventional workflow, the CBCT is done with a specially produced radiopaque prosthetic setup that makes the desired prosthetic situation visible during virtual implant planning. If an exclusively digital workflow is chosen, intraoral digital impressions are taken. On these digital models, the desired prosthetic suprastructures are designed. The entire datasets are virtually superimposed by a "registration" process on the corresponding structures (teeth) in the CBCTs. Thus, both the osseous and prosthetic structures are visible in one single 3D application and make it possible to consider surgical and prosthetic aspects. After having determined the implant positions on the computer screen, a drilling template is designed digitally. According to this design (CAD), a template is printed or milled in CAM process. This template is the first physically extant product in the entire workflow. The article discusses the options and limitations of this workflow.

Thermal Analysis of a Structural Solution for Sustainable, Modular and Prefabricated Buildings

NASA Astrophysics Data System (ADS)

Isopescu, D. N.; Maxineasa, S. G.; Neculai, O.

2017-06-01

In the construction field, the design principles for an efficient and operational use of buildings and a minimal impact on the environment are essential aspects of sustainable development. In this regard, several aspects must be taken into consideration, such as: durability, easy maintenance, flexibility in interior design, and reduced energy consumption. Decreasing energy consumption in buildings during the service life (heating / cooling / drinking water / electricity) can mean lower costs, but also a lower impact on the environment. The paper presents the thermal analysis for a GF+1F height structure, consisting of several identical, adjacent and / or overlapped metallic cubic modules. The spaces inside this cubes ensemble solve the functionality of a family home building. The good carrying capacity, the rapidity of execution, the superior degree of thermal insulation and the minimum losses of material in execution were the main advantages provided by this structural solution. Regarding the thermal comfort for the users of this constructive system, the thermal analysis showed that the internal temperatures are constant and uniform, without cold surfaces or temperature fluctuations. In addition, humidity is controlled and there is no risk of condensation.

Progress and Design Concerns of Nanostructured Solar Energy Harvesting Devices.

PubMed

Leung, Siu-Fung; Zhang, Qianpeng; Tavakoli, Mohammad Mahdi; He, Jin; Mo, Xiaoliang; Fan, Zhiyong

2016-05-01

Integrating devices with nanostructures is considered a promising strategy to improve the performance of solar energy harvesting devices such as photovoltaic (PV) devices and photo-electrochemical (PEC) solar water splitting devices. Extensive efforts have been exerted to improve the power conversion efficiencies (PCE) of such devices by utilizing novel nanostructures to revolutionize device structural designs. The thicknesses of light absorber and material consumption can be substantially reduced because of light trapping with nanostructures. Meanwhile, the utilization of nanostructures can also result in more effective carrier collection by shortening the photogenerated carrier collection path length. Nevertheless, performance optimization of nanostructured solar energy harvesting devices requires a rational design of various aspects of the nanostructures, such as their shape, aspect ratio, periodicity, etc. Without this, the utilization of nanostructures can lead to compromised device performance as the incorporation of these structures can result in defects and additional carrier recombination. The design guidelines of solar energy harvesting devices are summarized, including thin film non-uniformity on nanostructures, surface recombination, parasitic absorption, and the importance of uniform distribution of photo-generated carriers. A systematic view of the design concerns will assist better understanding of device physics and benefit the fabrication of high performance devices in the future. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Lightweight Thermoformed Structural Components and Optics

NASA Technical Reports Server (NTRS)

Zeiders, Glenn W.; Bradford, Larry J.

2004-01-01

A technique that involves the use of thermoformed plastics has been developed to enable the design and fabrication of ultra-lightweight structural components and mirrors for use in outer space. The technique could also be used to produce items for special terrestrial uses in which minimization of weight is a primary design consideration. Although the inherent strengths of thermoplastics are clearly inferior to those of metals and composite materials, thermoplastics offer a distinct advantage in that they can be shaped, at elevated temperatures, to replicate surfaces (e.g., prescribed mirror surfaces) precisely. Furthermore, multiple elements can be bonded into structures of homogeneous design that display minimal thermal deformation aside from simple expansion. The design aspect of the present technique is based on the principle that the deflection of a plate that has internal structure depends far more on the overall thickness than on the internal details; thus, a very stiff, light structure can be made from thin plastic that is heatformed to produce a sufficiently high moment of inertia. General examples of such structures include I beams and eggcrates.

Optimal placement of actuators and sensors in control augmented structural optimization

NASA Technical Reports Server (NTRS)

Sepulveda, A. E.; Schmit, L. A., Jr.

1990-01-01

A control-augmented structural synthesis methodology is presented in which actuator and sensor placement is treated in terms of (0,1) variables. Structural member sizes and control variables are treated simultaneously as design variables. A multiobjective utopian approach is used to obtain a compromise solution for inherently conflicting objective functions such as strucutal mass control effort and number of actuators. Constraints are imposed on transient displacements, natural frequencies, actuator forces and dynamic stability as well as controllability and observability of the system. The combinatorial aspects of the mixed - (0,1) continuous variable design optimization problem are made tractable by combining approximation concepts with branch and bound techniques. Some numerical results for example problems are presented to illustrate the efficacy of the design procedure set forth.

Design of Life Extending Controls Using Nonlinear Parameter Optimization

NASA Technical Reports Server (NTRS)

Lorenzo, Carl F.; Holmes, Michael S.; Ray, Asok

1998-01-01

This report presents the conceptual development of a life extending control system where the objective is to achieve high performance and structural durability of the plant. A life extending controller is designed for a reusable rocket engine via damage mitigation in both the fuel and oxidizer turbines while achieving high performance for transient responses of the combustion chamber pressure and the O2/H2 mixture ratio. This design approach makes use of a combination of linear and nonlinear controller synthesis techniques and also allows adaptation of the life extending controller module to augment a conventional performance controller of a rocket engine. The nonlinear aspect of the design is achieved using nonlinear parameter optimization of a prescribed control structure.

Comparison of Requirements for Composite Structures for Aircraft and Space Applications

NASA Technical Reports Server (NTRS)

Raju, Ivatury S.; Elliot, Kenny B.; Hampton, Roy W.; Knight, Norman F., Jr.; Aggarwal, Pravin; Engelstad, Stephen P.; Chang, James B.

2010-01-01

In this report, the aircraft and space vehicle requirements for composite structures are compared. It is a valuable exercise to study composite structural design approaches used in the airframe industry and to adopt methodology that is applicable for space vehicles. The missions, environments, analysis methods, analysis validation approaches, testing programs, build quantities, inspection, and maintenance procedures used by the airframe industry, in general, are not transferable to spaceflight hardware. Therefore, while the application of composite design approaches from aircraft and other industries is appealing, many aspects cannot be directly utilized. Nevertheless, experiences and research for composite aircraft structures may be of use in unexpected arenas as space exploration technology develops, and so continued technology exchanges are encouraged.

Preliminary Weight Savings Estimate for a Commercial Transport Wing Using Rod-Stiffened Stitched Composite Technology

NASA Technical Reports Server (NTRS)

Lovejoy, Andrew E.

2015-01-01

A structural concept called pultruded rod stitched efficient unitized structure (PRSEUS) was developed by the Boeing Company to address the complex structural design aspects associated with a pressurized hybrid wing body (HWB) aircraft configuration. While PRSEUS was an enabling technology for the pressurized HWB structure, limited investigation of PRSEUS for other aircraft structures, such as circular fuselages and wings, has been done. Therefore, a study was undertaken to investigate the potential weight savings afforded by using the PRSEUS concept for a commercial transport wing. The study applied PRSEUS to the Advanced Subsonic Technology (AST) Program composite semi-span test article, which was sized using three load cases. The initial PRSEUS design was developed by matching cross-sectional stiffnesses for each stringer/skin combination within the wing covers, then the design was modified to ensure that the PRSEUS design satisfied the design criteria. It was found that the PRSEUS wing design exhibited weight savings over the blade-stiffened composite AST Program wing of nearly 9%, and a weight savings of 49% and 29% for the lower and upper covers, respectively, compared to an equivalent metallic wing.

75 FR 43495 - Sunshine Act Notice

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-26

... DEFENSE NUCLEAR FACILITIES SAFETY BOARD Sunshine Act Notice AGENCY: Defense Nuclear Facilities..., structures, and components, and (5) safety-related design aspects of new facilities or modifications of existing facilities needed to deliver high-level waste feed. The Board will be prepared to accept any other...

The Philosophy which underlies the structural tests of a supersonic transport aircraft with particular attention to the thermal cycle

NASA Technical Reports Server (NTRS)

Ripley, E. L.

1972-01-01

The information presented is based on data obtained from the Concorde. Much of this data also applies to other supersonic transport aircraft. The design and development of the Concorde is a joint effort of the British and French, and the structural test program is shared, as are all the other activities. Vast numbers of small specimens have been tested to determine the behavior of the materials used in the aircraft. Major components of the aircraft structure, totalling almost a complete aircraft, have been made and are being tested to help the constructors in each country in the design and development of the structure. Tests on two complete airframes will give information for the certification of the aircraft. A static test was conducted in France and a fatigue test in the United Kingdom. Fail-safe tests are being made to demonstrate the crack-propagation characteristics of the structure and its residual strength. Aspects of the structural test program are described in some detail, dealing particularly with the problems associated with the thermal cycle. The biggest of these problems is the setting up of the fatigue test on the complete airframe; therefore, this is covered more extensively with a discussion about how the test time can be shortened and with a description of the practical aspects of the test.

Use Of Infrared Thermography For The Identification Of Design And Construction Faults In Buildings

NASA Astrophysics Data System (ADS)

Seeber, Stephen A.

1984-03-01

Many design and construction details can affect building energy consumption in unex-pected ways. Further, design and construction errors can increase building energy consumption, result in discomfort to building occupants and cause structural damage to the building. Infrared inspections can easily evaluate the energy efficiency of various aspects of a building's design and identify flaws that might otherwise be detected as a result of occupants' complaints or damage to the building's mechanical or structural systems. Infrared thermography can be used by the architect to evaluate his designs and by the contractor to control the quality of construction. This paper discusses a number of issues that can help determine the effectiveness of infrared building surveys. Following this, three case stud-ies will be presented to illustrate design flaws that were detected through infrared build-ing surveys.

Design verification and fabrication of active control systems for the DAST ARW-2 high aspect ratio wing. Part 2: Appendices

NASA Technical Reports Server (NTRS)

Mcgehee, C. R.

1986-01-01

This is Part 2-Appendices of a study conducted under Drones for Aerodynamic and Structural Testing (DAST) Program to accomplish the final design and hardware fabrication for four active control systems compatible with and ready for installation in the NASA Aeroelastic Research Wing No. 2 (ARW-2) and Firebee II drone flight test vehicle. The wing structure was designed so that Active Control Systems (ACS) are required in the normal flight envelope by integrating control system design with aerodynamics and structure technologies. The DAST ARW-2 configuration uses flutter suppression, relaxed static stability, and gust and maneuver load alleviation ACS systems, and an automatic flight control system. Performance goals and criteria were applied to individual systems and the systems collectively to assure that vehicle stability margins, flutter margins, flying qualities, and load reductions were achieved.

Design, Fabrication and Test of Composite Curved Frames for Helicopter Fuselage Structure

NASA Technical Reports Server (NTRS)

Lowry, D. W.; Krebs, N. E.; Dobyns, A. L.

1984-01-01

Aspects of curved beam effects and their importance in designing composite frame structures are discussed. The curved beam effect induces radial flange loadings which in turn causes flange curling. This curling increases the axial flange stresses and induces transverse bending. These effects are more important in composite structures due to their general inability to redistribute stresses by general yielding, such as in metal structures. A detailed finite element analysis was conducted and used in the design of composite curved frame specimens. Five specimens were statically tested and compared with predicted and test strains. The curved frame effects must be accurately accounted for to avoid premature fracture; finite element methods can accurately predict most of the stresses and no elastic relief from curved beam effects occurred in the composite frames tested. Finite element studies are presented for comparative curved beam effects on composite and metal frames.

Design of hat-stiffened composite panels loaded in axial compression

NASA Astrophysics Data System (ADS)

Paul, T. K.; Sinha, P. K.

An integrated step-by-step analysis procedure for the design of axially compressed stiffened composite panels is outlined. The analysis makes use of the effective width concept. A computer code, BUSTCOP, is developed incorporating various aspects of buckling such as skin buckling, stiffener crippling and column buckling. Other salient features of the computer code include capabilities for generation of data based on micromechanics theories and hygrothermal analysis, and for prediction of strength failure. Parametric studies carried out on a hat-stiffened structural element indicate that, for all practical purposes, composite panels exhibit higher structural efficiency. Some hybrid laminates with outer layers made of aluminum alloy also show great promise for flight vehicle structural applications.

A visualization framework for design and evaluation

NASA Astrophysics Data System (ADS)

Blundell, Benjamin J.; Ng, Gary; Pettifer, Steve

2006-01-01

The creation of compelling visualisation paradigms is a craft often dominated by intuition and issues of aesthetics, with relatively few models to support good design. The majority of problem cases are approached by simply applying a previously evaluated visualisation technique. A large body of work exists covering the individual aspects of visualisation design such as the human cognition aspects visualisation methods for specific problem areas, psychology studies and so forth, yet most frameworks regarding visualisation are applied after-the-fact as an evaluation measure. We present an extensible framework for visualisation aimed at structuring the design process, increasing decision traceability and delineating the notions of function, aesthetics and usability. The framework can be used to derive a set of requirements for good visualisation design and evaluating existing visualisations, presenting possible improvements. Our framework achieves this by being both broad and general, built on top of existing works, with hooks for extensions and customizations. This paper shows how existing theories of information visualisation fit into the scheme, presents our experience in the application of this framework on several designs, and offers our evaluation of the framework and the designs studied.

Virtual Levels and Role Models: N-Level Structural Equations Model of Reciprocal Ratings Data.

PubMed

Mehta, Paras D

2018-01-01

A general latent variable modeling framework called n-Level Structural Equations Modeling (NL-SEM) for dependent data-structures is introduced. NL-SEM is applicable to a wide range of complex multilevel data-structures (e.g., cross-classified, switching membership, etc.). Reciprocal dyadic ratings obtained in round-robin design involve complex set of dependencies that cannot be modeled within Multilevel Modeling (MLM) or Structural Equations Modeling (SEM) frameworks. The Social Relations Model (SRM) for round robin data is used as an example to illustrate key aspects of the NL-SEM framework. NL-SEM introduces novel constructs such as 'virtual levels' that allows a natural specification of latent variable SRMs. An empirical application of an explanatory SRM for personality using xxM, a software package implementing NL-SEM is presented. Results show that person perceptions are an integral aspect of personality. Methodological implications of NL-SEM for the analyses of an emerging class of contextual- and relational-SEMs are discussed.

Single macroscopic pillars as model system for bioinspired adhesives: influence of tip dimension, aspect ratio, and tilt angle.

PubMed

Micciché, Maurizio; Arzt, Eduard; Kroner, Elmar

2014-05-28

The goal of our study is to better understand the design parameters of bioinspired dry adhesives inspired by geckos. For this, we fabricated single macroscopic pillars of 400 μm diameter with different aspect ratios and different tip shapes (i.e., flat tips, spherical tips with different radii, and mushroom tips with different diameters). Tilt-angle-dependent adhesion measurements showed that although the tip shape of the pillars strongly influences the pull-off force, the pull-off strength is similar for flat and mushroom-shaped tips. We found no tilt-angle dependency of adhesion for spherical tip structures and, except for high tilt angle and low preload experiments, no tilt-angle effect for mushroom-tip pillars. For flat-tip pillars, we found a strong influence of tilt angle on adhesion, which decreased linearly with increasing aspect ratio. The experiments show that for the tested aspect ratios between 1 and 5, a linear decrease of tilt-angle dependency is found. The results of our studies will help to design bioinspired adhesives for application on smooth and rough surfaces.

Leisure Today--Managing Leisure Services.

ERIC Educational Resources Information Center

Edginton, Christopher R., Ed.; And Others

1982-01-01

A series of 12 articles on managing leisure services focuses on the aspects of: (1) cooperative goal structuring; (2) management by objectives; (3) designing organizational charts; (4) labor relations; (5) cost effectiveness analysis; (6) fund accounting; (7) employee selection; (8) developing a marketing strategy; and (9) equitable distribution…

An adaptive spoiler to control the transonic shock

NASA Astrophysics Data System (ADS)

Bein, Th; Hanselka, H.; Breitbach, E.

2000-04-01

Market research predicts, for the aircraft industry, a large growth in the number of passengers as well as the airfreight rate with the result of this leading to increased competition for the European aircraft industry, the efficiency of new aircraft has to be improved drastically. One approach, among others, is the aerodynamic optimization of the wing. The fixed wing is designed optimally only for one flight condition. This flight condition is described by the parameters altitude, mach number and aircraft weight, all of which permanently vary during the mission of the aircraft. Therefore, the aircraft is just periodically near to the chosen design point. To compensate for this major disadvantage, an `adaptive wing' for optimal adaptation and variation of the profile geometry to the actual flight conditions will be developed. Daimler-Benz Aerospace Airbus, Daimler-Benz Research and the German Aerospace Center (DLR) are working as project partners on concepts for a variable camber and a local spoiler bump. In this paper a structural concept developed by the DLR for the adaptive spoiler will be presented. The concept is designed under the aspect of adaptive structural systems and requires a high integration of actuators, sensor and controllers in the structure. Special aspects of the design will be discussed and the first results, analytical, numerical as well as experimental, will be presented. Part of the concept design is also the development of new actuators optimized for the specific problem. A new actuator concept for the adaptive spoiler based on a cylindrical tube and activated either by pressure or multifunctional materials (e.g. shape memory alloys) will additionally be shown.

Tools Lighten Designs, Maintain Structural Integrity

NASA Technical Reports Server (NTRS)

2009-01-01

Collier Research Corporation of Hampton, Virginia, licensed software developed at Langley Research Center to reduce design weight through the use of composite materials. The first license of NASA-developed software, it has now been used in everything from designing next-generation cargo containers, to airframes, rocket engines, ship hulls, and train bodies. The company now has sales of the NASA-derived software topping $4 million a year and has recently received several Small Business Innovation Research (SBIR) contracts to apply its software to nearly all aspects of the new Orion crew capsule design.

Advanced Technology Composite Fuselage-Structural Performance

NASA Technical Reports Server (NTRS)

Walker, T. H.; Minguet, P. J.; Flynn, B. W.; Carbery, D. J.; Swanson, G. D.; Ilcewicz, L. B.

1997-01-01

Boeing is studying the technologies associated with the application of composite materials to commercial transport fuselage structure under the NASA-sponsored contracts for Advanced Technology Composite Aircraft Structures (ATCAS) and Materials Development Omnibus Contract (MDOC). This report addresses the program activities related to structural performance of the selected concepts, including both the design development and subsequent detailed evaluation. Design criteria were developed to ensure compliance with regulatory requirements and typical company objectives. Accurate analysis methods were selected and/or developed where practical, and conservative approaches were used where significant approximations were necessary. Design sizing activities supported subsequent development by providing representative design configurations for structural evaluation and by identifying the critical performance issues. Significant program efforts were directed towards assessing structural performance predictive capability. The structural database collected to perform this assessment was intimately linked to the manufacturing scale-up activities to ensure inclusion of manufacturing-induced performance traits. Mechanical tests were conducted to support the development and critical evaluation of analysis methods addressing internal loads, stability, ultimate strength, attachment and splice strength, and damage tolerance. Unresolved aspects of these performance issues were identified as part of the assessments, providing direction for future development.

Comparative analysis of structural concrete quality assurance practices on nine nuclear power plant construction projects. Final report

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

Willenbrock, J.H.; Thomas, H.R. Jr.; Burati, J.L. Jr.

1978-06-01

The basic objective of this research effort was to perform a comparative analysis of the Quality Assurance practices related to the structural concrete phase on nine nuclear power plant projects which are (or have been) under construction in the United States in the past ten years. This analysis identified the response of each Quality Assurance program to the applicable criteria of 10 CFR Part 50, Appendix B as well as to the pertinent regulatory requirements and industry standards. The major emphasis was placed on the construction aspects of the structural concrete phase of each project. The engineering and design aspectsmore » were examined whenever they interfaced with the construction aspects. For those aspects of the Quality Assurance system which can be considered managerial in nature (i.e., organizational relationships, types of Quality Assurance programs, corrective action procedures, etc.) an attempt has been made to present the alternative approaches that were identified. For those aspects of the Quality Assurance system which are technical in nature (i.e., the frequency of testing for slump, compressive strength, etc.) an attempt has been made to present a comparative analysis between projects and in relation to the recommended or mandated practices presented in the appropriate industry codes and standards.« less

The Shock and Vibration Bulletin. Part 4. Structural Dynamics, Systems Identification, Computer Applications.

DTIC Science & Technology

1977-09-01

Division, Barry Wright Corporation, Watertown, MA DESIGN OF ELASTOMERIC COMPONENTS BY USING THE FINITE -" b ELEMENT TECHNIQUE R.H. Finney and B.P. Gupta...Alabama in Huntsville, Huntsville, AL PAPERS APPEARING IN PART 2 Vibration Analysis SOME ASPECTS OF VIBRATION CONTROL SUPPORT DESIGN 0 P. Bezler and J.R...at the Air Force Flight August 1968, pp. 239-248. Dynamics Laboratory (AFFDL). The laser force measuring mounting brackets were designed and 5. G. K

Designing algorithm visualization on mobile platform: The proposed guidelines

NASA Astrophysics Data System (ADS)

Supli, A. A.; Shiratuddin, N.

2017-09-01

This paper entails an ongoing study about the design guidelines of algorithm visualization (AV) on mobile platform, helping students learning data structures and algorithm (DSA) subject effectively. Our previous review indicated that design guidelines of AV on mobile platform are still few. Mostly, previous guidelines of AV are developed for AV on desktop and website platform. In fact, mobile learning has been proved to enhance engagement in learning circumstances, and thus effect student's performance. In addition, the researchers highly recommend including UI design and Interactivity in designing effective AV system. However, the discussions of these two aspects in previous AV design guidelines are not comprehensive. The UI design in this paper describes the arrangement of AV features in mobile environment, whereas interactivity is about the active learning strategy features based on learning experiences (how to engage learners). Thus, this study main objective is to propose design guidelines of AV on mobile platform (AVOMP) that entails comprehensively UI design and interactivity aspects. These guidelines are developed through content analysis and comparative analysis from various related studies. These guidelines are useful for AV designers to help them constructing AVOMP for various topics on DSA.

Design automation of load-bearing arched structures of roofs of tall buildings

NASA Astrophysics Data System (ADS)

Kulikov, Vladimir

2018-03-01

The article considers aspects of the possible use of arched roofs in the construction of skyscrapers. Tall buildings experience large load from various environmental factors. Skyscrapers are subject to various and complex types of deformation of its structural elements. The paper discusses issues related to the aerodynamics of various structural elements of tall buildings. The technique of solving systems of equations state method of Simpson. The article describes the optimization of geometric parameters of bearing elements of the arched roofs of skyscrapers.

Controls structures interaction, an interdisciplinary challenge for large spacecraft

NASA Technical Reports Server (NTRS)

Hanks, Brantley R.

1990-01-01

Controls structures interaction (CSI), a phenomenon which occurs when control forces interact with the flexible motion of a structure, can, if improperly treated in design and development, cause reduced performance or control instabilities. Properly applied, it can improve flexible spacecraft performance. In this paper, the NASA CSI technology program for future spacecraft applications is described. The program objectives and organization are outlined, and the nature of individual program tasks is described. The interdisciplinary aspects of CSI are also addressed.

Cancer Genetics and Signaling | Center for Cancer Research

Cancer.gov

The Cancer, Genetics, and Signaling (CGS) Group at the National Cancer Institute at Frederick  offers a competitive postdoctoral training and mentoring program focusing on molecular and genetic aspects of cancer. The CGS Fellows Program is designed to attract and train exceptional postdoctoral fellows interested in pursuing independent research career tracks. CGS Fellows participate in a structured mentoring program designed for scientific and career development and transition to independent positions.

Near hybrid passenger vehicle development program, phase 1. Appendices C and D, Volume 2

NASA Technical Reports Server (NTRS)

1979-01-01

Results of tradeoff studies are presented in summary form. Various aspects of the overall vehicle design discussed include selection of the base vehicle, the battery pack configuration, structural modifications, occupant protection, vehicle dynamics, and aerodynamics. The drivetrain design and integration, power conditioning unit, battery subsystem, control system, environmental system are described. Specifications, weight breakdown, and energy consumption measures, and advanced technology components are included.

Terrier Black Brant VC design characteristics and program status. [rocket development

NASA Technical Reports Server (NTRS)

Payne, B. R.; Mayo, E. E.

1979-01-01

In the present paper, the design analysis of the Terrier-Black Brant VC, representing the latest addition to the Black Brant rocket family, is discussed, including the aerodynamic, structural, thermal, and operational aspects. An appreciable increase in apogee, as compared to the BBVC and Nike/BBVC, is achieved without any modifications to the well-proven BBV motor or degradation of the thermal or dynamic flight environment.

Fatigue impact on Mod-1 wind turbine design

NASA Technical Reports Server (NTRS)

Stahle, C. V., Jr.

1978-01-01

Fatigue is a key consideration in the design of a long-life Wind Turbine Generator (WTG) system. This paper discusses the fatigue aspects of the large Mod-1 horizontal-axis WTG design starting with the characterization of the environment and proceeding through the design. Major sources of fatigue loading are discussed and methods of limiting fatigue loading are described. NASTRAN finite element models are used to determine dynamic loading and internal cyclic stresses. Recent developments in determining the allowable fatigue stress consistent with present construction codes are discussed relative to their application to WTG structural design.

Research study concerning the 3D printing adittion (FDM-fused deposition modeling) to design UAV (UAV-unconventional aerial vehicle) structures

NASA Astrophysics Data System (ADS)

Pascu, Nicoleta Elisabeta; CǎruÅ£aşu, Nicoleta LuminiÅ£a.; Geambaşu, Gabriel George; Adîr, Victor Gabriel; Arion, Aurel Florin; Ivaşcu, Laura

2018-02-01

Aerial vehicles have become indispensable. There are in this field UAV (Unconventional Aerial vehicle) and transportation airplanes and other aerospace vehicles for spatial tourism. Today, the research and development activity in aerospace industry is focused to obtain a good and efficient design for airplanes, to solve the problem of high pollution and to reduce the noise. For these goals are necessary to realize light and resistant components. The aerospace industry products are, generally, very complex concerning geometric shapes and the costs are high, usually. Due to the progress in this field (products obtained using FDM) was possible to reduce the number of used tools, welding belts, and, of course, to eliminate a lot of machine tools. In addition, the complex shapes are easier product using this high technology, the cost is more attractive and the time is lower. This paper allows to present a few aspects about FDM technology and the obtained structures using it, as follows: computer geometric modeling (different designing softs) to design and redesign complex structures using 3D printing, for this kind of vehicles; finite element analysis to identify what is the influence of design for different structures; testing the structures.

The design of automatic software testing module for civil aviation information system

NASA Astrophysics Data System (ADS)

Qi, Qi; Sun, Yang

2018-05-01

In this paper, the practical innovation design is carried out according to the urgent needs of the automatic testing module of civil aviation information system. Firstly, the background and significance of the automatic testing module of civil aviation information system is expounded, and the current research status of automatic testing module and the advantages and disadvantages of related software are analyzed. Then, from the three aspects of macro demand, module functional requirement and module nonfunctional demand, we further study the needs of automatic testing module of civil aviation information system. Finally, from the four aspects of module structure, module core function, database and security, we have made an innovative plan for the automatic testing module of civil aviation information system.

Carrier rockets

NASA Astrophysics Data System (ADS)

Aleksandrov, V. A.; Vladimirov, V. V.; Dmitriev, R. D.; Osipov, S. O.

This book takes into consideration domestic and foreign developments related to launch vehicles. General information concerning launch vehicle systems is presented, taking into account details of rocket structure, basic design considerations, and a number of specific Soviet and American launch vehicles. The basic theory of reaction propulsion is discussed, giving attention to physical foundations, the various types of forces acting on a rocket in flight, basic parameters characterizing rocket motion, the effectiveness of various approaches to obtain the desired velocity, and rocket propellants. Basic questions concerning the classification of launch vehicles are considered along with construction and design considerations, aspects of vehicle control, reliability, construction technology, and details of structural design. Attention is also given to details of rocket motor design, the basic systems of the carrier rocket, and questions of carrier rocket development.

Stochastic modeling and control system designs of the NASA/MSFC Ground Facility for large space structures: The maximum entropy/optimal projection approach

NASA Technical Reports Server (NTRS)

Hsia, Wei-Shen

1986-01-01

In the Control Systems Division of the Systems Dynamics Laboratory of the NASA/MSFC, a Ground Facility (GF), in which the dynamics and control system concepts being considered for Large Space Structures (LSS) applications can be verified, was designed and built. One of the important aspects of the GF is to design an analytical model which will be as close to experimental data as possible so that a feasible control law can be generated. Using Hyland's Maximum Entropy/Optimal Projection Approach, a procedure was developed in which the maximum entropy principle is used for stochastic modeling and the optimal projection technique is used for a reduced-order dynamic compensator design for a high-order plant.

Conceptual Design of an In-Space Cryogenic Fluid Management Facility

NASA Technical Reports Server (NTRS)

Willen, G. S.; Riemer, D. H.; Hustvedt, D. C.

1981-01-01

The conceptual design of a Spacelab experiment to develop the technology associated with low gravity propellant management is presented. The proposed facility consisting of a supply tank, receiver tank, pressurization system, instrumentation, and supporting hardware, is described. The experimental objectives, the receiver tank to be modeled, and constraints imposed on the design by the space shuttle, Spacelab, and scaling requirements, are described. The conceptual design, including the general configurations, flow schematics, insulation systems, instrumentation requirements, and internal tank configurations for the supply tank and the receiver tank, is described. Thermal, structural, fluid, and safety and reliability aspects of the facility are analyzed. The facility development plan, including schedule and cost estimates for the facility, is presented. A program work breakdown structure and master program schedule for a seven year program are included.

Improving Familytalk: Educating Families to Work Better.

ERIC Educational Resources Information Center

Barret, Robert L.

1982-01-01

Describes a structured group designed for families that include adolescents. The workshop, "Improving Familytalk": (1) assesses communication skills and weaknesses in families, (2) teaches improved communication skills, (3) applies skills by talking about problems and expectations, and (4) teaches how to build positive aspects of family life. (JAC)

Collaboration in Cultural Heritage Digitisation in East Asia

ERIC Educational Resources Information Center

Lee, Hyuk-Jin

2010-01-01

Purpose: The purpose of this paper is to review the current status of collaboration in cultural heritage preservation in East Asia, including digital projects, and to suggest practical improvements based on a cultural structuralism perspective. Design/methodology/approach: Through exploratory research, the paper addresses aspects for successful…

New Course Design: Classification Schemes and Information Architecture.

ERIC Educational Resources Information Center

Weinberg, Bella Hass

2002-01-01

Describes a course developed at St. John's University (New York) in the Division of Library and Information Science that relates traditional classification schemes to information architecture and Web sites. Highlights include functional aspects of information architecture, that is, the way content is structured; assignments; student reactions; and…

Engine Structures Modeling Software System (ESMOSS)

NASA Technical Reports Server (NTRS)

1991-01-01

Engine Structures Modeling Software System (ESMOSS) is the development of a specialized software system for the construction of geometric descriptive and discrete analytical models of engine parts, components, and substructures which can be transferred to finite element analysis programs such as NASTRAN. The NASA Lewis Engine Structures Program is concerned with the development of technology for the rational structural design and analysis of advanced gas turbine engines with emphasis on advanced structural analysis, structural dynamics, structural aspects of aeroelasticity, and life prediction. Fundamental and common to all of these developments is the need for geometric and analytical model descriptions at various engine assembly levels which are generated using ESMOSS.

In silico studies on tryparedoxin peroxidase of Leishmania infantum: structural aspects.

PubMed

Singh, Bishal Kumar; Dubey, Vikash Kumar

2009-09-01

Tryparedoxin peroxidase (TryP) is a key enzyme of the trypanothione-dependent metabolism for removal of oxidative stress in leishmania. These enzymes function as antioxidants through their peroxidase and peroxynitrite reductase activities. Inhibitors of this enzyme are presumed to be antilesihmania drugs and structural studies are prerequisite of rational drug design. We have constructed three dimensional structure of TryP of Leishmania infantum using comparative modeling. Structural analysis reveals several interesting features. Moreover, it shows remarkable structural difference with human host glutathione peroxidase, an enzyme involved in similar function and TryP from Leishmania major.

Gravity and thermal deformation of large primary mirror in space telescope

NASA Astrophysics Data System (ADS)

Wang, Xin; Jiang, Shouwang; Wan, Jinlong; Shu, Rong

2016-10-01

The technology of integrating mechanical FEA analysis with optical estimation is essential to simulate the gravity deformation of large main mirror and the thermal deformation such as static or temperature gradient of optical structure. We present the simulation results of FEA analysis, data processing, and image performance. Three kinds of support structure for large primary mirror which have the center holding structure, the edge glue fixation and back support, are designed and compared to get the optimal gravity deformation. Variable mirror materials Zerodur/SiC are chosen and analyzed to obtain the small thermal gradient distortion. The simulation accuracy is dependent on FEA mesh quality, the load definition of structure, the fitting error from discrete data to smooth surface. A main mirror with 1m diameter is designed as an example. The appropriate structure material to match mirror, the central supporting structure, and the key aspects of FEA simulation are optimized for space application.

Status of Advanced Stitched Unitized Composite Aircraft Structures

NASA Technical Reports Server (NTRS)

Jegley, Dawn C.; Velicki, Alex

2013-01-01

NASA has created the Environmentally Responsible Aviation (ERA) Project to explore and document the feasibility, benefits and technical risk of advanced vehicle configurations and enabling technologies that will reduce the impact of aviation on the environment. A critical aspect of this pursuit is the development of a lighter, more robust airframe that will enable the introduction of unconventional aircraft configurations that have higher lift-to-drag ratios, reduced drag, and lower community noise levels. The primary structural concept being developed under the ERA project in the Airframe Technology element is the Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) concept. This paper describes how researchers at NASA and The Boeing Company are working together to develop fundamental PRSEUS technologies that could someday be implemented on a transport size aircraft with high aspect ratio wings or unconventional shapes such as a hybrid wing body airplane design.

Biofilm based attached cultivation technology for microalgal biorefineries-A review.

PubMed

Wang, Junfeng; Liu, Wen; Liu, Tianzhong

2017-11-01

The attached cultivation for microalga has many superiorities over the conventional aqua-suspend methods, which make it a promising pathway to supply feedstock for microalgae based bio-refinery attempts. In this review, the current reports on bioreactor, application, modeling, substratum material and engineering aspects were summarized and the future research and developments should be focused on the following aspects: 1) Build principles and guidelines for rational structure design by studying the relationship of physiological properties with typical structures and light regimes; 2) Set up theory foundation of substratum material selection by studying the physic-chemical properties of algal cells and substratum materials; 3) Further understanding the mass transfer behaviors of both CO 2 and nutrients in biofilm for enhanced growth rate and products accumulation; 4) New equipment and machines for inoculation, harvesting and moisture keeping should be developed and integrated with bioreactor structure. Copyright © 2017 Elsevier Ltd. All rights reserved.

Composite foods: from structure to sensory perception.

PubMed

Scholten, Elke

2017-02-22

An understanding of the effect of structural features of foods in terms of specific sensory attributes is necessary to design foods with specific functionalities, such as reduced fat or increased protein content, and increased feeling of satiety or liking. Although the bulk rheological properties of both liquid and solid foods can be related to textural attributes such as thickness and firmness, they do not always correlate to more complex sensory attributes, such as creamy and smooth. These attributes are often a result of different contributions, including lubrication aspects and interactions between food and components present in the oral cavity. In this review, the different contributions for a variety of composite foods, such as dispersions, emulsions and emulsion-filled gels, are discussed. The rheological properties are discussed in relation to specific structural characteristics of the foods, which are then linked to lubrication aspects and sensory perception.

Enhancing Team Composition in Professional Networks: Problem Definitions and Fast Solutions

PubMed Central

Li, Liangyue; Tong, Hanghang; Cao, Nan; Ehrlich, Kate; Lin, Yu-Ru; Buchler, Norbou

2017-01-01

In this paper, we study ways to enhance the composition of teams based on new requirements in a collaborative environment. We focus on recommending team members who can maintain the team’s performance by minimizing changes to the team’s skills and social structure. Our recommendations are based on computing team-level similarity, which includes skill similarity, structural similarity as well as the synergy between the two. Current heuristic approaches are one-dimensional and not comprehensive, as they consider the two aspects independently. To formalize team-level similarity, we adopt the notion of graph kernel of attributed graphs to encompass the two aspects and their interaction. To tackle the computational challenges, we propose a family of fast algorithms by (a) designing effective pruning strategies, and (b) exploring the smoothness between the existing and the new team structures. Extensive empirical evaluations on real world datasets validate the effectiveness and efficiency of our algorithms. PMID:29104408

Social and Experiential Influences on the Development of Inheritance Concepts

ERIC Educational Resources Information Center

Williams, Joanne M.; Smith, Lesley A.

2006-01-01

This study explored social and experiential differences in children's (aged 4 to 14 years) concepts of inheritance. The study utilized semi-structured interviews including four tasks that were designed to elicit judgements and explanations about different aspects of inheritance understanding. A variety of social and experiential factors were…

A Guide for Planning Indoor Facilities for College Physical Education.

ERIC Educational Resources Information Center

Crawford, Wayne H.

Following a general consideration of the functional aspects of planning facilities and the relationship between program and facilities, a detailed presentation is made of planning buildings for college and university indoor physical education activities. Recommendations are made with regard to design, structural and functional features of…

Referential Communication Skills of Children with Williams Syndrome: Understanding when Messages Are Not Adequate

ERIC Educational Resources Information Center

John, Angela E.; Rowe, Melissa L.; Mervis, Carolyn B.

2009-01-01

Although children with Williams syndrome have relatively good structural language and concrete vocabulary abilities, they have difficulty with pragmatic aspects of language. To investigate the impact of pragmatic difficulties on listener-role referential communication, we administered a picture placement task designed to measure ability to…

Dynamic Architecture. New Style Forming Aspects

NASA Astrophysics Data System (ADS)

Belyaeva, T. V.

2017-11-01

The article deals with the methods of buildings and structures transformation in the light of modern solutions in dynamic architecture. The mechanism for the formation of a modern object is proposed. Such design methods are becoming rather relevant in view of today’s trends while the priority of dynamic architecture directions keeps increasing.

Environment and the Law. Legal Almanac Series.

ERIC Educational Resources Information Center

Sloan, Irving J.

This survey is designed to provide the general reader with some basic background on the legal aspects of the effort to achieve environmental quality. The first chapter discusses the structure of federal environmental control in terms of newly established agencies and recently enacted legislation. Other chapters deal individually with air, water,…

VI-G, Sec. 661, P.L. 91-230. Final Performance Report.

ERIC Educational Resources Information Center

1976

Presented is the final performance report of the CSDC model which is designed to provide services for learning disabled high school students. Sections cover the following program aspects: organizational structure, inservice sessions, identification of students, materials and equipment, evaluation of student performance, evaluation of the model,…

Technology of Cable Television.

ERIC Educational Resources Information Center

Cable Television Information Center, Washington, DC.

The technology of cable television (CATV) is one area in which local community officials need to develop knowledge so that their decisions about the structure of CATV within the community will be informed. Thus, this paper is designed to familiarize local decision makers with the technological aspects of cable communications, to isolate specific…

Study on utilization of advanced composites in commercial aircraft wing structures. Volume 1: Executive summary

NASA Technical Reports Server (NTRS)

Sakata, I. F.; Ostrom, R. B.; Cardinale, S. V.

1978-01-01

The effort required by commercial transport manufacturers to accomplish the transition from current construction materials and practices to extensive use of composites in aircraft wings was investigated. The engineering and manufacturing disciplines which normally participate in the design, development, and production of an aircraft were employed to ensure that all of the factors that would enter a decision to commit to production of a composite wing structure were addressed. A conceptual design of an advanced technology reduced energy aircraft provided the framework for identifying and investigating unique design aspects. A plan development effort defined the essential technology needs and formulated approaches for effecting the required wing development. The wing development program plans, resource needs, and recommendations are summarized.

Intrasystem Analysis Program (IAP) Structural Design Study.

DTIC Science & Technology

1981-06-01

accuracy constraints, and user competence . This report is designed to serve as a guide in con- structing procedures and identifying those aspects of the...parameters. 3.3.3 Userability The term "Userability" refers here to the level of competence assumed for an IAP analyst in need of a procedure. There...media the wires pass through is homogeneous along the length of the wires. Under these assumptions the wave propagation is predominantly tranverse

Cast Aluminum Structures Technology (CAST) Phase VI. Technology Transfer.

DTIC Science & Technology

1980-04-01

and other aspects of the program was provided as follows: o Phase I--Preliminary Design Richard C. Jones o Phase il--Manufacturing Methods Richard G...Christner o Phase Ill--Detailed Design Richard C. Jones o Phase IV--Fabrication of Demonstration Richard G. Christner Articles and Production... Richard C. Jones, assisted by Carlos J. Romero, Christian K. Gunther, Cecil E. Parsons, and Donald D. Goehler; and by Walter Hyler of Battelle Columbus

The Use of Meta-Level Control for Coordination in a Distributed Problem Solving Network,

DTIC Science & Technology

1983-01-01

crucial aspect of the design organizational structuring in coordinating the local activity of achs decentralized network control policies. It is...TEMTED EXflD.MENTS WITn and ratings of the subgoals." Threshold values indicating ORGANIZATIONAL STRUCIURING IkeA usaw lani of a subal are specif’ied in...the monitoring are. This environmental vehicle, approximate position, time frame, and belief. The scenario was designed to test the networks ability

Design Aspects of the VLBI2010 System - Progress Report of the IVS VLBI2010 Committee

NASA Technical Reports Server (NTRS)

Petrachenko, Bill; Niell, Arthur; Behrend, Dirk; Corey, Brian; Boehm, Johannes; Chralot, Patrick; Collioud, Arnaud; Gipson, John; Haas, Ruediger; Hobiger, Thomas;

Facial Emotion Recognition System – A Machine Learning Approach

NASA Astrophysics Data System (ADS)

Ramalingam, V. V.; Pandian, A.; Jayakumar, Lavanya

2018-04-01

Frown is a medium for people correlation and it could be exercised in multiple real systems. Single crucial stage for frown realizing is to exactly select hysterical aspects. This journal proposed a frown realization scheme applying transformative Particle Swarm Optimization (PSO) based aspect accumulation. This entity initially employs changed LVP, handles crisscross adjacent picture element contrast, for achieving the selective first frown portrayal. Then the PSO entity inserted with a concept of micro Genetic Algorithm (mGA) called mGA-embedded PSO designed for achieving aspect accumulation. This study, the technique subsumes no disposable memory, a little-populace insignificant flock, a latest acceleration that amends with the approach and a sub dimension-based in-depth local frown aspect examines. Assistance of provincial utilization and comprehensive inspection examine structure of alleviating of an immature concurrence complication of conventional PSO. Numerous identifiers are used to diagnose different frown expositions. Stationed on extensive study within and other-sphere pictures from the continued Cohn Kanade and MMI benchmark directory appropriately. Determination of the application exceeds most advanced level PSO variants, conventional PSO, classical GA and alternate relevant frown realization structures is described with powerful limit. Extending our accession to a motion based FER application for connecting patch-based Gabor aspects with continuous data in multi-frames.

Fault-tolerant control of large space structures using the stable factorization approach

NASA Technical Reports Server (NTRS)

Razavi, H. C.; Mehra, R. K.; Vidyasagar, M.

1986-01-01

Large space structures are characterized by the following features: they are in general infinite-dimensional systems, and have large numbers of undamped or lightly damped poles. Any attempt to apply linear control theory to large space structures must therefore take into account these features. Phase I consisted of an attempt to apply the recently developed Stable Factorization (SF) design philosophy to problems of large space structures, with particular attention to the aspects of robustness and fault tolerance. The final report on the Phase I effort consists of four sections, each devoted to one task. The first three sections report theoretical results, while the last consists of a design example. Significant results were obtained in all four tasks of the project. More specifically, an innovative approach to order reduction was obtained, stabilizing controller structures for plants with an infinite number of unstable poles were determined under some conditions, conditions for simultaneous stabilizability of an infinite number of plants were explored, and a fault tolerance controller design that stabilizes a flexible structure model was obtained which is robust against one failure condition.

Ultra-high aspect ratio replaceable AFM tips using deformation-suppressed focused ion beam milling.

PubMed

Savenko, Alexey; Yildiz, Izzet; Petersen, Dirch Hjorth; Bøggild, Peter; Bartenwerfer, Malte; Krohs, Florian; Oliva, Maria; Harzendorf, Torsten

2013-11-22

Fabrication of ultra-high aspect ratio exchangeable and customizable tips for atomic force microscopy (AFM) using lateral focused ion beam (FIB) milling is presented. While on-axis FIB milling does allow high aspect ratio (HAR) AFM tips to be defined, lateral milling gives far better flexibility in terms of defining the shape and size of the tip. Due to beam-induced deformation, it has so far not been possible to define HAR structures using lateral FIB milling. In this work we obtain aspect ratios of up to 45, with tip diameters down to 9 nm, by a deformation-suppressing writing strategy. Several FIB milling strategies for obtaining sharper tips are discussed. Finally, assembly of the HAR tips on a custom-designed probe as well as the first AFM scanning is shown.

CESA-1 receiver design review. Phase 1. Final report

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

Not Available

1980-07-01

The Central Electrica Solar de Almeria CESA-1 is a 1.0 MWe water/steam solar central receiver electric power plant being built by the Spanish in Almeria, Spain. Centro de Estudios de la Energia (CEE) is responsible for the management, design, and construction of the project. At the request of the Solar Energy Research Institute and with the approval of the Department of Energy, Sandia National Laboratories, Livermore is providing technical assistance in areas unique to solar applications to CEE. At the request of CEE, Sandia contracted with Foster Wheeler Development Corporation (FWDC) to critically review and evaluate the CESA-1 receiver design.more » Foster Wheeler Iberia (FWI) was subcontracted to FWDC to coordinate efforts with CEE in Madrid. The FWDC program which was started on July 9, 1979, was subdivided into three tasks: (1) design basis review: critical review of the receiver design specifications and requirements; (2) design review and analyses: critical review of thermal/hydraulic, structural, and materials aspects of the receiver design and the design and analysis procedures used by the designer in critical areas of the design; and (3) operational review: critical review of receiver instrumentation and controls and the operational and safety aspects of the receiver. Results of the design review and evaluation are presented. (WHK)« less

Planetary/DOD entry technology flight experiments. Volume 2: Planetary entry flight experiments

NASA Technical Reports Server (NTRS)

Christensen, H. E.; Krieger, R. J.; Mcneilly, W. R.; Vetter, H. C.

1976-01-01

The technical feasibility of launching a high speed, earth entry vehicle from the space shuttle to advance technology for the exploration of the outer planets' atmospheres was established. Disciplines of thermodynamics, orbital mechanics, aerodynamics propulsion, structures, design, electronics and system integration focused on the goal of producing outer planet environments on a probe shaped vehicle during an earth entry. Major aspects of analysis and vehicle design studied include: planetary environments, earth entry environment capability, mission maneuvers, capabilities of shuttle upper stages, a comparison of earth entry planetary environments, experiment design and vehicle design.

Evaluation of nonmetallic thermal protection materials for the manned space shuttle. Volume 1, task 1: Assessment of technical risks associated with utilization of nonmetallic thermal protection system

NASA Technical Reports Server (NTRS)

Wilkinson, W. H.; Kirkhart, F. P.; Kistler, C. W.; Duckworth, W. H.; Ungar, E. W.; Foster, E. L.

1970-01-01

Technical problems of design and flight qualification of the proposed classes of surface insulation materials and leading edge materials were reviewed. A screening test plan, a preliminary design data test plan and a design data test plan were outlined. This program defined the apparent critical differences between the surface insulators and the leading edge materials, structuring specialized screening test plans for each of these two classes of materials. Unique testing techniques were shown to be important in evaluating the structural interaction aspects of the surface insulators and a separate task was defined to validate the test plan. In addition, a compilation was made of available information on proposed material (including metallic TPS), previous shuttle programs, pertinent test procedures, and other national programs of merit. This material was collected and summarized in an informally structured workbook.

Aircraft Interior Noise Control Using Distributed Piezoelectric Actuators

NASA Technical Reports Server (NTRS)

Sun, Jian Q.

1996-01-01

Developing a control system that can reduce the noise and structural vibration at the same time is an important task. This talk presents one possible technical approach for accomplishing this task. The target application of the research is for aircraft interior noise control. The emphasis of the present approach is not on control strategies, but rather on the design of actuators for the control system. In the talk, a theory of distributed piezoelectric actuators is introduced. A uniform cylindrical shell is taken as a simplified model of fuselage structures to illustrate the effectiveness of the design theory. The actuators developed are such that they can reduce the tonal structural vibration and interior noise in a wide range of frequencies. Extensive computer simulations have been done to study various aspects of the design theory. Experiments have also been conducted and the test results strongly support the theoretical development.

Static Structural Analysis of a Variable Span Morphing Wing for Unmanned Aerial Vehicle

NASA Astrophysics Data System (ADS)

Bashir, M.; Rajendran, P.

2018-05-01

While the primary reason to develop an adaptive wing is the aerodynamic benefits, the primary hindrance is the structural and vibrational considerations due to the unsteady nature of the airflow during the flight. Hence this study forms an important part of the morphable wing technology. In this paper, the design of a moderate aspect ratio variable span wing will be performed. The morphing wing is modeled structurally to observe the effect of spanwise load distribution on the wing structure. For the structural design and analysis of the unmanned aerial vehicle (UAV) under this study, commercial software Solidworks and Ansys/Static Structural/Modal are used. The static structural analyses of the wing are performed under different load conditions. The results of these analyses show that the designed structure is safe within the flight envelope. It is observed that the wing-root bending moment increases drastically due to an increase in the wingspan. Thus, the bending moment along the wingspan of the morphing wing is much larger than that of the conventional wing which results in an increase in the deflection of the free-end. The maximum stress for the un-extended wing configuration increases for the extended wing configuration.

Optimization of rotor blades for combined structural, dynamic, and aerodynamic properties

NASA Technical Reports Server (NTRS)

He, Cheng-Jian; Peters, David A.

1990-01-01

Optimal helicopter blade design with computer-based mathematical programming has received more and more attention in recent years. Most of the research has focused on optimum dynamic characteristics of rotor blades to reduce vehicle vibration. There is also work on optimization of aerodynamic performance and on composite structural design. This research has greatly increased our understanding of helicopter optimum design in each of these aspects. Helicopter design is an inherently multidisciplinary process involving strong interactions among various disciplines which can appropriately include aerodynamics; dynamics, both flight dynamics and structural dynamics; aeroelasticity: vibrations and stability; and even acoustics. Therefore, the helicopter design process must satisfy manifold requirements related to the aforementioned diverse disciplines. In our present work, we attempt to combine several of these important effects in a unified manner. First, we design a blade with optimum aerodynamic performance by proper layout of blade planform and spanwise twist. Second, the blade is designed to have natural frequencies that are placed away from integer multiples of the rotor speed for a good dynamic characteristics. Third, the structure is made as light as possible with sufficient rotational inertia to allow for autorotational landing, with safe stress margins and flight fatigue life at each cross-section, and with aeroelastical stability and low vibrations. Finally, a unified optimization refines the solution.

Structural Design for a Neptune Aerocapture Mission

NASA Technical Reports Server (NTRS)

Dyke, R. Eric; Hrinda, Glenn A.

2004-01-01

A multi-center study was conducted in 2003 to assess the feasibility of and technology requirements for using aerocapture to insert a scientific platform into orbit around Neptune. The aerocapture technique offers a potential method of greatly reducing orbiter mass and thus total spacecraft launch mass by minimizing the required propulsion system mass. This study involved the collaborative efforts of personnel from Langley Research Center (LaRC), Johnson Space Flight Center (JSFC), Marshall Space Flight Center (MSFC), Ames Research Center (ARC), and the Jet Propulsion Laboratory (JPL). One aspect of this effort was the structural design of the full spacecraft configuration, including the ellipsled aerocapture orbiter and the in-space solar electric propulsion (SEP) module/cruise stage. This paper will discuss the functional and structural requirements for each of these components, some of the design trades leading to the final configuration, the loading environments, and the analysis methods used to ensure structural integrity. It will also highlight the design and structural challenges faced while trying to integrate all the mission requirements. Component sizes, materials, construction methods and analytical results, including masses and natural frequencies, will be presented, showing the feasibility of the resulting design for use in a Neptune aerocapture mission. Lastly, results of a post-study structural mass optimization effort on the ellipsled will be discussed, showing potential mass savings and their influence on structural strength and stiffness

Optimal design of an alignment-free two-DOF rehabilitation robot for the shoulder complex.

PubMed

Galinski, Daniel; Sapin, Julien; Dehez, Bruno

2013-06-01

This paper presents the optimal design of an alignment-free exoskeleton for the rehabilitation of the shoulder complex. This robot structure is constituted of two actuated joints and is linked to the arm through passive degrees of freedom (DOFs) to drive the flexion-extension and abduction-adduction movements of the upper arm. The optimal design of this structure is performed through two steps. The first step is a multi-objective optimization process aiming to find the best parameters characterizing the robot and its position relative to the patient. The second step is a comparison process aiming to select the best solution from the optimization results on the basis of several criteria related to practical considerations. The optimal design process leads to a solution outperforming an existing solution on aspects as kinematics or ergonomics while being more simple.

The role of networks and artificial intelligence in nanotechnology design and analysis.

PubMed

Hudson, D L; Cohen, M E

2004-05-01

Techniques with their origins in artificial intelligence have had a great impact on many areas of biomedicine. Expert-based systems have been used to develop computer-assisted decision aids. Neural networks have been used extensively in disease classification and more recently in many bioinformatics applications including genomics and drug design. Network theory in general has proved useful in modeling all aspects of biomedicine from healthcare organizational structure to biochemical pathways. These methods show promise in applications involving nanotechnology both in the design phase and in interpretation of system functioning.

An overview of engineering concepts and current design algorithms for probabilistic structural analysis

NASA Technical Reports Server (NTRS)

Duffy, S. F.; Hu, J.; Hopkins, D. A.

1995-01-01

The article begins by examining the fundamentals of traditional deterministic design philosophy. The initial section outlines the concepts of failure criteria and limit state functions two traditional notions that are embedded in deterministic design philosophy. This is followed by a discussion regarding safety factors (a possible limit state function) and the common utilization of statistical concepts in deterministic engineering design approaches. Next the fundamental aspects of a probabilistic failure analysis are explored and it is shown that deterministic design concepts mentioned in the initial portion of the article are embedded in probabilistic design methods. For components fabricated from ceramic materials (and other similarly brittle materials) the probabilistic design approach yields the widely used Weibull analysis after suitable assumptions are incorporated. The authors point out that Weibull analysis provides the rare instance where closed form solutions are available for a probabilistic failure analysis. Since numerical methods are usually required to evaluate component reliabilities, a section on Monte Carlo methods is included to introduce the concept. The article concludes with a presentation of the technical aspects that support the numerical method known as fast probability integration (FPI). This includes a discussion of the Hasofer-Lind and Rackwitz-Fiessler approximations.

Optimal design of isotope labeling experiments.

PubMed

Yang, Hong; Mandy, Dominic E; Libourel, Igor G L

2014-01-01

Stable isotope labeling experiments (ILE) constitute a powerful methodology for estimating metabolic fluxes. An optimal label design for such an experiment is necessary to maximize the precision with which fluxes can be determined. But often, precision gained in the determination of one flux comes at the expense of the precision of other fluxes, and an appropriate label design therefore foremost depends on the question the investigator wants to address. One could liken ILE to shadows that metabolism casts on products. Optimal label design is the placement of the lamp; creating clear shadows for some parts of metabolism and obscuring others.An optimal isotope label design is influenced by: (1) the network structure; (2) the true flux values; (3) the available label measurements; and, (4) commercially available substrates. The first two aspects are dictated by nature and constrain any optimal design. The second two aspects are suitable design parameters. To create an optimal label design, an explicit optimization criterion needs to be formulated. This usually is a property of the flux covariance matrix, which can be augmented by weighting label substrate cost. An optimal design is found by using such a criterion as an objective function for an optimizer. This chapter uses a simple elementary metabolite units (EMU) representation of the TCA cycle to illustrate the process of experimental design of isotope labeled substrates.

Avian Feathers: An Examination of Lightweight Resilience and Bioinspired Designs

NASA Astrophysics Data System (ADS)

Sullivan, Tarah Naoe

In bird flight, the majority of the wing surface consists of highly refined and hierarchically organized beta-keratinous feathers. Thus, flight feathers contain ingenious combinations of components that optimize lift, stiffness, aerodynamics, and damage resistance. Their design involves two main parts: a central shaft which prescribes stiffness and lateral vanes that allow for the capture of air. Within the feather vane, barbs branch from the shaft and barbules branch from barbs, forming a flat surface and ensuring lift. Microhooks at the end of barbules hold barbs tightly together, providing a close-knit, unified structure and enabling repair of the vane through the reattachment of un-hooked junctions. In this dissertation, unique aspects of feather architecture are explored to uncover principles translatable to the design of modern aerospace materials and structures. Specifically, understudied aspects of the feather's lightweight yet resilient properties are investigated. This research has revealed several novel characteristics of the feather. Allometric scaling relationships are developed linking the geometry of a bird's wing components to its flight characteristics and total mass. Barbule spacing within the feather vane is found to be 8-16 microm for birds ranging from 0.02-11 kg. Additionally, it is discovered that strength is recovered with the shape recovery property of feathers, and a mechanism for this phenomenon is proposed. Barbule adhesion within the vane is found to prevent barbs from twisting in flexure, maintaining the vane's stiffness, and the extent to which unzipping these connections affects the feather's ability to capture air is related to barb shape. Directional permeability of the feather vane is experimentally confirmed and related to the intricate microstructure of barbules. Lastly, the exceptional architecture of the feather motivated the design of novel bioinspired structures with tailored and unique properties. The avian feather serves as an excellent springboard for designs that can be adapted to enhance synthetic materials and structures.

Computational Infrastructure for Engine Structural Performance Simulation

NASA Technical Reports Server (NTRS)

Chamis, Christos C.

1997-01-01

Select computer codes developed over the years to simulate specific aspects of engine structures are described. These codes include blade impact integrated multidisciplinary analysis and optimization, progressive structural fracture, quantification of uncertainties for structural reliability and risk, benefits estimation of new technology insertion and hierarchical simulation of engine structures made from metal matrix and ceramic matrix composites. Collectively these codes constitute a unique infrastructure readiness to credibly evaluate new and future engine structural concepts throughout the development cycle from initial concept, to design and fabrication, to service performance and maintenance and repairs, and to retirement for cause and even to possible recycling. Stated differently, they provide 'virtual' concurrent engineering for engine structures total-life-cycle-cost.

Geometric approach to the design of an imaging probe to evaluate the iridocorneal angle structures

NASA Astrophysics Data System (ADS)

Hong, Xun Jie Jeesmond; V. K., Shinoj; Murukeshan, V. M.; Baskaran, M.; Aung, Tin

2017-06-01

Photographic imaging methods allow the tracking of anatomical changes in the iridocorneal angle structures and the monitoring of treatment responses overtime. In this work, we aim to design an imaging probe to evaluate the iridocorneal angle structures using geometrical optics. We first perform an analytical analysis on light propagation from the anterior chamber of the eye to the exterior medium using Snell's law. This is followed by adopting a strategy to achieve uniform near field irradiance, by simplifying the complex non-rotational symmetric irradiance distribution of LEDs tilted at an angle. The optimization is based on the geometric design considerations of an angled circular ring array of 4 LEDs (or a 2 × 2 square LED array). The design equation give insights on variable parameters such as the illumination angle of the LEDs, ring array radius, viewing angle of the LEDs, and the working distance. A micro color CCD video camera that has sufficient resolution to resolve the iridocorneal angle structures at the required working distance is then chosen. The proposed design aspects fulfil the safety requirements recommended by the International Commission on Non-ionizing Radiation Protection.

Forced migrants involved in setting the agenda and designing research to reduce impacts of complex emergencies: combining Swarm with patient and public involvement.

PubMed

Brainard, Julii Suzanne; Al Assaf, Enana; Omasete, Judith; Leach, Steve; Hammer, Charlotte C; Hunter, Paul R

2017-01-01

The UK's National Institute for Health Research (NIHR) Health Protection Research Unit in Emergency Preparedness and Response was asked to undertake research on how to reduce the impact of complex national/international emergencies on public health. How to focus the research and decide on priority topics was challenging, given the nature of complex events. Using a type of structured brain-storming, the researchers identified the ongoing UK, European and international migration crisis as both complex and worthy of deeper research. To further focus the research, two representatives of forced migrant communities were invited to join the project team as patient and public (PPI) representatives. They attended regular project meetings, insightfully contributed to and advised on practical aspects of potential research areas. The representatives identified cultural obstacles and community needs and helped choose the final research study design, which was to interview forced migrants about their strategies to build emotional resilience and prevent mental illness. The representatives also helped design recruitment documents, and undertake recruitment and interviewer training. Many events with wide-ranging negative health impacts are notable for complexity: lack of predictability, non-linear feedback mechanisms and unexpected consequences. A multi-disciplinary research team was tasked with reducing the public health impacts from complex events, but without a pre-specified topic area or research design. This report describes using patient and public involvement within an adaptable but structured development process to set research objectives and aspects of implementation. An agile adaptive development approach, sometimes described as swarm , was used to identify possible research areas. Swarm is meant to quickly identify strengths and weaknesses of any candidate project, to accelerate early failure before resources are invested. When aspects of the European migration crisis were identified as a potential priority topic area, two representatives of forced migrant communities were recruited to explore possible research ideas. These representatives helped set the specific research objectives and advised on aspects of implementation, still within the swarm framework for project development. Over ten months, many research ideas were considered by the collaborative working group in a series of six group meetings, supplemented by email contact in between. Up to four possible research ideas were scrutinised at any one meeting, with a focus on identifying practical or desirable aspects of each proposed project. Interest settled on a study to solicit original data about successful strategies that forced migrants use to adapt to life in the UK, with an emphasis on successfully promoting resilience and minimizing emotional distress. "Success in resettlement" was identified to be a more novel theme than "barriers to adaption" research. A success approach encourages participation when individuals may find discussion of mental illness stigmatising. The patient representatives helped with design of patient-facing and interview training materials, interviewer training (mock interviews), and aspects of the recruitment. Using patient and public involvement (PPI) within an early failure development approach that itself arises from theory on complex adaptive systems, we successfully implemented a dynamic development process to determine research topic and study design. The PPI representatives were closely involved in setting research objectives and aspects of implementation.

Self-unloading, unmanned, reusable lunar lander project

NASA Technical Reports Server (NTRS)

Cowan, Kevin; Lewis, Ron; Mislinski, Philip; Rivers, Donna; Smith, Solar; Vasicek, Clifford; Verona, Matt

1991-01-01

A payload delivery system will be required to support the buildup and operation of a manned lunar base. In response, a self-unloading, unmanned, reusable lunar lander was conceptually designed. The lander will deliver a 7000 kg payload, with the same dimensions as a space station logistics module, from low lunar orbit to any location on the surface of the moon. The technical aspects of the design is introduced as well as the management structure and project cost.

Propulsion/airframe integration issues for waverider aircraft

NASA Technical Reports Server (NTRS)

Blankson, Isaiah M.; Hagseth, Paul

1993-01-01

While many propulsion concepts and technologies developed for nonwaverider-type hypersonic vehicles may apply to waveriders, some aspects of these configurations require unique technological approaches. An evaluation is made of such distinctive opportunities in the cases of engine cycle selection, inlets, nozzle designs and integration, longitudinal stability, and thermal management. Also discussed are waverider requirements for control surface effectiveness, inlet boundary layer ingestion effects, and structural/configurational optimization, giving attention to trades in volumetric/structural efficiency and vehicle L/D.

Designing an Internationationalised Curriculum for Higher Education: Embracing the Local and the Global Citizen

ERIC Educational Resources Information Center

Clifford, Valerie; Montgomery, Catherine

2017-01-01

In this article, differing interpretations of the internationalisation of higher education curriculum are explored analysing the structural and cultural aspects of the curriculum. Voices of tertiary staff from around the world taking part in a four-week, fully online course, entitled "Internationalising the curriculum for all students"…

Nonverbal Aspects of Verbal Behavior in French Canadian French-English Bilinguals.

ERIC Educational Resources Information Center

Grujic, Zdenda; Libby, William L., Jr.

The present study was designed to investigate whether known intercultural differences in nonverbal behavior extend to specific nonverbal repertoires accompanying, and perhaps facilitating the act of speaking a verbal language. Conversations in the form of structured interviews between 48 French-Canadian, French-English bilinguals (24 males and 24…

A Model for Outsourcing HRD

ERIC Educational Resources Information Center

Simmonds, David; Gibson, Rebecca

2008-01-01

Purpose: The purpose of this paper is to provide an overview of approaches to outsourcing HRD in the UK. Design/methodology/approach: This paper employs semi-structured interviews and case studies. The research model was developed from a literature review. Findings: There are many problems associated with outsourcing any or all aspects of the HRD…

Modeling Lolium perenne L. roots in the presence of empirical black holes

USDA-ARS?s Scientific Manuscript database

Plant root models are designed for understanding structural or functional aspects of root systems. When a process is not thoroughly understood, a black box object is used. However, when a process exists but empirical data do not indicate its existence, you have a black hole. The object of this re...

Design and construction principles in nature and architecture.

PubMed

Knippers, Jan; Speck, Thomas

2012-03-01

This paper will focus on how the emerging scientific discipline of biomimetics can bring new insights into the field of architecture. An analysis of both architectural and biological methodologies will show important aspects connecting these two. The foundation of this paper is a case study of convertible structures based on elastic plant movements.

CFD and Thermo Mechanical Analysis on Effect of Curved vs Step Surface in IC Engine Cylinder Head

NASA Astrophysics Data System (ADS)

Balaji, S.; Ganesh, N.; Kumarasamy, A.

2017-05-01

Current research in IC engines mainly focus on various methods to achieve higher efficiency and high specific power. As a single design parameter, combustion chamber peak spring pressure has increased more than before. Apart from the structural aspects of withstanding these loads, designer faces challenges of resolving thermal aspects of cylinder head. Methods to enhance the heat transfer without compromising load withstanding capability are being constantly explored. Conventional cylinder heads have got sat inner surface. In this paper we have suggested a modification in inner surface to enhance the heat transfer capability. To increase the heat transfer rate, inner same deck surface is configured as a curved and stepped surface instead of sat. We have reported the effectiveness of extend of curvature in the inner same deck surface in a different technical paper. Here, we are making a direct comparison between stepped and curved surface only. From this analysis it has been observed that curved surface reduces the ame deck temperature considerably without compromising the structural strength factors compared to step and sat surface.

Design and Analysis of AN Static Aeroelastic Experiment

NASA Astrophysics Data System (ADS)

Hou, Ying-Yu; Yuan, Kai-Hua; Lv, Ji-Nan; Liu, Zi-Qiang

2016-06-01

Static aeroelastic experiments are very common in the United States and Russia. The objective of static aeroelastic experiments is to investigate deformation and loads of elastic structure in flow field. Generally speaking, prerequisite of this experiment is that the stiffness distribution of structure is known. This paper describes a method for designing experimental models, in the case where the stiffness distribution and boundary condition of a real aircraft are both uncertain. The stiffness distribution form of the structure can be calculated via finite element modeling and simulation calculation and F141 steels and rigid foam are used to make elastic model. In this paper, the design and manufacturing process of static aeroelastic models is presented and a set of experiment model was designed to simulate the stiffness of the designed wings, a set of experiments was designed to check the results. The test results show that the experimental method can effectively complete the design work of elastic model. This paper introduces the whole process of the static aeroelastic experiment, and the experimental results are analyzed. This paper developed a static aeroelasticity experiment technique and established an experiment model targeting at the swept wing of a certain kind of large aspect ratio aircraft.

Friction Stir Welding

NASA Technical Reports Server (NTRS)

Nunes, Arthur C., Jr.

2008-01-01

Friction stir welding (FSW) is a solid state welding process invented in 1991 at The Welding Institute in the United Kingdom. A weld is made in the FSW process by translating a rotating pin along a weld seam so as to stir the sides of the seam together. FSW avoids deleterious effects inherent in melting and promises to be an important welding process for any industries where welds of optimal quality are demanded. This article provides an introduction to the FSW process. The chief concern is the physical effect of the tool on the weld metal: how weld seam bonding takes place, what kind of weld structure is generated, potential problems, possible defects for example, and implications for process parameters and tool design. Weld properties are determined by structure, and the structure of friction stir welds is determined by the weld metal flow field in the vicinity of the weld tool. Metal flow in the vicinity of the weld tool is explained through a simple kinematic flow model that decomposes the flow field into three basic component flows: a uniform translation, a rotating solid cylinder, and a ring vortex encircling the tool. The flow components, superposed to construct the flow model, can be related to particular aspects of weld process parameters and tool design; they provide a bridge to an understanding of a complex-at-first-glance weld structure. Torques and forces are also discussed. Some simple mathematical models of structural aspects, torques, and forces are included.

An analysis of the influence of framework aspects on the study design of health economic modeling evaluations.

PubMed

Gurtner, Sebastian

2013-04-01

Research and practical guidelines have many implications for how to structure a health economic study. A major focus in recent decades has been the quality of health economic research. In practice, the factors influencing a study design are not limited to the quest for quality. Moreover, the framework of the study is important. This research addresses three major questions related to these framework aspects. First, we want to know whether the design of health economic studies has changed over time. Second, we want to know how the subject of a study, whether it is a process or product innovation, influences the parameters of the study design. Third, one of the most important questions we will answer is whether and how the study's source of funding has an impact on the design of the research. To answer these questions, a total of 234 health economic studies were analyzed using a correspondence analysis and a logistic regression analysis. All three categories of framework factors have an influence on the aspects of the study design. Health economic studies have evolved over time, leading to the use of more advanced methods like complex sensitivity analyses. Additionally, the patient's point of view has increased in importance. The evaluation of product innovations has focused more on utility concepts. On the other hand, the source of funding may influence only a few aspects of the study design, such as the use of evaluation methods, the source of data, and the use of certain utility measures. The most important trends in health care, such as the emphasis on the patients' point of view, become increasingly established in health economic evaluations with the passage of time. Although methodological challenges remain, modern information and communication technologies provide a basis for increasing the complexity and quality of health economic studies if used frequently.

Topology-aware illumination design for volume rendering.

PubMed

Zhou, Jianlong; Wang, Xiuying; Cui, Hui; Gong, Peng; Miao, Xianglin; Miao, Yalin; Xiao, Chun; Chen, Fang; Feng, Dagan

2016-08-19

Direct volume rendering is one of flexible and effective approaches to inspect large volumetric data such as medical and biological images. In conventional volume rendering, it is often time consuming to set up a meaningful illumination environment. Moreover, conventional illumination approaches usually assign same values of variables of an illumination model to different structures manually and thus neglect the important illumination variations due to structure differences. We introduce a novel illumination design paradigm for volume rendering on the basis of topology to automate illumination parameter definitions meaningfully. The topological features are extracted from the contour tree of an input volumetric data. The automation of illumination design is achieved based on four aspects of attenuation, distance, saliency, and contrast perception. To better distinguish structures and maximize illuminance perception differences of structures, a two-phase topology-aware illuminance perception contrast model is proposed based on the psychological concept of Just-Noticeable-Difference. The proposed approach allows meaningful and efficient automatic generations of illumination in volume rendering. Our results showed that our approach is more effective in depth and shape depiction, as well as providing higher perceptual differences between structures.

Computer-aided design of polymers and composites

NASA Technical Reports Server (NTRS)

Kaelble, D. H.

1985-01-01

This book on computer-aided design of polymers and composites introduces and discusses the subject from the viewpoint of atomic and molecular models. Thus, the origins of stiffness, strength, extensibility, and fracture toughness in composite materials can be analyzed directly in terms of chemical composition and molecular structure. Aspects of polymer composite reliability are considered along with characterization techniques for composite reliability, relations between atomic and molecular properties, computer aided design and manufacture, polymer CAD/CAM models, and composite CAD/CAM models. Attention is given to multiphase structural adhesives, fibrous composite reliability, metal joint reliability, polymer physical states and transitions, chemical quality assurance, processability testing, cure monitoring and management, nondestructive evaluation (NDE), surface NDE, elementary properties, ionic-covalent bonding, molecular analysis, acid-base interactions, the manufacturing science, and peel mechanics.

Study of flutter related computational procedures for minimum weight structural sizing of advanced aircraft, supplemental data

NASA Technical Reports Server (NTRS)

Oconnell, R. F.; Hassig, H. J.; Radovcich, N. A.

1975-01-01

Computational aspects of (1) flutter optimization (minimization of structural mass subject to specified flutter requirements), (2) methods for solving the flutter equation, and (3) efficient methods for computing generalized aerodynamic force coefficients in the repetitive analysis environment of computer-aided structural design are discussed. Specific areas included: a two-dimensional Regula Falsi approach to solving the generalized flutter equation; method of incremented flutter analysis and its applications; the use of velocity potential influence coefficients in a five-matrix product formulation of the generalized aerodynamic force coefficients; options for computational operations required to generate generalized aerodynamic force coefficients; theoretical considerations related to optimization with one or more flutter constraints; and expressions for derivatives of flutter-related quantities with respect to design variables.

Customizing Monoclonal Antibodies for the Treatment of Methamphetamine Abuse: Current and Future Applications

PubMed Central

Peterson, Eric C.; Gentry, W. Brooks

2015-01-01

Monoclonal antibody-based medications designed to bind (+)-methamphetamine (METH) with high affinity are among the newest approaches to the treatment of METH abuse, and the associated medical complications. The potential clinical indications for these medications include treatment of overdose, reduction of drug dependence, and protection of vulnerable populations from METH-related complications. Research designed to discover and conduct preclinical and clinical testing of these antibodies suggest a scientific vision for how intact mAb (singular and plural) or small antigen binding fragments of mAb could be engineered to optimize the proteins for specific therapeutic applications. In this review we discuss keys to success in this development process including choosing predictors of specificity, efficacy, duration of action, and safety of the medications in disease models of acute and chronic drug abuse. We consider important aspects of METH-like hapten design and how hapten structural features influence specificity and affinity, with an example of a high-resolution x-ray crystal structure of a high affinity antibody to demonstrate this structural relationship. Additionally, several prototype anti-METH mAb forms such as antigen binding fragments (Fab) and single chain variable fragments (scFv) are under development. Unique, customizable aspects of these fragments are presented with specific possible clinical indications. Finally, we discuss clinical trial progress of the first in kind anti-METH mAb, for which the METH is the disease target instead of vulnerable central nervous system networks of receptors, binding sites and neuronal connections. PMID:24484976

Customizing monoclonal antibodies for the treatment of methamphetamine abuse: current and future applications.

PubMed

Peterson, Eric C; Gentry, W Brooks; Owens, S Michael

2014-01-01

Monoclonal antibody-based medications designed to bind (+)-methamphetamine (METH) with high affinity are among the newest approaches to the treatment of METH abuse and the associated medical complications. The potential clinical indications for these medications include treatment of overdose, reduction of drug dependence, and protection of vulnerable populations from METH-related complications. Research designed to discover and conduct preclinical and clinical testing of these antibodies suggests a scientific vision for how intact monoclonal antibody (mAb) (singular and plural) or small antigen-binding fragments of mAb could be engineered to optimize the proteins for specific therapeutic applications. In this review, we discuss keys to success in this development process including choosing predictors of specificity, efficacy, duration of action, and safety of the medications in disease models of acute and chronic drug abuse. We consider important aspects of METH-like hapten design and how hapten structural features influence specificity and affinity, with an example of a high-resolution X-ray crystal structure of a high-affinity antibody to demonstrate this structural relationship. Additionally, several prototype anti-METH mAb forms such as antigen-binding fragments and single-chain variable fragments are under development. Unique, customizable aspects of these fragments are presented with specific possible clinical indications. Finally, we discuss clinical trial progress of the first in kind anti-METH mAb, for which METH is the disease target instead of vulnerable central nervous system networks of receptors, binding sites, and neuronal connections. © 2014 Elsevier Inc. All rights reserved.

Methodologies for Quantitative Systems Pharmacology (QSP) Models: Design and Estimation.

PubMed

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.

Advanced grid-stiffened composite shells for applications in heavy-lift helicopter rotor blade spars

NASA Astrophysics Data System (ADS)

Narayanan Nampy, Sreenivas

Modern rotor blades are constructed using composite materials to exploit their superior structural performance compared to metals. Helicopter rotor blade spars are conventionally designed as monocoque structures. Blades of the proposed Heavy Lift Helicopter are envisioned to be as heavy as 800 lbs when designed using the monocoque spar design. A new and innovative design is proposed to replace the conventional spar designs with light weight grid-stiffened composite shell. Composite stiffened shells have been known to provide excellent strength to weight ratio and damage tolerance with an excellent potential to reduce weight. Conventional stringer--rib stiffened construction is not suitable for rotor blade spars since they are limited in generating high torsion stiffness that is required for aeroelastic stability of the rotor. As a result, off-axis (helical) stiffeners must be provided. This is a new design space where innovative modeling techniques are needed. The structural behavior of grid-stiffened structures under axial, bending, and torsion loads, typically experienced by rotor blades need to be accurately predicted. The overall objective of the present research is to develop and integrate the necessary design analysis tools to conduct a feasibility study in employing grid-stiffened shells for heavy-lift rotor blade spars. Upon evaluating the limitations in state-of-the-art analytical models in predicting the axial, bending, and torsion stiffness coefficients of grid and grid-stiffened structures, a new analytical model was developed. The new analytical model based on the smeared stiffness approach was developed employing the stiffness matrices of the constituent members of the grid structure such as an arch, helical, or straight beam representing circumferential, helical, and longitudinal stiffeners. This analysis has the capability to model various stiffening configurations such as angle-grid, ortho-grid, and general-grid. Analyses were performed using an existing state-of-the-art and newly developed model to predict the torsion, bending, and axial stiffness of grid and grid-stiffened structures with various stiffening configurations. These predictions were compared to results generated using finite element analysis (FEA) to observe excellent correlation (within 6%) for a range of parameters for grid and grid-stiffened structures such as grid density, stiffener angle, and aspect ratio of the stiffener cross-section. Experimental results from cylindrical grid specimen testing were compared with analytical prediction using the new analysis. The new analysis predicted stiffness coefficients with nearly 7% error compared to FEA results. From the parametric studies conducted, it was observed that the previous state-of-the-art analysis on the other hand exhibited errors of the order of 39% for certain designs. Stability evaluations were also conducted by integrating the new analysis with established stability formulations. A design study was conducted to evaluate the potential weight savings of a simple grid-stiffened rotor blade spar structure compared to a baseline monocoque design. Various design constraints such as stiffness, strength, and stability were imposed. A manual search was conducted for design parameters such as stiffener density, stiffener angle, shell laminate, and stiffener aspect ratio that provide lightweight grid-stiffened designs compared to the baseline. It was found that a weight saving of 9.1% compared to the baseline is possible without violating any of the design constraints.

Design principles of water sensitive in settlement area on the river banks

NASA Astrophysics Data System (ADS)

Ryanti, E.; Hasriyanti, N.; Utami, W. D.

2018-03-01

This research will formulate the principle of designing settlement area of Kapuas River Pontianak with the approach of water sensitive concept of urban design (WSUD) the densely populated settlement area. By using a case study the approach that is a dense settlement area located on the banks of the river with literature study techniques to formulate the aspects considered and components that are set in the design, descriptive analysis with the rationalistic paradigm for identification characteristics of the settlement in the river banks areas with consideration of WSUD elements and formulate the principles of designing water-sensitive settlement areas. This research is important to do because the problems related to the water management system in the existing riverside settlement in Pontianak has not been maximal to do. So the primary of this research contains several objectives that will be achieved that is identifying the characteristics of riverside settlement area based on consideration of design aspects of the area that are sensitive to water and the principle of designing the area so that the existing problem structure will be formulated in relation to the community’s need for infrastructure in settlement environment and formulate and develop appropriate technology guidelines for integrated water management systems in riverside settlement areas and design techniques for water-sensitive settlements (WSUD).

Evolutionary Design of Controlled Structures

NASA Technical Reports Server (NTRS)

Masters, Brett P.; Crawley, Edward F.

1997-01-01

Basic physical concepts of structural delay and transmissibility are provided for simple rod and beam structures. Investigations show the sensitivity of these concepts to differing controlled-structures variables, and to rational system modeling effects. An evolutionary controls/structures design method is developed. The basis of the method is an accurate model formulation for dynamic compensator optimization and Genetic Algorithm based updating of sensor/actuator placement and structural attributes. One and three dimensional examples from the literature are used to validate the method. Frequency domain interpretation of these controlled structure systems provide physical insight as to how the objective is optimized and consequently what is important in the objective. Several disturbance rejection type controls-structures systems are optimized for a stellar interferometer spacecraft application. The interferometric designs include closed loop tracking optics. Designs are generated for differing structural aspect ratios, differing disturbance attributes, and differing sensor selections. Physical limitations in achieving performance are given in terms of average system transfer function gains and system phase loss. A spacecraft-like optical interferometry system is investigated experimentally over several different optimized controlled structures configurations. Configurations represent common and not-so-common approaches to mitigating pathlength errors induced by disturbances of two different spectra. Results show that an optimized controlled structure for low frequency broadband disturbances achieves modest performance gains over a mass equivalent regular structure, while an optimized structure for high frequency narrow band disturbances is four times better in terms of root-mean-square pathlength. These results are predictable given the nature of the physical system and the optimization design variables. Fundamental limits on controlled performance are discussed based on the measured and fit average system transfer function gains and system phase loss.

Developing a framework for qualitative engineering: Research in design and analysis of complex structural systems

NASA Technical Reports Server (NTRS)

Franck, Bruno M.

1990-01-01

The research is focused on automating the evaluation of complex structural systems, whether for the design of a new system or the analysis of an existing one, by developing new structural analysis techniques based on qualitative reasoning. The problem is to identify and better understand: (1) the requirements for the automation of design, and (2) the qualitative reasoning associated with the conceptual development of a complex system. The long-term objective is to develop an integrated design-risk assessment environment for the evaluation of complex structural systems. The scope of this short presentation is to describe the design and cognition components of the research. Design has received special attention in cognitive science because it is now identified as a problem solving activity that is different from other information processing tasks (1). Before an attempt can be made to automate design, a thorough understanding of the underlying design theory and methodology is needed, since the design process is, in many cases, multi-disciplinary, complex in size and motivation, and uses various reasoning processes involving different kinds of knowledge in ways which vary from one context to another. The objective is to unify all the various types of knowledge under one framework of cognition. This presentation focuses on the cognitive science framework that we are using to represent the knowledge aspects associated with the human mind's abstraction abilities and how we apply it to the engineering knowledge and engineering reasoning in design.

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.

Factors of Safety, Historical Development, State of the Art and Future Outlook

DTIC Science & Technology

1977-11-01

The 1.33 value was a common factor used for pressure vessel designs, which was a major design aspect ior many missiles. The apparent intent was to...DISTRIBUTION AND AVAIL ABWLII-Tf ON BACK COVER TL~ - 211T, AGARD-R-661 ORGANISATION DU TRAITE DE L’ATLANTIQUE NORD GROUP CONSULTATIF POURLA RECHERCHE ET LE...Structural and Materials Panel formed an ad hoc Group to condense this discussion. The three pilot papers contained in this report address thedifferent

Designing an Advanced Instructional Design Advisor: Incorporating Visual Materials and Other Research Issues. Volume 4

DTIC Science & Technology

1991-12-01

property of graphics (such as concreteness) shared by other media that has benefitted performance. The exact componential aspect of a graphic...graphic will normally attempt to convey some substantive information, and it will do so using a "grammar" and "syntax" which are assumed to be shared ...and Ehrenfeucht (1982) specifically tried to equate content as well as structure between a narrative movie (The Unicorn in the Garden) and a text. They

System architectures for telerobotic research

NASA Technical Reports Server (NTRS)

Harrison, F. Wallace

1989-01-01

Several activities are performed related to the definition and creation of telerobotic systems. The effort and investment required to create architectures for these complex systems can be enormous; however, the magnitude of process can be reduced if structured design techniques are applied. A number of informal methodologies supporting certain aspects of the design process are available. More recently, prototypes of integrated tools supporting all phases of system design from requirements analysis to code generation and hardware layout have begun to appear. Activities related to system architecture of telerobots are described, including current activities which are designed to provide a methodology for the comparison and quantitative analysis of alternative system architectures.

Design and simulation of a semiconductor chip-based visible - NIR spectrometer for Earth observation

NASA Astrophysics Data System (ADS)

Coote, J.; Woolliams, E.; Fox, N.; Goodyer, I. D.; Sweeney, S. J.

2014-03-01

We present the development of a novel semiconductor chip-based spectrometer for calibration of Earth observation instruments. The chip follows the Solo spectroscopy approach utilising an array of microdisk resonators evanescently coupled to a central waveguide. Each resonator is tuned to select out a specific wavelength from the incoming spectrum, and forms a p-i-n junction in which current is generated when light of the correct wavelength is present. In this paper we discuss important design aspects including the choice of semiconductor material, design of semiconductor quantum well structures for optical absorption, and design and optimisation of the waveguide and resonators.

Electric power from vertical-axis wind turbines

NASA Astrophysics Data System (ADS)

Touryan, K. J.; Strickland, J. H.; Berg, D. E.

1987-12-01

Significant advancements have occurred in vertical axis wind turbine (VAWT) technology for electrical power generation over the last decade; in particular, well-proven aerodynamic and structural analysis codes have been developed for Darrieus-principle wind turbines. Machines of this type have been built by at least three companies, and about 550 units of various designs are currently in service in California wind farms. Attention is presently given to the aerodynamic characteristics, structural dynamics, systems engineering, and energy market-penetration aspects of VAWTs.

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.

The architecture of enterprise hospital information system.

PubMed

Lu, Xudong; Duan, Huilong; Li, Haomin; Zhao, Chenhui; An, Jiye

2005-01-01

Because of the complexity of the hospital environment, there exist a lot of medical information systems from different vendors with incompatible structures. In order to establish an enterprise hospital information system, the integration among these heterogeneous systems must be considered. Complete integration should cover three aspects: data integration, function integration and workflow integration. However most of the previous design of architecture did not accomplish such a complete integration. This article offers an architecture design of the enterprise hospital information system based on the concept of digital neural network system in hospital. It covers all three aspects of integration, and eventually achieves the target of one virtual data center with Enterprise Viewer for users of different roles. The initial implementation of the architecture in the 5-year Digital Hospital Project in Huzhou Central hospital of Zhejiang Province is also described.

Electron cyclotron resonance ion sources with arc-shaped coils.

PubMed

Suominen, P; Wenander, F

2008-02-01

The minimum-B magnetic field structure of electron cyclotron resonance ion sources (ECRIS) has conventionally been formed with a combination of solenoids and a hexapole magnet. However, minimum-B structure can also be formed with arc-shaped coils. Recently it was shown that multiply charged heavy-ions can be produced with an ECRIS based on such a structure. In the future, the ARC-ECRIS magnetic field structure can be an interesting option for radioactive ion-beam sources and charge-breeders as well as for high performance ECRIS allowing for 100 GHz plasma heating. This paper presents some design aspects of the ARC-ECRIS.

Broadband piezoelectric energy harvesting devices using multiple bimorphs with different operating frequencies.

PubMed

Xue, Huan; Hu, Yuantai; Wang, Qing-Ming

2008-09-01

This paper presents a novel approach for designing broadband piezoelectric harvesters by integrating multiple piezoelectric bimorphs (PBs) with different aspect ratios into a system. The effect of 2 connecting patterns among PBs, in series and in parallel, on improving energy harvesting performance is discussed. It is found for multifrequency spectra ambient vibrations: 1) the operating frequency band (OFB) of a harvesting structure can be widened by connecting multiple PBs with different aspect ratios in series; 2) the OFB of a harvesting structure can be shifted to the dominant frequency domain of the ambient vibrations by increasing or decreasing the number of PBs in parallel. Numerical results show that the OFB of the piezoelectric energy harvesting devices can be tailored by the connection patterns (i.e., in series and in parallel) among PBs.

Review of ship slamming loads and responses

NASA Astrophysics Data System (ADS)

Wang, Shan; Guedes Soares, C.

2017-12-01

The paper presents an overview of studies of slamming on ship structures. This work focuses on the hull slamming, which is one of the most important types of slamming problems to be considered in the ship design process and the assessment of the ship safety. There are three main research aspects related to the hull slamming phenomenon, a) where and how often a slamming event occurs, b) slamming load prediction and c) structural response due to slamming loads. The approaches used in each aspect are reviewed and commented, together with the presentation of some typical results. The methodology, which combines the seakeeping analysis and slamming load prediction, is discussed for the global analysis of the hull slamming of a ship in waves. Some physical phenomena during the slamming event are discussed also. Recommendations for the future research and developments are made.

[Providing regular relief; considerations for palliative care in the Netherlands].

PubMed

Crul, B J; van Weel, C

2001-10-20

Over the last few decades the attention devoted to the palliative aspects of medicine, particularly those in hospital care, has declined due to the emphasis on medical technology. In Anglo-Saxon countries a review of this development resulted in structured palliative care that benefited terminally ill patients with a progressive fatal disease, especially cancer patients. Due to increasing national and international criticism of both the practice of euthanasia (assumed to be too liberal) and the lack of attention devoted to structured palliative care in the Netherlands, the Dutch government decided to improve the structure of palliative care. The government's viewpoint is based on the assumption that good palliative care that includes adequate pain control benefits patient care and might eventually lead to fewer requests for euthanasia. The improvements to palliative care should be realised by means of improvements in the structure, training and knowledge. Six academic medical clusters have been designated as Centres for the Development of Palliative Care (Dutch acronym: COPZ) for a 5-year period. Each COPZ must develop the various aspects needed to improve palliative care within the region it serves and ensure that its activities are carefully coordinated with those in the other centres. Research will focus on measuring the efficacy of palliative care as well as ethical and epidemiological aspects. A government committee will assess the appropriateness of the activities undertaken by each of the centres.

Electrochemical Deposition of Conformal and Functional Layers on High Aspect Ratio Silicon Micro/Nanowires.

PubMed

Ozel, Tuncay; Zhang, Benjamin A; Gao, Ruixuan; Day, Robert W; Lieber, Charles M; Nocera, Daniel G

2017-07-12

Development of new synthetic methods for the modification of nanostructures has accelerated materials design advances to furnish complex architectures. Structures based on one-dimensional (1D) silicon (Si) structures synthesized using top-down and bottom-up methods are especially prominent for diverse applications in chemistry, physics, and medicine. Yet further elaboration of these structures with distinct metal-based and polymeric materials, which could open up new opportunities, has been difficult. We present a general electrochemical method for the deposition of conformal layers of various materials onto high aspect ratio Si micro- and nanowire arrays. The electrochemical deposition of a library of coaxial layers comprising metals, metal oxides, and organic/inorganic semiconductors demonstrate the materials generality of the synthesis technique. Depositions may be performed on wire arrays with varying diameter (70 nm to 4 μm), pitch (5 μ to 15 μ), aspect ratio (4:1 to 75:1), shape (cylindrical, conical, hourglass), resistivity (0.001-0.01 to 1-10 ohm/cm 2 ), and substrate orientation. Anisotropic physical etching of wires with one or more coaxial shells yields 1D structures with exposed tips that can be further site-specifically modified by an electrochemical deposition approach. The electrochemical deposition methodology described herein features a wafer-scale synthesis platform for the preparation of multifunctional nanoscale devices based on a 1D Si substrate.

Multiobjective optimization applied to structural sizing of low cost university-class microsatellite projects

NASA Astrophysics Data System (ADS)

Ravanbakhsh, Ali; Franchini, Sebastián

2012-10-01

In recent years, there has been continuing interest in the participation of university research groups in space technology studies by means of their own microsatellites. The involvement in such projects has some inherent challenges, such as limited budget and facilities. Also, due to the fact that the main objective of these projects is for educational purposes, usually there are uncertainties regarding their in orbit mission and scientific payloads at the early phases of the project. On the other hand, there are predetermined limitations for their mass and volume budgets owing to the fact that most of them are launched as an auxiliary payload in which the launch cost is reduced considerably. The satellite structure subsystem is the one which is most affected by the launcher constraints. This can affect different aspects, including dimensions, strength and frequency requirements. In this paper, the main focus is on developing a structural design sizing tool containing not only the primary structures properties as variables but also the system level variables such as payload mass budget and satellite total mass and dimensions. This approach enables the design team to obtain better insight into the design in an extended design envelope. The structural design sizing tool is based on analytical structural design formulas and appropriate assumptions including both static and dynamic models of the satellite. Finally, a Genetic Algorithm (GA) multiobjective optimization is applied to the design space. The result is a Pareto-optimal based on two objectives, minimum satellite total mass and maximum payload mass budget, which gives a useful insight to the design team at the early phases of the design.

Wing planform geometry effects on large subsonic military transport airplanes. Final technical report March 1976-February 1977

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

Kulfan, R.M.; Vachal, J.D.

1978-02-01

A Preliminary Design Study of large turbulent flow military transport aircraft has been made. The study airplanes were designed to carry a heavy payload (350,000 lb) for a long range (10,000 nmi). The study tasks included: Wing geometry/cruise speed optimization of a large cantilever wing military transport airplane; Preliminary design and performance evaluation of a strut-braced wing transport airplane; and Structural analyses of large-span cantilever and strut-braced wings of graphite/epoxy sandwich construction (1985 technology). The best cantilever wing planform for minimum takeoff gross weight, and minimum fuel requirements, as determined using statistical weight evaluations, has a high aspect ratio, lowmore » sweep, low thickness/chord ratio, and a cruise Mach number of 0.76. A near optimum wing planform with greater speed capability (M = 0.78) has an aspect ratio = 12, quarter chord sweep = 20 deg, and thickness/chord ratio of 0.14/0.08 (inboard/outboard).« less

Project-Based Learning Courses: The Relationship Between Faculty-Intended Course Implementation and Students' Perceptions

NASA Astrophysics Data System (ADS)

Simonovich, Jennifer A.; Towers, Emily; Zastavker, Yevgeniya V.

2012-02-01

Project-based learning (PjBL) has been shown to improve students' performance and satisfaction with their coursework, particularly in science and engineering courses. Specific aspects of PjBL that contribute to this improvement are student autonomy, course scaffolding, and instructor support. This study investigates two PjBL courses required for engineering majors at a small technical school, Introductory Mechanics Laboratory and Introductory Engineering Design. The three data sources used in this work are classroom observations (one laboratory and four design sessions) and semi-structured in-depth interviews with twelve students and six faculty. Grounded theory approach is used in a two-step fashion by (1) analyzing each data set individually and (2) performing full triangulation of all three data sets. In this talk, we demonstrate the relationship between faculty intentions and student perceptions regarding the three PjBL aspects -- student autonomy, course scaffolding, and instructor support -- within the context of these two courses. We further discuss implications for the course design and professional development of faculty.

Impact of Structured Group Activities on Pre-Service Teachers' Beliefs about Classroom Motivation: An Exploratory Study

ERIC Educational Resources Information Center

Mansfield, Caroline F.; Volet, Simone E.

2014-01-01

Pre-service teachers' beliefs about classroom motivation, and how these beliefs may be developed during initial teacher preparation, is a relatively new aspect of enquiry in the fields of motivation and teacher education. An empirical study, grounded in a social constructivist perspective, was designed to examine the impact of providing…

Qualitative Assessment of Adolescents Views about Improving Exposure to Internet-Delivered Interventions

ERIC Educational Resources Information Center

Crutzen, Rik; de Nooijer, Jascha; Brouwer, Wendy; Oenema, Anke; Brug, Johannes; de Vries, Nanne K.

2008-01-01

Purpose: The purpose of this paper is to gain first insight into factors which might be associated with exposure to internet-delivered interventions. Design/methodology/approach: Semi-structured focus group interviews were conducted with five groups of Dutch adolescents (n = 54), aged 12-17 years. Several aspects of exposure: a first visit;…

Effective Schools, Tinkering and School Cultures: Maintaining Schools That Sort by Race, Class, and Gender.

ERIC Educational Resources Information Center

Eubanks, Eugene; Parish, Ralph

The relationship between effective schools research and the cultural aspect of school organizations are examined in this paper. The first part discusses how effective schools projects are designed and implemented as opposed to what is actually practiced. Differences between "tinkering" with existing structures, a strategy to maintain the status…

Through a Different Lens: Bridging the Expectation-Perception (Quality) Divide in Higher Education

ERIC Educational Resources Information Center

Yeo, Roland K.; Marquardt, Michael J.

2011-01-01

The paper draws on the underpinnings of SERVQUAL (a Service Quality measurement model) and explores three key aspects of service standards as adopted by an Engineering School in Singapore: customer orientation, course design/delivery and support services. Qualitative methodology was employed and data were collected by means of structured in-depth…

Clinical Use of the Pediatric Attention Disorders Diagnostic Screener for Children at Risk for Attention Deficit Hyperactivity Disorder: Case Illustrations

ERIC Educational Resources Information Center

Keiser, Ashley; Reddy, Linda

2013-01-01

The Pediatric Attention Disorders Diagnostic Screener is a multidimensional, computerized screening tool designed to assess attention and global aspects of executive functioning in children at risk for attention disorders. The screener consists of a semi-structured diagnostic interview, brief parent and teacher rating scales, 3 computer-based…

Into Adolescence: A Time of Change. A Curriculum for Grades 5-8. Contemporary Health Series.

ERIC Educational Resources Information Center

Golliher, Catherine S.

This book introduces middle school students to the basic facts of human reproduction and explains the physical, emotional, and social aspects of growing into adolescence. Designed with a structured sequence of six lessons and activities, this module includes teacher scripts, reproducible worksheets, and transparency masters. Lessons cover: (1)…

Negotiating the Rub between Cultures: Teacher Talk and Sustained Shifts in Practice

ERIC Educational Resources Information Center

Meth, Jessica Matthews; Azano, Amy

2012-01-01

This article examines the outcomes of an eight-month professional development initiative, designed to support six Writing Project teachers' classroom inquiry projects, each focused on improving an aspect of student writing. We begin by introducing the genesis of these classroom research projects as well as the structure and content of the support…

Molecular Design of Low-Density Multifunctional Hybrid Materials

DTIC Science & Technology

2016-01-01

properties, but also the synergistic interactions of reactive chemical and simulated solar UV environments with the hybrid film which leads to...applications possible including microelectronic interlayer dielectrics, antireflective coatings for solar cells , optical waveguides, size-selective...membranes, biosensors, micro-fluidic structures, and membranes in fuel cells . A critical aspect for all of these applications is that the hybrids

Integrated multidisciplinary design optimization of rotorcraft

NASA Technical Reports Server (NTRS)

Adelman, Howard M.; Mantay, Wayne R.

1989-01-01

The NASA/Army research plan for developing the logic elements for helicopter rotor design optimization by integrating appropriate disciplines and accounting for important interactions among the disciplines is discussed. The paper describes the optimization formulation in terms of the objective function, design variables, and constraints. The analysis aspects are discussed, and an initial effort at defining the interdisciplinary coupling is summarized. Results are presented on the achievements made in the rotor aerodynamic performance optimization for minimum hover horsepower, rotor dynamic optimization for vibration reduction, rotor structural optimization for minimum weight, and integrated aerodynamic load/dynamics optimization for minimum vibration and weight.

Benchmarking Inverse Statistical Approaches for Protein Structure and Design with Exactly Solvable Models.

PubMed

Jacquin, Hugo; Gilson, Amy; Shakhnovich, Eugene; Cocco, Simona; Monasson, Rémi

2016-05-01

Inverse statistical approaches to determine protein structure and function from Multiple Sequence Alignments (MSA) are emerging as powerful tools in computational biology. However the underlying assumptions of the relationship between the inferred effective Potts Hamiltonian and real protein structure and energetics remain untested so far. Here we use lattice protein model (LP) to benchmark those inverse statistical approaches. We build MSA of highly stable sequences in target LP structures, and infer the effective pairwise Potts Hamiltonians from those MSA. We find that inferred Potts Hamiltonians reproduce many important aspects of 'true' LP structures and energetics. Careful analysis reveals that effective pairwise couplings in inferred Potts Hamiltonians depend not only on the energetics of the native structure but also on competing folds; in particular, the coupling values reflect both positive design (stabilization of native conformation) and negative design (destabilization of competing folds). In addition to providing detailed structural information, the inferred Potts models used as protein Hamiltonian for design of new sequences are able to generate with high probability completely new sequences with the desired folds, which is not possible using independent-site models. Those are remarkable results as the effective LP Hamiltonians used to generate MSA are not simple pairwise models due to the competition between the folds. Our findings elucidate the reasons for the success of inverse approaches to the modelling of proteins from sequence data, and their limitations.

Holliday Junction Thermodynamics and Structure: Coarse-Grained Simulations and Experiments

NASA Astrophysics Data System (ADS)

Wang, Wujie; Nocka, Laura M.; Wiemann, Brianne Z.; Hinckley, Daniel M.; Mukerji, Ishita; Starr, Francis W.

2016-03-01

Holliday junctions play a central role in genetic recombination, DNA repair and other cellular processes. We combine simulations and experiments to evaluate the ability of the 3SPN.2 model, a coarse-grained representation designed to mimic B-DNA, to predict the properties of DNA Holliday junctions. The model reproduces many experimentally determined aspects of junction structure and stability, including the temperature dependence of melting on salt concentration, the bias between open and stacked conformations, the relative populations of conformers at high salt concentration, and the inter-duplex angle (IDA) between arms. We also obtain a close correspondence between the junction structure evaluated by all-atom and coarse-grained simulations. We predict that, for salt concentrations at physiological and higher levels, the populations of the stacked conformers are independent of salt concentration, and directly observe proposed tetrahedral intermediate sub-states implicated in conformational transitions. Our findings demonstrate that the 3SPN.2 model captures junction properties that are inaccessible to all-atom studies, opening the possibility to simulate complex aspects of junction behavior.

Evaluation of Waveform Structure Features on Time Domain Target Recognition under Cross Polarization

NASA Astrophysics Data System (ADS)

Selver, M. A.; Seçmen, M.; Zoral, E. Y.

2016-08-01

Classification of aircraft targets from scattered electromagnetic waves is a challenging application, which suffers from aspect angle dependency. In order to eliminate the adverse effects of aspect angle, various strategies were developed including the techniques that rely on extraction of several features and design of suitable classification systems to process them. Recently, a hierarchical method, which uses features that take advantage of waveform structure of the scattered signals, is introduced and shown to have effective results. However, this approach has been applied to the special cases that consider only a single planar component of electric field that cause no-cross polarization at the observation point. In this study, two small scale aircraft models, Boeing-747 and DC-10, are selected as the targets and various polarizations are used to analyse the cross-polarization effects on system performance of the aforementioned method. The results reveal the advantages and the shortcomings of using waveform structures in time-domain target identification.

Development of a low-cost x-ray mask for high-aspect-ratio MEM smart structures

NASA Astrophysics Data System (ADS)

Ajmera, Pratul K.; Stadler, Stefan; Abdollahi, Neda

1998-07-01

A cost-effective process with short fabrication time for making x-ray masks for research and development purposes is described here for fabricating high-aspect ratio microelectromechanical structures using synchrotron based x- ray lithography. Microscope cover glass slides as membrane material is described. Slides with an initial thickness of 175 micrometers are etched to a thickness in the range of 10 - 25 micrometers using a diluted HF and buffered hydrofluoric acid solutions. The thinned slides are glued on supportive mask frames and sputtered with a chromium/silver sandwich layer which acts as a plating base layer for the deposition of the gold absorber. The judicial choice of glue and mask frame material are significant parameters in a successful fabrication process. Gold absorber structures are electroplated on the membrane. Calculations are done for contrast and dose ratio obtained in the photoresist after synchrotron radiation as a function of the mask design parameters. Exposure experiments are performed to prove the applicability of the fabricated x-ray mask.

Space Shuttle Orbiter Structures and Mechanisms

NASA Technical Reports Server (NTRS)

Gilmore, Adam L.; Estes, Lynda R.; Eilers, James A.; Logan, Jeffrey S.; Evernden, Brent A.; Decker, William S.; Hagen, Jeffrey D.; Davis, Robert E.; Broughton, James K.; Campbell, Carlisle C.;

Which Aspects of Professional Commitment Can Effectively Retain Nurses in the Nursing Profession?

PubMed

Chang, Hao-Yuan; Shyu, Yea-Ing Lotus; Wong, May-Kuen; Friesner, Daniel; Chu, Tsung-Lan; Teng, Ching-I

2015-09-01

This study examined which aspects of professional commitment can effectively retain nurses in the nursing profession. This study used a longitudinal design, simple random sampling, and two-wave data collection to survey and follow up a representative sample of 579 nurses for 1 year in a major medical center in northern Taiwan. Items measuring each aspect of professional commitment came from Meyer et al.'s scale. In the second wave, administrative data were culled to determine whether these nurses remain employed as nurses. Structural equation modeling is used to analyze the data. Analytical results indicate that continuance commitment predicts nurse retention in the nursing profession (path coefficient = 0.34, p < .01). Institutional efforts to improve continuance commitment (e.g., improved salary structures and enhanced professional development opportunities) likely retain nurses in the nursing profession. The findings of this study indicate the importance of continuance intention in retaining nurses. Nursing managers who face staff retention issues may consider making efforts to improve nurse salary and employer-sponsored benefits. © 2015 Sigma Theta Tau International.

Composite Crew Module: Primary Structure

NASA Technical Reports Server (NTRS)

Kirsch, Michael T.

2011-01-01

In January 2007, the NASA Administrator and Associate Administrator for the Exploration Systems Mission Directorate chartered the NASA Engineering and Safety Center to design, build, and test a full-scale crew module primary structure, using carbon fiber reinforced epoxy based composite materials. The overall goal of the Composite Crew Module project was to develop a team from the NASA family with hands-on experience in composite design, manufacturing, and testing in anticipation of future space exploration systems being made of composite materials. The CCM project was planned to run concurrently with the Orion project's baseline metallic design within the Constellation Program so that features could be compared and discussed without inducing risk to the overall Program. This report discusses the project management aspects of the project including team organization, decision making, independent technical reviews, and cost and schedule management approach.

Metal-free organic dyes for dye-sensitized solar cells: from structure: property relationships to design rules.

PubMed

Mishra, Amaresh; Fischer, Markus K R; Bäuerle, Peter

2009-01-01

Dye-sensitized solar cells (DSSC) have attracted considerable attention in recent years as they offer the possibility of low-cost conversion of photovoltaic energy. This Review focuses on recent advances in molecular design and technological aspects of metal-free organic dyes for applications in dye-sensitized solar cells. Special attention has been paid to the design principles of these dyes and on the effect of various electrolyte systems. Cosensitization, an emerging technique to extend the absorption range, is also discussed as a way to improve the performance of the device. In addition, we report on inverted dyes for photocathodes, which constitutes a relatively new approach for the production of tandem cells. Special consideration has been paid to the correlation between the molecular structure and physical properties to their performance in DSSCs.

Structural integrity and containment aspects of small gas turbine engines

NASA Astrophysics Data System (ADS)

Gupta, S. S.; Gomuc, R.

1994-03-01

Structural integrity of rotating components in gas turbine engines is very crucial since their failure implies high impact energy, which, if uncontained, could mean damage to aircraft structures, controls, and so forth, and, in the worst scenario, even loss of lives. This final consequence has led to very stringent airworthiness regulations for engine/aircraft certifications. This paper discusses the historical statistics of noncontainment events in turbofans, turboprops, and turboshafts and shows how the damage severity varies between different applications and how changes to regulations are continuing in order to improve the reliability of aircraft/rotorcraft. The paper also presents design challenges resulting from the analysis complexity of containment/noncontainment event and the way Pratt & Whitney Canada design/analysis/test system caters to all the requirements. The weight and cost impact of possible changes to current regulations are also presented.

NASA GRC Fatigue Crack Initiation Life Prediction Models

NASA Technical Reports Server (NTRS)

Arya, Vinod K.; Halford, Gary R.

2002-01-01

Metal fatigue has plagued structural components for centuries, and it remains a critical durability issue in today's aerospace hardware. This is true despite vastly improved and advanced materials, increased mechanistic understanding, and development of accurate structural analysis and advanced fatigue life prediction tools. Each advance is quickly taken advantage of to produce safer, more reliable, more cost effective, and better performing products. In other words, as the envelope is expanded, components are then designed to operate just as close to the newly expanded envelope as they were to the initial one. The problem is perennial. The economic importance of addressing structural durability issues early in the design process is emphasized. Tradeoffs with performance, cost, and legislated restrictions are pointed out. Several aspects of structural durability of advanced systems, advanced materials and advanced fatigue life prediction methods are presented. Specific items include the basic elements of durability analysis, conventional designs, barriers to be overcome for advanced systems, high-temperature life prediction for both creep-fatigue and thermomechanical fatigue, mean stress effects, multiaxial stress-strain states, and cumulative fatigue damage accumulation assessment.

A Primer In Advanced Fatigue Life Prediction Methods

NASA Technical Reports Server (NTRS)

Halford, Gary R.

2000-01-01

Metal fatigue has plagued structural components for centuries, and it remains a critical durability issue in today's aerospace hardware. This is true despite vastly improved and advanced materials, increased mechanistic understanding, and development of accurate structural analysis and advanced fatigue life prediction tools. Each advance is quickly taken advantage of to produce safer, more reliable more cost effective, and better performing products. In other words, as the envelop is expanded, components are then designed to operate just as close to the newly expanded envelop as they were to the initial one. The problem is perennial. The economic importance of addressing structural durability issues early in the design process is emphasized. Tradeoffs with performance, cost, and legislated restrictions are pointed out. Several aspects of structural durability of advanced systems, advanced materials and advanced fatigue life prediction methods are presented. Specific items include the basic elements of durability analysis, conventional designs, barriers to be overcome for advanced systems, high-temperature life prediction for both creep-fatigue and thermomechanical fatigue, mean stress effects, multiaxial stress-strain states, and cumulative fatigue damage accumulation assessment.

NASA GRC Fatigue Crack Initiation Life Prediction Models

NASA Astrophysics Data System (ADS)

Arya, Vinod K.; Halford, Gary R.

2002-10-01

Metal fatigue has plagued structural components for centuries, and it remains a critical durability issue in today's aerospace hardware. This is true despite vastly improved and advanced materials, increased mechanistic understanding, and development of accurate structural analysis and advanced fatigue life prediction tools. Each advance is quickly taken advantage of to produce safer, more reliable, more cost effective, and better performing products. In other words, as the envelope is expanded, components are then designed to operate just as close to the newly expanded envelope as they were to the initial one. The problem is perennial. The economic importance of addressing structural durability issues early in the design process is emphasized. Tradeoffs with performance, cost, and legislated restrictions are pointed out. Several aspects of structural durability of advanced systems, advanced materials and advanced fatigue life prediction methods are presented. Specific items include the basic elements of durability analysis, conventional designs, barriers to be overcome for advanced systems, high-temperature life prediction for both creep-fatigue and thermomechanical fatigue, mean stress effects, multiaxial stress-strain states, and cumulative fatigue damage accumulation assessment.

Design of High Altitude Long Endurance UAV: Structural Analysis of Composite Wing using Finite Element Method

NASA Astrophysics Data System (ADS)

Kholish Rumayshah, Khodijah; Prayoga, Aditya; Mochammad Agoes Moelyadi, Ing., Dr.

2018-04-01

Research on a High Altitude Long Endurance (HALE) Unmanned Aerial Vehicle (UAV) is currently being conducted at Bandung Institute of Technology (ITB). Previously, the 1st generation of HALE UAV ITB used balsa wood for most of its structure. Flight test gave the result of broken wings due to extreme side-wind that causes large bending to its high aspect ratio wing. This paper conducted a study on designing the 2nd generation of HALE UAV ITB which used composite materials in order to substitute balsa wood at some critical parts of the wing’s structure. Finite element software ABAQUS/CAE is used to predict the stress and deformation that occurred. Tsai-Wu and Von-Mises failure criteria were applied to check whether the structure failed or not. The initial configuration gave the results that the structure experienced material failure. A second iteration was done by proposing a new configuration and it was proven safe against the load given.

Thermal Analysis of a Finite Element Model in a Radiation Dominated Environment

NASA Technical Reports Server (NTRS)

Page, Arthur T.

2001-01-01

This paper presents a brief overview of thermal analysis, evaluating the University of Arizona mirror design, for the Next Generation Space Telescope (NGST) Pre-Phase A vehicle concept. Model building begins using Thermal Desktop(TM), by Cullimore and Ring Technologies, to import a NASTRAN bulk data file from the structural model of the mirror assembly. Using AutoCAD(R) capabilities, additional surfaces are added to simulate the thermal aspects of the problem which, for due reason, are not part of the structural model. Surfaces are then available to accept thermophysical and thermo-optical properties. Thermal Desktop(TM) calculates radiation conductors using Monte Carlo simulations. Then Thermal Desktop(TM) generates the SINDA input file having a one-to-one correspondence with the NASTRAN node and element definitions. A model is now available to evaluate the mirror design in the radiation dominated environment, conduct parametric trade studies of the thermal design, and provide temperatures to the finite element structural model.

Thermal Analysis of a Finite Element Model in a Radiation Dominated Environment

NASA Technical Reports Server (NTRS)

Page, Arhur T.

1999-01-01

This paper presents a brief overview of thermal analysis, evaluating the University of Arizona mirror design, for the Next Generation Space Telescope (NGST) Pre-Phase A vehicle concept. Model building begins using Thermal Desktop(Tm), by Cullimore and Ring Technologies, to import a NASTRAN bulk data file from the structural model of the mirror assembly. Using AutoCAD(R) capabilities, additional surfaces are added to simulate the thermal aspects of the problem which, for due reason, are not part of the structural model. Surfaces are then available to accept thermophysical and thermo-optical properties. Thermal Desktop(Tm) calculates radiation conductors using Monte Carlo simulations. Then Thermal Desktop(Tm) generates the SINDA/Fluint input file having a one-to-one correspondence with the NASTRAN node and element definitions. A model is now available to evaluate the mirror design in the radiation dominated environment conduct parametric trade studies of the thermal design, and provide temperatures to the finite element structural model.

Core compressor exit stage study, 2

NASA Technical Reports Server (NTRS)

Behlke, R. F.; Burdsall, E. A.; Canal, E., Jr.; Korn, N. D.

1979-01-01

A total of two three-stage compressors were designed and tested to determine the effects of aspect ratio on compressor performance. The first compressor was designed with an aspect ratio of 0.81; the other, with an aspect ratio of 1.22. Both compressors had a hub-tip ratio of 0.915, representative of the rear stages of a core compressor, and both were designed to achieve a 15.0% surge margin at design pressure ratios of 1.357 and 1.324, respectively, at a mean wheel speed of 167 m/sec. At design speed the 0.81 aspect ratio compressor achieved a pressure ratio of 1.346 at a corrected flow of 4.28 kg/sec and an adiabatic efficiency of 86.1%. The 1.22 aspect ratio design achieved a pressure ratio of 1.314 at 4.35 kg/sec flow and 87.0% adiabatic efficiency. Surge margin to peak efficiency was 24.0% with the lower aspect ratio blading, compared with 12.4% with the higher aspect ratio blading.

Biophysically Inspired Rational Design of Structured Chimeric Substrates for DNAzyme Cascade Engineering

PubMed Central

Lakin, Matthew R.; Brown, Carl W.; Horwitz, Eli K.; Fanning, M. Leigh; West, Hannah E.; Stefanovic, Darko; Graves, Steven W.

2014-01-01

The development of large-scale molecular computational networks is a promising approach to implementing logical decision making at the nanoscale, analogous to cellular signaling and regulatory cascades. DNA strands with catalytic activity (DNAzymes) are one means of systematically constructing molecular computation networks with inherent signal amplification. Linking multiple DNAzymes into a computational circuit requires the design of substrate molecules that allow a signal to be passed from one DNAzyme to another through programmed biochemical interactions. In this paper, we chronicle an iterative design process guided by biophysical and kinetic constraints on the desired reaction pathways and use the resulting substrate design to implement heterogeneous DNAzyme signaling cascades. A key aspect of our design process is the use of secondary structure in the substrate molecule to sequester a downstream effector sequence prior to cleavage by an upstream DNAzyme. Our goal was to develop a concrete substrate molecule design to achieve efficient signal propagation with maximal activation and minimal leakage. We have previously employed the resulting design to develop high-performance DNAzyme-based signaling systems with applications in pathogen detection and autonomous theranostics. PMID:25347066

A proposal of a perfect graphene absorber with enhanced design and fabrication tolerance.

PubMed

Lee, Sangjun; Tran, Thang Q; Heo, Hyungjun; Kim, Myunghwan; Kim, Sangin

2017-07-06

We propose a novel device structure for the perfect absorption of a one-sided lightwavve illumination, which consists of a high-contrast grating (HCG) and an evanescently coupled slab with an absorbing medium (graphene). The operation principle and design process of the proposed structure are analyzed using the coupled mode theory (CMT), which is confirmed by the rigorous coupled wave analysis (RCWA). According to the CMT analysis, in the design of the proposed perfect absorber, the HCG, functioning as a broadband reflector, and the lossy slab structure can be optimized separately. In addition, we have more design parameters than conditions to satisfy; that is, we have more than enough degrees of freedom in the device design. This significantly relieves the complexity of the perfect absorber design. Moreover, in the proposed perfect absorber, most of the incident wave is confined in the slab region with strong field enhancement, so that the absorption performance is very tolerant to the variation of the design parameters near the optimal values for the perfect absorption. It has been demonstrated numerically that absorption spectrum tuning over a wider wavelength range of ~300 nm is possible, keeping significantly high maximum absorption (>95%). It is also shown that the proposed perfect absorber outperforms the previously proposed scheme in all aspects.

Optimal Control Allocation with Load Sensor Feedback for Active Load Suppression, Flight-Test Performance

NASA Technical Reports Server (NTRS)

Miller, Christopher J.; Goodrick, Dan

2017-01-01

The problem of control command and maneuver induced structural loads is an important aspect of any control system design. The aircraft structure and the control architecture must be designed to achieve desired piloted control responses while limiting the imparted structural loads. The classical approach is to utilize high structural margins, restrict control surface commands to a limited set of analyzed combinations, and train pilots to follow procedural maneuvering limitations. With recent advances in structural sensing and the continued desire to improve safety and vehicle fuel efficiency, it is both possible and desirable to develop control architectures that enable lighter vehicle weights while maintaining and improving protection against structural damage. An optimal control technique has been explored and shown to achieve desirable vehicle control performance while limiting sensed structural loads to specified values. This technique has been implemented and flown on the National Aeronautics and Space Administration Full-scale Advanced Systems Testbed aircraft. The flight tests illustrate that the approach achieves the desired performance and show promising potential benefits. The flights also uncovered some important issues that will need to be addressed for production application.

Solar photovoltaics: current state and trends

NASA Astrophysics Data System (ADS)

Milichko, V. A.; Shalin, A. S.; Mukhin, I. S.; Kovrov, A. E.; Krasilin, A. A.; Vinogradov, A. V.; Belov, P. A.; Simovski, C. R.

2016-08-01

Basic aspects of current solar photovoltaics (PVs) are reviewed, starting from the recently developed already-on-the-market first-generation solar cells and ending with promising but not yet commercialized third-generation cells and materials possibly leading to new cell designs. The emphasis is on the physical principles of operation of various solar cells, which are divided into several groups according to our classification scheme. To make the picture complete, some technological and economic aspects of the field are discussed. A separate chapter considers antireflection coatings and light-trapping textures — structures which, while not having appeared yet in the PV review literature, are an integral part of the solar cells.

OTEC cold water pipe design for problems caused by vortex-excited oscillations

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

Griffin, O. M.

1980-03-14

Vortex-excited oscillations of marine structures result in reduced fatigue life, large hydrodynamic forces and induced stresses, and sometimes lead to structural damage and to diestructive failures. The cold water pipe of an OTEC plant is nominally a bluff, flexible cylinder with a large aspect ratio (L/D = length/diameter), and is likely to be susceptible to resonant vortex-excited oscillations. The objective of this report is to survey recent results pertaining to the vortex-excited oscillations of structures in general and to consider the application of these findings to the design of the OTEC cold water pipe. Practical design calculations are given asmore » examples throughout the various sections of the report. This report is limited in scope to the problems of vortex shedding from bluff, flexible structures in steady currents and the resulting vortex-excited oscillations. The effects of flow non-uniformities, surface roughness of the cylinder, and inclination to the incident flow are considered in addition to the case of a smooth cyliner in a uniform stream. Emphasis is placed upon design procedures, hydrodynamic coefficients applicable in practice, and the specification of structural response parameters relevant to the OTEC cold water pipe. There are important problems associated with in shedding of vortices from cylinders in waves and from the combined action of waves and currents, but these complex fluid/structure interactions are not considered in this report.« less

Dielectric elastomer bending tube actuators with rigid electrode structures

NASA Astrophysics Data System (ADS)

Wehrheim, F.; Schlaak, H. F.; Meyer, J.-U.

2010-04-01

The common approach for dielectric elastomer actuators (DEA) is based on the assumption that compliant electrodes are a fundamental design requirement. For tube-like applications compliant electrodes cause a change of the actuator diameter during actuation and would require additional support-structures. Focused on thinwalled actuator-tube geometries room consumption and radial stabilityr epresent crucial criteria. Following the ambition of maximum functional integration, the concept of using a rigid electrode structure arises. This structure realizes both, actuation and support characteristics. The intended rigid electrode structure is based on a stacked DEA with a non-compressible dielectric. Byactu ation, the displaced dielectric causes an overlap. This overlap serves as an indicator for geometrical limitations and has been used to extract design rules regarding the electrode size, electrode distance and maximum electrode travel. Bycons idering the strain in anydir ection, the mechanical efficiencyhas been used to define further design aspects. To verifyt he theoretic analysis, a test for determination of the compressive stress-strain-characteristics has been applied for different electrode setups. As result the geometrydep ending elastic pressure module has been formulated by implementation of a shape factor. The presented investigations consider exclusive the static behavior of a DEA-setup with rigid electrodes.

Report Writing for Technical Staff. P.R.I.D.E. People Retraining for Industry Excellence.

ERIC Educational Resources Information Center

Burt, Lorna

This guide, part of a series of workplace-developed materials for retraining factory workers, provides teaching materials for a workplace course in report writing skills for technical staff. The course has been designed to help new engineers with all aspects of report writing. It covers the outline and structure of reports, brainstorming,…

Permanent-Magnet Motors and Generators for Aircraft

NASA Technical Reports Server (NTRS)

Echolds, E. F.

1983-01-01

Electric motors and generators that use permarotating machinery, but aspects of control and power conditioning are also considered. The discussion is structured around three basic areas: rotating machine design considerations presents various configuration and material options, generator applications provides insight into utilization areas and shows actual hardware and test results, and motor applications provides the same type of information for drive systems.

Angular velocity discrimination

NASA Technical Reports Server (NTRS)

Kaiser, Mary K.

1990-01-01

Three experiments designed to investigate the ability of naive observers to discriminate rotational velocities of two simultaneously viewed objects are described. Rotations are constrained to occur about the x and y axes, resulting in linear two-dimensional image trajectories. The results indicate that observers can discriminate angular velocities with a competence near that for linear velocities. However, perceived angular rate is influenced by structural aspects of the stimuli.

MEMS Reliability Assurance Guidelines for Space Applications

NASA Technical Reports Server (NTRS)

Stark, Brian (Editor)

1999-01-01

This guide is a reference for understanding the various aspects of microelectromechanical systems, or MEMS, with an emphasis on device reliability. Material properties, failure mechanisms, processing techniques, device structures, and packaging techniques common to MEMS are addressed in detail. Design and qualification methodologies provide the reader with the means to develop suitable qualification plans for the insertion of MEMS into the space environment.

MSFC Skylab Orbital Workshop, volume 1. [systems analysis and equipment specifications for orbital laboratory

NASA Technical Reports Server (NTRS)

1974-01-01

The technical aspects of the Skylab-Orbital Workshop are discussed. Original concepts, goals, design philosophy, hardware, and testing are reported. The final flight configuration, overall test program, and mission performance are analyzed. The systems which are examined are: (1) the structural system, (2) the meteoroid shield systems, and (3) the environmental/thermal control subsystem.

Simulation of Electric Propulsion Thrusters

DTIC Science & Technology

2011-01-01

and operational lifetime. The second area of modelling activity concerns the plumes produced by electric thrusters. Detailed information on the plumes ...to reproduce the in-orbit space environment using ground-based laboratory facilities. Device modelling also plays an important role in plume ...of the numerical analysis of other aspects of thruster design, such as thermal and structural processes, is omitted here. There are two fundamental

Free space-planning solutions in the architecture of multi-storey buildings

NASA Astrophysics Data System (ADS)

Ibragimov, Alexander; Danilov, Alexander

2018-03-01

Here some aspects of the development of steel frame structure design from the standpoint of geometry and morphogenesis of bearing steel structures of civil engineering objects. An alternative approach to forming constructive schemes may be application of curved steel elements in the main load-bearing system. As an example, it may be circular and parabolic arches or segments of varying outline and orientation. The considered approach implies creating large internal volumes without loss in the load-bearing capacity of the frame. The basic concept makes possible a wide variety of layout and design solutions. The presence of free internal spaces of large volume in buildings of a "skyscraper" type contributes to resolving a great number of problems, including those of communicative nature.

Shuttle Communications and Tracking, Avionics, and Electromagnetic Compatibility

NASA Technical Reports Server (NTRS)

deSilva, K.; Hwu, Shian; Kindt, Kaylene; Kroll, Quin; Nuss, Ray; Romero, Denise; Schuler, Diana; Sham, Catherine; Scully, Robert

2011-01-01

By definition, electromagnetic compatibility (EMC) is the capability of components, sub-systems, and systems, to operate in their intended electromagnetic environment, within an established margin of safety, and at design levels of performance. Practice of the discipline itself incorporates knowledge of various aspects of applied physics, materials science, and engineering across the board, and includes control and mitigation of undesirable electromagnetic interaction between intentional and unintentional emitters and receivers of radio frequency energy, both within and external to the vehicle; identification and control of the hazards of non-ionizing electromagnetic radiation to personnel, ordnance, and fuels and propellants; and vehicle and system protection from the direct and indirect effects of lightning and various other forms of electrostatic discharge (ESD) threats, such as triboelectrification and plasma charging. EMC is extremely complex and far-reaching, affecting in some degree every aspect of the vehicle s design and operation. The most successful efforts incorporate EMC design features and techniques throughout design and fabrication of the vehicle s structure and components, as well as appropriate operational considerations with regard to electromagnetic threats in the operational environment, from the beginning of the design effort to the end of the life cycle of the manufactured product. This approach yields the highest design performance with the lowest cost and schedule impact.

Design of a leak detection device for marine airtight container

NASA Astrophysics Data System (ADS)

Li, Yuan; Zhu, Faxin; Lu, Jinshu; Li, Yule; Wu, Wenfeng; Zhang, Jianwei; Qin, Beichen

2018-04-01

The ship airtight container as the research object, according to the tightness of the traditional detection methods of sealed container from the shortcomings of the design of modern ship sealed container leak detection device based on the requirements of the use of AutoCAD to design a ship leakage detection device using airtight container, and introduces its working principle and main components. Finally, from the aspects of technology, structure, operation and economy, the feasibility analysis of the leak detection device for marine airtight container is designed, and it is concluded that the device has the advantages of simple operation, short detection time, easy maintenance and cost control, and has high feasibility.

Deep Space Network (DSN), Network Operations Control Center (NOCC) computer-human interfaces

NASA Technical Reports Server (NTRS)

Ellman, Alvin; Carlton, Magdi

1993-01-01

The technical challenges, engineering solutions, and results of the NOCC computer-human interface design are presented. The use-centered design process was as follows: determine the design criteria for user concerns; assess the impact of design decisions on the users; and determine the technical aspects of the implementation (tools, platforms, etc.). The NOCC hardware architecture is illustrated. A graphical model of the DSN that represented the hierarchical structure of the data was constructed. The DSN spacecraft summary display is shown. Navigation from top to bottom is accomplished by clicking the appropriate button for the element about which the user desires more detail. The telemetry summary display and the antenna color decision table are also shown.

Electrical design for origami solar panels and a small spacecraft test mission

NASA Astrophysics Data System (ADS)

Drewelow, James; Straub, Jeremy

2017-05-01

Efficient power generation is crucial to the design of spacecraft. Mass, volume, and other limitations prevent the use of traditional spacecraft support structures from being suitable for the size of solar array required for some missions. Folding solar panel / panel array systems, however, present a number of design challenges. This paper considers the electrical design of an origami system. Specifically, it considers how to provide low impedance, durable channels for the generated power and the electrical aspects of the deployment system and procedure. The ability to dynamically reconfigure the electrical configuration of the solar cells is also discussed. Finally, a small satellite test mission to demonstrate the technology is proposed, before concluding.

Computer memory management system

DOEpatents

Kirk, III, Whitson John

2002-01-01

A computer memory management system utilizing a memory structure system of "intelligent" pointers in which information related to the use status of the memory structure is designed into the pointer. Through this pointer system, The present invention provides essentially automatic memory management (often referred to as garbage collection) by allowing relationships between objects to have definite memory management behavior by use of coding protocol which describes when relationships should be maintained and when the relationships should be broken. In one aspect, the present invention system allows automatic breaking of strong links to facilitate object garbage collection, coupled with relationship adjectives which define deletion of associated objects. In another aspect, The present invention includes simple-to-use infinite undo/redo functionality in that it has the capability, through a simple function call, to undo all of the changes made to a data model since the previous `valid state` was noted.

Surface-micromachined and high-aspect ratio electrostatic actuators for aeronautic and space applications: design and lifetime considerations

NASA Astrophysics Data System (ADS)

Vescovo, P.; Joseph, E.; Bourbon, G.; Le Moal, P.; Minotti, P.; Hibert, C.; Pont, G.

2003-09-01

This paper focuses on recent advances in the field of MEMS-based actuators and distributed microelectromechanical systems (MEMS). IC-processed actuators (e.g. actuators that are machined using integrated circuit batch processes) are expected to open a wide range of industrial applications on the near term. The most promising investigations deal with high-aspect ratio electric field driven microactuators suitable for use in numerous technical fields such as aeronautics and space industry. Because the silicon micromachining technology have the potential to integrate both mechanical components and control circuits within a single process, MEMS-based active control of microscopic and macroscopic structures appears to be one of the most promising challenges for the next decade. As a first step towards new generations of MEMS-based smart structures, recent investigations dealing with silicon mechanisms involving MEMS-based actuators are briefly discussed in this paper.

Organization of a tumor bank: the experience of the National Cancer Institute of Mexico.

PubMed

Ruíz-Godoy, L; Meneses-García, A; Suárez-Roa, L; Enriquez, V; Lechuga-Rojas, R; Reyes-Lira, E

2010-01-01

A tumor bank (TB) is an ordered collection of neoplastic samples, normal tissue, and/or fluids preserved under optimal conditions, as well as storing patients' clinical information. The objective of this article is to outline the planning and logistics necessary for the functioning of the Instituto Nacional de Cancerología (INCan) TB in Mexico City. For the planning and logistics of a TB, several technical, legal, medical, structural, and physical aspects were considered, which can be grouped under four headings: (1) design and structure, (2) equipping the area and informatics, (3) ethical-legal aspects, and (4) sample collection, preservation, and quality control. One crucial element of interinstitutional interest will be the transfer of these concepts to the different oncological centers, integrating in this manner a network that enables the exploration of the different pathologies from therapeutic, epidemiological, and molecular points of view. 2010 S. Karger AG, Basel.

Aspects concerning verification methods and rigidity increment of complex technological systems

NASA Astrophysics Data System (ADS)

Casian, M.

2016-11-01

Any technological process and technology aims a quality and precise product, something almost impossible without high rigidity machine tools, equipment and components. Therefore, from the design phase, it is very important to create structures and machines with high stiffness characteristics. At the same time, increasing the stiffness should not raise the material costs. Searching this midpoint between high rigidity and minimum expenses leads to investigations and checks in structural components through various methods and techniques and sometimes quite advanced methods. In order to highlight some aspects concerning the significance of the mechanical equipment rigidity, the finite element method and an analytical method based on the use Mathcad software were used, by taking into consideration a subassembly of a grinding machine. Graphical representations were elaborated, offering a more complete image about the stresses and deformations able to affect the considered mechanical subassembly.

Algebra for Enterprise Ontology: towards analysis and synthesis of enterprise models

NASA Astrophysics Data System (ADS)

Suga, Tetsuya; Iijima, Junichi

2018-03-01

Enterprise modeling methodologies have made enterprises more likely to be the object of systems engineering rather than craftsmanship. However, the current state of research in enterprise modeling methodologies lacks investigations of the mathematical background embedded in these methodologies. Abstract algebra, a broad subfield of mathematics, and the study of algebraic structures may provide interesting implications in both theory and practice. Therefore, this research gives an empirical challenge to establish an algebraic structure for one aspect model proposed in Design & Engineering Methodology for Organizations (DEMO), which is a major enterprise modeling methodology in the spotlight as a modeling principle to capture the skeleton of enterprises for developing enterprise information systems. The results show that the aspect model behaves well in the sense of algebraic operations and indeed constructs a Boolean algebra. This article also discusses comparisons with other modeling languages and suggests future work.

The combination of an Environmental Management System and Life Cycle Assessment at the territorial level

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

Mazzi, Anna; Toniolo, Sara; Catto, Stella

A framework to include a Life Cycle Assessment in the significance evaluation of the environmental aspects of an Environmental Management System has been studied for some industrial sectors, but there is a literature gap at the territorial level, where the indirect impact assessment is crucial. To overcome this criticality, our research proposes the Life Cycle Assessment as a framework to assess environmental aspects of public administration within an Environmental Management System applied at the territorial level. This research is structured in two parts: the design of a new methodological framework and the pilot application for an Italian municipality. The methodologicalmore » framework designed supports Initial Environmental Analysis at the territorial level thanks to the results derived from the impact assessment phase. The pilot application in an Italian municipality EMAS registered demonstrates the applicability of the framework and its effectiveness in evaluating the environmental impact assessment for direct and indirect aspects. Through the discussion of the results, we underline the growing knowledge derived by this research in terms of the reproducibility and consistency of the criteria to define the significance of the direct and indirect environmental aspects for a local public administration. - Highlights: • The combination between Environmental Management System and LCA is studied. • A methodological framework is elaborated and tested at the territorial level. • Life Cycle Impact Assessment supports the evaluation of aspects significance. • The framework assures consistency of evaluation criteria on the studied territory.« less

Computational Approaches for Designing Protein/Inhibitor Complexes and Membrane Protein Variants

NASA Astrophysics Data System (ADS)

Vijayendran, Krishna Gajan

Drug discovery of small-molecule protein inhibitors is a vast enterprise that involves several scientific disciplines (i.e. genomics, cell biology, x-ray crystallography, chemistry, computer science, statistics), with each discipline focusing on a particular aspect of the process. In this thesis, I use computational and experimental approaches to explore the most fundamental aspect of drug discovery: the molecular interactions of small-molecules inhibitors with proteins. In Part I (Chapters I and II), I describe how computational docking approaches can be used to identify structurally diverse molecules that can inhibit multiple protein targets in the brain. I illustrate this approach using the examples of microtubule-stabilizing agents and inhibitors of cyclooxygenase(COX)-I and 5-lipoxygenase (5-LOX). In Part II (Chapters III and IV), I focus on membrane proteins, which are notoriously difficult to work with due to their low natural abundances, low yields for heterologous over expression, and propensities toward aggregation. I describe a general approach for designing water-soluble variants of membrane proteins, for the purpose of developing cell-free, label-free, detergent-free, solution-phase studies of protein structure and small-molecule binding. I illustrate this approach through the design of a water-soluble variant of the membrane protein Smoothened, wsSMO. This wsSMO stands to serve as a first-step towards developing membrane protein analogs of this important signaling protein and drug target.

Recent Developments in Smart Adaptive Structures for Solar Sailcraft

NASA Technical Reports Server (NTRS)

Whorton, M. S.; Kim, Y. K.; Oakley, J.; Adetona, O.; Keel, L. H.

2007-01-01

The "Smart Adaptive Structures for Solar Sailcraft" development activity at MSFC has investigated issues associated with understanding how to model and scale the subsystem and multi-body system dynamics of a gossamer solar sailcraft with the objective of designing sailcraft attitude control systems. This research and development activity addressed three key tasks that leveraged existing facilities and core competencies of MSFC to investigate dynamics and control issues of solar sails. Key aspects of this effort included modeling and testing of a 30 m deployable boom; modeling of the multi-body system dynamics of a gossamer sailcraft; investigation of control-structures interaction for gossamer sailcraft; and development and experimental demonstration of adaptive control technologies to mitigate control-structures interaction.

Using Symmetry to Design Self-Assembling Protein Cages and Nanomaterials on the Mid-Nanometer Scale

NASA Astrophysics Data System (ADS)

Yeates, Todd

Self-assembling molecular structures having diverse cellular functions are widespread in nature. Some of the largest and most sophisticated types are built from many copies of the same or similar protein molecules arranged following principles of symmetry. A long-standing engineering goal has been to design novel protein molecules to self-assemble into geometrically specific structures similar to the extraordinary structures that have evolved in Nature. Practical routes to this goal have been developed by using ideas in symmetry to articulate the minimum design requirements for achieving various types of symmetric architectures, including cages, extended two-dimensional layers, and three-dimensional crystalline materials. The key requirement is that two distinct self-associating interfaces, each conferring one element of rotational symmetry, have to be engineered into the protein molecule (or molecules), following particular geometric specifications. The main principle is that combining two separate symmetry elements into a single molecular entity produces a molecule that necessarily assembles into an architecture dictated by a symmetry group that is the product of the two simpler contributing symmetries. Recent experiments have demonstrated success using a variety of symmetry-based strategies. Strategic variations are emerging that differ from each other with respect to biophysical features such as flexibility vs rigidity in the assembled structures, and with respect to design aspects such as whether the protein interfaces are inherited from natural oligomeric proteins or are designed de novo by advanced computational methods. The success of these strategies has been proven by determining crystal structures of several giant, self-assembling protein cages and clusters (10-25 nm in diameter), created by design. The ability to create sophisticated supramolecular structures from designed protein subunits opens the way to broad applications in synthetic biology and nanotechnology.

Field resonance propulsion concept

NASA Technical Reports Server (NTRS)

Holt, A. C.

1979-01-01

A propulsion concept was developed based on a proposed resonance between coherent, pulsed electromagnetic wave forms, and gravitational wave forms (or space-time metrics). Using this concept a spacecraft propulsion system potentially capable of galactic and intergalactic travel without prohibitive travel times was designed. The propulsion system utilizes recent research associated with magnetic field line merging, hydromagnetic wave effects, free-electron lasers, laser generation of megagauss fields, and special structural and containment metals. The research required to determine potential, field resonance characteristics and to evaluate various aspects of the spacecraft propulsion design is described.

References and conference proceedings towards the understanding of fracture mechanics

NASA Technical Reports Server (NTRS)

Toor, P. M.; Hudson, C. M.

1986-01-01

A list of books, reports, periodicals, and conference proceedings, as well as individual papers, centered on specific aspects of fracture phenomenon has been compiled by the ASTM Committee E-24 on Fracture Testing. A list of basic references includes the articles on the development of fracture toughness, evaluation of stress intensity factors, fatigue crack growth, fracture testing, fracture of brittle materials, and fractography. Special attention is given to the references on application of fracture mechanics to new designs and on reevaluation of failed designs, many of them concerned with naval and aircraft structures.

Application of lightweight materials in structure concept design of large-scale solar energy unmanned aerial vehicle

NASA Astrophysics Data System (ADS)

Zhang, Wei; Lv, Shengli; Guan, XiQi

2017-09-01

Carbon fiber composites and film materials can be effectively used in light aircraft structures, especially for solar unmanned aerial vehicles. The use of light materials can reduce the weight of the aircraft, but also can effectively improve the aircraft's strength and stiffness. The structure of the large aspect ratio solar energy UAV was analyzed in detail, taking Solar-impulse solar aircraft as an example. The solar energy UAV has a wing aspect ratio greater than 20, and the detailed digital model of the wing structure including beam, ribs and skin was built, also the Finite Element Method was applied to analyze the static and dynamic performance of the structure. The upper skin of the wing is covered with silicon solar cells, while the lower skin is light and transparent film. The single beam truss form of carbon fiber lightweight material is used in the wing structure. The wing beam is a box beam with rectangular cross sections. The box beam connected the front parts and after parts of the ribs together. The fuselage of the aircraft was built by space truss structure. According to the static and dynamic analysis with Finite Element method, it was found that the aircraft has a small wingtip deflection relative to the wingspan in the level flight state. The first natural frequency of the wing structure is pretty low, which is closed to the gust load.

Strategic Design and Fabrication of Engineered Scaffolds for Articular Cartilage Repair

PubMed Central

Izadifar, Zohreh; Chen, Xiongbiao; Kulyk, William

2012-01-01

Damage to articular cartilage can eventually lead to osteoarthritis (OA), a debilitating, degenerative joint disease that affects millions of people around the world. The limited natural healing ability of cartilage and the limitations of currently available therapies make treatment of cartilage defects a challenging clinical issue. Hopes have been raised for the repair of articular cartilage with the help of supportive structures, called scaffolds, created through tissue engineering (TE). Over the past two decades, different designs and fabrication techniques have been investigated for developing TE scaffolds suitable for the construction of transplantable artificial cartilage tissue substitutes. Advances in fabrication technologies now enable the strategic design of scaffolds with complex, biomimetic structures and properties. In particular, scaffolds with hybrid and/or biomimetic zonal designs have recently been developed for cartilage tissue engineering applications. This paper reviews critical aspects of the design of engineered scaffolds for articular cartilage repair as well as the available advanced fabrication techniques. In addition, recent studies on the design of hybrid and zonal scaffolds for use in cartilage tissue repair are highlighted. PMID:24955748

Structure-based drug design: docking and scoring.

PubMed

Kroemer, Romano T

2007-08-01

This review gives an introduction into ligand - receptor docking and illustrates the basic underlying concepts. An overview of different approaches and algorithms is provided. Although the application of docking and scoring has led to some remarkable successes, there are still some major challenges ahead, which are outlined here as well. Approaches to address some of these challenges and the latest developments in the area are presented. Some aspects of the assessment of docking program performance are discussed. A number of successful applications of structure-based virtual screening are described.

Materials and structures for hypersonic vehicles

NASA Technical Reports Server (NTRS)

Tenney, Darrel R.; Lisagor, W. Barry; Dixon, Sidney C.

1988-01-01

Hypersonic vehicles are envisioned to require, in addition to carbon-carbon and ceramic-matrix composities for leading edges heated to above 2000 F, such 600 to 1800 F operating temperature materials as advanced Ti alloys, nickel aluminides, and metal-matrix composited; These possess the necessary low density and high strength and stiffness. The primary design drivers are maximum vehicle heating rate, total heat load, flight envelope, propulsion system type, mission life requirements and liquid hydrogen containment systems. Attention is presently given to aspects of these materials and structures requiring more intensive development.

Segregating the core computational faculty of human language from working memory.

PubMed

Makuuchi, Michiru; Bahlmann, Jörg; Anwander, Alfred; Friederici, Angela D

2009-05-19

In contrast to simple structures in animal vocal behavior, hierarchical structures such as center-embedded sentences manifest the core computational faculty of human language. Previous artificial grammar learning studies found that the left pars opercularis (LPO) subserves the processing of hierarchical structures. However, it is not clear whether this area is activated by the structural complexity per se or by the increased memory load entailed in processing hierarchical structures. To dissociate the effect of structural complexity from the effect of memory cost, we conducted a functional magnetic resonance imaging study of German sentence processing with a 2-way factorial design tapping structural complexity (with/without hierarchical structure, i.e., center-embedding of clauses) and working memory load (long/short distance between syntactically dependent elements; i.e., subject nouns and their respective verbs). Functional imaging data revealed that the processes for structure and memory operate separately but co-operatively in the left inferior frontal gyrus; activities in the LPO increased as a function of structural complexity, whereas activities in the left inferior frontal sulcus (LIFS) were modulated by the distance over which the syntactic information had to be transferred. Diffusion tensor imaging showed that these 2 regions were interconnected through white matter fibers. Moreover, functional coupling between the 2 regions was found to increase during the processing of complex, hierarchically structured sentences. These results suggest a neuroanatomical segregation of syntax-related aspects represented in the LPO from memory-related aspects reflected in the LIFS, which are, however, highly interconnected functionally and anatomically.

Real World Evidence: A Quantitative and Qualitative Glance at Participant Feedback from a Free-Response Survey Investigating Experiences of a Structured Exercise Intervention for Men with Prostate Cancer.

PubMed

Fox, L; Cahill, F; Burgess, C; Peat, N; Rudman, S; Kinsella, J; Cahill, D; George, G; Santaolalla, A; Van Hemelrijck, M

2017-01-01

To explore patient experiences of a structured exercise intervention for men with prostate cancer (PCa). 41 men with either localised or advanced PCa who had been referred for a structured exercise programme by their physician and then subsequently consented to a telephone survey. Participants underwent a 10-week supervised exercise programme within a large cancer centre hospital consisting of 8 sessions. They then completed a short multiple choice telephone survey, elaborating on their responses where appropriate. Views expressed by participants were analysed using an affinity diagram and common themes were identified. Feedback from our telephone surveys was consistently positive and suggests that the structured exercise intervention provides exercise confidence, motivation to exercise, and social support and promotes positive health behaviour change in the context of exercise. Individual differences arose amongst participants in their perceived utility of the intervention, with 73.3% expressing a preference for structured exercise classes and 19.5% expressing a preference for exercising independently. Design of a structured exercise intervention for patients with PCa should embrace the positive aspects outlined here but consider patients' individual differences. Ongoing feedback from patients should be utilised alongside traditional study designs to inform intervention design in this area.

Practical design considerations for photovoltaic power station

NASA Astrophysics Data System (ADS)

Swanson, T. D.

Aspects of photovoltaic (PV) technology are discussed along with generic PV design considerations, taking into account the resource sunlight, PV modules and their reliability, questions of PV system design, the support structure subsystem, and a power conditioning unit subsystem. A description is presented of two recent projects which demonstrate the translation of an idea into actual working PV systems. A privately financed project in Denton, Maryland, went on line in early December, 1982, and began providing power to the local utility grid. It represents the first intermediate size, grid-connected, privately financed power station in the U.S. Based on firm quotes, the actual cost of this system is about $13/W peak. The other project, called the PV Breeder, is an energy independent facility which utilizes solar power to make new solar cells. It is also the first large industrial structure completely powered by the sun.

Recent Developments in Carbon Nanotube Membranes for Water Purification and Gas Separation

PubMed Central

Sears, Kallista; Dumée, Ludovic; Schütz, Jürg; She, Mary; Huynh, Chi; Hawkins, Stephen; Duke, Mikel; Gray, Stephen

2010-01-01

Carbon nanotubes (CNTs) are nanoscale cylinders of graphene with exceptional properties such as high mechanical strength, high aspect ratio and large specific surface area. To exploit these properties for membranes, macroscopic structures need to be designed with controlled porosity and pore size. This manuscript reviews recent progress on two such structures: (i) CNT Bucky-papers, a non-woven, paper like structure of randomly entangled CNTs, and (ii) isoporous CNT membranes, where the hollow CNT interior acts as a membrane pore. The construction of these two types of membranes will be discussed, characterization and permeance results compared, and some promising applications presented.

Analysis and characterizations of planar transmission structures and components for superconducting and monolithic integrated circuits

NASA Technical Reports Server (NTRS)

Itoh, Tatsuo

1991-01-01

The analysis and modeling of superconducting planar transmission lines were performed. Theoretically, the highest possible Q values of superconducting microstrip line was calculated and, as a result, it provided the Q value that the experiment can aim for. As an effort to search for a proper superconducting transmission line structure, the superconducting microstrip line and coplanar waveguide were compared in terms of loss characteristics and their design aspects. Also, the research was expanded to a superconducting coplanar waveguide family in the microwave packaging environment. Theoretically, it was pointed out that the substrate loss is critical in the superconducting transmission line structures.

Role of IAC in large space systems thermal analysis

NASA Technical Reports Server (NTRS)

Jones, G. K.; Skladany, J. T.; Young, J. P.

1982-01-01

Computer analysis programs to evaluate critical coupling effects that can significantly influence spacecraft system performance are described. These coupling effects arise from the varied parameters of the spacecraft systems, environments, and forcing functions associated with disciplines such as thermal, structures, and controls. Adverse effects can be expected to significantly impact system design aspects such as structural integrity, controllability, and mission performance. One such needed design analysis capability is a software system that can integrate individual discipline computer codes into a highly user-oriented/interactive-graphics-based analysis capability. The integrated analysis capability (IAC) system can be viewed as: a core framework system which serves as an integrating base whereby users can readily add desired analysis modules and as a self-contained interdisciplinary system analysis capability having a specific set of fully integrated multidisciplinary analysis programs that deal with the coupling of thermal, structures, controls, antenna radiation performance, and instrument optical performance disciplines.

Low voltage 30-cm ion thruster development. [including performance and structural integrity (vibration) tests

NASA Technical Reports Server (NTRS)

King, H. J.

1974-01-01

The basic goal was to advance the development status of the 30-cm electron bombardment ion thruster from a laboratory model to a flight-type engineering model (EM) thruster. This advancement included the more conventional aspects of mechanical design and testing for launch loads, weight reduction, fabrication process development, reliability and quality assurance, and interface definition, as well as a relatively significant improvement in thruster total efficiency. The achievement of this goal was demonstrated by the successful completion of a series of performance and structural integrity (vibration) tests. In the course of the program, essentially every part and feature of the original 30-cm Thruster was critically evaluated. These evaluations, led to new or improved designs for the ion optical system, discharge chamber, cathode isolator vaporizer assembly, main isolator vaporizer assembly, neutralizer assembly, packaging for thermal control, electrical terminations and structure.

Plant photosystem I design in the light of evolution.

PubMed

Amunts, Alexey; Nelson, Nathan

2009-05-13

Photosystem I (PSI) is a membrane protein complex that catalyzes sunlight-driven transmembrane electron transfer as part of the photosynthetic machinery. Photosynthetic organisms appeared on the Earth about 3.5 billion years ago and provided an essential source of potential energy for the development of life. During the course of evolution, these primordial organisms were phagocytosed by more sophisticated eukaryotic cells, resulting in the evolvement of algae and plants. Despite the extended time interval between primordial cyanobacteria and plants, PSI has retained its fundamental mechanism of sunlight conversion. Being probably the most efficient photoelectric apparatus in nature, PSI operates with a quantum efficiency close to 100%. However, adapting to different ecological niches necessitated structural changes in the PSI design. Based on the recently solved structure of plant PSI, which revealed a complex of 17 protein subunits and 178 prosthetic groups, we analyze the evolutionary development of PSI. In addition, some aspects of PSI structure determination are discussed.

Structural crashworthiness; International Symposium, 1st, University of Liverpool, Liverpool, England, September 14-16, 1983, Invited Lectures

NASA Astrophysics Data System (ADS)

Jones, N.; Wierzbicki, T.

The application of solid, structural, and experimental mechanics to predict the crumpling behavior and energy absorption of thin-walled structures under quasi-static compression and various dynamic crash loadings is examined in reviews of current research. Both fundamental aspects and specific problems in the design of crashworthy aircraft, automobiles, railroad cars, ships, and offshore installations are considered. Topics discussed include laterally compressed metal tubes as impact-energy absorbers, crushing behavior of plate intersections, axial crushing of fiber-reinforced composite tubes, finite-element analysis of structural crashworthiness in the automotive and aerospace industries, crash behavior of aircraft fuselage structures, aircraft crash analysis, ship collisions, and structural damage in airship and rolling-stock collisions. Photographs, graphs, drawings, and diagrams are provided.

Modeling and control of flexible structures

NASA Technical Reports Server (NTRS)

Gibson, J. S.; Mingori, D. L.

1988-01-01

This monograph presents integrated modeling and controller design methods for flexible structures. The controllers, or compensators, developed are optimal in the linear-quadratic-Gaussian sense. The performance objectives, sensor and actuator locations and external disturbances influence both the construction of the model and the design of the finite dimensional compensator. The modeling and controller design procedures are carried out in parallel to ensure compatibility of these two aspects of the design problem. Model reduction techniques are introduced to keep both the model order and the controller order as small as possible. A linear distributed, or infinite dimensional, model is the theoretical basis for most of the text, but finite dimensional models arising from both lumped-mass and finite element approximations also play an important role. A central purpose of the approach here is to approximate an optimal infinite dimensional controller with an implementable finite dimensional compensator. Both convergence theory and numerical approximation methods are given. Simple examples are used to illustrate the theory.

Wing optimization for space shuttle orbiter vehicles

NASA Technical Reports Server (NTRS)

Surber, T. E.; Bornemann, W. E.; Miller, W. D.

1972-01-01

The results were presented of a parametric study performed to determine the optimum wing geometry for a proposed space shuttle orbiter. The results of the study establish the minimum weight wing for a series of wing-fuselage combinations subject to constraints on aerodynamic heating, wing trailing edge sweep, and wing over-hang. The study consists of a generalized design evaluation which has the flexibility of arbitrarily varying those wing parameters which influence the vehicle system design and its performance. The study is structured to allow inputs of aerodynamic, weight, aerothermal, structural and material data in a general form so that the influence of these parameters on the design optimization process can be isolated and identified. This procedure displays the sensitivity of the system design of variations in wing geometry. The parameters of interest are varied in a prescribed fashion on a selected fuselage and the effect on the total vehicle weight is determined. The primary variables investigated are: wing loading, aspect ratio, leading edge sweep, thickness ratio, and taper ratio.

Automated Work Package: Conceptual Design and Data Architecture

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

Al Rashdan, Ahmad; Oxstrand, Johanna; Agarwal, Vivek

The automated work package (AWP) is one of the U.S. Department of Energy’s (DOE) Light Water Reactor Sustainability Program efforts to enhance the safety and economics of the nuclear power industry. An AWP is an adaptive and interactive work package that intelligently drives the work process according to the plant condition, resources status, and users progress. The AWP aims to automate several manual tasks of the work process to enhance human performance and reduce human errors. Electronic work packages (eWPs), studied by the Electric Power Research Institute (EPRI), are work packages that rely to various extent on electronic data processingmore » and presentation. AWPs are the future of eWPs. They are envisioned to incorporate the advanced technologies of the future, and thus address the unresolved deficiencies associated with the eWPs in a nuclear power plant. In order to define the AWP, it is necessary to develop an ideal envisioned scenario of the future work process without any current technology restriction. The approach followed to develop this scenario is specific to every stage of the work process execution. The scenario development resulted in fifty advanced functionalities that can be part of the AWP. To rank the importance of these functionalities, a survey was conducted involving several U.S. nuclear utilities. The survey aimed at determining the current need of the nuclear industry with respect to the current work process, i.e. what the industry is satisfied with, and where the industry envisions potential for improvement. The survey evaluated the most promising functionalities resulting from the scenario development. The results demonstrated a significant desire to adopt the majority of these functionalities. The results of the survey are expected to drive the Idaho National Laboratory (INL) AWP research and development (R&D). In order to facilitate this mission, a prototype AWP is needed. Since the vast majority of earlier efforts focused on the frontend aspects of the AWP, the backend data architecture was researched and developed in this effort. The backend design involved data architecture aspects. It was realized through this effort that the key aspects of this design are hierarchy, data configuration and live information, data templates and instances, the flow of work package execution, the introduction of properties, and the means to interface the backend to the frontend. After the backend design was developed, a data structure was built to reflect the developed data architecture. The data structure was developed to accommodate the fifty functionalities identified by the envisioned scenario development. The data structure was evaluated by incorporating an example work order from the nuclear power industry. The implementation resulted in several optimization iterations of the data structure. In addition, the rearrangement of the work order information to fit the data structure highlighted several possibilities for improvement in the current work order design, and significantly reduced the size of the work order.« less

The specificity of cortical region KO to depth structure.

PubMed

Tyler, Christopher W; Likova, Lora T; Kontsevich, Leonid L; Wade, Alex R

2006-03-01

Functional MRI studies have identified a cortical region designated as KO between retinotopic areas V3A/B and motion area V5 in human cortex as particularly responsive to motion-defined or kinetic borders. To determine the response of the KO region to more general aspects of structure, we used stereoscopic depth borders and disparate planes with no borders, together with three stimulus types that evoked no depth percept: luminance borders, line contours and illusory phase borders. Responses to these stimuli in the KO region were compared with the responses in retinotopically defined areas that have been variously associated with disparity processing in neurophysiological and fMRI studies. The strongest responses in the KO region were to stimuli evoking perceived depth structure from either disparity or motion cues, but it showed negligible responses either to luminance-based contour stimuli or to edgeless disparity stimuli. We conclude that the region designated as KO is best regarded as a primary center for the generic representation of depth structure rather than any kind of contour specificity.

Medical Textiles as Vascular Implants and Their Success to Mimic Natural Arteries

PubMed Central

Singh, Charanpreet; Wong, Cynthia S.; Wang, Xungai

2015-01-01

Vascular implants belong to a specialised class of medical textiles. The basic purpose of a vascular implant (graft and stent) is to act as an artificial conduit or substitute for a diseased artery. However, the long-term healing function depends on its ability to mimic the mechanical and biological behaviour of the artery. This requires a thorough understanding of the structure and function of an artery, which can then be translated into a synthetic structure based on the capabilities of the manufacturing method utilised. Common textile manufacturing techniques, such as weaving, knitting, braiding, and electrospinning, are frequently used to design vascular implants for research and commercial purposes for the past decades. However, the ability to match attributes of a vascular substitute to those of a native artery still remains a challenge. The synthetic implants have been found to cause disturbance in biological, biomechanical, and hemodynamic parameters at the implant site, which has been widely attributed to their structural design. In this work, we reviewed the design aspect of textile vascular implants and compared them to the structure of a natural artery as a basis for assessing the level of success as an implant. The outcome of this work is expected to encourage future design strategies for developing improved long lasting vascular implants. PMID:26133386

OSI-compatible protocols for mobile-satellite communications: The AMSS experience

NASA Technical Reports Server (NTRS)

Moher, Michael

1990-01-01

The protocol structure of the international aeronautical mobile satellite service (AMSS) is reviewed with emphasis on those aspects of protocol performance, validation, and conformance which are peculiar to mobile services. This is in part an analysis of what can be learned from the AMSS experience with protocols which is relevant to the design of other mobile satellite data networks, e.g., land mobile.

Preliminary study of a large span-distributed-load flying-wing cargo airplane concept

NASA Technical Reports Server (NTRS)

Jernell, L. S.

1978-01-01

An aircraft capable of transporting containerized cargo over intercontinental distances is analyzed. The specifications for payload weight, density, and dimensions in essence configure the wing and establish unusually low values of wing loading and aspect ratio. The structural weight comprises only about 18 percent of the design maximum gross weight. Although the geometric aspect ratio is 4.53, the winglet effect of the wing-tip-mounted vertical tails, increase the effective aspect ratio to approximately 7.9. Sufficient control power to handle the large rolling moment of inertia dictates a relatively high minimum approach velocity of 315 km/hr (170 knots). The airplane has acceptable spiral, Dutch roll, and roll-damping modes. A hardened stability augmentation system is required. The most significant noise source is that of the airframe. However, for both take-off and approach, the levels are below the FAR-36 limit of 108 db. The design mission fuel efficiency is approximately 50 percent greater than that of the most advanced, currently operational, large freighter aircraft. The direct operating cost is significantly lower than that of current freighters, the advantage increasing as fuel price increases.

Endless forms: human behavioural diversity and evolved universals.

PubMed

Smith, Eric Alden

2011-02-12

Human populations have extraordinary capabilities for generating behavioural diversity without corresponding genetic diversity or change. These capabilities and their consequences can be grouped into three categories: strategic (or cognitive), ecological and cultural-evolutionary. Strategic aspects include: (i) a propensity to employ complex conditional strategies, some certainly genetically evolved but others owing to directed invention or to cultural evolution; (ii) situations in which fitness payoffs (or utilities) are frequency-dependent, so that there is no one best strategy; and (iii) the prevalence of multiple equilibria, with history or minor variations in starting conditions (path dependence) playing a crucial role. Ecological aspects refer to the fact that social behaviour and cultural institutions evolve in diverse niches, producing various adaptive radiations and local adaptations. Although environmental change can drive behavioural change, in humans, it is common for behavioural change (especially technological innovation) to drive environmental change (i.e. niche construction). Evolutionary aspects refer to the fact that human capacities for innovation and cultural transmission lead to diversification and cumulative cultural evolution; critical here is institutional design, in which relatively small shifts in incentive structure can produce very different aggregate outcomes. In effect, institutional design can reshape strategic games, bringing us full circle.

Preliminary study of a large span-distributed-load flying-wing cargo airplane concept

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

Jernell, L.S.

1978-05-01

An aircraft capable of transporting containerized cargo over intercontinental distances is analyzed. The specifications for payload weight, density, and dimensions in essence configure the wing and establish unusually low values of wing loading and aspect ratio. The structural weight comprises only about 18 percent of the design maximum gross weight. Although the geometric aspect ratio is 4.53, the winglet effect of the wing-tip-mounted vertical tails, increase the effective aspect ratio to approximately 7.9. Sufficient control power to handle the large rolling moment of inertia dictates a relatively high minimum approach velocity of 315 km/hr (170 knots). The airplane has acceptablemore » spiral, Dutch roll, and roll-damping modes. A hardened stability augmentation system is required. The most significant noise source is that of the airframe. However, for both take-off and approach, the levels are below the FAR-36 limit of 108 db. The design mission fuel efficiency is approximately 50 percent greater than that of the most advanced, currently operational, large freighter aircraft. The direct operating cost is significantly lower than that of current freighters, the advantage increasing as fuel price increases.« less

Estimation of Gust Response Factor for a Tall Building Model with 1:1.5 Plan Ratios

NASA Astrophysics Data System (ADS)

Sarath Kumar, H.; Selvi Rajan, S.

2017-08-01

The purpose of structural analysis and design of structures as per the building codes and its corresponding standers is to ensure the safety of structure under maximum loads and remains functional under service load. The structure which is designed under consideration of codes should also satisfy the durability, economy and aesthetics. The primary purpose of this work is to understand and compare design wind loads according with the Gust Response Factor as per codes of practices. The paper is concerned with the calculation of design wind loads on a rectangular building model (1:300gemetric scale) of size 10cm x 15cm x 70cm with an aspect ratio of 1:1.5:7 at eight different levels over the height under sub-urban terrain category for 00 angle and 900 angle wind incidence. The experiment id conducted in an atmospheric boundary layer wind tunnel facility of CSIR-Structural engineering Research centre, Chennai. The measured pressures are integrated to evaluate mean and RMS (Root, Mean, Square). Further the variation of above mentioned loads and response factor along the heights of the building with respect to sub-urban terrain condition are discussed and summarized in addition, the codal values of various international standards [IS-875 part-3 1987, IS-875 part-3 draft, ASCE-07] have also considered for comparison.

Development of the PRSEUS Multi-Bay Pressure Box for a Hybrid Wing Body Vehicle

NASA Technical Reports Server (NTRS)

Jegley, Dawn C.; Velicki, Alexander

2015-01-01

NASA has created the Environmentally Responsible Aviation Project to explore and document the feasibility, benefits, and technical risk of advanced vehicle configurations and enabling technologies that will reduce the impact of aviation on the environment. A critical aspect of this pursuit is the development of a lighter, more robust airframe that will enable the introduction of unconventional aircraft configurations that have higher lift-to-drag ratios, reduced drag, and lower community noise. Although such novel configurations like the Hybrid Wing Body (HWB) offer better aerodynamic performance as compared to traditional tube-and-wing aircraft, their blended wing shapes also pose significant new design challenges. Developing an improved structural concept that is capable of meeting the structural weight fraction allocated for these non-circular pressurized cabins is the primary obstacle in implementing large lifting-body designs. To address this challenge, researchers at NASA and The Boeing Company are working together to advance new structural concepts like the Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS), which is an integrally stiffened panel design that is stitched together and designed to maintain residual load-carrying capabilities under a variety of damage scenarios. The large-scale multi-bay fuselage test article described in this paper is the final specimen in a building-block test program that was conceived to demonstrate the feasibility of meeting the structural weight goals established for the HWB pressure cabin.

Developing students' functional thinking in algebra through different visualisations of a growing pattern's structure

NASA Astrophysics Data System (ADS)

Wilkie, Karina J.; Clarke, Doug M.

2016-06-01

Spatial visualisation of geometric patterns and their generalisation have become a recognised pathway to developing students' functional thinking and understanding of variables in algebra. This design-based research project investigated upper primary students' development of explicit generalisation of functional relationships and their representation descriptively, graphically and symbolically. Ten teachers and their classes were involved in a sequence of tasks involving growing patterns and geometric structures over 1 year. This article focuses on two aspects of the study: visualising the structure of a geometric pattern in different ways and using this to generalise the functional relationship between two quantifiable aspects (variables). It was found that in an initial assessment task ( n = 222), students' initial visualisations could be categorised according to different types and some of these were more likely to lead either to recursive or explicit generalisation. In a later task, a small number of students demonstrated the ability to find more than one way to visualise the same geometric structure and thus represent their explicit generalisations as different but equivalent symbolic equations (using pronumerals). Implications for the teaching of functional thinking in middle-school algebra are discussed.

Transition support for new graduate and novice nurses in critical care settings: An integrative review of the literature.

PubMed

Innes, Tiana; Calleja, Pauline

2018-05-01

Transition into critical care areas for new graduate nurses may be more difficult than transitioning into other areas due to the specialised knowledge needed. It is unknown which aspects of transition programs best support new graduate nurses improve competence and confidence to transition into critical care nursing specialties. Identifying these aspects would assist to design and implement best practice transition programs for new graduates in critical care areas. Themes identified in the literature include; having a designated resource person, workplace culture, socialisation, knowledge and skill acquisition, orientation, and rotation. Allocation of a quality resource person/s, supportive workplace culture, positive socialisation experiences, knowledge and skill acquisition and structured orientation based on new graduates' learning needs all positively supported increased confidence, competence and transition into nursing practice. Rotations between areas within graduate programs can potentially have both positive and negative impacts on the transition process. Negative impacts of including a rotation component in a transition program should be carefully considered alongside perceived benefits when designing new graduate nurse transition programs. Copyright © 2018. Published by Elsevier Ltd.

Space debris mitigation - engineering strategies

NASA Astrophysics Data System (ADS)

Taylor, E.; Hammond, M.

The problem of space debris pollution is acknowledged to be of growing concern by space agencies, leading to recent activities in the field of space debris mitigation. A review of the current (and near-future) mitigation guidelines, handbooks, standards and licensing procedures has identified a number of areas where further work is required. In order for space debris mitigation to be implemented in spacecraft manufacture and operation, the authors suggest that debris-related criteria need to become design parameters (following the same process as applied to reliability and radiation). To meet these parameters, spacecraft manufacturers and operators will need processes (supported by design tools and databases and implementation standards). A particular aspect of debris mitigation, as compared with conventional requirements (e.g. radiation and reliability) is the current and near-future national and international regulatory framework and associated liability aspects. A framework for these implementation standards is presented, in addition to results of in-house research and development on design tools and databases (including collision avoidance in GTO and SSTO and evaluation of failure criteria on composite and aluminium structures).

Health and safety impacts of nuclear, geothermal, and fossil-fuel electric generation in California. Volume 9. Methodologies for review of the health and safety aspects of proposed nuclear, geothermal, and fossil-fuel sites and facilities

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

Nero, A.V.; Quinby-Hunt, M.S.

1977-01-01

This report sets forth methodologies for review of the health and safety aspects of proposed nuclear, geothermal, and fossil-fuel sites and facilities for electric power generation. The review is divided into a Notice of Intention process and an Application for Certification process, in accordance with the structure to be used by the California Energy Resources Conservation and Development Commission, the first emphasizing site-specific considerations, the second examining the detailed facility design as well. The Notice of Intention review is divided into three possible stages: an examination of emissions and site characteristics, a basic impact analysis, and an assessment of publicmore » impacts. The Application for Certification review is divided into five possible stages: a review of the Notice of Intention treatment, review of the emission control equipment, review of the safety design, review of the general facility design, and an overall assessment of site and facility acceptability.« less

Current advances in synchrotron radiation instrumentation for MX experiments

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

Owen, Robin L.; Juanhuix, Jordi; Fuchs, Martin

2016-07-01

Following pioneering work 40 years ago, synchrotron beamlines dedicated to macromolecular crystallography (MX) have improved in almost every aspect as instrumentation has evolved. Beam sizes and crystal dimensions are now on the single micron scale while data can be collected from proteins with molecular weights over 10 MDa and from crystals with unit cell dimensions over 1000 Å. Furthermore it is possible to collect a complete data set in seconds, and obtain the resulting structure in minutes. The impact of MX synchrotron beamlines and their evolution is reflected in their scientific output, and MX is now the method of choicemore » for a variety of aims from ligand binding to structure determination of membrane proteins, viruses and ribosomes, resulting in a much deeper understanding of the machinery of life. A main driving force of beamline evolution have been advances in almost every aspect of the instrumentation comprising a synchrotron beamline. In this review we aim to provide an overview of the current status of instrumentation at modern MX experiments. The most critical optical components are discussed, as are aspects of endstation design, sample delivery, visualisation and positioning, the sample environment, beam shaping, detectors and data acquisition and processing.« less

Current advances in synchrotron radiation instrumentation for MX experiments.

PubMed

Owen, Robin L; Juanhuix, Jordi; Fuchs, Martin

2016-07-15

Following pioneering work 40 years ago, synchrotron beamlines dedicated to macromolecular crystallography (MX) have improved in almost every aspect as instrumentation has evolved. Beam sizes and crystal dimensions are now on the single micron scale while data can be collected from proteins with molecular weights over 10 MDa and from crystals with unit cell dimensions over 1000 Å. Furthermore it is possible to collect a complete data set in seconds, and obtain the resulting structure in minutes. The impact of MX synchrotron beamlines and their evolution is reflected in their scientific output, and MX is now the method of choice for a variety of aims from ligand binding to structure determination of membrane proteins, viruses and ribosomes, resulting in a much deeper understanding of the machinery of life. A main driving force of beamline evolution have been advances in almost every aspect of the instrumentation comprising a synchrotron beamline. In this review we aim to provide an overview of the current status of instrumentation at modern MX experiments. The most critical optical components are discussed, as are aspects of endstation design, sample delivery, visualisation and positioning, the sample environment, beam shaping, detectors and data acquisition and processing. Copyright © 2016. Published by Elsevier Inc.

Current advances in synchrotron radiation instrumentation for MX experiments

PubMed Central

Owen, Robin L.; Juanhuix, Jordi; Fuchs, Martin

2017-01-01

Following pioneering work 40 years ago, synchrotron beamlines dedicated to macromolecular crystallography (MX) have improved in almost every aspect as instrumentation has evolved. Beam sizes and crystal dimensions are now on the single micron scale while data can be collected from proteins with molecular weights over 10 MDa and from crystals with unit cell dimensions over 1000 Å. Furthermore it is possible to collect a complete data set in seconds, and obtain the resulting structure in minutes. The impact of MX synchrotron beamlines and their evolution is reflected in their scientific output, and MX is now the method of choice for a variety of aims from ligand binding to structure determination of membrane proteins, viruses and ribosomes, resulting in a much deeper understanding of the machinery of life. A main driving force of beamline evolution have been advances in almost every aspect of the instrumentation comprising a synchrotron beamline. In this review we aim to provide an overview of the current status of instrumentation at modern MX experiments. The most critical optical components are discussed, as are aspects of endstation design, sample delivery, visualization and positioning, the sample environment, beam shaping, detectors and data acquisition and processing. PMID:27046341

Current advances in synchrotron radiation instrumentation for MX experiments

DOE PAGES

Owen, Robin L.; Juanhuix, Jordi; Fuchs, Martin

2016-04-01

Following pioneering work 40 years ago, synchrotron beamlines dedicated to macromolecular crystallography (MX) have improved in almost every aspect as instrumentation has evolved. Beam sizes and crystal dimensions are now on the single micron scale while data can be collected from proteins with molecular weights over 10 MDa and from crystals with unit cell dimensions over 1000 Å. Moreover, it is possible to collect a complete data set in seconds, and obtain the resulting structure in minutes. The impact of MX synchrotron beamlines and their evolution is reflected in their scientific output, and MX is now the method of choicemore » for a variety of aims from ligand binding to structure determination of membrane proteins, viruses and ribosomes, resulting in a much deeper understanding of the machinery of life. One main driving force of beamline evolution have been advances in almost every aspect of the instrumentation comprising a synchrotron beamline. In this review we aim to provide an overview of the current status of instrumentation at modern MX experiments. Furthermore, we discuss the most critical optical components, aspects of endstation design, sample delivery, visualisation and positioning, the sample environment, beam shaping, detectors and data acquisition and processing.« less

Towards a visual modeling approach to designing microelectromechanical system transducers

NASA Astrophysics Data System (ADS)

Dewey, Allen; Srinivasan, Vijay; Icoz, Evrim

1999-12-01

In this paper, we address initial design capture and system conceptualization of microelectromechanical system transducers based on visual modeling and design. Visual modeling frames the task of generating hardware description language (analog and digital) component models in a manner similar to the task of generating software programming language applications. A structured topological design strategy is employed, whereby microelectromechanical foundry cell libraries are utilized to facilitate the design process of exploring candidate cells (topologies), varying key aspects of the transduction for each topology, and determining which topology best satisfies design requirements. Coupled-energy microelectromechanical system characterizations at a circuit level of abstraction are presented that are based on branch constitutive relations and an overall system of simultaneous differential and algebraic equations. The resulting design methodology is called visual integrated-microelectromechanical VHDL-AMS interactive design (VHDL-AMS is visual hardware design language for analog and mixed signal).

Urban Principle of Water Sensitive Design in Kampung Kamboja at Pontianak City

NASA Astrophysics Data System (ADS)

Hasriyanti, N.; Ryanti, E.

2017-07-01

This study will define the design principles of settlement area banks of the Kapuas Pontianak to approach the concept of water sensitive urban design (WSUD) in densely populated residential areas. Using a case study of a region densely located on the banks of the river with engineering literature to formulate the aspects taken into consideration and the components are arranged in the design, analysis descriptive paradigm rationalistic to identify the characteristics of residential areas riverbank with consideration of elements WSUD and formulate design principles residential area that is sensitive to water. This research is important to do because of problems related to the water management system in the settlement bank of the river in the city of Pontianak do not maximize. So that the primacy of this study contains several objectives to be achieved is to identify the characteristics of the settlement area riverbanks under consideration aspects areas design that is sensitive to water and principle areas design that will formulate the structure of the existing problems related to the needs of the community infrastructure facilities infrastructure neighborhoods and formulate and create guidelines for appropriate technology for integrated water management systems in the residential area of the riverbank and engineering design for the settlements are sensitive to water (WSUD). The final aim of the study is expected to achieve water management systems in residential areas by utilizing the abundant rainwater availability by using LID (Low Impact Development) through the concept of urban design that sensitive water

Structure Design Approach and Technology Selection for Next Generation European Launchers

NASA Astrophysics Data System (ADS)

Baiocco, P.; Ramusat, G.; Kauffmann, J.; Jaredson, D.; Bouilly, Th.; Lavelle, F.; Louaas, E.

2012-07-01

In the framework of the next generation launchers activity at ESA, a top-down and a bottom-up approach has been performed for the alternative conception and promising technologies of NGL sub-assemblies and sub-systems. The top-down approach consisted in looking for system-driven design solutions and the bottom-up in the proposal of design solutions taking to substantial advantages for the system. The main investigations have been focused on structures and technologies tight to structures and interfaces. Specifications coming from a preliminary system design have been used in order to permit sub-system design with the goal to find the major advantage for the overall launch system. In this respect selection criteria have been identified and among these a specific evaluation of the payload mass over recurring cost advantage has been evaluated. The development cost, recurring cost and operational aspects have been considered as competitiveness factors for the identification of the most interesting solutions. The TRL/IRL has been assessed and a preliminary development plan has been identified. This approach is dedicated to reference NGL architectures, but alternative architectures have been investigated in order to assess their interest in terms of competitiveness factors and study of other technologies. This paper deals mainly with metallic and composite structures owing to sub-systems or sub-assemblies proposed for the NGL. The major sub-systems and structures analysed are the engine thrust frame (ETF), inter stage structures (ISS), cryogenic propellant tanks, feeding lines and attachments, pressurisation systems and fairing. The paper provides an overview of the main results of this investigation and the potential benefit it can provide.

Aspects on the design, implementation, and simulation of a tracked mini robot destined for special applications in theatres of operations

NASA Astrophysics Data System (ADS)

Petrişor, Silviu-Mihai; Bârsan, GhiÅ£Ä.ƒ

2013-12-01

The authors of this paper wish to highlight elements regarding the organology, functioning and simulation, in a real workspace, of a tracked mini robot structure destined for special applications in theatres of operation, a technological product which is subject to a national patent granted to our institution (patent no. RO a 2012 01051), the result of research activities undertaken under a contract won by national competition, a grant for young research teams, PN-RUTE- 2010 type. The issues outlined in this paper are aspects related to the original invention in comparison with other mini-robot structures, the inventors presenting succinctly the technological product description and its applicability both in the military and applicative area as well as in the educational one. Additionally, the advantages of using the technological product are shown in a real workspace, the constructive and functional solution before, finally, presenting, based on the modelling of the mechanical structure of the tilting module attached to the mini-robot, an application on the simulation and programming of the mini-robot under study.

Impacts of Launch Vehicle Fairing Size on Human Exploration Architectures

NASA Technical Reports Server (NTRS)

Jefferies, Sharon; Collins, Tim; Dwyer Cianciolo, Alicia; Polsgrove, Tara

2017-01-01

Human missions to Mars, particularly to the Martian surface, are grand endeavors that place extensive demands on ground infrastructure, launch capabilities, and mission systems. The interplay of capabilities and limitations among these areas can have significant impacts on the costs and ability to conduct Mars missions and campaigns. From a mission and campaign perspective, decisions that affect element designs, including those based on launch vehicle and ground considerations, can create effects that ripple through all phases of the mission and have significant impact on the overall campaign. These effects result in impacts to element designs and performance, launch and surface manifesting, and mission operations. In current Evolvable Mars Campaign concepts, the NASA Space Launch System (SLS) is the primary launch vehicle for delivering crew and payloads to cis-lunar space. SLS is currently developing an 8.4m diameter cargo fairing, with a planned upgrade to a 10m diameter fairing in the future. Fairing diameter is a driving factor that impacts many aspects of system design, vehicle performance, and operational concepts. It creates a ripple effect that influences all aspects of a Mars mission, including: element designs, grounds operations, launch vehicle design, payload packaging on the lander, launch vehicle adapter design to meet structural launch requirements, control and thermal protection during entry and descent at Mars, landing stability, and surface operations. Analyses have been performed in each of these areas to assess and, where possible, quantify the impacts of fairing diameter selection on all aspects of a Mars mission. Several potential impacts of launch fairing diameter selection are identified in each of these areas, along with changes to system designs that result. Solutions for addressing these impacts generally result in increased systems mass and propellant needs, which can further exacerbate packaging and flight challenges. This paper presents the results of the analyses performed, the potential changes to mission architectures and campaigns that result, and the general trends that are more broadly applicable to any element design or mission planning for human exploration.

Structural integrity of power generating speed bumps made of concrete foam composite

NASA Astrophysics Data System (ADS)

Syam, B.; Muttaqin, M.; Hastrino, D.; Sebayang, A.; Basuki, W. S.; Sabri, M.; Abda, S.

2018-02-01

In this paper concrete foam composite speed bumps were designed to generate electrical power by utilizing the movements of commuting vehicles on highways, streets, parking gates, and drive-thru station of fast food restaurants. The speed bumps were subjected to loadings generated by vehicles pass over the power generating mechanical system. In this paper, we mainly focus our discussion on the structural integrity of the speed bumps and discuss the electrical power generating speed bumps in another paper. One aspect of structural integrity is its ability to support designed loads without breaking and includes the study of past structural failures in order to prevent failures in future designs. The concrete foam composites were used for the speed bumps; the reinforcement materials are selected from empty fruit bunch of oil palm. In this study, the speed bump materials and structure were subjected to various tests to obtain its physical and mechanical properties. To analyze the structure stability of the speed bumps some models were produced and tested in our speed bump test station. We also conduct a FEM-based computer simulation to analyze stress responses of the speed bump structures. It was found that speed bump type 1 significantly reduced the radial voltage. In addition, the speed bump is equipped with a steel casing is also suitable for use as a component component in generating electrical energy.

Zeolites: Can they be synthesized by design

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

Davis, M.E.

1994-09-01

Zeolites and zeolite-like molecular sieves are crystalline oxides that have high surface-to-volume ratios and are able to recognize, discriminate, and organize molecules with differences of < 1 [angstrom]. The close connection between the atomic structure and macroscopic properties of these materials has led to uses in molecular recognition. For example, zeolites and zeolite-like molecular sieves can reveal marvelous molecular recognition specificity and sensitivity that can be applied to catalysis, separations technology, and chemical sensing. Additionally, they can serve as hosts to organize guest atoms and molecules that endow composite materials with optoelectric and electrochemical properties. Because of the high levelmore » of structural control necessary to create high-performance materials with zeolites or zeolite-like molecular sieves, the design and synthesis of these solids with specific architectures and properties are highly desired. Although this lofty goal is still elusive, advances have been made to allow the serious consideration of designing molecular sieves. Here, the author covers two aspects of this ongoing effort. First, he discusses the feasibility of designing pore architectures through the use of organic structure-directing agents. Second, he explores the possibility of creating zeolites through ''Lego chemistry.''« less

Social Network Theory in Engineering Education

NASA Astrophysics Data System (ADS)

Simon, Peter A.

Collaborative groups are important both in the learning environment of engineering education and, in the real world, the business of engineering design. Selecting appropriate individuals to form an effective group and monitoring a group's progress are important aspects of successful task performance. This exploratory study looked at using the concepts of cognitive social structures, structural balance, and centrality from social network analysis as well as the measures of emotional intelligence. The concepts were used to analyze potential team members to examine if an individual's ability to perceive emotion in others and the self and to use, understand, and manage those emotions are a factor in a group's performance. The students from a capstone design course in computer engineering were used as volunteer subjects. They were formed into groups and assigned a design exercise to determine whether and which of the above-mentioned tools would be effective in both selecting teams and predicting the quality of the resultant design. The results were inconclusive with the exception of an individual's ability to accurately perceive emotions. The instruments that were successful were the Self-Monitoring scale and the accuracy scores derived from cognitive social structures and Level IV of network levels of analysis.

Selective Laser Melting of Hot Gas Turbine Components: Materials, Design and Manufacturing Aspects

NASA Astrophysics Data System (ADS)

Goutianos, Stergios

2017-07-01

Selective Laser Melting (SLM) allows the design and manufacturing of novel parts and structures with improved performance e.g. by incorporating complex and more efficient cooling schemes in hot gas turbine parts. In contrast to conventional manufacturing of removing material, with SLM parts are built additively to nearly net shape. This allows the fabrication of arbitrary complex geometries that cannot be made by conventional manufacturing techniques. However, despite the powerful capabilities of SLM, a number of issues (e.g. part orientation, support structures, internal stresses), have to be considered in order to manufacture cost-effective and high quality parts at an industrial scale. These issues are discussed in the present work from an engineering point of view with the aim to provide simple quidelines to produce high quality SLM parts.

Buckling Design Studies of Inverted, Oblate Bulkheads for a Propellant Tank

NASA Technical Reports Server (NTRS)

Smeltzer, Stanley S., III; Bowman, Lynn M.

2002-01-01

An investigation of the deformation and buckling characteristics of a composite, oblate bulkhead that has an inverted geometry and is subjected to pressure-only loading is presented for three bulkhead geometries and thicknesses. The effects of a stiffening support ring at the bulkhead to cylinder interface are also evaluated. Buckling analyses conducted using the axisymmetric shell code BOSOR4 are discussed for several bulkhead configurations. These results are analytically verified using results from the Structural Analysis of General Shells (STAGS) code for a selected bulkhead configuration. The buckling characterization of an inverted, oblate bulkhead requires careful attention as small changes in bulkhead parameters can have a significant effect on the critical buckling load. Comparison of BOSOR4 and STAGS results provided a very good correlation between the two analysis methods. In addition, the analysis code BOSOR4 was found to be an efficient sizing tool that is useful during the preliminary design stage of a practical shell structure. Together, these two aspects should give the design engineer confidence in sizing these stability critical structures. Additional characterization is warranted, especially for a composite tank structure, since only one bulkhead configuration was examined closely.

Design of a dynamic test platform for autonomous robot vision systems

NASA Technical Reports Server (NTRS)

Rich, G. C.

1980-01-01

The concept and design of a dynamic test platform for development and evluation of a robot vision system is discussed. The platform is to serve as a diagnostic and developmental tool for future work with the RPI Mars Rover's multi laser/multi detector vision system. The platform allows testing of the vision system while its attitude is varied, statically or periodically. The vision system is mounted on the test platform. It can then be subjected to a wide variety of simulated can thus be examined in a controlled, quantitative fashion. Defining and modeling Rover motions and designing the platform to emulate these motions are also discussed. Individual aspects of the design process are treated separately, as structural, driving linkages, and motors and transmissions.

Design Development Analyses in Support of a Heatpipe-Brayton Cycle Heat Exchanger

NASA Technical Reports Server (NTRS)

Steeve, Brian E.; Kapernick, Richard J.

2004-01-01

One of the power systems under consideration for nuclear electric propulsion or as a planetary surface power source is a heatpipe-cooled reactor coupled to a Brayton cycle. In this system, power is transferred from the heatpipes to the Brayton gas via a heat exchanger attached to the heatpipes. This paper discusses the fluid, thermal and structural analyses that were performed in support of the design of the heat exchanger to be tested in the SAFE-100 experimental program at the Marshall Space Flight Center: An important consideration throughout the design development of the heat exchanger w its capability to be utilized for higher power and temperature applications. This paper also discusses this aspect of the design and presents designs for specific applications that are under consideration.

Maglev guideway design issues

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

Plotkin, D.; Kim, S.

1997-05-01

This paper reports results from guideway analyses conducted as part of the National Maglev Initiative (NMI), a government-industry effort from 1989 to 1994, formed to encourage the development of US maglev technology and to assess its potential application within the US transportation system. Covered here are some key guideway design issues that were common to the designs assessed for the NMI, and to maglev guideways in general. They represent aspects that will need additional attention in future efforts to produce structurally sound and economical maglev guideways. These recommendations come from the analyses conducted by a team from the US Armymore » Construction Engineering Research Laboratories, the Civil Engineering Department of the University of Illinois, and Alfred Benesch and Company. The recommendations focus on design philosophy and the development of general design criteria, guideway maintenance and the provision for future alignment adjustment in both the guideway and the magnets, foundation design, and the long-term performance of guideway materials and reinforcement. Generally, one of the main challenges to guideway designers is to produce a structure that will be easily maintainable to the narrow tolerances and precise alignment required for practical high-speed maglev operation.« less

Reverse engineering of wörner type drilling machine structure.

NASA Astrophysics Data System (ADS)

Wibowo, A.; Belly, I.; llhamsyah, R.; Indrawanto; Yuwana, Y.

2018-03-01

A product design needs to be modified based on the conditions of production facilities and existing resource capabilities without reducing the functional aspects of the product itself. This paper describes the reverse engineering process of the main structure of the wörner type drilling machine to obtain a machine structure design that can be made by resources with limited ability by using simple processes. Some structural, functional and the work mechanism analyzes have been performed to understand the function and role of each basic components. The process of dismantling of the drilling machine and measuring each of the basic components was performed to obtain sets of the geometry and size data of each component. The geometric model of each structure components and the machine assembly were built to facilitate the simulation process and machine performance analysis that refers to ISO standard of drilling machine. The tolerance stackup analysis also performed to determine the type and value of geometrical and dimensional tolerances, which could affect the ease of the components to be manufactured and assembled

Design of a Single Motor Based Leg Structure with the Consideration of Inherent Mechanical Stability

NASA Astrophysics Data System (ADS)

Taha Manzoor, Muhammad; Sohail, Umer; Noor-e-Mustafa; Nizami, Muhammad Hamza Asif; Ayaz, Yasar

2017-07-01

The fundamental aspect of designing a legged robot is constructing a leg design that is robust and presents a simple control problem. In this paper, we have successfully designed a robotic leg based on a unique four bar mechanism with only one motor per leg. The leg design parameters used in our platform are extracted from design principles used in biological systems, multiple iterations and previous research findings. These principles guide a robotic leg to have minimal mechanical passive impedance, low leg mass and inertia, a suitable foot trajectory utilizing a practical balance between leg kinematics and robot usage, and the resultant inherent mechanical stability. The designed platform also exhibits the key feature of self-locking. Theoretical tools and software iterations were used to derive these practical features and yield an intuitive sense of the required leg design parameters.

Design of optical metamaterial waveguide structures (Conference Presentation)

NASA Astrophysics Data System (ADS)

Ortega-Moñux, Alejandro; Halir, Robert; Sánchez-Postigo, Alejandro; Soler-Penadés, Jordi; Ctyroký, Jirí; Luque-González, José Manuel; Sarmiento-Merenguel, José Darío.; Wangüemert-Pérez, Juan Gonzalo; Schmid, Jens H.; Xu, Dan-Xia; Janz, Sigfried; Lapointe, Jean; Molina-Fernández, Iñigo; Nedeljkovic, Milos; Mashanovich, Goran Z.; Cheben, Pavel

2017-05-01

Subwavelength gratings (SWGs) are periodic structures with a pitch (Λ) smaller than the wavelength of the propagating wave (λ), so that diffraction effects are suppressed. These structures thus behave as artificial metamaterials where the refractive index and the dispersion profile can be controlled with a proper design of the geometry of the structure. SWG waveguides have found extensive applications in the field of integrated optics, such as efficient fiber-chip couplers, broadband multimode interference (MMI) couplers, polarization beam splitters or evanescent field sensors, among others. From the point of view of nano-fabrication, the subwavelength condition (Λ << λ) is much easier to meet for long, mid-infrared wavelengths than for the comparatively short near-infrared wavelengths. Since most of the integrated devices based on SWGs have been proposed for the near-infrared, the true potential of subwavelength structures has not yet been completely exploited. In this talk we summarize some valuable guidelines for the design of high performance SWG integrated devices. We will start describing some practical aspects of the design, such as the range of application of semi-analytical methods, the rigorous electromagnetic simulation of Floquet modes, the relevance of substrate leakage losses and the effects of the random jitter, inherent to any fabrication process, on the performance of SWG structures. Finally, we will show the possibilities of the design of SWG structures with two different state-of-the-art applications: i) ultra-broadband MMI beam splitters with an operation bandwidth greater than 300nm for telecom wavelengths and ii) a set of suspended waveguides with SWG lateral cladding for mid-infrared applications, including low loss waveguides, MMI couplers and Mach-Zehnder interferometers.

Finite element analysis of CFRP reinforced silo structure design method

NASA Astrophysics Data System (ADS)

Yuan, Long; Xu, Xinsheng

2017-11-01

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

Controllable rotational inversion in nanostructures with dual chirality.

PubMed

Dai, Lu; Zhu, Ka-Di; Shen, Wenzhong; Huang, Xiaojiang; Zhang, Li; Goriely, Alain

2018-04-05

Chiral structures play an important role in natural sciences due to their great variety and potential applications. A perversion connecting two helices with opposite chirality creates a dual-chirality helical structure. In this paper, we develop a novel model to explore quantitatively the mechanical behavior of normal, binormal and transversely isotropic helical structures with dual chirality and apply these ideas to known nanostructures. It is found that both direction and amplitude of rotation can be finely controlled by designing the cross-sectional shape. A peculiar rotational inversion of overwinding followed by unwinding, observed in some gourd and cucumber tendril perversions, not only exists in transversely isotropic dual-chirality helical nanobelts, but also in the binormal/normal ones when the cross-sectional aspect ratio is close to 1. Beyond this rotational inversion region, the binormal and normal dual-chirality helical nanobelts exhibit a fixed directional rotation of unwinding and overwinding, respectively. Moreover, in the binormal case, the rotation of these helical nanobelts is nearly linear, which is promising as a possible design for linear-to-rotary motion converters. The present work suggests new designs for nanoscale devices.

Solution Synthesis of Atomically Precise Graphene Nanoribbons

NASA Astrophysics Data System (ADS)

Shekhirev, Mikhail; Sinitskii, Alexander

2017-05-01

Bottom-up fabrication of narrow strips of graphene, also known as graphene nanoribbons or GNRs, is an attractive way to open a bandgap in semimetallic graphene. In this chapter, we review recent progress in solution-based synthesis of GNRs with atomically precise structures. We discuss a variety of atomically precise GNRs and highlight theoretical and practical aspects of their structural design and solution synthesis. These GNRs are typically synthesized through a polymerization of rationally designed molecular precursors followed by a planarization through a cyclodehydrogenation reaction. We discuss various synthetic techniques for polymerization and planarization steps, possible approaches for chemical modification of GNRs, and compare the properties of GNRs that could be achieved by different synthetic methods. We also discuss the importance of the rational design of molecular precursors to avoid isomerization during the synthesis and achieve GNRs that have only one possible structure. Significant attention in this chapter is paid to the methods of material characterization of solution-synthesized GNRs. The chapter is concluded with the discussion of the most significant challenges in the field and the future outlook.

Structurally Integrated, Damage-Tolerant, Thermal Spray Coatings

NASA Astrophysics Data System (ADS)

Vackel, Andrew; Dwivedi, Gopal; Sampath, Sanjay

2015-07-01

Thermal spray coatings are used extensively for the protection and life extension of engineering components exposed to harsh wear and/or corrosion during service in aerospace, energy, and heavy machinery sectors. Cermet coatings applied via high-velocity thermal spray are used in aggressive wear situations almost always coupled with corrosive environments. In several instances (e.g., landing gear), coatings are considered as part of the structure requiring system-level considerations. Despite their widespread use, the technology has lacked generalized scientific principles for robust coating design, manufacturing, and performance analysis. Advances in process and in situ diagnostics have provided significant insights into the process-structure-property-performance correlations providing a framework-enhanced design. In this overview, critical aspects of materials, process, parametrics, and performance are discussed through exemplary studies on relevant compositions. The underlying connective theme is understanding and controlling residual stresses generation, which not only addresses process dynamics but also provides linkage for process-property relationship for both the system (e.g., fatigue) and the surface (wear and corrosion). The anisotropic microstructure also invokes the need for damage-tolerant material design to meet future goals.

Thermal analysis and cooling structure design of the primary collimator in CSNS/RCS

NASA Astrophysics Data System (ADS)

Zou, Yi-Qing; Wang, Na; Kang, Ling; Qu, Hua-Min; He, Zhe-Xi; Yu, Jie-Bing

2013-05-01

The rapid cycling synchrotron (RCS) of the China Spallation Neutron Source (CSNS) is a high intensity proton ring with beam power of 100 kW. In order to control the residual activation to meet the requirements of hands-on maintenance, a two-stage collimation system has been designed for the RCS. The collimation system consists of one primary collimator made of thin metal to scatter the beam and four secondary collimators as absorbers. Thermal analysis is an important aspect in evaluating the reliability of the collimation system. The calculation of the temperature distribution and thermal stress of the primary collimator with different materials is carried out by using ANSYS code. In order to control the temperature rise and thermal stress of the primary collimator to a reasonable level, an air cooling structure is intended to be used. The mechanical design of the cooling structure is presented, and the cooling efficiency with different chin numbers and wind velocity is also analyzed. Finally, the fatigue lifetime of the collimator under thermal shocks is estimated.

The Acceptance of Universalism: The Importance of Selected Aspects of School Structure.

ERIC Educational Resources Information Center

Martin, Robert A.

This report describes a study that investigated empirically the relationships between selected aspects of the organizational structure of elementary schools and the extent to which students endorsed the norm of universalism. Four aspects of structure were studied: degree of departmentalization, school enrollment, student-teacher ratio, and extent…

Alkaloids and leishmania donovani UDP-galactopyarnose mutase: Anovel approach in drug designing against Visceral leishmaniasis.

PubMed

Srivastava, Ankita; Chandra, Deepak

2017-06-05

The unsatisfactory treatment options for Visceral Leishmaniasis (VL), needs identification of new drug targets. Among natural products, Alkaloids have been proved to be highly effective against number of diseases. In Leishmania UDP-galactopyranose mutase (UGM) is a critical enzyme required for cell wall synthesis and thus a drug target for structure based drug designing against L. donovani. To build the homology model of UDP galactopyranse mutase and investigate the interaction of selected alkaloids with this modeled UDP galactopyranose mutase by molecular docking. Since there is no crystal structure record has been found with this protein, a homology modeling was performed and a three dimensional structure of L. donovani UGM was created using MODELLER v9.9, structure quality was validated using PROCHECK and QMEAN programs which confirms that the structure is reliable. Further Molecular docking was performed with previously reported 15 alkaloids. It was found that Protopine shows a binding energy of -12.39Kcal/mole, binds at Flavin adenine dinucleotide (FAD) biding site. Concluding that Protopine, an alkaloid could interrupt the functional aspect of L. donovani UGM and thus may be useful for drug designing studies. These finding would contribute to the understanding of effect of drug on the parasite. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Aero-Thermo-Structural Design Optimization of Internally Cooled Turbine Blades

NASA Technical Reports Server (NTRS)

Dulikravich, G. S.; Martin, T. J.; Dennis, B. H.; Lee, E.; Han, Z.-X.

1999-01-01

A set of robust and computationally affordable inverse shape design and automatic constrained optimization tools have been developed for the improved performance of internally cooled gas turbine blades. The design methods are applicable to the aerodynamics, heat transfer, and thermoelasticity aspects of the turbine blade. Maximum use of the existing proven disciplinary analysis codes is possible with this design approach. Preliminary computational results demonstrate possibilities to design blades with minimized total pressure loss and maximized aerodynamic loading. At the same time, these blades are capable of sustaining significantly higher inlet hot gas temperatures while requiring remarkably lower coolant mass flow rates. These results suggest that it is possible to design internally cooled turbine blades that will cost less to manufacture, will have longer life span, and will perform as good, if not better than, film cooled turbine blades.

Nuclear design of a very-low-activation fusion reactor

NASA Astrophysics Data System (ADS)

Cheng, E. T.; Hopkins, G. R.

1983-06-01

The nuclear design aspects of using very-low-activation materials, such as SiC, MgO, and aluminum for fusion-reactor first wall, blanket, and shield applications were investigated. In addition to the advantage of very-low radioactive inventory, it was found that the very-low-activation fusion reactor can also offer an adequate tritium-breeding ratio and substantial amount of blanket nuclear heating as a conventional-material-structured reactor does. The most-stringent design constraint found in a very-low-activation fusion reactor is the limited space available in the inboard region of a Tokamak concept for shielding to protect the superconducting toroidal field coil. A reference design was developed which mitigates the constraint by adopting a removable tungsten shield design that retains the inboard dimensions and gives the same shield performance as the reference STARFIRE Tokamak reactor design.

Structural Design Strategies for Improved Small Overlap Crashworthiness Performance.

PubMed

Mueller, Becky C; Brethwaite, Andrew S; Zuby, David S; Nolan, Joseph M

2014-11-01

In 2012, the Insurance Institute for Highway Safety (IIHS) began a 64 km/h small overlap frontal crash test consumer information test program. Thirteen automakers already have redesigned models to improve test performance. One or more distinct strategies are evident in these redesigns: reinforcement of the occupant compartment, use of energy-absorbing fender structures, and the addition of engagement structures to induce vehicle lateral translation. Each strategy influences vehicle kinematics, posing additional challenges for the restraint systems. The objective of this two-part study was to examine how vehicles were modified to improve small overlap test performance and then to examine how these modifications affect dummy response and restraint system performance. Among eight models tested before and after design changes, occupant compartment intrusion reductions ranged from 6 cm to 45 cm, with the highest reductions observed in models with the largest number of modifications. All redesigns included additional occupant compartment reinforcement, one-third added structures to engage the barrier, and two modified a shotgun load path. Designs with engagement structures produced greater glance-off from the barrier and exhibited lower delta Vs but experienced more lateral outboard motion of the dummy. Designs with heavy reinforcement of the occupant compartment had higher vehicle accelerations and delta V. In three cases, these apparent trade-offs were not well addressed by concurrent changes in restraint systems and resulted in increased injury risk compared with the original tests. Among the 36 models tested after design changes, the extent of design changes correlated to structural performance. Half of the vehicles with the lowest intrusion levels incorporated aspects of all three design strategies. Vehicle kinematics and dummy and restraint system characteristics were similar to those observed in the before/after pairs. Different combinations of structural improvement strategies for improving small overlap test performance were found to be effective in reducing occupant compartment intrusion and improving dummy kinematics in the IIHS small overlap test with modest weight increase.

Structural insights into ligand recognition and selectivity for class A, B, and C GPCRs

PubMed Central

Lee, Sang-Min; Booe, Jason M.; Pioszak, Augen A.

2015-01-01

The G protein-coupled receptor (GPCR) superfamily constitutes the largest collection of cell surface signaling proteins with approximately 800 members in the human genome. GPCRs regulate virtually all aspects of physiology and they are an important class of drug targets with ~30% of drugs on the market targeting a GPCR. Breakthroughs in GPCR structural biology in recent years have significantly expanded our understanding of GPCR structure and function and ushered in a new era of structure-based drug design for GPCRs. Crystal structures for nearly thirty distinct GPCRs are now available including receptors from each of the major classes, A, B, C, and F. These structures provide a foundation for understanding the molecular basis of GPCR pharmacology. Here, we review structural mechanisms of ligand recognition and selectivity of GPCRs with a focus on selected examples from classes A, B, and C, and we highlight major unresolved questions for future structural studies. PMID:25981303

Structural Dynamics Experimental Activities in Ultra-Lightweight and Inflatable Space Structures

NASA Technical Reports Server (NTRS)

Pappa, Richard S.; Lassiter, John O.; Ross, Brian P.

2001-01-01

This paper reports recently completed structural dynamics experimental activities with new ultralightweight and inflatable space structures (a.k.a., "Gossamer" spacecraft) at NASA Langley Research Center, NASA Marshall Space Flight Center, and NASA Goddard Space Flight Center. Nine aspects of this work are covered, as follows: 1) inflated, rigidized tubes, 2) active control experiments, 3) photogrammetry, 4) laser vibrometry, 5) modal tests of inflatable structures, 6) in-vacuum modal tests, 7) tensioned membranes, 8) deployment tests, and 9) flight experiment support. Structural dynamics will play a major role in the design and eventual in-space deployment and performance of Gossamer spacecraft, and experimental R&D work such as this is required now to validate new analytical prediction methods. The activities discussed in the paper are pathfinder accomplishments, conducted on unique components and prototypes of future spacecraft systems.

A Rational Approach to Determine Minimum Strength Thresholds in Novel Structural Materials

NASA Technical Reports Server (NTRS)

Schur, Willi W.; Bilen, Canan; Sterling, Jerry

2003-01-01

Design of safe and survivable structures requires the availability of guaranteed minimum strength thresholds for structural materials to enable a meaningful comparison of strength requirement and available strength. This paper develops a procedure for determining such a threshold with a desired degree of confidence, for structural materials with none or minimal industrial experience. The problem arose in attempting to use a new, highly weight-efficient structural load tendon material to achieve a lightweight super-pressure balloon. The developed procedure applies to lineal (one dimensional) structural elements. One important aspect of the formulation is that it extrapolates to expected probability distributions for long length specimen samples from some hypothesized probability distribution that has been obtained from a shorter length specimen sample. The use of the developed procedure is illustrated using both real and simulated data.

Optimized structural designs for stretchable silicon integrated circuits.

PubMed

Kim, Dae-Hyeong; Liu, Zhuangjian; Kim, Yun-Soung; Wu, Jian; Song, Jizhou; Kim, Hoon-Sik; Huang, Yonggang; Hwang, Keh-Chih; Zhang, Yongwei; Rogers, John A

2009-12-01

Materials and design strategies for stretchable silicon integrated circuits that use non-coplanar mesh layouts and elastomeric substrates are presented. Detailed experimental and theoretical studies reveal many of the key underlying aspects of these systems. The results shpw, as an example, optimized mechanics and materials for circuits that exhibit maximum principal strains less than 0.2% even for applied strains of up to approximately 90%. Simple circuits, including complementary metal-oxide-semiconductor inverters and n-type metal-oxide-semiconductor differential amplifiers, validate these designs. The results suggest practical routes to high-performance electronics with linear elastic responses to large strain deformations, suitable for diverse applications that are not readily addressed with conventional wafer-based technologies.

External and internal factors influencing self-directed online learning of physiotherapy undergraduate students in Sweden: a qualitative study.

PubMed

Hammarlund, Catharina Sjödahl; Nilsson, Maria H; Gummesson, Christina

2015-01-01

Online courses have become common in health sciences education. This learning environment can be designed using different approaches to support student learning. To further develop online environment, it is important to understand how students perceive working and learning online. The aim of this study is to identify aspects influencing students' learning processes and their adaptation to self-directed learning online. Thirty-four physiotherapy students with a mean age of 25 years (range, 21 to 34 years) participated. Qualitative content analysis and triangulation was used when investigating the students' self-reflections, written during a five week self-directed, problem-oriented online course. Two categories emerged: 'the influence of the structured framework' and 'communication and interaction with teachers and peers.' The learning processes were influenced by external factors, e.g., a clear structure including a transparent alignment of assignments and assessment. Important challenges to over-come were primarily internal factors, e.g., low self-efficacy, difficulties to plan the work effectively and adapting to a new environment. The analyses reflected important perspectives targeting areas which enable further course development. The influences of external and internal factors on learning strategies and self-efficacy are important aspects to consider when designing online courses. Factors such as pedagogical design, clarity of purpose, goals, and guidelines were important as well as continuous opportunities for communication and collaboration. Further studies are needed to understand and scaffold the motivational factors among students with low self-efficacy.

Nonlinear aeroelastic analysis, flight dynamics, and control of a complete aircraft

NASA Astrophysics Data System (ADS)

Patil, Mayuresh Jayawant

The focus of this research was to analyze a high-aspect-ratio wing aircraft flying at low subsonic speeds. Such aircraft are designed for high-altitude, long-endurance missions. Due to the high flexibility and associated wing deformation, accurate prediction of aircraft response requires use of nonlinear theories. Also strong interactions between flight dynamics and aeroelasticity are expected. To analyze such aircraft one needs to have an analysis tool which includes the various couplings and interactions. A theoretical basis has been established for a consistent analysis which takes into account, (i) material anisotropy, (ii) geometrical nonlinearities of the structure, (iii) rigid-body motions, (iv) unsteady flow behavior, and (v) dynamic stall. The airplane structure is modeled as a set of rigidly attached beams. Each of the beams is modeled using the geometrically exact mixed variational formulation, thus taking into account geometrical nonlinearities arising due to large displacements and rotations. The cross-sectional stiffnesses are obtained using an asymptotically exact analysis, which can model arbitrary cross sections and material properties. An aerodynamic model, consisting of a unified lift model, a consistent combination of finite-state inflow model and a modified ONERA dynamic stall model, is coupled to the structural system to determine the equations of motion. The results obtained indicate the necessity of including nonlinear effects in aeroelastic analysis. Structural geometric nonlinearities result in drastic changes in aeroelastic characteristics, especially in case of high-aspect-ratio wings. The nonlinear stall effect is the dominant factor in limiting the amplitude of oscillation for most wings. The limit cycle oscillation (LCO) phenomenon is also investigated. Post-flutter and pre-flutter LCOs are possible depending on the disturbance mode and amplitude. Finally, static output feedback (SOF) controllers are designed for flutter suppression and gust alleviation. SOF controllers are very simple and thus easy to implement. For the case considered, SOF controllers with proper choice of sensors give results comparable to full state feedback (linear quadratic regulator) designs.

A Comparison of Structurally Connected and Multiple Spacecraft Interferometers

NASA Technical Reports Server (NTRS)

Surka, Derek M.; Crawley, Edward F.

1996-01-01

Structurally connected and multiple spacecraft interferometers are compared in an attempt to establish the maximum baseline (referred to as the "cross-over baseline") for which it is preferable to operate a single-structure interferometer in space rather than an interferometer composed of numerous, smaller spacecraft. This comparison is made using the total launched mass of each configuration as the comparison metric. A framework of study within which structurally connected and multiple spacecraft interferometers can be compared is presented in block diagram form. This methodology is then applied to twenty-two different combinations of trade space parameters to investigate the effects of different orbits, orientations, truss materials, propellants, attitude control actuators, onboard disturbance sources, and performance requirements on the cross-over baseline. Rotating interferometers and the potential advantages of adding active structural control to the connected truss of the structurally connected interferometer are also examined. The minimum mass design of the structurally connected interferometer that meets all performance-requirements and satisfies all imposed constraints is determined as a function of baseline. This minimum mass design is then compared to the design of the multiple spacecraft interferometer. It is discovered that the design of the minimum mass structurally connected interferometer that meets all performance requirements and constraints in solar orbit is limited by the minimum allowable aspect ratio, areal density, and gage of the struts. In the formulation of the problem used in this study, there is no advantage to adding active structural control to the truss for interferometers in solar orbit. The cross-over baseline for missions of practical duration (ranging from one week to thirty years) in solar orbit is approximately 400 m for non-rotating interferometers and 650 m for rotating interferometers.

Proceedings of the International Workshop on Water Waves and Floating Bodies (16th) Held in Hiroshima, Japan on April 22-25, 2001

DTIC Science & Technology

2001-04-25

design. The method should be easy to handle and should not be time consuming. In this aspect, Takagi and Kohara [2000] proposed an application of the...of a Very Large Floating Structure, Proc. of 14th Int. WWWFB, Port Huron, 1999, pp. 13 7- 14 0 . TAKAGI, K. and KOHARA , K. :Application of the Ray

Assessing Time Management Skills as an Important Aspect of Student Learning: The Construction and Evaluation of a Time Management Scale with Spanish High School Students

ERIC Educational Resources Information Center

Garcia-Ros, Rafael; Perez-Gonzalez, Francisco; Hinojosa, Eugenia

2004-01-01

The main purpose of this study is to analyse the factorial structure, psychometric properties and predictive capacity for academic achievement of a scale designed to evaluate the time management skills of Spanish high school students. An adaptation of the Time Management Questionnaire was presented to two samples of 350 Spanish high school…

Design aspects of zeppelin operations from case histories

NASA Technical Reports Server (NTRS)

Maiersperger, W. P.

1975-01-01

Some widely held beliefs concerning the practicability of rigid airships in air carrier operations are discussed. It is shown by a review of past operational experience, and some basic aerostatic theory, their actual record and the reasons for their demise. Problems of atmospheric density and temperature variations, meteorological factors, aerodynamic stability and control, and mooring difficulties are discussed and related to actual case histories. Structural and flight efficiencies are compared to airplane efficiencies for airplanes contemporary with the zeppelin as well as modern designs. The difficulty of supporting new, commercial airship developments on an economic basis is made clear.

Laminates and reinforced metals

NASA Technical Reports Server (NTRS)

Chamis, C. C.

1980-01-01

A selective review is presented of the state of the art of metallic laminates and fiber reinforced metals called metallic matrix laminates (MMLs). Design and analysis procedures that are used for, and typical structural components that have been made from MMLs are emphasized. Selected MMLs, constituent materials, typical material properties and fabrication procedures are briefly described, including hybrids and superhybrids. Advantages, disadvantages, and special considerations required during design, analysis, and fabrication of MMLs are examined. Tabular and graphical data are included to illustrate key aspects of MMLs. Appropriate references are cited to provide a selective bibliography of a rapidly expanding and very promising research and development field.

Metamaterials Application in Sensing

PubMed Central

Chen, Tao; Li, Suyan; Sun, Hui

2012-01-01

Metamaterials are artificial media structured on a size scale smaller than wavelength of external stimuli, and they can exhibit a strong localization and enhancement of fields, which may provide novel tools to significantly enhance the sensitivity and resolution of sensors, and open new degrees of freedom in sensing design aspect. This paper mainly presents the recent progress concerning metamaterials-based sensing, and detailedly reviews the principle, detecting process and sensitivity of three distinct types of sensors based on metamaterials, as well as their challenges and prospects. Moreover, the design guidelines for each sensor and its performance are compared and summarized. PMID:22736975

Life modeling of thermal barrier coatings for aircraft gas turbine engines

NASA Technical Reports Server (NTRS)

Miller, R. A.

1989-01-01

Thermal barrier coating life models developed under the NASA Lewis Research Center's Hot Section Technology (HOST) Program are summarized. An initial laboratory model and three design-capable models are discussed. Current understanding of coating failure mechanisms are also summarized. The materials and structural aspects of thermal barrier coatings have been successfully integrated under the HOST program to produce models which may now or in the near future be used in design. Efforts on this program continue at Pratt and Whitney Aircraft where their model is being extended to the life prediction of physical vapor deposited thermal barrier coatings.

Photogrammetric measurement to one part in a million

NASA Astrophysics Data System (ADS)

Fraser, Clive S.

1992-03-01

Industrial photogrammetric measurement to accuracies of 1 part in 1,000,000 of the size of the object is discussed. Network design concepts are reviewed, especially with regard both to the relationships between the first- and second-order design phases and to minimization of the influences of uncompensated systematic error. Photogrammetric system aspects are also briefly touched upon. The network optimization process for the measurement of a large compact range reflector is described and results of successive alignment surveys of this structure are summarized. These photogrammetric measurements yielded three dimensional (3D) coordinate accuracies surpassing one part in a million.

Modeling, system identification, and control of ASTREX

NASA Technical Reports Server (NTRS)

Abhyankar, Nandu S.; Ramakrishnan, J.; Byun, K. W.; Das, A.; Cossey, Derek F.; Berg, J.

1993-01-01

The modeling, system identification and controller design aspects of the ASTREX precision space structure are presented in this work. Modeling of ASTREX is performed using NASTRAN, TREETOPS and I-DEAS. The models generated range from simple linear time-invariant models to nonlinear models used for large angle simulations. Identification in both the time and frequency domains are presented. The experimental set up and the results from the identification experiments are included. Finally, controller design for ASTREX is presented. Simulation results using this optimal controller demonstrate the controller performance. Finally the future directions and plans for the facility are addressed.

Segregating the core computational faculty of human language from working memory

PubMed Central

Makuuchi, Michiru; Bahlmann, Jörg; Anwander, Alfred; Friederici, Angela D.

2009-01-01

In contrast to simple structures in animal vocal behavior, hierarchical structures such as center-embedded sentences manifest the core computational faculty of human language. Previous artificial grammar learning studies found that the left pars opercularis (LPO) subserves the processing of hierarchical structures. However, it is not clear whether this area is activated by the structural complexity per se or by the increased memory load entailed in processing hierarchical structures. To dissociate the effect of structural complexity from the effect of memory cost, we conducted a functional magnetic resonance imaging study of German sentence processing with a 2-way factorial design tapping structural complexity (with/without hierarchical structure, i.e., center-embedding of clauses) and working memory load (long/short distance between syntactically dependent elements; i.e., subject nouns and their respective verbs). Functional imaging data revealed that the processes for structure and memory operate separately but co-operatively in the left inferior frontal gyrus; activities in the LPO increased as a function of structural complexity, whereas activities in the left inferior frontal sulcus (LIFS) were modulated by the distance over which the syntactic information had to be transferred. Diffusion tensor imaging showed that these 2 regions were interconnected through white matter fibers. Moreover, functional coupling between the 2 regions was found to increase during the processing of complex, hierarchically structured sentences. These results suggest a neuroanatomical segregation of syntax-related aspects represented in the LPO from memory-related aspects reflected in the LIFS, which are, however, highly interconnected functionally and anatomically. PMID:19416819

Student perceptions: Importance of and satisfaction with aspects of an online biology course

NASA Astrophysics Data System (ADS)

Hendry, Sheila R.

Research of student satisfaction with various facets of an online biology course, as well as the perceived importance of these aspects, was conducted during the summer and fall 2004 semesters within a course, History of Biology, at a university in the southeastern United States. This research is based on the theory of transactional distance, which involves dialogue between the teacher and student, the physical environments of both the student and teacher, and the emotional environments of each. Student ratings of importance and satisfaction regarding aspects of convenience, grade earned/knowledge learned, emotional health, communication, and student support were collected toward the end of each semester, via the online course, using the researcher-designed Student Perceptions Survey. Statistics with repeated measures ANOVA, using an alpha of 0.05, determined differences between importance and satisfaction ratings for each of these aspects. Students perceived grade earned/knowledge learned to be the most important aspect of learning online, although it is not an aspect unique to online courses. All of the aspects included in the study were found to be at least somewhat important. Convenience was the aspect with which students were most satisfied, with students at least somewhat satisfied with the other aspects. Although convenience is an inherent strength of the online course format, instructors should be aware of how important it is to design requirements of the online class to help students acquire knowledge while allowing them to do so at their own pace. Well-structured content, prompt feedback, encouragement of quality student-instructor communication, and student support are all parts of a positive online course experience. The Student Perceptions Survey, created specifically for this research, can have substantial value both in the creation of new online courses and in the evaluation of pre-existing courses. It can provide important information that can be used in developing or modifying an online course, to determine whether revisions have been effective, or to assess changes in student perceptions. In addition, as changes in technology occur, the survey can be further revised, with maintenance of core items, so that it will remain an effective evaluation tool for online courses.

Molecular Designs for Enhancement of Polarity in Ferroelectric Soft Materials

NASA Astrophysics Data System (ADS)

Ohtani, Ryo; Nakaya, Manabu; Ohmagari, Hitomi; Nakamura, Masaaki; Ohta, Kazuchika; Lindoy, Leonard F.; Hayami, Shinya

2015-11-01

The racemic oxovanadium(IV) salmmen complexes, [VO((rac)-(4-X-salmmen))] (X = C12C10C5 (1), C16 (2), and C18 (3); salmmen = N,N‧-monomethylenebis-salicylideneimine) with “banana shaped” molecular structures were synthesized, and their ferroelectric properties were investigated. These complexes exhibit well-defined hysteresis loops in their viscous phases, moreover, 1 also displays liquid crystal behaviour. We observed a synergetic effect influenced by three structural aspects; the methyl substituents on the ethylene backbone, the banana shaped structure and the square pyramidal metal cores all play an important role in generating the observed ferroelectricity, pointing the way to a useful strategy for the creation of advanced ferroelectric soft materials.

Design issues for optimum solar cell configuration

NASA Astrophysics Data System (ADS)

Kumar, Atul; Thakur, Ajay D.

2018-05-01

A computer based simulation of solar cell structure is performed to study the optimization of pn junction configuration for photovoltaic action. The fundamental aspects of photovoltaic action viz, absorption, separation collection, and their dependence on material properties and deatails of device structures is discussed. Using SCAPS 1D we have simulated the ideal pn junction and shown the effect of band offset and carrier densities on solar cell performance. The optimum configuration can be achieved by optimizing transport of carriers in pn junction under effect of field dependent recombination (tunneling) and density dependent recombination (SRH, Auger) mechanisms.

Machine & electrical double control air dryer for vehicle air braking system

NASA Astrophysics Data System (ADS)

Zhang, Xuan; Yang, Liu; Wang, Xian Yan; Tan, Xiao Yan; Wang, Wei

2017-09-01

As is known to all, a vehicle air brake system, in which usually contains moisture. To solve the problem, it is common to use air dryer to dry compressed air effectively and completely remove the moisture and oil of braking system. However, the existing air dryer is not suitable for all commercial vehicles. According to the operational status of the new energy vehicles in the initial operating period, the structure design principle of the machine & electric control air dryer is expounded from the aspects of the structure and operating principle, research & development process.

Synthesizing information-update functions using off-line symbolic processing

NASA Technical Reports Server (NTRS)

Rosenschein, Stanley J.

1990-01-01

This paper explores the synthesis of programs that track dynamic conditions in their environment. An approach is proposed in which the designer specifies, in a declarative language, aspects of the environment in which the program will be embedded. This specification is then automatically compiled into a program that, when executed, updates internal data structures so as to maintain as an invariant a desired correspondence between internal data structures and states of the external environment. This approach retains much of the flexibility of declarative programming while guaranteeing a hard bound on the execution time of information-update functions.

Nonlinear Large Deflection Theory with Modified Aeroelastic Lifting Line Aerodynamics for a High Aspect Ratio Flexible Wing

NASA Technical Reports Server (NTRS)

Nguyen, Nhan; Ting, Eric; Chaparro, Daniel

2017-01-01

This paper investigates the effect of nonlinear large deflection bending on the aerodynamic performance of a high aspect ratio flexible wing. A set of nonlinear static aeroelastic equations are derived for the large bending deflection of a high aspect ratio wing structure. An analysis is conducted to compare the nonlinear bending theory with the linear bending theory. The results show that the nonlinear bending theory is length-preserving whereas the linear bending theory causes a non-physical effect of lengthening the wing structure under the no axial load condition. A modified lifting line theory is developed to compute the lift and drag coefficients of a wing structure undergoing a large bending deflection. The lift and drag coefficients are more accurately estimated by the nonlinear bending theory due to its length-preserving property. The nonlinear bending theory yields lower lift and span efficiency than the linear bending theory. A coupled aerodynamic-nonlinear finite element model is developed to implement the nonlinear bending theory for a Common Research Model (CRM) flexible wing wind tunnel model to be tested in the University of Washington Aeronautical Laboratory (UWAL). The structural stiffness of the model is designed to give about 10% wing tip deflection which is large enough that could cause the nonlinear deflection effect to become significant. The computational results show that the nonlinear bending theory yields slightly less lift than the linear bending theory for this wind tunnel model. As a result, the linear bending theory is deemed adequate for the CRM wind tunnel model.

Design and overall performance of four highly loaded, high speed inlet stages for an advanced high-pressure-ratio core compressor

NASA Technical Reports Server (NTRS)

Reid, L.; Moore, R. D.

1978-01-01

The detailed design and overall performances of four inlet stages for an advanced core compressor are presented. These four stages represent two levels of design total pressure ratio (1.82 and 2.05), two levels of rotor aspect ratio (1.19 and 1.63), and two levels of stator aspect ratio (1.26 and 1.78). The individual stages were tested over the stable operating flow range at 70, 90, and 100 percent of design speeds. The performances of the low aspect ratio configurations were substantially better than those of the high aspect ratio configurations. The two low aspect ratio configurations achieved peak efficiencies of 0.876 and 0.872 and corresponding stage efficiencies of 0.845 and 0.840. The high aspect ratio configurations achieved peak ratio efficiencies of 0.851 and 0.849 and corresponding stage efficiencies of 0.821 and 0.831.

Sexual dimorphism in multiple aspects of 3D facial symmetry and asymmetry defined by spatially dense geometric morphometrics.

PubMed

Claes, Peter; Walters, Mark; Shriver, Mark D; Puts, David; Gibson, Greg; Clement, John; Baynam, Gareth; Verbeke, Geert; Vandermeulen, Dirk; Suetens, Paul

2012-08-01

Accurate measurement of facial sexual dimorphism is useful to understanding facial anatomy and specifically how faces influence, and have been influenced by, sexual selection. An important facial aspect is the display of bilateral symmetry, invoking the need to investigate aspects of symmetry and asymmetry separately when examining facial shape. Previous studies typically employed landmarks that provided only a sparse facial representation, where different landmark choices could lead to contrasting outcomes. Furthermore, sexual dimorphism is only tested as a difference of sample means, which is statistically the same as a difference in population location only. Within the framework of geometric morphometrics, we partition facial shape, represented in a spatially dense way, into patterns of symmetry and asymmetry, following a two-factor anova design. Subsequently, we investigate sexual dimorphism in symmetry and asymmetry patterns separately, and on multiple aspects, by examining (i) population location differences as well as differences in population variance-covariance; (ii) scale; and (iii) orientation. One important challenge in this approach is the proportionally high number of variables to observations necessitating the implementation of permutational and computationally feasible statistics. In a sample of gender-matched young adults (18-25 years) with self-reported European ancestry, we found greater variation in male faces than in women for all measurements. Statistically significant sexual dimorphism was found for the aspect of location in both symmetry and asymmetry (directional asymmetry), for the aspect of scale only in asymmetry (magnitude of fluctuating asymmetry) and, in contrast, for the aspect of orientation only in symmetry. Interesting interplays with hypotheses in evolutionary and developmental biology were observed, such as the selective nature of the force underpinning sexual dimorphism and the genetic independence of the structural patterns of fluctuating asymmetry. Additionally, insights into growth patterns of the soft tissue envelope of the face and underlying skull structure can also be obtained from the results. © 2012 The Authors. Journal of Anatomy © 2012 Anatomical Society.

Sexual dimorphism in multiple aspects of 3D facial symmetry and asymmetry defined by spatially dense geometric morphometrics

PubMed Central

Claes, Peter; Walters, Mark; Shriver, Mark D; Puts, David; Gibson, Greg; Clement, John; Baynam, Gareth; Verbeke, Geert; Vandermeulen, Dirk; Suetens, Paul

2012-01-01

Accurate measurement of facial sexual dimorphism is useful to understanding facial anatomy and specifically how faces influence, and have been influenced by, sexual selection. An important facial aspect is the display of bilateral symmetry, invoking the need to investigate aspects of symmetry and asymmetry separately when examining facial shape. Previous studies typically employed landmarks that provided only a sparse facial representation, where different landmark choices could lead to contrasting outcomes. Furthermore, sexual dimorphism is only tested as a difference of sample means, which is statistically the same as a difference in population location only. Within the framework of geometric morphometrics, we partition facial shape, represented in a spatially dense way, into patterns of symmetry and asymmetry, following a two-factor anova design. Subsequently, we investigate sexual dimorphism in symmetry and asymmetry patterns separately, and on multiple aspects, by examining (i) population location differences as well as differences in population variance-covariance; (ii) scale; and (iii) orientation. One important challenge in this approach is the proportionally high number of variables to observations necessitating the implementation of permutational and computationally feasible statistics. In a sample of gender-matched young adults (18–25 years) with self-reported European ancestry, we found greater variation in male faces than in women for all measurements. Statistically significant sexual dimorphism was found for the aspect of location in both symmetry and asymmetry (directional asymmetry), for the aspect of scale only in asymmetry (magnitude of fluctuating asymmetry) and, in contrast, for the aspect of orientation only in symmetry. Interesting interplays with hypotheses in evolutionary and developmental biology were observed, such as the selective nature of the force underpinning sexual dimorphism and the genetic independence of the structural patterns of fluctuating asymmetry. Additionally, insights into growth patterns of the soft tissue envelope of the face and underlying skull structure can also be obtained from the results. PMID:22702244

Development of Methodologies for the Estimation of Thermal Properties Associated with Aerospace Vehicles

NASA Technical Reports Server (NTRS)

Scott, Elaine P.

1996-01-01

A thermal stress analysis is an important aspect in the design of aerospace structures and vehicles such as the High Speed Civil Transport (HSCT) at the National Aeronautics and Space Administration Langley Research Center (NASA-LaRC). These structures are complex and are often composed of numerous components fabricated from a variety of different materials. The thermal loads on these structures induce temperature variations within the structure, which in turn result in the development of thermal stresses. Therefore, a thermal stress analysis requires knowledge of the temperature distributions within the structures which consequently necessitates the need for accurate knowledge of the thermal properties, boundary conditions and thermal interface conditions associated with the structural materials. The goal of this proposed multi-year research effort was to develop estimation methodologies for the determination of the thermal properties and interface conditions associated with aerospace vehicles. Specific objectives focused on the development and implementation of optimal experimental design strategies and methodologies for the estimation of thermal properties associated with simple composite and honeycomb structures. The strategy used in this multi-year research effort was to first develop methodologies for relatively simple systems and then systematically modify these methodologies to analyze complex structures. This can be thought of as a building block approach. This strategy was intended to promote maximum usability of the resulting estimation procedure by NASA-LARC researchers through the design of in-house experimentation procedures and through the use of an existing general purpose finite element software.

Real World Evidence: A Quantitative and Qualitative Glance at Participant Feedback from a Free-Response Survey Investigating Experiences of a Structured Exercise Intervention for Men with Prostate Cancer

PubMed Central

Cahill, F.; Burgess, C.; Peat, N.; Rudman, S.; Kinsella, J.; Cahill, D.; George, G.; Santaolalla, A.; Van Hemelrijck, M.

2017-01-01

Aim To explore patient experiences of a structured exercise intervention for men with prostate cancer (PCa). Sample 41 men with either localised or advanced PCa who had been referred for a structured exercise programme by their physician and then subsequently consented to a telephone survey. Method Participants underwent a 10-week supervised exercise programme within a large cancer centre hospital consisting of 8 sessions. They then completed a short multiple choice telephone survey, elaborating on their responses where appropriate. Views expressed by participants were analysed using an affinity diagram and common themes were identified. Results Feedback from our telephone surveys was consistently positive and suggests that the structured exercise intervention provides exercise confidence, motivation to exercise, and social support and promotes positive health behaviour change in the context of exercise. Individual differences arose amongst participants in their perceived utility of the intervention, with 73.3% expressing a preference for structured exercise classes and 19.5% expressing a preference for exercising independently. Conclusion Design of a structured exercise intervention for patients with PCa should embrace the positive aspects outlined here but consider patients' individual differences. Ongoing feedback from patients should be utilised alongside traditional study designs to inform intervention design in this area. PMID:28758113

Imparting Barely Visible Impact Damage to a Stitched Composite Large-Scale Pressure Box

NASA Technical Reports Server (NTRS)

Lovejoy, Andrew E.; Przekop, Adam

2016-01-01

The Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) is a concept that was developed by The Boeing Company to address the complex structural design aspects associated with a pressurized hybrid wing body (HWB) aircraft configuration, which has been a focus of the NASA Environmentally Responsible Aviation Project. The NASA-Boeing structural development for the HWB aircraft culminated in testing of the multi-bay box, which is an 80%-scale representation of the pressurized center-body section. This structure was tested in the NASA Langley Research Center Combined Loads Test System facility. As part of this testing, barely visible impact damage was imparted to the interior and exterior of the test article to demonstrate compliance with a condition representative of the requirements for Category 1 damaged composite structure as defined by the Federal Aviation Regulations. Interior impacts were imparted using an existing spring-loaded impactor, while the exterior impacts were imparted using a newly designed, gravity-driven impactor. This paper describes the impacts to the test article, and the design of the gravitydriven guided-weight impactor. The guided-weight impactor proved to be a very reliable method to impart barely visible impact damage in locations which are not easily accessible for a traditional drop-weight impactor, while at the same time having the capability to be highly configurable for use on other aircraft structures.

On the design of high-rise buildings with a specified level of reliability

NASA Astrophysics Data System (ADS)

Dolganov, Andrey; Kagan, Pavel

2018-03-01

High-rise buildings have a specificity, which significantly distinguishes them from traditional buildings of high-rise and multi-storey buildings. Steel structures in high-rise buildings are advisable to be used in earthquake-proof regions, since steel, due to its plasticity, provides damping of the kinetic energy of seismic impacts. These aspects should be taken into account when choosing a structural scheme of a high-rise building and designing load-bearing structures. Currently, modern regulatory documents do not quantify the reliability of structures. Although the problem of assigning an optimal level of reliability has existed for a long time. The article shows the possibility of designing metal structures of high-rise buildings with specified reliability. Currently, modern regulatory documents do not quantify the reliability of high-rise buildings. Although the problem of assigning an optimal level of reliability has existed for a long time. It is proposed to establish the value of reliability 0.99865 (3σ) for constructions of buildings and structures of a normal level of responsibility in calculations for the first group of limiting states. For increased (construction of high-rise buildings) and reduced levels of responsibility for the provision of load-bearing capacity, it is proposed to assign respectively 0.99997 (4σ) and 0.97725 (2σ). The coefficients of the use of the cross section of a metal beam for different levels of security are given.

Engineering aspects of design and integration of ECE diagnostic in ITER

DOE PAGES

Udintsev, V. S.; Taylor, G.; Pandya, H. K.B.; ...

2015-03-12

ITER ECE diagnostic [1] needs not only to meet measurement requirements, but also to withstand various loads, such as electromagnetic, mechanical, neutronic and thermal, and to be protected from stray ECH radiation at 170 GHz and other millimeter wave emission, like Collective Thomson scattering which is planned to operate at 60 GHz. Same or similar loads will be applied to other millimetre-wave diagnostics [2], located both in-vessel and in-port plugs. These loads must be taken into account throughout the design phases of the ECE and other microwave diagnostics to ensure their structural integrity and maintainability. The integration of microwave diagnosticsmore » with other ITER systems is another challenging activity which is currently ongoing through port integration and in-vessel integration work. Port Integration has to address the maintenance and the safety aspects of diagnostics, too. Engineering solutions which are being developed to support and to operate ITER ECE diagnostic, whilst complying with safety and maintenance requirements, are discussed in this paper.« less

Putting a finishing touch on GECIs.

PubMed

Rose, Tobias; Goltstein, Pieter M; Portugues, Ruben; Griesbeck, Oliver

2014-01-01

More than a decade ago genetically encoded calcium indicators (GECIs) entered the stage as new promising tools to image calcium dynamics and neuronal activity in living tissues and designated cell types in vivo. From a variety of initial designs two have emerged as promising prototypes for further optimization: FRET (Förster Resonance Energy Transfer)-based sensors and single fluorophore sensors of the GCaMP family. Recent efforts in structural analysis, engineering and screening have broken important performance thresholds in the latest generation for both classes. While these improvements have made GECIs a powerful means to perform physiology in living animals, a number of other aspects of sensor function deserve attention. These aspects include indicator linearity, toxicity and slow response kinetics. Furthermore creating high performance sensors with optically more favorable emission in red or infrared wavelengths as well as new stably or conditionally GECI-expressing animal lines are on the wish list. When the remaining issues are solved, imaging of GECIs will finally have crossed the last milestone, evolving from an initial promise into a fully matured technology.

The thematic structure of passenger comfort experience and its relationship to the context features in the aircraft cabin.

PubMed

Ahmadpour, Naseem; Lindgaard, Gitte; Robert, Jean-Marc; Pownall, Bernard

2014-01-01

This paper describes passenger comfort as an experience generated by the cabin interior features. The findings of previous studies are affirmed regarding a set of 22 context features. Passengers experience a certain level of comfort when these features impact their body and elicit subjective perceptions. New findings characterise these perceptions in the form of eight themes and outline their particular eliciting features. Comfort is depicted as a complex construct derived by passengers' perceptions beyond the psychological (i.e. peace of mind) and physical (i.e. physical well-being) aspects, and includes perceptual (e.g. proxemics) and semantic (e.g. association) aspects. The seat was shown to have a focal role in eliciting seven of those themes and impacting comfort through its diverse characteristics. In a subsequent study, a group of aircraft cabin interior designers highlighted the possibility of employing the eight themes and their eliciting features as a framework for design and evaluation of new aircraft interiors.

Modelling sociocognitive aspects of students' learning

NASA Astrophysics Data System (ADS)

Koponen, I. T.; Kokkonen, T.; Nousiainen, M.

2017-03-01

We present a computational model of sociocognitive aspects of learning. The model takes into account a student's individual cognition and sociodynamics of learning. We describe cognitive aspects of learning as foraging for explanations in the epistemic landscape, the structure (set by instructional design) of which guides the cognitive development through success or failure in foraging. We describe sociodynamic aspects as an agent-based model, where agents (learners) compare and adjust their conceptions of their own proficiency (self-proficiency) and that of their peers (peer-proficiency) in using explanatory schemes of different levels. We apply the model here in a case involving a three-tiered system of explanatory schemes, which can serve as a generic description of some well-known cases studied in empirical research on learning. The cognitive dynamics lead to the formation of dynamically robust outcomes of learning, seen as a strong preference for a certain explanatory schemes. The effects of social learning, however, can account for half of one's success in adopting higher-level schemes and greater proficiency. The model also predicts a correlation of dynamically emergent interaction patterns between agents and the learning outcomes.

Concept Mapping Assessment of Media Assisted Learning in Interdisciplinary Science Education

NASA Astrophysics Data System (ADS)

Schaal, Steffen; Bogner, Franz X.; Girwidz, Raimund

2010-05-01

Acquisition of conceptual knowledge is a central aim in science education. In this study we monitored an interdisciplinary hypermedia assisted learning unit on hibernation and thermodynamics based on cooperative learning. We used concept mapping for the assessment, applying a pre-test/post-test design. In our study, 106 9th graders cooperated by working in pairs ( n = 53) for six lessons. As an interdisciplinary learning activity in such complex knowledge domains has to combine many different aspects, we focused on long-term knowledge. Learners working cooperatively in dyads constructed computer-supported concept maps which were analysed by specific software. The data analysis encompassed structural aspects of the knowledge corresponding to a target reference map. After the learning unit, the results showed the acquisition of higher-order domain-specific knowledge structures which indicates successful interdisciplinary learning through the hypermedia learning environment. The benefit of using a computer-assisted concept mapping assessment for research in science education, and in science classrooms is considered.

Mechanistics and photo-energetics of macrocycles and photodynamic therapy: An overview of aspects to consider for research.

PubMed

Horne, Tamarisk K; Cronjé, Marianne J

2017-02-01

Research within the field of photodynamic therapy has escalated over the past 20 years. The required conjunctional use of photosensitizers, particularly of the macrocycle structure, has lead to a vast repertoire of derivatives that branch classes and subclasses thereof. Each exhibits a differential range of physiochemical properties that influence their potential applications within the larger phototherapy field for use in either diagnostics, photodynamic therapy, both or none. Herein, we provide an overview of these properties as they relate to photodynamic therapy and to a lesser extent diagnostics. By summarizing the mechanistics of photodynamic therapy coupled to the photo-energetics displayed by macrocycle photosensitizers, we aimed to highlight the critical aspects any researcher should be aware of and consider when selecting and performing research for therapeutic application purposes. These include photosensitizer, photophysical and structural properties, synthesis design and subsequent attributes, main applications within research, common shortcomings exhibited and the current methods practiced to overcome them. © 2017 John Wiley & Sons A/S.

Factor Structure of the Escala de Autoeficacia para la Depresión en Adolescentes (EADA)

PubMed Central

Díaz-Santos, Mirella; Cumba-Avilés, Eduardo; Bernal, Guillermo; Rivera-Medina, Carmen

2018-01-01

The current concept and measures of self-efficacy for depression in adolescents do not consider developmental and cultural aspects essential to understand and assess this construct in Latino youth. We examined the factor structure of the Escala de Autoeficacia para la Depresión en Adolescentes (EADA): a Spanish instrument designed to assess this construct as experienced by this population. Participants were 116 Puerto Rican adolescents aged 13 to 17 years who completed the EADA and two other self-report measures. An exploratory factor analysis yielded a two-factor solution (Personal Self-Efficacy for Depression and Interpersonal Self-Efficacy for Depression) accounting for 37.57% of the total variance. Results revealed that EADA factors have excellent internal consistency as well as concurrent and construct validity, supporting its adequacy to assess Latino adolescents’ self-efficacy for depression. The conceptual meaning of the factors was consistent with the distinction between aspects of this construct hypothesized to be important among Latino youth.

Early Impacts of a Human-in-the-Loop Evaluation in a Space Vehicle Mock-up Facility

NASA Technical Reports Server (NTRS)

Byrne, Vicky; Vos, Gordon; Whitmore, Mihriban

2008-01-01

The development of a new space vehicle, the Orion Crew Exploration Vehicle (CEV), provides Human Factors engineers an excellent opportunity to have an impact early in the design process. This case study highlights a Human-in-the-Loop (HITL) evaluation conducted in a Space Vehicle Mock-Up Facility and will describe the human-centered approach and how the findings are impacting design and operational concepts early in space vehicle design. The focus of this HITL evaluation centered on the activities that astronaut crewmembers would be expected to perform within the functional internal volume of the Crew Module (CM) of the space vehicle. The primary objective was to determine if there are aspects of a baseline vehicle configuration that would limit or prevent the performance of dynamically volume-driving activities (e.g. six crewmembers donning their suits in an evacuation scenario). A second objective was to step through concepts of operations for known systems and evaluate them in integrated scenarios. The functional volume for crewmember activities is closely tied to every aspect of system design (e.g. avionics, safety, stowage, seats, suits, and structural support placement). As this evaluation took place before the Preliminary Design Review of the space vehicle with some designs very early in the development, it was not meant to determine definitely that the crewmembers could complete every activity, but rather to provide inputs that could improve developing designs and concepts of operations definition refinement.

A service life extension (SLEP) approach to operating aging aircraft beyond their original design lives

NASA Astrophysics Data System (ADS)

Pentz, Alan Carter

With today's uncertain funding climate (including sequestration and continuing budget resolutions), decision makers face severe budgetary challenges to maintain dominance through all aspects of the Department of Defense (DoD). To meet war-fighting capabilities, the DoD continues to extend aircraft programs beyond their design service lives by up to ten years, and occasionally much more. The budget requires a new approach to traditional extension strategies (i.e., reuse, reset, and reclamation) for structural hardware. While extending service life without careful controls can present a safety concern, future operations planning does not consider how much risk is present when operating within sound structural principles. Traditional structural hardware extension methods drive increased costs. Decision makers often overlook the inherent damage tolerance and fatigue capability of structural components and rely on simple time- and flight-based cycle accumulation when determining aircraft retirement lives. This study demonstrates that decision makers should consider risk in addition to the current extension strategies. Through an evaluation of eight military aircraft programs and the application and simulation of F-18 turbine engine usage data, this dissertation shows that insight into actual aircraft mission data, consideration of fatigue capability, and service extension length are key factors to consider. Aircraft structural components, as well as many critical safety components and system designs, have a predefined level of conservatism and inherent damage tolerance. The methods applied in this study would apply to extensions of other critical structures such as bridges. Understanding how much damage tolerance is built into the design compared to the original design usage requirements presents the opportunity to manage systems based on risk. The study presents the sensitivity of these factors and recommends avenues for further research.

Revision of seismic design codes corresponding to building damages in the ``5.12'' Wenchuan earthquake

NASA Astrophysics Data System (ADS)

Wang, Yayong

2010-06-01

A large number of buildings were seriously damaged or collapsed in the “5.12” Wenchuan earthquake. Based on field surveys and studies of damage to different types of buildings, seismic design codes have been updated. This paper briefly summarizes some of the major revisions that have been incorporated into the “Standard for classification of seismic protection of building constructions GB50223-2008” and “Code for Seismic Design of Buildings GB50011-2001.” The definition of seismic fortification class for buildings has been revisited, and as a result, the seismic classifications for schools, hospitals and other buildings that hold large populations such as evacuation shelters and information centers have been upgraded in the GB50223-2008 Code. The main aspects of the revised GB50011-2001 code include: (a) modification of the seismic intensity specified for the Provinces of Sichuan, Shanxi and Gansu; (b) basic conceptual design for retaining walls and building foundations in mountainous areas; (c) regularity of building configuration; (d) integration of masonry structures and pre-cast RC floors; (e) requirements for calculating and detailing stair shafts; and (f) limiting the use of single-bay RC frame structures. Some significant examples of damage in the epicenter areas are provided as a reference in the discussion on the consequences of collapse, the importance of duplicate structural systems, and the integration of RC and masonry structures.

The Blue Emu

NASA Technical Reports Server (NTRS)

Descalzi, Doug; Gillett, John; Gordon, Carlton; Keener, ED; Novak, Ken; Puente, Laura

1993-01-01

The primary goal in designing the Blue Emu was to provide an airline with a cost efficient and profitable means of transporting passengers between the major cities in Aeroworld. The design attacks the market where a demand for inexpensive transportation exists and for this reason the Blue Emu is an attractive investment for any airline. In order to provide a profitable aircraft, special attention was paid to cost and economics. For example, in manufacturing, simplicity was stressed in structural design to reduce construction time and cost. Aerodynamic design employed a tapered wing which reduced the induced drag coefficient while also reducing the weight of the wing. Even the propulsion system was selected with cost effectiveness in mind, yet also to maintain the marketability of the aircraft. Thus, in every aspect of the design, consideration was given to economics and marketability of the final product.

Guy cable design and damping for vertical axis wind turbines

NASA Technical Reports Server (NTRS)

Carne, T. G.

1981-01-01

Guy cables are frequently used to support vertical axis wind turbines since guying the turbine reduces some of the structural requirements on the tower. The guys must be designed to provide both the required strength and the required stiffness at the top of the turbine. The axial load which the guys apply to the tower, bearings, and foundations is an undesirable consequence of using guys to support the turbine. Limiting the axial load so that it does not significantly affect the cost of the turbine is an important objective of the cable design. The lateral vibrations of the cables is another feature of the cable design which needs to be considered. These aspects of the cable design are discussed, and a technique for damping cable vibrations was mathematically analyzed and demonstrated with experimental data.

Design of a colicin E7 based chimeric zinc-finger nuclease

NASA Astrophysics Data System (ADS)

Németh, Eszter; Schilli, Gabriella K.; Nagy, Gábor; Hasenhindl, Christoph; Gyurcsik, Béla; Oostenbrink, Chris

2014-08-01

Colicin E7 is a natural bacterial toxin. Its nuclease domain (NColE7) enters the target cell and kills it by digesting the nucleic acids. The HNH-motif as the catalytic centre of NColE7 at the C-terminus requires the positively charged N-terminal loop for the nuclease activity—offering opportunities for allosteric control in a NColE7-based artificial nuclease. Accordingly, four novel zinc finger nucleases were designed by computational methods exploiting the special structural features of NColE7. The constructed models were subjected to MD simulations. The comparison of structural stability and functional aspects showed that these models may function as safely controlled artificial nucleases. This study was complemented by random mutagenesis experiments identifying potentially important residues for NColE7 function outside the catalytic region.

[Kidney patients: aspects related to compliance with renal treatment].

PubMed

Caraballo Nazario, G L; Lebrón de avilés, C; Dávila Torres, R R; Burgos Calderón, R

2001-12-01

The Objective of this study was identify the aspects related with the adherence of medical treatment recommended to the patients that received hemodialysis in the tertiary public hospital. A non experimental transectional correlation design was utilized in this study. Fifty-three patients constituted the population study. A structure interview was utilized to gathered the data. Descriptive statistics and Chi-square tests were utilized to analysis. The response rate was 91.0%. The 75.0% of patients not compliance with the medical treatment. Significant association between compliance variable and educational level was encountered (p < or = 0.05). This study provides important findings to will develops educative intervention in the Renal Unit, directed to improve the adherence of the patient with medical treatment.

The Professional Development of High School Chemistry Coordinators

NASA Astrophysics Data System (ADS)

Hofstein, Avi; Carmeli, Miriam; Shore, Relly

2004-02-01

The implementation of new content and pedagogical standards in science education necessitates intensive, long-term professional development of science teachers. In this paper, we describe the rationale and structure of a comprehensive and intensive professional development program of school-based leaders, namely school chemistry coordinators. The year-long program was designed so that the chemistry teachers who enrolled in the program were able to develop in three interrelated aspects: content knowledge, pedagogical content knowledge, and leadership ability. Several strategies for the development of these aspects were adopted from Loucks-Horsley, Hewson, Love, & Stiles (1998). The evaluation of the program focused on the changes that participating teachers underwent regarding their personal beliefs and their functioning as school chemistry coordinators in their schools.

Knowledge-Based Manufacturing and Structural Design for a High Speed Civil Transport

NASA Technical Reports Server (NTRS)

Marx, William J.; Mavris, Dimitri N.; Schrage, Daniel P.

1994-01-01

The aerospace industry is currently addressing the problem of integrating manufacturing and design. To address the difficulties associated with using many conventional procedural techniques and algorithms, one feasible way to integrate the two concepts is with the development of an appropriate Knowledge-Based System (KBS). The authors present their reasons for selecting a KBS to integrate design and manufacturing. A methodology for an aircraft producibility assessment is proposed, utilizing a KBS for manufacturing process selection, that addresses both procedural and heuristic aspects of designing and manufacturing of a High Speed Civil Transport (HSCT) wing. A cost model is discussed that would allow system level trades utilizing information describing the material characteristics as well as the manufacturing process selections. Statements of future work conclude the paper.

Design Rules for Tailoring Antireflection Properties of Hierarchical Optical Structures

DOE PAGES

Leon, Juan J. Diaz; Hiszpanski, Anna M.; Bond, Tiziana C.; ...

2017-05-18

Hierarchical structures consisting of small sub-wavelength features stacked atop larger structures have been demonstrated as an effective means of reducing the reflectance of surfaces. However, optical devices require different antireflective properties depending on the application, and general unifying guidelines on hierarchical structures' design to attain a desired antireflection spectral response are still lacking. The type of reflectivity (diffuse, specular, or total/hemispherical) and its angular- and spectral-dependence are all dictated by the structural parameters. Through computational and experimental studies, guidelines have been devised to modify these various aspects of reflectivity across the solar spectrum by proper selection of the features ofmore » hierarchical structures. In this wavelength regime, micrometer-scale substructures dictate the long-wavelength spectral response and effectively reduce specular reflectance, whereas nanometer-scale substructures dictate primarily the visible wavelength spectral response and reduce diffuse reflectance. Coupling structures having these two length scales into hierarchical arrays impressively reduces surfaces' hemispherical reflectance across a broad spectrum of wavelengths and angles. Furthermore, such hierarchical structures in silicon are demonstrated having an average total reflectance across the solar spectrum of 1.1% (average weighted reflectance of 1% in the 280–2500 nm range of the AM 1.5 G spectrum) and specular reflectance <1% even at angles of incidence as high as 67°.« less

Clinical reasoning in neurology: use of the repertory grid technique to investigate the reasoning of an experienced occupational therapist.

PubMed

Kuipers, Kathy; Grice, James W

2009-08-01

The aim of this paper is to describe the use of a structured interview methodology, the repertory grid technique, for investigating the clinical reasoning of an experienced occupational therapist in the domain of upper limb hypertonia as a result of brain injury. Repertory grid interviews were completed before and after exposure to a protocol designed to guide clinical reasoning and decision-making in relation to upper limb neurological rehabilitation. Data were subjected to both qualitative and quantitative analyses. Qualitative analysis focussed on clinical reasoning content. Common themes across the pre- and post-exposure interviews were the use of theoretical frameworks and practice models, the significance of clinical expertise, and discrimination of 'broad' and 'specific' aspects, as well as differentiation between 'therapist and client-related' aspects of the clinical situation. Quantitative analysis indicated that for both pre- and post-exposure repertory grids, clinical reasoning was structured in terms of two main concepts. In the pre-exposure grid, these were related to the therapist's role, and to the 'scope' of practice tasks (either broad or specific). In the post-exposure grid the two main concepts were upper limb performance, and client-centred aspects of the therapy process. The repertory grid technique is proposed as an effective tool for exploring occupational therapy clinical reasoning, based on its capacity for accessing personal frames of reference, and elucidating both the meaning and the structure supporting clinical reasoning.

Performance of Integrated Fiber Optic, Piezoelectric, and Shape Memory Alloy Actuators/Sensors in Thermoset Composites

NASA Technical Reports Server (NTRS)

Trottier, C. Michael

1996-01-01

Recently, scientists and engineers have investigated the advantages of smart materials and structures by including actuators in material systems for controlling and altering the response of structural environments. Applications of these materials systems include vibration suppression/isolation, precision positioning, damage detection and tunable devices. Some of the embedded materials being investigated for accomplishing these tasks include piezoelectric ceramics, shape memory alloys, and fiber optics. These materials have some benefits and some shortcomings; each is being studied for use in active material design in the SPICES (Synthesis and Processing of Intelligent Cost Effective Structures) Consortium. The focus of this paper concerns the manufacturing aspects of smart structures by incorporating piezoelectric ceramics, shape memory alloys and fiber optics in a reinforced thermoset matrix via resin transfer molding (RTM).

Structural analysis of behavioral networks from the Internet

NASA Astrophysics Data System (ADS)

Meiss, M. R.; Menczer, F.; Vespignani, A.

2008-06-01

In spite of the Internet's phenomenal growth and social impact, many aspects of the collective communication behavior of its users are largely unknown. Understanding the structure and dynamics of the behavioral networks that connect users with each other and with services across the Internet is key to modeling the network and designing future applications. We present a characterization of the properties of the behavioral networks generated by several million users of the Abilene (Internet2) network. Structural features of these networks offer new insights into scaling properties of network activity and ways of distinguishing particular patterns of traffic. For example, we find that the structure of the behavioral network associated with Web activity is characterized by such extreme heterogeneity as to challenge any simple attempt to model Web server traffic.

Modeling Real-Time Applications with Reusable Design Patterns

NASA Astrophysics Data System (ADS)

Rekhis, Saoussen; Bouassida, Nadia; Bouaziz, Rafik

Real-Time (RT) applications, which manipulate important volumes of data, need to be managed with RT databases that deal with time-constrained data and time-constrained transactions. In spite of their numerous advantages, RT databases development remains a complex task, since developers must study many design issues related to the RT domain. In this paper, we tackle this problem by proposing RT design patterns that allow the modeling of structural and behavioral aspects of RT databases. We show how RT design patterns can provide design assistance through architecture reuse of reoccurring design problems. In addition, we present an UML profile that represents patterns and facilitates further their reuse. This profile proposes, on one hand, UML extensions allowing to model the variability of patterns in the RT context and, on another hand, extensions inspired from the MARTE (Modeling and Analysis of Real-Time Embedded systems) profile.

Nonlinear Control of a Reusable Rocket Engine for Life Extension

NASA Technical Reports Server (NTRS)

Lorenzo, Carl F.; Holmes, Michael S.; Ray, Asok

1998-01-01

This paper presents the conceptual development of a life-extending control system where the objective is to achieve high performance and structural durability of the plant. A life-extending controller is designed for a reusable rocket engine via damage mitigation in both the fuel (H2) and oxidizer (O2) turbines while achieving high performance for transient responses of the combustion chamber pressure and the O2/H2 mixture ratio. The design procedure makes use of a combination of linear and nonlinear controller synthesis techniques and also allows adaptation of the life-extending controller module to augment a conventional performance controller of the rocket engine. The nonlinear aspect of the design is achieved using non-linear parameter optimization of a prescribed control structure. Fatigue damage in fuel and oxidizer turbine blades is primarily caused by stress cycling during start-up, shutdown, and transient operations of a rocket engine. Fatigue damage in the turbine blades is one of the most serious causes for engine failure.

Bio-Optics and Bio-Inspired Optical Materials.

PubMed

Tadepalli, Sirimuvva; Slocik, Joseph M; Gupta, Maneesh K; Naik, Rajesh R; Singamaneni, Srikanth

2017-10-25

Through the use of the limited materials palette, optimally designed micro- and nanostructures, and tightly regulated processes, nature demonstrates exquisite control of light-matter interactions at various length scales. In fact, control of light-matter interactions is an important element in the evolutionary arms race and has led to highly engineered optical materials and systems. In this review, we present a detailed summary of various optical effects found in nature with a particular emphasis on the materials and optical design aspects responsible for their optical functionality. Using several representative examples, we discuss various optical phenomena, including absorption and transparency, diffraction, interference, reflection and antireflection, scattering, light harvesting, wave guiding and lensing, camouflage, and bioluminescence, that are responsible for the unique optical properties of materials and structures found in nature and biology. Great strides in understanding the design principles adapted by nature have led to a tremendous progress in realizing biomimetic and bioinspired optical materials and photonic devices. We discuss the various micro- and nanofabrication techniques that have been employed for realizing advanced biomimetic optical structures.

The multi-copy simultaneous search methodology: a fundamental tool for structure-based drug design.

PubMed

Schubert, Christian R; Stultz, Collin M

2009-08-01

Fragment-based ligand design approaches, such as the multi-copy simultaneous search (MCSS) methodology, have proven to be useful tools in the search for novel therapeutic compounds that bind pre-specified targets of known structure. MCSS offers a variety of advantages over more traditional high-throughput screening methods, and has been applied successfully to challenging targets. The methodology is quite general and can be used to construct functionality maps for proteins, DNA, and RNA. In this review, we describe the main aspects of the MCSS method and outline the general use of the methodology as a fundamental tool to guide the design of de novo lead compounds. We focus our discussion on the evaluation of MCSS results and the incorporation of protein flexibility into the methodology. In addition, we demonstrate on several specific examples how the information arising from the MCSS functionality maps has been successfully used to predict ligand binding to protein targets and RNA.

Supramolecular Chemistry of Selective Anion Recognition for Anions of Environmental Relevance

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

Bowman-James, Kristen

2004-12-01

This project have focuses on the basic chemical aspects of anion receptor design of functional pH independent systems, with the ultimate goal of targeting the selective binding of sulfate, as well as design of separations strategies for selective and efficient removal of targeted anions. Key findings include: (1) the first synthetic sulfate-selective anion-binding agents; (2) simple, structure-based methods for modifying the intrinsic anion selectivity of a given class of anion receptors; and (3) the first system capable of extracting sulfate anion from acidic, nitrate-containing aqueous media. Areas probed during the last funding period include: the design, synthesis, and physical andmore » structural characterization of receptors and investigation of anion and dual ion pair extraction using lipophilic amide receptors for anion binding. A new collaboration has been added to the project in addition to the one with Dr. Bruce Moyer at Oak Ridge National Laboratory, with Professor Jonathan Sessler at the University of Texas at Austin.« less

Thermal design of composite material high temperature attachments

NASA Technical Reports Server (NTRS)

1972-01-01

An evaluation has been made of the thermal aspects of utilizing advanced filamentary composite materials as primary structures on the shuttle vehicle. The technical objectives of this study are to: (1) establish and design concepts for maintaining material temperatures within allowable limits at TPS attachments and or penetrations applicable to the space shuttle; and (2) verify the thermal design analysis by testing selected concepts. Specific composite materials being evaluated are boron epoxy, graphite/epoxy, boron polyimide, and boron aluminum; graphite/polyimide has been added to this list for property data identification and preliminary evaluation of thermal design problems. The TPS standoff to composite structure attachment over-temperature problem is directly related to TPS maximum surface temperature. To provide a thermally comprehensive evaluation of attachment temperature characteristics, maximum surface temperatures of 900 F, 1200 F, 1800 F, 2500 F and 3000 F are considered in this study. This range of surface temperatures and the high and low maximum temperature capability of the selected composite materials will result in a wide range of thermal requirements for composite/TPS standoff attachments.

[Clinical research. XIII. Research design contribution in the structured revision of an article].

PubMed

Talavera, Juan O; Rivas-Ruiz, Rodolfo

2013-01-01

The quality of information obtained in accordance to research design is integrated to the revision structured in relation to the causality model, used in the article "Reduction in the Incidence of Nosocomial Pneumonia Poststroke by Using the 'Turn-mob' Program", which corresponds to a clinical trial design. Points to identify and analyze are ethical issues in order to safeguard the security and respect for patients, randomization that seek to create basal homogeneous groups, subjects with the same probability of receiving any of the maneuvers in comparison, with the same pre maneuver probability of adherence, and which facilitate the blinding of outcome measurement and the distribution between groups of subjects with the same probability of leaving the study for reasons beyond the maneuvers. Other aspects are the relativity of comparison, the blinding of the maneuver, the parallel application of comparative maneuver, early stopping, and analysis according to the degree of adherence. The analysis in accordance with the design is complementary, since it is done based on the architectural model of causality, and the statistical and clinical relevance consideration.

A tracked robot with novel bio-inspired passive "legs".

PubMed

Sun, Bo; Jing, Xingjian

2017-01-01

For track-based robots, an important aspect is the suppression design, which determines the trafficability and comfort of the whole system. The trafficability limits the robot's working capability, and the riding comfort limits the robot's working effectiveness, especially with some sensitive instruments mounted on or operated. To these aims, a track-based robot equipped with a novel passive bio-inspired suspension is designed and studied systematically in this paper. Animal or insects have very special leg or limb structures which are good for motion control and adaptable to different environments. Inspired by this, a new track-based robot is designed with novel "legs" for connecting the loading wheels to the robot body. Each leg is designed with passive structures and can achieve very high loading capacity but low dynamic stiffness such that the robot can move on rough ground similar to a multi-leg animal or insect. Therefore, the trafficability and riding comfort can be significantly improved without losing loading capacity. The new track-based robot can be well applied to various engineering tasks for providing a stable moving platform of high mobility, better trafficability and excellent loading capacity.

Decentralized regulation of dynamic systems. [for controlling large scale linear systems

NASA Technical Reports Server (NTRS)

Chu, K. C.

1975-01-01

A special class of decentralized control problem is discussed in which the objectives of the control agents are to steer the state of the system to desired levels. Each agent is concerned about certain aspects of the state of the entire system. The state and control equations are given for linear time-invariant systems. Stability and coordination, and the optimization of decentralized control are analyzed, and the information structure design is presented.

Aircraft energy efficiency. Overview

NASA Technical Reports Server (NTRS)

1981-01-01

Six advanced technology development projects that could cut fuel consumption of future civil air transports by as much as 50 percent are highlighted. These include improved engine components; better engine design; thin short blades for turboprop aircaft; using composite primary structures for weight reduction; the use of supercritical wings, higher aspect ratio, and winglets for improved aerodynamics; active controls; and laminar flow control. The time span of each of the six efforts and NASA's expected expenditures are also discussed.

Metropolitan Washington Area Water Supply Study. Appendix G. Non-Structural Studies.

DTIC Science & Technology

1983-09-01

should minimize any impacts to the surrounding areas. The effects of land application systems on the socio -economic aspects of a community include... conflict this outfall might create with respect to the Washington Aqueduct Emergency Estuary Pumping Station. The operation of this intake, designed for...PB 214 970). " Socio -Economic Impact Study of Alternative Water Supply Systems," Annex D, Volume II, Washington Metropolitan Area Water Supply Study

Fiber optic shape sensing for monitoring of flexible structures

NASA Astrophysics Data System (ADS)

Lally, Evan M.; Reaves, Matt; Horrell, Emily; Klute, Sandra; Froggatt, Mark E.

2012-04-01

Recent advances in materials science have resulted in a proliferation of flexible structures for high-performance civil, mechanical, and aerospace applications. Large aspect-ratio aircraft wings, composite wind turbine blades, and suspension bridges are all designed to meet critical performance targets while adapting to dynamic loading conditions. By monitoring the distributed shape of a flexible component, fiber optic shape sensing technology has the potential to provide valuable data during design, testing, and operation of these smart structures. This work presents a demonstration of such an extended-range fiber optic shape sensing technology. Three-dimensional distributed shape and position sensing is demonstrated over a 30m length using a monolithic silica fiber with multiple optical cores. A novel, helicallywound geometry endows the fiber with the capability to convert distributed strain measurements, made using Optical Frequency-Domain Reflectometry (OFDR), to a measurement of curvature, twist, and 3D shape along its entire length. Laboratory testing of the extended-range shape sensing technology shows

NASA advanced aeronautics design solar powered remotely piloted vehicle

NASA Technical Reports Server (NTRS)

Elario, David S.; Guillmette, Neal H.; Lind, Gregory S.; Webster, Jonathan D.; Ferreira, Michael J.; Konstantakis, George C.; Marshall, David L.; Windt, Cari L.

1991-01-01

Environmental problems such as the depletion of the ozone layer and air pollution demand a change in traditional means of propulsion that is sensitive to the ecology. Solar powered propulsion is a favorable alternative that is both ecologically harmless as well as cost effective. Integration of solar energy into designs ranging from futuristic vehicles to heating is beneficial to society. The design and construction of a Multi-Purpose Remotely Piloted Vehicle (MPRPV) seeks to verify the feasibility of utilizing solar propulsion as a primary fuel source. This task has been a year long effort by a group of ten students, divided into five teams, each dealing with different aspects of the design. The aircraft was designed to take-off, climb to the design altitude, fly in a sustained figure-eight flight path, and cruise for approximately one hour. This mission requires flight at Reynolds numbers between 150,000 and 200,000 and demands special considerations in the aerodynamic design in order to achieve flight in this regime. Optimal performance requires a light weight configuration with both structural integrity and maximum power availability. The structure design and choice of solar cells for the propulsion was governed by the weight, efficiency, and cost considerations. The final design is a MPRPV weighting 35 N which cruises 7 m/s at the design altitude of 50 m. The configuration includes a wing composed of balsa and foam NACA 6409 airfoil sections and carbon fiber spars, a tail of similar construction, and a truss structure fuselage. The propulsion system consists of 98 10 percent efficient solar cells donated by Mobil Solar, a NiCad battery for energy storage, and a folding propeller regulated by a lightweight and efficient control system. The airfoils and propeller chosen for the design were research and tested during the design process.

Mapping of ligand-binding cavities in proteins.

PubMed

Andersson, C David; Chen, Brian Y; Linusson, Anna

2010-05-01

The complex interactions between proteins and small organic molecules (ligands) are intensively studied because they play key roles in biological processes and drug activities. Here, we present a novel approach to characterize and map the ligand-binding cavities of proteins without direct geometric comparison of structures, based on Principal Component Analysis of cavity properties (related mainly to size, polarity, and charge). This approach can provide valuable information on the similarities and dissimilarities, of binding cavities due to mutations, between-species differences and flexibility upon ligand-binding. The presented results show that information on ligand-binding cavity variations can complement information on protein similarity obtained from sequence comparisons. The predictive aspect of the method is exemplified by successful predictions of serine proteases that were not included in the model construction. The presented strategy to compare ligand-binding cavities of related and unrelated proteins has many potential applications within protein and medicinal chemistry, for example in the characterization and mapping of "orphan structures", selection of protein structures for docking studies in structure-based design, and identification of proteins for selectivity screens in drug design programs. 2009 Wiley-Liss, Inc.

Mobility balance in the light-emitting layer governs the polaron accumulation and operational stability of organic light-emitting diodes

NASA Astrophysics Data System (ADS)

Kim, Jae-Min; Lee, Chang-Heon; Kim, Jang-Joo

2017-11-01

Organic light-emitting diode (OLED) displays are lighter and more flexible, have a wider color gamut, and consume less power than conventional displays. Stable materials and the structural design of the device are important for OLED longevity. Control of charge transport and accumulation in the device is particularly important because the interaction of excitons and polarons results in material degradation. This research investigated the charge dynamics of OLEDs experimentally and by drift-diffusion modeling. Parallel capacitance-voltage measurements of devices provided knowledge of charge behavior at different driving voltages. A comparison of exciplex-forming co-host and single host structures established that the mobility balance in the emitting layers determined the amount of accumulated polarons in those layers. Consequently, an exciplex-forming co-host provides a superior structure in terms of device lifetime and efficiency because of its well-balanced mobility. Minimizing polaron accumulation is key to achieving long OLED device lifetimes. This is a crucial aspect of device physics that must be considered in the device design structure.

Liquid rocket engine nozzles

NASA Technical Reports Server (NTRS)

1976-01-01

The nozzle is a major component of a rocket engine, having a significant influence on the overall engine performance and representing a large fraction of the engine structure. The design of the nozzle consists of solving simultaneously two different problems: the definition of the shape of the wall that forms the expansion surface, and the delineation of the nozzle structure and hydraulic system. This monography addresses both of these problems. The shape of the wall is considered from immediately upstream of the throat to the nozzle exit for both bell and annular (or plug) nozzles. Important aspects of the methods used to generate nozzle wall shapes are covered for maximum-performance shapes and for nozzle contours based on criteria other than performance. The discussion of structure and hydraulics covers problem areas of regeneratively cooled tube-wall nozzles and extensions; it treats also nozzle extensions cooled by turbine exhaust gas, ablation-cooled extensions, and radiation-cooled extensions. The techniques that best enable the designer to develop the nozzle structure with as little difficulty as possible and at the lowest cost consistent with minimum weight and specified performance are described.

Methodology to Support Dynamic Function Allocation Policies Between Humans and Flight Deck Automation

NASA Technical Reports Server (NTRS)

Johnson, Eric N.

2012-01-01

Function allocation assigns work functions to all agents in a team, both human and automation. Efforts to guide function allocation systematically have been studied in many fields such as engineering, human factors, team and organization design, management science, cognitive systems engineering. Each field focuses on certain aspects of function allocation, but not all; thus, an independent discussion of each does not address all necessary aspects of function allocation. Four distinctive perspectives have emerged from this comprehensive review of literature on those fields: the technology-centered, human-centered, team-oriented, and work-oriented perspectives. Each perspective focuses on different aspects of function allocation: capabilities and characteristics of agents (automation or human), structure and strategy of a team, and work structure and environment. This report offers eight issues with function allocation that can be used to assess the extent to which each of issues exist on a given function allocation. A modeling framework using formal models and simulation was developed to model work as described by the environment, agents, their inherent dynamics, and relationships among them. Finally, to validate the framework and metrics, a case study modeled four different function allocations between a pilot and flight deck automation during the arrival and approach phases of flight.

Investigating Recombination and Charge Carrier Dynamics in a One-Dimensional Nanopillared Perovskite Absorber.

PubMed

Kwon, Hyeok-Chan; Yang, Wooseok; Lee, Daehee; Ahn, Jihoon; Lee, Eunsong; Ma, Sunihl; Kim, Kyungmi; Yun, Seong-Cheol; Moon, Jooho

2018-05-22

Organometal halide perovskite materials have become an exciting research topic as manifested by intense development of thin film solar cells. Although high-performance solar-cell-based planar and mesoscopic configurations have been reported, one-dimensional (1-D) nanostructured perovskite solar cells are rarely investigated despite their expected promising optoelectrical properties, such as enhanced charge transport/extraction. Herein, we have analyzed the 1-D nanostructure effects of organometal halide perovskite (CH 3 NH 3 PbI 3- x Cl x ) on recombination and charge carrier dynamics by utilizing a nanoporous anodized alumina oxide scaffold to fabricate a vertically aligned 1-D nanopillared array with controllable diameters. It was observed that the 1-D perovskite exhibits faster charge transport/extraction characteristics, lower defect density, and lower bulk resistance than the planar counterpart. As the aspect ratio increases in the 1-D structures, in addition, the charge transport/extraction rate is enhanced and the resistance further decreases. However, when the aspect ratio reaches 6.67 (diameter ∼30 nm), the recombination rate is aggravated due to high interface-to-volume ratio-induced defect generation. To obtain the full benefits of 1-D perovskite nanostructuring, our study provides a design rule to choose the appropriate aspect ratio of 1-D perovskite structures for improved photovoltaic and other optoelectrical applications.

Design, performance, and grounding aspects of the International Thermonuclear Experimental Reactor ion cyclotron range of frequencies antenna

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

Durodié, F., E-mail: frederic.durodie@rma.ac.be; Dumortier, P.; Vrancken, M.

2014-06-15

ITER's Ion Cyclotron Range of Frequencies (ICRF) system [Lamalle et al., Fusion Eng. Des. 88, 517–520 (2013)] comprises two antenna launchers designed by CYCLE (a consortium of European associations listed in the author affiliations above) on behalf of ITER Organisation (IO), each inserted as a Port Plug (PP) into one of ITER's Vacuum Vessel (VV) ports. Each launcher is an array of 4 toroidal by 6 poloidal RF current straps specified to couple up to 20 MW in total to the plasma in the frequency range of 40 to 55 MHz but limited to a maximum system voltage of 45 kV andmore » limits on RF electric fields depending on their location and direction with respect to, respectively, the torus vacuum and the toroidal magnetic field. A crucial aspect of coupling ICRF power to plasmas is the knowledge of the plasma density profiles in the Scrape-Off Layer (SOL) and the location of the RF current straps with respect to the SOL. The launcher layout and details were optimized and its performance estimated for a worst case SOL provided by the IO. The paper summarizes the estimated performance obtained within the operational parameter space specified by IO. Aspects of the RF grounding of the whole antenna PP to the VV port and the effect of the voids between the PP and the Blanket Shielding Modules (BSM) surrounding the antenna front are discussed. These blanket modules, whose dimensions are of the order of the ICRF wavelengths, together with the clearance gaps between them will constitute a corrugated structure which will interact with the electromagnetic waves launched by ICRF antennas. The conditions in which the grooves constituted by the clearance gaps between the blanket modules can become resonant are studied. Simple analytical models and numerical simulations show that mushroom type structures (with larger gaps at the back than at the front) can bring down the resonance frequencies, which could lead to large voltages in the gaps between the blanket modules and perturb the RF properties of the antenna if they are in the ICRF operating range. The effect on the wave propagation along the wall structure, which is acting as a spatially periodic (toroidally and poloidally) corrugated structure, and hence constitutes a slow wave structure modifying the wall boundary condition, is examined.« less

The inner formal structure of the H-T-P drawings: an exploratory study.

PubMed

Vass, Z

1998-08-01

The study describes some interrelated patterns of traits of the House-Tree-Person (H-T-P) drawings with the instruments of hierarchical cluster analysis. First, according to the literature 1 7 formal or structural aspects of the projective drawings were collected, after which a detailed manual for coding was compiled. Second, the interrater reliability and the consistency of this manual was tested. Third, the hierarchical cluster structure of the reliable and consistent formal aspects was analysed. Results are: (a) a psychometrically tested coding manual of the investigated formal-structural aspects, each of them illustrated with drawings that showed the highest interrater agreement; and (b) the hierarchic cluster structure of the formal aspects of the H-T-P drawings of "normal" adults.

Magnetic-field enhancement beyond the skin-depth limit

NASA Astrophysics Data System (ADS)

Shin, Jonghwa; Park, Namkyoo; Fan, Shanhui; Lee, Yong-Hee

2010-02-01

Electric field enhancement has been actively studied recently and many metallic structures that are capable of locally enhancing electric field have been reported. The Babinet's principle can be utilized, especially in the form of Booker's extension, to transform the known electric field enhancing structures into magnetic field enhancing structures. The authors explain this transformation process and discuss the regime in which this principle breaks down. Unless the metals used can be well approximated with a PEC model, the principle's predictions fails to hold true. Authors confirm this aspect using numerical simulations based on realistic material parameters for actual metals. There is large discrepancy especially when the structural dimensions are comparable or less than the skin-depth at the wavelength of interest. An alternative way to achieve magnetic field enhancement is presented and the design of a connected bow-tie structure is proposed as an example. FDTD simulation results confirm the operation of the proposed structure.

Micro-structure and motion of two-dimensional dense short spherocylinder liquids

NASA Astrophysics Data System (ADS)

Wang, Wen; Lin, Jyun-Ting; Su, Yen-Shuo; I, Lin

2018-03-01

We numerically investigate the micro-structure and motion of 2D liquids composed of dense short spherocylinders, by reducing the shape aspect ratio from 3. It is found that reducing shape aspect ratio from 3 causes a smooth transition from heterogeneous structures composed of crystalline ordered domains with good tetratic alignment order to those with good hexagonal bond-orientational order at an aspect ratio equaling 1.35. In the intermediate regime, both structural orders are strongly deteriorated, and the translational hopping rate reaches a maximum due to the poor particle interlocking of the disordered structure. Shortening rod length allows easier rotation, induces monotonic increase of rotational hopping rates, and resumes the separation of rotational and translational hopping time scales at the small aspect ratio end, after the crossover of their rates in the intermediate regime. At the large shape aspect ratio end, the poor local tetratic order has the same positive effects on facilitating local rotational and translational hopping. In contrast, at the small shape aspect ratio end, the poor local bond orientational order has the opposite effects on facilitating local rotational and translational hopping.

Optimal design of high-rise buildings with respect to fundamental eigenfrequency

NASA Astrophysics Data System (ADS)

Alavi, Arsalan; Rahgozar, Reza; Torkzadeh, Peyman; Hajabasi, Mohamad Ali

2017-12-01

In modern tall and slender structures, dynamic responses are usually the dominant design requirements, instead of strength criteria. Resonance is often a threatening phenomenon for such structures. To avoid this problem, the fundamental eigenfrequency, an eigenfrequency of higher order, should be maximized. An optimization problem with this objective is constructed in this paper and is applied to a high-rise building. Using variational method, the objective function is maximized, contributing to a particular profile for the first mode shape. Based on this preselected profile, a parametric formulation for flexural stiffness is calculated. Due to some near-zero values for stiffness, the obtained formulation will be modified by adding a lower bound constraint. To handle this constraint some new parameters are introduced; thereby allowing for construction of a model relating the unknown parameters. Based on this mathematical model, a design algorithmic procedure is presented. For the sake of convenience, a single-input design graph is presented as well. The main merit of the proposed method, compared to previous researches, is its hand calculation aspect, suitable for parametric studies and sensitivity analysis. As the presented formulations are dimensionless, they are applicable in any dimensional system. Accuracy and practicality of the proposed method is illustrated at the end by applying it to a real-life structure.

Reaction-diffusion processes at the nano- and microscales

NASA Astrophysics Data System (ADS)

Epstein, Irving R.; Xu, Bing

2016-04-01

The bottom-up fabrication of nano- and microscale structures from primary building blocks (molecules, colloidal particles) has made remarkable progress over the past two decades, but most research has focused on structural aspects, leaving our understanding of the dynamic and spatiotemporal aspects at a relatively primitive stage. In this Review, we draw inspiration from living cells to argue that it is now time to move beyond the generation of structures and explore dynamic processes at the nanoscale. We first introduce nanoscale self-assembly, self-organization and reaction-diffusion processes as essential features of cells. Then, we highlight recent progress towards designing and controlling these fundamental features of life in abiological systems. Specifically, we discuss examples of reaction-diffusion processes that lead to such outcomes as self-assembly, self-organization, unique nanostructures, chemical waves and dynamic order to illustrate their ubiquity within a unifying context of dynamic oscillations and energy dissipation. Finally, we suggest future directions for research on reaction-diffusion processes at the nano- and microscales that we find hold particular promise for a new understanding of science at the nanoscale and the development of new kinds of nanotechnologies for chemical transport, chemical communication and integration with living systems.

A special purpose silicon compiler for designing supercomputing VLSI systems

NASA Technical Reports Server (NTRS)

Venkateswaran, N.; Murugavel, P.; Kamakoti, V.; Shankarraman, M. J.; Rangarajan, S.; Mallikarjun, M.; Karthikeyan, B.; Prabhakar, T. S.; Satish, V.; Venkatasubramaniam, P. R.

1991-01-01

Design of general/special purpose supercomputing VLSI systems for numeric algorithm execution involves tackling two important aspects, namely their computational and communication complexities. Development of software tools for designing such systems itself becomes complex. Hence a novel design methodology has to be developed. For designing such complex systems a special purpose silicon compiler is needed in which: the computational and communicational structures of different numeric algorithms should be taken into account to simplify the silicon compiler design, the approach is macrocell based, and the software tools at different levels (algorithm down to the VLSI circuit layout) should get integrated. In this paper a special purpose silicon (SPS) compiler based on PACUBE macrocell VLSI arrays for designing supercomputing VLSI systems is presented. It is shown that turn-around time and silicon real estate get reduced over the silicon compilers based on PLA's, SLA's, and gate arrays. The first two silicon compiler characteristics mentioned above enable the SPS compiler to perform systolic mapping (at the macrocell level) of algorithms whose computational structures are of GIPOP (generalized inner product outer product) form. Direct systolic mapping on PLA's, SLA's, and gate arrays is very difficult as they are micro-cell based. A novel GIPOP processor is under development using this special purpose silicon compiler.

Noise Reduction Design of the Volute for a Centrifugal Compressor

NASA Astrophysics Data System (ADS)

Song, Zhen; Wen, Huabing; Hong, Liangxing; Jin, Yudong

2017-08-01

In order to effectively control the aerodynamic noise of a compressor, this paper takes into consideration a marine exhaust turbocharger compressor as a research object. According to the different design concept of volute section, tongue and exit cone, six different volute models were established. The finite volume method is used to calculate the flow field, whiles the finite element method is used for the acoustic calculation. Comparison and analysis of different structure designs from three aspects: noise level, isentropic efficiency and Static pressure recovery coefficient. The results showed that under the concept of volute section model 1 yielded the best result, under the concept of tongue analysis model 3 yielded the best result and finally under exit cone analysis model 6 yielded the best results.

Using Concept Maps to Monitor Knowledge Structure Changes in a Science Classroom

NASA Astrophysics Data System (ADS)

Cook, Leah J.

The aim of this research is to determine what differences may exist in students' structural knowledge while using a variety of concept mapping assessments. A concept map can be used as an assessment which connects concepts in a knowledge domain. A single assessment may not be powerful enough to establish how students' new knowledge relates to prior knowledge. More research is needed to establish how various aspects of the concept mapping task influence the output of map creation by students. Using multiple concept maps and pre-instruction and post-instruction VNOS instruments during a 16-week semester, this study was designed to investigate the impact of concept map training and the impact of assessment design on the created maps. Also, this study was designed to determine what differences can be observed between expert and novice maps and if similarities and differences exist between concept maps and an open-ended assessment. Participants created individual maps and the maps were analyzed for structural complexity, overall structure, and content. The concept maps were then compared by their timing, design, and scores. The results indicate that concept mapping training does significantly impact the shape and structure complexity of the map created by students. Additionally, these data support that students should be frequently reminded of appropriate concept mapping skills and opportunities so that good mapping skills will be utilized. Changing the assessment design does appear to be able to impact the overall structure and complexity of created maps, while narrowing the content focus of the map does not necessarily restrict the overall structure or the complexity. Furthermore, significant differences in structural complexity were observed between novice and expert mappers. The fluctuations of NOS concepts identified in student created maps may suggest why some students were still confused or had incorrect conceptions of NOS, despite explicit and reflective instruction throughout the semester.

Playable stories: Making programming and 3D role-playing game design personally and socially relevant

NASA Astrophysics Data System (ADS)

Ingram-Goble, Adam

This is an exploratory design study of a novel system for learning programming and 3D role-playing game design as tools for social change. This study was conducted at two sites. Participants in the study were ages 9-14 and worked for up to 15 hours with the platform to learn how to program and design video games with personally or socially relevant narratives. This first study was successful in that students learned to program a narrative game, and they viewed the social problem framing for the practices as an interesting aspect of the experience. The second study provided illustrative examples of how providing less general structure up-front, afforded players the opportunity to produce the necessary structures as needed for their particular design, and therefore had a richer understanding of what those structures represented. This study demonstrates that not only were participants able to use computational thinking skills such as Boolean and conditional logic, planning, modeling, abstraction, and encapsulation, they were able to bridge these skills to social domains they cared about. In particular, participants created stories about socially relevant topics without to explicit pushes by the instructors. The findings also suggest that the rapid uptake, and successful creation of personally and socially relevant narratives may have been facilitated by close alignment between the conceptual tools represented in the platform, and the domain of 3D role-playing games.

Library design practices for success in lead generation with small molecule libraries.

PubMed

Goodnow, R A; Guba, W; Haap, W

2003-11-01

The generation of novel structures amenable to rapid and efficient lead optimization comprises an emerging strategy for success in modern drug discovery. Small molecule libraries of sufficient size and diversity to increase the chances of discovery of novel structures make the high throughput synthesis approach the method of choice for lead generation. Despite an industry trend for smaller, more focused libraries, the need to generate novel lead structures makes larger libraries a necessary strategy. For libraries of a several thousand or more members, solid phase synthesis approaches are the most suitable. While the technology and chemistry necessary for small molecule library synthesis continue to advance, success in lead generation requires rigorous consideration in the library design process to ensure the synthesis of molecules possessing the proper characteristics for subsequent lead optimization. Without proper selection of library templates and building blocks, solid phase synthesis methods often generate molecules which are too heavy, too lipophilic and too complex to be useful for lead optimization. The appropriate filtering of virtual library designs with multiple computational tools allows the generation of information-rich libraries within a drug-like molecular property space. An understanding of the hit-to-lead process provides a practical guide to molecular design characteristics. Examples of leads generated from library approaches also provide a benchmarking of successes as well as aspects for continued development of library design practices.

The Use of Conductive Ink in Antenna Education and Design

NASA Astrophysics Data System (ADS)

Addison, David W.

Conductive ink from a printer allows for the fabrication of conductive material with tight tolerances without the cost and time of chemical etching. This paper explores the use of AGIC printable conductive ink on a paper substrate as design tool for antennas as well as classroom use in antenna education. The antenna designs satisfy the requirements of a compact Global Navigation Satellite System (GNSS) antenna while showing a competitive performance within the current market. One best design is shown along with three other structures. These antennas consist of a bowtie cross-dipole over a reflective disc with conductive-ink grounded structures. In addition to the GNSS antennas, a linear elliptical dipole over a reflective disc with conductive grounded structures is presented. This elliptical antenna design attempts to find the maximum impedance bandwidth beyond the GNSS band. The inexpensive nature of conductive ink allows for its use in a classroom to demonstrate antenna behavior as part of antenna education. An inexpensive approach to the patch antenna using conductive ink is described and paired with a system made of off-the-shelf parts. The system is capable of measuring the power of the received signal. The received signal measurement is not as accurate as using a anechoic chamber but pattern details are visible. This is used to demonstrate aspects of the Friis transmission equation such as distance, polarization, radiation pattern shape, and loss.

Design and multiphysics analysis of a 176Â MHz continuous-wave radio-frequency quadrupole

NASA Astrophysics Data System (ADS)

Kutsaev, S. V.; Mustapha, B.; Ostroumov, P. N.; Barcikowski, A.; Schrage, D.; Rodnizki, J.; Berkovits, D.

2014-07-01

We have developed a new design for a 176 MHz cw radio-frequency quadrupole (RFQ) for the SARAF upgrade project. At this frequency, the proposed design is a conventional four-vane structure. The main design goals are to provide the highest possible shunt impedance while limiting the required rf power to about 120 kW for reliable cw operation, and the length to about 4 meters. If built as designed, the proposed RFQ will be the first four-vane cw RFQ built as a single cavity (no resonant coupling required) that does not require π-mode stabilizing loops or dipole rods. For this, we rely on very detailed 3D simulations of all aspects of the structure and the level of machining precision achieved on the recently developed ATLAS upgrade RFQ. A full 3D model of the structure including vane modulation was developed. The design was optimized using electromagnetic and multiphysics simulations. Following the choice of the vane type and geometry, the vane undercuts were optimized to produce a flat field along the structure. The final design has good mode separation and should not need dipole rods if built as designed, but their effect was studied in the case of manufacturing errors. The tuners were also designed and optimized to tune the main mode without affecting the field flatness. Following the electromagnetic (EM) design optimization, a multiphysics engineering analysis of the structure was performed. The multiphysics analysis is a coupled electromagnetic, thermal and mechanical analysis. The cooling channels, including their paths and sizes, were optimized based on the limiting temperature and deformation requirements. The frequency sensitivity to the RFQ body and vane cooling water temperatures was carefully studied in order to use it for frequency fine-tuning. Finally, an inductive rf power coupler design based on the ATLAS RFQ coupler was developed and simulated. The EM design optimization was performed using cst Microwave Studio and the results were verified using both hfss and ansys. The engineering analysis was performed using hfss and ansys and most of the results were verified using the newly developed cst Multiphysics package.

Solar powered multipurpose remotely powered aircraft

NASA Technical Reports Server (NTRS)

1991-01-01

Environmental problems such as the depletion of the ozone layer and air pollution demand a change in traditional means of propulsion that is sensitive to the ecology. Solar-powered propulsion is a favorable alternative that is both ecologically harmless as well as cost effective. Integration of solar energy into designs ranging from futuristic vehicles to heating is, therefore, beneficial to society. The design and construction of a Multipurpose Remotely Piloted Vehicle (MPRPV) seeks to verify the feasibility of using solar propulsion as a primary fuel source. This task has been a year-long effort by a group of eight students, divided into four teams, each dealing with different aspects of the design. The aircraft was designed to take off, climb to the design altitude, fly in a sustained figure-eight flight path, and cruise for approximately one hour. This mission requires flight at Reynolds numbers between 150,000 and 200,000 and demands special considerations in the aerodynamic design to achieve flight in this regime. Optimal performance requires a lightweight configuration with both structural integrity and maximum power availability. The structural design and choice of solar cells for the propulsion were governed by weight, efficiency, and cost considerations. The final design is an MPRPV weighing 35 N that cruises at 7 m/s at the design altitude of 50 m. The configuration includes a wing composed of balsa and foam NACA 6409 airfoil sections and carbon fiber spars, a tail of similar construction, and a truss structure fuselage. The propulsion system consists of 98 12.5 percent-efficient solar cells donated by Mobil Solar, a NiCad battery for energy storage, and a folding propeller regulated by a lightweight and efficient control system. The airfoils and propeller chosen for the design were researched and tested during the design process.

Dual wing, swept forward swept rearward wing, and single wing design optimization for high performance business airplanes

NASA Technical Reports Server (NTRS)

Rhodes, M. D.; Selberg, B. P.

1982-01-01

An investigation was performed to compare closely coupled dual wing and swept forward swept rearward wing aircraft to corresponding single wing 'baseline' designs to judge the advantages offered by aircraft designed with multiple wing systems. The optimum multiple wing geometry used on the multiple wing designs was determined in an analytic study which investigated the two- and three-dimensional aerodynamic behavior of a wide range of multiple wing configurations in order to find the wing geometry that created the minimum cruise drag. This analysis used a multi-element inviscid vortex panel program coupled to a momentum integral boundary layer analysis program to account for the aerodynamic coupling between the wings and to provide the two-dimensional aerodynamic data, which was then used as input for a three-dimensional vortex lattice program, which calculated the three-dimensional aerodynamic data. The low drag of the multiple wing configurations is due to a combination of two dimensional drag reductions, tailoring the three dimensional drag for the swept forward swept rearward design, and the structural advantages of the two wings that because of the structural connections permitted higher aspect ratios.

New type of standalone gas sensors based on dye, thin films, and subwavelength structures

NASA Astrophysics Data System (ADS)

Schnieper, Marc; Davoine, Laurent; Holgado, Miguel; Casquel del Campo, Rafael; Barranco, Angel

2009-02-01

A new gas sensor was developed to enable visual indication of a contamination by specific gases like NO2, SO2, UV, etc. The sensor works with a combination of subwavelength structures and specific active dye thin film layers. The objective is to use the optical changes of the dye thin films after exposure and a custom designed subwavelength structure, a suited combination of both will produce a strong color change. The indication should be visible for the human eye. To enhance this visual aspect, we used a reference sensor sealed into a non-contaminated atmosphere. This work was realized within the PHODYE STREP Project, a collaboration of the 6th Framework Program Priority Information Society Technologies.

Introduction to the Wetland Book 1: Wetland structure and function, management, and nethods

USGS Publications Warehouse

Davidson, Nick C.; Middleton, Beth A.; McInnes, Robert J.; Everard, Mark; Irvine, Kenneth; Van Dam, Anne A.; Finlayson, C. Max; Finlayson, C. Max; Everard, Mark; Irvine, Kenneth; McInnes, Robert J.; Middleton, Beth A.; Van Dam, Anne A.; Davidson, Nick C.

2016-01-01

The Wetland Book 1 is designed as a ‘first port-of-call’ reference work for information on the structure and functions of wetlands, current approaches to wetland management, and methods for researching and understanding wetlands. Contributions by experts summarize key concepts, orient the reader to the major issues, and support further research on such issues by individuals and multidisciplinary teams. The Wetland Book 1 is organized in three parts - Wetland structure and function; Wetland management; and Wetland methods - each of which is divided into a number of thematic Sections. Each Section starts with one or more overview chapters, supported by chapters providing further information and case studies on different aspects of the theme.

Structural sensitivity of x-ray Bragg projection ptychography to domain patterns in epitaxial thin films

NASA Astrophysics Data System (ADS)

Hruszkewycz, S. O.; Zhang, Q.; Holt, M. V.; Highland, M. J.; Evans, P. G.; Fuoss, P. H.

2016-10-01

Bragg projection ptychography (BPP) is a coherent diffraction imaging technique capable of mapping the spatial distribution of the Bragg structure factor in nanostructured thin films. Here, we show that, because these images are projections, the structural sensitivity of the resulting images depends on the film thickness and the aspect ratio and orientation of the features of interest and that image interpretation depends on these factors. We model changes in contrast in the BPP reconstructions of simulated PbTiO3 ferroelectric thin films with meandering 180∘ stripe domains as a function of film thickness, discuss their origin, and comment on the implication of these factors on the design of BPP experiments of general nanostructured films.

Supersonic compressor

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

Roberts, II, William Byron; Lawlor, Shawn P.; Breidenthal, Robert E.

A supersonic compressor including a rotor to deliver a gas at supersonic conditions to a diffuser. The diffuser includes a plurality of aerodynamic ducts that have converging and diverging portions, for deceleration of gas to subsonic conditions and then for expansion of subsonic gas, to change kinetic energy of the gas to static pressure. The aerodynamic ducts include vortex generating structures for controlling boundary layer, and structures for changing the effective contraction ratio to enable starting even when the aerodynamic ducts are designed for high pressure ratios, and structures for boundary layer control. In an embodiment, aerodynamic ducts are providedmore » having an aspect ratio of in excess of two to one, when viewed in cross-section orthogonal to flow direction at an entrance to the aerodynamic duct.« less

3D-printed Microfluidic Devices: Fabrication, Advantages and Limitations—a Mini Review

PubMed Central

Chen, Chengpeng; Mehl, Benjamin T.; Munshi, Akash S.; Townsend, Alexandra D.; Spence, Dana M.; Martin, R. Scott

2016-01-01

A mini-review with 79 references. In this review, the most recent trends in 3D-printed microfluidic devices are discussed. In addition, a focus is given to the fabrication aspects of these devices, with the supplemental information containing detailed instructions for designing a variety of structures including: a microfluidic channel, threads to accommodate commercial fluidic fittings, a flow splitter; a well plate, a mold for PDMS channel casting; and how to combine multiple designs into a single device. The advantages and limitations of 3D-printed microfluidic devices are thoroughly discussed, as are some future directions for the field. PMID:27617038

Integrated input protection against discharges for Micro Pattern Gas Detectors readout ASICs

NASA Astrophysics Data System (ADS)

Fiutowski, T.; Dąbrowski, W.; Koperny, S.; Wiącek, P.

2017-02-01

Immunity against possible random discharges inside active detector volume of MPGDs is one of the key aspects that should be addressed in the design of the front-end electronics. This issue becomes particularly critical for systems with high channel counts and high density readout employing the front-end electronics built as multichannel ASICs implemented in modern CMOS technologies, for which the breakdown voltages are in the range of a few Volts. The paper presents the design of various input protection structures integrated in the ASIC manufactured in a 350 nm CMOS process and test results using an electrical circuit to mimic discharges in the detectors.

3D-printed Microfluidic Devices: Fabrication, Advantages and Limitations-a Mini Review.

PubMed

Chen, Chengpeng; Mehl, Benjamin T; Munshi, Akash S; Townsend, Alexandra D; Spence, Dana M; Martin, R Scott

2016-08-21

A mini-review with 79 references. In this review, the most recent trends in 3D-printed microfluidic devices are discussed. In addition, a focus is given to the fabrication aspects of these devices, with the supplemental information containing detailed instructions for designing a variety of structures including: a microfluidic channel, threads to accommodate commercial fluidic fittings, a flow splitter; a well plate, a mold for PDMS channel casting; and how to combine multiple designs into a single device. The advantages and limitations of 3D-printed microfluidic devices are thoroughly discussed, as are some future directions for the field.

Applications of a damage tolerance analysis methodology in aircraft design and production

NASA Technical Reports Server (NTRS)

Woodward, M. R.; Owens, S. D.; Law, G. E.; Mignery, L. A.

1992-01-01

Objectives of customer mandated aircraft structural integrity initiatives in design are to guide material selection, to incorporate fracture resistant concepts in the design, to utilize damage tolerance based allowables and planned inspection procedures necessary to enhance the safety and reliability of manned flight vehicles. However, validated fracture analysis tools for composite structures are needed to accomplish these objectives in a timely and economical manner. This paper briefly describes the development, validation, and application of a damage tolerance methodology for composite airframe structures. A closed-form analysis code, entitled SUBLAM was developed to predict the critical biaxial strain state necessary to cause sublaminate buckling-induced delamination extension in an impact damaged composite laminate. An embedded elliptical delamination separating a thin sublaminate from a thick parent laminate is modelled. Predicted failure strains were correlated against a variety of experimental data that included results from compression after impact coupon and element tests. An integrated analysis package was developed to predict damage tolerance based margin-of-safety (MS) using NASTRAN generated loads and element information. Damage tolerance aspects of new concepts are quickly and cost-effectively determined without the need for excessive testing.

The Imagery of Sound

NASA Technical Reports Server (NTRS)

2000-01-01

Automated Analysis Corporation's COMET is a suite of acoustic analysis software for advanced noise prediction. It analyzes the origin, radiation, and scattering of noise, and supplies information on how to achieve noise reduction and improve sound characteristics. COMET's Structural Acoustic Foam Engineering (SAFE) module extends the sound field analysis capability of foam and other materials. SAFE shows how noise travels while airborne, how it travels within a structure, and how these media interact to affect other aspects of the transmission of noise. The COMET software reduces design time and expense while optimizing a final product's acoustical performance. COMET was developed through SBIR funding and Langley Research Center for Automated Analysis Corporation.

DNA-guided nanoparticle assemblies

DOEpatents

Gang, Oleg; Nykypanchuk, Dmytro; Maye, Mathew; van der Lelie, Daniel

2013-07-16

In some embodiments, DNA-capped nanoparticles are used to define a degree of crystalline order in assemblies thereof. In some embodiments, thermodynamically reversible and stable body-centered cubic (bcc) structures, with particles occupying <.about.10% of the unit cell, are formed. Designs and pathways amenable to the crystallization of particle assemblies are identified. In some embodiments, a plasmonic crystal is provided. In some aspects, a method for controlling the properties of particle assemblages is provided. In some embodiments a catalyst is formed from nanoparticles linked by nucleic acid sequences and forming an open crystal structure with catalytically active agents attached to the crystal on its surface or in interstices.

External and internal factors influencing self-directed online learning of physiotherapy undergraduate students in Sweden: a qualitative study

PubMed Central

Hammarlund, Catharina Sjödahl; Nilsson, Maria H.; Gummesson, Christina

2015-01-01

Purpose: Online courses have become common in health sciences education. This learning environment can be designed using different approaches to support student learning. To further develop online environment, it is important to understand how students perceive working and learning online. The aim of this study is to identify aspects influencing students’ learning processes and their adaptation to self-directed learning online. Methods: Thirty-four physiotherapy students with a mean age of 25 years (range, 21 to 34 years) participated. Qualitative content analysis and triangulation was used when investigating the students’ self-reflections, written during a five week self-directed, problem-oriented online course. Results: Two categories emerged: ‘the influence of the structured framework’ and ‘communication and interaction with teachers and peers.’ The learning processes were influenced by external factors, e.g., a clear structure including a transparent alignment of assignments and assessment. Important challenges to over-come were primarily internal factors, e.g., low self-efficacy, difficulties to plan the work effectively and adapting to a new environment. Conclusion: The analyses reflected important perspectives targeting areas which enable further course development. The influences of external and internal factors on learning strategies and self-efficacy are important aspects to consider when designing online courses. Factors such as pedagogical design, clarity of purpose, goals, and guidelines were important as well as continuous opportunities for communication and collaboration. Further studies are needed to understand and scaffold the motivational factors among students with low self-efficacy. PMID:26101401

Conceptual design of industrial process displays.

PubMed

Pedersen, C R; Lind, M

1999-11-01

Today, process displays used in industry are often designed on the basis of piping and instrumentation diagrams without any method of ensuring that the needs of the operators are fulfilled. Therefore, a method for a systematic approach to the design of process displays is needed. This paper discusses aspects of process display design taking into account both the designer's and the operator's points of view. Three aspects are emphasized: the operator tasks, the display content and the display form. The distinction between these three aspects is the basis for proposing an outline for a display design method that matches the industrial practice of modular plant design and satisfies the needs of reusability of display design solutions. The main considerations in display design in the industry are to specify the operator's activities in detail, to extract the information the operators need from the plant design specification and documentation, and finally to present this information. The form of the display is selected from existing standardized display elements such as trend curves, mimic diagrams, ecological interfaces, etc. Further knowledge is required to invent new display elements. That is, knowledge about basic visual means of presenting information and how humans perceive and interpret these means and combinations. This knowledge is required in the systematic selection of graphical items for a given display content. The industrial part of the method is first illustrated in the paper by a simple example from a plant with batch processes. Later the method is applied to develop a supervisory display for a condenser system in a nuclear power plant. The differences between the continuous plant domain of power production and the batch processes from the example are analysed and broad categories of display types are proposed. The problems involved in specification and invention of a supervisory display are analysed and conclusions from these problems are made. It is concluded that the design method proposed provides a framework for the progress of the display design and is useful in pin-pointing the actual problems. The method was useful in reducing the number of existing displays that could fulfil the requirements of the supervision task. The method provided at the same time a framework for dealing with the problems involved in inventing new displays based on structured analysis. However the problems in a systematic approach to display invention still need consideration.

Mucin-Type O-Glycosylation in Invertebrates.

PubMed

Staudacher, Erika

2015-06-09

O-Glycosylation is one of the most important posttranslational modifications of proteins. It takes part in protein conformation, protein sorting, developmental processes and the modulation of enzymatic activities. In vertebrates, the basics of the biosynthetic pathway of O-glycans are already well understood. However, the regulation of the processes and the molecular aspects of defects, especially in correlation with cancer or developmental abnormalities, are still under investigation. The knowledge of the correlating invertebrate systems and evolutionary aspects of these highly conserved biosynthetic events may help improve the understanding of the regulatory factors of this pathway. Invertebrates display a broad spectrum of glycosylation varieties, providing an enormous potential for glycan modifications which may be used for the design of new pharmaceutically active substances. Here, overviews of the present knowledge of invertebrate mucin-type O-glycan structures and the currently identified enzymes responsible for the biosynthesis of these oligosaccharides are presented, and the few data dealing with functional aspects of O-glycans are summarised.

Microchannel contacting of crystalline silicon solar cells

DOE PAGES

Bullock, James; Ota, Hiroki; Wang, Hanchen; ...

2017-08-22

There is tremendous interest in reducing losses caused by the metal contacts in silicon photovoltaics, particularly the optical and resistive losses of the front metal grid. One commonly sought-after goal is the creation of high aspect-ratio metal fingers which provide an optically narrow and low resistance pathway to the external circuit. Currently, the most widely used metal contact deposition techniques are limited to widths and aspect-ratios of ~40 μm and ~0.5, respectively. In this study, we introduce the use of a micropatterned polydimethylsiloxane encapsulation layer to form narrow (~20 μm) microchannels, with aspect-ratios up to 8, on the surface ofmore » solar cells. We demonstrate that low temperature metal pastes, electroless plating and atomic layer deposition can all be used within the microchannels. Further, we fabricate proof-of-concept structures including simple planar silicon heterojunction and homojunction solar cells. While preliminary in both design and efficiency, these results demonstrate the potential of this approach and its compatibility with current solar cell architectures.« less

Microchannel contacting of crystalline silicon solar cells

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

Bullock, James; Ota, Hiroki; Wang, Hanchen

There is tremendous interest in reducing losses caused by the metal contacts in silicon photovoltaics, particularly the optical and resistive losses of the front metal grid. One commonly sought-after goal is the creation of high aspect-ratio metal fingers which provide an optically narrow and low resistance pathway to the external circuit. Currently, the most widely used metal contact deposition techniques are limited to widths and aspect-ratios of ~40 μm and ~0.5, respectively. In this study, we introduce the use of a micropatterned polydimethylsiloxane encapsulation layer to form narrow (~20 μm) microchannels, with aspect-ratios up to 8, on the surface ofmore » solar cells. We demonstrate that low temperature metal pastes, electroless plating and atomic layer deposition can all be used within the microchannels. Further, we fabricate proof-of-concept structures including simple planar silicon heterojunction and homojunction solar cells. While preliminary in both design and efficiency, these results demonstrate the potential of this approach and its compatibility with current solar cell architectures.« less

An Undergraduate Electrical Engineering Course on Computer Organization.

ERIC Educational Resources Information Center

Commission on Engineering Education, Washington, DC.

Outlined is an undergraduate electrical engineering course on computer organization designed to meet the need for electrical engineers familiar with digital system design. The program includes both hardware and software aspects of digital systems essential to design function and correlates design and organizational aspects of the subject. The…

Reducing Design Cycle Time and Cost Through Process Resequencing

NASA Technical Reports Server (NTRS)

Rogers, James L.

2004-01-01

In today's competitive environment, companies are under enormous pressure to reduce the time and cost of their design cycle. One method for reducing both time and cost is to develop an understanding of the flow of the design processes and the effects of the iterative subcycles that are found in complex design projects. Once these aspects are understood, the design manager can make decisions that take advantage of decomposition, concurrent engineering, and parallel processing techniques to reduce the total time and the total cost of the design cycle. One software tool that can aid in this decision-making process is the Design Manager's Aid for Intelligent Decomposition (DeMAID). The DeMAID software minimizes the feedback couplings that create iterative subcycles, groups processes into iterative subcycles, and decomposes the subcycles into a hierarchical structure. The real benefits of producing the best design in the least time and at a minimum cost are obtained from sequencing the processes in the subcycles.

Module/array interface study

NASA Technical Reports Server (NTRS)

1978-01-01

Several aspects of module design are evaluated, including glass superstrate and metal substrate module configurations, the potential for hail damage, light absorption in glass superstrates, the economics of glass selection, and electrical design. Also, three alternate glass superstrate module configurations are evaluated by means of finite element computer analyses. Two panel sizes, 1.2 by 2.4 m (4 by 8 ft) and 2.4 by 4.8 m are used to support three module sizes, 0.6 by 1.2 m, 1.2 by 1.2 m, and 1.2 by 2.4 m, for design loadings of + or - 1.7 kPa, + or - 2.4 kPa, and + or - 3.6 kPa. Designs and cost estimates are presented for twenty panel types and nine array configurations at each of the three design loadings. Structural cost sensitivities of combined array configurations and panel cases are presented.

Air Force Human Systems Integration (HSI) in Test and Evaluation (T&E)

DTIC Science & Technology

2012-08-01

allow human aspects related to system design to be tested and evaluated. 15. SUBJECT TERMS Air Force, Human Systems Integration, HSI, Test and...Community that would allow human aspects related to system design to be tested and evaluated. The intent was to identify and develop means for greater...related documentation in order to monitor the human related aspects for system development and design . To address these work areas, the team adopted

Modular, Hierarchical Learning By Artificial Neural Networks

NASA Technical Reports Server (NTRS)

Baldi, Pierre F.; Toomarian, Nikzad

1996-01-01

Modular and hierarchical approach to supervised learning by artificial neural networks leads to neural networks more structured than neural networks in which all neurons fully interconnected. These networks utilize general feedforward flow of information and sparse recurrent connections to achieve dynamical effects. The modular organization, sparsity of modular units and connections, and fact that learning is much more circumscribed are all attractive features for designing neural-network hardware. Learning streamlined by imitating some aspects of biological neural networks.

Complementary aspects of diffusion imaging and fMRI; I: structure and function.

PubMed

Mulkern, Robert V; Davis, Peter E; Haker, Steven J; Estepar, Raul San Jose; Panych, Lawrence P; Maier, Stephan E; Rivkin, Michael J

2006-05-01

Studying the intersection of brain structure and function is an important aspect of modern neuroscience. The development of magnetic resonance imaging (MRI) over the last 25 years has provided new and powerful tools for the study of brain structure and function. Two tools in particular, diffusion imaging and functional MRI (fMRI), are playing increasingly important roles in elucidating the complementary aspects of brain structure and function. In this work, we review basic technical features of diffusion imaging and fMRI for studying the integrity of white matter structural components and for determining the location and extent of cortical activation in gray matter, respectively. We then review a growing body of literature in which the complementary aspects of diffusion imaging and fMRI, applied as separate examinations but analyzed in tandem, have been exploited to enhance our knowledge of brain structure and function.

Neonicotinoid insecticides: highlights of a symposium on strategic molecular designs.

PubMed

Tomizawa, Motohiro; Casida, John E

2011-04-13

Neonicotinoids are the newest of the five major classes of insecticides (the others are chlorinated hydrocarbons, organophosphorus compounds, methylcarbamates, and pyrethroids), and they make up approximately one-fourth of the world insecticide market. Nithiazine was the lead compound from Shell Development Co. in California later optimized by Shinzo Kagabu of Nihon Tokushu Noyaku Seizo to increase the potency and photostability, resulting in imidacloprid and thiacloprid. These discoveries are the basis for the International Award for Research in Agrochemicals of the American Chemical Society presented in 2010 to Professor Shinzo Kagabu. Five other neonicotinoids were added by others for the current set of seven commercial compounds. This symposium considers the progress in discovery and development of novel chemotype nicotinic insecticides with enhanced effectiveness, unique biological properties, and maximal safety. Chemorational approaches considered include physicochemical properties, metabolic activation and detoxification, and chemical and structural biology aspects potentially facilitating receptor structure-guided insecticide design.

Tunable Molecular-Scale Materials for Catalyzing the Low-Overpotential Electrochemical Conversion of CO2.

PubMed

Rosen, Brian A; Hod, Idan

2018-04-25

Electrochemical CO 2 reduction provides a clean and viable alternative for mitigating the environmental aspects of global greenhouse gas emissions. To date, the simultaneous goals of CO 2 reduction at high selectivity and activity have yet to be achieved. Here, the importance of engineering both sides of the electrode-electrolyte interface as a rational strategy for achieving this milestone is highlighted. An emphasis is placed on researchers contributing to the design of solid electrodes based on metal-organic frameworks (MOFs) and electrolytes based on room-temperature ionic liquids (RTILs). Future research geared toward optimizing the electrode-electrolyte interface for efficient and selective CO 2 reduction can be achieved by understanding the structure of newly designed RTILs at the electrified interface, as well as structure-activity relationships in highly tunable MOF platforms. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

ETF system code: composition and applications

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

Reid, R.L.; Wu, K.F.

1980-01-01

A computer code has been developed for application to ETF tokamak system and conceptual design studies. The code determines cost, performance, configuration, and technology requirements as a function of tokamak parameters. The ETF code is structured in a modular fashion in order to allow independent modeling of each major tokamak component. The primary benefit of modularization is that it allows updating of a component module, such as the TF coil module, without disturbing the remainder of the system code as long as the input/output to the modules remains unchanged. The modules may be run independently to perform specific design studies,more » such as determining the effect of allowable strain on TF coil structural requirements, or the modules may be executed together as a system to determine global effects, such as defining the impact of aspect ratio on the entire tokamak system.« less

Nanowires precisely grown on the ends of microwire electrodes permit the recording of intracellular action potentials within deeper neural structures

PubMed Central

Ferguson, John E; Boldt, Christopher; Puhl, Joshua G; Stigen, Tyler W; Jackson, Jadin C; Crisp, Kevin M; Mesce, Karen A; Netoff, Theoden I; Redish, A David

2012-01-01

Aims Nanoelectrodes are an emerging biomedical technology that can be used to record intracellular membrane potentials from neurons while causing minimal damage during membrane penetration. Current nanoelectrode designs, however, have low aspect ratios or large substrates and thus are not suitable for recording from neurons deep within complex natural structures, such as brain slices. Materials & methods We describe a novel nanoelectrode design that uses nanowires grown on the ends of microwire recording electrodes similar to those frequently used in vivo. Results & discussion We demonstrate that these nanowires can record intracellular action potentials in a rat brain slice preparation and in isolated leech ganglia. Conclusion Nanoelectrodes have the potential to revolutionize intracellular recording methods in complex neural tissues, to enable new multielectrode array technologies and, ultimately, to be used to record intracellular signals in vivo. PMID:22475650

Applying the chronic care model to an employee benefits program: a qualitative inquiry.

PubMed

Schauer, Gillian L; Wilson, Mark; Barrett, Barbara; Honeycutt, Sally; Hermstad, April K; Kegler, Michelle C

2013-12-01

To assess how employee benefits programs may strengthen and/or complement elements of the chronic care model (CCM), a framework used by health systems to improve chronic illness care. A qualitative inquiry consisting of semi-structured interviews with employee benefit administrators and partners from a self-insured, self-administered employee health benefits program was conducted at a large family-owned business in southwest Georgia. Results indicate that the employer adapted and used many health system-related elements of the CCM in the design of their benefit program. Data also suggest that the employee benefits program contributed to self-management skills and to informing and activating patients to interact with the health system. Findings suggest that employee benefits programs can use aspects of the CCM in their own benefit design, and can structure their benefits to contribute to patient-related elements from the CCM.

Design and testing of an oblique all-wing supersonic transport

NASA Technical Reports Server (NTRS)

Lee, Christopher A.

1994-01-01

This report describes the preliminary design of an Oblique All-Wing (OAW) supersonic transport and a corresponding wind-tunnel model that was tested in the NASA Ames 9- by 7-Foot supersonic wind tunnel. The main goal was the determination of the cruise performance (lift/drag ratio) of a realistically configured OAW. To achieve an acceptable level of realism, it was necessary to consider many issues of design practicality such as the need for a viable propulsion system, adequate control surfaces, landing gear, provisions for 450 passengers, and fuel to fly 5,000 nautical miles. The aircraft had to be stable, structurally sound, and needed to fit into airports across the world. Support was directed primarily towards integration of the propulsion system, however, there were notable contributions to many aspects of the configuration design, wind tunnel model, and wind tunnel test.

Control Oriented Modeling and Validation of Aeroservoelastic Systems

NASA Technical Reports Server (NTRS)

Crowder, Marianne; deCallafon, Raymond (Principal Investigator)

2002-01-01

Lightweight aircraft design emphasizes the reduction of structural weight to maximize aircraft efficiency and agility at the cost of increasing the likelihood of structural dynamic instabilities. To ensure flight safety, extensive flight testing and active structural servo control strategies are required to explore and expand the boundary of the flight envelope. Aeroservoelastic (ASE) models can provide online flight monitoring of dynamic instabilities to reduce flight time testing and increase flight safety. The success of ASE models is determined by the ability to take into account varying flight conditions and the possibility to perform flight monitoring under the presence of active structural servo control strategies. In this continued study, these aspects are addressed by developing specific methodologies and algorithms for control relevant robust identification and model validation of aeroservoelastic structures. The closed-loop model robust identification and model validation are based on a fractional model approach where the model uncertainties are characterized in a closed-loop relevant way.

Biocuration in the structure-function linkage database: the anatomy of a superfamily.

PubMed

Holliday, Gemma L; Brown, Shoshana D; Akiva, Eyal; Mischel, David; Hicks, Michael A; Morris, John H; Huang, Conrad C; Meng, Elaine C; Pegg, Scott C-H; Ferrin, Thomas E; Babbitt, Patricia C

2017-01-01

With ever-increasing amounts of sequence data available in both the primary literature and sequence repositories, there is a bottleneck in annotating molecular function to a sequence. This article describes the biocuration process and methods used in the structure-function linkage database (SFLD) to help address some of the challenges. We discuss how the hierarchy within the SFLD allows us to infer detailed functional properties for functionally diverse enzyme superfamilies in which all members are homologous, conserve an aspect of their chemical function and have associated conserved structural features that enable the chemistry. Also presented is the Enzyme Structure-Function Ontology (ESFO), which has been designed to capture the relationships between enzyme sequence, structure and function that underlie the SFLD and is used to guide the biocuration processes within the SFLD. http://sfld.rbvi.ucsf.edu/. © The Author 2017. Published by Oxford University Press.

Structural properties of matrix metalloproteinases.

PubMed

Bode, W; Fernandez-Catalan, C; Tschesche, H; Grams, F; Nagase, H; Maskos, K

1999-04-01

Matrix metalloproteinases (MMPs) are involved in extracellular matrix degradation. Their proteolytic activity must be precisely regulated by their endogenous protein inhibitors, the tissue inhibitors of metalloproteinases (TIMPs). Disruption of this balance results in serious diseases such as arthritis, tumour growth and metastasis. Knowledge of the tertiary structures of the proteins involved is crucial for understanding their functional properties and interference with associated dysfunctions. Within the last few years, several three-dimensional MMP and MMP-TIMP structures became available, showing the domain organization, polypeptide fold and main specificity determinants. Complexes of the catalytic MMP domains with various synthetic inhibitors enabled the structure-based design and improvement of high-affinity ligands, which might be elaborated into drugs. A multitude of reviews surveying work done on all aspects of MMPs have appeared in recent years, but none of them has focused on the three-dimensional structures. This review was written to close the gap.

Vibroacoustic Characterization of Corrugated-Core and Honeycomb-Core Sandwich Panels

NASA Technical Reports Server (NTRS)

Allen, Albert; Schiller, Noah

2016-01-01

The vibroacoustic characteristics of two candidate launch vehicle fairing structures, corrugated- core and honeycomb-core sandwich designs, were studied. The study of these structures has been motivated by recent risk reduction efforts focused on mitigating high noise levels within the payload bays of large launch vehicles during launch. The corrugated-core sandwich concept is of particular interest as a dual purpose structure due to its ability to harbor resonant noise control systems without appreciably adding mass or taking up additional volume. Specifically, modal information, wavelength dispersion, and damping were determined from a series of vibrometer measurements and subsequent analysis procedures carried out on two test panels. Numerical and analytical modeling techniques were also used to assess assumed material properties and to further illuminate underlying structural dynamic aspects. Results from the tests and analyses described herein may serve as a reference for additional vibroacoustic studies involving these or similar structures.

Manual for the prediction of blast and fragment loadings on structures

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

Not Available

1980-11-01

The purpose of this manual is to provide Architect-Engineer (AE) firms guidance for the prediction of air blast, ground shock and fragment loadings on structures as a result of accidental explosions in or near these structures. Information in this manual is the result of an extensive literature survey and data gathering effort, supplemented by some original analytical studies on various aspects of blast phenomena. Many prediction equations and graphs are presented, accompanied by numerous example problems illustrating their use. The manual is complementary to existing structural design manuals and is intended to reflect the current state-of-the-art in prediction of blastmore » and fragment loads for accidental explosions of high explosives at the Pantex Plant. In some instances, particularly for explosions within blast-resistant structures of complex geometry, rational estimation of these loads is beyond the current state-of-the-art.« less

Integration of Composite Structures in Modern Day Architecture: Case Study of City Business Centre, Timisoara, Romania

NASA Astrophysics Data System (ADS)

Vataman, Adina; Gaivoronschi, Vlad; Mosoarca, Marius

2017-10-01

In current day structural design the use of composite steel-concrete structures has become the norm; because of the advantages that each of these materials has to offer. Composite structures also have the benefit of a faster execution at a lower cost, compared to traditional structures. While the arguments in favour of designing composite structures are well-known and appreciated by civil engineers; there remains a question of integrating these structures in modern-day urban landscapes. Eastern European countries are welcoming a blossoming of culture, arts, economy and industry, which unavoidably and necessarily will lead to a change in urban landscapes. With an increasing amount of foreign companies opening offices in these areas, the need for modern office solutions has arisen. The current paper presents a case study of an office building complex situated in the western part of Romania, in the city of Timişoara. The complex consists of 5 office buildings; all designed in composite steel-concrete structure, an underground parking lot, multiple terraces and adjacent promenade areas. Within the context of rapid growth and development of the city, the City Business Centre has offered high quality office spaces in the heart of the city, while considering the needs of the community. A very important aspect in the successful completion of the project was the efficient and professional collaboration between the separate project teams, between the owner, represented by the project management team, the architect, the structural designer and the building company. The successful joining of seismic structural solutions with modern architectural aesthetics has led to a dynamic, vibrant environment, making the City Business Centre the core of the region’s business life, at the same time redefining Timisoara’s architectural landscape. A testimony to the success of the project was the Civil Engineering Structural Designers Associations’ (AICPS) 3rd Prize awarded for great performance and quality in structural design. The project was also awarded a „Green Building of the Year” award by the Romanian Green Building Council and also the „Office Development of the Year” in South-Eastern Europe awarded at the Real Estate Awards by an international jury of renowned real estate developers, consulting firms and investment banks. The project was also selected by the European Architects’ Council to represent Romania in a Sustainable Architecture Exhibition at the European Parliament in Brussels.

T-Cap Pull-Off and Bending Behavior for Stitched Structure

NASA Technical Reports Server (NTRS)

Lovejoy, Andrew E.; Leone, Frank A., Jr.

2016-01-01

The Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) is a structural concept that was developed by The Boeing Company to address the complex structural design aspects associated with a pressurized hybrid wing body aircraft configuration. An important design feature required for assembly is the integrally stitched T-cap, which provides connectivity of the corner (orthogonal) joint between adjacent panels. A series of tests were conducted on T-cap test articles, with and without a rod stiffener penetrating the T-cap web, under tension (pull-off) and bending loads. Three designs were tested, including the baseline design used in largescale test articles. The baseline had only the manufacturing stitch row adjacent to the fillet at the base of the T-cap web. Two new designs added stitching rows to the T-cap web at either 0.5- or 1.0-inch spacing along the height of the web. Testing was conducted at NASA Langley Research Center to determine the behavior of the T-cap region resulting from the applied loading. Results show that stitching arrests the initial delamination failures so that the maximum strength capability exceeds the load at which the initial delaminations develop. However, it was seen that the added web stitching had very little effect on the initial delamination failure load, but actually decreased the initial delamination failure load for tension loading of test articles without a stiffener passing through the web. Additionally, the added web stitching only increased the maximum load capability by between 1% and 12.5%. The presence of the stiffener, however, did increase the initial and maximum loads for both tension and bending loading as compared to the stringerless baseline design. Based on the results of the few samples tested, the additional stitching in the T-cap web showed little advantage over the baseline design in terms of structural failure at the T-cap web/skin junction for the current test articles.

Quantitative structure-antifungal activity relationships of some benzohydrazides against Botrytis cinerea.

PubMed

Reino, José L; Saiz-Urra, Liane; Hernandez-Galan, Rosario; Aran, Vicente J; Hitchcock, Peter B; Hanson, James R; Gonzalez, Maykel Perez; Collado, Isidro G

2007-06-27

Fourteen benzohydrazides have been synthesized and evaluated for their in vitro antifungal activity against the phytopathogenic fungus Botrytis cinerea. The best antifungal activity was observed for the N',N'-dibenzylbenzohydrazides 3b-d and for the N-aminoisoindoline-derived benzohydrazide 5. A quantitative structure-activity relationship (QSAR) study has been developed using a topological substructural molecular design (TOPS-MODE) approach to interpret the antifungal activity of these synthetic compounds. The model described 98.3% of the experimental variance, with a standard deviation of 4.02. The influence of an ortho substituent on the conformation of the benzohydrazides was investigated by X-ray crystallography and supported by QSAR study. Several aspects of the structure-activity relationships are discussed in terms of the contribution of different bonds to the antifungal activity, thereby making the relationships between structure and biological activity more transparent.

Structures, Material and Processes Technology in the Future Launchers Preparatory Program

NASA Astrophysics Data System (ADS)

Baiocco, P.; Ramusat, G.; Breteau, J.; Bouilly, Th.; Lavelle, Fl.; Cardone, T.; Fischer, H.; Appel, S.; Block, U.

2014-06-01

In the frame of the technology / demonstration activity for European launchers developments and evolutions, a top-down / bottom-up approach has been employed to identify promising technologies and alternative conception. The top-down approach consists in looking for system-driven design solutions and the bottom-up approach features design solutions leading to substantial advantages for the system. The main investigations have been devoted to structures, material and process technology.Preliminary specifications have been used in order to permit sub-system design with the goal to find the major benefit for the overall launch system. In this respect competitiveness factors have been defined to down- select the technology and the corresponding optimized design. The development cost, non-recurring cost, industrialization and operational aspects have been considered for the identification of the most interesting solutions. The TRL/IRL has been assessed depending on the manufacturing company and a preliminary development plan has been issued for some technology.The reference launch systems for the technology and demonstration programs are mainly Ariane 6 with its evolutions, VEGA C/E and others possible longer term systems. Requirements and reference structures architectures have been considered in order to state requirements for representative subscale or full scale demonstrators. The major sub-systems and structures analyzed are for instance the upper stage structures, the engine thrust frame (ETF), the inter stage structures (ISS), the cryogenic propellant tanks, the feeding lines and their attachments, the pressurization systems, the payload adapters and fairings. A specific analysis has been devoted to the efficiency of production processes associated to technologies and design features.The paper provides an overview of the main results of the technology and demonstration activities with the associated system benefits. The materials used for the main structures are metallic and composite owing to sub-systems or sub-assemblies proposed for the European launch systems in development and their evolutions.

Modelling and simulation of complex sociotechnical systems: envisioning and analysing work environments

PubMed Central

Hettinger, Lawrence J.; Kirlik, Alex; Goh, Yang Miang; Buckle, Peter

2015-01-01

Accurate comprehension and analysis of complex sociotechnical systems is a daunting task. Empirically examining, or simply envisioning the structure and behaviour of such systems challenges traditional analytic and experimental approaches as well as our everyday cognitive capabilities. Computer-based models and simulations afford potentially useful means of accomplishing sociotechnical system design and analysis objectives. From a design perspective, they can provide a basis for a common mental model among stakeholders, thereby facilitating accurate comprehension of factors impacting system performance and potential effects of system modifications. From a research perspective, models and simulations afford the means to study aspects of sociotechnical system design and operation, including the potential impact of modifications to structural and dynamic system properties, in ways not feasible with traditional experimental approaches. This paper describes issues involved in the design and use of such models and simulations and describes a proposed path forward to their development and implementation. Practitioner Summary: The size and complexity of real-world sociotechnical systems can present significant barriers to their design, comprehension and empirical analysis. This article describes the potential advantages of computer-based models and simulations for understanding factors that impact sociotechnical system design and operation, particularly with respect to process and occupational safety. PMID:25761227

Comparison of High Aspect Ratio Cooling Channel Designs for a Rocket Combustion Chamber with Development of an Optimized Design

NASA Technical Reports Server (NTRS)

Wadel, Mary F.

1998-01-01

An analytical investigation on the effect of high aspect ratio (height/width) cooling channels, considering different coolant channel designs, on hot-gas-side wall temperature and coolant pressure drop for a liquid hydrogen cooled rocket combustion chamber, was performed. Coolant channel design elements considered were: length of combustion chamber in which high aspect ratio cooling was applied, number of coolant channels, and coolant channel shape. Seven coolant channel designs were investigated using a coupling of the Rocket Thermal Evaluation code and the Two-Dimensional Kinetics code. Initially, each coolant channel design was developed, without consideration for fabrication, to reduce the hot-gas-side wall temperature from a given conventional cooling channel baseline. These designs produced hot-gas-side wall temperature reductions up to 22 percent, with coolant pressure drop increases as low as 7.5 percent from the baseline. Fabrication constraints for milled channels were applied to the seven designs. These produced hot-gas-side wall temperature reductions of up to 20 percent, with coolant pressure drop increases as low as 2 percent. Using high aspect ratio cooling channels for the entire length of the combustion chamber had no additional benefit on hot-gas-side wall temperature over using high aspect ratio cooling channels only in the throat region, but increased coolant pressure drop 33 percent. Independent of coolant channel shape, high aspect ratio cooling was able to reduce the hot-gas-side wall temperature by at least 8 percent, with as low as a 2 percent increase in coolant pressure drop. ne design with the highest overall benefit to hot-gas-side wall temperature and minimal coolant pressure drop increase was the design which used bifurcated cooling channels and high aspect ratio cooling in the throat region. An optimized bifurcated high aspect ratio cooling channel design was developed which reduced the hot-gas-side wall temperature by 18 percent and reduced the coolant pressure drop by 4 percent. Reductions of coolant mass flow rate of up to 50 percent were possible before the hot-gas-side wall temperature reached that of the baseline. These mass flow rate reductions produced coolant pressure drops of up to 57 percent.

Coupling of electromagnetics and structural/fluid dynamics - application to the dual coolant blanket subjected to plasma disruptions

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

Jordan, T.

Some aspects concerning the coupling of quasi-stationary electromagnetics and the dynamics of structure and fluid are investigated. The necessary equations are given in a dimensionless form. The dimensionless parameters in these equations are used to evaluate the importance of the different coupling effects. A finite element formulation of the eddy-current damping in solid structures is developed. With this formulation, an existing finite element method (FEM) structural dynamics code is extended and coupled to an FEM eddy-current code. With this program system, the influence of the eddy-current damping on the dynamic loading of the dual coolant blanket during a centered plasmamore » disruption is determined. The analysis proves that only in loosely fixed or soft structures will eddy-current damping considerably reduce the resulting stresses. Additionally, the dynamic behavior of the liquid metal in the blankets` poloidal channels is described with a simple two-dimensional magnetohydrodynamic approach. The analysis of the dimensionless parameters shows that for small-scale experiments, which are designed to model the coupled electromagnetic and structural/fluid dynamic effects in such a blanket, the same magnetic fields must be applied as in the real fusion device. This will be the easiest way to design experiments that produce transferable results. 10 refs., 7 figs.« less

Redesigning of a Canard Control Surface of an Advanced Fighter Aircraft: Effect on Buckling and Aerodynamic Behavior

NASA Astrophysics Data System (ADS)

Shrivastava, Sachin; Mohite, P. M.

2015-01-01

A redesign of canard control-surface of an advanced all-metallic fighter aircraft was carried out by using carbon fibre composite (CFC) for ribs and panels. In this study ply-orientations of CFC structure are optimized using a Genetic-Algorithm (GA) with an objective function to have minimum failure index (FI) according to Tsai-Wu failure criterion. The redesigned CFC structure was sufficiently strong to withstand aerodynamic loads from stress and deflection points of view. Now, in the present work CFC canard structure has been studied for its buckling strength in comparison to existing metallic design. In this study, the existing metallic design was found to be weak in buckling. Upon a detailed investigation, it was revealed that there are reported failures in the vicinity of zones where initial buckling modes are excited as predicted by the finite element based buckling analysis. In view of buckling failures, the redesigned CFC structure is sufficiently reinforced with stringers at specific locations. After providing reinforcements against buckling, the twist and the camber variations of the airfoil are checked and compared with existing structure data. Finally, the modal analysis has been carried out to compare the variation in excitation frequency due to material change. The CFC structure thus redesigned is safe from buckling and aerodynamic aspects as well.

Modeling Of Object- And Scene-Prototypes With Hierarchically Structured Classes

NASA Astrophysics Data System (ADS)

Ren, Z.; Jensch, P.; Ameling, W.

1989-03-01

The success of knowledge-based image analysis methodology and implementation tools depends largely on an appropriately and efficiently built model wherein the domain-specific context information about and the inherent structure of the observed image scene have been encoded. For identifying an object in an application environment a computer vision system needs to know firstly the description of the object to be found in an image or in an image sequence, secondly the corresponding relationships between object descriptions within the image sequence. This paper presents models of image objects scenes by means of hierarchically structured classes. Using the topovisual formalism of graph and higraph, we are currently studying principally the relational aspect and data abstraction of the modeling in order to visualize the structural nature resident in image objects and scenes, and to formalize. their descriptions. The goal is to expose the structure of image scene and the correspondence of image objects in the low level image interpretation. process. The object-based system design approach has been applied to build the model base. We utilize the object-oriented programming language C + + for designing, testing and implementing the abstracted entity classes and the operation structures which have been modeled topovisually. The reference images used for modeling prototypes of objects and scenes are from industrial environments as'well as medical applications.

[Motivation and self-directed learning among medical students].

PubMed

Fasce H, Eduardo; Ortega B, Javiera; Ibáñez G, Pilar; Márquez U, Carolina; Pérez V, Cristhian; Bustamante D, Carolina; Ortiz M, Liliana; Matus B, Olga; Bastías V, Nancy; Espinoza P, Camila

2016-05-01

Motivation is an essential aspect in the training process of medical students. The association that motivation can have with learning self-regulation is of utmost importance for the design of curriculum, teaching methods and evaluation. To describe the motivational aspects of self-directed learning among medical students from a traditional Chilean University. A qualitative, descriptive study based on grounded theory of Strauss and Corbin. Twenty 4th and 5th year medical students were selected using a maximum variation sampling technique. After obtaining an informed consent, semi-structured interviews and field notes were carried out. Data were analyzed to the level of open coding through Atlas-ti 7.5.2. From the student point of view, personal motivational aspects are linked to the search for information, constant updating, the perception of the physician-patient relationship and interest in subject matters. From the scope of teachers, a main issue is related to their ability to motivate students to develop independent study skills. Personal motivational aspects facilitate the development of independent study skills, specifically in the search of information. The role of teachers is crucial in promoting these skills and the perception of medical students from their learning process.

Closing the door on flaviviruses: entry as a target for antiviral drug design.

PubMed

Perera, Rushika; Khaliq, Mansoora; Kuhn, Richard J

2008-10-01

With the emergence and rapid spread of West Nile virus in the United States since 1999, and the 50-100 million infections per year caused by dengue virus globally, the threat of flaviviruses as re-emerging human pathogens has become a reality. To support the efforts that are currently being pursued to develop effective vaccines against these viruses, researchers are also actively pursuing the development of small molecule compounds that target various aspects of the virus life cycle. Recent advances in the structural characterization of the flaviviruses have provided a strong foundation towards these efforts. These studies have provided the pseudo-atomic structures of virions from several members of the genus as well as atomic resolution structures of several viral proteins. Most importantly, these studies have highlighted specific structural rearrangements that occur within the virion that are necessary for the virus to complete its life cycle. These rearrangements occur when the virus must transition from immature, to mature, to fusion-active states and rely heavily on the conformational flexibility of the envelope (E) protein that forms the outer glycoprotein shell of the virus. Analysis of these conformational changes can suggest promising targets for structure-based antiviral design. For instance, by targeting the flexibility of the E protein, it might be possible to inhibit required rearrangements of this protein and trap the virus in a specific state. This would interfere with a productive flaviviral infection. This review presents a structural perspective of the flavivirus life cycle and focuses on the role of the E protein as an opportune target for structure-based antiviral drug design.

[Liquidation of barriers: realization issues and legislative aspects].

PubMed

Półchłopek, T

1998-01-01

Designing for the handicapped persons, aiming at the liquidation of the barriers is actually an essential part of the architects activity. It results from the fact that the handicapped persons issue became the interdisciplinary one. The architect, being responsible for the living space and environment creation, is to design the friendly environment for the handicapped persons. The space favourable for the handicapped is favourable for all. There are many aspects of the designing for the handicapped; legislative or execution issues are the examples. The legislative aspect is presented in this paper on the base of the contemporary legal rules of the Polish Republic, whereas the execution aspect is introduced and discussed on the basis of the two projects designed by the Design Bureau in Cracow and being currently in realization. These are: housing & service unit (Boruty-Spiechowicza Str., Cracow) and the Faculty of Philosophy complex at the Jesuits College (Kopernika Str., Cracow).

Putting a finishing touch on GECIs

PubMed Central

Rose, Tobias; Goltstein, Pieter M.; Portugues, Ruben; Griesbeck, Oliver

2014-01-01

More than a decade ago genetically encoded calcium indicators (GECIs) entered the stage as new promising tools to image calcium dynamics and neuronal activity in living tissues and designated cell types in vivo. From a variety of initial designs two have emerged as promising prototypes for further optimization: FRET (Förster Resonance Energy Transfer)-based sensors and single fluorophore sensors of the GCaMP family. Recent efforts in structural analysis, engineering and screening have broken important performance thresholds in the latest generation for both classes. While these improvements have made GECIs a powerful means to perform physiology in living animals, a number of other aspects of sensor function deserve attention. These aspects include indicator linearity, toxicity and slow response kinetics. Furthermore creating high performance sensors with optically more favorable emission in red or infrared wavelengths as well as new stably or conditionally GECI-expressing animal lines are on the wish list. When the remaining issues are solved, imaging of GECIs will finally have crossed the last milestone, evolving from an initial promise into a fully matured technology. PMID:25477779

Questions for Surveys

PubMed Central

Schaeffer, Nora Cate; Dykema, Jennifer

2011-01-01

We begin with a look back at the field to identify themes of recent research that we expect to continue to occupy researchers in the future. As part of this overview, we characterize the themes and topics examined in research about measurement and survey questions published in Public Opinion Quarterly in the past decade. We then characterize the field more broadly by highlighting topics that we expect to continue or to grow in importance, including the relationship between survey questions and the total survey error perspective, cognitive versus interactional approaches, interviewing practices, mode and technology, visual aspects of question design, and culture. Considering avenues for future research, we advocate for a decision-oriented framework for thinking about survey questions and their characteristics. The approach we propose distinguishes among various aspects of question characteristics, including question topic, question type and response dimension, conceptualization and operationalization of the target object, question structure, question form, response categories, question implementation, and question wording. Thinking about question characteristics more systematically would allow study designs to take into account relationships among these characteristics and identify gaps in current knowledge. PMID:24970951

Introducing depolarisation into an inexpensive, simple cloud sensor for standoff aerosol detection

NASA Astrophysics Data System (ADS)

Hopkins, Rebecca J.; Jones, Joseph W.; Barrington, Stephen J.; Foot, Virginia; Baxter, Karen L.

2008-04-01

Light detection and ranging (LIDAR) has potential to be a successful technique for remote detection of airborne biological warfare agents (BWA) that pose a health hazard. Potential techniques for detecting BWA often use spectroscopy to probe molecular structure properties (e.g. UV-fluorescence, Raman and differential absorption spectroscopy). An alternative approach is to differentiate BWA from background interferents by their differing morphology; depolarisation offers one such method. Here, we investigate the feasibility of introducing depolarisation into a short range (approximately 10 m) LIDAR designed to be a simple, inexpensive, low power consumption, portable instrument. T-matrix calculations are presented for a randomly oriented, polydisperse size distribution of Bacillus atrophaeus spheroids. The relationship between backscatter depolarisation and particle aspect ratio is investigated at several incident wavelengths corresponding to those produced by low cost, commercially available laser sources. Through a series of simulations, we determine the best combination of wavelengths for a multi-wavelength instrument design that exploits the concept of normalised depolarisation to determine particle aspect ratio, with the possibility of facilitating BWA detection.

User Evaluation of Neonatology Ward Design.

PubMed

Trujillo, Juan Luis Higuera; Aviñó, Antoni Montañana I; Millán, Carmen Llinares

2017-01-01

The object of this article is to identify the set of affective and emotional factors behind users' assessments of a space in a neonatology unit and to propose design guidelines based on these. The importance of the neonatology service and the variety of users place great demands on the space at all levels. Despite the repercussions, the emotional aspects of the environment have received less attention. To avoid incurring limitations in the user mental scheme, this study uses two complementary methodologies: focus group and semantic differential. The (qualitative) focus group methodology provides exploratory information and concepts. The (quantitative) semantic differential methodology then uses these concepts to extract the conceptual structures that users employ in their assessment of the space. Of the total 175 subjects, 31 took part in focus groups and 144 in semantic differential. Five independent concepts were identified: privacy, functionality and professional nature, spaciousness, lighting, and cleanliness. In relation to the importance of the overall positive assessment of the space, the perception of privacy and sensations of dominance and pleasure are fundamental. Six relevant design aspects were also identified: provide spacious surroundings, facilitate sufficient separation between the different posts or cots, use different colors from those usually found in health-care centers, as some aversion was found to white and especially green, design areas with childhood themes, use warm artificial light, and choose user-friendly equipment. Results provide design recommendations of interest and show the possibilities offered by combining both systems to analyze user response.

Rotorcraft system identification techniques for handling qualities and stability and control evaluation

NASA Technical Reports Server (NTRS)

Hall, W. E., Jr.; Gupta, N. K.; Hansen, R. S.

1978-01-01

An integrated approach to rotorcraft system identification is described. This approach consists of sequential application of (1) data filtering to estimate states of the system and sensor errors, (2) model structure estimation to isolate significant model effects, and (3) parameter identification to quantify the coefficient of the model. An input design algorithm is described which can be used to design control inputs which maximize parameter estimation accuracy. Details of each aspect of the rotorcraft identification approach are given. Examples of both simulated and actual flight data processing are given to illustrate each phase of processing. The procedure is shown to provide means of calibrating sensor errors in flight data, quantifying high order state variable models from the flight data, and consequently computing related stability and control design models.

Humanisation and soft qualities in emergency rooms.

PubMed

Buffoli, Maddalena; Bellini, Eva; Dell'Ovo, Marta; Gola, Marco; Nachiero, Dario; Rebecchi, Andrea; Capolongo, Stefano

2016-01-01

Scenario. Currently, there are few evaluation methods that analyse social aspects in healthcare issues, especially humanisation and well-being, as perceived by users in emergency departments which are places in which patients' psycho-physical well-being is decisive. For this reason, research was conducted to create a tool to improve the quality of these areas. In order to conduct the research, the work was structured in three phases: the first, based on the analysis of State-of-the-Art and the current studies on the interactions established between the physical and emotional conditions of the structure and the users; the second, through the definition of a questionnaire which explores humanisation and comfort aspects; the third, through the application of the instrument. The paper presents and analyses data collected from the application on a case study in Milan, analysing the responses and proposing design suggestions for increasing the quality of emergency environments. In anticipation of future works, the application of such a tool can provide the opportunity to improve and enhance quality and staff efficiency in emergency department spaces.

Recommendations on basic requirements for intensive care units: structural and organizational aspects.

PubMed

Valentin, Andreas; Ferdinande, Patrick

2011-10-01

To provide guidance and recommendations for the planning or renovation of intensive care units (ICUs) with respect to the specific characteristics relevant to organizational and structural aspects of intensive care medicine. The Working Group on Quality Improvement (WGQI) of the European Society of Intensive Care Medicine (ESICM) identified the basic requirements for ICUs by a comprehensive literature search and an iterative process with several rounds of consensus finding with the participation of 47 intensive care physicians from 23 countries. The starting point of this process was an ESICM recommendation published in 1997 with the need for an updated version. The document consists of operational guidelines and design recommendations for ICUs. In the first part it covers the definition and objectives of an ICU, functional criteria, activity criteria, and the management of equipment. The second part deals with recommendations with respect to the planning process, floorplan and connections, accommodation, fire safety, central services, and the necessary communication systems. This document provides a detailed framework for the planning or renovation of ICUs based on a multinational consensus within the ESICM.

Rectenna session: Micro aspects. [energy conversion

NASA Technical Reports Server (NTRS)

Gutmann, R. J.

1980-01-01

Two micro aspects of the rectenna design are addressed: evaluation of the degradation in net rectenna RF to DC conversion efficiency due to power density variations across the rectenna (power combining analysis) and design of Yagi-Uda receiving elements to reduce rectenna cost by decreasing the number of conversion circuits (directional receiving elements). The first of these micro aspects involves resolving a fundamental question of efficiency potential with a rectenna, while the second involves a design modification with a large potential cost saving.

Theoretical Aspects of Laser-Induced Periodic Surface Structure Formation,

DTIC Science & Technology

1983-11-01

r AD-A134 875 UNCLASSIFIED THEORETICAL ASPECTS OF LASER -INUUCtl) PtKlUUlt bUKhALt STRUCTURE FORMATION(U) ROCHESTER UNIV NY DEPT OF CHEMISTRY M...UR0CHESTER/DC/83/TR-43 2. COVT ACCESSION NO A. TITLE (and Subllllm) Theoretical Aspects of Laser -Induced Periodic Surface Structure Formation 7...publication in Laser -Controlled Chemical Processing of Surfaces, ed. by A. W. Johnson and D. J. Ehrlich (Elsevier, New York) 19 KEY WORDS (Continue

Aminooxylated Carbohydrates: Synthesis and Applications.

PubMed

Pifferi, Carlo; Daskhan, Gour Chand; Fiore, Michele; Shiao, Tze Chieh; Roy, René; Renaudet, Olivier

2017-08-09

Among other classes of biomolecules, carbohydrates and glycoconjugates are widely involved in numerous biological functions. In addition to addressing the related synthetic challenges, glycochemists have invested intense efforts in providing access to structures that can be used to study, activate, or inhibit these biological processes. Over the past few decades, aminooxylated carbohydrates have been found to be key building blocks for achieving these goals. This review provides the first in-depth overview covering several aspects related to the syntheses and applications of aminooxylated carbohydrates. After a brief introduction to oxime bonds and their relative stabilities compared to related C═N functions, synthetic aspects of oxime ligation and methodologies for introducing the aminooxy functionality onto both glycofuranosyls and glycopyranosyls are described. The subsequent section focuses on biological applications involving aminooxylated carbohydrates as components for the construcion of diverse architectures. Mimetics of natural structures represent useful tools for better understanding the features that drive carbohydrate-receptor interaction, their biological output and they also represent interesting structures with improved stability and tunable properties. In the next section, multivalent structures such as glycoclusters and glycodendrimers obtained through oxime ligation are described in terms of synthetic design and their biological applications such as immunomodulators. The second-to-last section discusses miscellaneous applications of oxime-based glycoconjugates, such as enantioselective catalysis and glycosylated oligonucleotides, and conclusions and perspectives are provided in the last section.

Conceptual Design of the Chornobyl New Safe Confinement - an Overview

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

Kulishenko, Valery N.; Hogg, Charles; Schmieman, Eric A.

2006-05-01

The Object Shelter, constructed over the Chornobyl nuclear power plant that was destroyed by a 1986 accident, is at risk of collapse. The Consortium of Bechtel, Electricité De France, and Battelle, in cooperation with subcontractor КСК, recently completed the conceptual design for a New Safe Confinement (NSC) building to reduce Shelter corrosion, to mitigate the consequences of potential collapse, and to enable the safe deconstruction of unstable structures. The arch-shaped NSC will be constructed at a distance from the Shelter to minimize radiation exposure to construction workers, and then slid into place over the Shelter. After sliding, cranes and othermore » tools inside the NSC will be remotely operated for deconstruction of the Shelter. The NSC is designed for a 100-year life. Bechtel designed the arch structure and was responsible for project management functions. Electricité De France designed the foundations and designed deconstruction of the Object Shelter unstable elements. Battelle performed safety analyses and environmental impact assessment. КСК (a consortium of КIЕЛ [KIEP], НДIБК [NIISK], and МНТЦ [ISTC]), as a working partner in all aspects of the design and analysis processes, was the Ukrainian licensed engineer for conceptual design. The design is currently being reviewed by Ukrainian regulatory authorities. An open international tender for detailed design and construction is anticipated to be announced by the European Bank for Reconstruction and Development in December, 2003, with two-stage bid evaluation beginning in April, 2004.« less

Design of a Nanoscale, CMOS-Integrable, Thermal-Guiding Structure for Boolean-Logic and Neuromorphic Computation.

PubMed

Loke, Desmond; Skelton, Jonathan M; Chong, Tow-Chong; Elliott, Stephen R

2016-12-21

One of the requirements for achieving faster CMOS electronics is to mitigate the unacceptably large chip areas required to steer heat away from or, more recently, toward the critical nodes of state-of-the-art devices. Thermal-guiding (TG) structures can efficiently direct heat by "meta-materials" engineering; however, some key aspects of the behavior of these systems are not fully understood. Here, we demonstrate control of the thermal-diffusion properties of TG structures by using nanometer-scale, CMOS-integrable, graphene-on-silica stacked materials through finite-element-methods simulations. It has been shown that it is possible to implement novel, controllable, thermally based Boolean-logic and spike-timing-dependent plasticity operations for advanced (neuromorphic) computing applications using such thermal-guide architectures.

3D capacitive tactile sensor using DRIE micromachining

NASA Astrophysics Data System (ADS)

Chuang, Chiehtang; Chen, Rongshun

2005-07-01

This paper presents a three dimensional micro capacitive tactile sensor that can detect normal and shear forces which is fabricated using deep reactive ion etching (DRIE) bulk silicon micromachining. The tactile sensor consists of a force transmission plate, a symmetric suspension system, and comb electrodes. The sensing character is based on the changes of capacitance between coplanar sense electrodes. High sensitivity is achieved by using the high aspect ratio interdigital electrodes with narrow comb gaps and large overlap areas. The symmetric suspension mechanism of this sensor can easily solve the coupling problem of measurement and increase the stability of the structure. In this paper, the sensor structure is designed, the capacitance variation of the proposed device is theoretically analyzed, and the finite element analysis of mechanical behavior of the structures is performed.

Structural sensitivity of x-ray Bragg projection ptychography to domain patterns in epitaxial thin films

DOE PAGES

Hruszkewycz, S. O.; Zhang, Q.; Holt, M. V.; ...

2016-10-04

Bragg projection ptychography (BPP) is a coherent diffraction imaging technique capable of mapping the spatial distribution of the Bragg structure factor in nanostructured thin films. Here, we show that, because these images are projections, the structural sensitivity of the resulting images depends on the film thickness and the aspect ratio and orientation of the features of interest and that image interpretation depends on these factors. Lastly, we model changes in contrast in the BPP reconstructions of simulated PbTiO 3 ferroelectric thin films with meandering 180° stripe domains as a function of film thickness, discuss their origin, and comment on themore » implication of these factors on the design of BPP experiments of general nanostructured films.« less

Evaluation of the Implications of Nanoscale Architectures on Contextual Knowledge Discovery and Memory: Self-Assembled Architectures and Memory

DTIC Science & Technology

2008-05-01

patterns. Our strategy to nucleate Ag nanoparticles has been to use a templating protein (e.g., streptavidin) that has been chemically pre- charged with...assembly is used to direct the formation of switching devices and wires to create logic circuitry, memory, and I/O interfaces . We can control the reaction...determines the formation of structures (through complementarity ). Sequence design is important because it determines many aspects of the target DNA

An overview of removable partial overdentures.

PubMed

McDermott, I G; Samant, A

1990-02-01

As an alternative to complete dentures, overdentures are well established as a sound therapeutic modality for patients with terminal dentition. By utilizing natural tooth roots and their periodontal structures to aid in support, overdentures maintain proprioceptive mediation and a mechanism for masticatory force vectors that favor bone retention over bond resorption. The degree of stability enhancement and denture retention from retained roots varies with the design and environment of the prosthesis. This article reviews various aspects of removable partial over-denture use.

Spaceborne synthetic aperture radar pilot study

NASA Technical Reports Server (NTRS)

1974-01-01

A pilot study of a spaceborne sidelooking radar is summarized. The results of the system trade studies are given along with the electrical parameters for the proposed subsystems. The mechanical aspects, packaging, thermal control and dynamics of the proposed design are presented. Details of the data processor are given. A system is described that allows the data from a pass over the U. S. to be in hard copy form within two hours. Also included are the proposed schedule, work breakdown structure, and cost estimate.

Acicular photomultiplier photocathode structure

DOEpatents

Craig, Richard A.; Bliss, Mary

2003-09-30

A method and apparatus for increasing the quantum efficiency of a photomultiplier tube by providing a photocathode with an increased surface-to-volume ratio. The photocathode includes a transparent substrate, upon one major side of which is formed one or more large aspect-ratio structures, such as needles, cones, fibers, prisms, or pyramids. The large aspect-ratio structures are at least partially composed of a photoelectron emitting material, i.e., a material that emits a photoelectron upon absorption of an optical photon. The large aspect-ratio structures may be substantially composed of the photoelectron emitting material (i.e., formed as such upon the surface of a relatively flat substrate) or be only partially composed of a photoelectron emitting material (i.e., the photoelectron emitting material is coated over large aspect-ratio structures formed from the substrate material itself.) The large aspect-ratio nature of the photocathode surface allows for an effective increase in the thickness of the photocathode relative the absorption of optical photons, thereby increasing the absorption rate of incident photons, without substantially increasing the effective thickness of the photocathode relative the escape incidence of the photoelectrons.

Multidisciplinary Design Techniques Applied to Conceptual Aerospace Vehicle Design. Ph.D. Thesis Final Technical Report

NASA Technical Reports Server (NTRS)

Olds, John Robert; Walberg, Gerald D.

1993-01-01

Multidisciplinary design optimization (MDO) is an emerging discipline within aerospace engineering. Its goal is to bring structure and efficiency to the complex design process associated with advanced aerospace launch vehicles. Aerospace vehicles generally require input from a variety of traditional aerospace disciplines - aerodynamics, structures, performance, etc. As such, traditional optimization methods cannot always be applied. Several multidisciplinary techniques and methods were proposed as potentially applicable to this class of design problem. Among the candidate options are calculus-based (or gradient-based) optimization schemes and parametric schemes based on design of experiments theory. A brief overview of several applicable multidisciplinary design optimization methods is included. Methods from the calculus-based class and the parametric class are reviewed, but the research application reported focuses on methods from the parametric class. A vehicle of current interest was chosen as a test application for this research. The rocket-based combined-cycle (RBCC) single-stage-to-orbit (SSTO) launch vehicle combines elements of rocket and airbreathing propulsion in an attempt to produce an attractive option for launching medium sized payloads into low earth orbit. The RBCC SSTO presents a particularly difficult problem for traditional one-variable-at-a-time optimization methods because of the lack of an adequate experience base and the highly coupled nature of the design variables. MDO, however, with it's structured approach to design, is well suited to this problem. The result of the application of Taguchi methods, central composite designs, and response surface methods to the design optimization of the RBCC SSTO are presented. Attention is given to the aspect of Taguchi methods that attempts to locate a 'robust' design - that is, a design that is least sensitive to uncontrollable influences on the design. Near-optimum minimum dry weight solutions are determined for the vehicle. A summary and evaluation of the various parametric MDO methods employed in the research are included. Recommendations for additional research are provided.

Atomic layer deposition frequency-multiplied Fresnel zone plates for hard x-rays focusing

DOE PAGES

Moldovan, Nicolaie; Divan, Ralu; Zeng, Hongjun; ...

2017-12-01

The design and fabrication of Fresnel zone plates for hard x-ray focusing up to 25 keV photon energies with better than 50 nm imaging half-pitch resolution is reported as performed by forming an ultrananocrystalline diamond (UNCD) scaffold, subsequently coating it with atomic layer deposition (ALD) with an absorber/phase shifting material, followed by back side etching of Si to form a diamond membrane device. The scaffold is formed by chemical vapor-deposited UNCD, electron beam lithography, and deep-reactive ion etching of diamond to desired specifications. The benefits of using diamond are as follows: improved mechanical robustness to prevent collapse of high-aspect-ratio ringmore » structures, a known high-aspect-ratio etch method, excellent radiation hardness, extremely low x-ray absorption, and significantly improved thermal/dimensional stability as compared to alternative materials. Central to the technology is the high-resolution patterning of diamond membranes at wafer scale, which was pushed to 60 nm lines and spaces etched 2.2-mu m-deep, to an aspect ratio of 36:1. The absorber growth was achieved by ALD of Ir, Pt, or W, while wafer-level processing allowed to obtain up to 121 device chips per 4 in. wafer with yields better than 60%. X-ray tests with such zone plates allowed resolving 50 nm lines and spaces, at the limit of the available resolution test structures.« less

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

Moldovan, Nicolaie; Divan, Ralu; Zeng, Hongjun

The design and fabrication of Fresnel zone plates for hard x-ray focusing up to 25 keV photon energies with better than 50 nm imaging half-pitch resolution is reported as performed by forming an ultrananocrystalline diamond (UNCD) scaffold, subsequently coating it with atomic layer deposition (ALD) with an absorber/phase shifting material, followed by back side etching of Si to form a diamond membrane device. The scaffold is formed by chemical vapor-deposited UNCD, electron beam lithography, and deep-reactive ion etching of diamond to desired specifications. The benefits of using diamond are as follows: improved mechanical robustness to prevent collapse of high-aspect-ratio ringmore » structures, a known high-aspect-ratio etch method, excellent radiation hardness, extremely low x-ray absorption, and significantly improved thermal/dimensional stability as compared to alternative materials. Central to the technology is the high-resolution patterning of diamond membranes at wafer scale, which was pushed to 60 nm lines and spaces etched 2.2-mu m-deep, to an aspect ratio of 36:1. The absorber growth was achieved by ALD of Ir, Pt, or W, while wafer-level processing allowed to obtain up to 121 device chips per 4 in. wafer with yields better than 60%. X-ray tests with such zone plates allowed resolving 50 nm lines and spaces, at the limit of the available resolution test structures.« less

QSAR modeling based on structure-information for properties of interest in human health.

PubMed

Hall, L H; Hall, L M

2005-01-01

The development of QSAR models based on topological structure description is presented for problems in human health. These models are based on the structure-information approach to quantitative biological modeling and prediction, in contrast to the mechanism-based approach. The structure-information approach is outlined, starting with basic structure information developed from the chemical graph (connection table). Information explicit in the connection table (element identity and skeletal connections) leads to significant (implicit) structure information that is useful for establishing sound models of a wide range of properties of interest in drug design. Valence state definition leads to relationships for valence state electronegativity and atom/group molar volume. Based on these important aspects of molecules, together with skeletal branching patterns, both the electrotopological state (E-state) and molecular connectivity (chi indices) structure descriptors are developed and described. A summary of four QSAR models indicates the wide range of applicability of these structure descriptors and the predictive quality of QSAR models based on them: aqueous solubility (5535 chemically diverse compounds, 938 in external validation), percent oral absorption (%OA, 417 therapeutic drugs, 195 drugs in external validation testing), AMES mutagenicity (2963 compounds including 290 therapeutic drugs, 400 in external validation), fish toxicity (92 substituted phenols, anilines and substituted aromatics). These models are established independent of explicit three-dimensional (3-D) structure information and are directly interpretable in terms of the implicit structure information useful to the drug design process.

Thiazolidine-2,4-dione derivatives: programmed chemical weapons for key protein targets of various pathological conditions.

PubMed

Chadha, Navriti; Bahia, Malkeet Singh; Kaur, Maninder; Silakari, Om

2015-07-01

Thiazolidine-2,4-dione is an extensively explored heterocyclic nucleus for designing of novel agents implicated for a wide variety of pathophysiological conditions, that is, diabetes, diabetic complications, cancer, arthritis, inflammation, microbial infection, and melanoma, etc. The current paradigm of drug development has shifted to the structure-based drug design, since high-throughput screenings have continued to generate disappointing results. The gap between hit generation and drug establishment can be narrowed down by investigation of ligand interactions with its receptor protein. Therefore, it would always be highly beneficial to gain knowledge of molecular level interactions between specific protein target and developed ligands; since this information can be maneuvered to design new molecules with improved protein fitting. Thus, considering this aspect, we have corroborated the information about molecular (target) level implementations of thiazolidine-2,4-diones (TZD) derivatives having therapeutic implementations such as, but not limited to, anti-diabetic (glitazones), anti-cancer, anti-arthritic, anti-inflammatory, anti-oxidant and anti-microbial, etc. The structure based SAR of TZD derivatives for various protein targets would serve as a benchmark for the alteration of existing ligands to design new ones with better binding interactions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Behaviour of Reinforced Concrete Columns of Various Cross-Sections Subjected to Fire

NASA Astrophysics Data System (ADS)

Balaji, Aneesha; Muhamed Luquman, K.; Nagarajan, Praveen; Madhavan Pillai, T. M.

2016-09-01

Fire resistance is one of the crucial design regulations which are now mandatory in most of the design codes. Therefore, a thorough knowledge of behaviour of structures exposed to fire is required in this aspect. Columns are the most vulnerable structural member to fire as it can be exposed to fire from all sides. However, the data available for fire resistant design for columns are limited. Hence the present work is focused on the effect of cross-sectional shape of column in fire resistance design. The various cross-sections considered are Square, Ell (L), Tee (T), and Plus (`+') shape. Also the effect of size and shape and distribution of steel reinforcement on fire resistance of columns is studied. As the procedure for determining fire resistance is not mentioned in Indian Standard code IS 456 (2000), the simplified method (500 °C isotherm method) recommended in EN 1992-1-2:2004 (E) (Eurocode 2) is adopted. The temperature profiles for various cross-sections are developed using finite element method and these profiles are used to predict fire resistance capability of compression members. The fire resistance based on both numerical and code based methods are evaluated and compared for various types of cross-section.

CavityPlus: a web server for protein cavity detection with pharmacophore modelling, allosteric site identification and covalent ligand binding ability prediction.

PubMed

Xu, Youjun; Wang, Shiwei; Hu, Qiwan; Gao, Shuaishi; Ma, Xiaomin; Zhang, Weilin; Shen, Yihang; Chen, Fangjin; Lai, Luhua; Pei, Jianfeng

2018-05-10

CavityPlus is a web server that offers protein cavity detection and various functional analyses. Using protein three-dimensional structural information as the input, CavityPlus applies CAVITY to detect potential binding sites on the surface of a given protein structure and rank them based on ligandability and druggability scores. These potential binding sites can be further analysed using three submodules, CavPharmer, CorrSite, and CovCys. CavPharmer uses a receptor-based pharmacophore modelling program, Pocket, to automatically extract pharmacophore features within cavities. CorrSite identifies potential allosteric ligand-binding sites based on motion correlation analyses between cavities. CovCys automatically detects druggable cysteine residues, which is especially useful to identify novel binding sites for designing covalent allosteric ligands. Overall, CavityPlus provides an integrated platform for analysing comprehensive properties of protein binding cavities. Such analyses are useful for many aspects of drug design and discovery, including target selection and identification, virtual screening, de novo drug design, and allosteric and covalent-binding drug design. The CavityPlus web server is freely available at http://repharma.pku.edu.cn/cavityplus or http://www.pkumdl.cn/cavityplus.

Knowledge based system and decision making methodologies in materials selection for aircraft cabin metallic structures

NASA Astrophysics Data System (ADS)

Adhikari, Pashupati Raj

Materials selection processes have been the most important aspects in product design and development. Knowledge-based system (KBS) and some of the methodologies used in the materials selection for the design of aircraft cabin metallic structures are discussed. Overall aircraft weight reduction means substantially less fuel consumption. Part of the solution to this problem is to find a way to reduce overall weight of metallic structures inside the cabin. Among various methodologies of materials selection using Multi Criterion Decision Making (MCDM) techniques, a few of them are demonstrated with examples and the results are compared with those obtained using Ashby's approach in materials selection. Pre-defined constraint values, mainly mechanical properties, are employed as relevant attributes in the process. Aluminum alloys with high strength-to-weight ratio have been second-to-none in most of the aircraft parts manufacturing. Magnesium alloys that are much lighter in weight as alternatives to the Al-alloys currently in use in the structures are tested using the methodologies and ranked results are compared. Each material attribute considered in the design are categorized as benefit and non-benefit attribute. Using Ashby's approach, material indices that are required to be maximized for an optimum performance are determined, and materials are ranked based on the average of consolidated indices ranking. Ranking results are compared for any disparity among the methodologies.