A study of pressure losses in residential air distribution systems

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

Abushakra, Bass; Walker, Iain S.; Sherman, Max H.

2002-07-01

An experimental study was conducted to evaluate the pressure drop characteristics of residential duct system components that are either not available or not thoroughly (sometimes incorrectly) described in existing duct design literature. The tests were designed to imitate cases normally found in typical residential and light commercial installations. The study included three different sizes of flexible ducts, under different compression configurations, splitter boxes, supply boots, and a fresh air intake hood. The experimental tests conformed to ASHRAE Standard 120P--''Methods of Testing to Determine Flow Resistance of HVAC Air Ducts and Fittings''. The flexible duct study covered compressibility and bending effectsmore » on the total pressure drop, and the results showed that the available published references tend to underestimate the effects of compression in flexible ducts that can increase pressure drops by up to a factor of nine. The supply boots were tested under different configurations including a setup where a flexible duct elbow connection was considered as an integral part of the supply boot. The supply boots results showed that diffusers can increase the pressure drop by up to a factor of two in exit fittings, and the installation configuration can increase the pressure drop by up to a factor of five. The results showed that it is crucial for designers and contractors to be aware of the compressibility effects of the flexible duct, and the installation of supply boots and diffusers.« less

Flexibility in Flood Management Design: Proactive Planning Under Climate Change Uncertainty

NASA Astrophysics Data System (ADS)

Smet, K.; de Neufville, R.; van der Vlist, M.

2015-12-01

This paper presents an innovative, value-enhancing procedure for effective planning and design of long-lived flood management infrastructure given uncertain future flooding threats due to climate change. Designing infrastructure that can be adapted over time is a method to safeguard the efficacy of current design decisions given uncertainty about rates and future impacts of climate change. This paper explores the value of embedding "options" in a physical structure, where an option is the right but not the obligation to do something at a later date (e.g. over-dimensioning a floodwall foundation now facilitates a future height addition in response to observed increases in sea level; building of extra pump bays in a pumping station now enables the addition of pumping capacity whenever increased precipitation warrants an expansion.) The proposed procedure couples a simulation model that captures future climate induced changes to the hydrologic operating environment of a structure, with an economic model that estimates the lifetime economic performance of alternative investments. The economic model uses Real "In" Options analysis, a type of cash flow analysis that quantifies the implicit value of options and the flexibility they provide. This procedure is demonstrated using replacement planning for the multi-functional pumping station IJmuiden on the North Sea Canal in the Netherlands. Flexibility in design decisions is modelled, varying the size and specific options included in the new structure. Results indicate that the incorporation of options within the structural design has the potential to improve its economic performance, as compared to more traditional, "build it once and build it big" designs where flexibility is not an explicit design criterion. The added value resulting from the incorporation of flexibility varies with the range of future conditions considered, as well as the options examined. This procedure could be applied more broadly to explore investment strategies for the design of other flood management structures.

A comparative study of bio-inspired protective scales using 3D printing and mechanical testing.

PubMed

Martini, Roberto; Balit, Yanis; Barthelat, Francois

2017-06-01

Flexible natural armors from fish, alligators or armadillo are attracting an increasing amount of attention for their unique combinations of hardness, flexibility and light weight. The extreme contrast of stiffness between hard scales and surrounding soft tissues gives rise to unusual and attractive mechanisms, which now serve as models for the design of bio-inspired armors. Despite this growing interest, there is little guideline for the choice of materials, optimum thickness, size, shape and arrangement for the protective scales. In this work, we explore how the geometry and arrangement of hard scales can be tailored to promote scale-scale interactions. We use 3D printing to fabricate arrays of scales with increasingly complex geometries and arrangements, from simple squares with no overlap to complex ganoid-scales with overlaps and interlocking features. We performed puncture tests and flexural tests on each of the 3D printed materials, and we report the puncture resistance - compliance characteristics of each design on an Ashby chart. The interactions between the scales can significantly increase the resistance to puncture, and these interactions can be maximized by tuning the geometry and arrangement of the scales. Interestingly, the designs that offer the best combinations of puncture resistance and flexural compliance are similar to the geometry and arrangement of natural teleost and ganoid scales, which suggests that natural evolution has shaped these systems to maximize flexible protection. This study yields new insights into the mechanisms of natural dermal armor, and also suggests new designs for personal protective systems. Flexible natural armors from fishes, alligators or armadillos are attracting an increasing amount of attention for their unique and attractive combinations of hardness, flexibility and low weight. Despite a growing interest in bio-inspired flexible protection, there is still little guideline for the choice of materials, optimum thickness, size, shape and arrangement of the protective scales. In this work, we explore how the geometry and arrangement of hard scales affect puncture resistance and flexural compliance, using 3D printing and mechanical testing. Our main finding is that the performance of the scaled skin in terms of puncture resistance can be significantly improved by slight changes in their geometry and arrangement. Our results also suggest that natural evolution has shaped scaled skins to maximize flexible protection. This study yields new insights into the mechanics of natural dermal armors, and also suggests new designs for personal protective systems. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Valuing flexibilities in the design of urban water management systems.

PubMed

Deng, Yinghan; Cardin, Michel-Alexandre; Babovic, Vladan; Santhanakrishnan, Deepak; Schmitter, Petra; Meshgi, Ali

2013-12-15

Climate change and rapid urbanization requires decision-makers to develop a long-term forward assessment on sustainable urban water management projects. This is further complicated by the difficulties of assessing sustainable designs and various design scenarios from an economic standpoint. A conventional valuation approach for urban water management projects, like Discounted Cash Flow (DCF) analysis, fails to incorporate uncertainties, such as amount of rainfall, unit cost of water, and other uncertainties associated with future changes in technological domains. Such approach also fails to include the value of flexibility, which enables managers to adapt and reconfigure systems over time as uncertainty unfolds. This work describes an integrated framework to value investments in urban water management systems under uncertainty. It also extends the conventional DCF analysis through explicit considerations of flexibility in systems design and management. The approach incorporates flexibility as intelligent decision-making mechanisms that enable systems to avoid future downside risks and increase opportunities for upside gains over a range of possible futures. A water catchment area in Singapore was chosen to assess the value of a flexible extension of standard drainage canals and a flexible deployment of a novel water catchment technology based on green roofs and porous pavements. Results show that integrating uncertainty and flexibility explicitly into the decision-making process can reduce initial capital expenditure, improve value for investment, and enable decision-makers to learn more about system requirements during the lifetime of the project. Copyright © 2013 Elsevier Ltd. All rights reserved.

Flexible Molybdenum Electrodes towards Designing Affinity Based Protein Biosensors.

PubMed

Kamakoti, Vikramshankar; Panneer Selvam, Anjan; Radha Shanmugam, Nandhinee; Muthukumar, Sriram; Prasad, Shalini

2016-07-18

Molybdenum electrode based flexible biosensor on porous polyamide substrates has been fabricated and tested for its functionality as a protein affinity based biosensor. The biosensor performance was evaluated using a key cardiac biomarker; cardiac Troponin-I (cTnI). Molybdenum is a transition metal and demonstrates electrochemical behavior upon interaction with an electrolyte. We have leveraged this property of molybdenum for designing an affinity based biosensor using electrochemical impedance spectroscopy. We have evaluated the feasibility of detection of cTnI in phosphate-buffered saline (PBS) and human serum (HS) by measuring impedance changes over a frequency window from 100 mHz to 1 MHz. Increasing changes to the measured impedance was correlated to the increased dose of cTnI molecules binding to the cTnI antibody functionalized molybdenum surface. We achieved cTnI detection limit of 10 pg/mL in PBS and 1 ng/mL in HS medium. The use of flexible substrates for designing the biosensor demonstrates promise for integration with a large-scale batch manufacturing process.

A Water-/Fireproof Flexible Lithium-Oxygen Battery Achieved by Synergy of Novel Architecture and Multifunctional Separator.

PubMed

Yin, Yan-Bin; Yang, Xiao-Yang; Chang, Zhi-Wen; Zhu, Yun-Hai; Liu, Tong; Yan, Jun-Min; Jiang, Qing

2018-01-01

To meet the increasing demands for portable and flexible devices in a rapidly developing society, it is urgently required to develop highly safe and flexible electrochemical energy-storage systems. Flexible lithium-oxygen batteries with high theoretical specific energy density are promising candidates; however, the conventional half-open structure design prevents it from working properly under water or fire conditions. Herein, as a proof-of-concept experiment, a highly safe flexible lithium-oxygen battery achieved by the synergy of a vital multifunctional structure design and a unique composite separator is proposed and fabricated. The structure can effectively prevent the invasion of water from the environment and combustion, which is further significantly consolidated with the help of a polyimide and poly(vinylidene fluoride-co-hexafluoropropylene) composite separator, which holds good water resistance, thermal stability, and ionic conductivity. Unexpectedly, the obtained lithium-oxygen battery exhibits superior flexibility, water resistance, thermal resistance, and cycling stability (up to 218 cycles; at a high current of 1 mA and capacity of 4 mA h). This novel water/fireproof, flexible lithium-oxygen battery is a promising candidate to power underwater flexible electronics. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Student Perceptions of a 21st Century Learning Space

ERIC Educational Resources Information Center

Adedokun, Omolola A.; Henke, Jacqueline N.; Parker, Loran Carleton; Burgess, Wilella D.

2017-01-01

Higher education institutions are increasingly building or remodeling classrooms to be flexible spaces that support learner-centered instruction. However, little is known about the actual impact of these spaces on student outcomes. Using a mixed method design, this study examined student perceptions of a flexible learning space on student learning…

Control and trajectory design of a highly flexible air vehicle with a distributed sensing architecture

NASA Astrophysics Data System (ADS)

Pachikara, Abraham James

Next generational aircraft are becoming very flexible due to efforts to reduce weight and increase aerodynamic efficiency. As a result, flight control systems and trajectories that were designed with traditional rigid body assumptions may no longer become valid. When an aircraft becomes more flexible, the shape of the aircraft can deform significantly due to the aeroservoelastic dynamics. No longer are few sensors located at the CG and elsewhere will be enough to maximize performance. Instead, a full suite of sensors will be needed all throughout the aircraft to accurately measure the complete aerodynamic distribution and dynamics. First, a parametric study will be conducted to understand how flexibility impacts both the open-loop and closed-loop dynamics of a generic micro air vehicle (MAV). Once the impact of flexibility on the MAV's aeroservoelastic dynamics is well understood, an aeroservoelastic flight controller will be designed that leverages a "Fly-By-Feel" sensor architecture. A sensor architecture will be developed that uses several sensors to estimate the MAV's full aerodynamic and inertial distribution along with inertial sensors at the CG. A modal filtering approach will be used for the relevant sensor management and to extract useful modal characteristics from the sensor data. Once that is done, a controller will be designed for maneuver tracking. Once a flight controller has been designed, a set of representative motion primitives for the MAV can be developed that model how the aircraft moves for trajectory generation. Then trajectories can be developed for the flexible vehicle. Analysis will then be conducted to understand how flexibility impacts the creation of trajectories and MAV performance metrics.

Encompassing receptor flexibility in virtual screening using ensemble docking-based hybrid QSAR: discovery of novel phytochemicals for BACE1 inhibition.

PubMed

Chakraborty, Sandipan; Ramachandran, Balaji; Basu, Soumalee

2014-10-01

Mimicking receptor flexibility during receptor-ligand binding is a challenging task in computational drug design since it is associated with a large increase in the conformational search space. In the present study, we have devised an in silico design strategy incorporating receptor flexibility in virtual screening to identify potential lead compounds as inhibitors for flexible proteins. We have considered BACE1 (β-secretase), a key target protease from a therapeutic perspective for Alzheimer's disease, as the highly flexible receptor. The protein undergoes significant conformational transitions from open to closed form upon ligand binding, which makes it a difficult target for inhibitor design. We have designed a hybrid structure-activity model containing both ligand based descriptors and energetic descriptors obtained from molecular docking based on a dataset of structurally diverse BACE1 inhibitors. An ensemble of receptor conformations have been used in the docking study, further improving the prediction ability of the model. The designed model that shows significant prediction ability judged by several statistical parameters has been used to screen an in house developed 3-D structural library of 731 phytochemicals. 24 highly potent, novel BACE1 inhibitors with predicted activity (Ki) ≤ 50 nM have been identified. Detailed analysis reveals pharmacophoric features of these novel inhibitors required to inhibit BACE1.

Living in a Flexible Space

NASA Astrophysics Data System (ADS)

Canepa, Simona

2017-10-01

How long does a space or an object have to last? If in the past an object or a building manufacturing was designed to last as much as possible, nowadays it is designed to have a life related to the time in which it will be used. Flexibility is what characterizes a space, it’s the ability to be variable and adaptable to changes in the lives of users or in relation to the use which these will make over time. The evolution of the labour market, the difficulty of inserting within it and the need to push more and more frequent move today in the trial of living space models increasingly flexible: people, especially young people, are forced to move on territory outlining a new condition to which the flexible nomadic dwellings offer an adequate response, ensuring high functional performance in confined spaces.

An Approach to Automated Fusion System Design and Adaptation

PubMed Central

Fritze, Alexander; Mönks, Uwe; Holst, Christoph-Alexander; Lohweg, Volker

2017-01-01

Industrial applications are in transition towards modular and flexible architectures that are capable of self-configuration and -optimisation. This is due to the demand of mass customisation and the increasing complexity of industrial systems. The conversion to modular systems is related to challenges in all disciplines. Consequently, diverse tasks such as information processing, extensive networking, or system monitoring using sensor and information fusion systems need to be reconsidered. The focus of this contribution is on distributed sensor and information fusion systems for system monitoring, which must reflect the increasing flexibility of fusion systems. This contribution thus proposes an approach, which relies on a network of self-descriptive intelligent sensor nodes, for the automatic design and update of sensor and information fusion systems. This article encompasses the fusion system configuration and adaptation as well as communication aspects. Manual interaction with the flexibly changing system is reduced to a minimum. PMID:28300762

An Approach to Automated Fusion System Design and Adaptation.

PubMed

Fritze, Alexander; Mönks, Uwe; Holst, Christoph-Alexander; Lohweg, Volker

2017-03-16

Industrial applications are in transition towards modular and flexible architectures that are capable of self-configuration and -optimisation. This is due to the demand of mass customisation and the increasing complexity of industrial systems. The conversion to modular systems is related to challenges in all disciplines. Consequently, diverse tasks such as information processing, extensive networking, or system monitoring using sensor and information fusion systems need to be reconsidered. The focus of this contribution is on distributed sensor and information fusion systems for system monitoring, which must reflect the increasing flexibility of fusion systems. This contribution thus proposes an approach, which relies on a network of self-descriptive intelligent sensor nodes, for the automatic design and update of sensor and information fusion systems. This article encompasses the fusion system configuration and adaptation as well as communication aspects. Manual interaction with the flexibly changing system is reduced to a minimum.

Using IMS Learning Design to Model Curricula

ERIC Educational Resources Information Center

Tattersall, Colin; Janssen, Jose; van den Berg, Bert; Hummel, Hans; Koper, Rob

2007-01-01

The traditional notion of the curriculum as a fixed list of topics to be studied sequentially is under strain as the pressure for flexibility in education increases. However, curriculum flexibility can lead to curriculum complexity, so that guidance systems are needed to assist learners in their study choices. This article proposes the use of the…

A Study of Flexible Composites for Expandable Space Structures

NASA Technical Reports Server (NTRS)

Scotti, Stephen J.

2016-01-01

Payload volume for launch vehicles is a critical constraint that impacts spacecraft design. Deployment mechanisms, such as those used for solar arrays and antennas, are approaches that have successfully accommodated this constraint, however, providing pressurized volumes that can be packaged compactly at launch and expanded in space is still a challenge. One approach that has been under development for many years is to utilize softgoods - woven fabric for straps, cloth, and with appropriate coatings, bladders - to provide this expandable pressure vessel capability. The mechanics of woven structure is complicated by a response that is nonlinear and often nonrepeatable due to the discrete nature of the woven fiber architecture. This complexity reduces engineering confidence to reliably design and certify these structures, which increases costs due to increased requirements for system testing. The present study explores flexible composite materials systems as an alternative to the heritage softgoods approach. Materials were obtained from vendors who utilize flexible composites for non-aerospace products to determine some initial physical and mechanical properties of the materials. Uniaxial mechanical testing was performed to obtain the stress-strain response of the flexible composites and the failure behavior. A failure criterion was developed from the data, and a space habitat application was used to provide an estimate of the relative performance of flexible composites compared to the heritage softgoods approach. Initial results are promising with a 25% mass savings estimated for the flexible composite solution.

Process design and economics of a flexible ethanol-butanol plant annexed to a eucalyptus kraft pulp mill.

PubMed

Pereira, Guilherme C Q; Braz, Danilo S; Hamaguchi, Marcelo; Ezeji, Thaddeus C; Maciel Filho, Rubens; Mariano, Adriano P

2018-02-01

This work proposes a strategy, from a process design standpoint, for pulp companies to enter the Brazilian ethanol market. The flexible plant converts eucalyptus-derived glucose to either ethanol or butanol (according to market conditions) and xylose only to butanol production. Depending on the biomass pretreatment technology, Monte Carlo simulations showed that the Net Present Value (NPV) of the flexible plant increases by 20-28% in relation to an ethanol-dedicated plant. Whereas the lower costs of the steam explosion technology turns the investment more attractive (NPV = 184 MMUSD; IRR = 29%), the organosolv technology provides better flexibility to the plant. This work also shows that excessive power consumption is a hurdle in the development of flash fermentation technology chosen for the flexible plant. These results indicate that conventional batch fermentation is preferable if the enzymatic hydrolysis step operates with solids loading up to 20 wt%. Copyright © 2017 Elsevier Ltd. All rights reserved.

Flexible Molybdenum Electrodes towards Designing Affinity Based Protein Biosensors

PubMed Central

Kamakoti, Vikramshankar; Panneer Selvam, Anjan; Radha Shanmugam, Nandhinee; Muthukumar, Sriram; Prasad, Shalini

2016-01-01

Molybdenum electrode based flexible biosensor on porous polyamide substrates has been fabricated and tested for its functionality as a protein affinity based biosensor. The biosensor performance was evaluated using a key cardiac biomarker; cardiac Troponin-I (cTnI). Molybdenum is a transition metal and demonstrates electrochemical behavior upon interaction with an electrolyte. We have leveraged this property of molybdenum for designing an affinity based biosensor using electrochemical impedance spectroscopy. We have evaluated the feasibility of detection of cTnI in phosphate-buffered saline (PBS) and human serum (HS) by measuring impedance changes over a frequency window from 100 mHz to 1 MHz. Increasing changes to the measured impedance was correlated to the increased dose of cTnI molecules binding to the cTnI antibody functionalized molybdenum surface. We achieved cTnI detection limit of 10 pg/mL in PBS and 1 ng/mL in HS medium. The use of flexible substrates for designing the biosensor demonstrates promise for integration with a large-scale batch manufacturing process. PMID:27438863

Learn More | Energy Analysis | NREL

Science.gov Websites

flexibility. Value of Demand Response: Quantities from Production Cost Modeling (Presentation) (2014 adding variable renewable generation to the grid. Market Design Evolution of Wholesale Electricity Market Design with Increasing Levels of Renewable Generation (2014) Reviewed market design approaches focused on

Optical fiber cabling technologies for flexible access network

NASA Astrophysics Data System (ADS)

Tanji, Hisashi

2008-07-01

Fiber-to-the-home (FTTH) outside plant infrastructure should be so designed and constructed as to flexibly deal with increasing subscribers and system evolution to be expected in the future, taking minimization of total cost (CAPEX and OPEX) into consideration. With this in mind, fiber access architectures are reviewed and key technologies on optical fiber and cable for supporting flexible access network are presented. Low loss over wide wavelength (low water peak) and bend-insensitive single mode fiber is a future proof solution. Enhanced separable ribbon facilitates mid-span access to individual fibers in a cable installed, improving fiber utilizing efficiency and flexibility of distribution design. It also contributes to an excellent low PMD characteristic which could be required for video RF overlay system or high capacity long reach metro-access convergence network in the future. Bend-insensitive fiber based cabling technique including field installable connector greatly improves fiber/cable handling in installation and maintenance work.

Workforce flexibility - in defence of professional healthcare work.

PubMed

Wise, Sarah; Duffield, Christine; Fry, Margaret; Roche, Michael

2017-06-19

Purpose The desirability of having a more flexible workforce is emphasised across many health systems yet this goal is as ambiguous as it is ubiquitous. In the absence of empirical studies in healthcare that have defined flexibility as an outcome, the purpose of this paper is to draw on classic management and sociological theory to reduce this ambiguity. Design/methodology/approach The paper uses the Weberian tool of "ideal types". Key workforce reforms are held against Atkinson's model of functional flexibility which aims to increase responsiveness and adaptability through multiskilling, autonomy and teams; and Taylorism which seeks stability and reduced costs through specialisation, fragmentation and management control. Findings Appeals to an amorphous goal of increasing workforce flexibility make an assumption that any reform will increase flexibility. However, this paper finds that the work of healthcare professionals already displays most of the essential features of functional flexibility but many widespread reforms are shifting healthcare work in a Taylorist direction. This contradiction is symptomatic of a failure to confront inevitable trade-offs in reform: between the benefits of specialisation and the costs of fragmentation; and between management control and professional autonomy. Originality/value The paper questions the conventional conception of "the problem" of workforce reform as primarily one of professional control over tasks. Holding reforms against the ideal types of Taylorism and functional flexibility is a simple, effective way the costs and benefits of workforce reform can be revealed.

Online English Language Learning: Theory-Based Course Design and Pedagogy

ERIC Educational Resources Information Center

Andrade, Maureen Snow

2017-01-01

The demand for higher education is increasing worldwide. To meet this demand, and to provide increased access, flexible forms of delivery are needed. Although online courses are criticized for a lack of interaction, when intentionally designed, they can provide learners with opportunities for collaboration that supports the achievement of desired…

Flexible energy-storage devices: design consideration and recent progress.

PubMed

Wang, Xianfu; Lu, Xihong; Liu, Bin; Chen, Di; Tong, Yexiang; Shen, Guozhen

2014-07-23

Flexible energy-storage devices are attracting increasing attention as they show unique promising advantages, such as flexibility, shape diversity, light weight, and so on; these properties enable applications in portable, flexible, and even wearable electronic devices, including soft electronic products, roll-up displays, and wearable devices. Consequently, considerable effort has been made in recent years to fulfill the requirements of future flexible energy-storage devices, and much progress has been witnessed. This review describes the most recent advances in flexible energy-storage devices, including flexible lithium-ion batteries and flexible supercapacitors. The latest successful examples in flexible lithium-ion batteries and their technological innovations and challenges are reviewed first. This is followed by a detailed overview of the recent progress in flexible supercapacitors based on carbon materials and a number of composites and flexible micro-supercapacitors. Some of the latest achievements regarding interesting integrated energy-storage systems are also reviewed. Further research direction is also proposed to surpass existing technological bottle-necks and realize idealized flexible energy-storage devices. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Design and fabrication of a flexible tunnel for Sortie Laboratory

NASA Technical Reports Server (NTRS)

1975-01-01

A program was conducted to update a prototype design and to fabricate a flexible tunnel for a space shuttle/spacelab interface structure. The significant changes in the prototype are as follows: (1) elimination of foam from bladder laminate to increase bladder flexibility, (2) heat treat pulley brackets, bolts, and hinge pin to 160,000 psi minimum tensile strength, and (3) reduction of the meteoroid barrier from 0.5 inch to 0.375 inch. The thermal blanket installation study resulted in developing a method of installation by properly folding the various layers so that a uniform thickness could be maintained under the clamps. A single-lobe mockup was fabricated and cycled open and closed several times with no apparent damage to the blanket.

Design of sensor node platform for wireless biomedical sensor networks.

PubMed

Xijun, Chen; -H Meng, Max; Hongliang, Ren

2005-01-01

Design of low-cost, miniature, lightweight, ultra low-power, flexible sensor platform capable of customization and seamless integration into a wireless biomedical sensor network(WBSN) for health monitoring applications presents one of the most challenging tasks. In this paper, we propose a WBSN node platform featuring an ultra low-power microcontroller, an IEEE 802.15.4 compatible transceiver, and a flexible expansion connector. The proposed solution promises a cost-effective, flexible platform that allows easy customization, energy-efficient computation and communication. The development of a common platform for multiple physical sensors will increase reuse and alleviate costs of transition to a new generation of sensors. As a case study, we present an implementation of an ECG (Electrocardiogram) sensor.

An efficient representation of spatial information for expert reasoning in robotic vehicles

NASA Technical Reports Server (NTRS)

Scott, Steven; Interrante, Mark

1987-01-01

The previous generation of robotic vehicles and drones was designed for a specific task, with limited flexibility in executing their mission. This limited flexibility arises because the robotic vehicles do not possess the intelligence and knowledge upon which to make significant tactical decisions. Current development of robotic vehicles is toward increased intelligence and capabilities, adapting to a changing environment and altering mission objectives. The latest techniques in artificial intelligence (AI) are being employed to increase the robotic vehicle's intelligent decision-making capabilities. This document describes the design of the SARA spatial database tool, which is composed of request parser, reasoning, computations, and database modules that collectively manage and derive information useful for robotic vehicles.

Design of a Compact Actuation and Control System for Flexible Medical Robots.

PubMed

Morimoto, Tania K; Hawkes, Elliot Wright; Okamura, Allison M

2017-07-01

Flexible medical robots can improve surgical procedures by decreasing invasiveness and increasing accessibility within the body. Using preoperative images, these robots can be designed to optimize a procedure for a particular patient. To minimize invasiveness and maximize biocompatibility, the actuation units of flexible medical robots should be placed fully outside the patient's body. In this letter, we present a novel, compact, lightweight, modular actuation, and control system for driving a class of these flexible robots, known as concentric tube robots. A key feature of the design is the use of three-dimensional printed waffle gears to enable compact control of two degrees of freedom within each module. We measure the precision and accuracy of a single actuation module and demonstrate the ability of an integrated set of three actuation modules to control six degrees of freedom. The integrated system drives a three-tube concentric tube robot to reach a final tip position that is on average less than 2 mm from a given target. In addition, we show a handheld manifestation of the device and present its potential applications.

Optimizing Organization Design for the Future.

ERIC Educational Resources Information Center

Creth, Sheila

2000-01-01

Discussion of planning organization design within the higher education environment stresses the goal of integrating structure and process to maintain stability while increasing organizational flexibility. Considers organization culture, organization structure and processes, networked organizations, a networked organization in action, and personal…

Flexible displays as key for high-value and unique automotive design

NASA Astrophysics Data System (ADS)

Isele, Robert

2011-03-01

Within the last few years' car industry changed very fast. Information and Communication became more important and displays are now standard in nearly every car. But this is not the only trend which could be recognized in this industry. CO2 emission, fuel price as well as the increasing traffic inside the Mega Cities initialized a big change in the behavior of the customers. The big battle for the car industry will enter the interior extremely fast, and the premium cars need ore innovative design icons. Flexible Displays are one big step that enables totally different designs and a new value of the driver experience.

Reach a New Threshold of Freedom and Control with Dell's Flexible Computing Solution: On-Demand Desktop Streaming

ERIC Educational Resources Information Center

Technology & Learning, 2008

2008-01-01

When it comes to IT, there has always been an important link between data center control and client flexibility. As computing power increases, so do the potentially crippling threats to security, productivity and financial stability. This article talks about Dell's On-Demand Desktop Streaming solution which is designed to centralize complete…

Novel Concept for Flexible and Resilient Large Power Transformers

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

Upadhyay, Parag; Englebretson, Steven; Ramanan, V. R. R.

This feasibility study investigates a flexible and adaptable LPT design solution which can facilitate long-term replacement in the event of both catastrophic failures as well as scheduled replacements, thereby increasing grid resilience. The scope of this project has been defined based on an initial system study and identification of the transformer requirements from an overall system load flow perspective.

Training for Leisure. Flexible Training Packages for Operatives in Leisure-Related Industries. Part 1.

ERIC Educational Resources Information Center

Hunt, Merle; Specht, Carolynne

A project was designed to identify and define training needs at the operative level in the sport, leisure, and recreation industry in the United Kingdom. The industry is attracting increasing attention in further education (FE) as a result of rapid development. The industry, however, is diverse. Provision of FE must be flexible if it is to meet…

Study of space shuttle orbiter system management computer function. Volume 1: Analysis, baseline design

NASA Technical Reports Server (NTRS)

1975-01-01

A system analysis of the shuttle orbiter baseline system management (SM) computer function is performed. This analysis results in an alternative SM design which is also described. The alternative design exhibits several improvements over the baseline, some of which are increased crew usability, improved flexibility, and improved growth potential. The analysis consists of two parts: an application assessment and an implementation assessment. The former is concerned with the SM user needs and design functional aspects. The latter is concerned with design flexibility, reliability, growth potential, and technical risk. The system analysis is supported by several topical investigations. These include: treatment of false alarms, treatment of off-line items, significant interface parameters, and a design evaluation checklist. An in-depth formulation of techniques, concepts, and guidelines for design of automated performance verification is discussed.

Direct writing of half-meter long CNT based fiber for flexible electronics.

PubMed

Huang, Sihan; Zhao, Chunsong; Pan, Wei; Cui, Yi; Wu, Hui

2015-03-11

Rapid construction of flexible circuits has attracted increasing attention according to its important applications in future smart electronic devices. Herein, we introduce a convenient and efficient "writing" approach to fabricate and assemble ultralong functional fibers as fundamental building blocks for flexible electronic devices. We demonstrated that, by a simple hand-writing process, carbon nanotubes (CNTs) can be aligned inside a continuous and uniform polymer fiber with length of more than 50 cm and diameters ranging from 300 nm to several micrometers. The as-prepared continuous fibers exhibit high electrical conductivity as well as superior mechanical flexibility (no obvious conductance increase after 1000 bending cycles to 4 mm diameter). Such functional fibers can be easily configured into designed patterns with high precision according to the easy "writing" process. The easy construction and assembly of functional fiber shown here holds potential for convenient and scalable fabrication of flexible circuits in future smart devices like wearable electronics and three-dimensional (3D) electronic devices.

Effect of Tip-Speed Constraints on the Optimized Design of a Wind Turbine

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

Dykes, K.; Resor, B.; Platt, A.

This study investigates the effect of tip-velocity constraints on system levelized cost of energy (LCOE). The results indicate that a change in maximum tip speed from 80 to 100~m/s could produce a 32% decrease in gearbox weight (a 33% reduction in cost) which would result in an overall reduction of 1%-9% in system LCOE depending on the design approach. Three 100~m/s design cases were considered including a low tip-speed ratio/high-solidity rotor design, a high tip-speed ratio/ low-solidity rotor design, and finally a flexible blade design in which a high tip-speed ratio was used along with removing the tip deflection constraintmore » on the rotor design. In all three cases, the significant reduction in gearbox weight caused by the higher tip-speed and lower overall gear ratio was counterbalanced by increased weights for the rotor and/or other drivetrain components and the tower. As a result, the increased costs of either the rotor or drivetrain components offset the overall reduction in turbine costs from down-sizing the gearbox. Other system costs were not significantly affected, whereas energy production was slightly reduced in the 100~m/s case low tip-speed ratio case and increased in the high tip-speed ratio case. This resulted in system cost of energy reductions moving from the 80~m/s design to the 100~m/s designs of 1.2% for the low tip-speed ratio, 4.6% for the high tip-speed ratio, and 9.5% for the final flexible case (the latter result is optimistic because the impact of deflection of the flexible blade on power production was not modeled). Overall, the results demonstrate that there is a trade-off in system design between the maximum tip velocity and the overall wind plant cost of energy, and there are many trade-offs within the overall system in designing a turbine for a high maximum tip velocity.« less

Design and experimental validation of a flutter suppression controller for the active flexible wing

NASA Technical Reports Server (NTRS)

Waszak, Martin R.; Srinathkumar, S.

1992-01-01

The synthesis and experimental validation of an active flutter suppression controller for the Active Flexible Wing wind tunnel model is presented. The design is accomplished with traditional root locus and Nyquist methods using interactive computer graphics tools and extensive simulation based analysis. The design approach uses a fundamental understanding of the flutter mechanism to formulate a simple controller structure to meet stringent design specifications. Experimentally, the flutter suppression controller succeeded in simultaneous suppression of two flutter modes, significantly increasing the flutter dynamic pressure despite modeling errors in predicted flutter dynamic pressure and flutter frequency. The flutter suppression controller was also successfully operated in combination with another controller to perform flutter suppression during rapid rolling maneuvers.

Flexible design in water and wastewater engineering--definitions, literature and decision guide.

PubMed

Spiller, Marc; Vreeburg, Jan H G; Leusbrock, Ingo; Zeeman, Grietje

2015-02-01

Urban water and wastewater systems face uncertain developments including technological progress, climate change and urban development. To ensure the sustainability of these systems under dynamic conditions it has been proposed that technologies and infrastructure should be flexible, adaptive and robust. However, in literature it is often unclear what these technologies and infrastructure are. Furthermore, the terms flexible, adaptive and robust are often used interchangeably, despite important differences. In this paper we will i) define the terminology, ii) provide an overview of the status of flexible infrastructure design alternatives for water and wastewater networks and treatment, and iii) develop guidelines for the selection of flexible design alternatives. Results indicate that, with the exception of Net Present Valuation methods, there is little research available on the design and evaluation of technologies that can enable flexibility. Flexible design alternatives reviewed include robust design, phased design, modular design, modular/component platform design and design for remanufacturing. As developments in the water sector are driven by slow variables (climate change, urban development), rather than market forces, it is suggested that phased design or component platform designs are suitable for responding to change, while robust design is an option when operations face highly dynamic variability. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effects of Thermal Resistance on One-Dimensional Thermal Analysis of the Epidermal Flexible Electronic Devices Integrated with Human Skin

NASA Astrophysics Data System (ADS)

Li, He; Cui, Yun

2017-12-01

Nowadays, flexible electronic devices are increasingly used in direct contact with human skin to monitor the real-time health of human body. Based on the Fourier heat conduction equation and Pennes bio-heat transfer equation, this paper deduces the analytical solutions of one - dimensional heat transfer for flexible electronic devices integrated with human skin under the condition of a constant power. The influence of contact thermal resistance between devices and skin is considered as well. The corresponding finite element model is established to verify the correctness of analytical solutions. The results show that the finite element analysis agrees well with the analytical solution. With bigger thermal resistance, temperature increase of skin surface will decrease. This result can provide guidance for the design of flexible electronic devices to reduce the negative impact that exceeding temperature leave on human skin.

Impact Evaluation of Service Programs: Three Flexible Designs.

ERIC Educational Resources Information Center

McKillip, Jack

1979-01-01

Flexibility in evaluative research design does not necessitate the abandonment of randomly constructed comparison groups. Three designs are reviewed which provide at least the option of randomization while maintaining great flexibility. The strengths and weaknesses of the designs are discussed. (Author)

Risk management with substitution options: Valuing flexibility in small-scale energy systems

NASA Astrophysics Data System (ADS)

Knapp, Karl Eric

Several features of small-scale energy systems make them more easily adapted to a changing operating environment than large centralized designs. This flexibility is often manifested as the ability to substitute inputs. This research explores the value of this substitution flexibility and the marginal value of becoming a "little more flexible" in the context of real project investment in developing countries. The elasticity of substitution is proposed as a stylized measure of flexibility and a choice variable. A flexible alternative (elasticity > 0) can be thought of as holding a fixed-proportions "nflexible" asset plus a sequence of exchange options---the option to move to another feasible "recipe" each period. Substitutability derives value from following a contour of anticipated variations and from responding to new information. Substitutability value, a "cost savings option", increases with elasticity and price risk. However, the required premium to incrementally increase flexibility can in some cases decrease with an increase in risk. Variance is not always a measure of risk. Tools from stochastic dominance are newly applied to real options with convex payoffs to correct some misperceptions and clarify many common modeling situations that meet the criteria for increased variance to imply increased risk. The behavior of the cost savings option is explored subject to a stochastic input price process. At the point where costs are identical for all alternatives, the stochastic process for cost savings becomes deterministic, with savings directly proportional to elasticity of substitution and price variance. The option is also formulated as a derivative security via dynamic programming. The partial differential equation is solved for the special case of Cobb-Douglas (elasticity = 1) (also shown are linear (infinite elasticity), Leontief (elasticity = 0)). Risk aversion is insufficient to prefer a more flexible alternative with the same expected value. Intertemporal links convert the sequence of independent options to a single compound option and require an expansion of the flexibility concept. Additional options increase the value of the project but generally decrease flexibility value. The framework is applied to case study in India: an urban industry electricity strategy decision with reliability risk.

Flutter suppression control law synthesis for the Active Flexible Wing model

NASA Technical Reports Server (NTRS)

Mukhopadhyay, Vivek; Perry, Boyd, III; Noll, Thomas E.

1989-01-01

The Active Flexible Wing Project is a collaborative effort between the NASA Langley Research Center and Rockwell International. The objectives are the validation of methodologies associated with mathematical modeling, flutter suppression control law development and digital implementation of the control system for application to flexible aircraft. A flutter suppression control law synthesis for this project is described. The state-space mathematical model used for the synthesis included ten flexible modes, four control surface modes and rational function approximation of the doublet-lattice unsteady aerodynamics. The design steps involved developing the full-order optimal control laws, reducing the order of the control law, and optimizing the reduced-order control law in both the continuous and the discrete domains to minimize stochastic response. System robustness was improved using singular value constraints. An 8th order robust control law was designed to increase the symmetric flutter dynamic pressure by 100 percent. Preliminary results are provided and experiences gained are discussed.

Highly flexible SRAM cells based on novel tri-independent-gate FinFET

NASA Astrophysics Data System (ADS)

Liu, Chengsheng; Zheng, Fanglin; Sun, Yabin; Li, Xiaojin; Shi, Yanling

2017-10-01

In this paper, a novel tri-independent-gate (TIG) FinFET is proposed for highly flexible SRAM cells design. To mitigate the read-write conflict, two kinds of SRAM cells based on TIG FinFETs are designed, and high tradeoff are obtained between read stability and speed. Both cells can offer multi read operations for frequency requirement with single voltage supply. In the first TIG FinFET SRAM cell, the strength of single-fin access transistor (TIG FinFET) can be flexibly adjusted by selecting five different modes to meet the needs of dynamic frequency design. Compared to the previous double-independent-gate (DIG) FinFET SRAM cell, 12.16% shorter read delay can be achieved with only 1.62% read stability decrement. As for the second TIG FinFET SRAM cell, pass-gate feedback technology is applied and double-fin TIG FinFETs are used as access transistors to solve the severe write-ability degradation. Three modes exist to flexibly adjust read speed and stability, and 68.2% larger write margin and 51.7% shorter write delay are achieved at only the expense of 26.2% increase in leakage power, with the same layout area as conventional FinFET SRAM cell.

Flexible and Robust Thermoelectric Generators Based on All-Carbon Nanotube Yarn without Metal Electrodes.

PubMed

Choi, Jaeyoo; Jung, Yeonsu; Yang, Seung Jae; Oh, Jun Young; Oh, Jinwoo; Jo, Kiyoung; Son, Jeong Gon; Moon, Seung Eon; Park, Chong Rae; Kim, Heesuk

2017-08-22

As practical interest in flexible/or wearable power-conversion devices increases, the demand for high-performance alternatives to thermoelectric (TE) generators based on brittle inorganic materials is growing. Herein, we propose a flexible and ultralight TE generator (TEG) based on carbon nanotube yarn (CNTY) with excellent TE performance. The as-prepared CNTY shows a superior electrical conductivity of 3147 S/cm due to increased longitudinal carrier mobility derived from a highly aligned structure. Our TEG is innovative in that the CNTY acts as multifunctions in the same device. The CNTY is alternatively doped into n- and p-types using polyethylenimine and FeCl 3 , respectively. The highly conductive CNTY between the doped regions is used as electrodes to minimize the circuit resistance, thereby forming an all-carbon TEG without additional metal deposition. A flexible TEG based on 60 pairs of n- and p-doped CNTY shows the maximum power density of 10.85 and 697 μW/g at temperature differences of 5 and 40 K, respectively, which are the highest values among reported TEGs based on flexible materials. We believe that the strategy proposed here to improve the power density of flexible TEG by introducing highly aligned CNTY and designing a device without metal electrodes shows great potential for the flexible/or wearable power-conversion devices.

Flutter suppression for the Active Flexible Wing - Control system design and experimental validation

NASA Technical Reports Server (NTRS)

Waszak, M. R.; Srinathkumar, S.

1992-01-01

The synthesis and experimental validation of a control law for an active flutter suppression system for the Active Flexible Wing wind-tunnel model is presented. The design was accomplished with traditional root locus and Nyquist methods using interactive computer graphics tools and with extensive use of simulation-based analysis. The design approach relied on a fundamental understanding of the flutter mechanism to formulate understanding of the flutter mechanism to formulate a simple control law structure. Experimentally, the flutter suppression controller succeeded in simultaneous suppression of two flutter modes, significantly increasing the flutter dynamic pressure despite errors in the design model. The flutter suppression controller was also successfully operated in combination with a rolling maneuver controller to perform flutter suppression during rapid rolling maneuvers.

Making a Difference in Migrant Summer School: Testing a Healthy Weight Intervention

PubMed Central

Kilanowski, Jill F.; Gordon, Nahida H.

2014-01-01

Objective Evaluate the effectiveness of a healthy weight intervention designed for children of migrant farmworkers embedded in a 7-week summer Midwest Migrant Education Program (MEP) for changes in: weight, Body Mass Index (BMI); BMI percentiles (BMI-p); muscle strength and muscle flexibility; nutrition knowledge; attitudes and behaviors. Design This is a two-group pre-post quasi-experimental study. Sample Latino children of migrant farmworkers attending summer MEP in grades 1 through 8 were enrolled (n=171: comparison n=33, intervention n=138). Measurements Weight, BMI, BMI-p, muscle strength and flexibility, knowledge and healthy behaviors. Intervention Classroom content included: food variety; increasing fruits and vegetables; healthy breakfasts; more family meals; increasing family time; decreasing TV and electronic game time; increasing physical activity; limiting sugar-sweetened drinks; portion sizes; and food labels. Results Statistically significant were: increase in comparison group mean weight, decrease in intervention group BMI-p, and improvements in muscle flexibility and healthy behavior attitudes. The intervention students showed trends towards healthy BMI. The number of MEP days attended was significantly correlated in four outcomes. Conclusion Study findings have the potential to decrease incidence of unhealthy weight in Latino migrant children, reduce rates of premature adult diseases in these children, and a potential to decrease future health care costs. PMID:25611178

Approaches to Learning Design: Past the Head and the Hands to the HEART of the Matter

ERIC Educational Resources Information Center

Donald, Claire; Blake, Adam; Girault, Isabelle; Datt, Ashwini; Ramsay, Elizabeth

2009-01-01

Digital technologies have been used increasingly in open, distance, and flexible learning to both facilitate learning and depict learning designs. While the portable nature of a learning design once captured in digital form appears to offer limitless possibilities for sharing and reuse, dissemination initiatives have failed to thrive. This may be…

Incorporating operational flexibility into electric generation planning Impacts and methods for system design and policy analysis

NASA Astrophysics Data System (ADS)

Palmintier, Bryan S.

This dissertation demonstrates how flexibility in hourly electricity operations can impact long-term planning and analysis for future power systems, particularly those with substantial variable renewables (e.g., wind) or strict carbon policies. Operational flexibility describes a power system's ability to respond to predictable and unexpected changes in generation or demand. Planning and policy models have traditionally not directly captured the technical operating constraints that determine operational flexibility. However, as demonstrated in this dissertation, this capability becomes increasingly important with the greater flexibility required by significant renewables (>= 20%) and the decreased flexibility inherent in some low-carbon generation technologies. Incorporating flexibility can significantly change optimal generation and energy mixes, lower system costs, improve policy impact estimates, and enable system designs capable of meeting strict regulatory targets. Methodologically, this work presents a new clustered formulation that tractably combines a range of normally distinct power system models, from hourly unit-commitment operations to long-term generation planning. This formulation groups similar generators into clusters to reduce problem size, while still retaining the individual unit constraints required to accurately capture operating reserves and other flexibility drivers. In comparisons against traditional unit commitment formulations, errors were generally less than 1% while run times decreased by several orders of magnitude (e.g., 5000x). Extensive numerical simulations, using a realistic Texas-based power system show that ignoring flexibility can underestimate carbon emissions by 50% or result in significant load and wind shedding to meet environmental regulations. Contributions of this dissertation include: 1. Demonstrating that operational flexibility can have an important impact on power system planning, and describing when and how these impacts occur; 2. Demonstrating that a failure to account for operational flexibility can result in undesirable outcomes for both utility planners and policy analysts; and 3. Extending the state of the art for electric power system models by introducing a tractable method for incorporating unit commitment based operational flexibility at full 876o hourly resolution directly into planning optimization. Together these results encourage and offer a new flexibility-aware approach for capacity planning and accompanying policy design that can enable cleaner, less expensive electric power systems for the future. (Copies available exclusively from MIT Libraries, libraries.mit.edu/docs - docs mit.edu)

High-throughput optical inter-board interconnects for next-generation on-board digital transparent processors

NASA Astrophysics Data System (ADS)

Venet, N.; Sotom, M.; Gachon, H.; Foucal, V.; Pez, M.; Heikkinen, V.; Tuominen, T.; Pantoja, S.

2017-11-01

The satellite telecommunication sector is continuously facing new challenges. Operators turn towards increasing capacity payloads with higher number of beams and broader bandwidth, in order to cope with exhausting orbital positions and to lower the cost of in-orbit delivery of bit. Only satellites able to provide high data rate connections to numerous users are expected to achieve affordable communication prices. On the other hand, as the telecom market grows and the range of offered services (HDTV, Video On Demand, Triple Play), operators call for more versatile solutions to quickly grasp new markets and to adapt to these evolutions over the average 15 years of a satellite lifetime. Flexible payloads have found an increasing interest for a number of years. Flexibility is considered as a means for a better commercial exploitation of a satellite fleet and a better allocation of resource in response to traffic evolution and/or changing business plans, with potential advantages such as a wider range of applications, less customization for specific missions, increased production runs of equipment, enhancement of reliability, reduction of equipment cost, reduction of program schedules [1]. Flexibility is expected to be offered in spectrum management and frequency plan, in coverage, or in the repeater power allocation. The industry is taking up the challenge both by improving current telecom satellites and offering new payload technology, more flexible and able to address the new markets. From a system integrator perspective, flexibility is as an opportunity to design more generic payloads, that can be customized during or after fabrication only, thus shortening the design-to-manufacturing cycle, and improving the industry competitiveness.

3D-FEM Analysis on Geogrid Reinforced Flexible Pavement Roads

NASA Astrophysics Data System (ADS)

Calvarano, Lidia Sarah; Palamara, Rocco; Leonardi, Giovanni; Moraci, Nicola

2017-12-01

Nowadays, the need to increase pavement service life, guarantee high performance, reduce service and maintenance costs has been turned a greater attention on the use of reinforcements. This paper presents findings of a numerical investigation on geogrid reinforced flexible pavement roads, under wheel traffic loads, using a three-dimensional Finite Element Method (FEM). The results obtained show the effectiveness of glass fibre grids as reinforcement which, with appropriate design and correct installation, by improving interface shear resistance, can be used to expand the performance of flexible pavements in different ways: by increasing the road service life providing a relevant contribution against superficial rutting or by decreasing the construction costs due to the reduction in the reinforced HMA layer thickness and thus of mineral aggregate required for its construction.

Investigating an Open Methodology for Designing Domain-Specific Language Collections

ERIC Educational Resources Information Center

Fitzgerald, Alannah; Wu, Shaoqun; Barge, Martin

2014-01-01

With this research and design paper, we are proposing that Open Educational Resources (OERs) and Open Access (OA) publications give increasing access to high quality online educational and research content for the development of powerful domain-specific language collections that can be further enhanced linguistically with the Flexible Language…

Flexible Educational Facilities. An Annotated Reference List.

ERIC Educational Resources Information Center

Wakefield, Howard E.

These references on flexible educational facilities are abstracted by the ERIC Clearinghouse on Educational Facilities. College material includes an experimental learning center, a college health center, a fine arts center, and university library design. References on schools include secondary school design, flexible high school design, standard…

MILSTAR's flexible substrate solar array: Lessons learned, addendum

NASA Technical Reports Server (NTRS)

Gibb, John

1990-01-01

MILSTAR's Flexible Substrate Solar Array (FSSA) is an evolutionary development of the lightweight, flexible substrate design pioneered at Lockheed during the seventies. Many of the features of the design are related to the Solar Array Flight Experiment (SAFE), flown on STS-41D in 1984. FSSA development has created a substantial technology base for future flexible substrate solar arrays such as the array for the Space Station Freedom. Lessons learned during the development of the FSSA can and should be applied to the Freedom array and other future flexible substrate designs.

Damage Detection Sensor System for Aerospace and Multiple Applications

NASA Technical Reports Server (NTRS)

Williams, Martha; Lewis, Mark; Gibson, Tracy L.; Lane, John; Medelius, Pedro

2017-01-01

NASA has identified structural health monitoring and damage detection and verification as critical needs in multiple technology roadmaps. The sensor systems can be customized for detecting location, damage size, and depth, with velocity options and can be designed for particular environments for monitoring of impact or physical damage to a structure. The damage detection system has been successfully demonstrated in a harsh environment and remote integration tested over 1000 miles apart. Multiple applications includes: Spacecraft and Aircraft; Inflatable, Deployable and Expandable Structures; Space Debris Monitoring; Space Habitats; Military Shelters; Solar Arrays, Smart Garments and Wearables, Extravehicular activity (EVA) suits; Critical Hardware Enclosures; Embedded Composite Structures; and Flexible Hybrid Printed Electronics and Systems. For better implementation and infusion into more flexible architectures, important and improved designs in advancing embedded software and GUI interface, and increasing flexibility, modularity, and configurable capabilities of the system are currently being carried out.

Damage Detection Sensor System for Aerospace and Multiple Applications

NASA Technical Reports Server (NTRS)

Williams, M.; Lewis, M.; Gibson, T.; Medelius, P.; Lane, J.

2017-01-01

The damage detection sensory system is an intelligent damage detection ‘skin’ that can be embedded into rigid or flexible structures, providing a lightweight capability for in-situ health monitoring for applications such as spacecraft, expandable or inflatable structures, extravehicular activities (EVA) suits, smart wearables, and other applications where diagnostic impact damage monitoring might be critical. The sensor systems can be customized for detecting location, damage size, and depth, with velocity options and can be designed for particular environments for monitoring of impact or physical damage to a structure. The operation of the sensor detection system is currently based on the use of parallel conductive traces placed on a firm or flexible surface. Several detection layers can be implemented, where alternate layers are arranged in orthogonal direction with respect to the adjacent layers allowing for location and depth calculations. Increased flexibility of the damage detection sensor system designs will also be introduced.

Flexible Programmes in Higher Professional Education: Expert Validation of a Flexible Educational Model

ERIC Educational Resources Information Center

Schellekens, Ad; Paas, Fred; Verbraeck, Alexander; van Merrienboer, Jeroen J. G.

2010-01-01

In a preceding case study, a process-focused demand-driven approach for organising flexible educational programmes in higher professional education (HPE) was developed. Operations management and instructional design contributed to designing a flexible educational model by means of discrete-event simulation. Educational experts validated the model…

Design, Synthesis, and Characterization of Nanostructured Materials for Energy Storage Devices and Flexible Chemical Sensors

NASA Astrophysics Data System (ADS)

Kang, Ning

Nanomaterials have shown increasing applications in the design and fabrication of functional devices such as energy storage devices and sensor devices. A key challenge is the ability to harness the nanostructures in terms of size, shape, composition and structure so that the unique nanoscale functional properties can be exploited. This dissertation describes our findings in design, synthesis, and characterization of nanoparticles towards applications in two important fronts. The first involves the investigation of nanoalloy catalysts and functional nanoparticles for energy storage devices, including Li-air and Li-ion batteries, aiming at increasing the capacity and cycle performance. Part of this effort focuses on design of bifunctional nanocatalysts through alloying noble metal with non-noble transition metal to improve the ORR and OER activity of Li-air batteries. By manipulating the composition and alloying structure of the catalysts, synergetic effect has been demonstrated, which is substantiated by both experimental results and theoretical calculation for the charge/discharge process. The other part of the effort focuses on modification of Si nanoparticles towards high-capacity anode materials. The modification involved dopant elements, carbon coating, and graphene composite formation to manipulate the ability of the nanoparticles in accommodating the volume expansion. The second part focuses on the design, preparation and characterization of metal nanoparticles and nanocomposite materials for the application in flexible sensing devices. The investigation focuses on fabrication of a novel class of nanoparticle-nanofibrous membranes consisting of gold nanoparticles embedded in a multi-layered fibrous membrane as a tunable interfacial scaffold for flexible sweat sensors. Sensing responses to different ionic species in aqueous solutions and relative humidity changes in the environment were demonstrated, showing promising potential as flexible sensing devices for applications in wearable sweat sensors. Moreover, printing technique was also applied in the fabrication of conductive patterns as the sensing electrodes. The results shed new lights on the understanding of the structural tuning of the nanomaterials for the ultimate applications in advanced energy storage devices and chemical sensor devices.

Modeling, design, and control of flexible manipulator arms: Status and trends

NASA Technical Reports Server (NTRS)

Book, Wayne J.

1989-01-01

The desire for higher performance manipulators has lead to dynamic behavior in which the flexibility is an essential aspect. The mathematical representations commonly used in modeling flexible arms and arms with flexible drives are examined first. Then design considerations directly arising from the flexible nature of the arm are discussed. Finally, controls of joints for general and tip motion are discussed.

Building Safer Systems With SpecTRM

NASA Technical Reports Server (NTRS)

2003-01-01

System safety, an integral component in software development, often poses a challenge to engineers designing computer-based systems. While the relaxed constraints on software design allow for increased power and flexibility, this flexibility introduces more possibilities for error. As a result, system engineers must identify the design constraints necessary to maintain safety and ensure that the system and software design enforces them. Safeware Engineering Corporation, of Seattle, Washington, provides the information, tools, and techniques to accomplish this task with its Specification Tools and Requirements Methodology (SpecTRM). NASA assisted in developing this engineering toolset by awarding the company several Small Business Innovation Research (SBIR) contracts with Ames Research Center and Langley Research Center. The technology benefits NASA through its applications for Space Station rendezvous and docking. SpecTRM aids system and software engineers in developing specifications for large, complex safety critical systems. The product enables engineers to find errors early in development so that they can be fixed with the lowest cost and impact on the system design. SpecTRM traces both the requirements and design rationale (including safety constraints) throughout the system design and documentation, allowing engineers to build required system properties into the design from the beginning, rather than emphasizing assessment at the end of the development process when changes are limited and costly.System safety, an integral component in software development, often poses a challenge to engineers designing computer-based systems. While the relaxed constraints on software design allow for increased power and flexibility, this flexibility introduces more possibilities for error. As a result, system engineers must identify the design constraints necessary to maintain safety and ensure that the system and software design enforces them. Safeware Engineering Corporation, of Seattle, Washington, provides the information, tools, and techniques to accomplish this task with its Specification Tools and Requirements Methodology (SpecTRM). NASA assisted in developing this engineering toolset by awarding the company several Small Business Innovation Research (SBIR) contracts with Ames Research Center and Langley Research Center. The technology benefits NASA through its applications for Space Station rendezvous and docking. SpecTRM aids system and software engineers in developing specifications for large, complex safety critical systems. The product enables engineers to find errors early in development so that they can be fixed with the lowest cost and impact on the system design. SpecTRM traces both the requirements and design rationale (including safety constraints) throughout the system design and documentation, allowing engineers to build required system properties into the design from the beginning, rather than emphasizing assessment at the end of the development process when changes are limited and costly.

Flexible power and bandwidth allocation in mobile satellites

NASA Astrophysics Data System (ADS)

Keyes, L. A.

The introduction of L-band mobile communication services by spot beam satellites creates a payload design challenge due to uncertainty in the location and size of the new market to be served. A combination of payload technologies that allow a flexible allocation of power and bandwidth to any portion of the coverage area is described. Power flexibility is achieved by a novel combination of a low-level beam-forming network and a matrix power module which ensures equal sharing of power among individual amplifiers. This eliminates the loss of efficiency and increased mass when an amplifier associated with a beam must be over-designed to meet uncertainties in power distribution between beams. Flexibility in allocation of bandwidth to beams is achieved by intermediate frequency subdivision of the L-band service categories defined by ITU. These spectral subdivisions are assigned to beams by an IF interconnect matrix having beam ports and filter ports as inputs and outputs, respectively. Two such filter switch matrices are required, one for the inbound L-band to feeder link transponder, and one for the outbound feeder link to L-band transponder.

Experimental Test Rig for Optimal Control of Flexible Space Robotic Arms

DTIC Science & Technology

2016-12-01

was used to refine the test bed design and the experimental workflow. Three concepts incorporated various strategies to design a robust flexible link...used to refine the test bed design and the experimental workflow. Three concepts incorporated various strategies to design a robust flexible link... designed to perform the experimentation . The first and second concepts use traditional elastic springs in varying configurations while a third uses a

Flutter Phenomenon in Flow Driven Energy Harvester-A Unified Theoretical Model for "Stiff" and "Flexible" Materials.

PubMed

Chen, Yu; Mu, Xiaojing; Wang, Tao; Ren, Weiwei; Yang, Ya; Wang, Zhong Lin; Sun, Chengliang; Gu, Alex Yuandong

2016-10-14

Here, we report a stable and predictable aero-elastic motion in the flow-driven energy harvester, which is different from flapping and vortex-induced-vibration (VIV). A unified theoretical frame work that describes the flutter phenomenon observed in both "stiff" and "flexible" materials for flow driven energy harvester was presented in this work. We prove flutter in both types of materials is the results of the coupled effects of torsional and bending modes. Compared to "stiff" materials, which has a flow velocity-independent flutter frequency, flexible material presents a flutter frequency that almost linearly scales with the flow velocity. Specific to "flexible" materials, pre-stress modulates the frequency range in which flutter occurs. It is experimentally observed that a double-clamped "flexible" piezoelectric P(VDF-TrFE) thin belt, when driven into the flutter state, yields a 1,000 times increase in the output voltage compared to that of the non-fluttered state. At a fixed flow velocity, increase in pre-stress level of the P(VDF-TrFE) thin belt up-shifts the flutter frequency. In addition, this work allows the rational design of flexible piezoelectric devices, including flow-driven energy harvester, triboelectric energy harvester, and self-powered wireless flow speed sensor.

Design Mechanisms for Mediawiki to Support Collaborative Writing in a Mandatory Context

ERIC Educational Resources Information Center

Kasemvilas, Sumonta

2011-01-01

Because MediaWiki is not appropriate for use in the classroom setting due to its decentralization, arbitrariness, and sharing, its flexible characteristics complicate concepts of practical design when applying MediaWiki in a mandatory writing context. This dissertation identifies a need to add extensions to facilitate increased accountability,…

Analysis of flexible aircraft longitudinal dynamics and handling qualities. Volume 1: Analysis methods

NASA Technical Reports Server (NTRS)

Waszak, M. R.; Schmidt, D. S.

1985-01-01

As aircraft become larger and lighter due to design requirements for increased payload and improved fuel efficiency, they will also become more flexible. For highly flexible vehicles, the handling qualities may not be accurately predicted by conventional methods. This study applies two analysis methods to a family of flexible aircraft in order to investigate how and when structural (especially dynamic aeroelastic) effects affect the dynamic characteristics of aircraft. The first type of analysis is an open loop model analysis technique. This method considers the effects of modal residue magnitudes on determining vehicle handling qualities. The second method is a pilot in the loop analysis procedure that considers several closed loop system characteristics. Volume 1 consists of the development and application of the two analysis methods described above.

Three-Dimensional Networked Metal-Organic Frameworks with Conductive Polypyrrole Tubes for Flexible Supercapacitors.

PubMed

Xu, Xingtao; Tang, Jing; Qian, Huayu; Hou, Shujin; Bando, Yoshio; Hossain, Md Shahriar A; Pan, Likun; Yamauchi, Yusuke

2017-11-08

Metal-organic frameworks (MOFs) with high porosity and a regular porous structure have emerged as a promising electrode material for supercapacitors, but their poor electrical conductivity limits their utilization efficiency and capacitive performance. To increase the overall electrical conductivity as well as the efficiency of MOF particles, three-dimensional networked MOFs are developed via using preprepared conductive polypyrrole (PPy) tubes as the support for in situ growth of MOF particles. As a result, the highly conductive PPy tubes that run through the MOF particles not only increase the electron transfer between MOF particles and maintain the high effective porosity of the MOFs but also endow the MOFs with flexibility. Promoted by such elaborately designed MOF-PPy networks, the specific capacitance of MOF particles has been increased from 99.2 F g -1 for pristine zeolitic imidazolate framework (ZIF)-67 to 597.6 F g -1 for ZIF-PPy networks, indicating the importance of the design of the ZIF-PPy continuous microstructure. Furthermore, a flexible supercapacitor device based on ZIF-PPy networks shows an outstanding areal capacitance of 225.8 mF cm -2 , which is far above other MOFs-based supercapacitors reported up to date, confirming the significance of in situ synthetic chemistry as well as the importance of hybrid materials on the nanoscale.

Operation DOMINIC, SHOT SWORD FISH. Scientific Director’s Summary Report

DTIC Science & Technology

1985-09-01

charges, undoubtedly reflects a design decision that balanced thp tactical need for flexibility in using the weapon against the desire to ensure...further if the commanding officer is to take maximum advantage of his increased weapon delivery flexibility . i.2 SIGNIFICANCE OF SWORD FISH AS AN...turn, is governed by the pulsation and upward z.gration of the steam bubble formed in the water after the burst. The base surge, at ranges of delivery

The latest generation in flexible bronchoscopes: a description and evaluation.

PubMed

Hsia, David W; Tanner, Nichole T; Shamblin, Clayton; Mehta, Hiren J; Silvestri, Gerard A; Musani, Ali I

2013-10-01

Since the introduction of the flexible bronchoscope over 50 years ago, bronchoscopists have seen vast improvement in the technology available for diagnostics and therapeutics in the bronchoscopy laboratory. We set forth to evaluate the latest evolution in flexible bronchoscopes with features designed to improve imaging and airway navigation. The BF-Q190, BF-H190, and/or BF-1TH190 bronchoscopes were evaluated prospectively in 105 patients undergoing bronchoscopy from November 2010 to August 2011 at 2 tertiary care centers in the United States. Data collected from each procedure included method of insertion, airway images, and therapeutic interventions. At the completion of the study, 10 bronchoscopists were surveyed using a 7-point Likert scale to identify the perceived benefits of the design. Insertion methods included nasal, oral, laryngeal mask airway or endotracheal tube, and tracheostomy. Procedures performed included bronchoalveolar lavage, endobronchial biopsy or brushing, transbronchial biopsy, transbronchial needle aspiration or injection, peripheral navigation, and large airway therapeutic interventions. Survey of bronchoscopists revealed that when compared with current bronchoscopes, the features rated as having the most significant impact on functionality are the 210-degree tip angulation (average 2.4/3) and rotational capability of the insertion tube (average 2.4/3). The new-generation flexible bronchoscope offers improvement in image quality, magnification options, unique insertion tube rotation, and an increased 210-degree distal tip angulation over currently available flexible bronchoscopes. The bronchoscopes are an overall improvement to the current generation of bronchoscopes. The increased tip angulation and novel rotating insertion tube add the most to improvement in functionality.

Design and operations technologies - Integrating the pieces. [for future space systems design

NASA Technical Reports Server (NTRS)

Eldred, C. H.

1979-01-01

As major elements of life-cycle costs (LCC) having critical impacts on the initiation and utilization of future space programs, the areas of vehicle design and operations are reviewed in order to identify technology requirements. Common to both areas is the requirement for efficient integration of broad, complex systems. Operations technologies focus on the extension of space-based capabilities and cost reduction through the combination of innovative design, low-maintenance hardware, and increased manpower productivity. Design technologies focus on computer-aided techniques which increase productivity while maintaining a high degree of flexibility which enhances creativity and permits graceful design changes.

Prospects for Advanced Tokamak Operation of ITER

NASA Astrophysics Data System (ADS)

Neilson, George H.

1996-11-01

Previous studies have identified steady-state (or "advanced") modes for ITER, based on reverse-shear profiles and significant bootstrap current. A typical example has 12 MA of plasma current, 1,500 MW of fusion power, and 100 MW of heating and current-drive power. The implementation of these and other steady-state operating scenarios in the ITER device is examined in order to identify key design modifications that can enhance the prospects for successfully achieving advanced tokamak operating modes in ITER compatible with a single null divertor design. In particular, we examine plasma configurations that can be achieved by the ITER poloidal field system with either a monolithic central solenoid (as in the ITER Interim Design), or an alternate "hybrid" central solenoid design which provides for greater flexibility in the plasma shape. The increased control capability and expanded operating space provided by the hybrid central solenoid allows operation at high triangularity (beneficial for improving divertor performance through control of edge-localized modes and for increasing beta limits), and will make it much easier for ITER operators to establish an optimum startup trajectory leading to a high-performance, steady-state scenario. Vertical position control is examined because plasmas made accessible by the hybrid central solenoid can be more elongated and/or less well coupled to the conducting structure. Control of vertical-displacements using the external PF coils remains feasible over much of the expanded operating space. Further work is required to define the full spectrum of axisymmetric plasma disturbances requiring active control In addition to active axisymmetric control, advanced tokamak modes in ITER may require active control of kink modes on the resistive time scale of the conducting structure. This might be accomplished in ITER through the use of active control coils external to the vacuum vessel which are actuated by magnetic sensors near the first wall. The enhanced shaping and positioning flexibility provides a range of options for reducing the ripple-induced losses of fast alpha particles--a major limitation on ITER steady-state modes. An alternate approach that we are pursuing in parallel is the inclusion of ferromagnetic inserts to reduce the toroidal field ripple within the plasma chamber. The inclusion of modest design changes such as the hybrid central solenoid, active control coils for kink modes, and ferromagnetic inserts for TF ripple reduction show can greatly increase the flexibility to accommodate advance tokamak operation in ITER. Increased flexibility is important because the optimum operating scenario for ITER cannot be predicted with certainty. While low-inductance, reverse shear modes appear attractive for steady-state operation, high-inductance, high-beta modes are also viable candidates, and it is important that ITER have the flexibility to explore both these, and other, operating regimes.

Laser surface modification of electrically conductive fabrics: Material performance improvement and design effects

NASA Astrophysics Data System (ADS)

Tunakova, Veronika; Hrubosova, Zuzana; Tunak, Maros; Kasparova, Marie; Mullerova, Jana

2018-01-01

Development of lightweight flexible materials for electromagnetic interference shielding has obtained increased attention in recent years particularly for clothing, textiles in-house use and technical applications especially in areas of aircraft, aerospace, automobiles and flexible electronics such as portable electronics and wearable devices. There are many references in the literature concerning development and investigation of electromagnetic shielding lightweight flexible materials especially textile based with different electrically conductive additives. However, only little attention is paid to designing and enhancing the properties of these special fabrics by textile finishing processes. Laser technology applied as a physical treatment method is becoming very popular and can be used in different applications to make improvement and even overcome drawbacks of some of the traditional processes. The main purpose of this study is firstly to analyze the possibilities of transferring design onto the surface of electrically conductive fabrics by laser beam and secondly to study of effect of surface modification degree on performance of conductive fabric including electromagnetic shielding ability and mechanical properties. Woven fabric made of yarns containing 10% of extremely thin stainless steel fiber was used as a conductive substrate.

NASA lithium cell applications

NASA Technical Reports Server (NTRS)

Juvinall, G. L.

1978-01-01

The advantages of lithium systems are described and a general summary of their application in present and future NASA programs is presented. Benefits of the lithium systems include an increased payload weight and an increased cost effectiveness to the customer. This also allows for more flexibility in the design of future space transportation systems.

The Conductive Silver Nanowires Fabricated by Two-beam Laser Direct Writing on the Flexible Sheet.

PubMed

He, Gui-Cang; Zheng, Mei-Ling; Dong, Xian-Zi; Jin, Feng; Liu, Jie; Duan, Xuan-Ming; Zhao, Zhen-Sheng

2017-02-02

Flexible electrically conductive nanowires are now a key component in the fields of flexible devices. The achievement of metal nanowire with good flexibility, conductivity, compact and smooth morphology is recognized as one critical milestone for the flexible devices. In this study, a two-beam laser direct writing system is designed to fabricate AgNW on PET sheet. The minimum width of the AgNW fabricated by this method is 187 ± 34 nm with the height of 84 ± 4 nm. We have investigated the electrical resistance under different voltages and the applicable voltage per meter range is determined to be less than 7.5 × 10 3  V/m for the fabricated AgNW. The flexibility of the AgNW is very excellent, since the resistance only increases 6.63% even after the stretched bending of 2000 times at such a small bending radius of 1.0 mm. The proposed two-beam laser direct writing is an efficient method to fabricate AgNW on the flexible sheet, which could be applied in flexible micro/nano devices.

Spare capacity and phenotypic flexibility in the digestive system of a migratory bird: defining the limits of animal design

PubMed Central

McWilliams, Scott R.; Karasov, William H.

2014-01-01

Flexible phenotypes enable animals to live in environments that change over space and time, and knowing the limits to and the required time scale for this flexibility provides insights into constraints on energy and nutrient intake, diet diversity and niche width. We quantified the level of immediate and ultimate spare capacity, and thus the extent of phenotypic flexibility, in the digestive system of a migratory bird in response to increased energy demand, and identified the digestive constraints responsible for the limits on sustained energy intake. Immediate spare capacity decreased from approximately 50% for birds acclimated to relatively benign temperatures to less than 20% as birds approached their maximum sustainable energy intake. Ultimate spare capacity enabled an increase in feeding rate of approximately 126% as measured in birds acclimated for weeks at −29°C compared with +21°C. Increased gut size and not tissue-specific differences in nutrient uptake or changes in digestive efficiency or retention time were primarily responsible for this increase in capacity with energy demand, and this change required more than 1–2 days. Thus, the pace of change in digestive organ size may often constrain energy intake and, for birds, retard the pace of their migration. PMID:24718764

Spare capacity and phenotypic flexibility in the digestive system of a migratory bird: defining the limits of animal design.

PubMed

McWilliams, Scott R; Karasov, William H

2014-05-22

Flexible phenotypes enable animals to live in environments that change over space and time, and knowing the limits to and the required time scale for this flexibility provides insights into constraints on energy and nutrient intake, diet diversity and niche width. We quantified the level of immediate and ultimate spare capacity, and thus the extent of phenotypic flexibility, in the digestive system of a migratory bird in response to increased energy demand, and identified the digestive constraints responsible for the limits on sustained energy intake. Immediate spare capacity decreased from approximately 50% for birds acclimated to relatively benign temperatures to less than 20% as birds approached their maximum sustainable energy intake. Ultimate spare capacity enabled an increase in feeding rate of approximately 126% as measured in birds acclimated for weeks at -29°C compared with +21°C. Increased gut size and not tissue-specific differences in nutrient uptake or changes in digestive efficiency or retention time were primarily responsible for this increase in capacity with energy demand, and this change required more than 1-2 days. Thus, the pace of change in digestive organ size may often constrain energy intake and, for birds, retard the pace of their migration.

Increasing work-time influence: consequences for flexibility, variability, regularity and predictability.

PubMed

Nabe-Nielsen, Kirsten; Garde, Anne Helene; Aust, Birgit; Diderichsen, Finn

2012-01-01

This quasi-experimental study investigated how an intervention aiming at increasing eldercare workers' influence on their working hours affected the flexibility, variability, regularity and predictability of the working hours. We used baseline (n = 296) and follow-up (n = 274) questionnaire data and interviews with intervention-group participants (n = 32). The work units in the intervention group designed their own intervention comprising either implementation of computerised self-scheduling (subgroup A), collection of information about the employees' work-time preferences by questionnaires (subgroup B), or discussion of working hours (subgroup C). Only computerised self-scheduling changed the working hours and the way they were planned. These changes implied more flexible but less regular working hours and an experience of less predictability and less continuity in the care of clients and in the co-operation with colleagues. In subgroup B and C, the participants ended up discussing the potential consequences of more work-time influence without actually implementing any changes. Employee work-time influence may buffer the adverse effects of shift work. However, our intervention study suggested that while increasing the individual flexibility, increasing work-time influence may also result in decreased regularity of the working hours and less continuity in the care of clients and co-operation with colleagues.

An improved output feedback control of flexible large space structures

NASA Technical Reports Server (NTRS)

Lin, Y. H.; Lin, J. G.

1980-01-01

A special output feedback control design technique for flexible large space structures is proposed. It is shown that the technique will increase both the damping and frequency of selected modes for more effective control. It is also able to effect integrated control of elastic and rigid-body modes and, in particular, closed-loop system stability and robustness to modal truncation and parameter variation. The technique is seen as marking an improvement over previous work concerning large space structures output feedback control.

The control of flexible structure vibrations using a cantilevered adaptive truss

NASA Technical Reports Server (NTRS)

Wynn, Robert H., Jr.; Robertshaw, Harry H.

1991-01-01

Analytical and experimental procedures and design tools are presented for the control of flexible structure vibrations using a cantilevered adaptive truss. Simulated and experimental data are examined for three types of structures: a slender beam, a single curved beam, and two curved beams. The adaptive truss is shown to produce a 6,000-percent increase in damping, demonstrating its potential in vibration control. Good agreement is obtained between the simulated and experimental data, thus validating the modeling methods.

Factors impeding flexible inpatient unit design.

PubMed

Pati, Debajyoti; Evans, Jennie; Harvey, Thomas E; Bazuin, Doug

2012-01-01

To identify and examine factors extraneous to the design decision-making process that could impede the optimization of flexibility on inpatient units. A 2006 empirical study to identify domains of design decisions that affect flexibility on inpatient units found some indication in the context of the acuity-adaptable operational model that factors extraneous to the design process could have negatively influenced the successful implementation of the model. This raised questions regarding extraneous factors that might influence the successful optimization of flexibility. An exploratory, qualitative method was adopted to examine the question. Stakeholders from five recently built acute care inpatient units participated in the study, which involved three types of data collection: (1) verbal protocol data from a gaming session; (2) in-depth semi-structured interviews; and (3) shadowing frontline personnel. Data collection was conducted between June 2009 and November 2010. The study revealed at least nine factors extraneous to the design process that have the potential to hinder the optimization of flexibility in four domains: (1) systemic; (2) cultural; (3) human; and (4) financial. Flexibility is critical to hospital operations in the new healthcare climate, where cost reduction constitutes a vital target. From this perspective, flexibility and efficiency strategies can be influenced by (1) return on investment, (2) communication, (3) culture change, and (4) problem definition. Extraneous factors identified in this study could also affect flexibility in other care settings; therefore, these findings may be viewed from the overall context of hospital design.

Application of robotics in gastrointestinal endoscopy: A review

PubMed Central

Yeung, Baldwin Po Man; Chiu, Philip Wai Yan

2016-01-01

Multiple robotic flexible endoscope platforms have been developed based on cross specialty collaboration between engineers and medical doctors. However, significant number of these platforms have been developed for the natural orifice transluminal endoscopic surgery paradigm. Increasing amount of evidence suggest the focus of development should be placed on advanced endolumenal procedures such as endoscopic submucosal dissection instead. A thorough literature analysis was performed to assess the current status of robotic flexible endoscopic platforms designed for advanced endolumenal procedures. Current efforts are mainly focused on robotic locomotion and robotic instrument control. In the future, advances in actuation and servoing technology, optical analysis, augmented reality and wireless power transmission technology will no doubt further advance the field of robotic endoscopy. Globally, health systems have become increasingly budget conscious; widespread acceptance of robotic endoscopy will depend on careful design to ensure its delivery of a cost effective service. PMID:26855540

The Acute Effects of Aerobic Exercise on Cognitive Flexibility and Task-Related Heart Rate Variability in Children With ADHD and Healthy Controls.

PubMed

Ludyga, Sebastian; Gerber, Markus; Mücke, Manuel; Brand, Serge; Weber, Peter; Brotzmann, Mark; Pühse, Uwe

2018-02-01

To investigate cognitive flexibility and task-related heart rate variability following moderately intense aerobic exercise and after watching a video in both children with ADHD and healthy controls. Using a cross-over design, participants completed cognitive assessments following exercise and a physically inactive control condition. Behavioral performance was assessed using the Alternate Uses task. Heart rate variability was recorded via electrocardiography during the cognitive task. The statistical analysis revealed that in comparison with the control condition, both groups showed higher cognitive flexibility following aerobic exercise. Moreover, decreased low frequency and high frequency power was observed in the exercise condition. The findings suggest that exercise elicits similar benefits for cognitive flexibility in children with ADHD and healthy controls, partly due to an increase in arousal induced by parasympathetic withdrawal.

Mixture design procedure for flexible base.

DOT National Transportation Integrated Search

2013-04-01

This document provides information on mixture design requirements for a flexible base course. Sections : design requirements, job mix formula, contractor's responsibility, and engineer's responsibility. Tables : material requirements; requirements fo...

Integrated Controls-Structures Design Methodology for Flexible Spacecraft

NASA Technical Reports Server (NTRS)

Maghami, P. G.; Joshi, S. M.; Price, D. B.

1995-01-01

This paper proposes an approach for the design of flexible spacecraft, wherein the structural design and the control system design are performed simultaneously. The integrated design problem is posed as an optimization problem in which both the structural parameters and the control system parameters constitute the design variables, which are used to optimize a common objective function, thereby resulting in an optimal overall design. The approach is demonstrated by application to the integrated design of a geostationary platform, and to a ground-based flexible structure experiment. The numerical results obtained indicate that the integrated design approach generally yields spacecraft designs that are substantially superior to the conventional approach, wherein the structural design and control design are performed sequentially.

Impact of a daily 10-minute strength and flexibility program in a manufacturing plant.

PubMed

Pronk, S J; Pronk, N P; Sisco, A; Ingalls, D S; Ochoa, C

1995-01-01

In summary, employees' flexibility and mood showed modest improvements following the implementation of a plant-wide, 10-minute, daily flexibility and strength program. The initial six-week pilot study, administered prior to the plant-wide program implementation, successfully assessed program feasibility, assessed the efficiency of program implementation, identified administrative and logistical concerns, and generated pilot data needed to secure managerial support. Despite the noted significant increases in grip strength in the pilot study, no increases were observed following the six months of plant-wide implementation. This may be related to the differences in low average pretest grip strength for the pilot study compared to the higher scores for the main study population. The pilot study subjects may have received a sufficient exercise stimulus to increase grip strength over the course of six weeks. In contrast, this may not have been the case for the main study subjects due to their higher initial mean grip strength. An increased number of exercises designed to directly impact grip strength may be needed to improve this parameter.

Pinhole occulter experiment

NASA Technical Reports Server (NTRS)

Ring, Jeff; Pflug, John

1987-01-01

Viewgraphs and charts from a briefing summarize the accomplishments, results, conclusions, and recommendations of a feasibility study using the Pinhole Occulter Facility (POF). Accomplishments for 1986 include: (1) improved IPS Gimbal Model; (2) improved Crew Motion Disturbance Model; (3) use of existing shuttle on-orbit simulation to study the effects of orbiter attitude deadband size on POF performance; (4) increased understanding of maximum performance expected from current actuator/sensor set; (5) use of TREETOPS nonlinear time domain program to obtain system dynamics describing the complex multibody flexible structures; (6) use of HONEY-X design tool to design and evaluate multivariable compensator for stability, robustness, and performance; (7) application of state-of-the-art compensator design methodology Linear Quadratic Gaussian/Loop Transfer Recovery (LQG/LTR); and (8) examination of tolerance required on knowledge of the POF boom flexible mode frequencies to insure stability, using structure uncertainty analysis.

Increasing Sequence Diversity with Flexible Backbone Protein Design: The Complete Redesign of a Protein Hydrophobic Core

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

Murphy, Grant S.; Mills, Jeffrey L.; Miley, Michael J.

2015-10-15

Protein design tests our understanding of protein stability and structure. Successful design methods should allow the exploration of sequence space not found in nature. However, when redesigning naturally occurring protein structures, most fixed backbone design algorithms return amino acid sequences that share strong sequence identity with wild-type sequences, especially in the protein core. This behavior places a restriction on functional space that can be explored and is not consistent with observations from nature, where sequences of low identity have similar structures. Here, we allow backbone flexibility during design to mutate every position in the core (38 residues) of a four-helixmore » bundle protein. Only small perturbations to the backbone, 12 {angstrom}, were needed to entirely mutate the core. The redesigned protein, DRNN, is exceptionally stable (melting point >140C). An NMR and X-ray crystal structure show that the side chains and backbone were accurately modeled (all-atom RMSD = 1.3 {angstrom}).« less

Flexible sequential designs for multi-arm clinical trials.

PubMed

Magirr, D; Stallard, N; Jaki, T

2014-08-30

Adaptive designs that are based on group-sequential approaches have the benefit of being efficient as stopping boundaries can be found that lead to good operating characteristics with test decisions based solely on sufficient statistics. The drawback of these so called 'pre-planned adaptive' designs is that unexpected design changes are not possible without impacting the error rates. 'Flexible adaptive designs' on the other hand can cope with a large number of contingencies at the cost of reduced efficiency. In this work, we focus on two different approaches for multi-arm multi-stage trials, which are based on group-sequential ideas, and discuss how these 'pre-planned adaptive designs' can be modified to allow for flexibility. We then show how the added flexibility can be used for treatment selection and sample size reassessment and evaluate the impact on the error rates in a simulation study. The results show that an impressive overall procedure can be found by combining a well chosen pre-planned design with an application of the conditional error principle to allow flexible treatment selection. Copyright © 2014 John Wiley & Sons, Ltd.

Flexible Ferroelectric Sensors with Ultrahigh Pressure Sensitivity and Linear Response over Exceptionally Broad Pressure Range.

PubMed

Lee, Youngoh; Park, Jonghwa; Cho, Soowon; Shin, Young-Eun; Lee, Hochan; Kim, Jinyoung; Myoung, Jinyoung; Cho, Seungse; Kang, Saewon; Baig, Chunggi; Ko, Hyunhyub

2018-04-24

Flexible pressure sensors with a high sensitivity over a broad linear range can simplify wearable sensing systems without additional signal processing for the linear output, enabling device miniaturization and low power consumption. Here, we demonstrate a flexible ferroelectric sensor with ultrahigh pressure sensitivity and linear response over an exceptionally broad pressure range based on the material and structural design of ferroelectric composites with a multilayer interlocked microdome geometry. Due to the stress concentration between interlocked microdome arrays and increased contact area in the multilayer design, the flexible ferroelectric sensors could perceive static/dynamic pressure with high sensitivity (47.7 kPa -1 , 1.3 Pa minimum detection). In addition, efficient stress distribution between stacked multilayers enables linear sensing over exceptionally broad pressure range (0.0013-353 kPa) with fast response time (20 ms) and high reliability over 5000 repetitive cycles even at an extremely high pressure of 272 kPa. Our sensor can be used to monitor diverse stimuli from a low to a high pressure range including weak gas flow, acoustic sound, wrist pulse pressure, respiration, and foot pressure with a single device.

Workplace flexibility: from research to action.

PubMed

Galinsky, Ellen; Sakai, Kelly; Wigton, Tyler

2011-01-01

Ellen Galinsky, Kelly Sakai, and Tyler Wigton explore the "time famine" among American workers-the continuing sense among employees of not having enough time to manage the multiple responsibilities of work and personal and family life. Noting that large shares of U.S. employees report feeling the need for greater workplace flexibility to enable them to take better care of family responsibilities, the authors examine a large-scale community-engagement initiative to increase workplace flexibility voluntarily. Using the 2008 National Study of the Changing Workforce as a primary source of data, the authors begin with an overview of the prevalence of flexibility in today's American workplace. They track which categories of employees have access to various flexibility options, as well as the extent to which employees with access to various types of flexibility use those options. Findings from the study indicate that the majority of employees want flexibility but that access to it varies, with more advantaged employees--those who are well educated, have high salaries, and work full time, for example--being doubly advantaged in having greater access to flexibility. A number of employers, say the authors, tend to be skeptical of the value of workplace flexibility and to fear that employees will abuse it if it is offered. But the study data reveal that most employees use flexibility quite conservatively. When the authors use their nationally representative data set to investigate correlations between access to workplace flexibility and a range of workplace outcomes especially valued by employers--employee engagement, job satisfaction, retention, and health--they find that employers as well as employees can benefit from flexibility. Finally, the authors discuss When Work Works, a large, national community-based initiative under way since 2003 to increase voluntary adoption of workplace flexibility. The authors detail the conceptual basis of the project's design, noting its emphasis on flexibility as one component of effective workplaces that can benefit employers, employees, and communities alike. Galinsky, Sakai, and Wigton conclude by drawing lessons learned from the project and briefly discussing the implications of using research to bring about workplace change.

Design and Implementation of a REST API for the Human Well Being Index (HWBI)

EPA Science Inventory

Interoperable software development uses principles of component reuse, systems integration, flexible data transfer, and standardized ontological documentation to promote access, reuse, and integration of code. While interoperability principles are increasingly considered technolo...

Design and Implementation of a REST API for the ?Human Well Being Index (HWBI)

EPA Science Inventory

Interoperable software development uses principles of component reuse, systems integration, flexible data transfer, and standardized ontological documentation to promote access, reuse, and integration of code. While interoperability principles are increasingly considered technolo...

Flexible Mechanical Conveyors for Regolith Extraction and Transport

NASA Technical Reports Server (NTRS)

Walton, Otis R.; Vollmer, Hubert J.

2013-01-01

A report describes flexible mechanical conveying systems for transporting fine cohesive regolith under microgravity and vacuum conditions. They are totally enclosed, virtually dust-free, and can include enough flexibility in the conveying path to enable an expanded range of extraction and transport scenarios, including nonlinear drill-holes and excavation of enlarged subsurface openings without large entry holes. The design of the conveyors is a modification of conventional screw conveyors such that the central screw-shaft and the outer housing or conveyingtube have a degree of bending flexibility, allowing the conveyors to become nonlinear conveying systems that can convey around gentle bends. The central flexible shaft is similar to those used in common tools like a weed whacker, consisting of multiple layers of tightly wound wires around a central wire core. Utilization of compliant components (screw blade or outer wall) increases the robustness of the conveying, allowing an occasional oversized particle to pass hough the conveyor without causing a jam or stoppage

Stretch shorten cycle performance enhancement through flexibility training.

PubMed

Wilson, G J; Elliott, B C; Wood, G A

1992-01-01

Sixteen experienced male powerlifters served as subjects in a training study designed to examine the effect of flexibility training on: (i) the stiffness of the series elastic components (SEC) of the upper body musculature and (ii) rebound and purely concentric bench press performance. Nine of the subjects participated in two sessions of flexibility training twice per week for 8 wk. Prior to and after the training period the subjects' static flexibility, SEC stiffness, rebound bench press (RBP), and purely concentric bench press (PCBP) performance were recorded. The flexibility training induced a significant reduction in the maximal stiffness of the SEC. Furthermore, the experimental subjects produced significantly more work during the initial concentric portion of the RBP lift, enabling a significantly greater load to be lifted in the post-training testing occasion. The benefits to performance achieved by the experimental group consequent to flexibility training were greater during the RBP lift as compared with the PCBP lift. The control subjects exhibited no change in any variable over the training period. These results implied that the RBP performance enhancement observed consequent to flexibility training was directly caused by a reduction in SEC stiffness, increasing the utilization of elastic strain energy during the RBP lift.

Sensing human physiological response using wearable carbon nanotube-based fabrics

NASA Astrophysics Data System (ADS)

Wang, Long; Loh, Kenneth J.; Koo, Helen S.

2016-04-01

Flexible and wearable sensors for human monitoring have received increased attention. Besides detecting motion and physical activity, measuring human vital signals (e.g., respiration rate and body temperature) provide rich data for assessing subjects' physiological or psychological condition. Instead of using conventional, bulky, sensing transducers, the objective of this study was to design and test a wearable, fabric-like sensing system. In particular, multi-walled carbon nanotube (MWCNT)-latex thin films of different MWCNT concentrations were first fabricated using spray coating. Freestanding MWCNT-latex films were then sandwiched between two layers of flexible fabric using iron-on adhesive to form the wearable sensor. Second, to characterize its strain sensing properties, the fabric sensors were subjected to uniaxial and cyclic tensile load tests, and they exhibited relatively stable electromechanical responses. Finally, the wearable sensors were placed on a human subject for monitoring simple motions and for validating their practical strain sensing performance. Overall, the wearable fabric sensor design exhibited advances such as flexibility, ease of fabrication, light weight, low cost, noninvasiveness, and user comfort.

Design and implementation of flexible TWDM-PON with PtP WDM overlay based on WSS for next-generation optical access networks

NASA Astrophysics Data System (ADS)

Wu, Bin; Yin, Hongxi; Qin, Jie; Liu, Chang; Liu, Anliang; Shao, Qi; Xu, Xiaoguang

2016-09-01

Aiming at the increasing demand of the diversification services and flexible bandwidth allocation of the future access networks, a flexible passive optical network (PON) scheme combining time and wavelength division multiplexing (TWDM) with point-to-point wavelength division multiplexing (PtP WDM) overlay is proposed for the next-generation optical access networks in this paper. A novel software-defined optical distribution network (ODN) structure is designed based on wavelength selective switches (WSS), which can implement wavelength and bandwidth dynamical allocations and suits for the bursty traffic. The experimental results reveal that the TWDM-PON can provide 40 Gb/s downstream and 10 Gb/s upstream data transmission, while the PtP WDM-PON can support 10 GHz point-to-point dedicated bandwidth as the overlay complement system. The wavelengths of the TWDM-PON and PtP WDM-PON are allocated dynamically based on WSS, which verifies the feasibility of the proposed structure.

Flexible devices: from materials, architectures to applications

NASA Astrophysics Data System (ADS)

Zou, Mingzhi; Ma, Yue; Yuan, Xin; Hu, Yi; Liu, Jie; Jin, Zhong

2018-01-01

Flexible devices, such as flexible electronic devices and flexible energy storage devices, have attracted a significant amount of attention in recent years for their potential applications in modern human lives. The development of flexible devices is moving forward rapidly, as the innovation of methods and manufacturing processes has greatly encouraged the research of flexible devices. This review focuses on advanced materials, architecture designs and abundant applications of flexible devices, and discusses the problems and challenges in current situations of flexible devices. We summarize the discovery of novel materials and the design of new architectures for improving the performance of flexible devices. Finally, we introduce the applications of flexible devices as key components in real life. Project supported by the National Key R&D Program of China (Nos. 2017YFA0208200, 2016YFB0700600, 2015CB659300), the National Natural Science Foundation of China (Nos. 21403105, 21573108), and the Fundamental Research Funds for the Central Universities (No. 020514380107).

Use of Field Programmable Gate Array Technology in Future Space Avionics

NASA Technical Reports Server (NTRS)

Ferguson, Roscoe C.; Tate, Robert

2005-01-01

Fulfilling NASA's new vision for space exploration requires the development of sustainable, flexible and fault tolerant spacecraft control systems. The traditional development paradigm consists of the purchase or fabrication of hardware boards with fixed processor and/or Digital Signal Processing (DSP) components interconnected via a standardized bus system. This is followed by the purchase and/or development of software. This paradigm has several disadvantages for the development of systems to support NASA's new vision. Building a system to be fault tolerant increases the complexity and decreases the performance of included software. Standard bus design and conventional implementation produces natural bottlenecks. Configuring hardware components in systems containing common processors and DSPs is difficult initially and expensive or impossible to change later. The existence of Hardware Description Languages (HDLs), the recent increase in performance, density and radiation tolerance of Field Programmable Gate Arrays (FPGAs), and Intellectual Property (IP) Cores provides the technology for reprogrammable Systems on a Chip (SOC). This technology supports a paradigm better suited for NASA's vision. Hardware and software production are melded for more effective development; they can both evolve together over time. Designers incorporating this technology into future avionics can benefit from its flexibility. Systems can be designed with improved fault isolation and tolerance using hardware instead of software. Also, these designs can be protected from obsolescence problems where maintenance is compromised via component and vendor availability.To investigate the flexibility of this technology, the core of the Central Processing Unit and Input/Output Processor of the Space Shuttle AP101S Computer were prototyped in Verilog HDL and synthesized into an Altera Stratix FPGA.

The Challenge of Designing Blended Courses: From Structured Design to Creative Faculty Support!

ERIC Educational Resources Information Center

Carré, Catherine

2015-01-01

This case study deals with the implementation of an e-learning program in a business school in Canada. Cabot Business School decided to offer the program in a blended format so as to increase the flexibility of the program for clientele enrolled in the undergraduate certificate program. A pilot was initiated in 2009 starting with four hybrid…

Physics-based Morphology Analysis and Adjoint Optimization of Flexible Flapping Wings

DTIC Science & Technology

2016-08-30

understand the underlying physics of flexible wings in flying insects and birds towards the bio -inspired wing designs with superior aerodynamic...flapping flights have been developed to understand the underlying physics of flexible wings in flying insects and birds towards the bio -inspired wing...been developed to understand the underlying physics of flexible wings in flying insects and birds towards the bio -inspired wing designs with superior

Are flexibility and muscle-strengthening activities associated with a higher risk of developing low back pain?

PubMed Central

Sandler, Robert D.; Sui, Xuemei; Church, Timothy S.; Fritz, Stacy L.; Beattie, Paul F.; Blair, Steven N.

2013-01-01

Objective To examine the association between participation in flexibility or muscle-strengthening activities with the development of low back pain (LBP). Design Observational cohort study. Methods The cohort included 4,610 adults, 17% female, between 20 and 81 years of age (mean 46.6, s.d. 4.96). The cohort was followed for a mean of 4.9 years for self-reported LBP. All participants reported at baseline whether they performed flexibility or muscle-strengthening activities, including specific sub-types. Results Neither general performance of flexibility or muscle-strengthening activities were associated with a higher incidence of LBP compared to those who did not perform these activities. Those who reported stretching, as a specific flexibility activity were at a higher risk of developing LBP compared with those who performed no flexibility exercises, reported calisthenic flexibility activities, or attended exercise classes. Those who reported using weight training machines, as part of muscle-strengthening activities, had a higher risk of reporting LBP, compared with those who did not perform muscle-strengthening activities or performed calisthenic or free weight activities. Conclusion In this sample, stretching or use of weight training machines is associated with increased risk of developing LBP compared to use of free weights, calisthenics or flexibility classes. PMID:23988784

Computational protein design with backbone plasticity

PubMed Central

MacDonald, James T.; Freemont, Paul S.

2016-01-01

The computational algorithms used in the design of artificial proteins have become increasingly sophisticated in recent years, producing a series of remarkable successes. The most dramatic of these is the de novo design of artificial enzymes. The majority of these designs have reused naturally occurring protein structures as ‘scaffolds’ onto which novel functionality can be grafted without having to redesign the backbone structure. The incorporation of backbone flexibility into protein design is a much more computationally challenging problem due to the greatly increased search space, but promises to remove the limitations of reusing natural protein scaffolds. In this review, we outline the principles of computational protein design methods and discuss recent efforts to consider backbone plasticity in the design process. PMID:27911735

Flexibility in Early Stage Design of U. S. Navy Ships: An Analysis of Options

DTIC Science & Technology

2011-01-01

Flexibility in Early Stage Design of US Navy Ships: An Analysis of Options by Jonathan Page B.S., Systems Engineering, US Naval Academy, 2002...8217C/ v = (;!;!: ;: Pat Hale Director, Systems Design and Ma~ement Fellows Program E~i_yfering.S~~pivi~i~ Acceptedby...2. REPORT TYPE 3. DATES COVERED 00-00-2012 to 00-00-2012 4. TITLE AND SUBTITLE Flexibility in Early Stage Design of U. S. Navy Ships: An

RosettaRemodel: A Generalized Framework for Flexible Backbone Protein Design

PubMed Central

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

2011-01-01

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

Evolution of Wholesale Electricity Market Design with Increasing Levels of Renewable Generation

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

Ela, E.; Milligan, M.; Bloom, A.

2014-09-01

Variable generation such as wind and photovoltaic solar power has increased substantially in recent years. Variable generation has unique characteristics compared to the traditional technologies that supply energy in the wholesale electricity markets. These characteristics create unique challenges in planning and operating the power system, and they can also influence the performance and outcomes from electricity markets. This report focuses on two particular issues related to market design: revenue sufficiency for long-term reliability and incentivizing flexibility in short-term operations. The report provides an overview of current design and some designs that have been proposed by industry or researchers.

System identification for modeling for control of flexible structures

NASA Technical Reports Server (NTRS)

Mettler, Edward; Milman, Mark

1986-01-01

The major components of a design and operational flight strategy for flexible structure control systems are presented. In this strategy an initial distributed parameter control design is developed and implemented from available ground test data and on-orbit identification using sophisticated modeling and synthesis techniques. The reliability of this high performance controller is directly linked to the accuracy of the parameters on which the design is based. Because uncertainties inevitably grow without system monitoring, maintaining the control system requires an active on-line system identification function to supply parameter updates and covariance information. Control laws can then be modified to improve performance when the error envelopes are decreased. In terms of system safety and stability the covariance information is of equal importance as the parameter values themselves. If the on-line system ID function detects an increase in parameter error covariances, then corresponding adjustments must be made in the control laws to increase robustness. If the error covariances exceed some threshold, an autonomous calibration sequence could be initiated to restore the error enveloped to an acceptable level.

Orexins Mediate Sex Differences in the Stress Response and in Cognitive Flexibility.

PubMed

Grafe, Laura A; Cornfeld, Amanda; Luz, Sandra; Valentino, Rita; Bhatnagar, Seema

2017-04-15

Women are twice as likely as men to experience stress-related psychiatric disorders. The biological basis of these sex differences is poorly understood. Orexins are altered in anxious and depressed patients. Using a rat model of repeated stress, we examined whether orexins contribute to sex differences in outcomes relevant to stress-related psychiatric diseases. Behavioral, neural, and endocrine habituation to repeated restraint stress and subsequent cognitive flexibility was examined in adult male and female rats. In parallel, orexin expression and activation were determined in both sexes, and chromatin immunoprecipitation was used to determine transcription factors acting at the orexin promoter. Designer receptors exclusively activated by designer drugs were used to inhibit orexin activation throughout repeated restraint to determine if the stress-related impairments in female rats could be reduced. Female rats exhibited impaired habituation to repeated restraint with subsequent deficits in cognitive flexibility compared with male rats. Increased orexin expression and activation were observed in female rats compared with male rats. The higher expression of orexin messenger RNA in female rats was due to actions of glucocorticoid receptors on the orexin promoter, as determined by chromatin immunoprecipitation. Inhibition of orexins using designer receptors exclusively activated by designer drugs in female rats throughout repeated restraint abolished their heightened hypothalamic-pituitary-adrenal responsivity and reduced stress-induced cognitive impairments. Orexins mediate the impairments in adaptations to repeated stress and in subsequent cognitive flexibility exhibited by female rats and provide evidence for a broader role for orexins in mediating functions relevant to stress-related psychiatric diseases. Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

A Framework for Open, Flexible and Distributed Learning.

ERIC Educational Resources Information Center

Khan, Badrul H.

Designing open, flexible distance learning systems on the World Wide Web requires thoughtful analysis and investigation combined with an understanding of both the Web's attributes and resources and the ways instructional design principles can be applied to tap the Web's potential. A framework for open, flexible, and distributed learning has been…

Year-Round Education: Learning More for Less.

ERIC Educational Resources Information Center

Ballinger, Charles

1990-01-01

Advantages and examples of year-round education are discussed in this publication. Advantages include instructional benefits, relief from overcrowding, savings on operational and capital costs, increased teacher flexibility, improved attendance, and reduced vandalism. Guidelines for implementation, calendar design, and descriptions of various…

On the Move with the Waukesha Walkers.

ERIC Educational Resources Information Center

Gissal, Mary L.; Ray, Robert O.

1981-01-01

As part of a research study, a fitness trail was designed for older adults to increase their physical fitness and cardiovascular health. Exercise stations placed at quarter-mile intervals introduced exercises effective in improving flexibility, muscular strength, endurance, balance, and coordination. (JN)

Improving Video Game Development: Facilitating Heterogeneous Team Collaboration through Flexible Software Processes

NASA Astrophysics Data System (ADS)

Musil, Juergen; Schweda, Angelika; Winkler, Dietmar; Biffl, Stefan

Based on our observations of Austrian video game software development (VGSD) practices we identified a lack of systematic processes/method support and inefficient collaboration between various involved disciplines, i.e. engineers and artists. VGSD includes heterogeneous disciplines, e.g. creative arts, game/content design, and software. Nevertheless, improving team collaboration and process support is an ongoing challenge to enable a comprehensive view on game development projects. Lessons learned from software engineering practices can help game developers to increase game development processes within a heterogeneous environment. Based on a state of the practice survey in the Austrian games industry, this paper presents (a) first results with focus on process/method support and (b) suggests a candidate flexible process approach based on Scrum to improve VGSD and team collaboration. Results showed (a) a trend to highly flexible software processes involving various disciplines and (b) identified the suggested flexible process approach as feasible and useful for project application.

Technology support of the handover: promoting observability, flexibility and efficiency.

PubMed

Patterson, Emily S

2012-12-01

Efforts to standardise data elements and increase the comprehensiveness of information included in patient handovers have produced a growing interest in augmenting the verbal exchange of information with written communications conducted through health information technology (HIT). The aim of this perspective is to offer recommendations to optimise technology support of handovers, based on a review of the relevant scientific literature. Review of the literature on human factors and the study of communication produced three recommendations. The first entails making available "shared knowledge" relevant to the handover and subsequent clinical management with intended and unintended recipients. The second is to create a flexible narrative structure (unstructured text fields) for human-human communications facilitated by technology. The third recommendation is to avoid reliance on real-time data entry during busy periods. Implementing these recommendations is anticipated to increase the observability (the ability to readily determine current status), flexibility, and efficiency of HIT-supported patient handovers. Anticipated benefits of technology-supported handovers include reducing reliance on human memory, increasing the efficiency and structure of the verbal exchange, avoiding readbacks of numeric data, and aiding clinical management following the handover. In cases when verbal handovers are delayed, do not occur, or involve members of the health care team without first-hand access to critical information, making 'common ground' observable for all recipients, creating a flexible narrative structure for communication and avoiding reliance on real-time data entry during the busiest times has implications for HIT design and day to day data entry and management operations. Benefits include increased observability, flexibility, and efficiency of HIT-supported patient handovers.

Flexible Wing Model for Structural Sizing and Multidisciplinary Design Optimization of a Strut-Braced Wing

NASA Technical Reports Server (NTRS)

Gern, Frank H.; Naghshineh, Amir H.; Sulaeman, Erwin; Kapania, Rakesh K.; Haftka, Raphael T.

2000-01-01

This paper describes a structural and aeroelastic model for wing sizing and weight calculation of a strut-braced wing. The wing weight is calculated using a newly developed structural weight analysis module considering the special nature of strut-braced wings. A specially developed aeroelastic model enables one to consider wing flexibility and spanload redistribution during in-flight maneuvers. The structural model uses a hexagonal wing-box featuring skin panels, stringers, and spar caps, whereas the aerodynamics part employs a linearized transonic vortex lattice method. Thus, the wing weight may be calculated from the rigid or flexible wing spanload. The calculations reveal the significant influence of the strut on the bending material weight of the wing. The use of a strut enables one to design a wing with thin airfoils without weight penalty. The strut also influences wing spanload and deformations. Weight savings are not only possible by calculation and iterative resizing of the wing structure according to the actual design loads. Moreover, as an advantage over the cantilever wing, employment of the strut twist moment for further load alleviation leads to increased savings in structural weight.

Dynamic analysis and control of lightweight manipulators with flexible parallel link mechanisms

NASA Technical Reports Server (NTRS)

Lee, Jeh Won

1991-01-01

The flexible parallel link mechanism is designed for increased rigidity to sustain the buckling when it carries a heavy payload. Compared to a one link flexible manipulator, a two link flexible manipulator, especially the flexible parallel mechanism, has more complicated characteristics in dynamics and control. The objective of this research is the theoretical analysis and the experimental verification of dynamics and control of a two link flexible manipulator with a flexible parallel link mechanism. Nonlinear equations of motion of the lightweight manipulator are derived by the Lagrangian method in symbolic form to better understand the structure of the dynamic model. A manipulator with a flexible parallel link mechanism is a constrained dynamic system whose equations are sensitive to numerical integration error. This constrained system is solved using singular value decomposition of the constraint Jacobian matrix. The discrepancies between the analytical model and the experiment are explained using a simplified and a detailed finite element model. The step response of the analytical model and the TREETOPS model match each other well. The nonlinear dynamics is studied using a sinusoidal excitation. The actuator dynamic effect on a flexible robot was investigated. The effects are explained by the root loci and the Bode plot theoretically and experimentally. For the base performance for the advanced control scheme, a simple decoupled feedback scheme is applied.

Pathways to agility in the production of neutron generators

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

Stoltz, R.E.; Beavis, L.C.; Cutchen, J.T.

1994-02-01

This report is the result of a study team commissioned to explore pathways for increased agility in the manufacture of neutron generators. As a part of Sandia`s new responsibility for generator production, the goal of the study was to identify opportunities to reduce costs and increase flexibility in the manufacturing operation. Four parallel approaches (or pathways) were recommended: (1) Know the goal, (2) Use design leverage effectively, (3) Value simplicity, and (4) Configure for flexibility. Agility in neutron generator production can be enhanced if all of these pathways are followed. The key role of the workforce in achieving agility wasmore » also noted, with emphasis on ownership, continuous learning, and a supportive environment.« less

Flexibility.

ERIC Educational Resources Information Center

Humphrey, L. Dennis

1981-01-01

Flexibility is an important aspect of all sports and recreational activities. Flexibility can be developed and maintained by stretching exercises. Exercises designed to develop flexibility in ankle joints, knees, hips, and the lower back are presented. (JN)

Bendability optimization of flexible optical nanoelectronics via neutral axis engineering

PubMed Central

2012-01-01

The enhancement of bendability of flexible nanoelectronics is critically important to realize future portable and wearable nanoelectronics for personal and military purposes. Because there is an enormous variety of materials and structures that are used for flexible nanoelectronic devices, a governing design rule for optimizing the bendability of these nanodevices is required. In this article, we suggest a design rule to optimize the bendability of flexible nanoelectronics through neutral axis (NA) engineering. In flexible optical nanoelectronics, transparent electrodes such as indium tin oxide (ITO) are usually the most fragile under an external load because of their brittleness. Therefore, we representatively focus on the bendability of ITO which has been widely used as transparent electrodes, and the NA is controlled by employing a buffer layer on the ITO layer. First, we independently investigate the effect of the thickness and elastic modulus of a buffer layer on the bendability of an ITO film. Then, we develop a design rule for the bendability optimization of flexible optical nanoelectronics. Because NA is determined by considering both the thickness and elastic modulus of a buffer layer, the design rule is conceived to be applicable regardless of the material and thickness that are used for the buffer layer. Finally, our design rule is applied to optimize the bendability of an organic solar cell, which allows the bending radius to reach about 1 mm. Our design rule is thus expected to provide a great strategy to enhance the bending performance of a variety of flexible nanoelectronics. PMID:22587757

Bendability optimization of flexible optical nanoelectronics via neutral axis engineering.

PubMed

Lee, Sangmin; Kwon, Jang-Yeon; Yoon, Daesung; Cho, Handong; You, Jinho; Kang, Yong Tae; Choi, Dukhyun; Hwang, Woonbong

2012-05-15

The enhancement of bendability of flexible nanoelectronics is critically important to realize future portable and wearable nanoelectronics for personal and military purposes. Because there is an enormous variety of materials and structures that are used for flexible nanoelectronic devices, a governing design rule for optimizing the bendability of these nanodevices is required. In this article, we suggest a design rule to optimize the bendability of flexible nanoelectronics through neutral axis (NA) engineering. In flexible optical nanoelectronics, transparent electrodes such as indium tin oxide (ITO) are usually the most fragile under an external load because of their brittleness. Therefore, we representatively focus on the bendability of ITO which has been widely used as transparent electrodes, and the NA is controlled by employing a buffer layer on the ITO layer. First, we independently investigate the effect of the thickness and elastic modulus of a buffer layer on the bendability of an ITO film. Then, we develop a design rule for the bendability optimization of flexible optical nanoelectronics. Because NA is determined by considering both the thickness and elastic modulus of a buffer layer, the design rule is conceived to be applicable regardless of the material and thickness that are used for the buffer layer. Finally, our design rule is applied to optimize the bendability of an organic solar cell, which allows the bending radius to reach about 1 mm. Our design rule is thus expected to provide a great strategy to enhance the bending performance of a variety of flexible nanoelectronics.

Interconversion of Functional Motions between Mesophilic and Thermophilic Adenylate Kinases

PubMed Central

Daily, Michael D.; Phillips, George N.; Cui, Qiang

2011-01-01

Dynamic properties are functionally important in many proteins, including the enzyme adenylate kinase (AK), for which the open/closed transition limits the rate of catalytic turnover. Here, we compare our previously published coarse-grained (double-well Gō) simulation of mesophilic AK from E. coli (AKmeso) to simulations of thermophilic AK from Aquifex aeolicus (AKthermo). In AKthermo, as with AKmeso, the LID domain prefers to close before the NMP domain in the presence of ligand, but LID rigid-body flexibility in the open (O) ensemble decreases significantly. Backbone foldedness in O and/or transition state (TS) ensembles increases significantly relative to AKmeso in some interdomain backbone hinges and within LID. In contact space, the TS of AKthermo has fewer contacts at the CORE-LID interface but a stronger contact network surrounding the CORE-NMP interface than the TS of AKmeso. A “heated” simulation of AKthermo at 375K slightly increases LID rigid-body flexibility in accordance with the “corresponding states” hypothesis. Furthermore, while computational mutation of 7 prolines in AKthermo to their AKmeso counterparts produces similar small perturbations, mutation of these sites, especially positions 8 and 155, to glycine is required to achieve LID rigid-body flexibility and hinge flexibilities comparable to AKmeso. Mutating the 7 sites to proline in AKmeso reduces some hinges' flexibilities, especially hinge 2, but does not reduce LID rigid-body flexibility, suggesting that these two types of motion are decoupled in AKmeso. In conclusion, our results suggest that hinge flexibility and global functional motions alike are correlated with but not exclusively determined by the hinge residues. This mutational framework can inform the rational design of functionally important flexibility and allostery in other proteins toward engineering novel biochemical pathways. PMID:21779157

Enhancing Icing Training for Pilots Through Web-Based Multimedia

NASA Technical Reports Server (NTRS)

Fletcher, William; Nolan, Gary; Adanich, Emery; Bond, Thomas H.

2006-01-01

The Aircraft Icing Project of the NASA Aviation Safety Program has developed a number of in-flight icing education and training aids designed to increase pilot awareness about the hazards associated with various icing conditions. The challenges and advantages of transitioning these icing training materials to a Web-based delivery are discussed. Innovative Web-based delivery devices increased course availability to pilots and dispatchers while increasing course flexibility and utility. These courses are customizable for both self-directed and instructor-led learning. Part of our goal was to create training materials with enough flexibility to enable Web-based delivery and downloadable portability while maintaining a rich visual multimedia-based learning experience. Studies suggest that using visually based multimedia techniques increases the effectiveness of icing training materials. This paper describes these concepts, gives examples, and discusses the transitional challenges.

Attitude Control Tradeoff Study Between the Use of a Flexible Beam and a Tether Configuration for the Connection of Two Bodies in Orbit

NASA Technical Reports Server (NTRS)

Graff, S. H.

1985-01-01

Sometimes it is necessary to mount a payload remotely from the main body of a spacecraft or space station. The reasons for this vary from vibration isolation to avoidance of measurement contamination. For example the SP-100 project, which grew out of the increased interest in nuclear power in space for space stations and for deep space explorations, requires separation of the nuclear reactor from the user because of vibration, heat and radiation. The different attitude control problems for beam and tether configurations are discussed. The beam configuration uses a conservative design approach. The vibration, beam flexibility and deployment concerns are analyzed. The tether configuration offers some very attractive design features, but not without several thorny problems. These problems are analyzed. One configuration will be recommended for the main thrust of the SP-100 design effort based on attitude control considerations.

Development of Variable Camber Continuous Trailing Edge Flap for Performance Adaptive Aeroelastic Wing

NASA Technical Reports Server (NTRS)

Nguyen, Nhan; Kaul, Upender; Lebofsky, Sonia; Ting, Eric; Chaparro, Daniel; Urnes, James

2015-01-01

This paper summarizes the recent development of an adaptive aeroelastic wing shaping control technology called variable camber continuous trailing edge flap (VCCTEF). As wing flexibility increases, aeroelastic interactions with aerodynamic forces and moments become an increasingly important consideration in aircraft design and aerodynamic performance. Furthermore, aeroelastic interactions with flight dynamics can result in issues with vehicle stability and control. The initial VCCTEF concept was developed in 2010 by NASA under a NASA Innovation Fund study entitled "Elastically Shaped Future Air Vehicle Concept," which showed that highly flexible wing aerodynamic surfaces can be elastically shaped in-flight by active control of wing twist and bending deflection in order to optimize the spanwise lift distribution for drag reduction. A collaboration between NASA and Boeing Research & Technology was subsequently funded by NASA from 2012 to 2014 to further develop the VCCTEF concept. This paper summarizes some of the key research areas conducted by NASA during the collaboration with Boeing Research and Technology. These research areas include VCCTEF design concepts, aerodynamic analysis of VCCTEF camber shapes, aerodynamic optimization of lift distribution for drag minimization, wind tunnel test results for cruise and high-lift configurations, flutter analysis and suppression control of flexible wing aircraft, and multi-objective flight control for adaptive aeroelastic wing shaping control.

Wind-Friendly Flexible Ramping Product Design in Multi-Timescale Power System Operations

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

Cui, Mingjian; Zhang, Jie; Wu, Hongyu

With increasing wind power penetration in the electricity grid, system operators are recognizing the need for additional flexibility, and some are implementing new ramping products as a type of ancillary service. However, wind is generally thought of as causing the need for ramping services, not as being a potential source for the service. In this paper, a multi-timescale unit commitment and economic dispatch model is developed to consider the wind power ramping product (WPRP). An optimized swinging door algorithm with dynamic programming is applied to identify and forecast wind power ramps (WPRs). Designed as positive characteristics of WPRs, the WPRPmore » is then integrated into the multi-timescale dispatch model that considers new objective functions, ramping capacity limits, active power limits, and flexible ramping requirements. Numerical simulations on the modified IEEE 118-bus system show the potential effectiveness of WPRP in increasing the economic efficiency of power system operations with high levels of wind power penetration. It is found that WPRP not only reduces the production cost by using less ramping reserves scheduled by conventional generators, but also possibly enhances the reliability of power system operations. Moreover, wind power forecasts play an important role in providing high-quality WPRP service.« less

Kinetics of DNA Tile Dimerization

PubMed Central

2015-01-01

Investigating how individual molecular components interact with one another within DNA nanoarchitectures, both in terms of their spatial and temporal interactions, is fundamentally important for a better understanding of their physical behaviors. This will provide researchers with valuable insight for designing more complex higher-order structures that can be assembled more efficiently. In this report, we examined several spatial factors that affect the kinetics of bivalent, double-helical (DH) tile dimerization, including the orientation and number of sticky ends (SEs), the flexibility of the double helical domains, and the size of the tiles. The rate constants we obtained confirm our hypothesis that increased nucleation opportunities and well-aligned SEs accelerate tile–tile dimerization. Increased flexibility in the tiles causes slower dimerization rates, an effect that can be reversed by introducing restrictions to the tile flexibility. The higher dimerization rates of more rigid tiles results from the opposing effects of higher activation energies and higher pre-exponential factors from the Arrhenius equation, where the pre-exponential factor dominates. We believe that the results presented here will assist in improved implementation of DNA tile based algorithmic self-assembly, DNA based molecular robotics, and other specific nucleic acid systems, and will provide guidance to design and assembly processes to improve overall yield and efficiency. PMID:24794259

Kinetics of DNA tile dimerization.

PubMed

Jiang, Shuoxing; Yan, Hao; Liu, Yan

2014-06-24

Investigating how individual molecular components interact with one another within DNA nanoarchitectures, both in terms of their spatial and temporal interactions, is fundamentally important for a better understanding of their physical behaviors. This will provide researchers with valuable insight for designing more complex higher-order structures that can be assembled more efficiently. In this report, we examined several spatial factors that affect the kinetics of bivalent, double-helical (DH) tile dimerization, including the orientation and number of sticky ends (SEs), the flexibility of the double helical domains, and the size of the tiles. The rate constants we obtained confirm our hypothesis that increased nucleation opportunities and well-aligned SEs accelerate tile-tile dimerization. Increased flexibility in the tiles causes slower dimerization rates, an effect that can be reversed by introducing restrictions to the tile flexibility. The higher dimerization rates of more rigid tiles results from the opposing effects of higher activation energies and higher pre-exponential factors from the Arrhenius equation, where the pre-exponential factor dominates. We believe that the results presented here will assist in improved implementation of DNA tile based algorithmic self-assembly, DNA based molecular robotics, and other specific nucleic acid systems, and will provide guidance to design and assembly processes to improve overall yield and efficiency.

A Flexible Pilot-Scale Setup for Real-Time Studies in Process Systems Engineering

ERIC Educational Resources Information Center

Panjapornpon, Chanin; Fletcher, Nathan; Soroush, Masoud

2006-01-01

This manuscript describes a flexible, pilot-scale setup that can be used for training students and carrying out research in process systems engineering. The setup allows one to study a variety of process systems engineering concepts such as design feasibility, design flexibility, control configuration selection, parameter estimation, process and…

Factor Structure of the Behavior Flexibility Rating Scale (BFRS)

ERIC Educational Resources Information Center

Pituch, Keenan A.; Green, Vanessa A.; Sigafoos, Jeff; Itchon, Jonathan; O'Reilly, Mark; Lancioni, Giulio E.; Didden, Robert

2007-01-01

The Behavior Flexibility Rating Scale (BFRS) is designed to assess insistence on sameness or lack of behavioral flexibility, which is often associated with autism and other developmental disabilities. This study was designed to assess the factor structure of this scale for a sample of 968 individuals with autism, Asperger's syndrome, and Down…

SAFE (strategy, assessment, flexibility, and efficiency) for future use? Stages in master planning, programming, and architectural design.

PubMed

Westlake, P

1995-10-01

Health care facility design must incorporate four key elements: Strategy, Assessment, Flexibility, and Efficiency. These SAFE elements will offer the organization the greatest return on investment, because they encompass both present needs and future demand. They respect the integrated nature of functional operations by clustering them in ways that permit growth or consolidation. In the rapidly changing health care environment, flexibility is fundamental to successful design.

Spatial Modeling for Resources Framework (SMRF)

USDA-ARS?s Scientific Manuscript database

Spatial Modeling for Resources Framework (SMRF) was developed by Dr. Scott Havens at the USDA Agricultural Research Service (ARS) in Boise, ID. SMRF was designed to increase the flexibility of taking measured weather data and distributing the point measurements across a watershed. SMRF was developed...

48 CFR 1318.270 - Emergency acquisition flexibilities.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Procurement Executive. (b) Continuity of Operations Plan. Each Contracting Activity shall have an updated Continuity of Operations Plan, in place designating emergency personnel with warrant levels. (c) Management... appropriate management controls are established and maintained to support the use of the increased thresholds...

Robust lateral blended-wing-body aircraft feedback control design using a parameterized LFR model and DGK-iteration

NASA Astrophysics Data System (ADS)

Schirrer, A.; Westermayer, C.; Hemedi, M.; Kozek, M.

2013-12-01

This paper shows control design results, performance, and limitations of robust lateral control law designs based on the DGK-iteration mixed-μ-synthesis procedure for a large, flexible blended wing body (BWB) passenger aircraft. The aircraft dynamics is preshaped by a low-complexity inner loop control law providing stabilization, basic response shaping, and flexible mode damping. The μ controllers are designed to further improve vibration damping of the main flexible modes by exploiting the structure of the arising significant parameter-dependent plant variations. This is achieved by utilizing parameterized Linear Fractional Representations (LFR) of the aircraft rigid and flexible dynamics. Designs with various levels of LFR complexity are carried out and discussed, showing the achieved performance improvement over the initial controller and their robustness and complexity properties.

Texas flexible pavements overlays : review and analysis of existing databases.

DOT National Transportation Integrated Search

2011-12-01

Proper calibration of pavement design and rehabilitation performance models to : conditions in Texas is essential for cost-effective flexible pavement design. The degree of : excellence with which TxDOTs pavement design models is calibrated will d...

Flexible and composite structures for premium pavements. Volume 2, Design manual

DOT National Transportation Integrated Search

1980-11-01

This design manual presents the results of a detailed study to identify and design flexible and composite pavement configurations which will perform as premium or "zero-maintenance" pavements. This manual includes identification and classification of...

Experimental demonstration of the control of flexible structures

NASA Technical Reports Server (NTRS)

Schaechter, D. B.; Eldred, D. B.

1984-01-01

The Large Space Structure Technology Flexible Beam Experiment employs a pinned-free flexible beam to demonstrate such required methods as dynamic and adaptive control, as well as various control law design approaches and hardware requirements. An attempt is made to define the mechanization difficulties that may inhere in flexible structures. Attention is presently given to analytical work performed in support of the test facility's development, the final design's specifications, the control laws' synthesis, and experimental results obtained.

Sense of Community in a Blended Technology Integration Course: A Design-Based Research Study

ERIC Educational Resources Information Center

Harrison, J. Buckley; West, Richard E.

2014-01-01

This design-based research study explored whether "sense of community" was maintained while flexibility in the course was increased through an adoption of a unique blended learning model. Data collected in this study show a significant drop in the sense of connectedness score from a mean of 50.8 out of 66 to a mean of 39.68 in the first…

Towards automated visual flexible endoscope navigation.

PubMed

van der Stap, Nanda; van der Heijden, Ferdinand; Broeders, Ivo A M J

2013-10-01

The design of flexible endoscopes has not changed significantly in the past 50 years. A trend is observed towards a wider application of flexible endoscopes with an increasing role in complex intraluminal therapeutic procedures. The nonintuitive and nonergonomical steering mechanism now forms a barrier in the extension of flexible endoscope applications. Automating the navigation of endoscopes could be a solution for this problem. This paper summarizes the current state of the art in image-based navigation algorithms. The objectives are to find the most promising navigation system(s) to date and to indicate fields for further research. A systematic literature search was performed using three general search terms in two medical-technological literature databases. Papers were included according to the inclusion criteria. A total of 135 papers were analyzed. Ultimately, 26 were included. Navigation often is based on visual information, which means steering the endoscope using the images that the endoscope produces. Two main techniques are described: lumen centralization and visual odometry. Although the research results are promising, no successful, commercially available automated flexible endoscopy system exists to date. Automated systems that employ conventional flexible endoscopes show the most promising prospects in terms of cost and applicability. To produce such a system, the research focus should lie on finding low-cost mechatronics and technologically robust steering algorithms. Additional functionality and increased efficiency can be obtained through software development. The first priority is to find real-time, robust steering algorithms. These algorithms need to handle bubbles, motion blur, and other image artifacts without disrupting the steering process.

Evaluation on Compressive Characteristics of Medical Stents Applied by Mesh Structures

NASA Astrophysics Data System (ADS)

Hirayama, Kazuki; He, Jianmei

2017-11-01

There are concerns about strength reduction and fatigue fracture due to stress concentration in currently used medical stents. To address these problems, meshed stents applied by mesh structures were interested for achieving long life and high strength perfromance of medical stents. The purpose of this study is to design basic mesh shapes to obatin three dimensional (3D) meshed stent models for mechanical property evaluation. The influence of introduced design variables on compressive characteristics of meshed stent models are evaluated through finite element analysis using ANSYS Workbench code. From the analytical results, the compressive stiffness are changed periodically with compressive directions, average results need to be introduced as the mean value of compressive stiffness of meshed stents. Secondly, compressive flexibility of meshed stents can be improved by increasing the angle proportional to the arm length of the mesh basic shape. By increasing the number of basic mesh shapes arranged in stent’s circumferential direction, compressive rigidity of meshed stent tends to be increased. Finaly reducing the mesh line width is found effective to improve compressive flexibility of meshed stents.

Chelating effect in short polymers for the design of bidentate binders of increased affinity and selectivity

PubMed Central

Fortuna, Sara; Fogolari, Federico; Scoles, Giacinto

2015-01-01

The design of new strong and selective binders is a key step towards the development of new sensing devices and effective drugs. Both affinity and selectivity can be increased through chelation and here we theoretically explore the possibility of coupling two binders through a flexible linker. We prove the enhanced ability of double binders of keeping their target with a simple model where a polymer composed by hard spheres interacts with a spherical macromolecule, such as a protein, through two sticky spots. By Monte Carlo simulations and thermodynamic integration we show the chelating effect to hold for coupling polymers whose radius of gyration is comparable to size of the chelated particle. We show the binding free energy of flexible double binders to be higher than that of two single binders and to be maximized when the binding sites are at distances comparable to the mean free polymer end-to-end distance. The affinity of two coupled binders is therefore predicted to increase non linearly and in turn, by targeting two non-equivalent binding sites, this will lead to higher selectivity. PMID:26496975

Integrated controls-structures design methodology development for a class of flexible spacecraft

NASA Technical Reports Server (NTRS)

Maghami, P. G.; Joshi, S. M.; Walz, J. E.; Armstrong, E. S.

1990-01-01

Future utilization of space will require large space structures in low-Earth and geostationary orbits. Example missions include: Earth observation systems, personal communication systems, space science missions, space processing facilities, etc., requiring large antennas, platforms, and solar arrays. The dimensions of such structures will range from a few meters to possibly hundreds of meters. For reducing the cost of construction, launching, and operating (e.g., energy required for reboosting and control), it will be necessary to make the structure as light as possible. However, reducing structural mass tends to increase the flexibility which would make it more difficult to control with the specified precision in attitude and shape. Therefore, there is a need to develop a methodology for designing space structures which are optimal with respect to both structural design and control design. In the current spacecraft design practice, it is customary to first perform the structural design and then the controller design. However, the structural design and the control design problems are substantially coupled and must be considered concurrently in order to obtain a truly optimal spacecraft design. For example, let C denote the set of the 'control' design variables (e.g., controller gains), and L the set of the 'structural' design variables (e.g., member sizes). If a structural member thickness is changed, the dynamics would change which would then change the control law and the actuator mass. That would, in turn, change the structural model. Thus, the sets C and L depend on each other. Future space structures can be roughly divided into four mission classes. Class 1 missions include flexible spacecraft with no articulated appendages which require fine attitude pointing and vibration suppression (e.g., large space antennas). Class 2 missions consist of flexible spacecraft with articulated multiple payloads, where the requirement is to fine-point the spacecraft and each individual payload while suppressing the elastic motion. Class 3 missions include rapid slewing of spacecraft without appendages, while Class 4 missions include general nonlinear motion of a flexible spacecraft with articulated appendages and robot arms. Class 1 and 2 missions represent linear mathematical modeling and control system design problems (except for actuator and sensor nonlinearities), while Class 3 and 4 missions represent nonlinear problems. The development of an integrated controls/structures design approach for Class 1 missions is addressed. The performance for these missions is usually specified in terms of (1) root mean square (RMS) pointing errors at different locations on the structure, and (2) the rate of decay of the transient response. Both of these performance measures include the contributions of rigid as well as elastic motion.

Design of an oil squeeze film damper bearing for a multimass flexible-rotor bearing system

NASA Technical Reports Server (NTRS)

Cunningham, R. E.; Gunter, E. J., Jr.; Fleming, D. P.

1975-01-01

A single-mass flexible-rotor analysis was used to optimize the stiffness and damping of a flexible support for a symmetric five-mass rotor. The flexible, damped support attenuates the amplitudes of motions and forces transmitted to the support bearings when the rotor operates through and above its first bending critical speed. An oil squeeze film damper was designed based on short bearing lubrication theory. The damper design was verified by an unbalance response computer program. Rotor amplitudes were reduced by a factor of 16 and loads reduced by a factor of 36 compared with the same rotor with rigid bearing supports.

Design of a squeeze-film damper for a multi-mass flexible rotor

NASA Technical Reports Server (NTRS)

Cunningham, R. E.; Fleming, D. P.; Gunter, E. J.

1975-01-01

A single mass flexible rotor analysis was used to optimize the stiffness and damping of a flexible support for a symmetric five-mass rotor. The flexible support attenuates the rotor motions and forces transmitted to the support bearings when the rotor operates through and above its first bending critical speed. An oil squeeze-film damper was designed based on short bearing lubrication theory. The damper design was verified by an unbalance response computer program. Rotor amplitudes were reduced by a factor of 16 and loads reduced by a factor of 36 compared with the same rotor on rigid bearing supports.

The design and fabrication of highly piezoelectric polymeric composites and their use in responsive devices

NASA Astrophysics Data System (ADS)

Baur, Cary Allen

In this work, novel approaches to the design of highly piezoelectric and flexible polymer composites were explored. Diverging from past work focused on the addition of piezoelectric particles into polymer matrices, this research explores the ability to increase the piezoelectric performance of a host polymer through the incorporation of charge via polarizable, organic particles. The ability to insert charge into polymers, known as electrets, is well documented but widely considered impractical because of the low lifetime and temperature resistance of the inserted charge. Through the addition of particles that are polarizable, charge can be inserted into a system in a stable manner that results in highly charged materials with long lifetimes. Here, carbon structures, such as Buckminsterfullerenes (C60) and single-walled nanotubes (SWNTs), were composited into poly(vinylidene difluoride) at very low loading levels (0.05-0.25 wt%), resulting in the ability to insert stable charge into the system. We show that these highly charged systems can result in a doubling of the piezoelectric response of the host polymer when optimized. The low amount of nanoparticle filler required to improve these materials allows for the advantageous properties of the polymer matrix such as flexibility and compliance to be preserved, enabling highly piezoelectric and flexible system. This dissertation outlines research efforts towards the design and fabrication of 1) polymer composites with high piezoelectric response, 2) piezoelectric composites with increased operating temperatures, 3) motion control devices that incorporate piezoelectric materials and shape memory polymers, and 4) artificial muscles with piezoelectric polymers. The piezoelectric polymer composites developed in this work have potential to be utilized as highly efficient, flexible energy harvesters that can be used to capture ambient energy from environmental vibrations and motion from the human body. As actuators, these materials may find use as rapid-response muscle replacements in legs, arms, fingers, or toes. As sensors, such devices may provide electrical impulses capable of sensing small vibrations due to structural damage or movements. There is a wide range of applications for flexible piezoelectric materials that will continue to expand as technologies in monitoring, energy harvesting, and motion control continue to develop.

Design of Adaptive Policy Pathways under Deep Uncertainties

NASA Astrophysics Data System (ADS)

Babovic, Vladan

2013-04-01

The design of large-scale engineering and infrastructural systems today is growing in complexity. Designers need to consider sociotechnical uncertainties, intricacies, and processes in the long- term strategic deployment and operations of these systems. In this context, water and spatial management is increasingly challenged not only by climate-associated changes such as sea level rise and increased spatio-temporal variability of precipitation, but also by pressures due to population growth and particularly accelerating rate of urbanisation. Furthermore, high investment costs and long term-nature of water-related infrastructure projects requires long-term planning perspective, sometimes extending over many decades. Adaptation to such changes is not only determined by what is known or anticipated at present, but also by what will be experienced and learned as the future unfolds, as well as by policy responses to social and water events. As a result, a pathway emerges. Instead of responding to 'surprises' and making decisions on ad hoc basis, exploring adaptation pathways into the future provide indispensable support in water management decision-making. In this contribution, a structured approach for designing a dynamic adaptive policy based on the concepts of adaptive policy making and adaptation pathways is introduced. Such an approach provides flexibility which allows change over time in response to how the future unfolds, what is learned about the system, and changes in societal preferences. The introduced flexibility provides means for dealing with complexities of adaptation under deep uncertainties. It enables engineering systems to change in the face of uncertainty to reduce impacts from downside scenarios while capitalizing on upside opportunities. This contribution presents comprehensive framework for development and deployment of adaptive policy pathway framework, and demonstrates its performance under deep uncertainties on a case study related to urban water catchment in Singapore. Ingredients of this approach are: (a) transient scenarios (time series of various uncertain developments such as climate change, economic developments, societal changes), (b) a methodology for exploring many options and sequences of these options across different futures, and (c) a stepwise policy analysis. The strategy is applied on case of flexible deployment of novel, so-called Next Generation Infrastructure, and assessed in context of the proposed. Results of the study show that flexible design alternatives deliver much enhanced performance compared to systems optimized under deterministic forecasts of the future. The work also demonstrates that explicit incorporation of uncertainty and flexibility into decision-making process reduces capital expenditures while allowing decision makers to learn about system evolution throughout the lifetime of the project.

Balance and flexibility.

PubMed

2003-12-01

The 'work-life balance' and flexible working are currently key buzz terms in the NHS. Those looking for more information on these topics should visit Flexibility at www.flexibility.co.uk for a host of resources designed to support new ways of working, including information on flexible workers and flexible rostering, the legal balancing act for work-life balance and home working.

Interfacial characterization of flexible hybrid electronics

NASA Astrophysics Data System (ADS)

Najafian, Sara; Amirkhizi, Alireza V.; Stapleton, Scott

2018-03-01

Flexible Hybrid Electronics (FHEs) are the new generation of electronics combining flexible plastic film substrates with electronic devices. Besides the electrical features, design improvements of FHEs depend on the prediction of their mechanical and failure behavior. Debonding of electronic components from the flexible substrate is one of the most common and critical failures of these devices, therefore, the experimental determination of material and interface properties is of great importance in the prediction of failure mechanisms. Traditional interface characterization involves isolated shear and normal mode tests such as the double cantilever beam (DCB) and end notch flexure (ENF) tests. However, due to the thin, flexible nature of the materials and manufacturing restrictions, tests mirroring traditional interface characterization experiments may not always be possible. The ideal goal of this research is to design experiments such that each mode of fracture is isolated. However, due to the complex nonlinear nature of the response and small geometries of FHEs, design of the proper tests to characterize the interface properties can be significantly time and cost consuming. Hence numerical modeling has been implemented to design these novel characterization experiments. This research involves loading case and specimen geometry parametric studies using numerical modeling to design future experiments where either shear or normal fracture modes are dominant. These virtual experiments will provide a foundation for designing similar tests for many different types of flexible electronics and predicting the failure mechanism independent of the specific FHE materials.

Ultra-slim flexible glass for roll-to-roll electronic device fabrication

NASA Astrophysics Data System (ADS)

Garner, Sean; Glaesemann, Scott; Li, Xinghua

2014-08-01

As displays and electronics evolve to become lighter, thinner, and more flexible, the choice of substrate continues to be critical to their overall optimization. The substrate directly affects improvements in the designs, materials, fabrication processes, and performance of advanced electronics. With their inherent benefits such as surface quality, optical transmission, hermeticity, and thermal and dimensional stability, glass substrates enable high-quality and long-life devices. As substrate thicknesses are reduced below 200 μm, ultra-slim flexible glass continues to provide these inherent benefits to high-performance flexible electronics such as displays, touch sensors, photovoltaics, and lighting. In addition, the reduction in glass thickness also allows for new device designs and high-throughput, continuous manufacturing enabled by R2R processes. This paper provides an overview of ultra-slim flexible glass substrates and how they enable flexible electronic device optimization. Specific focus is put on flexible glass' mechanical reliability. For this, a combination of substrate design and process optimizations has been demonstrated that enables R2R device fabrication on flexible glass. Demonstrations of R2R flexible glass processes such as vacuum deposition, photolithography, laser patterning, screen printing, slot die coating, and lamination have been made. Compatibility with these key process steps has resulted in the first demonstration of a fully functional flexible glass device fabricated completely using R2R processes.

High-performance, flexible, deployable array development for space applications

NASA Technical Reports Server (NTRS)

Gehling, Russell N.; Armstrong, Joseph H.; Misra, Mohan S.

1994-01-01

Flexible, deployable arrays are an attractive alternative to conventional solar arrays for near-term and future space power applications, particularly due to their potential for high specific power and low storage volume. Combined with low-cost flexible thin-film photovoltaics, these arrays have the potential to become an enabling or an enhancing technology for many missions. In order to expedite the acceptance of thin-film photovoltaics for space applications, however, parallel development of flexible photovoltaics and the corresponding deployable structure is essential. Many innovative technologies must be incorporated in these arrays to ensure a significant performance increase over conventional technologies. For example, innovative mechanisms which employ shape memory alloys for storage latches, deployment mechanisms, and array positioning gimbals can be incorporated into flexible array design with significant improvement in the areas of cost, weight, and reliability. This paper discusses recent activities at Martin Marietta regarding the development of flexible, deployable solar array technology. Particular emphasis is placed on the novel use of shape memory alloys for lightweight deployment elements to improve the overall specific power of the array. Array performance projections with flexible thin-film copper-indium-diselenide (CIS) are presented, and government-sponsored solar array programs recently initiated at Martin Marietta through NASA and Air Force Phillips Laboratory are discussed.

Wearable, Flexible, and Multifunctional Healthcare Device with an ISFET Chemical Sensor for Simultaneous Sweat pH and Skin Temperature Monitoring.

PubMed

Nakata, Shogo; Arie, Takayuki; Akita, Seiji; Takei, Kuniharu

2017-03-24

Real-time daily healthcare monitoring may increase the chances of predicting and diagnosing diseases in their early stages which, currently, occurs most frequently during medical check-ups. Next-generation noninvasive healthcare devices, such as flexible multifunctional sensor sheets designed to be worn on skin, are considered to be highly suitable candidates for continuous real-time health monitoring. For healthcare applications, acquiring data on the chemical state of the body, alongside physical characteristics such as body temperature and activity, are extremely important for predicting and identifying potential health conditions. To record these data, in this study, we developed a wearable, flexible sweat chemical sensor sheet for pH measurement, consisting of an ion-sensitive field-effect transistor (ISFET) integrated with a flexible temperature sensor: we intend to use this device as the foundation of a fully integrated, wearable healthcare patch in the future. After characterizing the performance, mechanical flexibility, and stability of the sensor, real-time measurements of sweat pH and skin temperature are successfully conducted through skin contact. This flexible integrated device has the potential to be developed into a chemical sensor for sweat for applications in healthcare and sports.

Development of a simplified flexible pavement design protocol for New York State Department of Transportation based on the AASHTO mechanistic-empirical pavement design guide : final report.

DOT National Transportation Integrated Search

2017-01-01

The New York State Department of Transportation (NYSDOT) has used the AASHTO 1993 Design Guide for the design of new flexible pavement structures for more than two decades. The AASHTO 1993 Guide is based on the empirical design equations developed fr...

Diversity by Design: Technology, Teamwork, and Teaching.

ERIC Educational Resources Information Center

Parsons, Michael H.

Significant changes in the educational environment have inspired structural and functional redefinitions to increase institutional competitiveness. To flourish, colleges now must be able to respond quickly and effectively to change. They must be adaptive, flexible, responsive, and innovative, especially in their application of new technology. They…

Whole shaft visibility and mechanical performance for active MR catheters using copper-nitinol braided polymer tubes.

PubMed

Kocaturk, Ozgur; Saikus, Christina E; Guttman, Michael A; Faranesh, Anthony Z; Ratnayaka, Kanishka; Ozturk, Cengizhan; McVeigh, Elliot R; Lederman, Robert J

2009-08-12

Catheter visualization and tracking remains a challenge in interventional MR.Active guidewires can be made conspicuous in "profile" along their whole shaft exploiting metallic core wire and hypotube components that are intrinsic to their mechanical performance. Polymer-based catheters, on the other hand, offer no conductive medium to carry radio frequency waves. We developed a new "active" catheter design for interventional MR with mechanical performance resembling braided X-ray devices. Our 75 cm long hybrid catheter shaft incorporates a wire lattice in a polymer matrix, and contains three distal loop coils in a flexible and torquable 7Fr device. We explored the impact of braid material designs on radiofrequency and mechanical performance. The incorporation of copper wire into in a superelastic nitinol braided loopless antenna allowed good visualization of the whole shaft (70 cm) in vitro and in vivo in swine during real-time MR with 1.5 T scanner. Additional distal tip coils enhanced tip visibility. Increasing the copper:nitinol ratio in braiding configurations improved flexibility at the expense of torquability. We found a 16-wire braid of 1:1 copper:nitinol to have the optimum balance of mechanical (trackability, flexibility, torquability) and antenna (signal attenuation) properties. With this configuration, the temperature increase remained less than 2 degrees C during real-time MR within 10 cm horizontal from the isocenter. The design was conspicuous in vitro and in vivo. We have engineered a new loopless antenna configuration that imparts interventional MR catheters with satisfactory mechanical and imaging characteristics. This compact loopless antenna design can be generalized to visualize the whole shaft of any general-purpose polymer catheter to perform safe interventional procedures.

Whole shaft visibility and mechanical performance for active MR catheters using copper-nitinol braided polymer tubes

PubMed Central

Kocaturk, Ozgur; Saikus, Christina E; Guttman, Michael A; Faranesh, Anthony Z; Ratnayaka, Kanishka; Ozturk, Cengizhan; McVeigh, Elliot R; Lederman, Robert J

2009-01-01

Background Catheter visualization and tracking remains a challenge in interventional MR. Active guidewires can be made conspicuous in "profile" along their whole shaft exploiting metallic core wire and hypotube components that are intrinsic to their mechanical performance. Polymer-based catheters, on the other hand, offer no conductive medium to carry radio frequency waves. We developed a new "active" catheter design for interventional MR with mechanical performance resembling braided X-ray devices. Our 75 cm long hybrid catheter shaft incorporates a wire lattice in a polymer matrix, and contains three distal loop coils in a flexible and torquable 7Fr device. We explored the impact of braid material designs on radiofrequency and mechanical performance. Results The incorporation of copper wire into in a superelastic nitinol braided loopless antenna allowed good visualization of the whole shaft (70 cm) in vitro and in vivo in swine during real-time MR with 1.5 T scanner. Additional distal tip coils enhanced tip visibility. Increasing the copper:nitinol ratio in braiding configurations improved flexibility at the expense of torquability. We found a 16-wire braid of 1:1 copper:nitinol to have the optimum balance of mechanical (trackability, flexibility, torquability) and antenna (signal attenuation) properties. With this configuration, the temperature increase remained less than 2°C during real-time MR within 10 cm horizontal from the isocenter. The design was conspicuous in vitro and in vivo. Conclusion We have engineered a new loopless antenna configuration that imparts interventional MR catheters with satisfactory mechanical and imaging characteristics. This compact loopless antenna design can be generalized to visualize the whole shaft of any general-purpose polymer catheter to perform safe interventional procedures. PMID:19674464

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

Dondero, Rachel Elizabeth

The increased use of Field Programmable Gate Arrays (FPGAs) in critical systems brings new challenges in securing the diversely programmable fabric from cyber-attacks. FPGAs are an inexpensive, efficient, and flexible alternative to Application Specific Integrated Circuits (ASICs), which are becoming increasingly expensive and impractical for low volume manufacturing as technology nodes continue to shrink. Unfortunately, FPGAs are not designed for high security applications, and their high-flexibility lends itself to low security and vulnerability to malicious attacks. Similar to securing an ASIC’s functionality, FPGA programmers can exploit the inherent randomness introduced into hardware structures during fabrication for security applications. Physically Unclonablemore » Functions (PUFs) are one such solution that uses the die specific variability in hardware fabrication for both secret key generation and verification. PUFs strive to be random, unique, and reliable. Throughout recent years many PUF structures have been presented to try and maximize these three design constraints, reliability being the most difficult of the three to achieve. This thesis presents a new PUF structure that combines two elementary PUF concepts (a bi-stable SRAM PUF and a delay-based arbiter PUF) to create a PUF with increased reliability, while maintaining both random and unique qualities. Properties of the new PUF will be discussed as well as the various design modifications that can be made to tweak the desired performance and overhead.« less

Synthesis study of nondestructive testing devices for use in overlay thickness design of flexible pavements

NASA Astrophysics Data System (ADS)

Smith, R. E.; Lytton, R. L.

1984-04-01

A ready reference for highway engineers who are interested in purchasing nondestructive testing (NDT) equipment for use in designing overlays for flexible pavements was prepared. All commercially available equipment is described. Information includes basic descriptions plus current prices quoted by the manufacturers/distributors. To determine user comments, a questionnaire was sent to nine State agencies, and one Federal agency. The responses to these questionnaires are summarized. Overlay thickness design procedures for flexible pavements are reviewed. Important components related to the use of NDT deflection measuremnts in overlay design are identified and addressed. Summary tables of equipment characteristics and overlay design procedures are presented.

A homotopy algorithm for synthesizing robust controllers for flexible structures via the maximum entropy design equations

NASA Technical Reports Server (NTRS)

Collins, Emmanuel G., Jr.; Richter, Stephen

1990-01-01

One well known deficiency of LQG compensators is that they do not guarantee any measure of robustness. This deficiency is especially highlighted when considering control design for complex systems such as flexible structures. There has thus been a need to generalize LQG theory to incorporate robustness constraints. Here we describe the maximum entropy approach to robust control design for flexible structures, a generalization of LQG theory, pioneered by Hyland, which has proved useful in practice. The design equations consist of a set of coupled Riccati and Lyapunov equations. A homotopy algorithm that is used to solve these design equations is presented.

Layout designs of surface barrier coatings for boosting the capability of oxygen/vapor obstruction utilized in flexible electronics

NASA Astrophysics Data System (ADS)

Lee, Chang-Chun; Huang, Pei-Chen; He, Jing-Yan

2018-04-01

Organic light-emitting diode-based flexible and rollable displays have become a promising candidate for next-generation flexible electronics. For this reason, the design of surface multi-layered barriers should be optimized to enhance the long-term mechanical reliability of a flexible encapsulation that prevents the penetration of oxygen and vapor. In this study, finite element-based stress simulation was proposed to estimate the mechanical reliability of gas/vapor barrier design with low-k/silicon nitride (low-k/SiNx) stacking architecture. Consequently, stress-induced failure of critical thin films within the flexible display under various bending conditions must be considered. The feasibility of one pair SiO2/SiNx barrier design, which overcomes the complex lamination process, and the critical bending radius, which is decreased to 1.22 mm, were also examined. In addition, the influence of distance between neutral axes to the concerned layer surface dominated the induced-stress magnitude rather than the stress compliant mechanism provided from stacked low-k films.

Maximizing propulsive thrust of a driven filament at low Reynolds number via variable flexibility.

PubMed

Peng, Zhiwei; Elfring, Gwynn J; Pak, On Shun

2017-03-22

At low Reynolds numbers the locomotive capability of a body can be dramatically hindered by the absence of inertia. In this work, we show how propulsive performance in this regime can be significantly enhanced by employing spatially varying flexibility. As a prototypical example, we consider the propulsive thrust generated by a filament periodically driven at one end. The rigid case leads to zero propulsion, as so constrained by Purcell's scallop theorem, while for uniform filaments there exists a bending stiffness maximizing the propulsive force at a given frequency; here we demonstrate explicitly how considerable further improvement can be achieved by simply varying the stiffness along the filament. The optimal flexibility distribution is strongly configuration-dependent: while increasing the flexibility towards the tail-end enhances the propulsion of a clamped filament, for a hinged filament decreasing the flexibility towards the tail-end is instead favorable. The results reveal new design principles for maximizing propulsion at low Reynolds numbers, potentially useful for developing synthetic micro-swimmers requiring large propulsive force for various biomedical applications.

Numerical simulation on a straight-bladed vertical axis wind turbine with auxiliary blade

NASA Astrophysics Data System (ADS)

Li, Y.; Zheng, Y. F.; Feng, F.; He, Q. B.; Wang, N. X.

2016-08-01

To improve the starting performance of the straight-bladed vertical axis wind turbine (SB-VAWT) at low wind speed, and the output characteristics at high wind speed, a flexible, scalable auxiliary vane mechanism was designed and installed into the rotor of SB-VAWT in this study. This new vertical axis wind turbine is a kind of lift-to-drag combination wind turbine. The flexible blade expanded, and the driving force of the wind turbines comes mainly from drag at low rotational speed. On the other hand, the flexible blade is retracted at higher speed, and the driving force is primarily from a lift. To research the effects of the flexible, scalable auxiliary module on the performance of SB-VAWT and to find its best parameters, the computational fluid dynamics (CFD) numerical calculation was carried out. The calculation result shows that the flexible, scalable blades can automatic expand and retract with the rotational speed. The moment coefficient at low tip speed ratio increased substantially. Meanwhile, the moment coefficient has also been improved at high tip speed ratios in certain ranges.

Developing an Advanced Life Support System for the Flexible Path into Deep Space

NASA Technical Reports Server (NTRS)

Jones, Harry W.; Kliss, Mark H.

2010-01-01

Long duration human missions beyond low Earth orbit, such as a permanent lunar base, an asteroid rendezvous, or exploring Mars, will use recycling life support systems to preclude supplying large amounts of metabolic consumables. The International Space Station (ISS) life support design provides a historic guiding basis for future systems, but both its system architecture and the subsystem technologies should be reconsidered. Different technologies for the functional subsystems have been investigated and some past alternates appear better for flexible path destinations beyond low Earth orbit. There is a need to develop more capable technologies that provide lower mass, increased closure, and higher reliability. A major objective of redesigning the life support system for the flexible path is achieving the maintainability and ultra-reliability necessary for deep space operations.

Children’s Attractiveness, Gender, and Race Biases: A Comparison of Their Strength and Generality

PubMed Central

Rennels, Jennifer L.; Langlois, Judith H.

2013-01-01

Although research suggests that facial attractiveness biases significantly affect social development and interactions, these biases are understudied in the developmental literature and are overlooked when designing interventions relative to gender and race. The authors, therefore, compared how much bias 3–11-year-olds (N=102) displayed in the three domains. They also examined whether bias and flexibility (understanding that different social groups can possess similar attributes) were related across domains. Children’s attractiveness biases, particularly for girl targets, were as strong as or stronger than gender or race biases. Flexibility, but not bias, was related across domains. Developmental scientists and policymakers should increase efforts toward understanding development of attractiveness biases and determine which methods of teaching flexibility are most successful at reducing bias across domains. PMID:24673180

Design and test of a squeeze-film damper for a flexible power transmission shaft

NASA Technical Reports Server (NTRS)

Darlow, M. S.; Smalley, A. J.

1978-01-01

For a flexible shaft designed to pass through a number of bending critical speeds, a squeeze-film damper has been designed and tested. The damper properties were selected to provide control of all critical speeds, while meeting additional constraints of high power transmission requirements and damper simplicity. The damper was fabricated and installed and its ability to control flexible shaft vibrations was demonstrated by the comparison of vibration amplitudes both with and without the damper.

Two strategies to engineer flexible loops for improved enzyme thermostability

PubMed Central

Yu, Haoran; Yan, Yihan; Zhang, Cheng; Dalby, Paul A.

2017-01-01

Flexible sites are potential targets for engineering the stability of enzymes. Nevertheless, the success rate of the rigidifying flexible sites (RFS) strategy is still low due to a limited understanding of how to determine the best mutation candidates. In this study, two parallel strategies were applied to identify mutation candidates within the flexible loops of Escherichia coli transketolase (TK). The first was a “back to consensus mutations” approach, and the second was computational design based on ΔΔG calculations in Rosetta. Forty-nine single variants were generated and characterised experimentally. From these, three single-variants I189H, A282P, D143K were found to be more thermostable than wild-type TK. The combination of A282P with H192P, a variant constructed previously, resulted in the best all-round variant with a 3-fold improved half-life at 60 °C, 5-fold increased specific activity at 65 °C, 1.3-fold improved kcat and a Tm increased by 5 °C above that of wild type. Based on a statistical analysis of the stability changes for all variants, the qualitative prediction accuracy of the Rosetta program reached 65.3%. Both of the two strategies investigated were useful in guiding mutation candidates to flexible loops, and had the potential to be used for other enzymes. PMID:28145457

Fast electrochemical membrane actuator: Design, fabrication and preliminary testing

NASA Astrophysics Data System (ADS)

Uvarov, I. V.; Postnikov, A. V.; Shlepakov, P. S.; Naumov, V. V.; Koroleva, O. M.; Izyumov, M. O.; Svetovoy, V. B.

2017-11-01

An actuator based on water electrolysis with a fast change of voltage polarity is presented. It demonstrates a new actuation principle allowing significant increase the operation frequency of the device due to fast termination of the produced gas. The actuator consists of a working chamber with metallic electrodes and supplying channels filled with an electrolyte. The chamber is formed in a layer of SU-8 and covered by a flexible polydimethylsiloxane membrane, which deforms as the pressure in the chamber increases. Design, fabrication procedure, and first tests of the actuator are described.

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

Glawe, Andrea; Eggerath, Daniel; Schäfer, Frank

The market of Large Area Organic Printed Electronics is developing rapidly to increase efficiency and quality as well as to lower costs further. Applications for OPV, OLED, RFID and compact Printed Electronic systems are increasing. In order to make the final products more affordable, but at the same time highly accurate, Roll to Roll (R2R) production on flexible transparent polymer substrates is the way forward. There are numerous printing and coating technologies suitable depending on the design, the product application and the chemical process technology. Mainly the product design (size, pattern, repeatability) defines the application technology.

Demonstration of transparent solar array module design

NASA Technical Reports Server (NTRS)

Pack, G. J.

1984-01-01

This report discusses the design, development, fabrication and testing of IR transparent solar array modules. Three modules, consisting of a baseline design using back surface reflector cells, and two modules using gridded back contact, IR transparent cells, were subjected to vacuum thermal balance testing to verify analytical predictions of lower operating emperature and increased efficiency. As a result of this test program, LMSC has verified that a significant degree of IR transparency can be designed into a flexible solar array. Test data correlates with both steady state and transient thermal analysis.

Making a successful transition to cash balance. Using employee choice and financial education.

PubMed

Scahill, P; Wiley, P

2000-01-01

As employee work patterns change, the need for flexible plan design has increased. Hybrid plans such as cash balance plans offer a plan design variation that incorporates elements of the traditional defined benefit plan as well as those of defined contribution plans. This article examines plan design trends and discusses both negative and positive reactions to those trends. Finally, the solution of offering choice to plan participants is suggested, and the issues that must be considered are discussed.

The Integrated Plasma Simulator: A Flexible Python Framework for Coupled Multiphysics Simulation

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

Foley, Samantha S; Elwasif, Wael R; Bernholdt, David E

2011-11-01

High-fidelity coupled multiphysics simulations are an increasingly important aspect of computational science. In many domains, however, there has been very limited experience with simulations of this sort, therefore research in coupled multiphysics often requires computational frameworks with significant flexibility to respond to the changing directions of the physics and mathematics. This paper presents the Integrated Plasma Simulator (IPS), a framework designed for loosely coupled simulations of fusion plasmas. The IPS provides users with a simple component architecture into which a wide range of existing plasma physics codes can be inserted as components. Simulations can take advantage of multiple levels ofmore » parallelism supported in the IPS, and can be controlled by a high-level ``driver'' component, or by other coordination mechanisms, such as an asynchronous event service. We describe the requirements and design of the framework, and how they were implemented in the Python language. We also illustrate the flexibility of the framework by providing examples of different types of simulations that utilize various features of the IPS.« less

Flexibility Support for Homecare Applications Based on Models and Multi-Agent Technology

PubMed Central

Armentia, Aintzane; Gangoiti, Unai; Priego, Rafael; Estévez, Elisabet; Marcos, Marga

2015-01-01

In developed countries, public health systems are under pressure due to the increasing percentage of population over 65. In this context, homecare based on ambient intelligence technology seems to be a suitable solution to allow elderly people to continue to enjoy the comforts of home and help optimize medical resources. Thus, current technological developments make it possible to build complex homecare applications that demand, among others, flexibility mechanisms for being able to evolve as context does (adaptability), as well as avoiding service disruptions in the case of node failure (availability). The solution proposed in this paper copes with these flexibility requirements through the whole life-cycle of the target applications: from design phase to runtime. The proposed domain modeling approach allows medical staff to design customized applications, taking into account the adaptability needs. It also guides software developers during system implementation. The application execution is managed by a multi-agent based middleware, making it possible to meet adaptation requirements, assuring at the same time the availability of the system even for stateful applications. PMID:26694416

Characterisation and optimisation of flexible transfer lines for liquid helium. Part I: Experimental results

NASA Astrophysics Data System (ADS)

Dittmar, N.; Haberstroh, Ch.; Hesse, U.; Krzyzowski, M.

2016-04-01

The transfer of liquid helium (LHe) into mobile dewars or transport vessels is a common and unavoidable process at LHe decant stations. During this transfer reasonable amounts of LHe evaporate due to heat leak and pressure drop. Thus generated helium gas needs to be collected and reliquefied which requires a huge amount of electrical energy. Therefore, the design of transfer lines used at LHe decant stations has been optimised to establish a LHe transfer with minor evaporation losses which increases the overall efficiency and capacity of LHe decant stations. This paper presents the experimental results achieved during the thermohydraulic optimisation of a flexible LHe transfer line. An extensive measurement campaign with a set of dedicated transfer lines equipped with pressure and temperature sensors led to unique experimental data of this specific transfer process. The experimental results cover the heat leak, the pressure drop, the transfer rate, the outlet quality, and the cool-down and warm-up behaviour of the examined transfer lines. Based on the obtained results the design of the considered flexible transfer line has been optimised, featuring reduced heat leak and pressure drop.

Flexible pavement overlay design procedures. Volume 1: Evaluation and modification of the design methods

NASA Astrophysics Data System (ADS)

Majidzadeh, K.; Ilves, G. J.

1981-08-01

A ready reference to design procedures for asphaltic concrete overlay of flexible pavements based on elastic layer theory is provided. The design procedures and the analytical techniques presented were formulated to predict the structural fatigue response of asphaltic concrete overlays for various design conditions, including geometrical and material properties, loading conditions and environmental variables.

Microstrip-antenna design for hyperthermia treatment of superficial tumors.

PubMed

Montecchia, F

1992-06-01

Microstrip antennas have many different advantages over other RF/MW radiative applicators employed for superficial hyperthermia treatment. This is mainly due to their compact and body-conformable structure as well as to printed circuit board techniques, both of which allow a wide design flexibility for superficial tumor heating. Among the wide variety of radiator configurations, three microstrip antennas of increasing complexity with electromagnetic and heating characteristics potentially suitable as applicators for superficial hyperthermia have been designed, developed, and tested in different radiative conditions: a microstrip disk, a microstrip annular-slot, and a microstrip spiral. Electromagnetic design criteria are presented together with the determinations of the applicator return loss versus frequency and thermograms of the near-field heating pattern in muscle-like phantom. The results are in good agreement with theory and indicate that: i) the operating frequency is either single or multiple according to the applicator-mode, "resonant" or "traveling-wave," and can be chosen in the useful frequency range for hyperthermia (200-1000 MHz) according to the tumor cross-section and depth; ii) the heating pattern flexibility increases going from the simple geometry disk to the annular-slot and spiral applicators; iii) a distilled-water bolus is required; iv) the annular-slot applicator exhibits the highest efficiency, while the spiral applicator provides the best performance.

Fast Track Option: An Accelerated Associate's Degree Program.

ERIC Educational Resources Information Center

Price, J. Randall

1998-01-01

Alternative instructional delivery options such as self-paced and flexible enrollment courses are designed to increase enrollment, promote retention, and encourage student success without lowering academic standards. The Fast Track Associate's Degree Program, developed by a team of faculty, staff, and administrators at Richland Community College,…

A flexible and miniaturized hair dye based photodetector via chemiluminescence pathway.

PubMed

Lin, Ching-Chang; Sun, Da-Shiuan; Lin, Ya-Lin; Tsai, Tsung-Tso; Cheng, Chieh; Sun, Wen-Hsien; Ko, Fu-Hsiang

2017-04-15

A flexible and miniaturized metal semiconductor metal (MSM) biomolecular photodetector was developed as the core photocurrent system through chemiluminescence for hydrogen peroxide sensing. The flexible photocurrent sensing system was manufactured on a 30-µm-thick crystalline silicon chip by chemical etching process, which produced a flexible silicon chip. A surface texturization design on the flexible device enhanced the light-trapping effect and minimized reflectivity losses from the incident light. The model protein streptavidin bound to horseradish peroxidase (HRP) was successfully immobilized onto the sensor surface through high-affinity conjugation with biotin. The luminescence reaction occurred with luminol, hydrogen peroxide and HRP enzyme, and the emission of light from the catalytic reaction was detected by underlying flexible photodetector. The chemiluminescence in the miniaturized photocurrent sensing system was successfully used to determine the hydrogen peroxide concentration in real-time analyses. The hydrogen peroxide detection limit of the flexible MSM photodetector was 2.47mM. The performance of the flexible MSM photodetector maintained high stability under bending at various bending radii. Moreover, for concave bending, a significant improvement in detection signal intensity (14.5% enhancement compared with a flat configuration) was observed because of the increased photocurrent, which was attributed to enhancement of light trapping. Additionally, this detector was used to detect hydrogen peroxide concentrations in commercial hair dye products, which is a significant issue in the healthcare field. The development of this novel, flexible and miniaturized MSM biomolecular photodetector with excellent mechanical flexibility and high sensitivity demonstrates the applicability of this approach to future wearable sensor development efforts. Copyright © 2016 Elsevier B.V. All rights reserved.

Integrated control-structure design

NASA Technical Reports Server (NTRS)

Hunziker, K. Scott; Kraft, Raymond H.; Bossi, Joseph A.

1991-01-01

A new approach for the design and control of flexible space structures is described. The approach integrates the structure and controller design processes thereby providing extra opportunities for avoiding some of the disastrous effects of control-structures interaction and for discovering new, unexpected avenues of future structural design. A control formulation based on Boyd's implementation of Youla parameterization is employed. Control design parameters are coupled with structural design variables to produce a set of integrated-design variables which are selected through optimization-based methodology. A performance index reflecting spacecraft mission goals and constraints is formulated and optimized with respect to the integrated design variables. Initial studies have been concerned with achieving mission requirements with a lighter, more flexible space structure. Details of the formulation of the integrated-design approach are presented and results are given from a study involving the integrated redesign of a flexible geostationary platform.

Comparative analysis on flexibility requirements of typical Cryogenic Transfer lines

NASA Astrophysics Data System (ADS)

Jadon, Mohit; Kumar, Uday; Choukekar, Ketan; Shah, Nitin; Sarkar, Biswanath

2017-04-01

The cryogenic systems and their applications; primarily in large Fusion devices, utilize multiple cryogen transfer lines of various sizes and complexities to transfer cryogenic fluids from plant to the various user/ applications. These transfer lines are composed of various critical sections i.e. tee section, elbows, flexible components etc. The mechanical sustainability (under failure circumstances) of these transfer lines are primary requirement for safe operation of the system and applications. The transfer lines need to be designed for multiple design constraints conditions like line layout, support locations and space restrictions. The transfer lines are subjected to single load and multiple load combinations, such as operational loads, seismic loads, leak in insulation vacuum loads etc. [1]. The analytical calculations and flexibility analysis using professional software are performed for the typical transfer lines without any flexible component, the results were analysed for functional and mechanical load conditions. The failure modes were identified along the critical sections. The same transfer line was then refurbished with the flexible components and analysed for failure modes. The flexible components provide additional flexibility to the transfer line system and make it safe. The results obtained from the analytical calculations were compared with those obtained from the flexibility analysis software calculations. The optimization of the flexible component’s size and selection was performed and components were selected to meet the design requirements as per code.

Life cycle, cost, and loading characteristics of AASHO designed rigid and flexible pavements in Louisiana : final report.

DOT National Transportation Integrated Search

1989-02-01

This report represents a study undertaken to determine the life cycle, load characteristics, and associated costs of a representative sample of the oldest rigid and flexible pavements designed in Louisiana (1963-1967) using the AASHO Guide for Design...

Characterizing seasonal variations in pavement material properties for use in a mechanistic-empirical design procedure

DOT National Transportation Integrated Search

2000-12-01

Recent advances in flexible pavement design have prompted agencies to move toward the development and use of mechanistic-empirical (M-E) design procedures. This report analyzed seasonal trends in flexible pavement layer moduli to calibrate a M-E desi...

Optimal output fast feedback in two-time scale control of flexible arms

NASA Technical Reports Server (NTRS)

Siciliano, B.; Calise, A. J.; Jonnalagadda, V. R. P.

1986-01-01

Control of lightweight flexible arms moving along predefined paths can be successfully synthesized on the basis of a two-time scale approach. A model following control can be designed for the reduced order slow subsystem. The fast subsystem is a linear system in which the slow variables act as parameters. The flexible fast variables which model the deflections of the arm along the trajectory can be sensed through strain gage measurements. For full state feedback design the derivatives of the deflections need to be estimated. The main contribution of this work is the design of an output feedback controller which includes a fixed order dynamic compensator, based on a recent convergent numerical algorithm for calculating LQ optimal gains. The design procedure is tested by means of simulation results for the one link flexible arm prototype in the laboratory.

Development of a simplified flexible pavement design protocol for New York State Department of Transportation based on the AASHTO Mechanistic-Empirical Pavement Design Guide : technical summary.

DOT National Transportation Integrated Search

2017-01-01

This report summarizes the local calibration of the distress models for the Northeast (NE) region of the United States and the development of new design tables for new flexible pavement structures. Design, performance, and traffic data collected on t...

Multi-Objective Flight Control for Drag Minimization and Load Alleviation of High-Aspect Ratio Flexible Wing Aircraft

NASA Technical Reports Server (NTRS)

Nguyen, Nhan; Ting, Eric; Chaparro, Daniel; Drew, Michael; Swei, Sean

2017-01-01

As aircraft wings become much more flexible due to the use of light-weight composites material, adverse aerodynamics at off-design performance can result from changes in wing shapes due to aeroelastic deflections. Increased drag, hence increased fuel burn, is a potential consequence. Without means for aeroelastic compensation, the benefit of weight reduction from the use of light-weight material could be offset by less optimal aerodynamic performance at off-design flight conditions. Performance Adaptive Aeroelastic Wing (PAAW) technology can potentially address these technical challenges for future flexible wing transports. PAAW technology leverages multi-disciplinary solutions to maximize the aerodynamic performance payoff of future adaptive wing design, while addressing simultaneously operational constraints that can prevent the optimal aerodynamic performance from being realized. These operational constraints include reduced flutter margins, increased airframe responses to gust and maneuver loads, pilot handling qualities, and ride qualities. All of these constraints while seeking the optimal aerodynamic performance present themselves as a multi-objective flight control problem. The paper presents a multi-objective flight control approach based on a drag-cognizant optimal control method. A concept of virtual control, which was previously introduced, is implemented to address the pair-wise flap motion constraints imposed by the elastomer material. This method is shown to be able to satisfy the constraints. Real-time drag minimization control is considered to be an important consideration for PAAW technology. Drag minimization control has many technical challenges such as sensing and control. An initial outline of a real-time drag minimization control has already been developed and will be further investigated in the future. A simulation study of a multi-objective flight control for a flight path angle command with aeroelastic mode suppression and drag minimization demonstrates the effectiveness of the proposed solution. In-flight structural loads are also an important consideration. As wing flexibility increases, maneuver load and gust load responses can be significant and therefore can pose safety and flight control concerns. In this paper, we will extend the multi-objective flight control framework to include load alleviation control. The study will focus initially on maneuver load minimization control, and then subsequently will address gust load alleviation control in future work.

Flexible benefits and managed care: making it work.

PubMed

Sperling, K L

1991-01-01

The concept of integrating flexible benefits and managed care may seem contradictory. Flexible benefits seek to maximize choice, while managed care attempts to restrict choice. Can these two disciplines be intertwined without delivering conflicting messages to employees? The answer is definitely yes. By following some basic ground rules in design, flexible benefits and managed care can be combined effectively in a way that is attractive to both employers and employees. This article presents some general guidelines for designing a successful "managed flex" program and raises other issues as well, including financial, administrative and communication concerns.

Design of Soil Salinity Policies with Tinamit, a Flexible and Rapid Tool to Couple Stakeholder-Built System Dynamics Models with Physically-Based Models

NASA Astrophysics Data System (ADS)

Malard, J. J.; Baig, A. I.; Hassanzadeh, E.; Adamowski, J. F.; Tuy, H.; Melgar-Quiñonez, H.

2016-12-01

Model coupling is a crucial step to constructing many environmental models, as it allows for the integration of independently-built models representing different system sub-components to simulate the entire system. Model coupling has been of particular interest in combining socioeconomic System Dynamics (SD) models, whose visual interface facilitates their direct use by stakeholders, with more complex physically-based models of the environmental system. However, model coupling processes are often cumbersome and inflexible and require extensive programming knowledge, limiting their potential for continued use by stakeholders in policy design and analysis after the end of the project. Here, we present Tinamit, a flexible Python-based model-coupling software tool whose easy-to-use API and graphical user interface make the coupling of stakeholder-built SD models with physically-based models rapid, flexible and simple for users with limited to no coding knowledge. The flexibility of the system allows end users to modify the SD model as well as the linking variables between the two models themselves with no need for recoding. We use Tinamit to couple a stakeholder-built socioeconomic model of soil salinization in Pakistan with the physically-based soil salinity model SAHYSMOD. As climate extremes increase in the region, policies to slow or reverse soil salinity buildup are increasing in urgency and must take both socioeconomic and biophysical spheres into account. We use the Tinamit-coupled model to test the impact of integrated policy options (economic and regulatory incentives to farmers) on soil salinity in the region in the face of future climate change scenarios. Use of the Tinamit model allowed for rapid and flexible coupling of the two models, allowing the end user to continue making model structure and policy changes. In addition, the clear interface (in contrast to most model coupling code) makes the final coupled model easily accessible to stakeholders with limited technical background.

Rapid Slewing of Flexible Space Structures

DTIC Science & Technology

2015-09-01

axis gimbal with elastic joints. The performance of the system can be enhanced by designing antenna maneuvers in which the flexible effects are...the effects of the nonlinearities so the vibrational motion can be constrained for a time-optimal slew. It is shown that by constructing an...joints. The performance of the system can be enhanced by designing antenna maneuvers in which the flexible effects are properly constrained, thus

Treatment of Chronic Pain for Adults 65 and Over: Analyses of Outcomes and Changes in Psychological Flexibility Following Interdisciplinary Acceptance and Commitment Therapy (ACT).

PubMed

Scott, Whitney; Daly, Aisling; Yu, Lin; McCracken, Lance M

2017-02-01

The purpose of this study was to examine the effectiveness of acceptance and commitment therapy (ACT) for older adults with chronic pain. Secondarily, we examined the associations between changes on processes of psychological flexibility and treatment outcome variables. Participants were 60 adults with chronic pain age 65 and older selected from a larger consecutive sample of 928 adults of any age. All participants had longstanding pain that was associated with significant distress and disability. Participants completed measures of pain, functioning, and depression, and processes of psychological flexibility at baseline, immediately post-treatment, and at a 9-month follow-up. Treatment consisted of a 2- or 4-week residential program based on principles of ACT delivered by an interdisciplinary team. Treatment was designed to increase daily functioning by enhancing key processes of psychological flexibility, including openness, awareness, and committed action. Participants showed significant improvements in functioning and mental health at posttreatment. Participants also showed significant increases in pain acceptance and committed action from pre- to post-treatment. Small effect sizes were observed for most treatment outcome and process variables in the pre-treatment to follow-up intervals; however, these improvements were not statistically significant. In secondary analyses, changes in facets of psychological flexibility were significantly associated with improvements in social functioning and mental health. This study supports the potential effectiveness of ACT for chronic pain among older adults. Future research is needed to determine how to maximize the impact of this treatment, particularly through greater impact on psychological flexibility.

Spectral design flexibility of LED brings better life

NASA Astrophysics Data System (ADS)

Ou, Haiyan; Corell, Dennis; Ou, Yiyu; Poulsen, Peter B.; Dam-Hansen, Carsten; Petersen, Paul-Michael

2012-03-01

Light-emitting diodes (LEDs) are penetrating into the huge market of general lighting because they are energy saving and environmentally friendly. The big advantage of LED light sources, compared to traditional incandescent lamps and fluorescent light tubes, is the flexible spectral design to make white light using different color mixing schemes. The spectral design flexibility of white LED light sources will promote them for novel applications to improve the life quality of human beings. As an initial exploration to make use of the spectral design flexibility, we present an example: 'no blue' white LED light source for sufferers of disease Porphyria. An LED light source prototype, made of high brightness commercial LEDs applying an optical filter, was tested by a patient suffering from Porphyria. Preliminary results have shown that the sufferer could withstand the light source for much longer time than the standard light source. At last future perspectives on spectral design flexibility of LED light sources improving human being's life will be discussed, with focus on the light and health. The good health is ensured by the spectrum optimized so that vital hormones (melatonin and serotonin) are produced during times when they support human daily rhythm.

Object-oriented design for accelerator control

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

Stok, P.D.V. van der; Berk, F. van den; Deckers, R.

1994-02-01

An object-oriented design for the distributed computer control system of the accelerator ring EUTERPE is presented. Because of the experimental nature of the ring, flexibility is of the utmost importance. The object-oriented principles have contributed considerably to the flexibility of the design incorporating multiple views, multi-level access and distributed surveillance.

Predictive design procedures, VESYS users manual : an interim design method for flexible pavements using the VESYS structural subsystem

DOT National Transportation Integrated Search

1978-01-01

This manual has been written to provide the pavement manager and design engineer with a ready reference of procedures to predict the structural responses and hence the integrity of flexible pavements. A pavement section of known geometry is chosen, a...

Capstone Portfolios and Geography Student Learning Outcomes

ERIC Educational Resources Information Center

Mossa, Joann

2014-01-01

Due to increasing demands regarding student learning outcomes and accreditation, a capstone portfolio was added to assess critical thinking and communication skills of geography majors at a large public university in the USA. The portfolio guidelines were designed to be adaptable to a flexible curriculum where about half of the requirements within…

Finite element simulation of structural performance on flexible pavements with stabilized base/treated subbase materials under accelerated loading : tech summary.

DOT National Transportation Integrated Search

2011-12-01

Accelerated pavement testing (APT) has been increasingly used by state highway agencies in recent years for evaluating pavement : design and performance through applying a simulative heavy vehicular load to the pavement section under controlled fi el...

Increasing Students' Interest with Low-Cost CellBots

ERIC Educational Resources Information Center

Aroca, R. V.; Gomes, R. B.; Tavares, D. M.; Souza, A. A. S; Burlamaqui, A. M. F.; Caurin, G. A. P.; Goncalves, L. M. G.

2013-01-01

This paper introduces the use of a flexible and affordable educational robot specifically developed for the practical experimentation inherent to technological disciplines. The robot has been designed to be reconfigurable and extendible, serving as an experimental platform across several undergraduate courses. As most students have a mobile cell…

Issues and Challenges Facing Flexible Lithium-Ion Batteries for Practical Application.

PubMed

Cha, Hyungyeon; Kim, Junhyeok; Lee, Yoonji; Cho, Jaephil; Park, Minjoon

2017-12-27

With the advent of flexible electronics, lithium-ion batteries have become a key component of high performance energy storage systems. Thus, considerable effort is made to keep up with the development of flexible lithium-ion batteries. To date, many researchers have studied newly designed batteries with flexibility, however, there are several significant challenges that need to be overcome, such as degradation of electrodes under external load, poor battery performance, and complicated cell preparation procedures. In addition, an in-depth understanding of the current challenges for flexible batteries is rarely addressed in a systematical and practical way. Herein, recent progress and current issues of flexible lithium-ion batteries in terms of battery materials and cell designs are reviewed. A critical overview of important issues and challenges for the practical application of flexible lithium-ion batteries is also provided. Finally, the strategies are discussed to overcome current limitations of the practical use of flexible lithium-based batteries, providing a direction for future research. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Flexible thermal laminate

NASA Technical Reports Server (NTRS)

Dawn, F. S.; Sauers, D. G.

1977-01-01

Lightweight flexible laminate of interwoven conducting and insulating yarns, designed to provide localized controlled heating for propellant tanks on space vehicles, is useful for nonspace applications where weight, bulk, and flexibility are critical concerns.

Flight Test Validation of Optimal Input Design and Comparison to Conventional Inputs

NASA Technical Reports Server (NTRS)

Morelli, Eugene A.

1997-01-01

A technique for designing optimal inputs for aerodynamic parameter estimation was flight tested on the F-18 High Angle of Attack Research Vehicle (HARV). Model parameter accuracies calculated from flight test data were compared on an equal basis for optimal input designs and conventional inputs at the same flight condition. In spite of errors in the a priori input design models and distortions of the input form by the feedback control system, the optimal inputs increased estimated parameter accuracies compared to conventional 3-2-1-1 and doublet inputs. In addition, the tests using optimal input designs demonstrated enhanced design flexibility, allowing the optimal input design technique to use a larger input amplitude to achieve further increases in estimated parameter accuracy without departing from the desired flight test condition. This work validated the analysis used to develop the optimal input designs, and demonstrated the feasibility and practical utility of the optimal input design technique.

Potential Applications of Modularity to Enable a Deep Space Habitation Capability for Future Human Exploration Beyond Low-Earth Orbit

NASA Technical Reports Server (NTRS)

Simon, Matthew A.; Toups, Larry; Smitherman, David

2012-01-01

Evaluating preliminary concepts of a Deep Space Habitat (DSH) enabling long duration crewed exploration of asteroids, the Moon, and Mars is a technically challenging problem. Sufficient habitat volumes and equipment, necessary to ensure crew health and functionality, increase propellant requirements and decrease launch flexibility to deliver multiple elements on a single launch vehicle; both of which increase overall mission cost. Applying modularity in the design of the habitat structures and subsystems can alleviate these difficulties by spreading the build-up of the overall habitation capability across several smaller parts. This allows for a more flexible habitation approach that accommodates various crew mission durations and levels of functionality. This paper provides a technical analysis of how various modular habitation approaches can impact the parametric design of a DSH with potential benefits in mass, packaging volume, and architectural flexibility. This includes a description of the desired long duration habitation capability, the definition of a baseline model for comparison, a small trade study to investigate alternatives, and commentary on potentially advantageous configurations to enable different levels of habitability. The approaches investigated include modular pressure vessel strategies, modular subsystems, and modular manufacturing approaches to habitat structure. The paper also comments upon the possibility of an integrated habitation strategy using modular components to create all short and long duration habitation elements required in the current exploration architectures.

A systems-based approach for integrated design of materials, products and design process chains

NASA Astrophysics Data System (ADS)

Panchal, Jitesh H.; Choi, Hae-Jin; Allen, Janet K.; McDowell, David L.; Mistree, Farrokh

2007-12-01

The concurrent design of materials and products provides designers with flexibility to achieve design objectives that were not previously accessible. However, the improved flexibility comes at a cost of increased complexity of the design process chains and the materials simulation models used for executing the design chains. Efforts to reduce the complexity generally result in increased uncertainty. We contend that a systems based approach is essential for managing both the complexity and the uncertainty in design process chains and simulation models in concurrent material and product design. Our approach is based on simplifying the design process chains systematically such that the resulting uncertainty does not significantly affect the overall system performance. Similarly, instead of striving for accurate models for multiscale systems (that are inherently complex), we rely on making design decisions that are robust to uncertainties in the models. Accordingly, we pursue hierarchical modeling in the context of design of multiscale systems. In this paper our focus is on design process chains. We present a systems based approach, premised on the assumption that complex systems can be designed efficiently by managing the complexity of design process chains. The approach relies on (a) the use of reusable interaction patterns to model design process chains, and (b) consideration of design process decisions using value-of-information based metrics. The approach is illustrated using a Multifunctional Energetic Structural Material (MESM) design example. Energetic materials store considerable energy which can be released through shock-induced detonation; conventionally, they are not engineered for strength properties. The design objectives for the MESM in this paper include both sufficient strength and energy release characteristics. The design is carried out by using models at different length and time scales that simulate different aspects of the system. Finally, by applying the method to the MESM design problem, we show that the integrated design of materials and products can be carried out more efficiently by explicitly accounting for design process decisions with the hierarchy of models.

Mechanistic design concepts for conventional flexible pavements

NASA Astrophysics Data System (ADS)

Elliott, R. P.; Thompson, M. R.

1985-02-01

Mechanical design concepts for convetional flexible pavement (asphalt concrete (AC) surface plus granular base/subbase) for highways are proposed and validated. The procedure is based on ILLI-PAVE, a stress dependent finite element computer program, coupled with appropriate transfer functions. Two design criteria are considered: AC flexural fatigue cracking and subgrade rutting. Algorithms were developed relating pavement response parameters (stresses, strains, deflections) to AC thickness, AC moduli, granular layer thickness, and subgrade moduli. Extensive analyses of the AASHO Road Test flexible pavement data are presented supporting the validity of the proposed concepts.

Lessons Learned in the Design and Use of IP1 / IP2 Flexible Packaging - 13621

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

Sanchez, Mike; Reeves, Wendall; Smart, Bill

2013-07-01

For many years in the USA, Low Level Radioactive Waste (LLW), contaminated soils and construction debris, have been transported, interim stored, and disposed of, using IP1 / IP2 metal containers. The performance of these containers has been more than adequate, with few safety occurrences. The containers are used under the regulatory oversight of the US Department of Transportation (DOT), 49 Code of Federal Regulations (CFR). In the late 90's the introduction of flexible packaging for the transport, storage, and disposal of low level contaminated soils and construction debris was introduced. The development of flexible packaging came out of a needmore » for a more cost effective package, for the large volumes of waste generated by the decommissioning of many of the US Department of Energy (DOE) legacy sites across the US. Flexible packaging had to be designed to handle a wide array of waste streams, including soil, gravel, construction debris, and fine particulate dust migration. The design also had to meet all of the IP1 requirements under 49CFR 173.410, and be robust enough to pass the IP2 testing 49 CFR 173.465 required for many LLW shipments. Tens of thousands of flexible packages have been safely deployed and used across the US nuclear industry as well as for hazardous non-radioactive applications, with no recorded release of radioactive materials. To ensure that flexible packages are designed properly, the manufacturer must use lessons learned over the years, and the tests performed to provide evidence that these packages are suitable for transporting low level radioactive wastes. The design and testing of flexible packaging for LLW, VLLW and other hazardous waste streams must be as strict and stringent as the design and testing of metal containers. The design should take into consideration the materials being loaded into the package, and should incorporate the right materials, and manufacturing methods, to provide a quality, safe product. Flexible packaging can be shown to meet the criteria for safe and fit for purpose packaging, by meeting the US DOT regulations, and the IAEA Standards for IP-1 and IP-2 including leak tightness. (authors)« less

Unsymmetric Lanczos model reduction and linear state function observer for flexible structures

NASA Technical Reports Server (NTRS)

Su, Tzu-Jeng; Craig, Roy R., Jr.

1991-01-01

This report summarizes part of the research work accomplished during the second year of a two-year grant. The research, entitled 'Application of Lanczos Vectors to Control Design of Flexible Structures' concerns various ways to use Lanczos vectors and Krylov vectors to obtain reduced-order mathematical models for use in the dynamic response analyses and in control design studies. This report presents a one-sided, unsymmetric block Lanczos algorithm for model reduction of structural dynamics systems with unsymmetric damping matrix, and a control design procedure based on the theory of linear state function observers to design low-order controllers for flexible structures.

Design Optimization Toolkit: Users' Manual

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

Aguilo Valentin, Miguel Alejandro

The Design Optimization Toolkit (DOTk) is a stand-alone C++ software package intended to solve complex design optimization problems. DOTk software package provides a range of solution methods that are suited for gradient/nongradient-based optimization, large scale constrained optimization, and topology optimization. DOTk was design to have a flexible user interface to allow easy access to DOTk solution methods from external engineering software packages. This inherent flexibility makes DOTk barely intrusive to other engineering software packages. As part of this inherent flexibility, DOTk software package provides an easy-to-use MATLAB interface that enables users to call DOTk solution methods directly from the MATLABmore » command window.« less

Ovarian tumor-initiating cells display a flexible metabolism

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

Anderson, Angela S.; Roberts, Paul C.; Frisard, Madlyn I.

2014-10-15

An altered metabolism during ovarian cancer progression allows for increased macromolecular synthesis and unrestrained growth. However, the metabolic phenotype of cancer stem or tumor-initiating cells, small tumor cell populations that are able to recapitulate the original tumor, has not been well characterized. In the present study, we compared the metabolic phenotype of the stem cell enriched cell variant, MOSE-L{sub FFLv} (TIC), derived from mouse ovarian surface epithelial (MOSE) cells, to their parental (MOSE-L) and benign precursor (MOSE-E) cells. TICs exhibit a decrease in glucose and fatty acid oxidation with a concomitant increase in lactate secretion. In contrast to MOSE-L cells,more » TICs can increase their rate of glycolysis to overcome the inhibition of ATP synthase by oligomycin and can increase their oxygen consumption rate to maintain proton motive force when uncoupled, similar to the benign MOSE-E cells. TICs have an increased survival rate under limiting conditions as well as an increased survival rate when treated with AICAR, but exhibit a higher sensitivity to metformin than MOSE-E and MOSE-L cells. Together, our data show that TICs have a distinct metabolic profile that may render them flexible to adapt to the specific conditions of their microenvironment. By better understanding their metabolic phenotype and external environmental conditions that support their survival, treatment interventions can be designed to extend current therapy regimens to eradicate TICs. - Highlights: • Ovarian cancer TICs exhibit a decreased glucose and fatty acid oxidation. • TICs are more glycolytic and have highly active mitochondria. • TICs are more resistant to AICAR but not metformin. • A flexible metabolism allows TICs to adapt to their microenvironment. • This flexibility requires development of specific drugs targeting TIC-specific changes to prevent recurrent TIC outgrowth.« less

Project coalitions in healthcare construction projects and the application of real options: an exploratory survey.

PubMed

van Reedt Dortland, Maartje; Dewulf, Geert; Voordijk, Hans

2013-01-01

Exploring the impact of the type of project coalition on types of flexibility by analyzing considered and exercised flexibilities in separated and integrated project coalitions in the design and construction phase and the operations and maintenance phase of a healthcare construction project. Flexibility in healthcare construction projects is increasingly needed in order to deal with growing uncertainties. Until now, little research has been carried out on how and to what extent flexibility is incorporated in different types of project coalitions chosen by healthcare organizations. An exploratory survey was conducted among health organizations in both cure and care. Questions were asked on the position of the real estate department within the organization, the type of project coalitions chosen and the rationale behind this choice, and the extent to which flexibility in terms of a real option was considered and to what extent it had been exercised in a project coalition. Integrated project coalitions pay more attention to flexibility in advance in both the process and the product, but exercise them to a lesser extent than separated project coalitions. The economic feasibility of real options is higher in integrated project coalitions. The study shows that real options thinking is already incorporated in real estate management of healthcare organizations, although more flexibility is considered in advance of the project than is actually realized during and after construction. Built environment, construction, decision making, hospitals, planning.

Flexible Multi-Body Spacecraft Simulator: Design, Construction, and Experiments

DTIC Science & Technology

2017-12-01

BODY SPACECRAFT SIMULATOR: DESIGN , CONSTRUCTION, AND EXPERIMENTS by Adam L. Atwood December 2017 Thesis Advisor: Mark Karpenko Second...TYPE AND DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE FLEXIBLE MULTI-BODY SPACECRAFT SIMULATOR: DESIGN , CONSTRUCTION, AND EXPERIMENTS 5...spacecraft simulator for use in testing optimal control-based slew and maneuver designs . The simulator is modified from an earlier prototype, which

Effect of structural flexibility on the design of vibration-isolating mounts for aircraft engines

NASA Technical Reports Server (NTRS)

Phillips, W. H.

1984-01-01

Previous analyses of the design of vibration-isolating mounts for a rear-mounted engine to decouple linear and rotational oscillations are extended to take into account flexibility of the engine-mount structure. Equations and curves are presented to allow the design of mount systems and to illustrate the results for a range of design conditions.

An operations concept methodology to achieve low-cost mission operations

NASA Technical Reports Server (NTRS)

Ledbetter, Kenneth W.; Wall, Stephen D.

1993-01-01

Historically, the Mission Operations System (MOS) for a space mission has been designed last because it is needed last. This has usually meant that the ground system must adjust to the flight vehicle design, sometimes at a significant cost. As newer missions have increasingly longer flight operations lifetimes, the MOS becomes proportionally more difficult and more resource-consuming. We can no longer afford to design the MOS last. The MOS concept may well drive the spacecraft, instrument, and mission designs, as well as the ground system. A method to help avoid these difficulties, responding to the changing nature of mission operations is presented. Proper development and use of an Operations Concept document results in a combined flight and ground system design yielding enhanced operability and producing increased flexibility for less cost.

Texas flexible pavements and overlays : year 5 report - complete data documentation.

DOT National Transportation Integrated Search

2017-05-01

Proper calibration and validation of pavement design and performance models to Texas conditions is : essential for cost-effective flexible pavement design, performance predictions, and maintenance/rehab : strategies. The veracity of the calibration o...

Design and milling manufacture of polyurethane custom contoured cushions for wheelchair users.

PubMed

da Silva, Fabio Pinto; Beretta, Elisa Marangon; Prestes, Rafael Cavalli; Kindlein Junior, Wilson

2011-01-01

The design of custom contoured cushions manufactured in flexible polyurethane foams is an option to improve positioning and comfort for people with disabilities that spend most of the day seated in the same position. These surfaces increase the contact area between the seat and the user. This fact contributes to minimise the local pressures that can generate problems like decubitus ulcers. The present research aims at establishing development routes for custom cushion production to wheelchair users. This study also contributes to the investigation of Computer Numerical Control (CNC) machining of flexible polyurethane foams. The proposed route to obtain the customised seat began with acquiring the user's contour in adequate posture through plaster cast. To collect the surface geometry, the cast was three-dimensionally scanned and manipulated in CAD/CAM software. CNC milling parameters such as tools, spindle speeds and feed rates to machine flexible polyurethane foams were tested. These parameters were analysed regarding the surface quality. The best parameters were then tested in a customised seat. The possible dimensional changes generated during foam cutting were analysed through 3D scanning. Also, the customised seat pressure and temperature distribution was tested. The best parameters found for foams with a density of 50kg/cm(3) were high spindle speeds (24000 rpm) and feed rates between 2400-4000mm/min. Those parameters did not generate significant deformities in the machined cushions. The custom contoured cushion satisfactorily increased the contact area between wheelchair and user, as it distributed pressure and heat evenly. Through this study it was possible to define routes for the development and manufacturing of customised seats using direct CNC milling in flexible polyurethane foams. It also showed that custom contoured cushions efficiently distribute pressure and temperature, which is believed to minimise tissue lesions such as pressure ulcers.

Mechanism Design and Testing of a Self-Deploying Structure Using Flexible Composite Tape Springs

NASA Technical Reports Server (NTRS)

Footdale, Joseph N.; Murphey, Thomas W.

2014-01-01

The detailed mechanical design of a novel deployable support structure that positions and tensions a membrane optic for space imagining applications is presented. This is a complex three-dimensional deployment using freely deploying rollable composite tape spring booms that become load bearing structural members at full deployment. The deployment tests successfully demonstrate a new architecture based on rolled and freely deployed composite tape spring members that achieve simultaneous deployment without mechanical synchronization. Proper design of the flexible component mounting interface and constraint systems, which were critical in achieving a functioning unit, are described. These flexible composite components have much potential for advancing the state of the art in deployable structures, but have yet to be widely adopted. This paper demonstrates the feasibility and advantages of implementing flexible composite components, including the design details on how to integrate with required traditional mechanisms.

Low-frequency and wideband vibration energy harvester with flexible frame and interdigital structure

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

Li, Pengwei, E-mail: lipengwei@tyut.edu.cn; Wang, Yanfen; Luo, Cuixian

2015-04-15

As an alternative to traditional cantilever beam structures and their evolutions, a flexible beam based, interdigital structure, vibration energy harvester has been presented and investigated. The proposed interdigital-shaped oscillator consists of a rectangular flexible frame and series of cantilever beams interdigitally bonded to it. In order to achieve low frequency and wide-bandwidth harvesting, Young’s modulus of materials, frame size and the amount of the cantilevers have been studied systematically. The measured frequency responses of the designed device (PDMS frame, quintuple piezoelectric cantilever beams) show a 460% increase in bandwidth below 80Hz. When excited at an acceleration of 1.0 g, themore » energy harvester achieves to a maximum open-circuit voltage of 65V, and the maximum output power 4.5 mW.« less

Transformational electronics are now reconfiguring

NASA Astrophysics Data System (ADS)

Rojas, Jhonathan P.; Hussain, Aftab M.; Arevalo, A.; Foulds, I. G.; Torres Sevilla, Galo A.; Nassar, Joanna M.; Hussain, Muhammad M.

2015-05-01

Current developments on enhancing our smart living experience are leveraging the increased interest for novel systems that can be compatible with foldable, wrinkled, wavy and complex geometries and surfaces, and thus become truly ubiquitous and easy to deploy. Therefore, relying on innovative structural designs we have been able to reconfigure the physical form of various materials, to achieve remarkable mechanical flexibility and stretchability, which provides us with the perfect platform to develop enhanced electronic systems for application in entertainment, healthcare, fitness and wellness, military and manufacturing industry. Based on these novel structural designs we have developed a siliconbased network of hexagonal islands connected through double-spiral springs, forming an ultra-stretchable (~1000%) array for full compliance to highly asymmetric shapes and surfaces, as well as a serpentine design used to show an ultrastretchable (~800%) and flexible, spatially reconfigurable, mobile, metallic thin film copper (Cu)-based, body-integrated and non-invasive thermal heater with wireless controlling capability, reusability, heating-adaptability and affordability due to low-cost complementary metal oxide semiconductor (CMOS)-compatible integration.

The BaBar Data Reconstruction Control System

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

Ceseracciu, A

2005-04-20

The BaBar experiment is characterized by extremely high luminosity and very large volume of data produced and stored, with increasing computing requirements each year. To fulfill these requirements a Control System has been designed and developed for the offline distributed data reconstruction system. The control system described in this paper provides the performance and flexibility needed to manage a large number of small computing farms, and takes full benefit of OO design. The infrastructure is well isolated from the processing layer, it is generic and flexible, based on a light framework providing message passing and cooperative multitasking. The system ismore » distributed in a hierarchical way: the top-level system is organized in farms, farms in services, and services in subservices or code modules. It provides a powerful Finite State Machine framework to describe custom processing models in a simple regular language. This paper describes the design and evolution of this control system, currently in use at SLAC and Padova on {approx}450 CPUs organized in 9 farms.« less

The BaBar Data Reconstruction Control System

NASA Astrophysics Data System (ADS)

Ceseracciu, A.; Piemontese, M.; Tehrani, F. S.; Pulliam, T. M.; Galeazzi, F.

2005-08-01

The BaBar experiment is characterized by extremely high luminosity and very large volume of data produced and stored, with increasing computing requirements each year. To fulfill these requirements a control system has been designed and developed for the offline distributed data reconstruction system. The control system described in this paper provides the performance and flexibility needed to manage a large number of small computing farms, and takes full benefit of object oriented (OO) design. The infrastructure is well isolated from the processing layer, it is generic and flexible, based on a light framework providing message passing and cooperative multitasking. The system is distributed in a hierarchical way: the top-level system is organized in farms, farms in services, and services in subservices or code modules. It provides a powerful finite state machine framework to describe custom processing models in a simple regular language. This paper describes the design and evolution of this control system, currently in use at SLAC and Padova on /spl sim/450 CPUs organized in nine farms.

A Bamboo-Inspired Nanostructure Design for Flexible, Foldable, and Twistable Energy Storage Devices.

PubMed

Sun, Yongming; Sills, Ryan B; Hu, Xianluo; Seh, Zhi Wei; Xiao, Xu; Xu, Henghui; Luo, Wei; Jin, Huanyu; Xin, Ying; Li, Tianqi; Zhang, Zhaoliang; Zhou, Jun; Cai, Wei; Huang, Yunhui; Cui, Yi

2015-06-10

Flexible energy storage devices are critical components for emerging flexible electronics. Electrode design is key in the development of all-solid-state supercapacitors with superior electrochemical performances and mechanical durability. Herein, we propose a bamboo-like graphitic carbon nanofiber with a well-balanced macro-, meso-, and microporosity, enabling excellent mechanical flexibility, foldability, and electrochemical performances. Our design is inspired by the structure of bamboos, where a periodic distribution of interior holes along the length and graded pore structure at the cross section not only enhance their stability under different mechanical deformation conditions but also provide a high surface area accessible to the electrolyte and low ion-transport resistance. The prepared nanofiber network electrode recovers its initial state easily after 3-folded manipulation. The mechanically robust membrane is explored as a free-standing electrode for a flexible all-solid-state supercapacitor. Without the need for extra support, the volumetric energy and power densities based on the whole device are greatly improved compared to the state-of-the-art devices. Even under continuous dynamic operations of forceful bending (90°) and twisting (180°), the as-designed device still exhibits stable electrochemical performances with 100% capacitance retention. Such a unique supercapacitor holds great promise for high-performance flexible electronics.

A bamboo-inspired nanostructure design for flexible foldable and twistable energy storage devices

DOE PAGES

Sun, Yongming; Sills, Ryan B; Hu, Xianluo; ...

2015-05-26

Flexible energy storage devices are critical components for emerging flexible electronics. Electrode design is key in the development of all-solid-state supercapacitors with superior electrochemical performances and mechanical durability. We propose a bamboo-like graphitic carbon nanofiber with a well-balanced macro-, meso-, and microporosity, enabling excellent mechanical flexibility, foldability, and electrochemical performances. Our design is inspired by the structure of bamboos, where a periodic distribution of interior holes along the length and graded pore structure at the cross section not only enhance their stability under different mechanical deformation conditions but also provide a high surface area accessible to the electrolyte and lowmore » ion-transport resistance. The prepared nanofiber network electrode recovers its initial state easily after 3-folded manipulation. The mechanically robust membrane is explored as a free-standing electrode for a flexible all-solid-state supercapacitor. Without the need for extra support, the volumetric energy and power densities based on the whole device are greatly improved compared to the state-of-the-art devices. Furthermore, even under continuous dynamic operations of forceful bending (90°) and twisting (180°), the as-designed device still exhibits stable electrochemical performances with 100% capacitance retention. As a result, such a unique supercapacitor holds great promise for high-performance flexible electronics.« less

Effect of oligonucleic acid (ONA) backbone features on assembly of ONA-star polymer conjugates: a coarse-grained molecular simulation study.

PubMed

Condon, Joshua E; Jayaraman, Arthi

2017-10-04

Understanding the impact of incorporating new physical and chemical features in oligomeric DNA mimics, termed generally as "oligonucleic acids" (ONAs), on their structure and thermodynamics will be beneficial in designing novel materials for a variety of applications. In this work, we conduct coarse-grained molecular simulations of ONA-star polymer conjugates with varying ONA backbone flexibility, ONA backbone charge, and number of arms in the star polymer at a constant ONA strand volume fraction to elucidate the effect of these design parameters on the thermodynamics and assembly of multi-arm ONA-star polymer conjugates. We quantify the thermo-reversible behavior of the ONA-star polymer conjugates by quantifying the hybridization of the ONA strands in the system as a function of temperature (i.e. melting curve). Additionally, we characterize the assembly of the ONA-star polymer conjugates by tracking cluster formation and percolation as a function of temperature, as well as cluster size distribution at temperatures near the assembly transition region. The key results are as follows. The melting temperature (T m ) of the ONA strands decreases upon going from a neutral to a charged ONA backbone and upon increasing flexibility of the ONA backbone. Similar behavior is seen for the assembly transition temperature (T a ) with varying ONA backbone charge and flexibility. While the number of arms in the ONA-star polymer conjugate has a negligible effect on the ONA T m in these systems, as the number of ONA-star polymer arms increase, the assembly temperature T a increases and local ordering in the assembled state improves. By understanding how factors like ONA backbone charge, backbone flexibility, and ONA-star polymer conjugate architecture impact the behavior of ONA-star polymer conjugate systems, we can better inform how the selection of ONA chemistry will influence resulting ONA-star polymer assembly.

Exploring mobility & workplace choice in a flexible office through post-occupancy evaluation.

PubMed

Göçer, Özgür; Göçer, Kenan; Ergöz Karahan, Ebru; İlhan Oygür, Işıl

2018-02-01

Developments in information and communication systems, organisational structure and the nature of work have contributed to the restructuring of work environments. In these new types of work environments, employees do not have assigned workplaces. This arrangement helps organisations to minimise rent costs and increase employee interaction and knowledge exchange through mobility. This post-occupancy evaluation (POE) study focuses on a flexible office in a Gold Leadership in Energy and Environmental Design-certified building in Istanbul. An integrated qualitative and quantitative POE technique with occupancy tracking via barcode scanning and instant surveying has been introduced. Using this unique approach, we examined the directives/drivers in workplace choice and mobility from different perspectives. The aggregated data was used to discern work-related consequences such as flexibility, workplace choice, work and indoor environment satisfaction, place attachment and identity. The results show that employees who have a conventional working culture develop a new working style: 'fixed-flexible working'. Practitioner Summary: This paper introduces a new POE approach for flexible offices based on occupancy tracking through barcode scanning to explore workplace choice and mobility. More than half (52.1%) of the participants have tended to choose the same desk every day. However, the satisfaction level of the 'mobile' employees was higher than that of the 'fixed flexible' employees.

Health and psychosocial effects of flexible working hours.

PubMed

Janssen, Daniela; Nachreiner, Friedhelm

2004-12-01

To examine whether any impairments in health and social lives can be found under different kinds of flexible working hours, and whether such effects are related to specific characteristics of these working hours. Two studies -- a company based survey (N=660) and an internet survey (N=528) -- have been conducted. The first one was a questionnaire study (paper and pencil) on employees working under some 'typical' kinds of different flexible working time arrangements in different companies and different occupational fields (health care, manufacturing, retail, administration, call centres). The second study was an internet-based survey, using an adaptation of the questionnaire from the first study. The results of both studies consistently show that high variability of working hours is associated with increased impairments in health and well-being and this is especially true if this variability is company controlled. These effects are less pronounced if variability is self-controlled; however, autonomy does not compensate the effects of variability. Recommendations for an appropriate design of flexible working hours should be developed in order to minimize any impairing effects on health and psychosocial well-being; these recommendations should include -- besides allowing for discretion in controlling one's (flexible) working hours -- that variability in flexible working hours should be kept low (or at least moderate), even if this variability is self-controlled.

Active vibration control techniques for flexible space structures

NASA Technical Reports Server (NTRS)

Parlos, Alexander G.; Jayasuriya, Suhada

1990-01-01

Two proposed control system design techniques for active vibration control in flexible space structures are detailed. Control issues relevant only to flexible-body dynamics are addressed, whereas no attempt was made to integrate the flexible and rigid-body spacecraft dynamics. Both of the proposed approaches revealed encouraging results; however, further investigation of the interaction of the flexible and rigid-body dynamics is warranted.

An approach to integrating and creating flexible software environments

NASA Technical Reports Server (NTRS)

Bellman, Kirstie L.

1992-01-01

Engineers and scientists are attempting to represent, analyze, and reason about increasingly complex systems. Many researchers have been developing new ways of creating increasingly open environments. In this research on VEHICLES, a conceptual design environment for space systems, an approach was developed, called 'wrapping', to flexibility and integration based on the collection and then processing of explicit qualitative descriptions of all the software resources in the environment. Currently, a simulation is available, VSIM, used to study both the types of wrapping descriptions and the processes necessary to use the metaknowledge to combine, select, adapt, and explain some of the software resources used in VEHICLES. What was learned about the types of knowledge necessary for the wrapping approach is described along with the implications of wrapping for several key software engineering issues.

Designing E-Learning Environments for Flexible Activity and Instruction

ERIC Educational Resources Information Center

Wilson, Brent G.

2004-01-01

The contributions to this issue share a focus on design of e-learning environments. Instructional designers stand at very early stages of knowledge in this area, but with great potential for growth and progress. This commentary offers an activity-based perspective on e-learning environments, resulting in a flexible stance toward instructional…

Improving Knowledge, Awareness, and Use of Flexible Career Policies through an Accelerator Intervention at the University of California, Davis, School of Medicine

PubMed Central

Villablanca, Amparo C.; Beckett, Laurel; Nettiksimmons, Jasmine; Howell, Lydia P.

2013-01-01

The challenges of balancing a career and family life disproportionately affect women in academic health sciences and medicine, contributing to their slower career advancement and/or their attrition from academia. In this article, the authors first describe their experiences at the University of California, Davis, School of Medicine developing and implementing an innovative accelerator intervention designed to promote faculty work-life balance by improving knowledge, awareness, and access to comprehensive flexible career policies. They then summarize the results of two faculty surveys--one conducted before the implementation of their intervention and the second conducted one year into their three-year intervention--designed to assess faculty’s use and intention to use the flexible career policies, their awareness of available options, barriers to their use of the policies, and their career satisfaction. The authors found that the intervention significantly increased awareness of the policies and attendance at related educational activities, improved attitudes toward the policies, and decreased perceived barriers to use. These results however were most pronounced for female faculty and faculty under the age of 50. The authors next discuss areas for future research on faculty use of flexible career policies and offer recommendations for other institutions of higher education, not just those in academic medicine, interested in implementing a similar intervention. They conclude that having flexible career policies alone is not enough to stem the attrition of female faculty. Such policies must be fully integrated into an institution’s culture such that faculty are both aware of them and willing to use them. PMID:23619063

Improving knowledge, awareness, and use of flexible career policies through an accelerator intervention at the University of California, Davis, School of Medicine.

PubMed

Villablanca, Amparo C; Beckett, Laurel; Nettiksimmons, Jasmine; Howell, Lydia P

2013-06-01

The challenges of balancing a career and family life disproportionately affect women in academic health sciences and medicine, contributing to their slower career advancement and/or their attrition from academia. In this article, the authors first describe their experiences at the University of California, Davis, School of Medicine developing and implementing an innovative accelerator intervention designed to promote faculty work-life balance by improving knowledge, awareness, and access to comprehensive flexible career policies. They then summarize the results of two faculty surveys--one conducted before the implementation of their intervention and the second conducted one year into their three-year intervention--designed to assess faculty's use and intention to use the flexible career policies, their awareness of available options, barriers to their use of the policies, and their career satisfaction. The authors found that the intervention significantly increased awareness of the policies and attendance at related educational activities, improved attitudes toward the policies, and decreased perceived barriers to use. These results, however, were most pronounced for female faculty and faculty under the age of 50. The authors next discuss areas for future research on faculty use of flexible career policies and offer recommendations for other institutions of higher education--not just those in academic medicine--interested in implementing a similar intervention. They conclude that having flexible career policies alone is not enough to stem the attrition of female faculty. Such policies must be fully integrated into an institution's culture such that faculty are both aware of them and willing to use them.

Effects of Flexible Dry Electrode Design on Electrodermal Activity Stimulus Response Detection.

PubMed

Haddad, Peter A; Servati, Amir; Soltanian, Saeid; Ko, Frank; Servati, Peyman

2017-12-01

The focus of this research is to evaluate the effects of design parameters including surface area, distance between and geometry of dry flexible electrodes on electrodermal activity (EDA) stimulus response detection. EDA is a result of the autonomic nervous system being stimulated, which causes sweat and changes the electrical characteristics of the skin. Standard silver/silver chloride (Ag/AgCl) EDA electrodes are rigid and lack conformability in contact with skin. In this study, flexible dry Ag/AgCl EDA electrodes were fabricated on a compliant substrate, used to monitor EDA stimulus responses and compared to results simultaneously collected by rigid dry Ag/AgCl electrodes. A repeatable fabrication process for flexible Ag/AgCl electrodes has been established. Surface area, distance between and geometry of electrodes are shown to affect the detectability of the EDA response and the minimum number of sweat glands to be covered by the electrodes has been estimated at 140, or more, in order to maintain functionality. The optimal flexible EDA electrode is a serpentine design with a 0.15 cm 2 surface area and a 0.20 cm distance with an average Pearson correlation coefficient of . Fabrication of flexible electrodes is described and an understanding of the effects of electrode designs on the EDA stimulus response detection has been established and is potentially related to the coverage of sweat glands. This work presents a novel systematic approach to understand the effects of electrode designs on monitoring EDA which is of importance for the design of wearable EDA monitoring devices.

Flexible HVAC System for Lab or Classroom.

ERIC Educational Resources Information Center

Friedan, Jonathan

2001-01-01

Discusses an effort to design a heating, ventilation, and air conditioning system flexible enough to accommodate an easy conversion of classrooms to laboratories and dry labs to wet labs. The design's energy efficiency and operations and maintenance are examined. (GR)

3D Printing the Complete CubeSat

NASA Technical Reports Server (NTRS)

Kief, Craig

2015-01-01

The 3D Printing the Complete CubeSat project is designed to advance the state-of-the-art in 3D printing for CubeSat applications. Printing in 3D has the potential to increase reliability, reduce design iteration time and provide greater design flexibility in the areas of radiation mitigation, communications, propulsion, and wiring, among others. This project is investigating the possibility of including propulsion systems into the design of printed CubeSat components. One such concept, an embedded micro pulsed plasma thruster (mPPT), could provide auxiliary reaction control propulsion for a spacecraft as a means to desaturate momentum wheels.

Printing versus coating - What will be the future production technology for printed electronics?

NASA Astrophysics Data System (ADS)

Glawe, Andrea; Eggerath, Daniel; Schäfer, Frank

2015-02-01

The market of Large Area Organic Printed Electronics is developing rapidly to increase efficiency and quality as well as to lower costs further. Applications for OPV, OLED, RFID and compact Printed Electronic systems are increasing. In order to make the final products more affordable, but at the same time highly accurate, Roll to Roll (R2R) production on flexible transparent polymer substrates is the way forward. There are numerous printing and coating technologies suitable depending on the design, the product application and the chemical process technology. Mainly the product design (size, pattern, repeatability) defines the application technology.

Training in élite young athletes (the Training of Young Athletes (TOYA) Study): injuries, flexibility and isometric strength.

PubMed Central

Maffulli, N; King, J B; Helms, P

1994-01-01

Using a mixed longitudinal design, the incidence of injuries, and the development of flexibility and isometric strength of the upper and lower limbs were studied for 2 years in 453 élite young athletes (aged between 9 and 18 years) practising football, gymnastics, swimming or tennis. The children suffered from a low incidence of injuries. Strength and flexibility did not exert a significant role in determining injuries. The rate of injury was not significantly different between the 2 years of the study. Young swimmers showed a greater generalized flexibility. Girls were more flexible than boys between the ages of 13 to 16 years. Athletic children are able to exert greater isometric strength than normal schoolchildren. Boys diverged from the normal population at 14 years, while athletic girls were stronger at all ages. Girls were stronger than boys up to age 12, who were still increasing their muscle strength at 19 years. The average maximal isometric strength exerted in both upper and lower limbs in the four sports was not significantly different. Male gymnasts over 11 years old were significantly stronger than all other athletes. PMID:7921912

Hyperspectral Imaging Using Flexible Endoscopy for Laryngeal Cancer Detection

PubMed Central

Regeling, Bianca; Thies, Boris; Gerstner, Andreas O. H.; Westermann, Stephan; Müller, Nina A.; Bendix, Jörg; Laffers, Wiebke

2016-01-01

Hyperspectral imaging (HSI) is increasingly gaining acceptance in the medical field. Up until now, HSI has been used in conjunction with rigid endoscopy to detect cancer in vivo. The logical next step is to pair HSI with flexible endoscopy, since it improves access to hard-to-reach areas. While the flexible endoscope’s fiber optic cables provide the advantage of flexibility, they also introduce an interfering honeycomb-like pattern onto images. Due to the substantial impact this pattern has on locating cancerous tissue, it must be removed before the HS data can be further processed. Thereby, the loss of information is to minimize avoiding the suppression of small-area variations of pixel values. We have developed a system that uses flexible endoscopy to record HS cubes of the larynx and designed a special filtering technique to remove the honeycomb-like pattern with minimal loss of information. We have confirmed its feasibility by comparing it to conventional filtering techniques using an objective metric and by applying unsupervised and supervised classifications to raw and pre-processed HS cubes. Compared to conventional techniques, our method successfully removes the honeycomb-like pattern and considerably improves classification performance, while preserving image details. PMID:27529255

Hyperspectral Imaging Using Flexible Endoscopy for Laryngeal Cancer Detection.

PubMed

Regeling, Bianca; Thies, Boris; Gerstner, Andreas O H; Westermann, Stephan; Müller, Nina A; Bendix, Jörg; Laffers, Wiebke

2016-08-13

Hyperspectral imaging (HSI) is increasingly gaining acceptance in the medical field. Up until now, HSI has been used in conjunction with rigid endoscopy to detect cancer in vivo. The logical next step is to pair HSI with flexible endoscopy, since it improves access to hard-to-reach areas. While the flexible endoscope's fiber optic cables provide the advantage of flexibility, they also introduce an interfering honeycomb-like pattern onto images. Due to the substantial impact this pattern has on locating cancerous tissue, it must be removed before the HS data can be further processed. Thereby, the loss of information is to minimize avoiding the suppression of small-area variations of pixel values. We have developed a system that uses flexible endoscopy to record HS cubes of the larynx and designed a special filtering technique to remove the honeycomb-like pattern with minimal loss of information. We have confirmed its feasibility by comparing it to conventional filtering techniques using an objective metric and by applying unsupervised and supervised classifications to raw and pre-processed HS cubes. Compared to conventional techniques, our method successfully removes the honeycomb-like pattern and considerably improves classification performance, while preserving image details.

A new design concept for knitted external vein-graft support mesh.

PubMed

Singh, Charanpreet; Wang, Xungai

2015-08-01

Autologous vein-graft failure significantly limits the long-term efficacy of coronary artery bypass procedures. The major cause behind this complication is biomechanical mismatch between the vein and coronary artery. The implanted vein experiences a sudden increase (10-12 fold) in luminal pressures. The resulting vein over-distension or 'ballooning' initiates wall thickening phenomenon and ultimate occlusion. Therefore, a primary goal in improving the longevity of a coronary bypass procedure is to inhibit vein over-distension using mechanical constriction. The idea of using an external vein-graft support mesh has demonstrated sustained benefits and wide acceptance in experimental studies. Nitinol based knitted structures have offered more promising mechanical features than other mesh designs owing to their unique loosely looped construction. However, the conventional plain knit construction still exhibits limitations (radial compliance, deployment ease, flexibility, and bending stresses) which limit this design from proving its real clinical advantage. The new knitted mesh design presented in this study is based on the concept of composite knitting utilising high modulus (nitinol and polyester) and low modulus (polyurethane) material components. The experimental comparison of the new design with a plain knit design demonstrated significant improvement in biomechanical (compliance, flexibility, extensibility, viscoelasticity) and procedural (deployment limit) parameters. The results are indicative of the promising role of new mesh in restoring the lost compliance and pulsatility of vein-graft at high arterial pressures. This way it can assist in controlled vein-graft remodelling and stepwise restoration of vein mechanical homoeostasis. Also, improvement in deployment limit parameter offers more flexibility for a surgeon to use a wide range of vein diameters, which may otherwise be rendered unusable for a plain knit mesh. Copyright © 2015 Elsevier Ltd. All rights reserved.

Hardware demonstration of flexible beam control

NASA Technical Reports Server (NTRS)

Schaechter, D. B.

1980-01-01

An experiment employing a pinned-free flexible beam has been constructed to demonstrate and verify several facets of the control of flexible structures. The desired features of the experiment are to demonstrate active shape control, active dynamic control, adaptive control, various control law design approaches, and associated hardware requirements and mechanization difficulties. This paper contains the analytical work performed in support of the facility development, the final design specifications, control law synthesis, and some preliminary results.

Schematic representation of case study research designs.

PubMed

Rosenberg, John P; Yates, Patsy M

2007-11-01

The paper is a report of a study to demonstrate how the use of schematics can provide procedural clarity and promote rigour in the conduct of case study research. Case study research is a methodologically flexible approach to research design that focuses on a particular case - whether an individual, a collective or a phenomenon of interest. It is known as the 'study of the particular' for its thorough investigation of particular, real-life situations and is gaining increased attention in nursing and social research. However, the methodological flexibility it offers can leave the novice researcher uncertain of suitable procedural steps required to ensure methodological rigour. This article provides a real example of a case study research design that utilizes schematic representation drawn from a doctoral study of the integration of health promotion principles and practices into a palliative care organization. The issues discussed are: (1) the definition and application of case study research design; (2) the application of schematics in research; (3) the procedural steps and their contribution to the maintenance of rigour; and (4) the benefits and risks of schematics in case study research. The inclusion of visual representations of design with accompanying explanatory text is recommended in reporting case study research methods.

Highly flexible, freestanding tandem sulfur cathodes for foldable Li–S batteries with a high areal capacity

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

Chang, Chi-Hao; Chung, Sheng-Heng; Manthiram, Arumugam

Li–S batteries with a high theoretical capacity are considered as the most promising candidate to satisfy the increasing demand for batteries with a high areal capacity. However, the low sulfur loading (<2 mg cm -2) and poor flexibility of current Li–S batteries limit their application in establishing foldable Li–S batteries with a high areal capacity. Here, to solve this problem, we employ here a free-standing flexible tandem sulfur cathode with a remarkably high sulfur loading to demonstrate foldable, high-areal-capacity Li–S batteries. The design of the tandem cathode readily increases the sulfur loading and effectively retards the migration of polysulfides. Therefore,more » the Li–S cell employing the tandem cathode exhibits a high initial areal capacity of 12.3 mA h cm -2 with stable cycling stability even with a high sulfur loading of up to 16 mg cm -2. These tandem cathodes are promising for foldable Li–S cells with a high areal capacity and energy density.« less

Markets to Facilitate Wind and Solar Energy Integration in the Bulk Power Supply: An IEA Task 25 Collaboration; Preprint

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

Milligan, M.; Holttinen, H.; Soder, L.

2012-09-01

Wind and solar power will give rise to challenges in electricity markets regarding flexibility, capacity adequacy, and the participation of wind and solar generators to markets. Large amounts of wind power will have impacts on bulk power system markets and electricity prices. If the markets respond to increased wind power by increasing investments in low-capital, high-cost or marginal-cost power, the average price may remain in the same range. However, experiences so far from Denmark, Germany, Spain, and Ireland are such that the average market prices have decreased because of wind power. This reduction may result in additional revenue insufficiency, whichmore » may be corrected with a capacity market, yet capacity markets are difficult to design. However, the flexibility attributes of the capacity also need to be considered. Markets facilitating wind and solar integration will include possibilities for trading close to delivery (either by shorter gate closure times or intraday markets). Time steps chosen for markets can enable more flexibility to be assessed. Experience from 5- and 10-minute markets has been encouraging.« less

Highly flexible, freestanding tandem sulfur cathodes for foldable Li–S batteries with a high areal capacity

DOE PAGES

Chang, Chi-Hao; Chung, Sheng-Heng; Manthiram, Arumugam

2017-01-05

Li–S batteries with a high theoretical capacity are considered as the most promising candidate to satisfy the increasing demand for batteries with a high areal capacity. However, the low sulfur loading (<2 mg cm -2) and poor flexibility of current Li–S batteries limit their application in establishing foldable Li–S batteries with a high areal capacity. Here, to solve this problem, we employ here a free-standing flexible tandem sulfur cathode with a remarkably high sulfur loading to demonstrate foldable, high-areal-capacity Li–S batteries. The design of the tandem cathode readily increases the sulfur loading and effectively retards the migration of polysulfides. Therefore,more » the Li–S cell employing the tandem cathode exhibits a high initial areal capacity of 12.3 mA h cm -2 with stable cycling stability even with a high sulfur loading of up to 16 mg cm -2. These tandem cathodes are promising for foldable Li–S cells with a high areal capacity and energy density.« less

Collection of materials and performance data for Texas flexible pavements and overlays : project summary.

DOT National Transportation Integrated Search

2015-08-31

Proper calibration of mechanistic-empirical : (M-E) design and rehabilitation performance : models to meet Texas conditions is essential : for cost-effective flexible pavement designs. : Such a calibration effort would require a : reliable source of ...

Mechanistic-empirical design, implementation, and monitoring for flexible pavements : a project summary.

DOT National Transportation Integrated Search

2014-05-01

This document is a summary of tasks performed for Project ICT-R27-060. : Mechanistic-empirical (M-E)based flexible pavement design concepts and procedures were : developed in previous Illinois Cooperative Highway Research Program projects (IHR-510...

The Diagnosis of Autism in Community Pediatric Settings: Does Advanced Training Facilitate Practice Change?

ERIC Educational Resources Information Center

Swanson, Amy R.; Warren, Zachary E.; Stone, Wendy L.; Vehorn, Alison C.; Dohrmann, Elizabeth; Humberd, Quentin

2014-01-01

The increased prevalence of autism spectrum disorder and documented benefits of early intensive intervention have created a need for flexible systems for determining eligibility for autism-specific services. This study evaluated the effectiveness of a training program designed to enhance autism spectrum disorder identification and assessment…

Course Management Systems in Higher Education: Understanding Student Experiences

ERIC Educational Resources Information Center

Yuen, Allan; Fox, Robert; Sun, Angie; Deng, Liping

2009-01-01

Purpose: The course management system (CMS), as an evolving tool and innovation, is increasingly used to promote the quality, efficiency and flexibility of teaching and learning in higher education. This paper aims to examine students' experiences of CMSs across faculties at a comprehensive university in Hong Kong. Design/methodology/approach:…

Blended Learning as an Effective Pedagogical Paradigm for Biomedical Science

ERIC Educational Resources Information Center

Hartfield, Perry

2013-01-01

Blended learning combines face-to-face class based and online teaching and learning delivery in order to increase flexibility in how, when, and where students study and learn. The development, integration, and promotion of blended learning in frameworks of curriculum design can optimize the opportunities afforded by information and communication…

Design and Emergence of a Pedagogical Online Infosec Laboratory as an Ensemble Artefact

ERIC Educational Resources Information Center

Iqbal, Sarfraz

2016-01-01

Information security (InfoSec) education becomes increasingly important. Building hands-on capabilities to tackle challenges is a precondition to mitigate and eliminate cyber threats. Existing studies, however, show that the field lacks pedagogically founded information security laboratories that can be used flexibly to educate both on-campus and…

Flexible robotic entry device for a nuclear materials production reactor

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

Heckendorn, F.M. II

1988-01-01

The Savannah River Laboratory has developed and is implementing a flexible robotic entry device (FRED) for the nuclear materials production reactors now operating at the Savannah River Plant (SRP). FRED is designed for rapid deployment into confinement areas of operating reactors to assess unknown conditions. A unique smart tether method has been incorporated into FRED for simultaneous bidirectional transmission of multiple video/audio/control/power signals over a single coaxial cable. This system makes it possible to use FRED under all operating and standby conditions, including those where radio/microwave transmissions are not possible or permitted, and increases the quantity of data available.

Flexibility as a Management Principle in Dementia Care: The Adards Example

ERIC Educational Resources Information Center

Cohen-Mansfield, Jiska; Bester, Allan

2006-01-01

Purpose: Flexibility is an essential ingredient of person-centered care. We illustrate the potential impact of flexibility by portraying a nursing home that uses flexibility in its approach to residents and staff members. Designs and Methods: The paper describes the management strategies, principles, and environmental features used by the Adards…

A Skin-attachable Flexible Piezoelectric Pulse Wave Energy Harvester

NASA Astrophysics Data System (ADS)

Yoon, Sunghyun; Cho, Young-Ho

2014-11-01

We present a flexible piezoelectric generator, capable to harvest energy from human arterial pulse wave on the human wrist. Special features and advantages of the flexible piezoelectric generator include the multi-layer device design with contact windows and the simple fabrication process for the higher flexibility with the better energy harvesting efficiency. We have demonstrated the design effectiveness and the process simplicity of our skin- attachable flexible piezoelectric pulse wave energy harvester, composed of the sensitive P(VDF-TrFE) piezoelectric layer on the flexible polyimide support layer with windows. We experimentally characterize and demonstrate the energy harvesting capability of 0.2~1.0μW in the Human heart rate range on the skin contact area of 3.71cm2. Additional physiological and/or vital signal monitoring devices can be fabricated and integrated on the skin attachable flexible generator, covered by an insulation layer; thus demonstrating the potentials and advantages of the present device for such applications to the flexible multi-functional selfpowered artificial skins, capable to detect physiological and/or vital signals on Human skin using the energy harvested from arterial pulse waves.

Flexible pavement overlay design procedures. Volume 2: User manual

NASA Astrophysics Data System (ADS)

Majidzadeh, K.; Ilves, G. J.

1981-08-01

This user manual outlines a procedure for the design of asphaltic concrete overlays on existing asphaltic concrete pavement surfaces. It is intended as a guide to the user on the type and form of information required as input to the procedure and contains all elements necessary for the user to prepare designs for flexible pavement overlays.

Design and Development of a Flexible Online Course for Making Accessible Online Courses.

ERIC Educational Resources Information Center

Koppi, Tony; Pearson, Elaine

The design rationale for the development of an exemplary, flexible online course for making accessible online courses is described. The authors developed the course by adopting the roles of content expert and instructional designer. The course has a dual purpose. The assessment for postgraduate students provides a guide to learning for academic…

Flexible missile autopilot design studies with PC-MATLAB/386

NASA Technical Reports Server (NTRS)

Ruth, Michael J.

1989-01-01

Development of a responsive, high-bandwidth missile autopilot for airframes which have structural modes of unusually low frequency presents a challenging design task. Such systems are viable candidates for modern, state-space control design methods. The PC-MATLAB interactive software package provides an environment well-suited to the development of candidate linear control laws for flexible missile autopilots. The strengths of MATLAB include: (1) exceptionally high speed (MATLAB's version for 80386-based PC's offers benchmarks approaching minicomputer and mainframe performance); (2) ability to handle large design models of several hundred degrees of freedom, if necessary; and (3) broad extensibility through user-defined functions. To characterize MATLAB capabilities, a simplified design example is presented. This involves interactive definition of an observer-based state-space compensator for a flexible missile autopilot design task. MATLAB capabilities and limitations, in the context of this design task, are then summarized.

Flexible Biomanufacturing Processes that Address the Needs of the Future.

PubMed

Diel, Bernhard; Manzke, Christian; Peuker, Thorsten

2014-01-01

: As the age of the blockbuster drug recedes, the business model for the biopharmaceutical industry is evolving at an ever-increasing pace. The personalization of medicine, the emergence of biosimilars and biobetters, and the need to provide vaccines globally are just some of the factors forcing biomanufacturers to rethink how future manufacturing capability is implemented. One thing is clear: the traditional manufacturing strategy of constructing large-scale, purpose-built, capital-intensive facilities will no longer meet the industry's emerging production and economic requirements. Therefore, the authors of this chapter describe the new approach for designing and implementing flexible production processes for monoclonal antibodies and focus on the points to consider as well as the lessons learned from past experience in engineering such systems. A conceptual integrated design is presented that can be used as a blueprint for next-generation biomanufacturing facilities. In addition, this chapter discusses the benefits of the new approach with respect to flexibility, cost, and schedule. The concept presented here can be applied to other biopharmaceutical manufacturing processes and facilities, including-but not limited to-vaccine manufacturing, multiproduct and/or multiprocess capability, clinical manufacturing, and so on.

Animation of multi-flexible body systems and its use in control system design

NASA Technical Reports Server (NTRS)

Juengst, Carl; Stahlberg, Ron

1993-01-01

Animation can greatly assist the structural dynamicist and control system analyst with better understanding of how multi-flexible body systems behave. For multi-flexible body systems, the structural characteristics (mode frequencies, mode shapes, and damping) change, sometimes dramatically with large angles of rotation between bodies. With computer animation, the analyst can visualize these changes and how the system responds to active control forces and torques. A characterization of the type of system we wish to animate is presented. The lack of clear understanding of the above effects was a key element leading to the development of a multi-flexible body animation software package. The resulting animation software is described in some detail here, followed by its application to the control system analyst. Other applications of this software can be determined on an individual need basis. A number of software products are currently available that make the high-speed rendering of rigid body mechanical system simulation possible. However, such options are not available for use in rendering flexible body mechanical system simulations. The desire for a high-speed flexible body visualization tool led to the development of the Flexible Or Rigid Mechanical System (FORMS) software. This software was developed at the Center for Simulation and Design Optimization of Mechanical Systems at the University of Iowa. FORMS provides interactive high-speed rendering of flexible and/or rigid body mechanical system simulations, and combines geometry and motion information to produce animated output. FORMS is designed to be both portable and flexible, and supports a number of different user interfaces and graphical display devices. Additional features have been added to FORMS that allow special visualization results related to the nature of the flexible body geometric representations.

Mechanistic-Empirical (M-E) Design Implementation & Monitoring for Flexible Pavements : 2018 PROJECT SUMMARY

DOT National Transportation Integrated Search

2018-06-01

This document is a summary of the tasks performed for Project ICT-R27-149-1. Mechanistic-empirical (M-E)based flexible pavement design concepts and procedures were previously developed in Illinois Cooperative Highway Research Program projects IHR-...

Flexible Pay Programs for the 1990s and Beyond.

ERIC Educational Resources Information Center

Clark, Maureen; Luthman, Elmer

1988-01-01

Collaboration of faculty and staff with administration to design flexible total compensation programs that can be "customized" to their particular needs is discussed. The implementation of the Ford Motor Company's Employee Involvement Program when designing the Taurus automobile is described. (MLW)

Bimorph material/structure designs for high sensitivity flexible surface acoustic wave temperature sensors.

PubMed

Tao, R; Hasan, S A; Wang, H Z; Zhou, J; Luo, J T; McHale, G; Gibson, D; Canyelles-Pericas, P; Cooke, M D; Wood, D; Liu, Y; Wu, Q; Ng, W P; Franke, T; Fu, Y Q

2018-06-13

A fundamental challenge for surface acoustic wave (SAW) temperature sensors is the detection of small temperature changes on non-planar, often curved, surfaces. In this work, we present a new design methodology for SAW devices based on flexible substrate and bimorph material/structures, which can maximize the temperature coefficient of frequency (TCF). We performed finite element analysis simulations and obtained theoretical TCF values for SAW sensors made of ZnO thin films (~5 μm thick) coated aluminum (Al) foil and Al plate substrates with thicknesses varied from 1 to 1600 μm. Based on the simulation results, SAW devices with selected Al foil or plate thicknesses were fabricated. The experimentally measured TCF values were in excellent agreements with the simulation results. A normalized wavelength parameter (e.g., the ratio between wavelength and sample thickness, λ/h) was applied to successfully describe changes in the TCF values, and the TCF readings of the ZnO/Al SAW devices showed dramatic increases when the normalized wavelength λ/h was larger than 1. Using this design approach, we obtained the highest reported TCF value of -760 ppm/K for a SAW device made of ZnO thin film coated on Al foils (50 μm thick), thereby enabling low cost temperature sensor applications to be realized on flexible substrates.

Characterizing DNA Star-Tile-Based Nanostructures Using a Coarse-Grained Model.

PubMed

Schreck, John S; Romano, Flavio; Zimmer, Matthew H; Louis, Ard A; Doye, Jonathan P K

2016-04-26

We use oxDNA, a coarse-grained model of DNA at the nucleotide level, to simulate large nanoprisms that are composed of multi-arm star tiles, in which the size of bulge loops that have been incorporated into the tile design is used to control the flexibility of the tiles. The oxDNA model predicts equilibrium structures for several different nanoprism designs that are in excellent agreement with the experimental structures as measured by cryoTEM. In particular we reproduce the chiral twisting of the top and bottom faces of the nanoprisms, as the bulge sizes in these structures are varied due to the greater flexibility of larger bulges. We are also able to follow how the properties of the star tiles evolve as the prisms are assembled. Individual star tiles are very flexible, but their structures become increasingly well-defined and rigid as they are incorporated into larger assemblies. oxDNA also finds that the experimentally observed prisms are more stable than their inverted counterparts, but interestingly this preference for the arms of the tiles to bend in a given direction only emerges after they are part of larger assemblies. These results show the potential for oxDNA to provide detailed structural insight as well as to predict the properties of DNA nanostructures and hence to aid rational design in DNA nanotechnology.

Fault Accommodation in Control of Flexible Systems

NASA Technical Reports Server (NTRS)

Maghami, Peiman G.; Sparks, Dean W., Jr.; Lim, Kyong B.

1998-01-01

New synthesis techniques for the design of fault accommodating controllers for flexible systems are developed. Three robust control design strategies, static dissipative, dynamic dissipative and mu-synthesis, are used in the approach. The approach provides techniques for designing controllers that maximize, in some sense, the tolerance of the closed-loop system against faults in actuators and sensors, while guaranteeing performance robustness at a specified performance level, measured in terms of the proximity of the closed-loop poles to the imaginary axis (the degree of stability). For dissipative control designs, nonlinear programming is employed to synthesize the controllers, whereas in mu-synthesis, the traditional D-K iteration is used. To demonstrate the feasibility of the proposed techniques, they are applied to the control design of a structural model of a flexible laboratory test structure.

Synthesis of Cross-Linked Polymeric Micelle pH Nanosensors: An Investigation of Design Flexibility.

PubMed

Kumar, E K Pramod; Jølck, Rasmus I; Andresen, Thomas L

2015-09-01

The design flexibility that polymeric micelles offer in the fabrication of optical nanosensors for ratiometric pH measurements is investigated. pH nanosensors based on polymeric micelles are synthesized either by a mixed-micellization approach or by a postmicelle modification strategy. In the mixed-micellization approach, self-assembly of functionalized unimers followed by shell cross-linking by copper-catalyzed azide-alkyne cycloaddition (CuAAC) results in stabilized cRGD-functionalized micelle pH nanosensors. In the postmicelle modification strategy, simultaneous cross-linking and fluorophore conjugation at the micelle shell using CuAAC results in a stabilized micelle pH nanosensor. Compared to the postmicelle modification strategy, the mixed-micellization approach increases the control of the overall composition of the nanosensors. Both approaches provide stable nanosensors with similar pKa profiles and thereby nanosensors with similar pH sensitivity. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Making a mixed-model line more efficient and flexible by introducing a bypass line

NASA Astrophysics Data System (ADS)

Matsuura, Sho; Matsuura, Haruki; Asada, Akiko

2017-04-01

This paper provides a design procedure for the bypass subline in a mixed-model assembly line. The bypass subline is installed to reduce the effect of the large difference in operation times among products assembled together in a mixed-model line. The importance of the bypass subline has been increasing in association with the rising necessity for efficiency and flexibility in modern manufacturing. The main topics of this paper are as follows: 1) the conditions in which the bypass subline effectively functions, and 2) how the load should be distributed between the main line and the bypass subline, depending on production conditions such as degree of difference in operation times among products and the mixing ratio of products. To address these issues, we analyzed the lower and the upper bounds of the line length. Based on the results, a design procedure and a numerical example are demonstrated.

Antibacterial Activity Affected by the Conformational Flexibility in Glycine-Lysine Based α-Helical Antimicrobial Peptides.

PubMed

Rončević, Tomislav; Vukičević, Damir; Ilić, Nada; Krce, Lucija; Gajski, Goran; Tonkić, Marija; Goić-Barišić, Ivana; Zoranić, Larisa; Sonavane, Yogesh; Benincasa, Monica; Juretić, Davor; Maravić, Ana; Tossi, Alessandro

2018-04-12

Antimicrobial peptides often show broad-spectrum activity due to a mechanism based on bacterial membrane disruption, which also reduces development of permanent resistance, a desirable characteristic in view of the escalating multidrug resistance problem. Host cell toxicity however requires design of artificial variants of natural AMPs to increase selectivity and reduce side effects. Kiadins were designed using rules obtained from natural peptides active against E. coli and a validated computational algorithm based on a training set of such peptides, followed by rational conformational alterations. In vitro activity, tested against ESKAPE strains (ATCC and clinical isolates), revealed a varied activity spectrum and cytotoxicity that only in part correlated with conformational flexibility. Peptides with a higher proportion of Gly were generally less potent and caused less bacterial membrane alteration, as observed by flow cytometry and AFM, which correlate to structural characteristics as observed by circular dichroism spectroscopy and predicted by molecular dynamics calculations.

AutoDockFR: Advances in Protein-Ligand Docking with Explicitly Specified Binding Site Flexibility

PubMed Central

Ravindranath, Pradeep Anand; Forli, Stefano; Goodsell, David S.; Olson, Arthur J.; Sanner, Michel F.

2015-01-01

Automated docking of drug-like molecules into receptors is an essential tool in structure-based drug design. While modeling receptor flexibility is important for correctly predicting ligand binding, it still remains challenging. This work focuses on an approach in which receptor flexibility is modeled by explicitly specifying a set of receptor side-chains a-priori. The challenges of this approach include the: 1) exponential growth of the search space, demanding more efficient search methods; and 2) increased number of false positives, calling for scoring functions tailored for flexible receptor docking. We present AutoDockFR–AutoDock for Flexible Receptors (ADFR), a new docking engine based on the AutoDock4 scoring function, which addresses the aforementioned challenges with a new Genetic Algorithm (GA) and customized scoring function. We validate ADFR using the Astex Diverse Set, demonstrating an increase in efficiency and reliability of its GA over the one implemented in AutoDock4. We demonstrate greatly increased success rates when cross-docking ligands into apo receptors that require side-chain conformational changes for ligand binding. These cross-docking experiments are based on two datasets: 1) SEQ17 –a receptor diversity set containing 17 pairs of apo-holo structures; and 2) CDK2 –a ligand diversity set composed of one CDK2 apo structure and 52 known bound inhibitors. We show that, when cross-docking ligands into the apo conformation of the receptors with up to 14 flexible side-chains, ADFR reports more correctly cross-docked ligands than AutoDock Vina on both datasets with solutions found for 70.6% vs. 35.3% systems on SEQ17, and 76.9% vs. 61.5% on CDK2. ADFR also outperforms AutoDock Vina in number of top ranking solutions on both datasets. Furthermore, we show that correctly docked CDK2 complexes re-create on average 79.8% of all pairwise atomic interactions between the ligand and moving receptor atoms in the holo complexes. Finally, we show that down-weighting the receptor internal energy improves the ranking of correctly docked poses and that runtime for AutoDockFR scales linearly when side-chain flexibility is added. PMID:26629955

Peer 2 peer: efficacy of a course-based peer education intervention to increase physical activity among college students.

PubMed

Boyle, Jennifer; Mattern, Craig O; Lassiter, Jill W; Ritzler, Julia A

2011-01-01

There are few physical activity (PA) interventions in higher education, and they have been only minimally effective. To determine if a course-based, peer education intervention was associated with increases in PA and physical fitness. Participants were 178 students enrolled in a personal health class during the 2007-2008 academic year. A quasi-experimental design was used to assess the effect of the intervention. Repeated measures analysis of covariance was employed to test the impact of the intervention on students' PA, body composition, waist-to-hip ratio, cardiovascular fitness, flexibility, and muscular strength. Women in the treatment group classified as "Inactive" at baseline increased PA, whereas "Inactive" control women had reductions in PA. Women in the treatment group who were "Active" at baseline reduced their waist-to-hip ratio and increased flexibility. There were no differences by treatment group among men. The intervention was effective in improving PA and physical fitness among college women.

Designing flexible engineering systems utilizing embedded architecture options

NASA Astrophysics Data System (ADS)

Pierce, Jeff G.

This dissertation develops and applies an integrated framework for embedding flexibility in an engineered system architecture. Systems are constantly faced with unpredictability in the operational environment, threats from competing systems, obsolescence of technology, and general uncertainty in future system demands. Current systems engineering and risk management practices have focused almost exclusively on mitigating or preventing the negative consequences of uncertainty. This research recognizes that high uncertainty also presents an opportunity to design systems that can flexibly respond to changing requirements and capture additional value throughout the design life. There does not exist however a formalized approach to designing appropriately flexible systems. This research develops a three stage integrated flexibility framework based on the concept of architecture options embedded in the system design. Stage One defines an eight step systems engineering process to identify candidate architecture options. This process encapsulates the operational uncertainty though scenario development, traces new functional requirements to the affected design variables, and clusters the variables most sensitive to change. The resulting clusters can generate insight into the most promising regions in the architecture to embed flexibility in the form of architecture options. Stage Two develops a quantitative option valuation technique, grounded in real options theory, which is able to value embedded architecture options that exhibit variable expiration behavior. Stage Three proposes a portfolio optimization algorithm, for both discrete and continuous options, to select the optimal subset of architecture options, subject to budget and risk constraints. Finally, the feasibility, extensibility and limitations of the framework are assessed by its application to a reconnaissance satellite system development problem. Detailed technical data, performance models, and cost estimates were compiled for the Tactical Imaging Constellation Architecture Study and leveraged to complete a realistic proof-of-concept.

Large planar maneuvers for articulated flexible manipulators

NASA Technical Reports Server (NTRS)

Huang, Jen-Kuang; Yang, Li-Farn

1988-01-01

An articulated flexible manipulator carried on a translational cart is maneuvered by an active controller to perform certain position control tasks. The nonlinear dynamics of the articulated flexible manipulator are derived and a transformation matrix is formulated to localize the nonlinearities within the inertia matrix. Then a feedback linearization scheme is introduced to linearize the dynamic equations for controller design. Through a pole placement technique, a robust controller design is obtained by properly assigning a set of closed-loop desired eigenvalues to meet performance requirements. Numerical simulations for the articulated flexible manipulators are given to demonstrate the feasibility and effectiveness of the proposed position control algorithms.

Optimization of flexible substrate by gradient elastic modulus design for performance improvement of flexible electronic devices

NASA Astrophysics Data System (ADS)

Xia, Minggang; Liang, Chunping; Hu, Ruixue; Cheng, Zhaofang; Liu, Shiru; Zhang, Shengli

2018-05-01

It is imperative and highly desirable to buffer the stress in flexible electronic devices. In this study, we designed and fabricated lamellate poly(dimethylsiloxane) (PDMS) samples with gradient elastic moduli, motivated by the protection of the pomelo pulp by its skin, followed by the measurements of their elastic moduli. We demonstrated that the electrical and fatigue performances of a Ag-nanowire thin film device on the PDMS substrate with a gradient elastic modulus are significantly better than those of a device on a substrate with a monolayer PDMS. This study provides a robust scheme to effectively protect flexible electronic devices.

Time‐efficient and flexible design of optimized multishell HARDI diffusion

PubMed Central

Tournier, J. Donald; Price, Anthony N.; Cordero‐Grande, Lucilio; Hughes, Emer J.; Malik, Shaihan; Steinweg, Johannes; Bastiani, Matteo; Sotiropoulos, Stamatios N.; Jbabdi, Saad; Andersson, Jesper; Edwards, A. David; Hajnal, Joseph V.

2017-01-01

Purpose Advanced diffusion magnetic resonance imaging benefits from collecting as much data as is feasible but is highly sensitive to subject motion and the risk of data loss increases with longer acquisition times. Our purpose was to create a maximally time‐efficient and flexible diffusion acquisition capability with built‐in robustness to partially acquired or interrupted scans. Our framework has been developed for the developing Human Connectome Project, but different application domains are equally possible. Methods Complete flexibility in the sampling of diffusion space combined with free choice of phase‐encode‐direction and the temporal ordering of the sampling scheme was developed taking into account motion robustness, internal consistency, and hardware limits. A split‐diffusion‐gradient preparation, multiband acceleration, and a restart capacity were added. Results The framework was used to explore different parameters choices for the desired high angular resolution diffusion imaging diffusion sampling. For the developing Human Connectome Project, a high‐angular resolution, maximally time‐efficient (20 min) multishell protocol with 300 diffusion‐weighted volumes was acquired in >400 neonates. An optimal design of a high‐resolution (1.2 × 1.2 mm2) two‐shell acquisition with 54 diffusion weighted volumes was obtained using a split‐gradient design. Conclusion The presented framework provides flexibility to generate time‐efficient and motion‐robust diffusion magnetic resonance imaging acquisitions taking into account hardware constraints that might otherwise result in sub‐optimal choices. Magn Reson Med 79:1276–1292, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. PMID:28557055

The effect of tooling design parameters on web-warping in the flexible roll forming of UHSS

NASA Astrophysics Data System (ADS)

Jiao, Jingsi; Rolfe, Bernard; Mendiguren, Joseba; Galdos, Lander; Weiss, Matthias

2013-12-01

To reduce weight and improve passenger safety there is an increased need in the automotive industry to use Ultra High Strength Steels (UHSS) for structural and crash components. However, the application of UHSS is restricted by their limited formability and the difficulty of forming them in conventional processes. An alternative method of manufacturing structural auto body parts from UHSS is the flexible roll forming process which can accommodate materials with high strength and limited ductility in the production of complex and weight-optimised components. However, one major concern in the flexible roll forming is web-warping, which is the height deviation of the profile web area. This paper investigates, using a numerical model, the effect on web-warping with respect to various forming methods. The results demonstrate that different forming methods lead to different amount of web-warping in terms of forming the product with identical geometry.

Development and investigation of flexible polymer neural probe for chronic neural recording

NASA Astrophysics Data System (ADS)

Smith, Courtney; Song, Kyo D.; Yoon, Hargsoon; Kim, Woong-Ki; Zeng, Tao; Sanford, Larry D.

2012-04-01

Neural recording through microelectrodes requires biocompatibility and long term chronic usage. With a potential for various applications and effort to improve the performance of neural recording probes, consideration is taken to the tissue and cellular effects in these device designs. The degeneration of neurons due to brain tissue motion is an issue along with brain tissue inflammation in the insertion of the probes. To account for motion and irritation the material structure of the probes must be improved upon. This research presents the fabrication of neural probes on the microscale utilizing flexible polymers. Polyimide neural probes have been considered possibly to reduce degradation in their variability caused by brain motion. The microfabrication of the polyimide neural probe has an increased flexibility while accounting for biocompatibility and the needs for chronic use. Through microfabrication processes a needle probe is produced and tested for neural recording.

Children's attractiveness, gender, and race biases: a comparison of their strength and generality.

PubMed

Rennels, Jennifer L; Langlois, Judith H

2014-01-01

Although research suggests that facial attractiveness biases significantly affect social development and interactions, these biases are understudied in the developmental literature and are overlooked when designing interventions relative to gender and race. The authors, therefore, compared how much bias 3- to 11-year-olds (N = 102) displayed in the three domains. They also examined whether bias and flexibility (understanding that different social groups can possess similar attributes) were related across domains. Children's attractiveness biases, particularly for girl targets, were as strong as or stronger than gender or race biases. Flexibility, but not bias, was related across domains. Developmental scientists and policy makers should increase efforts toward understanding development of attractiveness biases and determine which methods of teaching flexibility are most successful at reducing bias across domains. © 2014 The Authors. Child Development © 2014 Society for Research in Child Development, Inc.

Open building and flexibility in healthcare: strategies for shaping spaces for social aspects.

PubMed

Capolongo, Stefano; Buffoli, Maddalena; Nachiero, Dario; Tognolo, Chiara; Zanchi, Eleonora; Gola, Marco

2016-01-01

The fast development of technology and medicine influences the functioning of healthcare facilities as health promoter for the society, making the flexibility a fundamental requirement. Among the many ways to ensure adaptability, one that allows change without increasing the building's overall size is the Open Building approach. Starting from the analysis of the State-of-the-Art and many case-studies, eight parameters of evaluation were defined, appraising their relative importance through a weighting system defined with several experts. The resulting evaluation tool establishes in what measure healthcare facilities follow the Open Building principles. The tool is tested to ten case-studies, chosen for their flexible features, in order to determine his effectiveness and to identify projects' weaknesses and strengths. The results suggest that many Open Building's principles are already in use but, only through a good design thinking, it will be possible to guarantee architectures for health adaptable for future social challenges.

Study of design and control of remote manipulators. Modeling manipulator arms with distributed flexibility for design and control

NASA Technical Reports Server (NTRS)

Book, W. J.

1974-01-01

The interactions of control system and distributed flexible structural dynamics is explored for mechanical arms. A modeling process using 4 x 4 transfer matrices is described which permits the closed loop response of many current arm configurations to be evaluated. Root locus, frequency response, modal shapes, and time impulse response have all been obtained from the digital computer implementation of this model, which is oriented to arm design and allows for easy variation of the arm configuration through data cards. The model corresponds with experimentally observed natural frequencies with an average error of less than 5% in the first three flexible modes in the seven cases considered. The model was used to explore the limits imposed by structural flexibility on a nondimensionalized two link arm with one and two joints for planar motion.

A preliminary study of mechanistic approach in pavement design to accommodate climate change effects

NASA Astrophysics Data System (ADS)

Harnaeni, S. R.; Pramesti, F. P.; Budiarto, A.; Setyawan, A.

2018-03-01

Road damage is caused by some factors, including climate changes, overload, and inappropriate procedure for material and development process. Meanwhile, climate change is a phenomenon which cannot be avoided. The effects observed include air temperature rise, sea level rise, rainfall changes, and the intensity of extreme weather phenomena. Previous studies had shown the impacts of climate changes on road damage. Therefore, several measures to anticipate the damage should be considered during the planning and construction in order to reduce the cost of road maintenance. There are three approaches generally applied in the design of flexible pavement thickness, namely mechanistic approach, mechanistic-empirical (ME) approach and empirical approach. The advantages of applying mechanistic approach or mechanistic-empirical (ME) approaches are its efficiency and reliability in the design of flexible pavement thickness as well as its capacity to accommodate climate changes in compared to empirical approach. However, generally, the design of flexible pavement thickness in Indonesia still applies empirical approach. This preliminary study aimed to emphasize the importance of the shifting towards a mechanistic approach in the design of flexible pavement thickness.

Flexible Learning Strategies in First through Fourth-Year Courses

ERIC Educational Resources Information Center

Cassidy, Alice; Fu, Guopeng; Valley, Will; Lomas, Cyprien; Jovel, Eduardo; Riseman, Andrew

2016-01-01

Flexible Learning (FL) is a pedagogical approach allowing for flexibility of time, place, and audience, including but not solely focused on the use of technologies. We describe Flexible Learning as a pedagogical approach in four courses framed by three key themes: 1) objectives and aspects of course design, 2) evaluation and assessment, and 3)…

Inclusion of LCCA in Alaska flexible pavement design software manual.

DOT National Transportation Integrated Search

2012-10-01

Life cycle cost analysis is a key part for selecting materials and techniques that optimize the service life of a pavement in terms of cost and performance. While the Alaska : Flexible Pavement Design software has been in use since 2004, there is no ...

Design Principles for Digital Badges Used in Libraries

ERIC Educational Resources Information Center

Rimland, Emily; Raish, Victoria

2017-01-01

Digital badges give libraries greater flexibility in delivering impactful instruction to students. They serve as flexible, stackable microcredentials that sequence an information literacy experience across the curriculum. Design considerations rooted in learning theory have a foundation through which to drive decisions. Information literacy badges…

A flexible layout design method for passive micromixers.

PubMed

Deng, Yongbo; Liu, Zhenyu; Zhang, Ping; Liu, Yongshun; Gao, Qingyong; Wu, Yihui

2012-10-01

This paper discusses a flexible layout design method of passive micromixers based on the topology optimization of fluidic flows. Being different from the trial and error method, this method obtains the detailed layout of a passive micromixer according to the desired mixing performance by solving a topology optimization problem. Therefore, the dependence on the experience of the designer is weaken, when this method is used to design a passive micromixer with acceptable mixing performance. Several design disciplines for the passive micromixers are considered to demonstrate the flexibility of the layout design method for passive micromixers. These design disciplines include the approximation of the real 3D micromixer, the manufacturing feasibility, the spacial periodic design, and effects of the Péclet number and Reynolds number on the designs obtained by this layout design method. The capability of this design method is validated by several comparisons performed between the obtained layouts and the optimized designs in the recently published literatures, where the values of the mixing measurement is improved up to 40.4% for one cycle of the micromixer.

Flexible high-resolution display systems for the next generation of radiology reading rooms

NASA Astrophysics Data System (ADS)

Caban, Jesus J.; Wood, Bradford J.; Park, Adrian

2007-03-01

A flexible, scalable, high-resolution display system is presented to support the next generation of radiology reading rooms or interventional radiology suites. The project aims to create an environment for radiologists that will simultaneously facilitate image interpretation, analysis, and understanding while lowering visual and cognitive stress. Displays currently in use present radiologists with technical challenges to exploring complex datasets that we seek to address. These include resolution and brightness, display and ambient lighting differences, and degrees of complexity in addition to side-by-side comparison of time-variant and 2D/3D images. We address these issues through a scalable projector-based system that uses our custom-designed geometrical and photometrical calibration process to create a seamless, bright, high-resolution display environment that can reduce the visual fatigue commonly experienced by radiologists. The system we have designed uses an array of casually aligned projectors to cooperatively increase overall resolution and brightness. Images from a set of projectors in their narrowest zoom are combined at a shared projection surface, thus increasing the global "pixels per inch" (PPI) of the display environment. Two primary challenges - geometric calibration and photometric calibration - remained to be resolved before our high-resolution display system could be used in a radiology reading room or procedure suite. In this paper we present a method that accomplishes those calibrations and creates a flexible high-resolution display environment that appears seamless, sharp, and uniform across different devices.

Annular Momentum Control Device (AMCD). Volume 1: Laboratory model development

NASA Technical Reports Server (NTRS)

1975-01-01

The annular momentum control device (AMCD) a thin hoop-like wheel with neither shaft nor spokes is described. The wheel floats in a magnetic field and can be rotated by a segmented motor. Potential advantages of such a wheel are low weight, configuration flexibility, a wheel that stiffens with increased speed, vibration isolation, and increased reliability. The analysis, design, fabrication, and testing is described of the laboratory model of the AMCD.

Kinematic synthesis of adjustable robotic mechanisms

NASA Astrophysics Data System (ADS)

Chuenchom, Thatchai

1993-01-01

Conventional hard automation, such as a linkage-based or a cam-driven system, provides high speed capability and repeatability but not the flexibility required in many industrial applications. The conventional mechanisms, that are typically single-degree-of-freedom systems, are being increasingly replaced by multi-degree-of-freedom multi-actuators driven by logic controllers. Although this new trend in sophistication provides greatly enhanced flexibility, there are many instances where the flexibility needs are exaggerated and the associated complexity is unnecessary. Traditional mechanism-based hard automation, on the other hand, neither can fulfill multi-task requirements nor are cost-effective mainly due to lack of methods and tools to design-in flexibility. This dissertation attempts to bridge this technological gap by developing Adjustable Robotic Mechanisms (ARM's) or 'programmable mechanisms' as a middle ground between high speed hard automation and expensive serial jointed-arm robots. This research introduces the concept of adjustable robotic mechanisms towards cost-effective manufacturing automation. A generalized analytical synthesis technique has been developed to support the computational design of ARM's that lays the theoretical foundation for synthesis of adjustable mechanisms. The synthesis method developed in this dissertation, called generalized adjustable dyad and triad synthesis, advances the well-known Burmester theory in kinematics to a new level. While this method provides planar solutions, a novel patented scheme is utilized for converting prescribed three-dimensional motion specifications into sets of planar projections. This provides an analytical and a computational tool for designing adjustable mechanisms that satisfy multiple sets of three-dimensional motion specifications. Several design issues were addressed, including adjustable parameter identification, branching defect, and mechanical errors. An efficient mathematical scheme for identification of adjustable member was also developed. The analytical synthesis techniques developed in this dissertation were successfully implemented in a graphic-intensive user-friendly computer program. A physical prototype of a general purpose adjustable robotic mechanism has been constructed to serve as a proof-of-concept model.

Flexible Unicast-Based Group Communication for CoAP-Enabled Devices †

PubMed Central

Ishaq, Isam; Hoebeke, Jeroen; Van den Abeele, Floris; Rossey, Jen; Moerman, Ingrid; Demeester, Piet

2014-01-01

Smart embedded objects will become an important part of what is called the Internet of Things. Applications often require concurrent interactions with several of these objects and their resources. Existing solutions have several limitations in terms of reliability, flexibility and manageability of such groups of objects. To overcome these limitations we propose an intermediately level of intelligence to easily manipulate a group of resources across multiple smart objects, building upon the Constrained Application Protocol (CoAP). We describe the design of our solution to create and manipulate a group of CoAP resources using a single client request. Furthermore we introduce the concept of profiles for the created groups. The use of profiles allows the client to specify in more detail how the group should behave. We have implemented our solution and demonstrate that it covers the complete group life-cycle, i.e., creation, validation, flexible usage and deletion. Finally, we quantitatively analyze the performance of our solution and compare it against multicast-based CoAP group communication. The results show that our solution improves reliability and flexibility with a trade-off in increased communication overhead. PMID:24901978

No role of beta receptors in cognitive flexibility: Evidence from a task-switching paradigm in a randomized controlled trial.

PubMed

Steenbergen, L; Sellaro, R; de Rover, M; Hommel, B; Colzato, L S

2015-06-04

There is evidence that noradrenergic coeruleo-cortical projections are involved in different forms of cognitive flexibility. So far, no studies in humans have investigated the involvement of beta receptors on task-switching performance, a well-established measure of cognitive flexibility. The present study investigated whether the administration of propranolol (a central and peripheral beta-adrenergic antagonist) affected switching costs (i.e., the increase of reaction time in task-switching trials relative to task-repetition trials). Sixteen healthy adult human subjects performed a global-local task-switching paradigm in a double-blind, within-subjects design study investigating the effects of 80mg of propranolol hydrochloride (a β1 and β2 adrenergic receptor antagonist) vs. an oral dose of microcrystalline cellulose (placebo pill). The acute administration of propranolol did not affect the size of switching costs compared to the intake of the neutral placebo. Our results, corroborated by Bayesian inference, suggest that beta receptors do not modulate cognitive flexibility as measured by task-switching performance. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

Chemically Integrated Inorganic-Graphene Two-Dimensional Hybrid Materials for Flexible Energy Storage Devices.

PubMed

Peng, Lele; Zhu, Yue; Li, Hongsen; Yu, Guihua

2016-12-01

State-of-the-art energy storage devices are capable of delivering reasonably high energy density (lithium ion batteries) or high power density (supercapacitors). There is an increasing need for these power sources with not only superior electrochemical performance, but also exceptional flexibility. Graphene has come on to the scene and advancements are being made in integration of various electrochemically active compounds onto graphene or its derivatives so as to utilize their flexibility. Many innovative synthesis techniques have led to novel graphene-based hybrid two-dimensional nanostructures. Here, the chemically integrated inorganic-graphene hybrid two-dimensional materials and their applications for energy storage devices are examined. First, the synthesis and characterization of different kinds of inorganic-graphene hybrid nanostructures are summarized, and then the most relevant applications of inorganic-graphene hybrid materials in flexible energy storage devices are reviewed. The general design rules of using graphene-based hybrid 2D materials for energy storage devices and their current limitations and future potential to advance energy storage technologies are also discussed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Seismic response of elevated rectangular water tanks considering soil structure interaction

NASA Astrophysics Data System (ADS)

Visuvasam, J.; Simon, J.; Packiaraj, J. S.; Agarwal, R.; Goyal, L.; Dhingra, V.

2017-11-01

The overhead staged water tanks are susceptible for high lateral forces during earthquakes. Due to which, the failure of beam-columns joints, framing elements and toppling of tanks arise. To avoid such failures, they are analyzed and designed for lateral forced induced by devastating earthquakes assuming the base of the structures are fixed and considering functional needs, response reduction, soil types and severity of ground shaking. In this paper, the flexible base was provided as spring stiffness in order to consider the effect of soil properties on the seismic behaviour of water tanks. A linear time history earthquake analysis was performed using SAP2000. Parametric studies have been carried out based on various types of soils such as soft, medium and hard. The soil stiffness values highly influence the time period and base shear of the structure. The ratios of time period of flexible to fixed base and base shear of flexible to fixed base were observed against capacities of water tank and the overall height of the system. The both responses are found to be increased as the flexibility of soil medium decreases

End-point controller design for an experimental two-link flexible manipulator using convex optimization

NASA Technical Reports Server (NTRS)

Oakley, Celia M.; Barratt, Craig H.

1990-01-01

Recent results in linear controller design are used to design an end-point controller for an experimental two-link flexible manipulator. A nominal 14-state linear-quadratic-Gaussian (LQG) controller was augmented with a 528-tap finite-impulse-response (FIR) filter designed using convex optimization techniques. The resulting 278-state controller produced improved end-point trajectory tracking and disturbance rejection in simulation and experimentally in real time.

Computer aided design environment for the analysis and design of multi-body flexible structures

NASA Technical Reports Server (NTRS)

Ramakrishnan, Jayant V.; Singh, Ramen P.

1989-01-01

A computer aided design environment consisting of the programs NASTRAN, TREETOPS and MATLAB is presented in this paper. With links for data transfer between these programs, the integrated design of multi-body flexible structures is significantly enhanced. The CAD environment is used to model the Space Shuttle/Pinhole Occulater Facility. Then a controller is designed and evaluated in the nonlinear time history sense. Recent enhancements and ongoing research to add more capabilities are also described.

Multiscale Hierarchical Design of a Flexible Piezoresistive Pressure Sensor with High Sensitivity and Wide Linearity Range.

PubMed

Shi, Jidong; Wang, Liu; Dai, Zhaohe; Zhao, Lingyu; Du, Mingde; Li, Hongbian; Fang, Ying

2018-05-30

Flexible piezoresistive pressure sensors have been attracting wide attention for applications in health monitoring and human-machine interfaces because of their simple device structure and easy-readout signals. For practical applications, flexible pressure sensors with both high sensitivity and wide linearity range are highly desirable. Herein, a simple and low-cost method for the fabrication of a flexible piezoresistive pressure sensor with a hierarchical structure over large areas is presented. The piezoresistive pressure sensor consists of arrays of microscale papillae with nanoscale roughness produced by replicating the lotus leaf's surface and spray-coating of graphene ink. Finite element analysis (FEA) shows that the hierarchical structure governs the deformation behavior and pressure distribution at the contact interface, leading to a quick and steady increase in contact area with loads. As a result, the piezoresistive pressure sensor demonstrates a high sensitivity of 1.2 kPa -1 and a wide linearity range from 0 to 25 kPa. The flexible pressure sensor is applied for sensitive monitoring of small vibrations, including wrist pulse and acoustic waves. Moreover, a piezoresistive pressure sensor array is fabricated for mapping the spatial distribution of pressure. These results highlight the potential applications of the flexible piezoresistive pressure sensor for health monitoring and electronic skin. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Flexibility Requirements concerning the Design of Synchronous E-Learning Systems

ERIC Educational Resources Information Center

Jahn, Matthias; Piesche, Claudia; Jablonski, Stefan

2012-01-01

Purpose: Today's requirements concerning successful learning support comprise a variety of application scenarios. Therefore, the development of supporting software preferably aims at modular design. This article discusses requirements regarding flexibility of e-learning systems and presents important principles, which should be met by successful…

Design and performance of an ultra-flexible two-photon microscope for in vivo research.

PubMed

Mayrhofer, Johannes M; Haiss, Florent; Haenni, Dominik; Weber, Stefan; Zuend, Marc; Barrett, Matthew J P; Ferrari, Kim David; Maechler, Philipp; Saab, Aiman S; Stobart, Jillian L; Wyss, Matthias T; Johannssen, Helge; Osswald, Harald; Palmer, Lucy M; Revol, Vincent; Schuh, Claus-Dieter; Urban, Claus; Hall, Andrew; Larkum, Matthew E; Rutz-Innerhofer, Edith; Zeilhofer, Hanns Ulrich; Ziegler, Urs; Weber, Bruno

2015-11-01

We present a cost-effective in vivo two-photon microscope with a highly flexible frontend for in vivo research. Our design ensures fast and reproducible access to the area of interest, including rotation of imaging plane, and maximizes space for auxiliary experimental equipment in the vicinity of the animal. Mechanical flexibility is achieved with large motorized linear stages that move the objective in the X, Y, and Z directions up to 130 mm. 360° rotation of the frontend (rotational freedom for one axis) is achieved with the combination of a motorized high precision bearing and gearing. Additionally, the modular design of the frontend, based on commercially available optomechanical parts, allows straightforward updates to future scanning technologies. The design exceeds the mobility of previous movable microscope designs while maintaining high optical performance.

Design and performance of an ultra-flexible two-photon microscope for in vivo research

PubMed Central

Mayrhofer, Johannes M.; Haiss, Florent; Haenni, Dominik; Weber, Stefan; Zuend, Marc; Barrett, Matthew J. P.; Ferrari, Kim David; Maechler, Philipp; Saab, Aiman S.; Stobart, Jillian L.; Wyss, Matthias T.; Johannssen, Helge; Osswald, Harald; Palmer, Lucy M.; Revol, Vincent; Schuh, Claus-Dieter; Urban, Claus; Hall, Andrew; Larkum, Matthew E.; Rutz-Innerhofer, Edith; Zeilhofer, Hanns Ulrich; Ziegler, Urs; Weber, Bruno

2015-01-01

We present a cost-effective in vivo two-photon microscope with a highly flexible frontend for in vivo research. Our design ensures fast and reproducible access to the area of interest, including rotation of imaging plane, and maximizes space for auxiliary experimental equipment in the vicinity of the animal. Mechanical flexibility is achieved with large motorized linear stages that move the objective in the X, Y, and Z directions up to 130 mm. 360° rotation of the frontend (rotational freedom for one axis) is achieved with the combination of a motorized high precision bearing and gearing. Additionally, the modular design of the frontend, based on commercially available optomechanical parts, allows straightforward updates to future scanning technologies. The design exceeds the mobility of previous movable microscope designs while maintaining high optical performance. PMID:26600989

Systems 2020: Strategic Initiative

DTIC Science & Technology

2010-08-29

research areas that enable agile, assured, efficient, and scalable systems engineering approaches to support the development of these systems. This...To increase development efficiency and ensure flexible solutions in the field, systems engineers need powerful, agile, interoperable, and scalable...design and development will be transformed as a result of Systems 2020, along with complementary enabling acquisition practice improvements initiated in

New Kids on the Block Schedule: Beginning Teachers Face Challenges

ERIC Educational Resources Information Center

Zepeda, Sally J.; Mayers, R. Stewart

2001-01-01

Across the United States, an ever-increasing number of high schools have reevaluated their use of instructional time and have adopted some form of a block schedule. Block scheduling, an innovation grounded in Trump's Flexible Modular Scheduling Design, reorganizes the school day into extended blocks of time, each approximately 70 to 90 minutes.…

Summary of States' Strategies for ESEA Priority Schools. Solutions. Issue No. 6

ERIC Educational Resources Information Center

Perlman, Carole

2013-01-01

By the end of 2013, 42 states and the District of Columbia have been granted flexibility regarding specific requirements of the No Child Left Behind Act of 2001 (NCLB) in exchange for rigorous and comprehensive state-developed plans designed to improve educational outcomes for all students, close achievement gaps, increase equity, and improve the…

Institute for Defense Analysis. Annual Report 1994

DTIC Science & Technology

1994-01-01

activities with engineering and rines in submarine-unique roles. However, we manufacturing development into a single identified a number of other...development efforts. In addition, and mine-laying capabilities, with roughly 25 the panel proposed increasing both the number nations manufacturing ...the engineering concepts and design, and for implementing Synthetic Aperture Radar flexible manufacturing procedures for focal Reconnaissance

Flexible asymmetric supercapacitors with high energy and high power density in aqueous electrolytes

NASA Astrophysics Data System (ADS)

Cheng, Yingwen; Zhang, Hongbo; Lu, Songtao; Varanasi, Chakrapani V.; Liu, Jie

2013-01-01

Supercapacitors with both high energy and high power densities are critical for many practical applications. In this paper, we discuss the design and demonstrate the fabrication of flexible asymmetric supercapacitors based on nanocomposite electrodes of MnO2, activated carbon, carbon nanotubes and graphene. The combined unique properties of each of these components enable highly flexible and mechanically strong films that can serve as electrodes directly without using any current collectors or binders. Using these flexible electrodes and a roll-up approach, asymmetric supercapacitors with 2 V working voltage were successfully fabricated. The fabricated device showed excellent rate capability, with 78% of the original capacitance retained when the scan rate was increased from 2 mV s-1 to 500 mV s-1. Owing to the unique composite structure, these supercapacitors were able to deliver high energy density (24 W h kg-1) under high power density (7.8 kW kg-1) conditions. These features could enable supercapacitor based energy storage systems to be very attractive for a variety of critical applications, such as the power sources in hybrid electric vehicles and the back-up powers for wind and solar energy, where both high energy density and high power density are required.Supercapacitors with both high energy and high power densities are critical for many practical applications. In this paper, we discuss the design and demonstrate the fabrication of flexible asymmetric supercapacitors based on nanocomposite electrodes of MnO2, activated carbon, carbon nanotubes and graphene. The combined unique properties of each of these components enable highly flexible and mechanically strong films that can serve as electrodes directly without using any current collectors or binders. Using these flexible electrodes and a roll-up approach, asymmetric supercapacitors with 2 V working voltage were successfully fabricated. The fabricated device showed excellent rate capability, with 78% of the original capacitance retained when the scan rate was increased from 2 mV s-1 to 500 mV s-1. Owing to the unique composite structure, these supercapacitors were able to deliver high energy density (24 W h kg-1) under high power density (7.8 kW kg-1) conditions. These features could enable supercapacitor based energy storage systems to be very attractive for a variety of critical applications, such as the power sources in hybrid electric vehicles and the back-up powers for wind and solar energy, where both high energy density and high power density are required. Electronic supplementary information (ESI) available. See DOI: 10.1039/c2nr33136e

Self-Mobilization Using a Foam Roller Versus a Roller Massager: Which Is More Effective for Increasing Hamstrings Flexibility?

PubMed

DeBruyne, Danielle M; Dewhurst, Marina M; Fischer, Katelyn M; Wojtanowski, Michael S; Durall, Chris

2017-01-01

Clinical Scenario: Increasing the length of the muscle-tendon unit may prevent musculotendinous injury. Various methods have been proposed to increase muscle-tendon flexibility, including self-mobilization using foam rollers or roller massagers, although the effectiveness of these devices is uncertain. This review was conducted to determine if the use of foam rollers or roller massagers to improve hamstrings flexibility is supported by moderate- to high-quality evidence. Are foam rollers or roller massagers effective for increasing hamstrings flexibility in asymptomatic physically active adults? Summary of Key Findings: The literature was searched for studies on the effects of using foam rollers or roller massagers to increase hamstrings flexibility in asymptomatic physically active adults. Four randomized controlled trials were included; 2 studies provided level 2 or 3 evidence regarding foam rollers and 2 studies provided level 2 or 3 evidence regarding roller massagers. Both roller-massager studies reported increases in hamstrings flexibility after treatment. Data from the foam-roller studies did not demonstrate a statistically significant increase in hamstrings flexibility, but 1 study did demonstrate a strong effect size. Clinical Bottom Line: The reviewed moderate-quality studies support the use of roller massagers but provide limited evidence on the effectiveness of foam rolling to increase hamstrings flexibility in asymptomatic physically active adults. Flexibility gains may be improved by a longer duration of treatment and administration by a trained therapist. Gains appear to decline rapidly postrolling. Neither device has been shown to confer a therapeutic benefit superior to static stretching, and the effectiveness of these devices for preventing injury is unknown. Strength of Recommendation: Grade B evidence supports the use of roller massagers to increase hamstrings flexibility in asymptomatic physically active adults.

A flexible computer aid for conceptual design based on constraint propagation and component-modeling. [of aircraft in three dimensions

NASA Technical Reports Server (NTRS)

Kolb, Mark A.

1988-01-01

The Rubber Airplane program, which combines two symbolic processing techniques with a component-based database of design knowledge, is proposed as a computer aid for conceptual design. Using object-oriented programming, programs are organized around the objects and behavior to be simulated, and using constraint propagation, declarative statements designate mathematical relationships among all the equation variables. It is found that the additional level of organizational structure resulting from the arrangement of the design information in terms of design components provides greater flexibility and convenience.

Grant programs : design features shape flexibility, accountability, and performance information

DOT National Transportation Integrated Search

1998-06-01

Flexible grants--block grants and similar programs that give state or local governments the flexibility to adapt funded activities to fit the state or local context--are an adaptable policy tool and are found in fields from urban transit to community...

Flexible Learning in an Information Society

ERIC Educational Resources Information Center

Khan, Badrul, Ed.

2007-01-01

Flexible Learning in an Information Society uses a flexible learning framework to explain the best ways of creating a meaningful learning environment. This framework consists of eight factors--institutional, management, technological, pedagogical, ethical, interface design, resource support, and evaluation--and a systematic understanding of these…

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.

On the decomposition of synchronous state mechines using sequence invariant state machines

NASA Technical Reports Server (NTRS)

Hebbalalu, K.; Whitaker, S.; Cameron, K.

1992-01-01

This paper presents a few techniques for the decomposition of Synchronous State Machines of medium to large sizes into smaller component machines. The methods are based on the nature of the transitions and sequences of states in the machine and on the number and variety of inputs to the machine. The results of the decomposition, and of using the Sequence Invariant State Machine (SISM) Design Technique for generating the component machines, include great ease and quickness in the design and implementation processes. Furthermore, there is increased flexibility in making modifications to the original design leading to negligible re-design time.

Robotic Scaffolds for Tissue Engineering and Organ Growth

NASA Technical Reports Server (NTRS)

Stoica, Adrian

2011-01-01

The aim of tissue engineering (TE) is to restore tissue and organ functions with minimal host rejection. TE is seen as a future solution to solve the crisis of donor organs for transplant, which faces a shortage expected only to increase in the future. In this innovation, a flexible and configurable scaffold has been conceived that mechanically stresses cells that are seeded on it, stimulating them to increased growth. The influence of mechanical stress/ loading on cell growth has been observed on all forms of cells. For example, for cartilages, studies in animals, tissue explants, and engineered tissue scaffolds have all shown that cartilage cells (chondrocytes) modify their extracellular matrix in response to loading. The chondrocyte EMC production response to dynamics of the physical environment (in vivo cartilage development) illustrates a clear benefit (better growth) when stressed. It has been shown that static and dynamic compression regulates PRG4 biosynthesis by cartilage explants. Mechanical tissue stimulation is beneficial and (flexible) scaffolds with movable components, which are able to induce mechanical stimulation, offer advantages over the fixed, rigid scaffold design. In addition to improved cell growth from physical/mechanical stimulation, additional benefits include the ability to increase in size while preserving shape, or changing shape. By making scaffolds flexible, allowing relative movement between their components, adding sensing (e.g., for detecting response of cells to drug release and to mechanical actions), building controls for drug release and movement, and building even simple algorithms for mapping sensing to action, these structures can actually be made into biocompatible and biodegradable robots. Treating them as robots is a perspective shift that may offer advantages in the design and exploitation of these structures of the future.

Immediate Effects of Proprioceptive Neuromuscular Facilitation Stretching Programs Compared With Passive Stretching Programs for Hamstring Flexibility: A Critically Appraised Topic.

PubMed

Hill, Kristian J; Robinson, Kendall P; Cuchna, Jennifer W; Hoch, Matthew C

2017-11-01

Clinical Scenario: Increasing hamstring flexibility through clinical stretching interventions may be an effective means to prevent hamstring injuries. However the most effective method to increase hamstring flexibility has yet to be determined. For a healthy individual, are proprioceptive neuromuscular facilitation (PNF) stretching programs more effective in immediately improving hamstring flexibility when compared with static stretching programs? Summary of Key Findings: A thorough literature search returned 195 possible studies; 5 studies met the inclusion criteria and were included. Current evidence supports the use of PNF stretching or static stretching programs for increasing hamstring flexibility. However, neither program demonstrated superior effectiveness when examining immediate increases in hamstring flexibility. Clinical Bottom Line: There were consistent findings from multiple low-quality studies that indicate there is no difference in the immediate improvements in hamstring flexibility when comparing PNF stretching programs to static stretching programs in physically active adults. Strength of Recommendation: Grade B evidence exists that PNF and static stretching programs equally increase hamstring flexibility immediately following the stretching program.

Full-Scale Accelerated Testing of Multi-axial Geogrid Stabilized Flexible Pavements

DTIC Science & Technology

2017-06-01

costs and reduced budgets, transportation officials are often tasked with applying innovative solutions to pavement design and construction projects... pavement designers . 1.2 Objective The objective of this effort was to construct and traffic full-scale flexible pavement sections to provide...Development Center (ERDC) constructed the full-scale test section as designed by Tensar under shelter in its Hangar 2 Pavement Test Facility. During

Flexible Ablators: Applications and Arcjet Testing

NASA Technical Reports Server (NTRS)

Arnold, James O.; Venkatapathy, Ethiraj; Beck, Robin A S.; Mcguire, Kathy; Prabhu, Dinesh K.; Gorbunov, Sergey

2011-01-01

Flexible ablators were conceived in 2009 to meet the technology pull for large, human Mars Exploration Class, 23 m diameter hypersonic inflatable aerodynamic decelerators. As described elsewhere, they have been recently undergoing initial technical readiness (TRL) advancement by NASA. The performance limits of flexible ablators in terms of maximum heat rates, pressure and shear remain to be defined. Further, it is hoped that this emerging technology will vastly expand the capability of future NASA missions involving atmospheric entry systems. This paper considers four topics of relevance to flexible ablators: (1) Their potential applications to near/far term human and robotic missions (2) Brief consideration of the balance between heat shield diameter, flexible ablator performance limits, entry vehicle controllability and aft-body shear layer impingement of interest to designers of very large entry vehicles, (3) The approach for developing bonding processes of flexible ablators for use on rigid entry bodies and (4) Design of large arcjet test articles that will enable the testing of flexible ablators in flight-like, combined environments (heat flux, pressure, shear and structural tensile loading). Based on a review of thermal protection system performance requirements for future entry vehicles, it is concluded that flexible ablators have broad applications to conventional, rigid entry body systems and are enabling to large deployable (both inflatable and mechanical) heat shields. Because of the game-changing nature of flexible ablators, it appears that NASA's Office of the Chief Technologist (OCT) will fund a focused, 3-year TRL advancement of the new materials capable of performance in heat fluxes in the range of 200-600 W/sq. cm. This support will enable the manufacture and use of the large-scale arcjet test designs that will be a key element of this OCT funded activity.

Novel metamaterial based antennas for flexible wireless systems

NASA Astrophysics Data System (ADS)

Khaleel, Haider Raad

Recent years have witnessed a great deal of interest from both academia and industry in the field of flexible electronic systems. This research topic tops the pyramid of research priorities requested by many national research agencies. Consistently, flexible electronic systems require the integration of flexible antennas operating in specific frequency bands to provide wireless connectivity which is highly demanded by today's information oriented society. On the other hand, metamaterials have become very popular in the design of contemporary antenna and microwave devices due to their wide range of applications derived from their unique properties which significantly enhances the performance of antennas and RF systems. Accordingly, the integration of metamaterial structures within flexible wireless systems is very beneficial in this growing field of research. A systematic approach to the analysis and design of flexible and conformal antennas and metamaterials is ultimately needed. The research reported in this thesis focuses on developing flexible low profile antennas and metamaterial structures in addition to characterizing their performance when integrated within flexible wireless systems. Three flexible, compact, and extremely low profile (50.8 microm) antennas intended for WLAN, Bluetooth and Ultra Wide Band (UWB) applications are presented. Next, a novel miniaturized Artificial Magnetic Conductor (AMC) and a new technique to enhance the bandwidth of micro-Negative (MNG) metamaterial are reported. Furthermore, the effect of bending on the AMC and MNG metamaterial is investigated in this thesis for the first time. Finally, the findings of this research are utilized in practical applications with specific design constraints including mutual coupling reduction between radiating elements in antenna arrays and MIMO systems and Specific Absorption Rate (SAR) reduction in telemedicine systems.

Measurement of Residual Flexibility for Substructures Having Prominent Flexible Interfaces

NASA Technical Reports Server (NTRS)

Tinker, Michael L.; Bookout, Paul S.

1994-01-01

Verification of a dynamic model of a constrained structure requires a modal survey test of the physical structure and subsequent modification of the model to obtain the best agreement possible with test data. Constrained-boundary or fixed-base testing has historically been the most common approach for verifying constrained mathematical models, since the boundary conditions of the test article are designed to match the actual constraints in service. However, there are difficulties involved with fixed-base testing, in some cases making the approach impractical. It is not possible to conduct a truly fixed-base test due to coupling between the test article and the fixture. In addition, it is often difficult to accurately simulate the actual boundary constraints, and the cost of designing and constructing the fixture may be prohibitive. For use when fixed-base testing proves impractical or undesirable, alternate free-boundary test methods have been investigated, including the residual flexibility technique. The residual flexibility approach has been treated analytically in considerable detail and has had limited frequency response measurements for the method. This concern is well-justified for a number of reasons. First, residual flexibilities are very small numbers, typically on the order of 1.0E-6 in/lb for translational diagonal terms, and orders of magnitude smaller for off-diagonal values. This poses difficulty in obtaining accurate and noise-free measurements, especially for points removed from the excitation source. A second difficulty encountered in residual measurements lies in obtaining a clean residual function in the process of subtracting synthesized modal data from a measured response function. Inaccuracies occur since modes are not subtracted exactly, but only to the accuracy of the curve fits for each mode; these errors are compounded with increasing distance from the excitation point. In this paper, the residual flexibility method is applied to a simple structure in both test and analysis. Measured and predicted residual functions are compared, and regions of poor data in the measured curves are described. It is found that for accurate residual measurements, frequency response functions having prominent stiffness lines in the acceleration/force format are needed. The lack of such stiffness lines increases measurement errors. Interface drive point frequency respose functions for shuttle orbiter payloads exhibit dominant stiffness lines, making the residual test approach a good candidate for payload modal tests when constrained tests are inappropriate. Difficulties in extracting a residual flexibility value from noisy test data are discussed. It is shown that use of a weighted second order least-squares curve fit of the measured residual function allows identification of residual flexibility that compares very well with predictions for the simple structure. This approach also provides an estimate of second order residual mass effects.

Restoration of Muscle Mitochondrial Function and Metabolic Flexibility in Type 2 Diabetes by Exercise Training Is Paralleled by Increased Myocellular Fat Storage and Improved Insulin Sensitivity

PubMed Central

Meex, Ruth C.R.; Schrauwen-Hinderling, Vera B.; Moonen-Kornips, Esther; Schaart, Gert; Mensink, Marco; Phielix, Esther; van de Weijer, Tineke; Sels, Jean-Pierre; Schrauwen, Patrick; Hesselink, Matthijs K.C.

2010-01-01

OBJECTIVE Mitochondrial dysfunction and fat accumulation in skeletal muscle (increased intramyocellular lipid [IMCL]) have been linked to development of type 2 diabetes. We examined whether exercise training could restore mitochondrial function and insulin sensitivity in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS Eighteen male type 2 diabetic and 20 healthy male control subjects of comparable body weight, BMI, age, and Vo2max participated in a 12-week combined progressive training program (three times per week and 45 min per session). In vivo mitochondrial function (assessed via magnetic resonance spectroscopy), insulin sensitivity (clamp), metabolic flexibility (indirect calorimetry), and IMCL content (histochemically) were measured before and after training. RESULTS Mitochondrial function was lower in type 2 diabetic compared with control subjects (P = 0.03), improved by training in control subjects (28% increase; P = 0.02), and restored to control values in type 2 diabetic subjects (48% increase; P < 0.01). Insulin sensitivity tended to improve in control subjects (delta Rd 8% increase; P = 0.08) and improved significantly in type 2 diabetic subjects (delta Rd 63% increase; P < 0.01). Suppression of insulin-stimulated endogenous glucose production improved in both groups (−64%; P < 0.01 in control subjects and −52% in diabetic subjects; P < 0.01). After training, metabolic flexibility in type 2 diabetic subjects was restored (delta respiratory exchange ratio 63% increase; P = 0.01) but was unchanged in control subjects (delta respiratory exchange ratio 7% increase; P = 0.22). Starting with comparable pretraining IMCL levels, training tended to increase IMCL content in type 2 diabetic subjects (27% increase; P = 0.10), especially in type 2 muscle fibers. CONCLUSIONS Exercise training restored in vivo mitochondrial function in type 2 diabetic subjects. Insulin-mediated glucose disposal and metabolic flexibility improved in type 2 diabetic subjects in the face of near–significantly increased IMCL content. This indicates that increased capacity to store IMCL and restoration of improved mitochondrial function contribute to improved muscle insulin sensitivity. PMID:20028948

Experimental verification of a model of a two-link flexible, lightweight manipulator. M.S. Thesis

NASA Technical Reports Server (NTRS)

Huggins, James David

1988-01-01

Experimental verification is presented for an assumed modes model of a large, two link, flexible manipulator design and constructed in the School of Mechanical Engineering at Georgia Institute of Technology. The structure was designed to have typical characteristics of a lightweight manipulator.

Flexible-Wing-Based Micro Air Vehicles

NASA Technical Reports Server (NTRS)

Ifju, Peter G.; Jenkins, David A.; Ettinger, Scott; Lian, Yong-Sheng; Shyy, Wei; Waszak, Martin R.

2002-01-01

This paper documents the development and evaluation of an original flexible-wing-based Micro Air Vehicle (MAV) technology that reduces adverse effects of gusty wind conditions and unsteady aerodynamics, exhibits desirable flight stability, and enhances structural durability. The flexible wing concept has been demonstrated on aircraft with wingspans ranging from 18 inches to 5 inches. Salient features of the flexible-wing-based MAV, including the vehicle concept, flexible wing design, novel fabrication methods, aerodynamic assessment, and flight data analysis are presented.

Design and development an insect-inspired humanoid gripper that is structurally sound, yet very flexible

NASA Astrophysics Data System (ADS)

Hajjaj, S.; Pun, N.

2013-06-01

One of the biggest challenges in mechanical robotics design is the balance between structural integrity and flexibility. An industrial robotic gripper could be technically advanced, however it contains only 1 Degree of Freedom (DOF). If one is to add more DOFs the design would become complex. On the other hand, the human wrist and fingers contain 23 DOFs, and is very lightweight and highly flexible. Robotics are becoming more and more part of our social life, they are more and more being incorporated in social, medical, and personal application. Therefore, for such robots to be effective, they need to mimic human performance, both in performance as well as in mechanical design. In this work, a Humanoid Gripper is designed and built to mimic a simplified version of a human wrist and fingers. This is attempted by mimicking insect and human designs of grippes. The main challenge was to insure that the gripper is structurally sound, but at the same time flexible and lightweight. A combination of light weight material and a unique design of finger actuators were applied. The gripper is controlled by a PARALLAX servo controller 28823 (PSCI), which mounted on the assembly itself. At the end, a 6 DOF humanoid gripper made of lightweight material, similar in size to the human arm, and is able to carry a weight of 1 Kg has been designed and built.

Ultramicrowave communications system, phase 2

NASA Technical Reports Server (NTRS)

1980-01-01

Communications system design was completed and reviewed. Minor changes were made in order to make it more cost effective and to increase design flexibility. System design activities identified the techniques and procedures to generate and monitor high data rate test signals. Differential bi-phase demodulation is the proposed method for this system. The mockup and packaging designs were performed, and component layout and interconnection constraints were determined, as well as design drawings for dummy parts of the system. The possibility of adding a low cost option to the transceiver system was studied. The communications program has the advantage that new technology signal processing devices can be readily interfaced with the existing radio frequency subsystem to produce a short range radar.

Digital-flutter-suppression-system investigations for the active flexible wing wind-tunnel model

NASA Technical Reports Server (NTRS)

Perry, Boyd, III; Mukhopadhyay, Vivek; Hoadley, Sherwood Tiffany; Cole, Stanley R.; Buttrill, Carey S.

1990-01-01

Active flutter suppression control laws were designed, implemented, and tested on an aeroelastically-scaled wind-tunnel model in the NASA Langley Transonic Dynamics Tunnel. One of the control laws was successful in stabilizing the model while the dynamic pressure was increased to 24 percent greater than the measured open-loop flutter boundary. Other accomplishments included the design, implementation, and successful operation of a one-of-a-kind digital controller, the design and use of two simulation methods to support the project, and the development and successful use of a methodology for online controller performance evaluation.

Digital-flutter-suppression-system investigations for the active flexible wing wind-tunnel model

NASA Technical Reports Server (NTRS)

Perry, Boyd, III; Mukhopadhyay, Vivek; Hoadley, Sherwood T.; Cole, Stanley R.; Buttrill, Carey S.; Houck, Jacob A.

1990-01-01

Active flutter suppression control laws were designed, implemented, and tested on an aeroelastically-scaled wind tunnel model in the NASA Langley Transonic Dynamics Tunnel. One of the control laws was successful in stabilizing the model while the dynamic pressure was increased to 24 percent greater than the measured open-loop flutter boundary. Other accomplishments included the design, implementation, and successful operation of a one-of-a-kind digital controller, the design and use of two simulation methods to support the project, and the development and successful use of a methodology for on-line controller performance evaluation.

APPLICATIONS OF RESEARCH TO THE PROBLEM OF INSTRUCTIONAL FLEXIBILITY.

ERIC Educational Resources Information Center

SARTAIN, HARRY W.

SELECTED RESEARCH ON THE PROBLEM OF INSTRUCTIONAL FLEXIBILITY IS SURVEYED AND DISCUSSED. BROAD TOPICS OF DISCUSSION ARE DEPARTMENTALIZATION, HOMOGENEOUS SECTIONING, INTERCLASS ABILITY SECTIONING, THE EXTENT OF VARIABILITY IN READING DEVELOPMENT, AND PRACTICES THAT MAY INCREASE FLEXIBILITY. AMONG THOSE PRACTICES TO INCREASE FLEXIBILITY ARE TEAM…

Increasing Flexibility in Energy Code Compliance: Performance Packages

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

Hart, Philip R.; Rosenberg, Michael I.

Energy codes and standards have provided significant increases in building efficiency over the last 38 years, since the first national energy code was published in late 1975. The most commonly used path in energy codes, the prescriptive path, appears to be reaching a point of diminishing returns. As the code matures, the prescriptive path becomes more complicated, and also more restrictive. It is likely that an approach that considers the building as an integrated system will be necessary to achieve the next real gains in building efficiency. Performance code paths are increasing in popularity; however, there remains a significant designmore » team overhead in following the performance path, especially for smaller buildings. This paper focuses on development of one alternative format, prescriptive packages. A method to develop building-specific prescriptive packages is reviewed based on a multiple runs of prototypical building models that are used to develop parametric decision analysis to determines a set of packages with equivalent energy performance. The approach is designed to be cost-effective and flexible for the design team while achieving a desired level of energy efficiency performance. A demonstration of the approach based on mid-sized office buildings with two HVAC system types is shown along with a discussion of potential applicability in the energy code process.« less

OWC with vortex beams in data center networks

NASA Astrophysics Data System (ADS)

Kupferman, Judy; Arnon, Shlomi

2017-10-01

Data centers are a key building block in the rapidly growing area of internet technology. A typical data center has tens of thousands of servers, and communication between them must be flexible and robust. Vortex light beams have orbital angular momentum and can provide a useful and flexible method for optical wireless communication in data centers. Vortex beams can be generated with orbital angular momentum but independent of polarization, and used in a multiplexed system. We propose a multiplexing vortex system to increase the communication capacity using optical wireless communication for data center networks. We then evaluate performance. This paper is intended for use as an engineering guideline for design of vortex multiplexing in data center applications.

Development of Flexible Multilayer Circuits and Cables

NASA Technical Reports Server (NTRS)

Barnes, Kevin N.; Bryant, Robert; Holloway, Nancy; Draughon, Fred

2005-01-01

A continuing program addresses the development of flexible multilayer electronic circuits and associated flexible cables. This development is undertaken to help satisfy aerospace-system-engineering requirements for efficient, lightweight electrical and electronic subsystems that can fit within confined spaces, adhere to complexly shaped surfaces, and can be embedded within composite materials. Heretofore, substrate layers for commercial flexible circuitry have been made from sheets of Kapton (or equivalent) polyimide and have been bonded to copper conductors and to other substrate layers by means of adhesives. The substrates for the present developmental flexible circuitry are made from thin films of a polyimide known as LaRC(TM)-SI. This polyimide is thermoplastic and, therefore, offers the potential to eliminate delamination and the need for adhesives. The development work undertaken thus far includes experiments in the use of several techniques of design and fabrication (including computer-aided design and fabrication) of representative flexible circuits. Anticipated future efforts would focus on multilayer bonding, fabrication of prototypes, and overcoming limitations.

Applying Mass Customization Concepts to Core Courses: Increasing Student-Centered Customization and Enabling Cross-Functional Integration

ERIC Educational Resources Information Center

Wilson, Darryl D.

2011-01-01

This conceptual paper suggests a methodology for increasing student satisfaction in core courses by applying the principle of mass customization to increase student satisfaction. It proposes that customization can be increased by increasing course flexibility along three dimensions: content flexibility, schedule flexibility, and course length…

Impact of back squat training intensity on strength and flexibility of hamstring muscle group.

PubMed

Shariat, Ardalan; Lam, Eddie T C; Shaw, Brandon S; Shaw, Ina; Kargarfard, Mehdi; Sangelaji, Bahram

2017-01-01

True experimental design. The back squat is an integral aspect of any resistance training program to improve athletic performance. It is also used for injury prevention of the lower limbs. The purpose of this study was to examine the effect of back squat training at different intensities on strength and flexibility of the hamstring muscle group (HMG). Twenty-two male recreational bodybuilders with at least two years of experience in resistance training were recruited to participate in a nine-week training program. They were randomly assigned to a heavy back squat group (90-95% of one repetition maximum) or a moderate-intensity back squat group (60-65% of one repetition maximum). The heavy back squat group resulted in a significantly (p < 0.001) increased in one repetition maximum strength but a significant (p < 0.001) reduction in HMG flexibility when compared to their counterparts. The results of the study indicate that while a heavy back squat training program is effective in improving strength, it has an adverse effect on the flexibility of the HMG. The implication of this study is that there is a tradeoff between strength and flexibility and trainers should select the appropriate training protocols for their athletes to maximize athletic performance.

Simulations of Micropumps Based on Tilted Flexible Fibers

NASA Astrophysics Data System (ADS)

Hancock, Matthew; Elabbasi, Nagi; Demirel, Melik

2015-11-01

Pumping liquids at low Reynolds numbers is challenging because of the principle of reversibility. We report here a class of microfluidic pump designs based on tilted flexible structures that combines the concepts of cilia (flexible elastic elements) and rectifiers (e.g., Tesla valves, check valves). We demonstrate proof-of-concept with 2D and 3D fluid-structure interaction (FSI) simulations in COMSOL Multiphysics®of micropumps consisting of a source for oscillatory fluidic motion, e.g. a piston, and a channel lined with tilted flexible rods or sheets to provide rectification. When flow is against the rod tilt direction, the rods bend backward, narrowing the channel and increasing flow resistance; when flow is in the direction of rod tilt, the rods bend forward, widening the channel and decreasing flow resistance. The 2D and 3D simulations involve moving meshes whose quality is maintained by prescribing the mesh displacement on guide surfaces positioned on either side of each flexible structure. The prescribed displacement depends on structure bending and maintains mesh quality even for large deformations. Simulations demonstrate effective pumping even at Reynolds numbers as low as 0.001. Because rod rigidity may be specified independently of Reynolds number, in principle, rod rigidity may be reduced to enable pumping at arbitrarily low Reynolds numbers.

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.

Highly-wrinkled reduced graphene oxide-conductive polymer fibers for flexible fiber-shaped and interdigital-designed supercapacitors

NASA Astrophysics Data System (ADS)

Li, Bo; Cheng, Jianli; Wang, Zhuanpei; Li, Yinchuan; Ni, Wei; Wang, Bin

2018-02-01

Flexible supercapacitors have attracted great interest due to outstanding flexibility and light weight. Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) fibers have the great potential in using as electrodes for flexible supercapacitors due to the good flexibility. However, the reported conductivity and specific capacitance of these PEDOT: PSS fibers are not very high, which limit their electrochemical performances. In this work, composite fibers of reduced graphene oxide(rGO)-PEDOT: PSS with a highly-wrinkled structure on the surface and pores inside are prepared by wet spinning. The fibers with different ratios of graphene to PEDOT:PSS show a distinctly enhanced conductivity up to ca. 590 S·cm-1 and high strength up to ca. 18.4 MPa. Meanwhile, the composite fibers show an improved electrochemical performances, including a high specific areal capacitance of 131 mF cm-2 and high specific areal energy density of 4.55 μWh·cm-2. The flexible supercapacitors including fiber-shaped supercapacitors and interdigital designed supercapacitors not only could work in different bending states without obvious capacitance decay, but also have small leakage current. The interdigital design can further improve the performances of composite fibers with high capacitance and high utilization compared with traditional parallel connected structure.

Biologically Inspired, Anisoptropic Flexible Wing for Optimal Flapping Flight

DTIC Science & Technology

2013-01-31

Anisotropic Flexible Wing for Optimal Flapping Flight FA9550-07-1-0547 Sb. GRANT NUMBER Sc. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Sd. PROJECT NUMBER...anisotropic structural flexibility ; c) Conducted coordinated experimental and computational modeling to determine the roles of aerodynamic loading, wing inertia...and structural flexibility and elasticity; and d) Developed surrogate tools for flapping wing MA V design and optimization. Detailed research

Design of protein switches based on an ensemble model of allostery.

PubMed

Choi, Jay H; Laurent, Abigail H; Hilser, Vincent J; Ostermeier, Marc

2015-04-22

Switchable proteins that can be regulated through exogenous or endogenous inputs have a broad range of biotechnological and biomedical applications. Here we describe the design of switchable enzymes based on an ensemble allosteric model. First, we insert an enzyme domain into an effector-binding domain such that both domains remain functionally intact. Second, we induce the fusion to behave as a switch through the introduction of conditional conformational flexibility designed to increase the conformational entropy of the enzyme domain in a temperature- or pH-dependent fashion. We confirm the switching behaviour in vitro and in vivo. Structural and thermodynamic studies support the hypothesis that switching result from an increase in conformational entropy of the enzyme domain in the absence of effector. These results support the ensemble model of allostery and embody a strategy for the design of protein switches.

Balancing Flexible Constraints and Measurement Precision in Computerized Adaptive Testing

ERIC Educational Resources Information Center

Moyer, Eric L.; Galindo, Jennifer L.; Dodd, Barbara G.

2012-01-01

Managing test specifications--both multiple nonstatistical constraints and flexibly defined constraints--has become an important part of designing item selection procedures for computerized adaptive tests (CATs) in achievement testing. This study compared the effectiveness of three procedures: constrained CAT, flexible modified constrained CAT,…

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

NASA Technical Reports Server (NTRS)

Taylor, Lawrence W., Jr. (Compiler)

1989-01-01

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

Development and Preliminary Testing of a High Precision Long Stroke Slit Change Mechanism for the SPICE Instrument

NASA Technical Reports Server (NTRS)

Paciotti, Gabriel; Humphries, Martin; Rottmeier, Fabrice; Blecha, Luc

2014-01-01

In the frame of ESA's Solar Orbiter scientific mission, Almatech has been selected to design, develop and test the Slit Change Mechanism of the SPICE (SPectral Imaging of the Coronal Environment) instrument. In order to guaranty optical cleanliness level while fulfilling stringent positioning accuracies and repeatability requirements for slit positioning in the optical path of the instrument, a linear guiding system based on a double flexible blade arrangement has been selected. The four different slits to be used for the SPICE instrument resulted in a total stroke of 16.5 mm in this linear slit changer arrangement. The combination of long stroke and high precision positioning requirements has been identified as the main design challenge to be validated through breadboard models testing. This paper presents the development of SPICE's Slit Change Mechanism (SCM) and the two-step validation tests successfully performed on breadboard models of its flexible blade support system. The validation test results have demonstrated the full adequacy of the flexible blade guiding system implemented in SPICE's Slit Change Mechanism in a stand-alone configuration. Further breadboard test results, studying the influence of the compliant connection to the SCM linear actuator on an enhanced flexible guiding system design have shown significant enhancements in the positioning accuracy and repeatability of the selected flexible guiding system. Preliminary evaluation of the linear actuator design, including a detailed tolerance analyses, has shown the suitability of this satellite roller screw based mechanism for the actuation of the tested flexible guiding system and compliant connection. The presented development and preliminary testing of the high-precision long-stroke Slit Change Mechanism for the SPICE Instrument are considered fully successful such that future tests considering the full Slit Change Mechanism can be performed, with the gained confidence, directly on a Qualification Model. The selected linear Slit Change Mechanism design concept, consisting of a flexible guiding system driven by a hermetically sealed linear drive mechanism, is considered validated for the specific application of the SPICE instrument, with great potential for other special applications where contamination and high precision positioning are dominant design drivers.

A Comparative Study of Optimization Algorithms for Engineering Synthesis.

DTIC Science & Technology

1983-03-01

the ADS program demonstrates the flexibility a design engineer would have in selecting an optimization algorithm best suited to solve a particular...demonstrates the flexibility a design engineer would have in selecting an optimization algorithm best suited to solve a particular problem. 4 TABLE OF...algorithm to suit a particular problem. The ADS library of design optimization algorithms was . developed by Vanderplaats in response to the first

Object-Oriented Design for Sparse Direct Solvers

NASA Technical Reports Server (NTRS)

Dobrian, Florin; Kumfert, Gary; Pothen, Alex

1999-01-01

We discuss the object-oriented design of a software package for solving sparse, symmetric systems of equations (positive definite and indefinite) by direct methods. At the highest layers, we decouple data structure classes from algorithmic classes for flexibility. We describe the important structural and algorithmic classes in our design, and discuss the trade-offs we made for high performance. The kernels at the lower layers were optimized by hand. Our results show no performance loss from our object-oriented design, while providing flexibility, case of use, and extensibility over solvers using procedural design.

A practical approach to automate randomized design of experiments for ligand-binding assays.

PubMed

Tsoi, Jennifer; Patel, Vimal; Shih, Judy

2014-03-01

Design of experiments (DOE) is utilized in optimizing ligand-binding assay by modeling factor effects. To reduce the analyst's workload and error inherent with DOE, we propose the integration of automated liquid handlers to perform the randomized designs. A randomized design created from statistical software was imported into custom macro converting the design into a liquid-handler worklist to automate reagent delivery. An optimized assay was transferred to a contract research organization resulting in a successful validation. We developed a practical solution for assay optimization by integrating DOE and automation to increase assay robustness and enable successful method transfer. The flexibility of this process allows it to be applied to a variety of assay designs.

Evolutionary mechanics: new engineering principles for the emergence of flexibility in a dynamic and uncertain world.

PubMed

Whitacre, James M; Rohlfshagen, Philipp; Bender, Axel; Yao, Xin

2012-09-01

Engineered systems are designed to deftly operate under predetermined conditions yet are notoriously fragile when unexpected perturbations arise. In contrast, biological systems operate in a highly flexible manner; learn quickly adequate responses to novel conditions, and evolve new routines and traits to remain competitive under persistent environmental change. A recent theory on the origins of biological flexibility has proposed that degeneracy-the existence of multi-functional components with partially overlapping functions-is a primary determinant of the robustness and adaptability found in evolved systems. While degeneracy's contribution to biological flexibility is well documented, there has been little investigation of degeneracy design principles for achieving flexibility in systems engineering. Actually, the conditions that can lead to degeneracy are routinely eliminated in engineering design. With the planning of transportation vehicle fleets taken as a case study, this article reports evidence that degeneracy improves the robustness and adaptability of a simulated fleet towards unpredicted changes in task requirements without incurring costs to fleet efficiency. We find that degeneracy supports faster rates of design adaptation and ultimately leads to better fleet designs. In investigating the limitations of degeneracy as a design principle, we consider decision-making difficulties that arise from degeneracy's influence on fleet complexity. While global decision-making becomes more challenging, we also find degeneracy accommodates rapid distributed decision-making leading to (near-optimal) robust system performance. Given the range of conditions where favorable short-term and long-term performance outcomes are observed, we propose that degeneracy may fundamentally alter the propensity for adaptation and is useful within different engineering and planning contexts.

Role of framework mutations and antibody flexibility in the evolution of broadly neutralizing antibodies

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

Ovchinnikov, Victor; Louveau, Joy E.; Barton, John P.

Eliciting antibodies that are cross reactive with surface proteins of diverse strains of highly mutable pathogens (e.g., HIV, influenza) could be key for developing effective universal vaccines. Mutations in the framework regions of such broadly neutralizing antibodies (bnAbs) have been reported to play a role in determining their properties. We used molecular dynamics simulations and models of affinity maturation to study specific bnAbs against HIV. Our results suggest that there are different classes of evolutionary lineages for the bnAbs. If germline B cells that initiate affinity maturation have high affinity for the conserved residues of the targeted epitope, framework mutationsmore » increase antibody rigidity as affinity maturation progresses to evolve bnAbs. If the germline B cells exhibit weak/moderate affinity for conserved residues, an initial increase in flexibility via framework mutations may be required for the evolution of bnAbs. Subsequent mutations that increase rigidity result in highly potent bnAbs. Implications of our results for immunogen design are discussed.« less

Role of framework mutations and antibody flexibility in the evolution of broadly neutralizing antibodies

DOE PAGES

Ovchinnikov, Victor; Louveau, Joy E.; Barton, John P.; ...

2018-02-14

Eliciting antibodies that are cross reactive with surface proteins of diverse strains of highly mutable pathogens (e.g., HIV, influenza) could be key for developing effective universal vaccines. Mutations in the framework regions of such broadly neutralizing antibodies (bnAbs) have been reported to play a role in determining their properties. We used molecular dynamics simulations and models of affinity maturation to study specific bnAbs against HIV. Our results suggest that there are different classes of evolutionary lineages for the bnAbs. If germline B cells that initiate affinity maturation have high affinity for the conserved residues of the targeted epitope, framework mutationsmore » increase antibody rigidity as affinity maturation progresses to evolve bnAbs. If the germline B cells exhibit weak/moderate affinity for conserved residues, an initial increase in flexibility via framework mutations may be required for the evolution of bnAbs. Subsequent mutations that increase rigidity result in highly potent bnAbs. Implications of our results for immunogen design are discussed.« less

Role of framework mutations and antibody flexibility in the evolution of broadly neutralizing antibodies

PubMed Central

2018-01-01

Eliciting antibodies that are cross reactive with surface proteins of diverse strains of highly mutable pathogens (e.g., HIV, influenza) could be key for developing effective universal vaccines. Mutations in the framework regions of such broadly neutralizing antibodies (bnAbs) have been reported to play a role in determining their properties. We used molecular dynamics simulations and models of affinity maturation to study specific bnAbs against HIV. Our results suggest that there are different classes of evolutionary lineages for the bnAbs. If germline B cells that initiate affinity maturation have high affinity for the conserved residues of the targeted epitope, framework mutations increase antibody rigidity as affinity maturation progresses to evolve bnAbs. If the germline B cells exhibit weak/moderate affinity for conserved residues, an initial increase in flexibility via framework mutations may be required for the evolution of bnAbs. Subsequent mutations that increase rigidity result in highly potent bnAbs. Implications of our results for immunogen design are discussed. PMID:29442996

Design Flexibility for Uncertain Distributed Generation from Photovoltaics

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

Palmintier, Bryan; Krishnamurthy, Dheepak; Wu, Hongyu

2016-12-12

Uncertainty in the future adoption patterns for distributed energy resources (DERs) introduces a challenge for electric distribution system planning. This paper explores the potential for flexibility in design - also known as real options - to identify design solutions that may never emerge when future DER patterns are treated as deterministic. A test case for storage system design with uncertain distributed generation for solar photovoltaics (DGPV) demonstrates this approach and is used to study sensitivities to a range of techno-economic assumptions.

Incorporating Flexibility in the Design of Repairable Systems - Design of Microgrids

DTIC Science & Technology

2014-01-01

MICROGRIDS Vijitashwa Pandey1 Annette Skowronska1,2...optimization of complex systems such as a microgrid is however, computationally intensive. The problem is exacerbated if we must incorporate...flexibility in terms of allowing the microgrid architecture and its running protocol to change with time. To reduce the computational effort, this paper

Mechanistic-Empirical Pavement Design Guide Flexible Pavement Performance Prediction Models Volume III Field Guide - Calibration and User's Guide for the Mechanistic-Empirical Pavement Design Guide

DOT National Transportation Integrated Search

2007-08-01

The objective of this research study was to develop performance characteristics or variables (e.g., ride quality, rutting, : fatigue cracking, transverse cracking) of flexible pavements in Montana, and to use these characteristics in the : implementa...

The development and use of SPIO Lycra compression bracing in children with neuromotor deficits.

PubMed

Hylton, N; Allen, C

1997-01-01

The use of flexible compression bracing in persons with neuromotor deficits offers improved possibilities for stability and movement control without severely limiting joint movement options. At the Children's Therapy Center in Kent, Washington, this treatment modality has been explored with increasing application in children with moderate to severe cerebral palsy and other neuromotor deficits over the past 6 years, with good success. Significant functional improvements using Neoprene shoulder/trunk/hip Bracing led us to experiment with much lighter compression materials. The stabilizing pressure input orthosis or SPIO bracing system (developed by Cheryl Allen, parent and Chief Designer, and Nancy Hylton, PT) is custom-fitted to the stability, movement control and sensory deficit needs of a specific individual. SPIO bracing developed for a specific child has often become part of a rapidly increasing group of flexible bracing options which appear to provide an improved base of support for functional gains in balance, dynamic stability, general and specific movement control with improved postural and muscle readiness. Both deep sensory and subtle biomechanical factors may account for the functional changes observed. This article discusses the development and current use of flexible compression SPIO bracing in this area.

Stability of hard plates on soft substrates and application to the design of bioinspired segmented armor

NASA Astrophysics Data System (ADS)

Martini, R.; Barthelat, F.

2016-07-01

Flexible natural armors from fish, alligators or armadillo are attracting an increasing amount of attention from their unique and attractive combinations of hardness, flexibility and light weight. In particular, the extreme contrast of stiffness between hard plates and surrounding soft tissues give rise to unusual and attractive mechanisms, which now serve as model for the design of bio-inspired armors. Despite a growing interest in bio-inspired flexible protection, there is little guidelines as to the choice of materials, optimum thickness, size, shape and arrangement for the protective plates. In this work, we focus on a failure mode we recently observed on natural and bio-inspired scaled armors: the unstable tilting of individual scales subjected to off-centered point forces. We first present a series of experiments on this system, followed by a model based on contact mechanics and friction. We condense the result into a single stability diagram which capture the key parameters that govern the onset of plate tilting from a localized force. We found that the stability of individual plates is governed by the location of the point force on the plate, by the friction at the surface of the plate, by the size of the plate and by the stiffness of the substrate. We finally discuss how some of these parameters can be optimized at the design stage to produce bio-inspired protective systems with desired combination of surface hardness, stability and flexural compliance.

Flexible all-solid-state asymmetric supercapacitors based on free-standing carbon nanotube/graphene and Mn3O4 nanoparticle/graphene paper electrodes.

PubMed

Gao, Hongcai; Xiao, Fei; Ching, Chi Bun; Duan, Hongwei

2012-12-01

We report the design of all-solid-state asymmetric supercapacitors based on free-standing carbon nanotube/graphene (CNTG) and Mn(3)O(4) nanoparticles/graphene (MG) paper electrodes with a polymer gel electrolyte of potassium polyacrylate/KCl. The composite paper electrodes with carbon nanotubes or Mn(3)O(4) nanoparticles uniformly intercalated between the graphene nanosheets exhibited excellent mechanical stability, greatly improved active surface areas, and enhanced ion transportation, in comparison with the pristine graphene paper. The combination of the two paper electrodes with the polymer gel electrolyte endowed our asymmetric supercapacitor of CNTG//MG an increased cell voltage of 1.8 V, a stable cycling performance (capacitance retention of 86.0% after 10,000 continuous charge/discharge cycles), more than 2-fold increase of energy density (32.7 Wh/kg) compared with the symmetric supercapacitors, and importantly a distinguished mechanical flexibility.

The development of consistency and flexibility in manual pointing during middle childhood.

PubMed

Golenia, Laura; Schoemaker, Marina M; Otten, Egbert; Tuitert, Inge; Bongers, Raoul M

2018-05-21

Goal-directed actions become truly functional and skilled when they are consistent yet flexible. In manual pointing, end-effector consistency is characterized by the end position of the index fingertip, whereas flexibility in movement execution is captured by the use of abundant arm-joint configurations not affecting the index finger end position. Because adults have been shown to exploit their system's flexibility in challenging conditions, we wondered whether during middle childhood children are already able to exploit motor flexibility when demanded by the situation. We had children aged 5-10 years and adults perform pointing movements in a nonchallenging and challenging condition. Results showed that end-effector errors and flexibility in movement execution decreased with age. Importantly, only the 9-10-year-olds and adults showed increased flexibility in the challenging condition. Thus, while consistency increases and flexibility decreases during mid-childhood development, from the age of nine children appear able to employ more flexibility with increasing task demands. © 2018 Wiley Periodicals, Inc.

A Mixed Methods Program Evaluation on the Effectiveness of a School Redesign Model on Teacher Empowerment and Student Achievement

ERIC Educational Resources Information Center

Costa, Ann Marie

2012-01-01

A recent law in a New England state allowed public schools to operate with increased flexibility and autonomy through the authorization of the creation of Innovation Schools. This project study, a program evaluation using a convergent parallel mixed methods research design, allowed for a comprehensive evaluation of the first Innovation School…

Nanobiotechnology: Cell Membrane-Based Delivery Systems.

PubMed

Zhang, Pengfei; Liu, Gang; Chen, Xiaoyuan

2017-04-01

The increasingly rapid pace of research in the field of bioinspired drug delivery systems is revealing the promise of cell membrane-based nanovesicles for biomedical applications. Those cell membrane-based nanoparticles combine the natural functionalities of cell plasma membranes and the bioengineering flexibility of synthetic nanomaterials, and such versatility provides a means of designing exciting new drug formulations for personalized treatment in future nanomedicine.

49 CFR 178.1050 - Top lift test.

Code of Federal Regulations, 2014 CFR

2014-10-01

... designed to be lifted from the top, there may be no damage to the Flexible Bulk Container or its lifting devices that renders the Flexible Bulk Container unsafe for transport, and no loss of contents. ... permissible gross mass, the load being evenly distributed. (c) Test method. (1) A Flexible Bulk Container must...

49 CFR 178.1050 - Top lift test.

Code of Federal Regulations, 2013 CFR

2013-10-01

... designed to be lifted from the top, there may be no damage to the Flexible Bulk Container or its lifting devices that renders the Flexible Bulk Container unsafe for transport, and no loss of contents. ... permissible gross mass, the load being evenly distributed. (c) Test method. (1) A Flexible Bulk Container must...

Risk-based zoning for urbanizing floodplains.

PubMed

Porse, Erik

2014-01-01

Urban floodplain development brings economic benefits and enhanced flood risks. Rapidly growing cities must often balance the economic benefits and increased risks of floodplain settlement. Planning can provide multiple flood mitigation and environmental benefits by combining traditional structural measures such as levees, increasingly popular landscape and design features (green infrastructure), and non-structural measures such as zoning. Flexibility in both structural and non-structural options, including zoning procedures, can reduce flood risks. This paper presents a linear programming formulation to assess cost-effective urban floodplain development decisions that consider benefits and costs of development along with expected flood damages. It uses a probabilistic approach to identify combinations of land-use allocations (residential and commercial development, flood channels, distributed runoff management) and zoning regulations (development zones in channel) to maximize benefits. The model is applied to a floodplain planning analysis for an urbanizing region in the Baja Sur peninsula of Mexico. The analysis demonstrates how (1) economic benefits drive floodplain development, (2) flexible zoning can improve economic returns, and (3) cities can use landscapes, enhanced by technology and design, to manage floods. The framework can incorporate additional green infrastructure benefits, and bridges typical disciplinary gaps for planning and engineering.

Design and implementation of an automated compound management system in support of lead optimization.

PubMed

Quintero, Catherine; Kariv, Ilona

2009-06-01

To meet the needs of the increasingly rapid and parallelized lead optimization process, a fully integrated local compound storage and liquid handling system was designed and implemented to automate the generation of assay-ready plates directly from newly submitted and cherry-picked compounds. A key feature of the system is the ability to create project- or assay-specific compound-handling methods, which provide flexibility for any combination of plate types, layouts, and plate bar-codes. Project-specific workflows can be created by linking methods for processing new and cherry-picked compounds and control additions to produce a complete compound set for both biological testing and local storage in one uninterrupted workflow. A flexible cherry-pick approach allows for multiple, user-defined strategies to select the most appropriate replicate of a compound for retesting. Examples of custom selection parameters include available volume, compound batch, and number of freeze/thaw cycles. This adaptable and integrated combination of software and hardware provides a basis for reducing cycle time, fully automating compound processing, and ultimately increasing the rate at which accurate, biologically relevant results can be produced for compounds of interest in the lead optimization process.

Flexible Blades for Wind Turbines

NASA Astrophysics Data System (ADS)

Collins, Madeline Carlisle; Macphee, David; Harris, Caleb

2016-11-01

Previous research has shown that windmills with flexible blades are more efficient than those with rigid blades. Flexibility offers passive pitch control, preferable to active pitch control which is costly and requires maintenance. Flexible blades morph such that the blade more closely resembles its design point at part load and over load. The lift-to-drag ratios on individual blades was investigated. A mold was designed and machined from an acrylic slab for the casting of blades with a NACA 0012 cross section. A flexible blade was cast from silicone and a rigid blade was cast from polyurethane. Each of these blades was tested in a wind tunnel, cantilever mounted, spanning the whole test section. The angle of attack was varied by rotating the mount. All tests were performed at the same wind speed. A load cell within the mount measured forces on the blade, from which the lift and drag forces were calculated. The stall point for the flexible blade occurred later than for the rigid blade, which agrees with previous research. Lift-to-drag ratios were larger for the flexible blade at all angles of attack tested. Flexible blades seem to be a viable option for passive pitch control. Future research will include different airfoil cross sections, wind speeds, and blade materials. Funding from NSF REU site Grant EEC 1358991 is greatly appreciated.

Nature-Inspired Structural Materials for Flexible Electronic Devices.

PubMed

Liu, Yaqing; He, Ke; Chen, Geng; Leow, Wan Ru; Chen, Xiaodong

2017-10-25

Exciting advancements have been made in the field of flexible electronic devices in the last two decades and will certainly lead to a revolution in peoples' lives in the future. However, because of the poor sustainability of the active materials in complex stress environments, new requirements have been adopted for the construction of flexible devices. Thus, hierarchical architectures in natural materials, which have developed various environment-adapted structures and materials through natural selection, can serve as guides to solve the limitations of materials and engineering techniques. This review covers the smart designs of structural materials inspired by natural materials and their utility in the construction of flexible devices. First, we summarize structural materials that accommodate mechanical deformations, which is the fundamental requirement for flexible devices to work properly in complex environments. Second, we discuss the functionalities of flexible devices induced by nature-inspired structural materials, including mechanical sensing, energy harvesting, physically interacting, and so on. Finally, we provide a perspective on newly developed structural materials and their potential applications in future flexible devices, as well as frontier strategies for biomimetic functions. These analyses and summaries are valuable for a systematic understanding of structural materials in electronic devices and will serve as inspirations for smart designs in flexible electronics.

Improved design of support for large aperture space lightweight mirror

NASA Astrophysics Data System (ADS)

Wang, Chao; Ruan, Ping; Liu, Qimin

2013-08-01

In order to design a kind of rational large aperture space mirror which can adapt to the space gravity and thermal environment, by taking the choice of material, the lightweight of the mirror and the design of support into account in detail, a double-deck structure with traditional flexible hinge was designed, then the analytical mathematical model of the mirror system was established. The design adopts six supports on back. in order to avoid the constraints, mirror is connected to three middle transition pieces through six flexible hinges, and then the three transition pieces are connected to support plate through another three flexible hinges. However, the initial structure is unable to reach the expected design target and needs to be made further adjustments. By improving and optimizing the original structure, a new type of flexible hinge in the shape of the letter A is designed finally. Compared with the traditional flexible hinge structure, the new structure is simpler and has less influence on the surface figure accuracy of mirror. By using the finite element analysis method, the static and dynamic characteristics as well as the thermal characteristics of the mirror system are analyzed. Analysis results show that the maximum PV value is 37 nm and the maximum RMS value is 10.4 nm when gravity load is applied. Furthermore, the maximum PV value is 46 nm and the maximum RMS value is 10.5 nm under the load case of gravity coupled with 4℃ uniform temperature rise. The results satisfy the index of optical design. The first order natural frequency of the mirror component is 130 Hz according to the conclusion obtained by modal analytical solution, so the mirror structure has high enough fundamental frequency. And, the structural strength can meet the demand under the overload and the random vibration environment respectively. It indicates that the mirror component structure has enough dynamic, static stiffness and thermal stability, meeting the design requirements.

Structural dynamic interaction with solar tracking control for evolutionary Space Station concepts

NASA Technical Reports Server (NTRS)

Lim, Tae W.; Cooper, Paul A.; Ayers, J. Kirk

1992-01-01

The sun tracking control system design of the Solar Alpha Rotary Joint (SARJ) and the interaction of the control system with the flexible structure of Space Station Freedom (SSF) evolutionary concepts are addressed. The significant components of the space station pertaining to the SARJ control are described and the tracking control system design is presented. Finite element models representing two evolutionary concepts, enhanced operations capability (EOC) and extended operations capability (XOC), are employed to evaluate the influence of low frequency flexible structure on the control system design and performance. The design variables of the control system are synthesized using a constrained optimization technique to meet design requirements, to provide a given level of control system stability margin, and to achieve the most responsive tracking performance. The resulting SARJ control system design and performance of the EOC and XOC configurations are presented and compared to those of the SSF configuration. Performance limitations caused by the low frequency of the dominant flexible mode are discussed.

Opportunities and Benefits for Increasing Transmission Capacity between the US Eastern and Western Interconnections

NASA Astrophysics Data System (ADS)

Figueroa-Acevedo, Armando L.

Historically, the primary justification for building wide-area transmission lines in the US and around the world has been based on reliability and economic criteria. Today, the influence of renewable portfolio standards (RPS), Environmental Protection Agency (EPA) regulations, transmission needs, load diversity, and grid flexibility requirements drives interest in high capacity wide-area transmission. By making use of an optimization model to perform long-term (15 years) co-optimized generation and transmission expansion planning, this work explored the benefits of increasing transmission capacity between the US Eastern and Western Interconnections under different policy and futures assumptions. The model assessed tradeoffs between investments in cross-interconnection HVDC transmission, AC transmission needs within each interconnection, generation investment costs, and operational costs, while satisfying different policy compliance constraints. Operational costs were broken down into the following market products: energy, up-/down regulation reserve, and contingency reserve. In addition, the system operating flexibility requirements were modeled as a function of net-load variability so that the flexibility of the non-wind/non-solar resources increases with increased wind and solar investment. In addition, planning reserve constraints are imposed under the condition that they be deliverable to the load. Thus, the model allows existing and candidate generation resources for both operating reserves and deliverable planning reserves to be shared throughout the interconnections, a feature which significantly drives identification of least-cost investments. This model is used with a 169-bus representation of the North American power grid to design four different high-capacity wide-area transmission infrastructures. Results from this analysis suggest that, under policy that imposes a high-renewable future, the benefits of high capacity transmission between the Eastern and Western Interconnections outweigh its cost. A sensitivity analysis is included to test the robustness of each design under different future assumptions and approximate upper and lower bounds for cross-seam transmission between the Eastern and Western Interconnections.

Gains in flexibility related to measures of muscular performance: impact of flexibility on muscular performance.

PubMed

Ferreira, Gustavo Nunes Tasca; Teixeira-Salmela, Luci Fuscaldi; Guimarães, Cristiano Queiroz

2007-07-01

Studies that investigated possible correlations between flexibility and muscular performance are scarce in the literature. Therefore, the purpose of this study was to investigate the impact of a program of static stretching on the flexibility of the hamstrings and on muscular performance of the knee flexors and extensors. Pre-post experimental design. University laboratory. Thirty subjects aged 22.8 +/- 4.9 years with bilaterally shortened hamstrings. Using a protocol that has been previously described, the intervention consisted of 30 sessions of static stretching, performed bilaterally five times a week for 6 weeks. Measures of knee range of motion and isokinetic muscular performance (peak torque, angle of peak torque, and work) of knee flexors and extensors at speeds of 60 and 300 degrees/s. After intervention, significant gains in measures of flexibility (P < 0.0001) were observed, with an average gain of the knee-extension angle of 12.6 degrees, ranging from -1.2 to 30.7 degrees. In addition, we found significant increases in the following parameters of muscular performance: angle of peak torque of hamstrings at 60 and 300 degrees/s (P < 0.0001 and 0.018) and for work at 60 and 300 degrees/s for knee flexors (P = 0.012 and 0.005) and for knee extensors (P < 0.0001). The intervention resulted in gains in measures of flexibility, and these gains had a positive impact on some parameters of muscular performance.

AM OLED using a-Si TFT backplane on flexible plastic substrate

NASA Astrophysics Data System (ADS)

Sarma, Kalluri R.; Schmidt, John; Roush, Jerry; Chanley, Charles; Dodd, Sonia R.

2004-09-01

Amorphous silicon TFT technology continues to show promise for fabricating large area high resolution flexible AM OLED displays. This paper describes the recent progress in the flexible AM OLED development efforts at Honeywell since our publication in this conference's proceedings in 2003, describing the feasibility of fabricating a 64x64 pixel AM OLED on a flexible plastic substrate. In this paper we describe the design, and fabrication of a 160x160(x3) pixel AM OLED on a flexible plastic substrate with an equivalent 80cgpi resolution. Flexibility characteristics of the fabricated displays are discussed. Further advances and improvements required for extending the size and resolution of flexible AM OLED displays are discussed.

A Framework for Reliability and Safety Analysis of Complex Space Missions

NASA Technical Reports Server (NTRS)

Evans, John W.; Groen, Frank; Wang, Lui; Austin, Rebekah; Witulski, Art; Mahadevan, Nagabhushan; Cornford, Steven L.; Feather, Martin S.; Lindsey, Nancy

2017-01-01

Long duration and complex mission scenarios are characteristics of NASA's human exploration of Mars, and will provide unprecedented challenges. Systems reliability and safety will become increasingly demanding and management of uncertainty will be increasingly important. NASA's current pioneering strategy recognizes and relies upon assurance of crew and asset safety. In this regard, flexibility to develop and innovate in the emergence of new design environments and methodologies, encompassing modeling of complex systems, is essential to meet the challenges.

Integral Manifold in System Design with Application to Flexible Link Robot Control

DTIC Science & Technology

1988-06-01

environment. I am very grateful to my advisor . Professor Kokotovic. whose insight and guidance in my research work led me to the beginning of my...MANIFOLD IN SVSTEM DESIGN WITH RPLICATION TT 2Z2 FLEXIBLE LINK ROBO (U) ILLINOIS UNIV AT URBANA DECISION AND CONTROL LAB H C TSENG JUN 98

Design for a Unitary Graphite Composite Instrument Boom

NASA Technical Reports Server (NTRS)

Alexander, Wes; Carlos, Rene; Sturm, James; Rossoni, Peter

2004-01-01

This paper describes development of a Unitary graphite composite instrument boom that incorporates carpenter-tape like hinges for stowage. While light and stiff, graphite composite is not ordinarily thought of as a flexible material. This design has taken advantage of the stiffness of the composite in tubular geometry, yet leveraged its thin- section behavior to place flexibility at the required locations. Key is the proprietary layup, which results in a tough yet flexible hinge capable of rotating over 90 degrees in each direction. When the boom deploys, there is enough torque to overcome parasitic resistance from harness, etc. It will snap to the fully extended, rigid shape. The design has addressed materials issues such as out-of-plane bending, edge cracking, and interlaminar ply separation.

SYFSA: A Framework for Systematic Yet Flexible Systems Analysis

PubMed Central

Johnson, Todd R.; Markowitz, Eliz; Bernstam, Elmer V.; Herskovic, Jorge R.; Thimbleby, Harold

2013-01-01

Although technological or organizational systems that enforce systematic procedures and best practices can lead to improvements in quality, these systems must also be designed to allow users to adapt to the inherent uncertainty, complexity, and variations in healthcare. We present a framework, called Systematic Yet Flexible Systems Analysis (SYFSA) that supports the design and analysis of Systematic Yet Flexible (SYF) systems (whether organizational or technical) by formally considering the tradeoffs between systematicity and flexibility. SYFSA is based on analyzing a task using three related problem spaces: the idealized space, the natural space, and the system space. The idealized space represents the best practice—how the task is to be accomplished under ideal conditions. The natural space captures the task actions and constraints on how the task is currently done. The system space specifies how the task is done in a redesigned system, including how it may deviate from the idealized space, and how the system supports or enforces task constraints. The goal of the framework is to support the design of systems that allow graceful degradation from the idealized space to the natural space. We demonstrate the application of SYFSA for the analysis of a simplified central line insertion task. We also describe several information-theoretic measures of flexibility that can be used to compare alternative designs, and to measure how efficiently a system supports a given task, the relative cognitive workload, and learnability. PMID:23727053

An event-based vibration control for a two-link flexible robotic arm: Numerical and experimental observations

NASA Astrophysics Data System (ADS)

Özer, Abdullah; Eren Semercigil, S.

2008-06-01

Flexible robot manipulators have numerous advantages over their rigid counterparts. They have increased payload-to-weight ratio, they run at higher speeds, use less energy and smaller actuators, and they are safer during interaction with their environments. On the other hand, light design combined with external effects result in components which can oscillate with excessive amplitudes. These oscillations cause deviation from the desired path and long idle periods between tasks in order to perform the intended operation safely and accurately. This paper is on an investigation into the effectiveness of a vibration control technique for a two-link flexible robotic arm. Variable stiffness control (VSC) technique is used to control the excessive oscillations. Owing to its dissipative nature, the technique is stable, it is relatively insensitive to significant parameter changes and suitable to be implemented on existing robots. This research considers that the source of the flexibility is either the joints or the links or both. Simulation results of the response of the arm are presented to show the versatility of the proposed control technique. Experiments are performed on a laboratory prototype and the results are presented to test the validity of simulations.

PeptideDepot: flexible relational database for visual analysis of quantitative proteomic data and integration of existing protein information.

PubMed

Yu, Kebing; Salomon, Arthur R

2009-12-01

Recently, dramatic progress has been achieved in expanding the sensitivity, resolution, mass accuracy, and scan rate of mass spectrometers able to fragment and identify peptides through MS/MS. Unfortunately, this enhanced ability to acquire proteomic data has not been accompanied by a concomitant increase in the availability of flexible tools allowing users to rapidly assimilate, explore, and analyze this data and adapt to various experimental workflows with minimal user intervention. Here we fill this critical gap by providing a flexible relational database called PeptideDepot for organization of expansive proteomic data sets, collation of proteomic data with available protein information resources, and visual comparison of multiple quantitative proteomic experiments. Our software design, built upon the synergistic combination of a MySQL database for safe warehousing of proteomic data with a FileMaker-driven graphical user interface for flexible adaptation to diverse workflows, enables proteomic end-users to directly tailor the presentation of proteomic data to the unique analysis requirements of the individual proteomics lab. PeptideDepot may be deployed as an independent software tool or integrated directly with our high throughput autonomous proteomic pipeline used in the automated acquisition and post-acquisition analysis of proteomic data.

Flexible and polarization-controllable diffusion metasurface with optical transparency

NASA Astrophysics Data System (ADS)

Zhuang, Yaqiang; Wang, Guangming; Liang, Jiangang; Cai, Tong; Guo, Wenlong; Zhang, Qingfeng

2017-11-01

In this paper, a novel coding metasurface is proposed to realize polarization-controllable diffusion scattering. The anisotropic Jerusalem-cross unit cell is employed as the basic coding element due to its polarization-dependent phase response. The isotropic random coding sequence is firstly designed to obtain diffusion scattering, and the anisotropic random coding sequence is subsequently realized by adding different periodic coding sequences to the original isotropic one along different directions. For demonstration, we designed and fabricated a flexible polarization-controllable diffusion metasurface (PCDM) with both chessboard diffusion and hedge diffusion under different polarizations. The specular scattering reduction performance of the anisotropic metasurface is better than the isotropic one because the scattered energies are redirected away from the specular reflection direction. For potential applications, the flexible PCDM wrapped around a cylinder structure is investigated and tested for polarization-controllable diffusion scattering. The numerical and experimental results coincide well, indicating anisotropic low scatterings with comparable performances. This paper provides an alternative approach for designing high-performance, flexible, low-scattering platforms.

Co-Design Method and Wafer-Level Packaging Technique of Thin-Film Flexible Antenna and Silicon CMOS Rectifier Chips for Wireless-Powered Neural Interface Systems.

PubMed

Okabe, Kenji; Jeewan, Horagodage Prabhath; Yamagiwa, Shota; Kawano, Takeshi; Ishida, Makoto; Akita, Ippei

2015-12-16

In this paper, a co-design method and a wafer-level packaging technique of a flexible antenna and a CMOS rectifier chip for use in a small-sized implantable system on the brain surface are proposed. The proposed co-design method optimizes the system architecture, and can help avoid the use of external matching components, resulting in the realization of a small-size system. In addition, the technique employed to assemble a silicon large-scale integration (LSI) chip on the very thin parylene film (5 μm) enables the integration of the rectifier circuits and the flexible antenna (rectenna). In the demonstration of wireless power transmission (WPT), the fabricated flexible rectenna achieved a maximum efficiency of 0.497% with a distance of 3 cm between antennas. In addition, WPT with radio waves allows a misalignment of 185% against antenna size, implying that the misalignment has a less effect on the WPT characteristics compared with electromagnetic induction.

Co-Design Method and Wafer-Level Packaging Technique of Thin-Film Flexible Antenna and Silicon CMOS Rectifier Chips for Wireless-Powered Neural Interface Systems

PubMed Central

Okabe, Kenji; Jeewan, Horagodage Prabhath; Yamagiwa, Shota; Kawano, Takeshi; Ishida, Makoto; Akita, Ippei

2015-01-01

In this paper, a co-design method and a wafer-level packaging technique of a flexible antenna and a CMOS rectifier chip for use in a small-sized implantable system on the brain surface are proposed. The proposed co-design method optimizes the system architecture, and can help avoid the use of external matching components, resulting in the realization of a small-size system. In addition, the technique employed to assemble a silicon large-scale integration (LSI) chip on the very thin parylene film (5 μm) enables the integration of the rectifier circuits and the flexible antenna (rectenna). In the demonstration of wireless power transmission (WPT), the fabricated flexible rectenna achieved a maximum efficiency of 0.497% with a distance of 3 cm between antennas. In addition, WPT with radio waves allows a misalignment of 185% against antenna size, implying that the misalignment has a less effect on the WPT characteristics compared with electromagnetic induction. PMID:26694407

UK Health and Social Care Case Studies: Iterative Technology Development.

PubMed

Blanchard, Adie; Gilbert, Laura; Dawson, Tom

2017-01-01

As a result of increasing demand in the face of reducing resources, technology has been implemented in many social and health care services to improve service efficiency. This paper outlines the experiences of deploying a 'Software as a Service' application in the UK social and health care sectors. The case studies demonstrate that every implementation is different, and unique to each organisation. Technology design and integration can be facilitated by ongoing engagement and collaboration with all stakeholders, flexible design, and attention to interoperability to suit services and their workflows.

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

Yang, C.

Almost every computer architect dreams of achieving high system performance with low implementation costs. A multigauge machine can reconfigure its data-path width, provide parallelism, achieve better resource utilization, and sometimes can trade computational precision for increased speed. A simple experimental method is used here to capture the main characteristics of multigauging. The measurements indicate evidence of near-optimal speedups. Adapting these ideas in designing parallel processors incurs low costs and provides flexibility. Several operational aspects of designing a multigauge machine are discussed as well. Thus, this research reports the technical, economical, and operational feasibility studies of multigauging.

The New BaBar Data Reconstruction Control System

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

Ceseracciu, Antonio

2003-06-02

The BaBar experiment is characterized by extremely high luminosity, a complex detector, and a huge data volume, with increasing requirements each year. To fulfill these requirements a new control system has been designed and developed for the offline data reconstruction system. The new control system described in this paper provides the performance and flexibility needed to manage a large number of small computing farms, and takes full benefit of OO design. The infrastructure is well isolated from the processing layer, it is generic and flexible, based on a light framework providing message passing and cooperative multitasking. The system is activelymore » distributed, enforces the separation between different processing tiers by using different naming domains, and glues them together by dedicated brokers. It provides a powerful Finite State Machine framework to describe custom processing models in a simple regular language. This paper describes this new control system, currently in use at SLAC and Padova on {approx}450 CPUs organized in 12 farms.« less

2007 Precision Strike Annual Programs Review

DTIC Science & Technology

2007-04-25

Adapting our methods • Remaining a flexible combined-arms force • Enabling a generation of combat- experienced decision-makers by distributing...Sustain Propulsion Network RadioMEMS IMU Flexible Engagement Options Requirements Capabilities Precision Attack Missile (PAM) 67” (with Canister...Aimpoint 6 PAM Seeker Modes PAM’s Multiple Targeting Modes Increase Flexibility , Improve Lethality PAM’s Multiple Targeting Modes Increase Flexibility

Flexibly Applying the Distributive Law--Students' Individual Ways of Perceiving the Distributive Property

ERIC Educational Resources Information Center

Schueler-Meyer, Alexander

2016-01-01

Flexibility in transforming algebraic expressions is recognized as fundamental for a rich procedural knowledge. Here, flexibility in-depth is proposed as the ability to apply one strategy to a wide range of unfamiliar expressions. In this study, design experiments with four groups of students were conducted to support students' flexibility…

The effect of tooling design parameters on web-warping in the flexible roll forming of UHSS

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

Jiao, Jingsi; Weiss, Matthias; Rolfe, Bernard

To reduce weight and improve passenger safety there is an increased need in the automotive industry to use Ultra High Strength Steels (UHSS) for structural and crash components. However, the application of UHSS is restricted by their limited formability and the difficulty of forming them in conventional processes. An alternative method of manufacturing structural auto body parts from UHSS is the flexible roll forming process which can accommodate materials with high strength and limited ductility in the production of complex and weight-optimised components. However, one major concern in the flexible roll forming is web-warping, which is the height deviation ofmore » the profile web area. This paper investigates, using a numerical model, the effect on web-warping with respect to various forming methods. The results demonstrate that different forming methods lead to different amount of web-warping in terms of forming the product with identical geometry.« less

Advanced shape tracking to improve flexible endoscopic diagnostics

NASA Astrophysics Data System (ADS)

Cao, Caroline G. L.; Wong, Peter Y.; Lilge, Lothar; Gavalis, Robb M.; Xing, Hua; Zamarripa, Nate

2008-03-01

Colonoscopy is the gold standard for screening for inflammatory bowel disease and colorectal cancer. Flexible endoscopes are difficult to manipulate, especially in the distensible and tortuous colon, sometimes leading to disorientation during the procedure and missed diagnosis of lesions. Our goal is to design a navigational aid to guide colonoscopies, presenting a three dimensional representation of the endoscope in real-time. Therefore, a flexible sensor that can track the position and shape of the entire length of the endoscope is needed. We describe a novel shape-tracking technology utilizing a single modified optical fiber. By embedding fluorophores in the buffer of the fiber, we demonstrated a relationship between fluorescence intensity and fiber curvature. As much as a 40% increase in fluorescence intensity was achieved when the fiber's local bend radius decreased from 58 mm to 11 mm. This approach allows for the construction of a three-dimensional shape tracker that is small enough to be easily inserted into the biopsy channel of current endoscopes.

Highly adhesive and high fatigue-resistant copper/PET flexible electronic substrates

NASA Astrophysics Data System (ADS)

Park, Sang Jin; Ko, Tae-Jun; Yoon, Juil; Moon, Myoung-Woon; Oh, Kyu Hwan; Han, Jun Hyun

2018-01-01

A voidless Cu/PET substrate is fabricated by producing a superhydrophilic PET surface comprised of nanostructures with large width and height and then by Cu electroless plating. Effect of PET surface nanostructure size on the failure mechanism of the Cu/PET substrate is studied. The fabricated Cu/PET substrate exhibits a maximum peel strength of 1300 N m-1 without using an interlayer, and virtually no increase in electrical resistivity under the extreme cyclic bending condition of 1 mm curvature radius after 300 k cycles. The authors find that there is an optimum nanostructure size for the highest Cu/PET adhesion strength, and the failure mechanism of the Cu/PET flexible substrate depends on the PET surface nanostructure size. Thus, this work presents the possibility to produce flexible metal/polymer electronic substrates that have excellent interfacial adhesion between the metal and polymer and high fatigue resistance against repeated bending. Such metal/polymer substrates provides new design opportunities for wearable electronic devices that can withstand harsh environments and have extended lifetimes.

Wearable woven supercapacitor fabrics with high energy density and load-bearing capability.

PubMed

Shen, Caiwei; Xie, Yingxi; Zhu, Bingquan; Sanghadasa, Mohan; Tang, Yong; Lin, Liwei

2017-10-30

Flexible power sources with load bearing capability are attractive for modern wearable electronics. Here, free-standing supercapacitor fabrics that can store high electrical energy and sustain large mechanical loads are directly woven to be compatible with flexible systems. The prototype with reduced package weight/volume provides an impressive energy density of 2.58 mWh g -1 or 3.6 mWh cm -3 , high tensile strength of over 1000 MPa, and bearable pressure of over 100 MPa. The nanoporous thread electrodes are prepared by the activation of commercial carbon fibers to have three-orders of magnitude increase in the specific surface area and 86% retention of the original strength. The novel device configuration woven by solid electrolyte-coated threads shows excellent flexibility and stability during repeated mechanical bending tests. A supercapacitor watchstrap is used to power a liquid crystal display as an example of load-bearing power sources with various form-factor designs for wearable electronics.

The young skater.

PubMed

Smith, A D

2000-10-01

Figure skating is one of the best lifetime sports. Participants may skate alone or with a group, recreationally or competitively, at all ages and at all skill levels. As a sport that improves physical fitness, skating builds strength, flexibility, and cardiopulmonary endurance. As a weight-bearing or high-impact activity, it is one of the best sports for increasing bone mineral density and perhaps for preventing osteoporosis. At least half of all competitive figure skating injuries appear preventable. Boots should be as flexible as the skater can control and should be carefully fitted. Normal flexibility of lower extremity muscles, especially in the growing athlete, markedly decreases the incidence of overuse symptoms of the knee. Core body strength is critical for controlling high-impact jump landings and decreasing injuries to the spine, pelvis, and hip girdle. Adequate shoulder strength is required for pair skaters and ice dancers. A well-designed off-ice training program decreases injury incidence and enhances performance. Assisting these dedicated athletes is truly rewarding as they train and compete at their highest potential, with passion for their sport.

Modeling and control for vibration suppression of a flexible smart structure

NASA Technical Reports Server (NTRS)

Dosch, J.; Leo, D.; Inman, D.

1993-01-01

Theoretical and experimental results of the modeling and control of a flexible ribbed antenna are presented. The antenna consists of eight flexible ribs which constitutes a smart antenna in the sense that the actuator and sensors are an integral part of the structure. The antenna exhibits closely space and repeated modes, thus multi-input multi-output (MIMO) control is necessary for controllability and observability of the structure. The structure also exhibits mode localization phenomenon and contains post buckled members making an accurate finite element model of the structure difficult to obtain. An identified MIMO minimum order model of the antenna is synthesized from identified single-input single-output (SISO) transfer functions curve fit in the frequency domain. The identified model is used to design a positive position feedback (PPF) controller that increases damping in all of the modes in the targeted frequency range. Due to the accuracy of the open loop model of the antenna, the closed loop response predicted by the identified model correlates well wtih experimental results.

Resilient Flexible Pressure-Activated Seal

NASA Technical Reports Server (NTRS)

Steinetz, Bruce M. (Inventor); Dunlap, Patrick H., Jr. (Inventor)

2009-01-01

A resilient, flexible, pressure-activated, high-temperature seal is adapted to be interposed between high and low pressure regions to provide sealing between opposing surfaces of adjacent relatively movable structures. The seal comprises at least one C-shaped sheet element. The C-shaped element design enables the seal to be pressure-activated to provide a radially outward biasing force, responsive to a seal-activating pressure differential acting across the seal thereby increasing resiliency. A centrally-located, resilient core structure provides load bearing and insulating properties. In an exemplary embodiment where at least two seal elements are used, each layer has a cutout slot pattern and the remaining strip material pattern. The slots provide flexibility to the seal, enabling the seal to be manually contoured to seal around corners and curves. The strip material of each layer covers the slots in each adjacent layer to minimize leakage through the slots. Attached barrier strips can block interface leakage between the seal and the opposing surfaces.

An innovative SNP genotyping method adapting to multiple platforms and throughputs.

PubMed

Long, Y M; Chao, W S; Ma, G J; Xu, S S; Qi, L L

2017-03-01

An innovative genotyping method designated as semi-thermal asymmetric reverse PCR (STARP) was developed for genotyping individual SNPs with improved accuracy, flexible throughputs, low operational costs, and high platform compatibility. Multiplex chip-based technology for genome-scale genotyping of single nucleotide polymorphisms (SNPs) has made great progress in the past two decades. However, PCR-based genotyping of individual SNPs still remains problematic in accuracy, throughput, simplicity, and/or operational costs as well as the compatibility with multiple platforms. Here, we report a novel SNP genotyping method designated semi-thermal asymmetric reverse PCR (STARP). In this method, genotyping assay was performed under unique PCR conditions using two universal priming element-adjustable primers (PEA-primers) and one group of three locus-specific primers: two asymmetrically modified allele-specific primers (AMAS-primers) and their common reverse primer. The two AMAS-primers each were substituted one base in different positions at their 3' regions to significantly increase the amplification specificity of the two alleles and tailed at 5' ends to provide priming sites for PEA-primers. The two PEA-primers were developed for common use in all genotyping assays to stringently target the PCR fragments generated by the two AMAS-primers with similar PCR efficiencies and for flexible detection using either gel-free fluorescence signals or gel-based size separation. The state-of-the-art primer design and unique PCR conditions endowed STARP with all the major advantages of high accuracy, flexible throughputs, simple assay design, low operational costs, and platform compatibility. In addition to SNPs, STARP can also be employed in genotyping of indels (insertion-deletion polymorphisms). As vast variations in DNA sequences are being unearthed by many genome sequencing projects and genotyping by sequencing, STARP will have wide applications across all biological organisms in agriculture, medicine, and forensics.

Soft Encapsulation of Flexible Electrical Stimulation Implant: Challenges and Innovations

PubMed Central

Debelle, Adrien; Hermans, Laura; Bosquet, Maxime; Dehaeck, Sam; Lonys, Laurent; Scheid, Benoit; Nonclercq, Antoine; Vanhoestenberghe, Anne

2016-01-01

In this document we discuss the main challenges encountered when producing flexible electrical stimulation implants, and present our approach to solving them for prototype production. We include a study of the optimization of the flexible PCB design, the selection of additive manufacturing materials for the mold, and the chemical compatibility of the different materials. Our approach was tested on a flexible gastro-stimulator as part of the ENDOGES research program. PMID:28078073

Universal Design and the Smart Home.

PubMed

Pennick, Tim; Hessey, Sue; Craigie, Roland

2016-01-01

The related concepts of Universal Design, Inclusive Design, and Design For All, all recognise that no one solution will fit the requirements of every possible user. This paper considers the extent to which current developments in smart home technology can help to reduce the numbers of users for whom mainstream technology is not sufficiently inclusive, proposing a flexible approach to user interface (UI) implementation focussed on the capabilities of the user. This implies development of the concepts underlying Universal Design to include the development of a flexible inclusive support infrastructure, servicing the requirements of individual users and their personalised user interface devices.

A Distributed Trajectory-Oriented Approach to Managing Traffic Complexity

NASA Technical Reports Server (NTRS)

Idris, Husni; Wing, David J.; Vivona, Robert; Garcia-Chico, Jose-Luis

2007-01-01

In order to handle the expected increase in air traffic volume, the next generation air transportation system is moving towards a distributed control architecture, in which ground-based service providers such as controllers and traffic managers and air-based users such as pilots share responsibility for aircraft trajectory generation and management. While its architecture becomes more distributed, the goal of the Air Traffic Management (ATM) system remains to achieve objectives such as maintaining safety and efficiency. It is, therefore, critical to design appropriate control elements to ensure that aircraft and groundbased actions result in achieving these objectives without unduly restricting user-preferred trajectories. This paper presents a trajectory-oriented approach containing two such elements. One is a trajectory flexibility preservation function, by which aircraft plan their trajectories to preserve flexibility to accommodate unforeseen events. And the other is a trajectory constraint minimization function by which ground-based agents, in collaboration with air-based agents, impose just-enough restrictions on trajectories to achieve ATM objectives, such as separation assurance and flow management. The underlying hypothesis is that preserving trajectory flexibility of each individual aircraft naturally achieves the aggregate objective of avoiding excessive traffic complexity, and that trajectory flexibility is increased by minimizing constraints without jeopardizing the intended ATM objectives. The paper presents conceptually how the two functions operate in a distributed control architecture that includes self separation. The paper illustrates the concept through hypothetical scenarios involving conflict resolution and flow management. It presents a functional analysis of the interaction and information flow between the functions. It also presents an analytical framework for defining metrics and developing methods to preserve trajectory flexibility and minimize its constraints. In this framework flexibility is defined in terms of robustness and adaptability to disturbances and the impact of constraints is illustrated through analysis of a trajectory solution space with limited degrees of freedom and in simple constraint situations involving meeting multiple times of arrival and resolving a conflict.

Flexible radiator system

NASA Technical Reports Server (NTRS)

Oren, J. A.

1982-01-01

The soft tube radiator subsystem is described including applicable system requirements, the design and limitations of the subsystem components, and the panel manufacturing method. The soft tube radiator subsystem is applicable to payloads requiring 1 to 12 kW of heat rejection for orbital lifetimes per mission of 30 days or less. The flexible radiator stowage volume required is about 60% and the system weight is about 40% of an equivalent heat rejection rigid panel. The cost should also be considerably less. The flexible radiator is particularly suited to shuttle orbiter sortie payloads and also whose mission lengths do not exceed the 30 day design life.

"Reverse fleximers": introduction of a series of 5-substituted carbocyclic uridine analogues.

PubMed

Sadler, Joshua M; Ojewoye, Olubukola; Seley-Radtke, Katherine L

2008-01-01

Nucleosides are ubiquitous in biological systems and as such, have been a focus of medicinal chemistry research in the search for new and potent therapeutic compounds. There are a number of modified nucleosides on the market, however increasing reports of resistance by mutation of either the enzyme binding site or the pathway that they are designed to interrupt are surfacing. As shown in recent reports, a candidate that can change conformation and still maintain recognition by the target enzyme would be highly desirable, and it is for this reason that flexible substrates have recently been sought as potential therapeutics. With this goal in mind, we have begun investigation into novel flexible scaffolds capable of overcoming viral resistance mechanisms resulting from binding site mutations.

Flexible manufacturing system handbook. Volume 1: Executive summary

NASA Astrophysics Data System (ADS)

1983-02-01

Flexible Manufacturing Systems (FMSs) represent a relatively new strategy to increase productivity. The technology is especially attractive for manufacturers who produce in the middle ranges of production volumes, neither mass production nor one of a kind. Today's unpredictable market environment demands low-cost solutions that provide quick product start-up, adaptability and responsiveness to changes in demand, and the capacity to easily resurrect out-of-production designs. In many instances, FMSs provide a direct hardware/software solution to this threefold management challenge. The adoption of FMS technology requires that one address many questions beforehand. This handbook provides a methodical approach to answering these questions. But it is not a cookbook; it cannot be. Each application of FMS technology is unique, therefore, the guidelines presented are fairly general.

Measure Guideline: Optimizing the Configuration of Flexible Duct Junction Boxes

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

Beach, R.; Burdick, A.

2014-03-01

This measure guideline offers additional recommendations to heating, ventilation, and air conditioning (HVAC) system designers for optimizing flexible duct, constant-volume HVAC systems using junction boxes within Air Conditioning Contractors of America (ACCA) Manual D guidance (Rutkowski, H. Manual D -- Residential Duct Systems, 3rd edition, Version 1.00. Arlington, VA: Air Conditioning Contractors of America, 2009.). IBACOS used computational fluid dynamics software to explore and develop guidance to better control the airflow effects of factors that may impact pressure losses within junction boxes among various design configurations (Beach, R., Prahl, D., and Lange, R. CFD Analysis of Flexible Duct Junction Boxmore » Design. Golden, CO: National Renewable Energy Laboratory, submitted for publication 2013). These recommendations can help to ensure that a system aligns more closely with the design and the occupants' comfort expectations. Specifically, the recommendations described herein show how to configure a rectangular box with four outlets, a triangular box with three outlets, metal wyes with two outlets, and multiple configurations for more than four outlets. Designers of HVAC systems, contractors who are fabricating junction boxes on site, and anyone using the ACCA Manual D process for sizing duct runs will find this measure guideline invaluable for more accurately minimizing pressure losses when using junction boxes with flexible ducts.« less

Performance Prediction Relationships for AM2 Airfield Matting Developed from Full-Scale Accelerated Testing and Laboratory Experimentation

DTIC Science & Technology

2018-01-01

work, the prevailing methods used to predict the performance of AM2 were based on the CBR design procedure for flexible pavements using a small number...suitable for design and evaluation frameworks currently used for airfield pavements and matting systems. DISCLAIMER: The contents of this report...methods used to develop the equivalency curves equated the mat-surfaced area to an equivalent thickness of flexible pavement using the CBR design

Modeling Interactions Between Flexible Flapping Wing Spars, Mechanisms, and Drive Motors

DTIC Science & Technology

2011-09-01

of dynamical equations is presented that allow micro air vehicle (MAV) or- nithopter designers to match drive motors to loads produced by flexible...aeroelastic systems is presented. One potential use for such a model is to serve as the basis for a vehicle design tool that matches drive motors to loads...friction. ∗Senior Aerospace Engineer, Control Design and Analysis Branch, 2210 Eighth Street, Ste. 21, Air Force Research Labora- tory, WPAFB, OH 45433

The Preliminary Design of a Standardized Spacecraft Bus for Small Tactical Satellites (Volume 1)

DTIC Science & Technology

1996-11-01

characteristics, and not detailed design recommendations, the team decided to avoid modeling the interaction among the objective attributes. 47 5.6 Flexibility of...in the Modsat computer model are necessarily "generic" in nature to provide both flexibility in design evaluation and a foundation on which more...the methods employed during the study, the scope of the problem, the value system used to evaluate alternatives, tradeoff studies performed, modeling

Modified independent modal space control method for active control of flexible systems

NASA Technical Reports Server (NTRS)

Baz, A.; Poh, S.

1987-01-01

A modified independent modal space control (MIMSC) method is developed for designing active vibration control systems for large flexible structures. The method accounts for the interaction between the controlled and residual modes. It incorporates also optimal placement procedures for selecting the optimal locations of the actuators in the structure in order to minimize the structural vibrations as well as the actuation energy. The MIMSC method relies on an important feature which is based on time sharing of a small number of actuators, in the modal space, to control effectively a large number of modes. Numerical examples are presented to illustrate the application of the method to generic flexible systems. The results obtained suggest the potential of the devised method in designing efficient active control systems for large flexible structures.

Development of Modular Outdoor Furniture Product Using Lightweight Concrete for Public Parks in Surabaya

NASA Astrophysics Data System (ADS)

Mulyono, Grace; Thamrin, Diana; Antoni

2017-09-01

The development of public parks into green city facilities in Surabaya has triggered the need of outdoor furniture designs that can resist the tropical wet and dry weather conditions while also having a certain mobility to support flexible park arrangement. However, present furniture designs made of concrete material are generally heavy and immovable. Flexible designs are needed for various activities that can take place at the same time such as sitting and playing, and to support changes in arrangement to keep the green open spaces attractive from time to time. This research develops the idea of a modular outdoor furniture design using cellular lightweight concrete (CLC) as the main material as a result from observing its resistance towards weather change and its relative light weight. It starts with analysis of problems, formulation of design concept, creation of design alternatives, selection of design, calculation of mouldings, adaptation of design to the mouldings and production of a scaled mock-up using CLC. Findings of this research reveal that the modular design along with the CLC material used not only support the flexibility of change in function and arrangement but also make these furniture resistant to the hot and humid weather of Surabaya.

Dynamics modelling and Hybrid Suppression Control of space robots performing cooperative object manipulation

NASA Astrophysics Data System (ADS)

Zarafshan, P.; Moosavian, S. Ali A.

2013-10-01

Dynamics modelling and control of multi-body space robotic systems composed of rigid and flexible elements is elaborated here. Control of such systems is highly complicated due to severe under-actuated condition caused by flexible elements, and an inherent uneven nonlinear dynamics. Therefore, developing a compact dynamics model with the requirement of limited computations is extremely useful for controller design, also to develop simulation studies in support of design improvement, and finally for practical implementations. In this paper, the Rigid-Flexible Interactive dynamics Modelling (RFIM) approach is introduced as a combination of Lagrange and Newton-Euler methods, in which the motion equations of rigid and flexible members are separately developed in an explicit closed form. These equations are then assembled and solved simultaneously at each time step by considering the mutual interaction and constraint forces. The proposed approach yields a compact model rather than common accumulation approach that leads to a massive set of equations in which the dynamics of flexible elements is united with the dynamics equations of rigid members. To reveal such merits of this new approach, a Hybrid Suppression Control (HSC) for a cooperative object manipulation task will be proposed, and applied to usual space systems. A Wheeled Mobile Robotic (WMR) system with flexible appendages as a typical space rover is considered which contains a rigid main body equipped with two manipulating arms and two flexible solar panels, and next a Space Free Flying Robotic system (SFFR) with flexible members is studied. Modelling verification of these complicated systems is vigorously performed using ANSYS and ADAMS programs, while the limited computations of RFIM approach provides an efficient tool for the proposed controller design. Furthermore, it will be shown that the vibrations of the flexible solar panels results in disturbing forces on the base which may produce undesirable errors and perturb the object manipulation task. So, it is shown that these effects can be significantly eliminated by the proposed Hybrid Suppression Control algorithm.

Assessment of the Relationship Between Flexibility and Adaptive Capacity in Flood Management Systems

NASA Astrophysics Data System (ADS)

DiFrancesco, K.; Tullos, D. D.

2013-12-01

Discussions around adapting water management systems to future changes often state the need to increase system flexibility. Intuitively, a flexible, easily modifiable system seems desirable when faced with a wide range of uncertain, but plausible future conditions. Yet, despite the frequent use of the terms flexibility, very little work has examined what exactly it means to have a flexible water management system, what makes one system more flexible than another, or the extent to which flexibility increases adaptive capacity. This study applies a methodology for assessing the inherent flexibility of the structural and non-structural components of flood management systems using original flexibility metrics in the categories of: slack, intensity, connectivity, adjustability, and coordination. We use these metrics to assess the flexibility of three sub-systems within the Sacramento Valley flood management system in California, USA under current system conditions as well as with proposed management actions in place. We then assess the range of hydrologic conditions under which each sub-system can meet flood risk targets in order to determine whether more flexible systems are also more robust and able to perform over a wider range of hydrologic conditions. In doing so, we identify flexible characteristics of flood management systems that enhance the ability of the system to preform over a wide range of conditions making them better suited to adapt to an uncertain hydrologic future. We find that the flexibility characteristics that increase the range of conditions under which the system can meet performance goals varies depending on whether the region is considered urban, rural, or a small community. In some cases, a decrease in certain flexibility characteristics is associated with an increase in robustness, indicating that more flexibility is not always desirable. Future work will assess the transferability of these results to other regions and systems.

Following the Dollars to the Classroom Door: Why and How Effective Student-Based Budgeting Must Be Linked with Strategic School Design

ERIC Educational Resources Information Center

Travers, Jonathan; Catallo, Courtney

2015-01-01

More and more districts--and several states--are adopting funding models like student-based budgeting (also called weighted student funding or fair student funding) to increase equity and promote principal autonomy. Giving school leaders new resources and new flexibility is a good first step, but it doesn't automatically lead to improved student…

Immediate Effects of Neurodynamic Sliding versus Muscle Stretching on Hamstring Flexibility in Subjects with Short Hamstring Syndrome

PubMed Central

Castellote-Caballero, Yolanda; Valenza, Maríe C.; Puentedura, Emilio J.; Fernández-de-las-Peñas, César; Alburquerque-Sendín, Francisco

2014-01-01

Background. Hamstring injuries continue to affect active individuals and although inadequate muscle extensibility remains a commonly accepted factor, little is known about the most effective method to improve flexibility. Purpose. To determine if an isolated neurodynamic sciatic sliding technique would improve hamstring flexibility to a greater degree than stretching or a placebo intervention in asymptomatic subjects with short hamstring syndrome (SHS). Study Design. Randomized double-blinded controlled trial. Methods. One hundred and twenty subjects with SHS were randomized to 1 of 3 groups: neurodynamic sliding, hamstring stretching, and placebo control. Each subject's dominant leg was measured for straight leg raise (SLR) range of motion (ROM) before and after interventions. Data were analyzed with a 3 × 2 mixed model ANOVA followed by simple main effects analyses. Results. At the end of the study, more ROM was observed in the Neurodynamic and Stretching groups compared to the Control group and more ROM in the Neurodynamic group compared to Stretching group. Conclusion. Findings suggest that a neurodynamic sliding technique will increase hamstring flexibility to a greater degree than static hamstring stretching in healthy subjects with SHS. Clinical Relevance. The use of neurodynamic sliding techniques to improve hamstring flexibility in sports may lead to a decreased incidence in injuries; however, this needs to be formally tested. PMID:26464889

Designing of a small wearable conformal phased array antenna for wireless communications

NASA Astrophysics Data System (ADS)

Roy, Sayan

In this thesis, a unique design of a self-adapting conformal phased-array antenna system for wireless communications is presented. The antenna system is comprised of one microstrip antenna array and a sensor circuit. A 1x4 printed microstrip patch antenna array was designed on a flexible substrate with a resonant frequency of 2.47 GHz. However, the performance of the antenna starts to degrade as the curvature of the surface of the substrate changes. To recover the performance of the system, a flexible sensor circuitry was designed. This sensor circuitry uses analog phase shifters, a flexible resistor and operational-amplifier circuitry to compensate the phase of each array element of the antenna. The proposed analytical method for phase compensation has been first verified by designing an RF test platform consisting of a microstrip antenna array, commercially available analog phase shifters, analog voltage attenuators, 4-port power dividers and amplifiers. The platform can be operated through a LabVIEW GUI interface using a 12-bit digital-to-analog converter. This test board was used to design and calibrate the sensor circuitry by observing the behavior of the antenna array system on surfaces with different curvatures. In particular, this phased array antenna system was designed to be used on the surface of a spacesuit or any other flexible prototype. This work was supported in part by the Defense Miroelectronics Activity (DMEA), NASA ND EPSCoR and DARPA/MTO.

The space station: Human factors and productivity

NASA Technical Reports Server (NTRS)

Gillan, D. J.; Burns, M. J.; Nicodemus, C. L.; Smith, R. L.

1986-01-01

Human factor researchers and engineers are making inputs into the early stages of the design of the Space Station to improve both the quality of life and work on-orbit. Effective integration of the human factors information related to various Intravehicular Activity (IVA), Extravehicular Activity (EVA), and teletobotics systems during the Space Station design will result in increased productivity, increased flexibility of the Space Stations systems, lower cost of operations, improved reliability, and increased safety for the crew onboard the Space Station. The major features of productivity examined include the cognitive and physical effort involved in work, the accuracy of worker output and ability to maintain performance at a high level of accuracy, the speed and temporal efficiency with which a worker performs, crewmember satisfaction with their work environment, and the relation between performance and cost.

Two-Time Scale Virtual Sensor Design for Vibration Observation of a Translational Flexible-Link Manipulator Based on Singular Perturbation and Differential Games

PubMed Central

Ju, Jinyong; Li, Wei; Wang, Yuqiao; Fan, Mengbao; Yang, Xuefeng

2016-01-01

Effective feedback control requires all state variable information of the system. However, in the translational flexible-link manipulator (TFM) system, it is unrealistic to measure the vibration signals and their time derivative of any points of the TFM by infinite sensors. With the rigid-flexible coupling between the global motion of the rigid base and the elastic vibration of the flexible-link manipulator considered, a two-time scale virtual sensor, which includes the speed observer and the vibration observer, is designed to achieve the estimation for the vibration signals and their time derivative of the TFM, as well as the speed observer and the vibration observer are separately designed for the slow and fast subsystems, which are decomposed from the dynamic model of the TFM by the singular perturbation. Additionally, based on the linear-quadratic differential games, the observer gains of the two-time scale virtual sensor are optimized, which aims to minimize the estimation error while keeping the observer stable. Finally, the numerical calculation and experiment verify the efficiency of the designed two-time scale virtual sensor. PMID:27801840

A novel vibration measurement and active control method for a hinged flexible two-connected piezoelectric plate

NASA Astrophysics Data System (ADS)

Qiu, Zhi-cheng; Wang, Xian-feng; Zhang, Xian-Min; Liu, Jin-guo

2018-07-01

A novel non-contact vibration measurement method using binocular vision sensors is proposed for piezoelectric flexible hinged plate. Decoupling methods of the bending and torsional low frequency vibration on measurement and driving control are investigated, using binocular vision sensors and piezoelectric actuators. A radial basis function neural network controller (RBFNNC) is designed to suppress both the larger and the smaller amplitude vibrations. To verify the non-contact measurement method and the designed controller, an experimental setup of the flexible hinged plate with binocular vision is constructed. Experiments on vibration measurement and control are conducted by using binocular vision sensors and the designed RBFNNC controllers, compared with the classical proportional and derivative (PD) control algorithm. The experimental measurement results demonstrate that the binocular vision sensors can detect the low-frequency bending and torsional vibration effectively. Furthermore, the designed RBF can suppress the bending vibration more quickly than the designed PD controller owing to the adjustment of the RBF control, especially for the small amplitude residual vibrations.

Drive-train dynamics technology - State-of-the-art and design of a test facility for advanced development

NASA Technical Reports Server (NTRS)

Badgley, R. H.; Fleming, D. P.; Smalley, A. J.

1975-01-01

A program for the development and verification of drive-train dynamic technology is described along with its basis and the results expected from it. A central feature of this program is a drive-train test facility designed for the testing and development of advanced drive-train components, including shaft systems, dampers, and couplings. Previous efforts in designing flexible dynamic drive-train systems are reviewed, and the present state of the art is briefly summarized. The design of the test facility is discussed with major attention given to the formulation of the test-rig concept, dynamic scaling of model shafts, and the specification of design parameters. Specific efforts envisioned for the test facility are briefly noted, including evaluations of supercritical test shafts, stability thresholds for various sources and types of instabilities that can exist in shaft systems, effects of structural flexibility on the dynamic performance of dampers, and methods for vibration control in two-level and three-level flexible shaft systems.

The mechanical design of a humanoid robot with flexible skin sensor for use in psychiatric therapy

NASA Astrophysics Data System (ADS)

Burns, Alec; Tadesse, Yonas

2014-03-01

In this paper, a humanoid robot is presented for ultimate use in the rehabilitation of children with mental disorders, such as autism. Creating affordable and efficient humanoids could assist the therapy in psychiatric disability by offering multimodal communication between the humanoid and humans. Yet, the humanoid development needs a seamless integration of artificial muscles, sensors, controllers and structures. We have designed a human-like robot that has 15 DOF, 580 mm tall and 925 mm arm span using a rapid prototyping system. The robot has a human-like appearance and movement. Flexible sensors around the arm and hands for safe human-robot interactions, and a two-wheel mobile platform for maneuverability are incorporated in the design. The robot has facial features for illustrating human-friendly behavior. The mechanical design of the robot and the characterization of the flexible sensors are presented. Comprehensive study on the upper body design, mobile base, actuators selection, electronics, and performance evaluation are included in this paper.

Materials Testing in Long Cane Design: Sensitivity, Flexibility, and Transmission of Vibration

ERIC Educational Resources Information Center

Rodgers, Mark D.; Emerson, Robert Wall

2005-01-01

Different materials that are used in manufacturing long cane shafts were assessed for their ability to transmit vibration and their sensitivity to tactile information, flexibility, and durability. It was found that the less flexible a cane shaft is, the better it transmits vibrations that are useful for discriminating surface textures and that…

Performance Evaluation of the Gravity Probe B Design

NASA Technical Reports Server (NTRS)

Francis, Ronnie; Wells, Eugene M.

1996-01-01

This report documents the simulation of the Lockheed Martin designed Gravity Probe B (GPB) spacecraft developed tool by bd Systems Inc using the TREETOPS simulation. This study quantifies the effects of flexibility and liquid helium slosh on GPB spacecraft control performance. The TREETOPS simulation tool permits the simulation of flexible structures given that a flexible body model of the structure is available. For purposes of this study, a flexible model of the GPB spacecraft was obtained from Lockheed Martin. To model the liquid helium slosh effects, computational fluid dynamics (CFD) results' were obtained, and used to develop a dynamic model of the slosh effects. The flexible body and slosh effects were incorporated separately into the TREETOPS simulation, which places the vehicle in a 650 km circular polar orbit and subjects the spacecraft to realistic environmental disturbances and sensor error quantities. In all of the analysis conducted in this study the spacecraft is pointed at an inertially fixed guide star (GS) and is rotating at a constant rate about this line of sight.

A Triblock Copolymer Design Leads to Robust Hybrid Hydrogels for High-Performance Flexible Supercapacitors.

PubMed

Zhang, Guangzhao; Chen, Yunhua; Deng, Yonghong; Wang, Chaoyang

2017-10-18

We report here an intriguing hybrid conductive hydrogel as electrode for high-performance flexible supercapacitor. The key is using a rationally designed water-soluble ABA triblock copolymer (termed as IAOAI) containing a central poly(ethylene oxide) block (A) and terminal poly(acrylamide) (PAAm) block with aniline moieties randomly incorporated (B), which was synthesized by reversible additional fragment transfer polymerization. The subsequent copolymerization of aniline monomers with the terminated aniline moieties on the IAOAI polymer generates a three-dimensional cross-linking hybrid network. The hybrid hydrogel electrode demonstrates robust mechanical flexibility, remarkable electrochemical capacitance (919 F/g), and cyclic stability (90% capacitance retention after 1000 cycles). Moreover, the flexible supercapacitor based on this hybrid hydrogel electrode presents a large specific capacitance (187 F/g), superior to most reported conductive hydrogel-based supercapacitors. With the demonstrated additional favorable cyclic stability and excellent capacitive and rate performance, this hybrid hydrogel-based supercapacitor holds great promise for flexible energy-storage device.

High-performance and compact-designed flexible thermoelectric modules enabled by a reticulate carbon nanotube architecture

PubMed Central

Zhou, Wenbin; Fan, Qingxia; Zhang, Qiang; Cai, Le; Li, Kewei; Gu, Xiaogang; Yang, Feng; Zhang, Nan; Wang, Yanchun; Liu, Huaping; Zhou, Weiya; Xie, Sishen

2017-01-01

It is a great challenge to substantially improve the practical performance of flexible thermoelectric modules due to the absence of air-stable n-type thermoelectric materials with high-power factor. Here an excellent flexible n-type thermoelectric film is developed, which can be conveniently and rapidly prepared based on the as-grown carbon nanotube continuous networks with high conductivity. The optimum n-type film exhibits ultrahigh power factor of ∼1,500 μW m−1 K−2 and outstanding stability in air without encapsulation. Inspired by the findings, we design and successfully fabricate the compact-configuration flexible TE modules, which own great advantages compared with the conventional π-type configuration modules and well integrate the superior thermoelectric properties of p-type and n-type carbon nanotube films resulting in a markedly high performance. Moreover, the research results are highly scalable and also open opportunities for the large-scale production of flexible thermoelectric modules. PMID:28337987

Two-dimensional polyaniline nanostructure to the development of microfluidic integrated flexible biosensors for biomarker detection.

PubMed

Liu, Pei; Zhu, Yisi; Lee, Seung Hee; Yun, Minhee

2016-12-01

In this work, we report a flexible field-effect-transistor (FET) biosensor design based on two-dimensional (2-D) polyaniline (PANI) nanostructure. The flexible biosensor devices were fabricated through a facile and inexpensive method that combines top-down and bottom-up processes. The chemically synthesized PANI nanostructure showed excellent p-type semiconductor properties as well as good compatibility with flexible design. With the 2-D PANI nanostructure being as thin as 80 nm and its extremely large surface-area-to-volume (SA/V) ratio due to the intrinsic properties of PANI chemical synthesis, the developed flexible biosensor exhibited outstanding sensing performance in detecting B-type natriuretic peptide (BNP) biomarkers, and was able to achieve high specificity (averagely 112 folds) with the limit of detection as low as 100 pg/mL. PANI nanostructure under bending condition was also investigated and showed controllable conductance changes being less than 20% with good restorability which may open up the possibility for wearable applications.

Automated Docking with Protein Flexibility in the Design of Femtomolar “Click Chemistry” Inhibitors of Acetylcholinesterase

PubMed Central

Morris, Garrett M.; Green, Luke G.; Radić, Zoran; Taylor, Palmer; Sharpless, K. Barry; Olson, Arthur J.; Grynszpan, Flavio

2013-01-01

The use of computer-aided structure-based drug design prior to synthesis has proven to be generally valuable in suggesting improved binding analogues of existing ligands.1 Here we describe the application of the program AutoDock2 to the design of a focused library that was used in the “click chemistry in-situ” generation of the most potent non-covalent inhibitor of the enzyme acetylcholinesterase (AChE) yet developed (Kd = ~100 fM).3 AutoDock version 3.0.5 has been widely distributed and successfully used to predict bound conformations of flexible ligands. Here, we also used a version of AutoDock which permits additional conformational flexibility in selected amino acid sidechains of the target protein. PMID:23451944

Design of a smart ECG garment based on conductive textile electrode and flexible printed circuit board.

PubMed

Cai, Zhipeng; Luo, Kan; Liu, Chengyu; Li, Jianqing

2017-08-09

A smart electrocardiogram (ECG) garment system was designed for continuous, non-invasive and comfortable ECG monitoring, which mainly consists of four components: Conductive textile electrode, garment, flexible printed circuit board (FPCB)-based ECG processing module and android application program. Conductive textile electrode and FPCB-based ECG processing module (6.8 g, 55 mm × 53 mm × 5 mm) are identified as two key techniques to improve the system's comfort and flexibility. Preliminary experimental results verified that the textile electrodes with circle shape, 40 mm size in diameter, and 5 mm thickness sponge are best suited for the long-term ECG monitoring application. The tests on the whole system confirmed that the designed smart garment can obtain long-term ECG recordings with high signal quality.

Control and structural optimization for maneuvering large spacecraft

NASA Technical Reports Server (NTRS)

Chun, H. M.; Turner, J. D.; Yu, C. C.

1990-01-01

Presented here are the results of an advanced control design as well as a discussion of the requirements for automating both the structures and control design efforts for maneuvering a large spacecraft. The advanced control application addresses a general three dimensional slewing problem, and is applied to a large geostationary platform. The platform consists of two flexible antennas attached to the ends of a flexible truss. The control strategy involves an open-loop rigid body control profile which is derived from a nonlinear optimal control problem and provides the main control effort. A perturbation feedback control reduces the response due to the flexibility of the structure. Results are shown which demonstrate the usefulness of the approach. Software issues are considered for developing an integrated structures and control design environment.

Application of Lanczos vectors to control design of flexible structures, part 2

NASA Technical Reports Server (NTRS)

Craig, Roy R., Jr.; Su, Tzu-Jeng

1992-01-01

This report covers the period of the grant from January 1991 until its expiration in June 1992. Together with an Interim Report (Ref. 9), it summarizes the research conducted under NASA Grant NAG9-357 on the topic 'Application of Lanczos Vectors to Control Design of Flexible Structures.' The research concerns various ways to obtain reduced-order mathematical models of complex structures for use in dynamics analysis and in the design of control systems for these structures. This report summarizes the research.

Liquid Rocket Lines, Bellows, Flexible Hoses, and Filters

NASA Technical Reports Server (NTRS)

1977-01-01

Fluid-flow components in a liquid propellant rocket engine and the rocket vehicle which it propels are interconnected by lines, bellows, and flexible hoses. Elements involved in the successful design of these components are identified and current technologies pertaining to these elements are reviewed, assessed, and summarized to provide a technology base for a checklist of rules to be followed by project managers in guiding a design or assessing its adequacy. Recommended procedures for satisfying each of the design criteria are included.

Powersail High Power Propulsion System Design Study

NASA Astrophysics Data System (ADS)

Gulczinski, Frank S., III

2000-11-01

A desire by the United States Air Force to exploit the space environment has led to a need for increased on-orbit electrical power availability. To enable this, the Air Force Research Laboratory Space Vehicles Directorate (AFRL/ VS) is developing Powersail: a two-phased program to demonstrate high power (100 kW to 1 MW) capability in space using a deployable, flexible solar array connected to the host spacecraft using a slack umbilical. The first phase will be a proof-of-concept demonstration at 50 kW, followed by the second phase, an operational system at full power. In support of this program, the AFRL propulsion Directorate's Spacecraft Propulsion Branch (AFRL/PRS ) at Edwards AFB has commissioned a design study of the Powersail High Power Propulsion System. The purpose of this study, the results of which are summarized in this paper, is to perform mission and design trades to identify potential full-power applications (both near-Earth and interplanetary) and the corresponding propulsion system requirements and design. The design study shall farther identify a suitable low power demonstration flight that maximizes risk reduction for the fully operational system. This propulsion system is expected to be threefold: (1) primary propulsion for moving the entire vehicle, (2) a propulsion unit that maintains the solar array position relative to the host spacecraft, and (3) control propulsion for maintaining proper orientation for the flexible solar array.

Design, Prototyping and Control of a Flexible Cystoscope for Biomedical Applications

NASA Astrophysics Data System (ADS)

Sozer, Canberk; Ghorbani, Morteza; Alcan, Gokhan; Uvet, Huseyin; Unel, Mustafa; Kosar, Ali

2017-07-01

Kidney stone and prostate hyperplasia are very common urogenital diseases all over the world. To treat these diseases, one of the ESWL (Extracorporeal Shock Wave Lithotripsy), PCNL (Percutaneous Nephrolithotomy), cystoscopes or open surgery techniques can be used. Cystoscopes named devices are used for in-vivo intervention. A flexible or rigid cystoscope device is inserted into human body and operates on interested area. In this study, a flexible cystoscope prototype has been developed. The prototype is able to bend up to ±40°in X and Y axes, has a hydrodynamic cavitation probe for rounding sharp edges of kidney stone or resection of the filled prostate with hydrodynamic cavitation method and contains a waterproof medical camera to give visual feedback to the operator. The operator steers the flexible end-effector via joystick toward target region. This paper presents design, manufacturing, control and experimental setup of the tendon driven flexible cystoscope prototype. The prototype is 10 mm in outer diameter, 70 mm in flexible part only and 120 mm in total length with flexible part and rigid tube. The experimental results show that the prototype bending mechanism, control system, manufactured prototype parts and experimental setup function properly. A small piece of real kidney stone was broken in targeted area.

Nonlinear transient analysis of multi-mass flexible rotors - theory and applications

NASA Technical Reports Server (NTRS)

Kirk, R. G.; Gunter, E. J.

1973-01-01

The equations of motion necessary to compute the transient response of multi-mass flexible rotors are formulated to include unbalance, rotor acceleration, and flexible damped nonlinear bearing stations. A method of calculating the unbalance response of flexible rotors from a modified Myklestad-Prohl technique is discussed in connection with the method of solution for the transient response. Several special cases of simplified rotor-bearing systems are presented and analyzed for steady-state response, stability, and transient behavior. These simplified rotor models produce extensive design information necessary to insure stable performance to elastic mounted rotor-bearing systems under varying levels and forms of excitation. The nonlinear journal bearing force expressions derived from the short bearing approximation are utilized in the study of the stability and transient response of the floating bush squeeze damper support system. Both rigid and flexible rotor models are studied, and results indicate that the stability of flexible rotors supported by journal bearings can be greatly improved by the use of squeeze damper supports. Results from linearized stability studies of flexible rotors indicate that a tuned support system can greatly improve the performance of the units from the standpoint of unbalanced response and impact loading. Extensive stability and design charts may be readily produced for given rotor specifications by the computer codes presented in this analysis.

Capacity Payments in Restructured Markets under Low and High Penetration Levels of Renewable Energy

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

Jenkin, Thomas; Beiter, Philipp; Margolis, Robert

There is considerable debate about the degree to which restructured markets perform successfully in their use of capacity markets. In providing appropriate incentives for new and existing generation to meet reliability requirements, a variety of capacity market designs have developed across RTOs and ISOs in the United States and internationally. Growing levels of variable renewable energy (VRE) resources arguably create new challenges for capacity market designs, because VREs suppress energy prices while providing relatively little capacity, with these effects increase with VRE penetration. The purpose of this report is threefold. First, we provide a brief outline of the purpose andmore » design of various capacity markets under consideration using variable resource requirement (VRR) demand curves. Second, we discuss some of the main challenges raised in existing literature and a set of interviews that we conducted with market participants, regulators, and observers, including where there substantive differences in opinion. Third, we consider some of the challenges that may be specific to higher penetration levels of VRE. While the well known 'merit order' effect from VRE can be expected to suppress wholesale energy prices and revenue, this may be partly mitigated by increased capacity payments and the greater importance of AS payments for flexible capacity. The potential for greater reliance on capacity markets for generator revenues may amplify any inefficiency and costs associated with capacity price volatility and other suboptimal market design choices. Regulatory intervention to ensure adequate capacity payments and ancillary service revenue may become more prevalent under current market designs as the timescale for market signals shifts increasingly from near term (e.g., day-ahead in wholesale electricity markets) to longer term (annual intervals in capacity markets). Our review and discussion with market participants suggest substantive challenges may remain in implementing capacity markets that provide both adequate operational and investment incentives, particularly under high-VRE scenarios with greater need for flexible capacity.« less

Chemically modified graphene based supercapacitors for flexible and miniature devices

NASA Astrophysics Data System (ADS)

Ghosh, Debasis; Kim, Sang Ouk

2015-09-01

Rapid progress in the portable and flexible electronic devises has stimulated supercapacitor research towards the design and fabrication of high performance flexible devices. Recent research efforts for flexible supercapacitor electrode materials are highly focusing on graphene and chemically modified graphene owing to the unique properties, including large surface area, high electrical and thermal conductivity, excellent mechanical flexibility, and outstanding chemical stability. This invited review article highlights current status of the flexible electrode material research based on chemically modified graphene for supercapacitor application. A variety of electrode architectures prepared from chemically modified graphene are summarized in terms of their structural dimensions. Novel prototypes for the supercapacitor aiming at flexible miniature devices, i.e. microsupercapacitor with high energy and power density are highlighted. Future challenges relevant to graphene-based flexible supercapacitors are also suggested. [Figure not available: see fulltext.

Composite flexible blanket insulation

NASA Technical Reports Server (NTRS)

Kourtides, Demetrius A. (Inventor); Lowe, David M. (Inventor)

1994-01-01

An improved composite flexible blanket insulation is presented comprising top silicon carbide having an interlock design, wherein the reflective shield is composed of single or double aluminized polyimide and wherein the polyimide film has a honeycomb pattern.

Experimental flexible pavements.

DOT National Transportation Integrated Search

1971-01-01

A program of construction and the performance evaluation of three major Virginia experimental flexible pavements is reported. The objective of the program was to evaluate the performance of pavements incorporating new or timely design concepts and to...

All-solid-state flexible supercapacitors fabricated with bacterial nanocellulose papers, carbon nanotubes, and triblock-copolymer ion gels.

PubMed

Kang, Yu Jin; Chun, Sang-Jin; Lee, Sung-Suk; Kim, Bo-Yeong; Kim, Jung Hyeun; Chung, Haegeun; Lee, Sun-Young; Kim, Woong

2012-07-24

We demonstrate all-solid-state flexible supercapacitors with high physical flexibility, desirable electrochemical properties, and excellent mechanical integrity, which were realized by rationally exploiting unique properties of bacterial nanocellulose, carbon nanotubes, and ionic liquid based polymer gel electrolytes. This deliberate choice and design of main components led to excellent supercapacitor performance such as high tolerance against bending cycles and high capacitance retention over charge/discharge cycles. More specifically, the performance of our supercapacitors was highly retained through 200 bending cycles to a radius of 3 mm. In addition, the supercapacitors showed excellent cyclability with C(sp) (~20 mF/cm(2)) reduction of only <0.5% over 5000 charge/discharge cycles at the current density of 10 A/g. Our demonstration could be an important basis for material design and development of flexible supercapacitors.

Fuel cycle cost reduction through Westinghouse fuel design and core management

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

Frank, F.J.; Scherpereel, L.R.

1985-11-01

This paper describes advances in Westinghouse nuclear fuel and their impact on fuel cycle cost. Recent fabrication development has been aimed at maintaining high integrity, increased operating flexibility, longer operating cycles, and improved core margins. Development efforts at Westinghouse toward meeting these directions have culminated in VANTAGE 5 fuel. The current trend toward longer operating cycles provides a further driving force to minimize the resulting inherent increase in fuel cycle costs by further increases in region discharge burnup. Westinghouse studies indicate the capability of currently offered products to meet cycle lengths up to 24 months.

Flexible Plasmonic Sensors

PubMed Central

Shir, Daniel; Ballard, Zachary S.; Ozcan, Aydogan

2016-01-01

Mechanical flexibility and the advent of scalable, low-cost, and high-throughput fabrication techniques have enabled numerous potential applications for plasmonic sensors. Sensitive and sophisticated biochemical measurements can now be performed through the use of flexible plasmonic sensors integrated into existing medical and industrial devices or sample collection units. More robust sensing schemes and practical techniques must be further investigated to fully realize the potentials of flexible plasmonics as a framework for designing low-cost, embedded and integrated sensors for medical, environmental, and industrial applications. PMID:27547023

Self-organisation of semi-flexible rod-like particles

NASA Astrophysics Data System (ADS)

de Braaf, Bart; Oshima Menegon, Mariana; Paquay, Stefan; van der Schoot, Paul

2017-12-01

We report on a comprehensive computer simulation study of the liquid-crystal phase behaviour of purely repulsive, semi-flexible rod-like particles. For the four aspect ratios we consider, the particles form five distinct phases depending on their packing fraction and bending flexibility: the isotropic, nematic, smectic A, smectic B, and crystal phase. Upon increasing the particle bending flexibility, the various phase transitions shift to larger packing fractions. Increasing the aspect ratio achieves the opposite effect. We find two different ways in which the layer thickness of the particles in the smectic A phase may respond to an increase in concentration. The layer thickness may either decrease or increase depending on the aspect ratio and flexibility. For the smectic B and the crystalline phases, increasing the concentration always decreases the layer thickness. Finally, we find that the layer spacing jumps to a larger value on transitioning from the smectic A phase to the smectic B phase.

High-Speed Rotor Analytical Dynamics on Flexible Foundation Subjected to Internal and External Excitation

NASA Astrophysics Data System (ADS)

Jivkov, Venelin S.; Zahariev, Evtim V.

2016-12-01

The paper presents a geometrical approach to dynamics simulation of a rigid and flexible system, compiled of high speed rotating machine with eccentricity and considerable inertia and mass. The machine is mounted on a vertical flexible pillar with considerable height. The stiffness and damping of the column, as well as, of the rotor bearings and the shaft are taken into account. Non-stationary vibrations and transitional processes are analyzed. The major frequency and modal mode of the flexible column are used for analytical reduction of its mass, stiffness and damping properties. The rotor and the foundation are modelled as rigid bodies, while the flexibility of the bearings is estimated by experiments and the requirements of the manufacturer. The transition effects as a result of limited power are analyzed by asymptotic methods of averaging. Analytical expressions for the amplitudes and unstable vibrations throughout resonance are derived by quasi-static approach increasing and decreasing of the exciting frequency. Analytical functions give the possibility to analyze the influence of the design parameter of many structure applications as wind power generators, gas turbines, turbo-generators, and etc. A numerical procedure is applied to verify the effectiveness and precision of the simulation process. Nonlinear and transitional effects are analyzed and compared to the analytical results. External excitations, as wave propagation and earthquakes, are discussed. Finite elements in relative and absolute coordinates are applied to model the flexible column and the high speed rotating machine. Generalized Newton - Euler dynamics equations are used to derive the precise dynamics equations. Examples of simulation of the system vibrations and nonstationary behaviour are presented.

Flexible radiator thermal vacuum test report

NASA Technical Reports Server (NTRS)

Oren, J. A.; Hixon, C. W.

1982-01-01

Two flexible, deployable/retraction radiators were designed and fabricated. The two radiator panels are distinguishable by their mission life design. One panel is designed with a 90 percent probability of withstanding the micrometeoroid environment of a low earth orbit for 30 days. This panel is designated the soft tube radiator after the PFA Teflon tubes which distribute the transport fluid over the panel. The second panel is designed with armored flow tubes to withstand the same micrometeoroid environment for 5 years. It is designated the hard tube radiator after its stainless steel flow tubes. The thermal performance of the radiators was tested under anticipated environmental conditions. The two deployment systems of the radiators were evaluated in a thermal vacuum environment.

Design and development of a hard tube flexible radiator system

NASA Technical Reports Server (NTRS)

Hixon, C. W.

1980-01-01

The construction and operational characteristics of an extended life flexible radiator panel is described. The radiator panel consists of a flexible fin laminate and stainless steel flow tubes designed for a 90 percent probability of surviving 5 years in an Earth orbit micrometeoroid environment. The radiator panel rejects 1.1 kW sub t of heat into an environmental sink temperature of 0 F. Total area is 170 square feet and the panel extends 25 feet in the fully deployed position. When retracted the panel rolls onto a 11.5 inch diameter by 52 inch long storage drum, for a final stored diameter of 22 inches.

A Delphi Study of Additive Manufacturing Applicability for United States Air Force Civil Engineer Contingency Operations

DTIC Science & Technology

2015-03-26

10 Table 2. Additive Manufacturing Categories (ASTM International , 2012) ..................... 14 Table 3. Delphi... flexibility in the design and structure of manufactured parts. It also allows for the creation of thousands of possible parts or tools from a single...machine. These benefits of 3 precision and flexibility in design and manufacturing show promising possibilities for addressing the general nature of

Lean healthcare from a change management perspective.

PubMed

van Rossum, Lisa; Aij, Kjeld Harald; Simons, Frederique Elisabeth; van der Eng, Niels; Ten Have, Wouter Dirk

2016-05-16

Purpose - Lean healthcare is used in a growing number of hospitals to increase efficiency and quality of care. However, healthcare organizations encounter problems with the implementation of change initiatives due to an implementation gap: the gap between strategy and execution. From a change management perspective, the purpose of this paper is to increase scientific knowledge regarding factors that diminish the implementation gap and make the transition from the "toolbox lean" toward an actual transformation to lean healthcare. Design/methodology/approach - A cross-sectional study was executed in an operating theatre of a Dutch University Medical Centre. Transformational leadership was expected to ensure the required top-down commitment, whereas team leadership creates the required active, bottom-up behavior of employees. Furthermore, professional and functional silos and a hierarchical structure were expected to impede the workforce flexibility in adapting organizational elements and optimize the entire process flow. Findings - The correlation and regression analyses showed positive relations between the transformational leadership and team leadership styles and lean healthcare implementation. The results also indicated a strong relation between workforce flexibility and the implementation of lean healthcare. Originality/value - With the use of a recently developed change management model, the Change Competence Model, the authors suggest leadership and workforce flexibility to be part of an organization's change capacity as crucial success factor for a sustainable transformation to lean healthcare.

Into the Square and out of the Box: The effects of Quadrato Motor Training on Creativity and Alpha Coherence

PubMed Central

Dotan Ben-Soussan, Tal; Glicksohn, Joseph; Goldstein, Abraham; Berkovich-Ohana, Aviva; Donchin, Opher

2013-01-01

The objective of the present study was to investigate the body-cognitive relationship through behavioral and electrophysiological measures in an attempt to uncover the underlying mediating neuronal mechanism for movement-induced cognitive change. To this end we examined the effects of Quadrato Motor Training (QMT), a new whole-body training paradigm on cognitive performance, including creativity and reaction time tasks, and electrophysiological change, using a within-subject pre-post design. Creativity was studied by means of the Alternate Uses Task, measuring ideational fluency and ideational flexibility. Electrophysiological effects were measured in terms of alpha power and coherence. In order to determine whether training-induced changes were driven by the cognitive or the motor aspects of the training, we used two control groups: Verbal Training (VT, identical cognitive training with verbal response) and Simple Motor Training (SMT, similar motor training with reduced choice requirements). Twenty-seven participants were randomly assigned to one of the groups. Following QMT, we found enhanced inter-hemispheric and intra-hemispheric alpha coherence, and increased ideational flexibility, which was not the case for either the SMT or VT groups. These findings indicate that it is the combination of the motor and cognitive aspects embedded in the QMT which is important for increasing ideational flexibility and alpha coherence. PMID:23383043

Flexible Lithium-Ion Fiber Battery by the Regular Stacking of Two-Dimensional Titanium Oxide Nanosheets Hybridized with Reduced Graphene Oxide.

PubMed

Hoshide, Tatsumasa; Zheng, Yuanchuan; Hou, Junyu; Wang, Zhiqiang; Li, Qingwen; Zhao, Zhigang; Ma, Renzhi; Sasaki, Takayoshi; Geng, Fengxia

2017-06-14

Increasing interest has recently been devoted to developing small, rapid, and portable electronic devices; thus, it is becoming critically important to provide matching light and flexible energy-storage systems to power them. To this end, compared with the inevitable drawbacks of being bulky, heavy, and rigid for traditional planar sandwiched structures, linear fiber-shaped lithium-ion batteries (LIB) have become increasingly important owing to their combined superiorities of miniaturization, adaptability, and weavability, the progress of which being heavily dependent on the development of new fiber-shaped electrodes. Here, we report a novel fiber battery electrode based on the most widely used LIB material, titanium oxide, which is processed into two-dimensional nanosheets and assembled into a macroscopic fiber by a scalable wet-spinning process. The titania sheets are regularly stacked and conformally hybridized in situ with reduced graphene oxide (rGO), thereby serving as efficient current collectors, which endows the novel fiber electrode with excellent integrated mechanical properties combined with superior battery performances in terms of linear densities, rate capabilities, and cyclic behaviors. The present study clearly demonstrates a new material-design paradigm toward novel fiber electrodes by assembling metal oxide nanosheets into an ordered macroscopic structure, which would represent the most-promising solution to advanced flexible energy-storage systems.

Development of flexible Ni80Fe20 magnetic nano-thin films

NASA Astrophysics Data System (ADS)

Vopson, M. M.; Naylor, J.; Saengow, T.; Rogers, E. G.; Lepadatu, S.; Fetisov, Y. K.

2017-11-01

Flexible magnetic Ni80Fe20 thin films with excellent adhesion, mechanical and magnetic properties have been fabricated using magnetron plasma deposition. We demonstrate that flexible Ni80Fe20 thin films maintain their non-flexible magnetic properties when the films are over 60 nm thick. However, when their thickness is reduced, the flexible thin films display significant increase in their magnetic coercive field compared to identical films coated on a solid Silicon substrate. For a 15 nm flexible Ni80Fe20 film coated onto 110 μm Polyvinylidene fluoride polymer substrate, we achieved a remarkable 355% increase in the magnetic coercive field relative to the same film deposited onto a Si substrate. Experimental evidence, backed by micro-magnetic modelling, indicates that the increase in the coercive fields is related to the larger roughness texture of the flexible substrates. This effect essentially transforms soft Ni80Fe20 permalloy thin films into medium/hard magnetic films allowing not only mechanical flexibility of the structure, but also fine tuning of their magnetic properties.

Design of a 7kW power transfer solar array drive mechanism

NASA Technical Reports Server (NTRS)

Sheppard, J. G.

1982-01-01

With the availability of the Shuttle and the European launcher, Ariane, there will be a continuing trend towards large payload satellite missions requiring high-power, high-inertia, flexible solar arrays. The need arises for a solar array drive with a large power transfer capability which can rotate these solar arrays without disturbing the satellite body pointing. The modular design of such a Solar Array Drive Mechanism (SADM) which is capable of transferring 7kW of power or more is described. Total design flexibility has been achieved, enabling different spacecraft power requirements to be accommodated within the SADM design.

Digital robust active control law synthesis for large order flexible structure using parameter optimization

NASA Technical Reports Server (NTRS)

Mukhopadhyay, V.

1988-01-01

A generic procedure for the parameter optimization of a digital control law for a large-order flexible flight vehicle or large space structure modeled as a sampled data system is presented. A linear quadratic Guassian type cost function was minimized, while satisfying a set of constraints on the steady-state rms values of selected design responses, using a constrained optimization technique to meet multiple design requirements. Analytical expressions for the gradients of the cost function and the design constraints on mean square responses with respect to the control law design variables are presented.

Matrix Transfer Function Design for Flexible Structures: An Application

NASA Technical Reports Server (NTRS)

Brennan, T. J.; Compito, A. V.; Doran, A. L.; Gustafson, C. L.; Wong, C. L.

1985-01-01

The application of matrix transfer function design techniques to the problem of disturbance rejection on a flexible space structure is demonstrated. The design approach is based on parameterizing a class of stabilizing compensators for the plant and formulating the design specifications as a constrained minimization problem in terms of these parameters. The solution yields a matrix transfer function representation of the compensator. A state space realization of the compensator is constructed to investigate performance and stability on the nominal and perturbed models. The application is made to the ACOSSA (Active Control of Space Structures) optical structure.

Coral-Inspired Nanoengineering Design for Long-Cycle and Flexible Lithium-Ion Battery Anode.

PubMed

Sun, Yangyong; Wang, Cheng; Xue, Yinghui; Zhang, Qin; Mendes, Rafael G; Chen, Linfeng; Zhang, Tao; Gemming, Thomas; Rümmeli, Mark H; Ai, Xinping; Fu, Lei

2016-04-13

Conversion reaction electrode materials (CREMs) have gained significant interest in lithium-ion batteries (LIBs) owing to their high theoretical gravimetric capacity. However, traditional CREMs-based electrodes, with large strain arising from Li(+) intercalation/deintercalation causes pulverization or electrical breakdown and cracking of the active materials which leads to structural collapse, limiting performance. Therefore, in order to construct electrodes with a strong tolerance to the strain incurred during the conversion reaction process, we design a coral-like three-dimensional (3D) hierarchical heterostructure by using cross-linked nanoflakes interspersed with nanoparticles (NPs) standing vertically on graphene foam (GF). The coral-like 3D hierarchical heterostructures can efficiently disperse the strain from both internal and external forces as well as increase the specific surface area for enhanced electrochemical reactions. These features lead to long-cycle stability and excellent flexibility in LIBs. Fe3O4 NPs and CoO NFs are utilized as a model system to demonstrate our strategy. The as-prepared coral-like hierarchical electrode is studied as an anode in LIBs for the first time and is shown to deliver a high reversible specific gravimetric capacity of ∼1200 mA h g(-1) at a rate of 0.5 A g(-1) for 400 cycles. In addition, our batteries can even power a green light-emitting diode when bent to high degrees confirming the excellent flexibility of the material.

Glass Fiber Reinforced Metal Pressure Vessel Design Guide

NASA Technical Reports Server (NTRS)

Landes, R. E.

1972-01-01

The Engineering Guide presents curves and general equations for safelife design of lightweight glass fiber reinforced (GFR) metal pressure vessels operating under anticipated Space Shuttle service conditions. The high composite vessel weight efficiency is shown to be relatively insensitive to shape, providing increased flexibility to designers establishing spacecraft configurations. Spheres, oblate speroids, and cylinders constructed of GFR Inconel X-750, 2219-T62 aluminum, and cryoformed 301 stainless steel are covered; design parameters and performance efficiencies for each configuration are compared at ambient and cryogenic temperature for an operating pressure range of 690 to 2760 N/sq cm (1000 to 4000 psi). Design variables are presented as a function of metal shell operating to sizing (proof) stress ratios for use with fracture mechanics data generated under a separate task of this program.

Redistribution of flexibility in stabilizing antibody fragment mutants follows Le Châtelier's principle.

PubMed

Li, Tong; Tracka, Malgorzata B; Uddin, Shahid; Casas-Finet, Jose; Jacobs, Donald J; Livesay, Dennis R

2014-01-01

Le Châtelier's principle is the cornerstone of our understanding of chemical equilibria. When a system at equilibrium undergoes a change in concentration or thermodynamic state (i.e., temperature, pressure, etc.), La Châtelier's principle states that an equilibrium shift will occur to offset the perturbation and a new equilibrium is established. We demonstrate that the effects of stabilizing mutations on the rigidity ⇔ flexibility equilibrium within the native state ensemble manifest themselves through enthalpy-entropy compensation as the protein structure adjusts to restore the global balance between the two. Specifically, we characterize the effects of mutation to single chain fragments of the anti-lymphotoxin-β receptor antibody using a computational Distance Constraint Model. Statistically significant changes in the distribution of both rigidity and flexibility within the molecular structure is typically observed, where the local perturbations often lead to distal shifts in flexibility and rigidity profiles. Nevertheless, the net gain or loss in flexibility of individual mutants can be skewed. Despite all mutants being exclusively stabilizing in this dataset, increased flexibility is slightly more common than increased rigidity. Mechanistically the redistribution of flexibility is largely controlled by changes in the H-bond network. For example, a stabilizing mutation can induce an increase in rigidity locally due to the formation of new H-bonds, and simultaneously break H-bonds elsewhere leading to increased flexibility distant from the mutation site via Le Châtelier. Increased flexibility within the VH β4/β5 loop is a noteworthy illustration of this long-range effect.

Redistribution of Flexibility in Stabilizing Antibody Fragment Mutants Follows Le Châtelier’s Principle

PubMed Central

Li, Tong; Tracka, Malgorzata B.; Uddin, Shahid; Casas-Finet, Jose; Jacobs, Donald J.; Livesay, Dennis R.

2014-01-01

Le Châtelier’s principle is the cornerstone of our understanding of chemical equilibria. When a system at equilibrium undergoes a change in concentration or thermodynamic state (i.e., temperature, pressure, etc.), La Châtelier’s principle states that an equilibrium shift will occur to offset the perturbation and a new equilibrium is established. We demonstrate that the effects of stabilizing mutations on the rigidity ⇔ flexibility equilibrium within the native state ensemble manifest themselves through enthalpy-entropy compensation as the protein structure adjusts to restore the global balance between the two. Specifically, we characterize the effects of mutation to single chain fragments of the anti-lymphotoxin-β receptor antibody using a computational Distance Constraint Model. Statistically significant changes in the distribution of both rigidity and flexibility within the molecular structure is typically observed, where the local perturbations often lead to distal shifts in flexibility and rigidity profiles. Nevertheless, the net gain or loss in flexibility of individual mutants can be skewed. Despite all mutants being exclusively stabilizing in this dataset, increased flexibility is slightly more common than increased rigidity. Mechanistically the redistribution of flexibility is largely controlled by changes in the H-bond network. For example, a stabilizing mutation can induce an increase in rigidity locally due to the formation of new H-bonds, and simultaneously break H-bonds elsewhere leading to increased flexibility distant from the mutation site via Le Châtelier. Increased flexibility within the VH β4/β5 loop is a noteworthy illustration of this long-range effect. PMID:24671209

Energy efficient flexible hybrid wavelength division multiplexing-time division multiplexing passive optical network with pay as you grow deployment

NASA Astrophysics Data System (ADS)

Garg, Amit Kumar; Madavi, Amresh Ashok; Janyani, Vijay

2017-02-01

A flexible hybrid wavelength division multiplexing-time division multiplexing passive optical network architecture that allows dual rate signals to be sent at 1 and 10 Gbps to each optical networking unit depending upon the traffic load is proposed. The proposed design allows dynamic wavelength allocation with pay-as-you-grow deployment capability. This architecture is capable of providing up to 40 Gbps of equal data rates to all optical distribution networks (ODNs) and up to 70 Gbps of a asymmetrical data rate to the specific ODN. The proposed design handles broadcasting capability with simultaneous point-to-point transmission, which further reduces energy consumption. In this architecture, each module sends a wavelength to each ODN, thus making the architecture fully flexible; this flexibility allows network providers to use only required OLT components and switch off others. The design is also reliable to any module or TRx failure and provides services without any service disruption. Dynamic wavelength allocation and pay-as-you-grow deployment support network extensibility and bandwidth scalability to handle future generation access networks.

Flexible manipulator control experiments and analysis

NASA Technical Reports Server (NTRS)

Yurkovich, S.; Ozguner, U.; Tzes, A.; Kotnik, P. T.

1987-01-01

Modeling and control design for flexible manipulators, both from an experimental and analytical viewpoint, are described. From the application perspective, an ongoing effort within the laboratory environment at the Ohio State University, where experimentation on a single link flexible arm is underway is described. Several unique features of this study are described here. First, the manipulator arm is slewed by a direct drive dc motor and has a rigid counterbalance appendage. Current experimentation is from two viewpoints: (1) rigid body slewing and vibration control via actuation with the hub motor, and (2) vibration suppression through the use of structure-mounted proof-mass actuation at the tip. Such an application to manipulator control is of interest particularly in design of space-based telerobotic control systems, but has received little attention to date. From an analytical viewpoint, parameter estimation techniques within the closed-loop for self-tuning adaptive control approaches are discussed. Also introduced is a control approach based on output feedback and frequency weighting to counteract effects of spillover in reduced-order model design. A model of the flexible manipulator based on experimental measurements is evaluated for such estimation and control approaches.

Printable Fabrication of Nanocoral-Structured Electrodes for High-Performance Flexible and Planar Supercapacitor with Artistic Design.

PubMed

Lin, Yuanjing; Gao, Yuan; Fan, Zhiyong

2017-11-01

Planar supercapacitors with high flexibility, desirable operation safety, and high performance are considered as attractive candidates to serve as energy-storage devices for portable and wearable electronics. Here, a scalable and printable technique is adopted to construct novel and unique hierarchical nanocoral structures as the interdigitated electrodes on flexible substrates. The as-fabricated flexible all-solid-state planar supercapacitors with nanocoral structures achieve areal capacitance up to 52.9 mF cm -2 , which is 2.5 times that of devices without nanocoral structures, and this figure-of-merit is among the highest in the literature for the same category of devices. More interestingly, due to utilization of the inkjet-printing technique, excellent versatility on electrode-pattern artistic design is achieved. Particularly, working supercapacitors with artistically designed patterns are demonstrated. Meanwhile, the high scalability of such a printable method is also demonstrated by fabrication of large-sized artistic supercapacitors serving as energy-storage devices in a wearable self-powered system as a proof of concept. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Development and Implementation of Training Curriculum/Program in Solar Heating and Cooling at the Technician Level, December 1, 1976 - November 30, 1977. Final Report.

ERIC Educational Resources Information Center

Kuhnle, Carl J., Jr.

The program proposal is designed to address the increasing demand for trained personnel to support the installation and maintenance of solar energy systems at residential and commercial sites. The three main objectives of the proposed program are: (1) to develop a flexible curricula to train a solar heating and cooling workforce; (2) to identify…

Carbon Nanotube Reinforced Flexible Windows for Blast Protection

DTIC Science & Technology

2010-07-01

transparent plastic composite for use as a material for window or as a laminate layer in the blast-resistant glazed window. This program focused...materials for window or as a laminate layer in the blast-resistant glazed window. It is obvious that further increasing the mechanical properties of...Dr. Ben Wang led the effort for design/fabrication of windows from the nanotube assembly and lamination experiments. 6 3. RESULTS AND

Protected area management

USGS Publications Warehouse

Fagre, Daniel B.; Prato, Tony; Wang, Yeqiao

2014-01-01

Designated protected areas are diverse in scope and purpose and have expanded from Yellowstone National Park in the United States, the world’s first national park, to 157,897 parks and protected areas distributed globally. Most are publicly owned and serve multiple needs that reflect regional or national cultures. With ever-increasing threats to the integrity of protected areas, managers are turning to flexible management practices such as scenario planning and adaptive management.

A shut-off valve for flexible tubing

NASA Technical Reports Server (NTRS)

Reyburn, W. W.

1972-01-01

Design of light weight valve for flexible tubing is described. Valve is hand operated and provides positive sealing in normally closed position. Diagram is provided to show construction of valve. Principles of operation are explained.

Evaluation of experimental flexible pavements : final report.

DOT National Transportation Integrated Search

1979-01-01

The construction and performance of seven Virginia flexible pavements containing at least some experimental features were evaluated. The objective was to evaluate the performance of the pavements incorporating new or timely design concepts and to ass...

Radial Inflow Turboexpander Redesign

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

William G. Price

2001-09-24

Steamboat Envirosystems, LLC (SELC) was awarded a grant in accordance with the DOE Enhanced Geothermal Systems Project Development. Atlas-Copco Rotoflow (ACR), a radial expansion turbine manufacturer, was responsible for the manufacturing of the turbine and the creation of the new computer program. SB Geo, Inc. (SBG), the facility operator, monitored and assisted ACR's activities as well as provided installation and startup assistance. The primary scope of the project is the redesign of an axial flow turbine to a radial inflow turboexpander to provide increased efficiency and reliability at an existing facility. In addition to the increased efficiency and reliability, themore » redesign includes an improved reduction gear design, and improved shaft seal design, and upgraded control system and a greater flexibility of application« less

Tuning the Adsorption-Induced Phase Change in the Flexible Metal–Organic Framework Co(bdp)

DOE PAGES

Taylor, Mercedes K.; Runčevski, Tomče; Oktawiec, Julia; ...

2016-11-02

Metal–organic frameworks that flex to undergo structural phase changes upon gas adsorption are promising materials for gas storage and separations, and achieving synthetic control over the pressure at which these changes occur is crucial to the design of such materials for specific applications. To this end, a new family of materials based on the flexible metal–organic framework Co(bdp) (bdp 2– = 1,4-benzenedipyrazolate) has been prepared via the introduction of fluorine, deuterium, and methyl functional groups on the bdp 2– ligand, namely, Co(F-bdp), Co(p-F 2-bdp), Co(o-F 2-bdp), Co(D 4-bdp), and Co(p-Me 2-bdp). These frameworks are isoreticular to the parent framework andmore » exhibit similar structural flexibility, transitioning from a low-porosity, collapsed phase to high-porosity, expanded phases with increasing gas pressure. Powder X-ray diffraction studies reveal that fluorination of the aryl ring disrupts edge-to-face π–π interactions, which work to stabilize the collapsed phase at low gas pressures, while deuteration preserves these interactions and methylation strengthens them. In agreement with these observations, high-pressure CH 4 adsorption isotherms show that the pressure of the CH 4-induced framework expansion can be systematically controlled by ligand functionalization, as materials without edge-to-face interactions in the collapsed phase expand at lower CH 4 pressures, while frameworks with strengthened edge-to-face interactions expand at higher pressures. This work puts forth a general design strategy relevant to many other families of flexible metal–organic frameworks, which will be a powerful tool in optimizing these phase-change materials for industrial applications.« less

A novel flexible clinical multiphoton tomograph for early melanoma detection, skin analysis, testing of anti-age products, and in situ nanoparticle tracking

NASA Astrophysics Data System (ADS)

Weinigel, Martin; Breunig, Hans Georg; Gregory, Axel; Fischer, Peter; Kellner-Höfer, Marcel; Bückle, Rainer; König, Karsten

2010-02-01

High-resolution 3D microscopy based on multiphoton induced autofluorescence and second harmonic generation have been introduced in 1990. 13 years later, CE-marked clinical multiphoton systems for 3D imaging of human skin with subcellular resolution have first been launched by JenLab company with the tomography DermaInspect®. This year, the second generation of clinical multiphoton tomographs was introduced. The novel multiphoton tomograph MPTflex, equipped with a flexible articulated optical arm, provides an increased flexibility and accessibility especially for clinical and cosmetical examinations. Improved image quality and signal to noise ratio (SNR) are achieved by a very short source-drain spacing, by larger active areas of the detectors and by single photon counting (SPC) technology. Shorter image acquisition time due to improved image quality reduces artifacts and simplifies the operation of the system. The compact folded optical design and the light-weight structure of the optical head eases the handling. Dual channel detectors enable to distinguish between intratissue elastic fibers and collagenous structures simultaneously. Through the use of piezo-driven optics a stack of optical cross-sections (optical sectioning) can be acquired and 3D imaging can be performed. The multiphoton excitation of biomolecules like NAD(P)H, flavins, porphyrins, elastin, and melanin is done by picojoule femtosecond laser pulses from an tunable turn-key femtosescond near infrared laser system. The ability for rapid high-quality image acquisition, the user-friendly operation of the system and the compact and flexible design qualifies this system to be used for melanoma detection, diagnostics of dermatological disorders, cosmetic research and skin aging measurements as well as in situ drug monitoring and animal research.

“Reverse Fleximers”: Introduction of a series of 5-substituted carbocyclic uridine analogues

PubMed Central

Sadler, Joshua M.; Ojewoye, Olubukola; Seley-Radtke, Katherine L.

2009-01-01

Nucleosides are ubiquitous in biological systems and as such, have been a focus of medicinal chemistry research in the search for new and potent therapeutic compounds. There are a number of modified nucleosides on the market, however increasing reports of resistance by mutation of either the enzyme binding site or the pathway that they are designed to interrupt are surfacing. As shown in recent reports, a candidate that can change conformation and still maintain recognition by the target enzyme would be highly desirable, and it is for this reason that flexible substrates have recently been sought as potential therapeutics. With this goal in mind, we have begun investigation into novel flexible scaffolds capable of overcoming viral resistance mechanisms resulting from binding site mutations. PMID:18776508

Versatile Miniature Tunable Liquid Lenses Using Transparent Graphene Electrodes.

PubMed

Shahini, Ali; Xia, Jinjun; Zhou, Zhixian; Zhao, Yang; Cheng, Mark Ming-Cheng

2016-02-16

This paper presents, for the first time, versatile and low-cost miniature liquid lenses with graphene as electrodes. Tunable focal length is achieved by changing the droplet curvature using electrowetting on dielectric (EWOD). Ionic liquid and KCl solution are utilized as lens liquid on the top of a flexible Teflon-coated PDMS/parylene membrane. Transparent and flexible, graphene allows transmission of visible light as well as large deformation of the polymer membrane to achieve requirements for different lens designs and to increase the field of view without damaging of electrodes. The tunable range for the focal length is between 3 and 7 mm for a droplet with a volume of 3 μL. The visualization of bone marrow dendritic cells is demonstrated by the liquid lens system with a high resolution (456 lp/mm).

Modular survivable satellite support

NASA Astrophysics Data System (ADS)

Wagner, R. E.

The development of a highly mobile, survivable satellite system from the Transportable Mobile Ground Station (T/MGS) is proposed. The addition of advanced capabilities to the T/MGS such as telemetry processing equipment, and the flexibility of a modularly designed system are examined. The need to increase survivability and mobility while reducing life cycle costs is discussed. A modular survivable satellite support system which consists of a 40-foot van, a diesel tractor, and a multimedia communications subsystem is described. The use of planar and phased arrays to improve transportability and new materials and structural designs to enhance hardness are discussed. Diagrams of the system are provided.

An FPGA- Based General-Purpose Data Acquisition Controller

NASA Astrophysics Data System (ADS)

Robson, C. C. W.; Bousselham, A.; Bohm

2006-08-01

System development in advanced FPGAs allows considerable flexibility, both during development and in production use. A mixed firmware/software solution allows the developer to choose what shall be done in firmware or software, and to make that decision late in the process. However, this flexibility comes at the cost of increased complexity. We have designed a modular development framework to help to overcome these issues of increased complexity. This framework comprises a generic controller that can be adapted for different systems by simply changing the software or firmware parts. The controller can use both soft and hard processors, with or without an RTOS, based on the demands of the system to be developed. The resulting system uses the Internet for both control and data acquisition. In our studies we developed the embedded system in a Xilinx Virtex-II Pro FPGA, where we used both PowerPC and MicroBlaze cores, http, Java, and LabView for control and communication, together with the MicroC/OS-II and OSE operating systems

Overall Water Splitting with Room-Temperature Synthesized NiFe Oxyfluoride Nanoporous Films

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

Liang, Kun; Guo, Limin; Marcus, Kyle

Freestanding and lightweight thin-films were rationally designed to serve as robust electrodes for renewable energy applications. A facile and scalable nanomanufacturing process was developed to fabricate these transformative thin-film electrodes (iron group mixed oxides) that exhibit a nanoporous structure and controllable composition. More specifically, electrodeposition and anodic treatments were employed to produce freestanding and lightweight metal oxides nanoporous layers (NPL). These NPL can be directly used as flexible and additive-free electrodes for renewable energy generation (water splitting) and storage (supercapacitor) applications without requiring binders and current collector and other additives. Significantly enhanced electrochemical performance was achieved due to the uniquemore » merits of the NPL: i) highly porous structure considerably increases the electrode/electrolyte interface, which facilitate electrochemical reactions; ii) NPL substantially increase the number of active sites that are favorable in electrochemical reactions; iii) residual metal network within the NPL forms a conductive framework, drastically improving electrode strength, flexibility and conductivity.« less

Impact of Flexibility Options on Grid Economic Carrying Capacity of Solar and Wind: Three Case Studies

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

Denholm, Paul; Novacheck, Joshua; Jorgenson, Jennie

In this study, we attempt to quantify the benefits of various options of grid flexibility by measuring their impact on two measures: economic carrying capacity and system costs. Flexibility can increase ECC and reduce overall system costs. In some cases, options that provide a limited increase in ECC can provide significant operational savings, thus demonstrating the need to evaluate flexibility options using multiple metrics. The value of flexibility options varies regionally due to different generation mixes and types of renewables. The more rapid decline in PV value compared to wind makes PV more dependent on adding flexibility options, including transmissionmore » and energy storage.« less

Flexible thin film circuitry enabling ubiquitous electronics via post-fabrication customization (Presentation Recording)

NASA Astrophysics Data System (ADS)

Cobb, Brian

2015-09-01

For decades, the electronics industry has been accurately described by Moore's Law, where the march towards increasing density and smaller feature sizes has enabled continuous cost reductions and performance improvements. With flexible electronics, this perpetual scaling is not foreseen to occur. Instead, the industry will be dominated by Wright's Law, first proposed in 1936, where increasing demand for high volumes of product will drive costs down. We have demonstrated thin film based circuitry compatible with flexible substrates with high levels of functionality designed for such a high volume industry. This includes a generic 8-bit microprocessor totaling more than 3.5k TFTs operating at 2.1 kHz. We have also developed a post fabrication programming technique via inkjet printing of conductive spots to form a one-time programmable instruction generator, allowing customization of the processor for a specific task. The combination demonstrates the possibility to achieve the high volume production of identical products necessary to reap the benefits promised by Wright's Law, while still retaining the individualization necessary for application differentiation. This is of particular importance in the area of item level identification via RFID, where low cost and individualized identification are necessary. Remotely powered RFID tags have been fabricated using an oxide semiconductor based TFT process. This process is compatible with the post-fabrication printing process to detail individual identification codes, with the goal of producing low cost, high volume flexible tags. The goal is to produce tags compatible with existing NFC communication protocols in order to communicate with readers that are already ubiquitous in the market.

Flexible Design and Operation of a Smart Charging Microgrid (Briefing Charts)

DTIC Science & Technology

2014-04-08

release; distribution unlimited 13. SUPPLEMENTARY NOTES Briefing Charts for SAE World Congress 2014 14. ABSTRACT A microgrid is a controllable ...UNCLASSIFIED Distribution Statement A: Approved for Public Release Flexible Design and Operation of a Smart Charging Microgrid Annette G... control number. 1. REPORT DATE 08 APR 2014 2. REPORT TYPE Briefing Charts 3. DATES COVERED 08-01-2014 to 09-03-2014 4. TITLE AND SUBTITLE

A software architecture for hard real-time execution of automatically synthesized plans or control laws

NASA Technical Reports Server (NTRS)

Schoppers, Marcel

1994-01-01

The design of a flexible, real-time software architecture for trajectory planning and automatic control of redundant manipulators is described. Emphasis is placed on a technique of designing control systems that are both flexible and robust yet have good real-time performance. The solution presented involves an artificial intelligence algorithm that dynamically reprograms the real-time control system while planning system behavior.

Flexible Wing Base Micro Aerial Vehicles: Composite Materials for Micro Air Vehicles

NASA Technical Reports Server (NTRS)

Ifju, Peter G.; Ettinger, Scott; Jenkins, David; Martinez, Luis

2002-01-01

This paper will discuss the development of the University of Florida's Micro Air Vehicle concept. A series of flexible wing based aircraft that possess highly desirable flight characteristics were developed. Since computational methods to accurately model flight at the low Reynolds numbers associated with this scale are still under development, our effort has relied heavily on trial and error. Hence a time efficient method was developed to rapidly produce prototype designs. The airframe and wings are fabricated using a unique process that incorporates carbon fiber composite construction. Prototypes can be fabricated in around five man-hours, allowing many design revisions to be tested in a short period of time. The resulting aircraft are far more durable, yet lighter, than their conventional counterparts. This process allows for thorough testing of each design in order to determine what changes were required on the next prototype. The use of carbon fiber allows for wing flexibility without sacrificing durability. The construction methods developed for this project were the enabling technology that allowed us to implement our designs. The resulting aircraft were the winning entries in the International Micro Air Vehicle Competition for the past two years. Details of the construction method are provided in this paper along with a background on our flexible wing concept.

Flexible ferroelectric element based on van der Waals heteroepitaxy.

PubMed

Jiang, Jie; Bitla, Yugandhar; Huang, Chun-Wei; Do, Thi Hien; Liu, Heng-Jui; Hsieh, Ying-Hui; Ma, Chun-Hao; Jang, Chi-Yuan; Lai, Yu-Hong; Chiu, Po-Wen; Wu, Wen-Wei; Chen, Yi-Chun; Zhou, Yi-Chun; Chu, Ying-Hao

2017-06-01

We present a promising technology for nonvolatile flexible electronic devices: A direct fabrication of epitaxial lead zirconium titanate (PZT) on flexible mica substrate via van der Waals epitaxy. These single-crystalline flexible ferroelectric PZT films not only retain their performance, reliability, and thermal stability comparable to those on rigid counterparts in tests of nonvolatile memory elements but also exhibit remarkable mechanical properties with robust operation in bent states (bending radii down to 2.5 mm) and cycling tests (1000 times). This study marks the technological advancement toward realizing much-awaited flexible yet single-crystalline nonvolatile electronic devices for the design and development of flexible, lightweight, and next-generation smart devices with potential applications in electronics, robotics, automotive, health care, industrial, and military systems.

Flexible ferroelectric element based on van der Waals heteroepitaxy

PubMed Central

Jiang, Jie; Bitla, Yugandhar; Huang, Chun-Wei; Do, Thi Hien; Liu, Heng-Jui; Hsieh, Ying-Hui; Ma, Chun-Hao; Jang, Chi-Yuan; Lai, Yu-Hong; Chiu, Po-Wen; Wu, Wen-Wei; Chen, Yi-Chun; Zhou, Yi-Chun; Chu, Ying-Hao

2017-01-01

We present a promising technology for nonvolatile flexible electronic devices: A direct fabrication of epitaxial lead zirconium titanate (PZT) on flexible mica substrate via van der Waals epitaxy. These single-crystalline flexible ferroelectric PZT films not only retain their performance, reliability, and thermal stability comparable to those on rigid counterparts in tests of nonvolatile memory elements but also exhibit remarkable mechanical properties with robust operation in bent states (bending radii down to 2.5 mm) and cycling tests (1000 times). This study marks the technological advancement toward realizing much-awaited flexible yet single-crystalline nonvolatile electronic devices for the design and development of flexible, lightweight, and next-generation smart devices with potential applications in electronics, robotics, automotive, health care, industrial, and military systems. PMID:28630922

smiFISH and FISH-quant - a flexible single RNA detection approach with super-resolution capability.

PubMed

Tsanov, Nikolay; Samacoits, Aubin; Chouaib, Racha; Traboulsi, Abdel-Meneem; Gostan, Thierry; Weber, Christian; Zimmer, Christophe; Zibara, Kazem; Walter, Thomas; Peter, Marion; Bertrand, Edouard; Mueller, Florian

2016-12-15

Single molecule FISH (smFISH) allows studying transcription and RNA localization by imaging individual mRNAs in single cells. We present smiFISH (single molecule inexpensive FISH), an easy to use and flexible RNA visualization and quantification approach that uses unlabelled primary probes and a fluorescently labelled secondary detector oligonucleotide. The gene-specific probes are unlabelled and can therefore be synthesized at low cost, thus allowing to use more probes per mRNA resulting in a substantial increase in detection efficiency. smiFISH is also flexible since differently labelled secondary detector probes can be used with the same primary probes. We demonstrate that this flexibility allows multicolor labelling without the need to synthesize new probe sets. We further demonstrate that the use of a specific acrydite detector oligonucleotide allows smiFISH to be combined with expansion microscopy, enabling the resolution of transcripts in 3D below the diffraction limit on a standard microscope. Lastly, we provide improved, fully automated software tools from probe-design to quantitative analysis of smFISH images. In short, we provide a complete workflow to obtain automatically counts of individual RNA molecules in single cells. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

Flexible asymmetric supercapacitors with high energy and high power density in aqueous electrolytes.

PubMed

Cheng, Yingwen; Zhang, Hongbo; Lu, Songtao; Varanasi, Chakrapani V; Liu, Jie

2013-02-07

Supercapacitors with both high energy and high power densities are critical for many practical applications. In this paper, we discuss the design and demonstrate the fabrication of flexible asymmetric supercapacitors based on nanocomposite electrodes of MnO(2), activated carbon, carbon nanotubes and graphene. The combined unique properties of each of these components enable highly flexible and mechanically strong films that can serve as electrodes directly without using any current collectors or binders. Using these flexible electrodes and a roll-up approach, asymmetric supercapacitors with 2 V working voltage were successfully fabricated. The fabricated device showed excellent rate capability, with 78% of the original capacitance retained when the scan rate was increased from 2 mV s(-1) to 500 mV s(-1). Owing to the unique composite structure, these supercapacitors were able to deliver high energy density (24 W h kg(-1)) under high power density (7.8 kW kg(-1)) conditions. These features could enable supercapacitor based energy storage systems to be very attractive for a variety of critical applications, such as the power sources in hybrid electric vehicles and the back-up powers for wind and solar energy, where both high energy density and high power density are required.

A high-capacitance flexible solid-state supercapacitor based on polyaniline and Metal-Organic Framework (UiO-66) composites

NASA Astrophysics Data System (ADS)

Shao, Liang; Wang, Qian; Ma, Zhonglei; Ji, Zhanyou; Wang, Xiaoying; Song, Doudou; Liu, Yuguo; Wang, Ni

2018-03-01

Metal-Organic Frameworks (MOFs) attract increasing attention in the field of energy storage, however, poor conductivity in most MOFs largely hinders their electrical properties. In this work, an effective strategy is developed to make the polyaniline (PANI) molecular chains grow in the pores of UiO-66 as one of the MOFs (labeled as PANI/UiO-66) to form a fixed interpenetrating network structure by using the highly stable porous MOFs, through a variety of synergistic effects to enhance the conductivity and electrochemical properties. Moreover, the design and analysis about PANI/UiO-66 is reported for the first time to our knowledge. In addition, PANI/UiO-66 exhibits an extraordinary capacitance of 1015 F g-1 at 1 A g-1 by electrochemical test. At the same time, the symmetric flexible solid-state supercapacitors is also assembled and tested. The resultant supercapacitor shows a favorable specific capacitance of 647 F g-1 at 1 A g-1 and a high cycling stability (91% capacitance retention after 5000 cycles). The bending test indicates that the obtained supercapacitor is flexible and its performance is only decreased 10% after 800 bending cycles with a bending angle of 180. This flexible solid-state supercapacitor shows great potential in energy storage device.

PeptideDepot: Flexible Relational Database for Visual Analysis of Quantitative Proteomic Data and Integration of Existing Protein Information

PubMed Central

Yu, Kebing; Salomon, Arthur R.

2010-01-01

Recently, dramatic progress has been achieved in expanding the sensitivity, resolution, mass accuracy, and scan rate of mass spectrometers able to fragment and identify peptides through tandem mass spectrometry (MS/MS). Unfortunately, this enhanced ability to acquire proteomic data has not been accompanied by a concomitant increase in the availability of flexible tools allowing users to rapidly assimilate, explore, and analyze this data and adapt to a variety of experimental workflows with minimal user intervention. Here we fill this critical gap by providing a flexible relational database called PeptideDepot for organization of expansive proteomic data sets, collation of proteomic data with available protein information resources, and visual comparison of multiple quantitative proteomic experiments. Our software design, built upon the synergistic combination of a MySQL database for safe warehousing of proteomic data with a FileMaker-driven graphical user interface for flexible adaptation to diverse workflows, enables proteomic end-users to directly tailor the presentation of proteomic data to the unique analysis requirements of the individual proteomics lab. PeptideDepot may be deployed as an independent software tool or integrated directly with our High Throughput Autonomous Proteomic Pipeline (HTAPP) used in the automated acquisition and post-acquisition analysis of proteomic data. PMID:19834895

Fluid-structure coupling for wind turbine blade analysis using OpenFOAM

NASA Astrophysics Data System (ADS)

Dose, Bastian; Herraez, Ivan; Peinke, Joachim

2015-11-01

Modern wind turbine rotor blades are designed increasingly large and flexible. This structural flexibility represents a problem for the field of Computational Fluid Dynamics (CFD), which is used for accurate load calculations and detailed investigations of rotor aerodynamics. As the blade geometries within CFD simulations are considered stiff, the effect of blade deformation caused by aerodynamic loads cannot be captured by the common CFD approach. Coupling the flow solver with a structural solver can overcome this restriction and enables the investigation of flexible wind turbine blades. For this purpose, a new Finite Element (FE) solver was implemented into the open source CFD code OpenFOAM. Using a beam element formulation based on the Geometrically Exact Beam Theory (GEBT), the structural model can capture geometric non-linearities such as large deformations. Coupled with CFD solvers of the OpenFOAM package, the new framework represents a powerful tool for aerodynamic investigations. In this work, we investigated the aerodynamic performance of a state of the art wind turbine. For different wind speeds, aerodynamic key parameters are evaluated and compared for both, rigid and flexible blade geometries. The present work is funded within the framework of the joint project Smart Blades (0325601D) by the German Federal Ministry for Economic Affairs and Energy (BMWi) under decision of the German Federal Parliament.

The Moderating Effects of IT Training Programs: A Study of IT Flexibility Investments

ERIC Educational Resources Information Center

Plickebaum, Terry L.

2012-01-01

Information technology (IT) flexibility continues to grow in importance as organizations become increasingly dependent on IT in increasingly dynamic business environments. The contribution of IT infrastructure towards IT flexibility is fairly well understood and managed within organizations today. The contribution of IT personnel capabilities…

Developing a mixture design specification for flexible base construction.

DOT National Transportation Integrated Search

2012-06-01

In the Texas Department of Transportation (TxDOT), flexible base producers typically generate large stockpiles of material exclusively for TxDOT projects. This large state-only inventory often maintained by producers, along with time requiremen...

20 CFR 661.440 - What limitations apply to the State's Workforce Flexibility Plan authority under WIA?

Code of Federal Regulations, 2010 CFR

2010-04-01

... TRAINING ADMINISTRATION, DEPARTMENT OF LABOR STATEWIDE AND LOCAL GOVERNANCE OF THE WORKFORCE INVESTMENT... flexibility plan. Once approved, a State's work-flex designation is conditioned on the State demonstrating it...

Modified Dynamic Inversion to Control Large Flexible Aircraft: What's Going On?

NASA Technical Reports Server (NTRS)

Gregory, Irene M.

1999-01-01

High performance aircraft of the future will be designed lighter, more maneuverable, and operate over an ever expanding flight envelope. One of the largest differences from the flight control perspective between current and future advanced aircraft is elasticity. Over the last decade, dynamic inversion methodology has gained considerable popularity in application to highly maneuverable fighter aircraft, which were treated as rigid vehicles. This paper explores dynamic inversion application to an advanced highly flexible aircraft. An initial application has been made to a large flexible supersonic aircraft. In the course of controller design for this advanced vehicle, modifications were made to the standard dynamic inversion methodology. The results of this application were deemed rather promising. An analytical study has been undertaken to better understand the nature of the made modifications and to determine its general applicability. This paper presents the results of this initial analytical look at the modifications to dynamic inversion to control large flexible aircraft.

Study of design and control of remote manipulators. Part 2: Vibration considerations in manipulator design

NASA Technical Reports Server (NTRS)

Book, W. J.

1973-01-01

An investigation is reported involving a mathematical procedure using 4 x 4 transformation matrices for analyzing the vibrations of flexible manipulators. Previous studies with the procedure are summarized and the method is extended to include flexible joints as well as links, and to account for the effects of various power transmission schemes. A systematic study of the allocation of structural material and the placement of components such as motors and gearboxes was undertaken using the analytical tools developed. As one step in this direction the variables which relate the vibration parameters of the arm to the task and environment of the arm were isolated and nondimensionalized. The 4 x 4 transformation matrices were also used to develop analytical expressions for the terms of the complete 6 x 6 compliance matrix for the case of two flexible links joined by a rotating joint, flexible about its axis of rotation.

Gantries and dose delivery systems

NASA Astrophysics Data System (ADS)

Meer, David; Psoroulas, Serena

2015-06-01

Particle therapy is a field in remarkable development, with the goal of increasing the number of indications which could benefit from such treatments and the access to the therapy. The therapeutic usage of a particle beam defines the technical requirements of all the elements of the therapy chain: we summarize the main characteristics of accelerators, the beam line, the treatment room, the integrated therapy and imaging systems used in particle therapy. Aiming at a higher flexibility in the choice of treatments, an increasing number of centers around the world have chosen to equip their treatment rooms with gantries, rotating beam line structures that allow a complete flexibility in the choice of the treatment angle. We review the current designs. A particle therapy gantry though is a quite expensive structure, and future development will increasingly consider reducing the cost and the footprint. Increasing the number of indications also means development in the delivery techniques and solving some of the issues which traditionally affected particle therapy, for example the precision of the delivery in presence of motion and the large penumbras for low depths. We show the current strategies in these fields, focusing on pencil beam scanning (PBS), and give some hints about future developments.

Development and initial evaluation of an enhanced measure of boundary flexibility for the work and family domains.

PubMed

Matthews, Russell A; Barnes-Farrell, Janet L

2010-07-01

This manuscript reports the development of a measure of work and family domain boundary flexibility. Building on previous research, we propose an expanded definition of boundary flexibility that includes two components-flexibility-ability and flexibility-willingness-and we develop a measure designed to capture this more comprehensive definition of boundary flexibility. Flexibility-ability is conceptualized as an individual's perception of personal and situational constraints that affect boundary management, and flexibility-willingness is conceptualized as an individual difference variable that captures the motivation to engage in boundary flexing. An additional feature of domain boundaries, permeability, is also examined. Data are presented from two studies. Study 1 (N = 244) describes the development of a multiscale measure that extends current conceptual definitions of boundary flexibility. Study 2 (N = 225) describes the refinement and evaluation of this measure. Confirmatory factor analysis, reliability evidence, interscale correlations, and correlations with important work-family constructs (e.g., domain centrality, work-family conflict) provide initial construct validity evidence for the measure.

Measure Guideline: Optimizing the Configuration of Flexible Duct Junction Boxes

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

Beach, R.; Burdick, A.

2014-03-01

This measure guideline offers additional recommendations to heating, ventilation, and air conditioning (HVAC) system designers for optimizing flexible duct, constant-volume HVAC systems using junction boxes within Air Conditioning Contractors of America (ACCA) Manual D guidance. IBACOS used computational fluid dynamics software to explore and develop guidance to better control the airflow effects of factors that may impact pressure losses within junction boxes among various design configurations. These recommendations can help to ensure that a system aligns more closely with the design and the occupants' comfort expectations. Specifically, the recommendations described herein show how to configure a rectangular box with fourmore » outlets, a triangular box with three outlets, metal wyes with two outlets, and multiple configurations for more than four outlets. Designers of HVAC systems, contractors who are fabricating junction boxes on site, and anyone using the ACCA Manual D process for sizing duct runs will find this measure guideline invaluable for more accurately minimizing pressure losses when using junction boxes with flexible ducts.« less

The Flexibility Hypothesis of Healing.

PubMed

Hinton, Devon E; Kirmayer, Laurence J

2017-03-01

Theories of healing have attempted to identify general mechanisms that may work across different modalities. These include altering expectations, remoralization, and instilling hope. In this paper, we argue that many forms of healing and psychotherapy may work by inducing positive psychological states marked by flexibility or an enhanced ability to shift cognitive sets. Healing practices may induce these states of cognitive and emotional flexibility through specific symbolic interventions we term "flexibility primers" that can include images, metaphors, music, and other media. The flexibility hypothesis suggests that cognitive and emotional flexibility is represented, elicited, and enacted through multiple modalities in healing rituals. Identifying psychological processes and cultural forms that evoke and support cognitive and emotional flexibility provides a way to understand the cultural specificity and potential efficacy of particular healing practices and can guide the design of interventions that promote resilience and well-being.

Turgidity-dependent petiole flexibility enables efficient water use by a tree subjected to water stress.

PubMed

Gonzalez-Rodriguez, David; Cournède, Paul-Henry; de Langre, Emmanuel

2016-06-07

Water stress is a major cause of tree mortality. In response to drought, leaves wilt due to an increase in petiole flexibility. We present an analytical model coupling petiole mechanics, thermal balance, and xylem hydraulics to investigate the role of petiole flexibility in protecting a tree from water stress. Our model suggests that turgidity-dependent petiole flexibility can significantly attenuate the minimal xylem pressure and thus reduce the risk of cavitation. Moreover, we show that petiole flexibility increases water use efficiency by trees under water stress. Copyright © 2016 Elsevier Ltd. All rights reserved.

A linear parameter-varying multiobjective control law design based on youla parametrization for a flexible blended wing body aircraft

NASA Astrophysics Data System (ADS)

Demourant, F.; Ferreres, G.

2013-12-01

This article presents a methodology for a linear parameter-varying (LPV) multiobjective flight control law design for a blended wing body (BWB) aircraft and results. So, the method is a direct design of a parametrized control law (with respect to some measured flight parameters) through a multimodel convex design to optimize a set of specifications on the full-flight domain and different mass cases. The methodology is based on the Youla parameterization which is very useful since closed loop specifications are affine with respect to Youla parameter. The LPV multiobjective design method is detailed and applied to the BWB flexible aircraft example.

Flexible superior electrode architectures based on three-dimensional porous spinous α-Fe2O3 with a high performance as a supercapacitor.

PubMed

Nan, Honghong; Yu, Liutao; Ma, Wenqin; Geng, Baoyou; Zhang, Xiaojun

2015-05-28

Flexible supercapacitors have recently attracted increasing attention as they show unique promising advantages, such as flexibility and shape diversity, and they are light-weight and so on. Herein, we designed a series of 3D porous spinous iron oxide materials synthesized on a thin iron plate through a facile method under mild conditions. The unique nanostructural features endow them with excellent electrochemical performance. The electrochemical properties of the integrated electrodes as active electrode materials for supercapacitors have been investigated using different electrochemical techniques including cyclic voltammetry, and galvanostatic charge-discharge in Na2SO4 and LiPF6/EC : DEC electrolyte solutions. These integrated electrodes showed high specific capacitance (as high as 524.6 F g(-1) at the current density of 1 A g(-1)) in 1.0 M Na2SO4 (see Table S1). Moreover, the integrated electrodes also show high power densities and high energy densities in a LiPF6/EC : DEC electrolyte solution; for example, the energy densities were 319.3, 252.5, 152.1, 74.13 and 38.6 W h kg(-1) at different power densities of 8.81, 21.59, 56.65, 92.09 and 152.64 kW kg(-1), respectively. Additionally, the flexible superior electrode exhibited excellent stability with capacitance retention of 92.9% after 5000 cycles. Therefore, such flexible integrated devices might be used in smart and portable electronics.

Transparent conducting oxide-free nitrogen-doped graphene/reduced hydroxylated carbon nanotube composite paper as flexible counter electrodes for dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Zhang, Jindan; Yu, Mei; Li, Songmei; Meng, Yanbing; Wu, Xueke; Liu, Jianhua

2016-12-01

Three-dimensional nitrogen-doped graphene/reduced hydroxylated carbon nanotube composite aerogel (NG/CNT-OH) with unique hierarchical porosity and mechanical stability is developed through a two-step hydrothermal reaction. With plenty of exposed active sites and efficient multidimensional transport pathways of electrons and ions, NG/CNT-OH exhibits great electrocatalytic performances for I-/I3- redox couple. The subsequent compressed NG/CNT-OH papers possess high electrical conductivity and good flexibility, thus generating high-performance flexible counter electrodes (CEs) with transparent conducting oxide free (TCO-free) for dye-sensitized solar cells (DSSCs). The flexible NG/CNT-OH electrodes show good stability and the DSSCs with the optimized NG/CNT-OH CE had higher short-circuit current density (13.62 mA cm-2) and cell efficiency (6.36%) than DSSCs using Pt CE, whereas those of the DSSCs using Pt CE were only 12.81 mA cm-2 and 5.74%, respectively. Increasing the ratio of hydroxylated carbon nanotubes (CNT-OH) to the graphene oxide (GO) in the reactant would lead to less content of doped N, but better diffusion of electrolyte in the CEs because of more complete GO etching reaction. The design strategy presents a facile and cost effective way to synthesis three-dimensional graphene/CNT composite aerogel with excellent performance, and it can be potentially used as flexible TCO-free CE in other power conversion or energy storage devices.

Reliability Assessment of a Robust Design Under Uncertainty for a 3-D Flexible Wing

NASA Technical Reports Server (NTRS)

Gumbert, Clyde R.; Hou, Gene J. -W.; Newman, Perry A.

2003-01-01

The paper presents reliability assessment results for the robust designs under uncertainty of a 3-D flexible wing previously reported by the authors. Reliability assessments (additional optimization problems) of the active constraints at the various probabilistic robust design points are obtained and compared with the constraint values or target constraint probabilities specified in the robust design. In addition, reliability-based sensitivity derivatives with respect to design variable mean values are also obtained and shown to agree with finite difference values. These derivatives allow one to perform reliability based design without having to obtain second-order sensitivity derivatives. However, an inner-loop optimization problem must be solved for each active constraint to find the most probable point on that constraint failure surface.

Direct model reference adaptive control of a flexible robotic manipulator

NASA Technical Reports Server (NTRS)

Meldrum, D. R.

1985-01-01

Quick, precise control of a flexible manipulator in a space environment is essential for future Space Station repair and satellite servicing. Numerous control algorithms have proven successful in controlling rigid manipulators wih colocated sensors and actuators; however, few have been tested on a flexible manipulator with noncolocated sensors and actuators. In this thesis, a model reference adaptive control (MRAC) scheme based on command generator tracker theory is designed for a flexible manipulator. Quicker, more precise tracking results are expected over nonadaptive control laws for this MRAC approach. Equations of motion in modal coordinates are derived for a single-link, flexible manipulator with an actuator at the pinned-end and a sensor at the free end. An MRAC is designed with the objective of controlling the torquing actuator so that the tip position follows a trajectory that is prescribed by the reference model. An appealing feature of this direct MRAC law is that it allows the reference model to have fewer states than the plant itself. Direct adaptive control also adjusts the controller parameters directly with knowledge of only the plant output and input signals.

Towards flexible solid-state supercapacitors for smart and wearable electronics.

PubMed

Dubal, Deepak P; Chodankar, Nilesh R; Kim, Do-Heyoung; Gomez-Romero, Pedro

2018-03-21

Flexible solid-state supercapacitors (FSSCs) are frontrunners in energy storage device technology and have attracted extensive attention owing to recent significant breakthroughs in modern wearable electronics. In this study, we review the state-of-the-art advancements in FSSCs to provide new insights on mechanisms, emerging electrode materials, flexible gel electrolytes and novel cell designs. The review begins with a brief introduction on the fundamental understanding of charge storage mechanisms based on the structural properties of electrode materials. The next sections briefly summarise the latest progress in flexible electrodes (i.e., freestanding and substrate-supported, including textile, paper, metal foil/wire and polymer-based substrates) and flexible gel electrolytes (i.e., aqueous, organic, ionic liquids and redox-active gels). Subsequently, a comprehensive summary of FSSC cell designs introduces some emerging electrode materials, including MXenes, metal nitrides, metal-organic frameworks (MOFs), polyoxometalates (POMs) and black phosphorus. Some potential practical applications, such as the development of piezoelectric, photo-, shape-memory, self-healing, electrochromic and integrated sensor-supercapacitors are also discussed. The final section highlights current challenges and future perspectives on research in this thriving field.

An All-Freeze-Casting Strategy to Design Typographical Supercapacitors with Integrated Architectures.

PubMed

Wang, Qingrong; Wang, Xinyu; Wan, Fang; Chen, Kena; Niu, Zhiqiang; Chen, Jun

2018-06-01

The emergence of flexible and wearable electronics has raised the demand for flexible supercapacitors with accurate sizes and aesthetic shapes. Here, a strategy is developed to prepare flexible all-in-one integrated supercapacitors by combining all-freeze-casting with typography technique. The continuous seamless connection of all-in-one supercapacitor devices enhances the load and/or electron transfer capacity and avoids displacing and detaching between their neighboring components at bending status. Therefore, such a unique structure of all-in-one integrated devices is beneficial for retaining stable electrochemical performance at different bending levels. More importantly, the sizes and aesthetic shapes of integrated supercapacitors could be controlled by the designed molds, like type matrices of typography. The molds could be assembled together and typeset randomly, achieving the controllable construction and series and/or parallel connection of several supercapacitor devices. The preparation of flexible integrated supercapacitors will pave the way for assembling programmable all-in-one energy storage devices into highly flexible electronics. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Active-matrix OLED using 150°C a-Si TFT backplane built on flexible plastic substrate

NASA Astrophysics Data System (ADS)

Sarma, Kalluri R.; Chanley, Charles; Dodd, Sonia R.; Roush, Jared; Schmidt, John; Srdanov, Gordana; Stevenson, Matthew; Wessel, Ralf; Innocenzo, Jeffrey; Yu, Gang; O'Regan, Marie B.; MacDonald, W. A.; Eveson, R.; Long, Ke; Gleskova, Helena; Wagner, Sigurd; Sturm, James C.

2003-09-01

Flexible displays fabricated using plastic substrates have a potential for being very thin, light weight, highly rugged with greatly minimized propensity for breakage, roll-to-roll manufacturing and lower cost. The emerging OLED display media offers the advantage of being a solid state and rugged structure for flexible displays in addition to the many potential advantages of an AM OLED over the currently dominant AM LCD. The current high level of interest in flexible displays is facilitating the development of the required enabling technologies which include development of plastic substrates, low temperature active matrix device and backplane fabrication, and display packaging. In the following we will first discuss our development efforts in the PEN based plastic substrates, active matrix backplane technology, low temperature (150°C) a-Si TFT devices and an AM OLED test chip used for evaluating various candidate designs. We will then describe the design, fabrication and successful evaluation and demonstration of a 64x64 pixel AM OLED test display using a-Si TFT backplane fabricated at 150°C on the flexible plastic substrate.

Static aeroelastic analysis and tailoring of a single-element racing car wing

NASA Astrophysics Data System (ADS)

Sadd, Christopher James

This thesis presents the research from an Engineering Doctorate research programme in collaboration with Reynard Motorsport Ltd, a manufacturer of racing cars. Racing car wing design has traditionally considered structures to be rigid. However, structures are never perfectly rigid and the interaction between aerodynamic loading and structural flexibility has a direct impact on aerodynamic performance. This interaction is often referred to as static aeroelasticity and the focus of this research has been the development of a computational static aeroelastic analysis method to improve the design of a single-element racing car wing. A static aeroelastic analysis method has been developed by coupling a Reynolds-Averaged Navier-Stokes CFD analysis method with a Finite Element structural analysis method using an iterative scheme. Development of this method has included assessment of CFD and Finite Element analysis methods and development of data transfer and mesh deflection methods. Experimental testing was also completed to further assess the computational analyses. The computational and experimental results show a good correlation and these studies have also shown that a Navier-Stokes static aeroelastic analysis of an isolated wing can be performed at an acceptable computational cost. The static aeroelastic analysis tool was used to assess methods of tailoring the structural flexibility of the wing to increase its aerodynamic performance. These tailoring methods were then used to produce two final wing designs to increase downforce and reduce drag respectively. At the average operating dynamic pressure of the racing car, the computational analysis predicts that the downforce-increasing wing has a downforce of C[1]=-1.377 in comparison to C[1]=-1.265 for the original wing. The computational analysis predicts that the drag-reducing wing has a drag of C[d]=0.115 in comparison to C[d]=0.143 for the original wing.

Thermal design and validation of radiation detector for the ChubuSat-2 micro-satellite with high-thermal-conductive graphite sheets

NASA Astrophysics Data System (ADS)

Park, Daeil; Miyata, Kikuko; Nagano, Hosei

2017-07-01

This paper describes thermal design of the radiation detector (RD) for the ChubuSat-2 with the use of high-thermal-conductive materials. ChubuSat-2 satellite is a 50-kg-class micro-satellite joint development with Nagoya University and aerospace companies. The main mission equipment of ChubuSat-2 is a RD to observe neutrons and gamma rays. However, the thermal design of the RD encounters a serious problem, such as no heater for RD and electric circuit alignment constrain. To solve this issue, the RD needs a new thermal design and thermal control for successful space missions. This paper proposes high-thermal-conductive graphite sheets to be used as a flexible radiator fin for the RD. Before the fabrication of the device, the optimal thickness and surface area for the flexible radiator fin were determined by thermal analysis. Consequently, the surface area of flexible radiator fin was determined to be 8.6×104 mm2. To verify the effects of the flexible radiator fin, we constructed a verification model and analyzed the temperature distributions in the RD. Also, the thermal vacuum test was performed using a thermal vacuum chamber, which was evacuated at a pressure of around 10-4 Pa, and its internal temperature was cooled at -80 °C by using a refrigerant. As a result, it has been demonstrated that the flexible radiator fin is effective. And the thermal vacuum test results are presented good correlation with the analysis results.

Bioinspired Design of Strong, Tough, and Highly Conductive Polyol-Polypyrrole Composites for Flexible Electronics.

PubMed

Gao, Fengxian; Zhang, Ning; Fang, Xiaodong; Ma, Mingming

2017-02-22

Inspired by the dynamic network structure of animal dermis, we have designed and synthesized a series of polyol-polypyrrole (polyol-PPy) composites. Polyols and polypyrrole are cross-linked by hydrogen bonding and electrostatic interactions to form a dynamic network, which helps to dissipate destructive energy. We have found a clear correlation between the mechanical properties of polyol-PPy composites and the polyols structure. Particularly, the PEE-PPy film shows both high strength and flexibility, leading to a remarkable tensile toughness comparable to cocoon silk. The combination of outstanding strength, ductility, and conductivity enables polyol-PPy composites (especially PEE-PPy) as potential electronic materials for making flexible electronics.

Aeroservoelastic wind-tunnel investigations using the Active Flexible Wing Model: Status and recent accomplishments

NASA Technical Reports Server (NTRS)

Noll, Thomas E.; Perry, Boyd, III; Tiffany, Sherwood H.; Cole, Stanley R.; Buttrill, Carey S.; Adams, William M., Jr.; Houck, Jacob A.; Srinathkumar, S.; Mukhopadhyay, Vivek; Pototzky, Anthony S.

1989-01-01

The status of the joint NASA/Rockwell Active Flexible Wing Wind-Tunnel Test Program is described. The objectives are to develop and validate the analysis, design, and test methodologies required to apply multifunction active control technology for improving aircraft performance and stability. Major tasks include designing digital multi-input/multi-output flutter-suppression and rolling-maneuver-load alleviation concepts for a flexible full-span wind-tunnel model, obtaining an experimental data base for the basic model and each control concept and providing comparisons between experimental and analytical results to validate the methodologies. The opportunity is provided to improve real-time simulation techniques and to gain practical experience with digital control law implementation procedures.

The Research of Computer Aided Farm Machinery Designing Method Based on Ergonomics

NASA Astrophysics Data System (ADS)

Gao, Xiyin; Li, Xinling; Song, Qiang; Zheng, Ying

Along with agricultural economy development, the farm machinery product type Increases gradually, the ergonomics question is also getting more and more prominent. The widespread application of computer aided machinery design makes it possible that farm machinery design is intuitive, flexible and convenient. At present, because the developed computer aided ergonomics software has not suitable human body database, which is needed in view of farm machinery design in China, the farm machinery design have deviation in ergonomics analysis. This article puts forward that using the open database interface procedure in CATIA to establish human body database which aims at the farm machinery design, and reading the human body data to ergonomics module of CATIA can product practical application virtual body, using human posture analysis and human activity analysis module to analysis the ergonomics in farm machinery, thus computer aided farm machinery designing method based on engineering can be realized.

Remote manipulator system flexibility analysis program: Mission planning, mission analysis, and software formulation

NASA Technical Reports Server (NTRS)

Kumar, L.

1978-01-01

A computer program is described for calculating the flexibility coefficients as arm design changes are made for the remote manipulator system. The coefficients obtained are required as input for a second program which reduces the number of payload deployment and retrieval system simulation runs required to simulate the various remote manipulator system maneuvers. The second program calculates end effector flexibility and joint flexibility terms for the torque model of each joint for any arbitrary configurations. The listing of both programs is included in the appendix.

Age differences in workplace intervention effects on employees’ nighttime and daytime sleep

PubMed Central

Lee, Soomi; Almeida, David M.; Berkman, Lisa; Olson, Ryan; Moen, Phyllis; Buxton, Orfeu M.

2017-01-01

Objectives To examine the effects of a workplace flexibility/support intervention on employees’ sleep quantity and quality during nights and days and whether the effects differ by employee age. Design Cluster-randomized controlled trial. Setting Information technology industry workplaces. Participants US employees (Mage = 46.9 years) at an information technology firm who provided actigraphy at baseline and a 12-month follow-up (N = 396; n = 195 intervention, n = 201 control). Intervention The Work, Family, and Health Study intervention aimed to increase workplace flexibility and support. The intervention consisted of facilitated discussions to help employees increase control over when and where they work as well as manager-specific training sessions to increase manager support for employees’ work-family issues. Measurements Nighttime sleep duration, wake after sleep onset (WASO), and nap duration were measured with wrist actigraphy. Day-to-day variability in these variables (min2) was also estimated. Results Intervention employees increased nighttime sleep duration at 12 months, by 9 minutes per day, relative to control employees. There were interaction effects between the intervention and age on daytime nap duration and day-to-day variability in WASO. Older employees (56–70 years) in the intervention condition decreased nap duration at 12 months relative to older employees in the control condition. Older employees in the intervention condition also exhibited a greater decrease in day-to-day variability of WASO at 12 months compared with their baseline. Conclusions The workplace flexibility/support intervention was effective in enhancing employees’ sleep health by increasing nighttime sleep duration. Furthermore, the intervention was particularly effective for older employees in decreasing their daytime nap duration and day-to-day variability in WASO. PMID:28105463

Trunk-Rotation Flexibility in Collegiate Softball Players With or Without a History of Shoulder or Elbow Injury

PubMed Central

Aragon, Veronica J.; Oyama, Sakiko; Oliaro, Scott M.; Padua, Darin A.; Myers, Joseph B.

2012-01-01

Context: Throwing is a whole-body motion that requires the transfer of momentum from the lower extremity to the upper extremity via the trunk. No research to date examines the association between a history of shoulder or elbow injury and trunk flexibility in overhead athletes. Objective: To determine if injury history and trunk-rotation flexibility are associated and to compare trunk-rotation flexibility measured using 3 clinical tests: half-kneeling rotation test with the bar in the back, half-kneeling rotation test with the bar in the front, and seated rotation test in softball position players with or without a history of shoulder or elbow injury. Design: Cross-sectional design. Setting: University softball facilities. Patients or Other Participants: Sixty-five female National Collegiate Athletic Association Division I softball position players. Intervention(s): Trunk-rotation flexibility was measured with 3 clinical tests. Recent injury history was obtained using a questionnaire and verified by the certified athletic trainer. Main Outcome Measure(s): Binomial regression models were used to determine if injury history was associated with flexibility categories (high, normal, or limited tertiles) for each of the 6 (3 tests × 2 directions) trunk-rotation flexibility measures. Trunk-rotation flexibility measures from 3 clinical tests were compared between participants with and without a history of shoulder or elbow injury using analysis-of-variance models. Results: When measured using the half-kneeling rotation test with the bar in the back and the seated rotation test, injury history and forward trunk-rotation flexibility were associated. However, no mean group differences were seen in trunk-rotation flexibility between participants with and without a history of shoulder or elbow injury. Conclusions: Limited forward trunk-rotation flexibility may be a risk factor for shoulder or elbow injuries. However, further study is needed to confirm the study finding. PMID:23068587

Architectural evaluation of dynamic and partial reconfigurable systems designed with DREAMS tool

NASA Astrophysics Data System (ADS)

Otero, Andrés.; Gallego, Ángel; de la Torre, Eduardo; Riesgo, Teresa

2013-05-01

Benefits of dynamic and partial reconfigurable systems are increasingly being more accepted by the industry. For this reason, SRAM-based FPGA manufacturers have improved, or even included for the first time, the support they offer for the design of this kind of systems. However, commercial tools still offer a poor flexibility, which leads to a limited efficiency. This is witnessed by the overhead introduced by the communication primitives, as well as by the inability to relocate reconfigurable modules, among others. For this reason, authors have proposed an academic design tool called DREAMS, which targets the design of dynamically reconfigurable systems. In this paper, main features offered by DREAMS are described, comparing them with existing commercial and academic tools. Moreover, a graphic user interface (GUI) is originally described in this work, with the aim of simplifying the design process, as well as to hide the low level device dependent details to the system designer. The overall goal is to increase the designer productivity. Using the graphic interface, different reconfigurable architectures are provided as design examples. Among them, both conventional slot-based architectures and mesh type designs have been included.