The Use of Refundable Tax Credits to Increase Low-Income Children's After-School Physical Activity Level

PubMed Central

Dunton, Genevieve; Ebin, Vicki J.; Efrat, Merav W.; Efrat, Rafael; Lane, Christianne J.; Plunkett, Scott

2014-01-01

Objective The present study investigates the extent to which a refundable tax credit could be used to increase low income children's after-school physical activity levels. Methods An experimental study was conducted evaluating the effectiveness of an intervention offering a simulated refundable tax credit to parents of elementary school-age children (n=130) for enrollment in after-school physical activity programs. A randomized-controlled design was used, with data collected at baseline, immediately following the four month intervention (post-intervention), and six-weeks after the end of the intervention (follow-up). Evaluation measures included: (a) enrollment rate, time spent, weekly participation frequency, duration of enrollment and long term enrollment patterns in after-school physical activity programs; and (b) moderate-to-vigorous physical activity (MVPA). Results The simulated tax credits did not significantly influence low- income children's rates of enrollment in after-school physical activity programs, frequency of participation, time spent in after-school physical activity programs, and overall moderate-to-vigorous intensity physical activity at post-intervention or follow-up. Conclusion The use of refundable tax credits as incentives to increase participation in after-school physical activity programs in low-income families may have limited effectiveness. Lawmakers might consider other methods of fiscal policy to promote physical activity such as direct payment to after-school physical activity program providers for enrolling and serving a low- income child in a qualified program, or improvements to programming and infrastructure. PMID:25184738

Reduction of external noise of mobile energy facilities by using active noise control system in muffler

NASA Astrophysics Data System (ADS)

Polivaev, O. I.; Kuznetsov, A. N.; Larionov, A. N.; Beliansky, R. G.

2018-03-01

The paper describes a method for the reducing emission of low-frequency noise of modern automotive vehicles into the environment. The importance of reducing the external noise of modern mobile energy facilities made in Russia is substantiated. Standard methods for controlling external noise in technology are of low efficiency when low-frequency sound waves are reduced. In this case, it is in the low-frequency zone of the sound range that the main power of the noise emitted by the machinery lies. The most effective way to reduce such sound waves is to use active noise control systems. A design of a muffler using a similar system is presented. This muffler allowed one to reduce the emission of increased noise levels into the environment by 7-11 dB and to increase acoustic comfort at the operator's workplace by 3-5 dB.

Sixty Minutes of Physical Activity per Day Included within Preschool Academic Lessons Improves Early Literacy

ERIC Educational Resources Information Center

Kirk, Stacie M.; Kirk, Erik P.

2016-01-01

Background: The effects of increases in physical activity (PA) on early literacy skills in preschool children are not known. Methods: Fifty-four African-American preschool children from a low socioeconomic urban Head Start participated over 8 months. A 2-group, quasi-experimental design was used with one preschool site participating in the PA…

Nuclear design of a very-low-activation fusion reactor

NASA Astrophysics Data System (ADS)

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

1983-06-01

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

Facilitating Behavior Change With Low-literacy Patient Education Materials

PubMed Central

Seligman, Hilary K.; Wallace, Andrea S.; DeWalt, Darren A.; Schillinger, Dean; Arnold, Connie L.; Shilliday, Betsy Bryant; Delgadillo, Adriana; Bengal, Nikki; Davis, Terry C.

2014-01-01

Objective To describe a process for developing low-literacy health education materials that increase knowledge and activate patients toward healthier behaviors. Methods We developed a theoretically informed process for developing educational materials. This process included convening a multidisciplinary creative team, soliciting stakeholder input, identifying key concepts to be communicated, mapping concepts to a behavioral theory, creating a supporting behavioral intervention, designing and refining materials, and assessing efficacy. Results We describe the use of this process to develop a diabetes self-management guide. Conclusions Developing low-literacy health education materials that will activate patients toward healthier behaviors requires attention to factors beyond reading level. PMID:17931139

Effect of a Micro-Level, Three-Tiered Positive Behavior Support Plan for Absenteeism: A Mixed Method Study

ERIC Educational Resources Information Center

Clayton, Melinda

2012-01-01

Student absentee rates remain a problem in spite of increased attention to absenteeism since the passing of the No Child Left Behind Act in 2002. High rates of absenteeism correlate to low academic achievement, early drop out, and increased risk of alcohol and drug abuse and criminal activity. This mixed method research design incorporated…

Aeroservoelasticity

NASA Technical Reports Server (NTRS)

Noll, Thomas E.

1990-01-01

The paper describes recent accomplishments and current research projects along four main thrusts in aeroservoelasticity at NASA Langley. One activity focuses on enhancing the modeling and analysis procedures to accurately predict aeroservoelastic interactions. Improvements to the minimum-state method of approximating unsteady aerodynamics are shown to provide precise low-order models for design and simulation tasks. Recent extensions in aerodynamic correction-factor methodology are also described. With respect to analysis procedures, the paper reviews novel enhancements to matched filter theory and random process theory for predicting the critical gust profile and the associated time-correlated gust loads for structural design considerations. Two research projects leading towards improved design capability are also summarized: (1) an integrated structure/control design capability and (2) procedures for obtaining low-order robust digital control laws for aeroelastic applications.

The Effect of Simulated Flash-Heat Pasteurization on Immune Components of Human Milk

PubMed Central

Daniels, Brodie; Schmidt, Stefan; King, Tracy; Israel-Ballard, Kiersten; Amundson Mansen, Kimberly; Coutsoudis, Anna

2017-01-01

A pasteurization temperature monitoring system has been designed using FoneAstra, a cellphone-based networked sensing system, to monitor simulated flash-heat (FH) pasteurization. This study compared the effect of the FoneAstra FH (F-FH) method with the Sterifeed Holder method currently used by human milk banks on human milk immune components (immunoglobulin A (IgA), lactoferrin activity, lysozyme activity, interleukin (IL)-8 and IL-10). Donor milk samples (N = 50) were obtained from a human milk bank, and pasteurized. Concentrations of IgA, IL-8, IL-10, lysozyme activity and lactoferrin activity were compared to their controls using the Student’s t-test. Both methods demonstrated no destruction of interleukins. While the Holder method retained all lysozyme activity, the F-FH method only retained 78.4% activity (p < 0.0001), and both methods showed a decrease in lactoferrin activity (71.1% Holder vs. 38.6% F-FH; p < 0.0001) and a decrease in the retention of total IgA (78.9% Holder vs. 25.2% F-FH; p < 0.0001). Despite increased destruction of immune components compared to Holder pasteurization, the benefits of F-FH in terms of its low cost, feasibility, safety and retention of immune components make it a valuable resource in low-income countries for pasteurizing human milk, potentially saving infants’ lives. PMID:28241418

Rotating rake design for unique measurement of fan-generated spinning acoustic modes

NASA Technical Reports Server (NTRS)

Konno, Kevin E.; Hausmann, Clifford R.

1993-01-01

In light of the current emphasis on noise reduction in subsonic aircraft design, NASA has been actively studying the source of and propagation of noise generated by subsonic fan engines. NASA/LeRC has developed and tested a unique method of accurately measuring these spinning acoustic modes generated by an experimental fan. This mode measuring method is based on the use of a rotating microphone rake. Testing was conducted in the 9 x 15 Low-speed Wind Tunnel. The rotating rake was tested with the Advanced Ducted Propeller (ADP) model. This memorandum discusses the design and performance of the motor/drive system for the fan-synchronized rotating acoustic rake. This novel motor/drive design approach is now being adapted for additional acoustic mode studies in new test rigs as baseline data for the future design of active noise control for subsonic fan engines. Included in this memorandum are the research requirements, motor/drive specifications, test performance results, and a description of the controls and software involved.

Use of High Fidelity Methods in Multidisciplinary Optimization-A Preliminary Survey

NASA Technical Reports Server (NTRS)

Guruswamy, Guru P.; Kwak, Dochan (Technical Monitor)

2002-01-01

Multidisciplinary optimization is a key element of design process. To date multidiscipline optimization methods that use low fidelity methods are well advanced. Optimization methods based on simple linear aerodynamic equations and plate structural equations have been applied to complex aerospace configurations. However, use of high fidelity methods such as the Euler/ Navier-Stokes for fluids and 3-D (three dimensional) finite elements for structures has begun recently. As an activity of Multidiscipline Design Optimization Technical Committee (MDO TC) of AIAA (American Institute of Aeronautics and Astronautics), an effort was initiated to assess the status of the use of high fidelity methods in multidisciplinary optimization. Contributions were solicited through the members MDO TC committee. This paper provides a summary of that survey.

Application of multi-agent coordination methods to the design of space debris mitigation tours

NASA Astrophysics Data System (ADS)

Stuart, Jeffrey; Howell, Kathleen; Wilson, Roby

2016-04-01

The growth in the number of defunct and fragmented objects near to the Earth poses a growing hazard to launch operations as well as existing on-orbit assets. Numerous studies have demonstrated the positive impact of active debris mitigation campaigns upon the growth of debris populations, but comparatively fewer investigations incorporate specific mission scenarios. Furthermore, while many active mitigation methods have been proposed, certain classes of debris objects are amenable to mitigation campaigns employing chaser spacecraft with existing chemical and low-thrust propulsive technologies. This investigation incorporates an ant colony optimization routing algorithm and multi-agent coordination via auctions into a debris mitigation tour scheme suitable for preliminary mission design and analysis as well as spacecraft flight operations.

Efficacy of graded activity versus supervised exercises in patients with chronic non-specific low back pain: protocol of a randomised controlled trial

PubMed Central

2013-01-01

Background Low back pain is a relevant public health problem, being an important cause of work absenteeism worldwide, as well as affecting the quality of life of sufferers and their individual functional performances. Supervised active physical routines and of cognitive-behavioral therapies are recommended for the treatment of chronic Low back pain, although evidence to support the effectiveness of different techniques is missing. Accordingly, the aim of this study is to contrast the effectiveness of two types of exercises, graded activity or supervised, in decreasing symptoms of chronic low back pain. Methods/design Sample will consist of 66 patients, blindly allocated into one of two groups: 1) Graded activity which, based on an operant approach, will use time-contingent methods aiming to increase participants’ activity levels; 2) Supervised exercise, where participants will be trained for strengthening, stretching, and motor control targeting different muscle groups. Interventions will last one hour, and will happen twice a week for 6 weeks. Outcomes (pain, disability, quality of life, global perceived effect, return to work, physical activity, physical capacity, and kinesiophobia) will be assessed at baseline, at treatment end, and three and six months after treatment end. Data collection will be conducted by an investigator blinded to treatment allocation. Discussion This project describes the randomisation method that will be used to compare the effectiveness of two different treatments for chronic low back pain: graded activity and supervised exercises. Since optimal approach for patients with chronic back pain have yet not been defined based on evidence, good quality studies on the subject are necessary. Trial registration NCT01719276 PMID:23336703

Venting of fission products and shielding in thermionic nuclear reactor systems

NASA Technical Reports Server (NTRS)

Salmi, E. W.

1972-01-01

Most thermionic reactors are designed to allow the fission gases to escape out of the emitter. A scheme to allow the fission gases to escape is proposed. Because of the low activity of the fission products, this method should pose no radiation hazards.

Factors of physical activity among Chinese children and adolescents: a systematic review.

PubMed

Lu, Congchao; Stolk, Ronald P; Sauer, Pieter J J; Sijtsma, Anna; Wiersma, Rikstje; Huang, Guowei; Corpeleijn, Eva

2017-03-21

Lack of physical activity is a growing problem in China, due to the fast economic development and changing living environment over the past two decades. The aim of this review is to summarize the factors related to physical activity in Chinese children and adolescents during this distinct period of development. A systematic search was finished on Jan 10 th , 2017, and identified 2200 hits through PubMed and Web of Science. English-language published studies were included if they reported statistical associations between factors and physical activity. Adapted criteria from the Strengthening The Reporting of OBservational studies in Epidemiology (STROBE) statement and evaluation of the quality of prognosis studies in systematic reviews (QUIPS) were used to assess the risk of bias of the included studies. Related factors that were reported in at least three studies were summarized separately for children and adolescents using a semi-quantitative method. Forty two papers (published 2002-2016) were included. Most designs were cross-sectional (79%), and most studies used questionnaires to assess physical activity. Sample size was above 1000 in 18 papers (43%). Thirty seven studies (88%) showed acceptable quality by methodological quality assessment. Most studies reported a low level of physical activity. Boys were consistently more active than girls, the parental physical activity was positively associated with children and adolescents' physical activity, children in suburban/rural regions showed less activity than in urban regions, and, specifically in adolescents, self-efficacy was positively associated with physical activity. Family socioeconomic status and parental education were not associated with physical activity in children and adolescents. The studies included in this review were large but mostly of low quality in terms of study design (cross-sectional) and methods (questionnaires). Parental physical activity and self-efficacy are promising targets for future physical activity promotion programmes. The low level of physical activity raises concern, especially in suburban/rural regions. Future research is required to enhance our understanding of other influences, such as the physical environment, especially in early childhood.

Activated Carbon Fiber Paper Based Electrodes with High Electrocatalytic Activity for Vanadium Flow Batteries with Improved Power Density.

PubMed

Liu, Tao; Li, Xianfeng; Xu, Chi; Zhang, Huamin

2017-02-08

Vanadium flow batteries (VFBs) have received high attention for large-scale energy storage due to their advantages of flexibility design, long cycle life, high efficiency, and high safety. However, commercial progress of VFBs has so far been limited by its high cost induced by its low power density. Ultrathin carbon paper is believed to be a very promising electrode for VFB because it illustrates super-low ohmic polarization, however, is limited by its low electrocatalytic activity. In this paper, a kind of carbon paper (CP) with super-high electrocatalytic activity was fabricated via a universal and simple CO 2 activation method. The porosity and oxygen functional groups can be easily tuned via this method. The charge transfer resistance (denoting the electrochemical polarization) of a VFB with CP electrode after CO 2 activation decreased dramatically from 970 to 120 mΩcm 2 . Accordingly, the energy efficiency of a VFB with activated carbon paper as the electrode increased by 13% as compared to one without activation and reaches nearly 80% when the current density is 140 mAcm -2 . This paper provides an effective way to prepare high-performance porous carbon electrodes for VFBs and even for other battery systems.

Low back pain among workers in care facilities for the elderly after introducing welfare equipment.

PubMed

Iwakiri, Kazuyuki; Takahashi, Masaya; Sotoyama, Midori; Liu, Xinxin; Koda, Shigeki

2016-07-29

The purpose of this study was to clarify the causes of low back pain among workers in care facilities for the elderly after the introduction of welfare equipment. We conducted anonymous questionnaire surveys among administrators and care workers in eight elderly care facilities. The questionnaires were designed to investigate the status of both the care workers and facility. In reference to the care facility, the questionnaires were comprised items for investigating basic information, occupational safety, and health activities. For care workers, in addition to basic information, occupational safety, and health activities, the questionnaires also comprised items for investigating resident transfer and bathing methods, low back pain, and occupational stress. Completed questionnaires were returned by eight care facility administrators (response rate: 100%) and 373 care workers (response rate: 92.3%), among which 367 were used for analyses. Many care workers participated in a variety of occupational safety and health activities that were conducted in the facilities. Various types of welfare equipment were introduced into the care facilities and subsequently used by many care workers during resident transfer and bathing. As a result, 89.9% of the care workers reported having only slight or no low back pain. The remaining 10.1% reported having serious low back pain that interfered with their work. On the basis of logistic regression analysis, low back pain was associated with the following variables: failure to provide the appropriate method of care to each resident, failure of colleagues to discuss methods for improving care, lack of instructions regarding the use of welfare equipment, and inappropriate job rotation. An association was also found between low back pain and poor posture, poor resident-lifting technique, insufficient time to complete work, and a shortage of workers to assist with resident transfer or bathing. Although care workers received instructions on the health and safety activities extracted from the surveys, an association was still found between these activities and low back pain. This was thought to result from some care workers not establishing the appropriate method of care for each resident, not discussing methods for improving care with other colleagues, not using the welfare equipment, and failing to practice appropriate job rotation. These results suggest that low back pain among care workers in the facilities for the elderly that have introduced welfare equipment is caused by a failure to sufficiently conduct appropriate care methods.

Numerical simulations on active shielding methods comparison and wrapped angle optimization for gradient coil design in MRI with enhanced shielding effect

NASA Astrophysics Data System (ADS)

Wang, Yaohui; Xin, Xuegang; Guo, Lei; Chen, Zhifeng; Liu, Feng

2018-05-01

The switching of a gradient coil current in magnetic resonance imaging will induce an eddy current in the surrounding conducting structures while the secondary magnetic field produced by the eddy current is harmful for the imaging. To minimize the eddy current effects, the stray field shielding in the gradient coil design is usually realized by minimizing the magnetic fields on the cryostat surface or the secondary magnetic fields over the imaging region. In this work, we explicitly compared these two active shielding design methods. Both the stray field and eddy current on the cryostat inner surface were quantitatively discussed by setting the stray field constraint with an ultra-low maximum intensity of 2 G and setting the secondary field constraint with an extreme small shielding ratio of 0.000 001. The investigation revealed that the secondary magnetic field control strategy can produce coils with a better performance. However, the former (minimizing the magnetic fields) is preferable when designing a gradient coil with an ultra-low eddy current that can also strictly control the stray field leakage at the edge of the cryostat inner surface. A wrapped-edge gradient coil design scheme was then optimized for a more effective control of the stray fields. The numerical simulation on the wrapped-edge coil design shows that the optimized wrapping angles for the x and z coils in terms of our coil dimensions are 40° and 90°, respectively.

Computer-Aided Design of Low-Noise Microwave Circuits

NASA Astrophysics Data System (ADS)

Wedge, Scott William

1991-02-01

Devoid of most natural and manmade noise, microwave frequencies have detection sensitivities limited by internally generated receiver noise. Low-noise amplifiers are therefore critical components in radio astronomical antennas, communications links, radar systems, and even home satellite dishes. A general technique to accurately predict the noise performance of microwave circuits has been lacking. Current noise analysis methods have been limited to specific circuit topologies or neglect correlation, a strong effect in microwave devices. Presented here are generalized methods, developed for computer-aided design implementation, for the analysis of linear noisy microwave circuits comprised of arbitrarily interconnected components. Included are descriptions of efficient algorithms for the simultaneous analysis of noisy and deterministic circuit parameters based on a wave variable approach. The methods are therefore particularly suited to microwave and millimeter-wave circuits. Noise contributions from lossy passive components and active components with electronic noise are considered. Also presented is a new technique for the measurement of device noise characteristics that offers several advantages over current measurement methods.

A direct method for synthesizing low-order optimal feedback control laws with application to flutter suppression

NASA Technical Reports Server (NTRS)

Mukhopadhyay, V.; Newsom, J. R.; Abel, I.

1980-01-01

A direct method of synthesizing a low-order optimal feedback control law for a high order system is presented. A nonlinear programming algorithm is employed to search for the control law design variables that minimize a performance index defined by a weighted sum of mean square steady state responses and control inputs. The controller is shown to be equivalent to a partial state estimator. The method is applied to the problem of active flutter suppression. Numerical results are presented for a 20th order system representing an aeroelastic wind-tunnel wing model. Low-order controllers (fourth and sixth order) are compared with a full order (20th order) optimal controller and found to provide near optimal performance with adequate stability margins.

Can active proton interrogation find shielded nuclear threats at human-safe radiation levels?

NASA Astrophysics Data System (ADS)

Liew, Seth Van

2017-05-01

A new method of low-dose proton radiography is presented. The system is composed of an 800 MeV proton source, bending magnets, and compact detectors, and is designed for drive-through cargo scanning. The system has been simulated using GEANT4. Material identification algorithms and pixel sorting methods are presented that allow the system to perform imaging at doses low enough to scan passenger vehicles and people. Results are presented on imaging efficacy of various materials and cluttered cargoes. The identification of shielded nuclear materials at human-safe doses has been demonstrated.

Design of an Integrated Thermoelectric Generator Power Converter for Ultra-Low Power and Low Voltage Body Energy Harvesters aimed at EEG/ECG Active Electrodes

NASA Astrophysics Data System (ADS)

Ataei, Milad; Robert, Christian; Boegli, Alexis; Farine, Pierre-André

2014-11-01

This paper describes a design procedure for an efficient body thermal energy harvesting integrated power converter. This procedure is based on loss examination for a selfpowered medical device. All optimum system parameters are calculated respecting the transducer constraints and the application form factor. It is found that it is possible to optimize converter's working frequency with proper design of its pulse generator circuit. At selected frequency, it has been demonstrated that wide area voltage doubler can be eliminated at the expense of wider switches. With this method, more than 60% efficiency is achieved in simulation for just 20mV transducer output voltage and 30% of entire chip area is saved.

Spread spectrum time-resolved diffuse optical measurement system for enhanced sensitivity in detecting human brain activity

NASA Astrophysics Data System (ADS)

Mehta, Kalpesh; Hasnain, Ali; Zhou, Xiaowei; Luo, Jianwen; Penney, Trevor B.; Chen, Nanguang

2017-04-01

Diffuse optical spectroscopy (DOS) and imaging methods have been widely applied to noninvasive detection of brain activity. We have designed and implemented a low cost, portable, real-time one-channel time-resolved DOS system for neuroscience studies. Phantom experiments were carried out to test the performance of the system. We further conducted preliminary human experiments and demonstrated that enhanced sensitivity in detecting neural activity in the cortex could be achieved by the use of late arriving photons.

Development and coupling analysis of active skin antenna

NASA Astrophysics Data System (ADS)

Zhou, Jinzhu; Huang, Jin; He, Qingqang; Tang, Baofu; Song, Liwei

2017-02-01

An active skin antenna is a multifunctional composite structure that can provide load-bearing structure and steerable beam pointing functions, and is usually installed in the structural surface of aircraft, warships, and armored vehicles. This paper presents an innovative design of the active skin antenna, which consists of a package layer, control and signal processing layer, and RF (radio frequency) layer. The RF layer is fabricated by low temperature co-fired ceramics, with 64 microstrip antenna elements, tile transmitting and receiving modules, microchannel heat sinks, and feeding networks integrated into a functional block 2.8 mm thick. In this paper, a full-sized prototype of an active skin antenna was designed, fabricated, and tested. Moreover, a coupling analysis method was presented to evaluate the mechanical and electromagnetic performance of the active skin antenna subjected to aerodynamic loads. A deformed experimental system was built to validate the effectiveness of the coupling analysis method, which was also implemented to evaluate the performance of the active skin antenna when subjected to aerodynamic pressure. The fabricated specimen demonstrated structural configuration feasibility, and superior environmental load resistance.

A Novel Teaching Tool Combined With Active-Learning to Teach Antimicrobial Spectrum Activity.

PubMed

MacDougall, Conan

2017-03-25

Objective. To design instructional methods that would promote long-term retention of knowledge of antimicrobial pharmacology, particularly the spectrum of activity for antimicrobial agents, in pharmacy students. Design. An active-learning approach was used to teach selected sessions in a required antimicrobial pharmacology course. Students were expected to review key concepts from the course reader prior to the in-class sessions. During class, brief concept reviews were followed by active-learning exercises, including a novel schematic method for learning antimicrobial spectrum of activity ("flower diagrams"). Assessment. At the beginning of the next quarter (approximately 10 weeks after the in-class sessions), 360 students (three yearly cohorts) completed a low-stakes multiple-choice examination on the concepts in antimicrobial spectrum of activity. When data for students was pooled across years, the mean number of correct items was 75.3% for the items that tested content delivered with the active-learning method vs 70.4% for items that tested content delivered via traditional lecture (mean difference 4.9%). Instructor ratings on student evaluations of the active-learning approach were high (mean scores 4.5-4.8 on a 5-point scale) and student comments were positive about the active-learning approach and flower diagrams. Conclusion. An active-learning approach led to modestly higher scores in a test of long-term retention of pharmacology knowledge and was well-received by students.

A Novel Teaching Tool Combined With Active-Learning to Teach Antimicrobial Spectrum Activity

PubMed Central

2017-01-01

Objective. To design instructional methods that would promote long-term retention of knowledge of antimicrobial pharmacology, particularly the spectrum of activity for antimicrobial agents, in pharmacy students. Design. An active-learning approach was used to teach selected sessions in a required antimicrobial pharmacology course. Students were expected to review key concepts from the course reader prior to the in-class sessions. During class, brief concept reviews were followed by active-learning exercises, including a novel schematic method for learning antimicrobial spectrum of activity (“flower diagrams”). Assessment. At the beginning of the next quarter (approximately 10 weeks after the in-class sessions), 360 students (three yearly cohorts) completed a low-stakes multiple-choice examination on the concepts in antimicrobial spectrum of activity. When data for students was pooled across years, the mean number of correct items was 75.3% for the items that tested content delivered with the active-learning method vs 70.4% for items that tested content delivered via traditional lecture (mean difference 4.9%). Instructor ratings on student evaluations of the active-learning approach were high (mean scores 4.5-4.8 on a 5-point scale) and student comments were positive about the active-learning approach and flower diagrams. Conclusion. An active-learning approach led to modestly higher scores in a test of long-term retention of pharmacology knowledge and was well-received by students. PMID:28381885

Experimental validation of structural optimization methods

NASA Technical Reports Server (NTRS)

Adelman, Howard M.

1992-01-01

The topic of validating structural optimization methods by use of experimental results is addressed. The need for validating the methods as a way of effecting a greater and an accelerated acceptance of formal optimization methods by practicing engineering designers is described. The range of validation strategies is defined which includes comparison of optimization results with more traditional design approaches, establishing the accuracy of analyses used, and finally experimental validation of the optimization results. Examples of the use of experimental results to validate optimization techniques are described. The examples include experimental validation of the following: optimum design of a trussed beam; combined control-structure design of a cable-supported beam simulating an actively controlled space structure; minimum weight design of a beam with frequency constraints; minimization of the vibration response of helicopter rotor blade; minimum weight design of a turbine blade disk; aeroelastic optimization of an aircraft vertical fin; airfoil shape optimization for drag minimization; optimization of the shape of a hole in a plate for stress minimization; optimization to minimize beam dynamic response; and structural optimization of a low vibration helicopter rotor.

Active pharmaceutical ingredient (API) production involving continuous processes--a process system engineering (PSE)-assisted design framework.

PubMed

Cervera-Padrell, Albert E; Skovby, Tommy; Kiil, Søren; Gani, Rafiqul; Gernaey, Krist V

2012-10-01

A systematic framework is proposed for the design of continuous pharmaceutical manufacturing processes. Specifically, the design framework focuses on organic chemistry based, active pharmaceutical ingredient (API) synthetic processes, but could potentially be extended to biocatalytic and fermentation-based products. The method exploits the synergic combination of continuous flow technologies (e.g., microfluidic techniques) and process systems engineering (PSE) methods and tools for faster process design and increased process understanding throughout the whole drug product and process development cycle. The design framework structures the many different and challenging design problems (e.g., solvent selection, reactor design, and design of separation and purification operations), driving the user from the initial drug discovery steps--where process knowledge is very limited--toward the detailed design and analysis. Examples from the literature of PSE methods and tools applied to pharmaceutical process design and novel pharmaceutical production technologies are provided along the text, assisting in the accumulation and interpretation of process knowledge. Different criteria are suggested for the selection of batch and continuous processes so that the whole design results in low capital and operational costs as well as low environmental footprint. The design framework has been applied to the retrofit of an existing batch-wise process used by H. Lundbeck A/S to produce an API: zuclopenthixol. Some of its batch operations were successfully converted into continuous mode, obtaining higher yields that allowed a significant simplification of the whole process. The material and environmental footprint of the process--evaluated through the process mass intensity index, that is, kg of material used per kg of product--was reduced to half of its initial value, with potential for further reduction. The case-study includes reaction steps typically used by the pharmaceutical industry featuring different characteristic reaction times, as well as L-L separation and distillation-based solvent exchange steps, and thus constitutes a good example of how the design framework can be useful to efficiently design novel or already existing API manufacturing processes taking advantage of continuous processes. Copyright © 2012 Elsevier B.V. All rights reserved.

Congruence of Self-Reported Medications with Pharmacy Prescription Records in Low-Income Older Adults

ERIC Educational Resources Information Center

Caskie, Grace I. L.; Willis, Sherry L.

2004-01-01

Purpose: This study examined the congruence of self-reported medications with computerized pharmacy records. Design and Methods: Pharmacy records and self-reported medications were obtained for 294 members of a state pharmaceutical assistance program who also participated in ACTIVE, a clinical trial on cognitive training in nondemented elderly…

Impact of the Fit and Strong Intervention on Older Adults with Osteoarthritis

ERIC Educational Resources Information Center

Hughes, Susan L.; Seymour, Rachel B.; Campbell, Richard; Pollak, Naomi; Huber, Gail; Sharma, Leena

2004-01-01

Purpose: This study assessed the impact of a low cost, multicomponent physical activity intervention for older adults with lower extremity osteoarthritis. Design and Methods: A randomized controlled trial compared the effects of a facility-based multiple-component training program followed by home-based adherence (n = 80) to a wait list control…

Strand displacement activated peroxidase activity of hemin for fluorescent DNA sensing.

PubMed

Wang, Quanbo; Xu, Nan; Gui, Zhen; Lei, Jianping; Ju, Huangxian; Yan, Feng

2015-10-07

To efficiently regulate the catalytic activity of the peroxidase mimic hemin, this work designs a double-stranded DNA probe containing an intermolecular dimer of hemin, whose peroxidase activity can be activated by a DNA strand displacement reaction. The double-stranded probe is prepared by annealing two strands of hemin labelled DNA oligonucleotides. Using the fluorescent oxidation product of tyramine by H2O2 as a tracing molecule, the low peroxidase activity of the hemin dimer ensures a low fluorescence background. The strand displacement reaction of the target DNA dissociates the hemin dimer and thus significantly increases the catalytic activity of hemin to produce a large amount of dityramine for fluorescence signal readout. Based on the strand displacement regulated peroxidase activity, a simple and sensitive homogeneous fluorescent DNA sensing method is proposed. The detection can conveniently be carried out in a 96-well plate within 20 min with a detection limit of 0.18 nM. This method shows high specificity, which can effectively distinguish single-base mismatched DNA from perfectly matched target DNA. The DNA strand displacement regulated catalytic activity of hemin has promising application in the determination of various DNA analytes.

Active Subspaces of Airfoil Shape Parameterizations

NASA Astrophysics Data System (ADS)

Grey, Zachary J.; Constantine, Paul G.

2018-05-01

Design and optimization benefit from understanding the dependence of a quantity of interest (e.g., a design objective or constraint function) on the design variables. A low-dimensional active subspace, when present, identifies important directions in the space of design variables; perturbing a design along the active subspace associated with a particular quantity of interest changes that quantity more, on average, than perturbing the design orthogonally to the active subspace. This low-dimensional structure provides insights that characterize the dependence of quantities of interest on design variables. Airfoil design in a transonic flow field with a parameterized geometry is a popular test problem for design methodologies. We examine two particular airfoil shape parameterizations, PARSEC and CST, and study the active subspaces present in two common design quantities of interest, transonic lift and drag coefficients, under each shape parameterization. We mathematically relate the two parameterizations with a common polynomial series. The active subspaces enable low-dimensional approximations of lift and drag that relate to physical airfoil properties. In particular, we obtain and interpret a two-dimensional approximation of both transonic lift and drag, and we show how these approximation inform a multi-objective design problem.

De Novo Design of Bioactive Small Molecules by Artificial Intelligence.

PubMed

Merk, Daniel; Friedrich, Lukas; Grisoni, Francesca; Schneider, Gisbert

2018-01-01

Generative artificial intelligence offers a fresh view on molecular design. We present the first-time prospective application of a deep learning model for designing new druglike compounds with desired activities. For this purpose, we trained a recurrent neural network to capture the constitution of a large set of known bioactive compounds represented as SMILES strings. By transfer learning, this general model was fine-tuned on recognizing retinoid X and peroxisome proliferator-activated receptor agonists. We synthesized five top-ranking compounds designed by the generative model. Four of the compounds revealed nanomolar to low-micromolar receptor modulatory activity in cell-based assays. Apparently, the computational model intrinsically captured relevant chemical and biological knowledge without the need for explicit rules. The results of this study advocate generative artificial intelligence for prospective de novo molecular design, and demonstrate the potential of these methods for future medicinal chemistry. © 2018 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Conceptual design statement of work for the immobilized low-activity waste interim storage facility project

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

Carlson, T.A., Fluor Daniel Hanford

1997-02-06

The Immobilized Low-Activity Waste Interim Storage subproject will provide storage capacity for immobilized low-activity waste product sold to the U.S. Department of Energy by the privatization contractor. This statement of work describes the work scope (encompassing definition of new installations and retrofit modifications to four existing grout vaults), to be performed by the Architect-Engineer, in preparation of a conceptual design for the Immobilized Low-Activity Waste Interim Storage Facility.

Triggers for an episode of sudden onset low back pain: study protocol

PubMed Central

2012-01-01

Background Most research on risk factors for low back pain has focused on long term exposures rather than factors immediately preceding the onset of low back pain. The aim of this study is to quantify the transient increase in risk of a sudden episode of low back pain associated with acute exposure to a range of common physical and psychological factors. Methods/design This study uses a case-crossover design. One thousand adults with a sudden onset of low back pain presenting to primary care clinicians will be recruited. Basic demographic and clinical information including exposure to putative triggers will be collected using a questionnaire. These triggers include exposure to hazardous manual tasks, physical activity, a slip/trip or fall, consumption of alcohol, sexual activity, being distracted, and being fatigued or tired. Exposures in the case window (0-2 hours from the time when participants first notice their back pain) will be compared to exposures in two control time-windows (one 24-26 hours and another 48-50 hours before the case window). Discussion The completion of this study will provide the first-research based estimates of the increase in risk of a sudden episode of acute low back pain associated with transient exposure to a range of common factors thought to trigger low back pain. PMID:22273001

Predictive functional control for active queue management in congested TCP/IP networks.

PubMed

Bigdeli, N; Haeri, M

2009-01-01

Predictive functional control (PFC) as a new active queue management (AQM) method in dynamic TCP networks supporting explicit congestion notification (ECN) is proposed. The ability of the controller in handling system delay along with its simplicity and low computational load makes PFC a privileged AQM method in the high speed networks. Besides, considering the disturbance term (which represents model/process mismatches, external disturbances, and existing noise) in the control formulation adds some level of robustness into the PFC-AQM controller. This is an important and desired property in the control of dynamically-varying computer networks. In this paper, the controller is designed based on a small signal linearized fluid-flow model of the TCP/AQM networks. Then, closed-loop transfer function representation of the system is derived to analyze the robustness with respect to the network and controller parameters. The analytical as well as the packet-level ns-2 simulation results show the out-performance of the developed controller for both queue regulation and resource utilization. Fast response, low queue fluctuations (and consequently low delay jitter), high link utilization, good disturbance rejection, scalability, and low packet marking probability are other features of the developed method with respect to other well-known AQM methods such as RED, PI, and REM which are also simulated for comparison.

Integrating a Smartphone and Molecular Modeling for Determining the Binding Constant and Stoichiometry Ratio of the Iron(II)-Phenanthroline Complex: An Activity for Analytical and Physical Chemistry Laboratories

ERIC Educational Resources Information Center

de Morais, Camilo de L. M.; Silva, Se´rgio R. B.; Vieira, Davi S.; Lima, Ka´ssio M. G.

2016-01-01

The binding constant and stoichiometry ratio for the formation of iron(II)-(1,10-phenanthroline) or iron(II)-o-phenanthroline complexes has been determined by a combination of a low-cost analytical method using a smartphone and a molecular modeling method as a laboratory experiment designed for analytical and physical chemistry courses. Intensity…

Design and characterization of free-running InGaAsP single-photon detector with active-quenching technique

NASA Astrophysics Data System (ADS)

Liu, Junliang; Zhang, Tingfa; Li, Yongfu; Ding, Lei; Tao, Junchao; Wang, Ying; Wang, Qingpu; Fang, Jiaxiong

2017-07-01

A free-running single-photon detector for 1.06 μm wavelength based on an InGaAsP/InP single-photon avalanche diode is presented. The detector incorporates an ultra-fast active-quenching technique to greatly lessen the afterpulsing effects. An improved method for avalanche characterization using electroluminescence is proposed, and the performance of the detector is evaluated. The number of avalanche carriers is as low as 1.68 ×106 , resulting in a low total afterpulse probability of 4% at 233 K, 10% detection efficiency, and 1 μs hold-off time.

Mission design for an orbiting volcano observatory

NASA Technical Reports Server (NTRS)

Penzo, Paul A.; Johnston, M. Daniel

1990-01-01

The Mission to Planet Earth initiative will require global observation of land, sea, and atmosphere, and all associated phenomena over the coming years; perhaps for decades. A major phenomenon playing a major part in earth's environment is volcanic activity. Orbital observations, including IR, UV, and visible imaging, may be made to monitor many active sites, and eventually increase our understanding of volcanoes and lead to the predictability of eruptions. This paper presents the orbital design and maneuvering capability of a low cost, volcano observing satellite, flying in low earth orbit. Major science requirements include observing as many as 10 to 20 active sites daily, or every two or three days. Given specific geographic locations of these sites, it is necessary to search the trajectory space for those orbits which maximize overflight opportunities. Also, once the satellite is in orbit, it may be desirable to alter the orbit to fly over targets of opportunity. These are active areas which are not being monitored, but which give indications of erupting, or have in fact erupted. Multiple impulse orbital maneuvering methods have been developed to minimize propellant usage for these orbital changes.

The Use of Refundable Tax Credits to Increase Low-Income Children's After-School Physical Activity Level.

PubMed

Dunton, Genevieve; Ebin, Vicki J; Efrat, Merav W; Efrat, Rafael; Lane, Christianne J; Plunkett, Scott

2015-06-01

The current study investigates the extent to which a refundable tax credit could be used to increase low-income children's after-school physical activity levels. An experimental study was conducted evaluating the effectiveness of an intervention offering a simulated refundable tax credit to parents of elementary-school-age children (n = 130) for enrollment in after-school physical activity programs. A randomized controlled design was used, with data collected at baseline, immediately following the 4-month intervention (postintervention), and 6 weeks after the end of the intervention (follow-up). Evaluation measures included (1) enrollment rate, time spent, weekly participation frequency, duration of enrollment, and long-term enrollment patterns in after-school physical activity programs and (2) moderate to vigorous physical activity. The simulated tax credits did not significantly influence low-income children's rates of enrollment in after-school physical activity programs, frequency of participation, time spent in after-school physical activity programs, and overall moderate-to-vigorous intensity physical activity at postintervention or follow-up. The use of refundable tax credits as incentives to increase participation in after-school physical activity programs in low-income families may have limited effectiveness. Lawmakers might consider other methods of fiscal policy to promote physical activity such as direct payment to after-school physical activity program providers for enrolling and serving a low-income child in a qualified program, or improvements to programming and infrastructure.

A methodology for designing aircraft to low sonic boom constraints

NASA Technical Reports Server (NTRS)

Mack, Robert J.; Needleman, Kathy E.

1991-01-01

A method for designing conceptual supersonic cruise aircraft to meet low sonic boom requirements is outlined and described. The aircraft design is guided through a systematic evolution from initial three view drawing to a final numerical model description, while the designer using the method controls the integration of low sonic boom, high supersonic aerodynamic efficiency, adequate low speed handling, and reasonable structure and materials technologies. Some experience in preliminary aircraft design and in the use of various analytical and numerical codes is required for integrating the volume and lift requirements throughout the design process.

A High Power Density Single-Phase PWM Rectifier With Active Ripple Energy Storage

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

Wang, Ruxi; Wang, Fei; Boroyevich, Dushan

It is well known that single-phase pulse width modulation rectifiers have second-order harmonic currents and corresponding ripple voltages on the dc bus. The low-frequency harmonic current is normally filtered using a bulk capacitor in the bus, which results in low power density. However, pursuing high power density in converter design is a very important goal in the aerospace applications. This paper studies methods for reducing the energy storage capacitor for single-phase rectifiers. The minimum ripple energy storage requirement is derived independently of a specific topology. Based on theminimum ripple energy requirement, the feasibility of the active capacitor s reduction schemesmore » is verified. Then, we propose a bidirectional buck boost converter as the ripple energy storage circuit, which can effectively reduce the energy storage capacitance. The analysis and design are validated by simulation and experimental results.« less

Man vs. Machine: A Junior-level Laboratory Exercise Comparing Human and Instrumental Detection Limits

ERIC Educational Resources Information Center

Elias, Ryan J.; Hopfer, Helene; Hofstaedter, Amanda N.; Hayes, John E.

2017-01-01

The human nose is a very sensitive detector and is able to detect potent aroma compounds down to low ng/L levels. These levels are often below detection limits of analytical instrumentation. The following laboratory exercise is designed to compare instrumental and human methods for the detection of volatile odor active compounds. Reference…

Serendipity in Paperdoll Animation: Low Budget Methods for a Children's Workshop.

ERIC Educational Resources Information Center

Edwards, Emily D.

Part of a larger project to design a production curriculum and measure the impact of this production activity on children's writing, visual thinking, and problem solving skills, a project developed an effective but inexpensive video for use in teaching animation processes to students at the elementary school level. The project used "cutout" or…

Development and evaluation of a structured programme for promoting physical activity among seniors with intellectual disabilities: a study protocol for a cluster randomized trial

PubMed Central

2013-01-01

Background Older people with intellectual disabilities have very low physical activity levels. Well designed, theory-driven and evidence-based health promotion programmes for the target population are lacking. This paper describes the design of a cluster-randomised trial for a systematically developed health promotion programme aimed at improving physical activity and increasing fitness among seniors with intellectual disabilities. Methods and design The Intervention Mapping protocol was used for programme development. After defining the programme’s objectives, the following behavioural techniques were selected to achieve them: Tailoring, Education, Modelling, Mirroring, Feedback, Reinforcement and Grading. With professionals and managers of provider services for people with intellectual disabilities, we translated these strategies into a structured day-activity programme, that consisted of a physical activity and an education programme. The programme will be executed in five day-activity centres in groups of eight to ten seniors during eight months, whereas seniors in five other centres receive care as usual. The physical activity level, as measured in number of steps a day, will be used as primary outcome measurement. Secondary outcome measurements include motor fitness, cardio respiratory fitness, morphological and metabolic fitness, ADL, functional deterioration and depressive symptoms. Differences in the primary and secondary outcome measures between participants and controls will be analysed using generalized estimation equations, correcting for day-activity center as cluster. Discussion This paper provides insight into the development and content of a theory-driven intervention aimed at behavioural change in a population with a low intellectual level. Its evaluation design is described. The programme’s applicability to other populations is discussed. Trial registration Trial number: ISRCTN82341588 PMID:23938154

Design of electrolyzer for carbon dioxide conversion to fuels and chemicals

NASA Astrophysics Data System (ADS)

Rosen, Jonathan S.

The stabilization of global atmospheric CO2 levels requires a transition towards a renewable energy based economy as well as methods for handling current CO2 output from fossil fuels. Challenges with renewable energy intermittency have thus far limited the use of these alternative energy sources to only a fraction of the current energy portfolio. To enable more widespread use of renewable energy systems, methods of large scale energy storage must be developed to store excess renewable energy when demand is low and allow for combined use of energy storage and renewable systems when demand is high. To date, no one technique has demonstrated energy storage methods on the gigawatt scale needed for integration with renewable sources; therefore the development of suitable energy storage technologies, such as CO2 electrolysis to fuels is needed. In this work, research efforts have focused on two major thrusts related to electrochemical methods of CO 2 conversion to fuels. The first thrust focuses on the synthesis and design of highly efficient anode and cathode catalysts with emphasis on understanding structure-property relationships. A second thrust focuses on the design of novel electrochemical devices for CO2 conversion and integration of synthesized materials into flow cell systems. On the anode side, the synthesis of highly active catalysts using abundant transition metals is crucial to reducing capital costs and enabling widespread use of electrochemical CO2 conversion devices. Highly active mesoporous Co3O4 and metal-substituted Co3O4 water oxidation catalysts were designed to investigate the role of the spinel structure on water oxidation activity. Further analysis of metal substituted samples reveal the importance of the octahedral sites in the spinel structure, which was later used to design an Mg-Co3O4 sample with improved water oxidation activity. The design of efficient cathode materials which can selectivity reduce CO2 to fuels and chemicals is critical to the widespread use of CO2 electrolysis. A nanoporous Ag material was synthesized through a dealloying technique able to operate with less than 0.5 V overpotential and high selectivity towards CO. CO is a valuable intermediate chemical which can used in Fischer-Tropsch or Gas-to-liquids technologies to produce liquids fuels. A detailed investigation of nanostructured Ag catalysts found stepped sites to be responsible for enhanced CO2 reduction activity due to improved stabilization of the COOH intermediate on the catalyst surface. In addition, an low-cost Zn dendrite electrocatalyst was developed using an electroplating technique. Low coordinated sites formed through electrodeposition demonstrated the suppression of hydrogen evolution while maintaining CO activity. The Zn dendrite electrocatalyst was further examined using a newly developed in situ X-ray absorption technique able to probe catalyst stability and crystalline structure under CO2 reduction operating conditions. A final hurdle in the realization of CO2 electrolysis technologies is the integration of catalysts into working flow cell devices. To address this issue and enable testing in a practical system, a highly efficient and robust CO2 electrolysis flow cell was designed including the scale up of the previous nanoporous Ag synthesis procedure. Using the modified porous Ag catalyst, currents in the Amp regime were demonstrated approaching rates needed for energy storage applications. Stability on the order of days was successfully demonstrated due to use of robust system components and conditions suitable for process scale up.

A model for safety and health promotion among Danish farmers.

PubMed

Hjort, Charlotte; Højmose, Poul; Sherson, David

2003-01-01

In 1999, a project concerning the prevention of accidents and occupational diseases was started in Vejle County, Denmark. The aim of the project was to increase the safety and health in farming. The project was based on a participatory strategy. The main principles were local involvement in designing the project, multifaceted activities for defined target-groups and respect for occupational skills and integrity. This multilevel approach involved individuals, groups and organisations. Activities were initiated and adjusted throughout the project. This interactive work remodeling the activities throughout the project period and method encouraged empowerment leaving experiences among the participants. Target groups included farmers, farmers' wives, agricultural advisors, agricultural school teachers, employees and part-time assistants. Activities included dialog-meetings, information meetings in larger and smaller groups, as well as designing of educational safety material, e.g., for children and employees. The project is run with a very low degree of central organisational activities, and is also a so called "bottom-up" project with a low budget. Evaluations are undertaken throughout the project period. If this concept can be implemented in Denmark, it may well be useful in other developed as well as less industrialized countries.

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.

Label-free electrochemical detection of botulinum neurotoxin type E based on its enzymatic activity using interdigitated electrodes

NASA Astrophysics Data System (ADS)

Hyun, Sang Hwa; Park, Dae Keun; Kang, Aeyeon; Kim, Soohyun; Kim, Daehee; Shin, Yu Mi; Song, Ji-Joon; Yun, Wan Soo

2016-02-01

We report a simple label-free electrochemical method of detecting low concentrations of botulinum neurotoxin type E light chain (BoNT/E LC) based on its peptide cleavage activity. Dual-mode cyclic voltammetry was employed to observe changes in the redox signal of ferri-/ferro-cyanide on interdigitated microelectrodes, whose surfaces were covered by peptides designed from synaptosomal-associated protein 25 to be cleaved by BoNT/E LC. With the introduction of BoNT/E LC, the redox signal showed a time-dependent increase due to cleavage of the immobilized peptide molecules. In addition to the increased redox signal intensity, its time-dependence can be considered as a strong evidence of BoNT/E sensing, since the time-dependent increase can only result from the enzymatic activity of BoNT/E LC. Using this method, BoNT/E LC, at concentrations as low as 5 pg/ml, was readily measurable with only an hour of incubation.

Improved Low Temperature Performance of Supercapacitors

NASA Technical Reports Server (NTRS)

Brandon, Erik J.; West, William C.; Smart, Marshall C.; Gnanaraj, Joe

2013-01-01

Low temperature double-layer capacitor operation enabled by: - Base acetonitrile / TEATFB salt formulation - Addition of low melting point formates, esters and cyclic ethers center dot Key electrolyte design factors: - Volume of co-solvent - Concentration of salt center dot Capacity increased through higher capacity electrodes: - Zeolite templated carbons - Asymmetric cell designs center dot Continuing efforts - Improve asymmetric cell performance at low temperature - Cycle life testing Motivation center dot Benchmark performance of commercial cells center dot Approaches for designing low temperature systems - Symmetric cells (activated carbon electrodes) - Symmetric cells (zeolite templated carbon electrodes) - Asymmetric cells (lithium titanate/activated carbon electrodes) center dot Experimental results center dot Summary

Effect of the PiAstra Benchtop Flash-Heating Pasteurizer on Immune Factors of Donor Human Milk.

PubMed

Daniels, Brodie; Reimers, Penny; King, Tracy; Schmidt, Stefan; Coutsoudis, Anna

2018-05-01

PiAstra is a simulated flash-heat (FH) pasteurization temperature monitoring system designed using Raspberry Pi technology for the pasteurization of human milk. This study analyzed the effect of the PiAstra FH method on human milk immune components (immunoglobulin A [IgA] and lactoferrin activity). Donor milk samples (N = 45) were obtained from a human milk bank, and pasteurized. Concentrations of IgA and lactoferrin activity were compared to their unpasteurized controls using the Student's t test. The PiAstra FH method retained 34.2% of IgA (p < 0.0001) and 40.4% of lactoferrin activity (p < 0.0001) when compared to unpasteurized controls. The retention of IgA by the PiAstra is similar to previous FH studies, while retention of lactoferrin activity was higher than previous FH studies. The high-technology, low-cost PiAstra system, which is able to retain vital immune components of human milk, provides safe donor milk for low-resourced settings. This enables the use of pasteurized donor milk when human milk is not available, potentially saving vulnerable infant lives.

Self-catalyzed photo-initiated RAFT polymerization for fabrication of fluorescent polymeric nanoparticles with aggregation-induced emission feature.

PubMed

Zeng, Guangjian; Liu, Meiying; Jiang, Ruming; Huang, Qiang; Huang, Long; Wan, Qing; Dai, Yanfeng; Wen, Yuanqing; Zhang, Xiaoyong; Wei, Yen

2018-02-01

In recent years, the fluorescent polymeric nanoparticles (FPNs) with aggregation-induced emission (AIE) feature have been extensively exploited in various biomedical fields owing to their advantages, such as low toxicity, biodegradation, excellent biocompatibility, good designability and optical properties. Therefore, development of a facile, efficient and well designable strategy should be of great importance for the biomedical applications of these AIE-active FPNs. In this work, a novel method for the fabrication of AIE-active FPNs has been developed through the self-catalyzed photo-initiated reversible addition fragmentation chain transfer (RAFT) polymerization using an AIE dye containing chain transfer agent (CTA), which could initiate the RAFT polymerization under light irradiation. The results suggested that the final AIE-active FPNs (named as TPE-poly(St-PEGMA)) showed great potential for biomedical applications owing to their optical and biological properties. More importantly, the method described in the work is rather simple and effective and can be further extended to prepare many other different AIE-active FPNs owing to the good monomer adoptability of RAFT polymerization. Copyright © 2017 Elsevier B.V. All rights reserved.

Synthetic antimicrobial peptides as agricultural pesticides for plant-disease control.

PubMed

Montesinos, Emilio; Bardají, Eduard

2008-07-01

There is a need of antimicrobial compounds in agriculture for plant-disease control, with low toxicity and reduced negative environmental impact. Antimicrobial peptides are produced by living organisms and offer strong possibilities in agriculture because new compounds can be developed based on natural structures with improved properties of activity, specificity, biodegradability, and toxicity. Design of new molecules has been achieved using combinatorial-chemistry procedures coupled to high-throughput screening systems and data processing with design-of-experiments (DOE) methodology to obtain QSAR equation models and optimized compounds. Upon selection of best candidates with low cytotoxicity and moderate stability to protease digestion, anti-infective activity has been evaluated in plant-pathogen model systems. Suitable compounds have been submitted to acute toxicity testing in higher organisms and exhibited a low toxicity profile in a mouse model. Large-scale production can be achieved by solution organic or chemoenzymatic procedures in the case of very small peptides, but, in many cases, production can be performed by biotechnological methods using genetically modified microorganisms (fermentation) or transgenic crops (plant biofactories).

Improvement in Brightness Uniformity by Compensating for the Threshold Voltages of Both the Driving Thin-Film Transistor and the Organic Light-Emitting Diode for Active-Matrix Organic Light-Emitting Diode Displays

NASA Astrophysics Data System (ADS)

Ching-Lin Fan,; Hui-Lung Lai,; Jyu-Yu Chang,

2010-05-01

In this paper, we propose a novel pixel design and driving method for active-matrix organic light-emitting diode (AM-OLED) displays using low-temperature polycrystalline silicon thin-film transistors (LTPS-TFTs). The proposed threshold voltage compensation circuit, which comprised five transistors and two capacitors, has been verified to supply uniform output current by simulation work using the automatic integrated circuit modeling simulation program with integrated circuit emphasis (AIM-SPICE) simulator. The driving scheme of this voltage programming method includes four periods: precharging, compensation, data input, and emission. The simulated results demonstrate excellent properties such as low error rate of OLED anode voltage variation (<1%) and high output current. The proposed pixel circuit shows high immunity to the threshold voltage deviation characteristics of both the driving poly-Si TFT and the OLED.

Optimization of simultaneous tritium–radiocarbon internal gas proportional counting

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

Bonicalzi, R. M.; Aalseth, C. E.; Day, A. R.

Specific environmental applications can benefit from dual tritium and radiocarbon measurements in a single compound. Assuming typical environmental levels, it is often the low tritium activity relative to the higher radiocarbon activity that limits the dual measurement. In this paper, we explore the parameter space for a combined tritium and radiocarbon measurement using a methane sample mixed with an argon fill gas in low-background proportional counters of a specific design. We present an optimized methane percentage, detector fill pressure, and analysis energy windows to maximize measurement sensitivity while minimizing count time. The final optimized method uses a 9-atm fill ofmore » P35 (35% methane, 65% argon), and a tritium analysis window from 1.5 to 10.3 keV, which stops short of the tritium beta decay endpoint energy of 18.6 keV. This method optimizes tritium counting efficiency while minimizing radiocarbon beta decay interference.« less

Design of 2.5 GHz broad bandwidth microwave bandpass filter at operating frequency of 10 GHz using HFSS

NASA Astrophysics Data System (ADS)

Jasim, S. E.; Jusoh, M. A.; Mahmud, S. N. S.; Zamani, A. H.

2018-04-01

Development of low losses, small size and broad bandwidth microwave bandpass filter operating at higher frequencies is an active area of research. This paper presents a new route used to design and simulate microwave bandpass filter using finite element modelling and realized broad bandwidth, low losses, small dimension microwave bandpass filter operating at 10 GHz frequency using return loss method. The filter circuit has been carried out using Computer Aid Design (CAD), Ansoft HFSS software and designed with four parallel couple line model and small dimension (10 × 10 mm2) using LaAlO3 substrate. The response of the microwave filter circuit showed high return loss -50 dB at operating frequency at 10.4 GHz and broad bandwidth of 2.5 GHz from 9.5 to 12 GHz. The results indicate the filter design and simulation using HFSS is reliable and have the opportunity to transfer from lab potential experiments to the industry.

Magnetic decoupling of the linac in a low field biplanar linac-MR system.

PubMed

St Aubin, J; Steciw, S; Fallone, B G

2010-09-01

The integration of a low field biplanar magnetic resonance (MR) imager and linear accelerator (linac) causes magnetic interference at the linac due to the MR fringe fields. In order to eliminate this interference, passive and active magnetic shielding designs are investigated. The optimized design of passive magnetic shielding was performed using the finite element method. The design was required to achieve no greater than a 20% electron beam loss within the linac waveguide and electron gun, no greater than 0.06 T at the multileaf collimator (MLC) motors, and generate a distortion of the main MR imaging volume of no greater than 300 ppm. Through the superposition of the analytical solution for a single current carrying wire loop, active shielding designs in the form of three and four sets of coil pairs surrounding the linac waveguide and electron gun were also investigated. The optimized current and coil center locations that yielded the best cancellation of the MR fringe fields at the linac were determined using sequential quadratic programming. Optimized passive shielding in the form of two steel cylinders was designed to meet the required constraints. When shielding the MLC motors along with the waveguide and electron gun, the thickness of the cylinders was less than 1 mm. If magnetically insensitive MLC motors are used, no MLC shielding would be required and the waveguide shield (shielding the waveguide and electron gun) became 1.58 mm thick. In addition, the optimized current and coil spacing for active shielding was determined for both three and four coil pair configurations. The results of the active shielding optimization produced no beam loss within the waveguide and electron gun and a maximum MR field distortion of 91 ppm over a 30 cm diameter spherical volume. Very simple passive and active shielding designs have been shown to magnetically decouple the linac from the MR imager in a low field biplanar linac-MR system. The MLC passive shielding produced the largest distortion of the MR field over the imaging volume. With the use of magnetically insensitive motors, the MR field distortion drops substantially since no MLC shield is required. The active shielding designs yielded no electron beam loss within the linac.

Nanostructured electrocatalysts with tunable activity and selectivity

NASA Astrophysics Data System (ADS)

Mistry, Hemma; Varela, Ana Sofia; Kühl, Stefanie; Strasser, Peter; Cuenya, Beatriz Roldan

2016-04-01

The field of electrocatalysis has undergone tremendous advancement in the past few decades, in part owing to improvements in catalyst design at the nanoscale. These developments have been crucial for the realization of and improvement in alternative energy technologies based on electrochemical reactions such as fuel cells. Through the development of novel synthesis methods, characterization techniques and theoretical methods, rationally designed nanoscale electrocatalysts with tunable activity and selectivity have been achieved. This Review explores how nanostructures can be used to control electrochemical reactivity, focusing on three model reactions: O2 electroreduction, CO2 electroreduction and ethanol electrooxidation. The mechanisms behind nanoscale control of reactivity are discussed, such as the presence of low-coordinated sites or facets, strain, ligand effects and bifunctional effects in multimetallic materials. In particular, studies of how particle size, shape and composition in nanostructures can be used to tune reactivity are highlighted.

New Variable Porosity Flow Diverter (VPOD) Stent Design for Treatment of Cerebrovascular Aneurysms

PubMed Central

Ionita, Ciprian; Baier, Robert; Rudin, Stephen

2012-01-01

Using flow diverting Stents for intracranial aneurysm repair has been an area of recent active research. While current commercial flow diverting stents rely on a dense mesh of braided coils for flow diversion, our group has been developing a method to selectively occlude the aneurysm neck, without endangering nearby perforator vessels. In this paper, we present a new method of fabricating the low porosity patch, a key element of such asymmetric vascular stents (AVS). PMID:22254507

An investigation into the protective factors for overweight among low socio-economic status children.

PubMed

Boshoff, Kobie; Dollman, Jim; Magarey, Anthea

2007-08-01

In light of the current obesity epidemic, this study aimed to expand the knowledge base about the factors involved and the characteristics of children of low socio-economic status (SES) who display healthy behaviours in their eating and physical activity. This project was conducted in two phases: a non-experimental, quantitative design was used in phase one to assess the characteristics of a sample of children in a low SES community. This phase identified children who displayed healthy eating and physical activity behaviours. Phase two used interpretive qualitative methods to investigate the perceptions of these children and their parents about the protective factors involved. Focus groups with children and interviews with their mothers were conducted. In phase one, 45 of 227 children assessed met a priori criteria set for healthy eating and physical activity behaviours. Central themes identified in phase two include: the influence of perceived health benefits; parental and child values regarding healthy eating and physical activity; the sense of enjoyment that children experience; the impact of child preferences and choice; and social influences. The study illustrated the complexity of factors involved in physical activity and healthy eating among children in a low socio-economic community.

Development of interest in science and interest in teaching elementary science: Influence of informal, school, and inquiry methods course experiences

NASA Astrophysics Data System (ADS)

Bulunuz, Mizrap

Inquiry-based science instruction is a major goal of science education reform. However, there is little research examining how preservice elementary teachers might be motivated to teach through inquiry. This quantitative study was designed to examine the role of background experiences and an inquiry science methods course on interest in science and interest in teaching science. The course included many activities and assignments at varying levels of inquiry, designed to teach content and inquiry methods and to model effective teaching. The study involved analyses of surveys completed by students in the course on their experiences with science before, during, and at the end of the course. The following questions guided the design of this study and analysis of the data: (1) What science background experiences (school, home, and informal education) do participants have and how do those experiences affect initial interest in science? (2) Among the hands-on activities in the methods course, is there a relationship between level of inquiry of the activity and the motivational quality (interesting, fun, and learning) of the activity? (3) Does the course affect participants' interest and attitude toward science? (4) What aspects of the course contribute to participants' interest in teaching science and choice to teach science? Descriptive and inferential analysis of a background survey revealed that participants with high and low initial interest in science differed significantly on remembering about elementary school science and involvement in science related activities in childhood/youth. Analysis of daily ratings of each hands-on activity on motivational qualities (fun, interest, and learning) indicated that there were significant differences in motivational quality of the activities by level of inquiry with higher levels of inquiry rated more positively. Pre/post surveys indicated that participants increased in interest in science and a number of variables reflecting more positive feelings about science and science teaching. Regression analysis found that the best predictors for interest in teaching science were experiencing fun activities in the science methods course followed by the interest participants brought to the course. This study highlights the motivational aspects of the methods course in developing interest in science and interest in teaching science.

Infrared and visible image fusion scheme based on NSCT and low-level visual features

NASA Astrophysics Data System (ADS)

Li, Huafeng; Qiu, Hongmei; Yu, Zhengtao; Zhang, Yafei

2016-05-01

Multi-scale transform (MST) is an efficient tool for image fusion. Recently, many fusion methods have been developed based on different MSTs, and they have shown potential application in many fields. In this paper, we propose an effective infrared and visible image fusion scheme in nonsubsampled contourlet transform (NSCT) domain, in which the NSCT is firstly employed to decompose each of the source images into a series of high frequency subbands and one low frequency subband. To improve the fusion performance we designed two new activity measures for fusion of the lowpass subbands and the highpass subbands. These measures are developed based on the fact that the human visual system (HVS) percept the image quality mainly according to its some low-level features. Then, the selection principles of different subbands are presented based on the corresponding activity measures. Finally, the merged subbands are constructed according to the selection principles, and the final fused image is produced by applying the inverse NSCT on these merged subbands. Experimental results demonstrate the effectiveness and superiority of the proposed method over the state-of-the-art fusion methods in terms of both visual effect and objective evaluation results.

Antenna array geometry optimization for a passive coherent localisation system

NASA Astrophysics Data System (ADS)

Knott, Peter; Kuschel, Heiner; O'Hagan, Daniel

2012-11-01

Passive Coherent Localisation (PCL), also known as Passive Radar, making use of RF sources of opportunity such as Radio or TV Broadcasting Stations, Cellular Phone Network Base Stations, etc. is an advancing technology for covert operation because no active radar transmitter is required. It is also an attractive addition to existing active radar stations because it has the potential to discover low-flying and low-observable targets. The CORA (Covert Radar) experimental passive radar system currently developed at Fraunhofer-FHR features a multi-channel digital radar receiver and a circular antenna array with separate elements for the VHF- and the UHF-range and is used to exploit alternatively Digital Audio (DAB) or Video Broadcasting (DVB-T) signals. For an extension of the system, a wideband antenna array is being designed for which a new discone antenna element has been developed covering the full DVB-T frequency range. The present paper describes the outline of the system and the numerical modelling and optimisation methods applied to solve the complex task of antenna array design: Electromagnetic full wave analysis is required for the parametric design of the antenna elements while combinatorial optimization methods are applied to find the best array positions and excitation coefficients for a regular omni-directional antenna performance. The different steps are combined in an iterative loop until the optimum array layout is found. Simulation and experimental results for the current system will be shown.

Effect of Increasing the Choice of Active Options on Children’s Physical Activity

PubMed Central

Feda, Denise M.; Lambiase, Maya J.; McCarthy, Thomas F.; Barkley, Jacob E.; Roemmich, James. N.

2012-01-01

Objectives To determine whether increasing the choice of physical activity options increases the duration and intensity of children’s physically active play. Design This cross-sectional laboratory study included gender (male, female) and choice group [single toy (no choice), three toys (low choice), five toys (high choice)] as between participant factors. Methods Boys and girls (n = 36, 8–12 y) were stratified, randomly assigned to a choice group that always provided access to each participant’s most liked active toy(s), and allowed 60 min of free time. The same sedentary alternatives were freely available to all participants. Physical activity outcomes were measured by accelerometry, heart rate, and direct observation. Results The number of active toys the children played with increased (p < 0.001) across each choice group. Minutes spent in MPA were greater in the low choice (p < 0.05) and high choice (p < 0.02) groups than the no choice group. Active play time was greater (p < 0.01) in the low choice (79%) and high choice (95%) groups compared to the no choice group. Girls in the low and high choice groups had greater (p < 0.05) percent heart rate reserve when compared to girls in the no choice group. There was no difference in the boys’ percent heart rate reserve between the no choice, low choice and high choice groups. Conclusions Increasing the choice of active toys increases both the duration and intensity of physically active play, especially in girls. PMID:22342111

Care-physical activity initiatives in the neighbourhood: study protocol for mixed-methods research on participation, effective elements, impact, and funding methods.

PubMed

Wagemakers, Annemarie; Mulderij, Lisanne S; Verkooijen, Kirsten T; Groenewoud, Stef; Koelen, Maria A

2018-06-28

In the Netherlands, people with a low socioeconomic status (SES) live approximately 6 years less and are less engaged in physical activity (PA) than high SES citizens. This contributes to the persistent health inequalities between low and high SES citizens. Care-PA initiatives are deemed effective for stimulating PA and improving health and participation among peoples with a low SES. In those initiatives, multiple sectors (e.g. sports, health insurers, municipalities) collaborate to connect primary care and PA at neighbourhood level. This study focuses on two Dutch municipalities that aim to invest in Health in All Policies (HiAP) and care-PA initiatives to improve the health of people with low SES. The aim is to gain insight into (1) the short-term (3 months) and long-term (1 year) outcomes of participating in care-PA initiatives for low SES citizens in terms of health, quality of life, and societal participation, (2) the effective elements that contribute to these outcomes, (3) the direct and perceived societal costs and benefits of care-PA initiatives, and (4) alternative ways to fund integrated care, prevention, and care-PA initiatives at neighbourhood level. The study will be built on a mixed-methods design guided by action research to continuously facilitate participatory processes and practical solutions. To assess outcomes, body measurements and questionnaires will be used as part of a pre-test/post-test design. Focus groups and interviews will be conducted to gain an in-depth understanding of outcomes and action elements. Action elements will be explored by using multiple tools: concept mapping, the logic model, and capacity mapping. Direct and perceived societal costs will be measured by administrative data from healthcare insurers (before-after design) and the effectiveness arena. An alternative funding model will be identified based on literature study, expert meetings, and municipal workshops. Initiatives addressing multiple factors at different levels in an integral way are a challenge for evaluation. Multi-methods and tools are required, and data need to be interpreted comprehensively in order to contribute to a contextual insight into what works and why in relation to HiAP and care-PA initiatives.

A similitude method and the corresponding blade design of a low-speed large-scale axial compressor rotor

NASA Astrophysics Data System (ADS)

Yu, Chenghai; Ma, Ning; Wang, Kai; Du, Juan; Van den Braembussche, R. A.; Lin, Feng

2014-04-01

A similitude method to model the tip clearance flow in a high-speed compressor with a low-speed model is presented in this paper. The first step of this method is the derivation of similarity criteria for tip clearance flow, on the basis of an inviscid model of tip clearance flow. The aerodynamic parameters needed for the model design are then obtained from a numerical simulation of the target high-speed compressor rotor. According to the aerodynamic and geometric parameters of the target compressor rotor, a large-scale low-speed rotor blade is designed with an inverse blade design program. In order to validate the similitude method, the features of tip clearance flow in the low-speed model compressor are compared with the ones in the high-speed compressor at both design and small flow rate points. It is found that not only the trajectory of the tip leakage vortex but also the interface between the tip leakage flow and the incoming main flow in the high-speed compressor match well with that of its low speed model. These results validate the effectiveness of the similitude method for the tip clearance flow proposed in this paper.

Analysis of the characteristics of slot design affecting resistance to sliding during active archwire configurations

PubMed Central

2013-01-01

Background During orthodontic treatment, a low resistance to slide (RS) is desirable when sliding mechanics are used. Many studies showed that several variables affect the RS at the bracket-wire interface; among these, the design of the bracket slot has not been deeply investigated yet. This study aimed to clarify the effect of different slot designs on the RS expressed by five types of low-friction brackets in vertical and horizontal active configurations of the wire. Methods Five low-friction brackets (Damon SL II, Ormco, Orange, CA, USA; In-Ovation, GAC International, Bohemia, NY, USA; Quick, Forestadent, Pforzheim, Germany; Time 2, AO, Sheboygan, WI, USA; Synergy, RMO, Denver, CO, USA) coupled with an 0.014-in NiTi thermal wire (Therma-Lite, AO) were tested in two three-bracket experimental models simulating vertical and horizontal bracket displacements. A custom-made machine was used to measure frictional resistance with tests repeated on ten occasions for each bracket-wire combination. Design characteristics such as the mesio-distal slot width, slot depth, and presence of chamfered edges at the extremities of the slot were evaluated on SEM images (SUPRA, Carl Zeiss, Oberkochen, Germany) and analyzed in relation to the data of RS recorded. Results Time 2 was found to show the higher frictional forces (1.50 and 1.35 N) in both experimental models (p < 0.05), while Quick and Synergy brackets showed the lower frictional values in the vertical (0.66 N) and in the horizontal (0.68 N) bracket displacements, respectively. With vertically displaced brackets, the increased mesio-distal slot width and the presence of clear angle at mesial and distal slot edges increase the values of RS. With brackets horizontally displaced, the RS expressed by the wire is influenced simultaneously by the depth of the slot, the mesio-distal slot width, and the presence of clear angle at the extremities of the slot base, the clip, or the slide. Conclusion In order to select the proper low-friction bracket system, clinicians should consider specific characteristics of slot design apart from the wire engaging method. PMID:24325837

HEROs: Design of a Mixed-Methods Formative Research Phase for an Ecocultural Intervention to Promote Healthy Eating and Activity Behaviors in Rural Families With Preschoolers.

PubMed

Bellows, Laura L; McCloskey, Morgan; Clark, Lauren; Thompson, Darcy A; Bekelman, Traci A; Chamberlin, Barbara; Johnson, Susan L

2018-04-10

To describe the mixed-methods formative research phase in the development of the Healthy Environments Study (HEROs), a technology-based, interactive family intervention to promote healthy eating and activity behaviors for young children in the home environment. A mixed-method iterative approach, using ecocultural theory as a framework, will guide the development of both quantitative and qualitative formative research assessments. Rural eastern Colorado. Low-income families (n = 200) with preschool-aged children enrolled at 6 Head Start/preschool centers. Quantitative and qualitative methodologies will garner insights into 4 key topic areas: (1) food behaviors and environments (Remote Food Photography Method, parent focus group, and survey), (2) physical activity behaviors and environments (parent interview and survey), (3) mobile device use (parent survey and interview), and (4) daily life (ecocultural family interview and teacher/staff group discussions). Results will be interpreted in combination to allow for a holistic understanding of participant behaviors, beliefs, attitudes and values related to each of the 4 topic areas. Collectively, outcomes will provide a comprehensive picture of preschoolers' daily life and inform intervention design and strategies to enhance preschoolers' eating and activity behaviors in the home environment. Copyright © 2018 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

A Cabin Air Separator for EVA Oxygen

NASA Technical Reports Server (NTRS)

Graf, John C.

2011-01-01

Presently, the Extra-Vehicular Activities (EVAs) conducted from the Quest Joint Airlock on the International Space Station use high pressure, high purity oxygen that is delivered to the Space Station by the Space Shuttle. When the Space Shuttle retires, a new method of delivering high pressure, high purity oxygen to the High Pressure Gas Tanks (HPGTs) is needed. One method is to use a cabin air separator to sweep oxygen from the cabin air, generate a low pressure/high purity oxygen stream, and compress the oxygen with a multistage mechanical compressor. A main advantage to this type of system is that the existing low pressure oxygen supply infrastructure can be used as the source of cabin oxygen. ISS has two water electrolysis systems that deliver low pressure oxygen to the cabin, as well as chlorate candles and compressed gas tanks on cargo vehicles. Each of these systems can feed low pressure oxygen into the cabin, and any low pressure oxygen source can be used as an on-board source of oxygen. Three different oxygen separator systems were evaluated, and a two stage Pressure Swing Adsorption system was selected for reasons of technical maturity. Two different compressor designs were subjected to long term testing, and the compressor with better life performance and more favorable oxygen safety characteristics was selected. These technologies have been used as the basis of a design for a flight system located in Equipment Lock, and taken to Preliminary Design Review level of maturity. This paper describes the Cabin Air Separator for EVA Oxygen (CASEO) concept, describes the separator and compressor technology trades, highlights key technology risks, and describes the flight hardware concept as presented at Preliminary Design Review (PDR)

Controlled soil warming powered by alternative energy for remote field sites.

PubMed

Johnstone, Jill F; Henkelman, Jonathan; Allen, Kirsten; Helgason, Warren; Bedard-Haughn, Angela

2013-01-01

Experiments using controlled manipulation of climate variables in the field are critical for developing and testing mechanistic models of ecosystem responses to climate change. Despite rapid changes in climate observed in many high latitude and high altitude environments, controlled manipulations in these remote regions have largely been limited to passive experimental methods with variable effects on environmental factors. In this study, we tested a method of controlled soil warming suitable for remote field locations that can be powered using alternative energy sources. The design was tested in high latitude, alpine tundra of southern Yukon Territory, Canada, in 2010 and 2011. Electrical warming probes were inserted vertically in the near-surface soil and powered with photovoltaics attached to a monitoring and control system. The warming manipulation achieved a stable target warming of 1.3 to 2 °C in 1 m(2) plots while minimizing disturbance to soil and vegetation. Active control of power output in the warming plots allowed the treatment to closely match spatial and temporal variations in soil temperature while optimizing system performance during periods of low power supply. Active soil heating with vertical electric probes powered by alternative energy is a viable option for remote sites and presents a low-disturbance option for soil warming experiments. This active heating design provides a valuable tool for examining the impacts of soil warming on ecosystem processes.

Using CFD Surface Solutions to Shape Sonic Boom Signatures Propagated from Off-Body Pressure

NASA Technical Reports Server (NTRS)

Ordaz, Irian; Li, Wu

2013-01-01

The conceptual design of a low-boom and low-drag supersonic aircraft remains a challenge despite significant progress in recent years. Inverse design using reversed equivalent area and adjoint methods have been demonstrated to be effective in shaping the ground signature propagated from computational fluid dynamics (CFD) off-body pressure distributions. However, there is still a need to reduce the computational cost in the early stages of design to obtain a baseline that is feasible for low-boom shaping, and in the search for a robust low-boom design over the entire sonic boom footprint. The proposed design method addresses the need to reduce the computational cost for robust low-boom design by using surface pressure distributions from CFD solutions to shape sonic boom ground signatures propagated from CFD off-body pressure.

A Non-Parametric Approach for the Activation Detection of Block Design fMRI Simulated Data Using Self-Organizing Maps and Support Vector Machine.

PubMed

Bahrami, Sheyda; Shamsi, Mousa

2017-01-01

Functional magnetic resonance imaging (fMRI) is a popular method to probe the functional organization of the brain using hemodynamic responses. In this method, volume images of the entire brain are obtained with a very good spatial resolution and low temporal resolution. However, they always suffer from high dimensionality in the face of classification algorithms. In this work, we combine a support vector machine (SVM) with a self-organizing map (SOM) for having a feature-based classification by using SVM. Then, a linear kernel SVM is used for detecting the active areas. Here, we use SOM for feature extracting and labeling the datasets. SOM has two major advances: (i) it reduces dimension of data sets for having less computational complexity and (ii) it is useful for identifying brain regions with small onset differences in hemodynamic responses. Our non-parametric model is compared with parametric and non-parametric methods. We use simulated fMRI data sets and block design inputs in this paper and consider the contrast to noise ratio (CNR) value equal to 0.6 for simulated datasets. fMRI simulated dataset has contrast 1-4% in active areas. The accuracy of our proposed method is 93.63% and the error rate is 6.37%.

Applicability of linearized-theory attached-flow methods to design and analysis of flap systems at low speeds for thin swept wings with sharp leading edges

NASA Technical Reports Server (NTRS)

Carlson, Harry W.; Darden, Christine M.

1987-01-01

Low-speed experimental force and data on a series of thin swept wings with sharp leading edges and leading and trailing-edge flaps are compared with predictions made using a linearized-theory method which includes estimates of vortex forces. These comparisons were made to assess the effectiveness of linearized-theory methods for use in the design and analysis of flap systems in subsonic flow. Results demonstrate that linearized-theory, attached-flow methods (with approximate representation of vortex forces) can form the basis of a rational system for flap design and analysis. Even attached-flow methods that do not take vortex forces into account can be used for the selection of optimized flap-system geometry, but design-point performance levels tend to be underestimated unless vortex forces are included. Illustrative examples of the use of these methods in the design of efficient low-speed flap systems are included.

Ultrathin nitrogen-doped graphitized carbon shell encapsulating CoRu bimetallic nanoparticles for enhanced electrocatalytic hydrogen evolution.

PubMed

Xu, You; Li, Yinghao; Yin, Shuli; Yu, Hongjie; Xue, Hairong; Li, Xiaonian; Wang, Hongjing; Wang, Liang

2018-06-01

Design of highly active and cost-effective electrocatalysts is very important for the generation of hydrogen by electrochemical water-splitting. Herein, we report the fabrication of ultrathin nitrogen-doped graphitized carbon shell encapsulating CoRu bimetallic nanoparticles (CoRu@NCs) and demonstrate their promising feasibility for efficiently catalyzing the hydrogen evolution reaction (HER) over a wide pH range. The resultant CoRu@NC nanohybrids possess an alloy-carbon core-shell structure with encapsulated low-ruthenium-content CoRu bimetallic alloy nanoparticles (10-30 nm) as the core and ultrathin nitrogen-doped graphitized carbon layers (2-6 layers) as the shell. Remarkably, the optimized catalyst (CoRu@NC-2 sample) with a Ru content as low as 2.04 wt% shows superior catalytic activity and excellent durability for HER in acidic, neutral, and alkaline conditions. This work offers a new method for the design and synthesis of non-platium-based electrocatalysts for HER in all-pH.

Ultrathin nitrogen-doped graphitized carbon shell encapsulating CoRu bimetallic nanoparticles for enhanced electrocatalytic hydrogen evolution

NASA Astrophysics Data System (ADS)

Xu, You; Li, Yinghao; Yin, Shuli; Yu, Hongjie; Xue, Hairong; Li, Xiaonian; Wang, Hongjing; Wang, Liang

2018-06-01

Design of highly active and cost-effective electrocatalysts is very important for the generation of hydrogen by electrochemical water-splitting. Herein, we report the fabrication of ultrathin nitrogen-doped graphitized carbon shell encapsulating CoRu bimetallic nanoparticles (CoRu@NCs) and demonstrate their promising feasibility for efficiently catalyzing the hydrogen evolution reaction (HER) over a wide pH range. The resultant CoRu@NC nanohybrids possess an alloy–carbon core–shell structure with encapsulated low-ruthenium-content CoRu bimetallic alloy nanoparticles (10–30 nm) as the core and ultrathin nitrogen-doped graphitized carbon layers (2–6 layers) as the shell. Remarkably, the optimized catalyst (CoRu@NC-2 sample) with a Ru content as low as 2.04 wt% shows superior catalytic activity and excellent durability for HER in acidic, neutral, and alkaline conditions. This work offers a new method for the design and synthesis of non-platium-based electrocatalysts for HER in all-pH.

Adjusted active carbon fibers for solid phase microextraction.

PubMed

Jia, Jinping; Feng, Xue; Fang, Nenghu; Wang, Yalin; Chen, Hongjin; Dan, Wu

2002-01-01

Adjusted active carbon fiber (AACF) was evaluated for Solid Phase Microextraction (SPME), which showed higher sensitivity and stability than traditional coating fibers. The characteristics of AACF result from two different activation methods (chemical and water vapor) and from variable activation conditions (temperature and time). The fiber treated by water vapor appears to have stronger affinity to polar compounds, while that treated by chemical activation appears to have stronger affinity to non-polar compounds. For different target compounds ranged from non-polar to polar, AACF design could be effective with specific selections and sensitivities. As applications in this paper, benzoic acid in soy sauce was extracted onto water-vapor-activated-fiber, then analyzed using gas chromatograph-mass spectrometer (GC-MS). The chemical-activated-fiber SPME was applied in the analysis of benzene series compounds (BTEX) in water matrix. Compared with standard carbon disulfide extraction method, chemical-activated-fiber SPME is more convenient due to its simple process and turns to be of relative low detection limits.

A method for obtaining reduced-order control laws for high-order systems using optimization techniques

NASA Technical Reports Server (NTRS)

Mukhopadhyay, V.; Newsom, J. R.; Abel, I.

1981-01-01

A method of synthesizing reduced-order optimal feedback control laws for a high-order system is developed. A nonlinear programming algorithm is employed to search for the control law design variables that minimize a performance index defined by a weighted sum of mean-square steady-state responses and control inputs. An analogy with the linear quadractic Gaussian solution is utilized to select a set of design variables and their initial values. To improve the stability margins of the system, an input-noise adjustment procedure is used in the design algorithm. The method is applied to the synthesis of an active flutter-suppression control law for a wind tunnel model of an aeroelastic wing. The reduced-order controller is compared with the corresponding full-order controller and found to provide nearly optimal performance. The performance of the present method appeared to be superior to that of two other control law order-reduction methods. It is concluded that by using the present algorithm, nearly optimal low-order control laws with good stability margins can be synthesized.

Commissioning of the Active-Target Time Projection Chamber

NASA Astrophysics Data System (ADS)

Bradt, J.; Bazin, D.; Abu-Nimeh, F.; Ahn, T.; Ayyad, Y.; Beceiro Novo, S.; Carpenter, L.; Cortesi, M.; Kuchera, M. P.; Lynch, W. G.; Mittig, W.; Rost, S.; Watwood, N.; Yurkon, J.

2017-12-01

The Active-Target Time Projection Chamber (AT-TPC) was recently built and commissioned at the National Superconducting Cyclotron Laboratory at Michigan State University. This gas-filled detector uses an active-target design where the gas acts as both the tracking medium and the reaction target. Operating inside a 2T solenoidal magnetic field, the AT-TPC records charged particle tracks that can be reconstructed to very good energy and angular resolutions. The near- 4 π solid angle coverage and thick target of the detector are well-suited to experiments with low secondary beam intensities. In this paper, the design and instrumentation of theAT-TPC are described along with the methods used to analyze the data it produces. A simulation of the detector's performance and some results from its commissioning with a radioactive 46Ar beam are also presented.

Study protocol title: a prospective cohort study of low back pain

PubMed Central

2013-01-01

Background Few prospective cohort studies of workplace low back pain (LBP) with quantified job physical exposure have been performed. There are few prospective epidemiological studies for LBP occupational risk factors and reported data generally have few adjustments for many personal and psychosocial factors. Methods/design A multi-center prospective cohort study has been incepted to quantify risk factors for LBP and potentially develop improved methods for designing and analyzing jobs. Due to the subjectivity of LBP, six measures of LBP are captured: 1) any LBP, 2) LBP ≥ 5/10 pain rating, 3) LBP with medication use, 4) LBP with healthcare provider visits, 5) LBP necessitating modified work duties and 6) LBP with lost work time. Workers have thus far been enrolled from 30 different employment settings in 4 diverse US states and performed widely varying work. At baseline, workers undergo laptop-administered questionnaires, structured interviews, and two standardized physical examinations to ascertain demographics, medical history, psychosocial factors, hobbies and physical activities, and current musculoskeletal disorders. All workers’ jobs are individually measured for physical factors and are videotaped. Workers are followed monthly for the development of low back pain. Changes in jobs necessitate re-measure and re-videotaping of job physical factors. The lifetime cumulative incidence of low back pain will also include those with a past history of low back pain. Incident cases will exclude prevalent cases at baseline. Statistical methods planned include survival analyses and logistic regression. Discussion Data analysis of a prospective cohort study of low back pain is underway and has successfully enrolled over 800 workers to date. PMID:23497211

Measuring housing quality in the absence of a monetized real estate market.

PubMed

Rindfuss, Ronald R; Piotrowski, Martin; Thongthai, Varachai; Prasartkul, Pramote

2007-03-01

Measuring housing quality or value or both has been a weak component of demographic and development research in less developed countries that lack an active real estate (housing) market. We describe a new method based on a standardized subjective rating process. It is designed to be used in settings that do not have an active, monetized housing market. The method is applied in an ongoing longitudinal study in north-east Thailand and could be straightforwardly used in many other settings. We develop a conceptual model of the process whereby households come to reside in high-quality or low-quality housing units. We use this theoretical model in conjunction with longitudinal data to show that the new method of measuring housing quality behaves as theoretically expected, thus providing evidence of face validity.

How Learning Designs, Teaching Methods and Activities Differ by Discipline in Australian Universities

ERIC Educational Resources Information Center

Cameron, Leanne

2017-01-01

This paper reports on the learning designs, teaching methods and activities most commonly employed within the disciplines in six universities in Australia. The study sought to establish if there were significant differences between the disciplines in learning designs, teaching methods and teaching activities in the current Australian context, as…

Active Combustion Control for Aircraft Gas-Turbine Engines-Experimental Results for an Advanced, Low-Emissions Combustor Prototype

NASA Technical Reports Server (NTRS)

DeLaat, John C.; Kopasakis, George; Saus, Joseph R.; Chang, Clarence T.; Wey, Changlie

2012-01-01

Lean combustion concepts for aircraft engine combustors are prone to combustion instabilities. Mitigation of instabilities is an enabling technology for these low-emissions combustors. NASA Glenn Research Center s prior activity has demonstrated active control to suppress a high-frequency combustion instability in a combustor rig designed to emulate an actual aircraft engine instability experience with a conventional, rich-front-end combustor. The current effort is developing further understanding of the problem specifically as applied to future lean-burning, very low-emissions combustors. A prototype advanced, low-emissions aircraft engine combustor with a combustion instability has been identified and previous work has characterized the dynamic behavior of that combustor prototype. The combustor exhibits thermoacoustic instabilities that are related to increasing fuel flow and that potentially prevent full-power operation. A simplified, non-linear oscillator model and a more physics-based sectored 1-D dynamic model have been developed to capture the combustor prototype s instability behavior. Utilizing these models, the NASA Adaptive Sliding Phasor Average Control (ASPAC) instability control method has been updated for the low-emissions combustor prototype. Active combustion instability suppression using the ASPAC control method has been demonstrated experimentally with this combustor prototype in a NASA combustion test cell operating at engine pressures, temperatures, and flows. A high-frequency fuel valve was utilized to perturb the combustor fuel flow. Successful instability suppression was shown using a dynamic pressure sensor in the combustor for controller feedback. Instability control was also shown with a pressure feedback sensor in the lower temperature region upstream of the combustor. It was also demonstrated that the controller can prevent the instability from occurring while combustor operation was transitioning from a stable, low-power condition to a normally unstable high-power condition, thus enabling the high-power condition.

The vector of the tobacco epidemic: tobacco industry practices in low and middle-income countries

PubMed Central

Lee, Sungkyu; Ling, Pamela M.; Glantz, Stanton A.

2012-01-01

Purpose To understand transnational tobacco companiesr’ (TTCs) practices in low and middle-income countries which serve to block tobacco-control policies and promote tobacco use. Methods Systematic review of published research on tobacco industry activities to promote tobacco use and oppose tobacco-control policies in low and middle-income countries. Results TTCs’ strategies used in low and middle-income countries followed four main themes—economic activity; marketing/promotion; political activity; and deceptive/manipulative activity. Economic activity, including foreign investment and smuggling, was used to enter new markets. Political activities included lobbying, offering voluntary self-regulatory codes, and mounting corporate social responsibility campaigns. Deceptive activities included manipulation of science and use of third-party allies to oppose smoke-free policies, delay other tobacco-control policies, and maintain support of policymakers and the public for a pro-tobacco industry policy environment. TTCs used tactics for marketing, advertising, and promoting their brands that were tailored to specific market environments. These activities included direct and indirect tactis, targeting particular populations, and introducing new tobacco products designed to limit marketing restrictions and taxes, maintain the social acceptability of tobacco use, and counter tobacco-control efforts. Conclusions TTCs have used similar strategies in high-income countries as these being described in low and middle-income countries. As required by FCTC Article 5.3, to counter tobacco industry pressures and to implement effective tobacco-control policies, governments and health professionals in low and middle-income countries should fully understand TTCs practices and counter them. PMID:22370696

Modifying patterns of movement in people with low back pain -does it help? A systematic review.

PubMed

Laird, Robert A; Kent, Peter; Keating, Jennifer L

2012-09-07

Physiotherapy for people with low back pain frequently includes assessment and modification of lumbo-pelvic movement. Interventions commonly aim to restore normal movement and thereby reduce pain and improve activity limitation. The objective of this systematic review was to investigate: (i) the effect of movement-based interventions on movement patterns (muscle activation, lumbo-pelvic kinematics or postural patterns) of people with low back pain (LBP), and (ii) the relationship between changes in movement patterns and subsequent changes in pain and activity limitation. MEDLINE, Cochrane Central, EMBASE, AMI, CINAHL, Scopus, AMED, ISI Web of Science were searched from inception until January 2012. Randomised controlled trials or controlled clinical trials of people with LBP were eligible for inclusion. The intervention must have been designed to influence (i) muscle activity patterns, (ii) lumbo-pelvic kinematic patterns or (iii) postural patterns, and included measurement of such deficits before and after treatment, to allow determination of the success of the intervention on the lumbo-pelvic movement. Twelve trials (25% of retrieved studies) met the inclusion criteria. Two reviewers independently identified, assessed and extracted data. The PEDro scale was used to assess method quality. Intervention effects were described using standardised differences between group means and 95% confidence intervals. The included trials showed inconsistent, mostly small to moderate intervention effects on targeted movement patterns. There was considerable heterogeneity in trial design, intervention type and outcome measures. A relationship between changes to movement patterns and improvements in pain or activity limitation was observed in one of six studies on muscle activation patterns, one of four studies that examined the flexion relaxation response pattern and in two of three studies that assessed lumbo-pelvic kinematics or postural characteristics. Movement-based interventions were infrequently effective for changing observable movement patterns. A relationship between changes in movement patterns and improvement in pain or activity limitation was also infrequently observed. No independent studies confirm any observed relationships. Challenges for future research include defining best methods for measuring (i) movement aberrations, (ii) improvements in movements, and (iii) the relationship between changes in how people move and associated changes in other health indicators such as activity limitation.

Design-Filter Selection for H2 Control of Microgravity Isolation Systems: A Single-Degree-of-Freedom Case Study

NASA Technical Reports Server (NTRS)

Hampton, R. David; Whorton, Mark S.

2000-01-01

Many microgravity space-science experiments require active vibration isolation, to attain suitably low levels of background acceleration for useful experimental results. The design of state-space controllers by optimal control methods requires judicious choices of frequency-weighting design filters. Kinematic coupling among states greatly clouds designer intuition in the choices of these filters, and the masking effects of the state observations cloud the process further. Recent research into the practical application of H2 synthesis methods to such problems, indicates that certain steps can lead to state frequency-weighting design-filter choices with substantially improved promise of usefulness, even in the face of these difficulties. In choosing these filters on the states, one considers their relationships to corresponding design filters on appropriate pseudo-sensitivity- and pseudo-complementary-sensitivity functions. This paper investigates the application of these considerations to a single-degree-of-freedom microgravity vibration-isolation test case. Significant observations that were noted during the design process are presented. along with explanations based on the existent theory for such problems.

Project FIT: Rationale, design and baseline characteristics of a school- and community-based intervention to address physical activity and healthy eating among low-income elementary school children

PubMed Central

2011-01-01

Background This paper describes Project FIT, a collaboration between the public school system, local health systems, physicians, neighborhood associations, businesses, faith-based leaders, community agencies and university researchers to develop a multi-faceted approach to promote physical activity and healthy eating toward the general goal of preventing and reducing childhood obesity among children in Grand Rapids, MI, USA. Methods/design There are four overall components to Project FIT: school, community, social marketing, and school staff wellness - all that focus on: 1) increasing access to safe and affordable physical activity and nutrition education opportunities in the schools and surrounding neighborhoods; 2) improving the affordability and availability of nutritious food in the neighborhoods surrounding the schools; 3) improving the knowledge, self-efficacy, attitudes and behaviors regarding nutrition and physical activity among school staff, parents and students; 4) impacting the 'culture' of the schools and neighborhoods to incorporate healthful values; and 5) encouraging dialogue among all community partners to leverage existing programs and introduce new ones. Discussion At baseline, there was generally low physical activity (70% do not meet recommendation of 60 minutes per day), excessive screen time (75% do not meet recommendation of < 2 hours per day), and low intake of vegetables and whole grains and high intake of sugar-sweetened beverages, French fries and chips and desserts as well as a high prevalence of overweight and obesity (48.5% including 6% with severe obesity) among low income, primarily Hispanic and African American 3rd-5th grade children (n = 403). Trial registration ClinicalTrials.gov NCT01385046 PMID:21801411

Design, synthesis, and evaluation of salicyladimine derivatives as multitarget-directed ligands against Alzheimer's disease.

PubMed

Yang, Hua-Li; Cai, Pei; Liu, Qiao-Hong; Yang, Xue-Lian; Fang, Si-Qiang; Tang, Yan-Wei; Wang, Cheng; Wang, Xiao-Bing; Kong, Ling-Yi

2017-11-01

A series of salicyladimine derivatives were designed, synthesized and evaluated as multi-target-directed ligands for the treatment of Alzheimer's disease (AD). Biological activity results demonstrated that some derivatives possessed significant inhibitory activities against amyloid-β (Aβ) aggregation and human monoamine oxidase B (hMAO-B) as well as remarkable antioxidant effects and low cell toxicity. The optimal compound, 5, exhibited excellent potency for inhibition of self-induced Aβ 1-42 aggregation (91.3±2.1%, 25μM), inhibition of hMAO-B (IC 50 , 1.73±0.39μM), antioxidant effects (43.4±2.6μM of IC 50 by DPPH method, 0.67±0.06 trolox equivalent by ABTS method), metal chelation and BBB penetration. Furthermore, compound 5 had neuroprotective effects against ROS generation, H 2 O 2 -induced apoptosis, 6-OHDA-induced cell injury, and a significant in vitro anti-inflammatory activity. Collectively, these findings highlighted that compound 5 was a potential balanced multifunctional neuroprotective agent for the development of anti-AD drugs. Copyright © 2017. Published by Elsevier Ltd.

Design methodology for micro-discrete planar optics with minimum illumination loss for an extended source.

PubMed

Shim, Jongmyeong; Park, Changsu; Lee, Jinhyung; Kang, Shinill

2016-08-08

Recently, studies have examined techniques for modeling the light distribution of light-emitting diodes (LEDs) for various applications owing to their low power consumption, longevity, and light weight. The energy mapping technique, a design method that matches the energy distributions of an LED light source and target area, has been the focus of active research because of its design efficiency and accuracy. However, these studies have not considered the effects of the emitting area of the LED source. Therefore, there are limitations to the design accuracy for small, high-power applications with a short distance between the light source and optical system. A design method for compensating for the light distribution of an extended source after the initial optics design based on a point source was proposed to overcome such limits, but its time-consuming process and limited design accuracy with multiple iterations raised the need for a new design method that considers an extended source in the initial design stage. This study proposed a method for designing discrete planar optics that controls the light distribution and minimizes the optical loss with an extended source and verified the proposed method experimentally. First, the extended source was modeled theoretically, and a design method for discrete planar optics with the optimum groove angle through energy mapping was proposed. To verify the design method, design for the discrete planar optics was achieved for applications in illumination for LED flash. In addition, discrete planar optics for LED illuminance were designed and fabricated to create a uniform illuminance distribution. Optical characterization of these structures showed that the design was optimal; i.e., we plotted the optical losses as a function of the groove angle, and found a clear minimum. Simulations and measurements showed that an efficient optical design was achieved for an extended source.

The effect of on/off indicator design on state confusion, preference, and response time performance, executive summary

NASA Technical Reports Server (NTRS)

Donner, Kimberly A.; Holden, Kritina L.; Manahan, Meera K.

1991-01-01

Investigated are five designs of software-based ON/OFF indicators in a hypothetical Space Station Power System monitoring task. The hardware equivalent of the indicators used in the present study is the traditional indicator light that illuminates an ON label or an OFF label. Coding methods used to represent the active state were reverse video, color, frame, check, or reverse video with check. Display background color was also varied. Subjects made judgments concerning the state of indicators that resulted in very low error rates and high percentages of agreement across indicator designs. Response time measures for each of the five indicator designs did not differ significantly, although subjects reported that color was the best communicator. The impact of these results on indicator design is discussed.

Sunlight Responsive Thermochromic Window System

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

Millett, F,A; Byker,H, J

2006-10-27

Pleotint has embarked on a novel approach with our Sunlight Responsive Thermochromic, SRT™, windows. We are integrating dynamic sunlight control, high insulation values and low solar heat gain together in a high performance window. The Pleotint SRT window is dynamic because it reversibly changes light transmission based on thermochromics activated directly by the heating effect of sunlight. We can achieve a window package with low solar heat gain coefficient (SHGC), a low U value and high insulation. At the same time our windows provide good daylighting. Our innovative window design offers architects and building designers the opportunity to choose theirmore » desired energy performance, excellent sound reduction, external pane can be self-cleaning, or a resistance to wind load, blasts, bullets or hurricanes. SRT windows would provide energy savings that are estimated at up to 30% over traditional window systems. Glass fabricators will be able to use existing equipment to make the SRT window while adding value and flexibility to the basic design. Glazing installers will have the ability to fit the windows with traditional methods without wires, power supplies and controllers. SRT windows can be retrofit into existing buildings,« less

Active video games as a tool to prevent excessive weight gain in adolescents: rationale, design and methods of a randomized controlled trial

PubMed Central

2014-01-01

Background Excessive body weight, low physical activity and excessive sedentary time in youth are major public health concerns. A new generation of video games, the ones that require physical activity to play the games –i.e. active games- may be a promising alternative to traditional non-active games to promote physical activity and reduce sedentary behaviors in youth. The aim of this manuscript is to describe the design of a study evaluating the effects of a family oriented active game intervention, incorporating several motivational elements, on anthropometrics and health behaviors in adolescents. Methods/Design The study is a randomized controlled trial (RCT), with non-active gaming adolescents aged 12 – 16 years old randomly allocated to a ten month intervention (receiving active games, as well as an encouragement to play) or a waiting-list control group (receiving active games after the intervention period). Primary outcomes are adolescents’ measured BMI-SDS (SDS = adjusted for mean standard deviation score), waist circumference-SDS, hip circumference and sum of skinfolds. Secondary outcomes are adolescents’ self-reported time spent playing active and non-active games, other sedentary activities and consumption of sugar-sweetened beverages. In addition, a process evaluation is conducted, assessing the sustainability of the active games, enjoyment, perceived competence, perceived barriers for active game play, game context, injuries from active game play, activity replacement and intention to continue playing the active games. Discussion This is the first adequately powered RCT including normal weight adolescents, evaluating a reasonably long period of provision of and exposure to active games. Next, strong elements are the incorporating motivational elements for active game play and a comprehensive process evaluation. This trial will provide evidence regarding the potential contribution of active games in prevention of excessive weight gain in adolescents. Trial registration Dutch Trial register NTR3228. PMID:24661535

A flexible nanobrush pad for the chemical mechanical planarization of Cu/ultra-low-к materials

NASA Astrophysics Data System (ADS)

Han, Guiquan; Liu, Yuhong; Lu, Xinchun; Luo, Jianbin

2012-10-01

A new idea of polishing pad called flexible nanobrush pad (FNP) has been proposed for the low down pressure chemical mechanical planarization (CMP) process of Cu/ultra-low-к materials. The FNP was designed with a surface layer of flexible brush-like nanofibers which can `actively' carry nanoscale abrasives in slurry independent of the down pressure. Better planarization performances including high material removal rate, good planarization, good polishing uniformity, and low defectivity are expected in the CMP process under the low down pressure with such kind of pad. The FNP can be made by template-assisted replication or template-based synthesis methods, which will be driven by the development of the preparation technologies for ordered nanostructure arrays. The present work would potentially provide a new solution for the Cu/ultra-low-к CMP process.

New way of polymer design for organic solar cells using the quinoid structure

NASA Astrophysics Data System (ADS)

Berube, Nicolas; Gaudreau, Josiane; Cote, Michel

2013-03-01

Research in organic photovoltaic applications are receiving a great interest as they offer an environmentally clean and low-cost solution to the world's rising energy needs. Controlling the device's active polymer optical bandgap is an important step that affects its absorption of the solar spectrum, and ultimately, its power conversion efficiency. The use of fused heterocycles that favors the polymer's quinoid structure has been a known method to lower the bandgap, for example, with isothianapthene, but there is a lack of quantifiable data on this effect. Density functional theory (DFT) calculations were done on over 60 polymers with bandgaps between 0.5 eV and 4 eV. They clearly show that low bandgaps are observed in copolymers that carefully stands between their quinoid and aromatic structures. Such balance can be obtained by mixing monomer units with quinoid characteristics with aromatic ones. Time-dependant DFT results also links low bandgaps with lower reorganization energy, which means that polymers with this structural form could possess higher charge mobilities. This link between the geometrical structure and the bandgap is compatible with a vast variety of polymers and is more convincing than the commonly used donor-acceptor method of polymer design.

An adaptive sampling method for variable-fidelity surrogate models using improved hierarchical kriging

NASA Astrophysics Data System (ADS)

Hu, Jiexiang; Zhou, Qi; Jiang, Ping; Shao, Xinyu; Xie, Tingli

2018-01-01

Variable-fidelity (VF) modelling methods have been widely used in complex engineering system design to mitigate the computational burden. Building a VF model generally includes two parts: design of experiments and metamodel construction. In this article, an adaptive sampling method based on improved hierarchical kriging (ASM-IHK) is proposed to refine the improved VF model. First, an improved hierarchical kriging model is developed as the metamodel, in which the low-fidelity model is varied through a polynomial response surface function to capture the characteristics of a high-fidelity model. Secondly, to reduce local approximation errors, an active learning strategy based on a sequential sampling method is introduced to make full use of the already required information on the current sampling points and to guide the sampling process of the high-fidelity model. Finally, two numerical examples and the modelling of the aerodynamic coefficient for an aircraft are provided to demonstrate the approximation capability of the proposed approach, as well as three other metamodelling methods and two sequential sampling methods. The results show that ASM-IHK provides a more accurate metamodel at the same simulation cost, which is very important in metamodel-based engineering design problems.

Occupational Competence Strategies in old age: A mixed method comparison between Hispanic women with different levels of daily participation

PubMed Central

Orellano, Elsa M.; Mountain, Gail; Varas, Nelson; Labault, Nirzka

2014-01-01

In this pilot study we explore the difference in the use of occupational competence strategies for daily participation between highly active and low active Hispanic older women. Twenty-nine women, living alone who were ≥ 70 years participated in this study. We employed a mixed method design through which the principal investigator administered a tool to measure participation restrictions during the quantitative phase and conducted in-depth interviews with a subsample of the quantitative phase. Active women predominantly used transportation resources, emotional social support, and spirituality to support participation in life activities. Less active women used more practical social support, assistive technology, and environmental modifications. Personal facilitators seemed to directly modify these strategies. These results suggest that older women with different activity levels use distinct internal and external resources to maintain or enhance daily participation. Future studies should explore whether these resources remain consistent across gender, living status, and ethnicities. PMID:24669397

Texting to Increase Physical Activity Among Teenagers (TXT Me!): Rationale, Design, and Methods Proposal

PubMed Central

Cantu, Dora; Bhatt, Riddhi; Baranowski, Tom; Rodgers, Wendy; Jago, Russell; Anderson, Barbara; Liu, Yan; Mendoza, Jason A; Tapia, Ramsey; Buday, Richard

2014-01-01

Background Physical activity decreases from childhood through adulthood. Among youth, teenagers (teens) achieve the lowest levels of physical activity, and high school age youth are particularly at risk of inactivity. Effective methods are needed to increase youth physical activity in a way that can be maintained through adulthood. Because teens text a great deal, text messages promoting walking, a low cost physical activity, may be an effective method for promoting sustainable physical activity. Objective The objective of our study was to determine the effect of pedometers, self selected step goals, and texts grounded in the self-determination theory (SDT) on physical activity among the teens. Methods “TXT Me!” was a 12 week intervention that texted 14-17 year olds to increase their daily physical activity by increasing the number of steps they take each day. The intervention was grounded in the SDT. Formative research with the teens helped construct the intervention and develop the texts. A total of 84 texts were developed (12 to set a step goal, and 72 promoting autonomy, competence, and relatedness). The pilot evaluation used a four group, randomized design (n=160). After baseline data collection, the participants were randomized to one of four conditions (no treatment control, pedometer only, pedometer + weekly prompts, pedometer + weekly prompts + SDT grounded texts). Data were collected at baseline and immediately upon completion of the study. The primary outcome was physical activity, measured by 7 days of accelerometry. Basic psychological needs, physical activity motivation, process evaluation, and program satisfaction data were also collected. Results To our knowledge, this is one of the first studies to explore the use of stand alone, SDT grounded texts, supported by pedometers and prompts to set a self selected step goal, as a method for increasing physical activity among teens. Conclusions This pilot study will contribute valuable information regarding whether theoretically grounded text messages show promise as an effective method to increase physical activity among teens. Trial Registration Clinicaltrials.gov NCT01482234; http://clinicaltrials.gov/ct2/show/NCT01482234 (Archived by WebCite at http://www.webcitation.org/6NYvRMOoq). PMID:24622344

Virtual reality 3D headset based on DMD light modulators

NASA Astrophysics Data System (ADS)

Bernacki, Bruce E.; Evans, Allan; Tang, Edward

2014-06-01

We present the design of an immersion-type 3D headset suitable for virtual reality applications based upon digital micromirror devices (DMD). Current methods for presenting information for virtual reality are focused on either polarizationbased modulators such as liquid crystal on silicon (LCoS) devices, or miniature LCD or LED displays often using lenses to place the image at infinity. LCoS modulators are an area of active research and development, and reduce the amount of viewing light by 50% due to the use of polarization. Viewable LCD or LED screens may suffer low resolution, cause eye fatigue, and exhibit a "screen door" or pixelation effect due to the low pixel fill factor. Our approach leverages a mature technology based on silicon micro mirrors delivering 720p resolution displays in a small form-factor with high fill factor. Supporting chip sets allow rapid integration of these devices into wearable displays with high-definition resolution and low power consumption, and many of the design methods developed for DMD projector applications can be adapted to display use. Potential applications include night driving with natural depth perception, piloting of UAVs, fusion of multiple sensors for pilots, training, vision diagnostics and consumer gaming. Our design concept is described in which light from the DMD is imaged to infinity and the user's own eye lens forms a real image on the user's retina resulting in a virtual retinal display.

Cooling Duct Analysis for Transpiration/Film Cooled Liquid Propellant Rocket Engines

NASA Technical Reports Server (NTRS)

Micklow, Gerald J.

1996-01-01

The development of a low cost space transportation system requires that the propulsion system be reusable, have long life, with good performance and use low cost propellants. Improved performance can be achieved by operating the engine at higher pressure and temperature levels than previous designs. Increasing the chamber pressure and temperature, however, will increase wall heating rates. This necessitates the need for active cooling methods such as film cooling or transpiration cooling. But active cooling can reduce the net thrust of the engine and add considerably to the design complexity. Recently, a metal drawing process has been patented where it is possible to fabricate plates with very small holes with high uniformity with a closely specified porosity. Such a metal plate could be used for an inexpensive transpiration/film cooled liner to meet the demands of advanced reusable rocket engines, if coolant mass flow rates could be controlled to satisfy wall cooling requirements and performance. The present study investigates the possibility of controlling the coolant mass flow rate through the porous material by simple non-active fluid dynamic means. The coolant will be supplied to the porous material by series of constant geometry slots machined on the exterior of the engine.

Active control of an innovative seat suspension system with acceleration measurement based friction estimation

NASA Astrophysics Data System (ADS)

Ning, Donghong; Sun, Shuaishuai; Li, Hongyi; Du, Haiping; Li, Weihua

2016-12-01

In this paper, an innovative active seat suspension system for vehicles is presented. This seat suspension prototype is built with two low cost actuators each of which has one rotary motor and one gear reducer. A H∞ controller with friction compensation is designed for the seat suspension control system where the friction is estimated and compensated based on the measurement of seat acceleration. This principal aim of this research was to control the low frequency vibration transferred or amplified by the vehicle (chassis) suspension, and to maintain the passivity of the seat suspension at high frequency (isolation vibration) while taking into consideration the trade-off between the active seat suspension cost and its high frequency performance. Sinusoidal excitations of 1-4.5 Hz were applied to test the active seat suspension both when controlled and when uncontrolled and this is compared with a well-tuned passive heavy duty vehicle seat suspension. The results indicate the effectiveness of the proposed control algorithm within the tested frequencies. Further tests were conducted using the excitations generated from a quarter-car model under bump and random road profiles. The bump road tests indicate the controlled active seat suspension has good transient response performance. The Power Spectral Density (PSD) method and ISO 2631-1 standards were applied to analyse the seat suspension's acceleration under random road conditions. Although some low magnitude and high frequency noise will inevitably be introduced by the active system, the weighted-frequency Root Mean Square (RMS) acceleration shows that this may not have a large effect on ride comfort. In fact, the ride comfort is improved from being an 'a little uncomfortable' to a 'not uncomfortable' level when compared with the well-tuned passive seat suspension. This low cost active seat suspension design and the proposed controller with the easily measured feedback signals are very practical for real applications.

Methods for the evaluation of hospital cooperation activities (Systematic review protocol).

PubMed

Rotter, Thomas; Popa, Daniela; Riley, Beatrice; Ellermann, Tim; Ryll, Ulrike; Burazeri, Genc; Daemen, Piet; Peeters, Guy; Brand, Helmut

2012-02-10

Hospital partnerships, mergers and cooperatives are arrangements frequently seen as a means of improving health service delivery. Many of the assumptions used in planning hospital cooperatives are not stated clearly and are often based on limited or poor scientific evidence. This is a protocol for a systematic review, following the Cochrane EPOC methodology. The review aims to document, catalogue and synthesize the existing literature on the reported methods for the evaluation of hospital cooperation activities as well as methods of hospital cooperation. We will search the Database of Abstracts of Reviews of Effectiveness, the Effective Practice and Organisation of Care Register, the Cochrane Central Register of Controlled Trials and bibliographic databases including PubMed (via NLM), Web of Science, NHS EED, Business Source Premier (via EBSCO) and Global Health for publications that report on methods for evaluating hospital cooperatives, strategic partnerships, mergers, alliances, networks and related activities and methods used for such partnerships. The method proposed by the Cochrane EPOC group regarding randomized study designs, controlled clinical trials, controlled before and after studies, and interrupted time series will be followed. In addition, we will also include cohort, case-control studies, and relevant non-comparative publications such as case reports. We will categorize and analyze the review findings according to the study design employed, the study quality (low versus high quality studies) and the method reported in the primary studies. We will present the results of studies in tabular form. Overall, the systematic review aims to identify, assess and synthesize the evidence to underpin hospital cooperation activities as defined in this protocol. As a result, the review will provide an evidence base for partnerships, alliances or other fields of cooperation in a hospital setting. PROSPERO registration number: CRD42011001579.

Satellite-borne active phased array techniques for mobile communications

NASA Astrophysics Data System (ADS)

Sheehan, P. G.; Forrest, J. R.

1986-07-01

This paper investigates the design of active phased arrays for communications satellites. In particular, consideration is given to the problems occurring when active arrays are required to produce multiple beams. There is a real need to keep the complexity of the array electronics to a minimum, but this conflicts with the desire to obtain the greatest possible freedom of control of the radiation pattern produced. The paper demonstrates a method of coping with the problem. Low-gain elements are used to provide design freedom and they are grouped into subarrays to limit the complexity of the rest of the system. With appropriate configurations of subarrays, greatly improved radiation pattern characteristics can be obtained and frequency reuse between multiple beams becomes feasible. A demonstration model of 108 microstrip patches grouped into 32 subarrays, operating at 12 GHz, has been constructed and verifies that the technique is effective.

Climate Informed Low Flow Frequency Analysis Using Nonstationary Modeling

NASA Astrophysics Data System (ADS)

Liu, D.; Guo, S.; Lian, Y.

2014-12-01

Stationarity is often assumed for frequency analysis of low flows in water resources management and planning. However, many studies have shown that flow characteristics, particularly the frequency spectrum of extreme hydrologic events,were modified by climate change and human activities and the conventional frequency analysis without considering the non-stationary characteristics may lead to costly design. The analysis presented in this paper was based on the more than 100 years of daily flow data from the Yichang gaging station 44 kilometers downstream of the Three Gorges Dam. The Mann-Kendall trend test under the scaling hypothesis showed that the annual low flows had significant monotonic trend, whereas an abrupt change point was identified in 1936 by the Pettitt test. The climate informed low flow frequency analysis and the divided and combined method are employed to account for the impacts from related climate variables and the nonstationarities in annual low flows. Without prior knowledge of the probability density function for the gaging station, six distribution functions including the Generalized Extreme Values (GEV), Pearson Type III, Gumbel, Gamma, Lognormal, and Weibull distributions have been tested to find the best fit, in which the local likelihood method is used to estimate the parameters. Analyses show that GEV had the best fit for the observed low flows. This study has also shown that the climate informed low flow frequency analysis is able to exploit the link between climate indices and low flows, which would account for the dynamic feature for reservoir management and provide more accurate and reliable designs for infrastructure and water supply.

Active controls: A look at analytical methods and associated tools

NASA Technical Reports Server (NTRS)

Newsom, J. R.; Adams, W. M., Jr.; Mukhopadhyay, V.; Tiffany, S. H.; Abel, I.

1984-01-01

A review of analytical methods and associated tools for active controls analysis and design problems is presented. Approaches employed to develop mathematical models suitable for control system analysis and/or design are discussed. Significant efforts have been expended to develop tools to generate the models from the standpoint of control system designers' needs and develop the tools necessary to analyze and design active control systems. Representative examples of these tools are discussed. Examples where results from the methods and tools have been compared with experimental data are also presented. Finally, a perspective on future trends in analysis and design methods is presented.

Physical activity and cardiovascular risk factors among rural and urban groups and rural-to-urban migrants in Peru: a cross-sectional study

PubMed Central

Creber, Ruth M. Masterson; Smeeth, Liam; Gilman, Robert H.; Miranda, J. Jaime

2010-01-01

Objectives To compare physical activity and sedentary behavior patterns of rural-to-urban migrants in Peru versus lifetime rural and urban residents and to determine any associations between low physical activity and four cardiovascular risk factors: obesity (body mass index ≥ 30 kg/m2), systolic and diastolic blood pressure, hypertension, and metabolic syndrome. Methods The PERU MIGRANT (PEru’s Rural to Urban MIGRANTs) cross-sectional study was designed to measure physical activity among rural, urban, and rural-to-urban migrants with the International Physical Activity Questionnaire (IPAQ). Results The World Health Organization (WHO) age-standardized prevalence of low physical activity was 2.2% in lifetime rural residents, 32.2% in rural-to-urban migrants, and 39.2% in lifetime urban residents. The adjusted odds ratios for low physical activity were 21.43 and 32.98 for migrant and urban groups respectively compared to the rural group. The adjusted odds ratio for being obese was 1.94 for those with low physical activity. There was no evidence of an association between low physical activity and blood pressure levels, hypertension, or metabolic syndrome. Conclusions People living in a rural area had much higher levels of physical activity and lower risk of being overweight and obese compared to those living in an urban area of Lima. Study participants from the same rural area who had migrated to Lima had levels of physical inactivity and obesity similar to those who had always lived in Lima. Interventions aimed at maintaining higher levels of physical activity among rural-to-urban migrants may help reduce the epidemic of obesity in urban areas. PMID:20857014

Active Radiation Detectors for Use in Space Beyond Low Earth Orbit: Spatial and Energy Resolution Requirements and Methods for Heavy Ion Charge Classification

NASA Astrophysics Data System (ADS)

McBeth, Rafe A.

Space radiation exposure to astronauts will need to be carefully monitored on future missions beyond low earth orbit. NASA has proposed an updated radiation risk framework that takes into account a significant amount of radiobiological and heavy ion track structure information. These models require active radiation detection systems to measure the energy and ion charge Z. However, current radiation detection systems cannot meet these demands. The aim of this study was to investigate several topics that will help next generation detection systems meet the NASA objectives. Specifically, this work investigates the required spatial resolution to avoid coincident events in a detector, the effects of energy straggling and conversion of dose from silicon to water, and methods for ion identification (Z) using machine learning. The main results of this dissertation are as follows: 1. Spatial resolution on the order of 0.1 cm is required for active space radiation detectors to have high confidence in identifying individual particles, i.e., to eliminate coincident events. 2. Energy resolution of a detector system will be limited by energy straggling effects and the conversion of dose in silicon to dose in biological tissue (water). 3. Machine learning methods show strong promise for identification of ion charge (Z) with simple detector designs.

Improving the work position of worker based on manual material handling in rice mill industry

NASA Astrophysics Data System (ADS)

Astuti, Rahmaniyah Dwi; Susmartini, Susy; Kinanthi, Ade Putri

2017-11-01

In traditional industries still using manual material handling to weight lifting. Worker at the rice mill, especially in rice filtering activity has wrong ergonomic posture to enforce the body bends and carried loads too heavy cause of injury for lower back and waist. The work attitude is unnatural posture. This study aimed to determine the severity of the workload, the level of risk posed to the rice taking activities and suggested as an improvement to it. Identify the operator complaints used Nordic Body Map method. Rapid Entire Body Assessment (REBA) method is used to provide an assessment of the working posture of the operator. Assessment of the working posture on rice filtering process shows that REBA score is 12 with an explanation very high level of risk and action level is 4 which means the action needs to be repaired immediately. Biomechanics calculation shows result 6713.21 N, the result of the calculation of the biomechanics of worker in the rice filtering activities indicates that the activities would pose a risk or injury. Therefore, improvement in rice filtering activity by designing a tool for lowering the risk level worker. The design tools are illustrated with 2D modeling resulted in the level of risk that is working REBA score became 3 which shows a low risk level. Biomechanics calculation after designed of tools show the result is 6282.86 N. The results means the activities carried out are still in safe condition and does not pose a risk or injury.

Inward-Turning Streamline-Traced Inlet Design Method for Low-Boom, Low-Drag Applications

NASA Technical Reports Server (NTRS)

Otto, Samuel; Trefny, Charles J.; Slater, John W.

2015-01-01

A new design method for inward-turning, streamline-traced inlets is presented. Resulting designs are intended for moderate supersonic, low-drag, low-boom applications such as that required for NASA's proposed low-boom flight demonstration aircraft. A critical feature of these designs is the internal cowl lip angle that allows for little or no flow turning on the outer nacelle. Present methods using conical-flow Busemann parent flowfields have simply truncated, or otherwise modified the stream-traced contours to include this internal cowl angle. Such modifications disrupt the parent flowfield, reducing inlet performance and flow uniformity. The method presented herein merges a conical flowfield that includes a leading shock with a truncated Busemann flowfield in a manner that minimizes unwanted interactions. A leading internal cowl angle is now inherent in the parent flowfield, and inlet contours traced from this flowfield retain its high performance and good flow uniformity. CFD analysis of a candidate inlet design is presented that verifies the design technique, and reveals a starting issue with the basic geometry. A minor modification to the cowl lip region is shown to eliminate this phenomenon, thereby allowing starting and smooth transition to sub-critical operation as back-pressure is increased. An inlet critical-point total pressure recovery of 96 is achieved based on CFD results for a Mach 1.7 freestream design. Correction for boundary-layer displacement thickness, and sizing for a given engine airflow requirement are also discussed.

Detecting Low Incidents Effects: The Value of Mixed Methods Research Designs in Low-N Studies

ERIC Educational Resources Information Center

Newman, Isadore; Ridenour, Carolyn S.; Newman, Carole; Smith, Shannon; Brown, Russell C.

2013-01-01

Many important educational situations such as traumatic brain injury among preschoolers, school gun violence, preadolescent eating disorders, and adolescent suicide happen relatively infrequently. In this article, the authors explain why mixed methods research designs offer more meaningful empirical results than do qualitative or quantitative…

Predictive Array Design. A method for sampling combinatorial chemistry library space.

PubMed

Lipkin, M J; Rose, V S; Wood, J

2002-01-01

A method, Predictive Array Design, is presented for sampling combinatorial chemistry space and selecting a subarray for synthesis based on the experimental design method of Latin Squares. The method is appropriate for libraries with three sites of variation. Libraries with four sites of variation can be designed using the Graeco-Latin Square. Simulated annealing is used to optimise the physicochemical property profile of the sub-array. The sub-array can be used to make predictions of the activity of compounds in the all combinations array if we assume each monomer has a relatively constant contribution to activity and that the activity of a compound is composed of the sum of the activities of its constitutive monomers.

PLAYgrounds: Effect of a PE playground program in primary schools on PA levels during recess in 6 to 12 year old children. Design of a prospective controlled trial

PubMed Central

2011-01-01

Background The relative number of children meeting the minimal required dose of daily physical activity remains execrably low. It has been estimated that in 2015 one out of five children will be overweight. Therefore, low levels of physical activity during early childhood may compromise the current and future health and well-being of the population, and promoting physical activity in younger children is a major public health priority. This study is to gain insight into effects of a Physical Education based playground program on the PA levels during recess in primary school children aged 6-12. Methods/design The effectiveness of the intervention program will be evaluated using a prospective controlled trial design in which schools will be matched, with a follow-up of one school year. The research population will consist of 6-12 year old primary school children. The intervention program will be aimed at improving physical activity levels and will consist of a multi-component alteration of the schools' playground. In addition, playground usage will be increased through altered time management of recess times, as well as a modification of the Physical Education content. Discussion The effects of the intervention on physical activity levels during recess (primary outcome measure), overall daily physical activity and changes in physical fitness (secondary outcome measures) will be assessed. Results of this study could possibly lead to changes in the current playground system of primary schools and provide structured health promotion for future public health. Trial registration Netherlands Trial Register (NTR): NTR2386 PMID:21548998

Development of termination and utilization concepts for flat conductor cables. Volume 1: Development of low profile flat conductor cable connecting device and permanent splice

NASA Technical Reports Server (NTRS)

1972-01-01

The development of low-profile flat conductor cable (FCC) connecting device and FCC permanent splice methods are discussed. The design goal for the low-profile connecting device was to mate and unmate FCC harness to a typical spacecraft component with a maximum height of 3/8 in. The results indicate that the design, fabrication, and processing of the low-profile connecting device are feasible and practical. Some redesign will be required to achieve the goal of 3/8 in. Also, failures were experienced subsequent to salt spray and humidity exposure. Five different FCC permanent splice methods were considered. Subsequent to evaluation of these five methods, two design concepts were chosen for development tests.

Student Peer Review as a Tool for Efficiently Achieving Subject-Specific and Generic Learning Outcomes: Examples in Botany at the Faculty of Agriculture, University of Belgrade

ERIC Educational Resources Information Center

Quarrie, Sofija Pekic

2007-01-01

Several teachers at the Faculty of Agriculture at the University of Belgrade recognised the need to improve teaching methods in order to actively involve students in the teaching process, help them learn more effectively, and reduce the low exam pass rate. This led to a purpose-designed course on improving academic skills, after which the author…

Fast optimization method of designing a wideband metasurface without using the Pancharatnam-Berry phase.

PubMed

Sui, Sai; Ma, Hua; Lv, Yueguang; Wang, Jiafu; Li, Zhiqiang; Zhang, Jieqiu; Xu, Zhuo; Qu, Shaobo

2018-01-22

Arbitrary control of electromagnetic waves remains a significant challenge although it promises many important applications. Here, we proposed a fast optimization method of designing a wideband metasurface without using the Pancharatnam-Berry (PB) phase, of which the elements are non-absorptive and capable of predicting the wideband and smooth phase-shift. In our design method, the metasurface is composed of low-Q-factor resonant elements without using the PB phase, and is optimized by the genetic algorithm and nonlinear fitting method, having the advantages that the far field scattering patterns can be quickly synthesized by the hybrid array patterns. To validate the design method, a wideband low radar cross section metasurface is demonstrated, showing good feasibility and performance of wideband RCS reduction. This work reveals an opportunity arising from a metasurface in effective manipulation of microwave and flexible fast optimal design method.

Optimal design of a bank of spatio-temporal filters for EEG signal classification.

PubMed

Higashi, Hiroshi; Tanaka, Toshihisa

2011-01-01

The spatial weights for electrodes called common spatial pattern (CSP) are known to be effective in EEG signal classification for motor imagery based brain computer interfaces (MI-BCI). To achieve accurate classification in CSP, the frequency filter should be properly designed. To this end, several methods for designing the filter have been proposed. However, the existing methods cannot consider plural brain activities described with different frequency bands and different spatial patterns such as activities of mu and beta rhythms. In order to efficiently extract these brain activities, we propose a method to design plural filters and spatial weights which extract desired brain activity. The proposed method designs finite impulse response (FIR) filters and the associated spatial weights by optimization of an objective function which is a natural extension of CSP. Moreover, we show by a classification experiment that the bank of FIR filters which are designed by introducing an orthogonality into the objective function can extract good discriminative features. Moreover, the experiment result suggests that the proposed method can automatically detect and extract brain activities related to motor imagery.

High-Speed Research: Sonic Boom, volume 2

NASA Technical Reports Server (NTRS)

Darden, Christine M. (Compiler)

1992-01-01

A High-Speed Sonic Boom Workshop was held at NASA Langley Research Center on February 25-27, 1992. The purpose of the workshop was to make presentations on current research activities and accomplishments and to assess progress in the area of sonic boom since the program was initiated in FY-90. Twenty-nine papers were presented during the 2-1/2 day workshop. Attendees included representatives from academia, industry, and government who are actively involved in sonic-boom research. Volume 2 contains papers related to low sonic-boom design and analysis using both linear theory and higher order computational fluid dynamics (CFD) methods.

Design and Manufacturing of Desalination System Powered by Solar Energy Using CDI Technique

NASA Astrophysics Data System (ADS)

Rostami, Mohammad Sajjad; Khashehchi, Morteza; Pipelzadeh, Ehsan

2017-11-01

Capacitive deionization (CDI) is an emerging energy efficient, low pressure and low capital intensive desalination process where ions are separated by a pure electrostatic force imposed by a small bias potential as low as 1 V That funded by an external Renewable (Solar) power supply to materials with high specific surface area. The main objective of this configuration is to separate the cation and anions on oppositely charged electrodes. One of the key parameters for commercial realization of CDI is the salt adsorption capacity of the electrodes. State-of-the-art electrode materials are based on porous activated carbon particles or carbon aerogels. Various electrode materials have been developed in the past, which have suffered from instability and lack of performance. Preliminary experimental results using carbon black, graphite powder, graphene ∖ graphite ∖ PTFE (Active ∖ Conductive ∖ binder) show that the graphene reduced via urea method is a suitable method to develop CDI electrode materials. Although some progress has been made, production of efficient and stable carbon based electrode materials for large scale desalination has not been fully realized. A new desalination technique using capacitive deionization.

Compact, Low-Force, Low-Noise Linear Actuator

NASA Technical Reports Server (NTRS)

Badescu, Mircea; Sherrit, Stewart; Bar-Cohen, Yoseph

2012-01-01

Actuators are critical to all the robotic and manipulation mechanisms that are used in current and future NASA missions, and are also needed for many other industrial, aeronautical, and space activities. There are many types of actuators that were designed to operate as linear or rotary motors, but there is still a need for low-force, low-noise linear actuators for specialized applications, and the disclosed mechanism addresses this need. A simpler implementation of a rotary actuator was developed where the end effector controls the motion of a brush for cleaning a thermal sensor. The mechanism uses a SMA (shape-memory alloy) wire for low force, and low noise. The linear implementation of the actuator incorporates a set of springs and mechanical hard-stops for resetting and fault tolerance to mechanical resistance. The actuator can be designed to work in a pull or push mode, or both. Depending on the volume envelope criteria, the actuator can be configured for scaling its volume down to 4 2 1 cm3. The actuator design has an inherent fault tolerance to mechanical resistance. The actuator has the flexibility of being designed for both linear and rotary motion. A specific configuration was designed and analyzed where fault-tolerant features have been implemented. In this configuration, an externally applied force larger than the design force does not damage the active components of the actuator. The actuator housing can be configured and produced using cost-effective methods such as injection molding, or alternatively, its components can be mounted directly on a small circuit board. The actuator is driven by a SMA -NiTi as a primary active element, and it requires energy on the order of 20 Ws(J) per cycle. Electrical connections to points A and B are used to apply electrical power in the resistive NiTi wire, causing a phase change that contracts the wire on the order of 5%. The actuation period is of the order of a second for generating the stroke, and 4 to 10 seconds for resetting. Thus, this design allows the actuator to work at a frequency of up to 0.1 Hz. The actuator does not make use of the whole range of motion of the SMA material, allowing for large margins on the mechanical parameters of the design. The efficiency of the actuator is of the order of 10%, including the margins. The average dissipated power while driving at full speed is of the order of 1 W, and can be scaled down linearly if the rate of cycling is reduced. This design produces an extremely quiet actuator; it can generate a force greater than 2 N and a stroke greater than 1 cm. The operational duration of SMA materials is of the order of millions of cycles with some reduced stroke over a wide temperature range up to 150 C.

Compact, Low-Force, Low-Noise Linear Actuator

NASA Technical Reports Server (NTRS)

Badescu, Mircea; Sherrit, Stewart; Bar-Cohen, Yoseph

2012-01-01

Actuators are critical to all the robotic and manipulation mechanisms that are used in current and future NASA missions, and are also needed for many other industrial, aeronautical, and space activities. There are many types of actuators that were designed to operate as linear or rotary motors, but there is still a need for low-force, low-noise linear actuators for specialized applications, and the disclosed mechanism addresses this need. A simpler implementation of a rotary actuator was developed where the end effector controls the motion of a brush for cleaning a thermal sensor. The mechanism uses a SMA (shape-memory alloy) wire for low force, and low noise. The linear implementation of the actuator incorporates a set of springs and mechanical hard-stops for resetting and fault tolerance to mechanical resistance. The actuator can be designed to work in a pull or push mode, or both. Depending on the volume envelope criteria, the actuator can be configured for scaling its volume down to 4x2x1 cu cm. The actuator design has an inherent fault tolerance to mechanical resistance. The actuator has the flexibility of being designed for both linear and rotary motion. A specific configuration was designed and analyzed where fault-tolerant features have been implemented. In this configuration, an externally applied force larger than the design force does not damage the active components of the actuator. The actuator housing can be configured and produced using cost-effective methods such as injection molding, or alternatively, its components can be mounted directly on a small circuit board. The actuator is driven by a SMA -NiTi as a primary active element, and it requires energy on the order of 20 Ws(J) per cycle. Electrical connections to points A and B are used to apply electrical power in the resistive NiTi wire, causing a phase change that contracts the wire on the order of 5%. The actuation period is of the order of a second for generating the stroke, and 4 to 10 seconds for resetting. Thus, this design allows the actuator to work at a frequency of up to 0.1 Hz. The actuator does not make use of the whole range of motion of the SMA material, allowing for large margins on the mechanical parameters of the design. The efficiency of the actuator is of the order of 10%, including the margins. The average dissipated power while driving at full speed is of the order of 1 W, and can be scaled down linearly if the rate of cycling is reduced. This design produces an extremely quiet actuator; it can generate a force greater than 2 N and a stroke greater than 1 cm. The operational duration of SMA materials is of the order of millions of cycles with some reduced stroke over a wide temperature range up to 150 C.

Design of an integrated thermoelectric generator power converter for ultra-low power and low voltage body energy harvesters aimed at ExG active electrodes

NASA Astrophysics Data System (ADS)

Ataei, Milad; Robert, Christian; Boegli, Alexis; Farine, Pierre-André

2015-10-01

This paper describes a detailed design procedure for an efficient thermal body energy harvesting integrated power converter. The procedure is based on the examination of power loss and power transfer in a converter for a self-powered medical device. The efficiency limit for the system is derived and the converter is optimized for the worst case scenario. All optimum system parameters are calculated respecting the transducer constraints and the application form factor. Circuit blocks including pulse generators are implemented based on the system specifications and optimized converter working frequency. At this working condition, it has been demonstrated that the wide area capacitor of the voltage doubler, which provides high voltage switch gating, can be eliminated at the expense of wider switches. With this method, measurements show that 54% efficiency is achieved for just a 20 mV transducer output voltage and 30% of the chip area is saved. The entire electronic board can fit in one EEG or ECG electrode, and the electronic system can convert the electrode to an active electrode.

A new irradiation method with a neutron filter for silicon neutron transmutation doping at the Japan research reactor no. 3 (JRR-3).

PubMed

Komeda, Masao; Kawasaki, Kozo; Obara, Toru

2013-04-01

We studied a new silicon irradiation holder with a neutron filter designed to make the vertical neutron flux profile uniform. Since an irradiation holder has to be made of a low activation material, we applied aluminum blended with B4C as the holder material. Irradiation methods to achieve uniform flux with a filter are discussed using Monte-Carlo calculation code MVP. Validation of the use of the MVP code for the holder's analyses is also discussed via characteristic experiments. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of active-layer composition and structure on device performance of coplanar top-gate amorphous oxide thin-film transistors

NASA Astrophysics Data System (ADS)

Yue, Lan; Meng, Fanxin; Chen, Jiarong

2018-01-01

The thin-film transistors (TFTs) with amorphous aluminum-indium-zinc-oxide (a-AIZO) active layer were prepared by dip coating method. The dependence of properties of TFTs on the active-layer composition and structure was investigated. The results indicate that Al atoms acted as a carrier suppressor in IZO films. Meanwhile, it was found that the on/off current ratio (I on/off) of TFT was improved by embedding a high-resistivity AIZO layer between the low-resistivity AIZO layer and gate insulator. The improvement in I on/off was attributed to the decrease in off-state current of double-active-layer TFT due to an increase in the active-layer resistance and the contact resistance between active layer and source/drain electrode. Moreover, on-state current and threshold voltage (V th) can be mainly controlled through thickness and Al content of the low-resistivity AIZO layer. In addition, the saturation mobility (μ sat) of TFTs was improved with reducing the size of channel width or/and length, which was attributed to the decrease in trap states in the semiconductor and at the semiconductor/gate-insulator interface with the smaller channel width or/and shorter channel length. Thus, we can demonstrate excellent TFTs via the design of active-layer composition and structure by utilizing a low cost solution-processed method. The resulting TFT, operating in enhancement mode, has a high μ sat of 14.16 cm2 V-1 s-1, a small SS of 0.40 V/decade, a close-to-zero V th of 0.50 V, and I on/off of more than 105.

Design and control of the precise tracking bed based on complex electromechanical design theory

NASA Astrophysics Data System (ADS)

Ren, Changzhi; Liu, Zhao; Wu, Liao; Chen, Ken

2010-05-01

The precise tracking technology is wide used in astronomical instruments, satellite tracking and aeronautic test bed. However, the precise ultra low speed tracking drive system is one high integrated electromechanical system, which one complexly electromechanical design method is adopted to improve the efficiency, reliability and quality of the system during the design and manufacture circle. The precise Tracking Bed is one ultra-exact, ultra-low speed, high precision and huge inertial instrument, which some kind of mechanism and environment of the ultra low speed is different from general technology. This paper explores the design process based on complex electromechanical optimizing design theory, one non-PID with a CMAC forward feedback control method is used in the servo system of the precise tracking bed and some simulation results are discussed.

A Low Power, Parallel Wearable Multi-Sensor System for Human Activity Evaluation.

PubMed

Li, Yuecheng; Jia, Wenyan; Yu, Tianjian; Luan, Bo; Mao, Zhi-Hong; Zhang, Hong; Sun, Mingui

2015-04-01

In this paper, the design of a low power heterogeneous wearable multi-sensor system, built with Zynq System-on-Chip (SoC), for human activity evaluation is presented. The powerful data processing capability and flexibility of this SoC represent significant improvements over our previous ARM based system designs. The new system captures and compresses multiple color images and sensor data simultaneously. Several strategies are adopted to minimize power consumption. Our wearable system provides a new tool for the evaluation of human activity, including diet, physical activity and lifestyle.

The neutronic basis for elemental substitution in martensitic steels

NASA Astrophysics Data System (ADS)

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

1994-09-01

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

Single-handed helical carbonaceous nanotubes prepared using a pair of cationic low molecular weight gelators

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

Sun, Huayan; Wang, Qing; Guo, Yongmin

Highlights: • 3-aminophenol-formaldeyde resins were prepared through a templating method. • A pair of cationic gelators have been used as the templates. • Single-handed helical carbonaceous nanotubes were obtained after carbonization. • The carbonaceous nanotubes showed optical activity. - Abstract: We design a facile route to obtain enantiopure carbonaceous nanostructures, which have potential application as chiral sensors, electromagnetic wave absorbers, and asymmetric catalysts. A pair of cationic low molecular weight gelators was synthesized, which were able to self-assemble into twisted nanoribbons in ethanol at a concentration of 20 g L{sup −1} at 25 °C. Single-handed helical 3-aminophenol-formaldehyde resin nanotubes withmore » optical activity were prepared using the self-assembly of the low molecular weight gelators as templates. After carbonization, single-handed helical carbonaceous nanotubes were obtained and characterized using circular dichroism, wide-angle X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. The results indicate that the walls of the nanotubes are amorphous carbon. Moreover, the left- and right-handed helical nanotubes exhibit opposite optical activity.« less

Periodic equivalence ratio modulation method and apparatus for controlling combustion instability

DOEpatents

Richards, George A.; Janus, Michael C.; Griffith, Richard A.

2000-01-01

The periodic equivalence ratio modulation (PERM) method and apparatus significantly reduces and/or eliminates unstable conditions within a combustion chamber. The method involves modulating the equivalence ratio for the combustion device, such that the combustion device periodically operates outside of an identified unstable oscillation region. The equivalence ratio is modulated between preselected reference points, according to the shape of the oscillation region and operating parameters of the system. Preferably, the equivalence ratio is modulated from a first stable condition to a second stable condition, and, alternatively, the equivalence ratio is modulated from a stable condition to an unstable condition. The method is further applicable to multi-nozzle combustor designs, whereby individual nozzles are alternately modulated from stable to unstable conditions. Periodic equivalence ratio modulation (PERM) is accomplished by active control involving periodic, low frequency fuel modulation, whereby low frequency fuel pulses are injected into the main fuel delivery. Importantly, the fuel pulses are injected at a rate so as not to affect the desired time-average equivalence ratio for the combustion device.

Design and test of a hybrid foot force sensing and GPS system for richer user mobility activity recognition.

PubMed

Zhang, Zelun; Poslad, Stefan

2013-11-01

Wearable and accompanied sensors and devices are increasingly being used for user activity recognition. However, typical GPS-based and accelerometer-based (ACC) methods face three main challenges: a low recognition accuracy; a coarse recognition capability, i.e., they cannot recognise both human posture (during travelling) and transportation mode simultaneously, and a relatively high computational complexity. Here, a new GPS and Foot-Force (GPS + FF) sensor method is proposed to overcome these challenges that leverages a set of wearable FF sensors in combination with GPS, e.g., in a mobile phone. User mobility activities that can be recognised include both daily user postures and common transportation modes: sitting, standing, walking, cycling, bus passenger, car passenger (including private cars and taxis) and car driver. The novelty of this work is that our approach provides a more comprehensive recognition capability in terms of reliably recognising both human posture and transportation mode simultaneously during travel. In addition, by comparing the new GPS + FF method with both an ACC method (62% accuracy) and a GPS + ACC based method (70% accuracy) as baseline methods, it obtains a higher accuracy (95%) with less computational complexity, when tested on a dataset obtained from ten individuals.

Population-Level Exposure to Particulate Air Pollution during Active Travel: Planning for Low-Exposure, Health-Promoting Cities

PubMed Central

Hankey, Steve; Lindsey, Greg; Marshall, Julian D.

2016-01-01

Background: Providing infrastructure and land uses to encourage active travel (i.e., bicycling and walking) are promising strategies for designing health-promoting cities. Population-level exposure to air pollution during active travel is understudied. Objectives: Our goals were a) to investigate population-level patterns in exposure during active travel, based on spatial estimates of bicycle traffic, pedestrian traffic, and particulate concentrations; and b) to assess how those exposure patterns are associated with the built environment. Methods: We employed facility–demand models (active travel) and land use regression models (particulate concentrations) to estimate block-level (n = 13,604) exposure during rush-hour (1600–1800 hours) in Minneapolis, Minnesota. We used the model-derived estimates to identify land use patterns and characteristics of the street network that are health promoting. We also assessed how exposure is correlated with indicators of health disparities (e.g., household income, proportion of nonwhite residents). Our work uses population-level rates of active travel (i.e., traffic flows) rather than the probability of walking or biking (i.e., “walkability” or “bikeability”) to assess exposure. Results: Active travel often occurs on high-traffic streets or near activity centers where particulate concentrations are highest (i.e., 20–42% of active travel occurs on blocks with high population-level exposure). Only 2–3% of blocks (3–8% of total active travel) are “sweet spots” (i.e., high active travel, low particulate concentrations); sweet spots are located a) near but slightly removed from the city-center or b) on off-street trails. We identified 1,721 blocks (~ 20% of local roads) where shifting active travel from high-traffic roads to adjacent low-traffic roads would reduce exposure by ~ 15%. Active travel is correlated with population density, land use mix, open space, and retail area; particulate concentrations were mostly unchanged with land use. Conclusions: Public health officials and urban planners may use our findings to promote healthy transportation choices. When designing health-promoting cities, benefits (physical activity) as well as hazards (air pollution) should be evaluated. Citation: Hankey S, Lindsey G, Marshall JD. 2017. Population-level exposure to particulate air pollution during active travel: planning for low-exposure, health-promoting cities. Environ Health Perspect 125:–534; http://dx.doi.org/10.1289/EHP442 PMID:27713109

Performance evaluation of the active-flow personal DataRAM PM 2.5 mass monitor (Thermo Anderson pDR-1200) designed for continuous personal exposure measurements

NASA Astrophysics Data System (ADS)

Chakrabarti, Bhabesh; Fine, Philip M.; Delfino, Ralph; Sioutas, Constantinos

The need for continuous personal monitoring for exposure to particulate matter has been demonstrated by recent health studies showing effects of PM exposure on time scales of less than a few hours. Filter-based methods cannot measure this short-term variation of PM levels, which can be quite significant considering human activity patterns. The goal of this study was to evaluate the active-flow personal DataRAM for PM 2.5 (MIE pDR-1200; Thermo Electron Corp., Franklin, MA) designed as a wearable monitor to continuously measure particle exposure. The instrument precision was found to be good (2.1%) and significantly higher than the passive pDR configuration tested previously. A comparison to other proven continuous monitors resulted in good agreement at low relative humidities. Results at higher humidity followed predictable trends and provided a correction scheme that improved the accuracy of pDR readings. The pDR response to particle size also corresponded to previously observed and theoretical errors. The active flow feature of the pDR allows collection of the sampled particles on a back-up filter. The 24-h mass measured on this filter was found to compare very well with a Federal Reference Method for PM 2.5 mass.

Network Interventions on Physical Activity in an Afterschool Program: An Agent-Based Social Network Study

PubMed Central

Zhang, Jun; Shoham, David A.; Tesdahl, Eric

2015-01-01

Objectives. We studied simulated interventions that leveraged social networks to increase physical activity in children. Methods. We studied a real-world social network of 81 children (average age = 7.96 years) who lived in low socioeconomic status neighborhoods, and attended public schools and 1 of 2 structured afterschool programs. The sample was ethnically diverse, and 44% were overweight or obese. We used social network analysis and agent-based modeling simulations to test whether implementing a network intervention would increase children’s physical activity. We tested 3 intervention strategies. Results. The intervention that targeted opinion leaders was effective in increasing the average level of physical activity across the entire network. However, the intervention that targeted the most sedentary children was the best at increasing their physical activity levels. Conclusions. Which network intervention to implement depends on whether the goal is to shift the entire distribution of physical activity or to influence those most adversely affected by low physical activity. Agent-based modeling could be an important complement to traditional project planning tools, analogous to sample size and power analyses, to help researchers design more effective interventions for increasing children’s physical activity. PMID:25689202

"Get off the sofa and go and play": Family and socioeconomic influences on the physical activity of 10–11 year old children

PubMed Central

Brockman, Rowan; Jago, Russell; Fox, Kenneth R; Thompson, Janice L; Cartwright, Kim; Page, Angie S

2009-01-01

Background Physical activity declines as children approach puberty. Research has focussed on psychosocial, environmental, and demographic determinants. This paper explores how family and socioeconomic factors are related to children's physical activity. Methods Seventeen focus groups were conducted with 113, 10–11 year old children from 11 primary schools in Bristol, UK. Focus groups examined: 1) the way parents encourage their children to be physically active; 2) the extent to which physical activity is engaged in as a family; and 3) the types of non-family based physical activities Year 6 children commonly participate in. Results Participants from all socioeconomic (SES) groups reported that parents encouraged them to be physically active. However approaches differed. Children from middle/high SES schools were assisted through actions such as logistical and financial support, co-participation and modelling. Parents of children from low SES schools mainly restricted their input to verbal encouragement and demands. Participation in family-based activities was reported to be higher in children from middle/high SES schools than children from low SES schools. All SES groups reported time to be a limiting factor in family-based activity participation. Cost was reported as a significant barrier by children from low SES schools. Children from middle/high SES schools reported engaging in more sports clubs and organised activities than children from low SES schools, who reported participating in more unstructured activities or 'free play' with friends. Conclusion The family is important for encouraging children to be physically active, but families from different socioeconomic backgrounds support their children in different ways. This research suggests that the design of physical activity interventions, which might include working with families, requires tailoring to groups from different socio-economic backgrounds. PMID:19622143

A microdisplay-based HUD for automotive applications: Backplane design, planarization, and optical implementation

NASA Astrophysics Data System (ADS)

Schuck, Miller Harry

Automotive head-up displays require compact, bright, and inexpensive imaging systems. In this thesis, a compact head-up display (HUD) utilizing liquid-crystal-on-silicon microdisplay technology is presented from concept to implementation. The thesis comprises three primary areas of HUD research: the specification, design and implementation of a compact HUD optical system, the development of a wafer planarization process to enhance reflective device brightness and light immunity and the design, fabrication and testing of an inexpensive 640 x 512 pixel active matrix backplane intended to meet the HUD requirements. The thesis addresses the HUD problem at three levels, the systems level, the device level, and the materials level. At the systems level, the optical design of an automotive HUD must meet several competing requirements, including high image brightness, compact packaging, video-rate performance, and low cost. An optical system design which meets the competing requirements has been developed utilizing a fully-reconfigurable reflective microdisplay. The design consists of two optical stages, the first a projector stage which magnifies the display, and a second stage which forms the virtual image eventually seen by the driver. A key component of the optical system is a diffraction grating/field lens which forms a large viewing eyebox while reducing the optical system complexity. Image quality biocular disparity and luminous efficacy were analyzed and results of the optical implementation are presented. At the device level, the automotive HUD requires a reconfigurable, video-rate, high resolution image source for applications such as navigation and night vision. The design of a 640 x 512 pixel active matrix backplane which meets the requirements of the HUD is described. The backplane was designed to produce digital field sequential color images at video rates utilizing fast switching liquid crystal as the modulation layer. The design methodology is discussed, and the example of a clock generator is described from design to implementation. Electrical and optical test results of the fabricated backplane are presented. At the materials level, a planarization method was developed to meet the stringent brightness requirements of automotive HUD's. The research efforts described here have resulted in a simple, low cost post-processing method for planarizing microdisplay substrates based on a spin-cast polymeric resin, benzocyclobutene (BCB). Six- fold reductions in substrate step height were accomplished with a single coating. Via masking and dry etching methods were developed. High reflectivity metal was deposited and patterned over the planarized substrate to produce high aperture pixel mirrors. The process is simple, rapid, and results in microdisplays better able to meet the stringent requirements of high brightness display systems. Methods and results of the post- processing are described.

Generalized internal model robust control for active front steering intervention

NASA Astrophysics Data System (ADS)

Wu, Jian; Zhao, Youqun; Ji, Xuewu; Liu, Yahui; Zhang, Lipeng

2015-03-01

Because of the tire nonlinearity and vehicle's parameters' uncertainties, robust control methods based on the worst cases, such as H ∞, µ synthesis, have been widely used in active front steering control, however, in order to guarantee the stability of active front steering system (AFS) controller, the robust control is at the cost of performance so that the robust controller is a little conservative and has low performance for AFS control. In this paper, a generalized internal model robust control (GIMC) that can overcome the contradiction between performance and stability is used in the AFS control. In GIMC, the Youla parameterization is used in an improved way. And GIMC controller includes two sections: a high performance controller designed for the nominal vehicle model and a robust controller compensating the vehicle parameters' uncertainties and some external disturbances. Simulations of double lane change (DLC) maneuver and that of braking on split- µ road are conducted to compare the performance and stability of the GIMC control, the nominal performance PID controller and the H ∞ controller. Simulation results show that the high nominal performance PID controller will be unstable under some extreme situations because of large vehicle's parameters variations, H ∞ controller is conservative so that the performance is a little low, and only the GIMC controller overcomes the contradiction between performance and robustness, which can both ensure the stability of the AFS controller and guarantee the high performance of the AFS controller. Therefore, the GIMC method proposed for AFS can overcome some disadvantages of control methods used by current AFS system, that is, can solve the instability of PID or LQP control methods and the low performance of the standard H ∞ controller.

A comprehensive prediction and evaluation method of pilot workload

PubMed Central

Feng, Chuanyan; Wanyan, Xiaoru; Yang, Kun; Zhuang, Damin; Wu, Xu

2018-01-01

BACKGROUND: The prediction and evaluation of pilot workload is a key problem in human factor airworthiness of cockpit. OBJECTIVE: A pilot traffic pattern task was designed in a flight simulation environment in order to carry out the pilot workload prediction and improve the evaluation method. METHODS: The prediction of typical flight subtasks and dynamic workloads (cruise, approach, and landing) were built up based on multiple resource theory, and a favorable validity was achieved by the correlation analysis verification between sensitive physiological data and the predicted value. RESULTS: Statistical analysis indicated that eye movement indices (fixation frequency, mean fixation time, saccade frequency, mean saccade time, and mean pupil diameter), Electrocardiogram indices (mean normal-to-normal interval and the ratio between low frequency and sum of low frequency and high frequency), and Electrodermal Activity indices (mean tonic and mean phasic) were all sensitive to typical workloads of subjects. CONCLUSION: A multinominal logistic regression model based on combination of physiological indices (fixation frequency, mean normal-to-normal interval, the ratio between low frequency and sum of low frequency and high frequency, and mean tonic) was constructed, and the discriminate accuracy was comparatively ideal with a rate of 84.85%. PMID:29710742

Testing and evaluation for astronaut extravehicular activity (EVA) operability.

PubMed

Shields, N; King, L C

1998-09-01

Because it is the human component that defines space mission success, careful planning is required to ensure that hardware can be operated and maintained by crews on-orbit. Several methods exist to allow researchers and designers to better predict how hardware designs will behave under the harsh environment of low Earth orbit, and whether designs incorporate the necessary features for Extra Vehicular Activity (EVA) operability. Testing under conditions of simulated microgravity can occur during the design concept phase when verifying design operability, during mission training, or concurrently with on-orbit mission operations. The bulk of testing is focused on normal operations, but also includes evaluation of credible mission contingencies or "what would happen if" planning. The astronauts and cosmonauts who fly these space missions are well prepared and trained to survive and be productive in Earth's orbit. The engineers, designers, and training crews involved in space missions subject themselves to Earth based simulation techniques that also expose them to extreme environments. Aircraft falling ten thousand feet, alternating g-loads, underwater testing at 45 foot depth, enclosure in a vacuum chamber and subject to thermal extremes, each carries with it inherent risks to the humans preparing for space missions.

Rational Design of Highly Potent and Slow-Binding Cytochrome bc1 Inhibitor as Fungicide by Computational Substitution Optimization

PubMed Central

Hao, Ge-Fei; Yang, Sheng-Gang; Huang, Wei; Wang, Le; Shen, Yan-Qing; Tu, Wen-Long; Li, Hui; Huang, Li-Shar; Wu, Jia-Wei; Berry, Edward A.; Yang, Guang-Fu

2015-01-01

Hit to lead (H2L) optimization is a key step for drug and agrochemical discovery. A critical challenge for H2L optimization is the low efficiency due to the lack of predictive method with high accuracy. We described a new computational method called Computational Substitution Optimization (CSO) that has allowed us to rapidly identify compounds with cytochrome bc1 complex inhibitory activity in the nanomolar and subnanomolar range. The comprehensively optimized candidate has proved to be a slow binding inhibitor of bc1 complex, ~73-fold more potent (Ki = 4.1 nM) than the best commercial fungicide azoxystrobin (AZ; Ki = 297.6 nM) and shows excellent in vivo fungicidal activity against downy mildew and powdery mildew disease. The excellent correlation between experimental and calculated binding free-energy shifts together with further crystallographic analysis confirmed the prediction accuracy of CSO method. To the best of our knowledge, CSO is a new computational approach to substitution-scanning mutagenesis of ligand and could be used as a general strategy of H2L optimisation in drug and agrochemical design.

Laser-Etched Designs for Molding Hydrogel-Based Engineered Tissues

PubMed Central

Munarin, Fabiola; Kaiser, Nicholas J.; Kim, Tae Yun; Choi, Bum-Rak

2017-01-01

Rapid prototyping and fabrication of elastomeric molds for sterile culture of engineered tissues allow for the development of tissue geometries that can be tailored to different in vitro applications and customized as implantable scaffolds for regenerative medicine. Commercially available molds offer minimal capabilities for adaptation to unique conditions or applications versus those for which they are specifically designed. Here we describe a replica molding method for the design and fabrication of poly(dimethylsiloxane) (PDMS) molds from laser-etched acrylic negative masters with ∼0.2 mm resolution. Examples of the variety of mold shapes, sizes, and patterns obtained from laser-etched designs are provided. We use the patterned PDMS molds for producing and culturing engineered cardiac tissues with cardiomyocytes derived from human-induced pluripotent stem cells. We demonstrate that tight control over tissue morphology and anisotropy results in modulation of cell alignment and tissue-level conduction properties, including the appearance and elimination of reentrant arrhythmias, or circular electrical activation patterns. Techniques for handling engineered cardiac tissues during implantation in vivo in a rat model of myocardial infarction have been developed and are presented herein to facilitate development and adoption of surgical techniques for use with hydrogel-based engineered tissues. In summary, the method presented herein for engineered tissue mold generation is straightforward and low cost, enabling rapid design iteration and adaptation to a variety of applications in tissue engineering. Furthermore, the burden of equipment and expertise is low, allowing the technique to be accessible to all. PMID:28457187

From the Cover: Development and Application of a Dual Rat and Human AHR Activation Assay.

PubMed

Brown, Martin R; Garside, Helen; Thompson, Emma; Atwal, Saseela; Bean, Chloe; Goodall, Tony; Sullivan, Michael; Graham, Mark J

2017-12-01

Significant prolonged aryl hydrocarbon receptor (AHR) activation, classically exhibited following exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin, can cause a variety of undesirable toxicological effects. Novel pharmaceutical chemistries also have the potential to cause activation of AHR and consequent toxicities in pre-clinical species and man. Previous methods either employed relatively expensive and low-throughput primary hepatocyte dosing with PCR endpoint, or low resolution overexpressing reporter gene assays. We have developed, validated and applied an in vitro microtitre plate imaging-based medium throughput screening assay for the assessment of endogenous species-specific AHR activation potential via detection of induction of the surrogate transcriptional target Cytochrome P450 CYP1A1. Routine testing of pharmaceutical drug development candidate chemistries using this assay can influence the chemical design process and highlight AHR liabilities. This assay should be introduced such that human AHR activation liability is flagged early for confirmatory testing. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Implementation green and low cost on landscape design of Manggarai Integrated Station, Jakarta

NASA Astrophysics Data System (ADS)

Suryanti, T.; Meilianti, H.

2018-01-01

The Manggarai Integrated Station is the transit of various transportation modes. The Integrated Station located in Manggarai Jakarta and managed by PT. KAI. The Manggarai station is integrated and have terminal nature of transit areas (switching mode of transportation). There are several problems in the site, such as the problem of the site conditions in the urban area, topography, soil, vegetation, space, visual, users on the site can provide ideas for the concepts. The data was analyzed using the quantitative descriptive methode. The purpose of this research is to design the integrated station atmosphere, not only can support of the activities station users, but can also accommodate the needs of the community. It will “Green, Low cost” at the Manggarai integrated transport transit station in Jakarta. The potential that exists in this area is the lowliest integrated from various areas of the mode of transportation that make the users to facilitate transit transportation to the other. The basic concept of this design refers to the “Green, Low Cost” which unite with theme “user friendly” land use on a more efficient and effective site. The result of this research is landscape design development of Manggarai integrated station. Its consists of landscape design in west and east area, transition area, parking area, solar panel area, and social interaction area.

Influence of study approaches and course design on academic success in the undergraduate anatomy laboratory.

PubMed

Eleazer, Courtney D; Scopa Kelso, Rebecca

2018-01-04

Many pre-health professional programs require completion of an undergraduate anatomy course with a laboratory component, yet grades in these courses are often low. Many students perceive anatomy as a more challenging subject than other coursework, and the resulting anxiety surrounding this perception may be a significant contributor to poor performance. Well-planned and deliberate guidance from instructors, as well as thoughtful course design, may be necessary to assist students in finding the best approach to studying for anatomy. This article assesses which study habits are associated with course success and whether course design influences study habits. Surveys (n = 1,274) were administered to students enrolled in three undergraduate human anatomy laboratory courses with varying levels of cooperative learning and structured guidance. The surveys collected information on potential predictors of performance, including student demographics, educational background, self-assessment ability, and study methods (e.g., flashcards, textbooks, diagrams). Compared to low performers, high performers perceive studying in laboratory, asking the instructor questions, quizzing alone, and quizzing others as more effective for learning. Additionally, students co-enrolled in a flipped, active lecture anatomy course achieve higher grades and find active learning activities (e.g., quizzing alone and in groups) more helpful for their learning in the laboratory. These results strengthen previous research suggesting that student performance is more greatly enhanced by an active classroom environment that practices successful study strategies rather than one that simply encourages students to employ such strategies inside and outside the classroom. Anat Sci Educ. © 2018 American Association of Anatomists. © 2018 American Association of Anatomists.

Four experimental demonstrations of active vibration control for flexible structures

NASA Technical Reports Server (NTRS)

Phillips, Doug; Collins, Emmanuel G., Jr.

1990-01-01

Laboratory experiments designed to test prototype active-vibration-control systems under development for future flexible space structures are described, summarizing previously reported results. The control-synthesis technique employed for all four experiments was the maximum-entropy optimal-projection (MEOP) method (Bernstein and Hyland, 1988). Consideration is given to: (1) a pendulum experiment on large-amplitude LF dynamics; (2) a plate experiment on broadband vibration suppression in a two-dimensional structure; (3) a multiple-hexagon experiment combining the factors studied in (1) and (2) to simulate the complexity of a large space structure; and (4) the NASA Marshall ACES experiment on a lightweight deployable 45-foot beam. Extensive diagrams, drawings, graphs, and photographs are included. The results are shown to validate the MEOP design approach, demonstrating that good performance is achievable using relatively simple low-order decentralized controllers.

Study of active noise control system for a commercial HVAC unit

NASA Astrophysics Data System (ADS)

Devineni, Naga

Acoustic noise is a common problem in everyday life. If the appliances that are present in the work and living areas generate noise then it's a serious problem. One such appliance is the Heating, Ventilation and Air-conditioning system (HVAC) in which blower fan and compressor units are housed together. Operation of a HVAC system creates two kinds of noise. One is the noise due to the air flow and the other is the result of the compressor. Both of them exhibit different signal properties and need different strategies to control them. There has been previous efforts in designing noise control systems that can control noise from the HVAC system. These include passive methods which use sound absorption materials to attenuate noise and active methods which cancel noise by generating anti-noise. Passive methods are effective in limiting the high frequency noise, but are inefficient in controlling low frequency noise from the compressor. Compressor noise is one of the strong low frequency components that propagate through the walls, therefore there is need for deploying active signal processing methods that consider the signal properties into consideration to cancel the noise acoustically. The quasi periodic nature of the compressor noise is exploited in noise modeling which aids in implementing an adaptive linear prediction filter in estimating the anti noise [12]. In this thesis, a multi channel architecture has been studied for a specific HVAC system in order to improve noise cancellation by creating larger quiet zone. In addition to the multi-channel architecture, a real time narrow band Active Noise Control (ANC) was employed to cancel noise under practical conditions.

Low-cycle fatigue testing methods

NASA Technical Reports Server (NTRS)

Lieurade, H. P.

1978-01-01

The good design of highly stressed mechanical components requires accurate knowledge of the service behavior of materials. The main methods for solving the problems of designers are: determination of the mechanical properties of the material after cyclic stabilization; plotting of resistance to plastic deformation curves; effect of temperature on the life on low cycle fatigue; and simulation of notched parts behavior.

Low activation ferritic alloys

DOEpatents

Gelles, David S.; Ghoniem, Nasr M.; Powell, Roger W.

1986-01-01

Low activation ferritic alloys, specifically bainitic and martensitic stainless steels, are described for use in the production of structural components for nuclear fusion reactors. They are designed specifically to achieve low activation characteristics suitable for efficient waste disposal. The alloys essentially exclude molybdenum, nickel, nitrogen and niobium. Strength is achieved by substituting vanadium, tungsten, and/or tantalum in place of the usual molybdenum content in such alloys.

Low activation ferritic alloys

DOEpatents

Gelles, D.S.; Ghoniem, N.M.; Powell, R.W.

1985-02-07

Low activation ferritic alloys, specifically bainitic and martensitic stainless steels, are described for use in the production of structural components for nuclear fusion reactors. They are designed specifically to achieve low activation characteristics suitable for efficient waste disposal. The alloys essentially exclude molybdenum, nickel, nitrogen and niobium. Strength is achieved by substituting vanadium, tungsten, and/or tantalum in place of the usual molybdenum content in such alloys.

Effect of confounding variables on hemodynamic response function estimation using averaging and deconvolution analysis: An event-related NIRS study.

PubMed

Aarabi, Ardalan; Osharina, Victoria; Wallois, Fabrice

2017-07-15

Slow and rapid event-related designs are used in fMRI and functional near-infrared spectroscopy (fNIRS) experiments to temporally characterize the brain hemodynamic response to discrete events. Conventional averaging (CA) and the deconvolution method (DM) are the two techniques commonly used to estimate the Hemodynamic Response Function (HRF) profile in event-related designs. In this study, we conducted a series of simulations using synthetic and real NIRS data to examine the effect of the main confounding factors, including event sequence timing parameters, different types of noise, signal-to-noise ratio (SNR), temporal autocorrelation and temporal filtering on the performance of these techniques in slow and rapid event-related designs. We also compared systematic errors in the estimates of the fitted HRF amplitude, latency and duration for both techniques. We further compared the performance of deconvolution methods based on Finite Impulse Response (FIR) basis functions and gamma basis sets. Our results demonstrate that DM was much less sensitive to confounding factors than CA. Event timing was the main parameter largely affecting the accuracy of CA. In slow event-related designs, deconvolution methods provided similar results to those obtained by CA. In rapid event-related designs, our results showed that DM outperformed CA for all SNR, especially above -5 dB regardless of the event sequence timing and the dynamics of background NIRS activity. Our results also show that periodic low-frequency systemic hemodynamic fluctuations as well as phase-locked noise can markedly obscure hemodynamic evoked responses. Temporal autocorrelation also affected the performance of both techniques by inducing distortions in the time profile of the estimated hemodynamic response with inflated t-statistics, especially at low SNRs. We also found that high-pass temporal filtering could substantially affect the performance of both techniques by removing the low-frequency components of HRF profiles. Our results emphasize the importance of characterization of event timing, background noise and SNR when estimating HRF profiles using CA and DM in event-related designs. Copyright © 2017 Elsevier Inc. All rights reserved.

SoM: a smart sensor for human activity monitoring and assisted healthy ageing.

PubMed

Naranjo-Hernández, David; Roa, Laura M; Reina-Tosina, Javier; Estudillo-Valderrama, Miguel Ángel

2012-11-01

This paper presents the hardware and software design and implementation of a low-cost, wearable, and unobstructive intelligent accelerometer sensor for the monitoring of human physical activities. In order to promote healthy lifestyles to elders for an active, independent, and healthy ageing, as well as for the early detection of psychomotor abnormalities, the activity monitoring is performed in a holistic manner in the same device through different approaches: 1) a classification of the level of activity that allows to establish patterns of behavior; 2) a daily activity living classifier that is able to distinguish activities such as climbing or descending stairs using a simple method to decouple the gravitational acceleration components of the motion components; and 3) an estimation of metabolic expenditure independent of the activity performed and the anthropometric characteristics of the user. Experimental results have demonstrated the feasibility of the prototype and the proposed algorithms.

What research tells us about knowledge transfer strategies to improve public health in low-income countries: a scoping review.

PubMed

Siron, Stéphanie; Dagenais, Christian; Ridde, Valéry

2015-11-01

This study describes the current state of research on knowledge transfer strategies to improve public health in low-income countries, to identify the knowledge gaps on this topic. In this scoping review, a descriptive and systematic process was used to analyse, for each article retained, descriptions of research context and methods, types of knowledge transfer activities and results reported. 28 articles were analysed. They dealt with the evaluation of transfer strategies that employed multiple activities, mostly targeting health professionals and women with very young children. Most often these studies used quantitative designs and measurements of instrumental use with some methodological shortcomings. Results were positive and suggested recommendations for improving professional practices, knowledge and health-related behaviours. The review highlights the great diversity of transfer strategies used, strategies and many conditions for knowledge use. The review provides specific elements for understanding the transfer processes in low-income countries and highlights the need for systematic evaluation of the conditions for research results utilization.

Design and evaluation of low-cost stainless steel fiberglass foam blades for large wind driven generating systems

NASA Technical Reports Server (NTRS)

Eggert, W. S.

1982-01-01

A low cost wind turbine blade based on a stainless steel fiberglass foam Budd blade design concept, was evaluated for its principle characteristics, low cost features, and its advantages and disadvantages. A blade structure was designed and construction methods and materials were selected. A complete blade tooling concepts, various technical and economic analysis, and evaluations of the blade design were performed. A comprehensive fatigue test program is conducted to provide data to verify the design stress allowables.

Design and evaluation of low-cost stainless steel fiberglass foam blades for large wind driven generating systems

NASA Astrophysics Data System (ADS)

Eggert, W. S.

1982-10-01

A low cost wind turbine blade based on a stainless steel fiberglass foam Budd blade design concept, was evaluated for its principle characteristics, low cost features, and its advantages and disadvantages. A blade structure was designed and construction methods and materials were selected. A complete blade tooling concepts, various technical and economic analysis, and evaluations of the blade design were performed. A comprehensive fatigue test program is conducted to provide data to verify the design stress allowables.

Low-temperature kinetic measurements of microsecond freeze-hyperquench (MHQ) cytochrome oxidase monitored by UV-visible spectroscopy with a newly designed cuvette.

PubMed

Wiertz, F G M; de Vries, S

2006-02-01

A special cuvette was designed to measure optical changes of MHQ (microsecond freeze-hyperquench) powder samples at temperatures below approx. 250 K. Reduced cytochrome c oxidase from Paracoccus denitrificans was reacted with O(2) for 100 micros, frozen as a powder and transferred to the cuvette. Subsequently, cytochrome oxidase was allowed to react further following stepwise increments of the temperature from 100 K up to 250 K while recording spectra between 300 and 700 nm. The temperature was raised only when no further changes in the spectra could be detected. The experiment yielded spectra of the A, P(M), F and O intermediate states. This demonstrated that the catalytic cycle of cytochrome oxidase at low temperature is similar to that at room temperature and so verifies the suitability of this method for the study of enzymes with high catalytic-centre activity.

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

Huml, O.

The objective of this work was to determine the neutron flux density distribution in various places of the training reactor VR-1 Sparrow. This experiment was performed on the new core design C1, composed of the new low-enriched uranium fuel cells IRT-4M (19.7 %). This fuel replaced the old high-enriched uranium fuel IRT-3M (36 %) within the framework of the RERTR Program in September 2005. The measurement used the neutron activation analysis method with gold wires. The principle of this method consists in neutron capture in a nucleus of the material forming the activation detector. This capture can change the nucleusmore » in a radioisotope, whose activity can be measured. The absorption cross-section values were evaluated by MCNP computer code. The gold wires were irradiated in seven different positions in the core C1. All irradiations were performed at reactor power level 1E8 (1 kW{sub therm}). The activity of segments of irradiated wires was measured by special automatic device called 'Drat' (Wire in English). (author)« less

Design of the laser acupuncture therapeutic instrument.

PubMed

Li, Chengwei; Zhen, Huang

2006-01-01

Laser acupuncture is defined as the stimulation of traditional acupuncture points with low-intensity, non-thermal laser irradiation. It has been well applied in clinic since the 1970s; however, some traditional acupuncture manipulating methods still cannot be implemented in the design of this kind of instruments, such as lifting and thrusting manipulating method, and twisting and twirling manipulating method, which are the essential acupuncture method in traditional acupuncture. The objective of this work was to design and build a low cost portable laser acupuncture therapeutic instrument, which can implement the two essential acupuncture manipulating methods. Digital PID control theory is used to control the power of laser diode (LD), and to implement the lifting and thrusting manipulating method. Special optical system is designed to implement twisting and twirling manipulating method. M5P430 microcontroller system is used as the control centre of the instrument. The realization of lifting and thrusting manipulating method and twisting and twirling manipulating method are technological innovations in traditional acupuncture coming true in engineering.

Groundwater contamination from waste management sites: The interaction between risk-based engineering design and regulatory policy: 2. Results

NASA Astrophysics Data System (ADS)

Massmann, Joel; Freeze, R. Allan

1987-02-01

The risk-cost-benefit analysis developed in the companion paper (J. Massmann and R. A. Freeze, this issue) is here applied to (1) an assessment of the relative worth of containment-construction activities, site-exploration activities, and monitoring activities as components of a design strategy for the owner/operator of a waste management facility; (2) an assessment of alternative policy options available to a regulatory agency; and (3) a case history. Sensitivity analyses designed to address the first issue show that the allocation of resources by the owner/operator is sensitive to the stochastic parameters used to describe the hydraulic conductivity field at a site. For the cases analyzed, the installation of a dense monitoring network is of less value to the owner/operator than a more conservative containment design. Sensitivity analyses designed to address the second issue suggest that from a regulatory perspective, design standards should be more effective than performance standards in reducing risk, and design specifications on the containment structure should be more effective than those on the monitoring network. Performance bonds posted before construction have a greater potential to influence design than prospective penalties to be imposed at the time of failure. Siting on low-conductivity deposits is a more effective method of risk reduction than any form of regulatory influence. Results of the case history indicate that the methodology can be successfully applied at field sites.

A simulation environment for assisting system design of coherent laser doppler wind sensor for active wind turbine pitch control

NASA Astrophysics Data System (ADS)

Shinohara, Leilei; Pham Tran, Tuan Anh; Beuth, Thorsten; Umesh Babu, Harsha; Heussner, Nico; Bogatscher, Siegwart; Danilova, Svetlana; Stork, Wilhelm

2013-05-01

In order to assist a system design of laser coherent Doppler wind sensor for active pitch control of wind turbine systems (WTS), we developed a numerical simulation environment for modeling and simulation of the sensor system. In this paper we present this simulation concept. In previous works, we have shown the general idea and the possibility of using a low cost coherent laser Doppler wind sensing system for an active pitch control of WTS in order to achieve a reduced mechanical stress, increase the WTS lifetime and therefore reduce the electricity price from wind energy. Such a system is based on a 1.55μm Continuous-Wave (CW) laser plus an erbium-doped fiber amplifier (EDFA) with an output power of 1W. Within this system, an optical coherent detection method is chosen for the Doppler frequency measurement in megahertz range. A comparatively low cost short coherent length laser with a fiber delay line is used for achieving a multiple range measurement. In this paper, we show the current results on the improvement of our simulation by applying a Monte Carlo random generation method for positioning the random particles in atmosphere and extend the simulation to the entire beam penetrated space by introducing a cylindrical co-ordinate concept and meshing the entire volume into small elements in order to achieve a faster calculation and gain more realistic simulation result. In addition, by applying different atmospheric parameters, such as particle sizes and distributions, we can simulate different weather and wind situations.

Highly Efficient Flexible Hybrid Photovoltaic Cells Based on Low-Band-Gap Conjugated Polymers Sensitized by Nanoparticle-Grafted Carbon

DTIC Science & Technology

2010-09-01

modeling, synthesis , and characterization of several series functional and processable electro-active conjugated polymers with evolving frontier...tasks as a basic obligation of this award: Task #1. Low Band Gap Polymers The awardee (Professor Sun’s group at NSU) shall design, synthesis , and...design, modeling, synthesis , and characterizations of several series functional and processable electro-active conjugated polymers with evolving

Design method of high-efficient 
LED headlamp lens.

PubMed

Chen, Fei; Wang, Kai; Qin, Zong; Wu, Dan; Luo, Xiaobing; Liu, Sheng

2010-09-27

Low optical efficiency of light-emitting diode (LED) based headlamp is one of the most important issues to obstruct applications of LEDs in headlamp. An effective high-efficient LED headlamp freeform lens design method is introduced in this paper. A low-beam lens and a high-beam lens for LED headlamp are designed according to this method. Monte Carlo ray tracing simulation results demonstrate that the LED headlamp with these two lenses can fully comply with the ECE regulation without any other lens or reflector. Moreover, optical efficiencies of both these two lenses are more than 88% in theory.

Analysis and Design of Rotors at Ultra-Low Reynolds Numbers

NASA Technical Reports Server (NTRS)

Kunz, Peter J.; Strawn, Roger C.

2003-01-01

Design tools have been developed for ultra-low Reynolds number rotors, combining enhanced actuator-ring / blade-element theory with airfoil section data based on two-dimensional Navier-Stokes calculations. This performance prediction method is coupled with an optimizer for both design and analysis applications. Performance predictions from these tools have been compared with three-dimensional Navier Stokes analyses and experimental data for a 2.5 cm diameter rotor with chord Reynolds numbers below 10,000. Comparisons among the analyses and experimental data show reasonable agreement both in the global thrust and power required, but the spanwise distributions of these quantities exhibit significant deviations. The study also reveals that three-dimensional and rotational effects significantly change local airfoil section performance. The magnitude of this issue, unique to this operating regime, may limit the applicability of blade-element type methods for detailed rotor design at ultra-low Reynolds numbers, but these methods are still useful for evaluating concept feasibility and rapidly generating initial designs for further analysis and optimization using more advanced tools.

An analytical method for designing low noise helicopter transmissions

NASA Technical Reports Server (NTRS)

Bossler, R. B., Jr.; Bowes, M. A.; Royal, A. C.

1978-01-01

The development and experimental validation of a method for analytically modeling the noise mechanism in the helicopter geared power transmission systems is described. This method can be used within the design process to predict interior noise levels and to investigate the noise reducing potential of alternative transmission design details. Examples are discussed.

Density functional theory design D-D-A type small molecule with 1.03 eV narrow band gap: effect of electron donor unit for organic photovoltaic solar cell

NASA Astrophysics Data System (ADS)

Sıdır, İsa

2017-10-01

Six new low-band-gap copolymers of donor-donor-acceptor (D-D-A) architecture have been designed using density functional theory and time-dependent density functional theory methods in order to use them in organic photovoltaic cell (OPVC). Phenanthro[3,4-d:9,10-d‧]bis([1,2,3]thiadiazole)-10,12-dicarbonitrile moiety has been used as an acceptor for all compounds. We insert benzo[1,2-b:4,5-b‧]dithiophene and N,N-diphenylbenzo[1,2-b:4,5-b‧]dithiophen-2-amine units as donor to complete designing of copolymers. In order to tuning the optical and electronic properties, we have modified the donor unit by substituted with amine, methoxyamine, N-methylenethiophen-2-amine, methoxy, alkoxy moieties. The band gap (Eg), HOMO and LUMO values and plots, open circuit voltage (VOC) as well as optical properties have been analysed for designed copolymers. The optimised copolymers exhibit low-band-gap lying in the range of 1.03-2.24 eV. DPTD-6 copolymer presents the optimal properties to be used as an active layer due to its low Eg (1.03 eV) and a moderate VOC (0.56 eV). Thus, OPVC based on this copolymer in bulk-heterojunction composites with [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) as an acceptor has been modelled. Eg and VOC values of composite material DPTD-6:PCBM are found as 1.32 and 0.65 eV, respectively. A model band diagram has been established for OPVC, simulating the energy transfer between active layers.

Modular Bayesian Networks with Low-Power Wearable Sensors for Recognizing Eating Activities.

PubMed

Kim, Kee-Hoon; Cho, Sung-Bae

2017-12-11

Recently, recognizing a user's daily activity using a smartphone and wearable sensors has become a popular issue. However, in contrast with the ideal definition of an experiment, there could be numerous complex activities in real life with respect to its various background and contexts: time, space, age, culture, and so on. Recognizing these complex activities with limited low-power sensors, considering the power and memory constraints of the wearable environment and the user's obtrusiveness at once is not an easy problem, although it is very crucial for the activity recognizer to be practically useful. In this paper, we recognize activity of eating, which is one of the most typical examples of a complex activity, using only daily low-power mobile and wearable sensors. To organize the related contexts systemically, we have constructed the context model based on activity theory and the "Five W's", and propose a Bayesian network with 88 nodes to predict uncertain contexts probabilistically. The structure of the proposed Bayesian network is designed by a modular and tree-structured approach to reduce the time complexity and increase the scalability. To evaluate the proposed method, we collected the data with 10 different activities from 25 volunteers of various ages, occupations, and jobs, and have obtained 79.71% accuracy, which outperforms other conventional classifiers by 7.54-14.4%. Analyses of the results showed that our probabilistic approach could also give approximate results even when one of contexts or sensor values has a very heterogeneous pattern or is missing.

Job Design and Ethnic Differences in Working Women’s Physical Activity

PubMed Central

Grzywacz, Joseph G.; Crain, A. Lauren; Martinson, Brian C.; Quandt, Sara A.

2014-01-01

Objective To document the role job control and schedule control play in shaping women’s physical activity, and how it delineates educational and racial variability in associations of job and social control with physical activity. Methods Prospective data were obtained from a community-based sample of working women (N = 302). Validated instruments measured job control and schedule control. Steps per day were assessed using New Lifestyles 800 activity monitors. Results Greater job control predicted more steps per day, whereas greater schedule control predicted fewer steps. Small indirect associations between ethnicity and physical activity were observed among women with a trade school degree or less but not for women with a college degree. Conclusions Low job control created barriers to physical activity among working women with a trade school degree or less. Greater schedule control predicted less physical activity, suggesting women do not use time “created” by schedule flexibility for personal health enhancement. PMID:24034681

Complexation of sesquiterpene lactones with cyclodextrins: synthesis and effects on their activities on parasitic weeds.

PubMed

Cala, Antonio; Molinillo, José M G; Fernández-Aparicio, Mónica; Ayuso, Jesús; Álvarez, José A; Rubiales, Diego; Macías, Francisco A

2017-08-09

Allelochemicals are safer, more selective and more active alternatives than synthetic agrochemicals for weed control. However, the low solubility of these compounds in aqueous media limits their use as agrochemicals. Herein, we propose the application of α-, β- and γ-cyclodextrins to improve the physicochemical properties and biological activities of three sesquiterpene lactones: dehydrocostuslactone, costunolide and (-)-α-santonin. Complexation was achieved by kneading and coprecipitation methods. Aqueous solubility was increased in the range 100-4600% and the solubility-phase diagrams suggested that complex formation had been successful. The results of the PM3 semiempirical calculations were consistent with the experimental results. The activities on etiolated wheat coleoptiles, Standard Target Species and parasitic weeds were improved. Cyclodextrins preserved or enhanced the activity of the three sesquiterpene lactones. Free cyclodextrins did not show significant activity and therefore the enhancement in activity was due to complexation. These results are promising for applications in agrochemical design.

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

Composite Configuration Interventional Therapy Robot for the Microwave Ablation of Liver Tumors

NASA Astrophysics Data System (ADS)

Cao, Ying-Yu; Xue, Long; Qi, Bo-Jin; Jiang, Li-Pei; Deng, Shuang-Cheng; Liang, Ping; Liu, Jia

2017-11-01

The existing interventional therapy robots for the microwave ablation of liver tumors have a poor clinical applicability with a large volume, low positioning speed and complex automatic navigation control. To solve above problems, a composite configuration interventional therapy robot with passive and active joints is developed. The design of composite configuration reduces the size of the robot under the premise of a wide range of movement, and the robot with composite configuration can realizes rapid positioning with operation safety. The cumulative error of positioning is eliminated and the control complexity is reduced by decoupling active parts. The navigation algorithms for the robot are proposed based on solution of the inverse kinematics and geometric analysis. A simulation clinical test method is designed for the robot, and the functions of the robot and the navigation algorithms are verified by the test method. The mean error of navigation is 1.488 mm and the maximum error is 2.056 mm, and the positioning time for the ablation needle is in 10 s. The experimental results show that the designed robot can meet the clinical requirements for the microwave ablation of liver tumors. The composite configuration is proposed in development of the interventional therapy robot for the microwave ablation of liver tumors, which provides a new idea for the structural design of medical robots.

A 2385 MHz, 2-stage low noise amplifier design

NASA Technical Reports Server (NTRS)

Sifri, Jack D.

1986-01-01

This article shows the design aspects of a 2.385 GHz low noise preamplifier with a .7 dB noise figure and 16.5 dB gain using the NE 67383 FET. The design uses a unique method in matching the input which achieves optimum noise figure and unconditional stability.

Fan Noise Reduction: An Overview

NASA Technical Reports Server (NTRS)

Envia, Edmane

2001-01-01

Fan noise reduction technologies developed as part of the engine noise reduction element of the Advanced Subsonic Technology Program are reviewed. Developments in low-noise fan stage design, swept and leaned outlet guide vanes, active noise control, fan flow management, and scarfed inlet are discussed. In each case, a description of the method is presented and, where available, representative results and general conclusions are discussed. The review concludes with a summary of the accomplishments of the AST-sponsored fan noise reduction research and a few thoughts on future work.

Effects of Moderate Aerobic Exercise Combined with Caloric Restriction on Circulating Estrogens and IGF-I in Premenopausal Women

DTIC Science & Technology

2002-10-01

postprandial serum lipoprotein respomes to a hypocaloric low carbohydrate diet rich in monounsaturated fat and siqqjlemented with n-3 fatty aci...method of energy status assessment in large population-based applications, such as those addressing the role of physical activity and or diet in the...the degree to which an exercise and diet program that results in an energy deficit will reduce the risk of breast cancer. Body Study Design: The

Adopting an Evidence-Based Lifestyle Physical Activity Program: Dissemination Study Design and Methods.

PubMed

Dunn, Andrea L; Buller, David B; Dearing, James W; Cutter, Gary; Guerra, Michele; Wilcox, Sara; Bettinghaus, Erwin P

2012-06-01

BACKGROUND: There is a scarcity of research studies that have examined academic-commercial partnerships to disseminate evidence-based physical activity programs. Understanding this approach to dissemination is essential because academic-commercial partnerships are increasingly common. Private companies have used dissemination channels and strategies to a degree that academicians have not, and declining resources require academicians to explore these partnerships. PURPOSE: This paper describes a retrospective case-control study design including the methods, demographics, organizational decision-making, implementation rates, and marketing strategy for Active Living Every Day (ALED), an evidence-based lifestyle physical activity program that has been commercially available since 2001. Evidence-based public health promotion programs rely on organizations and targeted sectors to disseminate these programs although relatively little is known about organizational-level and sector-level influences that lead to their adoption and implementation. METHODS: Cases (n=154) were eligible if they had signed an ALED license agreement with Human Kinetics (HK), publisher of the program's textbooks and facilitator manuals, between 2001 and 2008. Two types of controls were matched (2:2:1) and stratified by sector and region. Active controls (Control 1; n=319) were organizations that contacted HK to consider adopting ALED. Passive controls (Control 2; n=328) were organizations that received unsolicited marketing materials and did not initiate contact with HK. We used Diffusion of Innovations Theory (DIT) constructs as the basis for developing the survey of cases and controls. RESULTS: Using the multi-method strategy recommended by Dillman, a total of n=801 cases and controls were surveyed. Most organizations were from the fitness sector followed by medical, nongovernmental, governmental, educational, worksite and other sectors with significantly higher response rates from government, educational and medical sectors compared with fitness and other sectors, (p=0.02). More cases reported being involved in the decision to adopt ALED (p<0.0001). Data indicate that a low percentage of controls had ever heard of ALED despite repeated marketing and offering other types of physical activity programs and services. Finally, slightly over half of the adopters reported they had actually implemented the ALED program. CONCLUSION: Dissemination research requires new perspectives and designs to produce valid insights about the results of dissemination efforts. This study design, survey methods and theoretically-based questions can serve as a useful model for other evidence-based public health interventions that are marketed by commercial publishers to better understand key issues related to adoption and implementation of evidence-based programs.

Application of computer-assisted molecular modeling for immunoassay of low molecular weight food contaminants: A review.

PubMed

Xu, Zhen-Lin; Shen, Yu-Dong; Beier, Ross C; Yang, Jin-Yi; Lei, Hong-Tao; Wang, Hong; Sun, Yuan-Ming

2009-08-11

Immunoassay for low molecular weight food contaminants, such as pesticides, veterinary drugs, and mycotoxins is now a well-established technique which meets the demand for a rapid, reliable, and cost-effective analytical method. However, due to limited understanding of the molecular structure of antibody binding sites and antigenic epitopes, as well as the intermolecular binding forces that come into play, the traditional 'trial and error' method used to develop antibodies still remains the method of choice. Therefore, development of enhanced immunochemical techniques for specific- and generic-assays, requires new approaches for antibody design that will improve affinity and specificity of the antibody in a more rapid and economic manner. Computer-assisted molecular modeling (CAMM) has been demonstrated to be a useful tool to help the immunochemist develop immunoassays. CAMM methods can be used to help direct improvements to important antibody features, and can provide insights into the effects of molecular structure on biological activity that are difficult or impossible to obtain in any other way. In this review, we briefly summarize applications of CAMM in immunoassay development, including assisting in hapten design, explaining cross-reactivity, modeling antibody-antigen interactions, and providing insights into the effects of the mouse body temperature on the three-dimensional conformation of a hapten during antibody production. The fundamentals and theory, programs and software, limitations, and prospects of CAMM in immunoassay development were also discussed.

Biomechanical effects of sitting with adjustable ischial and lumbar support on occupational low back pain: evaluation of sitting load and back muscle activity

PubMed Central

Makhsous, Mohsen; Lin, Fang; Bankard, James; Hendrix, Ronald W; Hepler, Matthew; Press, Joel

2009-01-01

Background Compared to standing posture, sitting decreases lumbar lordosis, increases low back muscle activity, disc pressure, and pressure on the ischium, which are associated with occupational LBP. A sitting device that reduces spinal load and low back muscle activities may help increase sitting comfort and reduce LBP risk. The objective of this study is to investigate the biomechanical effect of sitting with a reduced ischial support and an enhanced lumbar support (Off-Loading) on load, interface pressure and muscle activities. Methods A laboratory test in low back pain (LBP) and asymptomatic subjects was designed to test the biomechanical effect of using the Off-Loading sitting posture. The load and interface pressure on seat and the backrest, and back muscle activities associated with usual and this Off-Loading posture were recorded and compared between the two postures. Results Compared with Normal (sitting upright with full support of the seat and flat backrest) posture, sitting in Off-Loading posture significantly shifted the center of the force and the peak pressure on the seat anteriorly towards the thighs. It also significantly decreased the contact area on the seat and increased that on the backrest. It decreased the lumbar muscle activities significantly. These effects are similar in individuals with and without LBP. Conclusion Sitting with reduced ischial support and enhanced lumbar support resulted in reduced sitting load on the lumbar spine and reduced the lumbar muscular activity, which may potentially reduce sitting-related LBP. PMID:19193245

Design of a high altitude long endurance flying-wing solar-powered unmanned air vehicle

NASA Astrophysics Data System (ADS)

Alsahlani, A. A.; Johnston, L. J.; Atcliffe, P. A.

2017-06-01

The low-Reynolds number environment of high-altitude §ight places severe demands on the aerodynamic design and stability and control of a high altitude, long endurance (HALE) unmanned air vehicle (UAV). The aerodynamic efficiency of a §ying-wing configuration makes it an attractive design option for such an application and is investigated in the present work. The proposed configuration has a high-aspect ratio, swept-wing planform, the wing sweep being necessary to provide an adequate moment arm for outboard longitudinal and lateral control surfaces. A design optimization framework is developed under a MATLAB environment, combining aerodynamic, structural, and stability analysis. Low-order analysis tools are employed to facilitate efficient computations, which is important when there are multiple optimization loops for the various engineering analyses. In particular, a vortex-lattice method is used to compute the wing planform aerodynamics, coupled to a twodimensional (2D) panel method to derive aerofoil sectional characteristics. Integral boundary-layer methods are coupled to the panel method in order to predict §ow separation boundaries during the design iterations. A quasi-analytical method is adapted for application to flyingwing con¦gurations to predict the wing weight and a linear finite-beam element approach is used for structural analysis of the wing-box. Stability is a particular concern in the low-density environment of high-altitude flight for flying-wing aircraft and so provision of adequate directional stability and control power forms part of the optimization process. At present, a modified Genetic Algorithm is used in all of the optimization loops. Each of the low-order engineering analysis tools is validated using higher-order methods to provide con¦dence in the use of these computationally-efficient tools in the present design-optimization framework. This paper includes the results of employing the present optimization tools in the design of a HALE, flying-wing UAV to indicate that this is a viable design configuration option.

Design, test, and evaluation of three active flutter suppression controllers

NASA Technical Reports Server (NTRS)

Adams, William M., Jr.; Christhilf, David M.; Waszak, Martin R.; Mukhopadhyay, Vivek; Srinathkumar, S.

1992-01-01

Three control law design techniques for flutter suppression are presented. Each technique uses multiple control surfaces and/or sensors. The first method uses traditional tools (such as pole/zero loci and Nyquist diagrams) for producing a controller that has minimal complexity and which is sufficiently robust to handle plant uncertainty. The second procedure uses linear combinations of several accelerometer signals and dynamic compensation to synthesize the model rate of the critical mode for feedback to the distributed control surfaces. The third technique starts with a minimum-energy linear quadratic Gaussian controller, iteratively modifies intensity matrices corresponding to input and output noise, and applies controller order reduction to achieve a low-order, robust controller. The resulting designs were implemented digitally and tested subsonically on the active flexible wing wind-tunnel model in the Langley Transonic Dynamics Tunnel. Only the traditional pole/zero loci design was sufficiently robust to errors in the nominal plant to successfully suppress flutter during the test. The traditional pole/zero loci design provided simultaneous suppression of symmetric and antisymmetric flutter with a 24-percent increase in attainable dynamic pressure. Posttest analyses are shown which illustrate the problems encountered with the other laws.

iCalm: wearable sensor and network architecture for wirelessly communicating and logging autonomic activity.

PubMed

Fletcher, Richard Ribon; Dobson, Kelly; Goodwin, Matthew S; Eydgahi, Hoda; Wilder-Smith, Oliver; Fernholz, David; Kuboyama, Yuta; Hedman, Elliott Bruce; Poh, Ming-Zher; Picard, Rosalind W

2010-03-01

Widespread use of affective sensing in healthcare applications has been limited due to several practical factors, such as lack of comfortable wearable sensors, lack of wireless standards, and lack of low-power affordable hardware. In this paper, we present a new low-cost, low-power wireless sensor platform implemented using the IEEE 802.15.4 wireless standard, and describe the design of compact wearable sensors for long-term measurement of electrodermal activity, temperature, motor activity, and photoplethysmography. We also illustrate the use of this new technology for continuous long-term monitoring of autonomic nervous system and motion data from active infants, children, and adults. We describe several new applications enabled by this system, discuss two specific wearable designs for the wrist and foot, and present sample data.

Urban High School Student Engagement Through CincySTEM iTEST Projects

NASA Astrophysics Data System (ADS)

Beckett, Gulbahar H.; Hemmings, Annette; Maltbie, Catherine; Wright, Kathy; Sherman, Melissa; Sersion, Brian

2016-12-01

This paper focuses on the notable heightening of underrepresented students' engagement in STEM education through project-based learning CincySTEM iTEST projects. The projects, funded by an iTEST NSF grant, were designed and facilitated by teachers at a new STEM urban public high school serving low-income African-American students. Student engagement conceptualized as a psychological process involving affective and behavioral participation in classroom activities was evaluated through a mixed-methods approach. Findings indicate that affective and behavioral participation was significantly enhanced when project activities utilized digital devices in hands-on investigations of real-world project activities. Explanations for the success of CincySTEM iTEST projects are presented in the conclusion along with challenges for sustainability.

Design of Embedded-Hybrid Antimicrobial Peptides with Enhanced Cell Selectivity and Anti-Biofilm Activity

PubMed Central

Xu, Wei; Zhu, Xin; Tan, Tingting; Li, Weizhong; Shan, Anshan

2014-01-01

Antimicrobial peptides have attracted considerable attention because of their broad-spectrum antimicrobial activity and their low prognostic to induce antibiotic resistance which is the most common source of failure in bacterial infection treatment along with biofilms. The method to design hybrid peptide integrating different functional domains of peptides has many advantages. In this study, we designed an embedded-hybrid peptide R-FV-I16 by replacing a functional defective sequence RR7 with the anti-biofilm sequence FV7 embedded in the middle position of peptide RI16. The results demonstrated that the synthetic hybrid the peptide R-FV-I16 had potent antimicrobial activity over a wide range of Gram-negative and Gram-positive bacteria, as well as anti-biofilm activity. More importantly, R-FV-I16 showed lower hemolytic activity and cytotoxicity. Fluorescent assays demonstrated that R-FV-I16 depolarized the outer and the inner bacterial membranes, while scanning electron microscopy and transmission electron microscopy further indicated that this peptide killed bacterial cells by disrupting the cell membrane, thereby damaging membrane integrity. Results from SEM also provided evidence that R-FV-I16 inherited anti-biofilm activity from the functional peptide sequence FV7. Embedded-hybrid peptides could provide a new pattern for combining different functional domains and showing an effective avenue to screen for novel antimicrobial agents. PMID:24945359

A multi-fidelity framework for physics based rotor blade simulation and optimization

NASA Astrophysics Data System (ADS)

Collins, Kyle Brian

New helicopter rotor designs are desired that offer increased efficiency, reduced vibration, and reduced noise. Rotor Designers in industry need methods that allow them to use the most accurate simulation tools available to search for these optimal designs. Computer based rotor analysis and optimization have been advanced by the development of industry standard codes known as "comprehensive" rotorcraft analysis tools. These tools typically use table look-up aerodynamics, simplified inflow models and perform aeroelastic analysis using Computational Structural Dynamics (CSD). Due to the simplified aerodynamics, most design studies are performed varying structural related design variables like sectional mass and stiffness. The optimization of shape related variables in forward flight using these tools is complicated and results are viewed with skepticism because rotor blade loads are not accurately predicted. The most accurate methods of rotor simulation utilize Computational Fluid Dynamics (CFD) but have historically been considered too computationally intensive to be used in computer based optimization, where numerous simulations are required. An approach is needed where high fidelity CFD rotor analysis can be utilized in a shape variable optimization problem with multiple objectives. Any approach should be capable of working in forward flight in addition to hover. An alternative is proposed and founded on the idea that efficient hybrid CFD methods of rotor analysis are ready to be used in preliminary design. In addition, the proposed approach recognizes the usefulness of lower fidelity physics based analysis and surrogate modeling. Together, they are used with high fidelity analysis in an intelligent process of surrogate model building of parameters in the high fidelity domain. Closing the loop between high and low fidelity analysis is a key aspect of the proposed approach. This is done by using information from higher fidelity analysis to improve predictions made with lower fidelity models. This thesis documents the development of automated low and high fidelity physics based rotor simulation frameworks. The low fidelity framework uses a comprehensive code with simplified aerodynamics. The high fidelity model uses a parallel processor capable CFD/CSD methodology. Both low and high fidelity frameworks include an aeroacoustic simulation for prediction of noise. A synergistic process is developed that uses both the low and high fidelity frameworks together to build approximate models of important high fidelity metrics as functions of certain design variables. To test the process, a 4-bladed hingeless rotor model is used as a baseline. The design variables investigated include tip geometry and spanwise twist distribution. Approximation models are built for metrics related to rotor efficiency and vibration using the results from 60+ high fidelity (CFD/CSD) experiments and 400+ low fidelity experiments. Optimization using the approximation models found the Pareto Frontier anchor points, or the design having maximum rotor efficiency and the design having minimum vibration. Various Pareto generation methods are used to find designs on the frontier between these two anchor designs. When tested in the high fidelity framework, the Pareto anchor designs are shown to be very good designs when compared with other designs from the high fidelity database. This provides evidence that the process proposed has merit. Ultimately, this process can be utilized by industry rotor designers with their existing tools to bring high fidelity analysis into the preliminary design stage of rotors. In conclusion, the methods developed and documented in this thesis have made several novel contributions. First, an automated high fidelity CFD based forward flight simulation framework has been built for use in preliminary design optimization. The framework was built around an integrated, parallel processor capable CFD/CSD/AA process. Second, a novel method of building approximate models of high fidelity parameters has been developed. The method uses a combination of low and high fidelity results and combines Design of Experiments, statistical effects analysis, and aspects of approximation model management. And third, the determination of rotor blade shape variables through optimization using CFD based analysis in forward flight has been performed. This was done using the high fidelity CFD/CSD/AA framework and method mentioned above. While the low and high fidelity predictions methods used in the work still have inaccuracies that can affect the absolute levels of the results, a framework has been successfully developed and demonstrated that allows for an efficient process to improve rotor blade designs in terms of a selected choice of objective function(s). Using engineering judgment, this methodology could be applied today to investigate opportunities to improve existing designs. With improvements in the low and high fidelity prediction components that will certainly occur, this framework could become a powerful tool for future rotorcraft design work. (Abstract shortened by UMI.)

Comparative Measurements of Radon Concentration in Soil Using Passive and Active Methods in High Level Natural Radiation Area (HLNRA) of Ramsar

PubMed Central

Amanat, B; Kardan, M R; Faghihi, R; Hosseini Pooya, S M

2013-01-01

Background: Radon and its daughters are amongst the most important sources of natural exposure in the world. Soil is one of the significant sources of radon/thoron due to both radium and thorium so that the emanated thoron from it may cause increased uncertainties in radon measurements. Recently, a diffusion chamber has been designed and optimized for passive discriminative measurements of radon/thoron concentrations in soil. Objective: In order to evaluate the capability of the passive method, some comparative measurements (with active methods) have been performed. Method: The method is based upon measurements by a diffusion chamber, including two Lexan polycarbonate SSNTDs, which can discriminate the emanated radon/thorn from the soil by delay method. The comparative measurements have been done in ten selected points of HLNRA of Ramsar in Iran. The linear regression and correlation between the results of two methods have been studied. Results: The results show that the radon concentrations are within the range of 12.1 to 165 kBq/m3 values. The correlation between the results of active and passive methods was measured by 0.99 value. As well, the thoron concentrations have been measured between 1.9 to 29.5 kBq/m3 values at the points. Conclusion: The sensitivity as well as the strong correlation with active measurements shows that the new low-cost passive method is appropriate for accurate seasonal measurements of radon and thoron concentration in soil. PMID:25505760

32 CFR Appendix A to Part 169a - Codes and Definitions of Functional Areas

Code of Federal Regulations, 2011 CFR

2011-07-01

...) intermediate/direct/general maintenance performed by fixed activities that are not designed for deployment to combat areas and that provide direct support of organizations performing or designed to perform combat... commercial activities that are especially designed and constructed for the low-cost and efficient storage and...

32 CFR Appendix A to Part 169a - Codes and Definitions of Functional Areas

Code of Federal Regulations, 2010 CFR

2010-07-01

...) intermediate/direct/general maintenance performed by fixed activities that are not designed for deployment to combat areas and that provide direct support of organizations performing or designed to perform combat... commercial activities that are especially designed and constructed for the low-cost and efficient storage and...

32 CFR Appendix A to Part 169a - Codes and Definitions of Functional Areas

Code of Federal Regulations, 2012 CFR

2012-07-01

...) intermediate/direct/general maintenance performed by fixed activities that are not designed for deployment to combat areas and that provide direct support of organizations performing or designed to perform combat... commercial activities that are especially designed and constructed for the low-cost and efficient storage and...

32 CFR Appendix A to Part 169a - Codes and Definitions of Functional Areas

Code of Federal Regulations, 2014 CFR

2014-07-01

...) intermediate/direct/general maintenance performed by fixed activities that are not designed for deployment to combat areas and that provide direct support of organizations performing or designed to perform combat... commercial activities that are especially designed and constructed for the low-cost and efficient storage and...

32 CFR Appendix A to Part 169a - Codes and Definitions of Functional Areas

Code of Federal Regulations, 2013 CFR

2013-07-01

...) intermediate/direct/general maintenance performed by fixed activities that are not designed for deployment to combat areas and that provide direct support of organizations performing or designed to perform combat... commercial activities that are especially designed and constructed for the low-cost and efficient storage and...

A comparison of subjective and objective measures of physical activity from the Newcastle 85+ study.

PubMed

Innerd, Paul; Catt, Michael; Collerton, Joanna; Davies, Karen; Trenell, Michael; Kirkwood, Thomas B L; Jagger, Carol

2015-07-01

Little is known about physical activity (PA) in the very old, the fastest growing age group in the population. We aimed to examine the convergent validity of subjective and objective measures of PA in adults aged over 85 years. A total of 484 participants aged 87-89 years recruited to the Newcastle 85+ study completed a purpose-designed physical activity questionnaire (PAQ), which categorised participants as mildly active, moderately active and very active. Out of them, 337 participants wore a triaxial, raw accelerometer on the right wrist over a 5-7-day period to obtain objective measures of rest/activity, PA intensity and PA type. Data from subjective and objective measurement methods were compared. Self-reported PA was significantly associated with objective measures of the daily sedentary time, low-intensity PA and activity type classified as sedentary, activities of daily living and walking. Objective measures of PA were significantly different when low, moderate and high self-reported PA categories were compared (all P < 0.001). The Newcastle 85+ PAQ demonstrated convergent validity with objective measures of PA. Our findings suggest that this PAQ can be used in the very old to rank individuals according to their level of total PA. © The Author 2015. Published by Oxford University Press on behalf of the British Geriatrics Society.

Nonlinear damping based semi-active building isolation system

NASA Astrophysics Data System (ADS)

Ho, Carmen; Zhu, Yunpeng; Lang, Zi-Qiang; Billings, Stephen A.; Kohiyama, Masayuki; Wakayama, Shizuka

2018-06-01

Many buildings in Japan currently have a base-isolation system with a low stiffness that is designed to shift the natural frequency of the building below the frequencies of the ground motion due to earthquakes. However, the ground motion observed during the 2011 Tohoku earthquake contained strong long-period waves that lasted for a record length of 3 min. To provide a novel and better solution against the long-period waves while maintaining the performance of the standard isolation range, the exploitation of the characteristics of nonlinear damping is proposed in this paper. This is motivated by previous studies of the authors, which have demonstrated that nonlinear damping can achieve desired performance over both low and high frequency regions and the optimal nonlinear damping force can be realized by closed loop controlled semi-active dampers. Simulation results have shown strong vibration isolation performance on a building model with identified parameters and have indicated that nonlinear damping can achieve low acceleration transmissibilities round the structural natural frequency as well as the higher ground motion frequencies that have been frequently observed during most earthquakes in Japan. In addition, physical building model based laboratory experiments are also conducted, The results demonstrate the advantages of the proposed nonlinear damping technologies over both traditional linear damping and more advanced Linear-Quadratic Gaussian (LQG) feedback control which have been used in practice to address building isolation system design and implementation problems. In comparison with the tuned-mass damper and other active control methods, the proposed solution offers a more pragmatic, low-cost, robust and effective alternative that can be readily installed into the base-isolation system of most buildings.

Energy Intake and Energy Expenditure for Determining Excess Weight Gain in Pregnant Women

PubMed Central

Gilmore, L. Anne; Butte, Nancy F.; Ravussin, Eric; Han, Hongmei; Burton, Jeffrey H.; Redman, Leanne M.

2016-01-01

Objective To conduct a secondary analysis designed to test whether gestational weight gain is due to increased energy intake or adaptive changes in energy expenditures. Methods In this secondary analysis, energy intake and energy expenditure of 45 pregnant women (BMI 18.5–24.9 kg/m2, n=33 and BMI ≥ 25, n=12) were measured preconceptionally 22, and 36 weeks of gestation. Energy intake was calculated as the sum of total energy expenditure measured by doubly labeled water and energy deposition determined by the 4-compartment body composition model. Weight, body composition, and metabolic chamber measurement were completed preconceptionally, 9, 22, and 36 weeks of gestation. Basal metabolic rate was measured by indirect calorimetry in a room calorimeter and activity energy expenditure by doubly labeled water. Results Energy intake from 22 to 36 weeks of gestation was significantly higher in high gainers (n=19) (3437 ± 99 kcal/d) versus low + ideal gainers (n=26) (2687 ± 110 p< .001) within both BMI categories. Basal metabolic rate increased in proportion to gestational weight gain; however, basal metabolic rate adjusted for body composition changes with gestational weight gain was not significantly different between high gainers and low + ideal gainers (151 ± 33 vs. 129 ± 36 kcal/d; p=.66). Activity energy expenditure decreased throughout pregnancy in both groups (low + ideal gainers: −150 ± 70 kcal/d; p=.04 and high gainers: −230 ± 92 kcal/day; p=.01), but there was no difference between high gainers and low + ideal gainers (p=.49). Conclusion Interventions designed to increase adherence to the IOM guidelines for weight gain in pregnancy may have increased efficacy if focused on limiting energy intake while increasing nutrient density and maintaining levels of physical activity. PMID:27054928

Electricity generation from banana peels in an alkaline fuel cell with a Cu2O-Cu modified activated carbon cathode.

PubMed

Liu, Peng; Liu, Xianhua; Dong, Feng; Lin, Qingxia; Tong, Yindong; Li, Yang; Zhang, Pingping

2018-08-01

Low-cost and highly active catalyst for oxygen reduction reaction is of great importance in the design of alkaline fuel cells. In this work, Cu 2 O-Cu composite catalyst has been fabricated by a facile laser-irradiation method. The addition of Cu 2 O-Cu composite in activated carbon air-cathode greatly improves the performance of the cathode. Our results indicate the enhanced performance is likely attributed to the synergistic effect of high conductivity of Cu and the catalytic activity of Cu 2 O towards the oxygen reduction reaction. Furthermore, an alkaline fuel cell equipped with the composite air-cathode has been built to turn banana peels into electricity. Peak power density of 16.12Wm -2 is obtained under the condition of 3M KOH and 22.04gL -1 reducing sugar, which is higher than other reported low-temperature direct biomass alkaline fuel cells. HPLC results indicate the main oxidation products in the alkaline fuel cell were small organic acids. Copyright © 2018 Elsevier B.V. All rights reserved.

The Back 2 Activity Trial: education and advice versus education and advice plus a structured walking programme for chronic low back pain

PubMed Central

2010-01-01

Background Current evidence supports the use of exercise-based treatment for chronic low back pain that encourages the patient to assume an active role in their recovery. Walking has been shown it to be an acceptable type of exercise with a low risk of injury. However, it is not known whether structured physical activity programmes are any more effective than giving advice to remain active. Methods/Design The proposed study will test the feasibility of using a pedometer-driven walking programme, as an adjunct to a standard education and advice session in participants with chronic low back pain. Fifty adult participants will be recruited via a number of different sources. Baseline outcome measures including self reported function; objective physical activity levels; fear-avoidance beliefs and health-related quality of life will be recorded. Eligible participants will be randomly allocated under strict, double blind conditions to one of two treatments groups. Participants in group A will receive a single education and advice session with a physiotherapist based on the content of the 'Back Book'. Participants in group B will receive the same education and advice session. In addition, they will also receive a graded pedometer-driven walking programme prescribed by the physiotherapist. Follow up outcomes will be recorded by the same researcher, who will remain blinded to group allocation, at eight weeks and six months post randomisation. A qualitative exploration of participants' perception of walking will also be examined by use of focus groups at the end of the intervention. As a feasibility study, treatment effects will be represented by point estimates and confidence intervals. The assessment of participant satisfaction will be tabulated, as will adherence levels and any recorded difficulties or adverse events experienced by the participants or therapists. This information will be used to modify the planned interventions to be used in a larger randomised controlled trial. Discussion This paper describes the rationale and design of a study which will test the feasibility of using a structured, pedometer-driven walking programme in participants with chronic low back pain. Trial Registration [ISRCTN67030896] PMID:20633256

Decoding natural images from evoked brain activities using encoding models with invertible mapping.

PubMed

Li, Chao; Xu, Junhai; Liu, Baolin

2018-05-21

Recent studies have built encoding models in the early visual cortex, and reliable mappings have been made between the low-level visual features of stimuli and brain activities. However, these mappings are irreversible, so that the features cannot be directly decoded. To solve this problem, we designed a sparse framework-based encoding model that predicted brain activities from a complete feature representation. Moreover, according to the distribution and activation rules of neurons in the primary visual cortex (V1), three key transformations were introduced into the basic feature to improve the model performance. In this setting, the mapping was simple enough that it could be inverted using a closed-form formula. Using this mapping, we designed a hybrid identification method based on the support vector machine (SVM), and tested it on a published functional magnetic resonance imaging (fMRI) dataset. The experiments confirmed the rationality of our encoding model, and the identification accuracies for 2 subjects increased from 92% and 72% to 98% and 92% with the chance level only 0.8%. Copyright © 2018 Elsevier Ltd. All rights reserved.

Integrated active and passive control design methodology for the LaRC CSI evolutionary model

NASA Technical Reports Server (NTRS)

Voth, Christopher T.; Richards, Kenneth E., Jr.; Schmitz, Eric; Gehling, Russel N.; Morgenthaler, Daniel R.

1994-01-01

A general design methodology to integrate active control with passive damping was demonstrated on the NASA LaRC CSI Evolutionary Model (CEM), a ground testbed for future large, flexible spacecraft. Vibration suppression controllers designed for Line-of Sight (LOS) minimization were successfully implemented on the CEM. A frequency-shaped H2 methodology was developed, allowing the designer to specify the roll-off of the MIMO compensator. A closed loop bandwidth of 4 Hz, including the six rigid body modes and the first three dominant elastic modes of the CEM was achieved. Good agreement was demonstrated between experimental data and analytical predictions for the closed loop frequency response and random tests. Using the Modal Strain Energy (MSE) method, a passive damping treatment consisting of 60 viscoelastically damped struts was designed, fabricated and implemented on the CEM. Damping levels for the targeted modes were more than an order of magnitude larger than for the undamped structure. Using measured loss and stiffness data for the individual damped struts, analytical predictions of the damping levels were very close to the experimental values in the (1-10) Hz frequency range where the open loop model matched the experimental data. An integrated active/passive controller was successfully implemented on the CEM and was evaluated against an active-only controller. A two-fold increase in the effective control bandwidth and further reductions of 30 percent to 50 percent in the LOS RMS outputs were achieved compared to an active-only controller. Superior performance was also obtained compared to a High-Authority/Low-Authority (HAC/LAC) controller.

Active noise control: A tutorial for HVAC designers

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

Gelin, L.J.

1997-08-01

This article will identify the capabilities and limitations of ANC in its application to HVAC noise control. ANC can be used in ducted HVAC systems to cancel ductborne, low-frequency fan noise by injecting sound waves of equal amplitude and opposite phase into an air duct, as close as possible to the source of the unwanted noise. Destructive interference of the fan noise and injected noise results in sound cancellation. The noise problems that it solves are typically described as rumble, roar or throb, all of which are difficult to address using traditional noise control methods. This article will also contrastmore » the use of active against passive noise control techniques. The main differences between the two noise control measures are acoustic performance, energy consumption, and design flexibility. The article will first present the fundamentals and basic physics of ANC. The application to real HVAC systems will follow.« less

Globe rupture with post cataract-surgery safety sunglasses.

PubMed

Brooks, Clifford W; Howard, Robert C; Lyons, Robert A; Reilly, Charles D

2010-07-01

We report a case of globe rupture associated with the use of post cataract-surgery protective eyewear. The patient had routine cataract surgery 3 months before presentation and had adapted his post cataract-surgery glasses to use on the tennis court. He experienced a large posterior globe rupture after falling directly onto his face during a match. Spectacle torsion is the suspected biomechanical process that led to the rupture. We conclude that although the glasses given to many patients after cataract surgery are protective for most low-impact injuries, patients should be aware they are not designed for activities with a risk for significant impact. Patients should also be counseled to use protective eyewear specifically designed and approved for the sport or activity in which they participate. No author has a financial or proprietary interest in any material or method mentioned. Published by Elsevier Inc.

Micro-optical elements produced using an photo-embossing technique in photopolymers

NASA Astrophysics Data System (ADS)

O'Neill, Feidhlim T.; Rowsome, Ita C.; Carr, Alun J.; Daniels, Stephen M.; Gleeson, Michael R.; Kelly, John V.; Close, Ciara; Lawrence, Justin R.; Sheridan, John T.

2005-09-01

Micro-optical devices are very important in current high-tech consumer items. The development of future products depends on both the evolution of fabrication techniques and on the development of new low cost mass production methods. Polymers offer ease of fabrication and low cost and are therefore excellent materials for the development of micro-optical devices. Polymer optical devices include passive optical elements, such as microlens arrays and waveguides, as well as active devices such as polymer based lasers. One of the most important areas of micro-optics is that of microlens design, manufacture and testing. The wide diversity of fabrication methods used for the production of these elements indicates their importance. One of these fabrication techniques is photo-embossing. The use of the photo-embossing technique and a photopolymer holographic recording material will be examined in this paper. A discussion of current attempts to model the fabrication process and a review of the experimental method will be given.

Antimicrobial activity predictors benchmarking analysis using shuffled and designed synthetic peptides.

PubMed

Porto, William F; Pires, Állan S; Franco, Octavio L

2017-08-07

The antimicrobial activity prediction tools aim to help the novel antimicrobial peptides (AMP) sequences discovery, utilizing machine learning methods. Such approaches have gained increasing importance in the generation of novel synthetic peptides by means of rational design techniques. This study focused on predictive ability of such approaches to determine the antimicrobial sequence activities, which were previously characterized at the protein level by in vitro studies. Using four web servers and one standalone software, we evaluated 78 sequences generated by the so-called linguistic model, being 40 designed and 38 shuffled sequences, with ∼60 and ∼25% of identity to AMPs, respectively. The ab initio molecular modelling of such sequences indicated that the structure does not affect the predictions, as both sets present similar structures. Overall, the systems failed on predicting shuffled versions of designed peptides, as they are identical in AMPs composition, which implies in accuracies below 30%. The prediction accuracy is negatively affected by the low specificity of all systems here evaluated, as they, on the other hand, reached 100% of sensitivity. Our results suggest that complementary approaches with high specificity, not necessarily high accuracy, should be developed to be used together with the current systems, overcoming their limitations. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

James Schondel; Henry S. Chu

Lightweight panels have been designed to protect buildings and vehicles from blast pressures by activating energy dissipation mechanisms under the influence of blast loading. Panels were fabricated which featured a variety of granular materials and hydraulic dissipative deformation mechanisms and the test articles were subjected to full-scale blast loading. The force time-histories transmitted by each technology were measured by a novel method that utilized inexpensive custom-designed force sensors. The array of tests revealed that granular materials can effectively dissipate blast energy if they are employed in a way that they easily crush and rearrange. Similarly, hydraulic dissipation can effectively dissipatemore » energy if the panel features a high fraction of porosity and the panel encasement features low compressive stiffness.« less

QSAR-driven design, synthesis and discovery of potent chalcone derivatives with antitubercular activity.

PubMed

Gomes, Marcelo N; Braga, Rodolpho C; Grzelak, Edyta M; Neves, Bruno J; Muratov, Eugene; Ma, Rui; Klein, Larry L; Cho, Sanghyun; Oliveira, Guilherme R; Franzblau, Scott G; Andrade, Carolina Horta

2017-09-08

New anti-tuberculosis (anti-TB) drugs are urgently needed to battle drug-resistant Mycobacterium tuberculosis strains and to shorten the current 6-12-month treatment regimen. In this work, we have continued the efforts to develop chalcone-based anti-TB compounds by using an in silico design and QSAR-driven approach. Initially, we developed SAR rules and binary QSAR models using literature data for targeted design of new heteroaryl chalcone compounds with anti-TB activity. Using these models, we prioritized 33 compounds for synthesis and biological evaluation. As a result, 10 heteroaryl chalcone compounds (4, 8, 9, 11, 13, 17-20, and 23) were found to exhibit nanomolar activity against replicating mycobacteria, low micromolar activity against nonreplicating bacteria, and nanomolar and micromolar against rifampin (RMP) and isoniazid (INH) monoresistant strains (rRMP and rINH) (<1 μM and <10 μM, respectively). The series also show low activity against commensal bacteria and generally show good selectivity toward M. tuberculosis, with very low cytotoxicity against Vero cells (SI = 11-545). Our results suggest that our designed heteroaryl chalcone compounds, due to their high potency and selectivity, are promising anti-TB agents. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

A Rigidifying Salt-Bridge Favors the Activity of Thermophilic Enzyme at High Temperatures at the Expense of Low-Temperature Activity

PubMed Central

Lam, Sonia Y.; Yeung, Rachel C. Y.; Yu, Tsz-Ha; Sze, Kong-Hung; Wong, Kam-Bo

2011-01-01

Background Thermophilic enzymes are often less active than their mesophilic homologues at low temperatures. One hypothesis to explain this observation is that the extra stabilizing interactions increase the rigidity of thermophilic enzymes and hence reduce their activity. Here we employed a thermophilic acylphosphatase from Pyrococcus horikoshii and its homologous mesophilic acylphosphatase from human as a model to study how local rigidity of an active-site residue affects the enzymatic activity. Methods and Findings Acylphosphatases have a unique structural feature that its conserved active-site arginine residue forms a salt-bridge with the C-terminal carboxyl group only in thermophilic acylphosphatases, but not in mesophilic acylphosphatases. We perturbed the local rigidity of this active-site residue by removing the salt-bridge in the thermophilic acylphosphatase and by introducing the salt-bridge in the mesophilic homologue. The mutagenesis design was confirmed by x-ray crystallography. Removing the salt-bridge in the thermophilic enzyme lowered the activation energy that decreased the activation enthalpy and entropy. Conversely, the introduction of the salt-bridge to the mesophilic homologue increased the activation energy and resulted in increases in both activation enthalpy and entropy. Revealed by molecular dynamics simulations, the unrestrained arginine residue can populate more rotamer conformations, and the loss of this conformational freedom upon the formation of transition state justified the observed reduction in activation entropy. Conclusions Our results support the conclusion that restricting the active-site flexibility entropically favors the enzymatic activity at high temperatures. However, the accompanying enthalpy-entropy compensation leads to a stronger temperature-dependency of the enzymatic activity, which explains the less active nature of the thermophilic enzymes at low temperatures. PMID:21423654

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

Batchelor, D.B.; Carreras, B.A.; Hirshman, S.P.

Significant progress has been made in the development of new modest-size compact stellarator devices that could test optimization principles for the design of a more attractive reactor. These are 3 and 4 field period low-aspect-ratio quasi-omnigenous (QO) stellarators based on an optimization method that targets improved confinement, stability, ease of coil design, low-aspect-ratio, and low bootstrap current.

Design of 2.4Ghz CMOS Floating Active Inductor LNA using 130nm Technology

NASA Astrophysics Data System (ADS)

Muhamad, M.; Soin, N.; Ramiah, H.

2018-03-01

This paper presents about design and optimization of CMOS active inductor integrated circuit. This active inductor implements using Silterra 0.13μm technology and simulated using Cadence Virtuoso and Spectre RF. The center frequency for this active inductor is at 2.4 GHz which follow IEEE 802.11 b/g/n standard. To reduce the chip size of silicon, active inductor is used instead of passive inductor at low noise amplifier LNA circuit. This inductor test and analyse by low noise amplifier circuit. Comparison between active with passive inductor based on LNA circuit has been performed. Result shown that the active inductor has significantly reduce the chip size with 73 % area without sacrificing the noise figure and gain of LNA which is the most important criteria in LNA. The best low noise amplifier provides a power gain (S21) of 20.7 dB with noise figure (NF) of 2.1dB.

Rate-compatible protograph LDPC code families with linear minimum distance

NASA Technical Reports Server (NTRS)

Divsalar, Dariush (Inventor); Dolinar, Jr., Samuel J. (Inventor); Jones, Christopher R. (Inventor)

2012-01-01

Digital communication coding methods are shown, which generate certain types of low-density parity-check (LDPC) codes built from protographs. A first method creates protographs having the linear minimum distance property and comprising at least one variable node with degree less than 3. A second method creates families of protographs of different rates, all structurally identical for all rates except for a rate-dependent designation of certain variable nodes as transmitted or non-transmitted. A third method creates families of protographs of different rates, all structurally identical for all rates except for a rate-dependent designation of the status of certain variable nodes as non-transmitted or set to zero. LDPC codes built from the protographs created by these methods can simultaneously have low error floors and low iterative decoding thresholds.

Extreme triple asymmetric (ETAS) epitaxial designs for increased efficiency at high powers in 9xx-nm diode lasers

NASA Astrophysics Data System (ADS)

Kaul, T.; Erbert, G.; Maaßdorf, A.; Martin, D.; Crump, P.

2018-02-01

Broad area lasers that are tailored to be most efficient at the highest achievable optical output power are sought by industry to decrease operation costs and improve system performance. Devices using Extreme-Double-ASymmetric (EDAS) epitaxial designs are promising candidates for improved efficiency at high optical output powers due to low series resistance, low optical loss and low carrier leakage. However, EDAS designs leverage ultra-thin p-side waveguides, meaning that the optical mode is shifted into the n-side waveguide, resulting in a low optical confinement in the active region, low gain and hence high threshold current, limiting peak performance. We introduce here explicit design considerations that enable EDAS-based devices to be developed with increased optical confinement in the active layer without changing the p-side layer thicknesses. Specifically, this is realized by introducing a third asymmetric component in the vicinity of the quantum well. We call this approach Extreme-Triple-ASymmetric (ETAS) design. A series of ETAS-based vertical designs were fabricated into broad area lasers that deliver up to 63% power conversion efficiency at 14 W CW optical output power from a 100 μm stripe laser, which corresponds to the operation point of a kW optical output power in a laser bar. The design process, the impact of structural changes on power saturation mechanisms and finally devices with improved performance will be presented.

Design and Test of a Hybrid Foot Force Sensing and GPS System for Richer User Mobility Activity Recognition

PubMed Central

Zhang, Zelun; Poslad, Stefan

2013-01-01

Wearable and accompanied sensors and devices are increasingly being used for user activity recognition. However, typical GPS-based and accelerometer-based (ACC) methods face three main challenges: a low recognition accuracy; a coarse recognition capability, i.e., they cannot recognise both human posture (during travelling) and transportation mode simultaneously, and a relatively high computational complexity. Here, a new GPS and Foot-Force (GPS + FF) sensor method is proposed to overcome these challenges that leverages a set of wearable FF sensors in combination with GPS, e.g., in a mobile phone. User mobility activities that can be recognised include both daily user postures and common transportation modes: sitting, standing, walking, cycling, bus passenger, car passenger (including private cars and taxis) and car driver. The novelty of this work is that our approach provides a more comprehensive recognition capability in terms of reliably recognising both human posture and transportation mode simultaneously during travel. In addition, by comparing the new GPS + FF method with both an ACC method (62% accuracy) and a GPS + ACC based method (70% accuracy) as baseline methods, it obtains a higher accuracy (95%) with less computational complexity, when tested on a dataset obtained from ten individuals. PMID:24189333

Ultima Replicated Optics Research

NASA Technical Reports Server (NTRS)

Hadaway, James; Engelhaupt, Darell

1997-01-01

Designs are reviewed incorporating processes suitable for replication of precision spherical segments of very large (greater than 20 meter diameter) telescopes combining ultra-lightweight and high precision. These designs must be amenable to assembly and alignment after deployment . The methods considered lie outside the present scope of fabrication, deployment and alignment considered to date. Design guidelines for reducing the weight and low frequency resonance in low G environment were given by The Serius Group, Dr. Glenn Zeiders, and are considered baseline for this activity. The goal of a rigid design of 10 Kg/sq M is being persued for the Next Generation Space Telescope (NGST) and is not likely adequate for advanced efforts. Flexures have been considered for maintaining the figure of many lightweight structures by control loop processes. This adds to the complexity and weight to the extent that it becomes difficult to recover the benefits. Two fabrication guidelines lead to a stiffer and concurrently lighter structure. First the use of thin vertical wall triangular structural reinforcements to increase the resistance to bending is preferred over hexagonal or square similar sections. Secondly, the incorporation of a similar back sheet on a cellular structure markedly improves the geometric stiffness. Neither improves the short range stiffness. Also often overlooked is that selected material properties must include high microyield and low hysteresis in addition to high elastic modulus to weight (stiffness). The fabrication steps can easily exceed the strain requirement.

Low-Cost Optical Mapping Systems for Panoramic Imaging of Complex Arrhythmias and Drug-Action in Translational Heart Models

NASA Astrophysics Data System (ADS)

Lee, Peter; Calvo, Conrado J.; Alfonso-Almazán, José M.; Quintanilla, Jorge G.; Chorro, Francisco J.; Yan, Ping; Loew, Leslie M.; Filgueiras-Rama, David; Millet, José

2017-02-01

Panoramic optical mapping is the primary method for imaging electrophysiological activity from the entire outer surface of Langendorff-perfused hearts. To date, it is the only method of simultaneously measuring multiple key electrophysiological parameters, such as transmembrane voltage and intracellular free calcium, at high spatial and temporal resolution. Despite the impact it has already had on the fields of cardiac arrhythmias and whole-heart computational modeling, present-day system designs precludes its adoption by the broader cardiovascular research community because of their high costs. Taking advantage of recent technological advances, we developed and validated low-cost optical mapping systems for panoramic imaging using Langendorff-perfused pig hearts, a clinically-relevant model in basic research and bioengineering. By significantly lowering financial thresholds, this powerful cardiac electrophysiology imaging modality may gain wider use in research and, even, teaching laboratories, which we substantiated using the lower-cost Langendorff-perfused rabbit heart model.

Low-Cost Optical Mapping Systems for Panoramic Imaging of Complex Arrhythmias and Drug-Action in Translational Heart Models.

PubMed

Lee, Peter; Calvo, Conrado J; Alfonso-Almazán, José M; Quintanilla, Jorge G; Chorro, Francisco J; Yan, Ping; Loew, Leslie M; Filgueiras-Rama, David; Millet, José

2017-02-27

Panoramic optical mapping is the primary method for imaging electrophysiological activity from the entire outer surface of Langendorff-perfused hearts. To date, it is the only method of simultaneously measuring multiple key electrophysiological parameters, such as transmembrane voltage and intracellular free calcium, at high spatial and temporal resolution. Despite the impact it has already had on the fields of cardiac arrhythmias and whole-heart computational modeling, present-day system designs precludes its adoption by the broader cardiovascular research community because of their high costs. Taking advantage of recent technological advances, we developed and validated low-cost optical mapping systems for panoramic imaging using Langendorff-perfused pig hearts, a clinically-relevant model in basic research and bioengineering. By significantly lowering financial thresholds, this powerful cardiac electrophysiology imaging modality may gain wider use in research and, even, teaching laboratories, which we substantiated using the lower-cost Langendorff-perfused rabbit heart model.

The design and synthesis of new synthetic low molecular weight heparins

PubMed Central

Chandarajoti, K.; Liu, J.; Pawlinski, R.

2016-01-01

Low molecular weight heparins (LMWH) have remained the most favorable form of heparin in clinics since 1990s’ owing to its predictable pharmacokinetic properties. However, LMWH is mainly eliminated through kidney, thus limits its use in renal-impaired patients. In addition, the anticoagulant activity of LMWH is only partially neutralized by protamine. LMWH is obtained from a full-length, highly sulfated polysaccharide harvested from porcine mucosal tissue. The depolymerization involved in LMWH production generates a broad size distribution of LMWH fragments (6-22 sugar residues). This, combined with the various methods used to produce commercial LMWHs, result in variable pharmacological and pharmacokinetic properties. An alternative, chemoenzymatic approach offers a method for the synthesis of LMWH that has the potential to overcome the limitations of current LMWHs. This review summarizes the application of a chemoenzymatic approach to generate LMWH and the rationale for development of a synthetic LMWH. PMID:26990516

The design and synthesis of new synthetic low-molecular-weight heparins.

PubMed

Chandarajoti, K; Liu, J; Pawlinski, R

2016-06-01

Low-molecular-weight heparin (LMWH) has remained the most favorable form of heparin in clinics since the 1990s owing to its predictable pharmacokinetic properties. However, LMWH is mainly eliminated through the kidney, which limits its use in renal-impaired patients. In addition, the anticoagulant activity of LMWH is only partially neutralized by protamine. LMWH is obtained from a full-length, highly sulfated polysaccharide harvested from porcine mucosal tissue. The depolymerization involved in LMWH production generates a broad distribution of LMWH fragments (6-22 sugar residues). This, combined with the various methods used to produce commercial LMWHs, results in variable pharmacological and pharmacokinetic properties. An alternative chemoenzymatic approach offers a method for the synthesis of LMWH that has the potential to overcome the limitations of current LMWHs. This review summarizes the application of a chemoenzymatic approach to generate LMWH and the rationale for development of a synthetic LMWH. © 2016 International Society on Thrombosis and Haemostasis.

Reduction in Purchases of Sugar-Sweetened Beverages Among Low-Income Black Adolescents After Exposure to Caloric Information

PubMed Central

Herring, Bradley J.; Flagg, Desmond D.; Gary-Webb, Tiffany L.

2012-01-01

Objectives. We examined the effect of an intervention to provide caloric information about sugar-sweetened beverages (SSBs) on the number of SSB purchases. Methods. We used a case-crossover design with 4 corner stores located in low-income, predominately Black neighborhoods in Baltimore, Maryland. The intervention randomly posted 1 of 3 signs with the following caloric information: (1) absolute caloric count, (2) percentage of total recommended daily intake, and (3) physical activity equivalent. We collected data for 1600 beverage sales by Black adolescents, aged 12–18 years, including 400 during a baseline period and 400 for each of the 3 caloric condition interventions. Results. Providing Black adolescents with any caloric information significantly reduced the odds of SSB purchases relative to the baseline (odds ratio [OR] = 0.56; 95% confidence interval [CI] = 0.36, 0.89). When examining the 3 caloric conditions separately, the significant effect was observed when caloric information was provided as a physical activity equivalent (OR = 0.51; 95% CI = 0.31, 0.85). Conclusions. Providing easily understandable caloric information—particularly a physical activity equivalent—may reduce calorie intake from SSBs among low-income, Black adolescents. PMID:22390447

Dean Flow Dynamics in Low-Aspect Ratio Spiral Microchannels

PubMed Central

Nivedita, Nivedita; Ligrani, Phillip; Papautsky, Ian

2017-01-01

A wide range of microfluidic cell-sorting devices has emerged in recent years, based on both passive and active methods of separation. Curvilinear channel geometries are often used in these systems due to presence of secondary flows, which can provide high throughput and sorting efficiency. Most of these devices are designed on the assumption of two counter rotating Dean vortices present in the curved rectangular channels and existing in the state of steady rotation and amplitude. In this work, we investigate these secondary flows in low aspect ratio spiral rectangular microchannels and define their development with respect to the channel aspect ratio and Dean number. This work is the first to experimentally and numerically investigate Dean flows in microchannels for Re > 100, and show presence of secondary Dean vortices beyond a critical Dean number. We further demonstrate the impact of these multiple vortices on particle and cell focusing. Ultimately, this work offers new insights into secondary flow instabilities for low-aspect ratio, spiral microchannels, with improved flow models for design of more precise and efficient microfluidic devices for applications such as cell sorting and micromixing. PMID:28281579

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

Aalseth, Craig E.; Day, Anthony R.; Fuller, Erin S.

Abstract A new ultra-low-background proportional counter (ULBPC) design was recently developed at Pacific Northwest National Laboratory (PNNL). This design, along with an ultra-low-background counting system (ULBCS) which provides passive and active shielding with radon exclusion, has been developed to complement a new shallow underground laboratory (~30 meters water-equivalent) constructed at PNNL. After these steps to mitigate dominant backgrounds (cosmic rays, external gamma-rays, radioactivity in materials), remaining background events do not exclusively arise from ionization of the proportional counter gas. Digital pulse-shape discrimination (PSD) is thus employed to further improve measurement sensitivity. In this work, a template shape is generated formore » each individual sample measurement of interest, a "self-calibrating" template. Differences in event topology can also cause differences in pulse shape. In this work, the temporal region analyzed for each event is refined to maximize background discrimination while avoiding unwanted sensitivity to event topology. This digital PSD method is applied to sample and background data, and initial measurement results from a biofuel methane sample are presented in the context of low-background measurements currently being developed.« less

Conditional genomic rearrangement by designed meiotic recombination using VDE (PI-SceI) in yeast.

PubMed

Fukuda, Tomoyuki; Ohya, Yoshikazu; Ohta, Kunihiro

2007-10-01

Meiotic recombination plays critical roles in the acquisition of genetic diversity and has been utilized for conventional breeding of livestock and crops. The frequency of meiotic recombination is normally low, and is extremely low in regions called "recombination cold domains". Here, we describe a new and highly efficient method to modulate yeast meiotic gene rearrangements using VDE (PI-SceI), an intein-encoded endonuclease that causes an efficient unidirectional meiotic gene conversion at its recognition sequence (VRS). We designed universal targeting vectors, by use of which the strain that inserts the VRS at a desired site is acquired. Meiotic induction of the strains provided unidirectional gene conversions and frequent genetic rearrangements of flanking genes with little impact on cell viability. This system thus opens the way for the designed modulation of meiotic gene rearrangements, regardless of recombinational activity of chromosomal domains. Finally, the VDE-VRS system enabled us to conduct meiosis-specific conditional knockout of genes where VDE-initiated gene conversion disrupts the target gene during meiosis, serving as a novel approach to examine the functions of genes during germination of resultant spores.

Design of a cardiac monitor in terms of parameters of QRS complex.

PubMed

Chen, Zhen-cheng; Ni, Li-li; Su, Ke-ping; Wang, Hong-yan; Jiang, Da-zong

2002-08-01

Objective. To design a portable cardiac monitor system based on the available ordinary ECG machine and works on the basis of QRS parameters. Method. The 80196 single chip microcomputer was used as the central microprocessor and real time electrocardiac signal was collected and analyzed [correction of analysized] in the system. Result. Apart from the performance of an ordinary monitor, this machine possesses also the following functions: arrhythmia analysis, HRV analysis, alarm, freeze, and record of automatic papering. Convenient in carrying, the system is powered by AC or DC sources. Stability, low power and low cost are emphasized in the hardware design; and modularization method is applied in software design. Conclusion. Popular in usage and low cost made the portable monitor system suitable for use under simple conditions.

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

Klesmith, Justin R.; Bacik, John -Paul; Michalczyk, Ryszard

Synthetic metabolic pathways often suffer from low specific productivity, and new methods that quickly assess pathway functionality for many thousands of variants are urgently needed. Here we present an approach that enables the rapid and parallel determination of sequence effects on flux for complete gene-encoding sequences. We show that this method can be used to determine the effects of over 8000 single point mutants of a pyrolysis oil catabolic pathway implanted in Escherichia coli. Experimental sequence-function data sets predicted whether fitness-enhancing mutations to the enzyme levoglucosan kinase resulted from enhanced catalytic efficiency or enzyme stability. A structure of one designmore » incorporating 38 mutations elucidated the structural basis of high fitness mutations. One design incorporating 15 beneficial mutations supported a 15-fold improvement in growth rate and greater than 24-fold improvement in enzyme activity relative to the starting pathway. Lastly, this technique can be extended to improve a wide variety of designed pathways.« less

Perceived body discomfort and trunk muscle activity in three prolonged sitting postures

PubMed Central

Waongenngarm, Pooriput; Rajaratnam, Bala S.; Janwantanakul, Prawit

2015-01-01

[Purpose] This study aimed to investigate the perceived discomfort and trunk muscle activity in three different 1-hour sitting postures. [Subjects] A repeated-measures design study was conducted on 10 healthy subjects. [Methods] Each subject sat for an hour in three sitting postures (i.e., upright, slumped, and forward leaning sitting postures). Subjects rated perceived body discomfort using Borg’s CR-10 scale at the beginning and after 1 hour sitting. The electromyographic activity of the trunk muscle activity was recorded during the 1-hour period of sitting. [Results] The forward leaning sitting posture led to higher Borg scores in the low back than those in the upright (p = 0.002) and slumped sitting postures (p < 0.001). The forward leaning posture was significantly associated with increased iliocostalis lumborum pars thoracis (ICL) and superficial lumbar multifidus (MF) muscle activity compared with the upright and slumped sitting postures. The upright sitting posture was significantly associated with increased internal oblique (IO)/transversus abdominis (TrA) and ICL muscle activity compared with the slumped sitting posture. [Conclusion] The sitting posture with the highest low back discomfort after prolonged sitting was the forward leaning posture. Sitting in an upright posture is recommended because it increases IO/TrA muscle activation and induces only relatively moderate ICL and MF muscle activation. PMID:26311951

Participatory design of healthcare technology with children.

PubMed

Sims, Tara

2018-02-12

Purpose There are many frameworks and methods for involving children in design research. Human-Computer Interaction provides rich methods for involving children when designing technologies. The paper aims to discuss these issues. Design/methodology/approach This paper examines various approaches to involving children in design, considering whether users view children as study objects or active participants. Findings The BRIDGE method is a sociocultural approach to product design that views children as active participants, enabling them to contribute to the design process as competent and resourceful partners. An example is provided, in which BRIDGE was successfully applied to developing upper limb prostheses with children. Originality/value Approaching design in this way can provide children with opportunities to develop social, academic and design skills and to develop autonomy.

Calibration of an Ultra-Low-Background Proportional Counter for Measuring 37Ar

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

Seifert, Allen; Aalseth, Craig E.; Bonicalzi, Ricco

Abstract. An ultra-low-background proportional counter (ULBPC) design has been developed at Pacific Northwest National Laboratory (PNNL) using clean materials, primarily electrochemically-purified copper. This detector, along with an ultra-low-background counting system (ULBCS), was developed to complement a new shallow underground laboratory (30 meters water-equivalent) constructed at PNNL. The ULBCS design includes passive neutron and gamma shielding, along with an active cosmic-veto system. This system provides a capability for making ultra-sensitive measurements to support applications like age-dating soil hydrocarbons with 14C/3H, age-dating of groundwater with 39Ar, and soil-gas assay for 37Ar to support On-Site Inspection (OSI). On-Site Inspection is a key componentmore » of the verification regime for the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Measurements of radionuclides created by an underground nuclear explosion are valuable signatures of a Treaty violation. For OSI, the 35-day half-life of 37Ar, produced from neutron interactions with calcium in soil, provides both high specific activity and sufficient time for inspection before decay limits sensitivity. This work describes the calibration techniques and analysis methods developed to enable quantitative measurements of 37Ar samples over a broad range of pressures. These efforts, along with parallel work in progress on gas chemistry separation, are expected to provide a significant new capability for 37Ar soil gas background studies.« less

Conceptual design of the SMART dosimeter

NASA Astrophysics Data System (ADS)

Johnson, Erik B.; Vogel, Sam; Frank, Rebecca; Stoddard, Graham; Vera, Alonzo; Alexander, David; Christian, James

2017-08-01

Active dosimeters for astronauts and space weather monitors are critical tools for mitigating radiation induced health issues or system failure on capital equipment. Commercial spaceflight, deep space flight, and satellites require smarter, smaller, and lower power dosimeters. There are a number of instruments with flight heritage, yet as identified in NASA's roadmaps, these technologies do not lend themselves to a viable solution for active dosimetry for an astronaut, particularly for deep space missions. For future missions, nano- and micro-satellites will require compact instruments that will accurately assess the radiation hazard without consuming major resources on the spacecraft. RMD has developed the methods for growing an advanced scintillation material called phenylcarbazole, which provides pulse shape discrimination between protons and electrons. When used in combination with an anti-coincidence detector system, an assessment of the dose from charged ions and neutral particles can be determined. This is valuable as damage on a system (such as silicon or tissue) is dependent on the particle species. Using this crystal with readout electronics developed in partnership with COSMIAC at the University of New Mexico, the design of the Small Mixed field Autonomous Radiation Tracker (SMART) Dosimeter consists of a low-power analog to digital conversion scheme with low-power digital signal processing algorithms, which are to be implemented within a compact system on a chip, such as the Xilinx Zynq series. A review of the conceptual design is presented.

[Synthetic duration curve method for the design of the lowest navigable water level with inconsistent characters in dry seasons].

PubMed

Zhao, Jiang Yan; Xie, Ping; Sang, Yan Fang; Xui, Qiang Qiang; Wu, Zi Yi

2018-04-01

Under the influence of both global climate change and frequent human activities, the variability of second-moment in hydrological time series become obvious, indicating changes in the consistency of hydrological data samples. Therefore, the traditional hydrological series analysis methods, which only consider the variability of mean values, are not suitable for handling all hydrological non-consistency problems. Traditional synthetic duration curve methods for the design of the lowest navigable water level, based on the consistency of samples, would cause more risks to navigation, especially under low water level in dry seasons. Here, we detected both mean variation and variance variation using the hydrological variation diagnosis system. Furthermore, combing the principle of decomposition and composition of time series, we proposed the synthetic duration curve method for designing the lowest navigable water level with inconsistent characters in dry seasons. With the Yunjinghong Station in the Lancang River Basin as an example, we analyzed its designed water levels in the present, the distant past and the recent past, as well as the differences among three situations (i.e., considering second moment variation, only considering mean variation, not considering any variation). Results showed that variability of the second moment changed the trend of designed water levels alteration in the Yunjinghong Station. When considering the first two moments or just considering the mean variation, the difference ofdesigned water levels was as bigger as -1.11 m. When considering the first two moments or not, the difference of designed water levels was as bigger as -1.01 m. Our results indicated the strong effects of variance variation on the designed water levels, and highlighted the importance of the second moment variation analysis for the channel planning and design.

Minimally Clinically Important Change in the Activity Measure for Post-Acute Care (AM-PAC), a Generic Patient-Reported Outcome Tool, in People With Low Back Pain.

PubMed

Lee, Natalie; Thompson, Nicolas R; Passek, Sandra; Stilphen, Mary; Katzan, Irene L

2017-11-01

The Activity Measure for Post-Acute Care (AM-PAC) is a generic metric of patient-reported functional status. The minimal clinically important difference (MCID) in the AM-PAC score has not been determined. The study objective was to determine the MCID for AM-PAC in people with low back pain. This was a retrospective cohort study. Anchor-based and distribution-based methods were used to estimate the MCID. The Modified Low Back Pain Disability Questionnaire was used as the anchor. Adults who had a primary ICD-9 code for low back pain in at least 1 outpatient physical therapist visit during an episode of care and who completed both the AM-PAC and the Modified Low Back Pain Disability Questionnaire in at least 2 visits during the care episode were included. The MCID was calculated for the AM-PAC basic mobility version as well its adapted version, which the Cleveland Clinic uses for patients 65 years old or older. A total of 1,271 participants were eligible for study. For the AM-PAC basic mobility version, anchor-based methods yielded MCID estimates of between 3.4 and 5.1, whereas distribution-based methods yielded estimates of 1.7 to 4.2. The minimal detectable change (MDC) for the AM-PAC basic mobility version was 3.3. For the adapted AM-PAC basic mobility version, the MCID was estimated to be between 2.9 and 4.0 via anchor-based methods and between 1.2 to 3.5 via distribution-based methods. The MDC for the adapted AM-PAC basic mobility version was 3.5. The estimated MCID was designed for people with low back pain only. The MCID ranged from 3.3 to 5.1 for the AM-PAC basic mobility version and 3.5 to 4 for the adapted version, with the MDC as the lower limit. Changes in the AM-PAC for people with low back pain may be interpreted using the estimated MCID. Future studies are needed to determine the AM-PAC MCID for populations other than those with low back pain. © 2017 American Physical Therapy Association

Multimodal microscopy and the stepwise multi-photon activation fluorescence of melanin

NASA Astrophysics Data System (ADS)

Lai, Zhenhua

The author's work is divided into three aspects: multimodal microscopy, stepwise multi-photon activation fluorescence (SMPAF) of melanin, and customized-profile lenses (CPL) for on-axis laser scanners, which will be introduced respectively. A multimodal microscope provides the ability to image samples with multiple modalities on the same stage, which incorporates the benefits of all modalities. The multimodal microscopes developed in this dissertation are the Keck 3D fusion multimodal microscope 2.0 (3DFM 2.0), upgraded from the old 3DFM with improved performance and flexibility, and the multimodal microscope for targeting small particles (the "Target" system). The control systems developed for both microscopes are low-cost and easy-to-build, with all components off-the-shelf. The control system have not only significantly decreased the complexity and size of the microscope, but also increased the pixel resolution and flexibility. The SMPAF of melanin, activated by a continuous-wave (CW) mode near-infrared (NIR) laser, has potential applications for a low-cost and reliable method of detecting melanin. The photophysics of melanin SMPAF has been studied by theoretical analysis of the excitation process and investigation of the spectra, activation threshold, and photon number absorption of melanin SMPAF. SMPAF images of melanin in mouse hair and skin, mouse melanoma, and human black and white hairs are compared with images taken by conventional multi-photon fluorescence microscopy (MPFM) and confocal reflectance microscopy (CRM). SMPAF images significantly increase specificity and demonstrate the potential to increase sensitivity for melanin detection compared to MPFM images and CRM images. Employing melanin SMPAF imaging to detect melanin inside human skin in vivo has been demonstrated, which proves the effectiveness of melanin detection using SMPAF for medical purposes. Selective melanin ablation with micrometer resolution has been presented using the Target system. Compared to the traditional selective photothermolysis, this method demonstrates higher precision, higher specificity and deeper penetration. Therefore, the SMPAF guided selective ablation of melanin is a promising tool of removing melanin for both medical and cosmetic purposes. Three CPLs have been designed for low-cost linear-motion scanners, low-cost fast spinning scanners and high-precision fast spinning scanners. Each design has been tailored to the industrial manufacturing ability and market demands.

Robust, synergistic regulation of human gene expression using TALE activators.

PubMed

Maeder, Morgan L; Linder, Samantha J; Reyon, Deepak; Angstman, James F; Fu, Yanfang; Sander, Jeffry D; Joung, J Keith

2013-03-01

Artificial activators designed using transcription activator-like effector (TALE) technology have broad utility, but previous studies suggest that these monomeric proteins often exhibit low activities. Here we demonstrate that TALE activators can robustly function individually or in synergistic combinations to increase expression of endogenous human genes over wide dynamic ranges. These findings will encourage applications of TALE activators for research and therapy, and guide design of monomeric TALE-based fusion proteins.

Comparison of three methods reducing the beam parameter product of a laser diode stack for long range laser illumination applications

NASA Astrophysics Data System (ADS)

Lutz, Yves; Poyet, Jean-Michel; Metzger, Nicolas

2013-10-01

Laser diode stacks are interesting laser sources for active imaging illuminators. They allow the accumulation of large amounts of energy in multi-pulse mode, which is well suited for long-range image recording. Even when laser diode stacks are equipped with fast-axis collimation (FAC) and slow-axis collimation (SAC) microlenses, their beam parameter product (BPP) are not compatible with a direct use in highly efficient and compact illuminators. This is particularly true when narrow divergences are required such as for long range applications. To overcome these difficulties, we conducted investigations in three different ways. A first near infrared illuminator based on the use of conductively cooled mini-bars was designed, realized and successfully tested during outdoor experimentations. This custom specified stack was then replaced in a second step by an off-the-shelf FAC + SAC micro lensed stack where the brightness was increased by polarization overlapping. The third method still based on a commercial laser diode stack uses a non imaging optical shaping principle resulting in a virtually restacked laser source with enhanced beam parameters. This low cost, efficient and low alignment sensitivity beam shaping method allows obtaining a compact and high performance laser diode illuminator for long range active imaging applications. The three methods are presented and compared in this paper.

The "Interval Walking in Colorectal Cancer" (I-WALK-CRC) study: Design, methods and recruitment results of a randomized controlled feasibility trial.

PubMed

Banck-Petersen, Anna; Olsen, Cecilie K; Djurhuus, Sissal S; Herrstedt, Anita; Thorsen-Streit, Sarah; Ried-Larsen, Mathias; Østerlind, Kell; Osterkamp, Jens; Krarup, Peter-Martin; Vistisen, Kirsten; Mosgaard, Camilla S; Pedersen, Bente K; Højman, Pernille; Christensen, Jesper F

2018-03-01

Low physical activity level is associated with poor prognosis in patients with colorectal cancer (CRC). To increase physical activity, technology-based platforms are emerging and provide intriguing opportunities to prescribe and monitor active lifestyle interventions. The "Interval Walking in Colorectal Cancer"(I-WALK-CRC) study explores the feasibility and efficacy a home-based interval-walking intervention delivered by a smart-phone application in order to improve cardio-metabolic health profile among CRC survivors. The aim of the present report is to describe the design, methods and recruitment results of the I-WALK-CRC study.Methods/Results: The I-WALK-CRC study is a randomized controlled trial designed to evaluate the feasibility and efficacy of a home-based interval walking intervention compared to a waiting-list control group for physiological and patient-reported outcomes. Patients who had completed surgery for local stage disease and patients who had completed surgery and any adjuvant chemotherapy for locally advanced stage disease were eligible for inclusion. Between October 1st , 2015, and February 1st , 2017, 136 inquiries were recorded; 83 patients were eligible for enrollment, and 42 patients accepted participation. Age and employment status were associated with participation, as participants were significantly younger (60.5 vs 70.8 years, P < 0.001) and more likely to be working (OR 5.04; 95%CI 1.96-12.98, P < 0.001) than non-participants. In the present study, recruitment of CRC survivors was feasible but we aim to better the recruitment rate in future studies. Further, the study clearly favored younger participants. The I-WALK-CRC study will provide important information regarding feasibility and efficacy of a home-based walking exercise program in CRC survivors.

Method and apparatus for real time imaging and monitoring of radiotherapy beams

DOEpatents

Majewski, Stanislaw [Yorktown, VA; Proffitt, James [Newport News, VA; Macey, Daniel J [Birmingham, AL; Weisenberger, Andrew G [Yorktown, VA

2011-11-01

A method and apparatus for real time imaging and monitoring of radiation therapy beams is designed to preferentially distinguish and image low energy radiation from high energy secondary radiation emitted from a target as the result of therapeutic beam deposition. A detector having low sensitivity to high energy photons combined with a collimator designed to dynamically image in the region of the therapeutic beam target is used.

78 FR 20299 - National Institute on Disability and Rehabilitation Research; Long-Range Plan for Fiscal Years...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-04

... well-designed research and development activities using a range of appropriate methods. Adopt stages-of... research and development activities using a range of appropriate methods. Objective 2.1--Adopt a stages-of... range of well-designed research methods using a stages-of-research framework. When inviting applications...

Strain improvement studies on Microbacterium foliorum GA2 for production of α-amylase in solid state fermentation: Biochemical characteristics and wash performance analysis at low temperatures.

PubMed

Roohi; Kuddus, Mohammed

2018-01-15

Microbacterium foliorum GA2, an alkali-tolerant bacterium, was randomly mutated using UV radiation and sodium azide to obtain a mutant with a higher cold-active extracellular amylolytic activity. A mutant, designated as MFSD20, was selected owing to its higher amylase activity at 20°C. Under optimized conditions, amylase production was achieved best with raw banana peels (5000 units) in solid-state fermentation (SSF). The enzyme was purified by salt precipitation and chromatographic methods and afterwards characterized biochemically. The purified enzyme showed maximal activity at temperatures between 15-25°C and at pH 8.0. Interestingly, this mutant biocatalyst (MFSD20) displays higher catalytic activity under conditions of low temperature (4°C) and high pH (10.0), in the presence of SDS (0.1 and 1%), and exhibited 85% and 50% requirement of divalent metallic ions Ca 2+ and Mg 2+ , respectively. This mutant enzyme extract in combination with "Wheel detergent" was highly effective in the removal of tomato sauce and chocolate stains from white cotton fabric was demonstrated by ~50% additional reflectance compared with detergent alone, in a wash performance analysis at 20 ± 2°C. The features shown by mutant M. foliorum GA2 make it a promising candidate for industrial applications involving starch degradation at low temperatures.

Development and Characterization of a High Sensitivity Segmented Fast Neutron Spectrometer (FaNS-2)

PubMed Central

Langford, T.J.; Beise, E.J.; Breuer, H.; Heimbach, C.R.; Ji, G.; Nico, J.S.

2016-01-01

We present the development of a segmented fast neutron spectrometer (FaNS-2) based upon plastic scintillator and 3He proportional counters. It was designed to measure both the flux and spectrum of fast neutrons in the energy range of few MeV to 1 GeV. FaNS-2 utilizes capture-gated spectroscopy to identify neutron events and reject backgrounds. Neutrons deposit energy in the plastic scintillator before capturing on a 3He nucleus in the proportional counters. Segmentation improves neutron energy reconstruction while the large volume of scintillator increases sensitivity to low neutron fluxes. A main goal of its design is to study comparatively low neutron fluxes, such as cosmogenic neutrons at the Earth's surface, in an underground environment, or from low-activity neutron sources. In this paper, we present details of its design and construction as well as its characterization with a calibrated 252Cf source and monoenergetic neutron fields of 2.5 MeV and 14 MeV. Detected monoenergetic neutron spectra are unfolded using a Singular Value Decomposition method, demonstrating a 5% energy resolution at 14 MeV. Finally, we discuss plans for measuring the surface and underground cosmogenic neutron spectra with FaNS-2. PMID:27226807

DESIGN OF MEDICAL RADIOMETER FRONT-END FOR IMPROVED PERFORMANCE

PubMed Central

Klemetsen, Ø.; Birkelund, Y.; Jacobsen, S. K.; Maccarini, P. F.; Stauffer, P. R.

2011-01-01

We have investigated the possibility of building a singleband Dicke radiometer that is inexpensive, small-sized, stable, highly sensitive, and which consists of readily available microwave components. The selected frequency band is at 3.25–3.75 GHz which provides a reasonable compromise between spatial resolution (antenna size) and sensing depth for radiometry applications in lossy tissue. Foreseen applications of the instrument are non-invasive temperature monitoring for breast cancer detection and temperature monitoring during heating. We have found off-the-shelf microwave components that are sufficiently small (< 5 mm × 5 mm) and which offer satisfactory overall sensitivity. Two different Dicke radiometers have been realized: one is a conventional design with the Dicke switch at the front-end to select either the antenna or noise reference channels for amplification. The second design places a matched pair of low noise amplifiers in front of the Dicke switch to reduce system noise figure. Numerical simulations were performed to test the design concepts before building prototype PCB front-end layouts of the radiometer. Both designs provide an overall power gain of approximately 50 dB over a 500 MHz bandwidth centered at 3.5 GHz. No stability problems were observed despite using triple-cascaded amplifier configurations to boost the thermal signals. The prototypes were tested for sensitivity after calibration in two different water baths. Experiments showed superior sensitivity (36% higher) when implementing the low noise amplifier before the Dicke switch (close to the antenna) compared to the other design with the Dicke switch in front. Radiometer performance was also tested in a multilayered phantom during alternating heating and radiometric reading. Empirical tests showed that for the configuration with Dicke switch first, the switch had to be locked in the reference position during application of microwave heating to avoid damage to the active components (amplifiers and power meter). For the configuration with a low noise amplifier up front, damage would occur to the active components of the radiometer if used in presence of the microwave heating antenna. Nevertheless, this design showed significantly improved sensitivity of measured temperatures and merits further investigation to determine methods of protecting the radiometer for amplifier first front ends. PMID:21779411

Study on model current predictive control method of PV grid- connected inverters systems with voltage sag

NASA Astrophysics Data System (ADS)

Jin, N.; Yang, F.; Shang, S. Y.; Tao, T.; Liu, J. S.

2016-08-01

According to the limitations of the LVRT technology of traditional photovoltaic inverter existed, this paper proposes a low voltage ride through (LVRT) control method based on model current predictive control (MCPC). This method can effectively improve the photovoltaic inverter output characteristics and response speed. The MCPC method of photovoltaic grid-connected inverter designed, the sum of the absolute value of the predictive current and the given current error is adopted as the cost function with the model predictive control method. According to the MCPC, the optimal space voltage vector is selected. Photovoltaic inverter has achieved automatically switches of priority active or reactive power control of two control modes according to the different operating states, which effectively improve the inverter capability of LVRT. The simulation and experimental results proves that the proposed method is correct and effective.

Apparatus for decoupled thermo-photocatalytic pollution control

DOEpatents

Tabatabaie-Raissi, Ali; Muradov, Nazim Z.; Martin, Eric

2003-04-22

A new method for design and scale-up of photocatalytic and thermocatalytic processes is disclosed. The method is based on optimizing photoprocess energetics by decoupling of the process energy efficiency from the DRE for target contaminants. The technique is applicable to photo-thermocatalytic reactor design and scale-up. At low irradiance levels, the method is based on the implementation of low pressure drop biopolymeric and synthetic polymeric support for titanium dioxide and other band-gap media. At high irradiance levels, the method utilizes multifunctional metal oxide aerogels and other media within a novel rotating fluidized particle bed reactor.

Locking the 150-cavity open: in silico design and verification of influenza neuraminidase inhibitors.

PubMed

Han, Nanyu; Mu, Yuguang

2013-01-01

Neuraminidase (NA) of influenza is a key target for virus infection control and the recently discovered open 150-cavity in group-1 NA provides new opportunity for novel inhibitors design. In this study, we used a combination of theoretical methods including fragment docking, molecular linking and molecular dynamics simulations to design ligands that specifically target at the 150-cavity. Through in silico screening of a fragment compound library on the open 150-cavity of NA, a few best scored fragment compounds were selected to link with Zanamivir, one NA-targeting drug. The resultant new ligands may bind both the active site and the 150-cavity of NA simultaneously. Extensive molecular dynamics simulations in explicit solvent were applied to validate the binding between NA and the designed ligands. Moreover, two control systems, a positive control using Zanamivir and a negative control using a low-affinity ligand 3-(p-tolyl) allyl-Neu5Ac2en (ETT, abbreviation reported in the PDB) found in a recent experimental work, were employed to calibrate the simulation method. During the simulations, ETT was observed to detach from NA, on the contrary, both Zanamivir and our designed ligand bind NA firmly. Our study provides a prospective way to design novel inhibitors for controlling the spread of influenza virus.

Turning up the heat on aircraft structures. [design and analysis for high-temperature conditions

NASA Technical Reports Server (NTRS)

Dobyns, Alan; Saff, Charles; Johns, Robert

1992-01-01

An overview is presented of the current effort in design and development of aircraft structures to achieve the lowest cost for best performance. Enhancements in this area are focused on integrated design, improved design analysis tools, low-cost fabrication techniques, and more sophisticated test methods. 3D CAD/CAM data are becoming the method through which design, manufacturing, and engineering communicate.

Maintained Physical Activity Induced Changes in Delay Discounting.

PubMed

Sofis, Michael J; Carrillo, Ale; Jarmolowicz, David P

2017-07-01

Those who discount the subjective value of delayed rewards less steeply are more likely to engage in physical activity. There is limited research, however, showing whether physical activity can change rates of delay discounting. In a two-experiment series, treatment and maintenance effects of a novel, effort-paced physical activity intervention on delay discounting were evaluated with multiple baseline designs. Using a lap-based method, participants were instructed to exercise at individualized high and low effort levels and to track their own perceived effort. The results suggest that treatment-induced changes in discounting were maintained at follow-up for 13 of 16 participants. In Experiment 2, there were statistically significant group-level improvements in physical activity and delay discounting when comparing baseline with both treatment and maintenance phases. Percentage change in delay discounting was significantly correlated with session attendance and relative pace (min/mile) improvement over the course of the 7-week treatment. Implications for future research are discussed.

Physical Activity and Reported Barriers to Activity Among Type 2 Diabetic Patients in the United Arab Emirates

PubMed Central

Al-Kaabi, Juma; Al-Maskari, Fatma; Afandi, Bachar; Parkar, Hasratali; Nagelkerke, Nicolaas

2009-01-01

OBJECTIVES: This study was designed to assess the physical activity practice among type 2 diabetic patients in the United Arab Emirates (UAE). METHODS: This is a cross-sectional study of type 2 diabetic patients who participated in the outpatient clinics in Al-Ain District, during 2006. The patients completed an interviewer-administered questionnaire, and measurements of blood pressure, body mass index, body fat, abdominal circumference, glycemic control (HbA1c), and fasting lipid profile. RESULTS: Of the 390 patients recruited, only 25% reported an increase in their physical activity levels following the diagnosis of diabetes, and only 3% reported physical activity levels that meet the recommended guidelines. More than half of the study subjects had uncontrolled hypertension (53%) and unacceptable lipid profiles; 71% had a high low-density lipoprotein (LDL), 73% had low high-density lipoprotein (HDL), and 59% had hypertriglyceridemia. Forty-four percent were obese and a further 34% were overweight. Abdominal obesity was also common (59%). Only 32% had an acceptable glycemic control. CONCLUSIONS: The physical activity practice of type 2 diabetic patients in the UAE is largely inadequate to meet the recommended level necessary to prevent or ameliorate diabetic complications. Interventions aiming at overcoming the barriers to physical activity are urgently needed. PMID:20043039

Controlling sound radiation through an opening with secondary loudspeakers along its boundaries.

PubMed

Wang, Shuping; Tao, Jiancheng; Qiu, Xiaojun

2017-10-17

We propose a virtual sound barrier system that blocks sound transmission through openings without affecting access, light and air circulation. The proposed system applies active control technique to cancel sound transmission with a double layered loudspeaker array at the edge of the opening. Unlike traditional transparent glass windows, recently invented double-glazed ventilation windows and planar active sound barriers or any other metamaterials designed to reduce sound transmission, secondary loudspeakers are put only along the boundaries of the opening, which provides the possibility to make it invisible. Simulation and experimental results demonstrate its feasibility for broadband sound control, especially for low frequency sound which is usually hard to attenuate with existing methods.

Modular Bayesian Networks with Low-Power Wearable Sensors for Recognizing Eating Activities

PubMed Central

Kim, Kee-Hoon

2017-01-01

Recently, recognizing a user’s daily activity using a smartphone and wearable sensors has become a popular issue. However, in contrast with the ideal definition of an experiment, there could be numerous complex activities in real life with respect to its various background and contexts: time, space, age, culture, and so on. Recognizing these complex activities with limited low-power sensors, considering the power and memory constraints of the wearable environment and the user’s obtrusiveness at once is not an easy problem, although it is very crucial for the activity recognizer to be practically useful. In this paper, we recognize activity of eating, which is one of the most typical examples of a complex activity, using only daily low-power mobile and wearable sensors. To organize the related contexts systemically, we have constructed the context model based on activity theory and the “Five W’s”, and propose a Bayesian network with 88 nodes to predict uncertain contexts probabilistically. The structure of the proposed Bayesian network is designed by a modular and tree-structured approach to reduce the time complexity and increase the scalability. To evaluate the proposed method, we collected the data with 10 different activities from 25 volunteers of various ages, occupations, and jobs, and have obtained 79.71% accuracy, which outperforms other conventional classifiers by 7.54–14.4%. Analyses of the results showed that our probabilistic approach could also give approximate results even when one of contexts or sensor values has a very heterogeneous pattern or is missing. PMID:29232937

Grasp specific and user friendly interface design for myoelectric hand prostheses.

PubMed

Mohammadi, Alireza; Lavranos, Jim; Howe, Rob; Choong, Peter; Oetomo, Denny

2017-07-01

This paper presents the design and characterisation of a hand prosthesis and its user interface, focusing on performing the most commonly used grasps in activities of daily living (ADLs). Since the operation of a multi-articulated powered hand prosthesis is difficult to learn and master, there is a significant rate of abandonment by amputees in preference for simpler devices. In choosing so, amputees chose to live with fewer features in their prosthesis that would more reliably perform the basic operations. In this paper, we look simultaneously at a hand prosthesis design method that aims for a small number of grasps, a low complexity user interface and an alternative method to the current use of EMG as a preshape selection method through the use of a simple button; to enable amputees to get to and execute the intended hand movements intuitively, quickly and reliably. An experiment is reported at the end of the paper comparing the speed and accuracy with which able-bodied naive subjects are able to select the intended preshapes through the use of a simplified EMG method and a simple button. It is shown that the button was significantly superior in the speed of successful task completion and marginally superior in accuracy (success of first attempt).

Assessing Design Activity in Complex CMOS Circuit Design.

ERIC Educational Resources Information Center

Biswas, Gautam; And Others

This report characterizes human problem solving in digital circuit design. Protocols of 11 different designers with varying degrees of training were analyzed by identifying the designers' problem solving strategies and discussing activity patterns that differentiate the designers. These methods are proposed as a tentative basis for assessing…

Quasi-modal vibration control by means of active control bearings

NASA Technical Reports Server (NTRS)

Nonami, K.; Fleming, D. P.

1986-01-01

This paper investigates a design method of an active control bearing system with only velocity feedback. The study provides a new quasi-modal control method for a control system design of an active control bearing system in which feedback coefficients are determined on the basis of a modal analysis. Although the number of sensors and actuators is small, this quasi-modal control method produces a control effect close to an ideal modal control.

Design of a vibration isolation system for a cycle ergometer to be used onboard the Space Shuttle

NASA Technical Reports Server (NTRS)

Pearson, Lillian; Tait, Steven; Trevino, Maurice

1991-01-01

Low frequency vibrations generated during exercise using the cycle ergometer onboard the Space Shuttle are disrupting sensitive microgravity experiments. The design team is asked by NASA/USRA to generate alternatives for the design of a vibration isolation system for the cycle ergometer. It is the design team's objective to present alternative designs and a problem solution for a vibration isolation system for an exercise cycle ergometer to be used onboard the Space Shuttle. In the development of alternative designs, the design team emphasizes passive systems as opposed to active control systems. This decision is made because the team feels that passive systems are less complex than active control systems, external energy sources are not required, and mass is reduced due to the lack of machinery such as servomotors or compressors typical of active control systems. Eleven alternative designs are developed by the design team. From these alternatives, three active control systems are included to compare the benefits of active and passive systems. Also included in the alternatives is an isolation system designed by an independent engineer that was acquired late in the project. The eight alternatives using passive isolation systems are narrowed down by selection criteria to four considered to be the most promising by the design team. A feasibility analysis is performed on these four passive isolation systems. Based on the feasibility analysis, a final design solution is chosen and further developed. From the development of the design, the design team has concluded that passive systems are not effective at isolating vibrations for the low frequencies considered for this project. Recommendations are made for guidelines of passive isolation design and application of such systems.

Merits and limitations of optimality criteria method for structural optimization

NASA Technical Reports Server (NTRS)

Patnaik, Surya N.; Guptill, James D.; Berke, Laszlo

1993-01-01

The merits and limitations of the optimality criteria (OC) method for the minimum weight design of structures subjected to multiple load conditions under stress, displacement, and frequency constraints were investigated by examining several numerical examples. The examples were solved utilizing the Optimality Criteria Design Code that was developed for this purpose at NASA Lewis Research Center. This OC code incorporates OC methods available in the literature with generalizations for stress constraints, fully utilized design concepts, and hybrid methods that combine both techniques. Salient features of the code include multiple choices for Lagrange multiplier and design variable update methods, design strategies for several constraint types, variable linking, displacement and integrated force method analyzers, and analytical and numerical sensitivities. The performance of the OC method, on the basis of the examples solved, was found to be satisfactory for problems with few active constraints or with small numbers of design variables. For problems with large numbers of behavior constraints and design variables, the OC method appears to follow a subset of active constraints that can result in a heavier design. The computational efficiency of OC methods appears to be similar to some mathematical programming techniques.

A label-free fluorescent biosensor for the detection of protein kinase activity based on gold nanoclusters/graphene oxide hybrid materials.

PubMed

Liu, Qing; Li, Ning; Wang, Mengke; Wang, Lei; Su, Xingguang

2018-07-12

Protein kinase (PKA) can regulate many cellular biological processes by phosphorylation substrate peptide or protein. A new fluorescent biosensing method for the detection of PKA activity was developed by using 11-mercaptoundecanoic acid-capped gold nanoclusters (MUA-Au NCs) and graphene oxide (GO) with low background noise. In this strategy, the special designed peptide could be anchored on the surface of MUA-Au NCs by the Au-S bond and also adsorbed on the surface of GO owing to the electrostatic interaction. As a result, the fluorescence of MUA-Au NCs was quenched leading to low background fluorescence due to the forster resonance energy transfer (FRET) between MUA-Au NCs and GO via peptide as a bridge. However, when the substrate peptide was phosphorylated by PKA, the FRET between GO and MUA-Au NCs was disrupted because of the weakened interaction between the phosphorylated peptide and the GO, resulting in recovery of the fluorescence intensity. The developed label-free fluorescence "turn-off-on" method can detect protein kinase activity in the range of 0.6-2.0 U mL -1 with a detection limit of 0.17 U mL -1 (3σ). The feasibility of this present method for kinase inhibitor screening was also studied by assessment of H-89 kinase inhibition with an IC 50 value of 0.049 μmol L -1 . Copyright © 2018. Published by Elsevier B.V.

Parents' Reasons for Choosing Non-Public Non-Denominational Elementary Schools for Low Socioeconomic Students in Alabama: A Mixed-Methods Study

ERIC Educational Resources Information Center

Francis-Thomas, Kyle

2016-01-01

The purpose of this mixed-methods study was to determine parents' reasons for choosing Non-Public Non-Denominational Elementary Schools for low socioeconomic students in Alabama. Low socioeconomic students were defined as students who qualified for free/reduced lunches. The research was designed as a mixed methods study with data being collected…

Wide-field-of-view millimeter-wave telescope design with ultra-low cross-polarization

NASA Astrophysics Data System (ADS)

Bernacki, Bruce E.; Kelly, James F.; Sheen, David; Hatchell, Brian; Valdez, Patrick; Tedeschi, Jonathan; Hall, Thomas; McMakin, Douglas

2012-06-01

As millimeter-wave arrays become available, off-axis imaging performance of the fore optics increases in importance due to the relatively large physical extent of the arrays. Typically, simple optical telescope designs are adapted to millimeter-wave imaging but single-mirror spherical or classic conic designs cannot deliver adequate image quality except near the optical axis. Since millimeter-wave designs are quasi-optical, optical ray tracing and commercial design software can be used to optimize designs to improve off-axis imaging as well as minimize cross-polarization. Methods that obey the Dragone-Mizuguchi condition for the design of reflective millimeter-wave telescopes with low cross-polarization also provide additional degrees of freedom that offer larger fields of view than possible with single-reflector designs. Dragone's graphical design method does not lend itself readily to computer-based optical design approaches, but subsequent authors expanded on Dragone's geometric design approach with analytic expressions that describe the location, shape, off-axis height and tilt of the telescope elements that satisfy Dragone's design rules and can be used as a first-order design for subsequent computer-based design and optimization. We investigate two design variants that obey the Dragone-Mizuguchi conditions that exhibit ultra-low cross-polarization and a large diffraction-limited field of view well suited to millimeter-wave imaging arrays.

Computational Methods in Drug Discovery

PubMed Central

Sliwoski, Gregory; Kothiwale, Sandeepkumar; Meiler, Jens

2014-01-01

Computer-aided drug discovery/design methods have played a major role in the development of therapeutically important small molecules for over three decades. These methods are broadly classified as either structure-based or ligand-based methods. Structure-based methods are in principle analogous to high-throughput screening in that both target and ligand structure information is imperative. Structure-based approaches include ligand docking, pharmacophore, and ligand design methods. The article discusses theory behind the most important methods and recent successful applications. Ligand-based methods use only ligand information for predicting activity depending on its similarity/dissimilarity to previously known active ligands. We review widely used ligand-based methods such as ligand-based pharmacophores, molecular descriptors, and quantitative structure-activity relationships. In addition, important tools such as target/ligand data bases, homology modeling, ligand fingerprint methods, etc., necessary for successful implementation of various computer-aided drug discovery/design methods in a drug discovery campaign are discussed. Finally, computational methods for toxicity prediction and optimization for favorable physiologic properties are discussed with successful examples from literature. PMID:24381236

The effects of a physical activity intervention on employees in small and medium enterprises: a mixed methods study.

PubMed

Edmunds, Sarah; Stephenson, Duncan; Clow, Angela

2013-01-01

Workplaces have potential as a setting for physical activity promotion but evidence of the effectiveness of intervention programmes in small and medium sized enterprises is limited. This paper reports the impact of an intervention which trained existing employees to promote physical activity to their colleagues. Eighty-nine previously low-active employees from 17 small and medium sized organisations participated. A mixed methods evaluation design was used. Quantitative data were collected at baseline and 6 months later using an online questionnaire. Qualitative data from a series of 6 focus groups were analysed. Repeated measures t-tests showed significant increases over time in physical activity, general health rating, satisfaction with life and positive mood states. There were significant decreases in body mass index (BMI), perceived stress, negative mood states and presenteeism. There was no change in absenteeism. Analysis of focus group data provided further insight into the impact of the intervention. Five major themes emerged: awareness of physical activity; sustaining physical activity behaviour change; improved health and well-being; enhanced social networks; and embedding physical activity in the workplace culture. This study shows it is feasible and effective to train employees in small and medium sized enterprises to support their colleagues in physical activity behaviour change.

Thermal properties of simulated Hanford waste glasses

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

Rodriguez, Carmen P.; Chun, Jaehun; Crum, Jarrod V.

The Hanford Tank Waste Treatment and Immobilization Plant (WTP) will vitrify the mixed hazardous wastes generated from 45 years of plutonium production. The molten glasses will be poured into stainless steel containers or canisters and subsequently quenched for storage and disposal. Such highly energy-consuming processes require precise thermal properties of materials for appropriate facility design and operations. Key thermal properties (heat capacity, thermal diffusivity, and thermal conductivity) of representative high-level and low-activity waste glasses were studied as functions of temperature in the range of 200 to 800°C (relevant to the cooling process), implementing simultaneous differential scanning calorimetry-thermal gravimetry (DSC-TGA), Xe-flashmore » diffusivity, pycnometry, and dilatometry. The study showed that simultaneous DSC-TGA would be a reliable method to obtain heat capacity of various glasses at the temperature of interest. Accurate thermal properties from this study were shown to provide a more realistic guideline for capacity and time constraint of heat removal process, in comparison to the design basis conservative engineering estimates. The estimates, though useful for design in the absence measured physical properties, can now be supplanted and the measured thermal properties can be used in design verification activities.« less

An environmental intervention aimed at increasing physical activity levels in low-income women.

PubMed

Speck, Barbara J; Hines-Martin, Vicki; Stetson, Barbara A; Looney, Stephen W

2007-01-01

Regular physical activity is a health promotion and disease prevention behavior. Of all demographic groups, low-income women report the lowest levels of physical activity. The purpose of this study was to test an intervention aimed at reducing community environmental barriers to physical activity in low-income women. The research design was mixed methodology: (1) quantitative (quasi-experimental, pretest-posttest, cohort design in which no treatment partitioning was possible) and (2) qualitative (focus groups). The setting was a church-sponsored community center centrally located in a low-income urban neighborhood. The comparison group was recruited first followed by the intervention group to control for setting. The sample consisted of 104 women (comparison group, n = 53; intervention group, n = 51) between the ages of 18 and 63 years who were residents of neighborhoods served by the community center. No between-group differences were found for physical activity behavior. Significant between-group differences in cholesterol (P = .007) and perception of physical activity (P = .033) were observed. Significant intervention group increases from pretest to posttest were found related to advanced registered nurse practitioner support, friend support, and more positive physical activity environment at the community center. Qualitative data supported and enriched the quantitative data. Physical activity levels were not significantly different between the groups. In a sample of low-income women who have multiple barriers, improving attitudes, expanding their knowledge of community resources, and providing physical activity opportunities in their neighborhoods are important intermediate steps toward initiation and maintenance of regular physical activity.

Physics-based enzyme design: predicting binding affinity and catalytic activity.

PubMed

Sirin, Sarah; Pearlman, David A; Sherman, Woody

2014-12-01

Computational enzyme design is an emerging field that has yielded promising success stories, but where numerous challenges remain. Accurate methods to rapidly evaluate possible enzyme design variants could provide significant value when combined with experimental efforts by reducing the number of variants needed to be synthesized and speeding the time to reach the desired endpoint of the design. To that end, extending our computational methods to model the fundamental physical-chemical principles that regulate activity in a protocol that is automated and accessible to a broad population of enzyme design researchers is essential. Here, we apply a physics-based implicit solvent MM-GBSA scoring approach to enzyme design and benchmark the computational predictions against experimentally determined activities. Specifically, we evaluate the ability of MM-GBSA to predict changes in affinity for a steroid binder protein, catalytic turnover for a Kemp eliminase, and catalytic activity for α-Gliadin peptidase variants. Using the enzyme design framework developed here, we accurately rank the most experimentally active enzyme variants, suggesting that this approach could provide enrichment of active variants in real-world enzyme design applications. © 2014 Wiley Periodicals, Inc.

SKALA, a log-periodic array antenna for the SKA-low instrument: design, simulations, tests and system considerations

NASA Astrophysics Data System (ADS)

de Lera Acedo, E.; Razavi-Ghods, N.; Troop, N.; Drought, N.; Faulkner, A. J.

2015-10-01

The very demanding requirements of the SKA-low instrument call for a challenging antenna design capable of delivering excellent performance in radiation patterns, impedance matching, polarization purity, cost, longevity, etc. This paper is devoted to the development (design and test of the first prototypes) of an active ultra-wideband antenna element for the low-frequency instrument of the SKA radio telescope. The antenna element and differential low noise amplifier described here were originally designed to cover the former SKA-low band (70-450 MHz) but it is now aimed to cover the re-defined SKA-low band (50-350 MHz) and furthermore the antenna is capable of performing up to 650 MHz with the current design. The design is focused on maximum sensitivity in a wide field of view (+/- 45° from zenith) and low cross-polarization ratios. Furthermore, the size and cost of the element has to be kept to a minimum as millions of these antennas will need to be deployed for the full SKA in very compact configurations. The primary focus of this paper is therefore to discuss various design implications for the SKA-low telescope.

The catalytic removal of ammonia and nitrogen oxides from spacecabin atmospheres

NASA Technical Reports Server (NTRS)

Gully, A. J.; Graham, R. R.; Halligan, J. E.; Bentsen, P. C.

1973-01-01

Investigations were made on methods for the removal of ammonia and to a lesser extent nitrogen oxides in low concentrations from air. The catalytic oxidation of ammonia was studied over a temperature range of 250 F to 600 F and a concentration range 20 ppm to 500 ppm. Of the catalysts studied, 0.5 percent ruthenium supported on alumina was found to be superior. This material is active at temperatures as low as 250 F and was found to produce much less nitrous oxide than the other two active catalysts, platinum on alumina and Hopcalite. A quantitative design model was developed which will permit the performance of an oxidizer to be calculated. The ruthenium was found to be relatively insensitive to low concentrations of water and to oxygen concentration between 21 percent and 100 percent. Hydrogen sulfide was found to be a poison when injected in relatively large quantities. The adsorption of ammonia by copper sulfate treated silica gel was investigated at temperatures of 72 F and 100 F. A quantitative model was developed for predicting adsorption bed behavior.

Low current performance of the Bern medical cyclotron down to the pA range

NASA Astrophysics Data System (ADS)

Auger, M.; Braccini, S.; Ereditato, A.; Nesteruk, K. P.; Scampoli, P.

2015-09-01

A medical cyclotron accelerating H- ions to 18 MeV is in operation at the Bern University Hospital (Inselspital). It is the commercial IBA 18/18 cyclotron equipped with a specifically conceived 6 m long external beam line ending in a separate bunker. This feature is unique for a hospital-based facility and makes it possible to conduct routine radioisotope production for PET diagnostics in parallel with multidisciplinary research activities, among which are novel particle detectors, radiation biophysics, radioprotection, radiochemistry and radiopharmacy developments. Several of these activities, such as radiobiology experiments for example, require low current beams down to the pA range, while medical cyclotrons are designed for high current operation above 10 μA. In this paper, we present the first results on the low current performance of a PET medical cyclotron obtained by ion source, radio-frequency and main coil tuning. With this method, stable beam currents down to (1.5+/- 0.5 ) pA were obtained and measured with a high-sensitivity Faraday cup located at the end of the beam transport line.

A computer program for the design and analysis of low-speed airfoils

NASA Technical Reports Server (NTRS)

Eppler, R.; Somers, D. M.

1980-01-01

A conformal mapping method for the design of airfoils with prescribed velocity distribution characteristics, a panel method for the analysis of the potential flow about given airfoils, and a boundary layer method have been combined. With this combined method, airfoils with prescribed boundary layer characteristics can be designed and airfoils with prescribed shapes can be analyzed. All three methods are described briefly. The program and its input options are described. A complete listing is given as an appendix.

Eliminating Voltage Decay of Lithium-Rich Li 1.14Mn 0.54Ni 0.14Co 0.14O 2 Cathodes by Controlling the Electrochemical Process

DOE PAGES

Wei, Z.; Zhu, Y.; Zhang, W.; ...

2015-03-27

Lithium-rich material owns a particularly high capacity owing to the activation of electrochemical inactive Li 2MnO 3 phase. But at the same time, MnO 2 phase formed after Li 2MnO 3 activation confronts a severe problem of converting to spinel phase, and resulting in voltage decay. To our knowledge, this phenomenon is inherent property of layered manganese oxide materials and can hardly be overcome. Based on this, unlike previous reports, herein we design a method for the first time to accelerate the phase transformation by tuning the charge upper-limit voltage at a high value, so the phase transformation process canmore » be finished in a few cycles. Then material structure remains stable while cycling at a low upper-limit voltage. By this novel method voltage decay is eliminated significantly.« less

Increasing Recreational Physical Activity in Patients With Chronic Low Back Pain: A Pragmatic Controlled Clinical Trial.

PubMed

Ben-Ami, Noa; Chodick, Gabriel; Mirovsky, Yigal; Pincus, Tamar; Shapiro, Yair

2017-02-01

Study Design Prospective, pragmatic, nonrandomized controlled clinical trial. Background Clinical guidelines recommend physical activity for the treatment of chronic low back pain. But engaging patients in physical activity has proven difficult. Known obstacles to physical activity include low self-efficacy and fear avoidance. Objectives This study tested the effectiveness of an enhanced transtheoretical model intervention (ETMI) aimed at increasing recreational physical activity in patients with chronic low back pain, in comparison to usual physical therapy. Methods Patients (n = 220) referred to physical therapy for chronic low back pain were allocated to ETMI or to a control group. The ETMI was delivered by physical therapists and based on behavior-change principles, combined with increased reassurance, therapeutic alliance, and exposure to reduce fear avoidance. The primary outcome was back pain-related disability (Roland-Morris Disability Questionnaire). Secondary outcomes included pain intensity, mental and physical health, and levels of physical activity. Results Intention-to-treat analysis in 189 patients at 12 months indicated that patients in the ETMI group had significantly lower disability compared to usual physical therapy. The difference in mean change from baseline between the interventions was 2.7 points (95% confidence interval: 0.9, 4.5) on the Roland-Morris Disability Questionnaire. At 12 months, worst pain, physical activity, and physical health were all significantly better in patients receiving ETMI. The average number of sessions was 3.5 for the ETMI group and 5.1 for controls. Conclusion Targeting obstacles to physical activity with an intervention that includes components to address self-efficacy and fear avoidance appears to be more effective than usual physical therapy care in reducing long-term disability. Further research is needed to explore the mechanisms that impact outcomes in this intervention package. Level of Evidence Therapy, level 2b. Registered June 7, 2012 at ClinicalTrials.gov (NCT01631344). J Orthop Sports Phys Ther 2017;47(2):57-66. doi:10.2519/jospt.2017.7057.

Analysis of microstrip dipoles and slots transversely coupled to a microstrip line using the FDTD method

NASA Technical Reports Server (NTRS)

Tulintseff, A. N.

1993-01-01

Printed dipole elements and their complement, linear slots, are elementary radiators that have found use in low-profile antenna arrays. Low-profile antenna arrays, in addition to their small size and low weight characteristics, offer the potential advantage of low-cost, high-volume production with easy integration with active integrated circuit components. The design of such arrays requires that the radiation and impedance characteristics of the radiating elements be known. The FDTD (Finite-Difference Time-Domain) method is a general, straight-forward implementation of Maxwell's equations and offers a relatively simple way of analyzing both printed dipole and slot elements. Investigated in this work is the application of the FDTD method to the analysis of printed dipole and slot elements transversely coupled to an infinite transmission line in a multilayered configuration. Such dipole and slot elements may be used in dipole and slot series-fed-type linear arrays, where element offsets and interelement line lengths are used to obtain the desired amplitude distribution and beam direction, respectively. The design of such arrays is achieved using transmission line theory with equivalent circuit models for the radiating elements. In an equivalent circuit model, the dipole represents a shunt impedance to the transmission line, where the impedance is a function of dipole offset, length, and width. Similarly, the slot represents a series impedance to the transmission line. The FDTD method is applied to single dipole and slot elements transversely coupled to an infinite microstrip line using a fixed rectangular grid with Mur's second order absorbing boundary conditions. Frequency-dependent circuit and scattering parameters are obtained by saving desired time-domain quantities and using the Fourier transform. A Gaussian pulse excitation is applied to the microstrip transmission line, where the resulting reflected signal due to the presence of the radiating element is used to determine the equivalent element impedance.

Advances in electrometer vacuum tube design

NASA Technical Reports Server (NTRS)

1970-01-01

Single-ended, miniature-cathode tube with a relatively low grid current level is constructed. Adequate cathode temperature at relatively low heater power drain is provided by designing the supporting spacers to provide a square cathode hole. Method of assembling the mount and bonding the elements is discussed.

Characterization of dynamic changes of current source localization based on spatiotemporal fMRI constrained EEG source imaging

NASA Astrophysics Data System (ADS)

Nguyen, Thinh; Potter, Thomas; Grossman, Robert; Zhang, Yingchun

2018-06-01

Objective. Neuroimaging has been employed as a promising approach to advance our understanding of brain networks in both basic and clinical neuroscience. Electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) represent two neuroimaging modalities with complementary features; EEG has high temporal resolution and low spatial resolution while fMRI has high spatial resolution and low temporal resolution. Multimodal EEG inverse methods have attempted to capitalize on these properties but have been subjected to localization error. The dynamic brain transition network (DBTN) approach, a spatiotemporal fMRI constrained EEG source imaging method, has recently been developed to address these issues by solving the EEG inverse problem in a Bayesian framework, utilizing fMRI priors in a spatial and temporal variant manner. This paper presents a computer simulation study to provide a detailed characterization of the spatial and temporal accuracy of the DBTN method. Approach. Synthetic EEG data were generated in a series of computer simulations, designed to represent realistic and complex brain activity at superficial and deep sources with highly dynamical activity time-courses. The source reconstruction performance of the DBTN method was tested against the fMRI-constrained minimum norm estimates algorithm (fMRIMNE). The performances of the two inverse methods were evaluated both in terms of spatial and temporal accuracy. Main results. In comparison with the commonly used fMRIMNE method, results showed that the DBTN method produces results with increased spatial and temporal accuracy. The DBTN method also demonstrated the capability to reduce crosstalk in the reconstructed cortical time-course(s) induced by neighboring regions, mitigate depth bias and improve overall localization accuracy. Significance. The improved spatiotemporal accuracy of the reconstruction allows for an improved characterization of complex neural activity. This improvement can be extended to any subsequent brain connectivity analyses used to construct the associated dynamic brain networks.

Social Determinants of Health and Attempt to Change Unhealthy Lifestyle: A Population-based Study.

PubMed

Danaei, Mina; Palenik, Charles John; Abdollahifard, Gholamreza; Askarian, Mehrdad

2017-01-01

A healthy lifestyle is important because of its long-term benefits; however, there is a paucity of information concerning health choices among Iranians. We evaluated personal health behaviors, attempts to change unhealthy behaviors, and factors affecting attempts at change. The design of this cross-sectional study was to assemble a representative cadre of >18-year-old adults in Shiraz, Iran, using a multistage cluster sampling technique. Validated questionnaires collected participant's demographic information, such as weight, height, cigarette smoking history, physical activity, and attempts at lifestyle changes during the previous year. To determine predictors of attempts to change unhealthy lifestyle and to identify confounders, we applied single and multivariable logistic regression methods, respectively. A confidence interval of 95% was calculated for each odds ratio. The prevalence of attempts to change unhealthy lifestyle was 42%, 64.8%, and 27.8%, respectively, for losing weight, being more physically active, and smoking cessation. Unemployment, low levels of education, and decreased socioeconomic status have important roles in attempts to change lifestyle conditions. Low socioeconomic status was a risk factor for quitting smoking. Occupation (unemployed/homemaker) and low level of education were two significant factors for being more physically active. The prevalence of inadequate physical activity and being overweight or obese was considerable in Shiraz, Iran. Attempts to change unhealthy lifestyle were less than ideal. Social determinants of health factors including unemployment and low levels of education and socioeconomic status play important roles in attempts to change current lifestyles.

Modal processing for acoustic communications in shallow water experiment.

PubMed

Morozov, Andrey K; Preisig, James C; Papp, Joseph

2008-09-01

Acoustical array data from the Shallow Water Acoustics experiment was processed to show the feasibility of broadband mode decomposition as a preprocessing method to reduce the effective channel delay spread and concentrate received signal energy in a small number of independent channels. The data were collected by a vertical array designed at the Woods Hole Oceanographic Institution. Phase-shift Keying (PSK) m-sequence modulated signals with different carrier frequencies were transmitted at a distance 19.2 km from the array. Even during a strong internal waves activity a low bit error rate was achieved.

A comprehensive prediction and evaluation method of pilot workload.

PubMed

Feng, Chuanyan; Wanyan, Xiaoru; Yang, Kun; Zhuang, Damin; Wu, Xu

2018-01-01

The prediction and evaluation of pilot workload is a key problem in human factor airworthiness of cockpit. A pilot traffic pattern task was designed in a flight simulation environment in order to carry out the pilot workload prediction and improve the evaluation method. The prediction of typical flight subtasks and dynamic workloads (cruise, approach, and landing) were built up based on multiple resource theory, and a favorable validity was achieved by the correlation analysis verification between sensitive physiological data and the predicted value. Statistical analysis indicated that eye movement indices (fixation frequency, mean fixation time, saccade frequency, mean saccade time, and mean pupil diameter), Electrocardiogram indices (mean normal-to-normal interval and the ratio between low frequency and sum of low frequency and high frequency), and Electrodermal Activity indices (mean tonic and mean phasic) were all sensitive to typical workloads of subjects. A multinominal logistic regression model based on combination of physiological indices (fixation frequency, mean normal-to-normal interval, the ratio between low frequency and sum of low frequency and high frequency, and mean tonic) was constructed, and the discriminate accuracy was comparatively ideal with a rate of 84.85%.

Patterns of Alcohol Policy Enforcement Activities among Local Law Enforcement Agencies: A Latent Class Analysis

PubMed Central

Erickson, Darin J.; Rutledge, Patricia C.; Lenk, Kathleen M.; Nelson, Toben F.; Jones-Webb, Rhonda; Toomey, Traci L.

2015-01-01

Aims We assessed levels and patterns of alcohol policy enforcement activities among U.S. local law enforcement agencies. Design/Setting/Participants We conducted a cross-sectional survey of a representative sample of 1,631 local law enforcement agencies across the 50 states. Measures/Methods We assessed 29 alcohol policy enforcement activities within each of five enforcement domains—underage alcohol possession/consumption, underage alcohol provision, underage alcohol sales, impaired driving, and overservice of alcohol—and conducted a series of latent class analyses to identify unique classes or patterns of enforcement activity for each domain. Findings We identified three to four unique enforcement activity classes for each of the enforcement domains. In four of the domains, we identified a Uniformly Low class (i.e., little or no enforcement) and a Uniformly High enforcement activity class (i.e., relatively high levels of enforcement), with one or two middle classes where some but not all activities were conducted. The underage provision domain had a Uniformly Low class but not a Uniformly High class. The Uniformly Low class was the most prevalent class in three domains: underage provision (58%), underage sales (61%), and overservice (79%). In contrast, less than a quarter of agencies were in Uniformly High classes. Conclusions We identified qualitatively distinct patterns of enforcement activity, with a large proportion of agencies in classes characterized by little or no enforcement and fewer agencies in high enforcement classes. An important next step is to determine if these patterns are associated with rates of alcohol use and alcohol-related injury and mortality. PMID:26877822

Engineering assessment of low-level liquid waste disposal caisson locations at the 618-11 Burial Grounds

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

Phillips, S.J.; Fischer, D.D.; Crawford, R.C.

1982-06-01

Rockwell Hanford Operations is currently involved in an extensive effort to perform interim ground surface stabilization activities at retired low-level waste burial grounds located at the Hanford Site, Richland, Washington. The principal objective of these activities is to promote increased occupational and radiological safety at burial grounds. Interim stabilization activities include: (1) load testing (traversing burial ground surfaces with heavy equipment to promote incipient collapse of void spaces within the disposal structure and overburden), (2) barrier placement (placement of a {ge} 0.6 m soil barrier over existing overburden), and (3) revegetation (establishment of shallow rooted vegetation on the barrier tomore » mitigate deep rooted plant growth and to reduce erosion). Low-level waste disposal caissons were used in 300 Area Burial Grounds as internment structures for containerized liquid wastes. These caissons, by virtue of their contents, design and methods of closure, require long-term performance evaluation. As an initial activity to evaluate long-term performance, the accurate location of these structures is required. This topical report summarizes engineering activities used to locate caissons in the subsurface environment at the Burial Ground. Activities were conducted to locate caissons during surface stabilization activities. The surface locations were marked, photographed, and recorded on an as built engineering drawing. The recorded location of these caissons will augment long-term observations of confinement structure and engineered surface barrier performance. In addition, accurate caisson location will minimize occupational risk during monitoring and observation activities periodically conducted at the burial ground.« less

Evaluation of GaAs low noise and power MMIC technologies to neutron, ionizing dose and dose rate effects

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

Derewonko, H.; Bosella, A.; Pataut, G.

1996-06-01

An evaluation program of Thomson CSF-TCS GaAs low noise and power MMIC technologies to 1 MeV equivalent neutron fluence levels, up to 1 {times} 10{sup 15} n/cm{sup 2}, ionizing 1.17--1.33 MeV CO{sup 60} dose levels in excess of 200 Mrad(GaAs) and dose rate levels reaching 1.89 {times} 10{sup 11} rad(GaAs)/s is presented in terms of proper components and parameter choices, DC/RF electrical measurements and test methods under irradiation. Experimental results are explained together with drift analyses of electrical parameters that have determined threshold limits of component degradations. Modelling the effects of radiation on GaAs components relies on degradation analysis ofmore » active layer which appears to be the most sensitive factor. MMICs degradation under neutron fluence was simulated from irradiated FET data. Finally, based on sensitivity of technological parameters, rad-hard design including material, technology and MMIC design enhancement is discussed.« less

Irradiation, microwave and alternative energy-based treatments for low water activity foods

USDA-ARS?s Scientific Manuscript database

There is an increasing recognition of low water activity foods as vectors for human pathogens. Partially or fully dried agricultural commodities, along with modern formulated dried food products, are complex, and designed to meet a variety of nutritional, sensory, and market-oriented goal. This comp...

Using intervention mapping to develop a theory-driven, group-based complex intervention to support self-management of osteoarthritis and low back pain (SOLAS).

PubMed

Hurley, Deirdre A; Murphy, Laura Currie; Hayes, David; Hall, Amanda M; Toomey, Elaine; McDonough, Suzanne M; Lonsdale, Chris; Walsh, Nicola E; Guerin, Suzanne; Matthews, James

2016-04-26

The Medical Research Council framework provides a useful general approach to designing and evaluating complex interventions, but does not provide detailed guidance on how to do this and there is little evidence of how this framework is applied in practice. This study describes the use of intervention mapping (IM) in the design of a theory-driven, group-based complex intervention to support self-management (SM) of patients with osteoarthritis (OA) and chronic low back pain (CLBP) in Ireland's primary care health system. The six steps of the IM protocol were systematically applied to develop the self-management of osteoarthritis and low back pain through activity and skills (SOLAS) intervention through adaptation of the Facilitating Activity and Self-management in Arthritis (FASA) intervention. A needs assessment including literature reviews, interviews with patients and physiotherapists and resource evaluation was completed to identify the programme goals, determinants of SM behaviour, consolidated definition of SM and required adaptations to FASA to meet health service and patient needs and the evidence. The resultant SOLAS intervention behavioural outcomes, performance and change objectives were specified and practical application methods selected, followed by organised programme, adoption, implementation and evaluation plans underpinned by behaviour change theory. The SOLAS intervention consists of six weekly sessions of 90-min education and exercise designed to increase participants' physical activity level and use of evidence-based SM strategies (i.e. pain self-management, pain coping, healthy eating for weight management and specific exercise) through targeting of individual determinants of SM behaviour (knowledge, skills, self-efficacy, fear, catastrophizing, motivation, behavioural regulation), delivered by a trained physiotherapist to groups of up to eight individuals using a needs supportive interpersonal style based on self-determination theory. Strategies to support SOLAS intervention adoption and implementation included a consensus building workshop with physiotherapy stakeholders, development of a physiotherapist training programme and a pilot trial with physiotherapist and patient feedback. The SOLAS intervention is currently being evaluated in a cluster randomised controlled feasibility trial. IM is a time-intensive collaborative process, but the range of methods and resultant high level of transparency is invaluable and allows replication by future complex intervention and trial developers.

Low Carbon Design Research on the Space Layout Types of Office Buildings

NASA Astrophysics Data System (ADS)

Xia, Bing

2018-01-01

It is beneficial to find out the relationship of the spatial layout and low-carbon design in order to reduce buildings’ carbon emissions in the conceptual design phase. This paper analyzes and compares shape coefficient values, annual energy consumption and lighting performance of office buildings of different space layout types in Shanghai. Based on morphological characteristics of different types, the study also analyzes and presents low-carbon design strategies for each single type. This study assumes that architects should conduct passive and active design according to the specific building space layout, so that to make best use of the advantages and bypassing the disadvantages, in order to maximally reduce buildings’ carbon emissions.

[Review of research design and statistical methods in Chinese Journal of Cardiology].

PubMed

Zhang, Li-jun; Yu, Jin-ming

2009-07-01

To evaluate the research design and the use of statistical methods in Chinese Journal of Cardiology. Peer through the research design and statistical methods in all of the original papers in Chinese Journal of Cardiology from December 2007 to November 2008. The most frequently used research designs are cross-sectional design (34%), prospective design (21%) and experimental design (25%). In all of the articles, 49 (25%) use wrong statistical methods, 29 (15%) lack some sort of statistic analysis, 23 (12%) have inconsistencies in description of methods. There are significant differences between different statistical methods (P < 0.001). The correction rates of multifactor analysis were low and repeated measurement datas were not used repeated measurement analysis. Many problems exist in Chinese Journal of Cardiology. Better research design and correct use of statistical methods are still needed. More strict review by statistician and epidemiologist is also required to improve the literature qualities.

Smartphone application for emergency signal detection.

PubMed

Figueiredo, Isabel N; Leal, Carlos; Pinto, Luís; Bolito, Jason; Lemos, André

2016-09-01

Currently, a number of studies focus on the study and design of new healthcare technologies to improve elderly health and quality of life. Taking advantage of the popularity, portability, and inherent technology of smartphones, we present an emergency application for smartphones, designated as knock-to-panic (KTP). This innovative and novel system enables users to simply hit their devices in order to send an alarm signal to an emergency service. This application is a complete and autonomous emergency system, and can provide an economic, reliable, and unobtrusive method for elderly monitoring or safety protection. Moreover, the simple and fast activation of KTP makes it a viable and potentially superior alternative to traditional ambient assisted living emergency calls. Furthermore, KTP can be further extended to the general population as well and not just be limited for elderly persons. The proposed method is a threshold-based algorithm and is designed to require a low battery power consumption. The evaluation of the performance of the algorithm in collected data indicates that both sensitivity and specificity are above 90%. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

Active mixing of complex fluids at the microscale

DOE PAGES

Ober, Thomas J.; Foresti, Daniele; Lewis, Jennifer A.

2015-09-22

Mixing of complex fluids at low Reynolds number is fundamental for a broad range of applications, including materials assembly, microfluidics, and biomedical devices. Of these materials, yield stress fluids (and gels) pose the most significant challenges, especially when they must be mixed in low volumes over short timescales. New scaling relationships between mixer dimensions and operating conditions are derived and experimentally verified to create a framework for designing active microfluidic mixers that can efficiently homogenize a wide range of complex fluids. As a result, active mixing printheads are then designed and implemented for multimaterial 3D printing of viscoelastic inks withmore » programmable control of local composition.« less

Active mixing of complex fluids at the microscale

PubMed Central

Ober, Thomas J.; Foresti, Daniele; Lewis, Jennifer A.

2015-01-01

Mixing of complex fluids at low Reynolds number is fundamental for a broad range of applications, including materials assembly, microfluidics, and biomedical devices. Of these materials, yield stress fluids (and gels) pose the most significant challenges, especially when they must be mixed in low volumes over short timescales. New scaling relationships between mixer dimensions and operating conditions are derived and experimentally verified to create a framework for designing active microfluidic mixers that can efficiently homogenize a wide range of complex fluids. Active mixing printheads are then designed and implemented for multimaterial 3D printing of viscoelastic inks with programmable control of local composition. PMID:26396254

Engineering electrocatalytic activity in nanosized perovskite cobaltite through surface spin-state transition

PubMed Central

Zhou, Shiming; Miao, Xianbing; Zhao, Xu; Ma, Chao; Qiu, Yuhao; Hu, Zhenpeng; Zhao, Jiyin; Shi, Lei; Zeng, Jie

2016-01-01

The activity of electrocatalysts exhibits a strongly dependence on their electronic structures. Specifically, for perovskite oxides, Shao-Horn and co-workers have reported a correlation between the oxygen evolution reaction activity and the eg orbital occupation of transition-metal ions, which provides guidelines for the design of highly active catalysts. Here we demonstrate a facile method to engineer the eg filling of perovskite cobaltite LaCoO3 for improving the oxygen evolution reaction activity. By reducing the particle size to ∼80 nm, the eg filling of cobalt ions is successfully increased from unity to near the optimal configuration of 1.2 expected by Shao-Horn's principle. Consequently, the activity is significantly enhanced, comparable to those of recently reported cobalt oxides with eg∼1.2 configurations. This enhancement is ascribed to the emergence of spin-state transition from low-spin to high-spin states for cobalt ions at the surface of the nanoparticles, leading to more active sites with increased reactivity. PMID:27187067

Getting the Most from Working with Higher Education: A Review of Methods Used within a Participatory Design Activity Involving KS3 Special School Pupils and Undergraduate and Post-Graduate Industrial Design Students

ERIC Educational Resources Information Center

Torrens, George Edward; Newton, Helen

2013-01-01

This paper provides education-based researchers and practitioners with the preferred research and design methods used by Higher Education Institute (HEI) students and Key Stage 3 (KS3) pupils applied within a participatory approach to a design activity. The outcomes were that both pupils and students found informal (unstructured) interview to be…

Reduction of the sound power radiation of a typical helicopter panel by the use of piezoceramic actuators

NASA Astrophysics Data System (ADS)

De Vivo, Luciano; Concilio, Antonio

1996-04-01

"Design to Noise" is one of the new aspects considered during the planning phase of new aircraft, for different political, economical and enviromental reasons. In the low frequency range, active control seems to give the right answers to the needs. In propeller aircraft, active systems based on microphones-loudspeakers architectures5 have overtaken the classical methods based on the use of the Dynamic Vibration Absorbers.7 The problems of weight, cost and so on, could be solved by the application of "Smart Structures" , well summarised in many works and publications (e.g. C. Fuller6). Further work is being carried out at CIRA, on the use of piezoceramic devices as vibration actuators inside system architectures based on the approach known as Acousto Structural Active Control ( ASAC9'10). Recently, the attention of the aeronautical research world has been directed towards helicopters, where the acoustic problems are greater with respect to aeroplanes: extremely low frequencies involved, little noise insulation, etc. . . In addition, the inherent structural demands present some peculiarities, such as the use of large, flexible, composite elements, etc. .

Design of a Low-Light-Level Image Sensor with On-Chip Sigma-Delta Analog-to- Digital Conversion

NASA Technical Reports Server (NTRS)

Mendis, Sunetra K.; Pain, Bedabrata; Nixon, Robert H.; Fossum, Eric R.

1993-01-01

The design and projected performance of a low-light-level active-pixel-sensor (APS) chip with semi-parallel analog-to-digital (A/D) conversion is presented. The individual elements have been fabricated and tested using MOSIS* 2 micrometer CMOS technology, although the integrated system has not yet been fabricated. The imager consists of a 128 x 128 array of active pixels at a 50 micrometer pitch. Each column of pixels shares a 10-bit A/D converter based on first-order oversampled sigma-delta (Sigma-Delta) modulation. The 10-bit outputs of each converter are multiplexed and read out through a single set of outputs. A semi-parallel architecture is chosen to achieve 30 frames/second operation even at low light levels. The sensor is designed for less than 12 e^- rms noise performance.

Low speed airfoil design and analysis

NASA Technical Reports Server (NTRS)

Eppler, R.; Somers, D. M.

1979-01-01

A low speed airfoil design and analysis program was developed which contains several unique features. In the design mode, the velocity distribution is not specified for one but many different angles of attack. Several iteration options are included which allow the trailing edge angle to be specified while other parameters are iterated. For airfoil analysis, a panel method is available which uses third-order panels having parabolic vorticity distributions. The flow condition is satisfied at the end points of the panels. Both sharp and blunt trailing edges can be analyzed. The integral boundary layer method with its laminar separation bubble analog, empirical transition criterion, and precise turbulent boundary layer equations compares very favorably with other methods, both integral and finite difference. Comparisons with experiment for several airfoils over a very wide Reynolds number range are discussed. Applications to high lift airfoil design are also demonstrated.

The design of two sonic boom wind tunnel models from conceptual aircraft which cruise at Mach numbers of 2.0 and 3.0

NASA Technical Reports Server (NTRS)

Mack, Robert J.; Needleman, Kathy E.

1990-01-01

A method for designing wind tunnel models of conceptual, low-boom, supersonic cruise aircraft is presented. Also included is a review of the procedures used to design the conceptual low-boom aircraft. In the discussion, problems unique to, and encountered during, the design of both the conceptual aircraft and the wind tunnel models are outlined. The sensitivity of low-boom characteristics in the aircraft design to control the volume and lift equivalent area distributions was emphasized. Solutions to these problems are reported; especially the two which led to the design of the wind tunnel model support stings.

Physiotherapy for sleep disturbance in chronic low back pain: a feasibility randomised controlled trial

PubMed Central

2010-01-01

Background Sleep disturbance is becoming increasingly recognised as a clinically important symptom in people with chronic low back pain (CLBP, low back pain >12 weeks), associated with physical inactivity and depression. Current research and international clinical guidelines recommend people with CLBP assume a physically active role in their recovery to prevent chronicity, but the high prevalence of sleep disturbance in this population may be unknowingly limiting their ability to participate in exercise-based rehabilitation programmes and contributing to poor outcomes. There is currently no knowledge concerning the effectiveness of physiotherapy on sleep disturbance in people with chronic low back pain and no evidence of the feasibility of conducting randomized controlled trials that comprehensively evaluate sleep as an outcome measure in this population. Methods/Design This study will evaluate the feasibility of a randomised controlled trial (RCT), exploring the effects of three forms of physiotherapy (supervised general exercise programme, individualized walking programme and usual physiotherapy, which will serve as the control group) on sleep quality in people with chronic low back pain. A presenting sample of 60 consenting patients will be recruited in the physiotherapy department of Beaumont Hospital, Dublin, Ireland, and randomly allocated to one of the three groups in a concealed manner. The main outcomes will be sleep quality (self-report and objective measurement), and self-reported functional disability, pain, quality of life, fear avoidance, anxiety and depression, physical activity, and patient satisfaction. Outcome will be evaluated at baseline, 3 months and 6 months. Qualitative telephone interviews will be embedded in the research design to obtain feedback from a sample of participants' about their experiences of sleep monitoring, trial participation and interventions, and to inform the design of a fully powered future RCT. Planned analysis will explore trends in the data, effect sizes and clinically important effects (quantitative data), and thematic analysis (qualitative data). Discussion This study will evaluate the feasibility of a randomised controlled trial exploring the effects of three forms of physiotherapy (supervised general exercise programme, individualized walking programme and usual physiotherapy, which will serve as the control group) on sleep quality in people with chronic low back pain. Trial Registration Current controlled trial ISRCTN54009836 PMID:20398349

Launch vehicle systems design analysis

NASA Technical Reports Server (NTRS)

Ryan, Robert; Verderaime, V.

1993-01-01

Current launch vehicle design emphasis is on low life-cycle cost. This paper applies total quality management (TQM) principles to a conventional systems design analysis process to provide low-cost, high-reliability designs. Suggested TQM techniques include Steward's systems information flow matrix method, quality leverage principle, quality through robustness and function deployment, Pareto's principle, Pugh's selection and enhancement criteria, and other design process procedures. TQM quality performance at least-cost can be realized through competent concurrent engineering teams and brilliance of their technical leadership.

PCL foamed scaffolds loaded with 5-fluorouracil anti-cancer drug prepared by an eco-friendly route.

PubMed

Salerno, Aurelio; Domingo, Concepción; Saurina, Javier

2017-06-01

This study describes a new preparation method, which combines freeze drying and supercritical CO 2 foaming approaches, for the preparation of drug delivery scaffolds of polycaprolactone loaded with 5-fluorouracil, an anti-cancer drug, with low solubility in scCO 2 . It is a principal objective of this work to design a scCO 2 strategy to reduce 5-Fu solubility limitations in its homogeneous distribution into a PCL scaffold through the design of an innovative processing method. The design of this process is considered valuable for the development of clean technology in pharmacy and medicine, since most of the active agents have a null solubility in scCO 2 ·Supercritical CO 2 is used as a blowing agent to induce polymer foaming by means of the low temperature pressure quench process. The resulting samples have been prepared under different operational conditions focused on enhancing the performance of the release process. In this case, design of experiments (DOE) was considered for a more comprehensive and systematic optimization of the product. In particular, drug amount, equals to 4.8 or 9.1wt%, process temperature, of 45 or 50°C and depressurization rate, equals to 0.1MPas -1 or 2MPas -1 were selected as the factors to be investigated by a three-factor at two-level full factorial design. Samples were characterized to establish porosity data, drug loading percentage and, especially, release profile chromatographically monitored. Results from DOE have concluded which are the best samples providing a sustained drug release for several days, which may be of great interest to develop materials for tissue engineering and sustained release applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Low-Threshold Active Teaching Methods for Mathematic Instruction

ERIC Educational Resources Information Center

Marotta, Sebastian M.; Hargis, Jace

2011-01-01

In this article, we present a large list of low-threshold active teaching methods categorized so the instructor can efficiently access and target the deployment of conceptually based lessons. The categories include teaching strategies for lecture on large and small class sizes; student action individually, in pairs, and groups; games; interaction…

Optimizing Parameters of Axial Pressure-Compounded Ultra-Low Power Impulse Turbines at Preliminary Design

NASA Astrophysics Data System (ADS)

Kalabukhov, D. S.; Radko, V. M.; Grigoriev, V. A.

2018-01-01

Ultra-low power turbine drives are used as energy sources in auxiliary power systems, energy units, terrestrial, marine, air and space transport within the confines of shaft power N td = 0.01…10 kW. In this paper we propose a new approach to the development of surrogate models for evaluating the integrated efficiency of multistage ultra-low power impulse turbine with pressure stages. This method is based on the use of existing mathematical models of ultra-low power turbine stage efficiency and mass. It has been used in a method for selecting the rational parameters of two-stage axial ultra-low power turbine. The article describes the basic features of an algorithm for two-stage turbine parameters optimization and for efficiency criteria evaluating. Pledged mathematical models are intended for use at the preliminary design of turbine drive. The optimization method was tested at preliminary design of an air starter turbine. Validation was carried out by comparing the results of optimization calculations and numerical gas-dynamic simulation in the Ansys CFX package. The results indicate a sufficient accuracy of used surrogate models for axial two-stage turbine parameters selection

Control optimization, stabilization and computer algorithms for aircraft applications

NASA Technical Reports Server (NTRS)

1975-01-01

Research related to reliable aircraft design is summarized. Topics discussed include systems reliability optimization, failure detection algorithms, analysis of nonlinear filters, design of compensators incorporating time delays, digital compensator design, estimation for systems with echoes, low-order compensator design, descent-phase controller for 4-D navigation, infinite dimensional mathematical programming problems and optimal control problems with constraints, robust compensator design, numerical methods for the Lyapunov equations, and perturbation methods in linear filtering and control.

Design of dissipative low-authority controllers using an eigensystem assignment technique

NASA Technical Reports Server (NTRS)

Maghami, P. G.; Gupta, S.; Joshi, S. M.

1992-01-01

A novel method for the design of dissipative, low-authority controllers has been developed. The method uses a sequential approach along with eigensystem assignment to compute rate and position gain matrices that assign a number of closed-loop poles of the system to desired locations. Because the feedback gain matrices are symmetric and nonnegative definite, the closed-loop stability is always guaranteed regardless of the model order or parameter inaccuracies. The resulting (nominal) closed-loop system can have specified damping ratios for m modes, which makes the plant amenable to high-authority controller design, using methods such as LQG/LTR or H-infinity. A numerical example is worked out for a flexible structure in order to demonstrate the proposed technique.

Robust design of microchannel cooler

NASA Astrophysics Data System (ADS)

He, Ye; Yang, Tao; Hu, Li; Li, Leimin

2005-12-01

Microchannel cooler has offered a new method for the cooling of high power diode lasers, with the advantages of small volume, high efficiency of thermal dissipation and low cost when mass-produced. In order to reduce the sensitivity of design to manufacture errors or other disturbances, Taguchi method that is one of robust design method was chosen to optimize three parameters important to the cooling performance of roof-like microchannel cooler. The hydromechanical and thermal mathematical model of varying section microchannel was calculated using finite volume method by FLUENT. A special program was written to realize the automation of the design process for improving efficiency. The optimal design is presented which compromises between optimal cooling performance and its robustness. This design method proves to be available.

Seal Investigations of an Active Clearance Control System Concept

NASA Technical Reports Server (NTRS)

Steinetz, Bruce M.; Taylor, Shawn; Oswald, Jay; DeCastro, Jonathan A.

2006-01-01

In an effort to improve upon current thermal active clearance control methods, a first generation, fast-acting mechanically actuated, active clearance control system has been designed and installed into a non-rotating test rig. In order to harvest the benefit of tighter blade tip clearances, low-leakage seals are required for the actuated carrier segments of the seal shroud to prevent excessive leakage of compressor discharge (P3) cooling air. The test rig was designed and fabricated to facilitate the evaluation of these types of seals, identify seal leakage sources, and test other active clearance control system concepts. The objective of this paper is to present both experimental and analytical investigations into the nature of the face-seal to seal-carrier interface. Finite element analyses were used to examine face seal contact pressures and edge-loading under multiple loading conditions, varied E-seal positions and two new face seal heights. The analyses indicated that moving the E-seal inward radially and reducing face seal height would lead to more uniform contact conditions between the face seal and the carriers. Lab testing confirmed that moving the balance diameter inward radially caused a decrease in overall system leakage.

Design and Weighting Methods for a Nationally Representative Sample of HIV-infected Adults Receiving Medical Care in the United States-Medical Monitoring Project

PubMed Central

Iachan, Ronaldo; H. Johnson, Christopher; L. Harding, Richard; Kyle, Tonja; Saavedra, Pedro; L. Frazier, Emma; Beer, Linda; L. Mattson, Christine; Skarbinski, Jacek

2016-01-01

Background: Health surveys of the general US population are inadequate for monitoring human immunodeficiency virus (HIV) infection because the relatively low prevalence of the disease (<0.5%) leads to small subpopulation sample sizes. Objective: To collect a nationally and locally representative probability sample of HIV-infected adults receiving medical care to monitor clinical and behavioral outcomes, supplementing the data in the National HIV Surveillance System. This paper describes the sample design and weighting methods for the Medical Monitoring Project (MMP) and provides estimates of the size and characteristics of this population. Methods: To develop a method for obtaining valid, representative estimates of the in-care population, we implemented a cross-sectional, three-stage design that sampled 23 jurisdictions, then 691 facilities, then 9,344 HIV patients receiving medical care, using probability-proportional-to-size methods. The data weighting process followed standard methods, accounting for the probabilities of selection at each stage and adjusting for nonresponse and multiplicity. Nonresponse adjustments accounted for differing response at both facility and patient levels. Multiplicity adjustments accounted for visits to more than one HIV care facility. Results: MMP used a multistage stratified probability sampling design that was approximately self-weighting in each of the 23 project areas and nationally. The probability sample represents the estimated 421,186 HIV-infected adults receiving medical care during January through April 2009. Methods were efficient (i.e., induced small, unequal weighting effects and small standard errors for a range of weighted estimates). Conclusion: The information collected through MMP allows monitoring trends in clinical and behavioral outcomes and informs resource allocation for treatment and prevention activities. PMID:27651851

Development of a theater-based nutrition and physical activity intervention for low-income, urban, African American adolescents.

PubMed

Jackson, Caree J; Mullis, Rebecca M; Hughes, Marilyn

2010-01-01

Childhood overweight is disproportionately worse in minority and low-income populations. Theater is a promising and effective tool for delivering health education to these underserved populations, but no known studies have examined the use of theater to promote both nutrition and physical activity to minority youth. To develop an interactive, theater-based intervention that conveys health messages to low-income, urban, African Americans and engages them in learning ways to adopt a healthy lifestyle. Community partners worked to develop a theater-based nutrition and physical activity intervention. A focus group provided urban adolescents' thoughts about their desires for the intervention. Based on input from all community partners, the group created a theater-based intervention. Researchers used a quasi-experimental (pre-/posttest) design with a community-based participatory research (CBPR) approach. Participants learned health messages through theater, dance, and music and gave feedback on the program sessions and materials. The program ended with a dinner theater performance showcasing information that students learned during the intervention. Participants received six theater-based health lessons. Learning objectives for each health education session were achieved. Each participant contributed to and performed in the final performance. All program participants were highly satisfied with the theater-based method of learning health messages. A community-academic partnership succeeded in developing a theater-based nutrition and physical activity intervention that satisfied participating adolescents.

What to Build for Middle-Agers to Come? Attractive and Necessary Functions of Exercise-Promotion Mobile Phone Apps: A Cross-Sectional Study

PubMed Central

Chien, Yu-Tai; Chen, Yu-Jen; Hsiung, Hsiao-Fang; Chen, Hsiao-Jung; Hsieh, Meng-Hua; Wu, Wen-Jie

2017-01-01

Background Physical activity is important for middle-agers to maintain health both in middle age and in old age. Although thousands of exercise-promotion mobile phone apps are available for download, current literature offers little understanding regarding which design features can enhance middle-aged adults’ quality perception toward exercise-promotion apps and which factor may influence such perception. Objectives The aims of this study were to understand (1) which design features of exercise-promotion apps can enhance quality perception of middle-agers, (2) whether their needs are matched by current functions offered in app stores, and (3) whether physical activity (PA) and mobile phone self-efficacy (MPSE) influence quality perception. Methods A total of 105 middle-agers participated and filled out three scales: the International Physical Activity Questionnaire (IPAQ), the MPSE scale, and the need for design features questionnaire. The design features were developed based on the Coventry, Aberdeen, and London—Refined (CALO-RE) taxonomy. Following the Kano quality model, the need for design features questionnaire asked participants to classify design features into five categories: attractive, one-dimensional, must-be, indifferent, and reverse. The quality categorization was conducted based on a voting approach and the categorization results were compared with the findings of a prevalence study to realize whether needs match current availability. In total, 52 multinomial logistic regression models were analyzed to evaluate the effects of PA level and MPSE on quality perception of design features. Results The Kano analysis on the total sample revealed that visual demonstration of exercise instructions is the only attractive design feature, whereas the other 51 design features were perceived with indifference. Although examining quality perception by PA level, 21 features are recommended to low level, 6 features to medium level, but none to high-level PA. In contrast, high-level MPSE is recommended with 14 design features, medium level with 6 features, whereas low-level participants are recommended with 1 feature. The analysis suggests that the implementation of demanded features could be low, as the average prevalence of demanded design features is 20% (4.3/21). Surprisingly, social comparison and social support, most implemented features in current apps, were categorized into the indifferent category. The magnitude of effect is larger for MPSE because it effects quality perception of more design features than PA. Delving into the 52 regression models revealed that high MPSE more likely induces attractive or one- dimensional categorization, suggesting the importance of technological self-efficacy on eHealth care promotion. Conclusions This study is the first to propose middle-agers’ needs in relation to mobile phone exercise-promotion. In addition to the tailor-made recommendations, suggestions are offered to app designers to enhance the performance of persuasive features. An interesting finding on change of quality perception attributed to MPSE is proposed as future research. PMID:28546140

Parents' Perceived Barriers to Healthful Eating and Physical Activity for Low-Income Adolescents Who Are at Risk for Type 2 Diabetes

ERIC Educational Resources Information Center

Peterson, Sharon L.; Bell, Toya Wilson; Hasin, Afroza

2009-01-01

Healthful eating and regular physical activity are vitally important for low-income adolescents who are at risk for developing type 2 diabetes (T2DM). To design a relevant, community-based intervention for these at risk adolescents, parent perceptions of barriers to healthful eating and physical activity should be assessed. Such barriers have been…

Monolithic Gallium Arsenide Superheterodyne Front End.

DTIC Science & Technology

1982-06-01

which also provides a con - venient heat sink (not of primary importance in this application due to the low power dissipation of the monolithic...components utilized in the receiver front end). The thickness of the GaAs is then selected as a compromise between con - flicting requirements. A thick...International ERC41014.2FR 2.4 Analysis and Design for Low Noise The design of monolithic amplifiers for low noise must take into con - sideration active

Problem Solving Techniques for the Design of Algorithms.

ERIC Educational Resources Information Center

Kant, Elaine; Newell, Allen

1984-01-01

Presents model of algorithm design (activity in software development) based on analysis of protocols of two subjects designing three convex hull algorithms. Automation methods, methods for studying algorithm design, role of discovery in problem solving, and comparison of different designs of case study according to model are highlighted.…

Wide-Field-of-View Millimeter-Wave Telescope Design with Ultra-Low Cross-Polarization

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

Bernacki, Bruce E.; Kelly, James F.; Sheen, David M.

2012-05-01

As millimeter-wave arrays become available, off-axis imaging performance of the fore optics increases in importance due to the relatively large physical extent of the arrays. Typically, simple optical telescope designs are adapted to millimeter-wave imaging but single-mirror spherical or classic conic designs cannot deliver adequate image quality except near the optical axis. Since most millimeter-wave designs are quasi-optical, optical ray tracing and commercial design software can be used to optimize designs to improve off-axis imaging as well as minimize cross-polarization. Methods that obey the Dragone-Mizuguchi condition for the design of reflective millimeter-wave telescopes with low cross-polarization also provide additional degreesmore » of freedom that offer larger fields of view than possible with single-reflector designs. Dragone’s graphical design method does not lend itself readily to computer-based optical design approaches, but subsequent authors expanded on Dragone’s geometric design approach with analytic expressions that describe the location, shape, off-axis height and tilt of the telescope elements that satisfy Dragone’s design rules and can be used as a first-order design for subsequent computer-based design and optimization. We investigate two design variants that obey the Dragone-Mizuguchi conditions that exhibit ultra-low polarization crosstalk and a large diffraction-limited field of view well suited to millimeter-wave imaging arrays.« less

A Low-Technology Strategy for Increasing Engagement of Students with Autism and Significant Learning Needs

ERIC Educational Resources Information Center

Carnahan, Christi; Basham, James; Musti-Rao, Shobana

2009-01-01

Active engagement is critical to promote learning for students with autism. Although evidence-based strategies exist for promoting engagement for individual students with autism, there are few strategies designed for use with small groups. This study used an ABCAC design to assess the effects of a low-technology use strategy, namely interactive…

Effect of low-dose scopolamine on autonomic control of the heart

NASA Technical Reports Server (NTRS)

Raeder, E. A.; Stys, A.; Cohen, R. J.

1997-01-01

Background: In low doses, scopolamine paradoxically enhances parasympathetic outflow to the heart. The mechanisms which mediate this action are not fully understood. Moreover, there are conflicting data regarding the potential role of sympathetic activity. This study in 17 healthy individuals was designed to characterize the influence of low dose transdermal scopolamine on the gain of the baroreflex and respiratory heart rate reflex and to determine the role of sympathetic activity. Methods: The effect of scopolamine was analyzed in the time and frequency domain by computing heart rate variability indices. The gains of the respiratory heart rate reflex and the baroreflex were estimated simultaneously by means of a cardiovascular system identification approach using an optimized autoregressive moving average algorithm. Measurements were repeated in the upright posture to assess the influence of enhanced sympathetic activity. In six subjects ambulatory ECGs were recorded to determine whether there are diurnal variations of the effect of scopolamine. Results: Scopolamine enhances vagal modulation of heart rate through both the respiratory-heart rate reflex and the baroreflex, as the gains of both were augmented by the drug in the supine and in the upright postures. Conclusions: Scopolamine increases parasympathetic cardiac control by augmenting the gain of the respiratory-heart rate and baroreflex. This action is not attenuated in the upright posture when sympathetic tone is increased.

Are social relationships a healthy influence on obesogenic behaviors among racially/ethnically diverse and socio-economically disadvantaged residents?

PubMed Central

Tamers, Sara L.; Okechukwu, Cassandra; Allen, Jennifer; Yang, May; Stoddard, Anne; Tucker-Seeley, Reginald; Sorensen, Glorian

2012-01-01

Objective To examine associations between social support and ties (family, friend, neighbors) individually and jointly with diet and physical activity among an ethnically-diverse, low-income population. Methods The Health in Common study (2005–2009) was designed to examine risk factors among individuals residing in low-income housing in the Boston, MA area. Cross-sectional surveys (n = 828) were administered in residents’ homes. Linear/logistic multivariable analyses were employed with clustering of individuals within housing sites controlled as a random effect. Results In multivariable analyses, total social support was significantly associated with higher red meat consumption per day (p = 0.029). Having more friends was significantly associated with more daily fruit and vegetable intake (p = 0.007) and higher levels of daily vigorous physical activity (p = 0.011). Those who reported having a greater number of family ties also reported higher daily consumption of sugary drinks (p = 0.013) and fast food (p = 0.011). More neighbor social ties was associated with more fast food per day (p = 0.024). Conclusions Social relationships can have both positive and negative associations with health behaviors. Understanding these relationships could help to inform the design of interventions that promote healthy behavior change among vulnerable populations. PMID:23200880

Design and characterization of low-cost fabric-based flat pneumatic actuators for soft assistive glove application.

PubMed

Yap, Hong Kai; Sebastian, Frederick; Wiedeman, Christopher; Yeow, Chen-Hua

2017-07-01

We present the design of low-cost fabric-based Hat pneumatic actuators for soft assistive glove application. The soft assistive glove is designed to assist hand impaired patients in performing activities of daily living and rehabilitation. The actuators consist of flexible materials such as fabric and latex bladder. Using zero volume actuation concept, the 2D configuration of the actuators simplifies the manufacturing process and allows the actuators to be more compact. The actuators achieve bi-directional flexion and extension motions. Compared to previously developed inflatable soft actuators, the actuators generate sufficient force and torque to assist in both finger flexion and extension at lower air pressure. Preliminary evaluation results show that the glove is able to provide both active finger flexion and extension assistance for activities of daily living and rehabilitative training.

Comprehensive Design Reliability Activities for Aerospace Propulsion Systems

NASA Technical Reports Server (NTRS)

Christenson, R. L.; Whitley, M. R.; Knight, K. C.

2000-01-01

This technical publication describes the methodology, model, software tool, input data, and analysis result that support aerospace design reliability studies. The focus of these activities is on propulsion systems mechanical design reliability. The goal of these activities is to support design from a reliability perspective. Paralleling performance analyses in schedule and method, this requires the proper use of metrics in a validated reliability model useful for design, sensitivity, and trade studies. Design reliability analysis in this view is one of several critical design functions. A design reliability method is detailed and two example analyses are provided-one qualitative and the other quantitative. The use of aerospace and commercial data sources for quantification is discussed and sources listed. A tool that was developed to support both types of analyses is presented. Finally, special topics discussed include the development of design criteria, issues of reliability quantification, quality control, and reliability verification.

Increased Course Structure Improves Performance in Introductory Biology

PubMed Central

Freeman, Scott; Haak, David; Wenderoth, Mary Pat

2011-01-01

We tested the hypothesis that highly structured course designs, which implement reading quizzes and/or extensive in-class active-learning activities and weekly practice exams, can lower failure rates in an introductory biology course for majors, compared with low-structure course designs that are based on lecturing and a few high-risk assessments. We controlled for 1) instructor effects by analyzing data from quarters when the same instructor taught the course, 2) exam equivalence with new assessments called the Weighted Bloom's Index and Predicted Exam Score, and 3) student equivalence using a regression-based Predicted Grade. We also tested the hypothesis that points from reading quizzes, clicker questions, and other “practice” assessments in highly structured courses inflate grades and confound comparisons with low-structure course designs. We found no evidence that points from active-learning exercises inflate grades or reduce the impact of exams on final grades. When we controlled for variation in student ability, failure rates were lower in a moderately structured course design and were dramatically lower in a highly structured course design. This result supports the hypothesis that active-learning exercises can make students more skilled learners and help bridge the gap between poorly prepared students and their better-prepared peers. PMID:21633066

Increased course structure improves performance in introductory biology.

PubMed

Freeman, Scott; Haak, David; Wenderoth, Mary Pat

2011-01-01

We tested the hypothesis that highly structured course designs, which implement reading quizzes and/or extensive in-class active-learning activities and weekly practice exams, can lower failure rates in an introductory biology course for majors, compared with low-structure course designs that are based on lecturing and a few high-risk assessments. We controlled for 1) instructor effects by analyzing data from quarters when the same instructor taught the course, 2) exam equivalence with new assessments called the Weighted Bloom's Index and Predicted Exam Score, and 3) student equivalence using a regression-based Predicted Grade. We also tested the hypothesis that points from reading quizzes, clicker questions, and other "practice" assessments in highly structured courses inflate grades and confound comparisons with low-structure course designs. We found no evidence that points from active-learning exercises inflate grades or reduce the impact of exams on final grades. When we controlled for variation in student ability, failure rates were lower in a moderately structured course design and were dramatically lower in a highly structured course design. This result supports the hypothesis that active-learning exercises can make students more skilled learners and help bridge the gap between poorly prepared students and their better-prepared peers.

Innovation in preregistration midwifery education: Web based interactive storytelling learning.

PubMed

Scamell, Mandie; Hanley, Thomas

2017-07-01

through a critical description of the implementation of a web based interactive storytelling learning activity introduced into an undergraduate, preregistration midwifery education programme, this paper will explore how low-cost, low-fidelity online storytelling, designed using Moodle, can be used to enhance students' understanding of compassion and empathy in practice. cross sectional sample of first year undergraduate Midwifery students (n111) METHOD: drawing from both research and audit data collected in an Higher Education Institution in London England, the paper presents the case for using web based technology to create a sustainable model for midwifery education. initial results indicate that it is both the low cost and positive student evaluations of web based interactive storytelling, which make this approach to preregistration midwifery education which suggests that this approach has significant potential for learning and teaching in midwifery education in diverse settings around the world. Or how about: global relevance? . Copyright © 2017 Elsevier Ltd. All rights reserved.

A highly sensitive in-situ turbidity sensor with low power consumption

NASA Astrophysics Data System (ADS)

Hu, Yi; Sun, Lei; Ye, Shuming; Chen, Hang; Jiang, Kai; Pan, Jianming

2014-03-01

A highly sensitive in-situ turbidity sensor with the low power consumption was proposed and evaluated in this study. To meet the practical requirements of the in-situ detection, we have designed the light scattering path, watertight mechanical structure, and ultra-weak scattering light detecting method. Experiments showed that the sensor had a sensitivity of 0.0076 FTU with the concentration range of 0-25 FTU and the R-square of 0.9999. The sensor could withstand the water pressure in depth of 1000 m and had the low power consumption in the active mode 10.4 mA, sleep mode 65 μA with a supply voltage of 8.4 V. Southern China Sea buoy experiments indicated that the sensor could work well in the actual in-situ environment. In comparison with sensors of other companies, our sensor had relatively more comprehensive performance.

A Multi Directional Perfect Reconstruction Filter Bank Designed with 2-D Eigenfilter Approach: Application to Ultrasound Speckle Reduction.

PubMed

Nagare, Mukund B; Patil, Bhushan D; Holambe, Raghunath S

2017-02-01

B-Mode ultrasound images are degraded by inherent noise called Speckle, which creates a considerable impact on image quality. This noise reduces the accuracy of image analysis and interpretation. Therefore, reduction of speckle noise is an essential task which improves the accuracy of the clinical diagnostics. In this paper, a Multi-directional perfect-reconstruction (PR) filter bank is proposed based on 2-D eigenfilter approach. The proposed method used for the design of two-dimensional (2-D) two-channel linear-phase FIR perfect-reconstruction filter bank. In this method, the fan shaped, diamond shaped and checkerboard shaped filters are designed. The quadratic measure of the error function between the passband and stopband of the filter has been used an objective function. First, the low-pass analysis filter is designed and then the PR condition has been expressed as a set of linear constraints on the corresponding synthesis low-pass filter. Subsequently, the corresponding synthesis filter is designed using the eigenfilter design method with linear constraints. The newly designed 2-D filters are used in translation invariant pyramidal directional filter bank (TIPDFB) for reduction of speckle noise in ultrasound images. The proposed 2-D filters give better symmetry, regularity and frequency selectivity of the filters in comparison to existing design methods. The proposed method is validated on synthetic and real ultrasound data which ensures improvement in the quality of ultrasound images and efficiently suppresses the speckle noise compared to existing methods.

Design Principles and Practices for Implementation of MIL-STD-1760 in Aircraft and Stores

DTIC Science & Technology

1987-06-01

systems, a low level of interoperability is inevitable unless the designer recognizes the design risks , is aware of their causes and available means...for minimizing the risks , and organizes all phases of the weapon system development in the original design to enhance interoperability. Retrofitting...feet or more can be detected.) 105 TABLE VIII. Distrftl-dton method trade-offs. SWITCHING MAT=I FM ADVANTAGES: 1. Low techrical risk 1. Reduction in

Biomimetic/Bioinspired Design of Enzyme@capsule Nano/Microsystems.

PubMed

Shi, J; Jiang, Y; Zhang, S; Yang, D; Jiang, Z

2016-01-01

Enzyme@capsule nano/microsystems, which refer to the enzyme-immobilized capsules, have received tremendous interest owing to the combination of the high catalytic activities of encapsulated enzymes and the hierarchical structure of the capsule. The preparation of capsules and simultaneous encapsulation of enzymes is recognized as the core process for the rational design and construction of enzyme@capsule nano/microsystems. The strategy used has three major steps: (a) generation of the templates, (b) surface coating on the templates, and (c) removal of the templates, and it has been proven to be effective and versatile for the construction of enzyme@capsule nano/microsystems. Several conventional methods, including layer-by-layer assembly of polyelectrolytes, liquid crystalline templating method, etc., were used to design and construct enzyme@capsule nano/microsystems, but these have two major drawbacks. One is the low mechanical stability of the systems and the second is the harsh conditions used in the construction process. Learning from nature, several biomimetic/bioinspired methods such as biomineralization, biomimetic/bioinspired adhesion, and their combination have been exploited for the construction of enzyme@capsule nano/microsystems. In this chapter, we will present a general protocol for the construction of enzyme@capsule nano/microsystems using the latter approach. Some suggestions for improved design, construction, and characterization will also be presented with detailed procedures for specific examples. © 2016 Elsevier Inc. All rights reserved.

Teachers' Purposeful Design of Effective Technology Learning Activities

ERIC Educational Resources Information Center

Morgan, John Andrew Kerlin

2014-01-01

The goal of this study was to explore how exemplary teachers design learning activities that incorporate the use of technology. Teachers at three schools in a school district in Southern California were solicited for a survey regarding their use of technology in the classroom. Based on the surveys, high and low technology implementers were…

Using a Toolbox of Tailored Educational Lessons to Improve Fruit, Vegetable, and Physical Activity Behaviors among African American Women in California

ERIC Educational Resources Information Center

Backman, Desiree; Scruggs, Valarie; Atiedu, Akpene Ama; Bowie, Shene; Bye, Larry; Dennis, Angela; Hall, Melanie; Ossa, Alexandra; Wertlieb, Stacy; Foerster, Susan B.

2011-01-01

Objective: Evaluate the effectiveness of the "Fruit, Vegetable, and Physical Activity Toolbox for Community Educators" ("Toolbox"), an intervention originally designed for Spanish- and English-speaking audiences, in changing knowledge, attitudes, and behavior among low-income African American women. Design: Quasi-experimental…

Decoupling PI Controller Design for a Normal Conducting RF Cavity Using a Recursive LEVENBERG-MARQUARDT Algorithm

NASA Astrophysics Data System (ADS)

Kwon, Sung-il; Lynch, M.; Prokop, M.

2005-02-01

This paper addresses the system identification and the decoupling PI controller design for a normal conducting RF cavity. Based on the open-loop measurement data of an SNS DTL cavity, the open-loop system's bandwidths and loop time delays are estimated by using batched least square. With the identified system, a PI controller is designed in such a way that it suppresses the time varying klystron droop and decouples the In-phase and Quadrature of the cavity field. The Levenberg-Marquardt algorithm is applied for nonlinear least squares to obtain the optimal PI controller parameters. The tuned PI controller gains are downloaded to the low-level RF system by using channel access. The experiment of the closed-loop system is performed and the performance is investigated. The proposed tuning method is running automatically in real time interface between a host computer with controller hardware through ActiveX Channel Access.

An improved synchronous reference frame current control strategy for a photovoltaic grid-connected inverter under unbalanced and nonlinear load conditions.

PubMed

Naderipour, Amirreza; Asuhaimi Mohd Zin, Abdullah; Bin Habibuddin, Mohd Hafiz; Miveh, Mohammad Reza; Guerrero, Josep M

2017-01-01

In recent years, renewable energy sources have been considered the most encouraging resources for grid and off-grid power generation. This paper presents an improved current control strategy for a three-phase photovoltaic grid-connected inverter (GCI) under unbalanced and nonlinear load conditions. It is challenging to suppress the harmonic content in the output current below a pre-set value in the GCI. It is also difficult to compensate for unbalanced loads even when the grid is under disruption due to total harmonic distortion (THD) and unbalanced loads. The primary advantage and objective of this method is to effectively compensate for the harmonic current content of the grid current and microgrid without the use of any compensation devices, such as active and passive filters. This method leads to a very low THD in both the GCI currents and the current exchanged with the grid. The control approach is designed to control the active and reactive power and harmonic current compensation, and it also corrects the system unbalance. The proposed control method features the synchronous reference frame (SRF) method. Simulation results are presented to demonstrate the effective performance of the proposed method.

An improved synchronous reference frame current control strategy for a photovoltaic grid-connected inverter under unbalanced and nonlinear load conditions

PubMed Central

Naderipour, Amirreza; Asuhaimi Mohd Zin, Abdullah; Bin Habibuddin, Mohd Hafiz; Miveh, Mohammad Reza; Guerrero, Josep M.

2017-01-01

In recent years, renewable energy sources have been considered the most encouraging resources for grid and off-grid power generation. This paper presents an improved current control strategy for a three-phase photovoltaic grid-connected inverter (GCI) under unbalanced and nonlinear load conditions. It is challenging to suppress the harmonic content in the output current below a pre-set value in the GCI. It is also difficult to compensate for unbalanced loads even when the grid is under disruption due to total harmonic distortion (THD) and unbalanced loads. The primary advantage and objective of this method is to effectively compensate for the harmonic current content of the grid current and microgrid without the use of any compensation devices, such as active and passive filters. This method leads to a very low THD in both the GCI currents and the current exchanged with the grid. The control approach is designed to control the active and reactive power and harmonic current compensation, and it also corrects the system unbalance. The proposed control method features the synchronous reference frame (SRF) method. Simulation results are presented to demonstrate the effective performance of the proposed method. PMID:28192436

Low-disturbance manure application methods in a corn silage-rye cover crop system

USDA-ARS?s Scientific Manuscript database

Incorporation of manure by tillage can conserve manure N by reducing ammonia volatilization losses, but tillage also incorporates crop residue, which increases erosion potential. This study compared several low-disturbance manure application methods, designed to incorporate manure while still mainta...

Virtual screening and rational drug design method using structure generation system based on 3D-QSAR and docking.

PubMed

Chen, H F; Dong, X C; Zen, B S; Gao, K; Yuan, S G; Panaye, A; Doucet, J P; Fan, B T

2003-08-01

An efficient virtual and rational drug design method is presented. It combines virtual bioactive compound generation with 3D-QSAR model and docking. Using this method, it is possible to generate a lot of highly diverse molecules and find virtual active lead compounds. The method was validated by the study of a set of anti-tumor drugs. With the constraints of pharmacophore obtained by DISCO implemented in SYBYL 6.8, 97 virtual bioactive compounds were generated, and their anti-tumor activities were predicted by CoMFA. Eight structures with high activity were selected and screened by the 3D-QSAR model. The most active generated structure was further investigated by modifying its structure in order to increase the activity. A comparative docking study with telomeric receptor was carried out, and the results showed that the generated structures could form more stable complexes with receptor than the reference compound selected from experimental data. This investigation showed that the proposed method was a feasible way for rational drug design with high screening efficiency.

Analog integrated circuits design for processing physiological signals.

PubMed

Li, Yan; Poon, Carmen C Y; Zhang, Yuan-Ting

2010-01-01

Analog integrated circuits (ICs) designed for processing physiological signals are important building blocks of wearable and implantable medical devices used for health monitoring or restoring lost body functions. Due to the nature of physiological signals and the corresponding application scenarios, the ICs designed for these applications should have low power consumption, low cutoff frequency, and low input-referred noise. In this paper, techniques for designing the analog front-end circuits with these three characteristics will be reviewed, including subthreshold circuits, bulk-driven MOSFETs, floating gate MOSFETs, and log-domain circuits to reduce power consumption; methods for designing fully integrated low cutoff frequency circuits; as well as chopper stabilization (CHS) and other techniques that can be used to achieve a high signal-to-noise performance. Novel applications using these techniques will also be discussed.

Reduction of magnetic field fluctuations in powered magnets for NMR using inductive measurements and sampled-data feedback control.

PubMed

Li, Mingzhou; Schiano, Jeffrey L; Samra, Jenna E; Shetty, Kiran K; Brey, William W

2011-10-01

Resistive and hybrid (resistive/superconducting) magnets provide substantially higher magnetic fields than those available in low-temperature superconducting magnets, but their relatively low spatial homogeneity and temporal field fluctuations are unacceptable for high resolution NMR. While several techniques for reducing temporal fluctuations have demonstrated varying degrees of success, this paper restricts attention to methods that utilize inductive measurements and feedback control to actively cancel the temporal fluctuations. In comparison to earlier studies using analog proportional control, this paper shows that shaping the controller frequency response results in significantly higher reductions in temporal fluctuations. Measurements of temporal fluctuation spectra and the frequency response of the instrumentation that cancels the temporal fluctuations guide the controller design. In particular, we describe a sampled-data phase-lead-lag controller that utilizes the internal model principle to selectively attenuate magnetic field fluctuations caused by the power supply ripple. We present a quantitative comparison of the attenuation in temporal fluctuations afforded by the new design and a proportional control design. Metrics for comparison include measurements of the temporal fluctuations using Faraday induction and observations of the effect that the fluctuations have on nuclear resonance measurements. Copyright © 2011. Published by Elsevier Inc.

Cost-driven materials selection criteria for redox flow battery electrolytes

NASA Astrophysics Data System (ADS)

Dmello, Rylan; Milshtein, Jarrod D.; Brushett, Fikile R.; Smith, Kyle C.

2016-10-01

Redox flow batteries show promise for grid-scale energy storage applications but are presently too expensive for widespread adoption. Electrolyte material costs constitute a sizeable fraction of the redox flow battery price. As such, this work develops a techno-economic model for redox flow batteries that accounts for redox-active material, salt, and solvent contributions to the electrolyte cost. Benchmark values for electrolyte constituent costs guide identification of design constraints. Nonaqueous battery design is sensitive to all electrolyte component costs, cell voltage, and area-specific resistance. Design challenges for nonaqueous batteries include minimizing salt content and dropping redox-active species concentration requirements. Aqueous battery design is sensitive to only redox-active material cost and cell voltage, due to low area-specific resistance and supporting electrolyte costs. Increasing cell voltage and decreasing redox-active material cost present major materials selection challenges for aqueous batteries. This work minimizes cost-constraining variables by mapping the battery design space with the techno-economic model, through which we highlight pathways towards low price and moderate concentration. Furthermore, the techno-economic model calculates quantitative iterations of battery designs to achieve the Department of Energy battery price target of 100 per kWh and highlights cost cutting strategies to drive battery prices down further.

Pharmaceutical Services in Primary Health Care: are pharmacists and users on the same page?

PubMed

Luz, Tatiana Chama Borges; Costa, Maria Emília Silva de Souza; Portes, Daniela Santana; Santos, Lucas Barbi Costa E; Sousa, Samuel Rodrigues Almeida E; Luiza, Vera Lucia

2017-08-01

This study investigated structural and organizational characteristics of the Pharmaceutical Services based on Primary Health Care (PHCPS) from the viewpoints of users and pharmacists. A mixed method design was applied, combining one-to-one semi-structured interviews with four pharmacists in charge of five public dispensing facilities and 69 users, with a secondary database analysis. Data were collected from February to August 2014 in Divinópolis, a municipality in Minas Gerais State. PHCPS were similar in terms of general activities performed and staff profile and background. While users were concerned about medicines' availability and improvements related to the PHCPS' conveniences and personnel, pharmacists pointed out problems regarding infrastructure to storage. Despite most users had low information on how to use their medicines, no pharmacists declared to participate in medicines dispensing activities. There was a low match between users and pharmacists viewpoints and advantages for concentrate medicines dispensing in a smaller number of facilities were not clear.

A Colorimetric Microplate Assay for DNA-Binding Activity of His-Tagged MutS Protein.

PubMed

Banasik, Michał; Sachadyn, Paweł

2016-09-01

A simple microplate method was designed for rapid testing DNA-binding activity of proteins. The principle of the assay involves binding of tested DNA by his-tagged protein immobilized on a nickel-coated ELISA plate, following colorimetric detection of biotinylated DNA with avidin conjugated to horseradish peroxidase. The method was used to compare DNA mismatch binding activities of MutS proteins from three bacterial species. The assay required relatively low amounts of tested protein (approximately 0.5-10 pmol) and DNA (0.1-10 pmol) and a relatively short time of analysis (up to 60 min). The method is very simple to apply and convenient to test different buffer conditions of DNA-protein binding. Sensitive colorimetric detection enables naked eye observations and quantitation with an ELISA reader. The performance of the assay, which we believe is a distinguishing trait of the method, is based on two strong and specific molecular interactions: binding of a his-tagged protein to a nickel-coated microplate and binding of biotinylated DNA to avidin. In the reported experiments, the solution was used to optimize the conditions for DNA mismatch binding by MutS protein; however, the approach could be implemented to test nucleic acids interactions with any protein of interest.

Generative Recurrent Networks for De Novo Drug Design.

PubMed

Gupta, Anvita; Müller, Alex T; Huisman, Berend J H; Fuchs, Jens A; Schneider, Petra; Schneider, Gisbert

2018-01-01

Generative artificial intelligence models present a fresh approach to chemogenomics and de novo drug design, as they provide researchers with the ability to narrow down their search of the chemical space and focus on regions of interest. We present a method for molecular de novo design that utilizes generative recurrent neural networks (RNN) containing long short-term memory (LSTM) cells. This computational model captured the syntax of molecular representation in terms of SMILES strings with close to perfect accuracy. The learned pattern probabilities can be used for de novo SMILES generation. This molecular design concept eliminates the need for virtual compound library enumeration. By employing transfer learning, we fine-tuned the RNN's predictions for specific molecular targets. This approach enables virtual compound design without requiring secondary or external activity prediction, which could introduce error or unwanted bias. The results obtained advocate this generative RNN-LSTM system for high-impact use cases, such as low-data drug discovery, fragment based molecular design, and hit-to-lead optimization for diverse drug targets. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

The development of the experimental setup for measuring the cell membrane electrical potential by Sucrose-Gap Technique

NASA Astrophysics Data System (ADS)

Yuzhakov, AD; Nosarev, AV; Aleinik, AN

2017-11-01

This article describes the development of the experimental setup for measuring the cell membrane electrical potential by Double -Sucrose-Gap Technique. The double-gap isolation method allows the simultaneous measurement of electrical activity and tension output from contracting segments of muscle fibers. This technique has been widely used as a convenient tool for recording of the membrane activities from myelinated or unmyelinated nerves and muscle preparations. This device can be an effective way to provide undergraduate biomedical engineering students with invaluable experiences in neurophysiology. The installation design and its main characteristics are described. The advantages of the described device are the simplicity of the experiment, relatively low cost, the possibility of long-term experiment.

Rational design of syn-safencin, a novel linear antimicrobial peptide derived from the circular bacteriocin safencin AS-48.

PubMed

Fields, Francisco R; Carothers, Katelyn E; Balsara, Rashna D; Ploplis, Victoria A; Castellino, Francis J; Lee, Shaun W

2018-06-01

Bacteriocins hold unprecedented promise as a largely untapped source of antibiotic alternatives in the age of multidrug resistance. Here, we describe the first approach to systematically design variants of a novel AS-48 bacteriocin homologue, which we have termed safencin AS-48, from Bacillus safensis, to gain insights into engineering improved activity of bacteriocins. A library of synthetic peptides in which systematic amino acid substitutions to vary the periodicity and abundance of polar, acidic, aliphatic, and hydrophobic residues were generated for a total of 96 novel peptide variants of a single bacteriocin candidate. Using this method, we identified nine synthetic safencin (syn-safencin) variants with broad and potent antimicrobial activities with minimal inhibitory concentrations (MIC) as low as 250 nM against E. coli, P. aeruginosa, X. axonopodis, and S. pyogenes with minimal cytotoxicity to mammalian cells. It is anticipated that the strategies we have developed will serve as general guides for tuning the specificity of a given natural bacteriocin compound for therapeutic specificity.

Family leadership styles and adolescent dietary and physical activity behaviors: a cross-sectional study

PubMed Central

2012-01-01

Background Transformational leadership is conceptualized as a set of behaviors designed to inspire, energize and motivate others to achieve higher levels of functioning, and is associated with salient health-related outcomes in organizational settings. Given (a) the similarities that exist between leadership within organizational settings and parenting within families, and (b) the importance of the family environment in the promotion of adolescent health-enhancing behaviors, the purpose of this exploratory study was to examine the cross-sectional relationships between parents’ transformational leadership behaviors and adolescent dietary and physical activity behaviors. Methods 857 adolescents (aged 13–15, mean age = 14.70 yrs) completed measures of transformational parenting behaviors, healthful dietary intake and leisure-time physical activity. Regression analyses were conducted to examine relationships between family transformational leadership and adolescent health outcomes. A further ‘extreme group analysis’ was conducted by clustering families based on quartile splits. A MANCOVA (controlling for child gender) was conducted to examine differences between families displaying (a) HIGH levels of transformational parenting (consistent HIGH TP), (b) LOW levels of transformational parenting (consistent LOW TP), and (c) inconsistent levels of transformational parenting (inconsistent HIGH-LOW TP). Results Results revealed that adolescents’ perceptions of family transformational parenting were associated with both healthy dietary intake and physical activity. Adolescents who perceived their families to display the highest levels of transformational parenting (HIGH TP group) displayed greater healthy eating and physical activity behaviors than adolescents who perceived their families to display the lowest levels of transformational parenting behaviors (LOW TP group). Adolescents who perceived their families to display inconsistent levels of transformational parenting behaviors (HIGH-LOW TP group) displayed the same levels of healthy eating behaviors as those adolescents from the LOW TP group. For physical activity behaviors, adolescents who perceived their families to display inconsistent levels of transformational parenting behaviors (HIGH-LOW TP group) did not differ in terms of physical activity than those in either the HIGH TP or LOW TP group. Conclusions Family transformational parenting behaviors were positively associated with both healthful dietary intake and leisure-time physical activity levels amongst adolescents. The findings suggest that transformational leadership theory is a useful framework for understanding the relationship between family leadership behaviors and adolescent health outcomes. PMID:22546151

A unified, multifidelity quasi-newton optimization method with application to aero-structural designa

NASA Astrophysics Data System (ADS)

Bryson, Dean Edward

A model's level of fidelity may be defined as its accuracy in faithfully reproducing a quantity or behavior of interest of a real system. Increasing the fidelity of a model often goes hand in hand with increasing its cost in terms of time, money, or computing resources. The traditional aircraft design process relies upon low-fidelity models for expedience and resource savings. However, the reduced accuracy and reliability of low-fidelity tools often lead to the discovery of design defects or inadequacies late in the design process. These deficiencies result either in costly changes or the acceptance of a configuration that does not meet expectations. The unknown opportunity cost is the discovery of superior vehicles that leverage phenomena unknown to the designer and not illuminated by low-fidelity tools. Multifidelity methods attempt to blend the increased accuracy and reliability of high-fidelity models with the reduced cost of low-fidelity models. In building surrogate models, where mathematical expressions are used to cheaply approximate the behavior of costly data, low-fidelity models may be sampled extensively to resolve the underlying trend, while high-fidelity data are reserved to correct inaccuracies at key locations. Similarly, in design optimization a low-fidelity model may be queried many times in the search for new, better designs, with a high-fidelity model being exercised only once per iteration to evaluate the candidate design. In this dissertation, a new multifidelity, gradient-based optimization algorithm is proposed. It differs from the standard trust region approach in several ways, stemming from the new method maintaining an approximation of the inverse Hessian, that is the underlying curvature of the design problem. Whereas the typical trust region approach performs a full sub-optimization using the low-fidelity model at every iteration, the new technique finds a suitable descent direction and focuses the search along it, reducing the number of low-fidelity evaluations required. This narrowing of the search domain also alleviates the burden on the surrogate model corrections between the low- and high-fidelity data. Rather than requiring the surrogate to be accurate in a hyper-volume bounded by the trust region, the model needs only to be accurate along the forward-looking search direction. Maintaining the approximate inverse Hessian also allows the multifidelity algorithm to revert to high-fidelity optimization at any time. In contrast, the standard approach has no memory of the previously-computed high-fidelity data. The primary disadvantage of the proposed algorithm is that it may require modifications to the optimization software, whereas standard optimizers may be used as black-box drivers in the typical trust region method. A multifidelity, multidisciplinary simulation of aeroelastic vehicle performance is developed to demonstrate the optimization method. The numerical physics models include body-fitted Euler computational fluid dynamics; linear, panel aerodynamics; linear, finite-element computational structural mechanics; and reduced, modal structural bases. A central element of the multifidelity, multidisciplinary framework is a shared parametric, attributed geometric representation that ensures the analysis inputs are consistent between disciplines and fidelities. The attributed geometry also enables the transfer of data between disciplines. The new optimization algorithm, a standard trust region approach, and a single-fidelity quasi-Newton method are compared for a series of analytic test functions, using both polynomial chaos expansions and kriging to correct discrepancies between fidelity levels of data. In the aggregate, the new method requires fewer high-fidelity evaluations than the trust region approach in 51% of cases, and the same number of evaluations in 18%. The new approach also requires fewer low-fidelity evaluations, by up to an order of magnitude, in almost all cases. The efficacy of both multifidelity methods compared to single-fidelity optimization depends significantly on the behavior of the high-fidelity model and the quality of the low-fidelity approximation, though savings are realized in a large number of cases. The multifidelity algorithm is also compared to the single-fidelity quasi-Newton method for complex aeroelastic simulations. The vehicle design problem includes variables for planform shape, structural sizing, and cruise condition with constraints on trim and structural stresses. Considering the objective function reduction versus computational expenditure, the multifidelity process performs better in three of four cases in early iterations. However, the enforcement of a contracting trust region slows the multifidelity progress. Even so, leveraging the approximate inverse Hessian, the optimization can be seamlessly continued using high-fidelity data alone. Ultimately, the proposed new algorithm produced better designs in all four cases. Investigating the return on investment in terms of design improvement per computational hour confirms that the multifidelity advantage is greatest in early iterations, and managing the transition to high-fidelity optimization is critical.

Environmental control implications of generating electric power from coal. 1977 technology status report. Appendix D. Assessment of NO/sub x/ control technology for coal fired utility boilers. [Low-excess-air, staged combustion, flu gas recirculation and burner design

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

Not Available

1977-12-01

An NOx control technology assessment study was conducted to examine the effectiveness of low-excess-air firing, staged combustion, flue gas recirculation, and current burner/boiler designs as applied to coal-fired utility boilers. Significant variations in NOx emissions exist with boiler type, firing method, and coal type, but a relative comparison of emissions control performance, cost, and operational considerations is presented for each method. The study emphasized the numerous operational factors that are of major importance to the user in selecting and implementing a combustion modification technique. Staged combustion and low-excess-air operation were identified as the most cost-effective methods for existing units. Closemore » control of local air/fuel ratios and rigorous combustion equipment maintenance are essential to the success of both methods. Flue gas recirculation is relatively ineffective and has the added concern of tube erosion. More research is needed to resolve potential corrosion concerns with low-NOx operating modes. Low-NOx burners in conjunction with a compartmentalized windbox are capable of meeting a 0.6-lb/million Btu emission level on new units. Advanced burner designs are being developed to meet research emission goals of approximately 0.25 lb/MBtu.« less

The Minnesota Green Tea Trial (MGTT), a randomized controlled trial of the efficacy of green tea extract on biomarkers of breast cancer risk: Study rationale, design, methods, and participant characteristics

PubMed Central

Samavat, Hamed; Dostal, Allison M.; Wang, Renwei; Bedell, Sarah; Emory, Tim H.; Ursin, Giske; Torkelson, Carolyn J.; Gross, Myron D.; Le, Chap T.; Yu, Mimi C.; Yang, Chung S.; Yee, Douglas; Wu, Anna H.; Yuan, Jian-Min; Kurzer, Mindy S.

2015-01-01

Purpose The Minnesota Green Tea Trial (MGTT) was a randomized, placebo-controlled, double-blinded trial investigating the effect of daily green tea extract consumption for 12 months on biomarkers of breast cancer risk. Methods Participants were healthy postmenopausal women at high risk of breast cancer due to dense breast tissue with differing catechol-O-methyltransferase (COMT) genotypes. The intervention was a green tea catechin extract containing 843.0 ± 44.0 mg/day epigallocatechin gallate or placebo capsules for one year. Annual digital screening mammograms were obtained at baseline and month 12, and fasting blood and 24-hour urine samples were provided at baseline, months 6, and 12. Primary endpoints included changes in percent mammographic density, circulating endogenous sex hormones and insulin-like growth factor axis proteins; secondary endpoints were changes in urinary estrogens and estrogen metabolites and circulating F2-isoprostanes, a biomarker of oxidative stress. Results The MGTT screened more than 100,000 mammograms and randomized 1075 participants based on treatment (green tea extract vs. placebo), stratified by COMT genotype activity (high COMT vs. low/intermediate COMT genotype activity). 937 women successfully completed the study and 138 dropped out (overall dropout rate= 12.8%). Conclusions In this paper we report the rationale, design, recruitment, participant characteristics, and methods for biomarker and statistical analyses. PMID:26206423

Low-Income Low-Qualified Employees' Access to Workplace Learning

ERIC Educational Resources Information Center

McPherson, Rebecca; Wang, Jia

2014-01-01

Purpose: The purpose of this paper was to investigate the embedded process that enables or constrains low-income low-qualified employees' access to workplace learning in small organizations. Design/methodology/approach: Informed by the sociomaterial approach and cultural historical activity theory, this study adopted a qualitative cross-case study…

Teachers as Co-Designers of Technology-Rich Learning Activities for Early Literacy

ERIC Educational Resources Information Center

Cviko, Amina; McKenney, Susan; Voogt, Joke

2015-01-01

Although kindergarten teachers often struggle with implementing technology, they are rarely involved in co-designing technology-rich learning activities. This study involved teachers in the co-design of technology-rich learning activities and sought to explore implementation and pupil learning outcomes. A case-study method was used to investigate:…

Lift/cruise fan V/STOL technology aircraft design definition study. Volume 2: Propulsion transmission system design

NASA Technical Reports Server (NTRS)

Obrien, W. J.

1976-01-01

Two types of lift/cruise fan technology aircraft were conceptually designed. One aircraft used turbotip fans pneumatically interconnected to three gas generators, and the other aircraft used variable pitch fans mechanically interconnected to three turboshaft engines. The components of each propulsion transmission system were analyzed and designed to the depth necessary to determine areas of risk, development methods, performance, weights and costs. The types of materials and manufacturing processes were identified to show that the designs followed a low cost approach. The lift/cruise fan thrust vectoring hoods, which are applicable to either aircraft configuration, were also evaluated to assure a low cost/low risk approach.

Healthy food choices and physical activity opportunities in two contrasting Alabama cities.

PubMed

Bovell-Benjamin, A C; Hathorn, C S; Ibrahim, S; Gichuhi, P N; Bromfield, E M

2009-06-01

Food and physical activity access and availability in two contrasting cities in Alabama were investigated. An in-outlet, observational, cross-sectional design was utilized to assess the opportunities for healthy food choices and physical activity. Thirty retail food outlets and 29 physical activity outlets were inventoried. None of the convenience stores carried frozen, low-sodium or dark-green, yellow vegetables, low-fat milk or yogurt, low-sodium and low-fat cheese, while none of the supermarkets in Tuskegee stocked low-sodium vegetables. In Tuskegee, the single public recreational area, which offered activities such as basketball, fees ranged from $25 to $35/month. Tuskegee has a shortage of "chain" supermarkets and a dominance of convenience stores which stocked few healthy foods. Overall, there are limited opportunities for healthy food and physical activity choices, which could be a barrier for chronic disease prevention efforts.

An ultra-low-power filtering technique for biomedical applications.

PubMed

Zhang, Tan-Tan; Mak, Pui-In; Vai, Mang-I; Mak, Peng-Un; Wan, Feng; Martins, R P

2011-01-01

This paper describes an ultra-low-power filtering technique for biomedical applications designated as T-wave sensing in heart-activities detection systems. The topology is based on a source-follower-based Biquad operating in the sub-threshold region. With the intrinsic advantages of simplicity and high linearity of the source-follower, ultra-low-cutoff filtering can be achieved, simultaneously with ultra low power and good linearity. An 8(th)-order 2.4-Hz lowpass filter design example optimized in a 0.35-μm CMOS process was designed achieving over 85-dB dynamic range, 74-dB stopband attenuation and consuming only 0.36 nW at a 3-V supply.

Comprehensive sequence-flux mapping of a levoglucosan utilization pathway in E. coli

DOE PAGES

Klesmith, Justin R.; Bacik, John -Paul; Michalczyk, Ryszard; ...

2015-09-14

Synthetic metabolic pathways often suffer from low specific productivity, and new methods that quickly assess pathway functionality for many thousands of variants are urgently needed. Here we present an approach that enables the rapid and parallel determination of sequence effects on flux for complete gene-encoding sequences. We show that this method can be used to determine the effects of over 8000 single point mutants of a pyrolysis oil catabolic pathway implanted in Escherichia coli. Experimental sequence-function data sets predicted whether fitness-enhancing mutations to the enzyme levoglucosan kinase resulted from enhanced catalytic efficiency or enzyme stability. A structure of one designmore » incorporating 38 mutations elucidated the structural basis of high fitness mutations. One design incorporating 15 beneficial mutations supported a 15-fold improvement in growth rate and greater than 24-fold improvement in enzyme activity relative to the starting pathway. Lastly, this technique can be extended to improve a wide variety of designed pathways.« less

Physical and Psychological Effects of Head Treatment in the Supine Position Using Specialized Ayurveda-Based Techniques

PubMed Central

Iwawaki, Yoko; Uebaba, Kazuo; Yamamoto, Yoko; Takishita, Yukie; Harada, Kiyomi; Shibata, Akemi; Narumoto, Jin; Fukui, Kenji

2016-01-01

Abstract Objective: To clarify the physical and psychological effects of head massage performed in the supine position using Ayurveda-based techniques (head treatment). Design: Twenty-four healthy female students were included in the study. Using a crossover study design, the same participants were enrolled in both the head treatment intervention group and control group. There was an interval of 1 week or more between measurements. Outcome measures: The physiologic indices measured included blood pressure and heart rate fluctuations (high frequency and low frequency/high frequency). The psychological markers measured included liveliness, depression, and boredom using the visual analogue scale method. State anxiety was measured using the State-Trait Anxiety Inventory method. Results: The parasympathetic nerve activity increased immediately after head treatment. Upon completion of head treatment, the parasympathetic nerve predominance tended to gradually ease. Head treatment boosted freshness and relieved anxiety. Conclusions: The results suggest that head treatment has a relaxing and refreshing effect and may be used to provide comfort. PMID:27163344

Robust Control for Microgravity Vibration Isolation using Fixed Order, Mixed H2/Mu Design

NASA Technical Reports Server (NTRS)

Whorton, Mark

2003-01-01

Many space-science experiments need an active isolation system to provide a sufficiently quiescent microgravity environment. Modern control methods provide the potential for both high-performance and robust stability in the presence of parametric uncertainties that are characteristic of microgravity vibration isolation systems. While H2 and H(infinity) methods are well established, neither provides the levels of attenuation performance and robust stability in a compensator with low order. Mixed H2/H(infinity), controllers provide a means for maximizing robust stability for a given level of mean-square nominal performance while directly optimizing for controller order constraints. This paper demonstrates the benefit of mixed norm design from the perspective of robustness to parametric uncertainties and controller order for microgravity vibration isolation. A nominal performance metric analogous to the mu measure, for robust stability assessment is also introduced in order to define an acceptable trade space from which different control methodologies can be compared.

The detection error of thermal test low-frequency cable based on M sequence correlation algorithm

NASA Astrophysics Data System (ADS)

Wu, Dongliang; Ge, Zheyang; Tong, Xin; Du, Chunlin

2018-04-01

The problem of low accuracy and low efficiency of off-line detecting on thermal test low-frequency cable faults could be solved by designing a cable fault detection system, based on FPGA export M sequence code(Linear feedback shift register sequence) as pulse signal source. The design principle of SSTDR (Spread spectrum time-domain reflectometry) reflection method and hardware on-line monitoring setup figure is discussed in this paper. Testing data show that, this detection error increases with fault location of thermal test low-frequency cable.

Comparative research on activation technique for GaAs photocathodes

NASA Astrophysics Data System (ADS)

Chen, Liang; Qian, Yunsheng; Chang, Benkang; Chen, Xinlong; Yang, Rui

2012-03-01

The properties of GaAs photocathodes mainly depend on the material design and activation technique. In early researches, high-low temperature two-step activation has been proved to get more quantum efficiency than high-temperature single-step activation. But the variations of surface barriers for two activation techniques have not been well studied, thus the best activation temperature, best Cs-O ratio and best activation time for two-step activation technique have not been well found. Because the surface photovoltage spectroscopy (SPS) before activation is only in connection with the body parameters for GaAs photocathode such as electron diffusion length and the spectral response current (SRC) after activation is in connection with not only body parameters but also surface barriers, thus the surface escape probability (SEP) can be well fitted through the comparative research between SPS before activation and SEP after activation. Through deduction for the tunneling process of surface barriers by Schrödinger equation, the width and height for surface barrier I and II can be well fitted through the curves of SEP. The fitting results were well proved and analyzed by quantitative analysis of angle-dependent X-ray photoelectron spectroscopy (ADXPS) which can also study the surface chemical compositions, atomic concentration percentage and layer thickness for GaAs photocathodes. This comparative research method for fitting parameters of surface barriers through SPS before activation and SRC after activation shows a better real-time in system method for the researches of activation techniques.

Production of egg white protein hydrolysates with improved antioxidant capacity in a continuous enzymatic membrane reactor: optimization of operating parameters by statistical design.

PubMed

Jakovetić Tanasković, Sonja; Luković, Nevena; Grbavčić, Sanja; Stefanović, Andrea; Jovanović, Jelena; Bugarski, Branko; Knežević-Jugović, Zorica

2018-01-01

This study focuses on the influence of operating conditions on Alcalase-catalyzed egg white protein hydrolysis performed in a continuously stirred tank reactor coupled with ultrafiltration module (10 kDa). The permeate flow rate did not significantly affect the degree of hydrolysis (DH), but a significant increase in process productivity was apparent above flow rate of 1.9 cm 3 min -1 . By contrast, an increase in enzyme/substrate ( E / S ) ratio provided an increase in DH, but a negative correlation was observed between E / S ratio and productivity. The relationship between operating conditions and antioxidant properties of the hydrolysates, measured by three methods, was studied using Box-Behnken experimental design and response surface methodology. The statistical analysis showed that each variable (impeller speed, E / S ratio, and permeate flow rate) had a significant effect on the antioxidant capacity of all tested systems. Nevertheless, obtained response functions revealed that antioxidative activity measured by DPPH, ABTS and FRAP methods were affected differently by the same operating conditions. High impeller speeds and low permeate flow rates favor ABTS while high impeller speeds and high permeate flow rates had a positive effect on the DPPH scavenging activity. On the other hand, the best results obtained with FRAP method were achieved under moderate operating conditions. The integration of the reaction and ultrafiltration membrane separation in a continuous manner appears to be a right approach to improve and intensify the enzymatic process, enabling the production of peptides with desired antioxidant activity.

Objective assessment of obesogenic environments in youth: geographic information system methods and spatial findings from the Neighborhood Impact on Kids study.

PubMed

Frank, Lawrence D; Saelens, Brian E; Chapman, James; Sallis, James F; Kerr, Jacqueline; Glanz, Karen; Couch, Sarah C; Learnihan, Vincent; Zhou, Chuan; Colburn, Trina; Cain, Kelli L

2012-05-01

GIS-based walkability measures designed to explain active travel fail to capture "playability" and proximity to healthy food. These constructs should be considered when measuring potential child obesogenic environments. The aim of this study was to describe the development of GIS-based multicomponent physical activity and nutrition environment indicators of child obesogenic environments in the San Diego and Seattle regions. Block group-level walkability (street connectivity, residential density, land-use mix, and retail floor area ratio) measures were constructed in each region. Multiple sources were used to enumerate parks (∼900-1600 per region) and food establishments (∼10,000 per region). Physical activity environments were evaluated on the basis of walkability and presence and quality of parks. Nutrition environments were evaluated based on presence and density of fast-food restaurants and distance to supermarkets. Four neighborhood types were defined using high/low cut points for physical activity and nutrition environments defined through an iterative process dependent on regional counts of fast-food outlets and overall distance to parks and grocery stores from census block groups where youth live. To identify sufficient numbers of children aged 6-11 years, high physical activity environment block groups had at least one high-quality park within 0.25 miles and were above median walkability, whereas low physical activity environment groups had no parks and were below median walkability. High nutrition environment block groups had a supermarket within 0.5 miles, and fewer than 16 (Seattle) and 31 (San Diego) fast-food restaurants within 0.5 miles. Low nutrition environments had either no supermarket, or a supermarket and more than 16 (Seattle) and 31 (San Diego) fast-food restaurants within 0.5 miles. Income, educational attainment, and ethnicity varied across physical activity and nutrition environments. These approaches to defining neighborhood environments can be used to study physical activity, nutrition, and obesity outcomes. Findings presented in a companion paper validate these GIS methods for measuring obesogenic environments. Copyright © 2012 American Journal of Preventive Medicine. All rights reserved.

Designing Culturally Relevant Physical Activity Programs for African American Women: A Framework for Intervention Development

PubMed Central

Keller, Colleen; Affuso, Oliva; Ainsworth, Barbara E.

2016-01-01

Background African American women perform low levels of physical activity and are disproportionally burdened by associated cardiometabolic disease conditions (i.e. 57% are obese, 49% have cardiovascular disease) The marked health disparities among African American women indicate the need for innovative strategies to promote physical activity to help attenuate the chronic disease health disparities in this high-risk population. Culturally tailoring PA programs to address the sociocultural norms, values, beliefs, and behaviors of African American women is an advantageous strategy to enhance physical activity promotion efforts. The purpose of this article is to discuss critical aspects for researchers to consider when designing physical activity programs for African American women and to present a conceptual framework to guide intervention development. Methods Development of the framework was based on our previous physical activity research with African American women, seminal literature on the topics of cultural adaptation and health promotion, sociological and theoretical perspectives on the role of women in African American culture, and key determinants of physical activity engagement among African American women. Results Three key concepts are discussed in the conceptual framework: 1) Developmental milestones and life stage transitions of African American women, 2) Historical, social and cultural influences associated with physical activity engagement, and 3) Intervention delivery strategies. Discussion Using the framework to guide intervention development has the potential to enhance the physical activity and health outcomes of a physical activity program for African American women. PMID:27178447

Management of Total Pressure Recovery, Distortion and High Cycle Fatigue in Compact Air Vehicle Inlets

NASA Technical Reports Server (NTRS)

Anderson, Bernhard H.; Baust, Henry D.; Agrell, Johan

2002-01-01

It is the purpose of this study to demonstrate the viability and economy of Response Surface Methods (RSM) and Robustness Design Concepts (RDC) to arrive at micro-secondary flow control installation designs that maintain optimal inlet performance over a range of the mission variables. These statistical design concepts were used to investigate the robustness properties of 'low unit strength' micro-effector installations. 'Low unit strength' micro-effectors are micro-vanes set at very low angles-of-incidence with very long chord lengths. They were designed to influence the near wall inlet flow over an extended streamwise distance, and their advantage lies in low total pressure loss and high effectiveness in managing engine face distortion.

A feasibility study of a culturally and gender-specific dance to promote physical activity for South Asian immigrant women in the greater Toronto area.

PubMed

Vahabi, Mandana; Damba, Cynthia

2015-01-01

Despite ample evidence demonstrating the protective effect of physical activity, the uptake of regular physical activity among South Asian (SA) women remains relatively low. The purpose of this study was to explore the feasibility and health impacts of implementing a culture- and gender-specific physical activity among SA immigrant women residing in Greater Toronto Area (GTA) in Ontario, Canada. A community-based mixed methods approach combining cohort pretest and posttest design and qualitative methods employing in depth interviews was used. Twenty-seven SA women from the GTA participated in a 6-week, 2 days per week, Bollywood Dance exercise program led by a female SA instructor. The participation rate was considerably high (85%) and approximately 82% of the participants attended 10 or more of the classes offered. The participants' physical measurements (weight, waist and hip, and body mass index) decreased, although not significantly, over the 6-week period and there was an improvement in their physical, mental, and social health. During the face-to-face interviews, participants reported feeling less stressed and tired, being more mentally and physically robust, and having a sense of fulfillment and self-satisfaction. The only common criticism expressed was that the 6-week duration of the intervention was too short. The results showed that the Bollywood Dance was a feasible strategy in engaging SA immigrant women in physical activity. The key aspects when designing culture- and gender-specific dance interventions include community participation and active engagement in planning and implementation of the program, a supportive environment, same gender and culturally attuned dance instructor, easy access, and minimal to no cost. Copyright © 2015 Jacobs Institute of Women's Health. Published by Elsevier Inc. All rights reserved.

Analysis of alternatives for immobilized low activity waste disposal

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

Burbank, D.A.

This report presents a study of alternative disposal system architectures and implementation strategies to provide onsite near-surface disposal capacity to receive the immobilized low-activity waste produced by the private vendors. The analysis shows that a flexible unit strategy that provides a suite of design solutions tailored to the characteristics of the immobilized low-activity waste will provide a disposal system that best meets the program goals of reducing the environmental, health, and safety impacts; meeting the schedule milestones; and minimizing the life-cycle cost of the program.

Nudging socially isolated people towards well-being with the ‘Happiness Route’: design of a randomized controlled trial for the evaluation of a happiness-based intervention

PubMed Central

2013-01-01

Background The Happiness Route is an innovative intervention that uses a happiness-based approach for people with an accumulation of risk factors for low well-being: socially isolated people with health impairments and a low socioeconomic status. The goal of this intervention is to improve well-being by engaging participants in intrinsically motivated activities with methods from positive psychology. We hypothesize that the primary outcome measure, emotional, social and psychological well-being of participants of the Happiness Route, will increase in comparison to the traditional and commonly-used problem-based approach. Secondary outcome measures are health-related quality of life, psychosocial functioning and health care consumption. Methods and design Participants will be socially isolated people with health problems and a low socioeconomic status. Participants will be recruited in ten Dutch communities and candidates will be signed up by intermediaries, professionals from the health and social sector. Randomly assigned, half of the participants will follow the Happiness Route and half of the participants will follow the active, problem-focused control group ‘Customized Care’. In total, 256 participants will be included. In both conditions, participants will receive counseling sessions from trained counselors. In the control group, participants will talk about their problems and the care they get and counselors help to optimize their care. In the Happiness Route, the counselor ask questions such as “How do you want to live your life?”. The intervention helps people to find their ‘passion’, i.e., a positive goal-engaged and intrinsically motivated activity. It enables them to follow their passion through by a once-only personal happiness budget (maximal €500). We use well-validated and reliable questionnaires to measure primary and secondary outcome measures at baseline, directly after the intervention and at a nine-month follow-up. Discussion Shortcomings of earlier intervention studies in positive psychology will be tackled with this study, such as having a target group who is especially vulnerable for low well-being. The practice-based setting is especially interesting, as it can give valuable insights in how positive psychology interventions work in practice, but can also give rise to several challenges. Trial registration Dutch Trial Register, trial registration number TC=3377NTR. http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=3377. PMID:24053566

Synthesis of aircraft structures using integrated design and analysis methods

NASA Technical Reports Server (NTRS)

Sobieszczanski-Sobieski, J.; Goetz, R. C.

1978-01-01

A systematic research is reported to develop and validate methods for structural sizing of an airframe designed with the use of composite materials and active controls. This research program includes procedures for computing aeroelastic loads, static and dynamic aeroelasticity, analysis and synthesis of active controls, and optimization techniques. Development of the methods is concerned with the most effective ways of integrating and sequencing the procedures in order to generate structural sizing and the associated active control system, which is optimal with respect to a given merit function constrained by strength and aeroelasticity requirements.

OVERMODED HIGH-POWER RF MAGNETIC SWITCHES AND CIRCULATORS

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

Tantawi, Sami

2002-08-20

We present design methodology for active rf magnetic components which are suitable for pulse compression systems of future X-band linear colliders. These components comprise an array of active elements arranged together so that the total electromagnetic field is reduced and the power handling capabilities are increased. The active element of choice is a magnetic material (garnet), which can be switched by changing a biasing magnetic field. A novel design allows these components to operate in the low loss circular waveguide mode TE{sub 01}. We describe the design methodology, the switching elements and circuits.

An artificial viscosity method for the design of supercritical airfoils

NASA Technical Reports Server (NTRS)

Mcfadden, G. B.

1979-01-01

A numerical technique is presented for the design of two-dimensional supercritical wing sections with low wave drag. The method is a design mode of the analysis code H which gives excellent agreement with experimental results and is widely used in the aircraft industry. Topics covered include the partial differential equations of transonic flow, the computational procedure and results; the design procedure; a convergence theorem; and description of the code.

Structural optimisation of cage induction motors using finite element analysis

NASA Astrophysics Data System (ADS)

Palko, S.

The current trend in motor design is to have highly efficient, low noise, low cost, and modular motors with a high power factor. High torque motors are useful in applications like servo motors, lifts, cranes, and rolling mills. This report contains a detailed review of different optimization methods applicable in various design problems. Special attention is given to the performance of different methods, when they are used with finite element analysis (FEA) as an objective function, and accuracy problems arising from the numerical simulations. Also an effective method for designing high starting torque and high efficiency motors is presented. The method described in this work utilizes FEA combined with algorithms for the optimization of the slot geometry. The optimization algorithm modifies the position of the nodal points in the element mesh. The number of independent variables ranges from 14 to 140 in this work.

A Deep Learning Approach to on-Node Sensor Data Analytics for Mobile or Wearable Devices.

PubMed

Ravi, Daniele; Wong, Charence; Lo, Benny; Yang, Guang-Zhong

2017-01-01

The increasing popularity of wearable devices in recent years means that a diverse range of physiological and functional data can now be captured continuously for applications in sports, wellbeing, and healthcare. This wealth of information requires efficient methods of classification and analysis where deep learning is a promising technique for large-scale data analytics. While deep learning has been successful in implementations that utilize high-performance computing platforms, its use on low-power wearable devices is limited by resource constraints. In this paper, we propose a deep learning methodology, which combines features learned from inertial sensor data together with complementary information from a set of shallow features to enable accurate and real-time activity classification. The design of this combined method aims to overcome some of the limitations present in a typical deep learning framework where on-node computation is required. To optimize the proposed method for real-time on-node computation, spectral domain preprocessing is used before the data are passed onto the deep learning framework. The classification accuracy of our proposed deep learning approach is evaluated against state-of-the-art methods using both laboratory and real world activity datasets. Our results show the validity of the approach on different human activity datasets, outperforming other methods, including the two methods used within our combined pipeline. We also demonstrate that the computation times for the proposed method are consistent with the constraints of real-time on-node processing on smartphones and a wearable sensor platform.

Physical Activity Attenuates the Effect of Low Birth Weight on Insulin Resistance in Adolescents

PubMed Central

Ortega, Francisco B.; Ruiz, Jonatan R.; Hurtig-Wennlöf, Anita; Meirhaeghe, Aline; González-Gross, Marcela; Moreno, Luis A.; Molnar, Dénes; Kafatos, Anthony; Gottrand, Frederic; Widhalm, Kurt; Labayen, Idoia; Sjöström, Michael

2011-01-01

OBJECTIVE To examine whether physical activity influences the association between birth weight and insulin resistance in adolescents. RESEARCH DESIGN AND METHODS The study comprised adolescents who participated in two cross-sectional studies: the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study (n = 520, mean age = 14.6 years) and the Swedish part of the European Youth Heart Study (EYHS) (n = 269, mean age = 15.6 years). Participants had valid data on birth weight (parental recall), BMI, sexual maturation, maternal education, breastfeeding, physical activity (accelerometry, counts/minute), fasting glucose, and insulin. Insulin resistance was assessed by homeostasis model assessment–insulin resistance (HOMA-IR). Maternal education level and breastfeeding duration were reported by the mothers. RESULTS There was a significant interaction of physical activity in the association between birth weight and HOMA-IR (logarithmically transformed) in both the HELENA study and the EYHS (P = 0.05 and P = 0.03, respectively), after adjusting for sex, age, sexual maturation, BMI, maternal education level, and breastfeeding duration. Stratified analyses by physical activity levels (below/above median) showed a borderline inverse association between birth weight and HOMA-IR in the low-active group (standardized β = −0.094, P = 0.09, and standardized β = −0.156, P = 0.06, for HELENA and EYHS, respectively), whereas no evidence of association was found in the high-active group (standardized β = −0.031, P = 0.62, and standardized β = 0.053, P = 0.55, for HELENA and EYHS, respectively). CONCLUSIONS Higher levels of physical activity may attenuate the adverse effects of low birth weight on insulin sensitivity in adolescents. More observational data, from larger and more powerful studies, are required to test these findings. PMID:21752955

Empowerment in the process of health messaging for rural low-income mothers: an exploratory message design project.

PubMed

Aldoory, Linda; Braun, Bonnie; Maring, Elisabeth Fost; Duggal, Mili; Briones, Rowena Lynn

2015-01-01

Rural, low-income mothers face challenges to their health equal to or greater than those of low-income mothers from urban areas. This study put health message design into the hands of low-income rural mothers. The current study filled a research gap by analyzing a participatory process used to design health messages tailored to the everyday lives of rural low-income mothers. A total of forty-three mothers participated in nine focus groups, which were held from 2012 to 2013, in eight states. The mothers were from different racial and ethnic backgrounds. Participants discussed food security, physical activity, and oral health information. They created messages by considering several elements: visuals, length of message, voice/perspective, self-efficacy and personal control, emotional appeals, positive and negative reinforcements, and steps to health behavior change. This study was innovative in its focus on empowerment as a key process to health message design.

A combined Fisher and Laplacian score for feature selection in QSAR based drug design using compounds with known and unknown activities.

PubMed

Valizade Hasanloei, Mohammad Amin; Sheikhpour, Razieh; Sarram, Mehdi Agha; Sheikhpour, Elnaz; Sharifi, Hamdollah

2018-02-01

Quantitative structure-activity relationship (QSAR) is an effective computational technique for drug design that relates the chemical structures of compounds to their biological activities. Feature selection is an important step in QSAR based drug design to select the most relevant descriptors. One of the most popular feature selection methods for classification problems is Fisher score which aim is to minimize the within-class distance and maximize the between-class distance. In this study, the properties of Fisher criterion were extended for QSAR models to define the new distance metrics based on the continuous activity values of compounds with known activities. Then, a semi-supervised feature selection method was proposed based on the combination of Fisher and Laplacian criteria which exploits both compounds with known and unknown activities to select the relevant descriptors. To demonstrate the efficiency of the proposed semi-supervised feature selection method in selecting the relevant descriptors, we applied the method and other feature selection methods on three QSAR data sets such as serine/threonine-protein kinase PLK3 inhibitors, ROCK inhibitors and phenol compounds. The results demonstrated that the QSAR models built on the selected descriptors by the proposed semi-supervised method have better performance than other models. This indicates the efficiency of the proposed method in selecting the relevant descriptors using the compounds with known and unknown activities. The results of this study showed that the compounds with known and unknown activities can be helpful to improve the performance of the combined Fisher and Laplacian based feature selection methods.

A combined Fisher and Laplacian score for feature selection in QSAR based drug design using compounds with known and unknown activities

NASA Astrophysics Data System (ADS)

Valizade Hasanloei, Mohammad Amin; Sheikhpour, Razieh; Sarram, Mehdi Agha; Sheikhpour, Elnaz; Sharifi, Hamdollah

2018-02-01

Quantitative structure-activity relationship (QSAR) is an effective computational technique for drug design that relates the chemical structures of compounds to their biological activities. Feature selection is an important step in QSAR based drug design to select the most relevant descriptors. One of the most popular feature selection methods for classification problems is Fisher score which aim is to minimize the within-class distance and maximize the between-class distance. In this study, the properties of Fisher criterion were extended for QSAR models to define the new distance metrics based on the continuous activity values of compounds with known activities. Then, a semi-supervised feature selection method was proposed based on the combination of Fisher and Laplacian criteria which exploits both compounds with known and unknown activities to select the relevant descriptors. To demonstrate the efficiency of the proposed semi-supervised feature selection method in selecting the relevant descriptors, we applied the method and other feature selection methods on three QSAR data sets such as serine/threonine-protein kinase PLK3 inhibitors, ROCK inhibitors and phenol compounds. The results demonstrated that the QSAR models built on the selected descriptors by the proposed semi-supervised method have better performance than other models. This indicates the efficiency of the proposed method in selecting the relevant descriptors using the compounds with known and unknown activities. The results of this study showed that the compounds with known and unknown activities can be helpful to improve the performance of the combined Fisher and Laplacian based feature selection methods.

Rapid design and optimization of low-thrust rendezvous/interception trajectory for asteroid deflection missions

NASA Astrophysics Data System (ADS)

Li, Shuang; Zhu, Yongsheng; Wang, Yukai

2014-02-01

Asteroid deflection techniques are essential in order to protect the Earth from catastrophic impacts by hazardous asteroids. Rapid design and optimization of low-thrust rendezvous/interception trajectories is considered as one of the key technologies to successfully deflect potentially hazardous asteroids. In this paper, we address a general framework for the rapid design and optimization of low-thrust rendezvous/interception trajectories for future asteroid deflection missions. The design and optimization process includes three closely associated steps. Firstly, shape-based approaches and genetic algorithm (GA) are adopted to perform preliminary design, which provides a reasonable initial guess for subsequent accurate optimization. Secondly, Radau pseudospectral method is utilized to transcribe the low-thrust trajectory optimization problem into a discrete nonlinear programming (NLP) problem. Finally, sequential quadratic programming (SQP) is used to efficiently solve the nonlinear programming problem and obtain the optimal low-thrust rendezvous/interception trajectories. The rapid design and optimization algorithms developed in this paper are validated by three simulation cases with different performance indexes and boundary constraints.

Computer-aided drug design for AMP-activated protein kinase activators.

PubMed

Wang, Zhanli; Huo, Jianxin; Sun, Lidan; Wang, Yongfu; Jin, Hongwei; Yu, Hui; Zhang, Liangren; Zhou, Lishe

2011-09-01

AMP-activated protein kinase (AMPK) is an important therapeutic target for the potential treatment of metabolic disorders, cardiovascular disease and cancer. Recently, various classes of compounds that activate AMPK by direct or indirect interactions have been reported. The importance of computer-aided drug design approaches in the search for potent activators of AMPK is now established, including structure-based design, ligand-based design, fragment-based design, as well as structural analysis. This review article highlights the computer-aided drug design approaches utilized to discover of activators targeting AMPK. The principles, advantages or limitation of the different methods are also being discussed together with examples of applications taken from the literatures.

Computer-Aided Drug Design Methods.

PubMed

Yu, Wenbo; MacKerell, Alexander D

2017-01-01

Computational approaches are useful tools to interpret and guide experiments to expedite the antibiotic drug design process. Structure-based drug design (SBDD) and ligand-based drug design (LBDD) are the two general types of computer-aided drug design (CADD) approaches in existence. SBDD methods analyze macromolecular target 3-dimensional structural information, typically of proteins or RNA, to identify key sites and interactions that are important for their respective biological functions. Such information can then be utilized to design antibiotic drugs that can compete with essential interactions involving the target and thus interrupt the biological pathways essential for survival of the microorganism(s). LBDD methods focus on known antibiotic ligands for a target to establish a relationship between their physiochemical properties and antibiotic activities, referred to as a structure-activity relationship (SAR), information that can be used for optimization of known drugs or guide the design of new drugs with improved activity. In this chapter, standard CADD protocols for both SBDD and LBDD will be presented with a special focus on methodologies and targets routinely studied in our laboratory for antibiotic drug discoveries.

Discharge Chamber Primary Electron Modeling Activities in Three-Dimensions

NASA Technical Reports Server (NTRS)

Steuber, Thomas J.

2004-01-01

Designing discharge chambers for ion thrusters involves many geometric configuration decisions. Various decisions will impact discharge chamber performance with respect to propellant utilization efficiency, ion production costs, and grid lifetime. These hardware design decisions can benefit from the assistance of computational modeling. Computational modeling for discharge chambers has been limited to two-dimensional codes that leveraged symmetry for interpretation into three-dimensional analysis. This paper presents model development activities towards a three-dimensional discharge chamber simulation to aid discharge chamber design decisions. Specifically, of the many geometric configuration decisions toward attainment of a worthy discharge chamber, this paper focuses on addressing magnetic circuit considerations with a three-dimensional discharge chamber simulation as a tool. With this tool, candidate discharge chamber magnetic circuit designs can be analyzed computationally to gain insight into factors that may influence discharge chamber performance such as: primary electron loss width in magnetic cusps, cathode tip position with respect to the low magnetic field volume, definition of a low magnetic field region, and maintenance of a low magnetic field region across the grid span. Corroborating experimental data will be obtained from mockup hardware tests. Initially, simulated candidate magnetic circuit designs will resemble previous successful thruster designs. To provide opportunity to improve beyond previous performance benchmarks, off-design modifications will be simulated and experimentally tested.

Social influences on eating and physical activity behaviours of urban, minority youths

PubMed Central

Steeves, Elizabeth T Anderson; Johnson, Katherine A; Pollard, Suzanne L; Jones-Smith, Jessica; Pollack, Keshia; Johnson, Sarah Lindstrom; Hopkins, Laura; Gittelsohn, Joel

2017-01-01

Objective Social relationships can impact youths’ eating and physical activity behaviours; however, the best strategies for intervening in the social environment are unknown. The objectives of the present study were to provide in-depth information on the social roles that youths’ parents and friends play related to eating and physical activity behaviours and to explore the impact of other social relationships on youths’ eating and physical activity behaviours. Design Convergent parallel mixed-methods design. Setting Low-income, African American, food desert neighbourhoods in Baltimore City, MD, USA. Subjects Data were collected from 297 youths (53 % female, 91 % African American, mean age 12·3 (SD 1·5) years) using structured questionnaires and combined with in-depth interviews from thirty-eight youths (42 % female, 97 % African American, mean age 11·4 (SD 1·5) years) and ten parents (80 % female, 50 % single heads of house, 100 % African American). Results Combined interpretation of the results found that parents and caregivers have multiple, dynamic roles influencing youths’ eating and physical activity behaviours, such as creating health-promoting rules, managing the home food environment and serving as a role model for physical activity. Other social relationships have specific, but limited roles. For example, friends served as partners for physical activity, aunts provided exposure to novel food experiences, and teachers and doctors provided information related to eating and physical activity. Conclusions Obesity prevention programmes should consider minority youths’ perceptions of social roles when designing interventions. Specifically, future research is needed to test the effectiveness of intervention strategies that enhance or expand the supportive roles played by social relationships. PMID:27491967

A simple and precise method to detect sterol esterification activity of lecithin/cholesterol acyltransferase by high-performance liquid chromatography.

PubMed

Wang, Yu; Wang, Siming; Zhang, Lijiao; Zeng, Jie; Yang, Ruiyue; Li, Hongxia; Tang, Yueming; Chen, Wenxiang; Dong, Jun

2018-02-01

The measurement of lecithin: cholesterol acyltransferase (LCAT, EC 2.3.1.43) activity is important in high-density lipoprotein (HDL) metabolism study and cardiovascular disease (CVD) risk assessment. However, current methods suffer from complex design and preparation of exogenous substrate, low reproducibility, and interference of cofactors. In this study, we developed a simple and precise high performance liquid chromatography (HPLC) method for the measurement of LCAT activity. By using 7-dehydrocholesterol (7-DHC) and 1,2-didecanoyl-sn-glycero-3-phosphocholine(10:0PC) as substrates, and an LCAT activating peptide (P642) as activator and emulsifier, the substrate reagent was easily made by vortex. The substrate reagent was mixed with serum samples (50:1, v/v) and incubated at 37 °C for 1 h. After incubation, the lipid was extracted with hexane and ethanol. With a conjugated double bond and ultraviolet absorption, 7-DHC and its esterification product could be separated and analyzed by a single HPLC run without calibration. LCAT activity was a linear function of the serum sample volume and the intra- and total assay coefficients of variation (CV) less than 2.5% were obtained under the standardized conditions. The substrate reagent was stable, and assay result accurately reflected LCAT activity. LCAT activities in 120 healthy subjects were positively correlated with triglyceride (P < 0.05), fractional esterification rate of HDL cholesterol (FER HDL ) (P < 0.0001), and negatively correlated with apolipoprotein AI (apoAI) (P < 0.05) and HDL cholesterol (HDL-C) (P < 0.001). These results suggest that this method is sensitive, reproducible, and not greatly influenced by serum components and added substances, and will be a useful tool in the lipid metabolism study and the risk assessment of CVD.

Evaluation of Low-Tech Indoor Remediation Methods ...

EPA Pesticide Factsheets

Report This study identified, collected, evaluated, and summarized available articles, reports, guidance documents, and other pertinent information related to common housekeeping activities within the United States. This resulted in a summary compendium including relevant information about multiple low-tech cleaning methods from the literature search results. Through discussion and prioritization, an EPA project team, made up of several EPA scientists and emergency responders, focused the information into a list of 14 housekeeping activities for decontamination evaluation testing. These types of activities are collectively referred to as “low-tech” remediation methods because of the comparative simple tools, equipment, and operations involved. Similarly, eight common household surfaces were chosen that were contaminated using three different contamination conditions. Thirty-three combinations of methods and surfaces were chosen for testing under the three contamination conditions for a total of 99 tests.

Improving temporal resolution in fMRI using a 3D spiral acquisition and low rank plus sparse (L+S) reconstruction.

PubMed

Petrov, Andrii Y; Herbst, Michael; Andrew Stenger, V

2017-08-15

Rapid whole-brain dynamic Magnetic Resonance Imaging (MRI) is of particular interest in Blood Oxygen Level Dependent (BOLD) functional MRI (fMRI). Faster acquisitions with higher temporal sampling of the BOLD time-course provide several advantages including increased sensitivity in detecting functional activation, the possibility of filtering out physiological noise for improving temporal SNR, and freezing out head motion. Generally, faster acquisitions require undersampling of the data which results in aliasing artifacts in the object domain. A recently developed low-rank (L) plus sparse (S) matrix decomposition model (L+S) is one of the methods that has been introduced to reconstruct images from undersampled dynamic MRI data. The L+S approach assumes that the dynamic MRI data, represented as a space-time matrix M, is a linear superposition of L and S components, where L represents highly spatially and temporally correlated elements, such as the image background, while S captures dynamic information that is sparse in an appropriate transform domain. This suggests that L+S might be suited for undersampled task or slow event-related fMRI acquisitions because the periodic nature of the BOLD signal is sparse in the temporal Fourier transform domain and slowly varying low-rank brain background signals, such as physiological noise and drift, will be predominantly low-rank. In this work, as a proof of concept, we exploit the L+S method for accelerating block-design fMRI using a 3D stack of spirals (SoS) acquisition where undersampling is performed in the k z -t domain. We examined the feasibility of the L+S method to accurately separate temporally correlated brain background information in the L component while capturing periodic BOLD signals in the S component. We present results acquired in control human volunteers at 3T for both retrospective and prospectively acquired fMRI data for a visual activation block-design task. We show that a SoS fMRI acquisition with an acceleration of four and L+S reconstruction can achieve a brain coverage of 40 slices at 2mm isotropic resolution and 64 x 64 matrix size every 500ms. Copyright © 2017 Elsevier Inc. All rights reserved.

The design, analysis, and testing of a low-budget wind-tunnel flutter model with active aerodynamic controls

NASA Technical Reports Server (NTRS)

Bolding, R. M.; Stearman, R. O.

1976-01-01

A low budget flutter model incorporating active aerodynamic controls for flutter suppression studies was designed as both an educational and research tool to study the interfering lifting surface flutter phenomenon in the form of a swept wing-tail configuration. A flutter suppression mechanism was demonstrated on a simple semirigid three-degree-of-freedom flutter model of this configuration employing an active stabilator control, and was then verified analytically using a doublet lattice lifting surface code and the model's measured mass, mode shapes, and frequencies in a flutter analysis. Preliminary studies were significantly encouraging to extend the analysis to the larger degree of freedom AFFDL wing-tail flutter model where additional analytical flutter suppression studies indicated significant gains in flutter margins could be achieved. The analytical and experimental design of a flutter suppression system for the AFFDL model is presented along with the results of a preliminary passive flutter test.

Development of a High Performance, Low-Profile Translation Table with Wire Feedthrough

NASA Technical Reports Server (NTRS)

Few, Alex

2016-01-01

NEAScout, a 6U cubesat, will use an 85 sq m solar sail to travel to a near-earth asteroid for observation. Over the course of the 3-year mission, a combination of reaction wheels, cold gas reaction control system, and a slow rotisserie roll about the solar sail's normal axis were expected to handle attitude control and adjust for imperfections in the deployed sail. As the design for NEAScout matured, one of the critical design parameters, the offset in the center of mass and center of pressure (CP/CM offset), proved to be sub-optimal. After significant mission and control analysis, the CP/CM offset was addressed and a new subsystem was introduced to NEAScout. This system, called the Active Mass Translator (AMT), would reside near the geometric center of NEAScout and adjust the CM by moving one portion of the flight system relative to the other. The AMT was given limited design space-about 17 mm of the vehicle's assembly height-and was required to generate +/-10 cm by +/-5 cm translation to sub-millimeter accuracy. Furthermore, the design must accommodate a large wire bundle of small gage, single strand wire and coax cables fed through the center of the mechanism. The bend radius, bend resistance, and the exposure to deep space environment complicates the AMT design and operation and necessitated a unique design to mitigate risks of wire bundle damage, binding, and cold-welding during operation. This paper will outline the design constraints for the AMT, discuss the methods and reasoning for design, and identify the lessons learned through the design downselect process and breadboarding for designing low-profile translation stages with feedthrough capabilities.

Experimental Design for Hanford Low-Activity Waste Glasses with High Waste Loading

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

Piepel, Gregory F.; Cooley, Scott K.; Vienna, John D.

This report discusses the development of an experimental design for the initial phase of the Hanford low-activity waste (LAW) enhanced glass study. This report is based on a manuscript written for an applied statistics journal. Appendices A, B, and E include additional information relevant to the LAW enhanced glass experimental design that is not included in the journal manuscript. The glass composition experimental region is defined by single-component constraints (SCCs), linear multiple-component constraints (MCCs), and a nonlinear MCC involving 15 LAW glass components. Traditional methods and software for designing constrained mixture experiments with SCCs and linear MCCs are not directlymore » applicable because of the nonlinear MCC. A modification of existing methodology to account for the nonlinear MCC was developed and is described in this report. One of the glass components, SO 3, has a solubility limit in glass that depends on the composition of the balance of the glass. A goal was to design the experiment so that SO 3 would not exceed its predicted solubility limit for any of the experimental glasses. The SO 3 solubility limit had previously been modeled by a partial quadratic mixture model expressed in the relative proportions of the 14 other components. The partial quadratic mixture model was used to construct a nonlinear MCC in terms of all 15 components. In addition, there were SCCs and linear MCCs. This report describes how a layered design was generated to (i) account for the SCCs, linear MCCs, and nonlinear MCC and (ii) meet the goals of the study. A layered design consists of points on an outer layer, and inner layer, and a center point. There were 18 outer-layer glasses chosen using optimal experimental design software to augment 147 existing glass compositions that were within the LAW glass composition experimental region. Then 13 inner-layer glasses were chosen with the software to augment the existing and outer-layer glasses. The experimental design was completed by a center-point glass, a Vitreous State Laboratory glass, and replicates of the center point and Vitreous State Laboratory glasses.« less

Design, Assembly, and Characterization of TALE-Based Transcriptional Activators and Repressors.

PubMed

Thakore, Pratiksha I; Gersbach, Charles A

2016-01-01

Transcription activator-like effectors (TALEs) are modular DNA-binding proteins that can be fused to a variety of effector domains to regulate the epigenome. Nucleotide recognition by TALE monomers follows a simple cipher, making this a powerful and versatile method to activate or repress gene expression. Described here are methods to design, assemble, and test TALE transcription factors (TALE-TFs) for control of endogenous gene expression. In this protocol, TALE arrays are constructed by Golden Gate cloning and tested for activity by transfection and quantitative RT-PCR. These methods for engineering TALE-TFs are useful for studies in reverse genetics and genomics, synthetic biology, and gene therapy.

Experience with modified aerospace reliability and quality assurance method for wind turbines

NASA Technical Reports Server (NTRS)

Klein, W. E.

1982-01-01

The SR&QA approach assures that the machine is not hazardous to the public or operating personnel, can operate unattended on a utility grid, demonstrates reliability operation, and helps establish the quality assurance and maintainability requirements for future wind turbine projects. The approach consisted of modified failure modes and effects analysis (FMEA) during the design phase, minimal hardware inspection during parts fabrication, and three simple documents to control activities during machine construction and operation. Five years experience shows that this low cost approach works well enough that it should be considered by others for similar projects.

Active angular alignment of gauge blocks in double-ended interferometers.

PubMed

Buchta, Zdeněk; Reřucha, Simon; Hucl, Václav; Cížek, Martin; Sarbort, Martin; Lazar, Josef; Cíp, Ondřej

2013-09-27

This paper presents a method implemented in a system for automatic contactless calibration of gauge blocks designed at ISI ASCR. The system combines low-coherence interferometry and laser interferometry, where the first identifies the gauge block sides position and the second one measures the gauge block length itself. A crucial part of the system is the algorithm for gauge block alignment to the measuring beam which is able to compensate the gauge block lateral and longitudinal tilt up to 0.141 mrad. The algorithm is also important for the gauge block position monitoring during its length measurement.

Active Angular Alignment of Gauge Blocks in Double-Ended Interferometers

PubMed Central

Buchta, Zdeněk; Řeřucha, Šimon; Hucl, Václav; Čížek, Martin; Šarbort, Martin; Lazar, Josef; Číp, Ondřej

2013-01-01

This paper presents a method implemented in a system for automatic contactless calibration of gauge blocks designed at ISI ASCR. The system combines low-coherence interferometry and laser interferometry, where the first identifies the gauge block sides position and the second one measures the gauge block length itself. A crucial part of the system is the algorithm for gauge block alignment to the measuring beam which is able to compensate the gauge block lateral and longitudinal tilt up to 0.141 mrad. The algorithm is also important for the gauge block position monitoring during its length measurement. PMID:24084107

Efficient assessment of efficacy in post-traumatic peripheral neuropathic pain patients: pregabalin in a randomized, placebo-controlled, crossover study

PubMed Central

Jenkins, Tim M; Smart, Trevor S; Hackman, Frances; Cooke, Carol; Tan, Keith KC

2012-01-01

Background: Detecting the efficacy of novel analgesic agents in neuropathic pain is challenging. There is a critical need for study designs with the desirable characteristics of assay sensitivity, low placebo response, reliable pain recordings, low cost, short duration of exposure to test drug and placebo, and relevant and recruitable population. Methods: We designed a proof-of-concept, double-blind, randomized, placebo-controlled, crossover study in patients with post-traumatic peripheral neuropathic pain (PTNP) to evaluate whether such a study design had the potential to detect efficacious agents. Pregabalin, known to be efficacious in neuropathic pain, was used as the active analgesic. We also assessed physical activity throughout the study. Results: Twenty-five adults (20–70 years of age) with PTNP for ≥3 months entered a screening week and were then randomized to one of the two following treatment sequences: (1) pregabalin followed by placebo or (2) placebo followed by pregabalin. These 2-week treatment periods were separated by a 2-week washout period. Patients on pregabalin treatment received escalating doses to a final dosage of 300 mg/day (days 5–15). In an attempt to minimize placebo response, patients received placebo treatment during the screening week and the 2-week washout period. Average daily pain scores (primary endpoint) were significantly reduced for pregabalin versus placebo, with a mean treatment difference of −0.81 (95% confidence interval: −1.45 to −0.17; P = 0.015). Conclusion: The efficacy of pregabalin was similar to that identified in a large, parallel group trial in PTNP. Therefore, this efficient crossover study design has potential utility for future proof-of-concept studies in neuropathic pain. PMID:22888270

Low message sensation health promotion videos are better remembered and activate areas of the brain associated with memory encoding.

PubMed

Seelig, David; Wang, An-Li; Jagannathan, Kanchana; Jaganathan, Kanchana; Loughead, James W; Blady, Shira J; Childress, Anna Rose; Romer, Daniel; Langleben, Daniel D

2014-01-01

Greater sensory stimulation in advertising has been postulated to facilitate attention and persuasion. For this reason, video ads promoting health behaviors are often designed to be high in "message sensation value" (MSV), a standardized measure of sensory intensity of the audiovisual and content features of an ad. However, our previous functional Magnetic Resonance Imaging (fMRI) study showed that low MSV ads were better remembered and produced more prefrontal and temporal and less occipital cortex activation, suggesting that high MSV may divert cognitive resources from processing ad content. The present study aimed to determine whether these findings from anti-smoking ads generalize to other public health topics, such as safe sex. Thirty-nine healthy adults viewed high- and low MSV ads promoting safer sex through condom use, during an fMRI session. Recognition memory of the ads was tested immediately and 3 weeks after the session. We found that low MSV condom ads were better remembered than the high MSV ads at both time points and replicated the fMRI patterns previously reported for the anti-smoking ads. Occipital and superior temporal activation was negatively related to the attitudes favoring condom use (see Condom Attitudes Scale, Methods and Materials section). Psychophysiological interaction (PPI) analysis of the relation between occipital and fronto-temporal (middle temporal and inferior frontal gyri) cortices revealed weaker negative interactions between occipital and fronto-temporal cortices during viewing of the low MSV that high MSV ads. These findings confirm that the low MSV video health messages are better remembered than the high MSV messages and that this effect generalizes across public health domains. The greater engagement of the prefrontal and fronto-temporal cortices by low MSV ads and the greater occipital activation by high MSV ads suggest that that the "attention-grabbing" high MSV format could impede the learning and retention of public health messages.

Low Message Sensation Health Promotion Videos Are Better Remembered and Activate Areas of the Brain Associated with Memory Encoding

PubMed Central

Jaganathan, Kanchana; Loughead, James W.; Blady, Shira J.; Childress, Anna Rose; Romer, Daniel; Langleben, Daniel D.

2014-01-01

Greater sensory stimulation in advertising has been postulated to facilitate attention and persuasion. For this reason, video ads promoting health behaviors are often designed to be high in “message sensation value” (MSV), a standardized measure of sensory intensity of the audiovisual and content features of an ad. However, our previous functional Magnetic Resonance Imaging (fMRI) study showed that low MSV ads were better remembered and produced more prefrontal and temporal and less occipital cortex activation, suggesting that high MSV may divert cognitive resources from processing ad content. The present study aimed to determine whether these findings from anti-smoking ads generalize to other public health topics, such as safe sex. Thirty-nine healthy adults viewed high- and low MSV ads promoting safer sex through condom use, during an fMRI session. Recognition memory of the ads was tested immediately and 3 weeks after the session. We found that low MSV condom ads were better remembered than the high MSV ads at both time points and replicated the fMRI patterns previously reported for the anti-smoking ads. Occipital and superior temporal activation was negatively related to the attitudes favoring condom use (see Condom Attitudes Scale, Methods and Materials section). Psychophysiological interaction (PPI) analysis of the relation between occipital and fronto-temporal (middle temporal and inferior frontal gyri) cortices revealed weaker negative interactions between occipital and fronto-temporal cortices during viewing of the low MSV that high MSV ads. These findings confirm that the low MSV video health messages are better remembered than the high MSV messages and that this effect generalizes across public health domains. The greater engagement of the prefrontal and fronto-temporal cortices by low MSV ads and the greater occipital activation by high MSV ads suggest that that the “attention-grabbing” high MSV format could impede the learning and retention of public health messages. PMID:25409187

Muscle and intensity based hamstring exercise classification in elite female track and field athletes: implications for exercise selection during rehabilitation

PubMed Central

Tsaklis, Panagiotis; Malliaropoulos, Nikos; Mendiguchia, Jurdan; Korakakis, Vasileios; Tsapralis, Kyriakos; Pyne, Debasish; Malliaras, Peter

2015-01-01

Background Hamstring injuries are common in many sports, including track and field. Strains occur in different parts of the hamstring muscle but very little is known about whether common hamstring loading exercises specifically load different hamstring components. The purpose of this study was to investigate muscle activation of different components of the hamstring muscle during common hamstring loading exercises. Methods Twenty elite female track and field athletes were recruited into this study, which had a single-sample, repeated-measures design. Each athlete performed ten hamstring loading exercises, and an electromyogram (EMG) was recorded from the biceps femoris and semitendinosus components of the hamstring. Hamstring EMG during maximal voluntary isometric contraction (MVIC) was used to normalize the mean data across ten repetitions of each exercise. An electrogoniometer synchronized to the EMG was used to determine whether peak EMG activity occurred during muscle-tendon unit lengthening, shortening, or no change in length. Mean EMG values were compared between the two recording sites for each exercise using the Student’s t-test. Results The lunge, dead lift, and kettle swings were low intensity (<50% MVIC) and all showed higher EMG activity for semitendinosus than for biceps femoris. Bridge was low but approaching medium intensity, and the TRX, hamstring bridge, and hamstring curl were all medium intensity exercises (≥50% or <80% MVIC). The Nordic, fitball, and slide leg exercises were all high intensity exercises. Only the fitball exercise showed higher EMG activity in the biceps femoris compared with the semitendinosus. Only lunge and kettle swings showed peak EMG in the muscle-tendon unit lengthening phase and both these exercises involved faster speed. Conclusion Some exercises selectively activated the lateral and medial distal hamstrings. Low, medium, and high intensity exercises were demonstrated. This information enables the clinician, strength and conditioning coach and physiotherapist to better understand intensity- and muscle-specific activation during hamstring muscle rehabilitation. Therefore, these results may help in designing progressive strengthening and rehabilitation and prevention programs. PMID:26170726

Comparing methods suitable for monitoring marine mammals in low visibility conditions during seismic surveys.

PubMed

Verfuss, Ursula K; Gillespie, Douglas; Gordon, Jonathan; Marques, Tiago A; Miller, Brianne; Plunkett, Rachael; Theriault, James A; Tollit, Dominic J; Zitterbart, Daniel P; Hubert, Philippe; Thomas, Len

2018-01-01

Loud sound emitted during offshore industrial activities can impact marine mammals. Regulations typically prescribe marine mammal monitoring before and/or during these activities to implement mitigation measures that minimise potential acoustic impacts. Using seismic surveys under low visibility conditions as a case study, we review which monitoring methods are suitable and compare their relative strengths and weaknesses. Passive acoustic monitoring has been implemented as either a complementary or alternative method to visual monitoring in low visibility conditions. Other methods such as RADAR, active sonar and thermal infrared have also been tested, but are rarely recommended by regulatory bodies. The efficiency of the monitoring method(s) will depend on the animal behaviour and environmental conditions, however, using a combination of complementary systems generally improves the overall detection performance. We recommend that the performance of monitoring systems, over a range of conditions, is explored in a modelling framework for a variety of species. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Anticancer activity of Sargassum oligocystum water extract against human cancer cell lines.

PubMed

Zandi, K; Ahmadzadeh, S; Tajbakhsh, S; Rastian, Z; Yousefi, F; Farshadpour, F; Sartavi, K

2010-08-01

Antitumor drug resistance and side effects of antitumor compounds are the most common problems in medicine. Therefore, finding new antitumor agents with low side effects could be interesting. This study was designed to assay antitumor activity of the extract from brown alga Sargassum oligocystum, gathered from Persian Gulf seashore, against K562 and Daudi human cancer cell lines. The research was performed as an in vitro study. The effect of the alga extract on proliferation of cell lines were measured by two methods: MTT assay and trypan blue exclusion test. The most effective antitumor activity has been shown at concentrations 500 microg/ml and 400 microg/ml of the alga extract against Daudi and K562 cell lines, respectively. The results showed that the extracts of brown alga Sargassum oligocystum have remarkable antitumor activity against K562 and Daudi cell lines. It is justified to be suggested for further research such as algal extract fractionation and purification and in vivo studies in order to formulate natural compounds with antitumor activities.

Optimization of commercial scale photonuclear production of radioisotopes

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

Bindu, K. C.; Harmon, Frank; Starovoitova, Valeriia N.

2013-04-19

Photonuclear production of radioisotopes driven by bremsstrahlung photons using a linear electron accelerator in the suitable energy range is a promising method for producing radioisotopes. The photonuclear production method is capable of making radioisotopes more conveniently, cheaply and with much less radioactive waste compared to existing methods. Historically, photo-nuclear reactions have not been exploited for isotope production because of the low specific activity that is generally associated with this production process, although the technique is well-known to be capable of producing large quantities of certain radioisotopes. We describe an optimization technique for a set of parameters to maximize specific activitymore » of the final product. This set includes the electron beam energy and current, the end station design (an integrated converter and target as well as cooling system), the purity of materials used, and the activation time. These parameters are mutually dependent and thus their optimization is not trivial. {sup 67}Cu photonuclear production via {sup 68}Zn({gamma}p){sup 67}Cu reaction was used as an example of such an optimization process.« less

Future Technology Workshop: A Collaborative Method for the Design of New Learning Technologies and Activities

ERIC Educational Resources Information Center

Vavoula, Giasemi N.; Sharples, Mike

2007-01-01

We describe the future technology workshop (FTW), a method whereby people with everyday knowledge or experience in a specific area of technology use (such as using digital cameras) envision and design the interactions between current and future technology and activity. Through a series of structured workshop sessions, participants collaborate to…

A new approach to synthesize supported ruthenium phosphides for hydrodesulfurization

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

Wang, Qingfang; Key Laboratory of Advanced Energy Materials Chemistry; Wang, Zhiqiang

2016-02-15

Highlights: • We bring out a new method to synthesize noble metal phosphides at low temperature. • Both RuP and Ru{sub 2}P were synthesized using triphenylphosphine as phosphorus sources. • Ru{sub 2}P was the better active phase for HDS than RuP and metal Ru. • RuP/SiO{sub 2} prepared by new method had better HDS activity to that by TPR method. - Abstract: Supported noble metal ruthenium phosphides were synthesized by one-step H{sub 2}-thermal treatment method using triphenylphosphine (TPP) as phosphorus sources at low temperatures. Two phosphides RuP and Ru{sub 2}P can be prepared by this method via varying the molarmore » ratio of metal salt and TPP. The as-prepared phosphides were characterized by X-ray powder diffraction (XRD), low-temperature N{sub 2} adsorption, CO chemisorption and transmission electronic microscopy (TEM). The supported ruthenium phosphides prepared by new method and conventional method together with contradistinctive metallic ruthenium were evaluated in hydrodesulfurization (HDS) of dibenzothiophene (DBT). The catalytic results showed that metal-rich Ru{sub 2}P was the better active phase for HDS than RuP and metal Ru. Besides this, ruthenium phosphide catalyst prepared by new method exhibited superior HDS activity to that prepared by conventional method.« less

An analytical study for the design of advanced rotor airfoils

NASA Technical Reports Server (NTRS)

Kemp, L. D.

1973-01-01

A theoretical study has been conducted to design and evaluate two airfoils for helicopter rotors. The best basic shape, designed with a transonic hodograph design method, was modified to meet subsonic criteria. One airfoil had an additional constraint for low pitching-moment at the transonic design point. Airfoil characteristics were predicted. Results of a comparative analysis of helicopter performance indicate that the new airfoils will produce reduced rotor power requirements compared to the NACA 0012. The hodograph design method, written in CDC Algol, is listed and described.

Design, characterisation and application of alginate-based encapsulated pig liver esterase.

PubMed

Pauly, Jan; Gröger, Harald; Patel, Anant V

2018-06-05

Encapsulation of hydrolases in biopolymer-based hydrogels often suffers from low activities and encapsulation efficiencies along with high leaching and unsatisfactory recycling properties. Exemplified for the encapsulation of pig liver esterase the coating of alginate and chitosan beads have been studied by creating various biopolymer hydrogel beads. Enzyme activity and encapsulation efficiency were notably enhanced by chitosan coating of alginate beads while leaching remained nearly unchanged. This was caused by the enzymatic reaction acidifying the matrix, which increased enzyme retention through enhanced electrostatic enzyme-alginate interaction but decreased activity through enzyme deactivation. A practical and ready-to-use method for visualising pH in beads during reaction by co-encapsulation of a conventional pH indicator was also found. Our method proves that pH control inside the beads can only be realised by buffering. The resulting beads provided a specific activity of 0.267 μmol ∙ min -1 ∙ mg -1 , effectiveness factor 0.88, encapsulation efficiency of 88%, 5% leaching and good recycling properties. This work will contribute towards better understanding and application of encapsulated hydrolases for enzymatic syntheses. Copyright © 2018 Elsevier B.V. All rights reserved.

Design Criteria for Low Profile Flange Calculations

NASA Technical Reports Server (NTRS)

Leimbach, K. R.

1973-01-01

An analytical method and a design procedure to develop flanged separable pipe connectors are discussed. A previously established algorithm is the basis for calculating low profile flanges. The characteristics and advantages of the low profile flange are analyzed. The use of aluminum, titanium, and plastics for flange materials is described. Mathematical models are developed to show the mechanical properties of various flange configurations. A computer program for determining the structural stability of the flanges is described.

Rotor design for maneuver performance

NASA Technical Reports Server (NTRS)

Berry, John D.; Schrage, Daniel

1986-01-01

A method of determining the sensitivity of helicopter maneuver performance to changes in basic rotor design parameters is developed. Maneuver performance is measured by the time required, based on a simplified rotor/helicopter performance model, to perform a series of specified maneuvers. This method identifies parameter values which result in minimum time quickly because of the inherent simplicity of the rotor performance model used. For the specific case studied, this method predicts that the minimum time required is obtained with a low disk loading and a relatively high rotor solidity. The method was developed as part of the winning design effort for the American Helicopter Society student design competition for 1984/1985.

A novel highly flexible, simple, rapid and low-cost fabrication tool for paper-based microfluidic devices (μPADs) using technical drawing pens and in-house formulated aqueous inks.

PubMed

Nuchtavorn, Nantana; Macka, Mirek

2016-05-05

Paper-based microfluidic devices (μPADs) are capable of achieving rapid quantitative measurements of a variety of analytes inexpensively. μPADs rely on patterning hydrophilic-hydrophobic regions on a sheet of paper in order to create capillary channels within impermeable fluidic brakes on the paper. Here, we present a novel, highly flexible and low-cost fabrication method using a desktop digital craft plotter/cutter and technical drawing pens with tip size of 0.5 mm. The pens were used with either commercial black permanent ink for drawing fluidic brakes, or with specialty in-house formulated aqueous inks. With the permanent marker ink it was possible to create barriers on paper rapidly and in a variety of designs in a highly flexible manner. For instance, a design featuring eight reservoirs can be produced within 10 s for each μPAD with a consistent line width of brakes (%RSD < 1.5). Further, we investigated the optimal viscosity range of in-house formulated inks controlled with additions of poly(ethylene glycol). The viscosity was measured by capillary electrophoresis and the optimal viscosity was in the range of ∼3-6 mPa s. A functional test of these μPADs was conducted by the screening of antioxidant activity. Colorimetric measurements of flavonoid, phenolic compounds and DPPH free radical scavenging activity were carried out on μPADs. The results can be detected by the naked eye and simply quantified by using a camera phone and image analysis software. The fabrication method using technical drawing pens provides flexibility in the use of in-house formulated inks, short fabrication time, simplicity and low cost. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

Design of a wearable bio-patch for monitoring patient's temperature.

PubMed

Vicente, Jose M; Avila-Navarro, Ernesto; Juan, Carlos G; Garcia, Nicolas; Sabater-Navarro, Jose M

2016-08-01

New communication technologies allow us developing useful and more practical medical applications, in particular for ambulatory monitoring. NFC communication has the advantages of low powering and low influence range area, what makes this technology suitable for health applications. This work presents an explanation of the design process of planar NFC antennas in a wearable biopatch. The problem of optimizing the communication distance is addressed. Design of a biopatch for continuous temperature monitoring and experimental results obtained wearing this biopatch during daily activities are presented.

Rate-compatible protograph LDPC code families with linear minimum distance

NASA Technical Reports Server (NTRS)

Divsalar, Dariush (Inventor); Dolinar, Jr., Samuel J (Inventor); Jones, Christopher R. (Inventor)

2012-01-01

Digital communication coding methods are shown, which generate certain types of low-density parity-check (LDPC) codes built from protographs. A first method creates protographs having the linear minimum distance property and comprising at least one variable node with degree less than 3. A second method creates families of protographs of different rates, all having the linear minimum distance property, and structurally identical for all rates except for a rate-dependent designation of certain variable nodes as transmitted or non-transmitted. A third method creates families of protographs of different rates, all having the linear minimum distance property, and structurally identical for all rates except for a rate-dependent designation of the status of certain variable nodes as non-transmitted or set to zero. LDPC codes built from the protographs created by these methods can simultaneously have low error floors and low iterative decoding thresholds, and families of such codes of different rates can be decoded efficiently using a common decoding architecture.

Rationale and study protocol for the supporting children’s outcomes using rewards, exercise and skills (SCORES) group randomized controlled trial: A physical activity and fundamental movement skills intervention for primary schools in low-income communities

PubMed Central

2012-01-01

Background Many Australian children are insufficiently active to accrue health benefits and physical activity (PA) levels are consistently lower among youth of low socio-economic position. PA levels decline dramatically during adolescence and evidence suggests that competency in a range of fundamental movement skills (FMS) may serve as a protective factor against this trend. Methods/design The Supporting Children’s Outcomes Using Rewards Exercise and Skills (SCORES) intervention is a multi-component PA and FMS intervention for primary schools in low-income communities, which will be evaluated using a group randomized controlled trial. The socio-ecological model provided a framework for the 12-month intervention, which includes the following components: teacher professional learning, student leadership workshops (including leadership accreditation and rewards, e.g., stickers, water bottles), PA policy review, PA equipment packs, parental engagement via newsletters, FMS homework and a parent evening, and community partnerships with local sporting organizations. Outcomes will be assessed at baseline, 6- and 12-months. The primary outcomes are PA (accelerometers), FMS (Test of Gross Motor Development II) and cardiorespiratory fitness (multi-stage fitness test). Secondary outcomes include body mass index [using weight (kg)/height (m2)], perceived competence, physical self-esteem, and resilience. Individual and environmental mediators of behavior change (e.g. social support and enjoyment) will also be assessed. The System for Observing Fitness Instruction Time will be used to assess the impact of the intervention on PA within physical education lessons. Statistical analyses will follow intention-to-treat principles and hypothesized mediators of PA behavior change will be explored. Discussion SCORES is an innovative primary school-based PA and FMS intervention designed to support students attending schools in low-income communities to be more skilled and active. The findings from the study may be used to guide teacher pre-service education, professional learning and school policy in primary schools. Trial registration Australian New Zealand Clinical Trials Registry No: ACTRN12611001080910 PMID:22691451

Individuals with Low Working Memory Spans Show Greater Interference from Irrelevant Information Because of Poor Source Monitoring, Not Greater Activation

PubMed Central

Lilienthal, Lindsey; Rose, Nathan S.; Tamez, Elaine; Myerson, Joel; Hale, Sandra

2014-01-01

Although individuals with high and low working memory (WM) span appear to differ in the extent to which irrelevant information interferes with their performance on WM tasks, the locus of this interference is not clear. The present study investigated whether, when performing a WM task, high- and low-span individuals differ in the activation of formerly relevant, but now irrelevant items, and/or in their ability to correctly identify such irrelevant items. This was done in two experiments, both of which used modified complex WM span tasks. In Experiment 1, the span task included an embedded lexical decision task designed to obtain an implicit measure of the activation of both currently and formerly relevant items. In Experiment 2, the span task included an embedded recognition judgment task designed to obtain an explicit measure of both item and source recognition ability. The results of these experiments indicate that low-span individuals do not hold irrelevant information in a more active state in memory than high-span individuals, but rather that low-span individuals are significantly poorer at identifying such information as irrelevant at the time of retrieval. These results suggest that differences in the ability to monitor the source of information, rather than differences in the activation of irrelevant information, are the more important determinant of performance on WM tasks. PMID:25921723

The research on calibration methods of dual-CCD laser three-dimensional human face scanning system

NASA Astrophysics Data System (ADS)

Wang, Jinjiang; Chang, Tianyu; Ge, Baozhen; Tian, Qingguo; Yang, Fengting; Shi, Shendong

2013-09-01

In this paper, on the basis of considering the performance advantages of two-step method, we combines the stereo matching of binocular stereo vision with active laser scanning to calibrate the system. Above all, we select a reference camera coordinate system as the world coordinate system and unity the coordinates of two CCD cameras. And then obtain the new perspective projection matrix (PPM) of each camera after the epipolar rectification. By those, the corresponding epipolar equation of two cameras can be defined. So by utilizing the trigonometric parallax method, we can measure the space point position after distortion correction and achieve stereo matching calibration between two image points. Experiments verify that this method can improve accuracy and system stability is guaranteed. The stereo matching calibration has a simple process with low-cost, and simplifies regular maintenance work. It can acquire 3D coordinates only by planar checkerboard calibration without the need of designing specific standard target or using electronic theodolite. It is found that during the experiment two-step calibration error and lens distortion lead to the stratification of point cloud data. The proposed calibration method which combining active line laser scanning and binocular stereo vision has the both advantages of them. It has more flexible applicability. Theory analysis and experiment shows the method is reasonable.

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

Jacob, Reed B.; Ding, Feng; Ye, Dongmei

Organophosphates are widely used for peaceful (agriculture) and military purposes (chemical warfare agents). The extraordinary toxicity of organophosphates and the risk of deployment, make it critical to develop means for their rapid and efficient deactivation. Organophosphate hydrolase (OPH) already plays an important role in organophosphate remediation, but is insufficient for therapeutic or prophylactic purposes primarily due to low substrate affinity. Current efforts focus on directly modifying the active site to differentiate substrate specificity and increase catalytic activity. Here, we present a novel strategy for enhancing the general catalytic efficiency of OPH through computational redesign of the residues that are allostericallymore » coupled to the active site and validated our design by mutagenesis. Specifically, we identify five such hot-spot residues for allosteric regulation and assay these mutants for hydrolysis activity against paraoxon, a chemical-weapons simulant. A high percentage of the predicted mutants exhibit enhanced activity over wild-type (k cat =16.63 s -1), such as T199I/T54I (899.5 s -1) and C227V/T199I/T54I (848 s -1), while the Km remains relatively unchanged in our high-throughput cell-free expression system. Further computational studies of protein dynamics reveal four distinct distal regions coupled to the active site that display significant changes in conformation dynamics upon these identified mutations. These results validate a computational design method that is both efficient and easily adapted as a general procedure for enzymatic enhancement.« less

Increasing collective efficacy for physical activity: Design and rationale of Moms UNITE for Health.

PubMed

Dlugonski, Deirdre; Das, Bhibha M; Martin, Tiesha

2015-11-01

Mothers are a population that engages in low levels of physical activity due to unique barriers to physical activity. As such, there is a need to develop and implement physical activity interventions for mothers that can be delivered in community settings. The objective of this article is to describe the Moms UNITE (Using Networks to Increase Togetherness and Efficacy) for Health walking intervention. This intervention, based on social cognitive theory, is designed to compare a collective efficacy enhanced intervention to a standard intervention for increasing physical activity and secondary outcomes. In this 6-week, randomized controlled trial, mothers will be assigned to either the standard or intervention (collective efficacy) group. Both groups will receive the same walking intervention and an evidence-based health education program. Strategies and messages focusing on building collective efficacy will be used in the intervention group. Data will be collected at baseline, post-intervention, and follow-up (after a 3 month no-intervention period) using a mixed methods approach. Quantitative data will include anthropometric measurements, objective physical activity, and questionnaires assessing self- and collective-efficacy. Post-intervention focus groups and weekly process evaluation surveys will describe participants' experiences within the program. This paper will serve as a theoretical framework for researchers and public health practitioners to develop and implement community-based walking programs for mothers. Copyright © 2015 Elsevier Inc. All rights reserved.

Active Cells for Multifunctional Structures

DTIC Science & Technology

2014-09-24

techniques to explore a variety of cell designs.  Designed a simplified active cell using Nitinol as the actuation method and relying on Joule heating...for contraction of the cell.  Developed manufacturing techniques for reliably creating Nitinol spring coils in a variety of diameters and gauges...design of the active cells to maximum the stroked length of the active cells by tuning the stiffness of a passive spring in parallel with the Nitinol

A low delay transmission method of multi-channel video based on FPGA

NASA Astrophysics Data System (ADS)

Fu, Weijian; Wei, Baozhi; Li, Xiaobin; Wang, Quan; Hu, Xiaofei

2018-03-01

In order to guarantee the fluency of multi-channel video transmission in video monitoring scenarios, we designed a kind of video format conversion method based on FPGA and its DMA scheduling for video data, reduces the overall video transmission delay.In order to sace the time in the conversion process, the parallel ability of FPGA is used to video format conversion. In order to improve the direct memory access (DMA) writing transmission rate of PCIe bus, a DMA scheduling method based on asynchronous command buffer is proposed. The experimental results show that this paper designs a low delay transmission method based on FPGA, which increases the DMA writing transmission rate by 34% compared with the existing method, and then the video overall delay is reduced to 23.6ms.

A generalized theory for the design of contraction cones and other low speed ducts

NASA Technical Reports Server (NTRS)

Barger, R. L.; Bowen, J. T.

1972-01-01

A generalization of the Tsien method of contraction cone design is described. The design velocity distribution is expressed in such a form that the required high order derivatives can be obtained by recursion rather than by numerical or analytic differentiation. The method is applicable to the design of diffusers and converging-diverging ducts as well as contraction cones. The computer program is described and a FORTRAN listing of the program is provided.

Design techniques for low-voltage analog integrated circuits

NASA Astrophysics Data System (ADS)

Rakús, Matej; Stopjaková, Viera; Arbet, Daniel

2017-08-01

In this paper, a review and analysis of different design techniques for (ultra) low-voltage integrated circuits (IC) are performed. This analysis shows that the most suitable design methods for low-voltage analog IC design in a standard CMOS process include techniques using bulk-driven MOS transistors, dynamic threshold MOS transistors and MOS transistors operating in weak or moderate inversion regions. The main advantage of such techniques is that there is no need for any modification of standard CMOS structure or process. Basic circuit building blocks like differential amplifiers or current mirrors designed using these approaches are able to operate with the power supply voltage of 600 mV (or even lower), which is the key feature towards integrated systems for modern portable applications.

Design and Computational/Experimental Analysis of Low Sonic Boom Configurations

NASA Technical Reports Server (NTRS)

Cliff, Susan E.; Baker, Timothy J.; Hicks, Raymond M.

1999-01-01

Recent studies have shown that inviscid CFD codes combined with a planar extrapolation method give accurate sonic boom pressure signatures at distances greater than one body length from supersonic configurations if either adapted grids swept at the approximate Mach angle or very dense non-adapted grids are used. The validation of CFD for computing sonic boom pressure signatures provided the confidence needed to undertake the design of new supersonic transport configurations with low sonic boom characteristics. An aircraft synthesis code in combination with CFD and an extrapolation method were used to close the design. The principal configuration of this study is designated LBWT (Low Boom Wing Tail) and has a highly swept cranked arrow wing with conventional tails, and was designed to accommodate either 3 or 4 engines. The complete configuration including nacelles and boundary layer diverters was evaluated using the AIRPLANE code. This computer program solves the Euler equations on an unstructured tetrahedral mesh. Computations and wind tunnel data for the LBWT and two other low boom configurations designed at NASA Ames Research Center are presented. The two additional configurations are included to provide a basis for comparing the performance and sonic boom level of the LBWT with contemporary low boom designs and to give a broader experiment/CFD correlation study. The computational pressure signatures for the three configurations are contrasted with on-ground-track near-field experimental data from the NASA Ames 9x7 Foot Supersonic Wind Tunnel. Computed pressure signatures for the LBWT are also compared with experiment at approximately 15 degrees off ground track.

Effect of increasing the choice of active options on children’s physical activity

USDA-ARS?s Scientific Manuscript database

Objectives: To determine whether increasing the choice of physical activity options increases the duration and intensity of children’s physical activity. Design: This cross-sectional laboratory study included gender (male, female) and choice group [single toy (no choice), three toys (low choice...

HANFORD MEDIUM-LOW CURIE WASTE PRETREATMENT ALTERNATIVES PROJECT FRACTIONAL CRYSTALLIZATION PILOT SCALE TESTING FINAL REPORT

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

HERTING DL

2008-09-16

The Fractional Crystallization Pilot Plant was designed and constructed to demonstrate that fractional crystallization is a viable way to separate the high-level and low-activity radioactive waste streams from retrieved Hanford single-shell tank saltcake. The focus of this report is to review the design, construction, and testing details of the fractional crystallization pilot plant not previously disseminated.

Analysis of mathematical literacy ability based on self-efficacy in model eliciting activities using metaphorical thinking approach

NASA Astrophysics Data System (ADS)

Setiani, C.; Waluya, S. B.; Wardono

2018-03-01

The purposes of this research are: (1) to identify learning quality in Model Eliciting Activities (MEAs) using a Metaphorical Thinking (MT) approach regarding qualitative and quantitative; (2) to analyze mathematical literacy of students based on Self-Efficacy (SE). This research is mixed method concurrent embedded design with qualitative research as the primary method. The quantitative research used quasi-experimental with non-equivalent control group design. The population is VIII grade students of SMP Negeri 3 Semarang Indonesia. Quantitative data is examined by conducting completeness mean test, standard completeness test, mean differentiation test and proportional differentiation test. Qualitative data is analyzed descriptively. The result of this research shows that MEAs learning using MT approach accomplishes good criteria both quantitatively and qualitatively. Students with low self-efficacy can identify problems, but they are lack ability to arrange problem-solving strategy on mathematical literacy questions. Students with medium self-efficacy can identify information provided in issues, but they find difficulties to use math symbols in making a representation. Students with high self-efficacy are excellent to represent problems into mathematical models as well as figures by using appropriate symbols and tools, so they can arrange strategy easily to solve mathematical literacy questions.

A decentralized linear quadratic control design method for flexible structures

NASA Technical Reports Server (NTRS)

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

1990-01-01

A decentralized suboptimal linear quadratic control design procedure which combines substructural synthesis, model reduction, decentralized control design, subcontroller synthesis, and controller reduction is proposed for the design of reduced-order controllers for flexible structures. The procedure starts with a definition of the continuum structure to be controlled. An evaluation model of finite dimension is obtained by the finite element method. Then, the finite element model is decomposed into several substructures by using a natural decomposition called substructuring decomposition. Each substructure, at this point, still has too large a dimension and must be reduced to a size that is Riccati-solvable. Model reduction of each substructure can be performed by using any existing model reduction method, e.g., modal truncation, balanced reduction, Krylov model reduction, or mixed-mode method. Then, based on the reduced substructure model, a subcontroller is designed by an LQ optimal control method for each substructure independently. After all subcontrollers are designed, a controller synthesis method called substructural controller synthesis is employed to synthesize all subcontrollers into a global controller. The assembling scheme used is the same as that employed for the structure matrices. Finally, a controller reduction scheme, called the equivalent impulse response energy controller (EIREC) reduction algorithm, is used to reduce the global controller to a reasonable size for implementation. The EIREC reduced controller preserves the impulse response energy of the full-order controller and has the property of matching low-frequency moments and low-frequency power moments. An advantage of the substructural controller synthesis method is that it relieves the computational burden associated with dimensionality. Besides that, the SCS design scheme is also a highly adaptable controller synthesis method for structures with varying configuration, or varying mass and stiffness properties.

Comparison of doubly labeled water with respirometry at low- and high-activity levels

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

Westerterp, K.R.; Brouns, F.; Saris, W.H.

1988-07-01

In previous studies the doubly labeled water method for measuring energy expenditure in free-living humans has been validated against respirometry under sedentary conditions. In the present investigation, energy expenditure is measured simultaneously with doubly labeled water and respirometry at low- and high-activity levels. Over 6 days, five subjects were measured doing mainly sedentary activities like desk work; their average daily metabolic rate was 1.40 +/- 0.09 (SD) times sleeping metabolic rate. Four subjects were measured twice over 3.5 days, including 2 days with heavy bicycle ergometer work, resulting in an average daily metabolic rate of 2.61 +/- 0.25 (SD) timesmore » sleeping metabolic rate. At the low-activity level, energy expenditures from the doubly labeled water method were on the average 1.4 +/- 3.9% (SD) larger than those from respirometry. At the high-activity level, the doubly labeled water method yielded values that were 1.0 +/- 7.0% (SD) lower than those from respirometry. Results demonstrate the utility of the doubly labeled water method for the determination of energy expenditure in the range of activity levels in daily life.« less

Photoluminescence and photocatalytic properties of rhombohedral CuGaO2 nanoplates

PubMed Central

Shi, Linlin; Wang, Fei; Wang, Yunpeng; Wang, Dengkui; Zhao, Bin; Zhang, Ligong; Zhao, Dongxu; Shen, Dezhen

2016-01-01

Rhombohedral phase CuGaO2 nanoplates with a diameter of about 10 μm were synthesized via low temperature hydrothermal method. Room temperature and low temperature photoluminescence of the obtained CuGaO2 nanoplates were characterized. CuGaO2 nanoplates exhibited blue emission at room temperature and free exciton emission were appeared at low temperature. The blue emission is originated from defects such as Cu vacancies, which is the possible origin of p-type conductivity. The appearance of free exciton emission can demonstrate the direct bandgap transition behavior of CuGaO2 nanoplates. The as-prepared p-type CuGaO2 nanoplates were further decorated by n-type ZnO nanoparticles via calcination method to fabricate p-n junction nanocomposites. The nanocomposites exhibited enhanced photocatalytic activity which can be ascribed to the effective separation of photogenerated carriers by the internal electrostatic field in the p-n junction region, and the enhanced light absorption properties resulted from sub-bandgap absorption effect of p-n junction. This work has offered a new insight into the design of p-n junction devices using p-type CuGaO2 nanoplates. PMID:26887923

Assessing Health Promotion Interventions: Limitations of Traditional Research Methods in Community-Based Studies.

PubMed

Dressel, Anne; Schneider, Robert; DeNomie, Melissa; Kusch, Jennifer; Welch, Whitney; Sosa, Mirtha; Yeldell, Sally; Maida, Tatiana; Wineberg, Jessica; Holt, Keith; Bernstein, Rebecca

2017-09-01

Most low-income Americans fail to meet physical activity recommendations. Inactivity and poor diet contribute to obesity, a risk factor for multiple chronic diseases. Health promotion activities have the potential to improve health outcomes for low-income populations. Measuring the effectiveness of these activities, however, can be challenging in community settings. A "Biking for Health" study tested the impact of a bicycling intervention on overweight or obese low-income Latino and African American adults to reduce barriers to cycling and increase physical activity and fitness. A randomized controlled trial was conducted in Milwaukee, Wisconsin, in summer 2015. A 12-week bicycling intervention was implemented at two sites with low-income, overweight, or obese Latino and African American adults. We found that randomized controlled trial methodology was suboptimal for use in this small pilot study and that it negatively affected participation. More discussion is needed about the effectiveness of using traditional research methods in community settings to assess the effectiveness of health promotion interventions. Modifications or alternative methods may yield better results. The aim of this article is to discuss the effectiveness and feasibility of using traditional research methods to assess health promotion interventions in community-based settings.

Assessment of Objectively Measured Physical Activity Levels in Individuals with Intellectual Disabilities with and without Down's Syndrome

PubMed Central

Phillips, Alexander C.; Holland, Anthony J.

2011-01-01

Objective To investigate, using accelerometers, the levels of physical activity being undertaken by individuals with intellectual disabilities with and without Down's syndrome. Methods One hundred and fifty two individuals with intellectual disabilities aged 12–70 years from East and South-East England. Physical activity levels in counts per minute (counts/min), steps per day (steps/day), and minutes of sedentary, light, moderate, vigorous, and moderate to vigorous physical activity (MVPA) measured with a uni-axial accelerometer (Actigraph GT1M) for seven days. Results No individuals with intellectual disabilities met current physical activity recommendations. Males were more active than females. There was a trend for physical activity to decline and sedentary behaviour to increase with age, and for those with more severe levels of intellectual disability to be more sedentary and less physically active, however any relationship was not significant when adjusted for confounding variables. Participants with Down's syndrome engaged in significantly less physical activity than those with intellectual disabilities without Down's syndrome and levels of activity declined significantly with age. Conclusions Individuals with intellectual disabilities, especially those with Down's syndrome may be at risk of developing diseases associated with physical inactivity. There is a need for well-designed, accessible, preventive health promotion strategies and interventions designed to raise the levels of physical activity for individuals with intellectual disabilities. We propose that there are physiological reasons why individuals with Down's syndrome have particularly low levels of physical activity that also decline markedly with age. PMID:22205957

Digital Morphing Wing: Active Wing Shaping Concept Using Composite Lattice-Based Cellular Structures.

PubMed

Jenett, Benjamin; Calisch, Sam; Cellucci, Daniel; Cramer, Nick; Gershenfeld, Neil; Swei, Sean; Cheung, Kenneth C

2017-03-01

We describe an approach for the discrete and reversible assembly of tunable and actively deformable structures using modular building block parts for robotic applications. The primary technical challenge addressed by this work is the use of this method to design and fabricate low density, highly compliant robotic structures with spatially tuned stiffness. This approach offers a number of potential advantages over more conventional methods for constructing compliant robots. The discrete assembly reduces manufacturing complexity, as relatively simple parts can be batch-produced and joined to make complex structures. Global mechanical properties can be tuned based on sub-part ordering and geometry, because local stiffness and density can be independently set to a wide range of values and varied spatially. The structure's intrinsic modularity can significantly simplify analysis and simulation. Simple analytical models for the behavior of each building block type can be calibrated with empirical testing and synthesized into a highly accurate and computationally efficient model of the full compliant system. As a case study, we describe a modular and reversibly assembled wing that performs continuous span-wise twist deformation. It exhibits high performance aerodynamic characteristics, is lightweight and simple to fabricate and repair. The wing is constructed from discrete lattice elements, wherein the geometric and mechanical attributes of the building blocks determine the global mechanical properties of the wing. We describe the mechanical design and structural performance of the digital morphing wing, including their relationship to wind tunnel tests that suggest the ability to increase roll efficiency compared to a conventional rigid aileron system. We focus here on describing the approach to design, modeling, and construction as a generalizable approach for robotics that require very lightweight, tunable, and actively deformable structures.

Digital Morphing Wing: Active Wing Shaping Concept Using Composite Lattice-Based Cellular Structures

PubMed Central

Jenett, Benjamin; Calisch, Sam; Cellucci, Daniel; Cramer, Nick; Gershenfeld, Neil; Swei, Sean

2017-01-01

Abstract We describe an approach for the discrete and reversible assembly of tunable and actively deformable structures using modular building block parts for robotic applications. The primary technical challenge addressed by this work is the use of this method to design and fabricate low density, highly compliant robotic structures with spatially tuned stiffness. This approach offers a number of potential advantages over more conventional methods for constructing compliant robots. The discrete assembly reduces manufacturing complexity, as relatively simple parts can be batch-produced and joined to make complex structures. Global mechanical properties can be tuned based on sub-part ordering and geometry, because local stiffness and density can be independently set to a wide range of values and varied spatially. The structure's intrinsic modularity can significantly simplify analysis and simulation. Simple analytical models for the behavior of each building block type can be calibrated with empirical testing and synthesized into a highly accurate and computationally efficient model of the full compliant system. As a case study, we describe a modular and reversibly assembled wing that performs continuous span-wise twist deformation. It exhibits high performance aerodynamic characteristics, is lightweight and simple to fabricate and repair. The wing is constructed from discrete lattice elements, wherein the geometric and mechanical attributes of the building blocks determine the global mechanical properties of the wing. We describe the mechanical design and structural performance of the digital morphing wing, including their relationship to wind tunnel tests that suggest the ability to increase roll efficiency compared to a conventional rigid aileron system. We focus here on describing the approach to design, modeling, and construction as a generalizable approach for robotics that require very lightweight, tunable, and actively deformable structures. PMID:28289574

Design and baseline characteristics of the Short bouTs of Exercise for Preschoolers (STEP) study

PubMed Central

2012-01-01

Background Most preschool centers provide two 30-min sessions of gross-motor/outdoor playtime per preschool day. Within this time frame, children accumulate most of their activity within the first 10 min. This paper describes the design and baseline participant characteristics of the Short bouTs of Exercise for Preschoolers (STEP) study. The STEP study is a cluster randomized controlled study designed to examine the effects of short bouts of structured physical activity (SBS-PA) implemented within the classroom setting as part of designated gross-motor playtime on during-school physical activity (PA) in preschoolers. Methods/Design Ten preschool centers serving low-income families were randomized into SBS-PA versus unstructured PA (UPA). SBS-PA schools were asked to implement age-appropriate 10 min structured PA routines within the classroom setting, twice daily, followed by 20 min of usual unstructured playtime. UPA intervention consisted of 30 min of supervised unstructured free playtime twice daily. Interventions were implemented during the morning and afternoon designated gross-motor playtime for 30 min/session, five days/week for six months. Outcome measures were between group difference in during-preschool PA (accelerometers and direct observation) over six-months. Ten preschool centers, representing 34 classrooms and 315 children, enrolled in the study. The average age and BMI percentile for the participants was 4.1 ± 0.8 years and 69th percentile, respectively. Participants spent 74% and 6% of their preschool day engaged in sedentary and MVPA, respectively. Discussion Results from the STEP intervention could provide evidence that a PA policy that exposes preschoolers to shorter bouts of structured PA throughout the preschool day could potentially increase preschoolers’ PA levels. Trial registration Clinicaltrials.gov, NCT01588392 PMID:22853642

Linearization methods for optimizing the low thrust spacecraft trajectory: Theoretical aspects

NASA Astrophysics Data System (ADS)

Kazmerchuk, P. V.

2016-12-01

The theoretical aspects of the modified linearization method, which makes it possible to solve a wide class of nonlinear problems on optimizing low-thrust spacecraft trajectories (V. V. Efanov et al., 2009; V. V. Khartov et al., 2010) are examined. The main modifications of the linearization method are connected with its refinement for optimizing the main dynamic systems and design parameters of the spacecraft.

Design of Hybrid Nanostructural Arrays to Manipulate SERS-Active Substrates by Nanosphere Lithography.

PubMed

Zhao, Xiaoyu; Wen, Jiahong; Zhang, Mengning; Wang, Dunhui; Wang, Yaxin; Chen, Lei; Zhang, Yongjun; Yang, Jinghai; Du, Youwei

2017-03-01

An easy-handling and low-cost method is utilized to controllably fabricate nanopattern arrays as the surface-enhanced Raman scattering (SERS) active substrates with high density of SERS-active areas (hot spots). A hybrid silver array of nanocaps and nanotriangles are prepared by combining magnetron sputtering and plasma etching. By adjusting the etching time of polystyrene (PS) colloid spheres array in silver nanobowls, the morphology of the arrays can be easily manipulated to control the formation and distribution of hot spots. The experimental results show that the hybrid nanostructural arrays have large enhancement factor, which is estimated to be seven times larger than that in the array of nanocaps and three times larger than that in the array of nanorings and nanoparticles. According to the results of finite-difference time-domain simulation, the excellent SERS performance of this array is ascribed to the high density of hot spots and enhanced electromagnetic field.

Active terahertz wave imaging system for detecting hidden objects

NASA Astrophysics Data System (ADS)

Gan, Yuner; Liu, Ming; Zhao, Yuejin

2016-11-01

Terahertz wave can penetrate the common dielectric materials such as clothing, cardboard boxes, plastics and so on. Besides, the low photon energy and non-ionizing characteristic of the terahertz wave are especially suitable for the safety inspection of the human body. Terahertz imaging technology has a tremendous potential in the field of security inspection such as stations, airports and other public places. Terahertz wave imaging systems are divided into two categories: active terahertz imaging systems and passive terahertz imaging systems. So far, most terahertz imaging systems work at point to point mechanical scan pattern with the method of passive imaging. The imaging results of passive imaging tend to have low contrast and the image is not clear enough. This paper designs and implements an active terahertz wave imaging system combining terahertz wave transmitting and receiving with a Cassegrain antenna. The terahertz wave at the frequency of 94GHz is created by impact ionization avalanche transit time (IMPATT) diode, focused on the feed element for Cassegrain antenna by high density polyethylene (HDPE) lens, and transmitted to the human body by Cassegrain antenna. The reflected terahertz wave goes the same way it was emitted back to the feed element for Cassegrain antenna, focused on the horn antenna of detector by another high density polyethylene lens. The scanning method is the use of two-dimensional planar mirror, one responsible for horizontal scanning, and another responsible for vertical scanning. Our system can achieve a clear human body image, has better sensitivity and resolution than passive imaging system, and costs much lower than other active imaging system in the meantime.

Investigation of the Germination of Barley and Wheat Grains with a Design of Experiments for the Production of Hydrolases

PubMed Central

Kranz, Bertolt; Koch, Milena; Schapfl, Matthias

2015-01-01

Summary The production of hydrolases from cereals has been examined in order to investigate food-derived enzymes as an alternative source to microbial enzymes for the use in food processes. For that, the influence of temperature on the pretreatment, imbibition and germination of barley and wheat grains was determined by measuring the β-glucosidase, β-galactosidase and lipase activities using a design of experiments. The evaluation of the statistical model showed an increase of the β-glucosidase activity with low imbibition and low germination temperature for barley grains and low imbibition and high germination temperature for wheat grains. The maximum β-glucosidase activity in wheat extracts was (585±151) nkat per g of dry mass (dm), while in barley extracts it was (109±15) nkat per g of dm. The maximum β-galactosidase activities in barley and wheat extracts were (34±12) and (63±23) nkat per g of dm, respectively. The maximum lipase activities of (6.7±0.1) and (4.6±4.4) nkat per g of dm in barley and wheat extracts, respectively, were rather low compared to the glycosidase activities. The extracts were also tested for other hydrolase activities (e.g. peptidase and α-amylase activities). The insights obtained enable the basis for the potential use of cereal hydrolases in food processing, which might be attractive to consumers. PMID:27904341

Microgravity isolation system design: A modern control analysis framework

NASA Technical Reports Server (NTRS)

Hampton, R. D.; Knospe, C. R.; Allaire, P. E.; Grodsinsky, C. M.

1994-01-01

Many acceleration-sensitive, microgravity science experiments will require active vibration isolation from the manned orbiters on which they will be mounted. The isolation problem, especially in the case of a tethered payload, is a complex three-dimensional one that is best suited to modern-control design methods. These methods, although more powerful than their classical counterparts, can nonetheless go only so far in meeting the design requirements for practical systems. Once a tentative controller design is available, it must still be evaluated to determine whether or not it is fully acceptable, and to compare it with other possible design candidates. Realistically, such evaluation will be an inherent part of a necessary iterative design process. In this paper, an approach is presented for applying complex mu-analysis methods to a closed-loop vibration isolation system (experiment plus controller). An analysis framework is presented for evaluating nominal stability, nominal performance, robust stability, and robust performance of active microgravity isolation systems, with emphasis on the effective use of mu-analysis methods.

Creep-Fatigue Relationsihps in Electroactive Polymer Systems and Predicted Effects in an Actuator Design

NASA Technical Reports Server (NTRS)

Vinogradov, Aleksandra M.; Ihlefeld, Curtis M.; Henslee, Issac

2009-01-01

The paper concerns the time-dependent behavior of electroactive polymers (EAP) and their use in advanced intelligent structures for space exploration. Innovative actuator design for low weight and low power valves required in small plants planned for use on the moon for chemical analysis is discussed. It is shown that in-depth understanding of cyclic loading effects observed through accelerated creep rates due to creep-fatigue interaction in polymers is critical in terms of proper functioning of EAP based actuator devices. In the paper, an overview of experimental results concerning the creep properties and cyclic creep response of a thin film piezoelectric polymer polyvinylidene fluoride (PVDF) is presented. The development of a constitutive creep-fatigue interaction model to predict the durability and service life of electroactive polymers is discussed. A novel method is proposed to predict damage accumulation and fatigue life of polymers under oyclic loading conditions in the presence of creep. The study provides a basis for ongoing research initiatives at the NASA Kennedy Space Center in the pursuit of new technologies using EAP as active elements for lunar exploration systems.

Radioisotope Heater Unit-Based Stirling Power Convertor Development at NASA Glenn Research Center

NASA Technical Reports Server (NTRS)

Wilson, Scott D.; Geng, Steven M.; Penswick, Lawrence; Schmitz, Paul C.

2017-01-01

Stirling Radioisotope Power Systems (RPS) are being developed as an option to provide power on future space science missions where robotic spacecraft will orbit, flyby, land or rove. A variety of mission concepts have been studied by NASA and the U. S. Department of Energy that would utilize RPS for landers, probes, and rovers and only require milliwatts to tens of watts of power. These missions would contain science measuring instruments that could be distributed across planetary surfaces or near objects of interest in space solar flux insufficient for using solar cells. A low power Stirling convertor is being developed to provide an RPS option for future low power applications. Initial concepts convert heat available from several Radioisotope Heater Units to electrical power for spacecraft instruments and communication. Initial development activity includes defining and evaluating a variety of Stirling configurations and selecting one for detailed design, research of advanced manufacturing methods that could simplify fabrication, evaluating thermal interfaces, characterizing components and subassemblies to validate design codes, and preparing for an upcoming demonstration of proof of concept in a laboratory environment.

Child Abuse and Neglect, MAOA, and Mental Health Outcomes: A Prospective Examination

PubMed Central

Widom, Cathy Spatz; Brzustowicz, Linda M.

2012-01-01

Background Studies have examined the interaction of MAOA genotype with childhood maltreatment in relation to depressive symptomatology and alcohol abuse with conflicting findings. Both high and low activity allele combinations have been shown to be protective for maltreated children with direction of findings varying by study methodology and participant’s sex. Methods Participants in a prospective cohort design study involving court substantiated cases of child abuse and neglect and a matched comparison group were followed up into adulthood and interviewed (N = 802). Eighty-two percent consented to provide blood, 631 gave permission for DNA extraction and analyses, and 575 were included in the final sample. This sample included male, female, White, and Non-White (primarily Black) participants. Symptoms of dysthymia, major depression and alcohol abuse were assessed using the NIMH Diagnostic Interview Schedule-III-R. Results Significant three-way interactions, MAOA genotype by abuse by sex, predicted dysthymic symptoms. Low-activity MAOA genotype buffered against symptoms of dysthymia in physically abused and multiply maltreated women. Significant three-way interactions, MAOA genotype by sexual abuse by race, predicted all outcomes. Low-activity MAOA genotype buffered against symptoms of dysthymia, major depressive disorder and alcohol abuse for sexually abused White participants. The high-activity genotype was protective in the Non-White sexually abused group. Conclusions This prospective study provides evidence that MAOA interacts with child maltreatment to predict mental health outcomes. Reasons for sex differences and race findings are discussed. PMID:22030358

Effects of low-disturbance manure application methods on N2O and NH3 emissions in a silage corn - rye cover crop system

USDA-ARS?s Scientific Manuscript database

Incorporation of manure by tillage can conserve manure N by reducing ammonia volatilization losses, but tillage also incorporates crop residue, which may increase erosion potential. This study compared several low-disturbance manure application methods, designed to incorporate manure while maintaini...

Combustion Dynamics and Control for Ultra Low Emissions in Aircraft Gas-Turbine Engines

NASA Technical Reports Server (NTRS)

DeLaat, John C.

2011-01-01

Future aircraft engines must provide ultra-low emissions and high efficiency at low cost while maintaining the reliability and operability of present day engines. The demands for increased performance and decreased emissions have resulted in advanced combustor designs that are critically dependent on efficient fuel/air mixing and lean operation. However, all combustors, but most notably lean-burning low-emissions combustors, are susceptible to combustion instabilities. These instabilities are typically caused by the interaction of the fluctuating heat release of the combustion process with naturally occurring acoustic resonances. These interactions can produce large pressure oscillations within the combustor and can reduce component life and potentially lead to premature mechanical failures. Active Combustion Control which consists of feedback-based control of the fuel-air mixing process can provide an approach to achieving acceptable combustor dynamic behavior while minimizing emissions, and thus can provide flexibility during the combustor design process. The NASA Glenn Active Combustion Control Technology activity aims to demonstrate active control in a realistic environment relevant to aircraft engines by providing experiments tied to aircraft gas turbine combustors. The intent is to allow the technology maturity of active combustion control to advance to eventual demonstration in an engine environment. Work at NASA Glenn has shown that active combustion control, utilizing advanced algorithms working through high frequency fuel actuation, can effectively suppress instabilities in a combustor which emulates the instabilities found in an aircraft gas turbine engine. Current efforts are aimed at extending these active control technologies to advanced ultra-low-emissions combustors such as those employing multi-point lean direct injection.

Mystic: Implementation of the Static Dynamic Optimal Control Algorithm for High-Fidelity, Low-Thrust Trajectory Design

NASA Technical Reports Server (NTRS)

Whiffen, Gregory J.

2006-01-01

Mystic software is designed to compute, analyze, and visualize optimal high-fidelity, low-thrust trajectories, The software can be used to analyze inter-planetary, planetocentric, and combination trajectories, Mystic also provides utilities to assist in the operation and navigation of low-thrust spacecraft. Mystic will be used to design and navigate the NASA's Dawn Discovery mission to orbit the two largest asteroids, The underlying optimization algorithm used in the Mystic software is called Static/Dynamic Optimal Control (SDC). SDC is a nonlinear optimal control method designed to optimize both 'static variables' (parameters) and dynamic variables (functions of time) simultaneously. SDC is a general nonlinear optimal control algorithm based on Bellman's principal.

Compendium of Interdisciplinary Activities for an Introductory Course in Communication Systems at the Secondary Level.

ERIC Educational Resources Information Center

Lasko, David J.

This compendium of interdisciplinary learning activities is designed to assist technology education instructors who are conducting an introductory secondary-level course in communication technology. The 12 activities, which are sequenced from introductory, low-cost activities to more advanced and more involved activities, deal with the following…

A Vehicle Active Safety Model: Vehicle Speed Control Based on Driver Vigilance Detection Using Wearable EEG and Sparse Representation.

PubMed

Zhang, Zutao; Luo, Dianyuan; Rasim, Yagubov; Li, Yanjun; Meng, Guanjun; Xu, Jian; Wang, Chunbai

2016-02-19

In this paper, we present a vehicle active safety model for vehicle speed control based on driver vigilance detection using low-cost, comfortable, wearable electroencephalographic (EEG) sensors and sparse representation. The proposed system consists of three main steps, namely wireless wearable EEG collection, driver vigilance detection, and vehicle speed control strategy. First of all, a homemade low-cost comfortable wearable brain-computer interface (BCI) system with eight channels is designed for collecting the driver's EEG signal. Second, wavelet de-noising and down-sample algorithms are utilized to enhance the quality of EEG data, and Fast Fourier Transformation (FFT) is adopted to extract the EEG power spectrum density (PSD). In this step, sparse representation classification combined with k-singular value decomposition (KSVD) is firstly introduced in PSD to estimate the driver's vigilance level. Finally, a novel safety strategy of vehicle speed control, which controls the electronic throttle opening and automatic braking after driver fatigue detection using the above method, is presented to avoid serious collisions and traffic accidents. The simulation and practical testing results demonstrate the feasibility of the vehicle active safety model.

A Vehicle Active Safety Model: Vehicle Speed Control Based on Driver Vigilance Detection Using Wearable EEG and Sparse Representation

PubMed Central

Zhang, Zutao; Luo, Dianyuan; Rasim, Yagubov; Li, Yanjun; Meng, Guanjun; Xu, Jian; Wang, Chunbai

2016-01-01

In this paper, we present a vehicle active safety model for vehicle speed control based on driver vigilance detection using low-cost, comfortable, wearable electroencephalographic (EEG) sensors and sparse representation. The proposed system consists of three main steps, namely wireless wearable EEG collection, driver vigilance detection, and vehicle speed control strategy. First of all, a homemade low-cost comfortable wearable brain-computer interface (BCI) system with eight channels is designed for collecting the driver’s EEG signal. Second, wavelet de-noising and down-sample algorithms are utilized to enhance the quality of EEG data, and Fast Fourier Transformation (FFT) is adopted to extract the EEG power spectrum density (PSD). In this step, sparse representation classification combined with k-singular value decomposition (KSVD) is firstly introduced in PSD to estimate the driver’s vigilance level . Finally, a novel safety strategy of vehicle speed control, which controls the electronic throttle opening and automatic braking after driver fatigue detection using the above method, is presented to avoid serious collisions and traffic accidents. The simulation and practical testing results demonstrate the feasibility of the vehicle active safety model. PMID:26907278

Development of a vibration isolation prototype system for microgravity space experiments

NASA Technical Reports Server (NTRS)

Logsdon, Kirk A.; Grodsinsky, Carlos M.; Brown, Gerald V.

1990-01-01

The presence of small levels of low-frequency accelerations on the space shuttle orbiters has degraded the microgravity environment for the science community. Growing concern about this microgravity environment has generated interest in systems that can isolate microgravity science experiments from vibrations. This interest has resulted primarily in studies of isolation systems with active methods of compensation. The development of a magnetically suspended, six-degree-of-freedom active vibration isolation prototype system capable of providing the needed compensation to the orbital environment is presented. A design for the magnetic actuators is described, and the control law for the prototype system that gives a nonintrusive inertial isolation response to the system is also described. Relative and inertial sensors are used to provide an inertial reference for isolating the payload.

Effect of NASA advanced designs on thermal behavior of Ni-H2 cells

NASA Technical Reports Server (NTRS)

Gonzalez-Sanabria, Olga D.

1987-01-01

As part of an overall effort to advance the technology of nickel-hydrogen batteries for low Earth orbit (LEO) applications, advanced designs for individual pressure vessel (IPV) nickel-hydrogen cells have been conceived. These designs incorporate alternative methods of oxygen recombination which affect the thermal behavior of the cells. The effect of these oxygen recombination methods on the cell temperature profiles is examined.

Effect of NASA advanced designs on thermal behavior of Ni-H2 cells

NASA Technical Reports Server (NTRS)

Gonzalez-Sanabria, Olga D.

1988-01-01

As part of an overall effort to advance the technology of nickel-hydrogen batteries for low earth orbit (LEO) applications, advanced designs for individual pressure vessel (IPV) nickel-hydrogen cells have been conceived. These designs incorporate alternative methods of oxygen recombination which affect the thermal behavior of the cells. The effect of these oxygen recombination methods on the cell temperature profiles will be examined.

Conference on Low Reynolds Number Airfoil Aerodynamics, Notre Dame, IN, June 16-18, 1985, Proceedings

NASA Technical Reports Server (NTRS)

Mueller, T. J. (Editor)

1985-01-01

Topics of interest in the design, flow modeling and visualization, and turbulence and flow separation effects for low Reynolds number (Re) airfoils are discussed. Design methods are presented for Re from 50,000-500,000, including a viscous-inviscid coupling method and by using a constrained pitching moment. The effects of pressure gradients, unsteady viscous aerodynamics and separation bubbles are investigated, with particular note made of factors which most influence the size and location of separation bubbles and control their effects. Attention is also given to experimentation with low Re airfoils and to numerical models of symmetry breaking and lift hysteresis from separation. Both steady and unsteady flow experiments are reviewed, with the trials having been held in wind tunnels and the free atmosphere. The topics discussed are of interest to designers of RPVs, high altitude aircraft, sailplanes, ultralights and wind turbines.

The complex-scaled multiconfigurational spin-tensor electron propagator method for low-lying shape resonances in Be-, Mg- and Ca-

NASA Astrophysics Data System (ADS)

Tsogbayar, Tsednee; Yeager, Danny L.

2017-01-01

We further apply the complex scaled multiconfigurational spin-tensor electron propagator method (CMCSTEP) for the theoretical determination of resonance parameters with electron-atom systems including open-shell and highly correlated (non-dynamical correlation) atoms and molecules. The multiconfigurational spin-tensor electron propagator method (MCSTEP) developed and implemented by Yeager and his coworkers for real space gives very accurate and reliable ionization potentials and electron affinities. CMCSTEP uses a complex scaled multiconfigurational self-consistent field (CMCSCF) state as an initial state along with a dilated Hamiltonian where all of the electronic coordinates are scaled by a complex factor. CMCSTEP is designed for determining resonances. We apply CMCSTEP to get the lowest 2P (Be-, Mg-) and 2D (Mg-, Ca-) shape resonances using several different basis sets each with several complete active spaces. Many of these basis sets we employ have been used by others with different methods. Hence, we can directly compare results with different methods but using the same basis sets.

Three-phase short circuit calculation method based on pre-computed surface for doubly fed induction generator

NASA Astrophysics Data System (ADS)

Ma, J.; Liu, Q.

2018-02-01

This paper presents an improved short circuit calculation method, based on pre-computed surface to determine the short circuit current of a distribution system with multiple doubly fed induction generators (DFIGs). The short circuit current, injected into power grid by DFIG, is determined by low voltage ride through (LVRT) control and protection under grid fault. However, the existing methods are difficult to calculate the short circuit current of DFIG in engineering practice due to its complexity. A short circuit calculation method, based on pre-computed surface, was proposed by developing the surface of short circuit current changing with the calculating impedance and the open circuit voltage. And the short circuit currents were derived by taking into account the rotor excitation and crowbar activation time. Finally, the pre-computed surfaces of short circuit current at different time were established, and the procedure of DFIG short circuit calculation considering its LVRT was designed. The correctness of proposed method was verified by simulation.

A Mixed-Fidelity Approach for Design of Low-Boom Supersonic Aircraft

NASA Technical Reports Server (NTRS)

Li, Wu; Shields, Elwood; Geiselhart, Karl A.

2010-01-01

This paper documents a mixed-fidelity approach for the design of low-boom supersonic aircraft as a viable approach for designing a practical low-boom supersonic configuration. A low-boom configuration that is based on low-fidelity analysis is used as the baseline. Tail lift is included to help tailor the aft portion of the ground signature. A comparison of low- and high-fidelity analysis results demonstrates the necessity of using computational fluid dynamics (CFD) analysis in a low-boom supersonic configuration design process. The fuselage shape is modified iteratively to obtain a configuration with a CFD equivalent-area distribution that matches a predetermined low-boom target distribution. The mixed-fidelity approach can easily refine the low-fidelity low-boom baseline into a low-boom configuration with the use of CFD equivalent-area analysis. The ground signature of the final configuration is calculated by using a state-of-the-art CFD-based boom analysis method that generates accurate midfield pressure distributions for propagation to the ground with ray tracing. The ground signature that is propagated from a midfield pressure distribution has a shaped ramp front, which is similar to the ground signature that is propagated from the CFD equivalent-area distribution. This result confirms the validity of the low-boom supersonic configuration design by matching a low-boom equivalent-area target, which is easier to accomplish than matching a low-boom midfield pressure target.

Design and Mechanism of Tetrahydrothiophene-based GABA Aminotransferase Inactivators

PubMed Central

Le, Hoang V.; Hawker, Dustin D.; Wu, Rui; Doud, Emma; Widom, Julia; Sanishvili, Ruslan; Liu, Dali; Kelleher, Neil L.; Silverman, Richard B.

2015-01-01

Low levels of γ-aminobutyric acid (GABA), one of two major neurotransmitters that regulate brain neuronal activity, are associated with many neurological disorders, such as epilepsy, Parkinson’s disease, Alzheimer’s disease, Huntington’s disease, and cocaine addiction. One of the main methods to raise the GABA level in human brain is to use small molecules that cross the blood-brain barrier and inhibit the activity of γ-aminobutyric acid aminotransferase (GABA-AT), the enzyme that degrades GABA. We have designed a series of conformationally-restricted, tetrahydrothiophene-based GABA analogs with a properly-positioned leaving group that could facilitate a ring-opening mechanism, leading to inactivation of GABA-AT. One compound in the series is eight times more efficient an inactivator of GABA-AT than vigabatrin, the only FDA-approved inactivator of GABA-AT. Our mechanistic studies show that the compound inactivates GABA-AT by a new mechanism. The metabolite resulting from inactivation does not covalently bind to amino acid residues of GABA-AT but stays in the active site via H-bond interactions with Arg-192, a π-π interaction with Phe-189, and a weak nonbonded S···O=C interaction with Glu-270, thereby inactivating the enzyme. PMID:25781189

Design and Mechanism of Tetrahydrothiophene-Based γ-Aminobutyric Acid Aminotransferase Inactivators

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

Le, Hoang V.; Hawker, Dustin D.; Wu, Rui

Low levels of gamma-aminobutyric acid (GABA), one of two major neurotransmitters that regulate brain neuronal activity, are associated with many neurological disorders, such as epilepsy, Parkinsons disease, Alzheimers disease, Huntingtons disease, and cocaine addiction. One of the main methods to raise the GABA level in human brain is to use small molecules that cross the bloodbrain barrier and inhibit the activity of gamma-aminobutyric acid aminotransferase (GABA-AT), the enzyme that degrades GABA. We have designed a series of conformationally restricted tetrahydrothiophene-based GABA analogues with a properly positioned leaving group that could facilitate a ring-opening mechanism, leading to inactivation of GABA-AT. Onemore » compound in the series is 8 times more efficient an inactivator of GABA-AT than vigabatrin, the only FDA-approved inactivator of GABA-AT. Our mechanistic studies show that the compound inactivates GABA-AT by a new mechanism. The metabolite resulting from inactivation does not covalently bind to amino acid residues of GABA-AT but stays in the active site via H-bonding interactions with Arg-192, a pi-pi interaction with Phe-189, and a weak nonbonded (SO)-O-...=C interaction with Glu-270, thereby inactivating the enzyme.« less

Design and mechanism of tetrahydrothiophene-based γ-aminobutyric acid aminotransferase inactivators.

PubMed

Le, Hoang V; Hawker, Dustin D; Wu, Rui; Doud, Emma; Widom, Julia; Sanishvili, Ruslan; Liu, Dali; Kelleher, Neil L; Silverman, Richard B

2015-04-08

Low levels of γ-aminobutyric acid (GABA), one of two major neurotransmitters that regulate brain neuronal activity, are associated with many neurological disorders, such as epilepsy, Parkinson's disease, Alzheimer's disease, Huntington's disease, and cocaine addiction. One of the main methods to raise the GABA level in human brain is to use small molecules that cross the blood-brain barrier and inhibit the activity of γ-aminobutyric acid aminotransferase (GABA-AT), the enzyme that degrades GABA. We have designed a series of conformationally restricted tetrahydrothiophene-based GABA analogues with a properly positioned leaving group that could facilitate a ring-opening mechanism, leading to inactivation of GABA-AT. One compound in the series is 8 times more efficient an inactivator of GABA-AT than vigabatrin, the only FDA-approved inactivator of GABA-AT. Our mechanistic studies show that the compound inactivates GABA-AT by a new mechanism. The metabolite resulting from inactivation does not covalently bind to amino acid residues of GABA-AT but stays in the active site via H-bonding interactions with Arg-192, a π-π interaction with Phe-189, and a weak nonbonded S···O═C interaction with Glu-270, thereby inactivating the enzyme.

Informing Active Play and Screen Time Behaviour Change Interventions for Low Socioeconomic Position Mothers of Young Children: What Do Mothers Want?

PubMed Central

Campbell, Karen J.; Hesketh, Kylie D.

2016-01-01

Introduction. This study investigated views of mothers from disadvantaged urban and regional areas (i.e., beyond major capital cities) as potential end users of child active play and screen time behaviour change interventions, with a focus on text messaging and web-based delivery platforms. Methods. Thirty-two mothers (22 urban; 10 regional) were interviewed. Purpose-designed questions covered topics regarding mothers' preferences for accessing and receiving information related to parenting and child active play and screen time. Data from transcribed interviews were analysed to identify responses and key themes. Results. Mothers reported frequently accessing parenting- and child-related information online. Regional mothers reported seeking information by talking with other people less frequently than urban mothers and seemed to have a stronger preference for receiving information online. There were few differences between responses from low and high educated mothers. The majority of mothers reported that they would be happy to receive text messages containing information about active play and screen time and that they would find a dedicated website with this information useful. Conclusions. Mothers in this study held favourable views on the potential of receiving information via new communication technologies. Future interventions targeting socioeconomically disadvantaged mothers may benefit from delivering intervention messages via these technologies. PMID:28053979

Wireless system for explosion detection in underground structures

NASA Astrophysics Data System (ADS)

Chikhradze, M.; Bochorishvili, N.; Akhvlediani, I.; Kukhalashvili, D.; Kalichava, I.; Mataradze, E.

2009-06-01

Considering the growing threat of terrorist or accidental explosions in underground stations, underground highway and railway sections improvement of system for protecting people from explosions appears urgent. Current automatic protective devices with blast identification module and blast damping absorbers of various designs as their basic elements cannot be considered effective. Analysis revealed that low reliability of blast detection and delayed generation of start signal for the activation of an absorber are the major disadvantages of protective devices. Besides the transmission of trigger signal to an energy absorber through cable communication reduces the reliability of the operation of protective device due to a possible damage of electric wiring under blast or mechanical attack. This paper presents the outcomes of the studies conducted to select accurate criteria for blast identification and to design wireless system of activation of defensive device. The results of testing of blast detection methods (seismic, EMP, optical, on overpressure) showed that the proposed method, which implies constant monitoring of overpressure in terms of its reliability and response speed, best meets the requirements. Proposed wireless system for explosions identification and activation of protective device consists of transmitter and receiver modules. Transmitter module contains sensor and microprocessor equipped with blast identification software. Receiver module produces activation signal for operation of absorber. Tests were performed in the underground experimental base of Mining Institute. The time between the moment of receiving signal by the sensor and activation of absorber - 640 microsecond; distance between transmitter and receiver in direct tunnel - at least 150m; in tunnel with 900 bending - 50m. This research is sponsored by NATO's Public Diplomacy Division in the framework of "Science for Peace".

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.

Applications of the Integrated High-Performance CMOS Image Sensor to Range Finders - from Optical Triangulation to the Automotive Field.

PubMed

Wu, Jih-Huah; Pen, Cheng-Chung; Jiang, Joe-Air

2008-03-13

With their significant features, the applications of complementary metal-oxidesemiconductor (CMOS) image sensors covers a very extensive range, from industrialautomation to traffic applications such as aiming systems, blind guidance, active/passiverange finders, etc. In this paper CMOS image sensor-based active and passive rangefinders are presented. The measurement scheme of the proposed active/passive rangefinders is based on a simple triangulation method. The designed range finders chieflyconsist of a CMOS image sensor and some light sources such as lasers or LEDs. Theimplementation cost of our range finders is quite low. Image processing software to adjustthe exposure time (ET) of the CMOS image sensor to enhance the performance oftriangulation-based range finders was also developed. An extensive series of experimentswere conducted to evaluate the performance of the designed range finders. From theexperimental results, the distance measurement resolutions achieved by the active rangefinder and the passive range finder can be better than 0.6% and 0.25% within themeasurement ranges of 1 to 8 m and 5 to 45 m, respectively. Feasibility tests onapplications of the developed CMOS image sensor-based range finders to the automotivefield were also conducted. The experimental results demonstrated that our range finders arewell-suited for distance measurements in this field.

Perceptions and Practices Related to Obesity in Adolescent Students and Their Programmatic Implications: Qualitative Evidence from Ho Chi Minh City, Vietnam.

PubMed

Nguyen, Ngoc-Minh; Dibley, Michael J; Tang, Hong K; Alam, Ashraful

2017-12-01

Background Prevalence of obesity in children in Ho Chi Minh City is rising in the last 10 years. We conducted a formative study to explore the perceptions and practices related to obesity, diet and physical activity among the students in two junior high schools in two suburbs in Ho Chi Minh City to aid in the design of an intervention in preventing obesity among adolescent school children. Method We conducted in-depth interviews with twenty participants including students, their parents, physical education teachers and a representative of the Department of Education. Manually coded and organized data were analysed applying a thematic analysis approach to divulge trends, diversities and similarities among the emerging themes. Results The study revealed diversified perceptions of obesity, diet and physical activity and their relationship with adolescent obesity. The findings indicated low practice of physical activity among almost all students who participated in the study. The major barriers to obesity prevention included knowledge gaps, food environment in the school, devaluation of physical activity and academic burden. Conclusion The findings provide contextual insights to design a culturally appropriate and feasible intervention to tackle child and adolescent obesity by harnessing the perspectives of the target populations.

Nordic Walking and chronic low back pain: design of a randomized clinical trial

PubMed Central

Morsø, Lars; Hartvigsen, Jan; Puggaard, Lis; Manniche, Claus

2006-01-01

Background Low Back Pain is a major public health problem all over the western world. Active approaches including exercise in the treatment of low back pain results in better outcomes for patients, but it is not known exactly which types of back exercises are most beneficial or whether general physical activity provide similar benefits. Nordic Walking is a popular and fast growing type of exercise in Northern Europe. Initial studies have demonstrated that persons performing Nordic Walking are able to exercise longer and harder compared to normal walking thereby increasing their cardiovascular metabolism. Until now no studies have been performed to investigate whether Nordic Walking has beneficial effects in relation to low back pain. The primary aim of this study is to investigate whether supervised Nordic Walking can reduce pain and improve function in a population of chronic low back pain patients when compared to unsupervised Nordic Walking and advice to stay active. In addition we investigate whether there is an increase in the cardiovascular metabolism in persons performing supervised Nordic Walking compared to persons who are advised to stay active. Finally, we investigate whether there is a difference in compliance between persons receiving supervised Nordic Walking and persons doing unsupervised Nordic Walking. Methods One hundred and fifty patients with low back pain for at least eight weeks and referred to a specialized secondary sector outpatient back pain clinic are included in the study. After completion of the standard back centre treatment patients are randomized into one of three groups: A) Nordic Walking twice a week for eight weeks under supervision of a specially trained instructor; B) Unsupervised Nordic Walking for eight weeks after one training session with an instructor; C) A one hour motivational talk including advice to stay active. Outcome measures are pain, function, overall health, cardiovascular ability and activity level. Results No results available at this point. Discussion This study will investigate the effect of Nordic Walking on pain and function in a population of people with chronic LBP. Trial Registration registration # NCT00209820 PMID:17014731

Design, Assembly, and Characterization of TALE-Based Transcriptional Activators and Repressors

PubMed Central

Thakore, Pratiksha I.; Gersbach, Charles A.

2016-01-01

Transcription activator-like effectors (TALEs) are modular DNA-binding proteins that can be fused to a variety of effector domains to regulate the epigenome. Nucleotide recognition by TALE monomers follows a simple cipher, making this a powerful and versatile method to activate or repress gene expression. Described here are methods to design, assemble, and test TALE transcription factors (TALE-TFs) for control of endogenous gene expression. In this protocol, TALE arrays are constructed by Golden Gate cloning and tested for activity by transfection and quantitative RT-PCR. These methods for engineering TALE-TFs are useful for studies in reverse genetics and genomics, synthetic biology, and gene therapy. PMID:26443215

Design of Low Inductance Switching Power Cell for GaN HEMT Based Inverter

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

Gurpinar, Emre; Iannuzzo, Francesco; Yang, Yongheng

Here in this paper, an ultra-low inductance power cell is designed for a three-Level Active Neutral Point Clamped (3LANPC) based on 650 V gallium nitride (GaN) HEMT devices. The 3L-ANPC topology with GaN HEMT devices and the selected modulation scheme suitable for wide-bandgap (WBG) devices are presented. The commutation loops, which mainly contribute to voltage overshoots and increase of switching losses, are discussed. The ultra-low inductance power cell design based on a fourlayer Printed Circuit Board (PCB) with the aim to maximize the switching performance of GaN HEMTs is explained. The design of gate drivers for the GaN HEMT devicesmore » is presented. Parasitic inductance and resistance of the proposed design are extracted with finite element analysis and discussed. Common mode behaviours based on the SPICE model of the converter are analyzed. Experimental results on the designed 3L-ANPC with the output power of up to 1 kW are presented, which verifies the performance of the proposed design in terms of ultra-low inductance.« less

DESIGN MANUAL: PHOSPHORUS REMOVAL

EPA Science Inventory

This manual summarizes process design information for the best developed methods for removing phosphorus from wastewater. his manual discusses several proven phosphorus removal methods, including phosphorus removal obtainable through biological activity as well as chemical precip...

Stochastic Methods for Aircraft Design

NASA Technical Reports Server (NTRS)

Pelz, Richard B.; Ogot, Madara

1998-01-01

The global stochastic optimization method, simulated annealing (SA), was adapted and applied to various problems in aircraft design. The research was aimed at overcoming the problem of finding an optimal design in a space with multiple minima and roughness ubiquitous to numerically generated nonlinear objective functions. SA was modified to reduce the number of objective function evaluations for an optimal design, historically the main criticism of stochastic methods. SA was applied to many CFD/MDO problems including: low sonic-boom bodies, minimum drag on supersonic fore-bodies, minimum drag on supersonic aeroelastic fore-bodies, minimum drag on HSCT aeroelastic wings, FLOPS preliminary design code, another preliminary aircraft design study with vortex lattice aerodynamics, HSR complete aircraft aerodynamics. In every case, SA provided a simple, robust and reliable optimization method which found optimal designs in order 100 objective function evaluations. Perhaps most importantly, from this academic/industrial project, technology has been successfully transferred; this method is the method of choice for optimization problems at Northrop Grumman.

Predictors of Low-Care Prevalence in Florida Nursing Homes: The Role of Medicaid Waiver Programs

ERIC Educational Resources Information Center

Hahn, Elizabeth A.; Thomas, Kali S.; Hyer, Kathryn; Andel, Ross; Meng, Hongdao

2011-01-01

Purpose of the study: To examine the relationship between county-level Medicaid home- and community-based service (HCBS) waiver expenditures and the prevalence of low-care residents in Florida nursing homes (NHs). Design and Methods: The present study used a cross-sectional design. We combined two data sources: NH facility-level data (including…

Development and approach to low-frequency microgravity isolation systems

NASA Technical Reports Server (NTRS)

Grodsinsky, Carlos M.

1990-01-01

The low-gravity environment provided by space flight has afforded the science community a unique arena for the study of fundamental and technological sciences. However, the dynamic environment observed on space shuttle flights and predicted for Space Station Freedom has complicated the analysis of prior microgravity experiments and prompted concern for the viability of proposed space experiments requiring long-term, low-gravity environments. Thus, isolation systems capable of providing significant improvements to this random environment are being developed. The design constraints imposed by acceleration-sensitive, microgravity experiment payloads in the unique environment of space and a theoretical background for active isolation are discussed. A design is presented for a six-degree-of-freedom, active, inertial isolation system based on the baseline relative and inertial isolation techniques described.

Trace Contaminant Control During the International Space Station's On-Orbit Assembly and Outfitting

NASA Technical Reports Server (NTRS)

Perry, J. L.

2017-01-01

Achieving acceptable cabin air quality must balance competing elements during spacecraft design, assembly, ground processing, and flight operations. Among the elements that contribute to the trace chemical contaminant load and, therefore, the cabin air quality aboard crewed spacecraft are the vehicle configuration, crew size and activities, mission duration and objectives, materials selection, and vehicle manufacturing and preflight ground processing methods. Trace chemical contaminants produced from pervasive sources such as equipment offgassing, human metabolism, and cleaning fluids during preflight ground processing present challenges to maintaining acceptable cabin air quality. To address these challenges, both passive and active contamination control techniques are used during a spacecraft's design, manufacturing, preflight preparation, and operational phases. Passive contamination control methods seek to minimize the equipment offgassing load by selecting materials, manufacturing processes, preflight preparation processes, and in-flight operations that have low chemical offgassing characteristics. Passive methods can be employed across the spacecraft's entire life cycle from conceptual design through flight operations. However, because the passive contamination control techniques cannot fully eliminate the contaminant load, active contamination control equipment must be deployed aboard the spacecraft to purify and revitalize the cabin atmosphere during in-flight operations. Verifying that the passive contamination control techniques have successfully maintained the total trace contaminant load within the active contamination control equipment's capabilities occurs late in the preflight preparation stages. This verification consists of subjecting the spacecraft to an offgassing test to determine the trace contaminant load. This load is then assessed versus the active contamination control equipment's capabilities via trace contaminant control (TCC) engineering analysis. During the International Space Station's (ISS's) on-orbit assembly and outfitting, a series of engineering analyses were conducted to evaluate how effective the passive TCC methods were relative to providing adequate operational margin for the active TCC equipment's capabilities aboard the ISS. These analyses were based on habitable module and cargo vehicle offgassing test results. The offgassing test for a fully assembled module or cargo vehicle is an important preflight spacecraft evaluation method that has been used successfully during all crewed spacecraft programs to provide insight into how effectively the passive contamination control methods limit the equipment offgassing component of the overall trace contaminant generation load. The progression of TCC assessments beginning in 1998 with the ISS's first habitable element launch and continuing through the final pressurized element's arrival in 2010 are presented. Early cargo vehicle flight assessments between 2008 and 2011 are also presented as well as a discussion on predictive methods for assessing cargo via a purely analytical technique. The technical approach for TCC employed during this 13-year period successfully maintained the cabin atmospheric quality within specified parameters during the technically challenging ISS assembly and outfitting stages. The following narrative provides details on the important role of spacecraft offgassing testing, trace contaminant performance requirements, and flight rules for achieving the ultimate result-a cabin environment that enables people to live and work safely in space.

Tackling the conformational sampling of larger flexible compounds and macrocycles in pharmacology and drug discovery.

PubMed

Chen, I-Jen; Foloppe, Nicolas

2013-12-15

Computational conformational sampling underpins much of molecular modeling and design in pharmaceutical work. The sampling of smaller drug-like compounds has been an active area of research. However, few studies have tested in details the sampling of larger more flexible compounds, which are also relevant to drug discovery, including therapeutic peptides, macrocycles, and inhibitors of protein-protein interactions. Here, we investigate extensively mainstream conformational sampling methods on three carefully curated compound sets, namely the 'Drug-like', larger 'Flexible', and 'Macrocycle' compounds. These test molecules are chemically diverse with reliable X-ray protein-bound bioactive structures. The compared sampling methods include Stochastic Search and the recent LowModeMD from MOE, all the low-mode based approaches from MacroModel, and MD/LLMOD recently developed for macrocycles. In addition to default settings, key parameters of the sampling protocols were explored. The performance of the computational protocols was assessed via (i) the reproduction of the X-ray bioactive structures, (ii) the size, coverage and diversity of the output conformational ensembles, (iii) the compactness/extendedness of the conformers, and (iv) the ability to locate the global energy minimum. The influence of the stochastic nature of the searches on the results was also examined. Much better results were obtained by adopting search parameters enhanced over the default settings, while maintaining computational tractability. In MOE, the recent LowModeMD emerged as the method of choice. Mixed torsional/low-mode from MacroModel performed as well as LowModeMD, and MD/LLMOD performed well for macrocycles. The low-mode based approaches yielded very encouraging results with the flexible and macrocycle sets. Thus, one can productively tackle the computational conformational search of larger flexible compounds for drug discovery, including macrocycles. Copyright © 2013 Elsevier Ltd. All rights reserved.

Active shielding of cylindrical saddle-shaped coils: application to wire-wound RF coils for very low field NMR and MRI.

PubMed

Bidinosti, C P; Kravchuk, I S; Hayden, M E

2005-11-01

We provide an exact expression for the magnetic field produced by cylindrical saddle-shaped coils and their ideal shield currents in the low-frequency limit. The stream function associated with the shield surface current is also determined. The results of the analysis are useful for the design of actively shielded radio-frequency (RF) coils. Examples pertinent to very low field nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) are presented and discussed.

Development of Design Guidelines for Tools to Promote Differentiated Instruction in Classroom Teaching

ERIC Educational Resources Information Center

Cha, H. J.; Ahn, M. L.

2014-01-01

The purpose of this study was to elicit design guidelines for a teacher tool to support students' diverse needs by facilitating differentiated instructions (DIs). The study used a framework based on activity theory and principles from universal design for learning. As for the research methods, design-based research methods were adopted, and as the…

NIH State-of-the-Science Conference Statement: Role of active surveillance in the management of men with localized prostate cancer.

PubMed

Ganz, Patricia A; Barry, John M; Burke, Wylie; Col, Nananda F; Corso, Phaedra S; Dodson, Everett; Hammond, M Elizabeth; Kogan, Barry A; Lynch, Charles F; Newcomer, Lee; Seifter, Eric J; Tooze, Janet A; Viswanath, Kasisomayajula Vish; Wessells, Hunter

To provide healthcare providers, patients, and the general public with a responsible assessment of currently available data on the use of active surveillance and other observational management strategies for low-grade, localized prostate cancer. A non-U.S. Department of Health and Human Services, nonadvocate 14-member panel representing the fields of cancer prevention and control, urology, pathology, epidemiology, genetics, transplantation, bioethics, economics, health services research, shared decisionmaking, health communication, and community engagement. In addition, 22 experts from pertinent fields presented data to the panel and conference audience. Presentations by experts and a systematic review of the literature prepared by the Tufts Evidence-based Practice Center, through the Agency for Healthcare Research and Quality (AHRQ). Scientific evidence was given precedence over anecdotal experience. The panel drafted its statement based on scientific evidence presented in open forum and on published scientific literature. The draft statement was presented on the final day of the conference and circulated to the audience for comment. The panel released a revised statement later that day at http://consensus.nih.gov. This statement is an independent report of the panel and is not a policy statement of the NIH or the Federal Government. Prostate cancer screening with prostate-specific antigen (PSA) testing has identified many men with low-risk disease. Because of the very favorable prognosis of low-risk prostate cancer, strong consideration should be given to modifying the anxiety-provoking term "cancer" for this condition. Treatment of low-risk prostate cancer patients with radical prostatectomy or radiation therapy leads to side effects such as impotence and incontinence in a substantial number. Active surveillance has emerged as a viable option that should be offered to patients with low-risk prostate cancer. More than 100,000 men a year diagnosed with prostate cancer in the United States are candidates for this approach. However, there are many unanswered questions about active surveillance strategies and prostate cancer that require further research and clarification. These include: • Improvements in the accuracy and consistency of pathologic diagnosis of prostate cancer • Consensus on which men are the most appropriate candidates for active surveillance • The optimal protocol for active surveillance and the potential for individualizing the approach based on clinical and patient factors • Optimal ways to communicate the option of active surveillance to patients • Methods to assist patient decisionmaking • Reasons for acceptance or rejection of active surveillance as a treatment strategy • Short- and long-term outcomes of active surveillance. Well-designed studies to address these questions and others raised in this statement represent an important health research priority. Qualitative, observational, and interventional research designs are needed. Due to the paucity of evidence about this important public health problem, all patients being considered for active surveillance should be offered participation in multicenter research studies that incorporate community settings and partners.

Design of a 35-kilowatt bipolar nickel-hydrogen battery for low Earth orbit application

NASA Technical Reports Server (NTRS)

Cataldo, R. L.; Smithrick, J. J.

1982-01-01

The needs of multikilowatt storage for low Earth orbit applications are featured. The modular concept, with projected energy densities of 20-24 W-hr/lb and 700-900 W-hr/ft3, has significant improvements over state of the art capabilities. Other design features are; active cooling, a new scheme for H2-O2 recombination, and pore size engineering of all cell components.

Socioeconomic Disparities in Elementary School Practices and Children’s Physical Activity During School

PubMed Central

Carlson, Jordan A.; Mignano, Alexandra M.; Norman, Gregory J.; McKenzie, Thomas L.; Kerr, Jacqueline; Arredondo, Elva M.; Madanat, Hala; Cain, Kelli L.; Elder, John P.; Saelens, Brian E.; Sallis, James F.

2014-01-01

Purpose To examine school socioeconomic status (SES) in relation to school physical activity-related practices and children’s physical activity. Design A cross-sectional design was used for this study. Setting The study was set in 97 elementary schools (63% response rate) in two U.S. regions. Subjects Of the children taking part in this study, 172 were aged 10.2 (standard deviation (SD) = 1.5) years; 51.7% were girls, and 69.2% were White non-Hispanic. Measures School physical education (PE) teachers or principals responded to 15 yes/no questions on school physical activity-supportive practices. School SES (low, moderate, high) was derived from the percent of students eligible for free and reduced-price lunch. Children’s moderate to vigorous physical activity (MVPA) during school was measured with accelerometers. Analysis School level analyses involved linear and logistic regression; children’s MVPA analyses used mixed effects regression. Results Low-SES schools were less likely to have a PE teacher and had fewer physical activity-supportive PE practices than did high-SES schools (p < .05). Practices related to active travel to school were more favorable at low-SES schools (p < .05). Children attending high-SES schools had 4.4 minutes per day more of MVPA during school than did those at low-SES schools, but this finding was not statistically significant (p = .124). Conclusion These findings suggest that more low- and moderate-SES elementary schools need PE teachers in order to reduce disparities in school physical activity opportunities and that PE time needs to be supplemented by classroom teachers or other staff to meet guidelines. PMID:24380465

Impact of physical activity on the association of overweight and obesity with cardiovascular disease: The Rotterdam Study.

PubMed

Koolhaas, Chantal M; Dhana, Klodian; Schoufour, Josje D; Ikram, M Arfan; Kavousi, Maryam; Franco, Oscar H

2017-06-01

Background Being overweight or obese is associated with an increased risk of cardiovascular disease (CVD). Physical activity might reduce the risk associated with overweight and obesity. We examined the association between overweight and obesity and CVD risk as a function of physical activity levels in a middle-aged and elderly population. Design The study was a prospective cohort study. Methods The study included 5344 participants aged 55 years or older from the population-based Rotterdam Study. Participants were classified as having high or low physical activity based on the median of the population. Normal weight (18.5-24.9 kg/m 2 ), overweight (25.0-29.9 kg/m 2 ) and obese participants (≥30 kg/m 2 ) were categorized as having high or low physical activity to form six categories. We assessed the association of the six categories with CVD risk using Cox proportional hazard models adjusted for confounders. High physical activity and normal weight was used as the reference group. Results During 15 years of follow-up (median 10.3 years, interquartile range 8.2-11.7 years), 866 (16.2%) participants experienced a CVD event. Overweight and obese participants with low physical activity had a higher CVD risk than normal weight participants with high physical activity. The HRs and 95% confidence intervals (CIs) were 1.33 (1.07-1.66) and 1.35 (1.04-1.75), respectively. Overweight and obese participants with high physical activity did not show a higher CVD risk (HRs (95%CIs) 1.03 (0.82-1.29) and 1.12 (0.83-1.52), respectively). Conclusions Our findings suggest that the beneficial impact of physical activity on CVD might outweigh the negative impact of body mass index among middle-aged and elderly people. This emphasizes the importance of physical activity for everyone across all body mass index strata, while highlighting the risk associated with inactivity even among normal weight people.

Laser-based optoelectronic system for therapy by medical treatment of cardiovascular diseases

NASA Astrophysics Data System (ADS)

Chtchoupak, Oleg S.; Shpilevoj, Boris N.; Zapaeva, Natlia L.

1996-01-01

The method and design of a system for the laser treatment of ischemic heart disease is presented. Our conceptual approach to the development of the system is based on the theoretical and experimental works of the east and west scientists about positive influence of low intensity laser irradiation in the near infrared range by treatment of cardiovascular diseases. The method and system allow active influence on the subepicardial collateral blood circulation with near infrared (NIR) laser irradiation in wavelength ranges of 0.86-1.06 mkm. The presented technique makes it possible to achieve a higher effectiveness of treatment due to individual choice of radiation parameters on the basis of analysis of the patient conditions before and after laser therapy and due to simultaneous affection at several points of the human body. Finally, results of the tests are presented, which prove given methods.

Principles and Methods for the Rational Design of Core-Shell Nanoparticle Catalysts with Ultralow Noble Metal Loadings.

PubMed

Hunt, Sean T; Román-Leshkov, Yuriy

2018-05-15

Conspecuts Commercial and emerging renewable energy technologies are underpinned by precious metal catalysts, which enable the transformation of reactants into useful products. However, the noble metals (NMs) comprise the least abundant elements in the lithosphere, making them prohibitively scarce and expensive for future global-scale technologies. As such, intense research efforts have been devoted to eliminating or substantially reducing the loadings of NMs in various catalytic applications. These efforts have resulted in a plethora of heterogeneous NM catalyst morphologies beyond the traditional supported spherical nanoparticle. In many of these new architectures, such as shaped, high index, and bimetallic particles, less than 20% of the loaded NMs are available to perform catalytic turnovers. The majority of NM atoms are subsurface, providing only a secondary catalytic role through geometric and ligand effects with the active surface NM atoms. A handful of architectures can approach 100% NM utilization, but severe drawbacks limit general applicability. For example, in addition to problems with stability and leaching, single atom and ultrasmall cluster catalysts have extreme metal-support interactions, discretized d-bands, and a lack of adjacent NM surface sites. While monolayer thin films do not possess these features, they exhibit such low surface areas that they are not commercially relevant, serving predominantly as model catalysts. This Account champions core-shell nanoparticles (CS NPs) as a vehicle to design highly active, stable, and low-cost materials with high NM utilization for both thermo- and electrocatalysis. The unique benefits of the many emerging NM architectures could be preserved while their fundamental limitations could be overcome through reformulation via a core-shell morphology. However, the commercial realization of CS NPs remains challenging, requiring concerted advances in theory and manufacturing. We begin by formulating seven constraints governing proper core material design, which naturally point to early transition metal ceramics as suitable core candidates. Two constraints prove extremely challenging. The first relates to the core modifying the shell work function and d-band. To properly investigate materials that could satisfy this constraint, we discuss our development of a new heat, quench, and exfoliation (HQE) density functional theory (DFT) technique to model heterometallic interfaces. This technique is used to predict how transition metal carbides can favorably tune the catalytic properties of various NM monolayer shell configurations. The second challenging constraint relates to the scalable manufacturing of CS NP architectures with independent synthetic control of the thickness and composition of the shell and the size and composition of the core. We discuss our development of a synthetic method that enables high temperature self-assembly of tunable CS NP configurations. Finally, we discuss how these principles and methods were used to design catalysts for a variety of applications. These include the design of a thermally stable sub-monolayer CS catalyst, a highly active methanol electrooxidation catalyst, CO-tolerant Pt catalysts, and a hydrogen evolution catalyst that is less expensive than state-of-the-art NM-free catalysts. Such core-shell architectures offer the promise of ultralow precious metal loadings while ceramic cores hold the promise of thermodynamic stability and access to unique catalytic activity/tunability.

ESC Study Group of Sports Cardiology: recommendations for participation in leisure-time physical activity and competitive sports for patients with ischaemic heart disease.

PubMed

Börjesson, Mats; Assanelli, Deodato; Carré, François; Dugmore, Dorian; Panhuyzen-Goedkoop, Nicole M; Seiler, Christian; Senden, Jeff; Solberg, Erik E

2006-04-01

Evidence for the proper management of ischemic heart disease (IHD) in the general population is well established, but recommendations for physical activity and competitive sports in these patients are scarce. The aim of the present paper was to provide such recommendations to complement existing ESC and international guidelines on rehabilitation and primary/secondary prevention. Due to the lack of studies in this field, the current recommendations are the result of consensus among experts. Sports are classified into low/moderate/high dynamic and low/moderate/high static, respectively. Patients with a definitive IHD and higher probability of cardiac events are not eligible for competitive sports (CS) but for individually designed leisure time physical activity (LPA); patients with definitive IHD and lower probability of cardiac events as well as those with no IHD but with a positive exercise test and high risk profile (SCORE > 5%) are eligible for low/moderate static and low dynamic (IA-IIA) sports and individually designed LPA. Patients without IHD and a high risk profile+ a negative exercise-test and those with a low risk profile (SCORE < 5%) are allowed all LPA and competitive sports with a few exceptions. Individually designed LPA is possible and encouraged in patients with and without established IHD. Competitive sports may be restricted for patients with IHD, depending on the probability of cardiac events and the demands of the sport according to the current classification.

Communication style and exercise compliance in physiotherapy (CONNECT): a cluster randomized controlled trial to test a theory-based intervention to increase chronic low back pain patients' adherence to physiotherapists' recommendations: study rationale, design, and methods.

PubMed

Lonsdale, Chris; Hall, Amanda M; Williams, Geoffrey C; McDonough, Suzanne M; Ntoumanis, Nikos; Murray, Aileen; Hurley, Deirdre A

2012-06-15

Physical activity and exercise therapy are among the accepted clinical rehabilitation guidelines and are recommended self-management strategies for chronic low back pain. However, many back pain sufferers do not adhere to their physiotherapist's recommendations. Poor patient adherence may decrease the effectiveness of advice and home-based rehabilitation exercises. According to self-determination theory, support from health care practitioners can promote patients' autonomous motivation and greater long-term behavioral persistence (e.g., adherence to physiotherapists' recommendations). The aim of this trial is to assess the effect of an intervention designed to increase physiotherapists' autonomy-supportive communication on low back pain patients' adherence to physical activity and exercise therapy recommendations. This study will be a single-blinded cluster randomized controlled trial. Outpatient physiotherapy centers (N =12) in Dublin, Ireland (population = 1.25 million) will be randomly assigned using a computer-generated algorithm to either the experimental or control arm. Physiotherapists in the experimental arm (two hospitals and four primary care clinics) will attend eight hours of communication skills training. Training will include handouts, workbooks, video examples, role-play, and discussion designed to teach physiotherapists how to communicate in a manner that promotes autonomous patient motivation. Physiotherapists in the waitlist control arm (two hospitals and four primary care clinics) will not receive this training. Participants (N = 292) with chronic low back pain will complete assessments at baseline, as well as 1 week, 4 weeks, 12 weeks, and 24 weeks after their first physiotherapy appointment. Primary outcomes will include adherence to physiotherapy recommendations, as well as low back pain, function, and well-being. Participants will be blinded to treatment allocation, as they will not be told if their physiotherapist has received the communication skills training. Outcome assessors will also be blinded.We will use linear mixed modeling to test between arm differences both in the mean levels and the rates of change of the outcome variables. We will employ structural equation modeling to examine the process of change, including hypothesized mediation effects. This trial will be the first to test the effect of a self-determination theory-based communication skills training program for physiotherapists on their low back pain patients' adherence to rehabilitation recommendations.

Fabrication of copper decorated tungsten oxide-titanium oxide nanotubes by photochemical deposition technique and their photocatalytic application under visible light

NASA Astrophysics Data System (ADS)

Momeni, Mohamad Mohsen

2015-12-01

Copper decorated WO3-TiO2 nanotubes (Cu/WTNs) with a high photocatalytic activity were prepared by anodizing and photochemical deposition. Highly ordered WO3-TiO2 nanotubes (WTNs) on pure titanium foils were successfully fabricated by electrochemical anodizing and copper deposited on these nanotubes (Cu/WTNs) by photoreduction method. The resulting samples were characterized by various methods. Only the anatase phase was detected by X-ray diffraction analysis. The presence of copper in the structure of thin films was confirmed by energy dispersive X-ray spectrometry and X-ray diffraction. The extension of optical absorption into the visible region of as-prepared films was indicated by UV/Vis spectroscopy. The degradation of methylene blue was used as a model reaction to evaluate the photocatalytic activity of the obtained samples. Results showed that the photocatalytic activity of Cu/WTNs samples is higher than bare WTNs sample. Kinetic research showed that the reaction rate constant of Cu/WTNs is approximately 2.5 times higher than the apparent reaction rate constant of bare WTNs. These results not only offer an economical method for constructing Cu/WTNs photocatalysts, but also shed new insight on the rational design of a low cost and high-efficiency photocatalyst for environmental remediation.

Integrating Human Factors into Crew Exploration Vehicle Design

NASA Technical Reports Server (NTRS)

Whitmore, Mihriban; Baggerman, Susan; Campbell, paul

2007-01-01

With NASA's new Vision for Exploration to send humans beyond Earth orbit, it is critical to consider the human as a system that demands early and continuous user involvement, and an iterative prototype/test/redesign process. Addressing human-system interface issues early on can be very cost effective even cost reducing when performed early in the design and development cycle. To achieve this goal within Crew Exploration Vehicle (CEV) Project Office, human engineering (HE) team is formed. Key tasks are to apply HE requirements and guidelines to hardware/software, and provide HE design, analysis and evaluation of crew interfaces. Initial activities included many practice-orientated evaluations using low-fidelity CEV mock-ups. What follows is a description of such evaluations that focused on a HE requirement regarding Net Habitable Volume (NHV). NHV is defined as the total remaining pressurized volume available to on-orbit crew after accounting for the loss of volume due to deployed hardware and structural inefficiencies which decrease functional volume. The goal of the NHV evaluations was to develop requirements providing sufficient CEV NHV for crewmembers to live and perform tasks in support of mission goals. Efforts included development of a standard NHV calculation method using computer models and physical mockups, and crew/ stakeholder evaluations. Nine stakeholders and ten crewmembers participated in the unsuited evaluations. Six crewmembers also participated in a suited evaluation. The mock-up was outfitted with volumetric representation of sub-systems such as seats, and stowage bags. Thirteen scenarios were developed to represent mission/crew tasks and considered to be primary volume drivers (e.g., suit donning) for the CEV. Unsuited evaluations included a structured walkthrough of these tasks. Suited evaluations included timed donning of the existing launch and entry suit to simulate a contingency scenario followed by doffing/ stowing of the suits. All mockup evaluations were videotaped. Structured questionnaires were used to document user interface issues and volume impacts of layout configuration. Computer model and physical measures of the NHV agreed within 1 percent. This included measurement of the gross habitable volume, subtraction of intrusive volumes, and other non-habitable spaces. Calculation method developed was validated as a standard means of measuring NHV, and was recommended as a verification method for the NHV requirements. Evaluations confirmed that there was adequate volume for unsuited scenarios and suit donning/ doffing activity. Seats, suit design stowage and waste hygiene system noted to be critical volume drivers. The low-fidelity mock-up evaluations along with human modeling analysis generated discussions that will lead to high-level systems requirements and human-centered design decisions. This approach allowed HE requirements and operational concepts to evolve in parallel with engineering system concepts and design requirements. As the CEV design matures, these evaluations will continue and help with design decisions, and assessment, verification and validation of HE requirements.

Design and initial characterization of a compact, ultra high vacuum compatible, low frequency, tilt accelerometer

NASA Astrophysics Data System (ADS)

O'Toole, A.; Peña Arellano, F. E.; Rodionov, A. V.; Shaner, M.; Sobacchi, E.; Dergachev, V.; DeSalvo, R.; Asadoor, M.; Bhawal, A.; Gong, P.; Kim, C.; Lottarini, A.; Minenkov, Y.; Murphy, C.

2014-07-01

A compact tilt accelerometer with high sensitivity at low frequency was designed to provide low frequency corrections for the feedback signal of the Advanced Laser Interferometer Gravitational Wave Observatory active seismic attenuation system. It has been developed using a Tungsten Carbide ceramic knife-edge hinge designed to avoid the mechanical 1/f noise believed to be intrinsic in polycrystalline metallic flexures. Design and construction details are presented; prototype data acquisition and control limitations are discussed. The instrument's characterization reported here shows that the hinge is compatible with being metal-hysteresis-free, and therefore also free of the 1/f noise generated by the dislocation Self-Organized Criticality in the metal. A tiltmeter of this kind will be effective to separate the ground tilt component from the signal of horizontal low frequency seismometers, and to correct the ill effects of microseismic tilt in advanced seismic attenuation systems.

Design and initial characterization of a compact, ultra high vacuum compatible, low frequency, tilt accelerometer

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

O’Toole, A., E-mail: amandajotoole@gmail.com, E-mail: riccardo.desalvo@gmail.com; Peña Arellano, F. E.; Rodionov, A. V.

2014-07-15

A compact tilt accelerometer with high sensitivity at low frequency was designed to provide low frequency corrections for the feedback signal of the Advanced Laser Interferometer Gravitational Wave Observatory active seismic attenuation system. It has been developed using a Tungsten Carbide ceramic knife-edge hinge designed to avoid the mechanical 1/f noise believed to be intrinsic in polycrystalline metallic flexures. Design and construction details are presented; prototype data acquisition and control limitations are discussed. The instrument's characterization reported here shows that the hinge is compatible with being metal-hysteresis-free, and therefore also free of the 1/f noise generated by the dislocation Self-Organizedmore » Criticality in the metal. A tiltmeter of this kind will be effective to separate the ground tilt component from the signal of horizontal low frequency seismometers, and to correct the ill effects of microseismic tilt in advanced seismic attenuation systems.« less

Design and Analysis Tools for Supersonic Inlets

NASA Technical Reports Server (NTRS)

Slater, John W.; Folk, Thomas C.

2009-01-01

Computational tools are being developed for the design and analysis of supersonic inlets. The objective is to update existing tools and provide design and low-order aerodynamic analysis capability for advanced inlet concepts. The Inlet Tools effort includes aspects of creating an electronic database of inlet design information, a document describing inlet design and analysis methods, a geometry model for describing the shape of inlets, and computer tools that implement the geometry model and methods. The geometry model has a set of basic inlet shapes that include pitot, two-dimensional, axisymmetric, and stream-traced inlet shapes. The inlet model divides the inlet flow field into parts that facilitate the design and analysis methods. The inlet geometry model constructs the inlet surfaces through the generation and transformation of planar entities based on key inlet design factors. Future efforts will focus on developing the inlet geometry model, the inlet design and analysis methods, a Fortran 95 code to implement the model and methods. Other computational platforms, such as Java, will also be explored.

Neuronal current detection with low-field magnetic resonance: simulations and methods.

PubMed

Cassará, Antonino Mario; Maraviglia, Bruno; Hartwig, Stefan; Trahms, Lutz; Burghoff, Martin

2009-10-01

The noninvasive detection of neuronal currents in active brain networks [or direct neuronal imaging (DNI)] by means of nuclear magnetic resonance (NMR) remains a scientific challenge. Many different attempts using NMR scanners with magnetic fields >1 T (high-field NMR) have been made in the past years to detect phase shifts or magnitude changes in the NMR signals. However, the many physiological (i.e., the contemporarily BOLD effect, the weakness of the neuronal-induced magnetic field, etc.) and technical limitations (e.g., the spatial resolution) in observing the weak signals have led to some contradicting results. In contrast, only a few attempts have been made using low-field NMR techniques. As such, this paper was aimed at reviewing two recent developments in this front. The detection schemes discussed in this manuscript, the resonant mechanism (RM) and the DC method, are specific to NMR instrumentations with main fields below the earth magnetic field (50 microT), while some even below a few microteslas (ULF-NMR). However, the experimental validation for both techniques, with differentiating sensitivity to the various neuronal activities at specific temporal and spatial resolutions, is still in progress and requires carefully designed magnetic field sensor technology. Additional care should be taken to ensure a stringent magnetic shield from the ambient magnetic field fluctuations. In this review, we discuss the characteristics and prospect of these two methods in detecting neuronal currents, along with the technical requirements on the instrumentation.

Recent progress in low-temperature-process monolithic three dimension technology

NASA Astrophysics Data System (ADS)

Yang, Chih-Chao; Hsieh, Tung-Ying; Huang, Wen-Hsien; Shen, Chang-Hong; Shieh, Jia-Min; Yeh, Wen-Kuan; Wu, Meng-Chyi

2018-04-01

Monolithic three-dimension (3D) integration is an ultimate alternative method of fabricating high density, high performance, and multi-functional integrated circuits. It offers the promise of being a new approach to increase system performance. How to manage the thermal impact of multi-tiered processes, such as dopant activation, source/drain silicidation, and channel formation, and to prevent the degradation of pre-existing devices/circuits become key challenges. In this paper, we provide updates on several important monolithic 3D works, particularly in sequentially stackable channels, and our recent achievements in monolithic 3D integrated circuit (3D-IC). These results indicate that the advanced 3D architecture with novel design tools enables ultrahigh-density stackable circuits to have superior performance and low power consumption for future artificial intelligence (AI) and internet of things (IoTs) application.

Some effects of quiet geomagnetic field changes upon values used for main field modeling

USGS Publications Warehouse

Campbell, W.H.

1987-01-01

The effects of three methods of data selection upon the assumed main field levels for geomagnetic observatory records used in main field modeling were investigated for a year of very low solar-terrestrial activity. The first method concerned the differences between the year's average of quiet day field values and the average of all values during the year. For H these differences were 2-3 gammas, for D they were -0.04 to -0.12???, for Z the differences were negligible. The second method of selection concerned the effects of the daytime internal Sq variations upon the daily mean values of field. The midnight field levels when the Sq currents were a minimum deviated from the daily mean levels by as much as 4-7 gammas in H and Z but were negligible for D. The third method of selection was designed to avoid the annual and semi-annual quiet level changes of field caused by the seasonal changes in the magnetosphere. Contributions from these changes were found to be as much as 4-7 gammas in quiet years and expected to be greater than 10 gammas in active years. Suggestions for improved methods of improved data selection in main field modeling are given. ?? 1987.

Low and high speed propellers for general aviation - Performance potential and recent wind tunnel test results

NASA Technical Reports Server (NTRS)

Jeracki, R. J.; Mitchell, G. A.

1981-01-01

A survey is presented of current research efforts in general aviation, low-speed propeller design and high-speed propfan design, with attention on such features as (1) advanced blade shapes, with novel airfoils and sweep, (2) tip devices, (3) integrated propeller/nacelle designs, (4) area-ruled spinners, (5) lightweight, all-composite blade construction, and (6) contra-rotating propfan systems. The potential overall improvements associated with these design modifications are calculated to lie at 10-15% for low-speed rotors and 15-30% for high-speed ones. Emphasis is placed on noise reduction, blade drag, performance prediction methods and wind tunnel testing of alternative rotor configurations. Extensive use of graphs is made in performance comparisons between alternative blade and rotor designs.

Adaptive Control for Microgravity Vibration Isolation System

NASA Technical Reports Server (NTRS)

Yang, Bong-Jun; Calise, Anthony J.; Craig, James I.; Whorton, Mark S.

2005-01-01

Most active vibration isolation systems that try to a provide quiescent acceleration environment for space science experiments have utilized linear design methods. In this paper, we address adaptive control augmentation of an existing classical controller that employs a high-gain acceleration feedback together with a low-gain position feedback to center the isolated platform. The control design feature includes parametric and dynamic uncertainties because the hardware of the isolation system is built as a payload-level isolator, and the acceleration Sensor exhibits a significant bias. A neural network is incorporated to adaptively compensate for the system uncertainties, and a high-pass filter is introduced to mitigate the effect of the measurement bias. Simulations show that the adaptive control improves the performance of the existing acceleration controller and keep the level of the isolated platform deviation to that of the existing control system.

Third order LPF type compensator for flexible rotor suspension

NASA Technical Reports Server (NTRS)

Matsushita, Osami; Takahashi, Naohiko; Takagi, Michiyuki

1994-01-01

The tuning job of the compensator for levitating flexible rotors supported by active magnetic bearings (AMB) concerns providing a good damping effect to the critical speed modes while avoiding the spillover problem on the instability of higher bending modes. In this paper, an idea for design of the control law of the compensator based on utilizing a third order low pass filter (LPF) is proposed to essentially enable elimination of the spillover instability. According to the proposed design method, good damping effects for the critical speeds are obtained by the usual phase lead/lag function. Stabilization for all of higher bending modes is completed by the additional function of the 3rd order LPF due to its phase lag approaching about -270 degrees in the high frequency domain. This idea is made clear by experiments and simulations.

Summary of Apollo; A D- sup 3 He tokamak reactor design

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

Kulcinski, G.L.; Blanchard, T.P.; El-Guebaly, L.A.

1992-07-01

In this paper, the key features of Apollo, a conceptual D-{sup 3}He tokamak reactor for commercial electricity production, are summarized. The 1000-MW (electric) design utilizes direct conversion of transport, neutron, and bremsstrahlung radiation power. The direct conversion method uses reactants, and the thermal conversion cycle uses an organic coolant. Apollo operates in the first-stability regime, with a major radius of 7.89 m, a peak magnetic field on the toroidal field coils of 19.3 T, a 53-MA plasma current, and a 6.7% beta value. The low neutron production of the D-{sup 3}He fuel cycle greatly reduces the radiation damage rate andmore » allows a full-lifetime first wall and structure made of standard steels with only slight modifications to reduce activation levels.« less

Implementing AORN recommended practices for MIS: Part II.

PubMed

Morton, Paula J

2012-10-01

This article focuses on the equipment and workplace safety aspects of the revised AORN "Recommended practices for minimally invasive surgery." A multidisciplinary team that includes the perioperative nurse should be established to discuss aspects of the development and design of new construction or renovation (eg, room access, ergonomics, low-lighting, OR integration, hybrid OR considerations, design development). Equipment safety considerations during minimally invasive surgical procedures include using active electrode monitoring; verifying the properties of distention media; using smoke evacuation systems; reducing equipment, electrical, thermal, and fire hazards; performing routine safety checks on insufflation accessories; and minimizing the risk of ergonomic injuries to staff members. Additional considerations include using video recording devices, nonmagnetic equipment during magnetic resonance imaging, and fluid containment methods for fluid management. Copyright © 2012 AORN, Inc. Published by Elsevier Inc. All rights reserved.

Competency and an active learning program in undergraduate nursing education.

PubMed

Shin, Hyunsook; Sok, Sohyune; Hyun, Kyung Sun; Kim, Mi Ja

2015-03-01

To evaluate the effect of an active learning program on competency of senior students. Active learning strategies have been used to help students achieve desired nursing competency, but their effectiveness has not been systematically examined. A descriptive, cross-sectional comparative design was used. Two cohort group comparisons using t-test were made: one in an active learning group and the other in a traditional learning group. A total of 147 senior nursing students near graduation participated in this study: 73 in 2010 and 74 in 2013. The active learning program incorporated high-fidelity simulation, situation-based case studies, standardized patients, audio-video playback, reflective activities and technology such as a SmartPad-based program. The overall scores of the nursing competency in the active group were significantly higher than those in the traditional group. Of five overall subdomains, the scores of the special and general clinical performance competency, critical thinking and human understanding were significantly higher in the active group than in the traditional group. Importance-performance analysis showed that all five subdomains of the active group clustered in the high importance and high performance quadrant, indicating significantly better achievements. In contrast, the students in the traditional group showed scattered patterns in three quadrants, excluding the low importance and low performance quadrants. This pattern indicates that the traditional learning method did not yield the high performance in most important areas. The findings of this study suggest that an active learning strategy is useful for helping undergraduate students to gain competency. © 2014 John Wiley & Sons Ltd.

Experimental design

NASA Technical Reports Server (NTRS)

Lim, H. S.

1983-01-01

The design of long life, low weight nickel cadmium cells is studied. The status of a program to optimize nickel electrodes for the best performance is discussed. The pore size of the plaque, the mechanical strength and active material loading are considered in depth.

Texting to increase physical activity among teenagers (TXT Me!): Rationale, design, and methods proposal

USDA-ARS?s Scientific Manuscript database

Physical activity decreases from childhood through adulthood. Among youth, teenagers (teens) achieve the lowest levels of physical activity, and high school age youth are particularly at risk of inactivity. Effective methods are needed to increase youth physical activity in a way that can be maintai...

A High Performance Piezoelectric Sensor for Dynamic Force Monitoring of Landslide.

PubMed

Li, Ming; Cheng, Wei; Chen, Jiangpan; Xie, Ruili; Li, Xiongfei

2017-02-17

Due to the increasing influence of human engineering activities, it is important to monitor the transient disturbance during the evolution process of landslide. For this purpose, a high-performance piezoelectric sensor is presented in this paper. To adapt the high static and dynamic stress environment in slope engineering, two key techniques, namely, the self-structure pressure distribution method (SSPDM) and the capacitive circuit voltage distribution method (CCVDM) are employed in the design of the sensor. The SSPDM can greatly improve the compressive capacity and the CCVDM can quantitatively decrease the high direct response voltage. Then, the calibration experiments are conducted via the independently invented static and transient mechanism since the conventional testing machines cannot match the calibration requirements. The sensitivity coefficient is obtained and the results reveal that the sensor has the characteristics of high compressive capacity, stable sensitivities under different static preload levels and wide-range dynamic measuring linearity. Finally, to reduce the measuring error caused by charge leakage of the piezoelectric element, a low-frequency correction method is proposed and experimental verified. Therefore, with the satisfactory static and dynamic properties and the improving low-frequency measuring reliability, the sensor can complement dynamic monitoring capability of the existing landslide monitoring and forecasting system.

Design of c-band telecontrol transmitter local oscillator for UAV data link

NASA Astrophysics Data System (ADS)

Cao, Hui; Qu, Yu; Song, Zuxun

2018-01-01

A C-band local oscillator of an Unmanned Aerial Vehicle (UAV) data link radio frequency (RF) transmitter unit with high-stability, high-precision and lightweight was designed in this paper. Based on the highly integrated broadband phase-locked loop (PLL) chip HMC834LP6GE, the system performed fractional-N control by internal modules programming to achieve low phase noise and small frequency resolution. The simulation and testing methods were combined to optimize and select the loop filter parameters to ensure the high precision and stability of the frequency synthesis output. The theoretical analysis and engineering prototype measurement results showed that the local oscillator had stable output frequency, accurate frequency step, high spurious suppression and low phase noise, and met the design requirements. The proposed design idea and research method have theoretical guiding significance for engineering practice.

Low back pain and physical activity--A 6.5 year follow-up among young adults in their transition from school to working life.

PubMed

Lunde, Lars-Kristian; Koch, Markus; Hanvold, Therese N; Wærsted, Morten; Veiersted, Kaj B

2015-11-12

The association between leisure time physical activity and low back pain in young adults is unclear and is in the need of prospectively obtained evidence. This study examined the course of low back pain and the association between low back pain and leisure time physical activity in a cohort of young adults in their transition from school to working life. Both low back pain and leisure time physical activity was monitored over a 6.5 year period in 420 subjects starting out as students within hairdressing, electrical installation and media/design. The association between physical activity and low back pain was investigated through the follow-up period by using linear mixed models analysis. Low back pain was significantly influenced by time and overall there was a decreasing trend of low back pain prevalence throughout the follow-up. Analysis showed a weak trend of decreasing low back pain with moderate/high physical activity levels, but this association was not significant. Low back pain decreased during follow-up with baseline as reference. Findings in our study did show non-significant trends of reduced low back pain with increased leisure time physical activity. Still, we could not support the theory of moderate/high levels of physical activity acting protective against low back pain in young adults entering working life. Our results, in combination with previous relevant research, cannot support a clear relationship between physical activity and low back pain for young adults. Thus, recommendations regarding effect of physical activity on reducing low back pain for this group are not clear.

An ultrasensitive electrochemical biosensor for polynucleotide kinase assay based on gold nanoparticle-mediated lambda exonuclease cleavage-induced signal amplification.

PubMed

Cui, Lin; Li, Yueying; Lu, Mengfei; Tang, Bo; Zhang, Chun-Yang

2018-01-15

Polynucleotide kinase (PNK) plays an essential role in cellular nucleic acid metabolism and the cellular response to DNA damage. However, conventional methods for PNK assay suffer from low sensitivity and involve multiple steps. Herein, we develop a simply electrochemical method for sensitive detection of PNK activity on the basis of Au nanoparticle (AuNP)-mediated lambda exonuclease cleavage-induced signal amplification. We use [Ru(NH 3 ) 6 ] 3+ as the electrochemically active indicator and design two DNA strands (i.e., strand 1 and strand 2) to sense PNK. The assembly of strand 2 on the AuNP surface leads to the formation of AuNP-strand 2 conjugates which can be subsequently immobilized on the gold electrode through the hybridization of strand 1 with strand 2 for the generation of a high electrochemical signal. The presence of PNK induces the phosphorylation of the strand 2-strand 1 hybrid and the subsequent cleavage of double-stranded DNA (dsDNA) by lambda exonuclease, resulting in the release of AuNP-strand 2 conjugates and [Ru(NH 3 ) 6 ] 3+ from the gold electrode surface and consequently the decrease of electrochemical signal. The PNK activity can be simply monitored by the measurement of [Ru(NH 3 ) 6 ] 3+ peak current signal. This assay is very sensitive with a detection limit of as low as 7.762 × 10 -4 UmL -1 and exhibits a large dynamic range from 0.001 to 10UmL -1 . Moreover, this method can be used to screen the PNK inhibitors, and it shows excellent performance in real sample analysis, thus holding great potential for further applications in biological researches and clinic diagnosis. Copyright © 2017 Elsevier B.V. All rights reserved.

Advanced Extra-Vehicular Activity Pressure Garment Requirements Development

NASA Technical Reports Server (NTRS)

Ross, Amy; Aitchison, Lindsay; Rhodes, Richard

2015-01-01

The NASA Johnson Space Center advanced pressure garment technology development team is addressing requirements development for exploration missions. Lessons learned from the Z-2 high fidelity prototype development have reiterated that clear low-level requirements and verification methods reduce risk to the government, improve efficiency in pressure garment design efforts, and enable the government to be a smart buyer. The expectation is to provide requirements at the specification level that are validated so that their impact on pressure garment design is understood. Additionally, the team will provide defined verification protocols for the requirements. However, in reviewing exploration space suit high level requirements there are several gaps in the team's ability to define and verify related lower level requirements. This paper addresses the efforts in requirement areas such as mobility/fit/comfort and environmental protection (dust, radiation, plasma, secondary impacts) to determine the method by which the requirements can be defined and use of those methods for verification. Gaps exist at various stages. In some cases component level work is underway, but no system level effort has begun; in other cases no effort has been initiated to close the gap. Status of on-going efforts and potential approaches to open gaps are discussed.

Disposable amperometric biosensor based on nanostructured bacteriophages for glucose detection

NASA Astrophysics Data System (ADS)

Kang, Yu Ri; Hwang, Kyung Hoon; Kim, Ju Hwan; Nam, Chang Hoon; Kim, Soo Won

2010-10-01

The selection of electrode material profoundly influences biosensor science and engineering, as it heavily influences biosensor sensitivity. Here we propose a novel electrochemical detection method using a working electrode consisting of bio-nanowires from genetically modified filamentous phages and nanoparticles. fd-tet p8MMM filamentous phages displaying a three-methionine (MMM) peptide on the major coat protein pVIII (designated p8MMM phages) were immobilized on the active area of an electrochemical sensor through physical adsorption and chemical bonding. Bio-nanowires composed of p8MMM phages and silver nanoparticles facilitated sensitive, rapid and selective detection of particular molecules. We explored whether the composite electrode with bio-nanowires was an effective platform to detect the glucose oxidase. The current response of the bio-nanowire sensor was high at various glucose concentrations (0.1 µm-0.1 mM). This method provides a considerable advantage to demonstrate analyte detection over low concentration ranges. Especially, phage-enabled bio-nanowires can serve as receptors with high affinity and specificity for the detection of particular biomolecules and provide a convenient platform for designing site-directed multifunctional scaffolds based on bacteriophages and may serve as a simple method for label-free detection.

Integrating AgI/AgBr biphasic heterostructures encased by few layer h-BN with enhanced catalytic activity and stability.

PubMed

Wu, Wen; Lv, Xiaomeng; Wang, Jiaxi; Xie, Jimin

2017-06-15

Using freshly prepared water-soluble KBr crystal as facile, low-cost sacrificial template, AgBr nanocubes were synthesized through one-pot precipitation method, then navy bean shaped AgI/AgBr biphasic heterostructures were synthesized through anion-exchange reaction and encased within few-layer h-BN to obtain final product. The obtained heterostructured AgI/AgBr/h-BN composite without plasmonic noble metal nanoparticles was used as stable and high active photocatalyst for dye degradation under visible light irradiation, comparing both with self-prepared normal AgBr, AgBr cubes, AgI/AgBr navy beans and other related catalysts reported in the literature. The significant boosting of activity was attributed to the formation of AgI/AgBr interface and the coupling of few-layer h-BN, the latter of which not only effectively suppresses the reduction of silver ions but greatly enhance the charge separation. Furthermore, it was suggested that the photogenerated holes and superoxide radical were the main active species according to photoelectron chemical measurements, electron spin resonance spin-trap analysis and radical trapping experiments. Finally, the possible mechanism of enhanced photocatalytic activity and stability was discussed and proposed. The work demonstrates that engineering Ag-based semiconductor coupling with h-BN would profit the design strategy for low-cost, solar-driven photocatalysts. Copyright © 2017 Elsevier Inc. All rights reserved.

Comparative Study of Erythrina indica Lam. (Febaceae) Leaves Extracts for Antioxidant Activity

PubMed Central

Sakat, SS; Juvekar, AR

2010-01-01

The present study was designed to investigate the antioxidant activity of aqueous and methanol extracts of Erythrina indica Lam leaves by in vitro methods viz. 1, 1-Diphenyl-2-Picrylhydrazyl, nitric oxide radical scavenging activity, and inhibition of lipid peroxidation by thiobarbituric acid reactive substances (TBARS) method on isolated rat liver tissues. Quantitative analysis of antioxidative components like total amount of phenolics, flavonoids, and flavonols were estimated using the spectrophotometric method. Linear regression analysis was used to calculate the IC50 value. Results showed that the aqueous and methanol extracts exhibited significant DPPH radicals scavenging activity with an IC50 value 342.59 ± 19.59, 283.24 ± 12.28 µg/mL respectively. Nitric oxide radicals were significantly scavenged by the aqueous and methanol extracts (IC50 = 250.12 ± 10.66; 328.29 ± 3.74 µg/mL). Lipid peroxidation induced by the Fe2+ was inhibited by the aqueous extract with low IC50 value (97.29 ± 2.05 µg/mL) as compared to methanol extract (IC50 = 283.74 ± 5.70 µg/mL). Both the extracts were exhibited similar quantities of total phenolics. Total flavonoids were found to be in higher quantities than total flavonols in aqueous extract as compared to methanol extract. From the results, it is concluded that the aqueous and methanol extracts of E. indica leaves possesses significant antioxidant activity that may be due to the presence of flavonoids and related polyphenolic compounds. PMID:21331194

Implementation of a Low-Thrust Trajectory Optimization Algorithm for Preliminary Design

NASA Technical Reports Server (NTRS)

Sims, Jon A.; Finlayson, Paul A.; Rinderle, Edward A.; Vavrina, Matthew A.; Kowalkowski, Theresa D.

2006-01-01

A tool developed for the preliminary design of low-thrust trajectories is described. The trajectory is discretized into segments and a nonlinear programming method is used for optimization. The tool is easy to use, has robust convergence, and can handle many intermediate encounters. In addition, the tool has a wide variety of features, including several options for objective function and different low-thrust propulsion models (e.g., solar electric propulsion, nuclear electric propulsion, and solar sail). High-thrust, impulsive trajectories can also be optimized.

Confronting Analytical Dilemmas for Understanding Complex Human Interactions in Design-Based Research from a Cultural-Historical Activity Theory (CHAT) Framework

ERIC Educational Resources Information Center

Yamagata-Lynch, Lisa C.

2007-01-01

Understanding human activity in real-world situations often involves complicated data collection, analysis, and presentation methods. This article discusses how Cultural-Historical Activity Theory (CHAT) can inform design-based research practices that focus on understanding activity in real-world situations. I provide a sample data set with…

End user evaluation of a Kneeling Wheelchair with "on the fly" adjustable seating functions.

PubMed

Mattie, Johanne; Wong, Angie; Leland, Danny; Borisoff, Jaimie

2018-04-18

A "kneeling" ultralight wheelchair prototype has been developed that allows users to adjust seat position "on the fly" for different activities throughout the day. The wheelchair includes independent adjustment functions for rear seat height, front seat height ("kneeling") and backrest angle.  Aim: This work aimed to gather feedback about the wheelchair's functionality and performance through end user evaluation trials.  Methods: Eight manual wheelchair users evaluated the prototype Kneeling Wheelchair for a range of activities. User perspectives on parameters such as usability, comfort, stability and effectiveness were obtained through both open-ended and Likert-scale rating questions.  Results: Results indicate several potential benefits of the adjustment functions of the Kneeling Wheelchair. Rear seat height adjustment may facilitate a number of activities of daily living, as well as provide benefits for comfort and social interactions. Back rest adjustment may increase comfort and stability on slopes. Front seat height adjustment may be beneficial for transfers and conducting sustained low-to-the-ground activities. While benefits of this adjustment function were described by many participants, some struggled with usability of the kneeling mechanism and rated this function less favourably than the other two.  Conclusion: The findings of this study will inform future iterations of the Kneeling Wheelchair design and may spur future developments in wheeled mobility. In the long-term, it is anticipated that novel wheelchair solutions, such as the one described in this paper, may support improved health, quality of life and community participation for people with mobility impairments. Implications for rehabilitation Wheelchairs that allow users to easily adjust seat and backrest position "on the fly" to better suit different tasks throughout the day may provide benefits such as facilitating activities of daily living. A front seat height adjustment feature on a new wheelchair prototype may be beneficial for transfers and conducting sustained low-to-the ground activities. End user evaluations can provide valuable insight to direct future design modifications and innovation.

A portable low-cost 3D point cloud acquiring method based on structure light

NASA Astrophysics Data System (ADS)

Gui, Li; Zheng, Shunyi; Huang, Xia; Zhao, Like; Ma, Hao; Ge, Chao; Tang, Qiuxia

2018-03-01

A fast and low-cost method of acquiring 3D point cloud data is proposed in this paper, which can solve the problems of lack of texture information and low efficiency of acquiring point cloud data with only one pair of cheap cameras and projector. Firstly, we put forward a scene adaptive design method of random encoding pattern, that is, a coding pattern is projected onto the target surface in order to form texture information, which is favorable for image matching. Subsequently, we design an efficient dense matching algorithm that fits the projected texture. After the optimization of global algorithm and multi-kernel parallel development with the fusion of hardware and software, a fast acquisition system of point-cloud data is accomplished. Through the evaluation of point cloud accuracy, the results show that point cloud acquired by the method proposed in this paper has higher precision. What`s more, the scanning speed meets the demand of dynamic occasion and has better practical application value.

A Method for Designing Conforming Folding Propellers

NASA Technical Reports Server (NTRS)

Litherland, Brandon L.; Patterson, Michael D.; Derlaga, Joseph M.; Borer, Nicholas K.

2017-01-01

As the aviation vehicle design environment expands due to the in flux of new technologies, new methods of conceptual design and modeling are required in order to meet the customer's needs. In the case of distributed electric propulsion (DEP), the use of high-lift propellers upstream of the wing leading edge augments lift at low speeds enabling smaller wings with sufficient takeoff and landing performance. During cruise, however, these devices would normally contribute significant drag if left in a fixed or windmilling arrangement. Therefore, a design that stows the propeller blades is desirable. In this paper, we present a method for designing folding-blade configurations that conform to the nacelle surface when stowed. These folded designs maintain performance nearly identical to their straight, non-folding blade counterparts.

Parents' School Satisfaction and Academic Socialization Predict Adolescents' Autonomous Motivation: A Mixed-Method Study of Low-Income Ethnic Minority Families

ERIC Educational Resources Information Center

Suizzo, Marie-Anne; Jackson, Karen Moran; Pahlke, Erin; McClain, Shannon; Marroquin, Yesenia; Blondeau, Lauren A.; Hong, KyongJoo

2016-01-01

In this mixed-methods study, we used an explanatory sequential design to investigate the processes through which parental involvement influences adolescents' achievement motivation. One hundred twenty low-income urban parents and their sixth-grade adolescents completed questionnaires, and a subsample of 11 mothers and 11 adolescents were…

An Exploratory Mixed Method Assessment of Low Income, Pregnant Hispanic Women's Understanding of Gestational Diabetes and Dietary Change

ERIC Educational Resources Information Center

Rhoads-Baeza, Maria Elena; Reis, Janet

2012-01-01

Objective: To describe and assess low income, healthy, pregnant Hispanic women's understanding of gestational diabetes (GDM) and willingness to change aspects of their diet. Design: One-on-one, in-person interviews conducted in Spanish with 94 women (primarily Mexican). Setting: Federal Qualified Community Health Center's prenatal clinic. Method:…