A Learning Design Ontology Based on the IMS Specification

ERIC Educational Resources Information Center

Amorim, Ricardo R.; Lama, Manuel; Sanchez, Eduardo; Riera, Adolfo; Vila, Xose A.

2006-01-01

In this paper, we present an ontology to represent the semantics of the IMS Learning Design (IMS LD) specification, a meta-language used to describe the main elements of the learning design process. The motivation of this work relies on the expressiveness limitations found on the current XML-Schema implementation of the IMS LD conceptual model. To…

Neutral buoyancy testing of architectural and environmental concepts of space vehicle design

NASA Technical Reports Server (NTRS)

Lenda, J. A.; Rosener, A. A.; Stephenson, M. L.

1972-01-01

Design guidelines are presented that are applicable to providing habitability areas and furniture elements for extended periods in a zero gravity environment. This was accomplished by: (1) analyzing the existing habitability crew area requirements, mobility and restraint aids, cross-cultural design, and establishing a man model for zero gravity; (2) designing specific furniture elements, chair and table, and volumes for a stateroom, office, bathroom, galley, and wardroom; and (3) neutral buoyancy testing and evaluation of these areas.

Determination of photovoltaic concentrator optical design specifications using performance modeling

NASA Astrophysics Data System (ADS)

Kerschen, Kevin A.; Levy, Sheldon L.

The strategy used to develop an optical design specification for a 500X concentration photovoltaic module to be used with a 28-percent-efficient concentrator photovoltaic cell is reported. The computer modeling code (PVOPTICS) developed for this purpose, a Fresnel lens design strategy, and optical component specification procedures are described. Comparisons are made between the predicted performance and the measured performance of components fabricated to those specifications. An acrylic lens and a reflective secondary optical element have been tested, showing efficiencies exceeding 88 percent.

An intelligent case-adjustment algorithm for the automated design of population-based quality auditing protocols.

PubMed

Advani, Aneel; Jones, Neil; Shahar, Yuval; Goldstein, Mary K; Musen, Mark A

2004-01-01

We develop a method and algorithm for deciding the optimal approach to creating quality-auditing protocols for guideline-based clinical performance measures. An important element of the audit protocol design problem is deciding which guide-line elements to audit. Specifically, the problem is how and when to aggregate individual patient case-specific guideline elements into population-based quality measures. The key statistical issue involved is the trade-off between increased reliability with more general population-based quality measures versus increased validity from individually case-adjusted but more restricted measures done at a greater audit cost. Our intelligent algorithm for auditing protocol design is based on hierarchically modeling incrementally case-adjusted quality constraints. We select quality constraints to measure using an optimization criterion based on statistical generalizability coefficients. We present results of the approach from a deployed decision support system for a hypertension guideline.

Construction typification as the tool for optimizing the functioning of a robotized manufacturing system

NASA Astrophysics Data System (ADS)

Gwiazda, A.; Banas, W.; Sekala, A.; Foit, K.; Hryniewicz, P.; Kost, G.

2015-11-01

Process of workcell designing is limited by different constructional requirements. They are related to technological parameters of manufactured element, to specifications of purchased elements of a workcell and to technical characteristics of a workcell scene. This shows the complexity of the design-constructional process itself. The results of such approach are individually designed workcell suitable to the specific location and specific production cycle. Changing this parameters one must rebuild the whole configuration of a workcell. Taking into consideration this it is important to elaborate the base of typical elements of a robot kinematic chain that could be used as the tool for building Virtual modelling of kinematic chains of industrial robots requires several preparatory phase. Firstly, it is important to create a database element, which will be models of industrial robot arms. These models could be described as functional primitives that represent elements between components of the kinematic pairs and structural members of industrial robots. A database with following elements is created: the base kinematic pairs, the base robot structural elements, the base of the robot work scenes. The first of these databases includes kinematic pairs being the key component of the manipulator actuator modules. Accordingly, as mentioned previously, it includes the first stage rotary pair of fifth stage. This type of kinematic pairs was chosen due to the fact that it occurs most frequently in the structures of industrial robots. Second base consists of structural robot elements therefore it allows for the conversion of schematic structures of kinematic chains in the structural elements of the arm of industrial robots. It contains, inter alia, the structural elements such as base, stiff members - simple or angular units. They allow converting recorded schematic three-dimensional elements. Last database is a database of scenes. It includes elements of both simple and complex: simple models of technological equipment, conveyors models, models of the obstacles and like that. Using these elements it could be formed various production spaces (robotized workcells), in which it is possible to virtually track the operation of an industrial robot arm modelled in the system.

Finite element structural redesign by large admissible perturbations

NASA Technical Reports Server (NTRS)

Bernitsas, Michael M.; Beyko, E.; Rim, C. W.; Alzahabi, B.

1991-01-01

In structural redesign, two structural states are involved; the baseline (known) State S1 with unacceptable performance, and the objective (unknown) State S2 with given performance specifications. The difference between the two states in performance and design variables may be as high as 100 percent or more depending on the scale of the structure. A Perturbation Approach to Redesign (PAR) is presented to relate any two structural states S1 and S2 that are modeled by the same finite element model and represented by different values of the design variables. General perturbation equations are derived expressing implicitly the natural frequencies, dynamic modes, static deflections, static stresses, Euler buckling loads, and buckling modes of the objective S2 in terms of its performance specifications, and S1 data and Finite Element Analysis (FEA) results. Large Admissible Perturbation (LEAP) algorithms are implemented in code RESTRUCT to define the objective S2 incrementally without trial and error by postprocessing FEA results of S1 with no additional FEAs. Systematic numerical applications in redesign of a 10 element 48 degree of freedom (dof) beam, a 104 element 192 dof offshore tower, a 64 element 216 dof plate, and a 144 element 896 dof cylindrical shell show the accuracy, efficiency, and potential of PAR to find an objective state that may differ 100 percent from the baseline design.

Specific coil design for SENSE: a six-element cardiac array.

PubMed

Weiger, M; Pruessmann, K P; Leussler, C; Röschmann, P; Boesiger, P

2001-03-01

In sensitivity encoding (SENSE), the effects of inhomogeneous spatial sensitivity of surface coils are utilized for signal localization in addition to common Fourier encoding using magnetic field gradients. Unlike standard Fourier MRI, SENSE images exhibit an inhomogeneous noise distribution, which crucially depends on the geometrical sensitivity relations of the coils used. Thus, for optimum signal-to-noise-ratio (SNR) and noise homogeneity, specialized coil configurations are called for. In this article we study the implications of SENSE imaging for coil layout by means of simulations and imaging experiments in a phantom and in vivo. New, specific design principles are identified. For SENSE imaging, the elements of a coil array should be smaller than for common phased-array imaging. Furthermore, adjacent coil elements should not overlap. Based on the findings of initial investigations, a configuration of six coils was designed and built specifically for cardiac applications. The in vivo evaluation of this array showed a considerable SNR increase in SENSE images, as compared with a conventional array. Magn Reson Med 45:495-504, 2001. Copyright 2001 Wiley-Liss, Inc.

Comparative Study of Antenna Elements for TDRSS Enhanced Multiple Access System

NASA Technical Reports Server (NTRS)

Kory, Carol L.; Lambert, Kevin; Acosta, Roberto; Nessel, James

2006-01-01

We compare three antennas, which are candidates for the TDRSS-Continuation enhanced MA array antenna elements. Measured and simulated data show very good agreement for all antenna elements. All of the antennas meet the specifications with the exception of the SBA isolation. However, improvements can likely be made with further design efforts.

Design Evolutuion of Hot Isotatic Press Cans for NTP Cermet Fuel Fabrication

NASA Technical Reports Server (NTRS)

Mireles, O. R.; Broadway, J.; Hickman, R.

2014-01-01

Nuclear Thermal Propulsion (NTP) is under consideration for potential use in deep space exploration missions due to desirable performance properties such as a high specific impulse (> 850 seconds). Tungsten (W)-60vol%UO2 cermet fuel elements are under development, with efforts emphasizing fabrication, performance testing and process optimization to meet NTP service life requirements [1]. Fuel elements incorporate design features that provide redundant protection from crack initiation, crack propagation potentially resulting in hot hydrogen (H2) reduction of UO2 kernels. Fuel erosion and fission product retention barriers include W coated UO2 fuel kernels, W clad internal flow channels and fuel element external W clad resulting in a fully encapsulated fuel element design as shown.

The design and testing of a memory metal actuated boom release mechanism

NASA Technical Reports Server (NTRS)

Powley, D. G.; Brook, G. B.

1979-01-01

A boom latch and release mechanism was designed, manufactured and tested, based on a specification for the ISEE-B satellite mechanism. From experimental results obtained, it is possible to calculate the energy available and the operating torques which can be achieved from a torsional shape memory element in terms of the reversible strain induced by prior working. Some guidelines to be followed when designing mechanisms actuated by shape memory elements are included.

Safety envelope for load tolerance of structural element design based on multi-stage testing

DOE PAGES

Park, Chanyoung; Kim, Nam H.

2016-09-06

Structural elements, such as stiffened panels and lap joints, are basic components of aircraft structures. For aircraft structural design, designers select predesigned elements satisfying the design load requirement based on their load-carrying capabilities. Therefore, estimation of safety envelope of structural elements for load tolerances would be a good investment for design purpose. In this article, a method of estimating safety envelope is presented using probabilistic classification, which can estimate a specific level of failure probability under both aleatory and epistemic uncertainties. An important contribution of this article is that the calculation uncertainty is reflected in building a safety envelope usingmore » Gaussian process, and the effect of element test data on reducing the calculation uncertainty is incorporated by updating the Gaussian process model with the element test data. It is shown that even one element test can significantly reduce the calculation uncertainty due to lacking knowledge of actual physics, so that conservativeness in a safety envelope is significantly reduced. The proposed approach was demonstrated with a cantilever beam example, which represents a structural element. The example shows that calculation uncertainty provides about 93% conservativeness against the uncertainty due to a few element tests. As a result, it is shown that even a single element test can increase the load tolerance modeled with the safety envelope by 20%.« less

Wideband Low Side Lobe Aperture Coupled Patch Phased Array Antennas

NASA Astrophysics Data System (ADS)

Poduval, Dhruva

Low profile printed antenna arrays with wide bandwidth, high gain, and low Side Lobe Level (SLL) are in great demand for current and future commercial and military communication systems and radar. Aperture coupled patch antennas have been proposed to obtain wide impedance bandwidths in the past. Aperture coupling is preferred particularly for phased arrays because of their advantage of integration to other active devices and circuits, e.g. phase shifters, power amplifiers, low noise amplifiers, mixers etc. However, when designing such arrays, the interplay between array performance characteristics, such as gain, side lobe level, back lobe level, mutual coupling etc. must be understood and optimized under multiple design constraints, e.g. substrate material properties and thicknesses, element to element spacing, and feed lines and their orientation and arrangements with respect to the antenna elements. The focus of this thesis is to investigate, design, and develop an aperture coupled patch array with wide operating bandwidth (30%), high gain (17.5 dBi), low side lobe level (20 dB), and high Forward to Backward (F/B) ratio (21.8 dB). The target frequency range is 2.4 to 3 GHz given its wide application in WLAN, LTE (Long Term Evolution) and other communication systems. Notwithstanding that the design concept can very well be adapted at other frequencies. Specifically, a 16 element, 4 by 4 planar microstrip patch array is designed using HFSS and experimentally developed and tested. Starting from mutual coupling minimization a corporate feeding scheme is designed to achieve the needed performance. To reduce the SLL the corporate feeding network is redesigned to obtain a specific amplitude taper. Studies are conducted to determine the optimum location for a metallic reflector under the feed line to improve the F/B. An experimental prototype of the antenna was built and tested validating and demonstrating the performance levels expected from simulation predictions. Finally, simulated beam scanning in several angles of the array is shown considering specific phases for each antenna element in the array.

Program design by a multidisciplinary team. [for structural finite element analysis on STAR-100 computer

NASA Technical Reports Server (NTRS)

Voigt, S.

1975-01-01

The use of software engineering aids in the design of a structural finite-element analysis computer program for the STAR-100 computer is described. Nested functional diagrams to aid in communication among design team members were used, and a standardized specification format to describe modules designed by various members was adopted. This is a report of current work in which use of the functional diagrams provided continuity and helped resolve some of the problems arising in this long-running part-time project.

Design of Critical Components

NASA Technical Reports Server (NTRS)

Hendricks, Robert C.; Zaretsky, Erwin V.

2001-01-01

Critical component design is based on minimizing product failures that results in loss of life. Potential catastrophic failures are reduced to secondary failures where components removed for cause or operating time in the system. Issues of liability and cost of component removal become of paramount importance. Deterministic design with factors of safety and probabilistic design address but lack the essential characteristics for the design of critical components. In deterministic design and fabrication there are heuristic rules and safety factors developed over time for large sets of structural/material components. These factors did not come without cost. Many designs failed and many rules (codes) have standing committees to oversee their proper usage and enforcement. In probabilistic design, not only are failures a given, the failures are calculated; an element of risk is assumed based on empirical failure data for large classes of component operations. Failure of a class of components can be predicted, yet one can not predict when a specific component will fail. The analogy is to the life insurance industry where very careful statistics are book-kept on classes of individuals. For a specific class, life span can be predicted within statistical limits, yet life-span of a specific element of that class can not be predicted.

Designing Peace and Conflict Exercises: Level of Analysis, Scenario, and Role Specification

ERIC Educational Resources Information Center

Bartels, Elizabeth; McCown, Margaret; Wilkie, Timothy

2013-01-01

Attentiveness to and transparency about the methodological implications of the level of analysis selected for peace and conflict exercises constitute essential elements of good game design. The article explores the impact of level of analysis choices in the context of two key portions of exercises, scenario construction and role specification. It…

Criticality safety evaluation for the Advanced Test Reactor enhanced low enriched uranium fuel elements

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

Montierth, Leland M.

2016-07-19

The Global Threat Reduction Initiative (GTRI) convert program is developing a high uranium density fuel based on a low enriched uranium (LEU) uranium-molybdenum alloy. Testing of prototypic GTRI fuel elements is necessary to demonstrate integrated fuel performance behavior and scale-up of fabrication techniques. GTRI Enhanced LEU Fuel (ELF) elements based on the ATR-Standard Size elements (all plates fueled) are to be fabricated for testing in the Advanced Test Reactor (ATR). While a specific ELF element design will eventually be provided for detailed analyses and in-core testing, this criticality safety evaluation (CSE) is intended to evaluate a hypothetical ELF element designmore » for criticality safety purposes. Existing criticality analyses have analyzed Standard (HEU) ATR elements from which controls have been derived. This CSE documents analysis that determines the reactivity of the hypothetical ELF fuel elements relative to HEU ATR elements and whether the existing HEU ATR element controls bound the ELF element. The initial calculations presented in this CSE analyzed the original ELF design, now referred to as Mod 0.1. In addition, as part of a fuel meat thickness optimization effort for reactor performance, other designs have been evaluated. As of early 2014 the most current conceptual designs are Mk1A and Mk1B, that were previously referred to as conceptual designs Mod 0.10 and Mod 0.11, respectively. Revision 1 evaluates the reactivity of the ATR HEU Mark IV elements for a comparison with the Mark VII elements.« less

Finite-element analysis of NiTi wire deflection during orthodontic levelling treatment

NASA Astrophysics Data System (ADS)

Razali, M. F.; Mahmud, A. S.; Mokhtar, N.; Abdullah, J.

2016-02-01

Finite-element analysis is an important product development tool in medical devices industry for design and failure analysis of devices. This tool helps device designers to quickly explore various design options, optimizing specific designs and providing a deeper insight how a device is actually performing. In this study, three-dimensional finite-element models of superelastic nickel-titanium arch wire engaged in a three brackets system were developed. The aim was to measure the effect of binding friction developed on wire-bracket interaction towards the remaining recovery force available for tooth movement. Uniaxial and three brackets bending test were modelled and validated against experimental works. The prediction made by the three brackets bending models shows good agreement with the experimental results.

A drive based on an element made of a thermomechanical memory material

NASA Astrophysics Data System (ADS)

Krakhin, O. I.; Dubovik, I. N.; Rozarenova, Iu. A.

The advantages of using drives with active elements made of thermomechanical memory materials in aircraft structures are briefly reviewed. The choice of a particular type of active element based on a thermomechanical memory material is shown to depend on the specific operating conditions of the drive. The design of a rotary drive with an active element of TN-1 alloy is examined as an example.

Crashworthiness design modifications for locomotive and cab car anticlimbing systems

DOT National Transportation Integrated Search

2003-02-01

This study addressed the feasibility of incorporating complete anticlimbing systems into both passenger and freight locomotives. Complete systems include pushback couplers, vertically interlocking anticlimber elements, and zones specifically designed...

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

Park, Chanyoung; Kim, Nam H.

Structural elements, such as stiffened panels and lap joints, are basic components of aircraft structures. For aircraft structural design, designers select predesigned elements satisfying the design load requirement based on their load-carrying capabilities. Therefore, estimation of safety envelope of structural elements for load tolerances would be a good investment for design purpose. In this article, a method of estimating safety envelope is presented using probabilistic classification, which can estimate a specific level of failure probability under both aleatory and epistemic uncertainties. An important contribution of this article is that the calculation uncertainty is reflected in building a safety envelope usingmore » Gaussian process, and the effect of element test data on reducing the calculation uncertainty is incorporated by updating the Gaussian process model with the element test data. It is shown that even one element test can significantly reduce the calculation uncertainty due to lacking knowledge of actual physics, so that conservativeness in a safety envelope is significantly reduced. The proposed approach was demonstrated with a cantilever beam example, which represents a structural element. The example shows that calculation uncertainty provides about 93% conservativeness against the uncertainty due to a few element tests. As a result, it is shown that even a single element test can increase the load tolerance modeled with the safety envelope by 20%.« less

Investigation of the applicability of using the triple redundant hydrogen sensor for methane sensing

NASA Technical Reports Server (NTRS)

Lantz, J. B.; Wynveen, R. A.

1983-01-01

Application specifications for the methane sensor were assembled and design guidelines, development goals and evaluation criteria were formulated. This was done to provide a framework to evaluate sensor performance and any design adjustments to the preprototype sensor that could be required to provide methane sensitivity. Good response to hydrogen was experimentally established for four hydrogen sensor elements to be later evaluated for methane response. Prior results were assembled and analyzed for other prototype hydrogen sensor performance parameters to form a comparison base. The four sensor elements previously shown to have good hydrogen response were experimentally evaluated for methane response in 2.5% methane-in-air. No response was obtained for any of the elements, despite the high methane concentration used (50% of the Lower Flammability Limit). It was concluded that the preprototype sensing elements were insensitive to methane and were hydrogen specific. Alternative sensor operating conditions and hardware design changes were considered to provide methane sensitivity to the preprototype sensor, including a variety of different methane sensing techniques. Minor changes to the existing sensor elements, sensor geometry and operating conditions will not make the preprototype hydrogen sensor respond to methane. New sensor elements that will provide methane and hydrogen sensitivity require replacement of the existing thermistor type elements. Some hydrogen sensing characteristics of the modified sensor will be compromised (larger in situ calibration gas volume and H2 nonspecificity). The preprototype hydrogen sensor should be retained for hydrogen monitoring and a separate methane sensor should be developed.

Pictorial Conversations.

ERIC Educational Resources Information Center

Hooper, Kristina

1982-01-01

Provides the rationale for considering communication in a graphic domain and suggests a specific goal for designing work stations which provide graphic capabilities in educational settings. The central element of this recommendation is the "pictorial conversation", a highly interactive exchange that includes pictures as the central elements.…

Technical Specifications for Hardware and Software, and Maintenance in Support of Computer Literacy Program. Volume II.

ERIC Educational Resources Information Center

District of Columbia Public Schools, Washington, DC.

Designed for use by vendors, this guide provides an overview of the objectives for the 5-year computer literacy program to be implemented in the District of Columbia Public Schools; outlines requirements which are mandatory elements of vendors' bids unless explicitly designated "desirable"; and details specifications for computing…

24 CFR 3286.505 - Minimum elements to be inspected.

Code of Federal Regulations, 2010 CFR

2010-04-01

... with respect to home design and construction; (b) Consideration of site-specific conditions; (c) Site... HOUSING AND URBAN DEVELOPMENT MANUFACTURED HOME INSTALLATION PROGRAM Inspection of Installations in HUD-Administered States § 3286.505 Minimum elements to be inspected. The installation of every manufactured home...

Efficient finite element simulation of slot spirals, slot radomes and microwave structures

NASA Technical Reports Server (NTRS)

Gong, J.; Volakis, J. L.

1995-01-01

This progress report contains the following two documents: (1) 'Efficient Finite Element Simulation of Slot Antennas using Prismatic Elements' - A hybrid finite element-boundary integral (FE-BI) simulation technique is discussed to treat narrow slot antennas etched on a planar platform. Specifically, the prismatic elements are used to reduce the redundant sampling rates and ease the mesh generation process. Numerical results for an antenna slot and frequency selective surfaces are presented to demonstrate the validity and capability of the technique; and (2) 'Application and Design Guidelines of the PML Absorber for Finite Element Simulations of Microwave Packages' - The recently introduced perfectly matched layer (PML) uniaxial absorber for frequency domain finite element simulations has several advantages. In this paper we present the application of PML for microwave circuit simulations along with design guidelines to obtain a desired level of absorption. Different feeding techniques are also investigated for improved accuracy.

SEPAC flight software detailed design specifications, volume 1

NASA Technical Reports Server (NTRS)

1982-01-01

The detailed design specifications (as built) for the SEPAC Flight Software are defined. The design includes a description of the total software system and of each individual module within the system. The design specifications describe the decomposition of the software system into its major components. The system structure is expressed in the following forms: the control-flow hierarchy of the system, the data-flow structure of the system, the task hierarchy, the memory structure, and the software to hardware configuration mapping. The component design description includes details on the following elements: register conventions, module (subroutines) invocaton, module functions, interrupt servicing, data definitions, and database structure.

The neutronic basis for elemental substitution in martensitic steels

NASA Astrophysics Data System (ADS)

Sublet, J.-Ch.; Butterworth, G. J.

1994-09-01

A simple graphical approach has been developed to facilitate the design of low-activation steels by elemental tailoring. Noting that the iron base provides the best achievable target, the influence of candidate alloying elements becomes readily apparent when the contribution each makes to a particular activation parameter such as specific activity, dose rate or decay power, is expressed relative to the contribution from the iron base. This approach highlights the most critical activation parameters and times after shutdown with respect to safety and environmental objectives. Its application to the design of low activation martensitic stainless steels is discussed.

The confusion in complying with good manufacturing practice requirements in Malaysia

NASA Astrophysics Data System (ADS)

Jali, Mohd Bakri; Ghani, Maaruf Abdul; Nor, Norazmir Md

2016-11-01

Food manufacturing operations need to fulfil regulatory requirements related to hygiene and good manufacturing practices (GMP) to successfully market their products as safe and quality products. GMP based on its ten elements used as guidelines to ensure control over biological, chemical and physical hazards. This study aims to investigate the confusion for design and facilities elements among food industries. Both qualitative and quantitative techniques are used as systematic tools. Design and facilities elements lay a firm foundation for good manufacturing practice to ensure food hygiene and should be used in conjunction with each specific code of hygiene practice and guidelines.

Theoretical Studies of Microstrip Antennas : Volume I, General Design Techniques and Analyses of Single and Coupled Elements

DOT National Transportation Integrated Search

1979-09-01

Volume 1 of Theoretical Studies of Microstrip Antennas deals with general techniques and analyses of single and coupled radiating elements. Specifically, we review and then employ an important equivalence theorem that allows a pair of vector potentia...

Optimum structural design with plate bending elements - A survey

NASA Technical Reports Server (NTRS)

Haftka, R. T.; Prasad, B.

1981-01-01

A survey is presented of recently published papers in the field of optimum structural design of plates, largely with respect to the minimum-weight design of plates subject to such constraints as fundamental frequency maximization. It is shown that, due to the availability of powerful computers, the trend in optimum plate design is away from methods tailored to specific geometry and loads and toward methods that can be easily programmed for any kind of plate, such as finite element methods. A corresponding shift is seen in optimization from variational techniques to numerical optimization algorithms. Among the topics covered are fully stressed design and optimality criteria, mathematical programming, smooth and ribbed designs, design against plastic collapse, buckling constraints, and vibration constraints.

Application of finite element method in mechanical design of automotive parts

NASA Astrophysics Data System (ADS)

Gu, Suohai

2017-09-01

As an effective numerical analysis method, finite element method (FEM) has been widely used in mechanical design and other fields. In this paper, the development of FEM is introduced firstly, then the specific steps of FEM applications are illustrated and the difficulties of FEM are summarized in detail. Finally, applications of FEM in automobile components such as automobile wheel, steel plate spring, body frame, shaft parts and so on are summarized, compared with related research experiments.

Use of graphics and symbols on dynamic message signs : technical report.

DOT National Transportation Integrated Search

2009-03-01

This project has taken a step toward defining how graphic and symbol displays can improve or assist communication with drivers. Through three human factors evaluations of alternative designs, researchers identified specific design elements that shoul...

Compiler writing system detail design specification. Volume 1: Language specification

NASA Technical Reports Server (NTRS)

Arthur, W. J.

1974-01-01

Construction within the Meta language for both language and target machine specification is reported. The elements of the function language as a meaning and syntax are presented, and the structure of the target language is described which represents the target dependent object text representation of applications programs.

Modelling and simulation of a robotic work cell

NASA Astrophysics Data System (ADS)

Sękala, A.; Gwiazda, A.; Kost, G.; Banaś, W.

2017-08-01

The subject of considerations presented in this work concerns the designing and simulation of a robotic work cell. The designing of robotic cells is the process of synergistic combining the components in the group, combining this groups into specific, larger work units or dividing the large work units into small ones. Combinations or divisions are carried out in the terms of the needs of realization the assumed objectives to be performed in these unit. The designing process bases on the integrated approach what lets to take into consideration all needed elements of this process. Each of the elements of a design process could be an independent design agent which could tend to obtain its objectives.

Design Optimization Tool for Synthetic Jet Actuators Using Lumped Element Modeling

NASA Technical Reports Server (NTRS)

Gallas, Quentin; Sheplak, Mark; Cattafesta, Louis N., III; Gorton, Susan A. (Technical Monitor)

2005-01-01

The performance specifications of any actuator are quantified in terms of an exhaustive list of parameters such as bandwidth, output control authority, etc. Flow-control applications benefit from a known actuator frequency response function that relates the input voltage to the output property of interest (e.g., maximum velocity, volumetric flow rate, momentum flux, etc.). Clearly, the required performance metrics are application specific, and methods are needed to achieve the optimal design of these devices. Design and optimization studies have been conducted for piezoelectric cantilever-type flow control actuators, but the modeling issues are simpler compared to synthetic jets. Here, lumped element modeling (LEM) is combined with equivalent circuit representations to estimate the nonlinear dynamic response of a synthetic jet as a function of device dimensions, material properties, and external flow conditions. These models provide reasonable agreement between predicted and measured frequency response functions and thus are suitable for use as design tools. In this work, we have developed a Matlab-based design optimization tool for piezoelectric synthetic jet actuators based on the lumped element models mentioned above. Significant improvements were achieved by optimizing the piezoceramic diaphragm dimensions. Synthetic-jet actuators were fabricated and benchtop tested to fully document their behavior and validate a companion optimization effort. It is hoped that the tool developed from this investigation will assist in the design and deployment of these actuators.

Helium microwave-induced plasmas for element specific detection in chromatography

NASA Astrophysics Data System (ADS)

Long, Gary L.; Ducatte, Gerald R.; Lancaster, Edwin D.

1994-01-01

This review addresses the development and use of the microwave-induced plasma (MIP) using optical emission spectrometry for the purpose of element specific detection in chromatography. The plasma source that is the focus of this article is the He-based MIP operated at atmospheric pressure. The forms of chromatography that are covered include gas chromatography, liquid chromatography, and supercritical fluid chromatography. Concepts in plasma cavity design and the chromatograph-plasma interface are discussed along with the application of these hybrid systems to analytical determinations.

NUCLEAR REACTOR CORE

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

Bell, F.R.

1963-02-01

A nuclear reactor core composed of a number of identical elements of solid moderator material fitted together was designed. Each moderator element is apertured to provide channels for fuel and coolant. The elements have an external shape which permits them to be stacked in layers with similar elements, with the surfaces of adjacent elements fitting and in contact with each other. The cross section of the element is of a general hexagonal shape with identations and protrusions, so that the elements can be fitted together. The described core should not be liable to fracture under transverse loading. Specific arrangements ofmore » moderator elements and fuel and coolant apertures are described. (M.P.G.)« less

Aeronautical Situational Awareness - Airport Surface

NASA Technical Reports Server (NTRS)

Linetsky, Vladimir M.; Ivancic, William D.; Vaden, Karl R.

2017-01-01

This paper advocates for a specific design approach, based on simple principals, yet addresses challenges faced by the system engineers when designing complex data and information infrastructure. The document provides guidance for breaking out various work elements in the overall network architecture design, so that communication systems are conceived and effectively realized regardless of their location, size and local specifics. Although targeted at the Global Airspace System (GAS) and National Airspace System (NAS), this framework can be applied to any network-centric architecture.

Wrap-Attack Pack: Product Packaging Exercise

ERIC Educational Resources Information Center

Lee, Seung Hwan; Hoffman, K. Douglas

2016-01-01

Although many marketing courses discuss traditional concepts pertaining to product strategy, concepts specifically relating to packaging are often glossed over. This exercise, "Wrap-Attack Pack," teaches students about the utilitarian and hedonic design elements of packaging. More specifically, the primary objective is to creatively…

Feed-in Tariffs: Good Practices and Design Considerations

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

Cox, Sadie; Esterly, Sean

2016-01-02

In recent years, feed-in tariff (FIT) activity has focused primarily on revisions to current policies, underscoring the need for stable and predictable, yet flexible, policy environments. This policy brief provides a primer on key FIT design elements, lessons from country experience, and support resources to enable more detailed and country-specific FIT policy design.

Development and presentation of a roadway and roadside design course : final report, December 2009.

DOT National Transportation Integrated Search

2009-12-01

The overall goal of this course is to provide training in the elements of geometric highway : design. Specific course objectives are: : To review the geometry of horizontal and vertical alignment including simple circular : curves, compound curve...

Development of Integrated Programs for Aerospace-vehicle design (IPAD): Integrated information processing requirements

NASA Technical Reports Server (NTRS)

Southall, J. W.

1979-01-01

The engineering-specified requirements for integrated information processing by means of the Integrated Programs for Aerospace-Vehicle Design (IPAD) system are presented. A data model is described and is based on the design process of a typical aerospace vehicle. General data management requirements are specified for data storage, retrieval, generation, communication, and maintenance. Information management requirements are specified for a two-component data model. In the general portion, data sets are managed as entities, and in the specific portion, data elements and the relationships between elements are managed by the system, allowing user access to individual elements for the purpose of query. Computer program management requirements are specified for support of a computer program library, control of computer programs, and installation of computer programs into IPAD.

Geometrical specifications accuracy influence on the quality of electromechanical devices

NASA Astrophysics Data System (ADS)

Glukhov, V. I.; Lakeenko, M. N.; Dolzhikov, S. N.

2017-06-01

To improve the quality of electromechanical products is possible due to the geometrical specifications optimization of values and tolerances. Electromechanical products longevity designates the rolling-contact bearings of the armature shaft. Longevity of the rolling-contact bearings is less than designed one, since assembly and fitting alter gaps, sizes and geometric tolerances for the working parts of the basic rolling bearing details. Geometrical models of the rolling-contact bearing details for the armature shaft and the end shield are developed on the basis of an electric locomotive traction motor in the present work. The basic elements of the details conjugating with the adjacent details and materializing the generalized and auxiliary coordinate systems are determined. Function, informativeness and the number of geometrical specifications for the elements location are specified. The recommendations on amending the design documentation due to geometrical models to improve the accuracy and the quality of the products are developed: the replacement of the common axis of the shaft’s technological datums by the common axis of the basic design datums; coaxiality tolerances for these design datums with respect to their common axis; the modifiers for these auxiliary datums and these datums location tolerances according to the principles of datums uniformity, inversion and the shortest dimension chains. The investigation demonstrated that the problem of enhancing the durability, longevity, and efficiency coefficient for electromechanical products can be solved with the systematic normalizations of geometrical specifications accuracy on the basis of the coordinate systems introduced in the standards on geometrical product specifications (GPS).

English Language as a Requirement Course for Information Students--A Content Analysis of English Syllabus in the Faculty of Arabic and Islamic Studies/Nile Valley University

ERIC Educational Resources Information Center

Ahmed, Mustafa Shazali Mustafa

2009-01-01

The study investigated the importance of two elements in the process of syllabus design (ends / means specifications, program implementation) in the faculty of Islamic and Arabic studies, Nile Valley University, designed in 1995. Results indicate that the ends/means specifications stage is used to present the general aims and the objective of each…

Elements of museum mobile augmented reality for engaging hearing impaired visitors

NASA Astrophysics Data System (ADS)

Baker, Esraa Jaffar; Bakar, Juliana Aida Abu; Zulkifli, Abdul Nasir

2017-10-01

Nowadays, designers are more concern with the issue of engagement and informal learning at museum and gallery sites. This has made studies to focus more on the use of Mobile Augmented Reality (MAR) at museum and gallery sites. However, most of the MAR applications for museum visitors are largely tailored to normal hearing visitors while the hearing-impaired (HI) visitors are not supported. The hearing impaired (HI) community account for over 5% of the world's populace which is about 360 million people. Thus, this paper explores the design elements of mobile augmented reality for engaging hearing impaired visitors at the museum site. The findings of this paper argues that there are eleven major elements of engagement of MAR needed for the design of an efficient museum MAR app for hearing impaired visitors. These eleven elements include Aesthetics, Curiosity, Usability, Interaction, Motivation, Satisfaction, Self-Efficacy, Perceived Control, Enjoyment, Focused Attention and Interest. This study pointed out that for an efficient and engaged MAR app for the HI community especially HI visitors to museum sites, these eleven elements are critical. This finding will help MAR designers and developers on how to design an efficient and engaged MAR app for the HI community at large and museum HI visitors specifically.

Targeted polymeric nanoparticles for cancer gene therapy

PubMed Central

Kim, Jayoung; Wilson, David R.; Zamboni, Camila G.; Green, Jordan J.

2015-01-01

In this article, advances in designing polymeric nanoparticles for targeted cancer gene therapy are reviewed. Characterization and evaluation of biomaterials, targeting ligands, and transcriptional elements are each discussed. Advances in biomaterials have driven improvements to nanoparticle stability and tissue targeting, conjugation of ligands to the surface of polymeric nanoparticles enable binding to specific cancer cells, and the design of transcriptional elements has enabled selective DNA expression specific to the cancer cells. Together, these features have improved the performance of polymeric nanoparticles as targeted non-viral gene delivery vectors to treat cancer. As polymeric nanoparticles can be designed to be biodegradable, non-toxic, and to have reduced immunogenicity and tumorigenicity compared to viral platforms, they have significant potential for clinical use. Results of polymeric gene therapy in clinical trials and future directions for the engineering of nanoparticle systems for targeted cancer gene therapy are also presented. PMID:26061296

Space shuttle configuration accounting functional design specification

NASA Technical Reports Server (NTRS)

1974-01-01

An analysis is presented of the requirements for an on-line automated system which must be capable of tracking the status of requirements and engineering changes and of providing accurate and timely records. The functional design specification provides the definition, description, and character length of the required data elements and the interrelationship of data elements to adequately track, display, and report the status of active configuration changes. As changes to the space shuttle program levels II and III configuration are proposed, evaluated, and dispositioned, it is the function of the configuration management office to maintain records regarding changes to the baseline and to track and report the status of those changes. The configuration accounting system will consist of a combination of computers, computer terminals, software, and procedures, all of which are designed to store, retrieve, display, and process information required to track proposed and proved engineering changes to maintain baseline documentation of the space shuttle program levels II and III.

Design optimization of space structures

NASA Technical Reports Server (NTRS)

Felippa, Carlos

1991-01-01

The topology-shape-size optimization of space structures is investigated through Kikuchi's homogenization method. The method starts from a 'design domain block,' which is a region of space into which the structure is to materialize. This domain is initially filled with a finite element mesh, typically regular. Force and displacement boundary conditions corresponding to applied loads and supports are applied at specific points in the domain. An optimal structure is to be 'carved out' of the design under two conditions: (1) a cost function is to be minimized, and (2) equality or inequality constraints are to be satisfied. The 'carving' process is accomplished by letting microstructure holes develop and grow in elements during the optimization process. These holes have a rectangular shape in two dimensions and a cubical shape in three dimensions, and may also rotate with respect to the reference axes. The properties of the perforated element are obtained through an homogenization procedure. Once a hole reaches the volume of the element, that element effectively disappears. The project has two phases. In the first phase the method was implemented as the combination of two computer programs: a finite element module, and an optimization driver. In the second part, focus is on the application of this technique to planetary structures. The finite element part of the method was programmed for the two-dimensional case using four-node quadrilateral elements to cover the design domain. An element homogenization technique different from that of Kikuchi and coworkers was implemented. The optimization driver is based on an augmented Lagrangian optimizer, with the volume constraint treated as a Courant penalty function. The optimizer has to be especially tuned to this type of optimization because the number of design variables can reach into the thousands. The driver is presently under development.

The Ulysses Reference Mission (URM); Proceedings of the EUROAVIA Design Workshop, Friedrichshafen, Federal Republic of Germany, Apr. 8-19, 1991

NASA Astrophysics Data System (ADS)

The present design symposium on the Ulysses Reference Mission (URM) provides data on the feasibility of the URM with particular attention given to reference data for Ulysses in the ecliptic plane as it passes the southern and northern pole areas of the sun. Specific issues addressed during the design workshop include the scientific objectives of the URM, the elements of the URM payload, the configuration and structural elements of the spacecraft, thermal control requirements and considerations, a system-engineering analysis, and the scientific subsystems of the URM. Also examined are the solar array and battery package, power control and distribution, technology considerations for the transmission of telemetric data, and a functional analysis of the URM on-board data-handling equipment. The description of the workshop concludes by noting that design studies are required to establish the moment of inertia and center of gravity of the URM spacecraft as well as specific mission parameters.

The High Rise Low Cost Housing : Sustainable Neighbourhood Elements (Green Elements) in Malaysia

NASA Astrophysics Data System (ADS)

Wahi, Noraziah; Mohamad, Ismail; Mohamad Zin, Rosli; Munikanan, Vikneswaran; Junaini, Syahrizan

2018-03-01

The sustainable development is a vital measure to alleviate the greenhouse gas effect, global warming and any other environment issues. The sustainable neighbourhood concept is not new in Malaysia, However, the concept still needs attention and awareness from the stakeholders. This paper discusses on the sustainable neighbourhood elements specifically green elements application on the high rise low cost housing in Malaysia. Malaysia should have focused sustainable neighbourhood planning and design especially on the high rise low cost housing therefore the future generation can be benefited from this type development.

75 FR 9548 - Reduction of Use of Social Security Numbers (SSN) in the Department of Defense (DoD)

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-03

... authorization to receive specific categories of information. Computer network. The constituent element of an... elements reside on a computer. Form. A fixed arrangement of captioned spaces designed for entering and... activities of the Government or because of the information value of the data in them. Survey. An instrument...

DESIGN AND EVALUATION OF INDIVIDUAL ELEMENTS OF THE INTERFACE FOR AN AGRICULTURAL MACHINE.

PubMed

Rakhra, Aadesh K; Mann, Danny D

2018-01-29

If a user-centered approach is not used to design information displays, the quantity and quality of information presented to the user may not match the needs of the user, or it may exceed the capability of the human operator for processing and using that information. The result may be an excessive mental workload and reduced situation awareness of the operator, which can negatively affect the machine performance and operational outcomes. The increasing use of technology in agricultural machines may expose the human operator to excessive and undesirable information if the operator's information needs and information processing capabilities are ignored. In this study, a user-centered approach was used to design specific interface elements for an agricultural air seeder. Designs of the interface elements were evaluated in a laboratory environment by developing high-fidelity prototypes. Evaluations of the user interface elements yielded significant improvement in situation awareness (up to 11%; overall mean difference = 5.0 (4.8%), 95% CI (6.4728, 3.5939), p 0.0001). Mental workload was reduced by up to 19.7% (overall mean difference = -5.2 (-7.9%), n = 30, a = 0.05). Study participants rated the overall performance of the newly designed user-centered interface elements higher in comparison to the previous designs (overall mean difference = 27.3 (189.8%), 99% CI (35.150, 19.384), p 0.0001. Copyright© by the American Society of Agricultural Engineers.

FILTSoft: A computational tool for microstrip planar filter design

NASA Astrophysics Data System (ADS)

Elsayed, M. H.; Abidin, Z. Z.; Dahlan, S. H.; Cholan N., A.; Ngu, Xavier T. I.; Majid, H. A.

2017-09-01

Filters are key component of any communication system to control spectrum and suppress interferences. Designing a filter involves long process as well as good understanding of the basic hardware technology. Hence this paper introduces an automated design tool based on Matlab-GUI, called the FILTSoft (acronym for Filter Design Software) to ease the process. FILTSoft is a user friendly filter design tool to aid, guide and expedite calculations from lumped elements level to microstrip structure. Users just have to provide the required filter specifications as well as the material description. FILTSoft will calculate and display the lumped element details, the planar filter structure, and the expected filter's response. An example of a lowpass filter design was calculated using FILTSoft and the results were validated through prototype measurement for comparison purposes.

Development of analytical methods for multiplex bio-assay with inductively coupled plasma mass spectrometry.

PubMed

Ornatsky, Olga I; Kinach, Robert; Bandura, Dmitry R; Lou, Xudong; Tanner, Scott D; Baranov, Vladimir I; Nitz, Mark; Winnik, Mitchell A

2008-01-01

Advances in the development of highly multiplexed bio-analytical assays with inductively coupled plasma mass spectrometry (ICP-MS) detection are discussed. Use of novel reagents specifically designed for immunological methods utilizing elemental analysis is presented. The major steps of method development, including selection of elements for tags, validation of tagged reagents, and examples of multiplexed assays, are considered in detail. The paper further describes experimental protocols for elemental tagging of antibodies, immunostaining of live and fixed human leukemia cells, and preparation of samples for ICP-MS analysis. Quantitative analysis of surface antigens on model cell lines using a cocktail of seven lanthanide labeled antibodies demonstrated high specificity and concordance with conventional immunophenotyping.

Crossing the barrier between the laboratory working model and the practicable production model

NASA Astrophysics Data System (ADS)

Curby, William A.

1992-12-01

Transforming apparatus that has developed into a successfully working laboratory system into a system that is ready, or nearly ready for production, distribution and general use is not always accomplished in a cost effective or timely fashion. Several design elements must be considered interactively during the planning, construction, use and servicing of the final production form of the system. The basic design elements are: Operating Specifications, Reliability Factors, Safety Factors, Precision Limits, Accuracy Limits, Uniformity Factors, Cost Limits and Calibration Requirements. Secondary elements including: Human Engineering, Documentation, Training, Maintenance, Proprietary Rights, Protection, Marketing, Replacement of Parts, and Packing and Shipping must also be considered during the transition.

Cultural Viewpoint Metaphors Guiding the Collaborative Strategies Design of a Multitouch Tabletop Game for People with Autism

ERIC Educational Resources Information Center

Silva, Greis F. Mireya; Salgado, Luciana Cardoso de Castro; Suplino, Maryse; Raposo, Alberto Barbosa

2014-01-01

Collaborative multitouch applications have been designed to support social interaction and collaboration skills in people with mild autism. However, this kind of application generally is not designed specifically for people with severe autism. We have proposed a set of collaborative strategies to manipulate the elements in the interface aiming to…

Renewable Electricity Standards: Good Practices and Design Considerations

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

Cox, Sadie; Esterly, Sean

2016-01-02

In widespread use globally, renewable electricity standards (RES) are one of the most widely adopted renewable energy policies and a critical regulatory vehicle to accelerate renewable energy deployment. This policy brief provides an introduction to key RES design elements, lessons from country experience, and support resources to enable more detailed and country-specific RES policy design.

MODIS Information, Data, and Control System (MIDACS) system specifications and conceptual design

NASA Technical Reports Server (NTRS)

Han, D.; Salomonson, V.; Ormsby, J.; Ardanuy, P.; Mckay, A.; Hoyt, D.; Jaffin, S.; Vallette, B.; Sharts, B.; Folta, D.

1988-01-01

The MODIS Information, Data, and Control System (MIDACS) Specifications and Conceptual Design Document discusses system level requirements, the overall operating environment in which requirements must be met, and a breakdown of MIDACS into component subsystems, which include the Instrument Support Terminal, the Instrument Control Center, the Team Member Computing Facility, the Central Data Handling Facility, and the Data Archive and Distribution System. The specifications include sizing estimates for the processing and storage capacities of each data system element, as well as traffic analyses of data flows between the elements internally, and also externally across the data system interfaces. The specifications for the data system, as well as for the individual planning and scheduling, control and monitoring, data acquisition and processing, calibration and validation, and data archive and distribution components, do not yet fully specify the data system in the complete manner needed to achieve the scientific objectives of the MODIS instruments and science teams. The teams have not yet been formed; however, it was possible to develop the specifications and conceptual design based on the present concept of EosDIS, the Level-1 and Level-2 Functional Requirements Documents, the Operations Concept, and through interviews and meetings with key members of the scientific community.

DESAP 1: A structural design program with stress and displacement constraints. Volume 1: Theoretical and user's manual

NASA Technical Reports Server (NTRS)

Kiusalaas, J.; Reddy, G. B.

1977-01-01

A finite element program is presented for computer-automated, minimum weight design of elastic structures with constraints on stresses (including local instability criteria) and displacements. Volume 1 of the report contains the theoretical and user's manual of the program. Sample problems and the listing of the program are included in Volumes 2 and 3. The element subroutines are organized so as to facilitate additions and changes by the user. As a result, a relatively minor programming effort would be required to make DESAP 1 into a special purpose program to handle the user's specific design requirements and failure criteria.

Vibration attenuation of the NASA Langley evolutionary structure experiment using H(sub infinity) and structured singular value (micron) robust multivariable control techniques

NASA Technical Reports Server (NTRS)

Balas, Gary J.

1992-01-01

The use is studied of active control to attenuate structural vibrations of the NASA Langley Phase Zero Evolutionary Structure due to external disturbance excitations. H sub infinity and structured singular value (mu) based control techniques are used to analyze and synthesize control laws for the NASA Langley Controls Structures Interaction (CSI) Evolutionary Model (CEM). The CEM structure experiment provides an excellent test bed to address control design issues for large space structures. Specifically, control design for structures with numerous lightly damped, coupled flexible modes, collocated and noncollocated sensors and actuators and stringent performance specifications. The performance objectives are to attenuate the vibration of the structure due to external disturbances, and minimize the actuator control force. The control design problem formulation for the CEM Structure uses a mathematical model developed with finite element techniques. A reduced order state space model for the control design is formulated from the finite element model. It is noted that there are significant variations between the design model and the experimentally derived transfer function data.

Multi-Bandwidth Frequency Selective Surfaces for Near Infrared Filtering: Design and Optimization

NASA Technical Reports Server (NTRS)

Cwik, Tom; Fernandez, Salvador; Ksendzov, A.; LaBaw, Clayton C.; Maker, Paul D.; Muller, Richard E.

1999-01-01

Frequency selective surfaces are widely used in the microwave and millimeter wave regions of the spectrum for filtering signals. They are used in telecommunication systems for multi-frequency operation or in instrument detectors for spectroscopy. The frequency selective surface operation depends on a periodic array of elements resonating at prescribed wavelengths producing a filter response. The size of the elements is on the order of half the electrical wavelength, and the array period is typically less than a wavelength for efficient operation. When operating in the optical region, diffraction gratings are used for filtering. In this regime the period of the grating may be several wavelengths producing multiple orders of light in reflection or transmission. In regions between these bands (specifically in the infrared band) frequency selective filters consisting of patterned metal layers fabricated using electron beam lithography are beginning to be developed. The operation is completely analogous to surfaces made in the microwave and millimeter wave region except for the choice of materials used and the fabrication process. In addition, the lithography process allows an arbitrary distribution of patterns corresponding to resonances at various wavelengths to be produced. The design of sub-millimeter filters follows the design methods used in the microwave region. Exacting modal matching, integral equation or finite element methods can be used for design. A major difference though is the introduction of material parameters and thicknesses tha_ may not be important in longer wavelength designs. This paper describes the design of multi-bandwidth filters operating in the I-5 micrometer wavelength range. This work follows on previous design [1,2]. In this paper extensions based on further optimization and an examination of the specific shape of the element in the periodic cell will be reported. Results from the design, manufacture and test of linear wedge filters built using micro-lithographic techniques and used ir spectral imaging applications will be presented.

Multi-Bandwidth Frequency Selective Surfaces for Near Infrared Filtering: Design and Optimization

NASA Technical Reports Server (NTRS)

Cwik, Tom; Fernandez, Salvador; Ksendzov, A.; LaBaw, Clayton C.; Maker, Paul D.; Muller, Richard E.

1998-01-01

Frequency selective surfaces are widely used in the microwave and millimeter wave regions of the spectrum for filtering signals. They are used in telecommunication systems for multi-frequency operation or in instrument detectors for spectroscopy. The frequency selective surface operation depends on a periodic array of elements resonating at prescribed wavelengths producing a filter response. The size of the elements is on the order of half the electrical wavelength, and the array period is typically less than a wavelength for efficient operation. When operating in the optical region, diffraction gratings are used for filtering. In this regime the period of the grating may be several wavelengths producing multiple orders of light in reflection or transmission. In regions between these bands (specifically in the infrared band) frequency selective filters consisting of patterned metal layers fabricated using electron beam lithography are beginning to be developed. The operation is completely analogous to surfaces made in the microwave and millimeter wave region except for the choice of materials used and the fabrication process. In addition, the lithography process allows an arbitrary distribution of patterns corresponding to resonances at various wavelengths to be produced. The design of sub-millimeter filters follows the design methods used in the microwave region. Exacting modal matching, integral equation or finite element methods can be used for design. A major difference though is the introduction of material parameters and thicknesses that may not be important in longer wavelength designs. This paper describes the design of multi- bandwidth filters operating in the 1-5 micrometer wavelength range. This work follows on a previous design. In this paper extensions based on further optimization and an examination of the specific shape of the element in the periodic cell will be reported. Results from the design, manufacture and test of linear wedge filters built using microlithographic techniques and used in spectral imaging applications will be presented.

Textile antenna integrated with compact AMC and parasitic elements for WLAN/WBAN applications

NASA Astrophysics Data System (ADS)

Lago, Herwansyah; Soh, Ping Jack; Jamlos, Mohd Faizal; Shohaimi, Nursuriati; Yan, Sen; Vandenbosch, Guy A. E.

2016-12-01

A wearable antenna fully designed and fabricated using textile is presented. Both antenna and artificial magnetic conductor plane are designed for operation in the wireless local area network (WLAN)/wireless body area network (WBAN) band from 2.4 to 2.5 GHz. The AMC unit element is designed based on the rectangular patch structure, which is then integrated using slots and slits for bandwidth broadening. Meanwhile, the combination of the slits and L-shaped parasitic elements applied at four edges of the rectangular antenna structure enabled unidirectional radiation outwards from the body. The structure is coaxially fed using a rectangular ring slot centered on the radiating element. Simulated and measured reflection and radiation performance indicate a satisfactory agreement, fulfilling the requirements for WLAN/WBAN applications both in free space and on body. The shielding effectiveness provided by the AMC plane is also evaluated numerically in terms of specific absorption rate, indicating levels below the European regulatory limit of 2 W/kg.

Prism-type holographic optical element design and verification for the blue-light small-form-factor optical pickup head.

PubMed

Shih, Hsi-Fu; Chiu, Yi; Cheng, Stone; Lee, Yuan-Chin; Lu, Chun-Shin; Chen, Yung-Chih; Chiou, Jin-Chern

2012-08-20

This paper presents the prism-type holographic optical element (PT-HOE) design for a small-form-factor (SFF) optical pickup head (OPH). The surface of the PT-HOE was simulated by three steps of optimization and generated by binary optics. Its grating pattern was fabricated on the inclined plane of a microprism by using the standard photolithography and specific dicing procedures. The optical characteristics of the device were verified. Based on the virtual image method, the SFF-OPH with the device was assembled and realized.

Identifying Common Practice Elements to Improve Social, Emotional, and Behavioral Outcomes of Young Children in Early Childhood Classrooms.

PubMed

McLeod, Bryce D; Sutherland, Kevin S; Martinez, Ruben G; Conroy, Maureen A; Snyder, Patricia A; Southam-Gerow, Michael A

2017-02-01

Educators are increasingly being encouraged to implement evidence-based interventions and practices to address the social, emotional, and behavioral needs of young children who exhibit problem behavior in early childhood settings. Given the nature of social-emotional learning during the early childhood years and the lack of a common set of core evidence-based practices within the early childhood literature, selection of instructional practices that foster positive social, emotional, and behavioral outcomes for children in early childhood settings can be difficult. The purpose of this paper is to report findings from a study designed to identify common practice elements found in comprehensive intervention models (i.e., manualized interventions that include a number of components) or discrete practices (i.e., a specific behavior or action) designed to target social, emotional, and behavioral learning of young children who exhibit problem behavior. We conducted a systematic review of early childhood classroom interventions that had been evaluated in randomized group designs, quasi-experimental designs, and single-case experimental designs. A total of 49 published articles were identified, and an iterative process was used to identify common practice elements. The practice elements were subsequently reviewed by experts in social-emotional and behavioral interventions for young children. Twenty-four practice elements were identified and classified into content (the goal or general principle that guides a practice element) and delivery (the way in which a teacher provides instruction to the child) categories. We discuss implications that the identification of these practice elements found in the early childhood literature has for efforts to implement models and practices.

Contribution of transposable elements and distal enhancers to evolution of human-specific features of interphase chromatin architecture in embryonic stem cells.

PubMed

Glinsky, Gennadi V

2018-03-01

Transposable elements have made major evolutionary impacts on creation of primate-specific and human-specific genomic regulatory loci and species-specific genomic regulatory networks (GRNs). Molecular and genetic definitions of human-specific changes to GRNs contributing to development of unique to human phenotypes remain a highly significant challenge. Genome-wide proximity placement analysis of diverse families of human-specific genomic regulatory loci (HSGRL) identified topologically associating domains (TADs) that are significantly enriched for HSGRL and designated rapidly evolving in human TADs. Here, the analysis of HSGRL, hESC-enriched enhancers, super-enhancers (SEs), and specific sub-TAD structures termed super-enhancer domains (SEDs) has been performed. In the hESC genome, 331 of 504 (66%) of SED-harboring TADs contain HSGRL and 68% of SEDs co-localize with HSGRL, suggesting that emergence of HSGRL may have rewired SED-associated GRNs within specific TADs by inserting novel and/or erasing existing non-coding regulatory sequences. Consequently, markedly distinct features of the principal regulatory structures of interphase chromatin evolved in the hESC genome compared to mouse: the SED quantity is 3-fold higher and the median SED size is significantly larger. Concomitantly, the overall TAD quantity is increased by 42% while the median TAD size is significantly decreased (p = 9.11E-37) in the hESC genome. Present analyses illustrate a putative global role for transposable elements and HSGRL in shaping the human-specific features of the interphase chromatin organization and functions, which are facilitated by accelerated creation of novel transcription factor binding sites and new enhancers driven by targeted placement of HSGRL at defined genomic coordinates. A trend toward the convergence of TAD and SED architectures of interphase chromatin in the hESC genome may reflect changes of 3D-folding patterns of linear chromatin fibers designed to enhance both regulatory complexity and functional precision of GRNs by creating predominantly a single gene (or a set of functionally linked genes) per regulatory domain structures. Collectively, present analyses reveal critical evolutionary contributions of transposable elements and distal enhancers to creation of thousands primate- and human-specific elements of a chromatin folding code, which defines the 3D context of interphase chromatin both restricting and facilitating biological functions of GRNs.

Method and structure for skewed block-cyclic distribution of lower-dimensional data arrays in higher-dimensional processor grids

DOEpatents

Chatterjee, Siddhartha [Yorktown Heights, NY; Gunnels, John A [Brewster, NY

2011-11-08

A method and structure of distributing elements of an array of data in a computer memory to a specific processor of a multi-dimensional mesh of parallel processors includes designating a distribution of elements of at least a portion of the array to be executed by specific processors in the multi-dimensional mesh of parallel processors. The pattern of the designating includes a cyclical repetitive pattern of the parallel processor mesh, as modified to have a skew in at least one dimension so that both a row of data in the array and a column of data in the array map to respective contiguous groupings of the processors such that a dimension of the contiguous groupings is greater than one.

The MHOST finite element program: 3-D inelastic analysis methods for hot section components. Volume 2: User's manual

NASA Technical Reports Server (NTRS)

Nakazawa, Shohei

1989-01-01

The user options available for running the MHOST finite element analysis package is described. MHOST is a solid and structural analysis program based on the mixed finite element technology, and is specifically designed for 3-D inelastic analysis. A family of 2- and 3-D continuum elements along with beam and shell structural elements can be utilized, many options are available in the constitutive equation library, the solution algorithms and the analysis capabilities. The outline of solution algorithms is discussed along with the data input and output, analysis options including the user subroutines and the definition of the finite elements implemented in the program package.

Outward Bound...Into the Mainstream of Education.

ERIC Educational Resources Information Center

Outward Bound, Inc., Andover, MA.

Outward Bound schools have instituted advanced courses designed specifically for adults engaged in education and youth work. Benefits for teachers include greater development of capacitites and potentialities, greater confidence in their abilities, and the ability to relate more effectively to others. Some of the specific training elements in an…

25 CFR 301.3 - Specifications of dies.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 25 Indians 2 2010-04-01 2010-04-01 false Specifications of dies. 301.3 Section 301.3 Indians INDIAN ARTS AND CRAFTS BOARD, DEPARTMENT OF THE INTERIOR NAVAJO, PUEBLO, AND HOPI SILVER AND TURQUOISE... more mechanical than hand tools and vise. Dies shall contain only a single element of the design. ...

Strategic Design of an Interactive Video Learning Lab (IVL).

ERIC Educational Resources Information Center

Switzer, Ralph V., Jr.; Switzer, Jamie S.

1993-01-01

Describes a study that researched elements necessary for the design of an interactive video learning (IVL) lab for business courses. Highlights include a review of pertinent literature; guidelines for the use of an IVL lab; IVL systems integration; system specifications; hardware costs; and system software. (five references) (LRW)

Control of small phased-array antennas

NASA Technical Reports Server (NTRS)

Doland, G. D.

1978-01-01

Series of reports, patent descriptions, calculator programs, and other literature describes antenna control and steering apparatus for seven-element phased array. Though series contains information specific to particular system, it illustrates methods that can be applied to antennas with greater or fewer numbers of elements. Included are programs for calculating beam parameters and design functions and information to interfacing digital controller to beam-steering apparatus.

Acoustic transducer with damping means

DOEpatents

Smith, Richard W.; Adamson, Gerald E.

1976-11-02

An ultrasonic transducer specifically suited to high temperature sodium applications is described. A piezoelectric active element is joined to the transducer faceplate by coating the faceplate and juxtaposed active element face with wetting agents specifically compatible with the bonding procedure employed to achieve the joint. The opposite face of the active element is fitted with a backing member designed to assure continued electrical continuity during adverse operating conditions which can result in the fracturing of the active element. The fit is achieved employing a spring-loaded electrode operably arranged to electrically couple the internal transducer components, enclosed in a hermetically sealed housing, to accessory components normally employed in transducer applications. Two alternative backing members are taught for assuring electrical continuity. The first employs a resilient, discrete multipoint contact electrode in electrical communication with the active element face. The second employs a resilient, elastomeric, electrically conductive, damped member in electrical communication with the active element face in a manner to effect ring-down of the transducer. Each embodiment provides continued electrical continuity within the transducer in the event the active element fractures, while the second provides the added benefit of damping.

Air Land Sea Bulletin, Issue No. 2013-2, Joint Close Air Support

DTIC Science & Technology

2013-05-01

game plan between his aircraft or element and the coor- dinated attack aircraft or element (s) for a specific JTAC/FAC(A) designated target. However...5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME...Service Department of Defense field agency sponsored by the US Army Train - ing and Doctrine Command (TRADOC), Marine Corps Combat Development Command

Designing added functions in engineered cementitious composites

NASA Astrophysics Data System (ADS)

Yang, En-Hua

In this dissertation, a new and systematic material design approach is developed for ECC with added functions through material microstructures linkage to composite macroscopic behavior. The thesis research embodies theoretical development by building on previous ECC micromechanical models, and experimental investigations into three specific new versions of ECC with added functions aimed at addressing societal demands of our built infrastructure. Specifically, the theoretical study includes three important ECC modeling elements: Steady-state crack propagation analyses and simulation, predictive accuracy of the fiber bridging constitutive model, and development of the rate-dependent strain-hardening criteria. The first element establishes the steady-state cracking criterion as a fundamental requirement for multiple cracking behavior in brittle matrix composites. The second element improves the accuracy of crack-width prediction in ECC. The third element establishes the micromechanics basis for impact-resistant ECC design. Three new ECCs with added functions were developed and experimentally verified in this thesis research through the enhanced theoretical framework. A green ECC incorporating a large volume of industrial waste was demonstrated to possess reduced crack width and drying shrinkage. The self-healing ECC designed with tight crack width was demonstrated to recover transport and mechanical properties after microcrack damage when exposed to wet and dry cycles. The impact-resistant ECC was demonstrated to retain tensile ductility with increased strength under moderately high strain-rate loading. These new versions of ECC with added functions are expected to contribute greatly to enhancing the sustainability, durability, and safety of civil infrastructure built with ECC. This research establishes the effectiveness of micromechanics-based design and material ingredient tailoring for ECC with added new attributes but without losing its basic tensile ductile characteristics.

Seal Joint Analysis and Design for the Ares-I Upper Stage LOX Tank

NASA Technical Reports Server (NTRS)

Phillips, Dawn R.; Wingate, Robert J.

2011-01-01

The sealing capability of the Ares-I Upper Stage liquid oxygen tank-to-sump joint is assessed by analyzing the deflections of the joint components. Analyses are performed using three-dimensional symmetric wedge finite element models and the ABAQUS commercial finite element software. For the pressure loads and feedline interface loads, the analyses employ a mixed factor of safety approach to comply with the Constellation Program factor of safety requirements. Naflex pressure-assisted seals are considered first because they have been used successfully in similar seal joints in the Space Shuttle External Tank. For the baseline sump seal joint configuration with a Naflex seal, the predicted joint opening greatly exceeds the seal design specification. Three redesign options of the joint that maintain the use of a Naflex seal are studied. The joint openings for the redesigned seal joints show improvement over the baseline configuration; however, these joint openings still exceed the seal design specification. RACO pressure-assisted seals are considered next because they are known to also be used on the Space Shuttle External Tank, and the joint opening allowable is much larger than the specification for the Naflex seals. The finite element models for the RACO seal analyses are created by modifying the models that were used for the Naflex seal analyses. The analyses show that the RACO seal may provide sufficient sealing capability for the sump seal joint. The results provide reasonable data to recommend the design change and plan a testing program to determine the capability of RACO seals in the Ares-I Upper Stage liquid oxygen tank sump seal joint.

Low Cost Nuclear Thermal Rocket Cermet Fuel Element Environment Testing

NASA Technical Reports Server (NTRS)

Bradley, D. E.; Mireles, O. R.; Hickman, R. R.

2011-01-01

Deep space missions with large payloads require high specific impulse and relatively high thrust to achieve mission goals in reasonable time frames.1,2 Conventional storable propellants produce average specific impulse. Nuclear thermal rockets capable of producing high specific impulse are proposed. Nuclear thermal rockets employ heat produced by fission reaction to heat and therefore accelerate hydrogen, which is then forced through a rocket nozzle providing thrust. Fuel element temperatures are very high (up to 3000 K), and hydrogen is highly reactive with most materials at high temperatures. Data covering the effects of high-temperature hydrogen exposure on fuel elements are limited.3 The primary concern is the mechanical failure of fuel elements that employ high-melting-point metals, ceramics, or a combination (cermet) as a structural matrix into which the nuclear fuel is distributed. The purpose of the testing is to obtain data to assess the properties of the non-nuclear support materials, as-fabricated, and determine their ability to survive and maintain thermal performance in a prototypical NTR reactor environment of exposure to hydrogen at very high temperatures. The fission process of the planned fissile material and the resulting heating performance is well known and does not therefore require that active fissile material be integrated in this testing. A small-scale test bed designed to heat fuel element samples via non-contact radio frequency heating and expose samples to hydrogen is being developed to assist in optimal material and manufacturing process selection without employing fissile material. This paper details the test bed design and results of testing conducted to date.

MHOST version 4.2. Volume 1: Users' manual

NASA Technical Reports Server (NTRS)

Nakazawa, Shohei

1989-01-01

This manual describes the user options available for running the MHOST finite element analysis package. MHOST is a solid and structural analysis program based on mixed finite element technology, and is specifically designed for three-dimensional inelastic analysis. A family of two- and three-dimensional continuum elements along with beam and shell structural elements can be utilized. Many options are available in the constitutive equation library, the solution algorithms and the analysis capabilities. An overview of the algorithms, a general description of the input data formats, and a discussion of input data for selecting solution algorithms are given.

Development of analytical methods for multiplex bio-assay with inductively coupled plasma mass spectrometry

PubMed Central

Ornatsky, Olga I.; Kinach, Robert; Bandura, Dmitry R.; Lou, Xudong; Tanner, Scott D.; Baranov, Vladimir I.; Nitz, Mark; Winnik, Mitchell A.

2008-01-01

Advances in the development of highly multiplexed bio-analytical assays with inductively coupled plasma mass spectrometry (ICP-MS) detection are discussed. Use of novel reagents specifically designed for immunological methods utilizing elemental analysis is presented. The major steps of method development, including selection of elements for tags, validation of tagged reagents, and examples of multiplexed assays, are considered in detail. The paper further describes experimental protocols for elemental tagging of antibodies, immunostaining of live and fixed human leukemia cells, and preparation of samples for ICP-MS analysis. Quantitative analysis of surface antigens on model cell lines using a cocktail of seven lanthanide labeled antibodies demonstrated high specificity and concordance with conventional immunophenotyping. PMID:19122859

Civilian Radioactive Waste Management System Requirements Document

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

C.A. Kouts

2006-05-10

The CRD addresses the requirements of Department of Energy (DOE) Order 413.3-Change 1, ''Program and Project Management for the Acquisition of Capital Assets'', by providing the Secretarial Acquisition Executive (Level 0) scope baseline and the Program-level (Level 1) technical baseline. The Secretarial Acquisition Executive approves the Office of Civilian Radioactive Waste Management's (OCRWM) critical decisions and changes against the Level 0 baseline; and in turn, the OCRWM Director approves all changes against the Level 1 baseline. This baseline establishes the top-level technical scope of the CRMWS and its three system elements, as described in section 1.3.2. The organizations responsible formore » design, development, and operation of system elements described in this document must therefore prepare subordinate project-level documents that are consistent with the CRD. Changes to requirements will be managed in accordance with established change and configuration control procedures. The CRD establishes requirements for the design, development, and operation of the CRWMS. It specifically addresses the top-level governing laws and regulations (e.g., ''Nuclear Waste Policy Act'' (NWPA), 10 Code of Federal Regulations (CFR) Part 63, 10 CFR Part 71, etc.) along with specific policy, performance requirements, interface requirements, and system architecture. The CRD shall be used as a vehicle to incorporate specific changes in technical scope or performance requirements that may have significant program implications. Such may include changes to the program mission, changes to operational capability, and high visibility stakeholder issues. The CRD uses a systems approach to: (1) identify key functions that the CRWMS must perform, (2) allocate top-level requirements derived from statutory, regulatory, and programmatic sources, and (3) define the basic elements of the system architecture and operational concept. Project-level documents address CRD requirements by further defining system element functions, decomposing requirements into significantly greater detail, and developing designs of system components, facilities, and equipment. The CRD addresses the identification and control of functional, physical, and operational boundaries between and within CRWMS elements. The CRD establishes requirements regarding key interfaces between the CRWMS and elements external to the CRWMS. Project elements define interfaces between CRWMS program elements. The Program has developed a change management process consistent with DOE Order 413.3-Change 1. Changes to the Secretarial Acquisition Executive and Program-level baselines must be approved by a Program Baseline Change Control Board. Specific thresholds have been established for identifying technical, cost, and schedule changes that require approval. The CRWMS continually evaluates system design and operational concepts to optimize performance and/or cost. The Program has developed systems analysis tools to assess potential enhancements to the physical system and to determine the impacts from cost saving initiatives, scientific and technological improvements, and engineering developments. The results of systems analyses, if appropriate, are factored into revisions to the CRD as revised Programmatic Requirements.« less

Design and fabrication of Rene 41 advanced structural panels. [their performance under axial compression, shear, and bending loads

NASA Technical Reports Server (NTRS)

Greene, B. E.; Northrup, R. F.

1975-01-01

The efficiency was investigated of curved elements in the design of lightweight structural panels under combined loads of axial compression, inplane shear, and bending. The application is described of technology generated in the initial aluminum program to the design and fabrication of Rene 41 panels for subsequent performance tests at elevated temperature. Optimum designs for two panel configurations are presented. The designs are applicable to hypersonic airplane wing structure, and are designed specifically for testing at elevated temperature in the hypersonic wing test structure located at the NASA Flight Research Center. Fabrication methods developed to produce the Rene panels are described, and test results of smaller structural element specimens are presented to verify the design and fabrication methods used. Predicted strengths of the panels under several proposed elevated temperature test load conditions are presented.

The non-linear response of a muscle in transverse compression: assessment of geometry influence using a finite element model.

PubMed

Gras, Laure-Lise; Mitton, David; Crevier-Denoix, Nathalie; Laporte, Sébastien

2012-01-01

Most recent finite element models that represent muscles are generic or subject-specific models that use complex, constitutive laws. Identification of the parameters of such complex, constitutive laws could be an important limit for subject-specific approaches. The aim of this study was to assess the possibility of modelling muscle behaviour in compression with a parametric model and a simple, constitutive law. A quasi-static compression test was performed on the muscles of dogs. A parametric finite element model was designed using a linear, elastic, constitutive law. A multi-variate analysis was performed to assess the effects of geometry on muscle response. An inverse method was used to define Young's modulus. The non-linear response of the muscles was obtained using a subject-specific geometry and a linear elastic law. Thus, a simple muscle model can be used to have a bio-faithful, biomechanical response.

Specificity determinants for the abscisic acid response element.

PubMed

Sarkar, Aditya Kumar; Lahiri, Ansuman

2013-01-01

Abscisic acid (ABA) response elements (ABREs) are a group of cis-acting DNA elements that have been identified from promoter analysis of many ABA-regulated genes in plants. We are interested in understanding the mechanism of binding specificity between ABREs and a class of bZIP transcription factors known as ABRE binding factors (ABFs). In this work, we have modeled the homodimeric structure of the bZIP domain of ABRE binding factor 1 from Arabidopsis thaliana (AtABF1) and studied its interaction with ACGT core motif-containing ABRE sequences. We have also examined the variation in the stability of the protein-DNA complex upon mutating ABRE sequences using the protein design algorithm FoldX. The high throughput free energy calculations successfully predicted the ability of ABF1 to bind to alternative core motifs like GCGT or AAGT and also rationalized the role of the flanking sequences in determining the specificity of the protein-DNA interaction.

Electrostatic Discharge Effects on Thin Film Resistors

NASA Technical Reports Server (NTRS)

Sampson, Michael J.; Hull, Scott M.

1999-01-01

Recently, open circuit failures of individual elements in thin film resistor networks have been attributed to electrostatic discharge (ESD) effects. This paper will discuss the investigation that came to this conclusion and subsequent experimentation intended to characterize design factors that affect the sensitivity of resistor elements to ESD. The ESD testing was performed using the standard human body model simulation. Some of the design elements to be evaluated were: trace width, trace length (and thus width to length ratio), specific resistivity of the trace (ohms per square) and resistance value. However, once the experiments were in progress, it was realized that the ESD sensitivity of most of the complex patterns under evaluation was determined by other design and process factors such as trace shape and termination pad spacing. This paper includes pictorial examples of representative ESD failure sites, and provides some options for designing thin film resistors that are ESD resistant. The risks of ESD damage are assessed and handling precautions suggested.

Designing new institutions for implementing integrated disaster risk management: key elements and future directions.

PubMed

Gopalakrishnan, Chennat; Okada, Norio

2007-12-01

The goal of integrated disaster risk management is to promote an overall improvement in the quality of safety and security in a region, city or community at disaster risk. This paper presents the case for a thorough overhaul of the institutional component of integrated disaster risk management. A review of disaster management institutions in the United States indicates significant weaknesses in their ability to contribute effectively to the implementation of integrated disaster risk management. Our analysis and findings identify eight key elements for the design of dynamic new disaster management institutions. Six specific approaches are suggested for incorporating the identified key elements in building new institutions that would have significant potential for enhancing the effective implementation of integrated disaster risk management. We have developed a possible blueprint for effective design and construction of efficient, sustainable and functional disaster management institutions.

Validation of a SysML based design for wireless sensor networks

NASA Astrophysics Data System (ADS)

Berrachedi, Amel; Rahim, Messaoud; Ioualalen, Malika; Hammad, Ahmed

2017-07-01

When developing complex systems, the requirement for the verification of the systems' design is one of the main challenges. Wireless Sensor Networks (WSNs) are examples of such systems. We address the problem of how WSNs must be designed to fulfil the system requirements. Using the SysML Language, we propose a Model Based System Engineering (MBSE) specification and verification methodology for designing WSNs. This methodology uses SysML to describe the WSNs requirements, structure and behaviour. Then, it translates the SysML elements to an analytic model, specifically, to a Deterministic Stochastic Petri Net. The proposed approach allows to design WSNs and study their behaviors and their energy performances.

An Open Specification for Space Project Mission Operations Control Architectures

NASA Technical Reports Server (NTRS)

Hooke, A.; Heuser, W. R.

1995-01-01

An 'open specification' for Space Project Mission Operations Control Architectures is under development in the Spacecraft Control Working Group of the American Institute for Aeronautics and Astro- nautics. This architecture identifies 5 basic elements incorporated in the design of similar operations systems: Data, System Management, Control Interface, Decision Support Engine, & Space Messaging Service.

77 FR 16435 - Transmission Relay Loadability Reliability Standard

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-21

... are designed to read electrical measurements, such as current, voltage, and frequency, and can be set... an element of the system under its protection, it sends a signal to an interrupting device(s) (such... their relays according to one of thirteen specific settings (sub-parts R1.1 through R1.13) designed to...

49 CFR Appendix C to Part 236 - Safety Assurance Criteria and Processes

Code of Federal Regulations, 2010 CFR

2010-10-01

... system (all its elements including hardware and software) must be designed to assure safe operation with... unsafe errors in the software due to human error in the software specification, design, or coding phases... (hardware or software, or both) are used in combination to ensure safety. If a common mode failure exists...

Adoption and Design of Emerging Dietary Policies to Improve Cardiometabolic Health in the US.

PubMed

Huang, Yue; Pomeranz, Jennifer; Wilde, Parke; Capewell, Simon; Gaziano, Tom; O'Flaherty, Martin; Kersh, Rogan; Whitsel, Laurie; Mozaffarian, Dariush; Micha, Renata

2018-04-14

Suboptimal diet is a leading cause of cardiometabolic disease and economic burdens. Evidence-based dietary policies within 5 domains-food prices, reformulation, marketing, labeling, and government food assistance programs-appear promising at improving cardiometabolic health. Yet, the extent of new dietary policy adoption in the US and key elements crucial to define in designing such policies are not well established. We created an inventory of recent US dietary policy cases aiming to improve cardiometabolic health and assessed the extent of their proposal and adoption at federal, state, local, and tribal levels; and categorized and characterized the key elements in their policy design. Recent federal dietary policies adopted to improve cardiometabolic health include reformulation (trans-fat elimination), marketing (mass-media campaigns to increase fruits and vegetables), labeling (Nutrition Facts Panel updates, menu calorie labeling), and food assistance programs (financial incentives for fruits and vegetables in the Supplemental Nutrition Assistance Program (SNAP) and Women, Infant and Children (WIC) program). Federal voluntary guidelines have been proposed for sodium reformulation and food marketing to children. Recent state proposals included sugar-sweetened beverage (SSB) taxes, marketing restrictions, and SNAP restrictions, but few were enacted. Local efforts varied significantly, with certain localities consistently leading in the proposal or adoption of relevant policies. Across all jurisdictions, most commonly selected dietary targets included fruits and vegetables, SSBs, trans-fat, added sugar, sodium, and calories; other healthy (e.g., nuts) or unhealthy (e.g., processed meats) factors were largely not addressed. Key policy elements to define in designing these policies included those common across domains (e.g., level of government, target population, dietary target, dietary definition, implementation mechanism), and domain-specific (e.g., media channels for food marketing domain) or policy-specific (e.g., earmarking for taxes) elements. Characteristics of certain elements were similarly defined (e.g., fruit and vegetable definition, warning language used in SSB warning labels), while others varied across cases within a policy (e.g., tax base for SSB taxes). Several key elements were not always sufficiently characterized in government documents, and dietary target selections and definitions did not consistently align with the evidence-base. These findings highlight recent action on dietary policies to improve cardiometabolic health in the US; and key elements necessary to design such policies.

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

Bull, Diana L.; Costello, Ronan; Babarit, Aurelien

Capabilities and functions are hierarchical structures (i.e. taxonomies) that are used in a systems engineering framework to identify complimentary requirements for the system: what the system must do to achieve what it must be. In the case of capabilities, the taxonomy embodies the list of characteristics that are desired, from the perspective of the stakeholders, for the system to be successful. In terms of the functions, the hierarchy represents the solution agnostic (i.e. independent of specific design embodiments) elements that are needed to meet the stakeholder requirements. This paper will focus on the development of the functions. The functions definemore » the fundamental elements of the solution that must be provided in order to achieve the mission and deliver the capabilities. They identify the behaviors the farm must possess, i.e. the farm must be able to generate and deliver electricity from wave power. High-level functions are independent of the technology or design used to implement the function. However, detailed functions may begin to border on specific design choices. Hence a strong effort has been made to maintain functions that are design agnostic.« less

Paraxial diffractive elements for space-variant linear transforms

NASA Astrophysics Data System (ADS)

Teiwes, Stephan; Schwarzer, Heiko; Gu, Ben-Yuan

1998-06-01

Optical linear transform architectures bear good potential for future developments of very powerful hybrid vision systems and neural network classifiers. The optical modules of such systems could be used as pre-processors to solve complex linear operations at very high speed in order to simplify an electronic data post-processing. However, the applicability of linear optical architectures is strongly connected with the fundamental question of how to implement a specific linear transform by optical means and physical imitations. The large majority of publications on this topic focusses on the optical implementation of space-invariant transforms by the well-known 4f-setup. Only few papers deal with approaches to implement selected space-variant transforms. In this paper, we propose a simple algebraic method to design diffractive elements for an optical architecture in order to realize arbitrary space-variant transforms. The design procedure is based on a digital model of scalar, paraxial wave theory and leads to optimal element transmission functions within the model. Its computational and physical limitations are discussed in terms of complexity measures. Finally, the design procedure is demonstrated by some examples. Firstly, diffractive elements for the realization of different rotation operations are computed and, secondly, a Hough transform element is presented. The correct optical functions of the elements are proved in computer simulation experiments.

Benchmark model correction of monitoring system based on Dynamic Load Test of Bridge

NASA Astrophysics Data System (ADS)

Shi, Jing-xian; Fan, Jiang

2018-03-01

Structural health monitoring (SHM) is a field of research in the area, and it’s designed to achieve bridge safety and reliability assessment, which needs to be carried out on the basis of the accurate simulation of the finite element model. Bridge finite element model is simplified of the structural section form, support conditions, material properties and boundary condition, which is based on the design and construction drawings, and it gets the calculation models and the results.But according to the design and specification requirements established finite element model due to its cannot fully reflect the true state of the bridge, so need to modify the finite element model to obtain the more accurate finite element model. Based on Da-guan river crossing of Ma - Zhao highway in Yunnan province as the background to do the dynamic load test test, we find that the impact coefficient of the theoretical model of the bridge is very different from the coefficient of the actual test, and the change is different; according to the actual situation, the calculation model is adjusted to get the correct frequency of the bridge, the revised impact coefficient found that the modified finite element model is closer to the real state, and provides the basis for the correction of the finite model.

A Highly Flexible, Automated System Providing Reliable Sample Preparation in Element- and Structure-Specific Measurements.

PubMed

Vorberg, Ellen; Fleischer, Heidi; Junginger, Steffen; Liu, Hui; Stoll, Norbert; Thurow, Kerstin

2016-10-01

Life science areas require specific sample pretreatment to increase the concentration of the analytes and/or to convert the analytes into an appropriate form for the detection and separation systems. Various workstations are commercially available, allowing for automated biological sample pretreatment. Nevertheless, due to the required temperature, pressure, and volume conditions in typical element and structure-specific measurements, automated platforms are not suitable for analytical processes. Thus, the purpose of the presented investigation was the design, realization, and evaluation of an automated system ensuring high-precision sample preparation for a variety of analytical measurements. The developed system has to enable system adaption and high performance flexibility. Furthermore, the system has to be capable of dealing with the wide range of required vessels simultaneously, allowing for less cost and time-consuming process steps. However, the system's functionality has been confirmed in various validation sequences. Using element-specific measurements, the automated system was up to 25% more precise compared to the manual procedure and as precise as the manual procedure using structure-specific measurements. © 2015 Society for Laboratory Automation and Screening.

Mesh Deformation Based on Fully Stressed Design: The Method and Two-Dimensional Examples

NASA Technical Reports Server (NTRS)

Hsu, Su-Yuen; Chang, Chau-Lyan

2007-01-01

Mesh deformation in response to redefined boundary geometry is a frequently encountered task in shape optimization and analysis of fluid-structure interaction. We propose a simple and concise method for deforming meshes defined with three-node triangular or four-node tetrahedral elements. The mesh deformation method is suitable for large boundary movement. The approach requires two consecutive linear elastic finite-element analyses of an isotropic continuum using a prescribed displacement at the mesh boundaries. The first analysis is performed with homogeneous elastic property and the second with inhomogeneous elastic property. The fully stressed design is employed with a vanishing Poisson s ratio and a proposed form of equivalent strain (modified Tresca equivalent strain) to calculate, from the strain result of the first analysis, the element-specific Young s modulus for the second analysis. The theoretical aspect of the proposed method, its convenient numerical implementation using a typical linear elastic finite-element code in conjunction with very minor extra coding for data processing, and results for examples of large deformation of two-dimensional meshes are presented in this paper. KEY WORDS: Mesh deformation, shape optimization, fluid-structure interaction, fully stressed design, finite-element analysis, linear elasticity, strain failure, equivalent strain, Tresca failure criterion

Mapping Chemical Selection Pathways for Designing Multicomponent Alloys: an informatics framework for materials design.

PubMed

Srinivasan, Srikant; Broderick, Scott R; Zhang, Ruifeng; Mishra, Amrita; Sinnott, Susan B; Saxena, Surendra K; LeBeau, James M; Rajan, Krishna

2015-12-18

A data driven methodology is developed for tracking the collective influence of the multiple attributes of alloying elements on both thermodynamic and mechanical properties of metal alloys. Cobalt-based superalloys are used as a template to demonstrate the approach. By mapping the high dimensional nature of the systematics of elemental data embedded in the periodic table into the form of a network graph, one can guide targeted first principles calculations that identify the influence of specific elements on phase stability, crystal structure and elastic properties. This provides a fundamentally new means to rapidly identify new stable alloy chemistries with enhanced high temperature properties. The resulting visualization scheme exhibits the grouping and proximity of elements based on their impact on the properties of intermetallic alloys. Unlike the periodic table however, the distance between neighboring elements uncovers relationships in a complex high dimensional information space that would not have been easily seen otherwise. The predictions of the methodology are found to be consistent with reported experimental and theoretical studies. The informatics based methodology presented in this study can be generalized to a framework for data analysis and knowledge discovery that can be applied to many material systems and recreated for different design objectives.

Implementing Capsule Representation in a Total Hip Dislocation Finite Element Model

PubMed Central

Stewart, Kristofer J; Pedersen, Douglas R; Callaghan, John J; Brown, Thomas D

2004-01-01

Previously validated hardware-only finite element models of THA dislocation have clarified how various component design and surgical placement variables contribute to resisting the propensity for implant dislocation. This body of work has now been enhanced with the incorporation of experimentally based capsule representation, and with anatomic bone structures. The current form of this finite element model provides for large deformation multi-body contact (including capsule wrap-around on bone and/or implant), large displacement interfacial sliding, and large deformation (hyperelastic) capsule representation. In addition, the modular nature of this model now allows for rapid incorporation of current or future total hip implant designs, accepts complex multi-axial physiologic motion inputs, and outputs case-specific component/bone/soft-tissue impingement events. This soft-tissue-augmented finite element model is being used to investigate the performance of various implant designs for a range of clinically-representative soft tissue integrities and surgical techniques. Preliminary results show that capsule enhancement makes a substantial difference in stability, compared to an otherwise identical hardware-only model. This model is intended to help put implant design and surgical technique decisions on a firmer scientific basis, in terms of reducing the likelihood of dislocation. PMID:15296198

Design specification for the European Spallation Source neutron generating target element

NASA Astrophysics Data System (ADS)

Aguilar, A.; Sordo, F.; Mora, T.; Mena, L.; Mancisidor, M.; Aguilar, J.; Bakedano, G.; Herranz, I.; Luna, P.; Magan, M.; Vivanco, R.; Jimenez-Villacorta, F.; Sjogreen, K.; Oden, U.; Perlado, J. M.; Martinez, J. L.; Bermejo, F. J.

2017-06-01

The paper addresses some of the most relevant issues concerning the thermal hydraulics and radiation damage of the neutron generation target to be built at the European Spallation Source as recently approved after a critical design review. The target unit consists of a set of Tungsten blocks placed inside a wheel of 2.5 m diameter which rotates at some 0.5 Hz in order to distribute the heat generated from incoming protons which reach the target in the radial direction. The spallation material elements are composed of an array of Tungsten pieces which rest on a rotating steel support (the cassette) and are distributed in a cross-flow configuration. The thermal, mechanical and radiation effects resulting from the impact of a 2 GeV proton pulse are analysed in detail as well as an evaluation of the inventory of spallation products. The current design is found to conform to specifications and found to be robust enough to deal with several accident scenarios.

Piezoelectric Nanostructures for Mechanical Energy Harvesting

NASA Astrophysics Data System (ADS)

Ardila, G.; Hinchet, R.; Montès, L.; Mouis, M.

2013-05-01

We present the most studied piezoelectric materials at the nanoscale and discuss their vertical integration into harvesting devices. Finite element method (FEM) simulations are used to obtain optimization guidelines rules of a specific design.

Optimization of the sources in local hyperthermia using a combined finite element-genetic algorithm method.

PubMed

Siauve, N; Nicolas, L; Vollaire, C; Marchal, C

2004-12-01

This article describes an optimization process specially designed for local and regional hyperthermia in order to achieve the desired specific absorption rate in the patient. It is based on a genetic algorithm coupled to a finite element formulation. The optimization method is applied to real human organs meshes assembled from computerized tomography scans. A 3D finite element formulation is used to calculate the electromagnetic field in the patient, achieved by radiofrequency or microwave sources. Space discretization is performed using incomplete first order edge elements. The sparse complex symmetric matrix equation is solved using a conjugate gradient solver with potential projection pre-conditionning. The formulation is validated by comparison of calculated specific absorption rate distributions in a phantom to temperature measurements. A genetic algorithm is used to optimize the specific absorption rate distribution to predict the phases and amplitudes of the sources leading to the best focalization. The objective function is defined as the specific absorption rate ratio in the tumour and healthy tissues. Several constraints, regarding the specific absorption rate in tumour and the total power in the patient, may be prescribed. Results obtained with two types of applicators (waveguides and annular phased array) are presented and show the faculties of the developed optimization process.

UML activity diagram swimlanes in logic controller design

NASA Astrophysics Data System (ADS)

Grobelny, Michał; Grobelna, Iwona

2015-12-01

Logic controller behavior can be specified using various techniques, including UML activity diagrams and control Petri nets. Each technique has its advantages and disadvantages. Application of both specification types in one project allows to take benefits from both of them. Additional elements of UML models make it possible to divide a specification into some parts, considered from other point of view (logic controller, user or system). The paper introduces an idea to use UML activity diagrams with swimlanes to increase the understandability of design models.

Next-Generation NATO Reference Mobility Model (NG-NRMM)

DTIC Science & Technology

2016-05-11

facilitate comparisons between vehicle design candidates and to assess the mobility of existing vehicles under specific scenarios. Although NRMM has...of different deployed platforms in different areas of operation and routes  Improved flexibility as a design and procurement support tool through...Element Method DEM Digital Elevation Model DIL Driver in the Loop DP Drawbar Pull Force DOE Design of Experiments DTED Digital Terrain Elevation Data

Satellite Power Systems (SPS) concept definition study, exhibit C. Volume 6: In-depth element investigation

NASA Technical Reports Server (NTRS)

Hanley, G.

1979-01-01

Computer assisted design of a gallium arsenide solid state dc-to-RF converter with supportive fabrication data was investigated. Specific tasks performed include: computer program checkout; amplifier comparisons; computer design analysis of GaSa solar cells; and GaAs diode evaluation. Results obtained in the design and evaluation of transistors for the microwave space power system are presented.

Structured Analysis for the Logistic Support Analysis (LSA) Task and the Integrated Logistic Support (ILS) Element. Structured Analysis - ILS Assessment Element E11. Design Influence

DTIC Science & Technology

1989-01-01

format size of this report, the full identifying entry may well be forcibly shortened, thereby introducing the possibility of misunderstanding. Therefore...OF MATERIEL" 3d . "AR 570-9, "MANPOWER AND EQUIPMENT CONTROL - HOST NATION SUPPORT" 2. AR 700-9, "POLICIES OF THE ARMY LOGISTIC SYSTEM" 3. AR 700-82...PERSONNEL 4. TRAINING 5. SYSTEM SAFETY 6. HEALTH HAZARDS. TEE ASSESSMENT Or MANPRINT INFLUENCE ON DESIGNS IS ADDRESSED IN SIX (6) SPECIFIC AREAS IN

De novo design of a synthetic riboswitch that regulates transcription termination

PubMed Central

Wachsmuth, Manja; Findeiß, Sven; Weissheimer, Nadine; Stadler, Peter F.; Mörl, Mario

2013-01-01

Riboswitches are regulatory RNA elements typically located in the 5′-untranslated region of certain mRNAs and control gene expression at the level of transcription or translation. These elements consist of a sensor and an adjacent actuator domain. The sensor usually is an aptamer that specifically interacts with a ligand. The actuator contains an intrinsic terminator or a ribosomal binding site for transcriptional or translational regulation, respectively. Ligand binding leads to structural rearrangements of the riboswitch and to presentation or masking of these regulatory elements. Based on this modular organization, riboswitches are an ideal target for constructing synthetic regulatory systems for gene expression. Although riboswitches for translational control have been designed successfully, attempts to construct synthetic elements regulating transcription have failed so far. Here, we present an in silico pipeline for the rational design of synthetic riboswitches that regulate gene expression at the transcriptional level. Using the well-characterized theophylline aptamer as sensor, we designed the actuator part as RNA sequences that can fold into functional intrinsic terminator structures. In the biochemical characterization, several of the designed constructs show ligand-dependent control of gene expression in Escherichia coli, demonstrating that it is possible to engineer riboswitches not only for translational but also for transcriptional regulation. PMID:23275562

Earth Observatory Satellite system definition study. Report no. 5: System design and specifications. Part 2: Ground system element specifications

NASA Technical Reports Server (NTRS)

1974-01-01

The Ground System requirements for the Land Resources Management (LRM) type-A and type-B missions of the Earth Observatory Satellite (EOS) program are presented. Specifications for the Thematic Mapper data processing are provided (LRM A mission). The specifications also cover the R and D instruments (Thematic Mapper and High Resolution Pointable Imager) data processing for the LRM type-B mission.

Isolation, characterization and expression analysis of the BABY BOOM (BBM) gene from Larix kaempferi × L. olgensis during adventitious rooting.

PubMed

Li, Kui-Peng; Sun, Xiao-Mei; Han, Hua; Zhang, Shou-Gong

2014-11-10

The full-length cDNA and genomic sequences of the BABY BOOM (BBM) gene, designated LkBBM, were isolated from Larix kaempferi × Larix olgensis. The 3324 bp cDNA was cloned and its open reading frame (ORF) consists of 2370 nucleotides. The deduced 789 amino acid protein contains two AP2 domains and a BBM specific motif. Four conserved motifs between BBM and PLT were identified, which may be conducive to the similar function of BBM and PLT. The three dimensional (3D) structure of LkBBM was predicted and β-sheets in the AP2-R2 domain of LkBBM might recognize the specific base pairs in the major groove. Analysis of the LkBBM gene structure indicates that the gene has eight introns and nine exons. In the 5'-flanking promoter region of LkBBM, many important potential cis-acting elements were identified, such as the TATABOX5 element (a functional TATA element), ROOTMOTIFTAPOX1 element (element of root specificity), AUXREPSIAA4 element (element involved in auxin responsiveness and gene expression in root meristem), MYB1AT element (element involved in MYB recognition), ARR1AT element (element involved in cytokinin responsiveness), GARE1OSREP1 element (element involved in gibberellin responsiveness) and PYRIMIDINEBOXHVEPB1 element (element involved in abscisic acid responsiveness), which all suggested that the expression of LkBBM is highly regulated. Compared with gene expression levels in the stem, stem tip and leaf, LkBBM shows a specific expression in the root, which indicates that LkBBM plays a key role in regulating the development and growth of root in larch. In the processing of larch adventitious root formation, LkBBM started to express on the eighth day after rooting treatment and its transcript level increased continuously afterwards. According to the gene characteristics, LkBBM is proposed as a molecular marker for root primordia of larch, and the initial period of LkBBM expression may be the formation period of root primordia in the processing of adventitious rooting of larch. Copyright © 2014 Elsevier B.V. All rights reserved.

Design and testing of regulatory cassettes for optimal activity in skeletal and cardiac muscles.

PubMed

Himeda, Charis L; Chen, Xiaolan; Hauschka, Stephen D

2011-01-01

Gene therapy for muscular dystrophies requires efficient gene delivery to the striated musculature and specific, high-level expression of the therapeutic gene in a physiologically diverse array of muscles. This can be achieved by the use of recombinant adeno-associated virus vectors in conjunction with muscle-specific regulatory cassettes. We have constructed several generations of regulatory cassettes based on the enhancer and promoter of the muscle creatine kinase gene, some of which include heterologous enhancers and individual elements from other muscle genes. Since the relative importance of many control elements varies among different anatomical muscles, we are aiming to tailor these cassettes for high-level expression in cardiac muscle, and in fast and slow skeletal muscles. With the achievement of efficient intravascular gene delivery to isolated limbs, selected muscle groups, and heart in large animal models, the design of cassettes optimized for activity in different muscle types is now a practical goal. In this protocol, we outline the key steps involved in the design of regulatory cassettes for optimal activity in skeletal and cardiac muscle, and testing in mature muscle fiber cultures. The basic principles described here can also be applied to engineering tissue-specific regulatory cassettes for other cell types.

Emotion and interior space design: an ergonomic perspective.

PubMed

Reddy, Swathi Matta; Chakrabarti, Debkumar; Karmakar, Sougata

2012-01-01

Interaction between the users and their environment is spontaneous and unavoidable. This interaction can be positive or negative. A good interior space is about considering all the physical, environmental and cognitive elements and harmonizing them to make it a space that feels right, functionally and emotionally. The important element that has to be considered the most in an interior space is the "user". Balancing all these elements is a challenging job and results in a perfect interior space design. This paper intends to bring to light the necessity of designing an optimum interior space, which is a balance of the user's choice and the mandatory standards that ought to be followed for user safety and convenience. There has to be an intervening domain of ergonomics which will guide to bring out a balance between the personal choice of the user and the usual standards followed. It should also provide a step-by-step information, guidance and direction to act to the specifications and standards systematically to adapt an integrated approach of handling all the elements holistically which will indeed result in a good interior space.

Up Periscope! Designing a New Perceptual Metric for Imaging System Performance

NASA Technical Reports Server (NTRS)

Watson, Andrew B.

2016-01-01

Modern electronic imaging systems include optics, sensors, sampling, noise, processing, compression, transmission and display elements, and are viewed by the human eye. Many of these elements cannot be assessed by traditional imaging system metrics such as the MTF. More complex metrics such as NVTherm do address these elements, but do so largely through parametric adjustment of an MTF-like metric. The parameters are adjusted through subjective testing of human observers identifying specific targets in a set of standard images. We have designed a new metric that is based on a model of human visual pattern classification. In contrast to previous metrics, ours simulates the human observer identifying the standard targets. One application of this metric is to quantify performance of modern electronic periscope systems on submarines.

Review of high fidelity imaging spectrometer design for remote sensing

NASA Astrophysics Data System (ADS)

Mouroulis, Pantazis; Green, Robert O.

2018-04-01

We review the design and assessment techniques that underlie a number of successfully deployed space and airborne imaging spectrometers that have been demonstrated to achieve demanding specifications in terms of throughput and response uniformity. The principles are illustrated with telescope designs as well as spectrometer examples from the Offner and Dyson families. We also show how the design space can be extended with the use of freeform surfaces and provide additional design examples with grating as well as prism dispersive elements.

Orbital operations study. Appendix A: Interactivity analysis

NASA Technical Reports Server (NTRS)

1972-01-01

Supplemental analyses conducted to verify that safe, feasible, design concepts exist for accomplishing the attendant interface activities of the orbital operations mission are presented. The data are primarily concerned with functions and concepts common to more than one of the interfacing activities or elements. Specific consideration is given to state vector update, payload deployment, communications links, jet plume impingement, attached element operations, docking and structural interface assessment, and propellant transfer.

Inhibition Of Call-Cell Binding By Kipid Assemblies

DOEpatents

Nagy, Jon O. , Bargatze, Robert F.

2003-12-16

This invention relates generally to the field of therapeutic compounds designed to interfere between the binding of ligands and their receptors on cell surface. More specifically, it provides products and methods for inhibiting cell migration and activation using lipid assemblies with surface recognition elements that are specific for the receptors involved in cell migration and activation.

Inhibition of cell-cell binding by lipid assemblies

DOEpatents

Nagy, Jon O.; Bargatze, Robert F.

2001-05-22

This invention relates generally to the field of therapeutic compounds designed to interfere between the binding of ligands and their receptors on cell surface. More specifically, it provides products and methods for inhibiting cell migration and activation using lipid assemblies with surface recognition elements that are specific for the receptors involved in cell migration and activation.

Longitudinal Study of Middle Grades Chemistry Professional Development: Enhancement of Personal Science Teaching Self-Efficacy and Outcome Expectancy

ERIC Educational Resources Information Center

Khourey-Bowers, Claudia; Simonis, Doris G.

2004-01-01

The purpose of this research was to enhance self-efficacy beliefs, chemistry content, and pedagogical content knowledge of middle grades teachers by incorporating specific design elements into professional development. This study analyzed the influence of program design on achieving gains in personal science teaching self-efficacy, outcome…

India: A Myriad of Cultures. Three Learning Modules for Middle School Students.

ERIC Educational Resources Information Center

Jassim, Charlene

Three learning modules designed for middle school students by a middle school teacher are presented in this document. The three modules are designed to supplement the regular textbook program for teaching about India. They are specifically created to fulfill the needs and interests of 11- to 14-year-old students. The modules contain elements of…

OBE EAP-EOP Model: A Proposed Instructional Design in English for Specific Purposes

ERIC Educational Resources Information Center

Hernandez, Hjalmar Punla

2016-01-01

Outcome-Based Education (OBE) demands innovative Instructional Designs (ID) in the 21st century. Being a descriptive-qualitative research, this paper aimed to (1) identify the ID used in the English language curricula of a private tertiary level institution in the Southern Luzon, Philippines, (2) determined the elements that the ID of the English…

Web 2.0 systems supporting childhood chronic disease management: a pattern language representation of a general architecture.

PubMed

Timpka, Toomas; Eriksson, Henrik; Ludvigsson, Johnny; Ekberg, Joakim; Nordfeldt, Sam; Hanberger, Lena

2008-11-28

Chronic disease management is a global health concern. By the time they reach adolescence, 10-15% of all children live with a chronic disease. The role of educational interventions in facilitating adaptation to chronic disease is receiving growing recognition, and current care policies advocate greater involvement of patients in self-care. Web 2.0 is an umbrella term for new collaborative Internet services characterized by user participation in developing and managing content. Key elements include Really Simple Syndication (RSS) to rapidly disseminate awareness of new information; weblogs (blogs) to describe new trends, wikis to share knowledge, and podcasts to make information available on personal media players. This study addresses the potential to develop Web 2.0 services for young persons with a chronic disease. It is acknowledged that the management of childhood chronic disease is based on interplay between initiatives and resources on the part of patients, relatives, and health care professionals, and where the balance shifts over time to the patients and their families. Participatory action research was used to stepwise define a design specification in the form of a pattern language. Support for children diagnosed with diabetes Type 1 was used as the example area. Each individual design pattern was determined graphically using card sorting methods, and textually in the form Title, Context, Problem, Solution, Examples and References. Application references were included at the lowest level in the graphical overview in the pattern language but not specified in detail in the textual descriptions. The design patterns are divided into functional and non-functional design elements, and formulated at the levels of organizational, system, and application design. The design elements specify access to materials for development of the competences needed for chronic disease management in specific community settings, endorsement of self-learning through online peer-to-peer communication, and systematic accreditation and evaluation of materials and processes. The use of design patterns allows representing the core design elements of a Web 2.0 system upon which an 'ecological' development of content respecting these constraints can be built. Future research should include evaluations of Web 2.0 systems implemented according to the architecture in practice settings.

Design Optimization Considerations for the MROI

NASA Astrophysics Data System (ADS)

Creech-Eakman, M. J.; Buscher, D. F.; Haniff, C. A.; MROI Team

2014-04-01

The Magdalena Ridge Observatory Interferometer (MROI) has been conceived to be a 10 element 1.4m aperture imaging interferometer working in the optical and near-infrared and located at a altitude of 10,500 feet in the mountains of south-central New Mexico. When designing the MROI, we attempted to take lessons learned from the design of other similar facilities and specifically considered sensitivity, speed of data collection, scalability and mobility of the design, along with polarization preservation and imaging capabilities to attain the present model for the facility. Several papers detailing the specifics of the design of the MROI and the philosophy behind the certain choices or trade-offs have been published in the past few years. These references and those listed therein are listed below.

Brownfields City of Houston Solar Project: Solar Power Analysis and Design Specifications

EPA Pesticide Factsheets

This document details the scope of work elements completed in support of this project, as well as recommendations for next steps towards solar project development and power purchase agreement negotiation and finalization.

Integrating Science and Engineering to Implement Evidence-Based Practices in Health Care Settings.

PubMed

Wu, Shinyi; Duan, Naihua; Wisdom, Jennifer P; Kravitz, Richard L; Owen, Richard R; Sullivan, J Greer; Wu, Albert W; Di Capua, Paul; Hoagwood, Kimberly Eaton

2015-09-01

Integrating two distinct and complementary paradigms, science and engineering, may produce more effective outcomes for the implementation of evidence-based practices in health care settings. Science formalizes and tests innovations, whereas engineering customizes and optimizes how the innovation is applied tailoring to accommodate local conditions. Together they may accelerate the creation of an evidence-based healthcare system that works effectively in specific health care settings. We give examples of applying engineering methods for better quality, more efficient, and safer implementation of clinical practices, medical devices, and health services systems. A specific example was applying systems engineering design that orchestrated people, process, data, decision-making, and communication through a technology application to implement evidence-based depression care among low-income patients with diabetes. We recommend that leading journals recognize the fundamental role of engineering in implementation research, to improve understanding of design elements that create a better fit between program elements and local context.

Culture, Interface Design, and Design Methods for Mobile Devices

NASA Astrophysics Data System (ADS)

Lee, Kun-Pyo

Aesthetic differences and similarities among cultures are obviously one of the very important issues in cultural design. However, ever since products became knowledge-supporting tools, the visible elements of products have become more universal so that the invisible parts of products such as interface and interaction are getting more important. Therefore, the cultural design should be extended to the invisible elements of culture like people's conceptual models beyond material and phenomenal culture. This chapter aims to explain how we address the invisible cultural elements in interface design and design methods by exploring the users' cognitive styles and communication patterns in different cultures. Regarding cultural interface design, we examined users' conceptual models while interacting with mobile phone and website interfaces, and observed cultural difference in performing tasks and viewing patterns, which appeared to agree with cultural cognitive styles known as Holistic thoughts vs. Analytic thoughts. Regarding design methods for culture, we explored how to localize design methods such as focus group interview and generative session for specific cultural groups, and the results of comparative experiments revealed cultural difference on participants' behaviors and performance in each design method and led us to suggest how to conduct them in East Asian culture. Mobile Observation Analyzer and Wi-Pro, user research tools we invented to capture user behaviors and needs especially in their mobile context, were also introduced.

Capturing structured, pulmonary disease-specific data elements in electronic health records.

PubMed

Gronkiewicz, Cynthia; Diamond, Edward J; French, Kim D; Christodouleas, John; Gabriel, Peter E

2015-04-01

Electronic health records (EHRs) have the potential to improve health-care quality by allowing providers to make better decisions at the point of care based on electronically aggregated data and by facilitating clinical research. These goals are easier to achieve when key, disease-specific clinical information is documented as structured data elements (SDEs) that computers can understand and process, rather than as free-text/natural-language narrative. This article reviews the benefits of capturing disease-specific SDEs. It highlights several design and implementation considerations, including the impact on efficiency and expressivity of clinical documentation and the importance of adhering to data standards when available. Pulmonary disease-specific examples of collection instruments are provided from two commonly used commercial EHRs. Future developments that can leverage SDEs to improve clinical quality and research are discussed.

Chalcogenide glass sensors for bio-molecule detection

NASA Astrophysics Data System (ADS)

Lucas, Pierre; Coleman, Garrett J.; Cantoni, Christopher; Jiang, Shibin; Luo, Tao; Bureau, Bruno; Boussard-Pledel, Catherine; Troles, Johann; Yang, Zhiyong

2017-02-01

Chalcogenide glasses constitute the only class of materials that remain fully amorphous while exhibiting broad optical transparency over the full infrared region from 2-20 microns. As such, they can be shaped into complex optical elements while retaining a clear optical window that encompass the vibrational signals of virtually any molecules. Chalcogenide glasses are therefore ideal materials for designing biological and chemical sensors based on vibrational spectroscopy. In this paper we review the properties of these glasses and the corresponding design of optical elements for bio-chemical sensing. Amorphous chalcogenides offer a very wide compositional landscape that permit to tune their physical properties to match specific demands for the production of optical devices. This includes tailoring the infrared window over specific ranges of wavelength such as the long-wave infrared region to capture important vibrational signal including the "signature region" of micro-organisms or the bending mode of CO2 molecules. Additionally, compositional engineering enables tuning the viscosity-temperature dependence of the glass melt in order to control the rheological properties that are fundamental to the production of glass elements. Indeed, exquisite control of the viscosity is key to the fabrication process of many optical elements such as fiber drawing, lens molding, surface embossing or reflow of microresonators. Optimal control of these properties then enables the design and fabrication of optimized infrared sensors such as Fiber Evanescent Wave Spectroscopy (FEWS) sensors, Whispering Gallery Modes (WGM) micro-resonator sensors, nanostructured surfaces for integrated optics and surface-enhanced processes, or lens molding for focused collection of infrared signals. Many of these sensor designs can be adapted to collect and monitor the vibrational signal of live microorganisms to study their metabolism in controlled environmental conditions. Further materials engineering enable the design of opto-electrophoretic sensors that permit simultaneous capture and detection of hazardous bio-molecules such as bacteria, virus and proteins using a conducting glass that serves as both an electrode and an optical elements. Upon adequate spectral analysis such as Principal Component Analysis (PCA) or Partial Least Square (PLS) regression these devices enable highly selective identification of hazardous microorganism such as different strains of bacteria and food pathogens.

Distributing coil elements in three dimensions enhances parallel transmission multiband RF performance: A simulation study in the human brain at 7 Tesla.

PubMed

Wu, Xiaoping; Tian, Jinfeng; Schmitter, Sebastian; Vaughan, J Tommy; Uğurbil, Kâmil; Van de Moortele, Pierre-François

2016-06-01

We explore the advantages of using a double-ring radiofrequency (RF) array and slice orientation to design parallel transmission (pTx) multiband (MB) pulses for simultaneous multislice (SMS) imaging with whole-brain coverage at 7 Tesla (T). A double-ring head array with 16 elements split evenly in two rings stacked in the z-direction was modeled and compared with two single-ring arrays consisting of 8 or 16 elements. The array performance was evaluated by designing band-specific pTx MB pulses with local specific absorption rate (SAR) control. The impact of slice orientations was also investigated. The double-ring array consistently and significantly outperformed the other two single-ring arrays, with peak local SAR reduced by up to 40% at a fixed excitation error of 0.024. For all three arrays, exciting sagittal or coronal slices yielded better RF performance than exciting axial or oblique slices. A double-ring RF array can be used to drastically improve SAR versus excitation fidelity tradeoff for pTx MB pulse design for brain imaging at 7 T; therefore, it is preferable against single-ring RF array designs when pursuing various biomedical applications of pTx SMS imaging. In comparing the stripline arrays, coronal and sagittal slices are more advantageous than axial and oblique slices for pTx MB pulses. Magn Reson Med 75:2464-2472, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

A protocol for better design, application, and communication of population viability analyses.

PubMed

Pe'er, Guy; Matsinos, Yiannis G; Johst, Karin; Franz, Kamila W; Turlure, Camille; Radchuk, Viktoriia; Malinowska, Agnieszka H; Curtis, Janelle M R; Naujokaitis-Lewis, Ilona; Wintle, Brendan A; Henle, Klaus

2013-08-01

Population viability analyses (PVAs) contribute to conservation theory, policy, and management. Most PVAs focus on single species within a given landscape and address a specific problem. This specificity often is reflected in the organization of published PVA descriptions. Many lack structure, making them difficult to understand, assess, repeat, or use for drawing generalizations across PVA studies. In an assessment comparing published PVAs and existing guidelines, we found that model selection was rarely justified; important parameters remained neglected or their implementation was described vaguely; limited details were given on parameter ranges, sensitivity analysis, and scenarios; and results were often reported too inconsistently to enable repeatability and comparability. Although many guidelines exist on how to design and implement reliable PVAs and standards exist for documenting and communicating ecological models in general, there is a lack of organized guidelines for designing, applying, and communicating PVAs that account for their diversity of structures and contents. To fill this gap, we integrated published guidelines and recommendations for PVA design and application, protocols for documenting ecological models in general and individual-based models in particular, and our collective experience in developing, applying, and reviewing PVAs. We devised a comprehensive protocol for the design, application, and communication of PVAs (DAC-PVA), which has 3 primary elements. The first defines what a useful PVA is; the second element provides a workflow for the design and application of a useful PVA and highlights important aspects that need to be considered during these processes; and the third element focuses on communication of PVAs to ensure clarity, comprehensiveness, repeatability, and comparability. Thereby, DAC-PVA should strengthen the credibility and relevance of PVAs for policy and management, and improve the capacity to generalize PVA findings across studies. © 2013 Society for Conservation Biology.

SIENA Customer Problem Statement and Requirements

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

L. Sauer; R. Clay; C. Adams

2000-08-01

This document describes the problem domain and functional requirements of the SIENA framework. The software requirements and system architecture of SIENA are specified in separate documents (called SIENA Software Requirement Specification and SIENA Software Architecture, respectively). While currently this version of the document describes the problems and captures the requirements within the Analysis domain (concentrating on finite element models), it is our intention to subsequent y expand this document to describe problems and capture requirements from the Design and Manufacturing domains. In addition, SIENA is designed to be extendible to support and integrate elements from the other domains (see SIENAmore » Software Architecture document).« less

Finite element strategies to satisfy clinical and engineering requirements in the field of percutaneous valves.

PubMed

Capelli, Claudio; Biglino, Giovanni; Petrini, Lorenza; Migliavacca, Francesco; Cosentino, Daria; Bonhoeffer, Philipp; Taylor, Andrew M; Schievano, Silvia

2012-12-01

Finite element (FE) modelling can be a very resourceful tool in the field of cardiovascular devices. To ensure result reliability, FE models must be validated experimentally against physical data. Their clinical application (e.g., patients' suitability, morphological evaluation) also requires fast simulation process and access to results, while engineering applications need highly accurate results. This study shows how FE models with different mesh discretisations can suit clinical and engineering requirements for studying a novel device designed for percutaneous valve implantation. Following sensitivity analysis and experimental characterisation of the materials, the stent-graft was first studied in a simplified geometry (i.e., compliant cylinder) and validated against in vitro data, and then in a patient-specific implantation site (i.e., distensible right ventricular outflow tract). Different meshing strategies using solid, beam and shell elements were tested. Results showed excellent agreement between computational and experimental data in the simplified implantation site. Beam elements were found to be convenient for clinical applications, providing reliable results in less than one hour in a patient-specific anatomical model. Solid elements remain the FE choice for engineering applications, albeit more computationally expensive (>100 times). This work also showed how information on device mechanical behaviour differs when acquired in a simplified model as opposed to a patient-specific model.

Design of a muscle cell-specific expression vector utilising human vascular smooth muscle alpha-actin regulatory elements.

PubMed

Keogh, M C; Chen, D; Schmitt, J F; Dennehy, U; Kakkar, V V; Lemoine, N R

1999-04-01

The facility to direct tissue-specific expression of therapeutic gene constructs is desirable for many gene therapy applications. We describe the creation of a muscle-selective expression vector which supports transcription in vascular smooth muscle, cardiac muscle and skeletal muscle, while it is essentially silent in other cell types such as endothelial cells, hepatocytes and fibroblasts. Specific transcriptional regulatory elements have been identified in the human vascular smooth muscle cell (VSMC) alpha-actin gene, and used to create an expression vector which directs the expression of genes in cis to muscle cells. The vector contains an enhancer element we have identified in the 5' flanking region of the human VSMC alpha-actin gene involved in mediating VSMC expression. Heterologous pairing experiments have shown that the enhancer does not interact with the basal transcription complex recruited at the minimal SV40 early promoter. Such a vector has direct application in the modulation of VSMC proliferation associated with intimal hyperplasia/restenosis.

Design of optical mirror structures

NASA Technical Reports Server (NTRS)

Soosaar, K.

1971-01-01

The structural requirements for large optical telescope mirrors was studied with a particular emphasis placed on the three-meter Large Space Telescope primary mirror. Analysis approaches through finite element methods were evaluated with the testing and verification of a number of element types suitable for particular mirror loadings and configurations. The environmental conditions that a mirror will experience were defined and a candidate list of suitable mirror materials with their properties compiled. The relation of the mirror mechanical behavior to the optical performance is discussed and a number of suitable design criteria are proposed and implemented. A general outline of a systematic method to obtain the best structure for the three-meter diffraction-limited system is outlined. Finite element programs, using the STRUDL 2 analysis system, were written for specific mirror structures encompassing all types of active and passive mirror designs. Parametric studies on support locations, effects of shear deformation, diameter to thickness ratios, lightweight and sandwich mirror configurations, and thin shell active mirror needs were performed.

Methodological Rigor in Preclinical Cardiovascular Studies

PubMed Central

Ramirez, F. Daniel; Motazedian, Pouya; Jung, Richard G.; Di Santo, Pietro; MacDonald, Zachary D.; Moreland, Robert; Simard, Trevor; Clancy, Aisling A.; Russo, Juan J.; Welch, Vivian A.; Wells, George A.

2017-01-01

Rationale: Methodological sources of bias and suboptimal reporting contribute to irreproducibility in preclinical science and may negatively affect research translation. Randomization, blinding, sample size estimation, and considering sex as a biological variable are deemed crucial study design elements to maximize the quality and predictive value of preclinical experiments. Objective: To examine the prevalence and temporal patterns of recommended study design element implementation in preclinical cardiovascular research. Methods and Results: All articles published over a 10-year period in 5 leading cardiovascular journals were reviewed. Reports of in vivo experiments in nonhuman mammals describing pathophysiology, genetics, or therapeutic interventions relevant to specific cardiovascular disorders were identified. Data on study design and animal model use were collected. Citations at 60 months were additionally examined as a surrogate measure of research impact in a prespecified subset of studies, stratified by individual and cumulative study design elements. Of 28 636 articles screened, 3396 met inclusion criteria. Randomization was reported in 21.8%, blinding in 32.7%, and sample size estimation in 2.3%. Temporal and disease-specific analyses show that the implementation of these study design elements has overall not appreciably increased over the past decade, except in preclinical stroke research, which has uniquely demonstrated significant improvements in methodological rigor. In a subset of 1681 preclinical studies, randomization, blinding, sample size estimation, and inclusion of both sexes were not associated with increased citations at 60 months. Conclusions: Methodological shortcomings are prevalent in preclinical cardiovascular research, have not substantially improved over the past 10 years, and may be overlooked when basing subsequent studies. Resultant risks of bias and threats to study validity have the potential to hinder progress in cardiovascular medicine as preclinical research often precedes and informs clinical trials. Stroke research quality has uniquely improved in recent years, warranting a closer examination for interventions to model in other cardiovascular fields. PMID:28373349

Methodological Rigor in Preclinical Cardiovascular Studies: Targets to Enhance Reproducibility and Promote Research Translation.

PubMed

Ramirez, F Daniel; Motazedian, Pouya; Jung, Richard G; Di Santo, Pietro; MacDonald, Zachary D; Moreland, Robert; Simard, Trevor; Clancy, Aisling A; Russo, Juan J; Welch, Vivian A; Wells, George A; Hibbert, Benjamin

2017-06-09

Methodological sources of bias and suboptimal reporting contribute to irreproducibility in preclinical science and may negatively affect research translation. Randomization, blinding, sample size estimation, and considering sex as a biological variable are deemed crucial study design elements to maximize the quality and predictive value of preclinical experiments. To examine the prevalence and temporal patterns of recommended study design element implementation in preclinical cardiovascular research. All articles published over a 10-year period in 5 leading cardiovascular journals were reviewed. Reports of in vivo experiments in nonhuman mammals describing pathophysiology, genetics, or therapeutic interventions relevant to specific cardiovascular disorders were identified. Data on study design and animal model use were collected. Citations at 60 months were additionally examined as a surrogate measure of research impact in a prespecified subset of studies, stratified by individual and cumulative study design elements. Of 28 636 articles screened, 3396 met inclusion criteria. Randomization was reported in 21.8%, blinding in 32.7%, and sample size estimation in 2.3%. Temporal and disease-specific analyses show that the implementation of these study design elements has overall not appreciably increased over the past decade, except in preclinical stroke research, which has uniquely demonstrated significant improvements in methodological rigor. In a subset of 1681 preclinical studies, randomization, blinding, sample size estimation, and inclusion of both sexes were not associated with increased citations at 60 months. Methodological shortcomings are prevalent in preclinical cardiovascular research, have not substantially improved over the past 10 years, and may be overlooked when basing subsequent studies. Resultant risks of bias and threats to study validity have the potential to hinder progress in cardiovascular medicine as preclinical research often precedes and informs clinical trials. Stroke research quality has uniquely improved in recent years, warranting a closer examination for interventions to model in other cardiovascular fields. © 2017 The Authors.

Design and development of a quad copter (UMAASK) using CAD/CAM/CAE

NASA Astrophysics Data System (ADS)

Manarvi, Irfan Anjum; Aqib, Muhammad; Ajmal, Muhammad; Usman, Muhammad; Khurshid, Saqib; Sikandar, Usman

Micro flying vehicles1 (MFV) have become a popular area of research due to economy of production, flexibility of launch and variety of applications. A large number of techniques from pencil sketching to computer based software are being used for designing specific geometries and selection of materials to arrive at novel designs for specific requirements. Present research was focused on development of suitable design configuration using CAD/CAM/CAE tools and techniques. A number of designs were reviewed for this purpose. Finally, rotary wing Quadcopter flying vehicle design was considered appropriate for this research. Performance requirements were planned as approximately 10 meters ceiling, weight less than 500grams and ability to take videos and pictures. Parts were designed using Finite Element Analysis, manufactured using CNC machines and assembled to arrive at final design named as UMAASK. Flight tests were carried out which confirmed the design requirements.

Controlled Waveform Magnets

NASA Astrophysics Data System (ADS)

Campbell, L. J.; Schlllig, J. B.

Issues for the design and operation of high field controlled waveform magnets and their power supplies are discussed. The basic technical elements are reviewed and applied to problems specific to this class of magnets. Examples are given along with a guide to the literature.

Methodology for the systems engineering process. Volume 1: System functional activities

NASA Technical Reports Server (NTRS)

Nelson, J. H.

1972-01-01

Systems engineering is examined in terms of functional activities that are performed in the conduct of a system definition/design, and system development is described in a parametric analysis that combines functions, performance, and design variables. Emphasis is placed on identification of activities performed by design organizations, design specialty groups, as well as a central systems engineering organizational element. Identification of specific roles and responsibilities for doing functions, and monitoring and controlling activities within the system development operation are also emphasized.

Review and critical analysis: Rolling-element bearings for system life and reliability

NASA Technical Reports Server (NTRS)

Irwin, A. S.; Anderson, W. J.; Derner, W. J.

1985-01-01

A ball and cylindrical roller bearing technical specification which incorporates the latest state-of-the-art advancements was prepared for the purpose of improving bearing reliability in U.S. Army aircraft. The current U.S. Army aviation bearing designs and applications, including life analyses, were analyzed. A bearing restoration and refurbishment specification was prepared to improve bearing availability.

Water, energy, and biogeochemical budget research at Sleepers River Research Watershed, Vermont

USGS Publications Warehouse

Shanley, James B.; Sundquist, E.T.; Kendall, Carol

1995-01-01

The U.S. Geological Survey has selected the Sleepers River Research Watershed (Sleepers River) near Danville, Vt., as one of five sites for the investigation of Water, Energy, and Biogeochemical Budgets (WEBB). Sleepers River was chosen because it is a well-designed outdoor laboratory with a long history of hydrologic data collection and research, and also because it provides an ideal opportunity for collaboration among the U.S. Geological Survey, other Federal agencies, and universities at the site. The multiple subwatersheds at Sleepers River present a unique opportunity to investigate hydrologic, energy, and biogeochemical processes over a variety of spatial scales. This WEBB study builds on fundamental research on process mechanisms and rates at the plot scale (in this case, a hillslope). Results then are scaled up to interpret the hydrochemical response of first- and higher- order basins. Five research elements make up the Sleepers River WEBB project. Individually, each of the five elements is designed to investigate specific WEBB processes (such as CO2 efflux through a snowpack), address specific WEBB issues (such as scaling and flowpaths), or apply specific WEBB approaches (such as integrated chemical and physical study of a hillslope). The research elements overlap so that many of the processes investigated will be assessed in more than one way, thus allowing independent verification of research results. For example, flowpath information will be derived separately by use of isotopic tracers, conservative chemical solutes, and soil-moisture fluxes. Collectively, the five elements constitute an integrated approach to a comprehensive understanding of WEBB processes needed for the prediction of the effects of global change.

Drug Research

NASA Technical Reports Server (NTRS)

1989-01-01

NBOD2, a program developed at Goddard Space Flight Center to solve equations of motion coupled N-body systems is used by E.I. DuPont de Nemours & Co. to model potential drugs as a series of elements. The program analyses the vibrational and static motions of independent components in drugs. Information generated from this process is used to design specific drugs to interact with enzymes in designated ways.

Design and Impacts of a Youth-Directed Café Scientifique Program

ERIC Educational Resources Information Center

Hall, Michelle K.; Foutz, Susan; Mayhew, Michael A.

2013-01-01

We have modified the popular Cafe Scientifique model for engaging adults in dialog on issues at the nexus of science and society to address the specific needs and interests of high-school age youth. Key elements of the model are Youth Leadership Teams that guide the program design and assist with implementation; a speaker preparation process to…

Influence of pitting defects on quality of high power laser light field

NASA Astrophysics Data System (ADS)

Ren, Huan; Zhang, Lin; Yang, Yi; Shi, Zhendong; Ma, Hua; Jiang, Hongzhen; Chen, Bo; Yang, XiaoYu; Zheng, Wanguo; Zhu, Rihong

2018-01-01

With the split-step-Fourier-transform method for solving the nonlinear paraxial wave equation, the intensity distribution of the light field when the pits diameter or depth change is obtained by using numerical simulation, include the intensity distribution inside optical element, the beam near-field, the different distances behind the element and the beam far-field. Results show that with the increase of pits diameter or depth, the light field peak intensity and the contrast inside of element corresponding enhancement. The contrast of the intensity distribution of the rear surface of the element will increase slightly. The peak intensity produced by a specific location element downstream of thermal effect will continue to increase, the damage probability in optics placed here is greatly increased. For the intensity distribution of the far-field, increase the pitting diameter or depth will cause the focal spot intensity distribution changes, and the energy of the spectrum center region increase constantly. This work provide a basis for quantitative design and inspection for pitting defects, which provides a reference for the design of optical path arrangement.

A compact, in vivo screen of all 6-mers reveals drivers of tissue-specific expression and guides synthetic regulatory element design.

PubMed

Smith, Robin P; Riesenfeld, Samantha J; Holloway, Alisha K; Li, Qiang; Murphy, Karl K; Feliciano, Natalie M; Orecchia, Lorenzo; Oksenberg, Nir; Pollard, Katherine S; Ahituv, Nadav

2013-07-18

Large-scale annotation efforts have improved our ability to coarsely predict regulatory elements throughout vertebrate genomes. However, it is unclear how complex spatiotemporal patterns of gene expression driven by these elements emerge from the activity of short, transcription factor binding sequences. We describe a comprehensive promoter extension assay in which the regulatory potential of all 6 base-pair (bp) sequences was tested in the context of a minimal promoter. To enable this large-scale screen, we developed algorithms that use a reverse-complement aware decomposition of the de Bruijn graph to design a library of DNA oligomers incorporating every 6-bp sequence exactly once. Our library multiplexes all 4,096 unique 6-mers into 184 double-stranded 15-bp oligomers, which is sufficiently compact for in vivo testing. We injected each multiplexed construct into zebrafish embryos and scored GFP expression in 15 tissues at two developmental time points. Twenty-seven constructs produced consistent expression patterns, with the majority doing so in only one tissue. Functional sequences are enriched near biologically relevant genes, match motifs for developmental transcription factors, and are required for enhancer activity. By concatenating tissue-specific functional sequences, we generated completely synthetic enhancers for the notochord, epidermis, spinal cord, forebrain and otic lateral line, and show that short regulatory sequences do not always function modularly. This work introduces a unique in vivo catalog of short, functional regulatory sequences and demonstrates several important principles of regulatory element organization. Furthermore, we provide resources for designing compact, reverse-complement aware k-mer libraries.

Space shuttle orbit maneuvering engine, reusable thrust chamber program. Task 6: Data dump hot fuel element investigation

NASA Technical Reports Server (NTRS)

Nurick, W. H.

1974-01-01

An evaluation of reusable thrust chambers for the space shuttle orbit maneuvering engine was conducted. Tests were conducted using subscale injector hot-fire procedures for the injector configurations designed for a regenerative cooled engine. The effect of operating conditions and fuel temperature on combustion chamber performance was determined. Specific objectives of the evaluation were to examine the optimum like-doublet element geometry for operation at conditions consistent with a fuel regeneratively cooled engine (hot fuel, 200 to 250 F) and the sensitivity of the triplet injector element to hot fuels.

Optimization of custom cementless stem using finite element analysis and elastic modulus distribution for reducing stress-shielding effect.

PubMed

Saravana Kumar, Gurunathan; George, Subin Philip

2017-02-01

This work proposes a methodology involving stiffness optimization for subject-specific cementless hip implant design based on finite element analysis for reducing stress-shielding effect. To assess the change in the stress-strain state of the femur and the resulting stress-shielding effect due to insertion of the implant, a finite element analysis of the resected femur with implant assembly is carried out for a clinically relevant loading condition. Selecting the von Mises stress as the criterion for discriminating regions for elastic modulus difference, a stiffness minimization method was employed by varying the elastic modulus distribution in custom implant stem. The stiffness minimization problem is formulated as material distribution problem without explicitly penalizing partial volume elements. This formulation enables designs that could be fabricated using additive manufacturing to make porous implant with varying levels of porosity. Stress-shielding effect, measured as difference between the von Mises stress in the intact and implanted femur, decreased as the elastic modulus distribution is optimized.

Moly99 Production Facility: Report on Beamline Components, Requirements, Costs

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

Bishofberger, Kip A.

2015-12-23

In FY14 we completed the design of the beam line for the linear accelerator production design concept. This design included a set of three bending magnets, quadrupole focusing magnets, and octopoles to flatten the beam on target. This design was generic and applicable to multiple different accelerators if necessary. In FY15 we built on that work to create specifications for the individual beam optic elements, including power supply requirements. This report captures the specification of beam line components with initial cost estimates for the NorthStar production facility.This report is organized as follows: The motivation of the beamline design is introducedmore » briefly, along with renderings of the design. After that, a specific list is provided, which accounts for each beamline component, including part numbers and costs, to construct the beamline. After that, this report details the important sections of the beamline and individual components. A final summary and list of follow-on activities completes this report.« less

Design of polymer motifs for nucleic acid recognition and assembly stabilization

NASA Astrophysics Data System (ADS)

Zhou, Zhun

This dissertation describes the synthesis and assembly of bio-functional polymers and the applications of these polymers to drug encapsulation, delivery, and multivalent biomimetic macromolecular recognition between synthetic polymer and nucleic acids. The main content is divided into three parts: (1) polyacidic domains as strongly stabilizing design elements for aqueous phase polyacrylate diblock assembly; (2) small molecule/polymer recognition triggered macromolecular assembly and drug encapsulation; (3) trizaine derivatized polymer as a novel class of "bifacial polymer nucleic acid" (bPoNA) and applications of bPoNA to nanoparticle loading of DNA/RNA, silencing delivery as well as control of aptamer function. Through the studies in part (1) and part (2), it was demonstrated that well-designed polymer motifs are not only able to enhance assemblies driven by non-specific hydrophobic effect, but are also able to direct assemblies based on specific recognitions. In part (3) of this dissertation, this concept was further extended by the design of polyacrylate polymers that are capable of discrete and robust hybridization with nucleic acids. This surprising finding demonstrated both fundamental and practical applications. Overall, these studies provided insights into the rational design elements for improving the bio-functions of synthetic polymers, and significantly expanded the scope of biological applications in which polymers synthesized via controlled radical polymerization may play a role.

Structural basis of substrate specificity in the serine proteases.

PubMed Central

Perona, J. J.; Craik, C. S.

1995-01-01

Structure-based mutational analysis of serine protease specificity has produced a large database of information useful in addressing biological function and in establishing a basis for targeted design efforts. Critical issues examined include the function of water molecules in providing strength and specificity of binding, the extent to which binding subsites are interdependent, and the roles of polypeptide chain flexibility and distal structural elements in contributing to specificity profiles. The studies also provide a foundation for exploring why specificity modification can be either straightforward or complex, depending on the particular system. PMID:7795518

Crashworthiness analysis on alternative square honeycomb structure under axial loading

NASA Astrophysics Data System (ADS)

Li, Meng; Deng, Zongquan; Guo, Hongwei; Liu, Rongqiang; Ding, Beichen

2013-07-01

Hexagonal metal honeycomb is widely used in energy absorption field for its special construction. However, many other metal honeycomb structures also show good energy absorption characteristics. Currently, most of the researches focus on hexagonal honeycomb, while few are performed into different honeycomb structures. Therefore, a new alternative square honeycomb is developed to expand the non-hexagonal metal honeycomb applications in the energy absorption fields with the aim of designing low mass and low volume energy absorbers. The finite element model of alternative square honeycomb is built to analyze its specific energy absorption property. As the diversity of honeycomb structure, the parameterized metal honeycomb finite element analysis program is conducted based on PCL language. That program can automatically create finite element model. Numerical results show that with the same foil thickness and cell length of metal honeycomb, the alternative square has better specific energy absorption than hexagonal honeycomb. Using response surface method, the mathematical formulas of honeycomb crashworthiness properties are obtained and optimization is done to get the maximum specific energy absorption property honeycomb. Optimal results demonstrate that to absorb same energy, alternative square honeycomb can save 10% volume of buffer structure than hexagonal honeycomb can do. This research is significant in providing technical support in the extended application of different honeycomb used as crashworthiness structures, and is absolutely essential in low volume and low mass energy absorber design.

Air demand estimation in bottom outlets with the particle finite element method. Susqueda Dam case study

NASA Astrophysics Data System (ADS)

Salazar, Fernando; San-Mauro, Javier; Celigueta, Miguel Ángel; Oñate, Eugenio

2017-07-01

Dam bottom outlets play a vital role in dam operation and safety, as they allow controlling the water surface elevation below the spillway level. For partial openings, water flows under the gate lip at high velocity and drags the air downstream of the gate, which may cause damages due to cavitation and vibration. The convenience of installing air vents in dam bottom outlets is well known by practitioners. The design of this element depends basically on the maximum air flow through the air vent, which in turn is a function of the specific geometry and the boundary conditions. The intrinsic features of this phenomenon makes it hard to analyse either on site or in full scaled experimental facilities. As a consequence, empirical formulas are frequently employed, which offer a conservative estimate of the maximum air flow. In this work, the particle finite element method was used to model the air-water interaction in Susqueda Dam bottom outlet, with different gate openings. Specific enhancements of the formulation were developed to consider air-water interaction. The results were analysed as compared to the conventional design criteria and to information gathered on site during the gate operation tests. This analysis suggests that numerical modelling with the PFEM can be helpful for the design of this kind of hydraulic works.

Three tenets for secure cyber-physical system design and assessment

NASA Astrophysics Data System (ADS)

Hughes, Jeff; Cybenko, George

2014-06-01

This paper presents a threat-driven quantitative mathematical framework for secure cyber-physical system design and assessment. Called The Three Tenets, this originally empirical approach has been used by the US Air Force Research Laboratory (AFRL) for secure system research and development. The Tenets were first documented in 2005 as a teachable methodology. The Tenets are motivated by a system threat model that itself consists of three elements which must exist for successful attacks to occur: - system susceptibility; - threat accessibility and; - threat capability. The Three Tenets arise naturally by countering each threat element individually. Specifically, the tenets are: Tenet 1: Focus on What's Critical - systems should include only essential functions (to reduce susceptibility); Tenet 2: Move Key Assets Out-of-Band - make mission essential elements and security controls difficult for attackers to reach logically and physically (to reduce accessibility); Tenet 3: Detect, React, Adapt - confound the attacker by implementing sensing system elements with dynamic response technologies (to counteract the attackers' capabilities). As a design methodology, the Tenets mitigate reverse engineering and subsequent attacks on complex systems. Quantified by a Bayesian analysis and further justified by analytic properties of attack graph models, the Tenets suggest concrete cyber security metrics for system assessment.

Predicting the behavior of microfluidic circuits made from discrete elements

PubMed Central

Bhargava, Krisna C.; Thompson, Bryant; Iqbal, Danish; Malmstadt, Noah

2015-01-01

Microfluidic devices can be used to execute a variety of continuous flow analytical and synthetic chemistry protocols with a great degree of precision. The growing availability of additive manufacturing has enabled the design of microfluidic devices with new functionality and complexity. However, these devices are prone to larger manufacturing variation than is typical of those made with micromachining or soft lithography. In this report, we demonstrate a design-for-manufacturing workflow that addresses performance variation at the microfluidic element and circuit level, in context of mass-manufacturing and additive manufacturing. Our approach relies on discrete microfluidic elements that are characterized by their terminal hydraulic resistance and associated tolerance. Network analysis is employed to construct simple analytical design rules for model microfluidic circuits. Monte Carlo analysis is employed at both the individual element and circuit level to establish expected performance metrics for several specific circuit configurations. A protocol based on osmometry is used to experimentally probe mixing behavior in circuits in order to validate these approaches. The overall workflow is applied to two application circuits with immediate use at on the bench-top: series and parallel mixing circuits that are modularly programmable, virtually predictable, highly precise, and operable by hand. PMID:26516059

A review on high-resolution CMOS delay lines: towards sub-picosecond jitter performance.

PubMed

Abdulrazzaq, Bilal I; Abdul Halin, Izhal; Kawahito, Shoji; Sidek, Roslina M; Shafie, Suhaidi; Yunus, Nurul Amziah Md

2016-01-01

A review on CMOS delay lines with a focus on the most frequently used techniques for high-resolution delay step is presented. The primary types, specifications, delay circuits, and operating principles are presented. The delay circuits reported in this paper are used for delaying digital inputs and clock signals. The most common analog and digitally-controlled delay elements topologies are presented, focusing on the main delay-tuning strategies. IC variables, namely, process, supply voltage, temperature, and noise sources that affect delay resolution through timing jitter are discussed. The design specifications of these delay elements are also discussed and compared for the common delay line circuits. As a result, the main findings of this paper are highlighting and discussing the followings: the most efficient high-resolution delay line techniques, the trade-off challenge found between CMOS delay lines designed using either analog or digitally-controlled delay elements, the trade-off challenge between delay resolution and delay range and the proposed solutions for this challenge, and how CMOS technology scaling can affect the performance of CMOS delay lines. Moreover, the current trends and efforts used in order to generate output delayed signal with low jitter in the sub-picosecond range are presented.

Development of finite element model for customized prostheses design for patient with pelvic bone tumor.

PubMed

Iqbal, Taimoor; Shi, Lei; Wang, Ling; Liu, Yaxiong; Li, Dichen; Qin, Mian; Jin, Zhongmin

2017-06-01

The aim of this study was to design a hemi-pelvic prosthesis for a patient affected by pelvic sarcoma. To investigate the biomechanical functionality of the pelvis reconstructed with designed custom-made prosthesis, a patient-specific finite element model of whole pelvis with primary ligaments inclusive was constructed based on the computed tomography images of the patient. Then, a finite element analysis was performed to calculate and compare the stress distribution between the normal and implanted pelvis models when undergoing three different static conditions-both-leg standing, single-leg standing for the healthy and the affected one. No significant differences were observed in the stresses between the normal and reconstructed pelvis for both-leg standing, but 20%-40% larger stresses were predicted for the peak stress of the single-leg standing (affected side). Moreover, two- to threefold of peak stresses were predicted within the prostheses compared to that of the normal pelvis especially for single-leg standing case, however, still below the allowable fatigue limitation. The study on the load transmission functionality of prosthesis indicated that it is crucial to carry out finite element analysis for functional evaluation of the designed customized prostheses before three-dimensional printing manufacturing, allowing better understanding of the possible peak stresses within the bone as well as the implants for safety precaution. The finite element model can be equally applicable to other bone tumor model for biomechanical studying.

The Photoshop Smile Design technique (part 1): digital dental photography.

PubMed

McLaren, Edward A; Garber, David A; Figueira, Johan

2013-01-01

The proliferation of digital photography and imaging devices is enhancing clinicians' ability to visually document patients' intraoral conditions. By understanding the elements of esthetics and learning how to incorporate technology applications into clinical dentistry, clinicians can predictably plan smile design and communicate anticipated results to patients and ceramists alike. This article discusses camera, lens, and flash selection and setup, and how to execute specific types of images using the Adobe Photoshop Smile Design (PSD) technique.

Induction Heating Model of Cermet Fuel Element Environmental Test (CFEET)

NASA Technical Reports Server (NTRS)

Gomez, Carlos F.; Bradley, D. E.; Cavender, D. P.; Mireles, O. R.; Hickman, R. R.; Trent, D.; Stewart, E.

2013-01-01

Deep space missions with large payloads require high specific impulse and relatively high thrust to achieve mission goals in reasonable time frames. Nuclear Thermal Rockets (NTR) are capable of producing a high specific impulse by employing heat produced by a fission reactor to heat and therefore accelerate hydrogen through a rocket nozzle providing thrust. Fuel element temperatures are very high (up to 3000 K) and hydrogen is highly reactive with most materials at high temperatures. Data covering the effects of high-temperature hydrogen exposure on fuel elements are limited. The primary concern is the mechanical failure of fuel elements due to large thermal gradients; therefore, high-melting-point ceramics-metallic matrix composites (cermets) are one of the fuels under consideration as part of the Nuclear Cryogenic Propulsion Stage (NCPS) Advance Exploration System (AES) technology project at the Marshall Space Flight Center. The purpose of testing and analytical modeling is to determine their ability to survive and maintain thermal performance in a prototypical NTR reactor environment of exposure to hydrogen at very high temperatures and obtain data to assess the properties of the non-nuclear support materials. The fission process and the resulting heating performance are well known and do not require that active fissile material to be integrated in this testing. A small-scale test bed; Compact Fuel Element Environmental Tester (CFEET), designed to heat fuel element samples via induction heating and expose samples to hydrogen is being developed at MSFC to assist in optimal material and manufacturing process selection without utilizing fissile material. This paper details the analytical approach to help design and optimize the test bed using COMSOL Multiphysics for predicting thermal gradients induced by electromagnetic heating (Induction heating) and Thermal Desktop for radiation calculations.

Using Short Videos as Testing Elements in Skill Matching-Test Design in the Smart Project

ERIC Educational Resources Information Center

Beutner, Marc; Rüscher, Frederike Anna

2017-01-01

This paper provides insights in the development of a skill matching test which addresses soft skills integrated videos as media to provide information about situations to be rated. The design of the skill testing and matching tool is situated in the educational ERASMUS+ project SMART which is presented as well. With a specific view on team work…

The NASA Redox Storage System Development project, 1980

NASA Technical Reports Server (NTRS)

1982-01-01

The technical accomplishments pertaining to the development of Redox systems and related technology are outlined in terms of the task elements: prototype systems development, application analyses, and supporting technology. Prototype systems development provides for a major procurement to develop an industrial capability to take the current NASA Lewis technology and go on to the design, development, and commercialization of iron-chromium Redox storage systems. Application analyses provides for the definition of application concepts and technology requirements, specific definition studies, and the identification of market sectors and their penetration potential. Supporting technology includes both in house and contractual efforts that encompass implementation of technology improvements in membranes, electrodes, reactant processing, and system design. The status of all elements is discussed.

The NASA Redox Storage System Development project, 1980

NASA Astrophysics Data System (ADS)

1982-12-01

The technical accomplishments pertaining to the development of Redox systems and related technology are outlined in terms of the task elements: prototype systems development, application analyses, and supporting technology. Prototype systems development provides for a major procurement to develop an industrial capability to take the current NASA Lewis technology and go on to the design, development, and commercialization of iron-chromium Redox storage systems. Application analyses provides for the definition of application concepts and technology requirements, specific definition studies, and the identification of market sectors and their penetration potential. Supporting technology includes both in house and contractual efforts that encompass implementation of technology improvements in membranes, electrodes, reactant processing, and system design. The status of all elements is discussed.

Photopolymer based VPHGs: from materials to sky results

NASA Astrophysics Data System (ADS)

Zanutta, A.; Orselli, E.; Fäcke, T.; Bianco, A.

2016-07-01

Volume Phase Holographic Gratings cover a relevant position as transmission dispersing elements in astronomical spectrographs and each astronomical observation could take advantage of specific dispersive elements with features tailored for achieving the best performances. The design and manufacturing of high efficiency and reliable VPHGs require photosensitive materials where it is possible to control both the refractive index modulation and the film thickness. By means of Bayfol® HX photopolymers, we designed and manufactured six VPHGs for astronomical instrumentation in a GRISM configuration. We demonstrated how photopolymers are reliable holographic materials for making astronomical VPHGs with performances comparable to those provided by VPHGs based on Dichromated Gelatins (DCGs), but with a much simpler production process.

Design of strength characteristics on the example of a mining support

NASA Astrophysics Data System (ADS)

Gwiazda, A.; Sękala, A.; Banaś, W.; Topolska, S.; Foit, K.; Monica, Z.

2017-08-01

It is a special group of particular design aproches that could be characterized as “design for X”. All areas of specific these design methodology, taking into account the requirements of the life cycle are described with the acronym DfX. It means an integrated computing platform approach to design binding together both the area of design knowledge and area of computer systems. In this perspective, computer systems are responsible for the link between design requirements with the subject of the project and to filter the information being circulated throughout the operation of the project. The DfX methodologies together form an approach integrating to different functional areas of industrial organization. Among the internal elements it can distinguish the structure of the project team, the people making it, the same process design, control system design and implementation of the action tools to assist this process. Among the elements that are obtained in the framework of this approach should be distinguished: higher operating efficiency, professionalism, the ability to create innovation, incremental progress of the project and the appropriate focus of the project team. It have been done attempts to integrate identified specific areas for action in the field of design methodology. They have already taken place earlier in the design due to the Economic Design for Manufacture. This approach was characteristic for European industry. In this case, an approach was developed in methodology, which can be defined as the Design to/for Cost. The article presents the idea of an integrated design approach related with the DfX approach. The results are described on the base of a virtual 3D model of a mining support. This model was elaborated in the advanced engineering platform like Siemens PLM NX.

Technology's Impact on Library Interior Planning.

ERIC Educational Resources Information Center

Michaels, David Leroy

1987-01-01

Discusses issues to be considered in planning a library that will anticipate the needs of the future. Power and telecommunications capacity are stressed, and a checklist of items requiring specific writing services is included. Recommendations for workstation design and structural elements are offered. (MES)

40 CFR 85.1902 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... POLLUTION FROM MOBILE SOURCES Emission Defect Reporting Requirements § 85.1902 Definitions. For the purposes...) which affects any parameter or specification enumerated in appendix VIII of this part; or (2) A defect..., components, systems, software or elements of design which must function properly to ensure continued...

40 CFR 85.1902 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... POLLUTION FROM MOBILE SOURCES Emission Defect Reporting Requirements § 85.1902 Definitions. For the purposes...) which affects any parameter or specification enumerated in appendix VIII of this part; or (2) A defect..., components, systems, software or elements of design which must function properly to assure continued...

40 CFR 85.1902 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... POLLUTION FROM MOBILE SOURCES Emission Defect Reporting Requirements § 85.1902 Definitions. For the purposes...) which affects any parameter or specification enumerated in appendix VIII of this part; or (2) A defect..., components, systems, software or elements of design which must function properly to ensure continued...

40 CFR 85.1902 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... POLLUTION FROM MOBILE SOURCES Emission Defect Reporting Requirements § 85.1902 Definitions. For the purposes...) which affects any parameter or specification enumerated in appendix VIII of this part; or (2) A defect..., components, systems, software or elements of design which must function properly to ensure continued...

Quantification of Processing Effects on Filament Wound Pressure Vessels

NASA Technical Reports Server (NTRS)

Aiello, Robert A.; Chamis, Christos C.

1999-01-01

A computational simulation procedure is described which is designed specifically for the modeling and analysis of filament wound pressure vessels. Cylindrical vessels with spherical or elliptical end caps can be generated automatically. End caps other than spherical or elliptical may be modeled by varying circular sections along the x-axis according to the C C! end cap shape. The finite element model generated is composed of plate type quadrilateral shell elements on the entire vessel surface. This computational procedure can also be sued to generate grid, connectivity and material cards (bulk data) for component parts of a larger model. These bulk data are assigned to a user designated file for finite element structural/stress analysis of composite pressure vessels. The procedure accommodates filament would pressure vessels of all types of shells-of-revolution. It has provisions to readily evaluate initial stresses due to pretension in the winding filaments and residual stresses due to cure temperature.

Quantification of Processing Effects on Filament Wound Pressure Vessels. Revision

NASA Technical Reports Server (NTRS)

Aiello, Robert A.; Chamis, Christos C.

2002-01-01

A computational simulation procedure is described which is designed specifically for the modeling and analysis of filament wound pressure vessels. Cylindrical vessels with spherical or elliptical end caps can be generated automatically. End caps other than spherical or elliptical may be modeled by varying circular sections along the x-axis according to the end cap shape. The finite element model generated is composed of plate type quadrilateral shell elements on the entire vessel surface. This computational procedure can also be used to generate grid, connectivity and material cards (bulk data) for component parts of a larger model. These bulk data are assigned to a user designated file for finite element structural/stress analysis of composite pressure vessels. The procedure accommodates filament wound pressure vessels of all types of shells-of -revolution. It has provisions to readily evaluate initial stresses due to pretension in the winding filaments and residual stresses due to cure temperature.

Design of an ultrasonic micro-array for near field sensing during retinal microsurgery.

PubMed

Clarke, Clyde; Etienne-Cummings, Ralph

2006-01-01

A method for obtaining the optimal and specific sensor parameters for a tool-tip mountable ultrasonic transducer micro-array is presented. The ultrasonic transducer array sensor parameters, such as frequency of operation, element size, inter-element spacing, number of elements and transducer geometry are obtained using a quadratic programming method to obtain a maximum directivity while being constrained to a total array size of 4 mm2 and the required resolution for retinal imaging. The technique is used to design a uniformly spaced NxN transducer array that is capable of resolving structures in the retina that are as small as 2 microm from a distance of 100 microm. The resultant 37x37 array of 16 microm transducers with 26 microm spacing will be realized as a Capacitive Micromachined Ultrasonic Transducer (CMUT) array and used for imaging and robotic guidance during retinal microsurgery.

High performance VLSI telemetry data systems

NASA Technical Reports Server (NTRS)

Chesney, J.; Speciale, N.; Horner, W.; Sabia, S.

1990-01-01

NASA's deployment of major space complexes such as Space Station Freedom (SSF) and the Earth Observing System (EOS) will demand increased functionality and performance from ground based telemetry acquisition systems well above current system capabilities. Adaptation of space telemetry data transport and processing standards such as those specified by the Consultative Committee for Space Data Systems (CCSDS) standards and those required for commercial ground distribution of telemetry data, will drive these functional and performance requirements. In addition, budget limitations will force the requirement for higher modularity, flexibility, and interchangeability at lower cost in new ground telemetry data system elements. At NASA's Goddard Space Flight Center (GSFC), the design and development of generic ground telemetry data system elements, over the last five years, has resulted in significant solutions to these problems. This solution, referred to as the functional components approach includes both hardware and software components ready for end user application. The hardware functional components consist of modern data flow architectures utilizing Application Specific Integrated Circuits (ASIC's) developed specifically to support NASA's telemetry data systems needs and designed to meet a range of data rate requirements up to 300 Mbps. Real-time operating system software components support both embedded local software intelligence, and overall system control, status, processing, and interface requirements. These components, hardware and software, form the superstructure upon which project specific elements are added to complete a telemetry ground data system installation. This paper describes the functional components approach, some specific component examples, and a project example of the evolution from VLSI component, to basic board level functional component, to integrated telemetry data system.

Solar Pumped Solid State Lasers for Space Solar Power: Experimental Path

NASA Technical Reports Server (NTRS)

Fork, Richard L.; Carrington, Connie K.; Walker, Wesley W.; Cole, Spencer T.; Green, Jason J. A.; Laycock, Rustin L.

2003-01-01

We outline an experimentally based strategy designed to lead to solar pumped solid state laser oscillators useful for space solar power. Our method involves solar pumping a novel solid state gain element specifically designed to provide efficient conversion of sunlight in space to coherent laser light. Kilowatt and higher average power is sought from each gain element. Multiple such modular gain elements can be used to accumulate total average power of interest for power beaming in space, e.g., 100 kilowatts and more. Where desirable the high average power can also be produced as a train of pulses having high peak power (e.g., greater than 10(exp 10 watts). The modular nature of the basic gain element supports an experimental strategy in which the core technology can be validated by experiments on a single gain element. We propose to do this experimental validation both in terrestrial locations and also on a smaller scale in space. We describe a terrestrial experiment that includes diagnostics and the option of locating the laser beam path in vacuum environment. We describe a space based experiment designed to be compatible with the Japanese Experimental Module (JEM) on the International Space Station (ISS). We anticipate the gain elements will be based on low temperature (approx. 100 degrees Kelvin) operation of high thermal conductivity (k approx. 100 W/cm-K) diamond and sapphire (k approx. 4 W/cm-K). The basic gain element will be formed by sequences of thin alternating layers of diamond and Ti:sapphire with special attention given to the material interfaces. We anticipate this strategy will lead to a particularly simple, robust, and easily maintained low mass modelocked multi-element laser oscillator useful for space solar power.

Web 2.0 systems supporting childhood chronic disease management: A pattern language representation of a general architecture

PubMed Central

Timpka, Toomas; Eriksson, Henrik; Ludvigsson, Johnny; Ekberg, Joakim; Nordfeldt, Sam; Hanberger, Lena

2008-01-01

Background Chronic disease management is a global health concern. By the time they reach adolescence, 10–15% of all children live with a chronic disease. The role of educational interventions in facilitating adaptation to chronic disease is receiving growing recognition, and current care policies advocate greater involvement of patients in self-care. Web 2.0 is an umbrella term for new collaborative Internet services characterized by user participation in developing and managing content. Key elements include Really Simple Syndication (RSS) to rapidly disseminate awareness of new information; weblogs (blogs) to describe new trends, wikis to share knowledge, and podcasts to make information available on personal media players. This study addresses the potential to develop Web 2.0 services for young persons with a chronic disease. It is acknowledged that the management of childhood chronic disease is based on interplay between initiatives and resources on the part of patients, relatives, and health care professionals, and where the balance shifts over time to the patients and their families. Methods Participatory action research was used to stepwise define a design specification in the form of a pattern language. Support for children diagnosed with diabetes Type 1 was used as the example area. Each individual design pattern was determined graphically using card sorting methods, and textually in the form Title, Context, Problem, Solution, Examples and References. Application references were included at the lowest level in the graphical overview in the pattern language but not specified in detail in the textual descriptions. Results The design patterns are divided into functional and non-functional design elements, and formulated at the levels of organizational, system, and application design. The design elements specify access to materials for development of the competences needed for chronic disease management in specific community settings, endorsement of self-learning through online peer-to-peer communication, and systematic accreditation and evaluation of materials and processes. Conclusion The use of design patterns allows representing the core design elements of a Web 2.0 system upon which an 'ecological' development of content respecting these constraints can be built. Future research should include evaluations of Web 2.0 systems implemented according to the architecture in practice settings. PMID:19040738

Development of real-time software environments for NASA's modern telemetry systems

NASA Technical Reports Server (NTRS)

Horner, Ward; Sabia, Steve

1989-01-01

An effort has been made to maintain maximum performance and flexibility for NASA-Goddard's VLSI telemetry system elements through the development of two real-time systems: (1) the Base System Environment, which supports generic system integration and furnishes the basic porting of various manufacturers' cards, and (2) the Modular Environment for Data Systems, which supports application-specific developments and furnishes designers with a set of tested generic library functions that can be employed to speed up the development of such application-specific real-time codes. The performance goals and design rationale for these two systems are discussed.

Performance analysis and material dependence of micro holographic optical elements as couplers for fiber optic communication

NASA Astrophysics Data System (ADS)

Ambadiyil, Sajan; Prasannan, G.; Sathyan, Jithesh; Ajith Kumar, P. T.

2005-01-01

Holographic Optical Elements (HOEs) are gaining much importance and finding newer and better applications in areas of optical fiber communication and optical information processing systems. In contrast to conventional HOEs, optical communication and information systems require smaller and efficient elements of desired characteristics and transfer functions. Such Micro Holographic Optical Elements (MHOEs) can either be an HOE, recorded with two narrow beams of laser light or a segment cut from a larger HOE (SHOEs), and recorded in the conventional manner. In this study, micro holographic couplers, having specific focusing and diffraction characteristics were recorded in different holographic recording media such as silver halide and dichromated gelatin. Wavelength response of the elements was tested at 633 nm and 442 nm. Variation in diffraction efficiency/coupling factor, and insertion loss of the elements were studied. The paper reports in detail about the above results and related design considerations.

Rigorous Science: a How-To Guide

PubMed Central

Fang, Ferric C.

2016-01-01

ABSTRACT Proposals to improve the reproducibility of biomedical research have emphasized scientific rigor. Although the word “rigor” is widely used, there has been little specific discussion as to what it means and how it can be achieved. We suggest that scientific rigor combines elements of mathematics, logic, philosophy, and ethics. We propose a framework for rigor that includes redundant experimental design, sound statistical analysis, recognition of error, avoidance of logical fallacies, and intellectual honesty. These elements lead to five actionable recommendations for research education. PMID:27834205

Rigorous Science: a How-To Guide.

PubMed

Casadevall, Arturo; Fang, Ferric C

2016-11-08

Proposals to improve the reproducibility of biomedical research have emphasized scientific rigor. Although the word "rigor" is widely used, there has been little specific discussion as to what it means and how it can be achieved. We suggest that scientific rigor combines elements of mathematics, logic, philosophy, and ethics. We propose a framework for rigor that includes redundant experimental design, sound statistical analysis, recognition of error, avoidance of logical fallacies, and intellectual honesty. These elements lead to five actionable recommendations for research education. Copyright © 2016 Casadevall and Fang.

Guidelines and Capabilities for Designing Human Missions

NASA Technical Reports Server (NTRS)

2002-01-01

The human element is likely the most complex and difficult one of mission design; it significantly influences every aspect of mission planning, from the basic parameters like duration to the more complex tradeoffs between mass, volume, power, risk, and cost. For engineers who rely on precise specifications in data books and other such technical references, dealing with the uncertainty and the variability of designing for human beings can be frustrating. When designing for the human element, questions arise more often than definitive answers. Nonetheless, we do not doubt that the most captivating discoveries in future space missions will necessitate human explorers. These guidelines and capabilities are meant to identify the points of intersection between humans and mission considerations such as architecture, vehicle design, technologies, operations, and science requirements. We seek to provide clear, top-level guidelines for human-related exploration studies and technology research that address common questions and requirements. As a result, we hope that ongoing mission trade studies consider common, standard, and practical criteria for human interfaces.

Guidelines and Capabilities for Designing Human Missions

NASA Astrophysics Data System (ADS)

2002-03-01

The human element is likely the most complex and difficult one of mission design; it significantly influences every aspect of mission planning, from the basic parameters like duration to the more complex tradeoffs between mass, volume, power, risk, and cost. For engineers who rely on precise specifications in data books and other such technical references, dealing with the uncertainty and the variability of designing for human beings can be frustrating. When designing for the human element, questions arise more often than definitive answers. Nonetheless, we do not doubt that the most captivating discoveries in future space missions will necessitate human explorers. These guidelines and capabilities are meant to identify the points of intersection between humans and mission considerations such as architecture, vehicle design, technologies, operations, and science requirements. We seek to provide clear, top-level guidelines for human-related exploration studies and technology research that address common questions and requirements. As a result, we hope that ongoing mission trade studies consider common, standard, and practical criteria for human interfaces.

Thermion: Verification of a thermionic heat pipe in microgravity

NASA Technical Reports Server (NTRS)

1991-01-01

The design and development is examined of a small excore heat pipe thermionic space nuclear reactor power system (SEHPTR). The need was identified for an in-space flight demonstration of a solar powered, thermionic heat pipe element. A demonstration would examine its performance and verify its operation in microgravity. The design of a microsatellite based technology demonstration experiment is proposed to measure the effects of microgravity on the performance of an integrated thermionic heat pipe device in low earth orbit. The specific objectives are to verify the operation of the liquid metal heat pipe and the cesium reservior in the space environment. Two design configurations are described; THERMION-I and THERMION-II. THERMION-I is designed for a long lifetime study of the operations of the thermionic heat pipe element in low earth orbit. Heat input to the element is furnished by a large mirror which collects solar energy and focuses it into a cavity containing the heat pipe device. THERMION-II is a much simpler device which is used for short term operation. This experiment remains attached to the Delta II second stage and uses energy from 500 lb of alkaline batteries to supply heat energy to the heat pipe device.

Summary of Liquid Oxygen/Hydrogen, Direct Metal Laser Sintering Injector Testing and Evaluation Effort at Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

Barnett, Gregory; Bullard, David B.

2015-01-01

The last several years have witnessed a significant advancement in the area of additive manufacturing technology. One area that has seen substantial expansion in application has been laser sintering (or melting) in a powder bed. This technology is often termed 3D printing or various acronyms that may be industry, process, or company specific. Components manufactured via 3D printing have the potential to significantly reduce development and fabrication time and cost. The usefulness of 3D printed components is influenced by several factors such as material properties and surface roughness. This paper details three injectors that were designed, fabricated, and tested in order to evaluate the utility of 3D printed components for rocket engine applications. The three injectors were tested in a hot-fire environment with chamber pressures of approximately 1400 psia. One injector was a 28 element design printed by Directed Manufacturing. The other two injectors were identical 40 element designs printed by Directed Manufacturing and Solid Concepts. All the injectors were swirl-coaxial designs and were subscale versions of a full-scale injector currently in fabrication. The test and evaluation programs for the 28 element and 40 element injectors provided a substantial amount of data that confirms the feasibility of 3D printed parts for future applications. The operating conditions of previously tested, conventionally manufactured injectors were reproduced in the 28 and 40 element programs in order to contrast the performance of each. Overall, the 3D printed injectors demonstrated comparable performance to the conventionally manufactured units. The design features of the aforementioned injectors can readily be implemented in future applications with a high degree of confidence.

Substrate specificity of bacterial DD-peptidases (penicillin-binding proteins).

PubMed

Pratt, R F

2008-07-01

The DD-peptidase enzymes (penicillin-binding proteins) catalyze the final transpeptidation reaction of bacterial cell wall (peptidoglycan) biosynthesis. Although there is now much structural information available about these enzymes, studies of their activity as enzymes lag. It is now established that representatives of two low-molecular-mass classes of DD-peptidases recognize elements of peptidoglycan structure and rapidly react with substrates and inhibitors incorporating these elements. No members of other DD-peptidase classes, including the high-molecular-mass enzymes, essential for bacterial growth, appear to interact strongly with any particular elements of peptidoglycan structure. Rational design of inhibitors for these enzymes is therefore challenging.

Reusable rocket engine intelligent control system framework design, phase 2

NASA Technical Reports Server (NTRS)

Nemeth, ED; Anderson, Ron; Ols, Joe; Olsasky, Mark

1991-01-01

Elements of an advanced functional framework for reusable rocket engine propulsion system control are presented for the Space Shuttle Main Engine (SSME) demonstration case. Functional elements of the baseline functional framework are defined in detail. The SSME failure modes are evaluated and specific failure modes identified for inclusion in the advanced functional framework diagnostic system. Active control of the SSME start transient is investigated, leading to the identification of a promising approach to mitigating start transient excursions. Key elements of the functional framework are simulated and demonstration cases are provided. Finally, the advanced function framework for control of reusable rocket engines is presented.

Low Average Sidelobe Slot Array Antennas for Radiometer Applications

NASA Technical Reports Server (NTRS)

Rengarajan, Sembiam; Zawardzki, Mark S.; Hodges, Richard E.

2012-01-01

In radiometer applications, it is required to design antennas that meet low average sidelobe levels and low average return loss over a specified frequency bandwidth. It is a challenge to meet such specifications over a frequency range when one uses resonant elements such as waveguide feed slots. In addition to their inherent narrow frequency band performance, the problem is exacerbated due to modeling errors and manufacturing tolerances. There was a need to develop a design methodology to solve the problem. An iterative design procedure was developed by starting with an array architecture, lattice spacing, aperture distribution, waveguide dimensions, etc. The array was designed using Elliott s technique with appropriate values of the total slot conductance in each radiating waveguide, and the total resistance in each feed waveguide. Subsequently, the array performance was analyzed by the full wave method of moments solution to the pertinent integral equations. Monte Carlo simulations were also carried out to account for amplitude and phase errors introduced for the aperture distribution due to modeling errors as well as manufacturing tolerances. If the design margins for the average sidelobe level and the average return loss were not adequate, array architecture, lattice spacing, aperture distribution, and waveguide dimensions were varied in subsequent iterations. Once the design margins were found to be adequate, the iteration was stopped and a good design was achieved. A symmetric array architecture was found to meet the design specification with adequate margin. The specifications were near 40 dB for angular regions beyond 30 degrees from broadside. Separable Taylor distribution with nbar=4 and 35 dB sidelobe specification was chosen for each principal plane. A non-separable distribution obtained by the genetic algorithm was found to have similar characteristics. The element spacing was obtained to provide the required beamwidth and close to a null in the E-plane end-fire direction. Because of the alternating slot offsets, grating lobes called butterfly lobes are produced in non-principal planes close to the H-plane. An attempt to reduce the influence of such grating lobes resulted in a symmetric design.

Vector magnetometer design study: Analysis of a triaxial fluxgate sensor design demonstrates that all MAGSAT Vector Magnetometer specifications can be met

NASA Technical Reports Server (NTRS)

Adams, D. F.; Hartmann, U. G.; Lazarow, L. L.; Maloy, J. O.; Mohler, G. W.

1976-01-01

The design of the vector magnetometer selected for analysis is capable of exceeding the required accuracy of 5 gamma per vector field component. The principal elements that assure this performance level are very low power dissipation triaxial feedback coils surrounding ring core flux-gates and temperature control of the critical components of two-loop feedback electronics. An analysis of the calibration problem points to the need for improved test facilities.

Earthdata User Interface Patterns: Building Usable Web Interfaces Through a Shared UI Pattern Library

NASA Astrophysics Data System (ADS)

Siarto, J.

2014-12-01

As more Earth science software tools and services move to the web--the design and usability of those tools become ever more important. A good user interface is becoming expected and users are becoming increasingly intolerant of websites and web applications that work against them. The Earthdata UI Pattern Library attempts to give these scientists and developers the design tools they need to make usable, compelling user interfaces without the associated overhead of using a full design team. Patterns are tested and functional user interface elements targeted specifically at the Earth science community and will include web layouts, buttons, tables, typography, iconography, mapping and visualization/graphing widgets. These UI elements have emerged as the result of extensive user testing, research and software development within the NASA Earthdata team over the past year.

Into the Curriculum.

ERIC Educational Resources Information Center

School Library Media Activities Monthly, 1992

1992-01-01

Provides six fully developed library media activities that are designed to be used with specific curriculum units. Highlights include elementary student activities for art (winter holiday crafts); reading/language arts (fantasy in stories, elements of folk stories from India, writing sequels to fairy tales); science (animal symbiosis); and social…

Integrating Science and Engineering to Implement Evidence-Based Practices in Health Care Settings

PubMed Central

Wu, Shinyi; Duan, Naihua; Wisdom, Jennifer P.; Kravitz, Richard L.; Owen, Richard R.; Sullivan, Greer; Wu, Albert W.; Di Capua, Paul; Hoagwood, Kimberly Eaton

2015-01-01

Integrating two distinct and complementary paradigms, science and engineering, may produce more effective outcomes for the implementation of evidence-based practices in health care settings. Science formalizes and tests innovations, whereas engineering customizes and optimizes how the innovation is applied tailoring to accommodate local conditions. Together they may accelerate the creation of an evidence-based healthcare system that works effectively in specific health care settings. We give examples of applying engineering methods for better quality, more efficient, and safer implementation of clinical practices, medical devices, and health services systems. A specific example was applying systems engineering design that orchestrated people, process, data, decision-making, and communication through a technology application to implement evidence-based depression care among low-income patients with diabetes. We recommend that leading journals recognize the fundamental role of engineering in implementation research, to improve understanding of design elements that create a better fit between program elements and local context. PMID:25217100

Finite Element Development and Specifications of a Patched, Recessed Nomex Core Honeycomb Panel for Increased Sound Transmission Loss

NASA Technical Reports Server (NTRS)

Grosveld, Ferdinand W.

2007-01-01

This informal report summarizes the development and the design specifications of a recessed nomex core honeycomb panel in fulfillment of the deliverable in Task Order 13RBE, Revision 10, Subtask 17. The honeycomb panel, with 0.020-inch thick aluminum face sheets, has 0.016-inch thick aluminum patches applied to twenty-five, 6 by 6 inch, quarter inch thick recessed cores. A 10 dB higher transmission loss over the frequency range 250 - 1000 Hz was predicted by a MSC/NASTRAN finite element model when compared with the transmission loss of the base nomex core honeycomb panel. The static displacement, due to a unit force applied at either the core or recessed core area, was of the same order of magnitude as the static displacement of the base honeycomb panel when exposed to the same unit force. The mass of the new honeycomb design is 5.1% more than the base honeycomb panel. A physical model was constructed and is being tested.

Designing stereoscopic information visualization for 3D-TV: What can we can learn from S3D gaming?

NASA Astrophysics Data System (ADS)

Schild, Jonas; Masuch, Maic

2012-03-01

This paper explores graphical design and spatial alignment of visual information and graphical elements into stereoscopically filmed content, e.g. captions, subtitles, and especially more complex elements in 3D-TV productions. The method used is a descriptive analysis of existing computer- and video games that have been adapted for stereoscopic display using semi-automatic rendering techniques (e.g. Nvidia 3D Vision) or games which have been specifically designed for stereoscopic vision. Digital games often feature compelling visual interfaces that combine high usability with creative visual design. We explore selected examples of game interfaces in stereoscopic vision regarding their stereoscopic characteristics, how they draw attention, how we judge effect and comfort and where the interfaces fail. As a result, we propose a list of five aspects which should be considered when designing stereoscopic visual information: explicit information, implicit information, spatial reference, drawing attention, and vertical alignment. We discuss possible consequences, opportunities and challenges for integrating visual information elements into 3D-TV content. This work shall further help to improve current editing systems and identifies a need for future editing systems for 3DTV, e.g., live editing and real-time alignment of visual information into 3D footage.

Finite Element Analysis in the Estimation of Air-Gap Torque and Surface Temperature of Induction Machine

NASA Astrophysics Data System (ADS)

Mr., J. Ravi Kumar; Banakara, Basavaraja, Dr.

2017-08-01

This paper presents electromagnetic and thermal behavior of Induction Motor (IM) through the modeling and analysis by applying multiphysics coupled Finite Element Analysis (FEA). Therefore prediction of the magnetic flux, electromagnetic torque, stator and rotor losses and temperature distribution inside an operating electric motor are the most important issues during its design. Prediction and estimation of these parameters allows design engineers to decide capability of the machine for the proposed load, temperature rating and its application for which it is being designed ensuring normal motor operation at rated conditions. In this work, multiphysics coupled electromagnetic - thermal modeling and analysis of induction motor at rated and high frequency has carried out applying Arkkio’s torque method. COMSOL Multiphysics software is used for modeling and finite element analysis of IM. Transient electromagnetic torque, magnetic field distribution, speed-torque characteristics of IM were plotted and studied at different frequencies. This proposed work helps in the design and prediction of accurate performance of induction motor specific to various industrial drive applications. Results obtained are also validated with experimental analysis. The main purpose of this model is to use it as an integral part of the design aiming to system optimization of Variable Speed Drive (VSD) and its components using coupled simulations.

Design of the Park-in-Shape study: a phase II double blind randomized controlled trial evaluating the effects of exercise on motor and non-motor symptoms in Parkinson's disease.

PubMed

van der Kolk, Nicolien M; Overeem, Sebastiaan; de Vries, Nienke M; Kessels, Roy P C; Donders, Rogier; Brouwer, Marc; Berg, Daniela; Post, Bart; Bloem, Bas R

2015-04-16

Parkinson's disease (PD) is a neurodegenerative disorder with a wide range of motor and non-motor symptoms. Despite optimal medical management, PD still results in a high disability rate and secondary complications and many patients lead a sedentary lifestyle, which in turn is also associated with a higher co-morbidity and mortality. Exercise has been explored as a strategy to reduce secondary complications and results suggests that it not only provides general health benefits, but may also provide symptomatic relief. If this holds true exercise would be a very attractive addition to the therapeutic arsenal in PD. The supportive evidence remains incomplete. Here, we describe the design of the Park-in-Shape study, which primarily aims to evaluate whether aerobic exercise affords clinically relevant improvements in motor symptoms in sedentary PD patients. A specific new element is the introduction of gaming to optimize compliance to the exercise intervention. The Park-in-Shape study is a randomized controlled, assessor- and patient-blinded single center study. Two parallel groups will include a total of 130 patients, receiving either aerobic exercise on a home trainer equipped with gaming elements ("exergaming"), or a non-aerobic intervention (stretching, flexibility and relaxation exercises). Both groups are supported by a specifically designed motivational app that uses gaming elements to stimulate patients to exercise and rewards them after having completed the exercise. Both interventions are delivered at home at least 3 times a week for 30-45 minutes during 6 months. Eligible patients are community-dwelling, sedentary patients diagnosed with mild-moderate PD. The primary outcome is the MDS-UPDRS motor score (tested in the off state) after 6 months. Secondary outcomes include various motor and non-motor symptoms, quality of life, physical fitness, and adherence. This Park-in-Shape study is anticipated to answer the question whether high intensity aerobic exercise combined with gaming elements ("exergaming") provides symptomatic relief in PD. Strong elements include the double-blinded randomized controlled trial design, the MDS-UPDRS as valid primary outcome, the large sample size and unique combination of home-based pure aerobic exercise combined with gaming elements and motivational aspects. Dutch trial register NTR4743.

What makes an accurate and reliable subject-specific finite element model? A case study of an elephant femur

PubMed Central

Panagiotopoulou, O.; Wilshin, S. D.; Rayfield, E. J.; Shefelbine, S. J.; Hutchinson, J. R.

2012-01-01

Finite element modelling is well entrenched in comparative vertebrate biomechanics as a tool to assess the mechanical design of skeletal structures and to better comprehend the complex interaction of their form–function relationships. But what makes a reliable subject-specific finite element model? To approach this question, we here present a set of convergence and sensitivity analyses and a validation study as an example, for finite element analysis (FEA) in general, of ways to ensure a reliable model. We detail how choices of element size, type and material properties in FEA influence the results of simulations. We also present an empirical model for estimating heterogeneous material properties throughout an elephant femur (but of broad applicability to FEA). We then use an ex vivo experimental validation test of a cadaveric femur to check our FEA results and find that the heterogeneous model matches the experimental results extremely well, and far better than the homogeneous model. We emphasize how considering heterogeneous material properties in FEA may be critical, so this should become standard practice in comparative FEA studies along with convergence analyses, consideration of element size, type and experimental validation. These steps may be required to obtain accurate models and derive reliable conclusions from them. PMID:21752810

NASA/MSFC Large Stretch Press Study

NASA Technical Reports Server (NTRS)

Choate, M. W.; Nealson, W. P.; Jay, G. C.; Buss, W. D.

1985-01-01

The purpose of this study was to: A. assess and document the advantages/disadvantages of a government agency investment in a large stretch form press on the order of 5000 tons capacity (per jaw); B. develop a procurement specification for the press; and C. provide trade study data that will permit an optimum site location. Tasks were separated into four major elements: cost study, user survey, site selection, and press design/procurement specification.

Translating supportability requirements into design reality

NASA Astrophysics Data System (ADS)

Buche, J.; Cohen, I.

1986-10-01

This paper explores some of the principal issues in the integration of supportability into the design process. Roles of the contractor's design, supportability and management specialists and their government counterparts are discussed as they relate to logistics influence in design. Methods and processes by which weapon system logistics and readiness requirements are established, assessed, allocated to system elements and translated into specific design features are described. Tradeoff consideration, an approach to effective tradeoff criteria, and the progress of supportability issues through the program phases are identified with particular emphasis on the necessity for developing and maintaining an effective audit trail.

Mixed Methods Design Study Investigating the Use of a Music Authentic Performance Assessment Tool by High School Band Directors to Measure Student Musical Growth

ERIC Educational Resources Information Center

Beason, Christine F.

2017-01-01

This research project was designed to determine if the Model Cornerstone Assessment for Performance, Proficient level, published by the National Association for Music Education would be an appropriate tool to use to demonstrate student growth as one element of teacher evaluations, specifically the T-TESS. This study focused on four main research…

Design of a 12-GHz multicarrier earth-terminal for satellite-CATV interconnection

NASA Technical Reports Server (NTRS)

Newman, B. A.; Singh, J. P.; Rosenbaum, F. J.

1971-01-01

The design and development of the front-end for a multi-carrier system that allows multiplex signal transmission from satellite-borne transponders is described. Detailed systems analyses provided down-converter specifications. The 12 GHz carrier down-converter uses waveguide, coaxial, and microstrip transmission line elements in its implementation. Mixing is accomplished in a single-ended coaxial mixer employing a field-replacable cartridge style diode.

Alkali Metal Heat Pipe Life Issues

NASA Technical Reports Server (NTRS)

Reid, Robert S.

2004-01-01

One approach to space fission power system design is predicated on the use of alkali metal heat pipes, either as radiator elements, thermal management components, or as part of the core primary heat-transfer system. This synopsis characterizes long-life core heat pipes. References are included where more detailed information can be found. Specifics shown here are for demonstrational purposes and do not necessarily reflect current Project Prometheus point designs.

Realization of FRC interior and exterior furniture

NASA Astrophysics Data System (ADS)

Šonka, Š.; Frantová, M.; Štemberk, P.; Havrda, J.; Janouch, P.

2017-09-01

This article deals with the implementation of fibre reinforced concrete for interior and exterior furniture. The use of fibre reinforced concrete for non-traditional and small structures brings some specifics in design and realization. These are, in particular, the design of a suitable mixture, the choice of the shape of the structure in relation to the technological possibilities of realization, the static effects and finally the actual production of the element.

The STEIN Particle Detector

DTIC Science & Technology

2015-02-27

cubesats. The CINEMA (Cubesat for Ions Neutrals Electrons and Magnetic 1 Approved for public release; distribution is unlimited. fields) was the primary...intended host for STEIN. Additionally some calibration efforts were performed with the CINEMA spacecraft as an element of the readout. This resulted...designed to accept a clock from its host spacecraft (as was the design case for CINEMA ) of 8.38MHz (specifically 2^23 Hz). As well as a spacecraft

Preliminary design package for maxi-therm heat exchanger module

NASA Technical Reports Server (NTRS)

1978-01-01

Heat exchangers were developed for use in a solar heating and cooling system installed in a single family dwelling. Each of the three exchangers consisted of a heating and cooling module and a submersed electric water heating element. Information necessary to evaluate the preliminary design of the heat exchanger is presented in terms of the development and verification plans, performance specifications, installation and maintenance, and hazard analysis.

Differences in the stress distribution in the distal femur between patellofemoral joint replacement and total knee replacement: a finite element study

PubMed Central

2012-01-01

Background Patellofemoral joint replacement is a successful treatment option for isolated patellofemoral osteoarthritis. However, results of later conversion to total knee replacement may be compromised by periprosthetic bone loss. Previous clinical studies have demonstrated a decrease in distal femoral bone mineral density after patellofemoral joint replacement. It is unclear whether this is due to periprosthetic stress shielding. The main objective of the current study was to evaluate the stress shielding effect of prosthetic replacement with 2 different patellofemoral prosthetic designs and with a total knee prosthesis. Methods We developed a finite element model of an intact patellofemoral joint, and finite element models of patellofemoral joint replacement with a Journey PFJ prosthesis, a Richards II prosthesis, and a Genesis II total knee prosthesis. For each of these 4 finite element models, the average Von Mises stress in 2 clinically relevant regions of interest were evaluated during a simulated squatting movement until 120 degrees of flexion. Results During deep knee flexion, in the anterior region of interest, the average Von Mises stress with the Journey PFJ design was comparable to the physiological knee, while reduced by almost 25% for both the Richards II design and the Genesis II total knee joint replacement design. The average Von Mises stress in the supracondylar region of interest was similar for both patellofemoral prosthetic designs and the physiological model, with slightly lower stress for the Genesis II design. Conclusions Patellofemoral joint replacement results in periprosthetic stress-shielding, although to a smaller degree than in total knee replacement. Specific patellofemoral prosthetic design properties may result in differences in femoral stress shielding. PMID:22704638

Wide-Field InfraRed Survey Telescope (WFIRST) Slitless Spectrometer: Design, Prototype, and Results

NASA Technical Reports Server (NTRS)

Gong, Qian; Content, David; Dominguez, Margaret; Emmett, Thomas; Griesmann, Ulf; Hagopian, John; Kruk, Jeffrey; Marx, Catherine; Pasquale, Bert; Wallace, Thomas;

Characterization of transceive surface element designs for 7 tesla magnetic resonance imaging of the prostate: radiative antenna and microstrip.

PubMed

Ipek, O; Raaijmakers, A J E; Klomp, D W J; Lagendijk, J J W; Luijten, P R; van den Berg, C A T

2012-01-21

Ultra-high field magnetic resonance (≥7 tesla) imaging (MRI) faces challenges with respect to efficient spin excitation and signal reception from deeply situated organs. Traditional radio frequency surface coil designs relying on near-field coupling are suboptimal at high field strengths. Better signal penetration can be obtained by designing a radiative antenna in which the energy flux is directed to the target location. In this paper, two different radiative antenna designs are investigated to be used as transceive elements, which employ different dielectric permittivities for the antenna substrate. Their transmit and receive performances in terms of B(+)(1), local SAR (specific absorption rate) and SNR (signal-to-noise ratio) were compared using extensive electromagnetic simulations and MRI measurements with traditional surface microstrip coils. Both simulations and measurements demonstrated that the radiative element shows twofold gain in B(+)(1) and SNR at 10 cm depth, and additionally a comparable SAR peak value. In terms of transmit performance, the radiative antenna with a dielectric permittivity of 37 showed a 24% more favorable local SAR(10g avg)/(B(+)(1))(2) ratio than the radiative antenna with a dielectric permittivity of 90. In receive, the radiative element with a dielectric permittivity of 90 resulted in a 20% higher SNR for shallow depths, but for larger depths this difference diminished compared to the radiative element with a dielectric permittivity of 37. Therefore, to image deep anatomical regions effectively, the radiative antenna with a dielectric permittivity of 37 is favorable.

Increasing the efficiency of designing hemming processes by using an element-based metamodel approach

NASA Astrophysics Data System (ADS)

Kaiser, C.; Roll, K.; Volk, W.

2017-09-01

In the automotive industry, the manufacturing of automotive outer panels requires hemming processes in which two sheet metal parts are joined together by bending the flange of the outer part over the inner part. Because of decreasing development times and the steadily growing number of vehicle derivatives, an efficient digital product and process validation is necessary. Commonly used simulations, which are based on the finite element method, demand significant modelling effort, which results in disadvantages especially in the early product development phase. To increase the efficiency of designing hemming processes this paper presents a hemming-specific metamodel approach. The approach includes a part analysis in which the outline of the automotive outer panels is initially split into individual segments. By doing a para-metrization of each of the segments and assigning basic geometric shapes, the outline of the part is approximated. Based on this, the hemming parameters such as flange length, roll-in, wrinkling and plastic strains are calculated for each of the geometric basic shapes by performing a meta-model-based segmental product validation. The metamodel is based on an element similar formulation that includes a reference dataset of various geometric basic shapes. A random automotive outer panel can now be analysed and optimized based on the hemming-specific database. By implementing this approach into a planning system, an efficient optimization of designing hemming processes will be enabled. Furthermore, valuable time and cost benefits can be realized in a vehicle’s development process.

Comprehensive elements of a physiotherapy exercise programme in haemophilia--a global perspective.

PubMed

Blamey, G; Forsyth, A; Zourikian, N; Short, L; Jankovic, N; De Kleijn, P; Flannery, T

2010-07-01

Exercise programmes for people with haemophilia are usually designed and implemented to help manage the recovery after a haemarthrosis or a muscle bleed, or as a tool to help prevent bleeding episodes from occurring. In this article, we have identified individual components of exercise that are often applied as separate entities, but may also need to be implemented in concert for optimized impact. Although it may be necessary on occasion to bias an exercise programme towards one component over the others, it is important to recognize that the various elements of exercise are not mutually exclusive. Decreased flexibility, strength and proprioception, will result in an impairment of balance and a loss of function. Programme design should whenever possible be guided by proven methodology in terms of how each component is incorporated, and more specifically how long to perform the exercise for and how many repetitions should be performed. We recognize, however, that this is not always possible and that there is significant value in drawing from the experience of clinicians with specialized training in the management of haemophilia. In this study, both perspectives are presented, providing reference-based reviews of the mechanics of the various elements of exercise as well as the expert opinions of the authors. Research that has been completed using patients with conditions other than haemophilia may or may not have a direct application with the bleeding disorders population, but the programme design based on principles of tissue healing in addition to disease specific knowledge should be encouraged.

Stratified Volume Diffractive Optical Elements as Low-Mass Coherent Lidar Scanners

NASA Technical Reports Server (NTRS)

Chambers, Diana M.; Nordin, Gregory P.; Kavaya, Michael J.

1999-01-01

Transmissive scanning elements for coherent laser radar systems are typically optical wedges, or prisms, which deflect the lidar beam at a specified angle and are then rotated about the instrument optical axis to produce a scan pattern. The wedge is placed in the lidar optical system subsequent to a beam-expanding telescope, implying that it has the largest diameter of any element in the system. The combination of the wedge diameter and asymmetric profile result in the element having very large mass and, consequently, relatively large power consumption required for scanning. These two parameters, mass and power consumption, are among the instrument requirements which need to be minimized when designing a lidar for a space-borne platform. Reducing the scanner contributions in these areas will have a significant effect on the overall instrument specifications, Replacing the optical wedge with a diffraction grating on the surface of a thin substrate is a straight forward approach with potential to reduce the mass of the scanning element significantly. For example, the optical wedge that will be used for the SPAce Readiness Coherent Lidar Experiment (SPARCLE) is approximately 25 cm in diameter and is made from silicon with a wedge angle designed for 30 degree deflection of a beam operating at approx. 2 micrometer wavelength. The mass of this element could be reduced by a factor of four by instead using a fused silica substrate, 1 cm thick, with a grating fabricated on one of the surfaces. For a grating to deflect a beam with a 2 micrometer wavelength by 30 degrees, a period of approximately 4 micrometers is required. This is small enough that fabrication of appropriate high efficiency blazed or multi-phase level diffractive optical gratings is prohibitively difficult. Moreover, bulk or stratified volume holographic approaches appear impractical due to materials limitations at 2 micrometers and the need to maintain adequate wavefront quality. In order to avoid the difficulties encountered in these approaches, we have developed a new type of high-efficiency grating which we call a Stratified Volume Diffractive Optical Element (SVDOE). The features of the gratings in this approach can be easily fabricated using standard photolithography and etching techniques and the materials used in the grating can be chosen specifically for a given application, In this paper we will briefly discuss the SVDOE technique and will present an example design of a lidar scanner using this approach. We will also discuss performance predictions for the example design.

Scope Complexity Options Risks Excursions (SCORE) Factor Mathematical Description.

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

Gearhart, Jared Lee; Samberson, Jonell Nicole; Shettigar, Subhasini

The purpose of the Scope, Complexity, Options, Risks, Excursions (SCORE) model is to estimate the relative complexity of design variants of future warhead options, resulting in scores. SCORE factors extend this capability by providing estimates of complexity relative to a base system (i.e., all design options are normalized to one weapon system). First, a clearly defined set of scope elements for a warhead option is established. The complexity of each scope element is estimated by Subject Matter Experts (SMEs), including a level of uncertainty, relative to a specific reference system. When determining factors, complexity estimates for a scope element canmore » be directly tied to the base system or chained together via comparable scope elements in a string of reference systems that ends with the base system. The SCORE analysis process is a growing multi-organizational Nuclear Security Enterprise (NSE) effort, under the management of the NA-12 led Enterprise Modeling and Analysis Consortium (EMAC). Historically, it has provided the data elicitation, integration, and computation needed to support the out-year Life Extension Program (LEP) cost estimates included in the Stockpile Stewardship Management Plan (SSMP).« less

PILOT PLANT TESTING OF ELEMENTAL MERCURY RE-EMISSION FROM WET SCRUBBERS

EPA Science Inventory

A pilot-scale wet lime/limestone flue gas desulfurization scrubber system was designed to conduct mercury emission control research. The first tests focused on investigating the phenomenon of Hgo re-emission from wet scrubbers with a specific objective of developing a Hgo re-emis...

46 CFR 10.407 - Approval of training programs.

Code of Federal Regulations, 2014 CFR

2014-10-01

... programs designed to substitute for or fulfill any or all of the following: (1) A portion of sea service.... Performance objectives are statements, which identify the specific knowledge, skill, or ability the student... made up of three elements: Expected student performance, condition, and criterion. (4) Assessment...

Retail Training and Education.

ERIC Educational Resources Information Center

Bloodworth, Margaret

The book provides insight into training aims, principles, techniques, aids , and courses designed to meet the training needs of specific groups of staff, such as management staff, training staff, new staff, and established staff. It also covers the training and educational elements of the Certificate of Retail Management Principles. Training…

I(CES)-cubes: a modular self-reconfigurable bipartite robotic system

NASA Astrophysics Data System (ADS)

Unsal, Cem; Kiliccote, Han; Khosla, Pradeep K.

1999-08-01

In this manuscript, we introduce I(CES)-Cubes, a class of 3D modular robotic system that is capable of reconfiguring itself in order to adapt to its environment. This is a bipartite system, i.e. a collection of (i) active elements capable of actuation, and (ii) passive elements acting as connectors between actuated elements. Active elements, called links, are 3-DOF manipulators that are capable of attaching/detaching themselves to/from the passive elements. The cubes can then be positioned and oriented using links, which are independent mechatronic elements. Self- reconfiguration property enables the system to performed locomotion tasks over difficult terrain. For example, the system would be capable of moving over obstacles and climbing stairs. These task are performed by positing and orienting cubes and links to form a 3D network with required shape and position. This paper describes the design of the passive and active elements, the attachment mechanics, and several reconfiguration scenarios. Specifics of the hardware implementation and result of experiments with current prototypes are also given.

Trace element abundance determinations by Synchrotron X Ray Fluorescence (SXRF) on returned comet nucleus mineral grains

NASA Technical Reports Server (NTRS)

Flynn, G. J.; Sutton, S. R.

1989-01-01

Trace element analyses were performed on bulk cosmic dust particles by Proton Induced X Ray Emission (PIXE) and Synchrotron X Ray Fluorescence (SXRF). When present at or near chondritic abundances the trace elements K, Ti, Cr, Mn, Cu, Zn, Ga, Ge, Se, and Br are presently detectable by SXRF in particles of 20 micron diameter. Improvements to the SXRF analysis facility at the National Synchrotron Light Source presently underway should increase the range of detectable elements and permit the analysis of smaller samples. In addition the Advanced Photon Source will be commissioned at Argonne National Laboratory in 1995. This 7 to 8 GeV positron storage ring, specifically designed for high-energy undulator and wiggler insertion devices, will be an ideal source for an x ray microprobe with one micron spatial resolution and better than 100 ppb elemental sensitivity for most elements. Thus trace element analysis of individual micron-sized grains should be possible by the time of the comet nucleus sample return mission.

Modeling of Damage Initiation and Progression in a SiC/SiC Woven Ceramic Matrix Composite

NASA Technical Reports Server (NTRS)

Mital, Subodh K.; Goldberg, Robert K.; Bonacuse, Peter J.

2012-01-01

The goal of an ongoing project at NASA Glenn is to investigate the effects of the complex microstructure of a woven ceramic matrix composite and its variability on the effective properties and the durability of the material. Detailed analysis of these complex microstructures may provide clues for the material scientists who `design the material? or to structural analysts and designers who `design with the material? regarding damage initiation and damage propagation. A model material system, specifically a five-harness satin weave architecture CVI SiC/SiC composite composed of Sylramic-iBN fibers and a SiC matrix, has been analyzed. Specimens of the material were serially sectioned and polished to capture the detailed images of fiber tows, matrix and porosity. Open source analysis tools were used to isolate various constituents and finite elements models were then generated from simplified models of those images. Detailed finite element analyses were performed that examine how the variability in the local microstructure affected the macroscopic behavior as well as the local damage initiation and progression. Results indicate that the locations where damage initiated and propagated is linked to specific microstructural features.

Design of HIFU transducers to generate specific nonlinear ultrasound fields.

PubMed

Khokhlova, Vera A; Yuldashev, Petr V; Rosnitskiy, Pavel B; Maxwell, Adam D; Kreider, Wayne; Bailey, Michael R; Sapozhnikov, Oleg A

2016-01-01

Various clinical applications of high intensity focused ultrasound (HIFU) have different requirements on the pressure level and degree of nonlinear waveform distortion at the focus. Applications that utilize nonlinear waves with developed shocks are of growing interest, for example, for mechanical disintegration as well as for accelerated thermal ablation of tissue. In this work, an inverse problem of determining transducer parameters to enable formation of shocks with desired amplitude at the focus is solved. The solution was obtained by performing multiple direct simulations of the parabolic Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation for various parameters of the source. It is shown that results obtained within the parabolic approximation can be used to describe the focal region of single element spherical sources as well as complex transducer arrays. It is also demonstrated that the focal pressure level at which fully developed shocks are formed mainly depends on the focusing angle of the source and only slightly depends on its aperture and operating frequency. Using the simulation results, a 256-element HIFU array operating at 1.5 MHz frequency was designed for a specific application of boiling-histotripsy that relies on the presence of 90-100 MPa shocks at the focus. The size of the array elements and focusing angle of the array were chosen to satisfy technical limitations on the intensity at the array elements and desired shock amplitudes in the focal waveform. Focus steering capabilities of the array were analysed using an open-source T-Array software developed at Moscow State University.

Design of HIFU Transducers to Generate Specific Nonlinear Ultrasound Fields

NASA Astrophysics Data System (ADS)

Khokhlova, Vera A.; Yuldashev, Petr V.; Rosnitskiy, Pavel B.; Maxwell, Adam D.; Kreider, Wayne; Bailey, Michael R.; Sapozhnikov, Oleg A.

Various clinical applications of high intensity focused ultrasound (HIFU) have different requirements on the pressure level and degree of nonlinear waveform distortion at the focus. Applications that utilize nonlinear waves with developed shocks are of growing interest, for example, for mechanical disintegration as well as for accelerated thermal ablation oftissue. In this work, an inverse problem of determining transducer parameters to enable formation of shockswith desired amplitude at the focus is solved. The solution was obtained by performing multipledirect simulations of the parabolic Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation for various parameters of the source. It is shown that results obtained within the parabolic approximation can be used to describe the focal region of single element spherical sourcesas well as complex transducer arrays. It is also demonstrated that the focal pressure level at which fully developed shocksare formed mainly depends on the focusing angle of the source and only slightly depends on its aperture and operating frequency. Using the simulation results, a 256-element HIFU array operating at 1.5 MHz frequency was designed for a specific application of boiling-histotripsy that relies on the presence of 90-100 MPa shocks at the focus. The size of the array elements and focusing angle of the array were chosen to satisfy technical limitations on the intensity at the array elements and desired shock amplitudes in the focal waveform. Focus steering capabilities of the array were analysed using an open-source T-Array software developed at Moscow State University.

Enrichment Zoning Options for the Small Nuclear Rocket Engine (SNRE)

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

Bruce G. Schnitzler; Stanley K. Borowski

2010-07-01

Advancement of U.S. scientific, security, and economic interests through a robust space exploration program requires high performance propulsion systems to support a variety of robotic and crewed missions beyond low Earth orbit. In NASA’s recent Mars Design Reference Architecture (DRA) 5.0 study (NASA-SP-2009-566, July 2009), nuclear thermal propulsion (NTP) was again selected over chemical propulsion as the preferred in-space transportation system option because of its high thrust and high specific impulse (-900 s) capability, increased tolerance to payload mass growth and architecture changes, and lower total initial mass in low Earth orbit. An extensive nuclear thermal rocket technology development effortmore » was conducted from 1955-1973 under the Rover/NERVA Program. The Small Nuclear Rocket Engine (SNRE) was the last engine design studied by the Los Alamos National Laboratory during the program. At the time, this engine was a state-of-the-art design incorporating lessons learned from the very successful technology development program. Past activities at the NASA Glenn Research Center have included development of highly detailed MCNP Monte Carlo transport models of the SNRE and other small engine designs. Preliminary core configurations typically employ fuel elements with fixed fuel composition and fissile material enrichment. Uniform fuel loadings result in undesirable radial power and temperature profiles in the engines. Engine performance can be improved by some combination of propellant flow control at the fuel element level and by varying the fuel composition. Enrichment zoning at the fuel element level with lower enrichments in the higher power elements at the core center and on the core periphery is particularly effective. Power flattening by enrichment zoning typically results in more uniform propellant exit temperatures and improved engine performance. For the SNRE, element enrichment zoning provided very flat radial power profiles with 551 of the 564 fuel elements within 1% of the average element power. Results for this and alternate enrichment zoning options for the SNRE are compared.« less

Software design specification. Part 2: Orbital Flight Test (OFT) detailed design specification. Volume 3: Applications. Book 2: System management

NASA Technical Reports Server (NTRS)

1979-01-01

The functions performed by the systems management (SM) application software are described along with the design employed to accomplish these functions. The operational sequences (OPS) control segments and the cyclic processes they control are defined. The SM specialist function control (SPEC) segments and the display controlled 'on-demand' processes that are invoked by either an OPS or SPEC control segment as a direct result of an item entry to a display are included. Each processing element in the SM application is described including an input/output table and a structured control flow diagram. The flow through the module and other information pertinent to that process and its interfaces to other processes are included.

Design and fabrication of solar cell modules

NASA Technical Reports Server (NTRS)

Shaughnessy, T. P.

1978-01-01

A program conducted for design, fabrication and evaluation of twelve silicon solar cell modules is described. The purpose of the program was to develop a module design consistent with the requirements and objectives of JPL specification and to also incorporate elements of new technologies under development to meet LSSA Project goals. Module development emphasized preparation of a technically and economically competitive design based upon utilization of ion implanted solar cells and a glass encapsulation system. The modules fabricated, tested and delivered were of nominal 2 X 2 foot dimensions and 20 watt minimum rating. Basic design, design rationale, performance and results of environmental testing are described.

Automating FEA programming

NASA Technical Reports Server (NTRS)

Sharma, Naveen

1992-01-01

In this paper we briefly describe a combined symbolic and numeric approach for solving mathematical models on parallel computers. An experimental software system, PIER, is being developed in Common Lisp to synthesize computationally intensive and domain formulation dependent phases of finite element analysis (FEA) solution methods. Quantities for domain formulation like shape functions, element stiffness matrices, etc., are automatically derived using symbolic mathematical computations. The problem specific information and derived formulae are then used to generate (parallel) numerical code for FEA solution steps. A constructive approach to specify a numerical program design is taken. The code generator compiles application oriented input specifications into (parallel) FORTRAN77 routines with the help of built-in knowledge of the particular problem, numerical solution methods and the target computer.

Novel Type V Staphylococcal Cassette Chromosome mec Driven by a Novel Cassette Chromosome Recombinase, ccrC

PubMed Central

Ito, Teruyo; Ma, Xiao Xue; Takeuchi, Fumihiko; Okuma, Keiko; Yuzawa, Harumi; Hiramatsu, Keiichi

2004-01-01

Staphylococcal cassette chromosome mec (SCCmec) is a mobile genetic element composed of the mec gene complex, which encodes methicillin resistance, and the ccr gene complex, which encodes the recombinases responsible for its mobility. The mec gene complex has been classified into four classes, and the ccr gene complex has been classified into three allotypes. Different combinations of mec gene complex classes and ccr gene complex types have so far defined four types of SCCmec elements. Now we introduce the fifth allotype of SCCmec, which was found on the chromosome of a community-acquired methicillin-resistant Staphylococcus aureus strain (strain WIS [WBG8318]) isolated in Australia. The element shared the same chromosomal integration site with the four extant types of SCCmec and the characteristic nucleotide sequences at the chromosome-SCCmec junction regions. The novel SCCmec carried mecA bracketed by IS431 (IS431-mecA-ΔmecR1-IS431), which is designated the class C2 mec gene complex; and instead of ccrA and ccrB genes, it carried a single copy of a gene homologue that encoded cassette chromosome recombinase. Since the open reading frame (ORF) was found to encode an enzyme which catalyzes the precise excision as well as site- and orientation-specific integration of the element, we designated the ORF cassette chromosome recombinase C (ccrC), and we designated the element type V SCCmec. Type V SCCmec is a small SCCmec element (28 kb) and does not carry any antibiotic resistance genes besides mecA. Unlike the extant SCCmec types, it carries a set of foreign genes encoding a restriction-modification system that might play a role in the stabilization of the element on the chromosome. PMID:15215121

Analysis and comparison of wrist splint designs using the finite element method: Multi-material three-dimensional printing compared to typical existing practice with thermoplastics.

PubMed

Cazon, Aitor; Kelly, Sarah; Paterson, Abby M; Bibb, Richard J; Campbell, R Ian

2017-09-01

Rheumatoid arthritis is a chronic disease affecting the joints. Treatment can include immobilisation of the affected joint with a custom-fitting splint, which is typically fabricated by hand from low temperature thermoplastic, but the approach poses several limitations. This study focused on the evaluation, by finite element analysis, of additive manufacturing techniques for wrist splints in order to improve upon the typical splinting approach. An additive manufactured/3D printed splint, specifically designed to be built using Objet Connex multi-material technology and a virtual model of a typical splint, digitised from a real patient-specific splint using three-dimensional scanning, were modelled in computer-aided design software. Forty finite element analysis simulations were performed in flexion-extension and radial-ulnar wrist movements to compare the displacements and the stresses. Simulations have shown that for low severity loads, the additive manufacturing splint has 25%, 76% and 27% less displacement in the main loading direction than the typical splint in flexion, extension and radial, respectively, while ulnar values were 75% lower in the traditional splint. For higher severity loads, the flexion and extension movements resulted in deflections that were 24% and 60%, respectively, lower in the additive manufacturing splint. However, for higher severity loading, the radial defection values were very similar in both splints and ulnar movement deflection was higher in the additive manufacturing splint. A physical prototype of the additive manufacturing splint was also manufactured and was tested under normal conditions to validate the finite element analysis data. Results from static tests showed maximum displacements of 3.46, 0.97, 3.53 and 2.51 mm flexion, extension, radial and ulnar directions, respectively. According to these results, the present research argues that from a technical point of view, the additive manufacturing splint design stands at the same or even better level of performance in displacements and stress values in comparison to the typical low temperature thermoplastic approach and is therefore a feasible approach to splint design and manufacture.

Radiation and scattering from printed antennas on cylindrically conformal platforms

NASA Technical Reports Server (NTRS)

Kempel, Leo C.; Volakis, John L.; Bindiganavale, Sunil

1994-01-01

The goal was to develop suitable methods and software for the analysis of antennas on cylindrical coated and uncoated platforms. Specifically, the finite element boundary integral and finite element ABC methods were employed successfully and associated software were developed for the analysis and design of wraparound and discrete cavity-backed arrays situated on cylindrical platforms. This work led to the successful implementation of analysis software for such antennas. Developments which played a role in this respect are the efficient implementation of the 3D Green's function for a metallic cylinder, the incorporation of the fast Fourier transform in computing the matrix-vector products executed in the solver of the finite element-boundary integral system, and the development of a new absorbing boundary condition for terminating the finite element mesh on cylindrical surfaces.

Design and manufacture of a D-shape coil-based toroid-type HTS DC reactor using 2nd generation HTS wire

NASA Astrophysics Data System (ADS)

Kim, Kwangmin; Go, Byeong-Soo; Sung, Hae-Jin; Park, Hea-chul; Kim, Seokho; Lee, Sangjin; Jin, Yoon-Su; Oh, Yunsang; Park, Minwon; Yu, In-Keun

2014-09-01

This paper describes the design specifications and performance of a real toroid-type high temperature superconducting (HTS) DC reactor. The HTS DC reactor was designed using 2G HTS wires. The HTS coils of the toroid-type DC reactor magnet were made in the form of a D-shape. The target inductance of the HTS DC reactor was 400 mH. The expected operating temperature was under 20 K. The electromagnetic performance of the toroid-type HTS DC reactor magnet was analyzed using the finite element method program. A conduction cooling method was adopted for reactor magnet cooling. Performances of the toroid-type HTS DC reactor were analyzed through experiments conducted under the steady-state and charge conditions. The fundamental design specifications and the data obtained from this research will be applied to the design of a commercial-type HTS DC reactor.

Electronic Switch Arrays for Managing Microbattery Arrays

NASA Technical Reports Server (NTRS)

Mojarradi, Mohammad; Alahmad, Mahmoud; Sukumar, Vinesh; Zghoul, Fadi; Buck, Kevin; Hess, Herbert; Li, Harry; Cox, David

2008-01-01

Integrated circuits have been invented for managing the charging and discharging of such advanced miniature energy-storage devices as planar arrays of microscopic energy-storage elements [typically, microscopic electrochemical cells (microbatteries) or microcapacitors]. The architecture of these circuits enables implementation of the following energy-management options: dynamic configuration of the elements of an array into a series or parallel combination of banks (subarrarys), each array comprising a series of parallel combination of elements; direct addressing of individual banks for charging/or discharging; and, disconnection of defective elements and corresponding reconfiguration of the rest of the array to utilize the remaining functional elements to obtain the desited voltage and current performance. An integrated circuit according to the invention consists partly of a planar array of field-effect transistors that function as switches for routing electric power among the energy-storage elements, the power source, and the load. To connect the energy-storage elements to the power source for charging, a specific subset of switches is closed; to connect the energy-storage elements to the load for discharging, a different specific set of switches is closed. Also included in the integrated circuit is circuitry for monitoring and controlling charging and discharging. The control and monitoring circuitry, the switching transistors, and interconnecting metal lines are laid out on the integrated-circuit chip in a pattern that registers with the array of energy-storage elements. There is a design option to either (1) fabricate the energy-storage elements in the corresponding locations on, and as an integral part of, this integrated circuit; or (2) following a flip-chip approach, fabricate the array of energy-storage elements on a separate integrated-circuit chip and then align and bond the two chips together.

Graphic design of pinhole cameras

NASA Technical Reports Server (NTRS)

Edwards, H. B.; Chu, W. P.

1979-01-01

The paper describes a graphic technique for the analysis and optimization of pinhole size and focal length. The technique is based on the use of the transfer function of optical elements described by Scott (1959) to construct the transfer function of a circular pinhole camera. This transfer function is the response of a component or system to a pattern of lines having a sinusoidally varying radiance at varying spatial frequencies. Some specific examples of graphic design are presented.

Deep Borehole Disposal Safety Analysis.

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

Freeze, Geoffrey A.; Stein, Emily; Price, Laura L.

This report presents a preliminary safety analysis for the deep borehole disposal (DBD) concept, using a safety case framework. A safety case is an integrated collection of qualitative and quantitative arguments, evidence, and analyses that substantiate the safety, and the level of confidence in the safety, of a geologic repository. This safety case framework for DBD follows the outline of the elements of a safety case, and identifies the types of information that will be required to satisfy these elements. At this very preliminary phase of development, the DBD safety case focuses on the generic feasibility of the DBD concept.more » It is based on potential system designs, waste forms, engineering, and geologic conditions; however, no specific site or regulatory framework exists. It will progress to a site-specific safety case as the DBD concept advances into a site-specific phase, progressing through consent-based site selection and site investigation and characterization.« less

Flexible Learning Itineraries Based on Conceptual Maps

ERIC Educational Resources Information Center

Agudelo, Olga Lucía; Salinas, Jesús

2015-01-01

The use of learning itineraries based on conceptual maps is studied in order to propose a more flexible instructional design that strengthens the learning process focused on the student, generating non-linear processes, characterising its elements, setting up relationships between them and shaping a general model with specifications for each…

A pedagogical model for integrative training in conservation and sustainability

Treesearch

Meredith Welch-Devine; Dean Hardy; J. Peter Brosius; Nik Heynen

2014-01-01

The benefits and challenges of interdisciplinary training are well documented, and several reviews have discussed the particular importance of interdisciplinary training for conservation scholars and practitioners. We discuss the progress within one university program to implement specific training models, elements, and tools designed to move beyond remaining barriers...

Instructional Systems for Student Learning: The Burlington County College Approach.

ERIC Educational Resources Information Center

Evans, N. Dean, Ed.

Since its inception in 1969, Burlington County College (New Jersey) has been dedicated to implementing a systematically designed approach to instruction and student learning. The core elements of the approach are as follows: (1) development of a basic college philosophy; (2) specification of general institutional objectives; (3) selection of…

36 CFR 1234.10 - What are the facility requirements for all records storage facilities?

Code of Federal Regulations, 2014 CFR

2014-07-01

... the HVAC systems, fire alarm and fire protection systems. Manual switching between sources of service... elements are protected by a properly installed, properly maintained wet-pipe automatic sprinkler system, as... must provide documentation that the facility has a fire suppression system specifically designed to...

10 CFR 52.47 - Contents of applications; technical information.

Code of Federal Regulations, 2013 CFR

2013-01-01

... accidents, e.g., challenges to containment integrity caused by core-concrete interaction, steam explosion... such as the service water intake structure and the ultimate heat sink; (2) An application for... design except for site-specific elements such as the service water intake structure and the ultimate heat...

10 CFR 52.47 - Contents of applications; technical information.

Code of Federal Regulations, 2010 CFR

2010-01-01

... accidents, e.g., challenges to containment integrity caused by core-concrete interaction, steam explosion... such as the service water intake structure and the ultimate heat sink; (2) An application for... design except for site-specific elements such as the service water intake structure and the ultimate heat...

10 CFR 52.47 - Contents of applications; technical information.

Code of Federal Regulations, 2011 CFR

2011-01-01

... accidents, e.g., challenges to containment integrity caused by core-concrete interaction, steam explosion... such as the service water intake structure and the ultimate heat sink; (2) An application for... design except for site-specific elements such as the service water intake structure and the ultimate heat...

10 CFR 52.47 - Contents of applications; technical information.

Code of Federal Regulations, 2014 CFR

2014-01-01

... accidents, e.g., challenges to containment integrity caused by core-concrete interaction, steam explosion... such as the service water intake structure and the ultimate heat sink; (2) An application for... design except for site-specific elements such as the service water intake structure and the ultimate heat...

10 CFR 52.47 - Contents of applications; technical information.

Code of Federal Regulations, 2012 CFR

2012-01-01

... accidents, e.g., challenges to containment integrity caused by core-concrete interaction, steam explosion... such as the service water intake structure and the ultimate heat sink; (2) An application for... design except for site-specific elements such as the service water intake structure and the ultimate heat...

Principal Development: Self-Directed Project Efficacy

ERIC Educational Resources Information Center

Piggot-Irvine, Eileen

2011-01-01

The inclusion of self-directed projects as an element within a New Zealand principal development programme was designed to reflect increasing support internationally for such a context-specific "inquiry" approach. The results reported in this article suggest that considerable clarity is required for such projects if they are to realize…

RANDOMIZATION PROCEDURES FOR THE ANALYSIS OF EDUCATIONAL EXPERIMENTS.

ERIC Educational Resources Information Center

COLLIER, RAYMOND O.

CERTAIN SPECIFIC ASPECTS OF HYPOTHESIS TESTS USED FOR ANALYSIS OF RESULTS IN RANDOMIZED EXPERIMENTS WERE STUDIED--(1) THE DEVELOPMENT OF THE THEORETICAL FACTOR, THAT OF PROVIDING INFORMATION ON STATISTICAL TESTS FOR CERTAIN EXPERIMENTAL DESIGNS AND (2) THE DEVELOPMENT OF THE APPLIED ELEMENT, THAT OF SUPPLYING THE EXPERIMENTER WITH MACHINERY FOR…

GeoCARB design maturity and geostationary heritage

NASA Astrophysics Data System (ADS)

Sawyer, Kevin; Clark, Charles; Katz, Noah; Kumar, Jack; Nast, Ted; Palmer, Alice

2013-09-01

Our companion paper `Progress in development of Tropospheric Infrared Mapping Spectrometers (TIMS): geostationary greenhouse gas (GHG) application' describes geoCARB performance and science. Here we describe a geoCARB instrument design study leading to near PDR maturity. It is based on heritage geostationary (AIA and HMI on SDO, SBIRS GEO-1 and upcoming GLM on GOES-R as examples) and other (IRIS and NIRcam) flight instrumentation. Heritage work includes experience and well developed specifications for near a-thermal carbon fiber honeycomb composite optical benches and optical element mounting design forms that utilize a "family" of mounts for nearly any type of optical element. The geoCARB approach utilizes composite optical benches and bipod flexures to kinematically mount optics. Tooling for alignment and staking of all elements is integral to the design and is "removed before flight" for mass minimization. GeoCARB requires a cryogenic region for focal planes and spectrometers but front end optics and main structure are designed to run much warmer. A star tracker is used for geoCARB posteriori geolocation including pseudo-diurnal thermal distortion characterization. It is kinematically mounted by low conductance thermal isolators directly on to the low expansion high stiffness composite bench that defines the master optical surfaces including the scanning mirrors. The thermal load from the camera heads is routed away from the bench heat pipes. Use of kinematic mounting is advantageous for low thermal conduction designs. Honeycomb composites enable the design's low thermal mechanical distortions.

Integrating Cloud-Computing-Specific Model into Aircraft Design

NASA Astrophysics Data System (ADS)

Zhimin, Tian; Qi, Lin; Guangwen, Yang

Cloud Computing is becoming increasingly relevant, as it will enable companies involved in spreading this technology to open the door to Web 3.0. In the paper, the new categories of services introduced will slowly replace many types of computational resources currently used. In this perspective, grid computing, the basic element for the large scale supply of cloud services, will play a fundamental role in defining how those services will be provided. The paper tries to integrate cloud computing specific model into aircraft design. This work has acquired good results in sharing licenses of large scale and expensive software, such as CFD (Computational Fluid Dynamics), UG, CATIA, and so on.

The analysis of tensegrity structures for the design of a morphing wing

NASA Astrophysics Data System (ADS)

Moored, Keith W., III; Bart-Smith, Hilary

2005-05-01

Tensegrity structures have become of engineering interest in recent years, but very few have found practical use. This lack of integration is attributed to the lack of a well formulated design procedure. In this paper, a preliminary procedure is presented for developing morphing tensegrity structures that include actuating elements. To do this, the virtual work method has been modified to allow for individual actuation of struts and cables. A generalized connectivity matrix for a cantilever beam constructed from either a single 4-strut cell or multiple 4-strut cells has been developed. Global deflections resulting from actuation of specific elements have been calculated. Furthermore, the force density method is expanded to include a necessary upper bound condition such that a physically feasible structure can be designed. Finally, the importance of relative force density values on the overall shape of a structure comprising of multiple unit cells is discussed.

The Benefits of Nuclear Thermal Propulsion (NTP) in an Evolvable Mars Campaign

NASA Technical Reports Server (NTRS)

Borowski, Stanley K.; Mccurdy, David R.

2014-01-01

NTR: High thrust high specific impulse (2 x LOXLH2chemical) engine uses high power density fission reactor with enriched uranium fuel as thermal power source. Reactor heat is removed using H2propellant which is then exhausted to produce thrust. Conventional chemical engine LH2tanks, turbopumps, regenerative nozzles and radiation-cooled shirt extensions used --NTR is next evolutionary step in high performance liquid rocket engines During the Rover program, a common fuel element tie tube design was developed and used in the design of the 50 klbf Kiwi-B4E (1964), 75 klbf Phoebus-1B (1967), 250 klbf Phoebus-2A (June 1968), then back down to the 25 klbf Pewee engine (Nov-Dec 1968) NASA and DOE are using this same approach: design, build, ground then flight test a small engine using a common fuel element that is scalable to a larger 25 klbf thrust engine needed for human missions

A modified moment-fitted integration scheme for X-FEM applications with history-dependent material data

NASA Astrophysics Data System (ADS)

Zhang, Ziyu; Jiang, Wen; Dolbow, John E.; Spencer, Benjamin W.

2018-01-01

We present a strategy for the numerical integration of partial elements with the eXtended finite element method (X-FEM). The new strategy is specifically designed for problems with propagating cracks through a bulk material that exhibits inelasticity. Following a standard approach with the X-FEM, as the crack propagates new partial elements are created. We examine quadrature rules that have sufficient accuracy to calculate stiffness matrices regardless of the orientation of the crack with respect to the element. This permits the number of integration points within elements to remain constant as a crack propagates, and for state data to be easily transferred between successive discretizations. In order to maintain weights that are strictly positive, we propose an approach that blends moment-fitted weights with volume-fraction based weights. To demonstrate the efficacy of this simple approach, we present results from numerical tests and examples with both elastic and plastic material response.

An iterative synthetic approach to engineer a high-performing PhoB-specific reporter.

PubMed

Stoudenmire, Julie L; Essock-Burns, Tara; Weathers, Erena N; Solaimanpour, Sina; Mrázek, Jan; Stabb, Eric V

2018-05-11

Transcriptional reporters are common tools for analyzing either the transcription of a gene of interest or the activity of a specific transcriptional regulator. Unfortunately, the latter application has the shortcoming that native promoters did not evolve as optimal readouts for the activity of a particular regulator. We sought to synthesize an optimized transcriptional reporter for assessing PhoB activity, aiming for maximal "on" expression when PhoB is active, minimal background in the "off" state, and no control elements for other regulators. We designed specific sequences for promoter elements with appropriately spaced PhoB-binding sites, and at nineteen additional intervening nucleotide positions for which we did not predict sequence-specific effects the bases were randomized. Eighty-three such constructs were screened in Vibrio fischeri , enabling us to identify bases at particular randomized positions that significantly correlated with high "on" or low "off" expression. A second round of promoter design rationally constrained thirteen additional positions, leading to a reporter with high PhoB-dependent expression, essentially no background, and no other known regulatory elements. As expressed reporters, we used both stable and destabilized GFP, the latter with a half-life of eighty-one minutes in V. fischeri In culture, PhoB induced the reporter when phosphate was depleted below 10 μM. During symbiotic colonization of its host squid Euprymna scolopes , the reporter indicated heterogeneous phosphate availability in different light-organ microenvironments. Finally, testing this construct in other Proteobacteria demonstrated its broader utility. The results illustrate how a limited ability to predict synthetic promoter-reporter performance can be overcome through iterative screening and re-engineering. IMPORTANCE Transcriptional reporters can be powerful tools for assessing when a particular regulator is active; however, native promoters may not be ideal for this purpose. Optimal reporters should be specific to the regulator being examined and should maximize the difference between "on" and "off" states; however, these properties are distinct from the selective pressures driving the evolution of natural promoters. Synthetic promoters offer a promising alternative, but our understanding often does not enable fully predictive promoter design, and the large number of alternative sequence possibilities can be intractable. In a synthetic promoter region with over thirty-four billion sequence variants, we identified bases correlated with favorable performance by screening only eighty-three candidates, allowing us to rationally constrain our design. We thereby generated an optimized reporter that is induced by PhoB and used it to explore the low-phosphate response of V. fischeri This promoter-design strategy will facilitate the engineering of other regulator-specific reporters. Copyright © 2018 American Society for Microbiology.

Displacement Based Multilevel Structural Optimization

NASA Technical Reports Server (NTRS)

Sobieszezanski-Sobieski, J.; Striz, A. G.

1996-01-01

In the complex environment of true multidisciplinary design optimization (MDO), efficiency is one of the most desirable attributes of any approach. In the present research, a new and highly efficient methodology for the MDO subset of structural optimization is proposed and detailed, i.e., for the weight minimization of a given structure under size, strength, and displacement constraints. Specifically, finite element based multilevel optimization of structures is performed. In the system level optimization, the design variables are the coefficients of assumed polynomially based global displacement functions, and the load unbalance resulting from the solution of the global stiffness equations is minimized. In the subsystems level optimizations, the weight of each element is minimized under the action of stress constraints, with the cross sectional dimensions as design variables. The approach is expected to prove very efficient since the design task is broken down into a large number of small and efficient subtasks, each with a small number of variables, which are amenable to parallel computing.

Space Launch System Base Heating Test: Sub-Scale Rocket Engine/Motor Design, Development and Performance Analysis

NASA Technical Reports Server (NTRS)

Mehta, Manish; Seaford, Mark; Kovarik, Brian; Dufrene, Aaron; Solly, Nathan; Kirchner, Robert; Engel, Carl D.

2014-01-01

The Space Launch System (SLS) base heating test is broken down into two test programs: (1) Pathfinder and (2) Main Test. The Pathfinder Test Program focuses on the design, development, hot-fire test and performance analyses of the 2% sub-scale SLS core-stage and booster element propulsion systems. The core-stage propulsion system is composed of four gaseous oxygen/hydrogen RS-25D model engines and the booster element is composed of two aluminum-based model solid rocket motors (SRMs). The first section of the paper discusses the motivation and test facility specifications for the test program. The second section briefly investigates the internal flow path of the design. The third section briefly shows the performance of the model RS-25D engines and SRMs for the conducted short duration hot-fire tests. Good agreement is observed based on design prediction analysis and test data. This program is a challenging research and development effort that has not been attempted in 40+ years for a NASA vehicle.

Design and performance testing of an ultrasonic linear motor with dual piezoelectric actuators.

PubMed

Smithmaitrie, Pruittikorn; Suybangdum, Panumas; Laoratanakul, Pitak; Muensit, Nantakan

2012-05-01

In this work, design and performance testing of an ultrasonic linear motor with dual piezoelectric actuator patches are studied. The motor system consists of a linear stator, a pre-load weight, and two piezoelectric actuator patches. The piezoelectric actuators are bonded with the linear elastic stator at specific locations. The stator generates propagating waves when the piezoelectric actuators are subjected to harmonic excitations. Vibration characteristics of the linear stator are analyzed and compared with finite element and experimental results. The analytical, finite element, and experimental results show agreement. In the experiments, performance of the ultrasonic linear motor is tested. Relationships between velocity and pre-load weight, velocity and applied voltage, driving force and applied voltage, and velocity and driving force are reported. The design of the dual piezoelectric actuators yields a simpler structure with a smaller number of actuators and lower stator stiffness compared with a conventional design of an ultrasonic linear motor with fully laminated piezoelectric actuators.

Design and analysis of tubular permanent magnet linear generator for small-scale wave energy converter

NASA Astrophysics Data System (ADS)

Kim, Jeong-Man; Koo, Min-Mo; Jeong, Jae-Hoon; Hong, Keyyong; Cho, Il-Hyoung; Choi, Jang-Young

2017-05-01

This paper reports the design and analysis of a tubular permanent magnet linear generator (TPMLG) for a small-scale wave-energy converter. The analytical field computation is performed by applying a magnetic vector potential and a 2-D analytical model to determine design parameters. Based on analytical solutions, parametric analysis is performed to meet the design specifications of a wave-energy converter (WEC). Then, 2-D FEA is employed to validate the analytical method. Finally, the experimental result confirms the predictions of the analytical and finite element analysis (FEA) methods under regular and irregular wave conditions.

MapFactory - Towards a mapping design pattern for big geospatial data

NASA Astrophysics Data System (ADS)

Rautenbach, Victoria; Coetzee, Serena

2018-05-01

With big geospatial data emerging, cartographers and geographic information scientists have to find new ways of dealing with the volume, variety, velocity, and veracity (4Vs) of the data. This requires the development of tools that allow processing, filtering, analysing, and visualising of big data through multidisciplinary collaboration. In this paper, we present the MapFactory design pattern that will be used for the creation of different maps according to the (input) design specification for big geospatial data. The design specification is based on elements from ISO19115-1:2014 Geographic information - Metadata - Part 1: Fundamentals that would guide the design and development of the map or set of maps to be produced. The results of the exploratory research suggest that the MapFactory design pattern will help with software reuse and communication. The MapFactory design pattern will aid software developers to build the tools that are required to automate map making with big geospatial data. The resulting maps would assist cartographers and others to make sense of big geospatial data.

Passive front-ends for wideband millimeter wave electronic warfare

NASA Astrophysics Data System (ADS)

Jastram, Nathan Joseph

This thesis presents the analysis, design and measurements of novel passive front ends of interest to millimeter wave electronic warfare systems. However, emerging threats in the millimeter waves (18 GHz and above) has led to a push for new systems capable of addressing these threats. At these frequencies, traditional techniques of design and fabrication are challenging due to small size, limited bandwidth and losses. The use of surface micromachining technology for wideband direction finding with multiple element antenna arrays for electronic support is demonstrated. A wideband tapered slot antenna is first designed and measured as an array element for the subsequent arrays. Both 18--36 GHz and 75--110 GHz amplitude only and amplitude/phase two element direction finding front ends are designed and measured. The design of arrays using Butler matrix and Rotman lens beamformers for greater than two element direction finding over W band and beyond using is also presented. The design of a dual polarized high power capable front end for electronic attack over an 18--45 GHz band is presented. To combine two polarizations into the same radiating aperture, an orthomode transducer (OMT) based upon a new double ridge waveguide cross section is developed. To provide greater flexibility in needed performance characteristics, several different turnstile junction matching sections are tested. A modular horn section is proposed to address flexible and ever changing operational requirements, and is designed for performance criteria such as constant gain, beamwidth, etc. A multi-section branch guide coupler and low loss Rotman lens based upon the proposed cross section are also developed. Prototyping methods for the herein designed millimeter wave electronic warfare front ends are investigated. Specifically, both printed circuit board (PCB) prototyping of micromachined systems and 3D printing of conventionally machined horns are presented. A 4--8 GHz two element array with integrated beamformer fabricated using the stacking of PCB boards is shown, and measured results compare favorably with the micromachined front ends. A 3D printed small aperture horn is compared with a conventionally machined horn, and measured results show similar performance with a ten-fold reduction in cost and weight.

Measure Guideline: Incorporating Thick Layers of Exterior Rigid Insulation on Walls

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

Lstiburek, Joseph; Baker, Peter

This measure guideline provides information about the design and construction of wall assemblies that use layers of rigid exterior insulation thicker than 1-½ inches and that require a secondary cladding attachment location exterior to the insulation. The guideline is separated into several distinct sections that cover: fundamental building science principles relating to the use of exterior insulation on wall assemblies; design principles for tailoring this use to the specific project goals and requirements; and construction detailing to increase understanding about implementing the various design elements.

Fuzzy compromise: An effective way to solve hierarchical design problems

NASA Technical Reports Server (NTRS)

Allen, J. K.; Krishnamachari, R. S.; Masetta, J.; Pearce, D.; Rigby, D.; Mistree, F.

1990-01-01

In this paper, we present a method for modeling design problems using a compromise decision support problem (DSP) incorporating the principles embodied in fuzzy set theory. Specifically, the fuzzy compromise decision support problem is used to study hierarchical design problems. This approach has the advantage that although the system modeled has an element of uncertainty associated with it, the solution obtained is crisp and precise. The efficacy of incorporating fuzzy sets into the solution process is discussed in the context of results obtained for a portal frame.

Creation of Anatomically Accurate Computer-Aided Design (CAD) Solid Models from Medical Images

NASA Technical Reports Server (NTRS)

Stewart, John E.; Graham, R. Scott; Samareh, Jamshid A.; Oberlander, Eric J.; Broaddus, William C.

1999-01-01

Most surgical instrumentation and implants used in the world today are designed with sophisticated Computer-Aided Design (CAD)/Computer-Aided Manufacturing (CAM) software. This software automates the mechanical development of a product from its conceptual design through manufacturing. CAD software also provides a means of manipulating solid models prior to Finite Element Modeling (FEM). Few surgical products are designed in conjunction with accurate CAD models of human anatomy because of the difficulty with which these models are created. We have developed a novel technique that creates anatomically accurate, patient specific CAD solids from medical images in a matter of minutes.

Mammographic x-ray unit kilovoltage test tool based on k-edge absorption effect.

PubMed

Napolitano, Mary E; Trueblood, Jon H; Hertel, Nolan E; David, George

2002-09-01

A simple tool to determine the peak kilovoltage (kVp) of a mammographic x-ray unit has been designed. Tool design is based on comparing the effect of k-edge discontinuity of the attenuation coefficient for a series of element filters. Compatibility with the mammography accreditation phantom (MAP) to obtain a single quality control film is a second design objective. When the attenuation of a series of sequential elements is studied simultaneously, differences in the absorption characteristics due to the k-edge discontinuities are more evident. Specifically, when the incident photon energy is higher than the k-edge energy of a number of the elements and lower than the remainder, an inflection may be seen in the resulting attenuation data. The maximum energy of the incident photon spectra may be determined based on this inflection point for a series of element filters. Monte Carlo photon transport analysis was used to estimate the photon transmission probabilities for each of the sequential k-edge filter elements. The photon transmission corresponds directly to optical density recorded on mammographic x-ray film. To observe the inflection, the element filters chosen must have k-edge energies that span a range greater than the expected range of the end point energies to be determined. For the design, incident x-ray spectra ranging from 25 to 40 kVp were assumed to be from a molybdenum target. Over this range, the k-edge energy changes by approximately 1.5 keV between sequential elements. For this design 21 elements spanning an energy range from 20 to 50 keV were chosen. Optimum filter element thicknesses were calculated to maximize attenuation differences at the k-edge while maintaining optical densities between 0.10 and 3.00. Calculated relative transmission data show that the kVp could be determined to within +/-1 kV. To obtain experimental data, a phantom was constructed containing 21 different elements placed in an acrylic holder. MAP images were used to determine appropriate exposure techniques for a series of end point energies from 25 to 35 kVp. The average difference between the kVp determination and the calibrated dial setting was 0.8 and 1.0 kV for a Senographe 600 T and a Senographe DMR, respectively. Since the k-edge absorption energies of the filter materials are well known, independent calibration or a series of calibration curves is not required.

Nuclear Thermal Propulsion Mars Mission Systems Analysis and Requirements Definition

NASA Technical Reports Server (NTRS)

Mulqueen, Jack; Chiroux, Robert C.; Thomas, Dan; Crane, Tracie

2007-01-01

This paper describes the Mars transportation vehicle design concepts developed by the Marshall Space Flight Center (MSFC) Advanced Concepts Office. These vehicle design concepts provide an indication of the most demanding and least demanding potential requirements for nuclear thermal propulsion systems for human Mars exploration missions from years 2025 to 2035. Vehicle concept options vary from large "all-up" vehicle configurations that would transport all of the elements for a Mars mission on one vehicle. to "split" mission vehicle configurations that would consist of separate smaller vehicles that would transport cargo elements and human crew elements to Mars separately. Parametric trades and sensitivity studies show NTP stage and engine design options that provide the best balanced set of metrics based on safety, reliability, performance, cost and mission objectives. Trade studies include the sensitivity of vehicle performance to nuclear engine characteristics such as thrust, specific impulse and nuclear reactor type. Tbe associated system requirements are aligned with the NASA Exploration Systems Mission Directorate (ESMD) Reference Mars mission as described in the Explorations Systems Architecture Study (ESAS) report. The focused trade studies include a detailed analysis of nuclear engine radiation shield requirements for human missions and analysis of nuclear thermal engine design options for the ESAS reference mission.

Design and Validation of a 150 MHz HFFQCM Sensor for Bio-Sensing Applications

PubMed Central

Fernández, Román; García, Pablo; García, María; Jiménez, Yolanda; Arnau, Antonio

2017-01-01

Acoustic wave resonators have become suitable devices for a broad range of sensing applications due to their sensitivity, low cost, and integration capability, which are all factors that meet the requirements for the resonators to be used as sensing elements for portable point of care (PoC) platforms. In this work, the design, characterization, and validation of a 150 MHz high fundamental frequency quartz crystal microbalance (HFF-QCM) sensor for bio-sensing applications are introduced. Finite element method (FEM) simulations of the proposed design are in good agreement with the electrical characterization of the manufactured resonators. The sensor is also validated for bio-sensing applications. For this purpose, a specific sensor cell was designed and manufactured that addresses the critical requirements associated with this type of sensor and application. Due to the small sensing area and the sensor’s fragility, these requirements include a low-volume flow chamber in the nanoliter range, and a system approach that provides the appropriate pressure control for assuring liquid confinement while maintaining the integrity of the sensor with a good base line stability and easy sensor replacement. The sensor characteristics make it suitable for consideration as the elemental part of a sensor matrix in a multichannel platform for point of care applications. PMID:28885551

Flexible Models for Solar Sail Control

NASA Technical Reports Server (NTRS)

Weaver Smith, Suzanne; Song, Haiping; Baker, John R.; Black, Jonathan; Muheim, Danniella M.

2005-01-01

Solar sails employ a unique form of propulsion, gaining momentum from incident and reflected photons. However, the momentum transferred by an individual photon is extremely small. Consequently, a solar sail must have an extremely large surface area and also be extremely light. The flexibility of the sail then must be considered when designing or evaluating control laws. In this paper, solar sail flexibility and its influence on control effectiveness is considered using idealized two-dimensional models to represent physical phenomena rather than a specific design. Differential equations of motion are derived for a distributed parameter model of a flexible solar sail idealized as a rotating central hub with two opposing flexible booms. This idealization is appropriate for solar sail designs in which the vibrational modes of the sail and supporting booms move together allowing the sail mass to be distributed along the booms in the idealized model. A reduced analytical model of the flexible response is considered. Linear feedback torque control is applied at the central hub. Two translational disturbances and a torque disturbance also act at the central hub representing the equivalent effect of deflecting sail shape about a reference line. Transient simulations explore different control designs and their effectiveness for controlling orientation, for reducing flexible motion and for disturbance rejection. A second model also is developed as a two-dimensional "pathfinder" model to calculate the effect of solar sail shape on the resultant thrust, in-plane force and torque at the hub. The analysis is then extended to larger models using the finite element method. The finite element modeling approach is verified by comparing results from a two-dimensional finite element model with those from the analytical model. The utility of the finite element modeling approach for this application is then illustrated through examples based on a full finite element model.

Creating Shape Templates for Patient Specific Biventricular Modeling in Congenital Heart Disease

PubMed Central

Gilbert, Kathleen; Farrar, Genevieve; Cowan, Brett R.; Suinesiaputra, Avan; Occleshaw, Christopher; Pontré, Beau; Perry, James; Hegde, Sanjeet; Marsden, Alison; Omens, Jeff; McCulloch, Andrew; Young, Alistair A.

2018-01-01

Survival rates for infants with congenital heart disease (CHD) are improving, resulting in a growing population of adults with CHD. However, the analysis of left and right ventricular function is very time-consuming owing to the variety of congenital morphologies. Efficient customization of patient geometry and function depends on high quality shape templates specifically designed for the application. In this paper, we combine a method for creating finite element shape templates with an interactive template customization to patient MRI examinations. This enables different templates to be chosen depending on patient morphology. To demonstrate this pipeline, a new biventricular template with 162 elements was created and tested in place of an existing 82-element template. The method was able to provide fast interactive biventricular analysis with 0.31 sec per edit response time. The new template was customized to 13 CHD patients with similar biventricular topology, showing improved performance over the previous template and good agreement with clinical indices. PMID:26736353

Advances and trends in structures and dynamics; Proceedings of the Symposium, Washington, DC, October 22-25, 1984

NASA Technical Reports Server (NTRS)

Noor, A. K. (Editor); Hayduk, R. J. (Editor)

1985-01-01

Among the topics discussed are developments in structural engineering hardware and software, computation for fracture mechanics, trends in numerical analysis and parallel algorithms, mechanics of materials, advances in finite element methods, composite materials and structures, determinations of random motion and dynamic response, optimization theory, automotive tire modeling methods and contact problems, the damping and control of aircraft structures, and advanced structural applications. Specific topics covered include structural design expert systems, the evaluation of finite element system architectures, systolic arrays for finite element analyses, nonlinear finite element computations, hierarchical boundary elements, adaptive substructuring techniques in elastoplastic finite element analyses, automatic tracking of crack propagation, a theory of rate-dependent plasticity, the torsional stability of nonlinear eccentric structures, a computation method for fluid-structure interaction, the seismic analysis of three-dimensional soil-structure interaction, a stress analysis for a composite sandwich panel, toughness criterion identification for unidirectional composite laminates, the modeling of submerged cable dynamics, and damping synthesis for flexible spacecraft structures.

Learning and Recognition of Clothing Genres From Full-Body Images.

PubMed

Hidayati, Shintami C; You, Chuang-Wen; Cheng, Wen-Huang; Hua, Kai-Lung

2018-05-01

According to the theory of clothing design, the genres of clothes can be recognized based on a set of visually differentiable style elements, which exhibit salient features of visual appearance and reflect high-level fashion styles for better describing clothing genres. Instead of using less-discriminative low-level features or ambiguous keywords to identify clothing genres, we proposed a novel approach for automatically classifying clothing genres based on the visually differentiable style elements. A set of style elements, that are crucial for recognizing specific visual styles of clothing genres, were identified based on the clothing design theory. In addition, the corresponding salient visual features of each style element were identified and formulated with variables that can be computationally derived with various computer vision algorithms. To evaluate the performance of our algorithm, a dataset containing 3250 full-body shots crawled from popular online stores was built. Recognition results show that our proposed algorithms achieved promising overall precision, recall, and -score of 88.76%, 88.53%, and 88.64% for recognizing upperwear genres, and 88.21%, 88.17%, and 88.19% for recognizing lowerwear genres, respectively. The effectiveness of each style element and its visual features on recognizing clothing genres was demonstrated through a set of experiments involving different sets of style elements or features. In summary, our experimental results demonstrate the effectiveness of the proposed method in clothing genre recognition.

47 CFR 51.509 - Rate structure standards for specific elements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 3 2014-10-01 2014-10-01 false Rate structure standards for specific elements... SERVICES (CONTINUED) INTERCONNECTION Pricing of Elements § 51.509 Rate structure standards for specific elements. In addition to the general rules set forth in § 51.507, rates for specific elements shall comply...

47 CFR 51.509 - Rate structure standards for specific elements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 3 2012-10-01 2012-10-01 false Rate structure standards for specific elements... SERVICES (CONTINUED) INTERCONNECTION Pricing of Elements § 51.509 Rate structure standards for specific elements. In addition to the general rules set forth in § 51.507, rates for specific elements shall comply...

47 CFR 51.509 - Rate structure standards for specific elements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 3 2010-10-01 2010-10-01 false Rate structure standards for specific elements... SERVICES (CONTINUED) INTERCONNECTION Pricing of Elements § 51.509 Rate structure standards for specific elements. In addition to the general rules set forth in § 51.507, rates for specific elements shall comply...

47 CFR 51.509 - Rate structure standards for specific elements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 3 2011-10-01 2011-10-01 false Rate structure standards for specific elements... SERVICES (CONTINUED) INTERCONNECTION Pricing of Elements § 51.509 Rate structure standards for specific elements. In addition to the general rules set forth in § 51.507, rates for specific elements shall comply...

47 CFR 51.509 - Rate structure standards for specific elements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 3 2013-10-01 2013-10-01 false Rate structure standards for specific elements... SERVICES (CONTINUED) INTERCONNECTION Pricing of Elements § 51.509 Rate structure standards for specific elements. In addition to the general rules set forth in § 51.507, rates for specific elements shall comply...

Design, fabrication and characterization of Computer Generated Holograms for anti-counterfeiting applications using OAM beams as light decoders.

PubMed

Ruffato, Gianluca; Rossi, Roberto; Massari, Michele; Mafakheri, Erfan; Capaldo, Pietro; Romanato, Filippo

2017-12-21

In this paper, we present the design, fabrication and optical characterization of computer-generated holograms (CGH) encoding information for light beams carrying orbital angular momentum (OAM). Through the use of a numerical code, based on an iterative Fourier transform algorithm, a phase-only diffractive optical element (PO-DOE) specifically designed for OAM illumination has been computed, fabricated and tested. In order to shape the incident beam into a helicoidal phase profile and generate light carrying phase singularities, a method based on transmission through high-order spiral phase plates (SPPs) has been used. The phase pattern of the designed holographic DOEs has been fabricated using high-resolution Electron-Beam Lithography (EBL) over glass substrates coated with a positive photoresist layer (polymethylmethacrylate). To the best of our knowledge, the present study is the first attempt, in a comprehensive work, to design, fabricate and characterize computer-generated holograms encoding information for structured light carrying OAM and phase singularities. These optical devices appear promising as high-security optical elements for anti-counterfeiting applications.

Low Cost Nuclear Thermal Rocket Cermet Fuel Element Environment Testing

NASA Technical Reports Server (NTRS)

Bradley, David E.; Mireles, Omar R.; Hickman, Robert R.

2011-01-01

Deep space missions with large payloads require high specific impulse (Isp) and relatively high thrust in order to achieve mission goals in reasonable time frames. Conventional, storable propellants produce average Isp. Nuclear thermal rockets (NTR) capable of high Isp thrust have been proposed. NTR employs heat produced by fission reaction to heat and therefore accelerate hydrogen which is then forced through a rocket nozzle providing thrust. Fuel element temperatures are very high (up to 3000K) and hydrogen is highly reactive with most materials at high temperatures. Data covering the effects of high temperature hydrogen exposure on fuel elements is limited. The primary concern is the mechanical failure of fuel elements which employ high-melting-point metals, ceramics or a combination (cermet) as a structural matrix into which the nuclear fuel is distributed. It is not necessary to include fissile material in test samples intended to explore high temperature hydrogen exposure of the structural support matrices. A small-scale test bed designed to heat fuel element samples via non-contact RF heating and expose samples to hydrogen is being developed to assist in optimal material and manufacturing process selection without employing fissile material. This paper details the test bed design and results of testing conducted to date.

Compact Fuel Element Environment Test

NASA Technical Reports Server (NTRS)

Bradley, D. E.; Mireles, O. R.; Hickman, R. R.; Broadway, J. W.

2012-01-01

Deep space missions with large payloads require high specific impulse (I(sub sp)) and relatively high thrust to achieve mission goals in reasonable time frames. Conventional, storable propellants produce average I(sub sp). Nuclear thermal rockets (NTRs) capable of high I(sub sp) thrust have been proposed. NTR employs heat produced by fission reaction to heat and therefore accelerate hydrogen, which is then forced through a rocket nozzle providing thrust. Fuel element temperatures are very high (up to 3,000 K) and hydrogen is highly reactive with most materials at high temperatures. Data covering the effects of high-temperature hydrogen exposure on fuel elements are limited. The primary concern is the mechanical failure of fuel elements that employ high melting point metals, ceramics, or a combination (cermet) as a structural matrix into which the nuclear fuel is distributed. It is not necessary to include fissile material in test samples intended to explore high-temperature hydrogen exposure of the structural support matrices. A small-scale test bed designed to heat fuel element samples via noncontact radio frequency heating and expose samples to hydrogen for typical mission durations has been developed to assist in optimal material and manufacturing process selection without employing fissile material. This Technical Memorandum details the test bed design and results of testing conducted to date.

Designing patient-specific 3D printed craniofacial implants using a novel topology optimization method.

PubMed

Sutradhar, Alok; Park, Jaejong; Carrau, Diana; Nguyen, Tam H; Miller, Michael J; Paulino, Glaucio H

2016-07-01

Large craniofacial defects require efficient bone replacements which should not only provide good aesthetics but also possess stable structural function. The proposed work uses a novel multiresolution topology optimization method to achieve the task. Using a compliance minimization objective, patient-specific bone replacement shapes can be designed for different clinical cases that ensure revival of efficient load transfer mechanisms in the mid-face. In this work, four clinical cases are introduced and their respective patient-specific designs are obtained using the proposed method. The optimized designs are then virtually inserted into the defect to visually inspect the viability of the design . Further, once the design is verified by the reconstructive surgeon, prototypes are fabricated using a 3D printer for validation. The robustness of the designs are mechanically tested by subjecting them to a physiological loading condition which mimics the masticatory activity. The full-field strain result through 3D image correlation and the finite element analysis implies that the solution can survive the maximum mastication of 120 lb. Also, the designs have the potential to restore the buttress system and provide the structural integrity. Using the topology optimization framework in designing the bone replacement shapes would deliver surgeons new alternatives for rather complicated mid-face reconstruction.

Network operating system focus technology

NASA Technical Reports Server (NTRS)

1985-01-01

An activity structured to provide specific design requirements and specifications for the Space Station Data Management System (DMS) Network Operating System (NOS) is outlined. Examples are given of the types of supporting studies and implementation tasks presently underway to realize a DMS test bed capability to develop hands-on understanding of NOS requirements as driven by actual subsystem test beds participating in the overall Johnson Space Center test bed program. Classical operating system elements and principal NOS functions are listed.

Thermomechanical analysis of fast-burst reactors

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

Miller, J.D.

1994-08-01

Fast-burst reactors are designed to provide intense, short-duration pulses of neutrons. The fission reaction also produces extreme time-dependent heating of the nuclear fuel. An existing transient-dynamic finite element code was modified specifically to compute the time-dependent stresses and displacements due to thermal shock loads of reactors. Thermomechanical analysis was then applied to determine structural feasibility of various concepts for an EDNA-type reactor and to optimize the mechanical design of the new SPR III-M reactor.

Human Mars Ascent Vehicle Performance Sensitivities

NASA Technical Reports Server (NTRS)

Polsgrove, Tara P.; Thomas, Herbert D.

2016-01-01

Human Mars mission architecture studies have shown that the ascent vehicle mass drives performance requirements for the descent and in-space transportation elements. Understanding the sensitivity of Mars ascent vehicle (MAV) mass to various mission and vehicle design choices enables overall transportation system optimization. This paper presents the results of a variety of sensitivity trades affecting MAV performance including: landing site latitude, target orbit, initial thrust to weight ratio, staging options, specific impulse, propellant type and engine design.

Automated Antenna Design with Evolutionary Algorithms

NASA Technical Reports Server (NTRS)

Hornby, Gregory S.; Globus, Al; Linden, Derek S.; Lohn, Jason D.

2006-01-01

Current methods of designing and optimizing antennas by hand are time and labor intensive, and limit complexity. Evolutionary design techniques can overcome these limitations by searching the design space and automatically finding effective solutions. In recent years, evolutionary algorithms have shown great promise in finding practical solutions in large, poorly understood design spaces. In particular, spacecraft antenna design has proven tractable to evolutionary design techniques. Researchers have been investigating evolutionary antenna design and optimization since the early 1990s, and the field has grown in recent years as computer speed has increased and electromagnetic simulators have improved. Two requirements-compliant antennas, one for ST5 and another for TDRS-C, have been automatically designed by evolutionary algorithms. The ST5 antenna is slated to fly this year, and a TDRS-C phased array element has been fabricated and tested. Such automated evolutionary design is enabled by medium-to-high quality simulators and fast modern computers to evaluate computer-generated designs. Evolutionary algorithms automate cut-and-try engineering, substituting automated search though millions of potential designs for intelligent search by engineers through a much smaller number of designs. For evolutionary design, the engineer chooses the evolutionary technique, parameters and the basic form of the antenna, e.g., single wire for ST5 and crossed-element Yagi for TDRS-C. Evolutionary algorithms then search for optimal configurations in the space defined by the engineer. NASA's Space Technology 5 (ST5) mission will launch three small spacecraft to test innovative concepts and technologies. Advanced evolutionary algorithms were used to automatically design antennas for ST5. The combination of wide beamwidth for a circularly-polarized wave and wide impedance bandwidth made for a challenging antenna design problem. From past experience in designing wire antennas, we chose to constrain the evolutionary design to a monopole wire antenna. The results of the runs produced requirements-compliant antennas that were subsequently fabricated and tested. The evolved antenna has a number of advantages with regard to power consumption, fabrication time and complexity, and performance. Lower power requirements result from achieving high gain across a wider range of elevation angles, thus allowing a broader range of angles over which maximum data throughput can be achieved. Since the evolved antenna does not require a phasing circuit, less design and fabrication work is required. In terms of overall work, the evolved antenna required approximately three person-months to design and fabricate whereas the conventional antenna required about five. Furthermore, when the mission was modified and new orbital parameters selected, a redesign of the antenna to new requirements was required. The evolutionary system was rapidly modified and a new antenna evolved in a few weeks. The evolved antenna was shown to be compliant to the ST5 mission requirements. It has an unusual organic looking structure, one that expert antenna designers would not likely produce. This antenna has been tested, baselined and is scheduled to fly this year. In addition to the ST5 antenna, our laboratory has evolved an S-band phased array antenna element design that meets the requirements for NASA's TDRS-C communications satellite scheduled for launch early next decade. A combination of fairly broad bandwidth, high efficiency and circular polarization at high gain made for another challenging design problem. We chose to constrain the evolutionary design to a crossed-element Yagi antenna. The specification called for two types of elements, one for receive only and one for transmit/receive. We were able to evolve a single element design that meets both specifications thereby simplifying the antenna and reducing testing and integration costs. The highest performance antenna found using a getic algorithm and stochastic hill-climbing has been fabricated and tested. Laboratory results correspond well with simulation. Aerospace component design is an expensive and important step in space development. Evolutionary design can make a significant contribution wherever sufficiently fast, accurate and capable software simulators are available. We have demonstrated successful real-world design in the spacecraft antenna domain; and there is good reason to believe that these results could be replicated in other design spaces.

Key Topics for High-Lift Research: A Joint Wind Tunnel/Flight Test Approach

NASA Technical Reports Server (NTRS)

Fisher, David; Thomas, Flint O.; Nelson, Robert C.

1996-01-01

Future high-lift systems must achieve improved aerodynamic performance with simpler designs that involve fewer elements and reduced maintenance costs. To expeditiously achieve this, reliable CFD design tools are required. The development of useful CFD-based design tools for high lift systems requires increased attention to unresolved flow physics issues. The complex flow field over any multi-element airfoil may be broken down into certain generic component flows which are termed high-lift building block flows. In this report a broad spectrum of key flow field physics issues relevant to the design of improved high lift systems are considered. It is demonstrated that in-flight experiments utilizing the NASA Dryden Flight Test Fixture (which is essentially an instrumented ventral fin) carried on an F-15B support aircraft can provide a novel and cost effective method by which both Reynolds and Mach number effects associated with specific high lift building block flows can be investigated. These in-flight high lift building block flow experiments are most effective when performed in conjunction with coordinated ground based wind tunnel experiments in low speed facilities. For illustrative purposes three specific examples of in-flight high lift building block flow experiments capable of yielding a high payoff are described. The report concludes with a description of a joint wind tunnel/flight test approach to high lift aerodynamics research.

A programmable nonlinear acoustic metamaterial

NASA Astrophysics Data System (ADS)

Yang, Tianzhi; Song, Zhi-Guang; Clerkin, Eoin; Zhang, Ye-Wei; Sun, Jia-He; Su, Yi-Shu; Chen, Li-Qun; Hagedorn, Peter

2017-09-01

Acoustic metamaterials with specifically designed lattices can manipulate acoustic/elastic waves in unprecedented ways. Whereas there are many studies that focus on passive linear lattice, with non-reconfigurable structures. In this letter, we present the design, theory and experimental demonstration of an active nonlinear acoustic metamaterial, the dynamic properties of which can be modified instantaneously with reversibility. By incorporating active and nonlinear elements in a single unit cell, a real-time tunability and switchability of the band gap is achieved. In addition, we demonstrate a dynamic "editing" capability for shaping transmission spectra, which can be used to create the desired band gap and resonance. This feature is impossible to achieve in passive metamaterials. These advantages demonstrate the versatility of the proposed device, paving the way toward smart acoustic devices, such as logic elements, diode and transistor.

Piezoelectric Actuator with Frequency Characteristics for a Middle-Ear Implant.

PubMed

Shin, Dong Ho; Cho, Jin-Ho

2018-05-24

The design and implementation of a novel piezoelectric-based actuator for an implantable middle-ear hearing aid is described in this paper. The proposed actuator has excellent low-frequency output characteristics, and can generate high output in a specific frequency band by adjusting the mechanical resonance. The actuator consists of a piezoelectric element, a miniature bellows, a cantilever membrane, a metal ring support, a ceramic tip, and titanium housing. The optimal structure of the cantilever-membrane design, which determines the frequency characteristics of the piezoelectric actuator, was derived through finite element analysis. Based on the results, the piezoelectric actuator was implemented, and its performance was verified through a cadaveric experiment. It was confirmed that the proposed actuator provides better performance than currently used actuators, in terms of frequency characteristics.

Using computer graphics to design Space Station Freedom viewing

NASA Technical Reports Server (NTRS)

Goldsberry, B. S.; Lippert, B. O.; Mckee, S. D.; Lewis, J. L., Jr.; Mount, F. E.

1989-01-01

An important aspect of planning for Space Station Freedom at the United States National Aeronautics and Space Administration (NASA) is the placement of the viewing windows and cameras for optimum crewmember use. Researchers and analysts are evaluating the placement options using a three-dimensional graphics program called PLAID. This program, developed at the NASA Johnson Space Center (JSC), is being used to determine the extent to which the viewing requirements for assembly and operations are being met. A variety of window placement options in specific modules are assessed for accessibility. In addition, window and camera placements are analyzed to insure that viewing areas are not obstructed by the truss assemblies, externally-mounted payloads, or any other station element. Other factors being examined include anthropometric design considerations, workstation interfaces, structural issues, and mechanical elements.

The Liquid Annular Reactor System (LARS) propulsion

NASA Technical Reports Server (NTRS)

Powell, James; Ludewig, Hans; Horn, Frederick; Lenard, Roger

1990-01-01

A concept for very high specific impulse (greater than 2000 seconds) direct nuclear propulsion is described. The concept, termed the liquid annular reactor system (LARS), uses liquid nuclear fuel elements to heat hydrogen propellant to very high temperatures (approximately 6000 K). Operating pressure is moderate (approximately 10 atm), with the result that the outlet hydrogen is virtually 100 percent dissociated to monatomic H. The molten fuel is contained in a solid container of its own material, which is rotated to stabilize the liquid layer by centripetal force. LARS reactor designs are described, together with neutronic and thermal-hydraulic analyses. Power levels are on the order of 200 megawatts. Typically, LARS designs use seven rotating fuel elements, are beryllium moderated, and have critical radii of approximately 100 cm (core L/D approximately equal to 1.5).

The Systems Biology Markup Language (SBML): Language Specification for Level 3 Version 2 Core.

PubMed

Hucka, Michael; Bergmann, Frank T; Dräger, Andreas; Hoops, Stefan; Keating, Sarah M; Le Novère, Nicolas; Myers, Chris J; Olivier, Brett G; Sahle, Sven; Schaff, James C; Smith, Lucian P; Waltemath, Dagmar; Wilkinson, Darren J

2018-03-09

Computational models can help researchers to interpret data, understand biological functions, and make quantitative predictions. The Systems Biology Markup Language (SBML) is a file format for representing computational models in a declarative form that different software systems can exchange. SBML is oriented towards describing biological processes of the sort common in research on a number of topics, including metabolic pathways, cell signaling pathways, and many others. By supporting SBML as an input/output format, different tools can all operate on an identical representation of a model, removing opportunities for translation errors and assuring a common starting point for analyses and simulations. This document provides the specification for Version 2 of SBML Level 3 Core. The specification defines the data structures prescribed by SBML, their encoding in XML (the eXtensible Markup Language), validation rules that determine the validity of an SBML document, and examples of models in SBML form. The design of Version 2 differs from Version 1 principally in allowing new MathML constructs, making more child elements optional, and adding identifiers to all SBML elements instead of only selected elements. Other materials and software are available from the SBML project website at http://sbml.org/.

Comparison of radiofrequency body coils for MRI at 3 Tesla: a simulation study using parallel transmission on various anatomical targets

PubMed Central

Wu, Xiaoping; Zhang, Xiaotong; Tian, Jinfeng; Schmitter, Sebastian; Hanna, Brian; Strupp, John; Pfeuffer, Josef; Hamm, Michael; Wang, Dingxin; Nistler, Juergen; He, Bin; Vaughan, J. Thomas; Ugurbil, Kamil; Van de Moortele, Pierre-Francois

2015-01-01

The performance of multichannel transmit coil layouts and parallel transmission (pTx) radiofrequency (RF) pulse design was evaluated with respect to transmit B1 (B1+) homogeneity and Specific Absorption Rate (SAR) at 3 Tesla for a whole body coil. Five specific coils were modeled and compared: a 32-rung birdcage body coil (driven either in a fixed quadrature mode or a two-channel transmit mode), two single-ring stripline arrays (with either 8 or 16 elements), and two multi-ring stripline arrays (with 2 or 3 identical rings, stacked in the z-axis and each comprising eight azimuthally distributed elements). Three anatomical targets were considered, each defined by a 3D volume representative of a meaningful region of interest (ROI) in routine clinical applications. For a given anatomical target, global or local SAR controlled pTx pulses were designed to homogenize RF excitation within the ROI. At the B1+ homogeneity achieved by the quadrature driven birdcage design, pTx pulses with multichannel transmit coils achieved up to ~8 fold reduction in local and global SAR. When used for imaging head and cervical spine or imaging thoracic spine, the double-ring array outperformed all coils including the single-ring arrays. While the advantage of the double-ring array became much less pronounced for pelvic imaging with a substantially larger ROI, the pTx approach still provided significant gains over the quadrature birdcage coil. For all design scenarios, using the 3-ring array did not necessarily improve the RF performance. Our results suggest that pTx pulses with multichannel transmit coils can reduce local and global SAR substantially for body coils while attaining improved B1+ homogeneity, particularly for a “z-stacked” double-ring design with coil elements arranged on two transaxial rings. PMID:26332290

LOD BIM Element specification for Railway Turnout Systems Risk Mitigation using the Information Delivery Manual

NASA Astrophysics Data System (ADS)

Gigante-Barrera, Ángel; Dindar, Serdar; Kaewunruen, Sakdirat; Ruikar, Darshan

2017-10-01

Railway turnouts are complex systems designed using complex geometries and grades which makes them difficult to be managed in terms of risk prevention. This feature poses a substantial peril to rail users as it is considered a cause of derailment. In addition, derailment deals to financial losses due to operational downtimes and monetary compensations in case of death or injure. These are fundamental drivers to consider mitigating risks arising from poor risk management during design. Prevention through design (PtD) is a process that introduces tacit knowledge from industry professionals during the design process. There is evidence that Building Information Modelling (BIM) can help to mitigate risk since the inception of the project. BIM is considered an Information System (IS) were tacit knowledge can be stored and retrieved from a digital database making easy to take promptly decisions as information is ready to be analysed. BIM at the model element level entails working with 3D elements and embedded data, therefore adding a layer of complexity to the management of information along the different stages of the project and across different disciplines. In order to overcome this problem, the industry has created a framework for model progression specification named Level of Development (LOD). The paper presents an IDM based framework for design risk mitigation through code validation using the LOD. This effort resulted on risk datasets which describe graphically and non-graphically a rail turnout as the model progresses. Thus, permitting its inclusion within risk information systems. The assignment of an LOD construct to a set of data, requires specialised management and process related expertise. Furthermore, the selection of a set of LOD constructs requires a purpose based analysis. Therefore, a framework for LOD constructs implementation within the IDM for code checking is required for the industry to progress in this particular field.

Circuit design and simulation of a transmit beamforming ASIC for high-frequency ultrasonic imaging systems.

PubMed

Athanasopoulos, Georgios I; Carey, Stephen J; Hatfield, John V

2011-07-01

This paper describes the design of a programmable transmit beamformer application-specific integrated circuit (ASIC) with 8 channels for ultrasound imaging systems. The system uses a 20-MHz reference clock. A digital delay-locked loop (DLL) was designed with 50 variable delay elements, each of which provides a clock with different phase from a single reference. Two phase detectors compare the phase difference of the reference clock with the feedback clock, adjusting the delay of the delay elements to bring the feedback clock signal in phase with the reference clock signal. Two independent control voltages for the delay elements ensure that the mark space ratio of the pulses remain at 50%. By combining a 10- bit asynchronous counter with the delays from the DLL, each channel can be programmed to give a maximum time delay of 51 μs with 1 ns resolution. It can also give bursts of up to 64 pulses. Finally, for a single pulse, it can adjust the pulse width between 9 ns and 100 ns by controlling the current flowing through a capacitor in a one-shot circuit, for use with 40-MHz and 5-MHz transducers, respectively.

A 20-Year Examination of the Perceptions of Business School Interns: A Longitudinal Case Study

ERIC Educational Resources Information Center

Cook, Sherry James; Stokes, Amy; Parker, Richard Stephen

2015-01-01

The authors examined students' attitudes toward specific elements of an ongoing internship program. The study sample consisted of 816 student interns from 25 different colleges and universities. Results indicate that despite significant changes in instructional design and the incorporation of new technologies into the learning environment,…

LIQUID METAL REACTOR COOLING SYSTEMS

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

Aberdam, M.; Gros, G.

1965-02-01

This report is part of a series of bibliographies. The specific purpose of this report is to describe the various elements of the cooling systems in the principal liquid-metal-cooled reactors now operating, being contsructed, or in the design stage. The information given is drawn from reports or publicatios received during or before September 1964.

Using Specific Binding DNA Capture Elements to Direct Pulsed Power Killing of Biological Agents

DTIC Science & Technology

2003-06-01

Department of the Air Force position, policy, or decision unless so designated by other documentation. VI. REFERENCES [1] V. Majidi and M. R. Joseph...Spectroscopic applications of laser-induced plasmas,” Crit. Rev. Analyt. Chem. 23, 143-162, 1992. [2] V. Majidi , “Laser-induced plasmas: A versatile tool

Collaborative Approaches to Deepen Student Learning: Information Literacy, Curriculum Design, and Student Learning Workshops

ERIC Educational Resources Information Center

Hurvitz, Tate; Benvau, Roxane; Parry, Megan

2015-01-01

Creating a collaborative environment across student services and instruction is often more challenging than it may first seem. Although effective collaboration is context specific, keeping student learning at the center of the work is a powerful element in successful collaborations. Grossmont College's first year experience program has attempted…

49 CFR 178.345-6 - Supports and anchoring.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Specifications for Containers for Motor Vehicle Transportation § 178.345-6 Supports and anchoring. (a) A cargo tank with a frame not integral to the cargo tank must have the tank secured by restraining devices to..., or turning of the cargo tank motor vehicle. The design calculations of the support elements must...

49 CFR 178.345-6 - Supports and anchoring.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Specifications for Containers for Motor Vehicle Transportation § 178.345-6 Supports and anchoring. (a) A cargo tank with a frame not integral to the cargo tank must have the tank secured by restraining devices to..., or turning of the cargo tank motor vehicle. The design calculations of the support elements must...

49 CFR 178.345-6 - Supports and anchoring.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Specifications for Containers for Motor Vehicle Transportation § 178.345-6 Supports and anchoring. (a) A cargo tank with a frame not integral to the cargo tank must have the tank secured by restraining devices to..., or turning of the cargo tank motor vehicle. The design calculations of the support elements must...

49 CFR 178.345-6 - Supports and anchoring.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Specifications for Containers for Motor Vehicle Transportation § 178.345-6 Supports and anchoring. (a) A cargo tank with a frame not integral to the cargo tank must have the tank secured by restraining devices to..., or turning of the cargo tank motor vehicle. The design calculations of the support elements must...

Cooperative Engineering as a Joint Action

ERIC Educational Resources Information Center

Joffredo-Le Brun, Sophie; Morellato, Mireille; Sensevy, Gérard; Quilio, Serge

2018-01-01

This paper describes some elements of a specific kind of design-based research, cooperative engineering. In the first part of the paper, we argue that cooperative engineering can be analyzed through a joint action framework. We first present some conceptual tools that the Joint Action Theory in Didactics proposes in order to understand didactic…

TOPEX SDR Processing, October 1998. Volume 4

NASA Technical Reports Server (NTRS)

Lee, Jeffrey E.; Lockwood, Dennis W.

2003-01-01

This document is a compendium of the WFF TOPEX Software Development Team's knowledge regarding Sensor Data Record (SDR) Processing. It includes many elements of a requirements document, a software specification document, a software design document, and a user's manual. In the more technical sections, this document assumes the reader is familiar with TOPEX and instrument files.

Connecticut Music Trace Map for Grades 10 and 12. Revised.

ERIC Educational Resources Information Center

Connecticut State Board of Education, Hartford.

The Connecticut Curriculum Trace Maps for music are designed to help curriculum developers and teachers translate Connecticut's K-12 performance standards into objectives and classroom practice. The Trace Maps provide specific descriptions of what students should know and be able to do at smaller grade level clusters. The elements in the Trace…

Connecticut Music Trace Map for Grades 6 and 8. Revised.

ERIC Educational Resources Information Center

Connecticut State Board of Education, Hartford.

These Connecticut Curriculum Trace Maps for music are designed to help curriculum developers and teachers translate Connecticut's K-12 performance standards into objectives and classroom practices. Trace Maps provide specific descriptions of what students should know and be able to do at smaller grade level clusters. Elements in the Trace Maps are…

Standard plans for southern pine bridges

Treesearch

P. D. Hilbrich Lee; M. A. Ritter; M. H. Triche

1995-01-01

The development of standardized timber bridge plans and specifications is a key element in improving design and construction practices. The bridge plans presented were developed as a cooperative effort between the USDA Forest Service, Forest Products Laboratory (FPL); the University of Alabama; and the Southern Pine Council and are the first step in developing...

A Latin-cross-shaped integrated resonant cantilever with second torsion-mode resonance for ultra-resoluble bio-mass sensing

NASA Astrophysics Data System (ADS)

Xia, Xiaoyuan; Zhang, Zhixiang; Li, Xinxin

2008-03-01

Second torsion-mode resonance is proposed for microcantilever biosensors for ultra-high mass-weighing sensitivity and resolution. By increasing both the resonant frequency and Q-factor, the higher mode torsional resonance is favorable for improving the mass-sensing performance. For the first time, a Latin-cross-shaped second-mode resonant cantilever is constructed and optimally designed for both signal-readout and resonance-exciting elements. The cantilever sensor is fabricated by using silicon micromachining techniques. The transverse piezoresistive sensing element and the specific-shaped resonance-exciting loop are successfully integrated in the cantilever. Alpha-fetoprotein (AFP) antibody-antigen specific binding is implemented for the sensing experiment. The proposed cantilever sensor is designed with significantly superior sensitivity to the previously reported first torsion-mode one. After analysis with an Allan variance algorithm, which can be easily embedded in the sensing system, the Latin-cross-shaped second torsion-mode resonant cantilever is evaluated with ultra-high mass resolution. Therefore, the high-performance integrated micro-sensor is promising for on-the-spot bio-molecule detection.

FungalBraid: A GoldenBraid-based modular cloning platform for the assembly and exchange of DNA elements tailored to fungal synthetic biology.

PubMed

Hernanz-Koers, Miguel; Gandía, Mónica; Garrigues, Sandra; Manzanares, Paloma; Yenush, Lynne; Orzaez, Diego; Marcos, Jose F

2018-07-01

Current challenges in the study and biotechnological exploitation of filamentous fungi are the optimization of DNA cloning and fungal genetic transformation beyond model fungi, the open exchange of ready-to-use and standardized genetic elements among the research community, and the availability of universal synthetic biology tools and rules. The GoldenBraid (GB) cloning framework is a Golden Gate-based DNA cloning system developed for plant synthetic biology through Agrobacterium tumefaciens-mediated genetic transformation (ATMT). In this study, we develop reagents for the adaptation of GB version 3.0 from plants to filamentous fungi through: (i) the expansion of the GB toolbox with the domestication of fungal-specific genetic elements; (ii) the design of fungal-specific GB structures; and (iii) the ATMT and gene disruption of the plant pathogen Penicillium digitatum as a proof of concept. Genetic elements domesticated into the GB entry vector pUPD2 include promoters, positive and negative selection markers and terminators. Interestingly, some GB elements can be directly exchanged between plants and fungi, as demonstrated with the marker hph for Hyg R or the fluorescent protein reporter YFP. The iterative modular assembly of elements generates an endless number of diverse transcriptional units and other higher order combinations in the pDGB3α/pDGB3Ω destination vectors. Furthermore, the original plant GB syntax was adapted here to incorporate specific GB structures for gene disruption through homologous recombination and dual selection. We therefore have successfully adapted the GB technology for the ATMT of fungi. We propose the name of FungalBraid (FB) for this new branch of the GB technology that provides open, exchangeable and collaborative resources to the fungal research community. Copyright © 2018 Elsevier Inc. All rights reserved.

Design of HIFU transducers to generate specific nonlinear ultrasound fields

PubMed Central

Khokhlova, Vera A.; Yuldashev, Petr V.; Rosnitskiy, Pavel B.; Maxwell, Adam D.; Kreider, Wayne; Bailey, Michael R.; Sapozhnikov, Oleg A.

2017-01-01

Various clinical applications of high intensity focused ultrasound (HIFU) have different requirements on the pressure level and degree of nonlinear waveform distortion at the focus. Applications that utilize nonlinear waves with developed shocks are of growing interest, for example, for mechanical disintegration as well as for accelerated thermal ablation of tissue. In this work, an inverse problem of determining transducer parameters to enable formation of shocks with desired amplitude at the focus is solved. The solution was obtained by performing multiple direct simulations of the parabolic Khokhlov–Zabolotskaya–Kuznetsov (KZK) equation for various parameters of the source. It is shown that results obtained within the parabolic approximation can be used to describe the focal region of single element spherical sources as well as complex transducer arrays. It is also demonstrated that the focal pressure level at which fully developed shocks are formed mainly depends on the focusing angle of the source and only slightly depends on its aperture and operating frequency. Using the simulation results, a 256-element HIFU array operating at 1.5 MHz frequency was designed for a specific application of boiling-histotripsy that relies on the presence of 90–100 MPa shocks at the focus. The size of the array elements and focusing angle of the array were chosen to satisfy technical limitations on the intensity at the array elements and desired shock amplitudes in the focal waveform. Focus steering capabilities of the array were analysed using an open-source T-Array software developed at Moscow State University. PMID:28580038

Numerical simulation study on the optimization design of the crown shape of PDC drill bit.

PubMed

Ju, Pei; Wang, Zhenquan; Zhai, Yinghu; Su, Dongyu; Zhang, Yunchi; Cao, Zhaohui

The design of bit crown is an important part of polycrystalline diamond compact (PDC) bit design, although predecessors have done a lot of researches on the design principles of PDC bit crown, the study of the law about rock-breaking energy consumption according to different bit crown shape is not very systematic, and the mathematical model of design is over-simplified. In order to analyze the relation between rock-breaking energy consumption and bit crown shape quantificationally, the paper puts forward an idea to take "per revolution-specific rock-breaking work" as objective function, and analyzes the relationship between rock properties, inner cone angle, outer cone arc radius, and per revolution-specific rock-breaking work by means of explicit dynamic finite element method. Results show that the change law between per revolution-specific rock-breaking work and the radius of gyration is similar for rocks with different properties, it is beneficial to decrease rock-breaking energy consumption by decreasing inner cone angle or outer cone arc radius. Of course, we should also consider hydraulic structure and processing technology in the optimization design of PDC bit crown.

Development and fabrication of patient-specific knee implant using additive manufacturing techniques

NASA Astrophysics Data System (ADS)

Zammit, Robert; Rochman, Arif

2017-10-01

Total knee replacement is the most effective treatment to relief pain and restore normal function in a diseased knee joint. The aim of this research was to develop a patient-specific knee implant which can be fabricated using additive manufacturing techniques and has reduced wear rates using a highly wear resistant materials. The proposed design was chosen based on implant requirements, such as reduction in wear rates as well as strong fixation. The patient-specific knee implant improves on conventional knee implants by modifying the articulating surfaces and bone-implant interfaces. Moreover, tribological tests of different polymeric wear couples were carried out to determine the optimal materials to use for the articulating surfaces. Finite element analysis was utilized to evaluate the stresses sustained by the proposed design. Finally, the patient-specific knee implant was successfully built using additive manufacturing techniques.

Rotor-state feedback in the design of flight control laws for a hovering helicopter

NASA Technical Reports Server (NTRS)

Takahashi, Marc D.

1994-01-01

The use of rigid-body and rotor-state feedback gains in the design of helicopter flight control laws was investigated analytically on a blade element, articulated rotor, helicopter model. The study was conducted while designing a control law to meet an existing military rotorcraft handling qualities design specification (ADS-33C) in low-speed flight. A systematic approach to meet this specification was developed along with an assessment of the function of these gains in the feedback loops. Using the results of this assessment, the pitch and roll crossover behavior was easily modified by adjusting the body attitude and rotor-flap feedback gains. Critical to understanding the feedback gains is that the roll and pitch rate dynamics each have second-order behavior, not the classic first-order behavior, which arises from a quasi-static rotor, six degree-of-freedom model.

Conceptual design and structural analysis for an 8.4-m telescope

NASA Astrophysics Data System (ADS)

Mendoza, Manuel; Farah, Alejandro; Ruiz Schneider, Elfego

2004-09-01

This paper describes the conceptual design of the optics support structures of a telescope with a primary mirror of 8.4 m, the same size as a Large Binocular Telescope (LBT) primary mirror. The design goal is to achieve a structure for supporting the primary and secondary mirrors and keeping them joined as rigid as possible. With this purpose an optimization with several models was done. This iterative design process includes: specifications development, concepts generation and evaluation. Process included Finite Element Analysis (FEA) as well as other analytical calculations. Quality Function Deployment (QFD) matrix was used to obtain telescope tube and spider specifications. Eight spiders and eleven tubes geometric concepts were proposed. They were compared in decision matrixes using performance indicators and parameters. Tubes and spiders went under an iterative optimization process. The best tubes and spiders concepts were assembled together. All assemblies were compared and ranked according to their performance.

Lightning protection for shuttle propulsion elements

NASA Technical Reports Server (NTRS)

Goodloe, Carolyn C.; Giudici, Robert J.

1991-01-01

The results of lightning protection analyses and tests are weighed against the present set of waivers to the NASA lightning protection specification. The significant analyses and tests are contrasted with the release of a new and more realistic lightning protection specification, in September 1990, that resulted in an inordinate number of waivers. A variety of lightning protection analyses and tests of the Shuttle propulsion elements, the Solid Rocket Booster, the External Tank, and the Space Shuttle Main Engine, were conducted. These tests range from the sensitivity of solid propellant during shipping to penetration of cryogenic tanks during flight. The Shuttle propulsion elements have the capability to survive certain levels of lightning strikes at certain times during transportation, launch site operations, and flight. Changes are being evaluated that may improve the odds of withstanding a major lightning strike. The Solid Rocket Booster is the most likely propulsion element to survive if systems tunnel bond straps are improved. Wiring improvements were already incorporated and major protection tests were conducted. The External Tank remains vulnerable to burn-through penetration of its skin. Proposed design improvements include the use of a composite nose cone and conductive or laminated thermal protection system coatings.

Development of synthetic selfish elements based on modular nucleases in Drosophila melanogaster

PubMed Central

Simoni, Alekos; Siniscalchi, Carla; Chan, Yuk-Sang; Huen, David S.; Russell, Steven; Windbichler, Nikolai; Crisanti, Andrea

2014-01-01

Selfish genes are DNA elements that increase their rate of genetic transmission at the expense of other genes in the genome and can therefore quickly spread within a population. It has been suggested that selfish elements could be exploited to modify the genome of entire populations for medical and ecological applications. Here we report that transcription activator-like effector nuclease (TALEN) and zinc finger nuclease (ZFN) can be engineered into site-specific synthetic selfish elements (SSEs) and demonstrate their transmission of up to 70% in the Drosophila germline. We show here that SSEs can spread via DNA break-induced homologous recombination, a process known as ‘homing’ similar to that observed for homing endonuclease genes (HEGs), despite their fundamentally different modes of DNA binding and cleavage. We observed that TALEN and ZFN have a reduced capability of secondary homing compared to HEG as their repetitive structure had a negative effect on their genetic stability. The modular architecture of ZFNs and TALENs allows for the rapid design of novel SSEs against specific genomic sequences making them potentially suitable for the genetic engineering of wild-type populations of animals and plants, in applications such as gene replacement or population suppression of pest species. PMID:24803674

Diversity, distribution and dynamics of full-length Copia and Gypsy LTR retroelements in Solanum lycopersicum.

PubMed

Paz, Rosalía Cristina; Kozaczek, Melisa Eliana; Rosli, Hernán Guillermo; Andino, Natalia Pilar; Sanchez-Puerta, Maria Virginia

2017-10-01

Transposable elements are the most abundant components of plant genomes and can dramatically induce genetic changes and impact genome evolution. In the recently sequenced genome of tomato (Solanum lycopersicum), the estimated fraction of elements corresponding to retrotransposons is nearly 62%. Given that tomato is one of the most important vegetable crop cultivated and consumed worldwide, understanding retrotransposon dynamics can provide insight into its evolution and domestication processes. In this study, we performed a genome-wide in silico search of full-length LTR retroelements in the tomato nuclear genome and annotated 736 full-length Gypsy and Copia retroelements. The dispersion level across the 12 chromosomes, the diversity and tissue-specific expression of those elements were estimated. Phylogenetic analysis based on the retrotranscriptase region revealed the presence of 12 major lineages of LTR retroelements in the tomato genome. We identified 97 families, of which 77 and 20 belong to the superfamilies Copia and Gypsy, respectively. Each retroelement family was characterized according to their element size, relative frequencies and insertion time. These analyses represent a valuable resource for comparative genomics within the Solanaceae, transposon-tagging and for the design of cultivar-specific molecular markers in tomato.

Localized Overheating Phenomena and Optimization of Spark-Plasma Sintering Tooling Design

PubMed Central

Giuntini, Diletta; Olevsky, Eugene A.; Garcia-Cardona, Cristina; Maximenko, Andrey L.; Yurlova, Maria S.; Haines, Christopher D.; Martin, Darold G.; Kapoor, Deepak

2013-01-01

The present paper shows the application of a three-dimensional coupled electrical, thermal, mechanical finite element macro-scale modeling framework of Spark Plasma Sintering (SPS) to an actual problem of SPS tooling overheating, encountered during SPS experimentation. The overheating phenomenon is analyzed by varying the geometry of the tooling that exhibits the problem, namely by modeling various tooling configurations involving sequences of disk-shape spacers with step-wise increasing radii. The analysis is conducted by means of finite element simulations, intended to obtain temperature spatial distributions in the graphite press-forms, including punches, dies, and spacers; to identify the temperature peaks and their respective timing, and to propose a more suitable SPS tooling configuration with the avoidance of the overheating as a final aim. Electric currents-based Joule heating, heat transfer, mechanical conditions, and densification are imbedded in the model, utilizing the finite-element software COMSOL™, which possesses a distinguishing ability of coupling multiple physics. Thereby the implementation of a finite element method applicable to a broad range of SPS procedures is carried out, together with the more specific optimization of the SPS tooling design when dealing with excessive heating phenomena. PMID:28811398

Performance of masonry enclosure walls: lessons learned from recent earthquakes

NASA Astrophysics Data System (ADS)

Vicente, Romeu Silva; Rodrigues, Hugo; Varum, Humberto; Costa, Aníbal; Mendes da Silva, José António Raimundo

2012-03-01

This paper discusses the issue of performance requirements and construction criteria for masonry enclosure and infill walls. Vertical building enclosures in European countries are very often constituted by non-load-bearing masonry walls, using horizontally perforated clay bricks. These walls are generally supported and confined by a reinforced concrete frame structure of columns and beams/slabs. Since these walls are commonly considered to be nonstructural elements and their influence on the structural response is ignored, their consideration in the design of structures as well as their connection to the adjacent structural elements is frequently negligent or insufficiently detailed. As a consequence, nonstructural elements, as for wall enclosures, are relatively sensitive to drift and acceleration demands when buildings are subjected to seismic actions. Many international standards and technical documents stress the need for design acceptability criteria for nonstructural elements, however they do not specifically indicate how to prevent collapse and severe cracking, and how to enhance the overall stability in the case of moderate to high seismic loading. Furthermore, a review of appropriate measures to improve enclosure wall performance and both in-plane and out-of-plane integrity under seismic actions is addressed.

Integrated support structure for GASCAN 2

NASA Technical Reports Server (NTRS)

1990-01-01

The focus of the Worcester Polytechnic Institute (WPI) Advanced Space Design Program was the preliminary design of the Integrated Support Structure for GASCAN II, a Get Away Special canister donated by the MITRE Corporation. Two teams of three students each worked on the support structure. There was a structural design team and a thermal design team. The structure will carry three experiments also undergoing preliminary design this year, the mu-gravity Ignition Experiment, the Rotational Flow in Low Gravity Experiment, and the Ionospheric Properties and Propagation Experiment. The structural design team was responsible for the layout of the GASCAN and the preliminary design of the structure itself. They produced the physical interface specifications defining the baseline weights and volumes for the equipment and produced layout drawings of the system. The team produced static and modal finite element analysis of the structure using ANSYS. The thermal design team was responsible for the power and timing requirements of the payload and for the identification and preliminary analysis of potential thermal problems. The team produced the power, timing, and energy interface specifications and assisted in the development of the specification of the battery pack. The thermal parameters of each experiment were cataloged and the experiments were subjected to worst case heat transfer scenarios.

Molecular Chemistry and Engineering of Boron-Modified Polyorganosilazanes as New Processable and Functional SiBCN Precursors.

PubMed

Viard, Antoine; Fonblanc, Diane; Schmidt, Marion; Lale, Abhijeet; Salameh, Chrystelle; Soleilhavoup, Anne; Wynn, Mélanie; Champagne, Philippe; Cerneaux, Sophie; Babonneau, Florence; Chollon, Georges; Rossignol, Fabrice; Gervais, Christel; Bernard, Samuel

2017-07-06

A series of boron-modified polyorganosilazanes was synthesized from a poly(vinylmethyl-co-methyl)silazane and controlled amounts of borane dimethyl sulfide. The role of the chemistry behind their synthesis has been studied in detail by using solid-state NMR spectroscopy, FTIR spectroscopy, and elemental analysis. The intimate relationship between the chemistry and the processability of these polymers is discussed. Polymers with low boron contents displayed appropriate requirements for facile processing in solution, such as impregnation of host carbon materials, which resulted in the design of mesoporous monoliths with a high specific surface area after pyrolysis. Polymers with high boron content are more appropriate for solid-state processing to design mechanically robust monolith-type macroporous and dense structures after pyrolysis. Boron acts as a crosslinking element, which offers the possibility to extend the processability of polyorganosilazanes and suppress the distillation of oligomeric fragments in the low-temperature region of their thermal decomposition (i.e., pyrolysis) at 1000 °C under nitrogen. Polymers with controlled and high ceramic yields were generated. We provide a comprehensive mechanistic study of the two-step thermal decomposition based on a combination of thermogravimetric experiments coupled with elemental analysis, solid-state NMR spectroscopy, and FTIR spectroscopy. Selected characterization tools allowed the investigation of specific properties of the monolith-type SiBCN materials. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Artificial ferroic systems: novel functionality from structure, interactions and dynamics.

PubMed

Heyderman, L J; Stamps, R L

2013-09-11

Lithographic processing and film growth technologies are continuing to advance, so that it is now possible to create patterned ferroic materials consisting of arrays of sub-1 μm elements with high definition. Some of the most fascinating behaviour of these arrays can be realised by exploiting interactions between the individual elements to create new functionality. The properties of these artificial ferroic systems differ strikingly from those of their constituent components, with novel emergent behaviour arising from the collective dynamics of the interacting elements, which are arranged in specific designs and can be activated by applying magnetic or electric fields. We first focus on artificial spin systems consisting of arrays of dipolar-coupled nanomagnets and, in particular, review the field of artificial spin ice, which demonstrates a wide range of fascinating phenomena arising from the frustration inherent in particular arrangements of nanomagnets, including emergent magnetic monopoles, domains of ordered macrospins, and novel avalanche behaviour. We outline how demagnetisation protocols have been employed as an effective thermal anneal in an attempt to reach the ground state, comment on phenomena that arise in thermally activated systems and discuss strategies for selectively generating specific configurations using applied magnetic fields. We then move on from slow field and temperature driven dynamics to high frequency phenomena, discussing spinwave excitations in the context of magnonic crystals constructed from arrays of patterned magnetic elements. At high frequencies, these arrays are studied in terms of potential applications including magnetic logic, linear and non-linear microwave optics, and fast, efficient switching, and we consider the possibility to create tunable magnonic crystals with artificial spin ice. Finally, we discuss how functional ferroic composites can be incorporated to realise magnetoelectric effects. Specifically, we discuss artificial multiferroics (or multiferroic composites), which hold promise for new applications that involve electric field control of magnetism, or electric and magnetic field responsive devices for high frequency integrated circuit design in microwave and terahertz signal processing. We close with comments on how enhanced functionality can be realised through engineering of nanostructures with interacting ferroic components, creating opportunities for novel spin electronic devices that, for example, make use of the transport of magnetic charges, thermally activated elements, and reprogrammable nanomagnet systems.

CFD in the context of IHPTET: The Integrated High Performance Turbine Technology Program

NASA Technical Reports Server (NTRS)

Simoneau, Robert J.; Hudson, Dale A.

1989-01-01

The Integrated High Performance Turbine Engine Technology (IHPTET) Program is an integrated DOD/NASA technology program designed to double the performance capability of today's most advanced military turbine engines as we enter the twenty-first century. Computational Fluid Dynamics (CFD) is expected to play an important role in the design/analysis of specific configurations within this complex machine. In order to do this, a plan is being developed to ensure the timely impact of CFD on IHPTET. The developing philosphy of CFD in the context of IHPTET is discussed. The key elements in the developing plan and specific examples of state-of-the-art CFD efforts which are IHPTET turbine engine relevant are discussed.

Structural Analysis Methods for Structural Health Management of Future Aerospace Vehicles

NASA Technical Reports Server (NTRS)

Tessler, Alexander

2007-01-01

Two finite element based computational methods, Smoothing Element Analysis (SEA) and the inverse Finite Element Method (iFEM), are reviewed, and examples of their use for structural health monitoring are discussed. Due to their versatility, robustness, and computational efficiency, the methods are well suited for real-time structural health monitoring of future space vehicles, large space structures, and habitats. The methods may be effectively employed to enable real-time processing of sensing information, specifically for identifying three-dimensional deformed structural shapes as well as the internal loads. In addition, they may be used in conjunction with evolutionary algorithms to design optimally distributed sensors. These computational tools have demonstrated substantial promise for utilization in future Structural Health Management (SHM) systems.

Overview of Marshall Space Flight Center Activities for the Combustion Stability Tool Development Program

NASA Technical Reports Server (NTRS)

Kenny, R. J.; Greene, W. D.

2016-01-01

This presentation covers the overall scope, schedule, and activities associated with the NASA - Marshall Space Flight Center (MSFC) involvement with the Combustion Stability Tool Development (CSTD) program. The CSTD program is funded by the Air Force Space & Missile Systems Center; it is approximately two years in duration and; and it is sponsoring MSFC to: design, fabricate, & execute multi-element hardware testing, support Air Force Research Laboratory (AFRL) single element testing, and execute testing of a small-scale, multi-element combustion chamber. Specific MSFC Engineering Directorate involvement, per CSTD-sponsored task, will be outlined. This presentation serves a primer for the corresponding works that provide details of the technical work performed by individual groups within MSFC.

Application of holographic elements in displays and planar illuminators

NASA Astrophysics Data System (ADS)

Putilin, Andrew; Gustomiasov, Igor

2007-05-01

Holographic Optical Elements (HOE's) on planar waveguides can be used to design the planar optics for backlit units, color selectors or filters, lenses for virtual reality displays. The several schemes for HOE recording are proposed to obtain planar stereo backlit unit and private eye displays light source. It is shown in the paper that the specific light transformation grating permits to construct efficient backlit units for display holograms and LCD. Several schemes of reflection/transmission backlit units and scattering films based on holographic optical elements are also proposed. The performance of the waveguide HOE can be optimized using the parameters of recording scheme and etching parameters. The schemes of HOE application are discussed and some experimental results are shown.

Specifically Designed Constructed Wetlands: A Novel Treatment Approach for Scrubber Wastewater

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

John H. Rodgers Jr; James W. Castle; Chris Arrington: Derek Eggert

2005-09-01

A pilot-scale wetland treatment system was specifically designed and constructed at Clemson University to evaluate removal of mercury, selenium, and other constituents from flue gas desulfurization (FGD) wastewater. Specific objectives of this research were: (1) to measure performance of a pilot-scale constructed wetland treatment system in terms of decreases in targeted constituents (Hg, Se and As) in the FGD wastewater from inflow to outflow; (2) to determine how the observed performance is achieved (both reactions and rates); and (3) to measure performance in terms of decreased bioavailability of these elements (i.e. toxicity of sediments in constructed wetlands and toxicity ofmore » outflow waters from the treatment system). Performance of the pilot-scale constructed wetland treatment systems was assessed using two criteria: anticipated NPDES permit levels and toxicity evaluations using two sentinel toxicity-testing organisms (Ceriodaphnia dubia and Pimephales promelas). These systems performed efficiently with varied inflow simulations of FGD wastewaters removing As, Hg, and Se concentrations below NPDES permit levels and reducing the toxicity of simulated FGD wastewater after treatment with the constructed wetland treatment systems. Sequential extraction procedures indicated that these elements (As, Hg, and Se) were bound to residual phases within sediments of these systems, which should limit their bioavailability to aquatic biota. Sediments collected from constructed wetland treatment systems were tested to observe toxicity to Hyalella azteca or Chironomus tetans. Complete survival (100%) was observed for H. azteca in all cells of the constructed wetland treatment system and C. tentans had an average of 91% survival over the three treatment cells containing sediments. Survival and growth of H. azteca and C. tentans did not differ significantly between sediments from the constructed wetland treatment system and controls. Since the sediments of the constructed wetland treatment system are repositories for As, Hg, and Se and the bioavailability of these elements decreased after deposition, the pilot-scale constructed wetland treatment system contributed significantly to mitigation of risks to aquatic life from these elements.« less

User Manuals for a Primary Care Electronic Medical Record System: A Mixed Methods Study of User- and Vendor-Generated Documents.

PubMed

Shachak, Aviv; Dow, Rustam; Barnsley, Jan; Tu, Karen; Domb, Sharon; Jadad, Alejandro R; Lemieux-Charles, Louise

2013-06-04

Tutorials and user manuals are important forms of impersonal support for using software applications including electronic medical records (EMRs). Differences between user- and vendor documentation may indicate support needs, which are not sufficiently addressed by the official documentation, and reveal new elements that may inform the design of tutorials and user manuals. What are the differences between user-generated tutorials and manuals for an EMR and the official user manual from the software vendor? Effective design of tutorials and user manuals requires careful packaging of information, balance between declarative and procedural texts, an action and task-oriented approach, support for error recognition and recovery, and effective use of visual elements. No previous research compared these elements between formal and informal documents. We conducted an mixed methods study. Seven tutorials and two manuals for an EMR were collected from three family health teams and compared with the official user manual from the software vendor. Documents were qualitatively analyzed using a framework analysis approach in relation to the principles of technical documentation described above. Subsets of the data were quantitatively analyzed using cross-tabulation to compare the types of error information and visual cues in screen captures between user- and vendor-generated manuals. The user-developed tutorials and manuals differed from the vendor-developed manual in that they contained mostly procedural and not declarative information; were customized to the specific workflow, user roles, and patient characteristics; contained more error information related to work processes than to software usage; and used explicit visual cues on screen captures to help users identify window elements. These findings imply that to support EMR implementation, tutorials and manuals need to be customized and adapted to specific organizational contexts and workflows. The main limitation of the study is its generalizability. Future research should address this limitation and may explore alternative approaches to software documentation, such as modular manuals or participatory design.

A charging study of ACTS using NASCAP

NASA Technical Reports Server (NTRS)

Herr, Joel L.

1991-01-01

The NASA Charging Analyzer Program (NASCAP) computer code is a three dimensional finite element charging code designed to analyze spacecraft charging in the magnetosphere. Because of the characteristics of this problem, NASCAP can use an quasi-static approach to provide a spacecraft designer with an understanding of how a specific spacecraft will interact with a geomagnetic substorm. The results of the simulation can help designers evaluate the probability and location of arc discharges of charged surfaces on the spacecraft. A charging study of NASA's Advanced Communication Technology Satellite (ACTS) using NASCAP is reported. The results show that the ACTS metalized multilayer insulating blanket design should provide good electrostatic discharge control.

Data base systems in electronic design engineering

NASA Technical Reports Server (NTRS)

Williams, D.

1980-01-01

The concepts of an integrated design data base system (DBMS) as it might apply to an electronic design company are discussed. Data elements of documentation, project specifications, project tracking, firmware, software, electronic and mechanical design can be integrated and managed through a single DBMS. Combining the attributes of a DBMS data handler with specialized systems and functional data can provide users with maximum flexibility, reduced redundancy, and increased overall systems performance. Although some system overhead is lost due to redundancy in transitory data, it is believed the combination of the two data types is advisable rather than trying to do all data handling through a single DBMS.

An iterative requirements specification procedure for decision support systems.

PubMed

Brookes, C H

1987-08-01

Requirements specification is a key element in a DSS development project because it not only determines what is to be done, it also drives the evolution process. A procedure for requirements elicitation is described that is based on the decomposition of the DSS design task into a number of functions, subfunctions, and operators. It is postulated that the procedure facilitates the building of a DSS that is complete and integrates MIS, modelling and expert system components. Some examples given are drawn from the health administration field.

Engineering Solid-State Materials. Strategies for Modeling and Packing Control of Molecular Assemblies into 3-D Networks

DTIC Science & Technology

1993-04-22

cocrystal /materials design/hydrogen bonding 19 ABSTRACT (Continue on reverse if necessary and identify by block number) The crystal structure and...proterties of a number of urea cocrystals are studied with regard to symmetry of the hydrogen-bonded molecular assemblies. The logical consequences of...symmetry element A or M. ¶/or 2 Results: Our specific goals are to design and synthesize urea based cocrystals in which the twofold symmetry and hydrogen

Improving the value of clinical research through the use of Common Data Elements.

PubMed

Sheehan, Jerry; Hirschfeld, Steven; Foster, Erin; Ghitza, Udi; Goetz, Kerry; Karpinski, Joanna; Lang, Lisa; Moser, Richard P; Odenkirchen, Joanne; Reeves, Dianne; Rubinstein, Yaffa; Werner, Ellen; Huerta, Michael

2016-12-01

The use of Common Data Elements can facilitate cross-study comparisons, data aggregation, and meta-analyses; simplify training and operations; improve overall efficiency; promote interoperability between different systems; and improve the quality of data collection. A Common Data Element is a combination of a precisely defined question (variable) paired with a specified set of responses to the question that is common to multiple datasets or used across different studies. Common Data Elements, especially when they conform to accepted standards, are identified by research communities from variable sets currently in use or are newly developed to address a designated data need. There are no formal international specifications governing the construction or use of Common Data Elements. Consequently, Common Data Elements tend to be made available by research communities on an empiric basis. Some limitations of Common Data Elements are that there may still be differences across studies in the interpretation and implementation of the Common Data Elements, variable validity in different populations, and inhibition by some existing research practices and the use of legacy data systems. Current National Institutes of Health efforts to support Common Data Element use are linked to the strengthening of National Institutes of Health Data Sharing policies and the investments in data repositories. Initiatives include cross-domain and domain-specific resources, construction of a Common Data Element Portal, and establishment of trans-National Institutes of Health working groups to address technical and implementation topics. The National Institutes of Health is seeking to lower the barriers to Common Data Element use through greater awareness and encourage the culture change necessary for their uptake and use. As National Institutes of Health, other agencies, professional societies, patient registries, and advocacy groups continue efforts to develop and promote the responsible use of Common Data Elements, particularly if linked to accepted data standards and terminologies, continued engagement with and feedback from the research community will remain important. © The Author(s) 2016.

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.

Tapered slot antenna design for vehicular GPR applications

NASA Astrophysics Data System (ADS)

Bıçak, Emrullah; Yeǧin, Korkut; Nazlı, Hakki; Daǧ, Mahmut

2014-05-01

Vehicular applications of UWB GPR demand multiple GPR sensors operating in a harsh environment. One of the key elements of in the sensor is its UWB antenna which has minimal inter-element coupling, low group delay, high directivity and less prone to environmental conditions. Tapered slot antennas (TSA's) provide good impedance match, but they need to be modified for above specifications. Parasitic slot loaded TSA with balanced feed is proposed and a multi-channel antenna array structure is formed. Structural parameters are numerically analyzed and a prototype is built. Measurements show good performance for UWB GPR applications.

Automated benchmark generation based upon a specification language

NASA Technical Reports Server (NTRS)

Rajan, N.; Feteih, S. E.; Saito, J.

1984-01-01

The problem of validating and verifying digital flight control system (DFCS) software is addressed in this paper. A new specification language DIVERS is proposed, and is the keystone of the approach. This language consists of keywords where each keyword represents an element in the block diagram of a DFCS. DIVERS has a dictionary which contains all the keywords a DFCS designer might need. Translator programs convert the system specifications into an executable, high-level language program. The features of translators are discussed and are elucidated by examples. This language is used to describe a typical flight software module.

Prevention of errors and user alienation in healthcare IT integration programmes.

PubMed

Benson, Tim

2007-01-01

The design, development and implementation stages of integrated computer projects require close collaboration between users and developers, but this is particularly difficult where there are multiple specialties, organisations and system suppliers. Users become alienated if they are not consulted, but consultation is meaningless if they cannot understand the specifications showing exactly what is proposed. We need stringent specifications that users and developers can review and check before most of the work is done. Avoidable errors lead to delays and cost over-runs. The number of errors is a function of the likelihood of misunderstanding any part of the specification, the number of individuals involved and the number of choices or options. One way to reduce these problems is to provide a conceptual design specification, comprising detailed Unified Modelling Language (UML) class and activity diagrams, data definitions and terminology, in addition to conventional technology-specific specifications. A conceptual design specification needs to be straightforward to understand and use, transparent and unambiguous. People find structured diagrams, such as maps, charts and blueprints, easier to use than reports or tables. Other desirable properties include being technology-independent, comprehensive, stringent, coherent, consistent, composed from reusable elements and computer-readable (XML). When users and developers share the same agreed conceptual design specification, this can be one of the master documents of a formal contract between the stakeholders. No extra meaning should be added during the later stages of the project life cycle.

Mechanical design of SST-GATE, a dual-mirror telescope for the Cherenkov Telescope Array

NASA Astrophysics Data System (ADS)

Dournaux, Jean-Laurent; Huet, Jean-Michel; Amans, Jean-Philippe; Dumas, Delphine; Laporte, Philippe; Sol, Hélène; Blake, Simon

2014-07-01

The Cherenkov Telescope Array (CTA) project aims to create the next generation Very High Energy (VHE) gamma-ray telescope array. It will be devoted to the observation of gamma rays over a wide band of energy, from a few tens of GeV to more than 100 TeV. Two sites are foreseen to view the whole sky where about 100 telescopes, composed of three different classes, related to the specific energy region to be investigated, will be installed. Among these, the Small Size class of Telescopes, SSTs, are devoted to the highest energy region, to beyond 100 TeV. Due to the large number of SSTs, their unit cost is an important parameter. At the Observatoire de Paris, we have designed a prototype of a Small Size Telescope named SST-GATE, based on the dual-mirror Schwarzschild-Couder optical formula, which has never before been implemented in the design of a telescope. Over the last two years, we developed a mechanical design for SST-GATE from the optical and preliminary mechanical designs made by the University of Durham. The integration of this telescope is currently in progress. Since the early stages of mechanical design of SST-GATE, finite element method has been used employing shape and topology optimization techniques to help design several elements of the telescope. This allowed optimization of the mechanical stiffness/mass ratio, leading to a lightweight and less expensive mechanical structure. These techniques and the resulting mechanical design are detailed in this paper. We will also describe the finite element analyses carried out to calculate the mechanical deformations and the stresses in the structure under observing and survival conditions.

Terminological aspects of data elements

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

Strehlow, R.A.; Kenworthey, W.H. Jr.; Schuldt, R.E.

1991-01-01

The creation and display of data comprise a process that involves a sequence of steps requiring both semantic and systems analysis. An essential early step in this process is the choice, definition, and naming of data element concepts and is followed by the specification of other needed data element concept attributes. The attributes and the values of data element concept remain associated with them from their birth as a concept to a generic data element that serves as a template for final application. Terminology is, therefore, centrally important to the entire data creation process. Smooth mapping from natural language tomore » a database is a critical aspect of database, and consequently, it requires terminology standardization from the outset of database work. In this paper the semantic aspects of data elements are analyzed and discussed. Seven kinds of data element concept information are considered and those that require terminological development and standardization are identified. The four terminological components of a data element are the hierarchical type of a concept, functional dependencies, schematas showing conceptual structures, and definition statements. These constitute the conventional role of terminology in database design. 12 refs., 8 figs., 1 tab.« less

NASA Human Spaceflight Architecture Team: Lunar Surface Exploration Strategies

NASA Technical Reports Server (NTRS)

Mueller, Rob P.

2012-01-01

NASA s agency wide Human Spaceflight Architecture Team (HAT) has been developing Design Reference Missions (DRMs) to support the ongoing effort to characterize NASA s future human exploration strategy. The DRM design effort includes specific articulations of transportation and surface elements, technologies and operations required to enable future human exploration of various destinations including the moon, Near Earth Asteroids (NEAs) and Mars as well as interim cis-lunar targets. In prior architecture studies, transportation concerns have dominated the analysis. As a result, an effort was made to study the human utilization strategy at each specific destination and the resultant impacts on the overall architecture design. In particular, this paper considers various lunar surface strategies as representative scenarios that could occur in a human lunar return, and demonstrates their alignment with the internationally developed Global Exploration Roadmap (GER).

Launch Deployment Assembly Human Engineering Analysis

NASA Technical Reports Server (NTRS)

Loughead, T.

1996-01-01

This report documents the human engineering analysis performed by the Systems Branch in support of the 6A cargo element design. The human engineering analysis is limited to the extra vehicular activities (EVA) which are involved in removal of various cargo items from the LDA and specific activities concerning deployment of the Space Station Remote Manipulator System (SSRMS).

Effective Faculty Evaluation at the Teaching-Centered University: Building a Fair and Authentic Portfolio of Faculty Work

ERIC Educational Resources Information Center

Lakin, Amy L.

2016-01-01

Purpose: The purpose of this paper is to determine the most fair, authentic, and reliable elements to include in a portfolio of faculty work, specifically at teaching-centered institutions. Design/methodology/approach: This paper examines and evaluates relevant literature pertaining to faculty portfolios of work and recommends portfolio formats…

TOPEX Software Document Series. Volume 5; Rev. 1; TOPEX GDR Processing

NASA Technical Reports Server (NTRS)

Lee, Jeffrey; Lockwood, Dennis; Hancock, David W., III

2003-01-01

This document is a compendium of the WFF TOPEX Software Development Team's knowledge regarding Geophysical Data Record (GDR) Processing. It includes many elements of a requirements document, a software specification document, a software design document, and a user's manual. In the more technical sections, this document assumes the reader is familiar with TOPEX and instrument files.

Project visual analysis for the Allegheny National Forest

Treesearch

Gary W. Kell

1979-01-01

The Project Visual Analysis is a landscape assessment procedure involving forest vegetative manipulation. A logical step by step analysis leads the user to a specific set of landscape management guidelines to be used as an aid in designing a project or in evaluating whether the proposed project impacts will meet visual objectives. Key elements within the procedure are...

Engaged Cohorts: Can Gamification Engage All College Students in Class?

ERIC Educational Resources Information Center

Song, Donglei; Ju, Ping; Xu, Hao

2017-01-01

Many gamification designs in education do effectively mobilize students to some extent. Yet, there is still very little research to account for the specific influence on each student. It is essential to determine whether the students can be engaged by gamification in terms of various psychological factors. In this paper, the game element point was…

Error Management Practices Interacting with National and Organizational Culture: The Case of Two State University Departments in Turkey

ERIC Educational Resources Information Center

Göktürk, Söheyda; Bozoglu, Oguzhan; Günçavdi, Gizem

2017-01-01

Purpose: Elements of national and organizational cultures can contribute much to the success of error management in organizations. Accordingly, this study aims to consider how errors were approached in two state university departments in Turkey in relation to their specific organizational and national cultures. Design/methodology/approach: The…

Diving in and Exploring Curricular Frameworks: The New Zealand Marine Studies Centre Programme

ERIC Educational Resources Information Center

Riley, Tracy; MacIntyre, Bill; Bicknell, Brenda; Cutler, Steve

2010-01-01

The New Zealand Marine Studies Centre has developed a programme for secondary gifted and talented students offering hands-on science in the real world. These programmes are designed to include elements of the Enrichment Triad Model (ETM), specifically the three types of enrichment, and, to a lesser degree, some aspects of the Schoolwide Enrichment…

Diatomite Type Filters for Swimming Pools. Standard No. 9, Revised October, 1966.

ERIC Educational Resources Information Center

National Sanitation Foundation, Ann Arbor, MI.

Pressure and vacuum diatomite type filters are covered in this standard. The filters herein described are intended to be designed and used specifically for swimming pool water filtration, both public and residential. Included are the basic components which are a necessary part of the diatomite type filter such as filter housing, element supports,…

Supercritical and Transcritical Shear Flows in Microgravity: Experiments and Direct Numerical Simulations

DTIC Science & Technology

2006-08-01

Boiler and Pressure Vessel Code were con...GRC, and to specifically state a general operating requirement. 1.1. The entire apparatus will be designed to ASME Boiler and Pressure Vessel Code , whenever...calculations, including a finite element analysis (FEA) will be inspected to verify the ASME Boiler and Pressure Vessel Code has been me, whenever

From Isolation to Interaction? Network-Based Professional Development and Teacher Professional Communication.

ERIC Educational Resources Information Center

McMahon, Teresa A.

The Mathematics Learning Forums, a collaborative effort of Bank Street College and the Center for Children and Technology, Education Development Center, Inc., provided the primary research setting for this study. Each 8-week forum focuses on specific elements of a mathematics content area and is designed to address both student learning and…

The Way of the Web: Answers to Your Questions about Web Site Marketing.

ERIC Educational Resources Information Center

Wassom, Julie

2002-01-01

Provides suggestions for effective web site marketing for child care and early education programs. Includes key considerations in designing a web site, specific elements that cause visitors to stay on and return to the site, use of interactive sites, web-site updating and revision, and use of traditional marketing activities to direct prospective…

Using Video Records to Mediate Teaching Interns' Critical Reflection

ERIC Educational Resources Information Center

Scott, Sarah E.; Kucan, Linda; Correnti, Richard; Miller, Leigh A.

2013-01-01

In this study we investigated how the use of video records in a literacy methods course supports the development of reflective practitioners when video is a core element of the course design. Specifically, we detail how interns' video-based reflections provide evidence that the use of video records of teaching interns' promotes the development of…

Complementary Expertise in a Zoo Educator Professional Development Event Contributes to the Construction of Understandings of Affective Transformation

ERIC Educational Resources Information Center

Kelly, Lisa-Anne DeGregoria; Kassing, Sharon

2013-01-01

Cultural Historical Activity Theory served as the analytical framework for the study of a professional development event for a zoo's education department, specifically designed to build understandings of "Affective Transformation," an element pertinent to the organization's strategic plan. Three key products--an Affective…

Linking CALL and SLA: Using the IRIS Database to Locate Research Instruments

ERIC Educational Resources Information Center

Handley, Zöe; Marsden, Emma

2014-01-01

To establish an evidence base for future computer-assisted language learning (CALL) design, CALL research needs to move away from CALL versus non-CALL comparisons, and focus on investigating the differential impact of individual coding elements, that is, specific features of a technology which might have an impact on learning (Pederson, 1987).…

Selection of rolling-element bearing steels for long-life applications

NASA Technical Reports Server (NTRS)

Zaretsky, Erwin V.

1989-01-01

Nearly four decades of research in bearing steel metallurgy and processing have resulted in improvements in bearing life by a factor of 100 over that obtained in the early 1940s. For critical applications such as aircraft, these improvements have resulted in longer lived, more reliable commercial aircraft engines. Material factors such as hardness, retained austenite, grain size and carbide size, number, and area can influence rolling-element fatigue life. Bearing steel processing such as double vacuum melting can have a greater effect on bearing life than material chemistry. The selection and specification of a bearing steel is dependent on the integration of all these considerations into the bearing design and application. The paper reviews rolling-element fatigue data and analysis which can enable the engineer or metallurgist to select a rolling-element bearing steel for critical applications where long life is required.

Selection of rolling-element bearing steels for long-life application

NASA Technical Reports Server (NTRS)

Zaretsky, E. V.

1986-01-01

Nearly four decades of research in bearing steel metallurgy and processing have resulted in improvements in bearing life by a factor of 100 over that obtained in the early 1940's. For critical applications such as aircraft, these improvements have resulted in longer lived, more reliable commercial aircraft engines. Material factors such as hardness, retained austenite, grain size and carbide size, number, and area can influence rolling-element fatigue life. Bearing steel processing such as double vacuum melting can have a greater efect on bearing life than material chemistry. The selection and specification of a bearing steel is dependent on the integration of all these considerations into the bearing design and application. The paper reviews rolling-element fatigue data and analysis which can enable the engineer or metallurgist to select a rolling-element bearing steel for critical applications where long life is required.

Moral deliberation and nursing ethics cases: elements of a methodological proposal.

PubMed

Schneider, Dulcinéia Ghizoni; Ramos, Flávia Regina Souza

2012-11-01

A qualitative study with an exploratory, descriptive and documentary design that was conducted with the objective of identifying the elements to constitute a method for the analysis of accusations of and proceedings for professional ethics infringements. The method is based on underlying elements identified inductively during analysis of professional ethics hearings judged by and filed in the archives of the Regional Nursing Board of Santa Catarina, Brazil, between 1999 and 2007. The strategies developed were based on the results of an analysis of the findings of fact (occurrences/infractions, causes and outcomes) contained in the records of 128 professional ethics hearings and on the structural elements (statements, rules and practices) identified in five example professional ethics cases. The strategies suggested for evaluating accusations of ethics infringements and the procedures involved in deliberating on ethics hearings constitute a generic proposal that will require adaptation to the context of specific professional ethics accusations.

Innovation in collaborative health research training: the role of active learning.

PubMed

Poole, Gary; Egan, John P; Iqbal, Isabeau

2009-03-01

This paper describes and discusses the essential pedagogical elements of the Partnering in Community Health Research (PCHR) program, which was designed to address the training needs of researchers who participate in collaborative, interdisciplinary health research. These elements were intended to foster specific skills that helped learners develop research partnerships featuring knowledge, capabilities, values and attitudes needed for successful research projects. By establishing research teams called "clusters", PCHR provided research training and experience for graduate students and post-doctoral fellows, as well as for community health workers and professionals. Pedagogical elements relied on active learning approaches such as inquiry-based and experience-based learning. Links between these elements and learning approaches are explained. Through their work in cluster-based applied research projects, the development of learning plans, and cross-cluster learning events, trainees acquired collaborative research competencies that were valuable, relevant and theoretically informed.

Genome-Wide RNAi Ionomics Screen Reveals New Genes and Regulation of Human Trace Element Metabolism

PubMed Central

Malinouski, Mikalai; Hasan, Nesrin M.; Zhang, Yan; Seravalli, Javier; Lin, Jie; Avanesov, Andrei; Lutsenko, Svetlana; Gladyshev, Vadim N.

2017-01-01

Trace elements are essential for human metabolism and dysregulation of their homeostasis is associated with numerous disorders. Here we characterize mechanisms that regulate trace elements in human cells by designing and performing a genome-wide high-throughput siRNA/ionomics screen, and examining top hits in cellular and biochemical assays. The screen reveals high stability of the ionomes, especially the zinc ionome, and yields known regulators and novel candidates. We further uncover fundamental differences in the regulation of different trace elements. Specifically, selenium levels are controlled through the selenocysteine machinery and expression of abundant selenoproteins; copper balance is affected by lipid metabolism and requires machinery involved in protein trafficking and posttranslational modifications; and the iron levels are influenced by iron import and expression of the iron/heme-containing enzymes. Our approach can be applied to a variety of disease models and/or nutritional conditions, and the generated dataset opens new directions for studies of human trace element metabolism. PMID:24522796

Genetic therapy for the nervous system.

PubMed

Bowers, William J; Breakefield, Xandra O; Sena-Esteves, Miguel

2011-04-15

Genetic therapy is undergoing a renaissance with expansion of viral and synthetic vectors, use of oligonucleotides (RNA and DNA) and sequence-targeted regulatory molecules, as well as genetically modified cells, including induced pluripotent stem cells from the patients themselves. Several clinical trials for neurologic syndromes appear quite promising. This review covers genetic strategies to ameliorate neurologic syndromes of different etiologies, including lysosomal storage diseases, Alzheimer's disease and other amyloidopathies, Parkinson's disease, spinal muscular atrophy, amyotrophic lateral sclerosis and brain tumors. This field has been propelled by genetic technologies, including identifying disease genes and disruptive mutations, design of genomic interacting elements to regulate transcription and splicing of specific precursor mRNAs and use of novel non-coding regulatory RNAs. These versatile new tools for manipulation of genetic elements provide the ability to tailor the mode of genetic intervention to specific aspects of a disease state.

Design and experimental results of the 1-T Bitter Electromagnet Testing Apparatus (BETA)

NASA Astrophysics Data System (ADS)

Bates, E. M.; Birmingham, W. J.; Romero-Talamás, C. A.

2018-05-01

The Bitter Electromagnet Testing Apparatus (BETA) is a 1-Tesla (T) technical prototype of the 10 T Adjustable Long Pulsed High-Field Apparatus. BETA's final design specifications are highlighted in this paper which include electromagnetic, thermal, and stress analyses. We discuss here the design and fabrication of BETA's core, vessel, cooling, and electrical subsystems. The electrical system of BETA is composed of a scalable solid-state DC breaker circuit. Experimental results display the stable operation of BETA at 1 T. These results are compared to both analytical design and finite element calculations. Experimental results validate analytical magnet designing methods developed at the Dusty Plasma Laboratory. The theoretical steady state maxima and the limits of BETA's design are explored in this paper.

Design and experimental results of the 1-T Bitter Electromagnet Testing Apparatus (BETA).

PubMed

Bates, E M; Birmingham, W J; Romero-Talamás, C A

2018-05-01

The Bitter Electromagnet Testing Apparatus (BETA) is a 1-Tesla (T) technical prototype of the 10 T Adjustable Long Pulsed High-Field Apparatus. BETA's final design specifications are highlighted in this paper which include electromagnetic, thermal, and stress analyses. We discuss here the design and fabrication of BETA's core, vessel, cooling, and electrical subsystems. The electrical system of BETA is composed of a scalable solid-state DC breaker circuit. Experimental results display the stable operation of BETA at 1 T. These results are compared to both analytical design and finite element calculations. Experimental results validate analytical magnet designing methods developed at the Dusty Plasma Laboratory. The theoretical steady state maxima and the limits of BETA's design are explored in this paper.

Stacking interactions in PUF-RNA complexes

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

Yiling Koh, Yvonne; Wang, Yeming; Qiu, Chen

2012-07-02

Stacking interactions between amino acids and bases are common in RNA-protein interactions. Many proteins that regulate mRNAs interact with single-stranded RNA elements in the 3' UTR (3'-untranslated region) of their targets. PUF proteins are exemplary. Here we focus on complexes formed between a Caenorhabditis elegans PUF protein, FBF, and its cognate RNAs. Stacking interactions are particularly prominent and involve every RNA base in the recognition element. To assess the contribution of stacking interactions to formation of the RNA-protein complex, we combine in vivo selection experiments with site-directed mutagenesis, biochemistry, and structural analysis. Our results reveal that the identities of stackingmore » amino acids in FBF affect both the affinity and specificity of the RNA-protein interaction. Substitutions in amino acid side chains can restrict or broaden RNA specificity. We conclude that the identities of stacking residues are important in achieving the natural specificities of PUF proteins. Similarly, in PUF proteins engineered to bind new RNA sequences, the identity of stacking residues may contribute to 'target' versus 'off-target' interactions, and thus be an important consideration in the design of proteins with new specificities.« less

Design principles for elementary gene circuits: Elements, methods, and examples

NASA Astrophysics Data System (ADS)

Savageau, Michael A.

2001-03-01

The control of gene expression involves complex circuits that exhibit enormous variation in design. For years the most convenient explanation for these variations was historical accident. According to this view, evolution is a haphazard process in which many different designs are generated by chance; there are many ways to accomplish the same thing, and so no further meaning can be attached to such different but equivalent designs. In recent years a more satisfying explanation based on design principles has been found for at least certain aspects of gene circuitry. By design principle we mean a rule that characterizes some biological feature exhibited by a class of systems such that discovery of the rule allows one not only to understand known instances but also to predict new instances within the class. The central importance of gene regulation in modern molecular biology provides strong motivation to search for more of these underlying design principles. The search is in its infancy and there are undoubtedly many design principles that remain to be discovered. The focus of this three-part review will be the class of elementary gene circuits in bacteria. The first part reviews several elements of design that enter into the characterization of elementary gene circuits in prokaryotic organisms. Each of these elements exhibits a variety of realizations whose meaning is generally unclear. The second part reviews mathematical methods used to represent, analyze, and compare alternative designs. Emphasis is placed on particular methods that have been used successfully to identify design principles for elementary gene circuits. The third part reviews four design principles that make specific predictions regarding (1) two alternative modes of gene control, (2) three patterns of coupling gene expression in elementary circuits, (3) two types of switches in inducible gene circuits, and (4) the realizability of alternative gene circuits and their response to phased environmental cues. In each case, the predictions are supported by experimental evidence. These results are important for understanding the function, design, and evolution of elementary gene circuits.

CMOS Imaging of Pin-Printed Xerogel-Based Luminescent Sensor Microarrays.

PubMed

Yao, Lei; Yung, Ka Yi; Khan, Rifat; Chodavarapu, Vamsy P; Bright, Frank V

2010-12-01

We present the design and implementation of a luminescence-based miniaturized multisensor system using pin-printed xerogel materials which act as host media for chemical recognition elements. We developed a CMOS imager integrated circuit (IC) to image the luminescence response of the xerogel-based sensor array. The imager IC uses a 26 × 20 (520 elements) array of active pixel sensors and each active pixel includes a high-gain phototransistor to convert the detected optical signals into electrical currents. The imager includes a correlated double sampling circuit and pixel address/digital control circuit; the image data is read-out as coded serial signal. The sensor system uses a light-emitting diode (LED) to excite the target analyte responsive luminophores doped within discrete xerogel-based sensor elements. As a prototype, we developed a 4 × 4 (16 elements) array of oxygen (O 2 ) sensors. Each group of 4 sensor elements in the array (arranged in a row) is designed to provide a different and specific sensitivity to the target gaseous O 2 concentration. This property of multiple sensitivities is achieved by using a strategic mix of two oxygen sensitive luminophores ([Ru(dpp) 3 ] 2+ and ([Ru(bpy) 3 ] 2+ ) in each pin-printed xerogel sensor element. The CMOS imager consumes an average power of 8 mW operating at 1 kHz sampling frequency driven at 5 V. The developed prototype system demonstrates a low cost and miniaturized luminescence multisensor system.

Magnet design for a low-emittance storage ring

PubMed Central

Johansson, Martin; Anderberg, Bengt; Lindgren, Lars-Johan

2014-01-01

The MAX IV 3 GeV storage ring, currently under construction, pursues the goal of low electron beam emittance by using a multi-bend achromat magnet lattice, which is realised by having several consecutive magnet elements precision-machined out of a common solid iron block, 2.3–3.4 m long. With this magnet design solution, instead of having 1320 individual magnets, the MAX IV 3 GeV storage ring is built up using 140 integrated ‘magnet block’ units, containing all these magnet elements. Major features of this magnet block design are compactness, vibration stability and that the alignment of magnet elements within each unit is given by the mechanical accuracy of the CNC machining rather than individual field measurement and adjustment. This article presents practical engineering details of implementing this magnet design solution, and mechanical + magnetic field measurement results from the magnet production series. At the time of writing (spring 2014), the production series, which is totally outsourced to industry, is roughly half way through, with mechanical/magnetic QA conforming to specifications. It is the conclusion of the authors that the MAX IV magnet block concept, which has sometimes been described as new or innovative, is from a manufacturing point of view simply a collection of known mature production methods and measurement procedures, which can be executed at fixed cost with a low level of risk. PMID:25177980

Clinical extracts of biomedical literature for patient-centered problem solving.

PubMed Central

Florance, V

1996-01-01

This paper reports on a four-part qualitative research project aimed at designing an online document surrogate tailored to the needs of physicians seeking biomedical literature for use in clinical problem solving. The clinical extract, designed in collaboration with three practicing physicians, combines traditional elements of the MEDLINE record (e.g., title, author, source, abstract) with new elements (e.g., table captions, text headings, case profiles) suggested by the physicians. Specifications for the prototype clinical extract were developed through a series of relevance-scoring exercises and semi-structured interviews. For six clinical questions, three physicians assessed the applicability of selected articles and their document surrogates, articulating relevance criteria and reasons for their judgments. A prototype clinical extract based on their suggestions was developed, tested, evaluated, and revised. The final version includes content and format aids to make the extract easy to use. The goals, methods, and outcomes of the research study are summarized, and a template of the final design is provided. PMID:8883986

Discriminating between stabilizing and destabilizing protein design mutations via recombination and simulation.

PubMed

Johnson, Lucas B; Gintner, Lucas P; Park, Sehoo; Snow, Christopher D

2015-08-01

Accuracy of current computational protein design (CPD) methods is limited by inherent approximations in energy potentials and sampling. These limitations are often used to qualitatively explain design failures; however, relatively few studies provide specific examples or quantitative details that can be used to improve future CPD methods. Expanding the design method to include a library of sequences provides data that is well suited for discriminating between stabilizing and destabilizing design elements. Using thermophilic endoglucanase E1 from Acidothermus cellulolyticus as a model enzyme, we computationally designed a sequence with 60 mutations. The design sequence was rationally divided into structural blocks and recombined with the wild-type sequence. Resulting chimeras were assessed for activity and thermostability. Surprisingly, unlike previous chimera libraries, regression analysis based on one- and two-body effects was not sufficient for predicting chimera stability. Analysis of molecular dynamics simulations proved helpful in distinguishing stabilizing and destabilizing mutations. Reverting to the wild-type amino acid at destabilized sites partially regained design stability, and introducing predicted stabilizing mutations in wild-type E1 significantly enhanced thermostability. The ability to isolate stabilizing and destabilizing elements in computational design offers an opportunity to interpret previous design failures and improve future CPD methods. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Influence of residual elements in lead on oxygen- and hydrogen-gassing rates of lead-acid batteries

NASA Astrophysics Data System (ADS)

Lam, L. T.; Ceylan, H.; Haigh, N. P.; Lwin, T.; Rand, D. A. J.

Raw lead materials contain many residual elements. With respect to setting 'safe' levels for these elements, each country has its own standard, but the majority of the present specifications for the lead used to prepare battery oxide apply to flooded batteries that employ antimonial grids. In these batteries, the antimony in the positive and negative grids dominates gassing characteristics so that the influence of residual elements is of little importance. This is, however, not the case for valve-regulated lead-acid (VRLA) batteries, which use antimony-free grids and less sulfuric acid solution. Thus, it is necessary to specify 'acceptable' levels of residual elements for the production of VRLA batteries. In this study, 17 elements are examined, namely: antimony, arsenic, bismuth, cadmium, chromium, cobalt, copper, germanium, iron, manganese, nickel, selenium, silver, tellurium, thallium, tin, and zinc. The following strategy has been formulated to determine the acceptable levels: (i) selection of a control oxide; (ii) determination of critical float, hydrogen and oxygen currents; (iii) establishment of a screening plan for the elements; (iv) development of a statistical method for analysis of the experimental results. The critical values of the float, hydrogen and oxygen currents are calculated from a field survey of battery failure data. The values serve as a base-line for comparison with the corresponding measured currents from cells using positive and negative plates produced either from the control oxide or from oxide doped with different levels of the 17 elements in combination. The latter levels are determined by means of a screening plan which is based on the Plackett-Burman experimental design. Following this systematic and thorough exercise, two specifications are proposed for the purity of the lead to be used in oxide production for VRLA technology.

Principles for computational design of binding antibodies

PubMed Central

Pszolla, M. Gabriele; Lapidoth, Gideon D.; Norn, Christoffer; Dym, Orly; Unger, Tamar; Albeck, Shira; Tyka, Michael D.; Fleishman, Sarel J.

2017-01-01

Natural proteins must both fold into a stable conformation and exert their molecular function. To date, computational design has successfully produced stable and atomically accurate proteins by using so-called “ideal” folds rich in regular secondary structures and almost devoid of loops and destabilizing elements, such as cavities. Molecular function, such as binding and catalysis, however, often demands nonideal features, including large and irregular loops and buried polar interaction networks, which have remained challenging for fold design. Through five design/experiment cycles, we learned principles for designing stable and functional antibody variable fragments (Fvs). Specifically, we (i) used sequence-design constraints derived from antibody multiple-sequence alignments, and (ii) during backbone design, maintained stabilizing interactions observed in natural antibodies between the framework and loops of complementarity-determining regions (CDRs) 1 and 2. Designed Fvs bound their ligands with midnanomolar affinities and were as stable as natural antibodies, despite having >30 mutations from mammalian antibody germlines. Furthermore, crystallographic analysis demonstrated atomic accuracy throughout the framework and in four of six CDRs in one design and atomic accuracy in the entire Fv in another. The principles we learned are general, and can be implemented to design other nonideal folds, generating stable, specific, and precise antibodies and enzymes. PMID:28973872

Novel green tissue-specific synthetic promoters and cis-regulatory elements in rice.

PubMed

Wang, Rui; Zhu, Menglin; Ye, Rongjian; Liu, Zuoxiong; Zhou, Fei; Chen, Hao; Lin, Yongjun

2015-12-11

As an important part of synthetic biology, synthetic promoter has gradually become a hotspot in current biology. The purposes of the present study were to synthesize green tissue-specific promoters and to discover green tissue-specific cis-elements. We first assembled several regulatory sequences related to tissue-specific expression in different combinations, aiming to obtain novel green tissue-specific synthetic promoters. GUS assays of the transgenic plants indicated 5 synthetic promoters showed green tissue-specific expression patterns and different expression efficiencies in various tissues. Subsequently, we scanned and counted the cis-elements in different tissue-specific promoters based on the plant cis-elements database PLACE and the rice cDNA microarray database CREP for green tissue-specific cis-element discovery, resulting in 10 potential cis-elements. The flanking sequence of one potential core element (GEAT) was predicted by bioinformatics. Then, the combination of GEAT and its flanking sequence was functionally identified with synthetic promoter. GUS assays of the transgenic plants proved its green tissue-specificity. Furthermore, the function of GEAT flanking sequence was analyzed in detail with site-directed mutagenesis. Our study provides an example for the synthesis of rice tissue-specific promoters and develops a feasible method for screening and functional identification of tissue-specific cis-elements with their flanking sequences at the genome-wide level in rice.

Ex-vivo HIFU experiments using a 32 × 32-element CMUT array

PubMed Central

Yoon, Hyo-Seon; Chang, Chienliu; Jang, Ji Hoon; Bhuyan, Anshuman; Choe, Jung Woo; Nikoozadeh, Amin; Watkins, Ronald D.; Stephens, Douglas N.; Pauly, Kim Butts; Khuri-Yakub, Butrus T.

2016-01-01

High-intensity focused ultrasound (HIFU) has been used as noninvasive treatment for various diseases. For these therapeutic applications, capacitive micromachined ultrasonic transducers (CMUTs) have advantages that make them potentially preferred transducers over traditional piezoelectric transducers. In this paper, we present the design and the fabrication process of an 8 × 8-mm2, 32 × 32-element 2-D CMUT array for HIFU applications. To reduce the system complexity for addressing the 1024 transducer elements, we propose to group the CMUT array elements into eight HIFU channels based on the phase delay from the CMUT element to the targeted focal point. Designed to focus at an 8-mm depth with a 5-MHz exciting frequency, this grouping scheme was realized using a custom application-specific integrated circuit (ASIC). With a 40-V DC bias and a 60-V peak-to-peak AC excitation, the surface pressure was measured 1.2 MPa peak-to-peak and stayed stable for a long enough time to create a lesion. With this DC and AC voltage combination, the measured peak-to-peak output pressure at the focus was 8.5 MPa, which is expected to generate a lesion in a minute according to the temperature simulation. Following ex-vivo tissue experiments successfully demonstrated its capability to make lesions in both bovine muscle and liver tissue. PMID:27913330

Synthetic river valleys: Creating prescribed topography for form-process inquiry and river rehabilitation design

NASA Astrophysics Data System (ADS)

Brown, R. A.; Pasternack, G. B.; Wallender, W. W.

2014-06-01

The synthesis of artificial landforms is complementary to geomorphic analysis because it affords a reflection on both the characteristics and intrinsic formative processes of real world conditions. Moreover, the applied terminus of geomorphic theory is commonly manifested in the engineering and rehabilitation of riverine landforms where the goal is to create specific processes associated with specific morphology. To date, the synthesis of river topography has been explored outside of geomorphology through artistic renderings, computer science applications, and river rehabilitation design; while within geomorphology it has been explored using morphodynamic modeling, such as one-dimensional simulation of river reach profiles, two-dimensional simulation of river networks, and three-dimensional simulation of subreach scale river morphology. To date, no approach allows geomorphologists, engineers, or river rehabilitation practitioners to create landforms of prescribed conditions. In this paper a method for creating topography of synthetic river valleys is introduced that utilizes a theoretical framework that draws from fluvial geomorphology, computer science, and geometric modeling. Such a method would be valuable to geomorphologists in understanding form-process linkages as well as to engineers and river rehabilitation practitioners in developing design surfaces that can be rapidly iterated. The method introduced herein relies on the discretization of river valley topography into geometric elements associated with overlapping and orthogonal two-dimensional planes such as the planform, profile, and cross section that are represented by mathematical functions, termed geometric element equations. Topographic surfaces can be parameterized independently or dependently using a geomorphic covariance structure between the spatial series of geometric element equations. To illustrate the approach and overall model flexibility examples are provided that are associated with mountain, lowland, and hybrid synthetic river valleys. To conclude, recommended advances such as multithread channels are discussed along with potential applications.

Bi-functional, substrate mimicking RNA inhibits MSK1-mediated cAMP-response element-binding protein phosphorylation and reveals magnesium ion-dependent conformational changes of the kinase.

PubMed

Hamm, Jorg; Alessi, Dario R; Biondi, Ricardo M

2002-11-29

The design of specific inhibitors for protein kinases is an important step toward elucidation of intracellular signal transduction pathways and to guide drug discovery programs. We devised a model approach to generate specific, competitive kinase inhibitors by isolating substrate mimics containing two independent binding sites with an anti-idiotype strategy from combinatorial RNA libraries. As a general test for the ability to generate highly specific kinase inhibitors, we selected the transcription factor cAMP-response element-binding protein (CREB) that is phosphorylated on the same serine residue by the protein kinase MSK1 as well as by RSK1. The sequences and structures of these kinases are very similar, about 60% of their amino acids are identical. Nevertheless, we can demonstrate that the selected RNA inhibitors inhibit specifically CREB phosphorylation by MSK1 but do not affect CREB phosphorylation by RSK1. The inhibitors interact preferentially with the inactive form of MSK1. Furthermore, we demonstrate that RNA ligands can be conformation-specific probes, and this feature allowed us to describe magnesium ion-dependent conformational changes of MSK1 upon activation.

Identification of a recently active Prunus-specific non-autonomous Mutator element with considerable genome shaping force.

PubMed

Halász, Júlia; Kodad, Ossama; Hegedűs, Attila

2014-07-01

Miniature inverted-repeat transposable elements (MITEs) are known to contribute to the evolution of plants, but only limited information is available for MITEs in the Prunus genome. We identified a MITE that has been named Falling Stones, FaSt. All structural features (349-bp size, 82-bp terminal inverted repeats and 9-bp target site duplications) are consistent with this MITE being a putative member of the Mutator transposase superfamily. FaSt showed a preferential accumulation in the short AT-rich segments of the euchromatin region of the peach genome. DNA sequencing and pollination experiments have been performed to confirm that the nested insertion of FaSt into the S-haplotype-specific F-box gene of apricot resulted in the breakdown of self-incompatibility (SI). A bioinformatics-based survey of the known Rosaceae and other genomes and a newly designed polymerase chain reaction (PCR) assay verified the Prunoideae-specific occurrence of FaSt elements. Phylogenetic analysis suggested a recent activity of FaSt in the Prunus genome. The occurrence of a nested insertion in the apricot genome further supports the recent activity of FaSt in response to abiotic stress conditions. This study reports on a presumably active non-autonomous Mutator element in Prunus that exhibits a major indirect genome shaping force through inducing loss-of-function mutation in the SI locus. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

Distribution of rare earth elements in soil and grape berries of Vitis vinifera cv. "Glera".

PubMed

Pepi, Salvatore; Sansone, Luigi; Chicca, Milvia; Marrocchino, Elena; Vaccaro, Carmela

2016-08-01

The renowned Vitis vinifera L. cultivar "Glera" (Magnoliopsida Vitaceae) has been grown for hundreds of years in the Italian regions of Veneto and Friuli to produce the sparkling Prosecco wine, with controlled designation of origin (DOC). We evaluated the relationship among the concentrations of rare earth elements (REE) in soil and in "Glera" grape berries in vineyards belonging to five different localities in the Veneto alluvial plain, all included in the DOC area of Prosecco. The concentration of REE in samples of soil and juice or solid residues of grape berries was determined by inductively coupled plasma mass spectrometry (ICP-MS), and the index of bioaccumulation was calculated to define the specific assimilation of these elements from soil to grape berries. The concentration of REE in soil samples allowed an identification of each locality examined, and REE were mostly detected in solid grape berry residues in comparison to juice. These data may be useful to associate REE distribution in soil and grape berries to a specific geographical origin, in order to prevent fraudulent use of wine denomination labels.

Optimal design of structures with multiple design variables per group and multiple loading conditions on the personal computer

NASA Technical Reports Server (NTRS)

Nguyen, D. T.; Rogers, J. L., Jr.

1986-01-01

A finite element based programming system for minimum weight design of a truss-type structure subjected to displacement, stress, and lower and upper bounds on design variables is presented. The programming system consists of a number of independent processors, each performing a specific task. These processors, however, are interfaced through a well-organized data base, thus making the tasks of modifying, updating, or expanding the programming system much easier in a friendly environment provided by many inexpensive personal computers. The proposed software can be viewed as an important step in achieving a 'dummy' finite element for optimization. The programming system has been implemented on both large and small computers (such as VAX, CYBER, IBM-PC, and APPLE) although the focus is on the latter. Examples are presented to demonstrate the capabilities of the code. The present programming system can be used stand-alone or as part of the multilevel decomposition procedure to obtain optimum design for very large scale structural systems. Furthermore, other related research areas such as developing optimization algorithms (or in the larger level: a structural synthesis program) for future trends in using parallel computers may also benefit from this study.

Minimizing energy dissipation of matrix multiplication kernel on Virtex-II

NASA Astrophysics Data System (ADS)

Choi, Seonil; Prasanna, Viktor K.; Jang, Ju-wook

2002-07-01

In this paper, we develop energy-efficient designs for matrix multiplication on FPGAs. To analyze the energy dissipation, we develop a high-level model using domain-specific modeling techniques. In this model, we identify architecture parameters that significantly affect the total energy (system-wide energy) dissipation. Then, we explore design trade-offs by varying these parameters to minimize the system-wide energy. For matrix multiplication, we consider a uniprocessor architecture and a linear array architecture to develop energy-efficient designs. For the uniprocessor architecture, the cache size is a parameter that affects the I/O complexity and the system-wide energy. For the linear array architecture, the amount of storage per processing element is a parameter affecting the system-wide energy. By using maximum amount of storage per processing element and minimum number of multipliers, we obtain a design that minimizes the system-wide energy. We develop several energy-efficient designs for matrix multiplication. For example, for 6×6 matrix multiplication, energy savings of upto 52% for the uniprocessor architecture and 36% for the linear arrary architecture is achieved over an optimized library for Virtex-II FPGA from Xilinx.

Study of design and technology factors influencing gas turbine blade cooling

NASA Astrophysics Data System (ADS)

Shevchenko, I. V.; Garanin, I. V.; Rogalev, A. N.; Kindra, V. O.; Khudyakova, V. P.

2017-11-01

The knowledge of aerodynamic and thermal parameters of turbulators used in order to design an efficient blade cooling system. However, all experimental tests of the hydraulic and thermal characteristics of the turbulators were conducted on the rectangular shape channels with a strongly defined air flow direction. The actual blades have geometry of the channels that essentially differs from the rectangular shape. Specifically, the air flow in the back cavity of a blade with one and half-pass cooling channel changes its direction throughout the feather height. In most cases the ribs and pins are made with a tilt to the channel walls, which is determined by the moving element design of a mould for the ceramic rod element fabrication. All of the factors described above may result in the blade thermohydraulic model being developed failing to fully simulate the air flow and the heat exchange processes in some sections of the cooling path. Hence, the design temperature field will differ from the temperature field of an actual blade. This article studied the numerical data of design and technology factors influencing heat transfer in the cooling channels. The results obtained showed their substantial impact on the blade cooling efficiency.

A three-dimensional finite-element thermal/mechanical analytical technique for high-performance traveling wave tubes

NASA Technical Reports Server (NTRS)

Bartos, Karen F.; Fite, E. Brian; Shalkhauser, Kurt A.; Sharp, G. Richard

1991-01-01

Current research in high-efficiency, high-performance traveling wave tubes (TWT's) has led to the development of novel thermal/ mechanical computer models for use with helical slow-wave structures. A three-dimensional, finite element computer model and analytical technique used to study the structural integrity and thermal operation of a high-efficiency, diamond-rod, K-band TWT designed for use in advanced space communications systems. This analysis focused on the slow-wave circuit in the radiofrequency section of the TWT, where an inherent localized heating problem existed and where failures were observed during earlier cold compression, or 'coining' fabrication technique that shows great potential for future TWT development efforts. For this analysis, a three-dimensional, finite element model was used along with MARC, a commercially available finite element code, to simulate the fabrication of a diamond-rod TWT. This analysis was conducted by using component and material specifications consistent with actual TWT fabrication and was verified against empirical data. The analysis is nonlinear owing to material plasticity introduced by the forming process and also to geometric nonlinearities presented by the component assembly configuration. The computer model was developed by using the high efficiency, K-band TWT design but is general enough to permit similar analyses to be performed on a wide variety of TWT designs and styles. The results of the TWT operating condition and structural failure mode analysis, as well as a comparison of analytical results to test data are presented.

A three-dimensional finite-element thermal/mechanical analytical technique for high-performance traveling wave tubes

NASA Technical Reports Server (NTRS)

Shalkhauser, Kurt A.; Bartos, Karen F.; Fite, E. B.; Sharp, G. R.

1992-01-01

Current research in high-efficiency, high-performance traveling wave tubes (TWT's) has led to the development of novel thermal/mechanical computer models for use with helical slow-wave structures. A three-dimensional, finite element computer model and analytical technique used to study the structural integrity and thermal operation of a high-efficiency, diamond-rod, K-band TWT designed for use in advanced space communications systems. This analysis focused on the slow-wave circuit in the radiofrequency section of the TWT, where an inherent localized heating problem existed and where failures were observed during earlier cold compression, or 'coining' fabrication technique that shows great potential for future TWT development efforts. For this analysis, a three-dimensional, finite element model was used along with MARC, a commercially available finite element code, to simulate the fabrication of a diamond-rod TWT. This analysis was conducted by using component and material specifications consistent with actual TWT fabrication and was verified against empirical data. The analysis is nonlinear owing to material plasticity introduced by the forming process and also to geometric nonlinearities presented by the component assembly configuration. The computer model was developed by using the high efficiency, K-band TWT design but is general enough to permit similar analyses to be performed on a wide variety of TWT designs and styles. The results of the TWT operating condition and structural failure mode analysis, as well as a comparison of analytical results to test data are presented.

Conceptual design and multidisciplinary optimization of in-plane morphing wing structures

NASA Astrophysics Data System (ADS)

Inoyama, Daisaku; Sanders, Brian P.; Joo, James J.

2006-03-01

In this paper, the topology optimization methodology for the synthesis of distributed actuation system with specific applications to the morphing air vehicle is discussed. The main emphasis is placed on the topology optimization problem formulations and the development of computational modeling concepts. For demonstration purposes, the inplane morphing wing model is presented. The analysis model is developed to meet several important criteria: It must allow large rigid-body displacements, as well as variation in planform area, with minimum strain on structural members while retaining acceptable numerical stability for finite element analysis. Preliminary work has indicated that addressed modeling concept meets the criteria and may be suitable for the purpose. Topology optimization is performed on the ground structure based on this modeling concept with design variables that control the system configuration. In other words, states of each element in the model are design variables and they are to be determined through optimization process. In effect, the optimization process assigns morphing members as 'soft' elements, non-morphing load-bearing members as 'stiff' elements, and non-existent members as 'voids.' In addition, the optimization process determines the location and relative force intensities of distributed actuators, which is represented computationally as equal and opposite nodal forces with soft axial stiffness. Several different optimization problem formulations are investigated to understand their potential benefits in solution quality, as well as meaningfulness of formulation itself. Sample in-plane morphing problems are solved to demonstrate the potential capability of the methodology introduced in this paper.

Realizing the therapeutic potential of rare earth elements in designing nanoparticles to target and treat glioblastoma.

PubMed

Lu, Victor M; McDonald, Kerrie L; Townley, Helen E

2017-10-01

The prognosis of brain cancer glioblastoma (GBM) is poor, and despite intense research, there have been no significant improvements within the last decade. This stasis implicates the need for more novel therapeutic investigation. One such option is the use of nanoparticles (NPs), which can be beneficial due to their ability to penetrate the brain, overcome the blood-brain barrier and take advantage of the enhanced permeation and retention effect of GBM to improve specificity. Rare earth elements possess a number of interesting natural properties due to their unique electronic configuration, which may prove therapeutically advantageous in an NP formulation. The underexplored exciting potential for rare earth elements to augment the therapeutic potential of NPs in GBM treatment is discussed in this review.

CFD in the context of IHPTET - The Integrated High Performance Turbine Engine Technology Program

NASA Technical Reports Server (NTRS)

Simoneau, Robert J.; Hudson, Dale A.

1989-01-01

The Integrated High Performance Turbine Engine Technology (IHPTET) Program is an integrated DOD/NASA technology program designed to double the performance capability of today's most advanced military turbine engines as we enter the twenty-first century. Computational Fluid Dynamics (CFD) is expected to play an important role in the design/analysis of specific configurations within this complex machine. In order to do this, a plan is being developed to ensure the timely impact of CFD on IHPTET. The developing philosophy of CFD in the context of IHPTET is discussed. The key elements in the developing plan and specific examples of state-of-the-art CFD efforts which are IHPTET turbine engine relevant are discussed.

Compressed Natural Gas Vehicle Maintenance Facility Modification Handbook

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

Kelly, K.; Melendez, M.; Gonzales, J.

To ensure the safety of personnel and facilities, vehicle maintenance facilities are required by law and by guidelines of the National Fire Protection Association (NFPA) and the International Fire Code (IFC) to exhibit certain design features. They are also required to be fitted with certain fire protection equipment and devices because of the potential for fire or explosion in the event of fuel leakage or spills. All fuels have an explosion or fire potential if specific conditions are present. This handbook covers the primary elements that must be considered when developing a CNG vehicle maintenance facility design that will protectmore » against the ignition of natural gas releases. It also discusses specific protocols and training needed to ensure safety.« less

Discovery of rare, diagnostic AluYb8/9 elements in diverse human populations.

PubMed

Feusier, Julie; Witherspoon, David J; Scott Watkins, W; Goubert, Clément; Sasani, Thomas A; Jorde, Lynn B

2017-01-01

Polymorphic human Alu elements are excellent tools for assessing population structure, and new retrotransposition events can contribute to disease. Next-generation sequencing has greatly increased the potential to discover Alu elements in human populations, and various sequencing and bioinformatics methods have been designed to tackle the problem of detecting these highly repetitive elements. However, current techniques for Alu discovery may miss rare, polymorphic Alu elements. Combining multiple discovery approaches may provide a better profile of the polymorphic Alu mobilome. Alu Yb8/9 elements have been a focus of our recent studies as they are young subfamilies (~2.3 million years old) that contribute ~30% of recent polymorphic Alu retrotransposition events. Here, we update our ME-Scan methods for detecting Alu elements and apply these methods to discover new insertions in a large set of individuals with diverse ancestral backgrounds. We identified 5,288 putative Alu insertion events, including several hundred novel Alu Yb8/9 elements from 213 individuals from 18 diverse human populations. Hundreds of these loci were specific to continental populations, and 23 non-reference population-specific loci were validated by PCR. We provide high-quality sequence information for 68 rare Alu Yb8/9 elements, of which 11 have hallmarks of an active source element. Our subfamily distribution of rare Alu Yb8/9 elements is consistent with previous datasets, and may be representative of rare loci. We also find that while ME-Scan and low-coverage, whole-genome sequencing (WGS) detect different Alu elements in 41 1000 Genomes individuals, the two methods yield similar population structure results. Current in-silico methods for Alu discovery may miss rare, polymorphic Alu elements. Therefore, using multiple techniques can provide a more accurate profile of Alu elements in individuals and populations. We improved our false-negative rate as an indicator of sample quality for future ME-Scan experiments. In conclusion, we demonstrate that ME-Scan is a good supplement for next-generation sequencing methods and is well-suited for population-level analyses.

Designing synthetic RNAs to determine the relevance of structural motifs in picornavirus IRES elements

NASA Astrophysics Data System (ADS)

Fernandez-Chamorro, Javier; Lozano, Gloria; Garcia-Martin, Juan Antonio; Ramajo, Jorge; Dotu, Ivan; Clote, Peter; Martinez-Salas, Encarnacion

2016-04-01

The function of Internal Ribosome Entry Site (IRES) elements is intimately linked to their RNA structure. Viral IRES elements are organized in modular domains consisting of one or more stem-loops that harbor conserved RNA motifs critical for internal initiation of translation. A conserved motif is the pyrimidine-tract located upstream of the functional initiation codon in type I and II picornavirus IRES. By computationally designing synthetic RNAs to fold into a structure that sequesters the polypyrimidine tract in a hairpin, we establish a correlation between predicted inaccessibility of the pyrimidine tract and IRES activity, as determined in both in vitro and in vivo systems. Our data supports the hypothesis that structural sequestration of the pyrimidine-tract within a stable hairpin inactivates IRES activity, since the stronger the stability of the hairpin the higher the inhibition of protein synthesis. Destabilization of the stem-loop immediately upstream of the pyrimidine-tract also decreases IRES activity. Our work introduces a hybrid computational/experimental method to determine the importance of structural motifs for biological function. Specifically, we show the feasibility of using the software RNAiFold to design synthetic RNAs with particular sequence and structural motifs that permit subsequent experimental determination of the importance of such motifs for biological function.

Improved design of special boundary elements for T-shaped reinforced concrete walls

NASA Astrophysics Data System (ADS)

Ji, Xiaodong; Liu, Dan; Qian, Jiaru

2017-01-01

This study examines the design provisions of the Chinese GB 50011-2010 code for seismic design of buildings for the special boundary elements of T-shaped reinforced concrete walls and proposes an improved design method. Comparison of the design provisions of the GB 50011-2010 code and those of the American code ACI 318-14 indicates a possible deficiency in the T-shaped wall design provisions in GB 50011-2010. A case study of a typical T-shaped wall designed in accordance with GB 50011-2010 also indicates the insufficient extent of the boundary element at the non-flange end and overly conservative design of the flange end boundary element. Improved designs for special boundary elements of T-shaped walls are developed using a displacement-based method. The proposed design formulas produce a longer boundary element at the non-flange end and a shorter boundary element at the flange end, relative to those of the GB 50011-2010 provisions. Extensive numerical analysis indicates that T-shaped walls designed using the proposed formulas develop inelastic drift of 0.01 for both cases of the flange in compression and in tension.

Application-specific coarse-grained reconfigurable array: architecture and design methodology

NASA Astrophysics Data System (ADS)

Zhou, Li; Liu, Dongpei; Zhang, Jianfeng; Liu, Hengzhu

2015-06-01

Coarse-grained reconfigurable arrays (CGRAs) have shown potential for application in embedded systems in recent years. Numerous reconfigurable processing elements (PEs) in CGRAs provide flexibility while maintaining high performance by exploring different levels of parallelism. However, a difference remains between the CGRA and the application-specific integrated circuit (ASIC). Some application domains, such as software-defined radios (SDRs), require flexibility with performance demand increases. More effective CGRA architectures are expected to be developed. Customisation of a CGRA according to its application can improve performance and efficiency. This study proposes an application-specific CGRA architecture template composed of generic PEs (GPEs) and special PEs (SPEs). The hardware of the SPE can be customised to accelerate specific computational patterns. An automatic design methodology that includes pattern identification and application-specific function unit generation is also presented. A mapping algorithm based on ant colony optimisation is provided. Experimental results on the SDR target domain show that compared with other ordinary and application-specific reconfigurable architectures, the CGRA generated by the proposed method performs more efficiently for given applications.

Use of Probabilistic Engineering Methods in the Detailed Design and Development Phases of the NASA Ares Launch Vehicle

NASA Technical Reports Server (NTRS)

Fayssal, Safie; Weldon, Danny

2008-01-01

The United States National Aeronautics and Space Administration (NASA) is in the midst of a space exploration program called Constellation to send crew and cargo to the international Space Station, to the moon, and beyond. As part of the Constellation program, a new launch vehicle, Ares I, is being developed by NASA Marshall Space Flight Center. Designing a launch vehicle with high reliability and increased safety requires a significant effort in understanding design variability and design uncertainty at the various levels of the design (system, element, subsystem, component, etc.) and throughout the various design phases (conceptual, preliminary design, etc.). In a previous paper [1] we discussed a probabilistic functional failure analysis approach intended mainly to support system requirements definition, system design, and element design during the early design phases. This paper provides an overview of the application of probabilistic engineering methods to support the detailed subsystem/component design and development as part of the "Design for Reliability and Safety" approach for the new Ares I Launch Vehicle. Specifically, the paper discusses probabilistic engineering design analysis cases that had major impact on the design and manufacturing of the Space Shuttle hardware. The cases represent important lessons learned from the Space Shuttle Program and clearly demonstrate the significance of probabilistic engineering analysis in better understanding design deficiencies and identifying potential design improvement for Ares I. The paper also discusses the probabilistic functional failure analysis approach applied during the early design phases of Ares I and the forward plans for probabilistic design analysis in the detailed design and development phases.

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.

Brayton advanced heat receiver development program

NASA Technical Reports Server (NTRS)

Heidenreich, G. R.; Downing, R. S.; Lacey, Dovie E.

1989-01-01

NASA Lewis Research Center is managing an advanced solar dynamic (ASD) space power program. The objective of the ASD program is to develop small and lightweight solar dynamic systems which show significant improvement in efficiency and specific mass over the baseline design derived from the Space Station Freedom technology. The advanced heat receiver development program is a phased program to design, fabricate and test elements of a 7-kWe heat-receiver/thermal-energy-storage subsystem. Receivers for both Brayton and Stirling heat engines are being developed under separate contracts. Phase I, described here, is the current eighteen month effort to design and perform critical technology experiments on innovative concepts designed to reduce mass without compromising thermal efficiency and reliability.

High tech cognitive and acoustic enrichment for captive elephants.

PubMed

French, Fiona; Mancini, Clara; Sharp, Helen

2018-04-15

This paper investigates the potential for using technology to support the development of sensory and cognitive enrichment activities for captive elephants. It explores the usefulness of applying conceptual frameworks from interaction design and game design to the problem of developing species-specific smart toys that promote natural behaviours and provide stimulation. We adopted a Research through Design approach, and describe how scientific inquiry supported our design process, while the creation of artefacts guided our investigations into possible future solutions. Our fieldwork resulted in the development of an interactive prototype of an acoustic toy that elephants are able to control using interface elements constructed from a range of natural materials. Copyright © 2017 Elsevier B.V. All rights reserved.

Space Vehicle Terrestrial Environment Design Requirements Guidelines

NASA Technical Reports Server (NTRS)

Johnson, Dale L.; Keller, Vernon W.; Vaughan, William W.

2006-01-01

The terrestrial environment is an important driver of space vehicle structural, control, and thermal system design. NASA is currently in the process of producing an update to an earlier Terrestrial Environment Guidelines for Aerospace Vehicle Design and Development Handbook. This paper addresses the contents of this updated handbook, with special emphasis on new material being included in the areas of atmospheric thermodynamic models, wind dynamics, atmospheric composition, atmospheric electricity, cloud phenomena, atmospheric extremes, and sea state. In addition, the respective engineering design elements are discussed relative to terrestrial environment inputs that require consideration. Specific lessons learned that have contributed to the advancements made in the application and awareness of terrestrial environment inputs for aerospace engineering applications are presented.

Lasercom system architecture with reduced complexity

NASA Technical Reports Server (NTRS)

Lesh, James R. (Inventor); Chen, Chien-Chung (Inventor); Ansari, Homayoon (Inventor)

1994-01-01

Spatial acquisition and precision beam pointing functions are critical to spaceborne laser communication systems. In the present invention, a single high bandwidth CCD detector is used to perform both spatial acquisition and tracking functions. Compared to previous lasercom hardware design, the array tracking concept offers reduced system complexity by reducing the number of optical elements in the design. Specifically, the design requires only one detector and one beam steering mechanism. It also provides the means to optically close the point-ahead control loop. The technology required for high bandwidth array tracking was examined and shown to be consistent with current state of the art. The single detector design can lead to a significantly reduced system complexity and a lower system cost.

LaserCom System Architecture With Reduced Complexity

NASA Technical Reports Server (NTRS)

Lesh, James R. (Inventor); Chen, Chien-Chung (Inventor); Ansari, Homa-Yoon (Inventor)

1996-01-01

Spatial acquisition and precision beam pointing functions are critical to spaceborne laser communication systems. In the present invention a single high bandwidth CCD detector is used to perform both spatial acquisition and tracking functions. Compared to previous lasercom hardware design, the array tracking concept offers reduced system complexity by reducing the number of optical elements in the design. Specifically, the design requires only one detector and one beam steering mechanism. It also provides means to optically close the point-ahead control loop. The technology required for high bandwidth array tracking was examined and shown to be consistent with current state of the art. The single detector design can lead to a significantly reduced system complexity and a lower system cost.

A geometric nonlinear degenerated shell element using a mixed formulation with independently assumed strain fields. Final Report; Ph.D. Thesis, 1989

NASA Technical Reports Server (NTRS)

Graf, Wiley E.

1991-01-01

A mixed formulation is chosen to overcome deficiencies of the standard displacement-based shell model. Element development is traced from the incremental variational principle on through to the final set of equilibrium equations. Particular attention is paid to developing specific guidelines for selecting the optimal set of strain parameters. A discussion of constraint index concepts and their predictive capability related to locking is included. Performance characteristics of the elements are assessed in a wide variety of linear and nonlinear plate/shell problems. Despite limiting the study to geometric nonlinear analysis, a substantial amount of additional insight concerning the finite element modeling of thin plate/shell structures is provided. For example, in nonlinear analysis, given the same mesh and load step size, mixed elements converge in fewer iterations than equivalent displacement-based models. It is also demonstrated that, in mixed formulations, lower order elements are preferred. Additionally, meshes used to obtain accurate linear solutions do not necessarily converge to the correct nonlinear solution. Finally, a new form of locking was identified associated with employing elements designed for biaxial bending in uniaxial bending applications.

CAD/CAM approach to improving industry productivity gathers momentum

NASA Technical Reports Server (NTRS)

Fulton, R. E.

1982-01-01

Recent results and planning for the NASA/industry Integrated Programs for Aerospace-Vehicle Design (IPAD) program for improving productivity with CAD/CAM methods are outlined. The industrial group work is being mainly done by Boeing, and progress has been made in defining the designer work environment, developing requirements and a preliminary design for a future CAD/CAM system, and developing CAD/CAM technology. The work environment was defined by conducting a detailed study of a reference design process, and key software elements for a CAD/CAM system have been defined, specifically for interactive design or experiment control processes. Further work is proceeding on executive, data management, geometry and graphics, and general utility software, and dynamic aspects of the programs being developed are outlined

Engineering design aspects of the heat-pipe power system

NASA Technical Reports Server (NTRS)

Capell, B. M.; Houts, M. G.; Poston, D. I.; Berte, M.

1997-01-01

The Heat-pipe Power System (HPS) is a near-term, low-cost space power system designed at Los Alamos that can provide up to 1,000 kWt for many space nuclear applications. The design of the reactor is simple, modular, and adaptable. The basic design allows for the use of a variety of power conversion systems and reactor materials (including the fuel, clad, and heat pipes). This paper describes a project that was undertaken to develop a database supporting many engineering aspects of the HPS design. The specific tasks discussed in this paper are: the development of an HPS materials database, the creation of finite element models that will allow a wide variety of investigations, and the verification of past calculations.

Engineering specification and system design for CAD/CAM of custom shoes: UMC project effort

NASA Technical Reports Server (NTRS)

Bao, Han P.

1991-01-01

The goal of this project is to supplement the footwear design system of North Carolina State University (NCSU) with a software module to design and manufacture a combination sole. The four areas of concentration were: customization of NASCAD (NASA Computer Aided Design) to the footwear project; use of CENCIT data; computer aided manufacturing activities; and beginning work for the bottom elements of shoes. The task of generating a software module for producing a sole was completed with a demonstrated product realization. The software written in C was delivered to NCSU for inclusion in their design system for custom footwear known as LASTMOD. The machining process of the shoe last was improved using a spiral tool path approach.

Computational design and engineering of polymeric orthodontic aligners.

PubMed

Barone, S; Paoli, A; Razionale, A V; Savignano, R

2016-10-05

Transparent and removable aligners represent an effective solution to correct various orthodontic malocclusions through minimally invasive procedures. An aligner-based treatment requires patients to sequentially wear dentition-mating shells obtained by thermoforming polymeric disks on reference dental models. An aligner is shaped introducing a geometrical mismatch with respect to the actual tooth positions to induce a loading system, which moves the target teeth toward the correct positions. The common practice is based on selecting the aligner features (material, thickness, and auxiliary elements) by only considering clinician's subjective assessments. In this article, a computational design and engineering methodology has been developed to reconstruct anatomical tissues, to model parametric aligner shapes, to simulate orthodontic movements, and to enhance the aligner design. The proposed approach integrates computer-aided technologies, from tomographic imaging to optical scanning, from parametric modeling to finite element analyses, within a 3-dimensional digital framework. The anatomical modeling provides anatomies, including teeth (roots and crowns), jaw bones, and periodontal ligaments, which are the references for the down streaming parametric aligner shaping. The biomechanical interactions between anatomical models and aligner geometries are virtually reproduced using a finite element analysis software. The methodology allows numerical simulations of patient-specific conditions and the comparative analyses of different aligner configurations. In this article, the digital framework has been used to study the influence of various auxiliary elements on the loading system delivered to a maxillary and a mandibular central incisor during an orthodontic tipping movement. Numerical simulations have shown a high dependency of the orthodontic tooth movement on the auxiliary element configuration, which should then be accurately selected to maximize the aligner's effectiveness. Copyright © 2016 John Wiley & Sons, Ltd.

Development of synthetic selfish elements based on modular nucleases in Drosophila melanogaster.

PubMed

Simoni, Alekos; Siniscalchi, Carla; Chan, Yuk-Sang; Huen, David S; Russell, Steven; Windbichler, Nikolai; Crisanti, Andrea

2014-06-01

Selfish genes are DNA elements that increase their rate of genetic transmission at the expense of other genes in the genome and can therefore quickly spread within a population. It has been suggested that selfish elements could be exploited to modify the genome of entire populations for medical and ecological applications. Here we report that transcription activator-like effector nuclease (TALEN) and zinc finger nuclease (ZFN) can be engineered into site-specific synthetic selfish elements (SSEs) and demonstrate their transmission of up to 70% in the Drosophila germline. We show here that SSEs can spread via DNA break-induced homologous recombination, a process known as 'homing' similar to that observed for homing endonuclease genes (HEGs), despite their fundamentally different modes of DNA binding and cleavage. We observed that TALEN and ZFN have a reduced capability of secondary homing compared to HEG as their repetitive structure had a negative effect on their genetic stability. The modular architecture of ZFNs and TALENs allows for the rapid design of novel SSEs against specific genomic sequences making them potentially suitable for the genetic engineering of wild-type populations of animals and plants, in applications such as gene replacement or population suppression of pest species. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

Grasshopper, a long terminal repeat (LTR) retroelement in the phytopathogenic fungus Magnaporthe grisea.

PubMed

Dobinson, K F; Harris, R E; Hamer, J E

1993-01-01

The fungal phytopathogen Magnaporthe grisea parasitizes a wide variety of gramineous hosts. In the course of investigating the genetic relationship between pathogen genotype and host specificity we identified a retroelement that is present in some strains of M. grisea that infect finger millet and goosegrass (members of the plant genus Eleusine). The element, designated grasshopper (grh), is present in multiple copies and dispersed throughout the genome. DNA sequence analysis showed that grasshopper contains 198 base pair direct, long terminal repeats (LTRs) with features characteristic of retroviral and retrotransposon LTRs. Within the element we identified an open reading frame with sequences homologous to the reverse transcriptase, RNaseH, and integrase domains of retroelement pol genes. Comparison of the open reading frame with sequences from other retroelements showed that grh is related to the gypsy family of retrotransposons. Comparisons of the distribution of the grasshopper element with other dispersed repeated DNA sequences in M. grisea indicated that grasshopper was present in a broadly dispersed subgroup of Eleusine pathogens, suggesting that the element was acquired subsequent to the evolution of this host-specific form. We present arguments that the amplification of different retroelements within populations of M. grisea is a consequence of the clonal organization of the fungal populations.

NTREES Testing and Operations Status

NASA Technical Reports Server (NTRS)

Emrich, Bill

2007-01-01

Nuclear Thermal Rockets or NTR's have been suggested as a propulsion system option for vehicles traveling to the moon or Mars. These engines are capable of providing high thrust at specific impulses at least twice that of today's best chemical engines. The performance constraints on these engines are mainly the result of temperature limitations on the fuel coupled with a limited ability to withstand chemical attack by the hot hydrogen propellant. To operate at maximum efficiency, fuel forms are desired which can withstand the extremely hot, hostile environment characteristic of NTR operation for at least several hours. The simulation of such an environment would require an experimental device which could simultaneously approximate the power, flow, and temperature conditions which a nuclear fuel element (or partial element) would encounter during NTR operation. Such a simulation would allow detailed studies of the fuel behavior and hydrogen flow characteristics under reactor like conditions to be performed. Currently, the construction of such a simulator has been completed at the Marshall Space Flight Center, and will be used in the future to evaluate a wide variety of fuel element designs and the materials of which they are fabricated. This present work addresses the operational status of the Nuclear Thermal Rocket Element Environmental Simulator or NTREES and some of the design considerations which were considered prior to and during its construction.

Programmable Ultra-Lightweight System Adaptable Radio

NASA Technical Reports Server (NTRS)

Werkheiser, Arthur

2015-01-01

The programmable ultra-lightweight system adaptable radio (PULSAR) is a NASA Marshall Space Flight Center transceiver designed for the CubeSat market, but has the potential for other markets. The PULSAR project aims to reduce size, weight, and power while increasing telemetry data rate. The current version of the PULSAR has a mass of 2.2 kg and a footprint of 10.8 cm2. The height depends on the specific configuration. The PULSAR S-Band Communications Subsystem is an S- and X-band transponder system comprised of a receiver/detector (receiver) element, a transmitter element(s), and related power distribution, command, control, and telemetry element for operation and information interfaces. It is capable of receiving commands, encoding and transmitting telemetry, as well as providing tracking data in a manner compatible with Earthbased ground stations, near Earth network, and deep space network station resources. The software-defined radio's (SDR's) data format characteristics can be defined and reconfigured during spaceflight or prior to launch. The PULSAR team continues to evolve the SDR to improve the performance and form factor to meet the requirements that the CubeSat market space requires. One of the unique features is that the actual radio design can change (somewhat), but not require any hardware modifications due to the use of field programmable gate arrays.

Biomimetic Chemosensor: Designing Peptide Recognition Elements for Surface Functionalization of Carbon Nanotube Field Effect Transistors (Postprint)

DTIC Science & Technology

2009-12-01

Protein from the Honeybee Apis mellifera L. J. Biol. Chem. 2004, 279, 4459– 4464. 12. Mead, J. C. New Scientist 2007, November issue. 13. Inscentinel...of explo- sives and other analytes.12,13 The antennal-specific protein-1 (ASP1), an OBP from honeybee, Apis mel- lifera, contains a C-terminal tail

What If?: Writing Exercises for Fiction Writers. Revised and Expanded Edition.

ERIC Educational Resources Information Center

Bernays, Anne; Painter, Pamela

This book is designed to be a how-to-write-fiction guide that is long on specifics and short on theoretical material. Each section of the book deals with a separate element of fiction--characterization, dialogue, point of view, plot, etc. Every exercise in the book is introduced in an opening paragraph, followed by instructions for completing the…

Teaching Reflections about the Architectural Design of the Vocational Training Centers in Granada

ERIC Educational Resources Information Center

Rodríguez, Luis; Gallego, José L.; Rodríguez, Antonio V.

2016-01-01

If the specificity of the architectural space is considered as a measuring element in the education scope to value the prominence of teaching throughout history, it is worth mentioning that the configuration of the vocational training center as a first-rate education scenario that arrives half century of delay with respect to schools, has few…

Fire Safety's My Job. Eighth Grade. Fire Safety for Texans: Fire and Burn Prevention Curriculum Guide.

ERIC Educational Resources Information Center

Texas State Commission on Fire Protection, Austin.

This booklet comprises the eighth grade component of a series of curriculum guides on fire and burn prevention. Designed to meet the age-specific needs of eighth grade students, its objectives include: (1) focusing on technical aspects of fire hazards and detection, and (2) exploring fire hazards outside the home. Texas essential elements of…

WFF TOPEX Software Documentation Altimeter Instrument File (AIF) Processing, October 1998. Volume 3

NASA Technical Reports Server (NTRS)

Lee, Jeffrey; Lockwood, Dennis

2003-01-01

This document is a compendium of the WFF TOPEX Software Development Team's knowledge regarding Sensor Data Record (SDR) Processing. It includes many elements of a requirements document, a software specification document, a software design document, and a user's manual. In the more technical sections, this document assumes the reader is familiar with TOPEX and instrument files.

The Work Values of Teacher Training Students in a Spanish University. Symbiosis between Schwartz and Meaning of Work (MOW) Study Group

ERIC Educational Resources Information Center

Cortes Pascual, M. P. Alejandra

2009-01-01

Work values are linked with other relevant variables in career development, such as professional interests or vocational personality, are formed in a specific work context and influence the orientation intervention designed, for example, as an element of the professional portfolio or the development of transversal participatory and personal…

An Overview of the NASA Aviation Safety Program Propulsion Health Monitoring Element

NASA Technical Reports Server (NTRS)

Simon, Donald L.

2000-01-01

The NASA Aviation Safety Program (AvSP) has been initiated with aggressive goals to reduce the civil aviation accident rate, To meet these goals, several technology investment areas have been identified including a sub-element in propulsion health monitoring (PHM). Specific AvSP PHM objectives are to develop and validate propulsion system health monitoring technologies designed to prevent engine malfunctions from occurring in flight, and to mitigate detrimental effects in the event an in-flight malfunction does occur. A review of available propulsion system safety information was conducted to help prioritize PHM areas to focus on under the AvSP. It is noted that when a propulsion malfunction is involved in an aviation accident or incident, it is often a contributing factor rather than the sole cause for the event. Challenging aspects of the development and implementation of PHM technology such as cost, weight, robustness, and reliability are discussed. Specific technology plans are overviewed including vibration diagnostics, model-based controls and diagnostics, advanced instrumentation, and general aviation propulsion system health monitoring technology. Propulsion system health monitoring, in addition to engine design, inspection, maintenance, and pilot training and awareness, is intrinsic to enhancing aviation propulsion system safety.

Design and development of the mobile game based on the J2ME technology

NASA Astrophysics Data System (ADS)

He, Junhua

2011-12-01

With the continuous improvement of mobile performance, mobile entertainment applications market trend has been increasingly clear, mobile entertainment applications will be after the PC entertainment applications is another important business growth. Through the full analysis of the current mobile entertainment applications market demand and trends, the author has accumulated a lot of theoretical knowledge and practical experience. Rational, using of some new technology for a mobile entertainment games design, and described the development of key technologies required for mobile game an analysis and design of the game, and to achieve a complete game development. Light of the specific mobile game project - "Battle City", detailed the development of a mobile game based on the J2ME platform, the basic steps and the various key elements, focusing on how to use object-oriented thinking on the role of mobile phones in the abstract and Game Animation package, the source code with specific instructions.

Design and development of the mobile game based on the J2ME technology

NASA Astrophysics Data System (ADS)

He, JunHua

2012-01-01

With the continuous improvement of mobile performance, mobile entertainment applications market trend has been increasingly clear, mobile entertainment applications will be after the PC entertainment applications is another important business growth. Through the full analysis of the current mobile entertainment applications market demand and trends, the author has accumulated a lot of theoretical knowledge and practical experience. Rational, using of some new technology for a mobile entertainment games design, and described the development of key technologies required for mobile game an analysis and design of the game, and to achieve a complete game development. Light of the specific mobile game project - "Battle City", detailed the development of a mobile game based on the J2ME platform, the basic steps and the various key elements, focusing on how to use object-oriented thinking on the role of mobile phones in the abstract and Game Animation package, the source code with specific instructions.

Structural modeling for multicell composite rotor blades

NASA Technical Reports Server (NTRS)

Rehfield, Lawrence W.; Atilgan, Ali R.

1987-01-01

Composite material systems are currently good candidates for aerospace structures, primarily for the design flexibility they offer, i.e., it is possible to tailor the material and manufacturing approach to the application. A working definition of elastic or structural tailoring is the use of structural concept, fiber orientation, ply stacking sequence, and a blend of materials to achieve specific performance goals. In the design process, choices of materials and dimensions are made which produce specific response characteristics, and which permit the selected goals to be achieved. Common choices for tailoring goals are preventing instabilities or vibration resonances or enhancing damage tolerance. An essential, enabling factor in the design of tailored composite structures is structural modeling that accurately, but simply, characterizes response. The objective of this paper is to present a new multicell beam model for composite rotor blades and to validate predictions based on the new model by comparison with a finite element simulation in three benchmark static load cases.

Ground Operations Aerospace Language (GOAL). Volume 4: Interpretive code translator

NASA Technical Reports Server (NTRS)

1973-01-01

This specification identifies and describes the principal functions and elements of the Interpretive Code Translator which has been developed for use with the GOAL Compiler. This translator enables the user to convert a compliled GOAL program to a highly general binary format which is designed to enable interpretive execution. The translator program provides user controls which are designed to enable the selection of various output types and formats. These controls provide a means for accommodating many of the implementation options which are discussed in the Interpretive Code Guideline document. The technical design approach is given. The relationship between the translator and the GOAL compiler is explained and the principal functions performed by the Translator are described. Specific constraints regarding the use of the Translator are discussed. The control options are described. These options enable the user to select outputs to be generated by the translator and to control vrious aspects of the translation processing.

Robot-Assisted Fracture Surgery: Surgical Requirements and System Design.

PubMed

Georgilas, Ioannis; Dagnino, Giulio; Tarassoli, Payam; Atkins, Roger; Dogramadzi, Sanja

2018-03-09

The design of medical devices is a complex and crucial process to ensure patient safety. It has been shown that improperly designed devices lead to errors and associated accidents and costs. A key element for a successful design is incorporating the views of the primary and secondary stakeholders early in the development process. They provide insights into current practice and point out specific issues with the current processes and equipment in use. This work presents how information from a user-study conducted in the early stages of the RAFS (Robot Assisted Fracture Surgery) project informed the subsequent development and testing of the system. The user needs were captured using qualitative methods and converted to operational, functional, and non-functional requirements based on the methods derived from product design and development. This work presents how the requirements inform a new workflow for intra-articular joint fracture reduction using a robotic system. It is also shown how the various elements of the system are developed to explicitly address one or more of the requirements identified, and how intermediate verification tests are conducted to ensure conformity. Finally, a validation test in the form of a cadaveric trial confirms the ability of the designed system to satisfy the aims set by the original research question and the needs of the users.

Using Finite Element and Eigenmode Expansion Methods to Investigate the Periodic and Spectral Characteristic of Superstructure Fiber Bragg Gratings

PubMed Central

He, Yue-Jing; Hung, Wei-Chih; Lai, Zhe-Ping

2016-01-01

In this study, a numerical simulation method was employed to investigate and analyze superstructure fiber Bragg gratings (SFBGs) with five duty cycles (50%, 33.33%, 14.28%, 12.5%, and 10%). This study focuses on demonstrating the relevance between design period and spectral characteristics of SFBGs (in the form of graphics) for SFBGs of all duty cycles. Compared with complicated and hard-to-learn conventional coupled-mode theory, the result of the present study may assist beginner and expert designers in understanding the basic application aspects, optical characteristics, and design techniques of SFBGs, thereby indirectly lowering the physical concepts and mathematical skills required for entering the design field. To effectively improve the accuracy of overall computational performance and numerical calculations and to shorten the gap between simulation results and actual production, this study integrated a perfectly matched layer (PML), perfectly reflecting boundary (PRB), object meshing method (OMM), and boundary meshing method (BMM) into the finite element method (FEM) and eigenmode expansion method (EEM). The integrated method enables designers to easily and flexibly design optical fiber communication systems that conform to the specific spectral characteristic by using the simulation data in this paper, which includes bandwidth, number of channels, and band gap size. PMID:26861322

Advanced piloted aircraft flight control system design methodology. Volume 1: Knowledge base

NASA Technical Reports Server (NTRS)

Mcruer, Duane T.; Myers, Thomas T.

1988-01-01

The development of a comprehensive and electric methodology for conceptual and preliminary design of flight control systems is presented and illustrated. The methodology is focused on the design stages starting with the layout of system requirements and ending when some viable competing system architectures (feedback control structures) are defined. The approach is centered on the human pilot and the aircraft as both the sources of, and the keys to the solution of, many flight control problems. The methodology relies heavily on computational procedures which are highly interactive with the design engineer. To maximize effectiveness, these techniques, as selected and modified to be used together in the methodology, form a cadre of computational tools specifically tailored for integrated flight control system preliminary design purposes. While theory and associated computational means are an important aspect of the design methodology, the lore, knowledge and experience elements, which guide and govern applications are critical features. This material is presented as summary tables, outlines, recipes, empirical data, lists, etc., which encapsulate a great deal of expert knowledge. Much of this is presented in topical knowledge summaries which are attached as Supplements. The composite of the supplements and the main body elements constitutes a first cut at a a Mark 1 Knowledge Base for manned-aircraft flight control.

“Elegant Tool” Delivers Genome-Level Science for Electrolytes

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

Keith Arterburn

Now, a ‘disruptive, virtual scientific simulation tool’ delivers a new, genome-level investigation for electrolytes to develop better, more efficient batteries. Dr. Kevin Gering, an Idaho National Laboratory researcher, has developed the Advanced Electrolyte Model (AEM), a copyrighted molecular-based simulation tool that has been scientifically proven and validated using at least a dozen ‘real-world’ physical metrics. Nominated for the 2014 international R&D 100 Award, AEM revolutionizes electrolyte materials selection, optimizing combinations and key design elements to make battery design and experimentation quick, accurate and responsive to specific needs.

Space power reactor in-core thermionic multicell evolutionary (S-prime) design

NASA Astrophysics Data System (ADS)

Determan, William R.; Van Hagan, Tom H.

1993-01-01

A 5- to 40-kWe moderated in-core thermionic space nuclear power system (TI-SNPS) concept was developed to address the TI-SNPS program requirements. The 40-kWe baseline design uses multicell Thermionic Fuel Elements (TFEs) in a zirconium hydride moderated reactor to achieve a specific mass of 18.2 We/kg and a net end-of-mission (EOM) efficiency of 8.2%. The reactor is cooled with a single NaK-78 pumped loop, which rejects the heat through a 24 m2 heat pipe space radiator.

Improved On-Chip Measurement of Delay in an FPGA or ASIC

NASA Technical Reports Server (NTRS)

Chen, Yuan; Burke, Gary; Sheldon, Douglas

2007-01-01

An improved design has been devised for on-chip-circuitry for measuring the delay through a chain of combinational logic elements in a field-programmable gate array (FPGA) or application-specific integrated circuit (ASIC). In the improved design, the delay chain does not include input and output buffers and is not configured as an oscillator. Instead, the delay chain is made part of the signal chain of an on-chip pulse generator. The duration of the pulse is measured on-chip and taken to equal the delay.

Spacecraft Design Thermal Control Subsystem

NASA Technical Reports Server (NTRS)

Miyake, Robert N.

2008-01-01

The Thermal Control Subsystem engineers task is to maintain the temperature of all spacecraft components, subsystems, and the total flight system within specified limits for all flight modes from launch to end-of-mission. In some cases, specific stability and gradient temperature limits will be imposed on flight system elements. The Thermal Control Subsystem of "normal" flight systems, the mass, power, control, and sensing systems mass and power requirements are below 10% of the total flight system resources. In general the thermal control subsystem engineer is involved in all other flight subsystem designs.

Designing of plant artificial chromosome (PAC) by using the Chlorella smallest chromosome as a model system.

PubMed

Noutoshi, Y; Arai, R; Fujie, M; Yamada, T

1997-01-01

As a model for plant-type chromosomes, we have been characterizing molecular organization of the Chlorella vulgaris C-169 chromosome I. To identify chromosome structural elements including the centromeric region and replication origins, we constructed a chromosome I specific cosmid library and aligned each cosmid clones to generate contigs. So far, more than 80% of the entire chromosome I has been covered. A complete clonal physical reconstitution of chromosome I provides information on the structure and genomic organization of plant genome. We propose our strategy to construct an artificial chromosome by assembling the functional chromosome structural elements identified on Chrorella chromosome I.

Design of small-molecule epigenetic modulators

PubMed Central

Pachaiyappan, Boobalan

2013-01-01

The field of epigenetics has expanded rapidly to reveal multiple new targets for drug discovery. The functional elements of the epigenomic machinery can be catagorized as writers, erasers and readers, and together these elements control cellular gene expression and homeostasis. It is increasingly clear that aberrations in the epigenome can underly a variety of diseases, and thus discovery of small molecules that modulate the epigenome in a specific manner is a viable approach to the discovery of new therapeutic agents. In this Digest, the components of epigenetic control of gene expression will be briefly summarized, and efforts to identify small molecules that modulate epigenetic processes will be described. PMID:24300735

Low-speed single-element airfoil synthesis

NASA Technical Reports Server (NTRS)

Mcmasters, J. H.; Henderson, M. L.

1979-01-01

The use of recently developed airfoil analysis/design computational tools to clarify, enrich and extend the existing experimental data base on low-speed, single element airfoils is demonstrated. A discussion of the problem of tailoring an airfoil for a specific application at its appropriate Reynolds number is presented. This problem is approached by use of inverse (or synthesis) techniques, wherein a desirable set of boundary layer characteristics, performance objectives, and constraints are specified, which then leads to derivation of a corresponding viscous flow pressure distribution. Examples are presented which demonstrate the synthesis approach, following presentation of some historical information and background data which motivate the basic synthesis process.

Application of a Channel Design Method to High-Solidity Cascades and Tests of an Impulse Cascade with 90 Degrees of Turning

NASA Technical Reports Server (NTRS)

Stanitz, John D; Sheldrake, Leonard J

1953-01-01

A technique is developed for the application of a channel design method to the design of high-solidity cascades with prescribed velocity distributions as a function of arc length along the blade-element profile. The technique is applied to both incompressible and subsonic compressible, nonviscous, irrotational fluid motion. For compressible flow, the ratio of specific heats is assumed equal to -1.0. An impulse cascade with 90 degree turning was designed for incompressible flow and was tested at the design angle of attack over a range of downstream Mach number from 0.2 to coke flow. To achieve good efficiency, the cascade was designed for prescribed velocities and maximum blade loading according to limitations imposed by considerations of boundary-layer separation.

Genetic therapy for the nervous system

PubMed Central

Bowers, William J.; Breakefield, Xandra O.; Sena-Esteves, Miguel

2011-01-01

Genetic therapy is undergoing a renaissance with expansion of viral and synthetic vectors, use of oligonucleotides (RNA and DNA) and sequence-targeted regulatory molecules, as well as genetically modified cells, including induced pluripotent stem cells from the patients themselves. Several clinical trials for neurologic syndromes appear quite promising. This review covers genetic strategies to ameliorate neurologic syndromes of different etiologies, including lysosomal storage diseases, Alzheimer's disease and other amyloidopathies, Parkinson's disease, spinal muscular atrophy, amyotrophic lateral sclerosis and brain tumors. This field has been propelled by genetic technologies, including identifying disease genes and disruptive mutations, design of genomic interacting elements to regulate transcription and splicing of specific precursor mRNAs and use of novel non-coding regulatory RNAs. These versatile new tools for manipulation of genetic elements provide the ability to tailor the mode of genetic intervention to specific aspects of a disease state. PMID:21429918

Convenience of Statistical Approach in Studies of Architectural Ornament and Other Decorative Elements Specific Application

NASA Astrophysics Data System (ADS)

Priemetz, O.; Samoilov, K.; Mukasheva, M.

2017-11-01

An ornament is an actual phenomenon of the architecture modern theory, a common element in the practice of design and construction. It has been an important aspect of shaping for millennia. The description of the methods of its application occupies a large place in the studies on the theory and practice of architecture. However, the problem of the saturation of compositions with ornamentation, the specificity of its themes and forms have not been sufficiently studied yet. This aspect requires accumulation of additional knowledge. The application of quantitative methods for the plastic solutions types and a thematic diversity of facade compositions of buildings constructed in different periods creates another tool for an objective analysis of ornament development. It demonstrates the application of this approach for studying the features of the architectural development in Kazakhstan at the end of the XIX - XXI centuries.

Thermal modal analysis of novel non-pneumatic mechanical elastic wheel based on FEM and EMA

NASA Astrophysics Data System (ADS)

Zhao, Youqun; Zhu, Mingmin; Lin, Fen; Xiao, Zhen; Li, Haiqing; Deng, Yaoji

2018-01-01

A combination of Finite Element Method (FEM) and Experiment Modal Analysis (EMA) have been employed here to characterize the structural dynamic response of mechanical elastic wheel (ME-Wheel) operating under a specific thermal environment. The influence of high thermal condition on the structural dynamic response of ME-Wheel is investigated. The obtained results indicate that the EMA results are in accordance with those obtained using the proposed Finite Element (FE) model, indicting the high reliability of this FE model applied in analyzing the modal of ME-Wheel working under practical thermal environment. It demonstrates that the structural dynamic response of ME-Wheel operating under a specific thermal condition can be predicted and evaluated using the proposed analysis method, which is beneficial for the dynamic optimization design of the wheel structure to avoid tire temperature related vibration failure and improve safety of tire.

The elements of life and medicines

PubMed Central

Chellan, Prinessa; Sadler, Peter J

2015-01-01

Which elements are essential for human life? Here we make an element-by-element journey through the periodic table and attempt to assess whether elements are essential or not, and if they are, whether there is a relevant code for them in the human genome. There are many difficulties such as the human biochemistry of several so-called essential elements is not well understood, and it is not clear how we should classify elements that are involved in the destruction of invading microorganisms, or elements which are essential for microorganisms with which we live in symbiosis. In general, genes do not code for the elements themselves, but for specific chemical species, i.e. for the element, its oxidation state, type and number of coordinated ligands, and the coordination geometry. Today, the biological periodic table is in a position somewhat similar to Mendeleev's chemical periodic table of 1869: there are gaps and we need to do more research to fill them. The periodic table also offers potential for novel therapeutic and diagnostic agents, based on not only essential elements, but also non-essential elements, and on radionuclides. Although the potential for inorganic chemistry in medicine was realized more than 2000 years ago, this area of research is still in its infancy. Future advances in the design of inorganic drugs require more knowledge of their mechanism of action, including target sites and metabolism. Temporal speciation of elements in their biological environments at the atomic level is a major challenge, for which new methods are urgently needed. PMID:25666066

The elements of life and medicines.

PubMed

Chellan, Prinessa; Sadler, Peter J

2015-03-13

Which elements are essential for human life? Here we make an element-by-element journey through the periodic table and attempt to assess whether elements are essential or not, and if they are, whether there is a relevant code for them in the human genome. There are many difficulties such as the human biochemistry of several so-called essential elements is not well understood, and it is not clear how we should classify elements that are involved in the destruction of invading microorganisms, or elements which are essential for microorganisms with which we live in symbiosis. In general, genes do not code for the elements themselves, but for specific chemical species, i.e. for the element, its oxidation state, type and number of coordinated ligands, and the coordination geometry. Today, the biological periodic table is in a position somewhat similar to Mendeleev's chemical periodic table of 1869: there are gaps and we need to do more research to fill them. The periodic table also offers potential for novel therapeutic and diagnostic agents, based on not only essential elements, but also non-essential elements, and on radionuclides. Although the potential for inorganic chemistry in medicine was realized more than 2000 years ago, this area of research is still in its infancy. Future advances in the design of inorganic drugs require more knowledge of their mechanism of action, including target sites and metabolism. Temporal speciation of elements in their biological environments at the atomic level is a major challenge, for which new methods are urgently needed.

Advanced composites structural concepts and materials technologies for primary aircraft structures. Structural response and failure analysis: ISPAN modules users manual

NASA Technical Reports Server (NTRS)

Hairr, John W.; Huang, Jui-Ten; Ingram, J. Edward; Shah, Bharat M.

1992-01-01

The ISPAN Program (Interactive Stiffened Panel Analysis) is an interactive design tool that is intended to provide a means of performing simple and self contained preliminary analysis of aircraft primary structures made of composite materials. The program combines a series of modules with the finite element code DIAL as its backbone. Four ISPAN Modules were developed and are documented. These include: (1) flat stiffened panel; (2) curved stiffened panel; (3) flat tubular panel; and (4) curved geodesic panel. Users are instructed to input geometric and material properties, load information and types of analysis (linear, bifurcation buckling, or post-buckling) interactively. The program utilizing this information will generate finite element mesh and perform analysis. The output in the form of summary tables of stress or margins of safety, contour plots of loads or stress, and deflected shape plots may be generalized and used to evaluate specific design.

Water quality monitor (EMPAX instrument)

NASA Technical Reports Server (NTRS)

Kelliher, Warren C.; Clark, Ben; Thornton, Mike

1991-01-01

The impetus of the Viking Mission to Mars led to the first miniaturization of a X-ray Fluorescence Spectrometer (XRFS). Two units were flown on the Viking Mission and successfully operated for two years analyzing the elemental composition of the Martian soil. Under a Bureau of Mines/NASA Technology Utilization project, this XRFS design was utilized to produce a battery powered, portable unit for elemental analysis of geological samples. This paper will detail design improvements and additional sampling capabilities that were incorporated into a second generation portable XRFS that was funded by the EPA/NASA Technology Utilization project. The unit, Environment Monitoring with Portable Analysis by X-ray (EMPAX), was developed specifically for quantitative determination of the need of EPA and and any industry affected by environmental concerns, the EMPAX fulfills a critical need to provide on-site, real-time analysis of toxic metal contamination. A patent was issued on EMPAX, but a commercial manufacturer is still being sought.

Radiation Hard 0.13 Micron CMOS Library at IHP

NASA Astrophysics Data System (ADS)

Jagdhold, U.

2013-08-01

To support space applications we have developed an 0.13 micron CMOS library which should be radiation hard up to 200 krad. The article describes the concept to come to a radiation hard digital circuit and was introduces in 2010 [1]. By introducing new radiation hard design rules we will minimize IC-level leakage and single event latch-up (SEL). To reduce single event upset (SEU) we add two p-MOS transistors to all flip flops. For reliability reasons we use double contacts in all library elements. The additional rules and the library elements are integrated in our Cadence mixed signal design kit, “Virtuoso” IC6.1 [2]. A test chip is produced with our in house 0.13 micron BiCMOS technology, see Ref. [3]. As next step we will doing radiation tests according the european space agency (ESA) specifications, see Ref. [4], [5].

Antenna design for microwave hepatic ablation using an axisymmetric electromagnetic model

PubMed Central

Bertram, John M; Yang, Deshan; Converse, Mark C; Webster, John G; Mahvi, David M

2006-01-01

Background An axisymmetric finite element method (FEM) model was employed to demonstrate important techniques used in the design of antennas for hepatic microwave ablation (MWA). To effectively treat deep-seated hepatic tumors, these antennas should produce a highly localized specific absorption rate (SAR) pattern and be efficient radiators at approved generator frequencies. Methods and results As an example, a double slot choked antenna for hepatic MWA was designed and implemented using FEMLAB™ 3.0. Discussion This paper emphasizes the importance of factors that can affect simulation accuracy, which include boundary conditions, the dielectric properties of liver tissue, and mesh resolution. PMID:16504153

Results From PAPER/HERA

NASA Astrophysics Data System (ADS)

Pober, Jonathan C.

2018-05-01

The Precision Array for Probing the Epoch of Reionization (PAPER) was a first-generation 21 cm cosmology experiment with the specific goal of detecting the power spectrum of the 21 cm emission from the Epoch of Reionization. Analysis of PAPER data is still ongoing, but lessons learned from PAPER to date have played a critical role in designing the next-generation Hydrogen Epoch of Reionization Array (HERA) experiment. This article reviews five key design choices made by PAPER: use of a non-imaging configuration, redundancy, short baselines, small antenna elements, and a large instantaneous bandwidth. We describe the impact of these choices and the role they played in designing HERA.

Mind the gap - Deriving a compatible user mental model of the home heating system to encourage sustainable behaviour.

PubMed

Revell, Kirsten M A; Stanton, Neville A

2016-11-01

Householders' behaviour with their home heating systems is a considerable contributor to domestic energy consumption. To create a design specification for the 'scaffolding' needed for sustainable behaviour with home heating controls, Norman's (1986) Gulf of Execution and Evaluation was applied to the home heating system. A Home Heating Design Model (DM) was produced with a home heating expert. Norman's (1986) 7 Stages of Activity were considered to derive a Compatible User Mental Model (CUMM) of a typical Heating System. Considerable variation in the concepts needed at each stage was found. Elements that could be derived from the DM supported stages relating to action specification, execution, perception and interpretation, but many are not communicated in the design of typical heating controls. Stages relating to goals, intentions and evaluation required concepts beyond the DM. A systems view that tackles design for sustainable behaviour from a variety of levels is needed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Design and fabrication of microstrip antenna arrays

NASA Technical Reports Server (NTRS)

1978-01-01

A microstrip array project was conducted to demonstrate the feasibility of designing and fabricating simple, low cost, low sidelobe phased arrays with circular disk microstrip radiating elements. Design data were presented for microstrip elements and arrays including the effects of the protective covers, the mutual interaction between elements, and stripline feed network design. Low cost multilayer laminate fabrication techniques were also investigated. Utilizing this design data two C-band low sidelobe arrays were fabricated and tested: an eight-element linear and a sixty-four element planar array. These arrays incorporated stripline Butler matrix feed networks to produce a low sidelobe broadside beam.

Screen Layout Design: Research into the Overall Appearance of the Screen.

ERIC Educational Resources Information Center

Grabinger, R. Scott

1989-01-01

Examines the current state of research into the visual effects of screen designs used in computer-assisted instruction and suggests areas for future efforts. Topics discussed include technical elements and comprehensibility elements in layout design; single element and multiple element research methodologies; dependent variables; and learning…

Fuel element concept for long life high power nuclear reactors

NASA Technical Reports Server (NTRS)

Mcdonald, G. E.; Rom, F. E.

1969-01-01

Nuclear reactor fuel elements have burnups that are an order of magnitude higher than can currently be achieved by conventional design practice. Elements have greater time integrated power producing capacity per unit volume. Element design concept capitalizes on known design principles and observed behavior of nuclear fuel.

What housing features should inform the development of housing solutions for adults with neurological disability?: A systematic review of the literature.

PubMed

Wright, Courtney J; Zeeman, Heidi; Kendall, Elizabeth; Whitty, Jennifer A

2017-07-01

Despite the recent emphasis in Australian political, academic, and legislative narratives to more actively promote real housing choice for people with high healthcare and support needs, there is a lack of understanding regarding the specific housing features that might constitute better housing solutions for this population. Inclusive housing provision in Australia rightly emphasises safety and accessibility issues but often fails to incorporate factors related to broader psychosocial elements of housing such as dwelling location, neighbourhood quality, and overall design. While the importance of these broader elements appears obvious, it is not yet clear what specific housing features relate to these elements and how they might contribute to housing solutions for people with high healthcare and support needs. For individuals with complex neurological conditions such as brain injury or cerebral palsy, who require maximum support on a daily basis yet want to live independently and away from a primary care hospital or health facility, a more detailed understanding of the housing features that might influence design and development is needed. Thus, in order to clarify the broader factors related to housing solutions for this population, a systematic review was conducted to identify and synthesise the current research evidence (post-2003) and guide future housing design and development opportunities. From the included studies (n=26), 198 unique housing features were identified. From the 198 features, 142 related to housing design (i.e., internal or external characteristics of the dwelling and its land), 12 related to the dwelling's location (i.e., its proximity to available resources), and 54 related to the nature of the surrounding neighbourhood (i.e., the physical, social, and economic conditions of the area). The findings of this review contribute significantly to the literature by reporting a broader scope of relevant housing features for people with neurological disability, presenting preliminary guiding principles for housing design and development for this population, and identifying opportunities for future research. Copyright © 2017 Elsevier Ltd. All rights reserved.

Photopolymers for holographic optical elements in astronomy

NASA Astrophysics Data System (ADS)

Zanutta, A.; Orselli, E.; Fäcke, T.; Bianco, A.

2017-05-01

Holographic Optical Elements (HOEs) cover nowadays a relevant position as dispersing elements in astronomical spectrographs because each astronomical observation could take advantage of specific devices with features tailored for achieving the best performances. The design and manufacturing of highly efficient and reliable dispersive elements require photosensitive materials as recording substrate where it is possible to precisely control the parameters that define the efficiency response (namely both the refractive index modulation and the film thickness). The most promising materials in this field are the photopolymers because, beside the ability to provide the tuning feature, they bring also advantages such as self-developing, high refractive index modulation and ease of use thanks to their simple thin structure, which is insensitive from the external environment. In particular, Bayfol HX photopolymers were characterized with the purpose to use them as new material for astronomical Volume Phase Holographic Gratings. We designed and manufactured VPHGs for astronomical instrumentation and we demonstrated how photopolymers are reliable holographic materials for making astronomical devices with performances comparable to those provided by VPHGs based on Dichromated Gelatins (DCGs), but with a much simpler production process. Moreover, the versatility of these materials allowed us to propose and realize novel architectures of the spectroscopic dispersive elements. A compact and unique single prism device was realized for a FOSC spectrograph and new multi-layered devices are proposed, stacking VPHGs one on top of the other to obtain many spectra in the instrument's detector, with advantages as increase of resolution and signal to noise ratio with respect to the classical single dispersive element.

Design of ZnS/ZnSe Gradient-Index Lenses in the Mid-Wave Infrared and Design, Fabrication, and Thermal Metrology of Polymer Radial Gradient Index Lenses

NASA Astrophysics Data System (ADS)

Corsetti, James Anthony

Gradient-index (GRIN) materials are ones for which the index of refraction varies as a function of spatial coordinate within an optical element. The radial GRIN is a specific instance where the isoindicial surfaces, or surface of constant index of refraction, exist as concentric cylinders centered upon the optical axis. The variation of the index of refraction as a function of lens aperture yields a second source of optical power in the element with the first coming from the lens' surface curvatures. This fact, coupled with the chromatic variation of the GRIN profile, provides the optical designer with additional degrees of freedom as compared to a traditional homogeneous lens, most notably in the pursuit of correcting chromatic aberration. This thesis explores a number of topics related to the design, manufacture, and testing of radial GRIN elements. Such elements are used in a series of design studies, the first on the application of the crystalline ZnS/ZnSe GRIN material to the mid-wave infrared (MWIR) waveband between 3 and 5 mum and the second to a copolymer GRIN of polymethyl methacrylate (PMMA) and polystyrene over the visible spectrum. In both cases, GRIN singlets are seen to act as achromats over their respective wavebands. A series of zoom lens design studies are presented in which the GRIN designs consistently offer superior color correction and imaging performance over homogeneous designs of the same number of elements. Efforts to fabricate the PMMA/polystyrene radial GRIN are presented. For this purpose, a centrifugal force method is employed whereby both MMA and styrene monomer are rapidly rotated in a temperature-controlled environment. As copolymerization occurs, the spinning of the sample causes the isoindicial surfaces to take on a cylindrical shape. Process challenges including monomer-to-polymer volume reduction and haze are both presented along with a discussion of the fabricated radial samples. A profile manufactured in this way is modeled as part of the aforementioned zoom lens studies in CODEVRTM to determine the sensitivity of the design space to the GRIN profile shape. When designing any optical system, it is important to know how that system will behave with a change in temperature. In order to answer that, two key material parameters are defined: (1) the coefficient of thermal expansion (CTE) which dictates how much a material expands or contracts with a temperature change and (2) the temperature-dependent refractive index (dn/dT) which determines how the index of refraction changes. A series of computer models are presented for the purpose of determining how a radial GRIN element is affected by a given temperature change. Analogous to it being possible to achromatize a single radial GRIN element, modeling work shows that it is also possible to athermalize such an element. Finally, an interferometric system is presented for the purpose of measuring both the CTE and dn/dT of a sample simultaneously. The system operates by tracking changes in optical path difference between the sample and background as a function of temperature in order to carry out these measurements. Results on a number of samples including steel, ZrO2, CaF2, Zerodur, Sapphire, and a series of PMMA/polystyrene copolymers are presented.

Study of optical design of Blu-ray pickup head system with a liquid crystal element.

PubMed

Fang, Yi-Chin; Yen, Chih-Ta; Hsu, Jui-Hsin

2014-10-10

This paper proposes a newly developed optical design and an active compensation method for a Blu-ray pickup head system with a liquid crystal (LC) element. Different from traditional pickup lens design, this new optical design delivers performance as good as the conventional one but has more room for tolerance control, which plays a role in antishaking devices, such as portable Blu-ray players. A hole-pattern electrode and LC optics with external voltage input were employed to generate a symmetric nonuniform electrical field in the LC layer that directs LC molecules into the appropriate gradient refractive index distribution, resulting in the convergence or divergence of specific light beams. LC optics deliver fast and, most importantly, active compensation through optical design when errors occur. Simulations and tolerance analysis were conducted using Code V software, including various tolerance analyses, such as defocus, tilt, and decenter, and their related compensations. Two distinct Blu-ray pickup head system designs were examined in this study. In traditional Blu-ray pickup head system designs, the aperture stop is always set on objective lenses. In the study, the aperture stop is on the LC lens as a newly developed lens. The results revealed that an optical design with aperture stop set on the LC lens as an active compensation device successfully eliminated up to 57% of coma aberration compared with traditional optical designs so that this pickup head lens design will have more space for tolerance control.

A quantitative analysis study on the implementation of partnering in the design and build construction project

NASA Astrophysics Data System (ADS)

Halil, F. M.; Nasir, N. M.; Shukur, A. S.; Hashim, H.

2018-02-01

Design and Build construction project involved the biggest scale of the cost of investment as compared to the traditional approach. In Design and Build, the client hires a design professional that will design according to the client’s need and specification. This research aim is to explore the concept of partnering implementation practiced in the design and build procurement approach. Therefore, the selection of design professionals such as Contractors and consultants in the project is crucial to ensure the successful project completion on time, cost, and quality. The methodology adopted using quantitative approach. Administration of the questionnaire was distributed to the public client by using postal survey. Outcomes of the results, the public clients agreed that project management capabilities and commitment to budget as a crucial element of partnering from the design professional in design and build construction project.

Elements of Effective E-Learning Design

ERIC Educational Resources Information Center

Brown, Andrew R.; Voltz, Bradley D.

2005-01-01

Preparing and developing e-learning materials is a costly and time consuming enterprise. This paper highlights the elements of effective design that we consider assist in the development of high quality materials in a cost efficient way. We introduce six elements of design and discuss each in some detail. These elements focus on paying attention…

Custom-designed orthopedic implants evaluated using finite element analysis of patient-specific computed tomography data: femoral-component case study

PubMed Central

Harrysson, Ola LA; Hosni, Yasser A; Nayfeh, Jamal F

2007-01-01

Background Conventional knee and hip implant systems have been in use for many years with good success. However, the custom design of implant components based on patient-specific anatomy has been attempted to overcome existing shortcomings of current designs. The longevity of cementless implant components is highly dependent on the initial fit between the bone surface and the implant. The bone-implant interface design has historically been limited by the surgical tools and cutting guides available; and the cost of fabricating custom-designed implant components has been prohibitive. Methods This paper describes an approach where the custom design is based on a Computed Tomography scan of the patient's joint. The proposed design will customize both the articulating surface and the bone-implant interface to address the most common problems found with conventional knee-implant components. Finite Element Analysis is used to evaluate and compare the proposed design of a custom femoral component with a conventional design. Results The proposed design shows a more even stress distribution on the bone-implant interface surface, which will reduce the uneven bone remodeling that can lead to premature loosening. Conclusion The proposed custom femoral component design has the following advantages compared with a conventional femoral component. (i) Since the articulating surface closely mimics the shape of the distal femur, there is no need for resurfacing of the patella or gait change. (ii) Owing to the resulting stress distribution, bone remodeling is even and the risk of premature loosening might be reduced. (iii) Because the bone-implant interface can accommodate anatomical abnormalities at the distal femur, the need for surgical interventions and fitting of filler components is reduced. (iv) Given that the bone-implant interface is customized, about 40% less bone must be removed. The primary disadvantages are the time and cost required for the design and the possible need for a surgical robot to perform the bone resection. Some of these disadvantages may be eliminated by the use of rapid prototyping technologies, especially the use of Electron Beam Melting technology for quick and economical fabrication of custom implant components. PMID:17854508

Building Stories about Sea Level Rise through Interactive Visualizations

NASA Astrophysics Data System (ADS)

Stephens, S. H.; DeLorme, D. E.; Hagen, S. C.

2013-12-01

Digital media provide storytellers with dynamic new tools for communicating about scientific issues via interactive narrative visualizations. While traditional storytelling uses plot, characterization, and point of view to engage audiences with underlying themes and messages, interactive visualizations can be described as 'narrative builders' that promote insight through the process of discovery (Dove, G. & Jones, S. 2012, Proc. IHCI 2012). Narrative visualizations are used in online journalism to tell complex stories that allow readers to select aspects of datasets to explore and construct alternative interpretations of information (Segel, E. & Heer, J. 2010, IEEE Trans. Vis. Comp. Graph.16, 1139), thus enabling them to participate in the story-building process. Nevertheless, narrative visualizations also incorporate author-selected narrative elements that help guide and constrain the overall themes and messaging of the visualization (Hullman, J. & Diakopoulos, N. 2011, IEEE Trans. Vis. Comp. Graph. 17, 2231). One specific type of interactive narrative visualization that is used for science communication is the sea level rise (SLR) viewer. SLR viewers generally consist of a base map, upon which projections of sea level rise scenarios can be layered, and various controls for changing the viewpoint and scenario parameters. They are used to communicate the results of scientific modeling and help readers visualize the potential impacts of SLR on the coastal zone. Readers can use SLR viewers to construct personal narratives of the effects of SLR under different scenarios in locations that are important to them, thus extending the potential reach and impact of scientific research. With careful selection of narrative elements that guide reader interpretation, the communicative aspects of these visualizations may be made more effective. This presentation reports the results of a content analysis of a subset of existing SLR viewers selected in order to comprehensively identify and characterize the narrative elements that contribute to this storytelling medium. The results describe four layers of narrative elements in these viewers: data, visual representations, annotations, and interactivity; and explain the ways in which these elements are used to communicate about SLR. Most existing SLR viewers have been designed with attention to technical usability; however, careful design of narrative elements could increase their overall effectiveness as story-building tools. The analysis concludes with recommendations for narrative elements that should be considered when designing new SLR viewers, and offers suggestions for integrating these components to balance author-driven and reader-driven design features for more effective messaging.

CMOS Imaging of Temperature Effects on Pin-Printed Xerogel Sensor Microarrays.

PubMed

Lei Yao; Ka Yi Yung; Chodavarapu, Vamsy P; Bright, Frank V

2011-04-01

In this paper, we study the effect of temperature on the operation and performance of a xerogel-based sensor microarrays coupled to a complementary metal-oxide semiconductor (CMOS) imager integrated circuit (IC) that images the photoluminescence response from the sensor microarray. The CMOS imager uses a 32 × 32 (1024 elements) array of active pixel sensors and each pixel includes a high-gain phototransistor to convert the detected optical signals into electrical currents. A correlated double sampling circuit and pixel address/digital control/signal integration circuit are also implemented on-chip. The CMOS imager data are read out as a serial coded signal. The sensor system uses a light-emitting diode to excite target analyte responsive organometallic luminophores doped within discrete xerogel-based sensor elements. As a proto type, we developed a 3 × 3 (9 elements) array of oxygen (O2) sensors. Each group of three sensor elements in the array (arranged in a column) is designed to provide a different and specific sensitivity to the target gaseous O2 concentration. This property of multiple sensitivities is achieved by using a mix of two O2 sensitive luminophores in each pin-printed xerogel sensor element. The CMOS imager is designed to be low noise and consumes a static power of 320.4 μW and an average dynamic power of 624.6 μW when operating at 100-Hz sampling frequency and 1.8-V dc power supply.

Design of optical element combining Fresnel lens with microlens array for uniform light-emitting diode lighting.

PubMed

Wang, Guangzhen; Wang, Lili; Li, Fuli; Kong, Depeng

2012-09-01

One kind of optical element combining Fresnel lens with microlens array is designed simply for LED lighting based on geometrical optics and nonimaging optics. This design method imposes no restriction on the source intensity pattern. The designed element has compact construction and can produce multiple shapes of illumination distribution. Taking square lighting as an example, tolerance analysis is carried out to determine tolerance limits for applying the element in the assembly process. This element can produce on-axis lighting and off-axis lighting.

Acoustics in Halls for Speech and Music

NASA Astrophysics Data System (ADS)

Gade, Anders C.

This chapter deals specifically with concepts, tools, and architectural variables of importance when designing auditoria for speech and music. The focus will be on cultivating the useful components of the sound in the room rather than on avoiding noise from outside or from installations, which is dealt with in Chap. 11. The chapter starts by presenting the subjective aspects of the room acoustic experience according to consensus at the time of writing. Then follows a description of their objective counterparts, the objective room acoustic parameters, among which the classical reverberation time measure is only one of many, but still of fundamental value. After explanations on how these parameters can be measured and predicted during the design phase, the remainder of the chapter deals with how the acoustic properties can be controlled by the architectural design of auditoria. This is done by presenting the influence of individual design elements as well as brief descriptions of halls designed for specific purposes, such as drama, opera, and symphonic concerts. Finally, some important aspects of loudspeaker installations in auditoria are briefly touched upon.

MEMS 3-DoF gyroscope design, modeling and simulation through equivalent circuit lumped parameter model

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

Mian, Muhammad Umer, E-mail: umermian@gmail.com; Khir, M. H. Md.; Tang, T. B.

Pre-fabrication, behavioural and performance analysis with computer aided design (CAD) tools is a common and fabrication cost effective practice. In light of this we present a simulation methodology for a dual-mass oscillator based 3 Degree of Freedom (3-DoF) MEMS gyroscope. 3-DoF Gyroscope is modeled through lumped parameter models using equivalent circuit elements. These equivalent circuits consist of elementary components which are counterpart of their respective mechanical components, used to design and fabricate 3-DoF MEMS gyroscope. Complete designing of equivalent circuit model, mathematical modeling and simulation are being presented in this paper. Behaviors of the equivalent lumped models derived for themore » proposed device design are simulated in MEMSPRO T-SPICE software. Simulations are carried out with the design specifications following design rules of the MetalMUMPS fabrication process. Drive mass resonant frequencies simulated by this technique are 1.59 kHz and 2.05 kHz respectively, which are close to the resonant frequencies found by the analytical formulation of the gyroscope. The lumped equivalent circuit modeling technique proved to be a time efficient modeling technique for the analysis of complex MEMS devices like 3-DoF gyroscopes. The technique proves to be an alternative approach to the complex and time consuming couple field analysis Finite Element Analysis (FEA) previously used.« less

E622, a miniature, virulence-associated mobile element.

PubMed

Stavrinides, John; Kirzinger, Morgan W B; Beasley, Federico C; Guttman, David S

2012-01-01

Miniature inverted terminal repeat elements (MITEs) are nonautonomous mobile elements that have a significant impact on bacterial evolution. Here we characterize E622, a 611-bp virulence-associated MITE from Pseudomonas syringae, which contains no coding region but has almost perfect 168-bp inverted repeats. Using an antibiotic coupling assay, we show that E622 is transposable and can mobilize an antibiotic resistance gene contained between its borders. Its predicted parent element, designated TnE622, has a typical transposon structure with a three-gene operon, consisting of resolvase, integrase, and exeA-like genes, which is bounded by the same terminal inverted repeats as E622. A broader genome level survey of the E622/TnE622 inverted repeats identified homologs in Pseudomonas, Salmonella, Shewanella, Erwinia, Pantoea, and the cyanobacteria Nostoc and Cyanothece, many of which appear to encompass known virulence genes, including genes encoding toxins, enzymes, and type III secreted effectors. Its association with niche-specific genetic determinants, along with its persistence and evolutionary diversification, indicates that this mobile element family has played a prominent role in the evolution of many agriculturally and clinically relevant pathogenic bacteria.

Computer-Aided Design for Built-In-Test (CADBIT) - Software Specification. Volume 3

DTIC Science & Technology

1989-10-01

CADD COMAN WIDO IO-CNURET MSL PPLYING~ TET ATEN Figur 3-13- TUTORIA FIGUR PLCMI IN CAD-NVIOMENT ON BOAR SEFTST- 1"os-rnenu, long-tur d nnnih que- list...have software package for reliability calculation A-8 LIBRARY ELEMENT DATA SHE T’" BIT TECHNIQUE: ON-BOARD ROM CATEGORY: L’ONG TUTORIA PAGE ,5 of 14

Adding a Time-Series Design Element to the Success Case Method to Improve Methodological Rigor: An Application for Nonprofit Program Evaluation

ERIC Educational Resources Information Center

Coryn, Chris L. S.; Schroter, Daniela C.; Hanssen, Carl E.

2009-01-01

Brinkerhoff's Success Case Method (SCM) was developed with the specific purpose of assessing the impact of organizational interventions (e.g., training and coaching) on business goals by analyzing extreme groups using case study techniques and storytelling. As an efficient and cost-effective method of evaluative inquiry, SCM is attractive in other…

Moving Our Can(n)ons: Toward an Appreciation of Multimodal Texts in the Classroom

ERIC Educational Resources Information Center

Jiménez, Laura M.; Roberts, Kathryn L.; Brugar, Kristy A.; Meyer, Carla K.; Waito, Kim

2017-01-01

The growing popularity of graphic novels for younger readers is hard to miss. This article provides specific ways to think about, recognize, and teach with multimodal texts that leverage student interest. In this English language arts unit, we taught a sixth-grade class how to read and comprehend the complex design elements common to the graphic…

Key Design Considerations When Calculating Cost Savings for Population Health Management Programs in an Observational Setting.

PubMed

Murphy, Shannon M E; Hough, Douglas E; Sylvia, Martha L; Dunbar, Linda J; Frick, Kevin D

2018-02-08

To illustrate the impact of key quasi-experimental design elements on cost savings measurement for population health management (PHM) programs. Population health management program records and Medicaid claims and enrollment data from December 2011 through March 2016. The study uses a difference-in-difference design to compare changes in cost and utilization outcomes between program participants and propensity score-matched nonparticipants. Comparisons of measured savings are made based on (1) stable versus dynamic population enrollment and (2) all eligible versus enrolled-only participant definitions. Options for the operationalization of time are also discussed. Individual-level Medicaid administrative and claims data and PHM program records are used to match study groups on baseline risk factors and assess changes in costs and utilization. Savings estimates are statistically similar but smaller in magnitude when eliminating variability based on duration of population enrollment and when evaluating program impact on the entire target population. Measurement in calendar time, when possible, simplifies interpretability. Program evaluation design elements, including population stability and participant definitions, can influence the estimated magnitude of program savings for the payer and should be considered carefully. Time specifications can also affect interpretability and usefulness. © Health Research and Educational Trust.

Overview of NASA's Thermal Control System Development for Exploration Project

NASA Technical Reports Server (NTRS)

Stephan, Ryan A.

2011-01-01

The now-cancelled Constellation Program included the Orion, Altair, and Lunar Surface Systems project offices. The first two elements, Orion and Altair, were planned to be manned space vehicles while the third element was much more diverse and included several sub-elements. Among other things, these sub-elements were Rovers and a Lunar Habitat. The planned missions involving these systems and vehicles included several risks and design challenges. Due to the unique thermal operating environment, many of these risks and challenges were associated with the vehicles thermal control system. NASA s Exploration Technology Development Program (ETDP) consisted of various technology development projects. The project chartered with mitigating the aforementioned thermal risks and design challenges was the Thermal Control System Development for Exploration Project. These risks and design challenges were being addressed through a rigorous technology development process that was planned to culminate with an integrated thermal control system test. Although the technologies being developed were originally aimed towards mitigating specific Constellation risks, the technology development process is being continued within a new program. This continued effort is justified by the fact that many of the technologies are generically applicable to future spacecraft thermal control systems. The current paper summarizes the development efforts being performed by the technology development project. The development efforts involve heat acquisition and heat rejection hardware including radiators, heat exchangers, and evaporators. The project has also been developing advanced phase change material heat sinks and performing a material compatibility assessment for a promising thermal control system working fluid. The to-date progress and lessons-learned from these development efforts will be discussed throughout the paper.

Addressing Cultural Contexts in the Management of Stress via Narrative and Mobile Technology.

PubMed

Lee, Matthew D; Kang, Xiao; Hanrahan, Nancy

2014-01-01

In developing applications for stress management and mental health, developers have largely ignored cultural context in design, opting instead to produce apps for a general audience. However, apps designed without a specific population in mind actually have limited reach. Generally stress trackers and socalled "therapists in your pocket", tend to be lost among a jungle of other generic apps that appeal only to the quantified self population and those already predisposed to help-seeking behavior. To reach a broader audience, designing for a specific population may have appeal. The AppHappy Project's Journey to the West is a mobile app being developed by a multidisciplinary group of students at the University of Pennsylvania. The objective is to promote better stress management and mental health among Asian international college students and facilitate their social integration with the general student population. With a prevalence of depression twice that of domestic college students, a reluctance to engage in help-seeking behavior due to stigma, and the challenge of cultural integration, creating interventions for this population requires a different approach to app-mediated therapy. Journey to the West packages bite-sized pieces of Cognitive Behavioral Therapy techniques within the framework of a role-playing game. Every element of its design-from its characters to its art style, from its narrative to its mechanics to its approach to community features-is rooted in a culturally appropriate context. An avatar serves as a surrogate of self while experiencing externalized stressors. Each quest blends therapeutic elements into gameplay with the goal of building resilience towards stressful events.

Optimization of x-ray capillary optics for mammography

NASA Astrophysics Data System (ADS)

Ross, Richard E.; Bradford, Carla D.; Peppler, Walter W.

2002-05-01

The purpose of this study is to develop a full-field digital mammography system utilizing capillary optics. Specific aims are to identify optic properties that affect image quality and to optimize those properties in the design of a multi-element capillary array. It has been shown that polycapillary optics significantly improve mammographic image quality through increased resolution and reduced x-ray scatter. For practical clinical application much larger multi-element optics will be required. This study quantified the contributing factors to the multi-element optic MTF and investigated methods to determine optimal parameters for a practical design. Individual and a prototype multi-element array of linearly tapered optics with a common focal point were investigated. A conventional (MO/MO) mammography tube and computed radiography system were used. The system and optic MTF were measured using the angled slit method with a slit camera (10 micron slit). MTF measurements were performed with both stationary and scanned optics. Contributions to MTF included: distortion within individual optics, misalignment between optics, capillary channel size, and vibration. Measurement techniques used to identify and quantify the contributions to optic MTF included a phantom chosen specifically for polycapillary optics. This phantom provided a method for assessing the coherence among capillaries within an optic as well as the relative alignment of the optics within the array. In addition, modifications to the scanning procedure allowed for the isolation and quantification of several contributors to the system MTF. Specifically, measurements were made using a stationary optic, a scanning optic, and an optic placed at multiple locations within the imaged field of view. These techniques yielded the optic MTF, the degradation of MTF due to loss of coherence within the optic, and the degradation of MTF due to vibration of the scanning mechanism. Distortion within individual optics was, typically, quite small. However, MTF degradation resulting from twist was significant in some optics. MTF degradation due to misalignment was relatively large in the prototype triad. Modeling found that misalignment up to 50 microns reduced MTF by less than 10 percent up to 3 cycles/mm. Channel diameters of 52 microns and 85 microns reduced MTF by 9 percent to 20 percent at 5 cycles/mm and provided an optimal tradeoff between transmission and MTF. Vibration was identified as a significant degradation to MTF but can easily reduced with simple modifications. In spite of some reduced optic MTF values, system MTF has always been significantly improved - in some cases almost by the magnification ratio. These results allow for accurate modeling of optic performance and optimization of design parameters. This study demonstrates that a multi-element array can be produced with nearly optimal properties. A large area array suitable for clinical trial is feasible and is the next step in this program.

Simulative design in macroscale for prospective application to micro-catheters.

PubMed

Ha, Cheol Woo

2018-02-09

In this paper, a motion-transforming element is applied to the development of a new catheter device. The motion-transforming element structure allows a reduction of linear movement and converts linear movement to rotational movement. The simulative design of micro-catheters is based on a proposed structure called the Operating Mini Station (OMS). OMS is operated by movement of a motion-transforming element. A new motion-transforming element is designed using multiple links that are connected by hinged joints based on an elastic design. The design of the links and the hinges are optimized for precise and reliable movement of the motion-transforming element. Because of the elastic design, it is possible to realize a catheter that allows various movements in small spaces like capillaries.

Computational methods in sequence and structure prediction

NASA Astrophysics Data System (ADS)

Lang, Caiyi

This dissertation is organized into two parts. In the first part, we will discuss three computational methods for cis-regulatory element recognition in three different gene regulatory networks as the following: (a) Using a comprehensive "Phylogenetic Footprinting Comparison" method, we will investigate the promoter sequence structures of three enzymes (PAL, CHS and DFR) that catalyze sequential steps in the pathway from phenylalanine to anthocyanins in plants. Our result shows there exists a putative cis-regulatory element "AC(C/G)TAC(C)" in the upstream of these enzyme genes. We propose this cis-regulatory element to be responsible for the genetic regulation of these three enzymes and this element, might also be the binding site for MYB class transcription factor PAP1. (b) We will investigate the role of the Arabidopsis gene glutamate receptor 1.1 (AtGLR1.1) in C and N metabolism by utilizing the microarray data we obtained from AtGLR1.1 deficient lines (antiAtGLR1.1). We focus our investigation on the putatively co-regulated transcript profile of 876 genes we have collected in antiAtGLR1.1 lines. By (a) scanning the occurrence of several groups of known abscisic acid (ABA) related cisregulatory elements in the upstream regions of 876 Arabidopsis genes; and (b) exhaustive scanning of all possible 6-10 bps motif occurrence in the upstream regions of the same set of genes, we are able to make a quantative estimation on the enrichment level of each of the cis-regulatory element candidates. We finally conclude that one specific cis-regulatory element group, called "ABRE" elements, are statistically highly enriched within the 876-gene group as compared to their occurrence within the genome. (c) We will introduce a new general purpose algorithm, called "fuzzy REDUCE1", which we have developed recently for automated cis-regulatory element identification. In the second part, we will discuss our newly devised protein design framework. With this framework we have developed a software package which is capable of designing novel protein structures at the atomic resolution. This software package allows us to perform protein structure design with a flexible backbone. The backbone flexibility includes loop region relaxation as well as a secondary structure collective mode relaxation scheme. (Abstract shortened by UMI.)

User Manuals for a Primary Care Electronic Medical Record System: A Mixed Methods Study of User- and Vendor-Generated Documents

PubMed Central

Dow, Rustam; Barnsley, Jan; Tu, Karen; Domb, Sharon; Jadad, Alejandro R.; Lemieux-Charles, Louise

2015-01-01

Research problem Tutorials and user manuals are important forms of impersonal support for using software applications including electronic medical records (EMRs). Differences between user- and vendor documentation may indicate support needs, which are not sufficiently addressed by the official documentation, and reveal new elements that may inform the design of tutorials and user manuals. Research question What are the differences between user-generated tutorials and manuals for an EMR and the official user manual from the software vendor? Literature review Effective design of tutorials and user manuals requires careful packaging of information, balance between declarative and procedural texts, an action and task-oriented approach, support for error recognition and recovery, and effective use of visual elements. No previous research compared these elements between formal and informal documents. Methodology We conducted an mixed methods study. Seven tutorials and two manuals for an EMR were collected from three family health teams and compared with the official user manual from the software vendor. Documents were qualitatively analyzed using a framework analysis approach in relation to the principles of technical documentation described above. Subsets of the data were quantitatively analyzed using cross-tabulation to compare the types of error information and visual cues in screen captures between user- and vendor-generated manuals. Results and discussion The user-developed tutorials and manuals differed from the vendor-developed manual in that they contained mostly procedural and not declarative information; were customized to the specific workflow, user roles, and patient characteristics; contained more error information related to work processes than to software usage; and used explicit visual cues on screen captures to help users identify window elements. These findings imply that to support EMR implementation, tutorials and manuals need to be customized and adapted to specific organizational contexts and workflows. The main limitation of the study is its generalizability. Future research should address this limitation and may explore alternative approaches to software documentation, such as modular manuals or participatory design. PMID:26190888

Procedure for minimizing the cost per watt of photovoltaic systems

NASA Technical Reports Server (NTRS)

Redfield, D.

1977-01-01

A general analytic procedure is developed that provides a quantitative method for optimizing any element or process in the fabrication of a photovoltaic energy conversion system by minimizing its impact on the cost per watt of the complete system. By determining the effective value of any power loss associated with each element of the system, this procedure furnishes the design specifications that optimize the cost-performance tradeoffs for each element. A general equation is derived that optimizes the properties of any part of the system in terms of appropriate cost and performance functions, although the power-handling components are found to have a different character from the cell and array steps. Another principal result is that a fractional performance loss occurring at any cell- or array-fabrication step produces that same fractional increase in the cost per watt of the complete array. It also follows that no element or process step can be optimized correctly by considering only its own cost and performance

Horizontal and vertical variability of soil properties in a trace element contaminated area

NASA Astrophysics Data System (ADS)

Burgos, Pilar; Madejón, Engracia; Pérez-de-Mora, Alfredo; Cabrera, Francisco

2008-02-01

The spatial distribution of some soil chemical properties and trace element contents of a plot affected by the Aznalcóllar mine spill were investigated using statistical and geostatistical methods to assess the extent of soil contamination. Total and EDTA-extractable soil trace element concentrations and total S content showed great variability and high coefficients of variation in the three examined depths. Soil in the plot was found to be significantly contaminated by As, Cd, Cu, Pb and Zn within a wide range of pH. Total trace element concentrations at all depths (0-60 cm) were much higher than background values of non-affected soil, indicating that despite the clean-up operations, the concentration of trace elements in the experimental plot was still high. The spatial distribution of the different variables was estimated by kriging to design contour maps. These maps allowed the identification of specific zones with high metal concentrations and low pH values corresponding to spots of residual sludge. Moreover, kriged maps showed distinct spatial distribution and hence different behaviour for the elements considered. This information may be applied to optimise remediation strategies in highly and moderately contaminated areas.

Fitness landscapes, heuristics and technological paradigms: A critique on random search models in evolutionary economics

NASA Astrophysics Data System (ADS)

Frenken, Koen

2001-06-01

The biological evolution of complex organisms, in which the functioning of genes is interdependent, has been analyzed as "hill-climbing" on NK fitness landscapes through random mutation and natural selection. In evolutionary economics, NK fitness landscapes have been used to simulate the evolution of complex technological systems containing elements that are interdependent in their functioning. In these models, economic agents randomly search for new technological design by trial-and-error and run the risk of ending up in sub-optimal solutions due to interdependencies between the elements in a complex system. These models of random search are legitimate for reasons of modeling simplicity, but remain limited as these models ignore the fact that agents can apply heuristics. A specific heuristic is one that sequentially optimises functions according to their ranking by users of the system. To model this heuristic, a generalized NK-model is developed. In this model, core elements that influence many functions can be distinguished from peripheral elements that affect few functions. The concept of paradigmatic search can then be analytically defined as search that leaves core elements in tact while concentrating on improving functions by mutation of peripheral elements.

Design of an adiabatic demagnetization refrigerator for studies in astrophysics

NASA Technical Reports Server (NTRS)

Castles, S.

1983-01-01

An adiabatic demagnetization refrigerator was designed for cooling infrared bolometers for studies in astrophysics and aeronomy. The design was tailored to the requirements of a Shuttle sortie experiment. The refrigerator should be capable of maintaining three bolometers at 0.1 K with a 90% cycle. The advantage are of operations the bolometer at 0.1K. greater sensitivity, faster response time, and the ability to use larger bolometer elements without compromising the response time. The design presented is the first complete design of an ADR intended for use in space. The most important of these specifications are to survive a Shuttle launch, to operate with 1.5 K - 2.0 K space-pumped liquid helium as a heat sink, to have a 90% duty cycle, and to be highly efficient.

Room Temperature and Elevated Temperature Composite Sandwich Joint Testing

NASA Technical Reports Server (NTRS)

Walker, Sandra P.

1998-01-01

Testing of composite sandwich joint elements has been completed to verify the strength capacity of joints designed to carry specified running loads representative of a high speed civil transport wing. Static tension testing at both room and an elevated temperature of 350 F and fatigue testing at room temperature were conducted to determine strength capacity, fatigue life, and failure modes. Static tension test results yielded failure loads above the design loads for the room temperature tests, confirming the ability of the joint concepts tested to carry their design loads. However, strength reductions as large as 30% were observed at the elevated test temperature, where all failure loads were below the room temperature design loads for the specific joint designs tested. Fatigue testing resulted in lower than predicted fatigue lives.

How to effectively design and create a concept mobile application to aid in the management of type 1 diabetes in adolescents.

PubMed

McCulloch, Victoria; Hope, Sarah; Loranger, Brian; Rea, Paul

2017-07-01

Diabetes is one of the most prevalent chronic health conditions in the world; with a range of diabetes-related mobile applications available to the public to aid in glycaemic control and self-management. Statistically, adherence to medication is extremely low in adolescents with Type 1 Diabetes Mellitus (T1DM), therefore, this paper focuses on the research and design of an interactive and educational concept mobile application aimed at early to mid-adolescents to aid in their understanding of T1DM. As visual elements are an essential part of the design, this research outlines how visual components were designed specifically for adolescents with T1DM.

Lunar lander ground support system

NASA Technical Reports Server (NTRS)

1991-01-01

This year's project, like the previous Aerospace Group's project, involves a lunar transportation system. The basic time line will be the years 2010-2030 and will be referred to as a second generation system, as lunar bases would be present. The project design completed this year is referred to as the Lunar Lander Ground Support System (LLGSS). The area chosen for analysis encompasses a great number of vehicles and personnel. The design of certain elements of the overall lunar mission are complete projects in themselves. For this reason the project chosen for the Senior Aerospace Design is the design of specific servicing vehicles and additions or modifications to existing vehicles for the area of concern involving servicing and maintenance of the lunar lander while on the surface.

A semantic-web oriented representation of the clinical element model for secondary use of electronic health records data.

PubMed

Tao, Cui; Jiang, Guoqian; Oniki, Thomas A; Freimuth, Robert R; Zhu, Qian; Sharma, Deepak; Pathak, Jyotishman; Huff, Stanley M; Chute, Christopher G

2013-05-01

The clinical element model (CEM) is an information model designed for representing clinical information in electronic health records (EHR) systems across organizations. The current representation of CEMs does not support formal semantic definitions and therefore it is not possible to perform reasoning and consistency checking on derived models. This paper introduces our efforts to represent the CEM specification using the Web Ontology Language (OWL). The CEM-OWL representation connects the CEM content with the Semantic Web environment, which provides authoring, reasoning, and querying tools. This work may also facilitate the harmonization of the CEMs with domain knowledge represented in terminology models as well as other clinical information models such as the openEHR archetype model. We have created the CEM-OWL meta ontology based on the CEM specification. A convertor has been implemented in Java to automatically translate detailed CEMs from XML to OWL. A panel evaluation has been conducted, and the results show that the OWL modeling can faithfully represent the CEM specification and represent patient data.

A semantic-web oriented representation of the clinical element model for secondary use of electronic health records data

PubMed Central

Tao, Cui; Jiang, Guoqian; Oniki, Thomas A; Freimuth, Robert R; Zhu, Qian; Sharma, Deepak; Pathak, Jyotishman; Huff, Stanley M; Chute, Christopher G

2013-01-01

The clinical element model (CEM) is an information model designed for representing clinical information in electronic health records (EHR) systems across organizations. The current representation of CEMs does not support formal semantic definitions and therefore it is not possible to perform reasoning and consistency checking on derived models. This paper introduces our efforts to represent the CEM specification using the Web Ontology Language (OWL). The CEM-OWL representation connects the CEM content with the Semantic Web environment, which provides authoring, reasoning, and querying tools. This work may also facilitate the harmonization of the CEMs with domain knowledge represented in terminology models as well as other clinical information models such as the openEHR archetype model. We have created the CEM-OWL meta ontology based on the CEM specification. A convertor has been implemented in Java to automatically translate detailed CEMs from XML to OWL. A panel evaluation has been conducted, and the results show that the OWL modeling can faithfully represent the CEM specification and represent patient data. PMID:23268487

Degrees of connectivity: Systems model for upstream risk assessment and mitigation.

PubMed

Gambatese, John; AlOmari, Kasim

2016-08-01

There is growing recognition that in order to further improve safety performance, attention needs to be given beyond the immediate working conditions and worker actions. A systems approach to construction safety enables considering: multiple project elements simultaneously; connections between different elements; and all system elements affected by safety risk. This paper describes recent and current research to conceptualize a typical building project in terms of connections between workers, activities, and design elements, and to verify and analyze impacts of the design and worker interactions on worker safety. Prior research provides the basis for a network tying the design elements, construction activities, and work crews on a typical building project together along with the extent of interaction between each of the system elements in terms of safety. In conjunction with this systems approach, the researchers propose a concept for viewing and managing construction safety through four different types of connections, or "degrees of connectivity," between the different workers, activities, and design elements in the system. The degrees of connectivity are defined as: interacting with the design element during its construction (DoC #1); interacting with the design element in its final form to attach another component to it (DoC #2) or by working in the vicinity of it (DoC #3); and indirectly interacting with the design element through another worker (DoC #4). To support and verify the presence of the concept in practice, the researchers conducted a survey of construction personnel. The survey results confirm that the four different degrees of connectivity are present and felt during construction operations, and indicate that attention should be given to all design elements, activities, and workers to which a worker is "connected". According to the survey respondents, DoC's #1 and #2 are recognized as the most widely present on construction sites. Eighty percent of the respondents believe that the design element has a moderate or greater impact on worker safety while it is being constructed. These initial research steps provide the starting point for continuing study that aims to develop and demonstrate the degrees of connectivity concept linking workers and design elements, with the goal of understanding how to design a project and work operations in order to improve safety during construction. Copyright © 2015 Elsevier Ltd. All rights reserved.

Promoter and Terminator Discovery and Engineering.

PubMed

Deaner, Matthew; Alper, Hal S

Control of gene expression is crucial to optimize metabolic pathways and synthetic gene networks. Promoters and terminators are stretches of DNA upstream and downstream (respectively) of genes that control both the rate at which the gene is transcribed and the rate at which mRNA is degraded. As a result, both of these elements control net protein expression from a synthetic construct. Thus, it is highly important to discover and engineer promoters and terminators with desired characteristics. This chapter highlights various approaches taken to catalogue these important synthetic elements. Specifically, early strategies have focused largely on semi-rational techniques such as saturation mutagenesis to diversify native promoters and terminators. Next, in an effort to reduce the length of the synthetic biology design cycle, efforts in the field have turned towards the rational design of synthetic promoters and terminators. In this vein, we cover recently developed methods such as hybrid engineering, high throughput characterization, and thermodynamic modeling which allow finer control in the rational design of novel promoters and terminators. Emphasis is placed on the methodologies used and this chapter showcases the utility of these methods across multiple host organisms.

Design and analysis of frequency-selective surface enabled microbolometers

NASA Astrophysics Data System (ADS)

Liu, Tao; Qu, Chuang; Almasri, Mahmoud; Kinzel, Edward

2016-05-01

Frequency Selective Surfaces (FSS) are periodic array of sub-wavelength antenna elements. They allow the absorptance and reflectance of a surface to be engineered with respect to wavelength, polarization and angle-of-incidence. This paper applies this technique to microbolometers for uncooled infrared sensing applications. Both narrowband and broadband near perfect absorbing surfaces are synthesized and applied engineer the response of microbolometers. The paper focuses on simple FSS geometries (hexagonal close packed disk arrays) that can be fabricated using conventional lithographic tools for use at thermal infrared wavelengths (feature sizes > 1 μm). The affects of geometry and material selection for this geometry is described in detail. In the microbolometer application, the FSS controls the absorption rather than a conventional Fabry-Perot cavity and this permits an improved thermal design. A coupled full wave electromagnetic/transient thermal model of the entire microbolometer is presented and analyzed using the finite element method. The absence of the cavity also permits more flexibility in the design of the support arms/contacts. This combined modeling permits prediction of the overall device sensitivity, time-constant and the specific detectivity.

Recent progress in design and hybridization of planar grating-based transceivers

NASA Astrophysics Data System (ADS)

Bidnyk, S.; Pearson, M.; Balakrishnan, A.; Gao, M.

2007-06-01

We report on recent progress in simulations, physical layout, fabrication and hybridization of planar grating-based transceivers for passive optical networks (PONs). Until recently, PON transceivers have been manufactured using bulk micro-optical components. Today, advancements in modeling and simulation techniques has made it possible to design complex elements in the same silica-on silicon PLC platform and create an alternative platform for manufacturing of bi-directional transceivers. In our chips we simulated an integrated chip that monolithically combined planar reflective gratings and cascaded Mach-Zehnder interferometers. We used a combination of the finite element method and beam propagation method to model cascaded interferometers with enhanced coupling coefficients. Our simulations show that low-diffraction order planar reflective gratings, designed for small incidence and reflection angles, possess the required dispersion strength to meet the PON specifications. Subsequently, we created structures for passive alignment and hybridized photodetectors and lasers. We believe that advancements in simulation of planar lightwave circuits with embedded planar reflective gratings will result in displacement of the thin-film filters (TFFs) technology in many applications that require a high degree of monolithic and hybrid integration.

True Concurrent Thermal Engineering Integrating CAD Model Building with Finite Element and Finite Difference Methods

NASA Technical Reports Server (NTRS)

Panczak, Tim; Ring, Steve; Welch, Mark

1999-01-01

Thermal engineering has long been left out of the concurrent engineering environment dominated by CAD (computer aided design) and FEM (finite element method) software. Current tools attempt to force the thermal design process into an environment primarily created to support structural analysis, which results in inappropriate thermal models. As a result, many thermal engineers either build models "by hand" or use geometric user interfaces that are separate from and have little useful connection, if any, to CAD and FEM systems. This paper describes the development of a new thermal design environment called the Thermal Desktop. This system, while fully integrated into a neutral, low cost CAD system, and which utilizes both FEM and FD methods, does not compromise the needs of the thermal engineer. Rather, the features needed for concurrent thermal analysis are specifically addressed by combining traditional parametric surface based radiation and FD based conduction modeling with CAD and FEM methods. The use of flexible and familiar temperature solvers such as SINDA/FLUINT (Systems Improved Numerical Differencing Analyzer/Fluid Integrator) is retained.

METHOD AND APPARATUS FOR TESTING THE PRESENCE OF SPECIFIC ATOMIC ELEMENTS IN A SUBSTANCE

DOEpatents

Putman, J.L.

1960-01-26

Detection of specific atomic elements in a substance and particularly the applicability to well logging are discussed. The principal novelty resides in the determination of several of the auxiliary energy peaks in addition to the main energy peak of the gamma-ray energy spectrum of a substance and comparison of such peaks to the spectrum of the specific atomic element being tested for. thus resulting in identification of same. The invention facilitates the identification of specific elements even when in the presence of other elements having similar gamma energy spectra as to the main energy peaks.

Frontend Receiver Electronics for High Frequency Monolithic CMUT-on-CMOS Imaging Arrays

PubMed Central

Gurun, Gokce; Hasler, Paul; Degertekin, F. Levent

2012-01-01

This paper describes the design of CMOS receiver electronics for monolithic integration with capacitive micromachined ultrasonic transducer (CMUT) arrays for high-frequency intravascular ultrasound imaging. A custom 8-inch wafer is fabricated in a 0.35 μm two-poly, four-metal CMOS process and then CMUT arrays are built on top of the application specific integrated circuits (ASICs) on the wafer. We discuss advantages of the single-chip CMUT-on-CMOS approach in terms of receive sensitivity and SNR. Low-noise and high-gain design of a transimpedance amplifier (TIA) optimized for a forward-looking volumetric-imaging CMUT array element is discussed as a challenging design example. Amplifier gain, bandwidth, dynamic range and power consumption trade-offs are discussed in detail. With minimized parasitics provided by the CMUT-on-CMOS approach, the optimized TIA design achieves a 90 fA/√Hz input referred current noise, which is less than the thermal-mechanical noise of the CMUT element. We show successful system operation with a pulse-echo measurement. Transducer noise-dominated detection in immersion is also demonstrated through output noise spectrum measurement of the integrated system at different CMUT bias voltages. A noise figure of 1.8 dB is obtained in the designed CMUT bandwidth of 10 MHz to 20 MHz. PMID:21859585

Front-end receiver electronics for high-frequency monolithic CMUT-on-CMOS imaging arrays.

PubMed

Gurun, Gokce; Hasler, Paul; Degertekin, F

2011-08-01

This paper describes the design of CMOS receiver electronics for monolithic integration with capacitive micromachined ultrasonic transducer (CMUT) arrays for highfrequency intravascular ultrasound imaging. A custom 8-inch (20-cm) wafer is fabricated in a 0.35-μm two-poly, four-metal CMOS process and then CMUT arrays are built on top of the application specific integrated circuits (ASICs) on the wafer. We discuss advantages of the single-chip CMUT-on-CMOS approach in terms of receive sensitivity and SNR. Low-noise and high-gain design of a transimpedance amplifier (TIA) optimized for a forward-looking volumetric-imaging CMUT array element is discussed as a challenging design example. Amplifier gain, bandwidth, dynamic range, and power consumption trade-offs are discussed in detail. With minimized parasitics provided by the CMUT-on-CMOS approach, the optimized TIA design achieves a 90 fA/√Hz input-referred current noise, which is less than the thermal-mechanical noise of the CMUT element. We show successful system operation with a pulseecho measurement. Transducer-noise-dominated detection in immersion is also demonstrated through output noise spectrum measurement of the integrated system at different CMUT bias voltages. A noise figure of 1.8 dB is obtained in the designed CMUT bandwidth of 10 to 20 MHz.

Tools reference manual for a Requirements Specification Language (RSL), version 2.0

NASA Technical Reports Server (NTRS)

Fisher, Gene L.; Cohen, Gerald C.

1993-01-01

This report describes a general-purpose Requirements Specification Language, RSL. The purpose of RSL is to specify precisely the external structure of a mechanized system and to define requirements that the system must meet. A system can be comprised of a mixture of hardware, software, and human processing elements. RSL is a hybrid of features found in several popular requirements specification languages, such as SADT (Structured Analysis and Design Technique), PSL (Problem Statement Language), and RMF (Requirements Modeling Framework). While languages such as these have useful features for structuring a specification, they generally lack formality. To overcome the deficiencies of informal requirements languages, RSL has constructs for formal mathematical specification. These constructs are similar to those found in formal specification languages such as EHDM (Enhanced Hierarchical Development Methodology), Larch, and OBJ3.

Experimental strain analysis of the high pressure strain gauge pressure transducer and verification by using a finite element method

NASA Astrophysics Data System (ADS)

Orhan, M. H.; Dogan, Ç.; Kocabas, H.; Tepehan, G.

2001-03-01

The finite element method (FEM) was used in this study for the analysis of the strain distribution of a strain gauge pressure transducer for hydrostatic pressure measurements up to 150 MPa. The pressure transducer, which we investigated, on the basis of `thick-walled cylindrical vessel' theory has a free steel active element. Pressure is applied to the inside and both open ends of this active element. The symmetrical shape of the transducer and all the design parameters of the active element were selected in such a way as to ensure that a symmetrical stress and strain distribution was obtained even at the maximum working pressure of the transducer. The FEM analysis was conducted by investigating one half of the element in three dimensions. This paper presents the FEM output strain values for the area where the strain gauges were bonded. The validity of those values was established by comparing them with the results obtained from the strain gauge measurements. The relative difference between the two sets of values determined to be lower than 13% of the full scale. The two kinds of measuring elements were made of two different materials; AISI 4340 steel and Invar steel, which work in the hydraulic gauge pressure ranges of up to 150 and 100 MPa respectively. The transducers were calibrated using piston pressure balance. The metrological specifications of a total of eight specimens were evaluated. Although the scope of the study is only an application of the FEM, this evaluation also suggests that this type of transducer can be used with an estimated uncertainty of up to 0.1% of the full scale. However, this uncertainty can be improved by a small modification in design, to reduce the reproducibility and hysteresis errors of the device, which are the main parameters in the evaluation of the uncertainty. The results presented in this paper will be helpful for practical static pressure measurements as well as for the appropriate design of this kind of pressure transducer using the FEM.

Polishing techniques for MEGARA pupil elements optics

NASA Astrophysics Data System (ADS)

Izazaga, R.; Carrasco, E.; Aguirre, D.; Salas, A.; Gil de Paz, A.; Gallego, J.; Iglesias, J.; Arroyo, J. M.; Hernández, M.; López, N.; López, V.; Quechol, J. T.; Salazar, M. F.; Carballo, C.; Cruz, E.; Arriaga, J.; De la Luz, J. A.; Huepa, A.; Jaimes, G. L.; Reyes, J.

2016-07-01

MEGARA (Multi-Espectrógrafo en GTC de Alta Resolución para Astronomía) is the new integral-field and multi-object optical spectrograph for the 10.4m Gran Telescopio Canarias.. It will offer RFWHM 6,000, 12,000 and 18,700 for the low- , mid- and high-resolution, respectively in the wavelength range 3650-9700Å. .The dispersive elements are volume phase holographic (VPH) gratings, sandwiched between two flat Fused Silica windows of high optical precision in large apertures. The design, based in VPHs in combination with Ohara PBM2Y prisms allows to keep the collimator and camera angle fixed. Seventy three optical elements are being built in Mexico at INAOE and CIO. For the low resolution modes, the VPHs windows specifications in irregularity is 1 fringe in 210mm x 170mm and 0.5 fringe in 190mm x 160mm. for a window thickness of 25 mm. For the medium and high resolution modes the irregularity specification is 2 fringes in 220mm x 180mm and 1 fringe in 205mm x 160mm, for a window thickness of 20mm. In this work we present a description of the polishing techniques developed at INAOE optical workshop to fabricate the 36 Fused Silica windows and 24 PBM2Y prisms that allows us to achieve such demanding specifications. We include the processes of mounting, cutting, blocking, polishing and testing.

Adaptation of a Control Center Development Environment for Industrial Process Control

NASA Technical Reports Server (NTRS)

Killough, Ronnie L.; Malik, James M.

1994-01-01

In the control center, raw telemetry data is received for storage, display, and analysis. This raw data must be combined and manipulated in various ways by mathematical computations to facilitate analysis, provide diversified fault detection mechanisms, and enhance display readability. A development tool called the Graphical Computation Builder (GCB) has been implemented which provides flight controllers with the capability to implement computations for use in the control center. The GCB provides a language that contains both general programming constructs and language elements specifically tailored for the control center environment. The GCB concept allows staff who are not skilled in computer programming to author and maintain computer programs. The GCB user is isolated from the details of external subsystem interfaces and has access to high-level functions such as matrix operators, trigonometric functions, and unit conversion macros. The GCB provides a high level of feedback during computation development that improves upon the often cryptic errors produced by computer language compilers. An equivalent need can be identified in the industrial data acquisition and process control domain: that of an integrated graphical development tool tailored to the application to hide the operating system, computer language, and data acquisition interface details. The GCB features a modular design which makes it suitable for technology transfer without significant rework. Control center-specific language elements can be replaced by elements specific to industrial process control.

Grooved Fuel Rings for Nuclear Thermal Rocket Engines

NASA Technical Reports Server (NTRS)

Emrich, William

2009-01-01

An alternative design concept for nuclear thermal rocket engines for interplanetary spacecraft calls for the use of grooved-ring fuel elements. Beyond spacecraft rocket engines, this concept also has potential for the design of terrestrial and spacecraft nuclear electric-power plants. The grooved ring fuel design attempts to retain the best features of the particle bed fuel element while eliminating most of its design deficiencies. In the grooved ring design, the hydrogen propellant enters the fuel element in a manner similar to that of the Particle Bed Reactor (PBR) fuel element.

Design Trade Study for a 4-Meter Off-Axis Primary Mirror Substrate and Mount for the Habitable-Zone Exoplanet Direct Imaging Mission

NASA Technical Reports Server (NTRS)

Arnold, William R.; Stahl, H. Philip

2017-01-01

An extensive trade study was conducted to evaluate primary mirror substrate design architectures for the HabEx mission baseline 4-meter off-axis telescope. The study’s purpose is not to produce a final design, but rather to established a design methodology for matching the mirror’s properties (mass and stiffness) with the mission’s optical performance specifications (static dynamic wavefront error, WFE). The study systematically compares the effect of proven design elements (closed-back vs. open-back vs. partial-back; meniscus vs. flat back vs. shaped back; etc.), which can be implemented with proven space mirror materials (ULE and Zerodur), on static and dynamic WFE. Additionally, the study compares static and dynamic WFE of each substrate point design integrated onto three and six point mounts.

Design trade study for a 4-meter off-axis primary mirror substrate and mount for the Habitable-zone Exoplanet Direct Imaging Mission

NASA Astrophysics Data System (ADS)

Arnold, William R.; Stahl, H. Philip

2017-09-01

An extensive trade study was conducted to evaluate primary mirror substrate design architectures for the HabEx mission baseline 4-meter off-axis telescope. The study's purpose is not to produce a final design, but rather to established a design methodology for matching the mirror's properties (mass and stiffness) with the mission's optical performance specifications (static dynamic wavefront error, WFE). The study systematically compares the effect of proven design elements (closed-back vs open-back vs partial-back; meniscus vs flat back vs shaped back; etc.), which can be implemented with proven space mirror materials (ULE and Zerodur), on static and dynamic WFE. Additionally, the study compares static and dynamic WFE of each substrate point design integrated onto three and six point mounts.

Axial Crushing of Thin-Walled Columns with Octagonal Section: Modeling and Design

NASA Astrophysics Data System (ADS)

Liu, Yucheng; Day, Michael L.

This chapter focus on numerical crashworthiness analysis of straight thinwalled columns with octagonal cross sections. Two important issues in this analysis are demonstrated here: computer modeling and crashworthiness design. In the first part, this chapter introduces a method of developing simplified finite element (FE) models for the straight thin-walled octagonal columns, which can be used for the numerical crashworthiness analysis. Next, this chapter performs a crashworthiness design for such thin-walled columns in order to maximize their energy absorption capability. Specific energy absorption (SEA) is set as the design objective, side length of the octagonal cross section and wall thickness are selected as design variables, and maximum crushing force (Pm) occurs during crashes is set as design constraint. Response surface method (RSM) is employed to formulate functions for both SEA and Pm.

Environmental performance evaluation of an advanced-design solid-state television camera

NASA Technical Reports Server (NTRS)

1979-01-01

The development of an advanced-design black-and-white solid-state television camera which can survive exposure to space environmental conditions was undertaken. A 380 x 488 element buried-channel CCD is utilized as the image sensor to ensure compatibility with 525-line transmission and display equipment. Specific camera design approaches selected for study and analysis included: (1) component and circuit sensitivity to temperature; (2) circuit board thermal and mechanical design; and (3) CCD temperature control. Preferred approaches were determined and integrated into the final design for two deliverable solid-state TV cameras. One of these cameras was subjected to environmental tests to determine stress limits for exposure to vibration, shock, acceleration, and temperature-vacuum conditions. These tests indicate performance at the design goal limits can be achieved for most of the specified conditions.

Initial design of 12S-10P outer-rotor field excitation flux switching motor with different rotor width

NASA Astrophysics Data System (ADS)

Othman, Syed Muhammad Naufal bin Syed; Sulaiman, Erwan bin; Husin, Zhafir Aizat; Khan, Faisal; Mazlan, Mohamed Mubin Aizat

2015-05-01

This paper proposes an initial design of 12 slot, 10 pole outer-rotor field-excitation flux switching motor (FEFSM) with two different rotor width based from 2 different formula to design the rotor width. Hence, initial design include the three coil test to determine the U, W, V-phase, the flux strengthening and weakening, flux at various armature coil and field-excitation coil current, and finally the torque at various JA and JE. As for the materials, the stator and rotor consists of steel sheets made of electromagnetic steels, copper for armature coils and field excitation coils as the only field for magnetic flux source. There will be some design specification and restriction on outer-rotor FEFSM based on 2D-Finite Element Analysis will be applied to design the proposed machine.

TransFit: Finite element analysis data fitting software

NASA Technical Reports Server (NTRS)

Freeman, Mark

1993-01-01

The Advanced X-Ray Astrophysics Facility (AXAF) mission support team has made extensive use of geometric ray tracing to analyze the performance of AXAF developmental and flight optics. One important aspect of this performance modeling is the incorporation of finite element analysis (FEA) data into the surface deformations of the optical elements. TransFit is software designed for the fitting of FEA data of Wolter I optical surface distortions with a continuous surface description which can then be used by SAO's analytic ray tracing software, currently OSAC (Optical Surface Analysis Code). The improved capabilities of Transfit over previous methods include bicubic spline fitting of FEA data to accommodate higher spatial frequency distortions, fitted data visualization for assessing the quality of fit, the ability to accommodate input data from three FEA codes plus other standard formats, and options for alignment of the model coordinate system with the ray trace coordinate system. TransFit uses the AnswerGarden graphical user interface (GUI) to edit input parameters and then access routines written in PV-WAVE, C, and FORTRAN to allow the user to interactively create, evaluate, and modify the fit. The topics covered include an introduction to TransFit: requirements, designs philosophy, and implementation; design specifics: modules, parameters, fitting algorithms, and data displays; a procedural example; verification of performance; future work; and appendices on online help and ray trace results of the verification section.

Optimization of a GO2/GH2 Impinging Injector Element

NASA Technical Reports Server (NTRS)

Tucker, P. Kevin; Shyy, Wei; Vaidyanathan, Rajkumar

2001-01-01

An injector optimization methodology, method i, is used to investigate optimal design points for a gaseous oxygen/gaseous hydrogen (GO2/GH2) impinging injector element. The unlike impinging element, a fuel-oxidizer- fuel (F-O-F) triplet, is optimized in terms of design variables such as fuel pressure drop, (Delta)P(sub f), oxidizer pressure drop, (Delta)P(sub o), combustor length, L(sub comb), and impingement half-angle, alpha, for a given mixture ratio and chamber pressure. Dependent variables such as energy release efficiency, ERE, wall heat flux, Q(sub w), injector heat flux, Q(sub inj), relative combustor weight, W(sub rel), and relative injector cost, C(sub rel), are calculated and then correlated with the design variables. An empirical design methodology is used to generate these responses for 163 combinations of input variables. Method i is then used to generate response surfaces for each dependent variable. Desirability functions based on dependent variable constraints are created and used to facilitate development of composite response surfaces representing some, or all, of the five dependent variables in terms of the input variables. Three examples illustrating the utility and flexibility of method i are discussed in detail. First, joint response surfaces are constructed by sequentially adding dependent variables. Optimum designs are identified after addition of each variable and the effect each variable has on the design is shown. This stepwise demonstration also highlights the importance of including variables such as weight and cost early in the design process. Secondly, using the composite response surface which includes all five dependent variables, unequal weights are assigned to emphasize certain variables relative to others. Here, method i is used to enable objective trade studies on design issues such as component life and thrust to weight ratio. Finally, specific variable weights are further increased to illustrate the high marginal cost of realizing the last increment of injector performance and thruster weight.

H-P adaptive methods for finite element analysis of aerothermal loads in high-speed flows

NASA Technical Reports Server (NTRS)

Chang, H. J.; Bass, J. M.; Tworzydlo, W.; Oden, J. T.

1993-01-01

The commitment to develop the National Aerospace Plane and Maneuvering Reentry Vehicles has generated resurgent interest in the technology required to design structures for hypersonic flight. The principal objective of this research and development effort has been to formulate and implement a new class of computational methodologies for accurately predicting fine scale phenomena associated with this class of problems. The initial focus of this effort was to develop optimal h-refinement and p-enrichment adaptive finite element methods which utilize a-posteriori estimates of the local errors to drive the adaptive methodology. Over the past year this work has specifically focused on two issues which are related to overall performance of a flow solver. These issues include the formulation and implementation (in two dimensions) of an implicit/explicit flow solver compatible with the hp-adaptive methodology, and the design and implementation of computational algorithm for automatically selecting optimal directions in which to enrich the mesh. These concepts and algorithms have been implemented in a two-dimensional finite element code and used to solve three hypersonic flow benchmark problems (Holden Mach 14.1, Edney shock on shock interaction Mach 8.03, and the viscous backstep Mach 4.08).

Exploring Design Elements for Online STEM Courses: Active Learning, Engagement & Assessment Design

ERIC Educational Resources Information Center

Chen, Baiyun; Bastedo, Kathleen; Howard, Wendy

2018-01-01

The purpose of this study was to examine effective design elements for online courses in the science, technology, engineering, and mathematics (STEM) fields at a large four-year public university in southeastern United States. Our research questions addressed the influence of online design elements on students' perception of learning and learning…